英文文献及翻译
英文文献翻译

外文文献原稿和译文原稿Sodium Polyacrylate:Also known as super-absorbent or “SAP”(super absorbent polymer), Kimberly Clark used to call it SAM (super absorbent material). It is typically used in fine granular form (like table salt). It helps improve capacity for better retention in a disposable diaper, allowing the product to be thinner with improved performance and less usage of pine fluff pulp. The molecular structure of the polyacrylate has sodium carboxylate groups hanging off the main chain. When it comes in contact with water, the sodium detaches itself, leaving only carboxylions. Being negatively charged, these ions repel one another so that the polymer also has cross-links, which effectively leads to a three-dimensional structure. It has hige molecular weight of more than a million; thus, instead of getting dissolved, it solidifies into a gel. The Hydrogen in the water (H-O-H) is trapped by the acrylate due to the atomic bonds associated with the polarity forces between the atoms. Electrolytes in the liquid, such as salt minerals (urine contains 0.9% of minerals), reduce polarity, thereby affecting superabsorbent properties, especially with regard to the superabsorbent capacity for liquid retention. This is the main reason why diapers containing SAP should never be tested with plain water. Linear molecular configurations have less total capacity than non-linear molecules but, on the other hand, retention of liquid in a linear molecule is higher than in a non-linear molecule, due to improved polarity. For a list of SAP suppliers, please use this link: SAP, the superabsorbent can be designed to absorb higher amounts of liquids (with less retention) or very high retentions (but lower capacity). In addition, a surface cross linker can be added to the superabsorbent particle to help it move liquids while it is saturated. This helps avoid formation of "gel blocks", the phenomenon that describes the impossibility of moving liquids once a SAP particle gets saturated.History of Super Absorbent Polymer ChemistryUn til the 1980’s, water absorbing materials were cellulosic or fiber-based products. Choices were tissue paper, cotton, sponge, and fluff pulp. The water retention capacity of these types of materials is only 20 times their weight – at most.In the early 1960s, the United States Department of Agriculture (USDA) was conducting work on materials to improve water conservation in soils. They developed a resin based on the grafting of acrylonitrile polymer onto the backbone of starch molecules (i.e. starch-grafting). The hydrolyzed product of the hydrolysis of this starch-acrylonitrile co-polymer gave water absorption greater than 400 times its weight. Also, the gel did not release liquid water the way that fiber-based absorbents do.The polymer came to be known as “Super Slurper”.The USDA gave the technical know how several USA companies for further development of the basic technology. A wide range of grating combinations were attempted including work with acrylic acid, acrylamide and polyvinyl alcohol (PVA).Since Japanese companies were excluded by the USDA, they started independent research using starch, carboxy methyl cellulose (CMC), acrylic acid, polyvinyl alcohol (PVA) and isobutylene maleic anhydride (IMA).Early global participants in the development of super absorbent chemistry included Dow Chemical, Hercules, General Mills Chemical, DuPont, National Starch & Chemical, Enka (Akzo), Sanyo Chemical, Sumitomo Chemical, Kao, Nihon Starch and Japan Exlan.In the early 1970s, super absorbent polymer was used commercially for the first time –not for soil amendment applications as originally intended –but for disposable hygienic products. The first product markets were feminine sanitary napkins and adult incontinence products.In 1978, Park Davis (d.b.a. Professional Medical Products) used super absorbent polymers in sanitary napkins.Super absorbent polymer was first used in Europe in a baby diaper in 1982 when Schickendanz and Beghin-Say added the material to the absorbent core. Shortly thereafter, UniCharm introduced super absorbent baby diapers in Japan while Proctor & Gamble and Kimberly-Clark in the USA began to use the material.The development of super absorbent technology and performance has been largely led by demands in the disposable hygiene segment. Strides in absorption performance have allowed the development of the ultra-thin baby diaper which uses a fraction of the materials – particularly fluff pulp – which earlier disposable diapers consumed.Over the years, technology has progressed so that there is little if any starch-grafted super absorbent polymer used in disposable hygienic products. These super absorbents typically are cross-linked acrylic homo-polymers (usually Sodium neutralized).Super absorbents used in soil amendments applications tend to be cross-linked acrylic-acrylamide co-polymers (usually Potassium neutralized).Besides granular super absorbent polymers, ARCO Chemical developed a super absorbent fiber technology in the early 1990s. This technology was eventually sold to Camelot Absorbents. There are super absorbent fibers commercially available today. While significantly more expensive than the granular polymers, the super absorbent fibers offer technical advantages in certain niche markets including cable wrap, medical devices and food packaging.Sodium polyacrylate, also known as waterlock, is a polymer with the chemical formula [-CH2-CH(COONa)-]n widely used in consumer products. It has the ability to absorb as much as 200 to 300 times its mass in water. Acrylate polymers generally are considered to possess an anionic charge. While sodium neutralized polyacrylates are the most common form used in industry, there are also other salts available including potassium, lithium and ammonium.ApplicationsAcrylates and acrylic chemistry have a wide variety of industrial uses that include: ∙Sequestering agents in detergents. (By binding hard water elements such as calcium and magnesium, the surfactants in detergents work more efficiently.) ∙Thickening agents∙Coatings∙Fake snowSuper absorbent polymers. These cross-linked acrylic polymers are referred to as "Super Absorbents" and "Water Crystals", and are used in baby diapers. Copolymerversions are used in agriculture and other specialty absorbent applications. The origins of super absorbent polymer chemistry trace back to the early 1960s when the U.S. Department of Agriculture developed the first super absorbent polymer materials. This chemical is featured in the Maximum Absorbency Garment used by NASA.译文聚丙烯酸钠聚丙烯酸钠,又可以称为超级吸收剂或者又叫高吸水性树脂,凯博利克拉克教授曾经称它为SAM即:超级吸收性物质。
英文文献及翻译

原文:Serial Communication via RS232 PortBy Harsha Perla and Veena Pai from: /index.htmlRS232 is the most known serial port used in transmitting the data in communication and interface. Even though serial port is harder to program than the parallel port, this is the most effective method in which the data transmission requires less wires that yields to the less cost. The RS232 is the communication line which enables the data transmission by only using three wire links. The three links provides …transmit‟, …receive‟ and common ground...The …transmit‟ and …receive‟ line on this connecter send and receive data between the computers. As the name indicates, the data is transmitted serially. The two pins are TXD & RXD. There are other lines on this port as RTS, CTS, DSR, DTR, and RTS, RI. The …1‟ and …0‟ are the data which defines a voltage level of 3V to 25V and -3V to -25V respectively.The electrical characteristics of the serial port as per the EIA (Electronics Industry Association) RS232C Standard specifies a maximum baud rate of 20,000bps, which is slow compared to today‟s standard speed. For this reason, we have chosen the new RS-232D Standard, which was recently released.The RS-232D has existed in two types. i.e., D-TYPE 25 pin connector and D-TYPE 9 pin connector, which are male connectors on the back of the PC. You need a female connector on your communication from Host to Guest computer. The pin outs of both D-9 & D-25 are show below.D-Type-9 pin no. D-Type-25pin no.Pin outs Function3 2 RD Receive Data (Serial data input)2 3 TD Transmit Data (Serial data output)7 4 RTS Request to send (acknowledge tomodem that UART is ready toexchange data8 5 CTS Clear to send (i.e.; modem is readyto exchange data)6 6 DSR Data ready state (UART establishesa link)5 7 SG Signal ground1 8 DCD Data Carrier detect (This line isactive when modem detects a carrier4 20 DTR Data Terminal Ready.9 22 RI Ring Indicator (Becomes activewhen modem detects ringing signalfrom PSTNAbout DTE & DCE:Devices, which use serial cables for their communication, are split into two categories. These are DCE (Data Communications Equipment) and DTE (Data Terminal Equipment.) Data Communications Equipments are devices such as your modem, TA adapter, plotter etc while Data Terminal Equipment is your Computer or Terminal. A typical Data Terminal Device is a computer and a typical Data Communications Device is a Modem. Often people will talk about DTE to DCE or DCE to DCE speeds. DTE to DCE is the speed between your modem and computer, sometimes referred to as your terminal speed. This should run at faster speeds than the DCE to DCE speed. DCE to DCE is the link between modems, sometimes called the line speed.Most people today will have 28.8K or 33.6K modems. Therefore, we should expect the DCE to DCE speed to be either 28.8K or 33.6K. Considering the high speed of the modem we should expect the DTE to DCE speed to be about 115,200 BPS. (Maximum Speed of the 16550a UART) . The communications program, which we use, has settings for DCE to DTE speeds. However, the speed is 9.6 KBPS, 144 KBPS etc and the modem speed.If we were transferring that text file at 28.8K (DCE- DCE), then when the modem compresses it you are actually transferring 115.2 KBPS between computers and thus have a DCE- DTE speed of 115.2 KBPS. Thus, this is why the DCE- DTE should be much higher than the modem's connection speed. Therefore, if our DTE to DCE speed is several times faster than our DCE to DCE speed the PC can send data to your modem at 115,200 BPS.What is NULL MODEM?Null modem is used to connect two DTE's together. This is used to transfer files between the computers using protocols like Zmodem protocol, xmodem protocol, etcFigure :Above shows the connections of the Null modem usingRS-232D connecterAbove-mentioned figure shows the wiring of the null modem. The main feature indicated here is that the to make the computer to chat with the modem rather than another computer. The guest & host computer connected through the TD, RD, and SG pins. Any data that is transmitted through TD line from the Host to Guest is received on RD line. The Guest computer must have the same setup as the Host. The signalground (SG) line of the both must be shorted so that grounds are common to each computer.The Data Terminal Ready (DTR) is looped back to Data Set Ready and Carrier Detect on both computers. When the Data Terminal Ready is asserted active, then the Data Set Ready and Carrier Detect immediately become active. At this point, the computer thinks the Virtual Modem to which it is connected is ready and has detected the carrier of the other modem.All left to worry about now is the Request to Send and Clear To Send. As both computers communicate together at the same speed, flow control is not needed thus these two lines are also linked together on each computer. When the computer wishes to send data, it asserts the Request to Send high and as it is hooked together with the Clear to Send, It immediately gets a reply that it is ok to send and does so.The Ring indicator line is only used to tell the computer that there is a ringing signal on the phone line. As we do not have, a modem connected to the phone line this is left disconnectedTo know about the RS232 ports available in your computer, Right click on "My Computer", Goto 'Properties', Select tab 'Device Manager', go to Ports( COM & LPT ), In that you will find 'Communication Port(Com1)' etc. If you right click on that and go to properties, you will get device status. Make sure that you have enabled theport( Use this port is selected).How to program the Serial Port using C/C++?There are two popular methods of sending data to or from the serial port in Turbo C. One is using outportb(PORT_ID, DATA) or outport(PORT_ID,DATA) defined in “dos.h”. Another method is using bioscom() function defined in “bios.h”. Using outportb() :The function outportb () sends a data byte to the port …PORT_ID‟. The function outport() sends a data word. These functions can be used for any port including serial port, parallel ports. Similarly to receive data these are used.· inport reads a word from a hardware port·inportb reads a byte from a hardware port·outport outputs a word to a hardware port·outportb outputs a byte to a hardware portDeclaration:· int inport(int portid);·unsigned char inportb(int portid);·void outport(int portid, int value);·void outportb(int portid, unsigned char value);Remarks:·inport works just like the 80x86 instruction IN. It reads the low byte of a word from portid, the high byte from portid + 2.·inportb is a macro that reads a byte·outport works just like the 80x86 instruction OUT. It writes the low byte of value to portid, the high byte to portid + 1.·outportb is a macro that writes value Argumentportid:·Inport- port that inport and inportb read from;·Outport- port that outport and outportb write to value:·Word that outport writes to portid;·Byte- that outportb writes to portid.If you call inportb or outportb when dos.h has been included, they are treated as macros that expand to inline code.If you don't include dos.h, or if you do include dos.h and #undef the macro(s), you get the function(s) of the same name.Return Value:# inport and inportb return the value read# outport and outportb do not returnFor more details of these functions read article from Using bioscom:The macro bioscom () and function _bios_serialcom() are used in this method in the serial communication using RS-232 connecter. First we have to set the port with the settings depending on our need and availability. In this method, same function is used to make the settings using control word, to send data to the port andcheck the status of the port. These actions are distinguished using the first parameter of the function. Along with that we are sending data and the port to be used to communicate.Here are the deatails of the Turbo C Functions for communication ports. Declaration:bioscom(int cmd, char abyte, int port)_bios_serialcom(int cmd ,int port, char abyte)bioscom() and _bios_serialcom() uses the bios interrupt 0x14 to perform various communicate the serial communication over the I/O ports given in port.cmd: The I/O operation to be performed.cmdcmd(_bios_serialcom) Action(boiscom)0 _COM_INIT Initialise the parameters to the port1 _COM_SEND Send the character to the port2 _COM_RECEIVE Receive character from the port3 _COM_STATUS Returns rhe current status of thecommunication portportid: port to which data is to be sent or from which data is to be read.0: COM11: COM22: COM3abyte:When cmd =2 or 3 (_COM_SEND or _COM_RECEIVE) parameter abyte is ignored.When cmd = 0 (_COM_INIT), abyte is an OR combination of the following bits (One from each group):value of abyte Meaning Bioscom _bios_serialcom0x02 0x03 _COM_CHR7_COM_CHR87 data bits8 data bits0x00 0x04 _COM_STOP1_COM_STOP21 stop bit2 stop bits0x00 0x08 0X10 _COM_NOPARITY_COM_ODDPARITY_COM_EVENPARITYNo parityOdd parityEven parity0x00 0x20 0x40 0x60 0x80 0xA0 0xC0 0xE0 _COM_110_COM_150_COM_300_COM_600_COM_1200_COM_2400_COM_4800_COM_9600110 baud150 baud300 baud600 baud1200 baud2400 baud4800 baud9600 baudFor example, if abyte = 0x8B = (0x80 | 0x08 | 0x00 | 0x03) = (_COM_1200 | COM_ODDPARITY | _COM_STOP1 | _COM_CHR8)he communications port is set to1200 baud (0x80 = _COM_1200)Odd parity (0x08 = _COM_ODDPARITY)1 stop bit (0x00 = _COM_STOP1)8 data bits (0x03 = _COM_CHR8)To initialise the port with above settings we have to write bioscom(0, 0x8B, 0); To send a data to COM1, the format of the function will be bioscom(1, data, 0). Similarly bioscom(1, 0, 0 ) will read a data byte from the port.The following example illustrate how to serial port programs. When a data is available in the port, it inputs the data and displays onto the screen and if a key is pressed the ASCII value will be sent to the port.#include <bios.h>#include <conio.h>#define COM1 0#define DATA_READY 0x100#define SETTINGS ( 0x80 | 0x02 | 0x00 | 0x00)int main(void){int in, out, status;bioscom(0, SETTINGS, COM1); /*initialize the port*/cprintf("Data sent to you: ");while (1){status = bioscom(3, 0, COM1); /*wait until get a data*/if (status & DATA_READY)if ((out = bioscom(2, 0, COM1) & 0x7F) != 0) /*input a data*/putch(out);if (kbhit()){if ((in = getch()) == 27) /* ASCII of Esc*/break;bioscom(1, in, COM1); /*output a data*/}}return 0;}When you compile and run the above program in both the computers, The characters typed in one computer should appear on the other computer screen and vice versa. Initially, we set the port to desired settings as defined in macro settings. Thenwe waited in an idle loop until a key is pressed or a data is available on the port. If any key is pressed, then kbhit() function returns non zero value. So will go to getch function where we are finding out which key is pressed. Then we are sending it to the com port. Similarly, if any data is available on the port, we are receiving it from the port and displaying it on the screen.To check the port, If you have a single computer, you can use loop-back connection as follows. This is most commonly used method for developing communication programs. Here, data is transmitted to that port itself. Loop-back plug connection is as follows.Fig:Loop-back plug connectionIf you run the above program with the connection as in this diagram, the character entered in the keyboard should be displayed on the screen. This method is helpful in writing serial port program with single computer. Also you can make changes in the port id if your computer has 2 rs232ports. You can connect the com1 port to com2 of the same computer and change the port id in the program. The data sent to the port com1 should come to port com2. then also whatever you type in the keyboard should appear on the screen.The program given below is an example source code for serial communication programmers. It is a PC to PC communication using RS232. Download the code, unzip and run to chat in dos mode between two computers. Use the program to get more idea about serial port programming.译文:RS232串口通讯RS-232 简介RS232是一种常用的串口设备,它一般在通信和人机交互领域用于传输数据。
中英文文献以及翻译(化工类)

Foreign material:Chemical Industry1.Origins of the Chemical IndustryAlthough the use of chemicals dates back to the ancient civilizations, the evolution of what we know as the modern chemical industry started much more recently. It may be considered to have begun during the Industrial Revolution, about 1800, and developed to provide chemicals roe use by other industries. Examples are alkali for soapmaking, bleaching powder for cotton, and silica and sodium carbonate for glassmaking. It will be noted that these are all inorganic chemicals. The organic chemicals industry started in the 1860s with the exploitation of William Henry Perkin’s discovery if the first synthetic dyestuff—mauve. At the start of the twentieth century the emphasis on research on the applied aspects of chemistry in Germany had paid off handsomely, and by 1914 had resulted in the German chemical industry having 75% of the world market in chemicals. This was based on the discovery of new dyestuffs plus the development of both the contact process for sulphuric acid and the Haber process for ammonia. The later required a major technological breakthrough that of being able to carry out chemical reactions under conditions of very high pressure for the first time. The experience gained with this was to stand Germany in good stead, particularly with the rapidly increased demand for nitrogen-based compounds (ammonium salts for fertilizers and nitric acid for explosives manufacture) with the outbreak of world warⅠin 1914. This initiated profound changes which continued during the inter-war years (1918-1939).Since 1940 the chemical industry has grown at a remarkable rate, although this has slowed significantly in recent years. The lion’s share of this growth has been in the organic chemicals sector due to the development and growth of the petrochemicals area since 1950s. The explosives growth in petrochemicals in the 1960s and 1970s was largely due to the enormous increase in demand for synthetic polymers such as polyethylene, polypropylene, nylon, polyesters and epoxy resins.The chemical industry today is a very diverse sector of manufacturing industry, within which it plays a central role. It makes thousands of different chemicals whichthe general public only usually encounter as end or consumer products. These products are purchased because they have the required properties which make them suitable for some particular application, e.g. a non-stick coating for pans or a weedkiller. Thus chemicals are ultimately sold for the effects that they produce.2. Definition of the Chemical IndustryAt the turn of the century there would have been little difficulty in defining what constituted the chemical industry since only a very limited range of products was manufactured and these were clearly chemicals, e.g., alkali, sulphuric acid. At present, however, many intermediates to products produced, from raw materials like crude oil through (in some cases) many intermediates to products which may be used directly as consumer goods, or readily converted into them. The difficulty cones in deciding at which point in this sequence the particular operation ceases to be part of the chemical industry’s sphere of activities. To consider a specific example to illustrate this dilemma, emulsion paints may contain poly (vinyl chloride) / poly (vinyl acetate). Clearly, synthesis of vinyl chloride (or acetate) and its polymerization are chemical activities. However, if formulation and mixing of the paint, including the polymer, is carried out by a branch of the multinational chemical company which manufactured the ingredients, is this still part of the chemical industry of does it mow belong in the decorating industry?It is therefore apparent that, because of its diversity of operations and close links in many areas with other industries, there is no simple definition of the chemical industry. Instead each official body which collects and publishes statistics on manufacturing industry will have its definition as to which operations are classified as the chemical industry. It is important to bear this in mind when comparing statistical information which is derived from several sources.3. The Need for Chemical IndustryThe chemical industry is concerned with converting raw materials, such as crude oil, firstly into chemical intermediates and then into a tremendous variety of other chemicals. These are then used to produce consumer products, which make our livesmore comfortable or, in some cases such as pharmaceutical produces, help to maintain our well-being or even life itself. At each stage of these operations value is added to the produce and provided this added exceeds the raw material plus processing costs then a profit will be made on the operation. It is the aim of chemical industry to achieve this.It may seem strange in textbook this one to pose the question “do we need a chemical industry?” However trying to answer this question will provide(ⅰ) an indication of the range of the chemical industry’s activities, (ⅱ) its influence on our lives in everyday terms, and (ⅲ) how great is society’s need for a chemical industry. Our approach in answering the question will be to consider the industry’s co ntribution to meeting and satisfying our major needs. What are these? Clearly food (and drink) and health are paramount. Other which we shall consider in their turn are clothing and (briefly) shelter, leisure and transport.(1)Food. The chemical industry makes a major contribution to food production in at least three ways. Firstly, by making available large quantities of artificial fertilizers which are used to replace the elements (mainly nitrogen, phosphorus and potassium) which are removed as nutrients by the growing crops during modern intensive farming. Secondly, by manufacturing crop protection chemicals, i.e., pesticides, which markedly reduce the proportion of the crops consumed by pests. Thirdly, by producing veterinary products which protect livestock from disease or cure their infections.(2)Health. We are all aware of the major contribution which the pharmaceutical sector of the industry has made to help keep us all healthy, e.g. by curing bacterial infections with antibiotics, and even extending life itself, e.g. ß–blockers to lower blood pressure.(3)Clothing. The improvement in properties of modern synthetic fibers over the traditional clothing materials (e.g. cotton and wool) has been quite remarkable. Thus shirts, dresses and suits made from polyesters like Terylene and polyamides like Nylon are crease-resistant, machine-washable, and drip-dry or non-iron. They are also cheaper than natural materials.Parallel developments in the discovery of modern synthetic dyes and the technology to “bond” th em to the fiber has resulted in a tremendous increase in the variety of colors available to the fashion designer. Indeed they now span almost every color and hue of the visible spectrum. Indeed if a suitable shade is not available, structural modification of an existing dye to achieve this canreadily be carried out, provided there is a satisfactory market for the product.Other major advances in this sphere have been in color-fastness, i.e., resistance to the dye being washed out when the garment is cleaned.(4)Shelter, leisure and transport. In terms of shelter the contribution of modern synthetic polymers has been substantial. Plastics are tending to replace traditional building materials like wood because they are lighter, maintenance-free (i.e. they are resistant to weathering and do not need painting). Other polymers, e.g. urea-formaldehyde and polyurethanes, are important insulating materials f or reducing heat losses and hence reducing energy usage.Plastics and polymers have made a considerable impact on leisure activities with applications ranging from all-weather artificial surfaces for athletic tracks, football pitches and tennis courts to nylon strings for racquets and items like golf balls and footballs made entirely from synthetic materials.Like wise the chemical industry’s contribution to transport over the years has led to major improvements. Thus development of improved additives like anti-oxidants and viscosity index improves for engine oil has enabled routine servicing intervals to increase from 3000 to 6000 to 12000 miles. Research and development work has also resulted in improved lubricating oils and greases, and better brake fluids. Yet again the contribution of polymers and plastics has been very striking with the proportion of the total automobile derived from these materials—dashboard, steering wheel, seat padding and covering etc.—now exceeding 40%.So it is quite apparent even from a brief look at the chemical industry’s contribution to meeting our major needs that life in the world would be very different without the products of the industry. Indeed the level of a country’s development may be judged by the production level and sophistication of its chemical industry4. Research and Development (R&D) in Chemical IndustriesOne of the main reasons for the rapid growth of the chemical industry in the developed world has been its great commitment to, and investment in research and development (R&D). A typical figure is 5% of sales income, with this figure being almost doubled for the most research intensive sector, pharmaceuticals. It is important to emphasize that we are quoting percentages here not of profits but of sales income, i.e. the total money received, which has to pay for raw materials, overheads, staff salaries, etc. as well. In the past this tremendous investment has paid off well, leading to many useful and valuable products being introduced to the market. Examplesinclude synthetic polymers like nylons and polyesters, and drugs and pesticides. Although the number of new products introduced to the market has declined significantly in recent years, and in times of recession the research department is usually one of the first to suffer cutbacks, the commitment to R&D remains at a very high level.The chemical industry is a very high technology industry which takes full advantage of the latest advances in electronics and engineering. Computers are very widely used for all sorts of applications, from automatic control of chemical plants, to molecular modeling of structures of new compounds, to the control of analytical instruments in the laboratory.Individual manufacturing plants have capacities ranging from just a few tones per year in the fine chemicals area to the real giants in the fertilizer and petrochemical sectors which range up to 500,000 tonnes. The latter requires enormous capital investment, since a single plant of this size can now cost $520 million! This, coupled with the widespread use of automatic control equipment, helps to explain why the chemical industry is capital-rather than labor-intensive.The major chemical companies are truly multinational and operate their sales and marketing activities in most of the countries of the world, and they also have manufacturing units in a number of countries. This international outlook for operations, or globalization, is a growing trend within the chemical industry, with companies expanding their activities either by erecting manufacturing units in other countries or by taking over companies which are already operating there.化学工业1.化学工业的起源尽管化学品的使用可以追溯到古代文明时代,我们所谓的现代化学工业的发展却是非常近代(才开始的)。
英文文献用翻译

Adult【成年人】Aged【老年人】Aged, 80 and over【老年人, 80以上】Catheterization, Central Venous/*instrumentation/methods【*导管插入术, 中心静脉/*仪器/方法】Cost-Benefit Analysis【费用效益分析】Equipment Design【设备设计】Equipment Failure【设备失效】Equipment Safety【设备安全性】Female【女(雌)性】Humans【人类】Infusion Pumps, Implantable/adverse effects/*economics【*输注泵, 植入型/副作用/*经济学】Male【男(雄)性】Middle Aged【中年人】Neoplasms/*drug therapy/pathology【*肿瘤/*药物疗法/病理学】Probability【概率】Prospective Studies【前瞻性研究】Risk Assessment【危险性评估】Sensitivity and Specificity【敏感性与特异性】Treatment Outcome【治疗结果】Vascular Patency【血管未闭】Venous Thrombosis/prevention & control【静脉血栓形成】Adolescent【青少年】Adult【成年人】Aged【老年人】Aged, 80 andover【老年人, 80以上】AntineoplasticAgents/*administration& dosage【*抗肿瘤药】*Catheters,Indwelling/adverseeffects/economics【*导管, 留置/副作用/经济学】Female【女(雌)性】Humans【人类】*Infusion Pumps,Implantable/adverse。
英文文献全文翻译

英文文献全文翻译全文共四篇示例,供读者参考第一篇示例:LeGuin, Ursula K. (December 18, 2002). "Dancing at the Edge of the World: Thoughts on Words, Women, Places".《世界边缘的舞蹈:关于语言、女性和地方的思考》Introduction:In "Dancing at the Edge of the World," Ursula K. LeGuin explores the intersection of language, women, and places. She writes about the power of words, the role of women in society, and the importance of our connection to the places we inhabit. Through a series of essays, LeGuin invites readers to think critically about these topics and consider how they shape our understanding of the world.Chapter 1: LanguageConclusion:第二篇示例:IntroductionEnglish literature translation is an important field in the study of language and culture. The translation of English literature involves not only the linguistic translation of words or sentences but also the transfer of cultural meaning and emotional resonance. This article will discuss the challenges and techniques of translating English literature, as well as the importance of preserving the original author's voice and style in the translated text.Challenges in translating English literature第三篇示例:Title: The Importance of Translation of Full English TextsTranslation plays a crucial role in bringing different languages and cultures together. More specifically, translating full English texts into different languages allows for access to valuable information and insights that may otherwise be inaccessible to those who do not speak English. In this article, we will explore the importance of translating full English texts and the benefits it brings.第四篇示例:Abstract: This article discusses the importance of translating English literature and the challenges translators face when putting together a full-text translation. It highlights the skills and knowledge needed to accurately convey the meaning and tone of the original text while preserving its cultural and literary nuances. Through a detailed analysis of the translation process, this article emphasizes the crucial role translators play in bridging the gap between languages and making English literature accessible to a global audience.IntroductionEnglish literature is a rich and diverse field encompassing a wide range of genres, styles, and themes. From classic works by Shakespeare and Dickens to contemporary novels by authors like J.K. Rowling and Philip Pullman, English literature offers something for everyone. However, for non-English speakers, accessing and understanding these works can be a challenge. This is where translation comes in.Translation is the process of rendering a text from one language into another, while striving to preserve the original meaning, tone, and style of the original work. Translating afull-length English text requires a deep understanding of both languages, as well as a keen awareness of the cultural andhistorical context in which the work was written. Additionally, translators must possess strong writing skills in order to convey the beauty and complexity of the original text in a new language.Challenges of Full-text TranslationTranslating a full-length English text poses several challenges for translators. One of the most significant challenges is capturing the nuances and subtleties of the original work. English literature is known for its rich and layered language, with intricate wordplay, metaphors, and symbolism that can be difficult to convey in another language. Translators must carefully consider each word and phrase in order to accurately convey the author's intended meaning.Another challenge of full-text translation is maintaining the author's unique voice and style. Each writer has a distinct way of expressing themselves, and a good translator must be able to replicate this voice in the translated text. This requires a deep understanding of the author's writing style, as well as the ability to adapt it to the conventions of the target language.Additionally, translators must be mindful of the cultural and historical context of the original work. English literature is deeply rooted in the history and traditions of the English-speaking world, and translators must be aware of these influences in orderto accurately convey the author's intended message. This requires thorough research and a nuanced understanding of the social, political, and economic factors that shaped the work.Skills and Knowledge RequiredTo successfully translate a full-length English text, translators must possess a wide range of skills and knowledge. First and foremost, translators must be fluent in both the source language (English) and the target language. This includes a strong grasp of grammar, syntax, and vocabulary in both languages, as well as an understanding of the cultural and historical context of the works being translated.Translators must also have a keen eye for detail and a meticulous approach to their work. Every word, sentence, and paragraph must be carefully considered and translated with precision in order to accurately convey the meaning of the original text. This requires strong analytical skills and a deep understanding of the nuances and complexities of language.Furthermore, translators must possess strong writing skills in order to craft a compelling and engaging translation. Translating a full-length English text is not simply a matter of substituting one word for another; it requires creativity, imagination, and a deep appreciation for the beauty of language. Translators mustbe able to capture the rhythm, cadence, and tone of the original work in their translation, while also adapting it to the conventions of the target language.ConclusionIn conclusion, translating a full-length English text is a complex and challenging task that requires a high level of skill, knowledge, and creativity. Translators must possess a deep understanding of both the source and target languages, as well as the cultural and historical context of the work being translated. Through their careful and meticulous work, translators play a crucial role in making English literature accessible to a global audience, bridging the gap between languages and cultures. By preserving the beauty and complexity of the original text in their translations, translators enrich our understanding of literature and bring the works of English authors to readers around the world.。
英文文献+翻译

Characterization of production of Paclitaxel and related Taxanes in Taxus Cuspidata Densiformis suspension cultures by LC,LC/MS, and LC/MS/MSCHAPTER THEREPLANT TISSUE CULTUREⅠ. Potential of Plant cell Culture for Taxane ProductionSeveral alternative sources of paclitaxel have been identified and are currently the subjects of considerable investigation worldwide. These include the total synthesis and biosynthesis of paclitaxel, the agriculture supply of taxoids from needles of Taxus species, hemisynthesis (the attachment of a side chain to biogenetic precursors of paclitaxel such as baccatin Ⅲ or 10-deacetylbaccatin Ⅲ), fungus production, and the production of taxoids by cell and tissue culture. This reciew will concentrate only on the latter possibility.Plant tissue culture is one approach under investigation to provide large amounts and a stable supply of this compound exhibiting antineoplastic activity. A process to produce paclitaxel or paclitaxel-like compounds in cell culture has already been parented. The development of fast growing cell lines capable of producing paclitaxel would not only solve the limitations in paclitaxel supplies presently needed for clinical use, but would also help conserve the large number of trees that need to be harvested in order to isolate it. Currently, scientists and researchers have been successful in initiating fast plant growth but with limited paclitaxel production or vice versa. Therefore, it is the objective of researchers to find a method that will promote fast plant growth and also produce a large amount of paclitaxel at the same time.Ⅱ. Factors Influencing Growth Paclitaxel ContentA.Choice of Media for GrowthGamborg's (B5) and Murashige & Skoog's (MS) media seem to be superior for callus growth compared to White's (WP) medium. The major difference between these two media is that the MS medium contains 40 mM nitrate and 20mM ammonium, compared to 25mM nitrate and 2mM ammonium. Many researchers have selected the B5 medium over the MS medium for all subsequent studies, although they achieve similar results.Gamborg's B5 media was used throughout our experiments for initiation of callus cultures and suspension cultures due to successful published results. It was supplemented with 2% sucrose, 2 g/L casein hydrolysate, 2.4 mg/L picloram, and 1.8 mg/L α-naphthalene acetic acid. Agar (8 g/L) was used for solid cultures.B. Initiation of Callus CulturesPrevious work indicated that bark explants seem to be the most useful for establishing callus. The age of the tree did not appear to affect the ability to initiate callus when comparing both young and old tree materials grown on Gamborg's B5 medium supplemented with 1-2 mg/L of 2,4-dichlorophenoxyacetic acid. Callus cultures initiated and maintained in total darkness were generally pale-yellow to light brown in color. This resulted in sufficient masses of friable callus necessary for subculture within 3-4 weeks. However, the growth rate can decline substantially following the initial subculture and result in very slow-growing, brown-colored clumps of callus. It has been presumed that these brown-colored exudates are phenolic in nature and can eventually lead to cell death. This common phenomenon is totally random and unpredictable. Once this phenomenon has been triggered, the cells could not be saved by placing them in fresh media. However, adding polyvinylpyrrolidone to the culture media can help keep the cells alive and growing. Our experience with callus initiationwas similar to those studies.Our studies have found that callus which initiated early (usually within 2 weeks ) frequently did not proliferate when subcultured and turned brown and necrotic. In contrast, calli which developed from 4 weeks to 4 months after explants were fist placed on initiation media were able to be continuously subcultured when transferred at 1-2 month intervals. The presence of the survival of callus after subsequent subculturing. The relationship between paclitaxel concentration and callus initiation, however, has not been clarified.C. Effect of SugarSucrose is the preferred carbon source for growth in plant cell cultures, although the presence of more rapidly metabolized sugar such as glucose favors fast growth. Other sugars such as lactose, galactose, glucose, and fructose also support cell growth to some extent. On the other hand, sugar alcohols such as mannitol and sorbital which are generally used to raise the sugars added play a major role in the production of paclitaxel. In general, raising the initial sugar levels lead to an increase of secondary metabolite production. High initial levels of sugar increase the osmotic potential, although the role of osmotic pressure on the synthesis of secondary metabolites is not cleat. Kim and colleagues have shown that the highest level of paclitaxel was obtained with fructosel. The optimum concentration of each sugar for paclitaxel production was found to be the same at 6% in all cases. Wickremesinhe and Arteca have provided additional support that fructose is the most effective for paclitaxel production. However, other combinations of sugars such as sucrose combined with glucose also increased paclitaxel production.The presence of extracellular invertase activity and rapid extracellular sucrose hydrolysis has been observed in many cell cultures. These reports suggest that cells secrete or possess on their surface excess amounts of invertase, which result in the hydrolysis of sucrose at a much faster rate. The hydrolysis of sucrose coupled with the rapid utilization of fructose in the medium during the latter period of cell growth. This period of increased fructose availability coincided with the faster growth phase of the cells.D. Effect of Picloram and Methyl JasmonatePicloram (4-amino-3.5.6-trichloropicolinic acid) increases growth rate while methyl jasmonate has been reported to be an effective elicitor in the production of paclitaxel and other taxanes. However, little is known about the mechanisms or pathways that stimulate these secondary metabolites.Picloram had been used by Furmanowa and co-workers and Ketchum and Gibson but no details on the effect of picloram on growth rates were given. Furmanowa and hid colleagues observed growth of callus both in the presence and absence of light. The callus grew best in the dark showing a 9.3 fold increase, whereas there was only a 2-4 fold increase in the presence of light. Without picloram, callus growth was 0.9 fold. Unfortunately,this auxin had no effect on taxane production and the high callus growth rate was very unstable.Jasmonates exhibit various morphological and physiological activities when applied exogenously to plants. They induce transcriptional activation of genes involved in the formation of secondary metabolites. Methyl jasmonate was shown to stimulate paclitaxel and cephalomannine (taxane derivative) production in callus and suspension cultures. However, taxane production was best with White's medium compared to Gamborg's B5 medium. This may be due to the reduced concentration of potassium nitrate and a lack of ammonium sulfate with White's medium.E. Effect of Copper Sulfate and Mercuric ChlorideMetal ions have shown to play significant roles in altering the expression of secondary metabolic pathways in plant cell culture. Secondary metabolites,such as furano-terpenes, have been production by treatment of sweet potato root tissue with mercuric chloride. The results for copper sulfate, however, have not been reported. F. Growth Kinetics and Paclitaxel ProductionLow yields of paclitaxel may be attributed to the kinetics of taxane production that is not fully understood. Many reports stated inconclusive results on the kinetics of taxane production. More studies are needed in order to quantitate the taxane production. According to Nett-Fetto, the maximum instantaneous rate of paclitaxel production occurred at the third week upon further incubation. The paclitaxel level either declined or was not expected to increase upon further incubation. Paclitaxel production was very sensitive to slight variations in culture conditions. Due to this sensitivity, cell maintenance conditions, especially initial cell density, length of subculture interval, and temperature must be maintained as possible.Recently, Byun and co-workers have made a very detailed study on the kinetics of cell growth and taxane production. In their investigation, it was observed that the highest cell weight occurred at day 7 after inoculation. Similarly, the maximum concentration for 10-deacetyl baccatin Ⅲ and baccatin Ⅲ were detected at days 5 and 7, respectively. This result indicated that they are metabolic intermediates of paclitaxel. However, paclitaxel's maximum concentration was detected at day 22 but gradually declined. Byun and his colleagues suggested that paxlitaxel could be a metabolic intermediate like 10-deacetyl baccatin Ⅲ and baccatin Ⅲ or that pacliltaxel could be decomposed due to cellular morphological changes or DNA degradation characteristic of cell death.Pedtchanker's group also studied the kinetics of paclitaxel production by comparing the suspension cultures in shake flasks and Wilson-type reactors where bubbled air provided agitation and mixing. It was concluded that these cultures of Taxus cuspidata produced high levels of paclitaxel within three weeks (1.1 mg/L per day ). It was also determined that both cultures of the shake flask and Wilson-type reactor produced similar paclitaxel content. However, the Wilson-type reactor had a more rapid uptake of the nutrients (i.e. sugars, phosphate, calcium, and nitrate). This was probably due to the presence of the growth ring in the Wilson reactor. Therefor, the growth rate for the cultures from the Wilson reactor was only 135 mg./L while the shake flasks grew to 310 mg/L in three weeks.In retrospect, strictly controlled culture conditions are essential to consistent production and yield. Slight alterations in media formulations can have significant effects upon the physiology of cells, thereby affecting growth and product formation. All of the manipulations that affect growth and production of plant cells must be carefully integrated and controlled in order to maintain cell viability and stability.利用LC,LC/MS和LC/MS/MS悬浮培养生产紫杉醇及邓西佛米斯红豆杉中相关紫杉醇类的特征描述第三章植物组织培养Ⅰ.利用植物细胞培养生产紫杉的可能性紫杉醇的几个备选的来源已被确定,而且目前是全球大量调查的主题。
英文文献参考及翻译
原文:THE DISTRIBUTION OF PAYROLL ANDINCOME TAX BURDENS, 1979-1999Andrew MitrusiJames PoterbaWorking Paper 7707/papers/w7707NA TIONAL BUREAU OF ECONOMIC RESEARCH1050 Massachusetts AvenueCambridge, MA 02138May 20001. Federal Income and Payroll Tax Changes, 1979-1999There have been four major legislative changes in the federal personal income tax code in the last two decades. The payroll tax has also been changed several times, but the changes have been less dramatic than those in the income tax code. This section summarizes these legislative changes.1.1 Federal Income Tax Changes, 1979-1999There were four major federal income tax reforms during the 1979-1999 period. These were the Economic Recovery Tax Act of 1981 (ERTA), the Tax Reform Act of 1986 (TRA86), the Omnibus Budget Reconciliation Act of 1993 (OBRA93), and the Taxpayer Relief Act of 1997 (TRA97). These reforms are described in detail elsewhere, for example Steuerle (1992), so with the exception of TRA97, we will not provide an in-depth summary.ERTA significantly reduced personal income taxes across-the-board. It incorporated a three-year period of tax reduction, with marginal rates on all but the highest income taxpayers declining substantially during the 1981-1984 period. The top marginal tax rate on earned income was 50 percent before as well as after ERTA, but the legislation reduced the top marginal rate on unearned income from 70 percent to 50 percent beginning in 1981. This reform also reduced the top statutory marginal tax rate on long-term capital gains from 28 percent to 20 percent. We consider tax burdens in 1984 in our analysis below, because by 1984 the ERTA reforms were fully effective.TRA86 continued the reduction in top marginal tax rates that had been part of ERTA, but it also eliminated the capital gains tax preference for most taxpayers. For taxpayers at the highest income levels, TRA86 reduced marginal tax rates from 50percent in 1986, to 39 percent in 1987 and to 28 percent in 1988. TRA86 introduced a hump-shaped pattern in marginal tax rates, with some taxpayers below the highest income groups facing a 33 percent marginal tax rate. It also eliminated the tax preference for capital gains, although the tax rate on such gains was capped at 28 percent. This change increased the statutory tax rate on gains for many high-income taxpayers. TRA86 raised the standard deduction and the personal exemption, thereby reducing the number of low-income families that needed to file income tax returns. It also expanded the Earned Income Tax Credit, which reduced income tax liabilities for low-income families with earned income. Because some provisions in TRA86 phased in over two years, we consider tax liabilities in 1989 as an illustration of tax burdens under the TRA86 regime.OBRA93 partially reversed the changes in the top marginal tax rate that had been enacted in 1986. In many ways it extended and amplified changes that were enacted as part of the Omnibus Budget Reconciliation Act of 1990. The 1990 Act eliminated the "hump shaped" distribution of marginal tax rates that was embodied in the 1986 law and replaced it with a top marginal tax rate of 31 percent. This led to a three-bracket income tax rate schedule, with rates of 15, 28, and 31 percent. OBRA93 raised the top marginal tax rate to 36% for joint filers with incomes above $140,000 ($115,000 for single filers). In addition, it raised the marginal tax rate to 39.6% (36% plus a 10% surtax) for individual or married taxpayers with taxable incomes of more than $250,000. Many high-income taxpayers face tax rates above this statutory maximum of 39.6% as a result of the phase-out provisions governing various deductions. OBRA93 also raised the share of Social Security benefits that could be taxed from 50 to 85 percent.1.2 The Taxpayer Relief Act of 1997TRA97 included a number of new tax credits and once again altered the tax rate on long-term capital gains. The first such credit is the Child Tax Credit, which provides a $500 credit ($400 for 1998) for each qualified child of a taxpayer. To qualify, a child must be under the age of 17. This credit was fully available to married joint filers with modified adjusted gross income (AGI) of less than $110,000, and to single taxpayers or heads of household with modified AGI of less than $75,000. For each $1,000 of modified AGI in excess of these thresholds, the Child Tax Credit is reduced by $50 per child until the credit is exhausted.The Child Tax Credit is not refundable, and it is only available for dependent children who are under the age of 17. It does not generate any benefit for low-incomefamilies with no federal income tax liabilities. Our estimates, which are described in more detail in the appendix, suggest that the Child Tax Credit reduced family income tax liability for only 69.4 percent of under-17 dependents in 1999. (We estimate that 76.3 percent of all dependents claimed on tax returns in 1995 were under the age of 17.) Although some low-income families cannot use the Child Tax Credit to reduce their income tax liability, a large fraction of the tax benefits associated with the Child Tax Credit accrue to low- and modest-income families. We estimate that 35 percent of the under-17 dependents whose families benefit from the Child Tax Credit have family incomes of less than $40,000.TRA97 also reduced the maximum tax rate on long-term capital gains from 28 percent to 20 percent, effective May 7, 1997. For taxpayers in the 15-percent income tax bracket, the maximum longterm capital gains tax rate became 10 percent. TRA97 also introduced an "intermediate" capital gains tax rate that applied to gains held from twelve to thirty months, but this rate was eliminated in 1998. Because we consider tax liabilities for families facing the 1999 tax law, we do not consider the impact of the intermediate capital gains tax rate.Finally, TRA97 included a number of new tax incentives for college attendance. The two most significant are the HOPE Credit and the Lifetime Learning Credit (LLC). The HOPE credit is a nonrefundable credit of up to $1500 per student. It can be used to offset educational expenses in a student’s first two years of post-secondary education. It is a 100 percent credit on the first $1000 of tuition and fees, and a 50 percent credit on the next $1000 of such fees. The full value of the credit is available to married joint filers with modified AGI of less than $80,000. The credit is completely phased out for married joint filers with modified AGI of more than $100,000. For heads of household and single filers, the HOPE Credit phases out between $40,000 and $50,000 of modified AGI. The HOPE Credit can be claimed by the taxpayer, the taxpayer's spouse, or on behalf of any of the taxpayer's dependents.For families with a single HOPE Credit recipient, the phase-out of the credit raises marginal income tax rates by 7.5 percent in the relevant AGI range. Some tax returns might have more than one beneficiary, and for such returns, the marginal tax rate effects can be very large. To illustrate this, consider a family with two children, ages 19 and 20, who are attending college. Assume that the family has an adjusted gross income of $90,000. Before TRA97, this family faced a marginal federal income tax rate of 28 percent. The HOPE phase-out raises this tax rate to 43 (28 + 2*7.5)percent. For a singleparent family, the effect is even more dramatic, since the phase-out occurs over the $40-50,000 income range. A single parent household with two HOPE credit recipients could therefore face a 30 percent increase in marginal income tax rates as a result of the phase-out provisions.One important feature of the HOPE Credit, emphasized in Cronin (1997) and Dynarski (1999), is that it applies to net tuition and fees. Federal Pell grants and other financial aid that post-secondary schools provide to low-income enrollees can reduce the value of the HOPE Credit, and for some students, they may render the HOPE credit worthless. (This fact has led to interesting discussions, summarized in Dynarski (1999), about the ultimate incidence of the HOPE credit and the extent to which it benefits students attending college or is offset by increases in the net price charged by post-secondary institutions.)The Lifetime Learning Credit provides taxpayers with a credit equal to 20 percent of net educational expenditures, up to a maximum credit of $1,000. Like the HOPE Credit, the LLC is phased out for married joint filers over the $80,000-$100,000 modified AGI range, and for single filers over the $40-50,000 modified AGI range. The LLC is available to anyone enrolled in a post-secondary educational institution. The phase-out raises marginal tax rates by up to 5 percentage points for families in the phase-out income range. The LLC is computed on a per-return basis, rather than a per-student basis, and it is not possible to claim both a HOPE Credit and a Lifetime Learning Credit for the same eligible student. Because the HOPE Credit offers a 100 percent or a 50 percent credit, depending on the amount of tuition outlays, and the LLC offers only a 20 percent credit, those who can use the HOPE Credit will presumably choose to use it before utilizing the Lifetime Learning Credit. The LLC is not restricted to two years of higher education spending, as the HOPE Credit is.We estimate the distributional effects of the tax credits embodied in TRA97 by "aging" tax returns from 1995 to 1999, and then imputing information on whether families are likely to have dependents who are eligible for these credits. While detailed information on individual income tax returns filed for the 1998 tax year will not be available for some time, the IRS has released preliminary data on the use of education tax credits in 1998, and we compare our estimates with these actual data. 1.3 Changes in Payroll Tax Rates and the Payroll Tax Base, 1979-1999The payroll taxes that are used to finance the Social Security and Hospital Insurance (Medicare) programs have not changed as dramatically as federal incometaxes during the last twenty years.In 1979, the combined employer and employee payroll tax rate was 12.26 percent. In 1999, this rate was 15.3 percent. Table 1 shows the changes in the combined employer and employee tax rate over the last two decades, as well as in the taxable maximum level of earnings for both payroll taxes. For high-earning taxpayers, the most significant payroll tax changes during the last two decades were the increase in the Hospital Insurance maximum taxable earnings from $51,300 to $125,000 in 1991, and the subsequent elimination of the upper limit on taxable earnings in 1994. The payroll tax rates have been 12.4 percent for Social Security, and 2.9 percent for Hospital Insurance, since 1990.2. The Distribution of Income and Payroll Tax Liabilities, 1979-1999The NBER TAXSIM model is a computer program that calculates federal income tax and payroll tax liabilities for a representative sample of U.S. families. The program analyzes data from the Statistics of Income (SOI) Public Use File, which is a stratified random sample of U.S. taxpayers that oversamples high-income tax returns. Feenberg and Coutts (1993) describe this program in some detail.TAXSIM currently offers detailed federal tax calculators for the 1960-1999 period. While it has traditionally focused on federal income tax liability, we extend its capacity to include payroll taxes as well. We focus our analysis on the 1979-1999 period.We do not consider excise taxes at either the federal or state-local level, estate taxes, or corporate income taxes, in our analysis of tax burdens. Some other studies of household tax burdens, such as the ITEP model described by Ettlinger and O'Hare (1998) or some of the models analyzed by the Congressional Budget Office, also include taxes besides income and payroll taxes. Our limited analysis avoids a number of difficult incidence issues, discussed for example in Bradford (1995) and Joint Committee on Taxation (1993), associated with taxes other than income and payroll taxes.We focus our efforts on describing two taxes that have traditionally been assumed to fall on the families that pay them, namely the individual income tax and the payroll tax (including the employer's share of this tax).The most recent SOI Public Use File contains tax returns for the 1995 tax year. Because we are interested in family tax liabilities under the most recent federal tax law, we "age" the information from 1995 to 1999.We do this using an algorithm described in the appendix that relies on aggregate information on tax returns as reported by the Internal Revenue Service, along with data from the National Income and Product Accounts. We also augment the data from the SOI Public Use File with data from the Current Population Survey (CPS) on families that do not file tax returns.Our non-filer imputation procedure is also described in the appendix.Throughout our analysis, we focus on families as our basic unit of observation, and calendar years as the basic unit of time.We follow the tax code in defining "families" by excluding dependent tax filers from family units.When we stratify families according to their income, we focus on an "Adjusted AGI" measure.This is defined as Adjusted Gross Income (AGI) as reported on tax returns, plus employer-paid Social Security and Medicare taxes, plus the portion of Social Security benefits that are excluded from AGI, plus tax exempt bond interest, plus contributions to Individual Retirement Accounts and Keoghs.Some other studies of the distribution of income or payroll tax burdens, such as Ettlinger and O'Hare (1996), use even more expansive definitions of family income that include estimates of transfer payments and other resource flows. We restrict our analysis to an income measure that can be constructed from data on tax returns. The appendix describes how we impute each family's payroll taxes.There are several ways to summarize the distribution of income and payroll tax liabilities for the 1979-1999 period. We first describe the distribution of both types of taxes across families in different income categories in 1999. We then consider how the level of income and payroll taxes has varied over time, and also present information on the relative importance of the two taxes for families at different points in the income distribution.We finally isolate the effect of the Earned Income Tax Credit in affecting tax liabilities over the period that we study.2.1 Income Taxes and Payroll Taxes, 1999Table 2 presents our estimate of the distribution of income and payroll tax liabilities across families in calendar year 1999. Table 2 includes entries for the mean personal income tax and the mean payroll tax for families in different adjusted AGI categories. Our measure of the payroll tax burden combines both the employer and employee share of this tax, just as our measure of family income is defined before payment of either employer or employee payroll taxes. Table 2 also shows the fraction of families for whom the payroll tax is greater than the income tax, and for the fraction of families for whom the income tax is greater than the payroll tax, again stratified by adjusted AGI.A substantial group of families have zero payroll and income tax liabilities, so in some adjusted AGI categories, the sum of the percent of families with payroll taxes greater than income taxes, and the percent with income taxes greater than payroll taxes, adds up to less than 100 percent.Table 2 shows that for most families in income classes below $100,000, theaverage payroll tax burden exceeds the average personal income tax burden.The disparities are particularly clear at lower income levels. For families with between $20,000 and $30,000 in adjusted AGI, for example, mean payroll taxes are roughly three times as great as mean income taxes.For families in lower adjusted AGI categories, mean federal income taxes are negative. This reflects the refundable portion of the Earned Income Tax Credit generating negative income tax payments. The average federal income tax burden does not approximate the average payroll tax burden until the $75-100,000 adjusted AGI category. At higher adjusted AGI levels, income tax payments are substantially larger than payroll tax payments. This re flects both the capped base for the Social Security payroll tax, and the low rate for the Hospital Insurance payroll tax (relative to income tax rates).Payroll taxes exceed income taxes for 62 percent of families.At income levels below $50,000, more than three-quarters of families have payroll tax bills that exceed their income taxes.At adjusted AGI levels above $200,000, income taxes exceed payroll taxes for virtually all families.At the lowest income levels, there are a substantial number of families with no income or payroll tax liability.Nearly half of families with adjusted AGI of less than $10,000 have neither payroll nor income tax liabilities.These families are not classified as having payroll taxes greater than income taxes, or vice versa.The results on income versus payroll taxes in Table 2 are broadly consistent with findings reported by the Congressional Budget Office (CBO) (1998).For example, CBO (1998) reports that at family income between $40,000 and $50,000, 78 percent of families pay combined employer and employee payroll taxes that exceed their income tax.Our estimate is 74.5 percent.At lower income levels there are greater disparities between our calculations and those in CBO (1998), and there are also some significant differences at higher income levels.For families with incomes between $100,000 and $200,000, for example, we estimate that 84 percent face income taxes greater than their payroll taxes, while the CBO (1998) estimate is 66 percent.Several factors could account for differences between our results and those in CBO (1998).One is that we use a less expansive income definition than CBO, since we do not impute any information such as transfer payments that is not reported on tax returns.A second possibility is different assumptions about the recent time path of various income components, particularly capital gain realizations, that represent a large share of income for the highest-income families.Any analysis of post-1995 tax distributional patterns requires making a forecast of how the income distribution hasevolved since 1995 (the last year for which the SOI Public Use File is available).We describe in the appendix our algorithm for "aging" the 1995 income distribution to 1999, which differs from that used by CBO.We use more disaggregate information on the aggregate value of income flows to "age" the 1995 income distribution to 1999 than the CBO algorithm does.Finally, our approach to identifying nonfiler families may differ from that used by the CBO.In future work, we hope to explore the source of these differences.We have not made detailed comparisons of our findings and those from other models, such as the ITEP model described by Ettlinger and O'Hare (1998).We suspect, however, that what differences arise are likely to stem from factors similar to those that may cause divergence between our results and CBO's.2.2 Income Taxes and Payroll Taxes: The 1979-1999 ExperienceTable 2 provides information on the pattern of income tax and payroll tax liabilities in 1999, but it does not place these liabilities in historical context.Table 3 develops a longer-term perspective on the relative magnitude of tax liabilities.It shows the results of applying income and payroll tax rules from five years -- 1979, 1984, 1989, 1994, and 1999 -- to the set of families whose 1999 income and payroll taxes we analyzed in Table 2. Recall that this "1999 family income distribution" was constructed by "aging" families from the 1995 SOI Public Use File and the 1995 Current Population Survey to 1999.When we apply the tax laws from other years to this set of families, we re-define the income thresholds in each year's tax laws to correspond to 1999 price levels. We make these adjustments using price changes as reflected in the Consumer Price Index.Thus, if the Consumer Price Level for 1999 was double that for an earlier year, we would double all of the nominal magnitudes in the income tax law for the earlier year, and then apply the resulting tax code to our data set of 1999 families.The calculations in Table 3, and in several subsequent tables, indicate what would have happened if the bracket amounts in tax codes from earlier years had been indexed for inflation but not for other changes in the economy.They assume that the U.S. economy would have evolved precisely as it did over the last twenty years despite this difference in the tax code.By holding the pre-tax distribution of family income constant, we are able to focus on the impact of tax law changes alone.Our assumption that the tax law does not affect the pretax distribution of income is an important over-simplification, however.Many studies, such as Feldstein (1995), Gruber and Saez (2000), and others surveyed in the latter study, suggest that theremay be important links between the distribution of marginal tax rates and reported family income.Table 3 shows the percentage of families for whom the payroll tax would have exceeded the personal income tax if the tax laws from various years had applied in 1999. The table shows significant change in the relative importance of the income and the payroll tax over the 1979-1999 period.The upper panel of the table reports percentages as a share of all families in various adjusted AGI ranges. If the 1979 and 1984 tax laws had applied in 1999, only 19.1 and 28.8 percent of families with adjusted AGI between $50,000 and $75,000 ($1999) would have faced payroll taxes that were greater than their income tax liabilities.Under the 1999 tax law, two thirds of the families in this group faced greater payroll taxes than income taxes.Between 1984 and 1989, the percentage of families in this income group with payroll taxes greater than income taxes rose from 28.8 to 63.4 percent, highlighting the importance of the Tax Reform Act of 1986 in affecting the relative importance of income and payroll taxes.The last two decades have also seen some changes in the relative importance of payroll and income taxes for families at the top of the income distribution. In 1999, nearly one family in six with AGI between $100,000 and $200,000 paid more in payroll taxes than in income taxes.In years before the Tax Reform Act of 1986, this fraction was negligible.In 1989, less than one family in ten in this adjusted AGI category paid more in payroll than in income taxes.The increase in the number of high-income families with payroll taxes greater than income taxes thus appears to be due to both the changes in the Tax Reform Act of 1986, and the changes in the payroll tax cap in the early 1990s.The lower panel of Table 3 presents information on only those families who paid positive income or payroll tax in each year.While restricting the sample to this group has very little effect on our results for families with income of more than $40,000 in 1999, it has substantial effects at lower income levels.For families with 1999 adjusted AGI between $10,000 and $20,000, for example, 71.5 percent of all families but 87.1 percent of families who paid some taxes had 1999 payroll taxes in excess of personal income taxes.In general, the share of families with payroll taxes greater than income taxes is larger when we restrict the families we are considering to those with positive tax liability of some type.We find that just over 70 percent of families with positive taxes face payroll taxes that are larger than income taxes. CBO (1998) reports an even larger value, 80 percent. In our data, the effect ofconditioning on positive tax liability is similar in 1979, 1984, 1989, 1994, and 1999. Table 3 presents information on the relative magnitude of income and payroll tax liabilities, but it does not consider the absolute magnitude of either tax liability. Tables 4 and 5 present summary information on tax levels.The tables use two different family income distributions to compare the level of payroll taxes (Table 4) and personal income taxes (Table 5) for families at different income levels. The first is the 1999 family income distribution that was used to develop the summary statistics in Tables 2 and 3. As explained above, this income distribution is based on data from 1995 income tax returns, augmented with data from the 1995 Current Population Survey, and then "aged" to 1999. The second income distribution that we consider is the 1979 family income distribution.We construct this income distribution from the 1979 SOI Public Use File, augmented with data from the 1979 Current Population Survey.Nominal magnitudes in this 1979 family income distribution are then converted to 1999 quantities using the change in the Consumer Price Index between 1979 and 1999.We consider two income distributions to explore the robustness of our findings to shifts in the underlying characteristics of the families whose taxes we are studying. The 1979 family income distribution differs in various ways from the 1999 distribution. The share of wage income amongst the highest income families is lower, for example (see Feenberg and Poterba (2000)). There are differences in the relative importance of married couples and single filers at different family income levels. The average real income level of families in 1979 is also lower than that of families in 1999, since wages and other incomes have grown faster than the price level over the intervening two decades. Tables 4 and 5 reflect this in showing lower average payroll and income tax burdens when we use the 1979 family income distribution rather than the 1999 family income distribution.翻译:工资分配和所得税负担,1979-19991 联邦所得税和工资税变化,1979-1999在过去二十年中,已经有四个主要的联邦个人所得税编码的立法变化。
英文文献原文及对应翻译
Adsorption char acter istics of copper , lead, zinc and cadmium ions by tourmaline(环境科学学报英文版) 电气石对铜、铅、锌、镉离子的吸附特性JIANG Kan1,*, SUN Tie-heng1,2 , SUN Li-na2, LI Hai-bo2(1. School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090, China. jiangkan522@; 2. Key Laboratory of Environmental Engineering of Shenyang University, Shenyang 110041, China)摘要:本文研究了电气石对Cu2+、Pb2+、Zn2+和Cd2+的吸附特性,建立了吸附平衡方程。
研究四种金属离子的吸附等温线以及朗缪尔方程。
结果表明电气石能有效地去除水溶液中的重金属且具有选择性:Pb2+> Cu2+> Cd2+> Zn2+。
电气石对金属离子吸附量随着介质中金属离子的初始浓度的增加而增加。
电气石也可以增加金属溶液的pH值;发现电气石对Cu2+、Pb2+、Zn2+和Cd2+的最大吸附量为78.86、154.08、67.25和66.67mg/g;温度在25-55℃对电气石的吸附量影响很小。
此外研究了Cu2+、Pb2+、Zn2+和Cd2+的竞争吸附。
同时观察到电气石对单一金属离子的吸附能力为Pb>Cu>Zn>Cd,在两种金属系统中抑制支配地位是Pb>Cu,Pb>Zn,Pb>Cd,Cu>Zn,Cu>Cd,和Cd>Zn。
关键字:吸附;重金属含量;朗缪尔等温线;电气石介绍重金属是来自不同行业排出的废水,如电镀,金属表面处理,纺织,蓄电池,矿山,陶瓷,玻璃。
英文文献及翻译
Geotextile reinforced by soft soil1. IntroductionGeotextile known, it has high tensile strength, durability, corrosion resistance, texture, flexibility, combined with good sand, to form reinforced composite foundation, effectively increase the shear strength , tensile properties, and enhance the integrity and continuity of soil. Strengthening mechanism for the early 60's in the 20th century, Henri Vidal on the use of triaxial tests found a small amount of fiber in the sand, the soil shear strength can improve the image of more than 4 times in recent years, China's rock Laboratory workers also proved in the reinforced sand can effectively improve the soil's bearing capacity, reduce the vertical ground settlement, effectively overcome the poor soil and continuity of overall poor performance. As with the above properties of reinforced soil and the characteristics of its low price, so the project has broad application prospects.2.1 Project OverviewThe proposed retaining wall using rubble retaining wall of gravity, the wall is 6 meters high, the bearing capacity of foundation soil required to 250kPa, while the basement geology from the top down as follows: ①clay to a thickness of 0.7 to 2 meters saturated, soft plastic; ② muddy soil, about 22 - 24 meters thick, saturated, mainly plastic flow, local soft plastic; ③ sand layer to a thickness of 5 to 10 meters, containing silty soil and organic matter, saturated, slightly wet; ④ gravel layer, the thickness of the uneven distribution points, about 0 to 2.2 meters, slightly dense; ⑤ weathered sandstone. Including clay and silty soil bearing capacity is 70kPa, obviously do foundation reinforcement.2.2 Enhanced Treatment of reinforced foundation cushion Reinforcement replacement method can be used for sand and gravel used forsoil treatment, but due to loose bedding, based on past experience, witha gravel mat to treat a large settlement of the foundation always exist, even the characteristics of poor, often resulting in cracks in the superstructure, differential settlement of the image, this works for6-meter-high rubble retaining walls, height and large, and because the walls are 3 meters high wall, if there is differential settlement of retaining walls, cracks, will result in more serious consequences and thus should be used on the cushion reinforcement through economic and technical analysis, decide on the sand and gravel stratum were reinforced hardening. Reinforcement treatment method: first the design elevation and the basement excavation to 200mm thick layer of gravel bedding, and then capped with a layer of geotextile, and then in the thick sand and gravel on the 200, after leveling with the yellow sand using roller compaction; second with loaded bags of sand and gravel laying of geotextile, the gap filled with slag, geotextile bags capped 100 thick gravel, roller compaction. Its on repeat laying geotextile → → compacted gravel, until the design thickness of the cushion, the bridge is 1 m thick cushion, a total of 4 layers of geotextile, two bags of sand.This method works fast, simple machine, investment, after years of use, that reinforce good effect, building and construction units are satisfied.3 ExperienceTo achieve the reinforced soil reinforcement effect, must be reinforced earth construction technology, construction strict quality control: 1, geotextile should increase the initial pre-stress, and its end should be a reliable anchor to play the tensile strength of geotextile, anchoring more firmly, more capacity to improve, the foundation of the stress distribution more uniform, geotextile side Ministry of fixed length by laying end to ensure the fold, the folded end wrapped sand to increase its bond strength to ensure that the use will not be pulled out duringthe period.Second, the construction process have a significant effect on the reinforcement effect, the construction should be as soon as possible so that geotextile in tension, tensile strength geotextile can be played only when the deformation, so do not allow construction of geotextile crease occurs, the earth Fabric tension leveling as much as possible. Geotextile in order to have enough by the early Dutch strain, according to the following procedure works: ① laying geotextile; ② leveled the tension at both ends; both ends of the folded package gravel and sand filling at both ends; ③ center fill sand; ④ 2 higher end of sand; ⑤ Finally, the center of sand filling. Click here to enable the construction method of forming corrugated geotextile being stretched as soon as possible, to play a role in the early loaded.Third, the construction of geotextile-reinforced cushion should the level of shop using geotextile geotextile and laying of gravel bags cushion the turn to play bag cushion integrated turn out good, flexural rigidity, and dispersion of good and peace bedding layer of the overall continuity of good advantages.4 ConclusionGeotextile reinforced by soft soil is an effective, economical, safe, reliable, simple method, but the literature describes only qualitative, experience more components, yet the lack of rigorous The theoretical formula, reliable test data to be adequate, these are yet to be theoretical workers and the general engineering and technical personnel continue to explore.土工织物加筋垫层加固软土地基1. 引言土工织物又称土工聚合物,它具有高抗拉强度,耐久性、耐腐蚀性,质地柔韧,能与砂土很好地结合,组合成加筋土复合地基,有效地提高土的抗剪强度、抗拉性能,增强土体的整体性和连续性。
英文文献翻译
外文翻译(原文)Catalytic wet peroxide oxidation of azo dye (Congo red) using modified Y zeolite as catalystAbstractThe present study explores the degradation of azo dye (Congo red) by catalytic wet peroxide oxidation using Fe exchanged commercial Y zeolite as a catalyst. The effects of various operating parameters like temperature, initial pH, hydrogen peroxide concentration and catalyst loading on the removal of dye,color and COD from an aqueous solution were studied at atmospheric pressure. The percent removals of dye, color and COD at optimum pH07, 90◦C using 0.6 ml H 2 O2/350 ml solution and 1 g/l catalyst was 97% (in 4 h), 100% (in 45 min) and 58% (in 4 h), respectively. The % dye removal has been found to be less in comparison to % color removal at all conditions, e.g. dye removal in 45 min and at above conditions was 82%, whereas the color removal was 100%. The results indicate that the Fe exchanged Y zeolite is a promising catalyst for dye removal. Fe exchanged catalyst is characterized using XRD, SEM/EDAX, surface area analyzer and FTIR. Though the dye, color and COD removals were maximum at pH02 but as the leaching of Fe from the catalyst was more in acidic pH range, pH0 7 was taken as operating pH due to almost comparable removals as of pH0 2 and no leaching of Fe ions.© 2008 Elsevier B.V. All rights reserved.1. IntroductionReactive azo dyes from textile and dyeing industries pose grave environmental problem. An estimate shows that textiles account for 14% of India’s industrial production and around 27% of its export earnings[1]. Production during 2006 registered a growth of about 3.5% at 29,500 tonnes and the textile industry accounts for the largest consumption of dyestuffs at nearly 80% [2]. The waste containing these azo dyes is non-degradable. The process of dyeing is a combination of bleaching and coloring, which generates huge quantities of wastewaters causing environmental problems. The effluents from these industries consist of large quantities of sodium, chloride, sulphate, hardness, carcinogenic dye ingredients and total dissolved solids with very high BOD and COD values over 1500 mg/l and over 5000 mg/l, respectively [3]. Various methods have been used for dye removal like adsorption, coagulation, electrocoagulation, Fenton’s reagent and combination of these processes. Though these treatment processes are efficient in dye removal, they generate adsorbed waste/sludge, etc. which further causes a secondary pollution. In wet oxidation the sludge is disposed off to a great extent by oxidizing the organic pollutant. Catalytic wet oxidation method (CWAO and CWPO) is gaining more popularity. CWPO process using H2O2, in particular has advantages like better oxidation ability thanusing oxygen,as the former is carried out at lower pressure (atmospheric pres-sure).WAO usually acts under high temperatures (200–325◦C)and pressure (50–150 bar). A comparable oxidation efficiency is obtained at a less temperature of 100–120◦C when using hydrogen peroxide as the oxi dizing agent instead of oxygen [4].WAO is capital intensive whereas WPO needs limited capital but generates little higher running costs [4].Rivas et al.[5] showed that the addition of H2O2(as a source of free radicals) enhanced wet air oxidation of phenol, a highly non-degradable substance and found that the combined addition of H2O2 and a bivalent metal (i.e. Cu, Co or Mn) enhanced the rate of phenol removal. Various oxidation catalysts have been studied for the removal of different compounds like phenol, benzoic acid, dyes, etc. by CWPO process. Catalysts like Fe2O3/CeO2and WO3/CeO2 in the removal of phenolic solution, (Al–Fe) pillared clay named FAZA in the removal of 4-hydroxy benzoic acid, mixed (Al–Fe) pillared clays in the removal of organic compounds have been used[6–8] .Removal of dyes by CWPO process is gaining importance in recent times with a large number of catalysts. Kim and Lee [9] used Cu/Al2O3 and copper plate in treatment of dye house effluents. Liu and Sun [10] removed acid orange 52, acid orange 7 and reactive black 5 using CeO2doped Fe2O3/ -Al2O3 from dye waste water. Kim and Lee [11] reported the treatment of reactive dye solutions by using Al–Cu pillared clays as catalyst.Among these catalysts, modified zeolites are preferred for improved efficiency, lower by-product formation and less severe experimental conditions (temperatures and pressures). Theimproved efficiency of the catalyst is ascribed to its structure and large surface area with the ability of forming complex compounds. Zeolites can be ion exchanged using transition metal ions like Fe,Cu, Mn and others like Ca, Ba, etc. Zeolites are negatively charged because of the substitution of Si(IV) by Al(III) in the tetrahedral accounts for a negative charge of the structure and hence the Si/Al ratio determines the properties of zeolites like ion exchange capacity [12] . These metal ions neutralizethe negative charge on zeolites and their position, size and number determine the properties of zeolite. These metal ions are fixed to the rigid zeolite framework which prevents leaching and precipitation in various reactions[13–21] .In this work, catalytic wet peroxide oxidation of Congo red azo dye using Fe exchanged Y zeolite has been presented. Effect of variables like temperature, initial pH, peroxide concentration and catalyst loading on catalytic wet peroxide oxidation were examined and the optimum conditions evaluated.2.Materials and methods2.1. ChemicalsHydrogen peroxide (30% analytical grade), manganese dioxide,sodium hydroxide pellets (AR) and hydrochloric acid were obtained from RFCL limited (Mumbai), India. Congo red was obtained from Loba Chemie Pvt. Ltd. (Mumbai) and were obtained from RFCL limited (Mumbai), India.Commercial Na–Y zeolite was obtained from Sud chemie Pvt.Ltd. (Baroda), India. Commercial catalyst was iron exchanged with excess 1 M Fe(NO3)3 at 80◦C for 6 h. The process was repeated three times and the sample was thoroughly washed with distilled water and dried in oven in air at60◦C for 10-12 h. The amount of iron exchanged was 1.53 wt% estimated by A.A.S.2.2. Apparatus and procedureThe experimental studies were carried out in a 0.5 l three-necked glass reactor equipped with a magnetic stirrer with heater and a total reflux (Fig. 13). Water containing Congo red dye was transferred to the three-necked glass reactor. Thereafter, the catalyst was added to the solution. The temperature of the reaction mixture was raised using heater to the desired value and maintained by a P.I.D. temperature controller, which was fitted in one of the necks through the thermocouple. The raising of the temperature of the reaction mixture to 90◦C from ambient took about 30 min.The total reflux prevents any loss of vapor and magnetic stirrer to agitate the mixture. Hydrogen peroxide was added, the runs were conducted at 90◦C and the samples were taken at periodic intervals. The samples after collection were raised to pH-11 by adding 0.1N NaOH (so that no further reaction takes place) and the residual hydrogen peroxide was removed by adding MnO2 which catalyzed the decomposition of peroxide to water and oxygen. The samples were allowed to settle for overnight or one day (or centrifuged) and filtered. The supernatant was tested for color and COD. After the completion of the run, the mixture was allowed to cool and settle overnight.2.3. CharacterizationThe determination of structure of the heterogeneous catalyst was done by X-ray diffractometer (Bruker AXS, Diffraktometer D8,Germany). The catalyst structure was confirm ed by using Cu Kα as a source and Ni as a filter. Goniometer speed was kept at 1cm/min and the chart speed was 1 cm/min. The range of scanning angle(2θ) was kept at 3–60◦. The intensity peaks indicate the values of2θ , where Bragg’s law is applicable. The formation of compounds was tested by comparing the XRD patternusing JCPDS files (1971).The determination of images and composition of catalyst were done by SEM/EDAX QUANTA 200 FEG. Scanning for zeolite samples was taken at various magnifications and voltage to account for the crystal structure and size. From EDAX, the composition of the elements in weight percentage and atomic percentage were obtained along with the spectra for overall compositions and particular local area compositions. BET surface area of the samples was analyzed by Micromeritics CHEMISORB 2720. The FTIR spectra of the catalyst was recorded on a FTIR Spectrometer (Thermo Nicolet, USA, Software used: NEXUS) in the 4000–480 cm−1wave number range using KBr pellets. The internal tetrahedra and external linkage of the zeolites formed are identified and confirmed by FTIR. The IR spectra data in Table 2 is taken from literature[22] .2.4. AnalysisThe amount of the dye present in the solution was analyzed by direct reading TVS 25 (A) Visible Spectrophotometer. The visible range absorbance at the characteristic wavelength of the sample at 497 nm was recorded to follow the progress of decolorization during wet peroxide oxidation.The COD of the dye solution was estimated by the Standard Dichromator Closed Reflux Method (APHA-1989) using a COD analyzer (Aqualytic, Germany). The color in Pt–Co unit was estimated using a color meter (Hanna HI93727, Hanna Instruments, Singapore) at 470 nm and the pH was measured using a Thermo Orion, USA make pH meter. The treated dye solutions were centrifuged (Model R24, Remi Instruments Pvt. Ltd., Mumbai, India) to obtain the supernatant free of solid MnO2.A.A.S (Avanta GBC, Australia) was used to find the amount of iron exchanged and leached.3. Results and discussionDue to the iron present after the exchange process, the Y peaks diminished along with the rise in Fe peaks. Similar phenomena has also been observed by Yee and Yaacob [23] who obtained zeolite iron oxide by adding NaOH and H2O2(drop wise) at 60◦C to Na–Y zeolite. XRD pattern ( Fig. 2) showed diminishing zeolite peaks along with evolution of peaks corresponding to y-Fe2O3 with increasing NaOH concentration. The IR assignments from FTIR (Fig. 3) remain satisfied even after iron exchanging. The EDAX data (Table 1) show clearly an increase in the value of Fe conc. after ion exchange of Y-zeolite. The BET surface area (Table 1) has been found to decrease from 433 to 423 m2/g after Fe exchange. SEM image is shown in Fig. 1 . Table 2 presents FTIR specifications of zeolites (common to all zeolites).The effect of temperature, initial pH, hydrogen peroxide concentration and catalyst loading on catalytic wet peroxide oxidation of azo dye Congo red were investigated in detail.Fig. 1. SEM image of Fe-exchanged Y zeolite.Fig. 2. XRD of commercial and Fe-exchanged commercial Y zeolite.BET surface area (commercial Na–Y): 433.4 m2/g.BET surface area (Fe exchanged commercial Na–Y): 423 m2/g.Table 2Zeolite IR assignments (common for all zeolites) from FTIR.3.1. Effect of temperature on dye, color and COD removalThe temperatures during the experiments were varied from50◦Cto100◦C. A maximum conversion of dye of 99.1% was observed at 100◦C in 4 h (and 97% at 90◦C). The dye rem ovals at 80◦C, 70◦C, 60◦C and 50◦C and at 4 h are 56%, 52%, 42% and 30%,respectively. Fig. 4 shows that at a particular temperature, the dye concentration gradually decreases with time. The initial red color of the dye solution decreased into brown color in due course and finally the brown color disappeared into a colorless solution. Dye concentration decreases at faster rates with temperatures for initial 30 min and thereafter it decreases from 1 h to 2 h. The initial concentrations of dye did not change after a brief contact period of dye solution with the Fe-exchanged zeolite catalyst (before CWPO)confirming that there is negligible adsorption of the dye by the catalyst.Fig. 5 shows the results obtained for color removal as a function of time and temperature. The maximum color removal (100%) is obtained at 100◦C in 30 min and also at 90◦C in 45 min. At a particular temperature, the color continuously decreases with time atFig. 3. FTIR of Fe-exchanged Y zeolite.Fig. 4. % dye removal as function of temperature.faster rate in first few minutes until a certain point ( t = 45 min) and then remaining almost unchanged. At 50◦C, the color removal is very low, whereas at 60◦C, there is a sudden shift towards its greater removal. The color removal is much higher at higher temperatures(70–100◦C).Fig. 6 depicts the results obtained for %COD removal as a function of time and temperature. A maximum COD removal of 66% was obtained at 100◦C (at 4 h) followed by 58% at 90◦C (at 4 h). Until60◦C, the rate of COD removal is less and during 70–100◦C, the rate is much faster.3.2. Effect of initial pH on dye, color and COD removalThe influence of initial pH on dye (Congo red) removal was studied at different pH (pH0 2, 4, 7, 8, 9 and 11) without any adjustment of pH during the experiments. A maximum conversion of 99% was obtained at pH0 2 followed by 97% at pH0 7. The dye removal at pH0 4, 8, 9 and 11 were 94%, 29%, 5% and 0.6%, respectively. All the runs were conducted for 4 h duration. The color of the solution is violet blue at pH0 2 (a colloidal solution) and greenish blue at pH0 4 (colloidal solution). In neutral and basic pH0(7, 8, 9 and 11) range, color of the solution did not change during treatment and was same as original solution, i.e. red color. Fe cations can leach out from zeolite structure into the solution causing secondary pollution. Leaching of Fe cations out of zeolitesFig. 5. % color removal as function of temperature.Fig. 6. %COD removal as function of temperature.Fig. 7. % color removal as function of pH0depends strongly on pH of the solution. The leaching of iron ions was enhanced at low pH values [24,25] . In order to determine dissolved Fe concentration, final pH values of the solutions were analyzed by A.A.S. At initial pH0 2 and 4, Fe detected in the solution was 7.8 ppm and 3.9 ppm, respectively. At pH0 7 and in alkaline range, there wasFig. 8. %COD removal as function of pH0.Fig. 9. % color removal as function of peroxide concentration.Fig. 10. %COD removal as function of peroxide concentration.almost no leaching. pH0 7, therefore, was chosen to be optimum pH for future experiments. The final pH values pH f after the reaction corresponding to pH0 2, 4, 6, 8, 9 and 11 were 2.1, 4.2, 7.2, 7.7 and 8.7, respectively. This show that the pH f tend to reach to neutral pH for all starting pH values.Fig. 7 presents the results obtained for color removal as a function of time and pH0. A maximum color removal of 100% was obtained at pH0 2 (in 10 min) and also at pH0 7 (in 45 min). The color removal at a particular pH0 decreases at a faster rateinitially (0–1 h) and thereafter it has a slower rate. The lowest removal was observed at pH0 11 with almost no removal.Fig. 11. % color removal as function of catalyst loading.Fig. 12. %COD removal as function of catalyst loading.The results obtained for COD removal as a function of time and pH0 are shown in Fig. 8 . A maximum COD removal of 69% was obtained at pH0 2 in 4 h followed by 63% at pH0 4 and 58% at pH0 7in4h.Fig. 8 shows maximum decrease in COD value in the initial 30 mines at all pH0. The decrease in COD is not appreciable thereafter. The COD removal is more in acidic range with a maximum removal of 69%, moderate in neutral region and least in basic region.3.3. Effect of peroxide concentration on dye, color and COD removalThe influence of H2O2 concentration on dye removal was investigated at different concentrations of hydrogen peroxide (in the range 0–6 ml). A maximum removal of 99.02% was obtained at H2O2 concentration of 3 ml per 350 ml of solution, followed by 98.3% at 1ml and 97% at 0.6 ml. The dye removal at H2O2concentrations of 6 ml,0.3 ml and 0 ml (and at 4 h) were 94%, 82% and 8%, respectively. The dye removal rate at 90◦C temperature is gradual at all conc entrations of peroxide. At peroxide concentration of 0 ml, there is very little removal of dye, hardly 8%. Hence, it can be inferred that catalytic thermolysis (a process of effluent treatment by heating the effluent with/without catalyst) is not active and cannot be applied for dye removal.At the beginning of the reaction, the OH•radicals which are produced additionally when peroxide concentration is increased,speeds up the azo dye degradation. After a particular peroxide concentration, on further increase of the peroxide, the dye removal isFig. 13. Schematic diagram of the reactor.not increased. This may be because of the presence of excess peroxide concentration, hydroperoxyl radicals (HO2•) are produced from hydroxyl radicals that are already formed. The hydroperoxyl radicals do not contribute to the oxidative degradation of the organic substrate and are much less reactive. The degradation of the organic substrate occurs only by reaction with HO•[26] .The % color removal at a particular peroxide concentration increases at a faster rate in the initial 45 min and then at slower rates afterwards (Fig. 9). As H2O2 concentration increases, the rate of removal is much faster, reaching 100% in 45 minusing 6 ml H2O2 per 350 ml solution, whereas it is 100% in 1 h for both 0.3 ml and3ml.Fig. 10 shows the results obtained for COD removal as a function of time and H2O2 concentration. The maximum COD removal, 63% is obtained for H2O2 conc. 3 ml at 90◦C, pH0 7 and 2 h duration.3.4. Effect of catalyst loading on dye, color and COD removalThe influence of catalyst concentration on dye removal was investigated at different concentrations (in the range 0.5–1.5 g/l). A maximum dye removal of 98.6% was observed at 1.5 g/l followed by 98.3% at 1 g/l and 87.3% at 0.5 g/l in 4 h duration. The % dye removal without catalyst was very low with only 36% dye removal in 4 h. By comparing the results for the dye removal without catalyst and1.5 g/l catalyst, the removal for 1.5 g/l is approximately three times to that of without catalyst. The rate of removal is also more for higher concentrations of catalyst and increases with it.Fig. 11 shows the results obtained for color removal as a function of time and catalyst concentration. The maximum color removal of 100% was obtained using 1.5 g/l catalyst conc. in 1.5 h and also using 1 g/l catalyst in 3 h.Fig. 12 presents the results obtained for %COD removal as a function of time and catalyst concentration. A maximum COD removal of 58% was obtained at catalyst conc. 1 g/l, 51.8% at 1.5 g/l and 50.5% at 0.5 g/l in 4 h. Without catalyst, the COD removal was only 35%.4. ConclusionsThe % removals of dye, color and COD by catalytic wet peroxide oxidation obtained at 100◦C, 4 h duration using 0.6 ml H2O2/350 ml solution, 1 g/l Fe–Y catalyst and pH0 7 were 99.1%, 100% (30 min)and 66%, respectively. As at 100◦C the solution has tendency to vaporize during the operation, 90◦C was taken as operating temperature. The corresponding % removals at 90◦C were 97% dy e, 100%color (in 45 min) and 58% COD. Acidic range gave higher % removals in comparison to neutral and alkaline range. At pH0 2, the dye, color and COD removals of 99%,100% (in 10 min) and 69% were observed after 4 h duration. As at pH0 2, the leaching of Fe ions from Y zeolite catalyst is predominant,pH0 7 was taken as operating pH. Fe concentration of 7.8 ppm was observed in the solution at pH0 2. The values of removals, however,are comparable to pH0 2, with dye removal of 97%, color removal of100% (in 45 min) and COD removal of 58% in 4 h.The H2O2concentration was found to be optimum at 3 ml/350 ml solution giving dye, color and COD removals of 99%,100% (in 1 h) and 63%, respectively.The study on the effect of catalyst loading revealed 1.5 g/l as best among the catalyst concentrations studied. The results with 1 g/l and 1.5 g/l catalyst concentration were almost comparable.外文翻译(译文)使用改性Y沸石为催化剂湿式催化过氧化氢氧化偶氮染料(刚果红)摘要本研究主要探讨了使用改性Y沸石固载铁离子作为催化剂湿式催化过氧化氢氧化降解偶氮染料(刚果红)。
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附件:英文文献及翻译
英文文献
The Importance of Auditing Professional Judgment and
Its Application in Auditing Practice
LIU Huihe
Henan Institute of Engineering, Zhengzhou, Henan 450000
1.Importance of auditing professional judgment
Since the reform and opening up, with the development of economy, the further improvement of the market economy system and the establishment of the modem enterprise system, more and more attention has been paid to the auditing profession. With the integration of the world economy, China’s economy is gradually moving towards the world, the audit staff need to have a high level of audit quality, audit staff also face greater challenges. In today’s society more need to have a good reputation of the audit staff, and good reputation is a long-term accumulation of audit work, the success or failure of the audit depends on the quality of the audit professional judgment. Therfore, we need to re-examine the importance of audit judgment, pay attention to and scientific and rational use audit professional judgment, improve the level of audit judgment, improve audit quality, reduce audit risk.
1.1The importance of auditing professional judgment to the
constrection of auditing standards
In order to be in line with the international auditing standards, China’s auditing standards also need to keep pace with times, to
fuether reform and development. However, the most important is to
establish a new system of auditing standards. The work environment
of audit staff is very complicated, and the accounting and auditing
standards are generally only for the principle, especially the
development of audit standards lag behind the development of audit
business. If the audit personnel to use the audit judgment in a timely
manner to seek truth from facts, in accordance with the actual
situation of the audit unit to carry out specific research and analysis.
Audit professional knowledge and practical experience, strong
analysis and problem-solving skills. Under the guidance of auditing
standards, auditing professional judgment can be used as a tool for
auditing work, on the other hand, it can be used as the standards of
the actual combat experience of the audit personnel make up the
deficiency of the auditing standards in practical work, which can be
used as the realistic basis for the continuous development of the
auditing standards.
中文翻译
审计职业判断的重要性及其在审计实务中的应用
刘浍河
河南工程学院,郑州,450000
1、审计职业判断的重要性
改革开放以来,随着经济的发展,市场经济体制的进一步完善和现代企业制度的建立,审计职业越来越受到人们的重视。
随着世界经济的一体化,中国的经济正逐步走向世界,审计人员需要有较高的审计质量,审计人员也面临更大的挑战。
当今社会更需要具有良好声誉的审计人员,良好的信誉是审计工作的长期积累,审计的成败取决于审计质量的专业判断。
因此,我们需要重新审视审计判断的重要性,重视并科学合理使用,提高审计职业判断,审计判断的水平,提高审计质量,降低审计风险。
1.1审计职业判断的重要性审计准则建设
为了与国际审计接轨,中国的审计准则也需要跟上时代的步伐,要进一步改革和发展。
然而,最重要的是建立一个新的审计准则体系。
审计人员的工作环境十分复杂,会计与审计标准一般只为原则,尤其是审计准则的发展滞后于审计业务的发展。
如果审计人员要及时使用审计判断,实事求是,根据审计单位的实际情况进行具体的研究和分析。
审计专业知识和实践经验,较强的分析和解决问题的能力。
审计准则的指导下,审计职业判断可以用来作为一种工具的审计工作,另一方面,它可以作为对审计人员的实战经验的标准做了实际工作中的审计标准的不足,可以作为审计标准的不断发展的现实基础。