英文文献翻译

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英文文献翻译

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。

英文文献整篇翻译

英文文献整篇翻译

英文文献整篇翻译Title: The Impact of Climate Change on BiodiversityClimate change is a pressing issue that has significant impacts on biodiversity worldwide. Changes in temperature, precipitation patterns, and extreme weather events are altering ecosystems and threatening the survival of many species. The loss of biodiversity not only affects the natural world but also has implications for human societies.One of the major impacts of climate change onbiodiversity is the shifting of habitats. As temperatures rise, many species are forced to move to higher latitudesor elevations in search of suitable conditions. This can disrupt ecosystems and lead to the decline or extinction of species that are unable to adapt to the new conditions.In addition to habitat loss, climate change is also causing changes in the timing of biological events such as flowering, migration, and reproduction. These changes can disrupt the delicate balance of ecosystems and lead to mismatches between species that depend on each other for survival.Furthermore, climate change is exacerbating otherthreats to biodiversity such as habitat destruction, pollution, and overexploitation. The combination of these factors is putting immense pressure on many species and pushing them closer to extinction.It is essential that we take action to mitigate the impacts of climate change on biodiversity. This includes reducing greenhouse gas emissions, protecting and restoring habitats, and implementing conservation measures to safeguard vulnerable species. By addressing the root causes of climate change and protecting biodiversity, we canensure a sustainable future for both the natural world and human societies.气候变化对生物多样性的影响气候变化是一个紧迫的问题,对全球的生物多样性产生重大影响。

英文文献用翻译

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

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.。

英文文献原文及对应翻译

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

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。

八大英文文献翻译神器

八大英文文献翻译神器

你值得拥有的八大英文文献翻译神器不管是做科研还是写SCI论文,开始都需要阅读大量的文献,做课题至少查阅600篇,粗看300篇,细看100篇,研读50篇,在看到一叠叠论文后,由于语言问题,往往会觉得无从下手,下面分享几款常用的文献翻译神器。

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英文文献翻译

英文文献翻译

Political Stability and Foreign Direct InvestmentKim Haksoon1.INTRODUCTIONF oreign direct investment (FDI) has become the important issue in finance and economics since the globalization of capital markets. The saturation of domestic capital market drives each country to invest in the foreign capital markets in terms of financial internationalization. Recently, emerging market countries, especially China and India, become the world's foremost FDI targets. From the World Bank (2002) report, we can see that net FDI to developing countries has increased since 1985.Many researchers in finance and economics try to find the factors that affect the FDI. For example, Lucas (1990) argues that only political risk is an important factor in limiting capital flows. Investments in many developing countries are exposed to large political risks, so FDI inflows are large for politically unstable countries. By the same token, FDI outflows are large for politically stable countries to invest in countries with large political risks. Fry, Classens, Burridge, & Blanchet (1995) found that the requirement to surrender export proceeds to the monetary authorities and the existence of special exchange rates for some capital account transactions reduces the probability that FDI is independent. The more liberal a country's foreign exchange system, the more likely FDI is to be independent or exogenous. FDI is associated with a larger increase in capital formation when it is independent than when it is "Granger-caused" by other capital flows. Singh and Jun (1995) also show that political risk and business operating conditions have been important determinants of FDI for countries that have historically attracted high FDI. For countries with relatively low FDI, a key determinant was the degree of sociopolitical instability. A country's orientation toward exports is the strongest variable for explaining why a country attracts FDI. Chan and Gemayel (2004) find that the degree of instability associated with investment risk is a much more critical determinant of foreign investment in the Middle East and North Africa region countries than it is for developing countries, which have lower level investment risk.There are other factors, including above-mentioned ones of FDI. They are macroeconomic determinants、internalization theory、intangible assets、capital market mispricing、shareholder's wealth effect and stock market liberalization and corporategovernance.In view of related literature, we can see that there are numerous factors that affect FDI, but not dominant factors. The objective of this paper comes from the Lucas (1990)'s argument that only political risk is an important factor in limiting capital flows. According to his paper, either human capital based approach or monopoly rents approach is not an important factor in explaining capital flows. For the empirical support and extension of his argument, we examine the following hypothesis.a. Hypothesis 1FDI inflows are high for politically unstable countries, while FDI outflows are high for politically stable countries, after controlling for macroeconomic factors.La Porta et al. (1999) constructs the quality of government index around the world. They divide government quality variables by five categories, and find that rich nations have better governments than poor ones. Ethnolinguistically homogenous countries have better governments than the heterogeneous ones. Common law countries have better governments than French civil law or socialist law countries. Predominantly Protestant countries have better governments than either predominantly Catholic or predominantly Muslim countries. The quality of governments also is closely related to its interference with private sectors. However, they did not mention whether the political stability of governments goes hand in hand with its interference with private sectors. From their five categories, we use the direct measure of political stability. They are corruption index in the government efficiency category and political rights index and democratic index from political freedom category. Corruption index is the index of corruption in government from International Country Risk Guide (ICRG). Low corruption index means high political stability. Political rights index is the index of political rights from Freedom of the World, 1996. Democracy index is the average of democracy score for the period 1970-1994 from Polity III: Regime Type and Political Authority, 1800-1994. High political rights index and democracy index mean high political stability.We know that the quality of government is closely related to its interference with private sectors, leading to the performance of private sectors. However, we do not know whether the political stability of government is related to its interference with private sectors. We argue that political stability measures are closely related to the performance of the private sector in general, and it will also affect the FDI inwardperformance, by looking at the recent economic development of China and Russia. (Note 2) Their line of reasoning is also consistent with the view of Lucas (1990), because politically unstable countries attract more capital flows which lead to the higher possibility of better performance of FDI. By combining the argument of Lucas (1990) and La Porta et al. (1999), we can construct a following hypothesis.b. Hypothesis 2FDI inward performance is high for politically unstable countries, after controlling for macroeconomic factors.The remaining paper proceeds as follow. Section 2 describes the econometric techniques and the model setup that are used in this paper. Section 3 explains data and variable construction. Section 4 shows empirical results Section 5 ends the paper.2. THE REVIEW OF ECONOMETRIC TECHNIQUES AND MODEL SRTUPSince our sample is the panel data, we perform three different empirical techniques for the panel data to strengthen our empirical results. First, we perform pooled ordinary least squares (OLS) with robust standard errors for the panel data using robust (cluster) covariance matrix as in Wooldridge (2002). According to Wooldridge (2002), the error term in the panel data will be serially correlated, even if the pooled OLS meets the consistency assumption. Also, the serial correlation does not decrease as the cross-section and time-series increases. So, we need to use robust (cluster) covariance matrix.Second, we perform feasible generalized least squares (GLS) for the cross-sectional time-series linear models. This technique allows estimation in the presence of AR(1) autocorrelation within panels and cross-sectional correlation and heteroskedasticity across panels.3. DATA AND VARIABLE DESCRIPTIONDifferent data sources are used in this paper. FDI data is from World Investment Report (WIR) Annex Tables, the United Nations Conference on Trade and Development (UNCTAD). World Investment Report Annex Tables provide detailed statistical data on FDI flows, FDI stock and cross-border mergers and acquisitions. We use three year average FDI inflows, FDI outflows and the performance of FDI inflows as dependent variables in the regression analysis. We matched the latest year of the three year to the year of controlling variables. (Note 4) The three year average of FDI inflows is the three year average foreign direct investment inflows in millions of dollars. The three year average of FDI outflows is the three year average foreigndirect investment outflows in millions of dollars. The three year average performance of FDI inflows is the three year average inward foreign direct investment performance index. If the performance is better, the index shows greater value. These variables are all from World Investment Report (WIR) Annex Tables, the United Nations Conference on Trade and Development (UNCTAD).Controlling variables are as follow. GDP is the three year average GDP in millions of dollars. Three of them come from World Investment Report (WIR) Annex Tables, the United Nations Conference on Trade and Development (UNCTAD). The real exchange rate is calculated using nominal exchange rates and price indices from the IMF International Financial Statistics. There are several papers analyzing the relationship between exchange rate and FDI (Froot and Stein, 1991; Klein and Rosengren, 1994; Dewenter, 1995; Blonigen, 1997). Corporate top tax rates, which are the maximum marginal corporate tax rates in each country and year, are from the World Tax Database maintained by the Office of Tax Policy Research at the University of Michigan. There is a paper investigating the relationship between tax rate and FDI (Desai et al., 2004). Capital account openness is based on Brune et al. (2001). We form a closedness index, using Brune et al. (2001) data, as the way in Baker et al. (2006). Political stability measures are described briefly in the introduction section.4. EMPIRICAL RESULTSa. Summary statisticsDescriptive statistics for the entire sample is presented in Table 1. The definitions of the variables are the same as the ones in Table 1. Total of 305 country year observations are in the sample from 1990 till 2002 spanning 28 countries. Some countries have missing real exchange rate data, so the exchange rate series for these countries are indexed with the dollar exchange rate in the year that is observed first. Democratic index (democratic) and public sector employment ratio (PSEmpRatio) are missing for Hong Kong. Government consumption expenditures (GC/GDP) and total government transfers and subsidies are missing for China. Public sector employment ratio is missing for Israel. The mean FDI flows are similar, while their median is significantly different from the mean. The standard deviations of FDI flows are large.For example, the standard deviation of FDI outflows is almost the twice of its mean value. It suggests that each country's FDI flows vary over its characteristics. FDI inward performance also varies over each country's characteristics. The mean FDI inward performance is close to the standard deviation, while median value is relatively close to the mean. Overall, FDI flows and inward performance significantlydepend on each country's characteristics.The political stability also varies over the country's characteristics. The mean value ranges from 6.03 to 7.94. The mean value of corrupt is close to that of democratic, while the standard deviation is higher for democratic. Also, the difference between mean and median for democratic is the highest among the political stability variables. Democratic shows the highest standard deviation, while political shows the lowest standard deviation. From the minimum and maximum values of political stability variables, we can see that political stability varies from country to country. For the variables of the size of public sector category, GC/GDP and T&S/GDP have similar mean and median values. The standard deviation is a little higher for GC/GDP than that for T&S GDP. The highest government consumption or transfers and subsidies as a percentage of GDP is around five or twenty seven times greater than the lowest government consumption or transfers and subsides as a percentage of GDP, respectively. The mean value of the average ratio of public sector employment in general government as a percentage of total population is 5.71. So, on average, the 5.71 percent of total population is hired in public sector. The mean and median value is close with each other, but the standard deviation is high relative to the mean value. The maximum value is around seventeen times higher than the minimum value. Overall, the size of public sector varies from country to country.b. Pearson CorrelationThe Pearson correlations among independent variables are presented in Table 2. All the independent variables have the possible correlation with dependent variables judging from related literature. Overall, independent variables are correlated with one another within a conventional five percent significance level, except for some pairs. For example, Ex Rate is not correlated with political with statistical significance. GDP shows negative correlations with political stability variables. Interestingly, it suggests that high GDP countries have less corruption, while their political rights and the level of democracy are low. Also, Ex Rate shows negative correlations with corrupt and democratic, indicating high real exchange rate countries have less corruption, but their democratic level is low. Corp Tax shows positive correlations with political and democratic. So, countries with high maximum marginal corporate tax rate show high political rights and level of democracy. The result is also interesting, because countries which are not open to capital flows do not necessarily have corrupted government.c. Empirical ResultsAs you can see, corrupt and political consistently affect the FDI inflows and inward performance for pooled OLS and feasible GLS estimation. Corrupt has a positive relationship with the FDI inflows and inward performance, while political has a negative relationship with the FDI inflows and inward performance for pooled OLS and feasible GLS estimation. Countries with high corruption of government and low political rights have the high FDI inflows. The results are consistent with the argument of Lucas (1990) and our hypothesis 1. Consistent with our hypothesis 2, they have the high FDI inward performance. For the random effects estimation, corrupt is positively correlated with the FDI inward performance, while political is negatively correlated with the FDI inward performance. The results are consistent with our hypothesis 2.For the control variables, only GDP has consistently positive relationship withthe FDI flows, while it is negatively correlated with the FDI inward performance. High GDP countries have more FDI flows, while its FDI inward performance is low. Consistent with the argument of Lucas (1990), the FDI outflows in high GDP countries are high, assuming high GDP countries are politically stable, in general. However, those countries also have the high FDI inflows and low FDI inward performance. It seems that, in general, high GDP countries are politically stable and the FDI inflows should come from the low GDP countries with political instability. If Lucas (1990)'s argument is correct, the FDI inflows from countries with political instability is limited. Since this kind of FDI inflows are limited by countries with political stability, it seems that the FDI inward performance of this kind should be poor due to the limitation by the government of hosting countries. Also, the FDI inflows are high for the high GDP countries, not consistent with our hypothesis 1, assuming high GDP countries are politically stable. In general, high GDP countries have more foreign trades than low GDP countries, so the absolute volume of FDI flows should be higher for high GDP countries.5. CONCLUSIONThe determinants of FDI flows are well documented in the related literature. By using the three different techniques of panel data, we investigate the relationship between the FDI and the political stability in detail by looking at FDI flows, inward performance and the specifically categorized political stability variables as in La Porta et al. (1999).The main empirical results can be summarized as follow. First, hosting countries with higher political rights as in La Porta et al. (1999) have higher FDI outflows after controlling for macroeconomic variables. The result is consistent with Lucas (1990) and our hypothesis 1 in that politically stable countries produce capital flows to invest in politically unstable countries. Second, hosting countries with higher level of corruption of governments and lower level of democracy attract more FDI inflows after controlling for macroeconomic variables. The result is also consistent with the argument of Lucas (1990) and our hypothesis 1 that politically unstable countries attract capital flows from developed countries with high political stability. Third, consistent with our hypothesis 2, FDI inward performance is positively correlated with the corruption level of governments and negatively correlated with the level of democracy. Fourth, when the key variables of the factor analysis from La Porta et al. (1999) are included, countries with high corruption level of governments and lowerpolitical rights have higher FDI inward performance.The contribution of this paper is as follow. First, we support the related literature of Lucas (1990) that FDI flows are affected by the level of political stability of hosting countries, using the detailed political stability measures of governments, which is the approach that is not taken before. Second, our results contribute to the related literature by further looking at the relationship between FDI inward performance and the level of political stability of hosting countries with the combination of arguments of Lucas (1990) and La Porta et al. (1999). Finally, our empirical results are strengthened by taking three relevant econometric techniques of panel data: pooled OLS estimation with robust standard errors, cross-sectional time-series feasible GLS estimation and random effects estimation.政治的稳定性与外商直接投资哈克森·金1.引言随着资本市场的全球化,FDI已经成为金融和经济学界的重要议题。

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带有支路流的固定膜反应器的强化脱氮除磷工艺H. U. NAM, J. H. LEE, C. W. KIM M and T. J. PARK* M环境工程系,釜山国立大学,釜山,609-735,韩国于1999年3月1日首发,于1999年7月1日修订摘要——在一个固定膜反应器内以支路流的操作方式来有效使用碳源内部来脱氮除磷的可能性正在被研究。

有关证实在附有支流的固定膜反应器中,随着支流比例从0增加到0.4,城市污水中的氮磷是否能被有效去除的试验正在进行。

被用在这个实验中的固定膜反应器是一种结合A 2 /O工艺和生物膜过程的反应器。

支流被应用在这个实验中,部分出水直接被排入缺氧池中来有效的脱氮。

根据出水流量的比例,支路流的比例在0,0.3和0.4中调节。

在整个过程中,能观察到COD,NH+4-N,和T-P分别的去除效率超过87.2%,75.2%和52.8%。

进一步说,依据入流速度,除磷的最佳运行条件预测是在支路流比例为0.4,且内外循环比都为0.5的时候。

在支路流比例为0.4时,NH+4-N的去除率为88.0%,T-P的去除率为68.0%。

由于支路流比例的不同,除磷效果也会大大不同。

在支路流比例为0,0.3和0.4时,T-P的去除效率分别为52.8%,61.6%和68.0%。

有人指出,带有支路流的固定膜反应器能实现完全脱氮,并且有助于提高磷的去除。

2000 Elsevier 科学有限公司,版权所有。

关键词——合并的固定膜反应器,支路流,脱氮,磷的吸收,A2/O工艺,内循环,外循环,缺氧状态。

简介从观察营养成分所产生的有机物质的数量和未处理的污水所产生的有机物的数量的对比,可以阐述受纳水体的氧源所排出的营养物质的潜在影响。

韩国未经处理的污水所含的COD通常在200—250mg/L,根据是否磷酸盐洗涤剂在当地的禁令上磷的成分在4—6mg/L左右浮动,氮的含量在20—40mg/L之间(Choi,来表示,如果1kg磷被藻1996)。

假设藻类的组成能用化学式PCNHO10611016263类完全同化并且在光合作用和无机元素的作用下被生成新的生物质,那将生成111kg生物质和138kg的COD。

因此,每5mg/L的磷的排放会潜在的导致690mg/L 的COD的生成,或者相当于超过2倍的未经处理的污水中的有机物产生的COD 量。

据推测限制氮和磷的排量能控制富营养化因为相对硫、钾、钙、镁来说,生物质的生长所需氮磷的量相当大。

近年来学术界认为在淡水环境中磷是最主要的限制营养物,而氮则是河口和海洋水域中的主要限制营养物(Sedlak,1989)。

生物膜工艺有许多特点和优势(Park et al 1995,1996): (1)系统中使用的薄膜能有效的去除氮是由于所使用的菌类像硝化细菌之类有很缓慢的生长速率和很长的代谢时间;(2)由于薄膜上有更多生物物种的存在和活性污泥法的结合,能够实现广谱污染物的去除;(3)由于单元里有较大的生物量,每单元工艺的处理容量比活性污泥法要高出很多;(4)相较于活性污泥法,产生的剩余污泥量少。

更多的污泥被存在于该膜上的高热带水品生物体所消耗,于是产生的剩余污泥量就变少了;(5)该工艺能稳定操作。

该工艺能维持和适应液压波动和有机负荷,因为该工艺相对活性污泥法来说有大量的生物质和更长的食物链。

另一方面,生物膜工艺也存在着一些缺点:(1)由于需要很多的支撑物和媒介,所以需要大量的初始资金;(2)打破厌氧薄膜层的微小颗粒非常活跃,会使出水的浊度变得很高。

(Lee et al,1996; Su and Ouyang,1996)本文的目标是开发一个新的带有支路流的固定膜反应器来去除污水中的营养物质,开展一个实验室规模的研究来确保基本数据的升级,和有效的运用支路流的内部碳源来降低用于去除营养物质的外部碳源的支出。

因此我们认为这个研究能开发出一个经济的工艺。

所以,我们希望该新工艺能解决关于运行传统脱氮除磷工艺的冲突。

材料和方法实验条件和设备使用一个能够连续执行脱氮除磷的实验室规模实验的操作单元,就是把厌氧池、缺氧池和好氧池串联在一起使用。

A/2工艺和生物膜工艺。

图1显示是该工艺的示意图,它结合了O该工艺有两个循环回流:一个是内部循环回流,从好氧池流入缺氧池来脱硝;另一个是外部循环回流,从澄清池流入厌氧池来除磷。

根据入流比来定,内部循环比和外部循环比都是0.5。

当然,另一个特殊的流——支路流,被应用在固定膜反应器中,为了有效的脱硝,部分的入流直接被排入缺氧池。

厌氧池、缺氧池和好氧池有效容积分别是10:1,6:1和18:1,所有反应器的总有效容积为34:1。

缺氧池造成小容积有助于提高缺氧池的具体脱硝率(Randall et al,1992)。

实验室规模的实验的操作条件在表1中给出了。

所有反应器中都填充有孔隙率为96.3%网型合成树脂载体,根据各个反应池的有效容积,在厌氧池、缺氧池和好氧池中的包装率分别为20%、30%和40%,具体的表面积为40032/m m 。

在这个试验中所用的载体的包装率和特性都在表2中给出了。

每个厌氧池和缺氧池都安装有一个搅拌机。

在好氧池的底部有一个150l/min 的鼓风机,空气就从扩散管中被排入好氧池中。

好氧池中的空气入流速率在整个工艺过程中都保持在16l/min 不变(20摄氏度,1个工程大气压)。

厌氧池中的温度在一个温度控制器的控制在保持在37度左右,正负2度的误差。

合成污水中的COD 浓度为250mg/L,N NH -+4的浓度为20mg/L ,总磷的浓度为8mg/L 。

一个碳酸氢钠缓冲器保持在200mg 3CaCO /L 来阻止PH 的降低,而PH 的下降主要是由于硝化作用和合成城市污水中的限制碱度。

调理和操作在这项研究中,接种污泥是从现有的韩国釜山污水处理厂中获得的,每天调理0.1kgCOD/3m 的合成城市污水持续15天。

在启动阶段,空气流速被控制以便使生物膜在填料载体上生长出来,这些填料都是可简易拆卸的。

当调理好之后,在入流比例的基础上支路流的比例变成0(1号流)、0.3(2号流)和0.4(3号流),来评估带有支路流的固定膜反应器的脱氮除磷效率。

在一个稳定状态下,反应器要持续运行超过3个星期来收集数据以确保其精确性。

样品的分析入流水样每个星期收集两次,出流水样每3天收集一次。

样品中被测定出的可溶性成分会马上被用0.45um 的滤纸过滤和冷却,以便组织取样后的进一步反应。

除了N NO x --是用HPLC (Waters ,USA )测量到的之外,其他的样品都是用标准方法(19th )进行测量。

用来进行样品分析的方法在表3中给出。

成果与讨论有机化合物的去除1,2和3号出流中COD 的浓度在图2中显示出来。

这张图中给出的结果是结合3个不同的操作条件(1号流,2号流和3号流)得出的,都使用COD 浓度为250mg/L 的污水来得到从0到0.4不同比例的支路流。

在这个图表中,符号A 、B 、C 、D 和E 分别表示入流、厌氧池出流、缺氧池出流、好氧池出流和总出流。

在这3个系统中,无论支路流比例是否减少,出流中COD 浓度总是稳定不变的。

在不带有支路流的1号系统中厌氧反应池中减少的COD 的总量是最高的。

而在带有一个比例为0.4的支路流的3号系统中,厌氧反应池中COD 浓度是最低的,这是由于一个高比例的支路流会使进入到厌氧反应池中的入流变少的缘故。

研究发现,1号系统、2号系统和3号系统的COD 去除效率分别为88.8%、87.2%和89.6%,这优于浓度为0.05-0.50kgCOD/3m /天(Wang et al, 1991)的延时曝气淹没生物膜工艺中获得的79.4%-83.0%这一数据。

由于外部循环回流的稀释会使COD 浓度发生改变,而厌氧发酵细菌能去除厌氧反应池中的COD 。

脱氮:硝化和反硝化图3分别表示了1号系统、2号系统和3号系统的好氧反应池中N NH -+4浓度和C/N 比例的关系。

在3个系统中好氧反应池的入流中的N NH -+4的浓度分别为11.23-12.30mg/L ,10.98-11.60mg/L 和10.51-10.77mg/L 。

当支路流的比例从0增加到0.4时,好氧反应池中入流的N NH -+4的浓度会减少,但区别是浓度是0.46-1.79mg/L 。

从图中可以看到,1号系统的好氧反应池中入流的变动要比2号系统和3号系统大的多。

还可以发现,支路流能够有效稳定缺氧反应池的出流中N NH -+4的浓度。

在好氧反应池中,3个系统中被去除的氨的平均数量分别为7.01mg/L 、7.74mg/L 和8.20mg/L 。

而系统3中N NH -+4浓度的去除最好,这是由于较高的支路流比例导致较低的C/N 比。

如果C/N 比低于5,像硝化和亚硝化会有机会变成比异养菌更活跃的一些有关碳源去除的细菌,在好氧条件下,因此好氧反应池中的C/N 比会决定两个品种的主导地位。

( Tchobanoglous and Burton ,1991)图4说明了在CFFR 工艺的好氧反应池中的硝化氨浓度和消耗碱度浓度之间的关系。

假设在好氧条件下能完全硝化(Randall et al,1992),氧化每毫克N NH -+4需要消耗大约7.14mg 的碱(例如3CaCO )。

在这3个系统中,好氧反应池中N NH -+4的浓度分别为 6.80–7.57 mg/L 、7.40–8.11 mg/L 和8.08–8.39 mg/L 。

由于被硝化作用硝化的N NH -+4的浓度的增加导致支路流的比例从0增加到0.4,然而被硝化的N NH -+4浓度会随支路流的比例的增加而减少。

其中的实线表示由于好氧反应池中硝化引起的碱度的消耗。

当然,好氧反应池中的消耗碱度会随着支路流比例的增加而增加,在这里消耗碱度的变动则会减少。

在这个实验中反应硝化氨浓度和碱的消耗之间关系的比例系数比理论上的比例系数要小一点。

而这点不同之处则暗示着部分的N NH -+4在细胞合成中被消耗掉了。

要注意这些结论要和同时进行硝化和反硝化的的反应器中得到的结论相比较,水利停留时间为15-17小时左右(Moriyama et al,1990)。

图5分别说明各个系统的好氧出流中的N NH -+4、有机N 和N NO X --的浓度。

而N NH -+4、有机N 和N NO X --的总和可以看做是总氮。

各个系统中N NH -+4的去除主要是在好氧反应池中进行的,这是由自养细菌的硝化作用和异养细菌的同化作用引起的。

换句话说,各系统的脱硝主要是由于缺氧反应池,而N NO X --的去除则是由于异养菌的脱硝作用。

在图5中,当支路流的比例从0增加到0.4的时候,出水中N NO X --的浓度从0.40mg/L 降低到0.01mg/L ,总氮的去除效率从66%逐渐增加到74%。

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