(完整版)模具设计与制造_毕业论文中英文资料外文翻译_文献

(完整版)模具设计与制造_毕业论文中英文资料外文翻译_文献
(完整版)模具设计与制造_毕业论文中英文资料外文翻译_文献

模具设计与制造

模具是制造业的重要工艺基础,在我国,模具制造属于专用设备制造业。中国虽然很早就开始制造模具和使用模具,但长期未形成产业。直到20 世纪80 年代后期,中国模具工业才驶入发展的快车道。近年,不仅国有模具企业有了很大发展,三资企业、乡镇(个体)模具企业的发展也相当迅速。虽然中国模具工业发展迅速,但与需求相比,显然供不应求,其主要缺口集中于精密、大型、复杂、长寿命模具领域。由于在模具精度、寿命、制造周期及生产能力等方面,中国与国际平均水平和发达国家仍有力,今后更要着重于行业内部结构的调整和技术发展水平的提高。结构调整方面较大差距,因此,每年需要大量进口模具。中国模具产业除了要继续提高生产能,主要是企业结构向专业化调整,产品结构向着中高档模具发展,向进出口结构的改进,中高档汽车覆盖件模具成形分析及结构改进、多功能复合模具和复合加工及激光技术在模具设计制造上的应用、高速切削、超精加工及抛光技术、信息化方向发展。近年,模具行业结构调整和体制改革步伐加大,主要表现在,大型、精密、复杂、长寿命、中高档模具及模具标准件发展速度高于一般模具产品;塑料模和压铸模比例增大;专业模具厂数量及其生产能力增加;“三资”及私营企业发展迅速;股份制改造步伐加快等。从地区分布来看,以珠江三角洲和长江三角洲为中心的东南沿海地区发展快于中西部地区,南方的发展快于北方。目前发展最快、模具生产最为集中的省份是广东和浙江,江苏、上海、安徽和山东等地近几年也有较大发展。虽然我国模具总量目前已达到相当规模,模具水平也有很大提高,但设计制造水平总体上落后于德、美、日、法、意等工业发达国家许多。当前存在的问题和差距主要表现在以下几方面:(1)总量供不应求国内模具自配率只有70 左右。其中低档模具供过于求,中高档模具自配率只有50 左右。(2)企业组织结构、产品结构、技术结构和进出口结构

均不合理我国模具生产厂中多数是自产自配的工模具车间(分厂),自产自配比例高达60 左右,而国外模具超过70 属商品模具。专业模具厂大多是“大而全”、“小而全”的组织形式,而国外大多是“小而专”、“小而精”。国内大型、精密、复杂、长寿命的模具占总量比例不足30 ,而国外在50 以上。2004 年,模具进出口之比为3.7:1 ,进出口相抵后的净进口额达13.2 亿美元,为世界模具净进口量最大的国家。(3)模具产品水平大大低于国际水平,生产周期却高于国际水平产品水平低主要表现在模具的精度、型腔表面粗糙度、寿命及结构等方面。(4)开发能力较差,经济效益欠佳我国模具企业技术人员比例低,水平较低,且不重视产品开发,在市场中经常处于被动地位。我国每个模具职工平均年创造产值约合1万美元,国外模具工业发达国家大多是15?20 万美元,有的高达25?30万美元,与之相对的是我国相当一部分模具企业还沿用过去作坊式管理,真正实现现代化企业管理的企业较少。造成上述差距的原因很多,除了历史上模具作为产品长期未得到应有的重视,以及多数国有企业机制不能适应市场经济之外,还有下列几个原因:(1)

国家对模具工业的政策支持力度还不够虽然国家已经明确颁布了模具行业的产业政策,但配套政策少,执行力度弱。目前享受模具产品增值税的企业全国只有185 家,大多数企业仍旧税负过重。模具企业进行技术改造引进设备要缴纳相当数量的税金,影响技术进步,而且民营企业贷款十分困难。(2)人才严重不足,科研开发及技术攻关投入太少模具行业

是技术、资金、劳动密集的产业,随着时代的进步和技术的发展,掌握并且熟练运用新技术的人才异常短缺,高级模具钳工及企业管理人才也非常紧张。由于模具企业效益欠佳及对科研开发和技术攻关重视不够,科研单

位和大专院校的眼睛盯着创收,导致模具行业在科研开发和技术攻关方面投入太少,致使模具技术发展步伐不大,进展不快。(3)工艺装备水平低,且配套性不好,利用率低近年来我国机床行业进步较快,已能提供比较成套

的高精度加工设备,但与国外装备相比,仍有较大差距。虽然国内许多企业已引进许多国外先进设备,但总体的装备水平比国外许多企业低很多。由于体制和资金等方面的原因,引进设备不配套,设备与附件不配套现象十分普遍,设备利用率低的问题长期得不到较妥善的解决。(4)专业化、标准化、商品化程度低,协作能力差由于长期以来受“大而全”“小而全”影响,模具专业化水平低,专业分工不细致,商品化程度低。目前国内每年生产的模具,商品模具只占40 左右,其余为自产自用。模具企业之间协作不畅,难以完成较大规模的模具成套任务。模具标准化水平低,模具标准件使用覆盖率低也对模具质量、成本有较大影响,特别是对模具制造周期有很大影响。(5)模具材料及模具相关技术落后模具材料性能、质量和品种问题往往会影响模具质量、寿命及成本,国产模具钢与国外进口钢材相比有较大差距。塑料、板材、设备性能差,也直接影响模具水平的提高。目前,我国经济仍处于高速发展阶段,国际上经济全球化发展趋势日趋明显,这为我国模具工业高速发展提供了良好的条件和机遇。一方面,国内模具市场将继续高速发展,另一方面,模具制造也逐渐向我国转移以及跨国集团到我国进行模具采购趋向也十分明显。因此,放眼未来,国际、国内的模具市场总体发展趋势前景看好,预计中国模具将在良好的市场环境下得到高速发展,我国不但会成为模具大国,而且一定逐步向模具制造强国的行列迈进。“十一五”期间,中国模具工业水平不仅在量和质的方面有很大提高,而且行业结构、产品水平、开发创新能力、企业的体制与机制以及技术进步的方面也会取得较大发展。模具技术集合了机械、电子、化学、光学、材料、计算机、精密监测和信息网络等

诸多学科,是一个综合性多学科的系统工程。模具技术的发展趋势主要是模具产品向着更大型、更精密、更复杂及更经济的方向发展,模具产品的技术含量不断提高,模具制造周期不断缩短,模具生产朝着信息化、无图化、精细化、自动化的方向发展,模具企业向着技术集成化、设备精良化、产批品牌化、管理信息化、经营

国际化的方向发展。我国模具行业今后仍需提高的共性技术有:(1)建立在CADCAE 平台上的先进模具设计技术,提高模具设计的现代化、信息化、智能化、标准化水平。( 2)建立在CAMCAP基础上的先进模具加工技术与先进制造技术相结合,提高模具加工的自动化水平与生产效率。 ( 3)模具生产企业的信息化管理技术。例如PDM(产品数据管理)、ERP(企业资源管理)、MIS (模具制造管理信息系统)及INTERMET平台等信息网络技术的应用、推广及发展。(4) 高速、高精、复合模具加工技术的研究与应用。例如超精冲压模具制造技术、精密塑料和压铸模具制造技术等。 ( 5)提高模具生产效率、降低成本和缩短模具生产周期的各种快速经济模具制造技术。(6)先进制造技

术的应用。例如热流道技术、气辅技术、虚拟技术、纳米技术、高速扫描技术、逆向工程、并行工程等技术在模具研究、开发、加工过程中的应用 ( 7)原材料在模具中成形的仿真技术。( 8)先进的模具加工和专有设

备的研究与开发。 (9)模具及模具标准件、重要辅件的标准化技术。(10) 模具及其制品的检测技术。 (11)优质、新型模具材料的研究与开发及其正确应用。

(12)模具生产企业的现代化管理技术。模具行业在“十

一五”期间需要解决的重点关键技术应是模具信息化、数字化技术和精密、超精、高速、高效制造技术方面的突破。随着国民经济总量和工业产品技术的不断发展,各行各业对模具的需求量越来越大,技术要求也越来越高。虽然模具种类繁多,但其发展重点应该是既能满足大量需要,又有较高技术含量,特别是目前国内尚不能自给,需大量进口的模具和能代表发展方向的大型、精密、复杂、长寿命模具。模具标准件的种类、数量、水平、生产集中度等对整个模具行业的发展有重大影响。因此,一些重要的模具标准件也必须重点发展,而且其发展速度应快于模具的发展速度,这样才能不断提高我国模具标准化水平,从而提高模具质量,缩短模具生产周期,降低成本。由于我国的模具产品在国际市场上占有较大的价格优势,因此

对于出口前景好的模具产品也应作为重点来发展。根据上述需要量大、技术含量

高、代表发展方向、出口前景好的原则选择重点发展产品,而且所选产品必须目前已有一定技术基础,属于有条件、有可能发展起来的产品。根据“十一五”模具行业发展规划,“十一五”期间模具产品发展重点主要有如下几类:(1)汽车覆盖件模具冲压模具占模具总量的40 以上汽车覆盖件模具主要为汽车配套,也包括为农用车、工程机械和农机配套的覆盖件模具,它在冲压模具中具有很大的代表性,模具大都是大中型,结构复杂,技术要求高。尤其是为轿车配套的覆盖件模具,要求更高,可以代表冲压模具的水平。此类模具我国已有一定的技术基础,已为中档轿车配套,但水平还不高,能力不足,目前满足率只有一半左右。中高档轿车覆盖件模具主要依靠进口,已成为汽车发展的瓶颈,极大的影响着车型开发。(2)精密冲压模具多工位级进模和精冲模代表了冲压模具的发展方向,精度要求寿命要求极高,主要为电子工业、汽车、仪器仪表、电机电器等配套。这两种模具,国内已有相当基础,并已引进了国外技术及设备,个别企业生产的产品已达到世界水平,但大部分企业仍有较大差距,供应总量不足,进口很多。(3)大型精密塑料模具塑料模具占模具总量近40 ,而且这个比例还在上升。塑料模具中为汽车和家电配套的大型注塑模具,为集成电路配套的塑封模,为电子信息产业和机械及包装配套的多层、多腔、多材质、多色精密注塑模,为新型建材及节水农业配

套的塑料异型材挤出模及管路和喷头模具等,目前虽然已有相当技术基础并正

在快速发展,但技术水平与国外仍有较大差距,总量供不应求,每年的进口额达几亿美元。(4)主要模具标准件目前国内已有较大产量的模具标准件主要是模架、导向件、推杆推管、弹性元件等。这些产品不但国内配套大量需要,出口前景也很好,应继续大力发展。氮气缸和热流道元件主要依靠进口,应在现有基础上提高水平,形成标准并组织规模化生产。

(5)其他高技术含量的模具占模具总量给8 的压铸模具中,大型薄壁精密压铸技术含量高,难度大。镁合金压铸模具目前虽然刚起步,但发展前景好,有代表性。子午线橡胶轮胎模具也是发展方向,其中活络模技术难度最大。与快速成型技术相结合的一些快速制模技术及相应的快速经济模具具有很好的发展前景。这些高

技术含量的模具在“十一五”期间也应重点发展。

Mold design and manufacture

The mold is the manufacturing industry important craft foundation in ourcountry the mold manufacture belongs to the special purpose equipmentmanufacturing industry. China although very already

starts to make the mold and theuse mold but long-term drives into the developmentspeedway. Recent years not only the state-owned mold enterprise gap concentrates precisely tolarge-scale is complex the long life mold domain. As a result of in aspect and so onmold precision life manufacture cycle and productivity China and the internationalaverage the productivityfrom now on will internal structure adjustmentand the state-of-art enhancement. The

structure adjustment aspect mainly is theenterprise structure to the specialized adjustment the product structure to center theupscale mold development to the import and export structure improvement centerthe upscale automobile cover mold forming analysis and the structure improvementthe multi-purpose compound mold and the compoundprocessing and the lasertechnology in the mold design manufacture application the direction develops . The recent years the mold profession structure adjustment and the organizationalreform step enlarges mainly displayed in large-scale precise was complex the longlife center the upscale mold and the mold standard letter development speed is the commonmold product

The plastic mold and the compression casting moldproportion increases Specialized mold factory quantity and its productivity increasequotThe three investmentsquot and the private enterprise develops rapidly The joint stocksystem transformation step speeds up and so on. Distributes from the area lookedtake Zhujiang Delta and Yangtze River delta as central southeast coastal areadevelopment quickly to mid-west area south development quickly to north. Atpresent develops quickest the mold produces the most centralized province isGuangdong and Zhejiang places such as Jiangsu Shanghai Anhui and Shandong alsohas a bigger development

in recent years . Although our country mold total quantity manufacturehorizontal overall rise and fall industry developed country and so on Yu De Americadate France Italy many. The current existence question and the disparity mainlydisplay in following several aspects: 1 The total quantity falls short of demandDomestic mold assembling oneself rate only about 70. Low-grade mold center upscale mold assembling oneself rate only our country mold production factory to be most is from the labor moldworkshop which produces assembles oneself branch factory from producesassembles oneself the proportion to reach as form but overseas mostly is quotsmall butquotquotis specially small and finequot. Domestic large-scale precise complex the long lifemold accounts for the total quantity proportion to be insufficient 30 but overseas in50 above 2004 years ratio of the mold import and export is 3.7:1 the import andexport balances the after net import

毕业论文英文参考文献与译文

Inventory management Inventory Control On the so-called "inventory control", many people will interpret it as a "storage management", which is actually a big distortion. The traditional narrow view, mainly for warehouse inventory control of materials for inventory, data processing, storage, distribution, etc., through the implementation of anti-corrosion, temperature and humidity control means, to make the custody of the physical inventory to maintain optimum purposes. This is just a form of inventory control, or can be defined as the physical inventory control. How, then, from a broad perspective to understand inventory control? Inventory control should be related to the company's financial and operational objectives, in particular operating cash flow by optimizing the entire demand and supply chain management processes (DSCM), a reasonable set of ERP control strategy, and supported by appropriate information processing tools, tools to achieved in ensuring the timely delivery of the premise, as far as possible to reduce inventory levels, reducing inventory and obsolescence, the risk of devaluation. In this sense, the physical inventory control to achieve financial goals is just a means to control the entire inventory or just a necessary part; from the perspective of organizational functions, physical inventory control, warehouse management is mainly the responsibility of The broad inventory control is the demand and supply chain management, and the whole company's responsibility. Why until now many people's understanding of inventory control, limited physical inventory control? The following two reasons can not be ignored: First, our enterprises do not attach importance to inventory control. Especially those who benefit relatively good business, as long as there is money on the few people to consider the problem of inventory turnover. Inventory control is simply interpreted as warehouse management, unless the time to spend money, it may have been to see the inventory problem, and see the results are often very simple procurement to buy more, or did not do warehouse departments . Second, ERP misleading. Invoicing software is simple audacity to call it ERP, companies on their so-called ERP can reduce the number of inventory, inventory control, seems to rely on their small software can get. Even as SAP, BAAN ERP world, the field of

概率论毕业论文外文翻译

Statistical hypothesis testing Adriana Albu,Loredana Ungureanu Politehnica University Timisoara,adrianaa@aut.utt.ro Politehnica University Timisoara,loredanau@aut.utt.ro Abstract In this article,we present a Bayesian statistical hypothesis testing inspection, testing theory and the process Mentioned hypothesis testing in the real world and the importance of, and successful test of the Notes. Key words Bayesian hypothesis testing; Bayesian inference;Test of significance Introduction A statistical hypothesis test is a method of making decisions using data, whether from a controlled experiment or an observational study (not controlled). In statistics, a result is called statistically significant if it is unlikely to have occurred by chance alone, according to a pre-determined threshold probability, the significance level. The phrase "test of significance" was coined by Ronald Fisher: "Critical tests of this kind may be called tests of significance, and when such tests are available we may discover whether a second sample is or is not significantly different from the first."[1] Hypothesis testing is sometimes called confirmatory data analysis, in contrast to exploratory data analysis. In frequency probability,these decisions are almost always made using null-hypothesis tests. These are tests that answer the question Assuming that the null hypothesis is true, what is the probability of observing a value for the test statistic that is at [] least as extreme as the value that was actually observed?) 2 More formally, they represent answers to the question, posed before undertaking an experiment,of what outcomes of the experiment would lead to rejection of the null hypothesis for a pre-specified probability of an incorrect rejection. One use of hypothesis testing is deciding whether experimental results contain enough information to cast doubt on conventional wisdom. Statistical hypothesis testing is a key technique of frequentist statistical inference. The Bayesian approach to hypothesis testing is to base rejection of the hypothesis on the posterior probability.[3][4]Other approaches to reaching a decision based on data are available via decision theory and optimal decisions. The critical region of a hypothesis test is the set of all outcomes which cause the null hypothesis to be rejected in favor of the alternative hypothesis. The critical region is usually denoted by the letter C. One-sample tests are appropriate when a sample is being compared to the population from a hypothesis. The population characteristics are known from theory or are calculated from the population.

毕业论文之参考文献

毕业论文之参考文献 参考文献 [2] [美]罗伯特"吉尔平:《国际关系政治经济学》,杨宇光等译,经济科学出版社,版。 [5] [美]罗伯特"吉尔平:《全球政治经济学》(杨宇光等译),上海人民出版社,2021年版。 [6] [美]约瑟夫"奈:《硬权力与软权力》,门洪华译,北京大学出版社,2021年 10月第1版,第177、183、190页。 [7] [美]托克维尔:《论美国的民主》,商务印书馆,董果良译,2002年版,第 210页。 [8] [美]肯尼斯"沃尔兹:《国际政治理论》,信强译,上海世纪出版集团,2021年11月第1版,第37、45、54页。 [20] 丁松泉:《中国崛起与中美关系》,中国社会科学出版社,2021年5月第1版。 [22] W.Arthur Lenis,The Evolution of the International Economic Order ,Princeton: Princeton University Press,1978. [23] Henry Kissinger,America at the Apex. The national interest, Summer ,2001, p15. [26] Raymond Vernon, Sovereignty at Bay: The Multinational Spread of U.S. Enterprises, New York & London: Basic Books, Inc Publishers,1971. [27] Robert Gilpin, U.S. Power and the Multinational Corporation: The Political Economy of Foreign Direct Investment, New York: Basic Books,Inc.,Publishers,1975. 感谢您的阅读,祝您生活愉快。

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毕业论文(设计)外文翻译 题目:中国上市公司偏好股权融资:非制度性因素 系部名称:经济管理系专业班级:会计082班 学生姓名:任民学号: 200880444228 指导教师:冯银波教师职称:讲师 年月日

译文: 中国上市公司偏好股权融资:非制度性因素 国际商业管理杂志 2009.10 摘要:本文把重点集中于中国上市公司的融资活动,运用西方融资理论,从非制度性因素方面,如融资成本、企业资产类型和质量、盈利能力、行业因素、股权结构因素、财务管理水平和社会文化,分析了中国上市公司倾向于股权融资的原因,并得出结论,股权融资偏好是上市公司根据中国融资环境的一种合理的选择。最后,针对公司的股权融资偏好提出了一些简明的建议。 关键词:股权融资,非制度性因素,融资成本 一、前言 中国上市公司偏好于股权融资,根据中国证券报的数据显示,1997年上市公司在资本市场的融资金额为95.87亿美元,其中股票融资的比例是72.5%,,在1998年和1999年比例分别为72.6%和72.3%,另一方面,债券融资的比例分别是17.8%,24.9%和25.1%。在这三年,股票融资的比例,在比中国发达的资本市场中却在下跌。以美国为例,当美国企业需要的资金在资本市场上,于股权融资相比他们宁愿选择债券融资。统计数据显示,从1970年到1985年,美日企业债券融资占了境外融资的91.7%,比股权融资高很多。阎达五等发现,大约中国3/4的上市公司偏好于股权融资。许多研究的学者认为,上市公司按以下顺序进行外部融资:第一个是股票基金,第二个是可转换债券,三是短期债务,最后一个是长期负债。许多研究人员通常分析我国上市公司偏好股权是由于我们国家的经济改革所带来的制度性因素。他们认为,上市公司的融资活动违背了西方古典融资理论只是因为那些制度性原因。例如,优序融资理论认为,当企业需要资金时,他们首先应该转向内部资金(折旧和留存收益),然后再进行债权融资,最后的选择是股票融资。在这篇文章中,笔者认为,这是因为具体的金融环境激活了企业的这种偏好,并结合了非制度性因素和西方金融理论,尝试解释股权融资偏好的原因。

论文文献综述与参考文献--模版

1文献综述(一级标题,黑体三号加粗,居中) 1.1热油管道材料简介(二级标题,黑体四号) 自第一套轧机由美国轧机公司在Bulter成功建成后,美丽的故事们应该多样化的生 活………… 表23 辽宁石油化工--(表标题,宋体小四,加粗,居中,三线表)学生种类1998年1999年2000年 本科生100 150 300 硕士研究生20 60 100 博士研究生—— 5 12 点。表格可按全文统一编序,表格序号必须连续。表格允许下页接写,表题可省略,表头应重复写,并在右上方写"续表××"。表中各栏应注明量和相应的单位。表内数字须上下对齐。相邻栏内的数字或者内容相同,不能用“同上”、“同左”和其它类似用词,应一一重新标注。表格应写在离正文首次出现处的近处,不应过分超前或拖后。) 1.1.1热油管道钢质成分(三级标题,黑体小四) 23X1+32X2+45X3=380 (2.1)(公式书写说明:公式应另起一行,居中书写,公式的编号用圆括号括起放在公式右边行末(右对齐),公式和编号之间不加虚线。公式按全文统一编序号,公式序号必须连续。)

1.1.2 热油管道钢质性能 1.2 支持辊辊形技术 图23 北京科技大学校徽 (图像书写说明:毕业设计的插图必须精心制作,线条要匀称,图面要整洁美观。插图应与正文呼应,不得与正文脱节。每幅插图应有图序(图23)和图题(北京科技大学校徽),图序和图题应放在图位下方居中处。图应在描图纸或在洁白纸上用墨线绘成,也可以用计算机绘图。) 1.3 工作辊辊形的特点 E /V (S C E ) lg[i/(A ?cm -2 )] 图2 2024铝合金在不同浓度氯化镧海水中的动电位极化曲线

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