3,446 research outputs found
Preparation of CuCr2O4-based and TiO2-based composites and its performance as cathode of Li-Air batteries
众所周知,传统的化石能源在经济的飞速发展中扮演着重要的角色,但这种以环境换经济的发展方式愈发引起人们的反思。因此,清洁能源的开发,存储和转化技术的研究就显得尤为迫切。和其它化学储能技术相比,锂空气电池(Li-Airbatteries,LABs)以其超高的能量密度(1000-2000WhKg-1)而备受关注。最近几年,随着人们对正极催化剂材料(贵金属基材料,过渡金属基材料,碳材料和其他材料)研究的深入,越来越多的人发现过渡金属氧化物具有价格低廉,性能优异和可设计性强等难能可贵的优点。因此本文对CuCr2O4基和TiO2基纳米复合材料作为锂空气电池的正极催化剂进行了系统的研究,其主要结论如下: ...The traditional fossil energy has play an important role in the rapid development of the global industry. However, the Economic Developing Mode which is refer to the sacrifice of environment has draw more and more self-examination. Thus, it is necessary and impendency to research the new storage and conversion technology of clean energy. Compared with other chemical storage technology, Li-Air batt...学位:工学硕士院系专业:材料学院_工程硕士(材料工程)学号:2072013115010
One-pot synthesis of core-shell Cu@M nanosilks and the application as flexible transparent ohmic electrode in Deep-UV devices
随着LED照明、智能手机、平板电脑、液晶电视、智能穿戴等光电子技术器件产品的全面普及,光电子器件技术在日益趋于成熟的同时,仍然面临着诸多尚未解决的核心难题。透明电极作为光电子器件中的重要组成部分,一直备受关注和研究,特别是深紫外波段,透明电极材料极少存在。面对ITO为代表的传统电极材料的稀缺与高成本等问题,新型广谱透明电极材料已成为研究者们竞相追逐的目标。其中,Cu纳米线凭借其低成本(ITO的百分之一)和高性能,被公认为新一代的透明电极材料的希望之星。但在Cu纳米线的研究和应用中,其仍面临着稳定性、兼容性和拓展性方面的关键问题,亟待解决。针对这些问题,本论文从不同金属包裹的核壳结构超细Cu纳米...Recently, optoelectronic devices such as LED, smart phones,and wearable intelligent devices have been widely used in our daily life, however, several unresolvedcritical problems still hinder their further development due to the limitation by traditional technology. One of them is the transparent electrodes (TEs), which plays an important role in the construction of optoelectronicdevices. Uptodate,...学位:理学硕士院系专业:物理科学与技术学院_光学学号:1982014115296
Thermal Effect Mechanism and Surface Topography of the Micro-EDM Workpiece
微细电火花加工具有可以非接触加工、三维加工能力以及设备简单、可实施性强、加工性能与材料硬度强度无关等优点。这种方法能加工处理的材料非常广泛,不仅可以加工各种性能优良的金属、合金,还可以加工陶瓷、硅等半导体材料。因此,微细电火花加工在复杂微小零件的制作中有着独特的优越性,也得到了广泛的应用。目前,微细电火花加工的理论研究和工艺研究还存在很多问题,尤其在蚀除过程中,现在普遍采用普通电火花的加工机理来说明。微细电火花加工具有放电时间短、放电通道半径小及能量密度高等特点,所以其放电过程与普通电火花明显不同。因此,本文按照微细电火花加工蚀除过程和表面成形的先后顺序,对微细电火花窄脉宽放电加工的热源模型、...Micro-EDM(Electric Discharge Machining) has brilliant advantags in non-contact processing, 3-D machining ability as well as the equipment is simple, practical strong, processing performance has nothing to do with the material hardness, strength, etc. This method has a very wide range of materials’ processing ability, not only can process various metals and alloys with excellent properties, but als...学位:工学博士院系专业:物理与机电工程学院_机械电子工程学号:1992011015403
Research on the Quantification of Operational Risk in Banks
操作风险是指由不完善或失败的内部程序、人员及系统或外部事件所造成损失的风险。20世纪90年代,操作风险失控直接导致了几次银行的重大损失和倒闭事件,操作风险的威胁也随之受到各国金融机构和监管当局的关注,巴塞尔委员会适时地将操作风险纳入最低资本要求的计量框架,这引起了国际金融界对操作风险的广泛研究和讨论。在中国深化金融体制改革的时期,金融系统内却连续发生数起重大操作风险损失事件,这不仅扰乱了国家金融市场的正常秩序,也威胁着金融系统的稳健运行。因此,深刻认识新资本协议全面风险管理的理念,借鉴发达国家关于操作风险度量和管理的研究成果和成功经验,对于我国金融业的稳健运行和发展具有重要现实意义。本文通过解...Operational risk is defined as the risk of loss resulting from inadequate or failed internal processes, people and systems or from external events. Operational risk is now the focus of intense interest among industry participants, regulators and other observers. Concern has been prompted by a steady stream of significant operational risk losses at major international banks. Basel Committee on Bank...学位:经济学硕士院系专业:经济学院计划统计系_国民经济学学号:20021000
Dell and HP Coperation Financial Analysis and Enterprise Valuation
自一开始IBM将标准开放给微软及英特尔后,行业利润被Wintel联盟所获取,PC行业成为了一个低利润的行业。随着2010年Apple发布iPad,平板电脑对传统PC产生严重威胁,导致PC行业的销量下滑。 惠普公司和戴尔公司是两家典型的美国PC制造商,其业务的覆盖地区与业务类型非常相近。随着PC行业持续下滑,两家公司的前景如何,企业价值与市场价值是否有较大差距,哪家公司可能有更高的企业价值。本文试图通过对两家公司财务数据的分析比较,财务预测,以及不同的价值评估方法来进行相关的研究。写本文的意义一是提供了IT行业的价值评估文献,二是为为相关投资人士了解两家公司的前景并做出投资决策提供参考。 具...Since IBM published the PC standard to Microsoft and Intel, PC industry became an industry with low margin. When Apple released iPad in 2010, tablet PC caused significant impact on traditional PC business, the volume of PC shipment decreased. HP and Dell Inc are two typical US-based PC providers, and they have similar global coverage and business offering. Under the circumstance of PC industry ...学位:工程管理硕士院系专业:管理学院_工商管理硕士(MBA)学号:1792009115080
On the Processing Strategies of Reverse Thinking in English to Chinese Translation
英汉民族因为生存地域、生活习惯与文化习俗差异,导致英语与汉语说话者对同一客观事物有着不同、甚至截然相反的观察角度和思维方式。虽然翻译指把一种语言文字的意义用另一种语言文字表达出来,但翻译活动是个并非纯粹两种语言信息的转化,涉及极为复杂的人类思维的转换过程。 英汉语言结构差异反映了英汉民族思维方式的分歧,导致有时产生完全相反的语言结构形式。虽然张培基、喻云根、李宗杰、彭谟禹(1980)、连淑能(1993)、傅仲选(1993)、范仲英(1994)、余光中(2000)、刘宓庆(1999,2005,2006)、冯庆华(2002)、杨士焯(2006)等学者曾对逆向思维翻译进行研究,但多限于逆向思维翻译...English and Chinese speakers’ distinct geographic areas, diverse customs and life styles, as well as cultural difference engender dissimilar or even opposite angles of observation and thinking patterns on some identical objects. While conveying the sense of a source-language text by means of an appropriately equivalent target language, translation involves a complicated process of thought pattern ...学位:翻译硕士院系专业:外文学院英语语言文学系_翻译硕士学号:X200811001
Research and Design of an Unmanned Monitoring System with Wireless Sensor Networksused in the geracomium
随着中国进入老龄化社会,如何养老成了我们都要面对的问题。现在越来越多的人选择去养老院养老,但目前我国的养老院发展还比较落后。资金的缺少,专业人员的不足成了困扰养老院发展的瓶颈,阻碍了养老院服务质量的提高。基于无线传感网的养老院无人监护系统的研究能够加强养老院对老年人的管理,通过无线监护网络养老院可以为老年人提供实时的监护,提高了养老院的护理水平和保障能力,同时又节约了人力和财力,对养老院的发展有积极的作用。 基于以上需求,本文着重进行了建立适合养老院的无人监护系统的研究。本文的绪论介绍了文章的研究背景、意义及文章的基本结构,并介绍了无线传感网络的研究及医学方面的应用;随后本文从生理信号采集的...As the problem of Chinese population aging become serious, it is a puzzle for us to decide where we will spend our old age. Now more and more people chose to go to geracomium when they are old, but the geracomiums in china are still undeveloped. Because of shorting of money and professional, it is too hard for the geracomium to develop, and the quality of the service can not be ensured. The unman...学位:工学硕士院系专业:信息科学与技术学院电子工程系_仪器仪表工程学号:X20043000
Research on the Effects of the RMB Appreciation on Foreign Trade
自2005年人民币汇率形成机制改革以来,人民币对美元出现了较大幅度的升值。截至2011年4月5日,人民币兑美元年终名义汇率累计升幅超过20%。对于中国来说,改革开放以来对外贸易在国民经济增长中一直占有重要地位,如果人民币的快速升值对进出口贸易产生不利影响,必然会进一步影响国内经济发展。因此,人民币升值的外贸效应问题是目前人们所关注的重要问题之一。 从已有研究来看,对人民币升值外贸效应的研究主要集中在两个方面:一是人民币升值的贸易收支效应;二是人民币升值的贸易条件效应。多数研究认为,人民币升值将恶化我国的贸易收支,但会改善我国的价格贸易条件。然而,这一结论与中国的实际情况并不一致。1994年以...Since the reform of the RMB exchange rate system in 2005, the RMB exchange rate against U.S. dollar has had a more substantial appreciation more than 20% by April 5, 2011. In China, the foreign trade has played an important role in economic growth since the reform and opening. If the rapid appreciation of RMB affects the foreign trade adversely, it must affect the domestic economy. Therefore, one ...学位:经济学博士院系专业:经济学院经济系_西方经济学学号:1532008015029
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