12,835 research outputs found

    Detection of incoherent broadband terahertz light using antenna-coupled high-electron-mobility field-effect transistors

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    The sensitivity of direct terahertz detectors based on self-mixing of terahertz electromagnetic wave in field-effect transistors is being improved with noise-equivalent power close to that of Schottky-barrier-diode detectors. Here we report such detectors based on AlGaN/GaN two-dimensional electron gas at 77~K are able to sense broadband and incoherent terahertz radiation. The measured photocurrent as a function of the gate voltage agrees well with the self-mixing model and the spectral response is mainly determined by the antenna. A Fourier-transform spectrometer equipped with detectors designed for 340, 650 and 900~GHz bands allows for terahertz spectroscopy in a frequency range from 0.1 to 2.0~THz. The 900~GHz detector at 77~K offers an optical sensitivity about 1 pW/Hz1~\mathrm{pW/\sqrt{Hz}} being comparable to a commercial silicon bolometer at 4.2~K. By further improving the sensitivity, room-temperature detectors would find applications in active/passive terahertz imaging and terahertz spectroscopy.Comment: 4.5 pages, 5 figure

    Contribution of Different Processes in Wetland Soil N_2O Production in Different Restoration Phases of the Yellow River Estuary, China

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    采用时空替代法,选择黄河口生态恢复前后未恢复区(R_0)、2007年恢复区(R_(2007))和2002年恢复区(R_(2002))的芦苇湿地为研究对象,分析了生态恢复工程对湿地土壤N_2O产生不同过程与贡献的影响. 结果表明,尽管不同恢复阶段湿地土壤N_2O总产生量差异明显,但总体均表现为N_2O释放. 恢复区湿地土壤的N_2O产生量大于未恢复区. N_2O的产生主要以硝化作用和硝化细菌反硝化作用为主,而反硝化作用对N_2O的产生有较大削弱作用,这与不同恢复阶段湿地土壤理化性质密切相关. 非生物作用对N_2O产生量贡献较大,这与黄河口为高活性铁区,Fe的还原作用关系密切. 尽管黄河口不同恢复阶段湿地土壤N_2O的产生是生物作用与非生物作用共同作用的结果,但由于非生物作用对N_2O产生的影响较大,应受到特别关注. 温度和水分对不同恢复阶段湿地土壤N_2O产生过程的影响不尽一致,这与土壤微生物活性对温度和水分的响应差异有关. 黄河口不同恢复阶段湿地土壤的N_2O总产生量介于(0.37±0.08)~(9.75±7.64)nmol·(kg·h)~(-1),略高于闽江口互花米草湿地的N_2O总产生量,但明显低于富氧森林土壤、草原土壤和闽江口短叶茳芏湿地的N_2O总产生量. 研究发现,黄河口生态恢复工程的长期实施明显促进了N_2O的产生,因而下一步生态恢复工程应统筹考虑景观恢复与温室气体削弱这两方面因素

    One-step Deposition of Melanin-like Polymer on individual Escherichia Coli cells Exhibiting an Special Effect of UV- and Lysozyme - Resistance

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    尽管紫外线只占到达地球表面的阳光辐射能量中的一小部分,但若长期暴露于这部分紫外辐射之下,几乎所有的有机生命体都将直接或间接地因受到光损伤而导致其遗传物质核酸遭受破坏,进而造成机体死亡。为了应对太阳光中的这部分紫外辐射,某些微生物已经进化出了许多生物化学或生物行为光保护机制。黑色素,由于其具有很强光吸收和良好能量转换性质,可以将有害辐射能高效地转换为热能进而耗散至周围环境中,黑色素一直被认为是所有已知的光保护机制中最高效的。因此,结合黑色素的性质,人们可以使用其来提高某些生物工程菌的抗紫外性能,在生物医学领域开拓出更广阔的应用前景。 基于贻贝足丝蛋白独特的粘附性启发,人们发现多巴胺单体(Dop...In nature, almost all the organisms would gain cellular photodamage which directly or indirectly destroys their nucleic acids from prolonged exposure to UV radiation, although UV radiation constitutes only a minor proportion of the sunlight. In the microbiota, in order to protect themselves against UV radiation, certain microbes have evolved some important photoprotective mechanisms, such as bioch...学位:工学硕士院系专业:材料学院_材料物理与化学学号:2072012115002

    Design and Implementation of Suowei Cafe Website

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    某学院为给师生员工提供一处进行学术交流、工作交流和师生互动交流的公共场所,建设了索味咖啡厅。咖啡厅属于餐饮行业,要想为师生员工提供更加多样化的服务,首先必须保证咖啡厅能够良好地运营下去。索味咖啡厅周边已建成或在建的咖啡厅数目较多,竞争十分激烈,如果延续传统的经营模式,等客上门,必将严重影响咖啡厅的生存与发展。 索味咖啡厅面对的消费人群主要是高校师生,对网络的接受程度较高,这为咖啡厅利用现代化的、高效先进的信息管理手段来实行线上线下相结合的营销和管理模式提供了很好的条件。在此背景下,建设咖啡厅网站的需求应运而生。 通过咖啡厅网站系统,经营者可以及时发布咖啡厅的各类信息,扩大宣传效果;可以借助...The Suowei Cafe was set up by a college to provide a public venue for faculty and students’ academic and work exchanges and interactive activities. Being part of the catering business, the primary task for the Suowei Cafe is to ensure good management and keep running. But the big number of coffee shops which have been built or under way in the neighborhood makes the competition severe. If the Suow...学位:工程硕士院系专业:软件学院_工程硕士(软件工程)学号:X201323075

    The Study of the Influence of Fastener Manufacturing Industry’s Budgeting Manage System to Profitability

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    本世纪以来,关于预算制度的研究备受关注。在预算理论和预算实践方面,国内外已然形成了较丰富的研究成果。盈利是企业经营管理的核心,亦是企业生存发展的动力。关于预算制度对企业盈利能力的影响研究较少。通过研究预算制度对盈利能力的影响可以为企业的发展提供决策,发现企业的核心竞争力,优化管理结构和模式,最终提高企业的盈利能力。本文系统阐述了预算管理制度相关的国内外研究成果,结合我国的国情,对我国企业预算管理制度的实施做了发展性回顾。 随着经济全球化和现代工业的迅速发展,制造业水平已经成为衡量工业水平的重要指标。紧固件被称为“工业之米”,其制造水平可在一定程度上体现我国的工业水平。本文以紧固件制造行业上市...We have paid much attention on the budget manage system since 2000. Also we have obtained a lot of results of budget manage system. Profitability is not only the focus of enterprise management, but also the driving force for the survival and development of enterprises. While the research on the influence of the budget manage system to the enterprise profitability is not valid. By the study of the ...学位:工商管理硕士院系专业:管理学院_工商管理硕士(工商管理硕士)学号:X201315628

    The effect of thyroid hormone on GLUT4 and its relationship with cardiolipin

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    课题组前期的研究结果表明,甲亢性心脏功能变化与心磷脂关系密切,本研究拟从GLUT4(Glucosetransporter4,葡萄糖转运蛋白4)变化的角度进一步探讨心磷脂在甲亢中的作用。 心脏作为一个高能量代谢的组织,主要通过线粒体中氧化磷酸化产生ATP来提供能量,并且对葡萄糖体现出高度依赖性。而GLUT4是糖转运体蛋白家族中的一员,在葡萄糖的非ATP-依赖膜转运过程中起着重要作用。因此,对于以高代谢为主要变化的甲亢,探讨GLUT4是有必要的。而且,文献报道甲状腺激素可促进心肌组织中GLUT4的表达,进而促进对葡萄糖的利用来满足心脏基础代谢率升高对能量的需求。但是,GLUT4只有从胞浆中转移到...The previous research of our group has shown a significant relationship between CL and the functional alteration of heart induced by hyperthyroidism, based on which we planned to research the role of CL in hyperthyroidism from the point of view of GLUT4. Heart is a metabolic tissue with high level which products energy trough oxidative phosphorylation in mitochondria and shows high dependence...学位:理学硕士院系专业:医学院_生理学学号:2452013115342

    Design and Implementation of OA System for a State-owned Enterprises

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    随着某国有企业业务不断扩大,业务量不断增多,原有纸质办公会签系统已无法满足企业需求,同时随着企业发展,存档文件及留存的审批会签单也越来越多,纸质存档对于空间的要求及随时间推移不断损坏的弊端也逐渐凸显出来,因此更新为协同办公系统建立数据中心的工作势在必行。而随着应用从广度、深度、IT技术应用等各个方面都有了日新月异的发展以及变化,并且在高效办公的大前提下成为了推行无纸化办公模式的一大助力。协同办公系统同时也是组织中核心应用系统所不可或缺的一部分。 本文首先介绍了某国有企业协同办公系统设计和开发过程中涉及到的B/S、J2EE、Domino等相关技术。其次根据某国有企业现有的纸质会签流程及相关需求...As a state-owned enterprise business continues to expand, increasing the volume of business, the original paper office sign system has been unable to meet the needs of enterprises, along with the development of enterprises, archived documents and retained the approval will be more and more signing, For the space requirements and the drawbacks of the damage over time has gradually highlighted, so u...学位:工程硕士院系专业:软件学院_工程硕士(软件工程)学号:X201323224

    Design and Implementation of Vocational Training Information Management System for Xinjiang Autonomous Region

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    摘要 自改革开放以来,如何适应就业率的扩大和提高就业的质量需要,加强企业的竞争力,完善制度,创新机制,加大投入,开展职业技能培训和创业培训,切实提高和改善职业培训的重要性,并努力实现培训价值观“培训一人就业一人”和“雇用一个人训练一个人”的目标,为促进就业和经济社会发展提供技能人才的有力支撑;在“十二五”期间,如何使新进入人力资源市场的劳动者有机会并得到相应的培训,提高岗位工人的工作技能,使高技能人才培训满足行业等的结构优化和业务发展的需要。 本文以自治区职业培训管理为研究对象,对现有的职业培训管理业务提出可视化分析,设计了一套以自治区职业培训实际管理需求为标准的应用系统。 论文从项目背...Abstract Since reform and opening up, how to adapt to the employment of the need to expand and improve the quality of employment, strengthen the competitiveness of the enterprise, perfecting the system of innovation mechanism, increasing investment, carry out vocational skills training and entrepreneurship training, enhance and improve the importance of vocational training, and strive to achieve ...学位:工程硕士院系专业:软件学院_工程硕士(软件工程)学号:X201323065

    The relationship between the levels of white blood cell and lipopolysaccharide binding protein and intrahepatic triglyceride content , metabolic abnormalities in obese adults

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    研究目的 非酒精性脂肪性肝病(NAFLD)常常伴随炎性因子的增多,且其发生发展与代谢综合征和胰岛素抵抗紧密相关。本研究针对中心性肥胖人群进行横断面数据分析,探讨白细胞(WBC)及脂多糖结合蛋白水平(LBP)与肝脏脂质含量(IHTC)及其相关代谢异常的关系。 研究方法 本研究纳入485名40-65岁中心性肥胖受试者,进行问卷调查包括病史、生活方式等;测定生化指标并进行胰岛功能评估;通过氢质子磁共振波谱(1H-MRS)技术定量分析肝内甘油三酯含量;进行内脏脂肪含量等测定,分析白细胞及脂多糖结合蛋白水平与肝内甘油三酯含量及相关代谢指标的关系。 研究结果 1.白细胞及脂多糖结合蛋白与肝脏脂肪...Research objective Nonalcoholic fatty liver disease features the increase of inflammatory factors, which is closely related to metabolic syndrome and insulin resistance. Making cross-sectional data analysis on central obese population, this paper investigates the relationship between levels of the white blood cell and lipopolysaccharide binding protein of obese population and the proportion of li...学位:医学硕士院系专业:医学院_内科学学号:2452013115347

    Marketing Strategy of Xia men GoldenHome Decoration Projects

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    中国橱柜生产企业目前已覆盖全国所有省会城市、二线城市和超过90%的县级市 场,企业数量也从1994年的20多家发展到目前的3000多家,已经形成了庞大的产 业体系。但由于其准入门槛低,市场潜力大,导致业内竞争激烈且混乱。厦门金牌 厨柜股份有限公司(以下简称金牌厨柜)创建于1999年,专注厨柜17年,目前拥 有1000多家橱柜专卖店,遍布在全国700多个大中城市中,企业品牌及规模稳居国 内橱柜行业前三甲。金牌厨柜从零售起家,2009年开始启动工程渠道营销,同时于 2011年增设电商和海外营销渠道,但在近几年房地产形势严峻情况下橱柜行业发展 举步维艰,而金牌厨柜工程营销战略该如何调整...A large industry system has established, as current cabinet manufacturers locate all over capital cities, secondary cities and over 90% counties. The number of factories who are manufacturing cabinets in China nowadays has increased to more than 3000 from less than 20 in the year of 1994. In reasons of its low threshold and great market potential, the market competition becomes extremely inten...学位:工商管理硕士院系专业:管理学院_工商管理硕士(工商管理硕士)学号:1792012115086
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