1,416 research outputs found

    Design and Implementation of Network Teaching System Based on .NET

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    网络教学是随网络的发展与应用而兴起的,借助网络进行师生非面对面的教与学的活动。网络教学植根于传统教学,而不同于传统教学,其最大的特点是教学的中心从教师真正转移到学习的主体——学生。网络教学适应了教学计算化、网络化的发展要求,形成了自己的教学模式和特点,并且向完善的体系化发展。网络教学的技术实现依靠网络技术和相关的多媒体、信息交互技术,同时也形成自己的体系和实现技术。本文提出构建一个具有教学演示、答疑讨论、教学评价等功能一体化的网上教学系统,并详细分析和探讨了各部分的实现,对网络教学有一定的借鉴意义。 文章首先介绍了系统的总的方案设计,讲解了设计要素及设计方法。并对系统的总体规划进行了介绍;概...Network teaching is along with the development of the network and application, which is with the help of a network of face-to-face teaching and learning activities between teachers and students. Rooted in traditional teaching, network teaching and different from traditional teaching. Its biggest feature is the center of teaching from the teacher really is transferred to the main body of learning, ...学位:工程硕士院系专业:软件学院_软件工程学号:X201323012

    Study of Locally-Enhanced Interfacial Potential Based on Microelectrode Chips and Preparation of AuPd Alloy Nanocatalystfor Ethanol Electrooxidation

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    铂基金属纳米催化剂广泛应用于燃料电池、汽车尾气处理、石油化工、化学工业等其他领域。由于铂资源匮乏,价格昂贵,因此提高铂金属的利用率和寻找其替代金属,以减少铂金属的使用是现阶段研究的重大问题。 研究表明,高指数铂纳米催化剂由于其表面原子配位数少,具有较高的催化活性。本课题组在长期研究过程中发展了电化学流动反应体系(EFRS:ElectrochemicalFlowReactionSystem),实现了在液相中连续可控合成高指数纳米Pt/C、Pd/C以及PtPd/C等负载型金属纳米催化剂,不仅提高了铂的催化活性和利用率,而且使电化学制备铂族金属纳米催化剂规模化生产迈进了一大步。对于体系中的所涉及的...Pt-based metal nanocatalysts are widely applied as catalysts in a variety of fields such as fuel cell, automobile exhaust purification, petrochemical industry and chemical industry. Due to the rare reserves and the high price of platinum group metal, therefore,how to improve their utilization efficiency and find an alternative to Pt-based catalysts has been an important scientific and engineering ...学位:理学硕士院系专业:化学化工学院_物理化学学号:2052013115162

    Study on Gene Cloning, Expression and Characterization of Stylicin and Invertebrate Lysozyme in Marsupenaeus japonicus

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    日本囊对虾(Musupenaeusjaponicus)是我国沿海重要养殖对虾品种,具有非常高的经济价值。近年来日本囊对虾养殖规模受病害影响停滞不前,尤其是白斑综合症病毒(WSSV)等病毒性对虾病对日本囊对虾养殖产业造成严重的经济损失。目前,对虾病毒病的预防和治疗的方法效果均十分有限,而滥用乱用药物易诱发水质污染和药物残留等严重问题。因此,尽快找到环保高效的治疗方法与策略,成为当前海水对虾养殖产业迫切需要解决的重要科学问题。抗菌肽(AMPs)是对虾抵御病原入侵的一类重要的非特异性免疫成分,其抗细菌、真菌、病毒及寄生虫等特性引起了海洋生物学者的重视,正在开展进一步的研究与探索。 本研究以日本囊对...Kuruma shrimp (Marsupenaeus japonicus) is one of the most economically valuable and widely cultured species in China. During the last decade its development has been seriously affected by the outbreak of viral and bacterial diseases, especially by white spot syndrome virus (WSSV). Nowadays, the treatment methods controlling prawn virus diseases are limited and produce very limited effects. In addi...学位:理学博士院系专业:海洋与地球学院_海洋生物技术学号:3112011015360

    A Research on the Supply Chain Management Mechanism of Mobile Phone Industrial Clusters

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    自“供应链竞争”概念提出后,已经在诸多行业成为企业竞争的重要模式。近年来,智能手机与移动互联网的快速发展,手机产业成为产值高、创新快、竞争强度高的高新技术产业之一;但手机产业具有市场快速变化的特点,对手机供应链管理创新提出更高要求。在管理实践中,深圳近年来出现数量众多的平台型供应链管理企业,该类行业企业在经营效果(行业增长率、获得资本市场关注)方面获得较大成功。区域经济中比较成熟的多个主导性产业集群,为供应链管理模式的创新发展提供了现实环境,出现以高度专业化分工和高强度社会化协作为基础的供应链管理平台。 现有从供应链管理视角来分析产业集群效用机制的理论研究,一般从生态、绿色视角等来进行阐述。...Abstract Across a wide array of industries, “supply chain competition”, since its conceptual advent, has grown into a vital mode of business competition. Recent years has brought rapid advances to smartphones and mobile internet, placing mobile phone industry among high-tech industries, which features high output value, fast innovation and intense competition. As a norm, volatile cellphone market...学位:工商管理硕士院系专业:管理学院_工商管理硕士(高级管理人员工商管理硕士)学号:X201515603

    The study of the influence of the rough extract of Er-Zhi-Wan to the RANKL/ RANK/OPG system of the ovariectomized osteoporosis rats

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    一、目的: 阐明OPG/RANKL/RANK系统与去卵巢骨质疏松之间的关系,以及二至丸粗提液干预去卵巢骨质疏松模型鼠对此系统重要节点的调控作用,从OPG/RANKL/RANK系统方面探讨二至丸治疗PMOP的可能作用机制。 二、方法: 1实验动物分组、造模、模型鉴定、药物干预及取材 在170只6月龄的SPF级雌性SD大鼠适应实验动物房环境的3天后,抽签随机分成去势组130只与假手术组40只。取2%戊巴比妥钠对实验大鼠作腹腔内注射麻醉(40mg/kg),在腹部正中部位作切口,去势组大鼠进行双侧卵巢结扎切除术,假手术组只未进行卵巢结扎切除术,其他操作步骤均与假手术组相同。术后12周,在去势组...1.Objective The main objective of this research was to specify the concern between osteoporosis of ovariectomized SD rats and the OPG/RANKL/RANK system, and discover the mechanism of Er-Zhi-Wan defending the postmenopausal osteoporosis from the perspective of the OPG/RANKL/RANK system. 2. Methods 2.1 Experimental animal group, building model, model identification, drug intervention and drawing ...学位:医学硕士院系专业:医学院_外科学学号:2452014115354

    Electrochemically shape-controlled formation of concave AuPd alloy nanoparticles on ITO substrate

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    运用电化学方波电位法, 在氧化铟锡(ITO)透明导电膜玻璃基底上实现AuPd纳米粒子的形状控制合成. 当固定方波下限电位0.30 V,; 上限电位分别为0.64和0.70 V时, 分别制备出内凹三八面体(TOH)和内凹六八面体(HOH) AuPd合金纳米粒子.; 运用扫描电镜(SEM)、X射线能量散射谱(EDX)和电化学循环伏安法表征所制备的纳米粒子, 结果表明所制备的AuPd纳米粒子在ITO上分散均匀,; 具有清晰的内凹三八面体和内凹六八面体的形状, Au:Pd元素比均接近3:1. 但由于Au比Pd的表面自由能低,; 导致Au在AuPd合金纳米粒子表面富集.发现从合成的TOH AuPd合金纳米粒子出发, 对其施加下限电位0.30 V、上限电位0.70; V的方波电位处理, 可实现由TOH向HOH形状转变; 延长方波电位处理时间仅改变AuPd合金纳米粒子的尺寸, 但HOH形状保持不变.Shape-control of AuPd alloy nanoparticles (AuPd NPs) substrated on; indium-tin oxide (ITO) was successfully achieved, for the first time, by; using electrochemical square-wave-potential (SWP) method. Concave; trisoctahedral AuPd alloy NPs (TOH AuPd NPs) and concave hexoctahedral; AuPd alloy NPs (HOH AuPd NPs) were prepared under SWP conditions with; lower potential of 0.3 V while different upper potentials of 0.64 and; 0.70 V, respectively. Different techniques including SEM, EDX and; electrochemical cyclic voltammetry were employed to characterize the; morphology and composition of AuPd alloy NPs. The results demonstrated; that the as-prepared TOH AuPd NPs and HOH AuPd NPs are uniform in shape; of correspondingly concave TOH and concave HOH, and are well dispersed; on the ITO substrate. The composition in terms of and Au:Pd atomic ratio; of both TOH and HOH AuPd alloy NPs is determined by EDX around 3:1.; However, a surface enrichment of Au on the AuPd NPs was observed, and is; ascribed to the lower surface energy of Au in comparison with that of; Pd. It has been found that, starting from the as-synthesized TOH AuPd; NPs, shape transformation from TOH to HOH can be accomplished by; applying a treatment of square wave with lower potential of 0.3 V and; upper potential of 0.7 V. Prolonging the treatment time results in; increasing the size of AuPd NPs, while the HOH shape is preserved.国家自然科学基

    Design and Implementation of Underground Mine Personnel Locating System

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    随着我国经济快速发展,对能源的需求进一步加大。煤矿资源在我国能源格局中占主导地位,对我国有着重要的战略意义,但是传统的煤矿生产方式不但生产效率低而且安全问题严重。煤矿事故的发生,往往会造成重大的人员伤亡和经济损失,在事故发生后没有可靠的手段能及时统计井下人员的数量和所在位置,浪费的大量的救援时间和救援资金。为利用信息自动化监测、监控技术,改造传统产业,建设信息化、现代化矿井,国家出台相关政策推动煤矿企业的安全监管以及信息自动化升级。这对提升企业安全生产、经营管理水平,经济效益,企业核心竞争力都有深远的意义和积极的作用。 近几年来国家一直对煤矿的安全生产十分重视,同时为了加强监管力度,要求各级...With China's rapid economic development, to further increase the demand for energy. Coal resources in China's energy structure dominates the country has important strategic significance, but the traditional way of coal mine production safety is not only productive but also a serious problem. Coal mine accidents often result in significant casualties and economic losses, after the accident there is...学位:工程硕士院系专业:软件学院_工程硕士(软件工程)学号:X201123053

    The Scared and the Profane: Dujie Ritual of Landian Yao

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    蓝靛瑶族是瑶族的一个支系,自称“门”、“金门”,蓝靛瑶生活在大山深处的人。度戒仪式,蓝靛瑶称为“zaisei”,或过法,或打斋,是蓝靛瑶生命中最重要的仪式,把蓝靛瑶少年成为合格的、完整的蓝靛瑶男子,把蓝靛瑶社会最隆重的仪式。如果要真正弄清楚蓝靛瑶社会的全貌,就必须从研究度戒仪式开始。 本文以蓝靛瑶的度戒仪式为主题进行研究,并把度戒仪式放在整个社会背景下来研究。本文首次详细地记载了度戒仪式,留下了珍贵的文本。笔者在中越边境的蓝靛瑶村落进行了十二个月的田野工作,进行了全方位的参与式观察,我也由开始的“他者”,渐渐进入蓝靛瑶的社会生活,在长时间的田野工作中逐渐领略到蓝靛瑶的社会文化,最终理解蓝靛瑶...Landian Yao is a branch of the Yao people, claiming to be “men” or “jinmen”, who live in the depths of the mountains. Dujie ritual of Landian Yao, which is called “zaisei”, “guofa” or “dazhai” , is the most important ritual in the life of Landian Yao; This ritual switches teenagers to qualified, full Landian Yao adult men, and it is the most solemn ritual in Yao society. If you want to truly figur...学位:法学博士院系专业:人类学研究所_民族学学号:1062010015382

    Bouc-Wen-Baber-Noor i滞回模型的参数敏感性分析

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    本文以单自由度Bouc-Wen-Baber-Noori(BWBN)弹塑性体系为研究对象,利用MATLAB求解地震荷载作用下的弹塑性时程响应,在BWBN模型滞回参数的取值区间内,通过拉丁超立方抽样,研究了各种滞回参数对单自由度体系动力时程响应(最大弹塑性位移、最大速度、非线性滞回位移和累积滞回耗能)的敏感性。研究结果表明BWBN单自由度体系的弹塑性动力时程响应对结构屈服前后的刚度比α,刚度退化参数δη,捏缩强度系数q具有较大敏感性。国家青年自然科学基金项目(51908478)福建省教育厅中青年教师教育科研项目(JAT170005)厦门市交通基础设施智能管养工程技术研究中心开放基金(TCIMI201808

    跨界民族的学术史扫描:概念、分类和研究内容

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    20世纪30年代至40年代,一些学者开始以“边政学“为研究核心,到今天学者以“跨界民族“为研究内容,概念和研究重点都有很大变化。本文对跨界民族进行全方位的学术回顾,具体从概念、分类和研究内容三个方面进行梳理,希望从中能发现前辈关于跨界民族研究的得失和跨界民族研究的未来走向
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