Development of Ba(Zn1/3Nb2/3)O3 and ZnNb2O6 Microwave Dielectric Ceramics for Wireless Technologies

摘要微波介质陶瓷是在微波频段（300MHz～3000GHz）使用的电子陶瓷，它主要应用于微波谐振器和滤波器。要求具有较高的电容率εr，高品质因子Q和可调节的谐振频率温度系数τf。本论文采用传统的固相法合成了Ba(Zn1/3Nb2/3)O3和ZnNb2O6陶瓷，研究了工艺因素、不同晶位取代对材料结构与介电性能的影响，并对介电极化和损耗机理进行了初步的探讨。本论文第三章优化Ba(Zn1/3Nb2/3)O3陶瓷的预烧、烧结条件，得到最佳工艺条件：预烧条件1200℃×4h和烧结条件1400℃×4h，其介电性能为：εr＝40.3，Q×f＝48671GHz和τf＝30.7ppm/℃；第四章采用Mg取代Zn...Abstract Microwave dielectric ceramics(MWDC) is a kind of electric ceramics for microwave resonators and filters which are applied in wireless communications, 300MHz～3000GHz. It is expected for MWDC to have high permittivity εr, high quality factor Q and adjustable temperature coefficient of resonant frequency τf. In this thesis, Ba(Zn1/3Nb2/3)O3 and ZnNb2O6 ceramics are prepared by convent...学位：工学硕士院系专业：化学化工学院材料科学系_材料学学号：20022500

The Research on the Business Model Innovation of the Commercial Wi-Fi Based on the Theory of Value Chain ——Company D as an Example

互联网的迅速发展使O2O的消费模式得到迅速普及，应用场景得到迅速扩张，O2O已经渗入我们生活的方方面面。特别是移动互联网的迅猛发展，使消费者O2O的行为习惯发生了很大变化，同时也给O2O企业与商家带来了更多挑战与机遇。目前，Wi-Fi运营国内外都没有明确的商业模式可供参考实践，现有管道收费模式与互联网收费模式相悖离，对商用Wi-Fi运营模式的创新需求迫切。 本文通过对相关理论及国内外文献的梳理，选取以价值链为研究视角，尝试对运营商商用Wi-Fi经营商业模式进行创新研究。根据此理论，将价值链价值要素分配与商业模式创新进行有机结合，提出基于价值链重构的商业模式创新；并结合对互联网免费模式的分析和...The rapid development of the Internet makes the online to offline (O2O) consumption patterns becoming popular. O2O has infiltrated into every aspect of our lives. Especially the rapid development of mobile Internet, consumers’ behavior has changed greatly. At the same time, it also brings more challenges and opportunities for O2O enterprises. At present, at home and abroad there has no clear busin...学位：工商管理硕士院系专业：管理学院高级经理教育中心（EMBA项目）_高级管理人员工商管理硕士(EMBA)学号：X201015607

A New Method of Designing Artificial Neutral Network Based on Genetic Algorithm

神经网络的设计主要集中在网络权值的选取和神经网络结构的确定两个方面 ,与遗传算法结合是目前研究发展的趋势 .本文与一般的基于遗传算法的神经网络设计相比 ,提出一个新型算子—— BP算子 ,并对神经网络的权值和结构同时优化 .仿真结果表明该算法结果比较理想 .Currently research on ANN(Artificial Neutral Network) is mainly focused on the initial weight and structure. It is a developing tendency to combine ANN with GA(Genetic Algorithm). Compared with general ANN design, this paper puts forward a new operator, BP operator, and optimizes the ANN's initial weights and structure at the same time. The result of the emulation is very reasonable

正确理解马克思恩格斯的科学社会主义理论

马克思恩格斯所阐述的科学社会主义同我们已经建成的社会主义的主要差别 ,不仅表现在一般的生产力发展水平上 ,还表现在不同的前提条件。前者的前提是 :资本主义私有制已经严重阻碍生产力的发展 ;商品、货币存在已经成为社会发展的障碍 ,成为多余之物 ;社会化大生产使整个社会事实上成为一个大工厂 ,全国性的计划经济不仅成为必要 ,而且成为必然。这些前提不是一般的生产力发展所能达到的 ,充分发展的网络经济有助于其实现。这一点 ,马恩没有预见到。所以 ,我们必须先脚踏实地建设初级的社会主义 ,并积极参与网络经济建设 ,才能创造条件去逐步实现马恩的社会主

Corporate Performance,Financial Risk and Timeliness of Annual Report:Evidence from Chinese Energy Listed Companies

以沪深两市能源类102家A股上市公司2004~2006年间306组观测值为对象,研究公司绩效、财务风险与信息披露及时性之间的关系。研究结果表明,公司绩效和年报披露及时性显著正相关;财务风险和年报披露及时性显著负相关;财务风险能通过公司绩效影响年报披露及时性;财务风险会对公司绩效和年报披露及时性的关系产生明显的扰动作用。Using the data of 102 Chinese energy listed companies in Shanghai and Shenzhen Stock Exchange during 2004 to 2006,the empirical study shows that: corporate performance has a significant positive correlation with timeliness of annual report;financial risk significantly positive correlates with timeliness of annual report;financial risk has a further influence on timeliness of annual report through corporate performance,which is an intermediary variable;financial risk also interferes the relationship between corporate performance and timeliness of annual report.西安交通大学校长基金资助项目(011222

Acoustic Emission Warning Signals Change Law Research during Deformation and Failure of Gassy Coal Rock

为提高矿井瓦斯突出灾害预测准确率,基于力学、声学理论,采用实验室试验方法,以标准煤试样为研究对象,对含瓦斯煤岩变形破裂过程声发射(AE)预警声信号变化规律进行研究。试验结果表明:围岩应力增大,煤岩破裂由低围岩应力的脆性破坏逐渐过渡到高围岩应力状态的塑性破坏,可根据声发射高幅信号提前预测煤岩破裂时刻。瓦斯的力学和非力学作用对煤岩体力学性质和变形特性的影响均随瓦斯压力的增加而变大。瓦斯压力越大,则煤岩破裂进程加快,积累的声发射能量迅速释放,高值振铃计数声发射信号覆盖时间区段变长,声发射信号能及时反映含瓦斯煤岩的不稳定性

细菌三型分泌系统输出蛋白分泌信号研究进展

自提出三型分泌系统的概念以来,相关分子机制的研究让人们对其有了更深入的了解。与依赖信号肽分泌途径形成鲜明对比的是,蛋白通过细菌三型分泌系统分泌或者转运时没有可识别的保守信号序列。近期对三型分泌蛋白的研究发现了多种可以引导其分泌的分泌信号。本文分别介绍了细菌三型分泌系统的种类,分泌系统分泌蛋白的种类,并着重阐述了分泌信号的分子特性及其机制,以期为新型抗菌药物的研发提供新的思路。国家自然科学基金(81473251,31370166,31741006);;厦门大学校长基金(20720160060

The Optical Design and Simulation of Modular LED Freeform Reflector Dipped Headlight

本文从汽车用前照灯国标gb25991—2010出发,在已知光源属性的前提下,利用rEfCAd设计了适用于高亮度白光lEd的自由曲面反射器,将多套反射系统组合成汽车前照灯,并通过TrACEPrO仿真模拟,分析各测试点、区域的照度值,其设计结果能较好地符合国标对近光的要求。该方法能更充分发挥lEd的优点,提高了光能利用率,且大大优化和节省了设计空间。In this paper,a kind of car Head lamp integrating freeform reflectors for bright white LED is presented.Complying with the National Standard GB25991—2010 and considering light source properties known,at first,the freeform reflector is designed with RefCAD,and then several reflector models are integrated into a car head lamp model.The illumination values of the test points and regions are simulated with Tracepro.The simulation results show that it meets the requirement of low beam-GB.This design takes the advantage of LED,increases the utilization of optical energy,and greatly optimizes and saves the design space.福建省重大科技项目资助(2006H0092

闽南地区TT病毒的变异及经输血传播的初步证据

TT virus(TTV)DNA was tested by nested-PCR from sera of hepatitis patients and volunteer blood donors in Minnan area. The amplified segment was a 189 base pair region in TTV ORF2. A total of six sequences were obtained from three non-A to G hepatits patients and two from volunteer blood donors. The sequences were found to be with 82.9% to 99.3% homology to TTV Japanese strain and Chinese strain. The divergence of sequence in these six segments varied from 0.7% to 17.1%, which indicated that the TTV had been existing for a long time in this area. In the serum of a non-A to G hepatitis patient who was negative for TTV DNA in the 14th day of disease course turned to be positive in the 30th day, two TTV sequences were obtained which showed 92.1% nucleotide homology. It indicated that different TTV strains can co exist in the same person. This patient's blood had been transfused ten times between the collection of his TTV negative sample and his positive serum sample. Seven of the blood donors were traced an..

FIBER-REINFORCED COPPER MATRIX COMPOSITES FABRICATED BY ELECTROCHEMICAL INFILTRATION TECHNIQUE

［中文文摘］基于电化学浸渗技术(ECI)在室温下制备了连续铜纤维、碳纤维和玻璃纤维增强铜基复合材料。实验结果表明,在本实验工艺条件下可获得致密的纤维/Cu基复合材料,并具有优良的力学性能。复合材料的断口形貌及显微结构的SEM观察表明,纤维与铜基体之间的界面结合良好,纤维不受任何损伤。证实了ECI在室温下快速制备纤维增强金属基复合材料的可行性。［英文文摘］Continuous-fiber-reinforced Cu matrix composites were fabricated based on the electrochemical infiltration technique (ECI). The experimental results show that the dense fiber/Cu composites have been obtained on the present condition, which possess good mechanical properties. The fracture surface morphology and microstructures of the composites have been observed by SEM. It is indicated that the interfacial bond between fibers and Cu matrix is very well and the fibers do not have any damage. The ECI is　feasible to prepare rapidly fiber reinforced metal matrix composites at room temperature