六硼化镧材料的化学腐蚀工艺研究

目前,阴极发射体材料多存在逸出功大,可靠性及均匀性低,发射性能低、不能自动调节活性物质更替的速度等方面的问题．与之相比,六硼化镧既具有可恒定地维持一个活性阴极表面．同时具有高导电率和良好的热稳定性及化学稳定性,是作为阴极发射体的理想材料．而对六硼化镧的化学腐蚀在以其为阴极的阴极发射体制备工艺中起着至关重要的作用,本文简述了对材料的化学腐蚀工艺的初步研究,并得到了图形化的六硼化镧表面。     

含均二苯乙烯荧光探针的合成及其对金属离子的识别研究

通过Wittig-Horner反应合成了两个含有均二苯乙烯发色团, 一端为N,N-双(2-乙酰氧乙基)氨基受体, 另一端分别为N,N-二甲氨基(DMDE)或N,N-二苯氨基(DPDE)的荧光探针分子. 进行了NMR和MS表征. 测试了加入不同金属离子时探针分子的吸收和荧光光谱变化. 加入Ag+和Zn2+, DMDE在420 nm处出现强的荧光峰, 在600 nm的荧光峰先增强后减弱, 认为发生了分子间的荧光共振能量转移. 而DPDE在加入Ag+和Zn2+, 420 nm处无荧光发射, 600 nm处的荧光红移并减弱.     

淄博农村CATV网络采用光机直接覆盖用户方式的探讨与实践

本文阐述了淄博市有线电视网络农村（包括城区平房）部分建设与改造的思路：采用光接收机直接覆盖用户。取消电缆放大器．每光接收机覆盖80户左右。     

关于淄博CATV网络升级改造的规划与建设

淄博市有线电视网络的建设始于90年代初期，从1996年起有线电视开始全市联网。由于当时1550nm光传输设备尚未达到商用化水平，1310nm光设备比较成熟，大部分使用1310nm光发射机实现区域联网，同时由于当时光传输设备及光缆价格较高，从经济适用性考虑，每个光节点覆盖用户一般在2000—5000户；光接收机以下使用干线     

Investigation on the fabrication of the 3rd harmonic superconducting cavity for the SSRF storage ring

A third harmonic superconducting niobium cavity has been proposed for installation in the Shanghai Synchrotron Radiation Facility （SSRF） storage ring to improve the Touschek lifetime. In order to investigate the feasibility of the superconducting cavity fabrication indigenously and the possibility to master the fabrica tion techniques, cavities were fabricated from copper and niobium sheets by deep drawing and electron-beam welding, and a series of measurements, such as resonant frequency, shape dimensions and wall thickness, were carried out during this process. After analysis of various problems existing in the fabrication process, technique improvements were proposed, and finally the precise shape as designed and resonant frequency within 1.2 MHz were achieved for the new completed cavities. In addition, full annealing was finally proved to be a good cure for niobium sheets＇ tearing up during deep drawing. By fabricating niobium cavities successfully, some problems to the next step were cleared. This paper introduces the process of cavity fabrication and its technique improvements towards forming, and the initial vertical test result of niobium cavity is also presented.     

含二氯丙烯的亚硫酸酯类化合物的合成及杀虫活性测定

为了寻找和发现高效、广谱、低毒、低生态风险并与现有杀虫剂无交互抗性的新型杀虫剂,以对苯二酚为原料,经多步反应制得11个新型含二氯丙烯的亚硫酸酯类化合物,其结构经核磁共振氢谱、碳谱、元素分析确证.室内生物活性测定结果表明,目标化合物对小菜蛾(Plutella xylostella L.)具有较好的杀虫活性,其中3-[2,6-二氯-4-(3,3-二氯烯丙氧基)苯氧基]丙基正己基亚硫酸酯(7h)在10 mg/L下对小菜蛾的致死率可达到80%,优于对照药三氟甲吡醚.     

具有二维光子带隙结构的太赫兹谐振腔的谐振特性

采用数值计算方法,模拟了具有二维光子带隙结构的太赫兹频段谐振腔的谐振模式场分布,计算了这种谐振腔的品质因数,详细分析了光子晶体结构、缺陷腔几何参量对谐振特性的影响.计算得到频率落在光子晶体禁带内的单一、高阶谐振模式,且缺陷腔横向尺寸越大,谐振模式的阶数越高.这种谐振腔具有很高的品质因数,腔体的纵向长度对品质因数的影响较大.     

高集成电力电子设备外壳屏蔽效能评估

采用HFSS仿真分析了某高集成电力电子设备外壳的屏蔽效能,并按照IEC 61587-3:2006要求进行了测试对比验证,确认了屏蔽效能仿真评估手段的准确性及可行性.结果表明:对该电力电子设备而言,其外壳板厚、材质、缝隙参数的改变不能显著提高设备外壳的屏蔽效能,外壳背部、前部的大量开孔,是造成屏蔽效能偏低的主要原因.设备外壳屏蔽效能改善应从优化面板结构着手.     

THE GLOBAL EXISTENCE OF STRONG SOLUTIONS TO THE 3D COMPRESSIBLE ISOTHERMAL NAVIER-STOKES EQUATIONS

This paper concerns the global existence of strong solutions to the 3 D compressible isothermal Navier-Stokes equations with a vacuum at infinity.Based on the special structure of the Zlotnik inequality,the time uniform upper bounds for density are established through some time-dependant a priori estimates under the assumption that the total mass is suitably small.