2型猪链球菌中国强毒株05ZYH33 ofs N-片段基因敲除株的构建

通过生物信息学分析2型猪链球菌（Streptococcus suis serotype 2,S．suis2）中国强毒株05ZYH33的基凶组,预测并发现猪链球菌血清浑浊因子（Opacityfactor of S．suis,OFS）的编码基因ofs.为了构建ofsN-末端片段ofs^37-683的基因敲除株,首先构建中间为壮观霉素抗性基因,两侧为ofs^37-683上、下游同源序列的基因敲除质粒,并对该质粒进行PCR和酶切鉴定．根据同源重组的原理,通过电转化方法筛选得到ofs^37-683基因敲除株．PCR、测序和RT—PCR分析结果均显示ofs^37-683已完全被壮观霉素抗性基因替代,证实ofs^37-683基因敲除株构建成功．该敲除株的获得为进一步研究ofs在猪链球菌2型致病机制中的作用奠定基础．     

超导约瑟夫森结微波单光子量子态测量的研究

超导状态下用约瑟夫森结构成的微波单光子探测电路测量量子系统状态,定量分析并探讨约瑟夫森结的量子特征,作为一种新兴的固态量子位状态测量系统,对未来的量子信息理论与量子位的研究有着显著的帮助.     

2-(1-萘甲基)-3(2-四氢呋喃基)丙酸N,N-二乙氨基乙酯草酸盐的新法合成

改进２－（１－萘甲基）－３－（２－四氢呋喃基）丙酸Ｎ,Ｎ－二乙氨基乙酯草酸盐（Ⅵ）合成方法．方法在１－氯甲基萘和四氢糠基丙二酸二乙酯（Ⅰ）的烷基化反应中使用ＮａＨ／ＤＭＦ为催化剂;在２－（１－萘甲基）－３－（２－四氢呋喃基）丙酸（Ⅳ）与２－氯乙基－Ｎ,Ｎ－二乙基胺的酯化反应中加入相转移催化剂;在２－（１－萘甲基）－３－（２－四氢呋基）丙酸Ｎ,Ｎ二乙氨基乙酯（Ⅴ）与草酸成盐中,直接使用二水合草酸替代脱水草酸．结果烷基化反应产率提高到７５％,反应时间缩短到２ｈ;酯化反应产率从文献报道的７２％提高到９２％;二水合草酸成盐效果与脱水草酸相同．结论该方法较已有的合成方法产率有较大提高且操作简便,有较好的工业化前景．     

基于组合赋权法与欧几里德测度的公路飞机跑道选址优化

为解决公路飞机跑道选址方案优选问题,通过深入探讨和完善公路飞机跑道选址的评价指标,综合考虑适用、技术、经济和环保4个方面的要求,建立了公路飞机跑道选址的评价指标体系。结合熵值客观赋权法和改进层次分析主观赋权法,分别确定各评价指标权重初值,运用线性加权组合法将两者加以组合最终确定评价指标的权重值。进而提出以欧几里德距离为测度,比较各方案距离理想点的相对接近度,建立公路飞机跑道选址的多指标决策优化模型,对公路飞机跑道备选方案进行优选。结合公路飞机跑道选址实例,验证了公路飞机跑道选址的多指标决策优化模型的有效性和实用性。     

Undoped semi-insulating indium phosphide (InP) and its applications

During the past several years, the research and development of InP material has made great progress due to serving as the substrate for most optoelectronic devices operating at the communications wavelength of 1.31 and 1.55 μm. At present, InP has become an important semiconductor material together with Si and GaAs. When compared to GaAs, InP has higher electron velocity, higher radiation hardness and better heat-conducting property. The advantage of InP crystal material allows higher frequency operation and lower power requirements. Therefore, InP is widely being used for the manufacture of microwave devices, high-frequency devices and optoelectronic integrated circuits (OEICs) which are indispensable for wireless technology, satellite communications^[1—3]. Although n-type and p-type InP can meet actual needs, semi-insulating InP substrates remain to be improved due to their poor uniformity and consistency. For this reason, several possible approaches have been reported to the preparation of SI InP by wafer annealing under different conditions^[4—9].     

A study on nano-sized NiO electrodes doping with C and Co prepared by electrochemical deposition-sintering processes and their capacitance performance

In the present work, it was studied that nanoosized NiO electrodes doping with C and Co were prepared by electrochemical deposition in an ethanol solution containing nickel nitrate and cobalt nitrate and sintering processes. The capacitance performance of such electrodes was also studied. The results reveal that samples obtained by electrochemical deposition first on a porous nickel cathode in an ethanol solution contain 0.5 mol/L nitrates, in which Ni(NO3)2 and Co(NO3)2 were mixed in a molar proportion of 8 : 2. After sintering at 300℃ for 2 h, they exhibited the best performance. XRD analysis illustrates that the essential phase of the product is NiO doping with certain content of C and Co. The particles of product imaged a spherical morphology with sizes of 20---30 nm in diameter, and with an average crystal size of 4--5 nm. The capacitance measurement of the simulating C/NiO capacitors indicates that a single electrode can reach as high as 410.0 F/g, and still maintain the value of 323 F/g after 30 recycles showed as a stabilized value with increasing recycles, when it was discharged at a current of 5 mA.     

虚拟维修训练系统发展综述及其关键技术探讨

文章述说了虚拟维修训练系统的意义、原理、运用现状、结构级成和关键技术,着重探讨了基于知识和模糊网络的虚拟现实技术在维修训练领域中的运用,对系统中的效果评估子系统检出了一个实用的模糊子集。     

一种新的导音辅助OFDM符号定时算法

提出的算法仅利用一个导音符号来进行符号定时恢复，适合与突发模式的正交频分多路(OFDM)信号，而且OFDM帧同步和符号同步能一次完成，简化同步实现的复杂度，算法采用自相关计算，对载波频率偏移具有较强的鲁棒性。仿真结果表明，即使在频率选择性衰落信道中，提出的算法也能快速地实现符号定时同步。     

草莓的组织培养研究

采用组织培养方法,快速繁殖草莓,经研究认为最佳诱芽培养基是:MS+6-BA 0.5mg/l+NAA 0.01mg/l,最适宜于接种的处植体为:茎尖>叶柄>叶。而在最佳诱芽培养基 MS+6-BA 0.5mg/l+NAA 0.01mg/l 下能够很好地进行继代增殖。能大量诱根的培养基是 MS 基本培养基和 MS+IBAlmg/l。     

学校体育改革与终身体育发展关系研究

通过分析终身体育结构和终身体育习惯形成的基本过程,进一步探讨在当今学校体育教学改革形势下,如何发挥学校体育教学的关键作用,才能更好地使学校体育切实有效地为终身体育服务等方面进行讨论.从而深入研究学校体育改革的定向问题,处理好与终身体育发展关系,推动终身体育的发展和实现.