An investigation of electromagnetic wave propagation in plasma by shock tube

This paper presents the electromagnetic wave propagation characteristics in plasma and the attenuation coefficients of the microwave in terms of the parameters n(e), v, w, L, w(b). The phi800 mm high temperature shock tube has been used to produce a uniform plasma. In order to get the attenuation of the electromagnetic wave through the plasma behind a shock wave, the microwave transmission has been used to measure the relative change of the wave power. The working frequency is f = (2 similar to 35) GHz (w = 2pif, wave length lambda = 15 cm similar to 8 mm). The electron density in the plasma is n(e) = (3 x 10(10) similar to 1 x 10(14)) cm(-3). The collision frequency v = (1 x 10(8) similar to 6 x 10(10)) Hz. The thickness of the plasma layer L = (2 similar to 80) cm. The electron circular frequency w(b) = eB(0)/m(e), magnetic flux density B-0 = (0 similar to 0.84) T. The experimental results show that when the plasma layer is thick (such as L/lambda greater than or equal to 10), the correlation between the attenuation coefficients of the electromagnetic waves and the parameters n(e), v, w, L determined from the measurements are in good agreement with the theoretical predictions of electromagnetic wave propagations in the uniform infinite plasma. When the plasma layer is thin (such as when both L and lambda are of the same order), the theoretical results are only in a qualitative agreement with the experimental observations in the present parameter range, but the formula of the electromagnetic wave propagation theory in an uniform infinite plasma can not be used for quantitative computations of the correlation between the attenuation coefficients and the parameters n(e), v, w, L. In fact, if w < w(p), v(2) much less than w(2), the power attenuations K of the electromagnetic waves obtained from the measurements in the thin-layer plasma are much smaller than those of the theoretical predictions. On the other hand, if w > w(p), v(2) much less than w(2) (just v approximate to f), the measurements are much larger than the theoretical results. Also, we have measured the electromagnetic wave power attenuation value under the magnetic field and without a magnetic field. The result indicates that the value measured under the magnetic field shows a distinct improvement.

制备工艺条件对薄膜微结构的影响

用不同的方法在石英玻璃，YAG晶体，K9玻璃和LiNbO3晶体等几种衬底上制备了ZrO2，HfO2和TiO2薄膜。HfO2薄膜利用电子束蒸发（EB）、离子束辅助（IAD）和双束离子束溅射（DIBS）三种方法沉积。对其中的一些样品进行了不同温度下的退火处理，对所有的样品进行X射线衍射（XRD）测试，以获得不同条件下得到的薄膜的晶相及晶粒尺寸等的微结构参数。实验结果表明，薄膜的晶相结构以及晶粒尺寸强烈地依赖于沉积过程的各种技术参数，如衬底的种类、沉积温度、沉积方法和退火温度。利用薄膜表面扩散以及薄膜成核长大热

薄膜材料对TiO2基薄膜激光损伤阈值的影响

abstract {The optical property, structure, surface properties (roughness and defect density) and laser-induced damage threshold (LIDT) of TiO₂ films deposited by electronic beam (EB) evaporation of TiO₂ (rutile), TiO₂ (anatase) and TiO₂ + Ta₂O₅ composite materials are comparatively studied. All films show the polycrystalline anatase TiO₂ structure. The loose sintering state and phase transformation during evaporating TiO₂ anatase slice lead to the high surface defect density, roughness and extinction coefficient, and low LIDT of films. The TiO₂ + Ta₂O₅ composite films have the lowest extinction coefficient and the highest LIDT among all samples investigated. Guidance of selecting materials for high LIDT laser mirrors is given.}

Comparison of TiO2 and ZrO2 films deposited by electron-beam evaporation and by sol-gel process

TiO2 and ZrO2 films are deposited by electron-beam (EB) evaporation and by sol-gel process. The film properties are characterized by visible and Fourier-transform infrared spectrometry, x-ray diffraction analysis, surface roughness measure, absorption and laser-induced damage threshold (LIDT) test. It is found that the sol-gel Elms have lower refractive index, packing density and roughness than EB deposited films due to their amorphous structure and high OH group concentration in the film. The high LIDT of sol-gel films is mainly due to their amorphous and porous structure, and low absorption. LIDT of EB deposited film is considerably affected by defects in the Elm, and LIDT of sol-gel deposited film is mainly effected by residual organic impurities and solvent trapped in the film.

Influence of deposition conditions on the microstructure of oxides thin films

Thin films of ZrO2, HfO2 and TiO2 were deposited on kinds of substrates by electron beam evaporation (EB), ion assisted deposition (IAD) and dual ion beam sputtering (DIBS). Then some of them were annealed at different temperatures. X-ray diffraction (XRD) was applied to determine the crystalline phase and the grain size of these films, and the results revealed that their microstructures strongly depended on the deposition conditions such as substrate, deposition temperature, deposition method and annealing temperature. Theory of crystal growth and migratory diffusion were applied to explain the difference of crystalline structures between these thin films deposited and treated under various conditions. (c) 2007 Elsevier B.V. All rights reserved.

宁蒗保种黑头山羊血液蛋白多态性研究

　采用水平板淀粉胶电泳技术对来自云南保种宁蒗黑头山羊的31 个个 体的39 个基因座位的血液同功酶进行了分析, 结果得到A KP, CES- I, ESD, GO I, M E 和N P 共6 个座位出现多态, 多态座位A KPO , CES- I2, ESDB , GO IA ,M EB 和 N PB 的基因频率较高; 多态座位百分比P = 0. 1538, 平均杂合度H = 0. 0679 ± 0. 0241。本研究首次得到了该羊的遗传多样性特征, 为该羊的保种和利用提供了基础 数据。

肝细胞生长因子促进猕猴胚胎干细胞来源的神经前体细胞的增殖

肝细胞生长因子（HGF）是一个多效应因子，在神经系统中具有重要作用， 但是对于HGF在早期神经系统发育（特别是哺乳动物）中的具体作用还不明确， 这方面的研究还很少。我们早前的研究发现采用HGF和G5 supplement结合EB法 可诱导猕猴胚胎干细胞（rESCs）定向分化成高纯度（88.3± 8.1%）的可移植的 神经前体细胞，但是HGF在整个分化过程中的具体作用及HGF与其它因子的关 系还不清楚。 本研究改进先前研究体系，用单层培养诱导体系代替EB法诱导体系，用bFGF 代替G5 supplement。即采用单层培养的方式，分别用同时含bFGF和HGF、只含 HGF或bFGF以及两者都没有添加的成分确定的分化液诱导rESCs向神经细胞分 化。并检测HGF对rESCs来源的神经前体细胞的增殖速度的影响，旨在进一步研 究HGF在整个分化过程中的具体作用及HGF与bFGF的关系。主要结论如下：1） 采用单层培养法，同时添加HGF和bFGF可诱导rESCs在两周内定向分化为高纯度 （>85%）的神经前体细胞，从而建立了一种更为简单的诱导rESCs分化成神经细 胞的方法；2）不同分化条件下都得到了相似比例的神经前体细胞，表明外源性 的HGF在诱导rESC向神经前体细胞转变的过程中对于神经细胞命运的决定并不 起作用；3）HGF能有效地促进rESCs来源的神经前体细胞的增殖，并且与bFGF 具有协同作用。

体外分步诱导猕猴胚胎干细胞为肝细胞

采用分阶段诱导方法模拟肝细胞体内发育,建立体外诱导猕猴胚胎干细胞(rhesus monkey embryonic stem cells,rESCs)分化为成熟肝细胞的体系,对研究以ES细胞为基础的临床替代治疗人类晚期肝脏疾病具有重要的意义.将rESCs团块在含有10%FBS的DMEM培养基中悬浮培养11d,形成含有早期内胚层细胞的拟胚体(embryonic bodies,EB)并开始表达早期肝细胞的部分基因或蛋白,将11日龄EB接种至包被有ECM的组织培养皿,分阶段加入aFGF、BMP-4及OSM.经aFGF和BMP-4诱导7～10d后,分化细胞形态变为具有双核的多角形细胞,表达早期和中期肝细胞特异性的蛋白(AFP、ALB及CK18)和基因(AFP、ALB、APOH,G-6-P及TAT),并具有储存糖原的功能.撤除aFGF和BMP-4,添加OSM继续诱导7～10 d,分化的细胞表达成熟肝细胞所特有基因CYP1B1和ADH1C,并具有摄取靛青绿的能力.

肝细胞生长因子促进猕猴胚胎干细胞来源的神经前体细胞的增殖

肝细胞牛长因子(hepatoeyte growth factor,HGF)足一个多效应因子,在神经系统中具有重要作用.早前的研究发现采用HGF和G5 supplement结合EB(embryoid body)法可诱导猕猴胍胎干细胞(rhesus embryonic stem cells,rESCs)定向分化成高纯度的可移植的神经前体细胞(neural progenitors),但对于HGF在整个诱导分化过程中的具体作用及机制还不清楚.本研究改进先前研究体系,采用单层培养法,同时添加HGF和bFGF(basic fibroblast growth factor,碱性成纤维细胞生长因子)诱导rESCs在两周内定向分化为高纯度[(81.66±4.37)%]的神经前体细胞,并且单独添加HGF或bFGF以及两者都没有添加的条件下也得到了相似比例的神经前体细胞,表明外源性的HGF在诱导rESCs向神经前体细胞转变的过程中对十神经细胞命运的决定并不起作用;进一步研究发现HGF能有效地促进神经前体细胞的增殖,并且与bFGF具有协同作用.总之,本研究建立了一种更为简单的诱导rESCs分化成神经细胞的方法,发现外源性的HGF在rESCs向神经前体细胞分化的过程中并没有神经诱导的作用,但能与bFGF协同作用促进rESCs来源的神经前体细胞的增殖.

饲养层FGF2表达量对猕猴胚胎干细胞自我更新及多能性的影响

用转基因和RNA干扰(RNAi)法建立5组不同成纤维细胞生长因子-2(fibroblast growth factor-2,FGF2)表达量的猕猴耳部皮肤成纤维细胞(MESF)系:过表达FGF2组(f1),过表达的阴性对照组(f2),FGF2 RNA干扰组(f3),RNA干扰的阴性对照组(f4)和未作任何处理的对照组(f5).5组MESF的FGF2表达量相对值为f1:f2:f3:f4:f5=4:2:1:2:2;c-fos,TGF-β1,INHBA,Gremlinl在f1中表达量上升,在f3中表达量下降;BMP4,TGF-β2在f1中表达量下降,在f3中表达量上升;表明内源FGF2能够作用于MESF的TGF-β信号通路,引起相关基因表达量的变化.用这砦细胞作为饲养层长期培养(10代)猕猴胚胎干细胞(RhESC),结果在f1上培养的RhESC增殖速度都比对照组快,并且c-fos,TGF-β1,INHBA,Gremlinl,Oct-4,Nanog,Sox2表达量均上升,BMP4表达下调;在f3上培养的RhESC增殖较慢,BMP4表达上调,c-fos,TGF-β1,INHBA,Gremlinl,Oct-4,Nanog,Sox2表达下调.5组MESF上培养的RhESC形成的EB均表达各胚层早期标记基因(marker),说明RhESC的多能性没有受到影响,但表达量有差异,f1上RhESC形成的EB所有marker都低表达.结果表明饲养层的FGF2含量不仅影响自身相关基凶的表达,还对RhESC的自我更新有一定的作用.

中国白裤瑶永生细胞库的建立

目的　建立和保存白裤瑶B 淋巴母细胞永生细胞株。方法　采用EB 病毒转化外周血B 淋巴细胞,同 时加环孢菌素A 法。结果　成功地建立了含有44 株永生细胞的白裤瑶永生细胞库。供血者身体健康,三代均为 白裤瑶。结论　建立永生细胞库,可永久保存白裤瑶特有的基因组,为民族起源、演进和遗传多样性的研究提供细 胞资源。

一种简易的人艾滋病毒( HIV21) 载量测定方法的建立与初步评价

　目的:建立一种简易的HIV21 感染者和艾滋病人血浆病毒载量测定的方法。方法:构建含保守的引物SK145P SK431 扩增靶序列的重组质粒pSPgag737 ,重组质粒体外转录产物经系列稀释得到HIV21 定量测定的外参照,在同样条件下以 引物SK145PSK431 对外参照和待测样品进行RT2PCR 扩增,用电泳图谱分析系统分析经EB 染色的扩增产物电泳图谱,作出外 参照的初始加入拷贝数与光强度的标准曲线,获得相应的回归方程,进而计算出待测样品的HIV21 病毒载量。结果:重组质粒 pSPaga737 经酶切和PCR 鉴定,确认含有引物SK145PSK431 的扩增靶序列,用重组质粒体外转录,得到了1～105 copies 的10 倍系 列稀释的外参照,外参照标准曲线有较好的线性关系( r = 0196) 。该方法的测定范围为5 ×102～5 ×107 拷贝Pml 血浆。对10 个样品进行3 次重复测定,平均变异系数较小( CV = 20 %) 。结论:所建立的HTV21 病毒载量定量测定方法,操作简单,价格 便宜,特异性好,同时有较好的可重复性。

贵州布依族淋巴母细胞永生细胞株的研究

的：建立和保存贵州布依族B淋巴母细胞株。方法：采用EB病毒转化外周血B淋巴细胞， 同时加环孢霉素A法。结果：建立了7株永生细胞，供血者身体健康且三代均为布依族。绪论：建立永生 细胞株可长期保存布依族独特的基因组，为民族起源、演进及遗传多样性等研究提供细胞资源。

几种珍稀灵长类淋巴细胞系的建立和保存

报道了携带EB病毒的B95-8细胞的细胞遗传学特征以及在实验条件下, 用EBV转化建立的几 种珍稀灵长类动物转化细胞系的生物学特征。图版1图1表1参5

抗新霉素基因对草鱼肾细胞的磷酸钙共沉淀转移

<正> 自1973年 Graham 和 Van der Eb 首次成功地应用 DNA-磷酸钙共沉淀法转化哺乳动物培养细胞以来,又提出了电脉冲法;显微注射法;磷脂载体法及细菌原生质体融合法等多种培养细胞基因转移方法。然而,目前的研究多局限于哺乳动物细胞,鱼类培养细胞方面的报道却很少。建立鱼类培养细胞基因转移的方