45 resultados para Behn, Aphra, 1640-1689.

em Chinese Academy of Sciences Institutional Repositories Grid Portal


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1689-nm diode lasers used in medical apparatus have been fabricated and characterized. The lasers had pnpn InP current confinement structure, and the active region consisted of 5 pairs of InGaAs quantum wells and InGaAsP barriers. Stripe width and cavity length of the laser were 1.8 and 300 pm, respectively. After being cavity coated. and transistor outline (TO) packaged, the lasers showed high performance in practice. The threshold current was about 13 +/- 4 mA, the operation current and the lasing spectrum were about 58 6 mA and 1689 +/- 6 nm at 6-mW output power, respectively. Moreover, the maximum output power of the lasers was above 20 mW.

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文章建立并求解了不同线性组合边界条件下的煤层气井不定常渗流模型,得到了井底压力和压力导数的理论曲线,以及压力场分布图.在不稳定流动的早期,压力和压力导数曲线都是斜率为1的直线段.当流体流动进入稳定流动状态时,在压力导数曲线上出现一个值为0.5的水平直线段.在理论曲线的晚期,理论曲线与边界性质存在密切关系.对于全封闭煤层气藏,所有压力和压力导数曲线是斜率为1的直线段.对于存在定压边界煤层气藏,压力双对数曲线的晚期是水平直线段,压力导数双对数曲线的晚期都是急剧下掉的曲线.但是混合边界的压力导数存在上翘现象,上翘程度和早晚与封闭边界的数目多少以及距离大小有关.压力场中,在靠近封闭边界的等压线垂直于边界,在靠近定压边界的等压线平行于边界.在邻近定压和封闭边界交合处,定压边界起主导作用.所得到的理论曲线可以直接应用于煤层气田的试井测试资料分析,压力场分布图对了解煤层气藏的开发状况有积极的意义.

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The interaction of arbitrarily distributed penny-shaped cracks in three-dimensional solids is analyzed in this paper. Using oblate spheroidal coordinates and displacement functions, an analytic method is developed in which the opening and the sliding displacements on each crack surface are taken as the basic unknown functions. The basic unknown functions can be expanded in series of Legendre polynomials with unknown coefficients. Based on superposition technique, a set of governing equations for the unknown coefficients are formulated from the traction free conditions on each crack surface. The boundary collocation procedure and the average method for crack-surface tractions are used for solving the governing equations. The solution can be obtained for quite closely located cracks. Numerical examples are given for several crack problems. By comparing the present results with other existing results, one can conclude that the present method provides a direct and efficient approach to deal with three-dimensional solids containing multiple cracks.

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The influence of threshold stress on the estimation of the Weibull statistics is discussed in terms of the Akaike information criterion. Numerical simulations show that, if sample data are limited in number and threshold stress is not too large, the two-parameter Weibull distribution is still a preferred choice. For example, the fit of strength data of glass and ceramics to the two- and three-parameter Weibull distributions is compared.

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A method using two prisms for measurement of small dynamic angles is proposed in which the measurement is based on a simple tangent equation and a phase-modulating interferometer with a laser diode to measure dynamic optical path differences with higher accuracy. Owing to the simple tangent equation, the symmetry requirement on the two prisms in the optical configuration is eliminated, and easy measurement of the separations between two parallel beams with a position-sensitive detector is achieved. Small-dynamic-angle measurements are experimentally demonstrated with high accuracy. (C) 2007 Society of Photo-Optical Instrumentation Engineers.

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葡萄属(Vitis.L.)植物隶属于葡萄科(Vitaceae),主要分布于北温带,最南可以分布到南美洲的委内瑞拉和亚洲的越南以及印度北部。本文通过对该属分类研究历史的回顾,认为该属存在的问题主要表现在如下几个方面: 1)葡萄属自1753 年由Carl Linne创立以来,虽经planchon于1887年做了修订,但属的范围仍需进一步界定;2)在Planchon之后的100多年中未见有一全面的分类学修订工作,出现在该属的800多个名称需要考证;3)对一些广布种的变异认识不足,导致了大量可疑种。针对这些问题本文进行了如下几个方面的工作: l、形态学:通过大量的野外工作和标本观察,对该属植物的主要性状做了分析,讨论了这些性状状态在葡萄属中的变异规律及演化趋势,将灌木状习性、退化的卷须以及不裂的叶片视为进化的性状。 2、细胞学:利用前人对葡萄属(Vitis.L.)染色体数目的统计及一些杂交实验分析的结果,结合形态学等方面的特征分析,认为在葡萄科,染色体基数X=10为原始的,而x=19则为衍生的。葡萄属的染色体基数xl9(2n=38),多倍体较少见;麝香葡萄属[Muscadinia (Planch.) Sma11]的染色体基数为x=10 (2n=20).与蛇葡萄属、酸蔹藤属和爬山虎属的一致。葡萄属和麝香葡萄属间的杂种是不育的。 3、孢粉学:对葡萄属32种5变种及麝香葡萄属[Muscadinia (Planch.) Sma11]1种的花粉外壁做扫描电镜观察,结果发现花粉外壁雕纹在这两属间和葡萄属内变异较小,对区分属以及属下种上类群意义不大,但对种的鉴别有重要的价值。 4、植物化学:前人对植物化学的工作表明,植物的一些次生代谢产物如类黄酮化合物在葡萄科各类群中的分布规律较好地反映了各类群间的关系。这些结果较好地支持了Planchon对葡萄属范围的界定。 5、山葡萄复合体(V.amurensis complex)包括山葡萄(V.amurensis Rupr.)、燕山葡萄(V.amuresis Rupr. var. dissecta Skvorts.=var.yanshanensisD.Z.Lu et H.P.Liang)、百花山葡萄(V.baihuashanensis M.S.Kang et D.Z.Lu)、复叶葡萄(V.piasezkii Maxim.)、少毛复叶葡萄[V. piasezkii Maxux1.var. pagnuccii (Planch.) Rehd.]共3个种和2个变种,广泛分布于中国北方,形态变异较大。本文对该复合体做了形态分析,并用RAPD (Random Amplified Polymorphic DNAs)分子标记方法分析了这几个类群的关系。综合这些结果,归并了燕山葡萄和百花山葡萄。 在上述工作的基础上,我们得出了如下的结论: l、葡萄属在葡萄科中是一个进化的类群。整理后的葡萄属包括8系62种、l亚种和15变种,其中有2个新系、1个新组合系、2个新变种、1个新组合种和l3个新异名。 2、本文赞同SmaU在1903年作出的分类学处理,把麝香葡萄作为一个独立的属,比葡萄属原始但与葡萄属有着最近的亲缘关系。 3、依据形态特征和APD分析结果把山葡萄复合体的3个种2变种归并为2种l变种,即山葡萄、复叶葡萄和少毛复叶葡萄,认为分子标记技术在分析属内近缘种闻关系上很有价值。 4、葡萄属具有东亚和北美2个现代分布中心,该属可能起源于北美的东部,在晚白垩纪经白令陆桥散布至欧亚大陆。

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Changes of plasminogen activators (PA) during different stages of development of the corpus luteum, and their possible physiological role in luteolysis were studied in rhesus monkeys. It was demonstrated for the first time that monkey corpus luteal cells not only produce PA, but that the function of the corpus luteum is also closely related to the activity of this enzyme system. Generally, the life span for a corpus luteum in monkey is approximately 14-16 days, its demise beginning thereafter. In the present study, we found that urokinase in the corpus luteum is higher on day 5 and day 10 after human chorionic gonadotrophin injection, while the tissue type (t) PA is mainly produced on day 13 when luteolysis may take place. Progesterone production remained high on day 5 and day 10 and decreased dramatically from day 13, indicating the important role of tPA but not urokinase (u) PA in suppressing luteal function. When purified tPA (but not uPA) monoclonal antibody was added to luteal cell culture to neutralize endogenously produced tPA activity, progesterone production in the cells was increased significantly. Interestingly, prolactin alone was capable of increasing PA production by luteal cells; prolactin together with luteinizing hormone, however, had a synergistic luteotrophic effect.

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调查了宁夏新建二代防护林网主栽树种及辅栽乔、灌、草的生长表现和受害虫危害状况 ;列出了造林树种对主要害虫的抗性序列 ;将二代防护林网划分为 3个大类 ,每个大类又分为若干小类 ,并提出了各类防护林树种的选择。在以上研究的基础上提出无虫灾防护林树种的配置原则及设计方案。

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Background: The anti-HIV-1 neutralizing antibody assay is widely used in AIDS vaccine research and other experimental and clinical studies. The vital dye staining method applied in the detection of anti-HIV-1 neutralizing antibody has been used in many laboratories. However, the unknown factor(s) in sera or plasma affected cell growth and caused protection when the tested sera or plasma was continuously maintained in cell culture. In addition, the poor solubility of neutral red in medium (such as RPMI-1640) also limited the use of this assay. Methods: In this study, human T cell line C8166 was used as host cells, and 3-(4,5-Dimethyl-2-thiazolyl)- 2,5-diphenyl-2H-tetrazolium bromide (MTT) instead of neutral red was used as vital dye. In order to avoid the effect of the unknown factor( s), the tested sera or plasma was removed by a washout procedure after initial 3 - 6 h culture in the assay. Result: This new assay eliminated the effect of the tested sera or plasma on cell growth, improved the reliability of detection of anti-HIV-1 neutralizing antibody, and showed excellent agreement with the p24 antigen method. Conclusion: The results suggest that the improved assay is relatively simple, highly duplicable, cost-effective, and well reliable for evaluating anti-HIV-1 neutralizing antibodies from sera or plasma.

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运用PFU微型生物群落采样法在武汉东湖取样研究了六六六、滴滴涕、六氯苯等有机氯污染物在水中相间分布。将PFU(Polyurethanefoamunit)取样得到的挤出液 ,经细胞固定、超声、消解及分步萃取等不同的预处理步骤后 ,用GC ECD测定了各部分提取物中α HCH、β HCH、γ HCH、δ HCH、HCB、pp′ DDE等有机氯污染物的浓度。并用四膜虫模拟试验检验了细胞固定化、消解过程对微型生物的作用效果。结果分析表明 ,以上有机物主要以微型生物富集或颗粒物强吸附形式存在于水中 ,颗粒物弱吸附形

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Taking into account the compensation effect of B to Ge in strained SiGe layers for the first time, the effect of heavily doped boron on the bandgap narrowing of strained SiGe layers is calculated, and the classical Jain-Roulston (J-R) model is modified. The results show that our modified J-R model well fits the experimental values. Based on the modified J-R model, the real bandgap narrowing distribution between the conduction and valence bands is further calculated, which has great influence on modelling the electrical characteristics of SiGe heterojunction bipolar transistors.

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近来,朱梧槚、肖奚安等同志发表了一个称为“中介逻辑”的形式命题逻辑系统MP(见文献[1,2]及其所附参考文献),引起了国内一些学者与青年学生的注意。朱、肖等同志在系统内做了大量的形式推演而迄今未能给出系统的语义,并就此认定他们的中介逻辑“与通常的三值逻辑或任何多值逻辑系统是不同的”,是“精确性经典数学和未来的、处理模糊现象的不确定数

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首先分析了可信计算环境下多远程证明实例执行的动态性、并发性、一致性等问题,提出了一个完整的可信计算环境多远程证明实例动态更新证明方案,以保证通信双方终端计算环境的可信。然后阐述了主要由计算环境组件度量算法、会话组件树计算算法和多远程证明实例证明协议组成可信计算环境证明方法。最后对该证明方法的安全性和效率进行分析,并构建原型系统论证证明方案的可行性和高性能。