Flow Characteristics of Liquid with Pressure-Dependent Viscosities in Microtubes

It is obvious that the pressure gradient alone, the axial direction in a pipe flow keeps constant according to the Haoen-Poiseuille equation. However, recent experiments indicated that the distribution of the pressure seemed no longer linear for liquid flows in microtubes driven by high pressure (1-30MPa). Based on H-P equation with slip boundary condition and Bridgman's relation of viscosity vs. static pressure, the nonlinear distribution of pressure along the axial direction is analyzed in this paper. The revised standard Poiseuille number with the effect of pressure-dependent viscosity taken into account agrees well with the experimental results. Therefore, the dependence of the viscosity on the pressure is one of the dominating, factors under high driven pressure, and is represented by an important property coefficient et of the liquid.

One-dimensional improvement and two-dimensional and 3-dimensional treatments for stable oscillation condition, mode structure and power output in high-speed-flow lasers

For high-speed-flow lasers, the one-dimensional and first-order approximate treatment in[1] under approximation of geometrical optics is improved still within the scope of approx-imation of geometrical optics. The strict accurate results are obtained, and what is more,two- and three-dimensional treatments are done. Thus for two- and three-dimensional cases, thestable oscillation condition, the formulae of power output and analytical expression of modesunder approximation of geometrical optics (in terms of gain function) are derived. Accord-ing to the present theory, one-and two-dimensional calculations for the typical case of Gerry'sexperiment are presented. All the results coincide well with the experiment and are better thanthe results obtained in [1].In addition, the applicable scope of Lee's stable oscillation condition given by [1] is ex-panded; the condition for the approximation of gcometrical optics to be applied to mode con-structure in optical cavity is obtained for the first time and the difference between thiscondition and that for free space is also pointed out in the present work.

Genetic diversity and population history of the red panda (Ailurus fulgens) as inferred from mitochondrial DNA sequence variations

The red panda (Ailurus fulgens) is one of the flagship species in worldwide conservation and is of special interest in evolutionary studies due to its taxonomic uniqueness. We sequenced a 236-bp fragment of the mitochondrial D-loop region in a sample of 5

Assessment of cattle genetic introgression into domestic yak populations using mitochondrial and microsatellite DNA markers

Hybridization between yak Poephagus grunniens and taurine Bos taurus or indicine B. indicus cattle has been widely practiced throughout the yak geographical range, and gene flow is expected to have occurred between these species. To assess the impact of cattle admixture on domestic yak, we examined 1076 domestic yak from 29 populations collected in China, Bhutan, Nepal, India, Pakistan, Kyrgyzstan, Mongolia and Russia using mitochondrial DNA and 17 autosomal microsatellite loci. A cattle diagnostic marker-based analysis reveals cattle-specific mtDNA and/or autosomal microsatellite allele introgression in 127 yak individuals from 22 populations. The mean level of cattle admixture across the populations, calculated using allelic information at 17 autosomal microsatellite loci, remains relatively low (mY(cattle) = 2.66 +/- 0.53% and Q(cattle) = 0.69 +/- 2.58%), although it varies a lot across populations as well as among individuals within population. Although the level of cattle admixture shows a clear geographical structure, with higher levels of admixture in the Qinghai-Tibetan Plateau and Mongolian and Russian regions, and lower levels in the Himalayan and Pamir Plateau region, our results indicate that the level of cattle admixture is not significantly correlated with the altitude across geographical regions as well as within geographical region. Although yak-cattle hybridization is primarily driven to produce F-1 hybrids, our results show that the subsequent gene flow between yak and cattle took place and has affected contemporary genetic make-up of domestic yak. To protect yak genetic integrity, hybridization between yak and cattle should be tightly controlled.

412例性病患者的HIV感染状况及临床特征

目的了解性病患者的艾滋病病毒(HIV)感染状况并分析其临床特征。方法自愿接受HIV咨询检测的基础上,对临床确诊的412例性病患者进行HIV-1/2抗体检测,并对其临床特征进行分析研究。结果412例性病患者的HIV检出率为2.9%。性病患者中检出HIV阳性率依次为:尖锐湿疣6.2%,生殖器疱疹4.2%,梅毒3.4%,淋病1.5%,非淋菌性尿道炎1.0%。合并感染HIV的性病患者中,83.3%的患者有多性伴,商业性行为普遍存在,安全套使用率极低。感染HIV的尖锐湿疣患者及生殖器疱疹患者以频繁复发为突出表现,1例合并感染HIV的梅毒患者半年即进展为神经梅毒。结论性病患者是HIV感染的重要高危人群,危险性行为是其感染HIV和其它性病的主要原因,应该加强性病患者的HIV监测。对临床上频繁复发的尖锐湿疣及生殖器疱疹患者,快速进展的梅毒患者,应高度怀疑合并HIV感染的可能。

广东中山地区气单胞菌环境株的分离、鉴定及系统发生关系

从广东省中山市的池塘水样、底泥、健康鱼、肠道及稻田土样中用Aeromonas的选择培养基分离到10株气单胞菌。通过生理生化测试、16S rDNA序列测定、与气单胞菌典型菌株的16S rDNA序列进行比对和聚类分析,对它们进行了鉴定,并研究了它们之间的系统发生关系。结果显示该地区环境中气单胞菌的优势种除A.hydrophila(HG1组)外,还有A.caviae(HG4组)、A.jandaei(HG9组)和A.veronii(HG10组),其中后两种是国内新记录。这是国内首次对环境中气单胞菌多样性进行研究。

Kinetic Monte Carlo simulation of semiconductor quantum dot growth

Performing an event-based continuous kinetic Monte Carlo (KMC) simulation, We investigate the growth conditions which are important to form semiconductor quantum dot (QD) in molecular beam epitaxy (MBE) system. The simulation results provide a detailed characterization of the atomic kinetic effects. The KMC simulation is also used to explore the effects of periodic strain to the epitaxy growth of QD. The simulation results are in well qualitative agreement with experiments.

Web应用程序运行响应时间的实验研究

性能测试是保证Web应用程序成功的重要手段 ,但是如果不能采用正确的方法测试或者不能完全理解测试结果对测试环境的依赖性 ,那么测试结果很可能会起误导作用 响应时间则是性能的一个重要指标 ,特别是从用户的角度来看 因此进行了一系列探索性的实验来研究Web应用程序运行响应时间的特性 ,用统计的方法对实验结果做了分析 ,发现Web事务的响应时间和用户数之间呈线性关系 ,测试的时间和测试配置对响应时间也有一定影响

硅基波导光开关及开关阵列的研究进展

光开关是光网络中实现光交换的核心器件。硅基波导光开关作为一类重要的开关器件，具有体积小、开关速度快、兼容性好等优点。近年来随着硅基波导制作技术的成熟，硅基波导光开关及开关阵列的研究日益受到人们的重视。文章介绍了SOI（silicon—on—insulater）光波导、聚合物光波导和SiO_2光波导等三类常见的硅基波导在光开关及开关阵列方面的一些研究进展。

非晶硅Pin二极管的1MeV电子幅照效应

报道a-Si:H本征膜及Pin二极管的1MeV1.4×10~(15),4.2×10~(15),8.4×10~(15)/cm~2电子幅照实验结果和退火行为。测量了电子辐照对a-Si:H光暗电导率和光致发光谱的影响，以及a-Si:H Pin二极管光伏特性和光谱响应随电子辐照剂量的变化。发现电子辐照在a-Si:H本征膜和二极管中引起严重的损伤，和二极管光谱响应的峰值“红移”。但未见饱和现象，还观测到明显的室温恢复现象；但高温退火处理后未能完全恢复。该文对以上实验结果给出了合理的解释。