高速掺气水流的压缩性准则

利用双流体连续介质模型建立了高速掺气水流基本方程，通过量级分析等方法研究了高速掺气水流的压缩性准则。在定常均质掺气水流中，绝热Mach数M决定着压缩性效应的强弱: M< 0.3时流动可视为不可压的，否则需要考虑压缩性效应。

水平动载下饱和砂土地基液化区扩展

　对一侧受沿深度分布的水平振动载荷时,半无限饱和砂土地基液化区域的扩展进行了数值分析。结果表明: 在水平振动载荷作用下,砂土地基液化区域从载荷端由近到远逐渐发展;随载荷强度和频率的增加,以及土体模量的减小,液 化发展逐渐加快。在考虑的频率范围内,随着载荷频率的增加,土体表面的变形和土中的孔隙压力上升速度增加。

Possibility of lifetime measurement in a flowing medium with phase fluorometry

The possibility of lifetime measurement in a flowing medium with phase fluorometry is investigated theoretically. A 3-D time dependent partial differential equation of the number density of atoms (or molecules) in the upper level of the fluorescence transition is solved analytically, taking flow, diffusion, optical excitation, decay, Doppler shift, and thickness of the excitation light sheet into account. An analytical expression of the intensity of the fluorescence signal in the flowing medium is deduced. Conditions are given, in which the principle of lifetime measurement with phase fluorometry in the static sample cell can be used in a flowing medium.

Phase unwrapping based on branch cut placing and reliability ordering

A new 2-D quality-guided phase-unwrapping algorithm, based on the placement of the branch cuts, is presented. Its framework consists of branch cut placing guided by an original quality map and reliability ordering performed on a final quality map. To improve the noise immunity of the new algorithm, a new quality map, which is used as the original quality map to guide the placement of the branch cuts, is proposed. After a complete description of the algorithm and the quality map, several wrapped images are used to examine the effectiveness of the algorithm. Computer simulation and experimental results make it clear that the proposed algorithm works effectively even when a wrapped phase map contains error sources, such as phase discontinuities, noise, and undersampling. (c) 2005 Society of Photo-Optical Instrumentation Engineers.

Frequency upconversion properties of Er3+/Yb3+-codoped lead-germanium-bismuth oxide glasses

The frequency upconversion properties of Er3+/Yb3+-codoped heavy metal oxide lead-germanium-bismuth oxide glasses under 975 mn excitation are investigated. Intense green and red emission bands centered at 536, 556 and 672 run, corresponding to the H-2(1/2) --> I-4(15/2), S-4(3/2) --> I-4(15/2) and F-4(9/2) -->I-4(15/2) transitions of Er3+, respectively, were simultaneously observed at room temperature. The influences of PbO on upconversion intensity for the green (536 and 556 nm) and red (672 nm) emissions were compared and discussed. The optimized rare earth doping ratio of Er3+ and Yb3+, is 1:5 for these glasses, which results in the stronger upconversion fluorescence intensities. The dependence of intensities of upconversion emission on excitation power and possible upconversion mechanisms were evaluated and analyzed. The structure of glass has been investigated by means of infrared (IR) spectral analysis. The results indicate that the Er3+/Yb3+-codoped heavy metal oxide lead-germanium-bismuth oxide glasses may be a potential materials for developing upconversion fiber optic devices. (C) 2006 Published by Elsevier Ltd.

男性不育患者精浆中表皮生长因子含量测定

为了探讨表皮生长因子与男性精子发生的关系, 采用放射免疫学方法对正常男性精浆中表皮生长因子 (EGF) 含量进行测定, 结果二组之间EGF 含量经t′检验差异有显著性( P < 0105) , 提示EGF 可能参与了男性生殖 系统中精子发生的调控。

福尔马林固定白鱀豚标本DNA提取及其遗传多样性的初步研究

福尔马林固定标本是宝贵的遗传资源,但是如何有效利用其中的遗传信息一直存在问题。本文尝试从标本预处理、消化、PCR扩增各方面综合考虑和优化改进,成功提取并扩增21头福尔马林固定白豚标本线粒体DNA控制区410bp片段。采用了3种预处理方法尽量去除固定标本中残存的甲醛,从试验结果来看,从酒精梯度+临界点干燥处理的标本中提取的DNA在扩增时具有明显优势。通过蛋白酶K消化过程中对于酶的浓度、温浴时间的比较试验,发现随着采用大幅提高酶浓度、延长消化时间等高强度的蛋白酶消化操作后,DNA的质量和产量均得到显著提高。

湖北省梁子湖水生植物的多样性

将断面法与地理信息系统(G IS)和全球定位系统(GPS)相结合,通过广泛的野外调查,研究了湖北省梁子湖水生植物物种多样性和群落多样性.结果表明:2002年梁子湖分布有水生植物34科、64属、96种,优势种为菹草、微齿眼子菜、密齿苦草、双角菱、野菱、金鱼藻、穗花狐尾藻、轮叶黑藻和菰;梁子湖的水生植被可划分为19个群丛类型,分布面积最大的为菹草群丛,物种多样性指数最高的是菰群丛;2002年植被覆盖率为37.88%,总生物量为3.037 5×108kg(鲜质量),全湖植被平均单位面积生物量为998.20 g/

Phylogenetic relationships among the genera of the Penaeidae (Crustacea : Decapoda) revealed by mitochondrial 16S rRNA gene sequences

The phylogenetic relationships within the family Penaeidae are examined based on mitochondrial 16S rRNA gene sequence analysis of 30 species from 20 genera. The analysis generally supports the three- tribe scheme proposed by Burkenroad ( 1983) but it is not consistent with the five- group classification of Kubo ( 1949). Three clades are resolved: ( Penaeus sensu stricto + Fenneropenaeus + Litopenaeus + Farfantepenaeus + Marsupenaeus + Melicertus + Funchalia + Heteropenaeus), ( Metapenaeus + Parapenaeopsis + Xiphopenaeus + Rimapenaeus + Megokris + Trachysalambria) and ( Metapenaeopsis + Penaeopsis + Parapenaeus), corresponding to the Penaeini, Trachypenaeini and Parapenaeini respectively, while the affinities of Atypopenaeus and Trachypenaeopsis are obscure. The molecular data support that Miyadiella represents the juvenile stage of Atypopenaeus. Within the Trachypenaeini, Trachypenaeus sensu lato is clearly paraphyletic, while the monophyly of Penaeus sensu lato in the Penaeini is questionable.