毛乌素沙地油蒿与籽蒿种子萌发对光照的反应

油蒿(Artemisia ordosica)与籽蒿(Artemisia sphaerocephala)为毛乌素沙地的优势物种，广泛用于我国北方干旱、半干旱区的生态恢复。油蒿与籽蒿种子萌发对温度、水分等环境条件的反应已有较为明确的研究结果，但关于这两种蒿属植物种子萌发对光照反应的研究目前存在两种不同的结论，对飞播技术的改善造成一定影响。 影响油蒿与籽蒿种子萌发对光照反应的因素较多。如种源地、结实部位、种子颜色、种子保存方式与时间、实验条件、温度等。考虑种源地、种子保存时间与方式、结实部位及温度，从多方面系统研究油蒿与籽蒿种子萌发对光照的反应。结果表明当温度较低时(10:20C)，萌发率和萌发速率在黑暗条件下显著高于在光照条件下。采自榆林地区的种子萌发状况相对较差，萌发率和萌发速率在大多数情况下显著低于其他两地;各种源地上下部种子萌发率有一定差异，大多数结实部位为上部的种子最终萌发率和萌发速率高于下部的种子;保存几周的种子萌发率变化不大，但在温度较高和较低时，随着种子保存时间的延长，萌发率下降较快，而在适宜温度下种子萌发率变化不明显;种子保存方式的不同造成种子萌发情况的差异，但差异不明显;黑暗条件下比近似黑暗条件下的种子萌发率略低。上述因素对种子萌发均具有一定影响，但总体特征是种子萌发对光照的反应表现为强光抑制种子的萌发，黑暗促进种子萌发。当温度较高时(15:25C)，光照与黑暗条件下种子萌发率差异不大，但黑暗条件下种子的萌发速率显著高于光照条件下;当其它条件相同时，种子萌发率和萌发速率显著高于温度较低时(10:20C)。因而，适宜的温度和黑暗条件有利于油蒿与籽蒿种子的萌发。在飞播实践时应为种子创造一定的沙埋条件，创造有利于种子萌发的黑暗环境，促进种子的萌发，提高飞播工作的成效。

Microstructure and superconducting properties of single grains of Y-Ba-Cu-O containing Y-2411(M) and Y2O3

Y-Ba-Cu-O (YBCO) single grains have the potential to generate large trapped magnetic fields for engineering applications, and research on the processing and properties of this material has attracted interest world-wide over the past 20 years. In particular, the introduction of flux pinning centers to the large grain microstructure to improve its current density Jc, and hence trapped field, has been investigated extensively. Y2Ba 4CuMO2 [Y-2411(M)], where M = Nb, Ta, Mo, W, Ru, Zr, Bi and Ag, has been discovered recently to form very effective flux pinning centers due primarily to its ability to form nano-size inclusions in the superconducting phase matrix. However, the addition of the Y-2411(M) phase to the precursor composition complicates the melt-processing of single grains. The addition of Y2O3 to the precursor composition, however, broadens the growth window of single YBCO grains containing Y-2411 (M). We report an investigation of the microstructures and superconducting properties of single grains of this composition grown by top seeded melt growth (TSMG). © 2010 IEEE.

天花粉蛋白对体外无血清培养的人早期绒毛细胞滋养层细胞hCG，孕酮分泌的影响

本研究以体外无血清培养的人早期绒毛细胞滋养层细胞和绒毛组织培养为模型，测定了天花粉蛋白对滋养层细胞ｈＣＧ、孕酮分泌的影响，发现体外无血清培养的细胞滋养层细胞分泌的ｈＣＧ在天花粉蛋白浓度为０．１μｇ／ｍｌ即下降５０％，而后下降缓慢，８μｇ／ｍｌ以上方降为零，而绒毛组织培养在天花粉蛋白浓度为０．１μｇ／ｍｌ时ｈＣＧ下降近９０％，而后下降缓慢，至８μｇ／ｍｌ以上降到零，说明体外培养的细胞滋养层细胞中有两个群体，其中一个对天花粉蛋白敏感，另一个不敏感，尽管在形态上很难区别。孕酮的反应则不同，在细胞滋养层细胞和绒毛组织培养中，随天花粉蛋白浓度升高，孕酮分泌均缓慢下降，未出现两阶段下降过程。

Strength mobilization in clays and silts

A large database of 115 triaxial, direct simple shear, and cyclic tests on 19 clays and silts is presented and analysed to develop an empirical framework for the prediction of the mobilization of the undrained shear strength, cu, of natural clays tested from an initially isotropic state of stress. The strain at half the peak undrained strength (γM=2) is used to normalize the shear strain data between mobilized strengths of 0.2cu and 0.8cu. A power law with an exponent of 0.6 is found to describe all the normalized data within a strain factor of 1.75 when a representative sample provides a value for γM=2. Multi-linear regression analysis shows that γM=2 is a function of cu, plasticity index Ip, and initial mean effective stress p′0. Of the 97 stress-strain curves for which cu, Ip, and p′0 were available, the observed values of γM=2 fell within a factor of three of the regression; this additional uncertainty should be acknowledged if a designer wished to limit immediate foundation settlements on the basis of an undrained strength profile and the plasticity index of the clay. The influence of stress history is also discussed. The application of these stress-strain relations to serviceability design calculations is portrayed through a worked example. The implications for geotechnical decision-making and codes of practice are considered.

雄性生殖道局部免疫

：雄性生殖道局部免疫在性传播疾病的防治、免疫不育的防治和免疫避孕方面都具有十分重要的作用。本文 结合作者的研究工作，介绍了雄性泌尿生殖道的结构特征、天然和获得性的抗感染因子、抗精子免疫反应、性激素 对雄性生殖道免疫力的调控作用以及雄性生殖道的获得性免疫应答的激活等方面的研究动态，提出了今后的研究 方向，认为除了深入研究获得性免疫之外，雄性生殖道内天然免疫力的研究，应是十分值得关注的新方向。 39600016) ,云南省应用基础基金(96C097Q ,97C092M) 等资助。