A New Generalized Similarity-Based Topic Distillation Algorithm

The procedure of hypertext induced topic search based on a semantic relation model is analyzed, and the reason for the topic drift of HITS algorithm was found to prove that Web pages are projected to a wrong latent semantic basis. A new concept-generalized similarity is introduced and, based on this, a new topic distillation algorithm GSTDA（generalized similarity based topic distillation algorithm） was presented to improve the quality of topic distillation. GSTDA was applied not only to avoid the topic drift, but also to explore relative topics to user query. The experimental results on 10 queries show that GSTDA reduces topic drift rate by 10% to 58% compared to that of HITS（hypertext induced topic search） algorithm, and discovers several relative topics to queries that have multiple meanings.     

蒺藜皂甙对大强度训练大鼠血清ALT、AST、CK、LDH、BUN及睾酮的影响

研究了蒺藜皂甙对大强度训练大鼠血清ALT、AST、CK、LDH、BUN、睾酮水平生化指标的影响。对雄性SD大鼠进行7周大强度跑台训练,采用递增强度跑台训练,建立大强度耐力运动模型。结果显示:力竭运动后,蒺藜皂甙组大鼠血清ALT、AST、CK、LDH活性明显低于空白对照组(p<0.05p<0.01);蒺藜皂甙组大鼠血清BUN含量较空白对照组有显著的降低(p<0.01);蒺藜皂甙组大鼠血清睾酮水平明显高于空白对照组(p<0.01)。表明:蒺藜皂甙能减轻大强度耐力运动对大鼠肝脏、心肌、骨骼肌等组织细胞的损伤;蒺藜皂甙能提高大鼠睾酮水平,降低运动大鼠体内蛋白质分解,从而延缓大鼠运动性疲劳的产生。     

关于“诱导映射的一些性质”

纠正了Gentry K R的一篇论文(Some properties of the induced map, Fundamenta Mathematicae 66 (1969) 55-59)中的错误并推广该文中的一些定理，还给出了逆系统间的映射为极限正则映射的一个充分条件.     

RLC电路中类电磁感应透明现象的实验研究

RLC电路可以用来模拟原子系统中的电磁感应透明(Electromagnetically induced transparency,EIT)现象.在电容耦合RLC电路中,通过改变外部信号源的频率,测量了传输到第一个RLC回路的功率随信号频率的变化关系,观察到了由于经典干涉导致的类EIT现象.用两网孔电路模拟了A型原子系统,研究了耦合强度和失谐对类EIT信号的影响；用三网孔电路模拟了倒Y型和N型原子系统,研究了失谐对类EIT信号的影响.     

次子空间与不变次子空间的一些性质

本文给出了次子空间与不变次子空间的概念，并探讨了它们的一些性质。     

An investigation of predator‐induced defence responses in ciliated protozoa

Predator‐induced defence responses have been reported in 15 species of ciliates representing three subclasses: Hypotrichia, Stichotrichia and Hymenostomia. However, the discovery of this phenomenon in such distantly related groups suggests that it could be more widespread within the Ciliophora. In laboratory experiments, we tested 23 potential prey species with a range of potential predators including other ciliates (12 spp.), amoebae (two spp.), rotifers (two spp.), a turbellarian worm (Stenostomum sphagnetorum), and an oligochaete worm (Chaetogaster sp.). In each experiment, one predator species was incubated for 24?h with one potential prey species and the latter was examined for evidence of a defence response. One new example of predator‐induced morphological change was recorded (Euplotes viridis) and detailed observations were made for one poorly known example (E. eurystomus). Both species significantly increased their width (by about 35% and 23%, respectively) in the presence of the turbellarian worm S. sphagnetorum. An induced life cycle change was recorded for the first time among hypotrichs with E. muscorum exhibiting significantly increased rates of encystation in the presence of the ciliate predators Dileptus anser and Spathidium sp. Finally, Euplotes patella, Euplotes sp. and Stylonychia pustulata, which are usually regarded as omnivorous rather than predatory ciliates, all induced morphological change in Colpidium kleini, the C. kleini cells becoming significantly shorter and wider. No examples of induced defence response were found among groups other than hypotrichs and hymenostomes.     

多绳摩擦提升机绳槽磨损的一般规律

本文建立了绳槽磨损的一般微分方程.并通过具体数值计算研究了不同条件下的磨损规律.     

A Note on Abelian Extensions

Let K/Q be any abelian extension where Q is the field of rational numbers. By Galois theory and the Frobenius formula for induced characters, we prove that there exists a metabelian group G and an irreducible character X of G such that K=Q（X）.     

大银鱼卵膜孔结构的数学模型及其功能

继1987年发现泥鳅成熟卵卵膜孔涡旋状结构之后,我们又发现了大银鱼(Protosalanx hyalocranius)卵膜孔呈现特异的沟脊放射状结构。本文进一步确证了又一种真骨鱼精子入卵除化学因素外,还存在着不容忽视的数学物理因素——机械动力作用,这两者相得益彰,形成了一个完整的精子引导系统。