聚合物基复合材料蜗轮传动润滑剂的特性研究

利用台架试验评价了一种较好的适于聚合物基复合材料蜗轮传动润滑的ＷＬ润滑剂，并考察其润滑特性，结果表明，在ＷＬ润滑剂润滑下，由于材料本身的自润滑性以及水份的影响和弹性流体动力润滑三者的共同作用，使蜗轮传动效率明显提高。     

Comparative morphology and evolution of the nephridia in Nemertea

In various discussions on the phylogenetic position of the Nemertea, nephridial morphology seems to support current hypotheses for a close relationship to lophotrochozoan subtaxa. These arguments are based on isolated findings and suffer from the lack of a phylogeny-based inference. In order to fill in this gap, the structure of the nemertean nephridia is reviewed. Based on the structural data presently available for nemertean nephridia, 30 characters are described. Their ancestral states are inferred from cladograms derived from recent molecular analyses. According to these, paired protonephridia restricted to the foregut region and associated with the blood vascular system represent the primary state in nemerteans. The terminal cells are covered by the blood vessel endothelium and have no open connection to the lumen of the blood vascular system. Serially arranged protonephridia that could support the hypothesis of an annelid–nemertean–relationship are either apomorphic for Cephalothricidae, a nemertean subgroup, or a cephalothricid ingroup.     

Schistosoma mansoni: Onset of chemoattraction in developing worms

Summary Heterosexual chemoattraction studies on juvenile worms showed that 20- and 21-day-old worms do not attract each other, whereas 23- and 28-day-old worms are attracted to each other and pair with worms of the opposite sex. This onset of chemoattraction in vitro corresponds to the time when worms begin pairing in vivo. The ability of single worms to locate each other and mate is presumably mediated by chemoreceptors.     

Instant Messaging Worms Propagation Simulation and Countermeasures

Instant messaging （IM） has become one of the most popular online communication tools among consumer and enterprise IM users. It provides instant message delivery, as well as convenient file transfer services. The increasing popularity and functionalities of IM programs have made it increasingly attractive for attackers, especially for worm writers. IM contact list offers worm an easy way of finding potential victims so that the worm could achieve a surprising spreading speed. This paper first presents our experimental results of simulating IM worm propagation in the logical network defined by IM contact lists, which is reported to be a scale-free network. Then, the existing proposals for detecting and containing IM worm epidemics are discussed. At last, a new algorithm for this purpose is presented, which is based on the observation of the bi-directional nature of IM worm traffic, and its advantages and possible improvements in implementation are analyzed. The simulation results show the proposed algorithm is of significant effect on restricting IM worm propagation.