基于人机工程学3E原则的防暴弹安全因素分析

对防暴弹的安全因素进行分析，运用人机工程学事故控制的3E原则，并结合国外的一些先进的做法加以指导和借鉴。旨在用人机工程学事故控制理论对防暴弹安全生产使用进行优化。     

Formation of C4 species in the deactivation of a Pd/SiO2 catalyst during the selective hydrogenation of acetylene

The deactivation characteristics of Pd/SiO₂ in the selective hydrogenation of acetylene were correlated with changes in the amount of the C4 species produced. The amounts of butenes produced changed in parallel with the catalyst activity, indicating that the rate limiting step for butene production was the same as that for acetylene hydrogenation. On the other hand, the amount of 1,3-butadiene produced changed, showing a maximum with catalyst deactivation because 1,3-butadiene is an intermediate in the sequential reaction process which involves both the production and consumption of 1,3-butadiene. This was verified by a simultaneous TG/reaction experiment showing that 1,3-butadiene was a precursor of green oil. The catalyst showed a self-regenerative behavior in its activity and the amounts of C4 species produced during the early stage of deactivation because two opposite factors, which contributed to either the lowering or the promotion of activity, were involved in the process. A specific type of polymer species, produced during the initial period of deactivation, is proposed to be responsible for the promotion of catalyst activity.     

论高校开放式实验教学体系的构建

实施开放式实验教学已成为当前高校实验教学改革的突破口。实施开放式实验教学，必须构建科学的运行体系，主要包括教学目标体系、内容体系、保障体系和效能考评体系四个方面。     

1999年长江洪水及几点认识

Following the basin wide heavy flood on Changjiang River in 1998, a si gnificant flood occurred in 1999. Comparative analysis of both floods in terms of flows and flooding situations shows that both floods had one common feature, that is, the flood stages were fairly high. But they differed greatly at the sa me time, that is, the 1998 flood was a basin wide heavy one while the 1999 flood was a significant local one. At Yichang station there occurred eight flood pea ks in 1998, while in 1999 only three peaks took place. The maximum peak dischar ge at this station in 1999 was 57 600 cubic meters per second, which was smaller than that in 1998. The maximum flood-volume in 30 d of the 1998 flood at this s t ation equaled that in 1954, when an extraordinary heavy flood happened on the River, while the maximum flood-volume in 30 d in 1999 was 25.8 billion cubic me t ers per second smaller than the 1998 one. It is seen that inflow floods from th e upstream Changjiang River (above Yichang) in 1999 were not so big. Comparison of flood volumes in longer period shows that the 1999 flood was relatively conc entrated while the 1998 one had lasted longer duration. Analysis shows that flo oding situations in both years differed significantly in terms of the flood volu mes diverted from river channels due to dyke breaches and collapses, the cases o f polder embankment collapses, the areas of inundated cultivated land and the nu mbers of dangerous events for hydraulic structures. These differences had been resulted from the different properties of both floods and the dyke strengthening efforts made after the 1998 flood. It is seen that flood control engineering c onstructions initiated in the days following the 1998 flood have played an impor tant role in fighting the 1999 flood.     

铝电解槽磁流体稳定性有限元分析

本文采用有限元法求解分层磁流体小扰动方程系统特征值，研究铝电解槽稳定性。研究结果表明，在没有电磁力时，铝液表面波动（内波）是稳定的。存在电磁力时，它会激发铝液表面波动的某些低频长波分量不稳定性，高频短波不受影响。被激发的不稳定波动频率和扰动增长率与电流密度，磁感应强度垂直分量，铝电解槽长宽比，电解质和铝液的密度差，厚度等因素密切相关。减少电流密度，磁感应强度，增加电极距离和铝液厚度可以提高铝电解槽的稳定性。这对铝电解槽优化设计和在线控制有重要意义。     

用于微波/射频集成电路的一种新型低损耗介质——多孔硅及氧化多孔硅厚膜

提出在单片微波集成电路(MMIC)中用多孔硅/氧化多孔硅厚膜作微波无源器件的低损耗介质膜.研究了厚度为70μm的多孔硅/氧化多孔硅厚膜在低阻硅衬底上的形成,这层厚膜增加了衬底的电阻率,减少了微波的有效介质损耗.通过测量在低阻硅衬底上形成的氧化多孔硅厚膜上的共平面波导的微波特性,证明了在低阻硅衬底上用厚膜氧化多孔硅可以提高共平面传输线(CPW)的微波特性.     

存储媒体的媒体内同步反馈控制算法

本文提出了一种存储媒体的媒体内同步反馈控制算法，该方案是建立在缓冲区占用率控制基础上，通过周期性地检查缓冲区的占用情况来检测失步，并将其反馈给发送方，由发送方对发送帧速率进行调整。文章给出了接收方所需缓冲区的设计准则及发送帧速率的调整方法，并分析了算法中各参数对同步性能的影响。实验表明该方案能够处理由于网络传输时延特性变化引起的失步，与其它反馈控制方案相比具有更低的数据丢弃率，从而使接收端播放平滑连续，具有良好的视频播放质量。     

X射线三轴晶衍射法测量半绝缘GaAs单晶的化学配比

采用X射线三轴晶衍射法,根据As间隙原子对作为过量As在GaAs单晶材料中存在的主要形式的模型,可以无损、高精度测量半绝缘GaAs单晶的化学配比.并探讨了引起晶格变化的原因及其与熔体组分的关系,对于制备高质量GaAs单晶及其光电器件具有重要的意义.     

Lattice Effects and Irreversible Magnetoresistance in Gd Doped La—Ca—Mn—O

The Gd substituting effects for La in La0.67Ca0.33MnO3 has been studied .With increasing the substituting amount of Gd,the phase transition temperature of metal-isolator for the samples decreases,the corresponding peak resistivity increases,the Curie temperature decreases monotonically.The substitution of La-Ca-Mn-O with 11% Gd for La improved the magnetoresistance ratio by an order of magnitude.The effects of substituting Gd can be explained in terms of the lattice effects.An irreversible MR behaviour was observed in Gd-substituting compounds.This effect became marked when the substituting amount of Gd was greater than 7%.A maximum irreversible increment of MR ratio as large as 91% was obtained when Gd substituting amount was 11%.