Cell death, axonal damage, and cell birth in the immature rat brain following induction of hydrocephalus

We hypothesized that hydrocephalus can cause death of brain cells and that generation of new brain cells might compensate for the cell loss. Hydrocephalus was induced in 3-week-old rats by injection of kaolin into the cisterna magna. The brains were studied 1 to 4 weeks later by histochemical, immunochemical, and ultrastructural methods. The ventricles enlarged progressively. Some axons in the corpus callosum were injured as early as 1 week, but axonal damage was not prevalent until 4 weeks when ventriculomegaly became severe. Dying cells detected by DNA end labeling and often identified as oligodendrocytes by electron microscopy were evident in white matter. Late-stage hydrocephalus was associated with a significant increase in the quantity of dying cells. Hydrocephalus was associated with increased Ki67 labeling and bromodeoxyuridine incorporation in the subependymal zone. Reactive changes were identified among astrocytes, oligodendroglia, and microglia. We conclude that hydrocephalus causes, in addition to axonal injury, gradual cell death in the cerebrum, particularly the white matter. The brain response includes production of new glial cells, but whether the new cells play any beneficial role remains unknown.     

智能工作站主机的MMPIS实验模型研究──一个全互连式结构MMPIS硬件环境的设计与实现

本文介绍中日国际合作开发研究的Ａ１型智能网（Ａ１型ＩＮ）智能工作站（ＩＷ）主机的并行推理硬件结构的实验模型设计与实现，给出了一种并行推理硬件支持环境实现方案和该方案在实现中若干问题的解决方法。     

Relationship of the Yttrium Compounds with the Alloying Method in ODS Ferritic Stainless Steel

ＲｅｌａｔｉｏｎｓｈｉｐｏｆｔｈｅＹｔｔｒｉｕｍＣｏｍｐｏｕｎｄｓｗｉｔｈｔｈｅ　ＡｌｌｏｙｉｎｇＭｅｔｈｏｄｉｎＯＤＳＦｅｒｒｉｔｉｃＳｔａｉｎｌｅｓｓＳｔｅｅｌＺｈａｎｇＹｏｎｇ（张勇）；ＣｈｅｎＭｉｎｇｂｉａｏ（陈明彪）；ＷｕＣｈｅｎｇＪｉａｎ...     

一种性能可调的新型节能材料－电致变色膜

本文介绍了一种性能可调的新型节能材料—电致色薄膜，描述了以其为核心的全固态灵巧窗结构、工作原理和光学调节性能，回顾了电致色材料、离子存储层和固态锂离子导体及其性质，并展望了这种新型节能材料的应用。     

高效率平面磁控溅射器的研制

介绍一种新型磁控溅射装置。它采用两块极性相对的环状磁铁的设计方法，通过扩大靶表面的等离子放电区域面积，使传统磁控溅射枪使用中经常受到的两个限制──溅射速率与靶的利用率得到了较大的改善。实验中铜靶在溅射功率密度为11W／cm~2时溅射速率约为800nm／min，如果继续提高功率则可获得更高的速率。而靶的利用率可达64％左右。另外，在认为出射粒子符合cos~nθ分布的前提下，发现当n＝3．3时，实验数据和理论数据符合得较好。     

硬件握手双向选通型串行通信共享器的设计

本文介绍了ＩＢＭ－ＰＣ系列计算机通过ＲＳ－２３２Ｃ串行口与多个单片微机组成的分布式系统中一种可双向选通串行通信共享器的设计方法。给出通信共享器的设计电路；并对电路工作原理进行了详细剖析。     

Singular value decomposition-based MA order determination ofnon-Gaussian ARMA models

Singular-value-decomposition (SVD)-based moving-average (MA) order determination of non-Gaussian processes using higher-order statistics is addressed. It is shown that the MA order determination of autoregressive moving-average (ARMA) models is equivalent to the rank determination of a certain error matrix, and a SVD approach is proposed. Its simplified form is applied to pure MA models. To improve the robustness of the order selection, a combination of the SVD and the product of diagonal entries (PODE) test is proposed. Some interesting applications of the two SVD approaches are presented, and simulations verify their performance     

不锈钢管子—管板的激光焊接

试验研究了不锈钢的深溶焊接。研究了聚焦光束回转的光具。在工件不动的情况下,焊接管子—管板连接环缝。焊缝质量满足压力容器的要求,焊接效率大大提高。     

热镀钢丝膜层的冷凝计算

分析了热镀钢丝自液池引出过程中的热传导，得出了温度分布的解析解，从而计算钢丝表面膜层达到凝固温度时的提抽高度，为结构设计及确定冷却装置的合理位置提供依据。     

Efficient third-harmonic generation of a picosecond laser pulsewith time delay

A new configuration based on the polarization-mismatching scheme with time delay for efficient frequency tripling conversion is proposed in this paper. The calculated results showed that the requirement for the efficient frequency tripling conversion of a 1-ps laser pulse is not only the optimization of peak intensity of the second-harmonic pulse, but also the optimization of the pulse duration ratio and temporal difference between the o-polarization second-harmonic pulse and the e-polarization first-harmonic pulse due to group-velocity mismatch among the interacting pulses. With the proposed scheme the group velocity mismatch can be compensated. Overall energy conversion efficiency increases from 55% to 75% under the optimized conditions at the intensity of 6 GW/cm². The temporal shape of the third-harmonic pulse with 1 ps pulse duration has no subpulses. The optimization of the efficient frequency tripling conversion for intensities of over 75 GW/cm² is also described. The results showed that the maximum tripling energy conversion efficiency is close to 80% with the optimized doubler and tripler