一种应用于二次布局的有效划分方法

提出了一种基于二次布局的结合MFFC结群和hMETIS划分的算法.实验表明:这种方法能得到很好的布局结果,但是运行消耗的时间比较长.为了缩短划分在二次布局中运行的时间,提出了一种改进的结群算法IMFFC,用它在二次布局中做划分.与前者相比较,这种方法虽然布局质量稍差,但速度更快.     

基于S5933的PCI总线与8051的接口设计

简要介绍了PCI总线的特点，重点介绍了AMCC公司推出的S593X系列的高性能接口控制器，并通过实践给出基于S5933的PCI总线和8051的接口设计技术。     

降低精炼钢中氢氧含量的探索

主要介绍通过优化炼钢生产工艺,使产品满足新的技术要求:S≤0.010％,P≤0.015％.[H]≤0.0002％,[O]≤0.0045％,[N]≤0.0055％。     

管内含蜡原油降温过程中的放热问题

利用两种管段和两种原油，进行了降温过程自然对流放热参数的测试和研究。采用滞流点确定降温第二阶段中凝油边界的移动，区分管内的对流区与导热区。由实验数据回归得到适用于含蜡原油降温过程的自然对流放热准则方程式。用该方程式计算的自然对流放热系数值比按无限空间自然对流准则方程式计算值小20％～50％。     

微合金化高强度钢轧制采用的工艺技术

本文综述微合金化高强度钢轧制采用的工艺技术，其中包括热装热送、板坯加热、控轧控冷、快速冷却、采用的新设备等工艺技术。重点是生产低碳、高韧性、高强度、易焊接的造船用钢采用形变热处理技术，以提高产量和质量，节省昂贵的Ｎｉ、Ｃｒ、Ｍｏ等合金，降低生产成本。     

过共晶Al－Si合金共生区激光表面处理

用２ｋＷ连续ＣＯ２激光对过共晶Ａｌ－１８Ｓｉ合金以不同能量密度和扫描速度进行快速熔凝处理。用扫描电镜、电子微区分析仪分析了微观结构。从计算机对Ａｌ－Ｓｉ合金ｆ－ｎｆ系统的非平衡理论计算所得的共生区及实验结果的分析可见，当能量密度和扫描速度决定的凝固条件处于共生区中部时，过共晶Ａｌ－Ｓｉ合金激光表面处理可以得到共晶间距低于２００ｎｍ的完全共晶结构。     

亲电聚合路线合成聚醚醚酮酮砜的研究

用4,4′-二苯氧基二苯砜(DPODPS)分别与对苯二甲酰氯(TPC)、间苯二甲酰氯(IPC)或2,5-二氯对苯二甲酰氯(DCC)在1,2-二氯乙烷(DCE)中,以无水 AlCl_3为催化剂,在 N-甲基吡咯烷酮(NMP)存在下,通过付-克亲电聚合反应,制得了五种不同结构的聚醚醚酮酮砜(简称PEEKKS)。用红外光谱(IR)、X-射线衍射(XRD)、扫描电镜(SEM)、差示扫描量热(DSC)、热重(TG)及耐溶剂试验,对聚合物进行了表征。结果表明,五种聚合物的对数比浓粘度(η_(inh))均达到0.85以上.具有较低的熔融温度、良好的溶解性能和耐高温性能,PEEKKS 属于非晶态聚合物。     

Dynamical correlations and the direct summation method of evaluating infinite continued fractions

Testes from 11.5-day-old mouse embryos, with and without attached mesonephroi, were cultured for 7 days. Isolated testes failed to develop well-differentiated testis cords: however, when cultured attached to a mesonephros from either a male or a female donor embryo, testes developed cords that were normal in appearance. Testes cultured next to a mesonephric region but separated from it by a permeable filter, did not develop normal cords, nor did testes grafted to fragments of embryonic limb or heart. When testes were grafted to mesonephric regions from mice carrying a transgenic marker, the marker was found in some of the peritubular myoid cells and other interstitial cells of the testis, but not in the Sertoli cells or the germ cells. We conclude that after 11.5 days post coitum, cells can migrate from the mesonephric region into the differentiating testis and can contribute to the interstitial cell population, and that this contribution is necessary for the establishment of normal cord structure. The germ cells in all cultured testes, whether or not differentiated cords were present, were T1 prospermatogonia: no meiotic germ cells were seen.