miPP/ziPP共混体系的流动性能

首次对茂金属聚丙烯(miPP)／齐格勒-纳塔聚丙烯(ziPP)共混体系的流动性进行了系统的研究。研究发现，在miPP／ziPP共混体系中，miPP含量的变化改变了共混体系的相结构，这种相结构会随着温度和剪切速率的变化而产生明显的变化，从而改变了体系的流动性能，且该共混体系在不同剪切速率下的流动曲线可以分别通过两个模型进行模拟。     

抗乙肝病毒表面抗原PreS1(20-47)的单链抗体在转基因烟草根分泌物中的初步表达

为探索利用植物根分泌表达重组蛋白的可行性，构建了含有抗乙肝病毒表面抗原PreS1(20—47)单链抗体(ScFv)基因的表达载体。该ScFv基因转化烟草后在烟草根部细胞的细胞质和内质网中获得表达。实验结果表明，5’端融合ER导向信号肽的重组ScFv可通过根分泌表达。     

A medium-access control protocol for a cellular packet CDMAcarrying multirate traffic

We propose and evaluate a medium-access control (MAC) protocol for synchronous cellular packet direct-sequence code-division multiple-access (DS/CDMA). The protocol is designed for handling a variety of multimedia traffic types in an integrated wireless-access network (IWAN). For instance, the protocol is suited for carrying multiple traffic types of different priorities. An analytical model for the equilibrium state has been developed for the proposed protocol. A comparative evaluation of the protocol is done for three different radio frequency bandwidths currently under consideration for personal communication services (PCS), i.e., 1.25 MHz, 5 MHz, and 10 MHz. Our results demonstrate that the proposed protocol is both robust and flexible for the intended IWAN applications. It offers a significant multiplexing gain as the bandwidth increases     

环境保护地理信息系统的设计

本文主要介绍基于计算机网络的通用型环境保护地理信息系统的功能和实现方法。     

基于DICOM标准全方向M型心动图的软件系统设计

本文介绍了基于DICOM标准全方向M型心动图软件系统的设计方案,详细分析了系统结构及各个模块功能.通过该系统可以直接准确地定量检测分析心脏各结构的舒、缩、形变过程及其数据,同时可以生成多个任意方向且互相同步的M型心动图.各个模块设计完全遵循DICOM标准,同时结合数据库管理,方便查询索引.该系统分析的影像数据可以来自PACS服务器,也可以来自本地系统,分析结果数据可以回传PACS服务器,也可以保存本地.该系统实现了国家发明专利"全方向M型心动图方法及其系统98 125713.5"系统数据和国际医学图像传递标准的接口.     

JOINING MECHANISMS OF β''''-Al2O3 CERAMIC AND PYREX GLASS TO Al MATRIX COMPOSITE

The bonding of β'-Al2O3 and pyrex glass to Al matrix composites by anodic bonding process is achieved. The microstructure of the bonded interface and the joining mechanisms are analyzed with scanning electron microscope (SEM), energy dispersive X-ray fluorescence spectrometer (EDX). It is observed that the bonding region across the interface consists of the metal layer, oxide transitional layer and the ceramic layer, with the transitional layer composed of surface region and sub-surface region. The bonding process can mainly be categorized into anodic bonding process and solid state diffusing process. The pile-up of the ions and its drift in the interface area are the main reasons for anode oxidation and joining of the interface. The temperature, voltage and the drift ions in the ceramic or glass during the bonding process are the essential conditions to solid state diffusing and oxide bonding at the interface. The voltages, temperature, pressure as well as the surface state are the main factors that influence the anodic bonding.     

兰州重离子加速器大型真空室

已建成的兰州重离子加速器的真空室是一个大型整体结构的超高真空容器,直径约10m,高4.5m,重65000kg,内表面积211m~2,容积100m~3,工作真空度为5×10~(-5)Pa。采用有限单元法在计算机上用SAP-5C程序对真空室受力分析进行了计算。真空室结构材料选用瑞典Uddeholm钢厂生产的316 L 超低碳不锈钢。承制此大型容器的是航天工业部风华机器厂。由于结构庞大,首先将真空室分成八大块和几小块在工厂制造,然后运至现场焊制成一整体容器并进行机械加工。所有密封焊缝均用着色渗透液,X-射线探伤和氦质谱探漏仪进行检查和探漏。     

Tri-Gate Bulk MOSFET Design for CMOS Scaling to the End of the Roadmap

A tri-gate bulk MOSFET design utilizing a low-aspect-ratio channel is proposed to provide an evolutionary pathway for CMOS scaling to the end of the roadmap. 3-D device simulations indicate that this design offers the advantages of a multi-gate FET (reduced variability in performance and improved scalability) together with the advantages of a conventional planar MOSFET (low substrate cost and capability for dynamic threshold-voltage control).