基于PCI总线的1553B总线接口卡设计

针对MIL-STD-1553B数据总线协议及其接口技术要求．介绍了一种基于PCI总线的1553B接口卡的工作原理和设计方案．该接口卡可编程选择工作在BC、RT或BM模式，并介绍了在这三种模式下的软件编程的基本例程。     

PVA/PAA/BC复合水凝胶的制备与性能

利用冰冻-解冻循环法制备聚乙烯醇（PVA）/聚丙烯酸（PAA）/细菌纤维素（BC）复合水凝胶.研究BC与单体丙烯酸（AA）用量对PVA/PAA/BC复合水凝胶的力学性能和溶胀特性的影响,初步探讨PVA/PAA/BC复合水凝胶的pH敏感性.实验结果表明：随着BC添加量的增多,PVA/PAA/BC复合水凝胶的含水率和拉伸强度与PVA/PAA水凝胶相比均有一定程度的提高,SEM表明复合水凝胶的网络交联点增多;加入AA会使复合水凝胶拉伸强度减小,但溶胀性能提高很多.综合考虑,BC添加量为4%,AA添加量为8%时,各项性能均较好.     

Turbulent natural convection in an enclosure with localized heating from below

This study reports the results of a numerical investigation of turbulent natural convection in a square enclosure with localized heating from below and symmetrical cooling from the vertical side walls. The present study simulates the case of an accidental heat generation due to fire in a typical isolated building of a nuclear reactor or electronic components cabin. The source of fire is considered to be centrally located at the bottom wall with different heated widths, which is assumed to be either isothermal or with isoflux. For the purpose of the analysis, the source length is varied from 20 to 80% of the total width of the bottom wall. The top wall and the unheated portion of the bottom wall are considered to be adiabatic, whereas sidewalls are isothermal. Steady as well as transient forms of two-dimensional Reynolds–Averaged-Navier–Stokes equations and conservation equations of mass and energy, coupled with the Boussinesq approximation, are solved by the control volume based discretisation method employing the SIMPLE algorithm for pressure–velocity coupling. Turbulence is modeled using the standard k–ε model. Rayleigh number, Ra, based on the enclosure height is varied from 10⁸ to 10¹². Stream lines and isotherms are presented for various combinations of Ra and the heated width. A double cell flow pattern is observed with marginal loss in symmetry as Ra increases. The results are reported in the form of local and average Nusselt number on the heated floor. Correlations are developed to predict the heat transfer rates from the enclosure as a function of dimensionless heated width of the bottom wall and Ra, by least square linear regression analysis.     

在氢环境中16Mng钢的短裂纹低频疲劳特性

研究了在氢环境中１６Ｍｎｇ钢的低频短裂纹扩展规律。应用弹塑性断裂力学和△Ｊ参数,用ｄａ／ｄＮ＝Ｃ（△Ｊ）ｎ计算裂纹的扩散速率。结果表明ｄａ／ｄＮ～△Ｊ关系曲线分三个阶段;并得到了在氢环境中裂纹扩展的门槛值△Ｊ（ｔｈ）。用金相法考察了裂纹扩展的途径。     

基于CPLD的GPIB控制器的设计与实现

设计中采用LATTICE公司的LC4512芯片实现GPIB控制器BC1400.采用模块化设计方法,使设计过程简化,并具有设计再利用和优良的可扩展性.     

高分子树脂对正己烷的吸附－脱附性能研究

以ＤＡ－１,ＤＡ－２和Ｄ８三种商业树脂为吸附剂,考察了高分子树脂对典型油气废气正己烷的 吸附－脱附性能．研究表明：在吸附实验中,高分子树脂对正己烷均表现出良好的吸附性能,其中 ＤＡ－１和ＤＡ－２树脂具有大孔容、大比表面积和较小的孔径等特点,更有利于正己烷分子吸附;脱附 实验中,真空脱附效果优于热脱附,在脱附温度达９０℃,脱附时间３０ｍｉｎ,真空度为０．８时,脱附效 率接近１００％．     

催化剂LV-23 BC在蜡油催化裂化装置上的工业应用

在100万t/a蜡油催化裂化装置上进行了催化剂LV-23 BC的工业应用试验。结果表明,在原料和主要操作条件基本不变的情况下,产品干气收率下降了0.83个百分点,焦炭收率下降了1.24个百分点,汽油收率下降了3.02个百分点,液化气收率提高了0.85个百分点,柴油收率提高了4.24个百分点,液收提高了2.07个百分点;LV-23 BC中铁、镍等金属含量较低,且对产品柴油、干气、液化气等质量无不良影响。     

AZ81镁合金压入蠕变性能

采用自制装置对AZ81镁合金进行压入蠕变实验,通过建立稳态压入蠕变本构模型分析合金的蠕变机制,利用扫描电镜(SEM)和X射线衍射(XRD)等方法研究合金蠕变前后的组织和成分。结果表明:压铸AZ81合金在稳态蠕变阶段的应力指数n为2.08,蠕变激活能QC为87.26 kJ/mol;蠕变诱导β相首先由非连续方式析出,到达一定程度后连续析出;沿晶界析出的β相导致合金抗蠕变性能降低;蠕变温度越高,基体和析出相的晶粒尺寸越大;压铸AZ81合金的压入蠕变机制为晶界扩散主导的位错交滑移运动。     

超薄Ni81Fe19薄膜的各向异性磁电阻及磁性能

利用磁控溅射方法制备了一系列超薄Ta(5nm)/Ni81Fe19(20nm)/Ta(3nm)磁性薄膜。着重研究了基片温度、缓冲层厚度对Ni81Fe19薄膜各相异性磁电阻(AMR)及磁性能的影响。利用X射线衍射仪分析了薄膜结构、晶粒取向;用四探针技术测量了薄膜的电阻率和各向异性磁电阻;用FD-SMOKE-A表面磁光克尔效应试验系统测量了薄膜的磁滞回线。结果表明:在基片温度为400℃时制备的Ni81Fe19薄膜具有较大的各向异性磁电阻效应和较低的磁化饱和场,薄膜最大各向异性磁电阻为3.5%,最低磁化饱和场为739.67A/m。基片温度为500℃制备的薄膜,饱和磁化强度Ms值最大。随着缓冲层厚度x的增加,坡莫合金薄膜的AMR值先变大后减小,在x=5nm时达到最大值。