铝基印制板的成型及压板翘工艺

简述铝基板冲板模具的设计、调试的要点及发生问题的解决方案,重点叙述了通过利用压板翘模具得以成功解决铝基板冲板后板翘的问题。     

基于μC/OS-II生物脱氮工艺中多参数实时检测

为实现对生物脱氮工艺中多参数的实时检测,以及解决常规化学检测过程中带来的污染和耗时问题。应用了一种基于电化学和嵌入式系统,可同时对水温、pH值、氨氮3个相关参数进行实时检测,并对理论值和实测值进行数据分析对比。实验结果表明,该系统实时性良好、稳定可靠,且满足了该工艺实时检测要求。     

Magnetic,Photoluminescent and Semiconductive Properties of a Novel 4f-5d Bromide Compound (La6HgsBr26) [4(HgBr2)l (2Br)

An unprecedented 4f-5d material(La6Hg5Br26)[4(HgBr2)](2Br)(1)was syn-thesized by hydrothermal reactions and structurally characterized by single-crystal X-ray diffraction method.Complex 1 crystallizes in the Pbam space group of orthorhombic system with a=13.0980(10),b=13.6650(9),c=28.010(2)?,V=5013.4(6)?^3,Br36Hg9La6,Mr=5515.53,Z=2,Dc=3.613 g/cm^3,μ(MoKα)=29.457 mm^–1 and F(000)=4598.Compound 1 is characteristic of a two-dimensional(2D)layered structure.The photoluminescent measurements with solid-state samples reveal that compound 1 has a strong emission in the green region of light spectrum.It has remarkable CIE chromaticity coordinates of(0.2499,0.3589).A wide optical band gap of 3.41 eV is discovered by the solid-state UV/vis diffuse reflectance spectrum.The variable-temperature magnetic susceptibility obeys the Curie-Weiss law(cm=c/(T–q))with C=2.48 K and a negative Weiss constantθ=–169.07 K as revealed by the magnetic measurements,indicating the existence of an antiferromagnetic interaction in compound 1.     

NUMERICAL SIMULATION OF THREE-DIMENSIONAL INCOMPRESSIBLE FLOW BY A NEW FORMULATION

A new mathematical formulation, called the pseudovorticity–velocity formulation, of the three-dimensional incompressible Navier–Stokes equations is presented as an alternative to the vorticity–velocity approach. For the model lid-driven cavity flow problem in two and three dimensions, combined with an explicit mixed spectral /finite different numerical scheme the proposed formulation is found to be efficient and very accurate as compared with the results available in the literature. In particular, the simulation results demonstrate an attractive feature of the present formulation compared with the vorticity–velocity approach, namely that the divergence-free condition of the velocity field can always be achieved on a non-staggered mesh.     

IMPACT OF BUSY LINES AND MOBILITY ON CALL BLOCKING IN A PCS NETWORK

Several analytical models have been proposed to study the blocking probability for personal communications service networks or mobile phone networks. These models cannot accurately predict the blocking probability because they do not capture two important features. First, they do not capture the busy-line effect. Even if a cell has free channels, incoming and outgoing calls must be dropped when the destination portable is already in a conversation. Second, they do not capture the mobility of individual portables. In these models, mobility is addressed by net hand-off traffic to a cell, which results in traffic with a smaller variance to a cell compared with the true situation. We propose a new analytic model which addresses both the busy-line effect and individual portable mobility. Furthermore, our model can be used to derive the portable population distribution in a cell. The model is validated against the simulation experiments. We indicate that the previously proposed models approximate a special case of our model where the number of portables in a cell is 40 times larger than the number of channels.     

可编程序控制器(PLC)在电台的应用

1概述 可编程序控制器（PLC）是一种数字运算操作的电子系统,是以微处理器为基础,综合了计算机技术、自动控制技术和通信技术的一种新型的、通用的自动控制装置,虽然它专为在工业环境下应用而设计,但是,它采用了可编程序的存储器,用来在其内部存储执行逻辑运算、顺序控制、定时、计数和算术运算等操作命令,并通过数字式、模拟式的输入和输出控制各种类型的设备。它具有体积小、功能强、程序设计简单、可靠性高、使用灵活方便、     

Nonexistence of Global Solutions for a Semilinear Double-Wave Equation with Nonlinearity of Derivative Type

In this paper,we study the blow-up of solutions to a semilinear double-wave equation with nonlinearity of derivative type.By using the iteration method and the ...     

三功能合一的含铽高聚物的光谱性质研究

制备了一种新型的可平衡电荷(空穴与电子)传输的含铽高聚物。用红外光谱、飞行时间二次离子质谱、紫外光谱研究了其光谱性质,确认这种高聚物含有咔唑、铽络合物、噁二唑单元。用荧光光谱研究了不同状态下高聚物的荧光性质,来自共轭基团的荧光出现“荧光猝灭”。在紫外光照射下,高聚物可发出具有铽离子特征发射的纯绿光。     

一种小型校园网的组网方案

提出一种小型校园网的组网方案,从逻辑上把校园网分成校务网、教学网、公共网等三个独立的业务网,使用MA5200F作为核心组网设备,使用Quidway○RS2026和Quidway○RS3026做为各逻辑组成的交换机,使用Eudemon 100为专用硬件防火墙设备,并通过S2026的端口的VLAN特性对其用户进行VLAN的划分和访问权限的控制,这使得构建出来的校园网具有性能高、扩展性高、安全性高和管理简单等特点.