基于CANopen的自动化船舶监控系统

针对目前船舶监控系统的应用需求,基于CAN现场总线,采用CANopen船舶应用协议,开发了一套船舶监控自动化系统。该系统由上位监控主站和下位数据采集从站组成。上位监控主站是整个系统的控制中心,接收并处理CAN总线上监控从站发送过来的数据,完成对各个被测对象的监管。测试结果表明,该系统可以实时、稳定地实现对船舶各舱液位、温度、压力等监控对象数据的接收、分析、处理、显示、报警等功能,在船舶监控自动化领域有较高的应用价值。     

总线事务级验证模型仿真性能研究

系统芯片的功能验证一直是芯片设计中最具挑战性的部分。基于事务的验证方法学被用来解决功能验证中的困难。该方法学通过提高验证的抽象层次来降低验证复杂度。但同时也对使用该方法学构建的验证平台组件可重用性有了更高的要求。其中总线功能模型可以在验证中模拟设计中的其他模块,是构建验证平台的重要组件。本文在方法学的基础上,讨论了两种类型的总线功能模型,并给出了verilog硬件描述语言的实现模型,最后通过实验比较了两种总线功能模型的仿真性能。     

CMOS MEMS技术的现状及展望

简要介绍了MEMS的发展状况及CMOS工艺在MEMS中的地位。主要介绍了pre-CMOS，intermediate-CMOS和post-CMOS三种不同的CMOS MEMS工艺。详细讨论了CMOS MEMS今后将面临的挑战及其未来应用领域，最后，根据国内情况对我国CMOS MEMS的发展提出了建议。     

电力线载波通讯在热网温度监测系统中的应用

采用智能温度传感器DS18B20、热电偶及电力线载波应用于热网温度监测系统。建立了系统总体方案和拓扑结构图、选择了温度传感器,及相应的软硬件系统。实际运行表明,该系统抗干扰能力强,信号传输距离远,能够满足监测系统的要求。     

A flexible array synthesis method using quadratic programming

A highly flexible synthesis method for an arbitrary array is proposed to best approximate a desired array pattern in a minimum-mean-square-error sense. The basic idea of the technique is to form a quadratic program with its cost function given by the mean-square error between the array response and a properly selected pattern described by a known mathematical function. This quadratic program can be a constrained or unconstrained optimization problem depending on the requirements of the desired array pattern. In formulating the quadratic program, no assumption has been made on the gain/phase response or characteristics of the individual array elements. Therefore, one can synthesize an array of arbitrary shape to any appropriate pattern with the characteristic of the array elements taken into consideration as long as one is able to model the array accurately. The proposed method is used to synthesize arrays of different shapes, linear as well as planar arrays (including rectangular and circular planar arrays), using a Chebyshev polynomial or zero function as a design template, to illustrate the feasibility of the proposed method     

高效Nd:S-VAP激光器的特性研究

报道了激光二极管泵浦高效ＮｄＳ－ＶＡＰ激光器输出特性的研究结果。激光晶体掺钕浓度为～３％，厚度为２．６ｍｍ，基横模输出功率为２３３．０ｍＷ，斜率效率为４２．２％     

Support Vector Regression Model for Millimeter Wave Transitions

In this paper, we introduce a new method, support vector regression (SVR) method, to model millimeter wave transitions. SVR is based on the structural risk minimization (SRM) principle, which leads to good generalization ability for regression problem. The SVR model can be electromagnetically developed with a set of training data and testing data which produced by the electromagnetic simulation. Two Ka-band millimeter wave transitions, i.e., waveguide to microstrip transition and coaxial to waveguide adapter, are used as examples to validate the method. Experimental results show that the developed SVR models have a good predictive ability, and they are useful for interactive CAD of millimeter wave transitions.     

RAM技术在隐身飞行器薄型翼设计中的应用

雷达吸波材料 ( RAM)技术是隐身技术中的重要技术之一 ,并且在隐身武器 ,尤其是隐身飞行器系统设计中得到广泛应用。本文首先简要阐述了雷达吸波材料吸波的基本原理 ,然后以隐身导弹薄型弹翼的低雷达散射截面 ( RCS)设计为例 ,探讨了涂覆型雷达吸波材料涂覆方案的设计思想和方法 ,最后给出一部分隐身飞行器薄型翼面低 RCS设计的样例。     

Second-Order Absorbing Boundary Conditions for TLM Analysis of Open Region Scattering Problems

A set of second-order absorbing boundary conditions is derived for the three-dimensional finite-difference TLM analysis of open region scattering problems. These boundary conditions are implemented into a computer code using a two-level discretization scheme. A simulation experiment using a 4-term Blackman-Harris pulse excitation with very low sidelobes is used to examine the efficiency of the boundary conditions. It is observed that the absorbing boundaries are perfectly transparent to waves impinging upon them at angles between 0 and 45 degrees, and the normal incidence reflection coefficient is less than -35 dB.     

太湖流域不同种浮萍淀粉积累的研究

对在太湖采集的15株浮萍进行分子鉴定,从中筛选出3株高淀粉含量浮萍作为供试材料,对其生长培养基进行优化,并研究饥饿条件对其生长和淀粉积累的影响。结果表明:采集到的浮萍分布于5个种,分别为Lemna aequinoctialis,Lemna minor,Lemna turionfera,Spirodela polyrhiza,Landoltia punctata;与SH培养基相比,改良的培养基SH-1和SH-2均能显著促进浮萍的生长;在饥饿试验中,筛选的3种浮萍S.polyrhizza,L.aequinoctialis和L.punctata每周的生长速率(以鲜重计)分别为18.64,20.77和16.52g/m2,饥饿培养33 d后,淀粉含量分别达到20.6%,21.98%和24.30%,较饥饿前分别增加了73.4%,75.4%和137.5%。相较于S.polyrhiza和L.aequinoctialis,L.punctata在淀粉积累方面表现出一定的优势。