基于AD7730动态称重系统研究

AD7730是一款专门应用于质量和压力等低频信号处理的变换单元,它包含A/D转换器、数字滤波器、串行通信端口和自动校准微处理器。文中针对邮政物流配送中心恶劣的称重环境,使用AD7730设计一种简单、可靠性高的动态称重系统,给出了系统电路框图和部分软件流程。     

基于 LZ77 算法的文本压缩软件的实现

为了研究LZ77算法的对文本文件的压缩性能,在分析LZ77算法的基础上给出了实现压缩和解压缩软件的方法,并且采用该软件分别对英文文本和中文文本压缩情况进行了测试,最后给出了测试结果分析。     

基于虚拟仪器技术的 77 GHz 毫米波雷达 目标运动参数模拟校准装置

77 GHz 毫米波雷达技术已臻成熟且被广泛应用于智能汽车环境感知、机动车安全车距检测等领域。 为了评价和确保 其在实际使用中的工作性能,77 GHz 毫米波雷达的目标运动参数在使用前必须进行校准。 提出了基于虚拟仪器技术的 77 GHz 毫米波雷达目标运动参数模拟校准方法,并搭建了一套基于虚拟仪器技术的模拟校准装置。 分析了模拟校准方法的基本原理 以及模拟校准装置的主要设计思路与技术参数,选取了一款 77 GHz 毫米波雷达样品进行速度与距离模拟校准试验,从测量重 复性、雷达分辨力及模拟校准装置精度等方面对试验结果进行了不确定度评定。 速度与距离模拟校准试验结果的扩展不确定 度分别为 0. 7 km/ h 和 0. 12 m (k = 2),初步验证了模拟校准方法的可行性及模拟校准装置的模拟性能。     

A series of 0‐3 composites of lead zirconate titanate and ferroelectric nylon77: Preparation and electrical properties

A series of 0‐3 composites of lead zirconate titanate (PZT) and nylon77 was prepared with PZT volume fractions between 0.1 and 0.6 using the combined method of solvent casting and hot pressing. Depending upon the volume fraction of PZT, the relative permittivities of the composites were found to be in the range of 200–2000 when measured at the highest practically possible temperature of 200°C. As PZT volume fraction increases, both the relative permittivity and the piezoelectric constant d₃₃ increase. The best combination of electrical properties and flexibility was obtained in 0.5 PZT volume fraction composites. At this composition, the remanent polarization P_r of composites was up to 1000 mC/m² at the applied electric field of 40 MV/m and it increased with an increase in temperature. The highest piezoelectric strain coefficient d₃₃ was obtained at 17 pC/N in 0.6 PZT volume fraction composites. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

HAl77-2铜合金管在低温多效海水淡化装置中的耐蚀性

采用实验室模拟研究的方法,通过腐蚀电化学测试和腐蚀形貌观察,借助表面物相结构和元素成分分析,比较了3种海水淡化所用的HAl77-2铜合金热交换管的耐蚀性以及平均晶粒度,分析了它们在海水介质中的腐蚀失效机制。结果表明:HAl77-2铜合金管的电化学阻抗均随浸泡时间的延长而逐渐增大,在达到极大值后,又会出现在极大值附近波动的现象;相比较而言,1号管样的耐蚀性最好、晶粒度最小,而3号管样的耐蚀性最差、晶粒度最大。     

The implementation and use of toolpack/1 on a graphics workstation

We report on the implementation and some of the extensions to the Toolpack/1 suite of Fortran software tools and the porting of a number of numerical software libraries to the ICL PERQ workstation.     

Gewerbliche Betriebsanlagen; Immissionsschutz; Restkompetenzen der Baubehörden

Bei gewerblichen Betriebsanlagen obliegt es der Baubeh?rde im Rahmen ihrer Restkompetenzen nur zu prüfen, ob eine ?rtlich unzumutbare Bel?stigung von Menschen durch Emissionen vorliegt. Die ?rtliche Zumutbarkeit ist nach der für das Baugrundstück im Fl?chenwidmungsplan festgelegten Widmungsart (hier: Industriegebiet) und der sich daraus ergebenden zul?ssigen Auswirkung des Bauwerks und dessen Benützung auf einen gesunden, normal empfindenden Menschen zu beurteilen. Es kommt dabei auf die Immissionsbelastung an der Grundgrenze des Nachbarn an.     

TILTVEC: A fortran-77 program for the tilt correction of paleocurrent data with resolution of incongruities

TILTVEC is a FORTRAN-77 program for tilt corrections of paleocurrent data, which may be measurements on planar crossbeds or trough crossbeds. Tilt correction is effected by rotation of the dipping formation to its assumed initial horizontal position around present formation strike. The program borrows partly from a rotation of poles algorithm based on the transformation of the axes of the reference coordinate system. But new program modules take care of fallacies arising out of the distinction between axial data (poles) and vector data (paleocurrent directions).     

The catalytic activity of Ru and Ir supported on Eu2O3 for the reaction,CO2 + CH4 ⇄ 2 H2 + 2 CO: a viable solar-thermal energy system

Methane and carbon dioxide which often co-exist in nature, constitute valuable potential resources both for the storage of solar (thermal) energy and the convenient production of synthesis gas. Ru and Ir supported on Eu₂O₃ are effective catalysts for the reforming of methane with carbon dioxide to produce synthesis gas with no significant coke formation even after prolonged activity. Ru catalysts show onset of activity around 673 K reaching a maximum at about 973 K. Loadings as low as 1% by weight of Ru are highly effective. Ir catalysts show onset around 823 K reaching a maximum conversion in excess of 94% with respect to CO₂ at 1023 K for a 1% loading of the metal. X-ray absorption studies on the spent Ru/Eu₂O₃ catalysts indicate the presence of the reduced metal, primarily in the form of large spherical particles (> 30 Å) of hexagonal structure. 5% Ir supported on Eu₂O₂ was found to transform an equimolar mixture of H₂ and CO to methane and carbon dioxide with a 42% conversion with respect to H₂ at around 848 K and atmospheric pressure. A 5% loading of Ru on Eu₂O₃ produced a 14% conversion with respect to H₂ at 973 K under similar conditions.Commonwealth Academic Fellow on leave from University of Peradeniya, Peradeniya, Sri Lanka.     

基于单片机的多媒体自动控制系统的设计

利用投影仪提供的RS-232串口连接器和W77E58单片机与PC机之间的串口通信,设计了多媒体设备的自动控制方案:阐述了PC机、单片机通过串口通信控制投影仪和其它多媒体设备的过程,并给出了串口通信协议;以VB6.0编写了PC杌上的控制软件,最后经过整体测试效果很好,证明在工程实施中是切实可行的.