Separation of mixtures in connected channels

The stationary modes of thermal convection of a binary mixture in connected channels of finite height were studied experimentally and theoretically. The effects of positive and negative thermal diffusion on the convection were examined. The ranges of parameters corresponding to the modes of soft and rigid initiation of convection were determined. Vertical distributions of the temperature and concentration fields were found for various values of the thermal diffusion parameter. __________ Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 50, No. 1, pp. 68–77, January–February, 2009.     

Determination of the Stoichiometric Composition of High-Temperature Superconductors by ICP-OES for Production Control

 A procedure to dissolve and analyse different types of high-temperature superconducting materials in order to determine their stoichiometric com- position is described. As sample materials Y-Ba-Cu-O and (Pb)Bi-Sr-Ca-Cu-O were analysed. They were dissolved with hydrochloric acid and analysed by simultaneous ICP-OES, which fits best for this analytical task because of its multielement capacity, its high precision of determination and accuracy. Each of the relevant metals (Pb, Bi, Sr, Ca, Y, Ba, Cu) could be determined successfully. The precision of the determination was found to be better than 2% relative standard deviation and usually even below 1%. The sample preparation and determination procedure described allows a high sample throughput, which is essential for production control. Also precursors of the superconducting materials (e.g. nitrate solutions) could be analysed by the procedure described.     

航空摄影陀螺稳定平台的嵌入式计算机控制系统

针对航空摄影陀螺稳定平台的特殊要求，论证了嵌入式控制模型，采用数据流程图对系统软件进行了分析，设计了应用于陀螺稳定平台的计算机控制系统。系统试验和飞行试用结果表明：该计算机控制系统具有功能强，可靠性高的特点。陀螺稳定平台已成功地应用于航空摄影领域。     

Momentum and energy exchange in nonequilibrium multicomponent media

In multicomponent media, the equilibrium states are defined by thermodynamic equilibrium conditions in the form of the equalities between the pressures and temperatures of the components, the maximum entropy principle (or the free-energy minimum) for the mixture, and the equality of the velocities of the components. The conservation laws for the components allow for their interaction with each other in the form of forces and energy fluxes containing the differences of the velocities, pressures, and temperatures of the components. The form of momentum and energy exchange between each component and the continuum expressing the collective properties of the ensemble of components, is also considered. It is shown that these momentum and energy fluxes are different from zero only for the states of multicomponent media with velocity nonequilibrium.Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 46, No. 1, pp. 7–15, January–February, 2005.     

A new N-body potential and its application

Based on the embedded atom method (EAM) proposed by Daw and Baskes and Johnson's model, this paper constructs a new N-body potential for bcc crystal Mo. The procedure of constructing the new N-body potential can be applied to other metals. The dislocation emission from a crack tip has been simulated successfully using molecular dynamics method, the result is in good agreement with the elastic solution. The project supported by the National Science Foundation of China     

用内埋电阻丝检测复合材料层压板损伤的可行性研究

本文利用低速冲击装置冲击四周简支复合材料板试样，用以模拟低速低能量冲击而造成的分层损伤；用中心钻孔复合材料板试样用以模拟因高速冲击而造成穿透性损伤。探讨利用内埋康铜电阻丝阵列构成检测网络实现对复合材料中损伤位置和损伤程度检测。这种方法可利用较成熟的电测技术，装置简单，具有良好的工程应用前景     

基于μC／OS-Ⅱ的嵌入式USB控制软件的实现

在此以杭州中天32位RISCCPUCK510为内核的HM1521_B芯片上,基于μC／OS-Ⅱ操作系统,实现对USB设备的读写控制。系统采用嵌入式USB主机控制软件的分层结构,着重阐述FAT32文件系统、USB设备枚举和BULK—ONLY传输的具体实现过程。为了节省硬件资源,放弃了USB协议中的繁文缛节,抓住协议核心,设计了精简高效的驱动程序。考虑到各种U盘的不同特性,增强了驱动兼容性方面的设计。整个阶段都由逻辑分析仪给出实测数据抓包截图。     

A Quantitative Determination of Atmospheric Deposition Sources in the “Campo de Gibraltar” Region,Using Factor Analysis and Chemical Element Balance

Abstract

Factor analysis and chemical element balance were employed to identify and quantify the major atmospheric deposition sources at 12 sampling stations in the “Campo de Gibraltar” Region. The data were best represented with 5 sources: soil, marine aerosol, residual fuel oil, refuse and limestone. Predicted concentrations account for about 80% of measured total deposition.     

一种变周期区间内随机信号的监控方案

利用Cyclone III系列FPGA实现了对变周期区间内随机信号的监控,并提供一种随机反馈信号的监控算法。     

嵌入式Web污染源自动监测系统

针对当前我国污染源监测系统存在的问题．采用基于32位AT91SAM7X系列微处理器的嵌入式Web服务器实现基于B／S模式的污染源自动监测系统。给出硬件结构图,并对其主要功能器件进行描述;给出软件平台结构图及其层次功能设计,讲解如何结合Ajax技术实现高效的Web服务器,并对系统功能做设计说明。经测试表明,系统功能完备,具有稳定性高和响应性能好的优点。