建筑墙体表面传热系数辨识研究

对实验房间南向墙体内表面中心区域的换热过程进行实验，发现当风速在0－5．5m/s之间时，表面传热系数在8－18W（m^2.K）之间波动，而风向对墙体表面传热系数影响不大；用辅助变量法分析墙体表面传热过程，并结合实验推导出墙体表面传热系数。模型的预测结果与实测结果吻合良好。     

三峡地下电站变顶高尾水洞水动力特性

在国内首次应用模型水轮发电机组对三峡地下电站变顶高尾水洞方案进行水力过渡过程试验研究。对水轮机导叶实行分段关闭 ,并求出了二段关闭的最佳拐点 ,试验证实了二段关闭对减小尾水管进口的负压和机组转速上升有明显的作用。通过有关水力参数的测试 ,认为变顶高尾水洞可以满足各项技术要求 ,是一个减少山体开挖、节省投资的新型设计方案。在地下电站中具有广泛的应用前景     

冲击噪声背景下的近场源二维参数估计方法

本文针对背景噪声为冲击噪声的情况,提出了一种新的近场源二维参数估计方法.本方法利用协变异(或协变异系数)构造矩阵,并通过求根的方法估计近场源的方向角和距离参数.该算法可以抑制冲击噪声对估计性能的影响,同时具有无需谱峰搜索的优点.仿真实验证明了该算法的有效性.     

变频器在暖通空调行业中的应用

本文提出中央空调系统的一种变频调速改造方案，介绍了该系统的结构组成及运行原理，对系统各部分的作用进行了讨论。     

高速逆流色谱(HSCCC)在食品色素制备中的应用

综述了高速逆流色谱在食品色素制备中的应用情况，包括溶剂选择、色素种类等。     

Extracellular polysaccharides production by Arthrobacter viscosus

In this study the production of extracellular polysaccharides by the non-pathogenic soil bacteria Arthrobacter viscosus has been investigated. Different variables affecting extracellular polysaccharide production such as the carbon source (glucose or xylose), the agitation speed and the pH have been analysed.

In a first stage, experiments in shaken conical flasks (250 ml), containing 50 ml of culture medium, were carried out. Using xylose (25 g/l) as the carbon source at an initial pH 8 improved the extracellular polysaccharides levels obtained.

In a second stage, the experiments were scaling in bioreactors. Cultivation was carried out in discontinuous mode and with/without pH control. Polysaccharide production reached a maximum of 10 g of crude product per litre of growth medium after 14 days and the relationship between product formation and cell growth of A. viscosus is 2.7 g polysaccharide per gram biomass. This production was obtained at the optimal conditions determined with pH control at pH 7, xylose as carbon source (25 g/l) and an agitation rate of 800 rpm.     

Experience, Context, and the Visual Perception of Human Movement.

Why are human observers particularly sensitive to human movement? Seven experiments examined the roles of visual experience and motor processes in human movement perception by comparing visual sensitivities to point-light displays of familiar, unusual, and impossible gaits across gait-speed and identity discrimination tasks. In both tasks, visual sensitivity to physically possible gaits was superior to visual sensitivity to physically impossible gaits, supporting perception-action coupling theories of human movement perception. Visual experience influenced walker-identity perception but not gait-speed discrimination. Thus, both motor experience and visual experience define visual sensitivity to human movement. An ecological perspective can be used to define the conditions necessary for experience-dependent sensitivity to human movement. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

计算机高速并行通信的实现方案

利用CPLD芯片实现单片机与ISA总线接口之间的高速并行通信，给出系统的总体设计方法及程序框图。采用这种通信方式，在12MHz晶振的MCS51单片机控制的数据采集系统中，可以满足与PCI04 ISA总线接口实时通信的要求，通信速率达200khit／s。在开发工具MAX plusⅡ下，完成了整个设计的输入、编译和仿真，达到了预期效果。本设计方案能够推广应用到计算机的高速并行通信中。     

S7-226PLC与MM440变频器在光缆护套机中的应用

本文介绍了由西门子S7—226PLC与MM440变频器组成的电气控制系统在光缆护套机速度控制中的应用。并对该系统的控制原理作了详细的阐述。     

A Modified Variational-Gradient Method for Quasilinear Equations

A modified variational-gradient method is proposed and substantiated for quasilinear operator equations in a Hilbert space.