On-line estimation of concentration parameters in fermentation processes

INTRODUCTION Saccharomycete, closely linked with human life, is the only microbe that has been utilized to the extent of over a million tons in the world, and is one of the modelled biological bacteria mostly used in modern genetic engineering. Since there are no effective online instruments for measuring the production or resultant concentration, which is a very important quality index in fermentation process, soft sensors (Martin, 1997; Tham et al., 1991; Assis and Filho, 2000; Salgad…     

浅谈计算机网络在学籍管理中的应用

讨论网络化过程中应该重点关注的几个问题:网络环境中学籍管理模式的改变,部门之间的数据共享,学籍数据的安全性问题,由单纯的成绩处理转型为业务型+辅助决策型。     

Modeling of D-STATCOM in distribution systems load flow

This paper presents modeling of Distribution STATCOM (D-STATCOM) in load flow calculations for the steady- state voltage compensation. An accurate model for D-STATCOM is derived to use in load flow calculations. The rating of this device as well as the direction of required reactive power injection for voltage compensation in the desired value (1 p.u.) is de- rived and discussed analytically and mathematically by the phasor diagram method. Furthermore, an efficient method for node and line identification used in load flow calculations is presented. The validity of the proposed model is examined by using two standard distribution systems consisting of 33 and 69 nodes, respectively. The best location of D-STATCOM for under voltage problem mitigation approach in the distribution networks is determined. The results validate the proposed model for D- STATCOM in large distribution systems.     

新加坡的教育分流制度及对我国教育改革的启示

本分析了新加坡教育分流制度的理论依据，对其教育分流制度进行了详细的阐述，并从精英与大众，划一与求多，职教与普教三个方面研究 新加坡的教育分流制度对我国教育改革的启示。     

浅谈普通高校涉密人才流动中的保密管理

随着我国市场竞争机制的逐步建立和完善,普通高校涉密人才竞争和流动不可避免地频繁和活跃起来。涉密人才流动在推动经济社会进步方面发挥着其不可替代的作用。但也存在不少问题,导致失泄密和窃密事件的发生。尽快解决这些问题,促使普通高校人才流动走向合理、合法,将能进一步发挥人才流动的积极作用。     

PEMFC分散发电系统的压力控制研究

NomenclatureA-area ( m2)Dw-membrane water diffusivity ( m2/s)F-=96 487I-current (A)M-molecule mass (kg/mol)T-temperature (K)W-mass flowrate (kg/s)cw-water concentration in membrane ( mol/m3)m-mass (kg)n-cell numbernd-electro-osmotic drag coefficientp-pres…     

CuO气敏元件的制备及气敏性能研究

用Cu2O制备CuO气敏元件，对乙醇、汽油、丁烷和氢气等气氛进行气敏试验，并进行机理分析，结果表明，由Cu2O制备的CuO气敏元件，对所测气体的灵敏度优于由CuO制备的气敏元件。     

液固两相槽道流中柱状粒子取向的数值研究

对柱状粒子在槽道流场内的运动进行数值模拟，然后用统计方法得出大量柱状粒子的取向分布；给出了粒子长径比、粒子密度和流场区域对粒子取向分布的影响．计算结果表明，柱状粒子长径比的变化对粒子取向分布的影响不明显，粒子密度对粒子取向分布有一定影响，而流场区域所造成的流场横向速度梯度对粒子取向分布有重要影响．随着流场横向速度梯度增大，粒子取向趋势愈加明显，且当流场横向速度梯度增大到一定程度时，粒子取向都趋向于流动方向．文中部分结果与相关实验进行了比较，两者定性吻合较好。     

嘉善县水稻土和稻米的硒含量状况及提高稻米硒水平的研究

对嘉善县水稻土和稻米的硒含量进行了分析.水稻土的有效态硒含量为9.52±2.26ppb,稻米硒平均为0.029±0.006ppm,普遍低于0.040ppm.提高稻米硒的田间试验表明,在水稻齐穗期喷施20ppm亚硒酸钠,可使稻米硒水平提高3～4倍,早、晚稻的稻米硒含量分别为0.197±0.149ppm和0.153±0.101ppm.     

论网站信息流整合及其对人流的导引

网站信息流是互联网信息传递的基本形式和唯一介质，是众多形态“流”中最具影响，并对人流的产生与变化发挥巨大的导引作用。本文以网站信息流的整合为切入点，从信息流受众接受信息的角度出发，将网站信息流对人流的导引视为主动式导引、被动式导引和互动式导引，剖析了与网站信息流导引密切相关的多种人流规律。