互感器传输窄脉冲RC展宽的驱动器设计方法( 下)

介绍了RC展宽电路工作原理、稳定工作的条件、防交互干扰措施、窄脉冲宽度τ1=τ2的选择原则,分析了RC展宽电路顶降产生的原因和不可消除性、RC时间常数与脉宽τ的比例关系以及负偏压保存的条件,讨论了铁芯Sc的选择原则和采用平衡变压器的可行性,并提出一种新型的R+ VS2加速网络和更为简化的RC展宽电路.     

基于B/S的组合机床设计系统开发

利用PRO/E软件、SQL2005数据库和VS.net编程软件为开发平台,采用Top-Down技术,建立了组合机床的参数化三维模型图库并开发了基于B/S的组合机床异地设计系统.用户通过浏览器在组合机床设计系统的引导下可完成对组合机床设计的动力头功率计算模块、自动匹配组合机床模块、自动装配、生成三图一卡等总体设计和主轴箱等模块的详细设计,提高了产品的开发能力,缩短了产品的设计周期,降低了生产成本.     

Mild alkaline pre-treatments loosen fibre structure enhancing methane production from biomass crops and residues

Three ligno-cellulosic substrates representing varying levels of biodegradability (giant reed, GR; fibre sorghum, FS; barley straw, BS) were combined with mild alkaline pre-treatments (NaOH 0.05, 0.10 and 0.15 N at 25 °C for 24 h) plus untreated controls, to study pre-treatment effects on physical-chemical structure, anaerobic digestibility and methane output of the three substrates. In a batch anaerobic digestion (AD) assay (58 days; 35 °C; 4 g VS l⁻¹), the most recalcitrant substrate (GR) staged the highest increase in cumulative methane yield: +30% with NaOH 0.15 N over 190 ml CH₄ g⁻¹ VS in untreated GR. Conversely, the least recalcitrant substrate (FS) exhibited the lowest gain (+10% over 248 ml CH₄ g⁻¹ VS), while an intermediate behaviour was shown by BS (+15% over 232 ml CH₄ g⁻¹ VS). Pre-treatments speeded AD kinetics and reduced technical digestion time (i.e., the time needed to achieve 80% methane potential), which are the premises for increased production capacity of full scale AD plants. Fibre components (cellulose, hemicellulose and acid insoluble lignin determined after acid hydrolysis) and substrate structure (Fourier transform infra-red spectroscopy and scanning electron microscopy) outlined reductions of the three fibre components after pre-treatments, supporting claims of loosened binding of lignin with cellulose and hemicellulose. Hence, mild alkaline pre-treatments were shown to improve the biodegradability of ligno-cellulosic substrates to an extent proportional to their recalcitrance. In turn, this contributes to mitigate the food vs. fuel controversy raised by the use of whole plant cereals (namely, maize) as feedstocks for biogas production.     

数字化医院网络平台建设研究

数字化医院是我国现代医疗发展的趋势,是医院业务软件、数字化医疗设备、网络平台组成的三位一体的综合信息系统,可以有效实现医院资源整合、流程优化,进一步提高医疗服务质量、工作效率和管理水平,而网络平台是数字化医院建设中重要组成部分和通信链路支撑。文章通过研究数字化医院数据流量模型特征,分析医院网络架构要求,引入基于网络虚拟化的新型网络系统和安全域策略,实现网络资源的灵活调度,更好的适应未来数字医疗领域的多业务发展。     

光伏电站的无线监控系统设计与实现

本文介绍了几种普遍应用于光伏系统中的远程监控技术,并在东方日立（成都）电控设备有限公司自主研发的光伏逆变器基础上,开发了结合RS485总线和射频无线通讯的光伏电站监控系统,使远程控制中心可实时监控多台光伏逆变器的运行情况和数据。系统已在两个光伏电站长时间连续稳定地运行,表明该方案具备工程应用性。     

SOL Server2000数据库部署的C#实现方法

介绍VS2008环境下,利用Installer类完成SQL Server 2000数据库部署的设计思路,并给出了创建一个安装程序的基本实现步骤技巧和详细的程序代码、技巧     

分幅等高线接边算法的设计与实现

分幅数字化后相邻图幅的等高线拼接问题,是地理信息系统中数据处理方面必须解决的问题.在吸取了ArcGIS处理该问题的优点的基础上,提出了分幅等高线智能化接边的约束条件和算法,并利用ArcGIS Engine实现该处理方法.在该算法的实现过程中,运用等高线的几何关系和属性特征进行对接边等高线的筛选,在充分考虑接边存在的各种异常情况前提下,确定接边规则,从而实现等高线的无缝拼接.     

Evaluation and simultaneous optimization of bio-hydrogen production using 3 factorial design and the desirability function

Various mixtures incorporating a simulated organic fraction of municipal solid wastes and blood from a poultry slaughterhouse were used as substrate in a dark fermentation process for the production of hydrogen. The individual and interactive effects of hydraulic retention time (HRT), solid content in the feed (%TS) and proportion of residues (%Blood) on bio-hydrogen production were studied in this work. A central composite design and response surface methodology were employed to determine the optimum conditions for the hydrogen production process. Experimental results were approximated to a second-order model with the principal effects of the three factors considered being statistically significant (P < 0.05). The production of hydrogen obtained from the experimental point at conditions close to best operability was 0.97 L Lr⁻¹ day⁻¹. Moreover, a desirability function was employed in order to optimize the process when a second, methanogenic, phase is coupled with it. In this last case, the optimum conditions lead to a reduction in the production of hydrogen when the optimization process involves the maximization of intermediary products.