Experiments of a prototype wind-driven reverse osmosis desalination system with feedback control

A prototype wind-powered reverse osmosis desalination system was constructed and tested on Coconut Island off the northern coast of Oahu, Hawaii, for brackish water desalination. The system has four major subsystems: a multi-vaned windmill/pump, a flow/pressure stabilizer, a reverse osmosis module, and a control mechanism. The feedback control mechanism, developed by this study, allowed this prototype system to be operated satisfactorily under mild ambient wind of 5 m/s or less. No auxiliary power source was needed. The system operational data showed that at an average wind speed of 5 m/s, brackish feedwater at a total dissolved solids concentration of 3000 mg/1 and at a flow rate of 13 1/min could be processed by this system. The average rejection rate of this prototype system was 97% and the average recovery ratio was 20%. The energy efficiency of the system was measured at 3 5%, which is comparable to the typical energy efficiency of well-operated multi-vaned windmills. Generally, the system's energy efficiency decreases as wind speed increases.     

可监控EXE进程的Windows服务程序设计

EXE进程一旦意外停止,将给应用带来严重后果。该文基于微软的基础平台开发库设计了一个Windows服务程序,该服务程序在机器启动时自动运行指定EXE进程,在服务程序工作线程组中监控EXE进程运行状态,自动重启已停止进程,此服务程序可实现一个或多个EXE进程不间断运行。     

低雷诺数气液交叉流装置研究（I）——孔流液柱流动特性数值模拟

针对低雷诺数的气液交叉流气体净化过程,提出有效避免二次雾沫夹带的液柱流体力学条件。数值模拟结果表明,液柱表面随着离开孔口的距离而变化,采用公式Lb／d=2．84We^0.694能有效预测液柱的断裂行为。     

工业酚水稀释的RBF神经网络预测控制

针对酚水稀释过程中酚水流量不便测量的工程情况,提出了一种基于RBF（径向基）神经网络的预测控制方法.在酚水罐每个液位变化周期内使用计算机定时测量液位高度,并将这些高度值作为目标输出,在每个循环结束时训练RBF网络,利用RBF网络的逼近能力来实时预测酚水流量,从而控制清水的配比,实现酚水质量浓度的稳定.该方法可避免测量误差带来的干扰,提高控制精度.     

Discrimination for ablative control mechanism in solid-propellant rocket nozzle

The ablation in solid-propellant rocket nozzle is a coupling process resulted by chemistry, heat and mass transfer. Based on the heat and mass transfer theory, the aero-thermo-dynamic, and thermo-chemical kinetics, the thermal-chemical ablation model is established. Simulations are completed on the heat flow field and chemical ablation in the nozzle with different concentrations, frequency factors and activation energy of H2. The calculation results show that the concentration and the activation energy of H...     

Changes in liquid hold-up in foam and size of foam by perforated plates and contribution to mechanical foam-breaking

Changes in the liquid hold-up, ?, and the diameter of d, of a foam that are induced by perforated plates (PPs) and the contribution of PPs to foam-breaking were studied. A foaming system containing a dilute detergent solution in a column with mechanical agitation fitted with a rotating-disk foam-breaker (MFRD) was used. After the foam passed through the PPs, ? and d decreased and increased, respectively. The use of PPs to achieve a maximum reduction in ? and a maximum increase in d is confirmed. It is also demonstrated that use of PPs contributes not only to improving the foam-breaking performance of the MFRD, but also to power savings.     

风机冷风保安控制系统优化

介绍菜钢型钢AV80风机冷风保安控制系统的优化改造,以增加其控制安全性及可靠性.     

分子筛自控系统原理

介绍分子筛的主要用途,阐述分子筛自动控制原理及故障形成原理.     

断路器控制回路断线技术分析及处理方法

分析变电运行中出现断路器＂控制回路断线＂告警信号的原因,并根据实际运行情况提出处理方法。     

物联网环境下企业内部控制环境研究

物联网作为未来的发展趋势之一,将在各个方面决定未来世界和人类社会的发展方向。而自智慧地球、感知中国等战略提出以来,世界各国也纷纷开展物联网领域的规划布局,将物联网建设上升到国家战略。物联网在全世界范围内掀起了继计算机和互联网之后的第三次信息革命浪潮。在这空前火爆的物联网宏观背景下,微观企业也不可避免的受到物联网影响。在这一背景下,通过分析物联网环境对企业内部控制环境的影响。本文认为,物联网环境下企业内部控制环境将更加信息化、虚拟化、智能化。