A simplified cascade current‐source inverter interconnected to a single‐phase three‐wire distribution system and its application to electric energy storage systems with batteries

A novel current source inverter system interconnected to the single‐phase grid is proposed. It has the same construction as the conventional three‐phase current source inverter that is interconnected to the single‐phase three‐wire distribution system. Though the proposed circuit has no output transformer, it can be equivalently performed as the single‐phase double cascade inverter by diverting the pole transformer in the utility system. By controlling the appropriate scheme, the output currents can be obtained as the five‐level waveforms and their distortions can be decreased sufficiently. It is applied to the interactive electric energy storage system with batteries and the basic discharging characteristics are discussed experimentally. © 2004 Wiley Periodicals, Inc. Electr Eng Jpn, 150(2): 50–61, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.10380     

Simulation of Natural Depletion and Miscible Gas Injection Effects on Asphaltene Stability in Petroleum Reservoir Fluids

Natural depletion of petroleum reservoirs as well as gas injection for enhance oil recovery, are unavoidable processes in the oil industry. Foremost, prediction of the problems due to these two processes is very necessary and important. So many field and experimental experiences have shown that heavy organic depositions, especially asphaltene deposition, are principal results during these processes. Results of laboratory simulation of asphaltene deposition during the natural depletion of petroleum reservoirs and also during gas injection and enhanced oil recovery (EOR) processes are reported here. This is achieved through the design of a new experimental setup for the investigation of pressure and composition effects on asphaltene deposition in petroleum fluids at high pressure and high temperature conditions. In this work, asphaltene deposition during decreasing pressure, from pressures greater than reservoir pressure to pressures below the bubble point pressure (natural depletion) and also asphaltene deposition during natural gas injection in reservoir conditions, are studied for three samples—one recombined sample and two bottomhole samples. All of the obtained results from this work conform to theoretical and other experimental works.     

高炉喷吹半焦的可行性

本文介绍了煤的热解和半焦性质。煤在快速热解过程中脱除热解水、焦油、部分的硫和煤气。半焦含有比煤低的硫含量和较高的热值。半焦的可磨性、反应性及燃烧性都比煤好，因此，半焦是高炉理想的喷吹燃料。     

削弱永磁同步伺服电机齿谐波电势方法的比较

讨论了四种结构修理工削弱永磁同步伺服电机齿谐波电势的影响，并对他们的效果进行了比较。     

高炉炉缸内铁水环流与内衬侵蚀

从分析中心焦柱在炉缸内的受力出发，计算了１０００￣５５８０ｍ＾３高炉大喷煤前后中心焦柱在炉缸铁水内的沉入深度，分析了炉缸内铁水环流的产生与炉缸内衬侵的关系，分析表明大喷煤有得利抑制铁水环流对缸内补的冲刷，提出了降低铁水环流对炉缸内衬侵蚀的途径。     

碳酸盐岩油藏改善注水开发效果试验研究

双重孔隙介质的碳酸盐岩油藏在稳定注水采油后岩块系统还存在大量剩余油，而不稳定注水方法可在一定程度上提高水驱油效率。室内物理模型实验、数值模拟计算及现场试验结果一致表明：在碳酸盐岩油藏注水开发后期采用衰竭式降压开采，周期注水等不稳定注水方式，能够提高水驱油效率，改善油藏开发效果，获得良好的经济效益。     

通信接收机的抗信道干扰问题

接收机产生干扰的机理分析是提高其抗干扰性能的基础和前提,为此文中对其作了详细阐述,并对降低接收机共信道干扰的改善措施也作了简明分析研究。本文为从事通信工作者理解与应用有关内容提供一轮廓性依据。     

电晕放电注入双向拉伸聚丙烯薄膜驻极性能的探讨

以一种双向拉伸聚丙烯（ＢＯＰＰ）薄膜在不同温度下进行恒温处理，然后进行负电晕驻极。结果表明，ＢＯＰＰ薄膜随恒温处理的温度升高，热刺激电流（ＴＳＣ）峰值愈低。利用经验方法，估算了它们的活化能，并探讨了导致ＴＳＣ峰温变化的原因。     

基于8098单片机的伏安特性测量系统的设计

伏安特性测量技术有着广泛用途。本文介绍一种用８０９８单片机为控制核心的智能化通用伏安特性测量系统的设计要点。包括系统的硬件和软件设计，以及针对实际问题所采用的一些设计技巧。成果分析表明，采用８０９８单片机有着独特的优越性和推广价值。     

谈井下矿山二次破碎裸露爆破方法

井下矿山二次破碎裸露爆破可采用聚能药包和水封聚能药包破碎大块，聚能药包能改变药柱某个方向的猛度，提高炸药能量利用率，水封爆破利用了炸药的猛度和一部分爆力作用，从而有效地利用了炸药本身的能量，降低了爆破危害。