页岩膨胀性及分散性特征实验分析

页岩通常含有一定比例的黏土矿物,大液量、大排量压裂施工可能导致黏土矿物膨胀、水化分散,而目前开展的研究工作还没有建立起相关的评价体系。为此,在借鉴前人研究成果的基础上,采用自吸实验法、吸水膨胀实验法、X射线衍射（XRD）矿物成分分析等方法对其膨胀、分散特征进行了大量的实验研究。结论认为： ①对于烃源页岩而言,自吸实验、吸水膨胀实验等可作为页岩气藏膨胀和分散特征评价的有效方法;②具备生、储烃能力的页岩虽然具有较高的黏土含量,但膨胀和分散特征明显不同于常规的泥页岩及黏土含量较高的砂岩;③岩心CST（毛细管吸入时间）实验结果及膨胀实验结果表明,对于页岩气藏而言,如何有效抑制初期的自吸及膨胀应该引起高度的重视;④对四川盆地的页岩气藏而言,完井及压裂过程中由于化学原因导致的页岩膨胀、分散特征等不属于井壁稳定性及压裂方案设计考虑的主要因素。     

软起动器在胶带运输机上的应用

论文介绍了平煤集团公司一矿、十三矿煤矿胶带运输机采用的几种软起动装置的结构、工作原理及使用情况.对调速型液力偶合器、液体粘性软起动器、CST调速、变频调速装置及交流调压电机软起动器的优缺点进行了比较.     

PCB平面变压器漏感与自互感精确仿真

从变压器完备的自互感模型出发导出漏感表示式,表明精确的自互感模型是漏感精确估值的前提。通过电磁仿真软件CST电磁工作室叼寸一个四绕组多层PCB平面变压器模型的自互感进行仿真计算,说明上述结论。     

CST在李村矿主运皮带上的设计应用

带式输送机是煤炭矿山企业生产的核心设备。尽管对带式输送机装置的应用与维护理论日益成熟,但对于如何科学、经济的进行生产还需要进行进一步的研究,针对潞安集团李村矿带式输送机在生产过程中可能出现的问题,针对性的提出了以CST作为其控制方式,取得了良好的使用效果。     

吸顶全向天线电磁特性的研究

采用数值仿真技术CST,研究了一款全向吸顶天线的电磁特性,包括方向图和驻波比等。优化后的天线能够在双频带806~960 MHz和1 710~2 500 MHz上有效工作,回波损耗小于-10 d B,最大增益为3.5 d B。制作了吸顶天线的实验模型,利用网络矢量分析仪等设备对天线进行测量,其与仿真结果对比具有很好的一致性,并针对不同几何参数对吸顶天线物理性能的影响进行了多方面的分析。     

雷达前端强电磁脉冲前门耦合研究

针对强电磁脉冲能量经天线耦合进入雷达前端的威胁,给出了电磁脉冲炸弹的毁伤模型,并计算了目标点处的功率密度和场强振幅.然后通过分析天线的工作原理,以雷达抛物面天线为例,用电磁仿真软件CST仿真计算了强电磁脉冲途经矩形口径喇叭、波导同轴转换器、同轴线和带通滤波器时各点的时域电压波形,得出了前门耦合数据及其影响要素.这为深入分析雷达前门耦合规律、验证防护手段提供了方法.     

Novel Compact UWB Band Notch Antenna Design for Body-Centric Communications

In this paper, a novel and compact ultra-wideband (UWB) antenna with band-notched characteristics for body-centric communication is examined and implemented. The shape of the designed antenna looks like a ‘swan’ with a slotted patch. The performance parameters of this antenna for both the free space and on-body scenario for body-centric communication are analyzed and investigated through the simulation process using Computer Simulation Technology (CST). This antenna can avoid the interference caused by Wireless Local Area Network (WLAN) (5.15–5.825 GHz) and Worldwide Interoperability for Microwave Access (WiMAX) (5.25–5.85 GHz) systems with a band notch because of newly designed UWB antenna is revised small form factor sized. At first, the performance parameters like return loss response, gain, radiation patterns, and radiation efficiency on the free space of this UWB antenna are evaluated. After that, the on-body performance parameters of the antenna are also examined to place the antenna at various distances like 2 mm, 4 mm, 6 mm, 8 mm, and 10 mm away from 3-layers of phantom body model at frequencies of 3.5 GHz, 5.2 GHz, 5.8 GHz, 8 GHz, and 10 GHz. All the on-body performance parameter results are compared and analyzed with free space performance parameter results. Lastly, by changing patch slot length and ground plane length, parametric studies were done for performance comparison. Due to its compact size, novel shape and significant on-body performance, the proposed antenna is very suitable for multi-purpose healthcare applications and sports performance monitoring.     

Miniaturized Novel UWB Band-Notch Textile Antenna for Body Area Networks

This paper presents the design and analysis of a miniaturized and novel wearable ultra-wideband (UWB) band-notch textile antenna for Body Area Networks (BANs). The major goal of building the antenna for wearable applications with band notch in X-band is to reject the downlink band (7.25 to 7.75 GHz) of satellite communication in the UWB frequency ranges of 3.1–10.6 GHz to keep away from interference. Computer Simulation Technology (CST) TM Microwave Studio, which is user-friendly and reliable, was used to model and simulate the antenna. The radiating element of the antenna is designed on Jeans’ textile substrate, which has a relative permittivity of 1.7. The thickness of the jeans’ fabric substrate has been considered to be 1 mm. Return loss, gain, bandwidth, impedance, radiation, and total efficiency, and radiation patterns are presented and investigated. The antenna is simulated placed on the three layers of the human body model, and the on-body results are summarized in comparison with free space. Results and analysis indicate that this antenna has good band-notch characteristics in the frequency range of 7.25 GHz to 7.75 GHz. The parametric study varying the relative permittivity of Jeans’ fabric substrate of this antenna is also evaluated. In addition, effects on the antenna parameters of variation of ground plane size have been reported. The antenna is 25 mm × 16 mm × 1.07 mm in total volume. Results reveal that this antenna achieves the design goal and performs well both in free space and on the body.     

高空核电磁脉冲照射下车辆表面感应电流研究

高空核电磁脉冲(HEMP)照射下车辆表面感应电流的研究是装甲车辆电磁防护工作的组成部分。根据IEC6100发布的高空核电磁脉冲波形标准,文中建立了高空核电磁脉冲照射下车辆表面感应电流仿真电磁模型,并使用基于FDTD算法的CST软件进行仿真。通过改变HEMP照射方向和去除炮管部位,对比研究不同频点的车辆表面感应电流最大值和峰值区域的变化情况。实验结果表明,不同角度的车辆表面感应电流最大值与照射方向车辆表面结构的复杂度呈正相关变化,在炮管部位有远高于其它部位的感应电流。文中车辆最大感应电流参考值为1.82×103 A/m,重点防护频段为0~40 MHz。     

Revised capillary suction time (CST) test to reduce consumable costs and improve dewaterability interpretation

The aim of this paper is to critically assess the standard capillary suction time (CST) test and to propose a modified device (prototype) and a revised CST procedure. The empirical CST test (using a circular funnel) is well established as the leading method for the determination of sludge dewaterability in spite of its current shortcomings such as restricted modelling possibilities, and therefore the ability to predict physical processes such as the amount of water bound by the paper. Nevertheless, the CST apparatus is portable, and the method is easy to conduct, quick, cost‐effective and accurate, if the product of solid concentration and average specific resistance to filtration is of interest. A novel prototype with a rectangular instead of a circular funnel incorporating a stirrer (optional), and using a cheaper paper with similar or improved characteristics is proposed to reduce consumable costs and improve dewaterability interpretation. Copyright © 2005 Society of Chemical Industry