UPS输出端中性线接地问题探讨

从UPS工作原理入手,分析单相UPS和三相UPS“另起的系统”的接地问题,结论：UPS输出端的中性线做重复接地的规定有误。     

基坑支护中水土压力合算与分算的计算分析

对支护结构土压力的现状进行讨论和分析，比较分析水土分算和水土合算的计算方法，由工程实例的计算分析，得到考虑渗流水土分算的计算方法与，实际情况符合得较好，是一种具有实际运用价值的方法。     

3D Semantic Deep Learning Networks for Leukemia Detection

White blood cells (WBCs) are a vital part of the immune system that protect the body from different types of bacteria and viruses. Abnormal cell growth destroys the body’s immune system, and computerized methods play a vital role in detecting abnormalities at the initial stage. In this research, a deep learning technique is proposed for the detection of leukemia. The proposed methodology consists of three phases. Phase I uses an open neural network exchange (ONNX) and YOLOv2 to localize WBCs. The localized images are passed to Phase II, in which 3D-segmentation is performed using deeplabv3 as a base network of the pre-trained Xception model. The segmented images are used in Phase III, in which features are extracted using the darknet-53 model and optimized using Bhattacharyya separately criteria to classify WBCs. The proposed methodology is validated on three publically available benchmark datasets, namely ALL-IDB1, ALL-IDB2, and LISC, in terms of different metrics, such as precision, accuracy, sensitivity, and dice scores. The results of the proposed method are comparable to those of recent existing methodologies, thus proving its effectiveness.     

冶金企业供电线路设计探讨

为了满足冶金企业大容量供电的需要,采用相分裂导线方式供电,减少出线回路和出线走廊,经济效益显著。     

含锰甲醇合成催化剂的研制开发

通过实验,确定甲醇合成催化剂的最佳生产条件,同时通过对加料方式进行筛选,肯定了分步反加法制备的催化剂性能良好.对比含有几种不同助剂的铜基甲醇催化剂的活性和内部结构,证明含锰铜基甲醇催化剂具有较强的热稳定性和较高的活性.     

土工分析中水土分算与合算的概念、原理及其工程应用探讨

说明土体抗剪强度的两种确定方法的适用条件 ,叙述水土分算合算的概念及原理 .针对粘性土的水土合算问题 ,提出了一些解决方法 ,从有效应力原理出发 ,分析了水土合算的理论缺陷 .     

无磁链观测的电力动负荷物理模拟关键技术研究

电机性能及电源装置性能的测试试验,需要一套高效、实用的动负荷模拟系统。为此,提出了一种无需磁链观测的电力动负荷物理模拟方法,针对3种常见类型的电动机机械负载的模拟控制问题,给出了负荷模拟系统的总体结构,建立了控制系统的数学模型。采用保持励磁恒定,调节电枢电流来模拟不同类型动负荷的控制策略。借助PSCAD对模拟系统进行了仿真实验验证,结果表明模拟系统能够有效地对恒转矩、恒功率和风机类机械特性负载进行精确的动态模拟。     

他励直流电动机可变电阻型等效电路图及其应用

若将他励直流电动机输出功率的机理等效为一个与电动机电枢绕组并联网的可变电阻,可以得到他励直流电动机可变电阻型等效电路图。此等效电路图适用于电动机转速的任意变化范围,特别是起动与制动过程中各种特性参数的分析与计算。     

深圳抽水蓄能电站地下厂房排水方案设计探讨

深圳抽水蓄能电站安装高程为-5.00 m,集水廊道底板高程为-19.5 m,均在海平面以下,不具备自流排水的条件,因此地下厂房场内排水只能通过水泵动力排水。深蓄电站下库为一级饮用水源,对水质要求很高,通过比较分析,推荐采用清污分排的排水方案,避免了厂房排水对下库水体污染,同时达到了水资源的有效回收利用的效果,符合节能环保的设计理念,对同类型地下工程的排水设计具有参考价值。     

Separately frequency modulated single-ended type quasi-current resonant DC/DC converter with high-frequency-link incorporating forward and flyback hybrid transformer

This paper considers an improved bidirectional zero-current switching (ZCS) quasi-resonant-type single-ended soft-switching mode dc/dc converter with an HF center-tapped transformer link and ZCS commutated diode rectifier which is capable of minimizing switching losses of a power device, its electrical stresses and electromagnetic interference (EMI/RFI) noises. This converter topology can operate efficiently under a simple frequency-regulation strategy in the ultrasonic frequency ranges. The advanced exact computer-aided simulating analysis of the new converter circuit is presented introducing the normalized frequency variable and circuit system parameters. The open-loop/closed-loop steady-state voltage regulation characteristics in a variable frequency-modulation mode are illustrated and discussed in the normalized general-purpose expressions in addition to the load variation performance. The feasible high-power density SMPS breadboard with a full-wave quasi-current resonant switch assembly using a single MOS-gate switching power semiconductor device is originally developed and investigated, and is optimally designed for a distributed low-voltage large-current power supply system. Its experimental results in the PFM control implementation are demonstrated compared with the exact simulation ones from a practical viewpoint.