Kinetic characteristic for a synchronal rotary compressor

The synchronal rotary compressor is si mple instructure,but it has stronger adaptability for a vari-ety of working medium,so it is a good type as aircompressor,oil pump andrefrigerationsystemcom-pressor.The geometric theory and structure charac-teristics of this mechanis m are introduced[1].Itgives the designing background for the synchronalrotary compressor.The calculational methods of arotary speed of cylinder and relative speed bet weenthe cylinder and bladed rotor are deduced in detail;the…     

MODEL AND SIMULATION FOR A BRUSHLESS AC GENERATOR WITH AROTARY RECTIFIER

Objective For a brushless AC generator with a rotary rectifier, it is necessary and significant to model and simulate at normal and fault operation states. Methods Two new concepts, namely, Simulink signals and PSB (Power System Blockset) variables, are proposed, and the difference between the two concepts is clarified. Based on the new model for synchronous machines, a simulation model for a brushless AC generator with a rotary rectifier is constructed by Matlab/Simulink/PSB. This new model, which has a speed input terminal and an exciting voltage input one, can simulate the real electrical characters and direct mechanical connection between two synchronous machines perfectly. The rotary rectifier is a three-phase full-wave bridge rectifier which consists of six diodes. The model for the diodes is a macro-model which possesses much better accuracy than an ideal one of switches. Results Based on the present model, some simulation results such as exciting current waveform, phase current waveform and phase voltbge waveform are afftained at several operation conditions. Conclusion The simulation for a brushless AC generator with a rotary rectifier is demonstrated at normal and fault operation states, respectively. The results confirm the presented method.     

Codes From Strongly Regular （α,β）-reguli

Strongly regular (α, β)-reguli are a class of incidence structures with given conditions which were introduced by Hamilton and Mathon. We introduce two classes of codes constructed from strongly regular (α, β)-reguli within PG(k − 1, q). The codes are related with two-weight codes intimately. Foundation item: the Scientific Research Start-up Foundation of Qingdao University of Science and Technology in China (No. 0022327)     

铁道机车车辆通用旋转式涡流制动(RWB)

德国铁路公司(DB AG)ICE3快速列车的线性涡流制动(LWB)就是采用了电磁涡流制动的原理.该制动原理的优点是工作无磨损和对环境友好.但铁路日常运输使用LWB制动需强化线路的质量,而使用旋转式涡流制动(RWB)无需强化线路质量,因此原则上可在任何铁道机车车辆上补装RWB系统.多年来RWB作为电磁制动器已成功用于公路机动车辆上.现在已克服了起初所出现的各种的技术难题,在铁路运输中使用这种制动技术已趋于成熟.文章分析了使用旋转式涡流制动技术的可行性和经济性.     

基于推进压差和回转压力变化的钻孔参数自动匹配系统设计

为解决凿岩台车钻孔参数自动匹配的问题,对冲击回转凿岩形式的钻进过程进行建模仿真,分析不同推进压力、冲击压力和回转压力等凿岩参数对钻进效率的影响,获取最佳钻进状态下凿岩参数的匹配关系; 在此基础上,设计基于推进压差和回转压力的钻孔参数自动匹配液压控制系统,并用于某型凿岩台车进行实测,验证以下结论: 1)冲击压力能够随推进压差变化自动调整; 2)随着回转压力变化,系统能够判别卡钎状态,并准确做出减缓钻孔速度、停止推进、开始回退等响应动作。     

国内外标准在斜坡堤设计中的应用

在国内行业标准《防波堤设计与施工规范》中斜坡堤设计的基础上,参考国外标准The Rock Manual、SPM、BS 6349-7中相关内容,对其中的公式适用的边界条件进行了明确说明,并与《防波堤设计与施工规范》中相关内容进行比较,且有算例加以说明。     

可快速编码的多码率原模图LDPC码设计

原模图LDPC码的实际应用涉及到两个问题：快速编码和编码复杂性.与其他LDPC码相比,原模图LDPC码的结构适合快速解码,但不一定能够实现快速编码.现有的原模图LDPC码的编码是根据生成矩阵进行编码,因其生成矩阵不是稀疏的,所以存在编码复杂性问题,这给编码器的硬件实现带来较大的困难.为了降低原模图LDPC码编码复杂度,本文提出一种可快速编码的多码率原模图LDPC码的设计,提出的多码率原模图LDPC码不存在4环,无低码重码,其快速编码算法能够降低编码复杂性,使编码器的硬件易于实现.在AWGN信道仿真结果表明,提出的可快速编码的多码率LDPC码的误码率性能和纠错性能优于GB20600 LDPC码.     

水平旋喷桩超前预支护在风积沙隧道中的应用

榆神高速神木一号隧道风积沙地层颗粒单一,级配不良,结构松散,施工难度极大,通过对不同超前支护方式加固效果的分析,简要阐述了水平旋喷桩在不良地质地层加固中的优势和特点,并详细介绍了其主要施工工艺和关键技术要点.     

Turbo码S随机交织器的实现

Turbo码中交织器的设计直接影响着Turbo码的性能。在讨论Turbo码交织器的设计准则和类型的基础上,着重介绍了S随机交织器的原理,并给出了其一种基于冒泡排序算法的实现方法。仿真结果表明,中短长度的S随机交织器性能优良。     

高压喷射注浆法在广州港新沙港区的应用

该工程为我国首次采用三重管法旋喷桩进行格形钢板桩结构码头的升级改造工程。在不破坏码头结构面、保证码头正常生产的情况下,对后方地基进行三重管法旋喷桩加固、港池水深浚深至-13.5 m,由原来的3.5万吨级散货码头改造升级为10万吨级散货码头。该工程施工过程中的三重管法的多次工艺试桩试验和施工工艺,可为今后同类型工程提供借鉴。