EXPERIMENTAL INVESTIGATION ON TWO-DIMENSIONAL UNSTEADY COLD FLOW IN MPC EXHAUST MANIFOLD

IntroductionIt is obvious that the gas flow in the exhaustmanifolds,especially at the conjunctions has amulti- dimensional characteristic[1] .The study onthis characteristic is very important for the uti-lization of exhaustenergy and the decrease of ex-haust pumping loss.In this paper,the measure-ment of cold flow has been carried out to studythe multi- dimensional phenomena of unsteadyflow in the exhaust manifolds.In order to em-phasis the important characteristics of the flowand reduce the a…     

RESEARCH ON THE DOF DISPOSITION AND MECHANISMS DESIGN OF HUMANOID ROBOT

IntroductionSome researchers[1～ 3] in Yugoslavia,Japan andAmerica have got many achievements in bipedrobot since the beginning of1 970 s.The bipedrobot can walk in static and dynamic gait and al-so can turn around and go up stairs.Recentlyhumanoid robot has become a hot researchingpoint[4,5 ] .Humanoid robot has body includinghead,neck,waist and hands.Biped robot is abasis of humanoid robot.Usually a humanoidrobot should have more than 2 0 DOF.All thetechnology problems in DOF planning,m…     

AN EFFICIENT BTC IMAGE COMPRESSION ALGORITHM

IntroductionBlock truncation coding( BTC) [1] is a simple andfast lossy image coding technique,which has theadvantage of being easy to implement comparedto transform coding and vector quantization[2 ] .Its simplicity,performance and channel error re-sisting capability make it attractive in the real-time image transmission.BTC is a one- bit adap-tive moment- preserving quantizer that preservescertain statistical moments of small blocks of theinput image in the quantized output.The origi-nal …     

UNCERTAIN KNOWLEDGE MANAGEMENT IN EXPERT SYSTEMS USING FUZZY METAGRAPHS

IntroductionThe fuzzy graph- theoretic constructs are widelyapplied in modeling and analyzing fuzzy sys-tems[1] .Whereas,existing fuzzy constructs arenot suitable for the analysis of the directed rela-tionships between sets of elements.In addition,such relationships widely exist in fuzzy systems,for example,knowledge base in fuzzy expertsystem. So,based on the metagraph proposedby A.Basu and R.W.Blanning[2 ,3] ,this paperpresents a new graph- theoretic construct,afuzzy metagraph and applies …     

陕西咸阳某学院部分学生肠道蠕虫感染调查

本文对1986～1988年,来自西藏地区新入学的144名学生,入学进行肠道蠕虫调查,结果表明:绦虫感染率,藏族学生(15.7%)比汉族学生(2.4%)高,(P<0.05);蛔虫和鞭虫的感染率,汉族学生(33.3%和21.4%)比藏族学生(9.8%和7.8%)高,(P<0.01和0.05),另外,蛔虫和鞭虫在西藏地区的感染和分布,具有地区性差异。     

原发性高血压病血栓素A2-前列环素平衡及血小板功能改变的探讨

本文对63例正常人,126例原发性高血压(EH)患者的血浆TXB2、6-酮-PGF_(1a)及血小板聚集率进行了测定,并对单纯性高血压及合并心脏损害或缺血性脑血管病患者作了分析。结果表明,EH血浆TXB2水平较正常组明显升高。6-酮-PGF_(1a)水平则低于正常组,血小板聚集性较正常组高。单纯高血压组TXB2、血小板聚集率均低于有合并症组。提示EH存在TXA2-PGI2失衡及血小板功能亢进,其可能参与高血压的发生、发展,并为高血压合并心脏损害及缺血性脑血管症的病理基础之一。     

中间60°SPWM控制的特点及其电路的实现

着重分析了中间６０°脉宽调制（简称中间６０°ＳＰＷＭ）和正弦１８０°调制这两种控制方式对电压型逆变器输出电压的谐波含量、对称性等性能的影响，介绍了适合于１０００ｋｗ地面试验系统的中间６０°ＳＰＷＭ电路．试验结果表明，系统起动稳定，能满足系统的控制要求。     

稀浆封层施工技术

通过稀浆封层及施工技术的应用，着重介绍乳化沥青稀浆封层施工前的准备，各种原材料的配料计算。施工注意事项及施工质量检验。     

利用冗余态参与状态分配设计时序逻辑电路

在时序逻辑电路的设计中，利用电路所存原冗余来参与状态分配，更符合“A－H规则”，从而获得较简单的电路结构，并且消除了无效状态和所谓的自校正问题，是值得推广应用的一种新的状态分配技术。