排序方式: 共有16条查询结果,搜索用时 15 毫秒
1.
Thomas Khler Tobias Klinder Udo van Stevendaal Cristian Lorenz Peter Forthmann 《清华大学学报》2010,15(1):87-95
This paper investigates a reconstruction method for helical computed tomography which compensates for the motion artifacts in the thorax caused by patient breathing.The method takes into account a motion vector field determined from a four-dimensional(4-D) uncompensated image data set.Surface models of the lung and the ribs are tracked through the 4-D data set to create motion information within the entire thorax.Finally,an image is reconstructed using motion compensated back-projection.The results show tha... 相似文献
2.
Increasing the robustness to the unknown uncertainty and simultaneously enhancing the sensibility to the faults is one of the important issues considered in the fault detection development. Considering the L2-gain of residual system, this paper deals the observer-based fault detection problem. By using of H∞?control theory, an LMI approach to design fault detection observer is given. A numerical example is used to illustrate the effectiveness of the proposed approach. 相似文献
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WEPPNER Werner 《科学通报(英文版)》2009,(8)
Solid lithium ion conducting electrochemical cells using LiSiPO as solid electrolyte and Li2CO3 mixed with Au as electrodes were prepared and employed as chemical sensors for the detection of CO2 gas.The EMF of the cell depends on the concentration of CO2 in air according to the partial pressure dependence of Nernst's law in the investigated range from 100 to 2000 ppm over the temperature range from 473 K to 673 K. 相似文献
4.
XIAO Yang DU Xiyu Institute of Information Science Northern Northern Jiaotong University Beijing Rolf Unbehuen is with Lehrstuhl f Allgemeine und Theoretische Elektrotechnik UniversitT Erlangen Nrnberg Cauerstr. Germany 《系统科学与系统工程学报(英文版)》1998,(2)
1IntroductionSincestabilitymargindefinitionsandtestsfor2-Ddiscretesystemswereproposed[1,2],someimprovementshavebeenmade[3,4].... 相似文献
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英国曾是世界上最强大的经济实体,自命日不落帝国.但进入20世纪后,英国却不可挽回地迅速衰退了.与此同时,德国在1871年统一之前还是长期陷于四分五裂和处于封建割据的国家,却在20世纪初成为一个后起的资本主义国家,经济实力超过英国,仅次于美国跃居世界第二位.本文就英国的衰落和德国的崛起,从其在文化教育中所体现出的民族特性进行浅析,并藉此对中国当前的教育改革和发展作点探索和思考. 相似文献
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德美高校后勤运行模式对我国高校后勤改革的启示 总被引:1,自引:0,他引:1
一、“学生服务中心“--德国模式
德国高校后勤全国一盘棋,即由大学生服务中心统一服务.德国大学生服务中心创建于第一次世界大战后,经过80年的发展,如今德国大学生服务中心已成为一个现代化的大学生服务机构,在全德共有62个分部,工作人员1万6千人.…… 相似文献
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JUAN Zhicai YANG Yinsheng Transportation College Jilin University of Technology Changchun China WU Ning Rubr Univ. Bochun Germany 《系统科学与系统工程学报(英文版)》1997,(1)
ATraficSimulationModelforAnalysingCapacityandServiceLevelatSignalizedRoundaboutsJUANZhicaiYANGYinshengTransportationColege,Ji... 相似文献
8.
Due to the low density and excellent mechanical proper-ties,high performance fiber reinforced materials have aconsiderable application in the area of high technologyand dally usage.In this paper,the Ultra-high Molecu-lar Weight Polyethylene(UHMWPE)fiber reinforcedPE tape prepared with the method of powder impregnat-ion was studied.The effect of impregnate length and thetensile force of the yarn on the fiber content as well as on the strength and modulus of the tape were discussed.Calculation shows that the strength and the modulus ofthe ULMWPE fiber can keep about 85% after it undergothe process. 相似文献
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Hydrolytic polymerization of 8 - caprolactam is carried out by the use of trimesinic acid as molecular weight controlling agent, and polyamide 6 with three branched chains is obtained. The initial concentrations of regulators almost have no effect on the conversion of caprolactam , while relative viscosity of the polymer is affected by the concentrations. DSC investigation shows that DSC curve changes from single peak for regular polyamide 6 to one peak with one shoulder or one small peak for polyamide 6 with three branched chains and the melting point decreases with the increase of the amount of trimesinic acid. In addition, the concentration of trimesinic acid being the same, DSC curves change from almost sharp single peak to double peak with increasing reaction time. 相似文献