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991.
Design of the ECRH/ECCD Launcher System for HL-2A Tokamak   总被引:3,自引:0,他引:3  
An ECRH/ECCD system with two 68GHz/500kW/1S gyrotrons will be built up in HL-2A tokamak. The location of the Gaussian beam waist is 580 mm away from the center of the plasmas and the beam radius is 37 mm at the center of the plasmas. Compared to the minor plasma radius (420 mm), it is small enough for localized control. The launcher system covers a wide toroidal and poloidal steering range by the two steering plane mirrors. Therefore it is possible to explore the on- and off-axis heating over half of the plasma minor cross section and the co-current drive.  相似文献   
992.
本文利用(J,J')-无损矩阵的性质,研究了基于散射模型的H∞控制系统的闭环稳定性,获得了广义对象的散射模型为(J,J')-无损的H∞控制问题可解的充要条件。与文[1]中关于广义对象为一类内矩阵的H∞控制问题求解的结果相比,本文的结论对广义对象的限制要弱。  相似文献   
993.
本文建立了双机械臂协调系统的主从式控制的非结构模型,并针对两臂具有相同特性和不同特性这两种情形作了稳定性分析,提出特性校正的方法,本文还利用内模原理设计出动态补偿器来克服标定约束的不确定性对系统控制品质的影响,最后给出了实验结果。  相似文献   
994.
Utilization of polyhydroxylated C60 (fullerenols) in a condensation reaction with diisocyanated oligo(tetramethylene oxide) led to the successful fabrication of elastomeric poly (urethane-ether) networks. These polymer networks exhibit interesting thermal behavior at low temperatures, improved tensile strength and elongation at ambient temperatures, and enhanced thermal mechanical stability at high temperatures, as compared with those of the parent linear polyurethane analogues; or with the conventional oligo (tetramethylene oxide)-derived polyurethane elastomers cross-linked by trihydroxylated reagents (1,I,1-trismethylol propane) or tetrahydroxylated reagents (pentaerythritol). The presence of a limited quantity of water molecules in the condensation reaction of fullerenols with diisocyanated prepolymers modified the physical properties of the resulting elastomeric products with a notable increase in tensile strength, modulus, and Ts over those of elasotmers prepared under anhydrous conditions. These water molecules contributed effectively to the increase of the number of cross-linking centers during the reaction.  相似文献   
995.
Protoporphyria is a genetic disorder in which patients may develop severe protoporphyrin-induced liver damage and require transplantation. Because unique problems occur in the perioperative period and because excess production of protoporphyrin by the bone marrow continues after liver transplantation, the efficacy of this procedure for protoporphyric liver disease is uncertain. We present follow-up of nine patients who underwent liver transplantation. Two patients died within 2 months of transplantation, one from complications of abdominal bleeding and the other from sepsis after bowel perforations. The remaining seven patients had follow-up at 14 months to 8 years after transplantation (mean, 3.8 years). Two of the seven had suffered skin burns from exposure to operating room lights, which healed without scarring. Three had axonal neuropathies in the postoperative period requiring prolonged mechanical ventilation, and motor defects persisted in two. Five patients had normal liver chemistries at follow-up (mean, 3.5 years), with liver biopsy results normal or showing mild portal triad abnormalities, but erythrocyte protoporphyrin levels remained significantly elevated (1,765 +/- 365 mcg/dL; normal, < 65). The other two patients, both of whom had rejection, cytomegalovirus infection, and biliary tract obstruction requiring endoscopic therapy, had a recurrence of protoporphyric liver disease as indicated by liver biopsy features. One died 5 years after transplantation from complications of the liver disease. The other was stable 3.3 years after transplantation and was being monitored for possible retransplantation. Thus, liver transplantation can be performed successfully in patients with protoporphyric liver disease, with intermediate survival rates comparable to the general transplant population. However, disease may recur in the graft, particularly if there are complications that cause cholestasis.  相似文献   
996.
摇臂参数设计方法   总被引:2,自引:0,他引:2  
建立了中小功率内燃机常用摇臂参数化设计模型。采用可变参数构成摇臂结构,并作结构的有限元网络,此后再进行有限元分析,计算出摇的质量、刚度、转动惯量 力。使摇臂的设计归结为几个主要参数的优选。实例分析表明,计算值和实测值基本相符,优选出的摇避设计优于原设计。  相似文献   
997.
用缓慢升温法成功研制出非铁电性二元系压电新晶体Al0.88Ga0.12PO4,通过原子光谱吸收,Rutherford背散射及X射线粉末衍射测定其组分结构,并给出了新晶体和电弹常数和温度系数。  相似文献   
998.
形态学边缘检测的新算法及其应用   总被引:3,自引:0,他引:3  
提出了一种基于数学形态学的边缘检测的所算法,该算法具有简便和灵活可编程控制等优点,比原来主算法更国完善,在实际应用中有着很好的前景,并给出了实验结果。  相似文献   
999.
The intratracheal instillation of xanthine-xanthine oxidase caused a marked decrease in dynamic respiratory compliance, indicating airway constriction. The constriction was significantly attenuated by fullerenol-1, but not by other agents or receptor antagonists.  相似文献   
1000.
Previous analyses of the Wechsler Memory Scale-Revised (WMS-R; Wechsler, 1987) have reported one-, two-, and three-factor solutions and raised questions about the validity of the visual memory subtests. These various findings may stem in part from different methods of analysis, and from the study of different participant samples. To address these issues, we analysed data from the WMS-R and a spatial maze test administered to 154 participants with a history of alcohol dependence. Results from confirmatory factor analysis supported the interpretation of three factors underlying the WMS-R subtests and the spatial maze score in this sample, namely, attention-concentration, immediate memory, and delayed recall. This result held despite the inclusion of the maze score which is a well-validated measure of visuo-spatial memory.  相似文献   
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