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461.
针对水泥混凝土路面错台病害,系统介绍了环氧树脂砂浆薄层修补、增设传力杆预防性养护两种错台处治技术,以更好地指导高速公路路面养护工作。 相似文献
462.
To solve the resource-constrained multiple project scheduling problem (RCMPSP) more effectively, a method based on timed colored
Petri net (TCPN) was proposed. In this methodology, firstly a novel mapping mechanism between traditional network diagram
such as CPM (critical path method)/PERT (program evaluation and review technique) and TCPN was presented. Then a primary TCPN
(PTCPN) for solving RCMPSP was modeled based on the proposed mapping mechanism. Meanwhile, the object PTCPN was used to simulate
the multiple projects scheduling and to find the approximately optimal value of RCMPSP. Finally, the performance of the proposed
approach for solving RCMPSP was validated by executing a mould manufacturing example. 相似文献
463.
通过对玉柴2.5L4F国Ⅱ柴油机进行试验优化升级来匹配某轻型车国Ⅲ机的排放要求.试验主要针对电控燃油喷射系统中的喷油器锥角、突出高度、增压器、EGR进行优化升级,结果表明样机能够满足国Ⅲ排放要求. 相似文献
464.
Protective effect of glutamine pretreatment on ischemia-reperfusion injury of spinal cord in rabbits
Jian Lü 《西安交通大学学报(英文版)》2009,21(4):242-245
Objective To investigate the effect of glutamine (Gln) on the content of reduced glutathione hormone (GSH) and aminoglutaminic acid (Glu) of spinal cord following ischemia-reperfusion injury. Methods Totally 40 healthy adult male rabbits were randomly divided into five groups: sham-operation group (S group), ischemia-reperfusion injury group (I/R group), low-dose glutamine group (L Gln group), median-dose glutamine group (M Gln group) and high-dose glutamine group (H Gln group). After glutamine preconditioning, the model of spinal cord ischemia-reporfasion injury was established according to Zivin's method. The general status of animals was observed and the changes of Jacobs scoring were recorded in each group. Malondialdehydes (MDA), GSH, Glu and superoxide dismutase (SOD) activity in lumbar spinal cord tissues were determined using chemical colorimetry. The neuron number and deviation rate in spinal cord anterior horn were observed histopathologically. Results There was no significant difference between L Gin group and I/R group in behavior scoring, SOD activity, content of MDA and Glu, neuron number and deviation rate of spinal cord (P>0.05); however, there was a significant difference in GSH content of spinal cord (P<0.05). M Gln group and I/R group differed significantly (P<0.05) in behavior scoring, SOD activity, content of MDA, Glu, GSH, neuron number and deviation rate of spinal cord. Between H Gln group and M Gln group, there was no significant difference in behavior scoring, content of MDA and Glu, SOD activity, neuron number and aberration rate in spinal cord (P>0.05), whereas there was a significant difference in SOD activity and Giu content (P<0.05). Conclusion Pretreatment with medium-dose glutamine has a protective effect on spinal cord ischemia-reporfasion injury in rabbits, which may be related to the maintenance of GSH content, increase of SOD activity and reduction of MDA. 相似文献
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提出基于最小二乘支持向量机在线算法的α阶逆控制方法.引入系统控制误差不敏感函数,在控制误差大于不敏感函数时,利用增量一剪枝学习算法,对已建立的离线逆控制器实施在线学习,以增强控制系统的鲁棒性.仿真结果表明:在系统没有受到噪声干扰时,在线逆控制器可以很好地使被控对象跟踪参考输入信号;在系统受到噪声干扰时,在线逆控制器比离线逆控制器具有更强的鲁棒性. 相似文献
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