Abstract:针对参数不确定的中立型随机时滞系统,提出鲁棒稳定与H∞控制问题.通过构造Lyapunov泛函,由It(O)公式,并利用Schur补原理,结合分析方法,建立了用线性矩阵不等式(LMI)表示的保证闭环系统均方渐近稳定的充分条件,由此可对状态反馈控制器作出选择.进一步给出了不确定系统鲁棒H∞控制可解性的充分条件.所得结果解决了文献中的相关问题.
SHEN Pu-sheng , FANG Hui , XIA Xin-hong
Abstract:针对高层混合结构竖向变形差的计算与工程对策问题进行了研究.首先,给出了超高层混合结构竖向变形差的计算方法.在结构分析中,采用刚度逐层形成、荷载逐层施加的方法考虑施工过程的影响;根据ACI规范混凝土徐变收缩计算公式,假设构件荷载线性增加,引入平均龄期影响系数和平均持荷影响系数计算变荷载作用下混凝土的徐变和收缩.用龄期调整的有效模量法分析了构件配筋率对构件徐变的影响.分析中还考虑了核心筒超前施工的影响.然后,通过算例分析,给出了减小混合结构竖向变形差的工程对策.该法简单实用,可以在超高层混合结构设计中计算竖向变形差时使用.
SHANG Shou-ping , LEI Min , KUAI Xing-cheng
Abstract:The parameter inversion problem of soil-structure system was investigated. The 2-D lumped mass nonlinear model was established to simulate the soil-structure system, and the variables separated nonlinear parameters inversion method was proposed. The nonli
ZHU Zheng-rong , SHU Xing-ping
Abstract:对搭接N型方主管、圆支管的相贯节点进行了非线性有限元分析,揭示了平面N型搭接节点的受力性能,描述了搭接节点3个参数(支主管径宽比、主管宽厚比、支主管厚度比)的变化对节点极限承载力的影响,同时分析了主管荷载对节点极限承载力的影响,提出了影响系数.研究表明,主管承受轴力对节点极限承载力影响较大,规范公式未考虑主管轴力的影响,其计算结果与有限元计算结果和实验结果有一定的误差,有必要考虑主管应力对节点极限承载力的影响.
LIU Zhi-wen , CHEN Zheng-qing , LIU Gao , SHAO Xin-peng
Abstract:The aerodynamic interference effects on aerostatic coefficients of twin deck bridges with large span were investigated in details by means of wind tunnel test. The distances between the twin decks and wind attack angles were changed during the wind tunnel
YAN Zhi-tao , LI Zheng-liang , QI Ren-jun
Abstract:根据大跨度中承式拱桥的三维空间结构形式及主拱风荷载相互干扰的特点,提出了抖振响应的非线性时域分析方法.通过节段模型风洞试验,确定了前后拱在相互干扰下的静力三分力系数.结合试验得出的两榀拱的抖振力时程数据,求出前后拱在相互干扰下的脉动风速功率谱.采用谐波合成法模拟大跨度中承式拱桥的三维风场,通过FFT变换、功率谱插值等技术提高了模拟效率.以重庆菜园坝长江大桥为工程实例,进行了考虑几何非线性的时域抖振分析,计算结果与风洞试验结果吻合较好.
LIU Dun-ping , ZHAO Ming-hua , ZOU Xin-jun
Abstract:在无网格伽辽金法的基础上,利用应力应变增量形式表征了基于Drucker-Prager屈服准则的土体弹塑性本构关系;在小变形假设的前提下,实现了基于增量本构关系的弹塑性分析的无网格伽辽金法;采用罚参数修正了能量变分方程式,方便地实现了无网格伽辽金法的本质边界条件;并采用Newton-Raphson增量迭代法计算地基土体的极限荷载,其分析结果与静载试验结果吻合较好,验证了本文方法的合理性,进一步拓展了无网格伽辽金法的应用范围.同时与有限元计算结果作了对比研究,体现了无网格法的优越性.
TAN Qiong , LI Tian , ZHOU Yong-chao , LIN Li-feng
Abstract:In order to promote the application of urban storm water drainage model in storm water management in China, a case study of a residential district of Shanghai was carried out. Based on flow survey results, three commonly used rainfall-runoff models were c
GONG Jin-ke , YOU Li , CAI Hao , LIU Yun-qing
Abstract:Based on the deterioration mechanism of the three-way catalystic converter, the main deterioration performance parameters, such as mean diameter of Pt particles and frequency factors of reaction, were analyzed in detail. Then the reaction model, including
YAN Cuo , LI Li-jun , LI Da-sheng
Abstract:试验验证了PHC-1500型CO2激光器输出激光经传输光路转换后的偏振化方向.利用设计的反射率测定装置,测定了Al2O3陶瓷表面分别对不同入射角下垂直和平行于入射面的线偏振CO2激光的反射率,据此得到Al2O3陶瓷的折射率和布儒斯特角及吸收率,与采用Fresnel公式计算获得的相应的反射率和吸收率值变化趋势一致,吻合较好.试验发现,平行于入射面的线偏振CO2激光使Al2O3陶瓷的吸收率由零度入射角时的约75%提高到布儒斯特入射角时的95%.这一结论为在开展CO2激光辅助切削Al2O3陶瓷时,设计高能量利用率的传输光路和对温度场的准确计算提供了试验和理论依据.
CHEN Fang-zu , LI Guang-yao , YANG Hai
Abstract:In order to improve the accuracy of the upper-bound solutions of the unit upsetting force of the cylinder upsetting, a new method for solving the upper-bound solutions of the cylinder upsetting based on the complicated contact friction was proposed. Based
Abstract:Some problems in setting up forging - die flash metal consuming design criteria by means of traditional methods were analyzed. The idea of applying the step-by-step regressive analysis method to mining forging-die flash metal consuming design criteria was
ZENG Ming , LIU Bao-hua , XU Zhi-yong , YUAN De
Abstract:The promotion of the flaw was proposed by introducing the chaotic searching algorithm into the fuzzy neural networks as its learning tactic. Then, the improved model was implemented, based on a South China power gird operational load data. Simulation resu
CHEN Ding , XIA Shu-ren , JIANG Yong , LIU Fang , TENG Jie
Abstract:在液氮温度(-196℃)对工业用镁合金AZ31,AM60进行深冷处理,处理时间分别为2 h,4 h,8 h,24 h,48 h,72 h,并进行了力学性能测试、金相组织观察、XRD衍射测试和SEM断口扫描测试.结果发现:深冷处理可以明显提高镁合金的力学性能,改善其显微组织,同时深冷处理可以引起镁合金的晶粒转动现象.研究结果为提高镁合金性能提供了一种简单有效的方法.
DING Zhang-xiong , WANG Qun , CHENG Zhen-hua , ZHANG Shi-ying , ZHAO Gang
Abstract:采用氧乙炔火焰喷熔法在Q235钢表面制备了镍基和钴基合金涂层.利用光学显微镜(OM)和X射线衍射仪(XRD)对涂层进行了组织和相结构分析,测试了涂层的硬度和抗汽蚀性能,并利用扫描电子显微镜(SEM)对两种涂层的汽蚀形貌进行了观察,探讨了镍基和钴基喷熔层的汽蚀破坏机理.实验结果表明:镍基和钴基喷熔层都优于常用于水利机械的抗汽蚀马氏体不锈钢ZG06Cr16Ni5Mo(16-5钢),适用于对水利机械零件进行修复和预防护.
LIU Yun-guo , FENG Bao-ying , FAN Ting , PAN Cui , PENG Li-jun
Abstract:利用黑曲霉和简青霉制备生物吸附剂,研究了它们对重金属Pb2 离子和Cd2 离子的吸附、解吸行为以及实验条件对吸附的影响,包括吸附剂用量、溶液pH值、吸附时间以及共存离子等因素.结果表明,黑曲霉和简青霉吸附Pb2 离子的最适pH值均为5,吸附Cd2 离子时均为3.二者对Pb2 离子的吸附均在4 h达到平衡,吸附量分别为29.07 mg·g-1和36.65 mg·g-1.Cd2 离子吸附也在约4 h达到最大吸附量,分别为26 mg·g-1和26.5mg·g-1.溶液中Zn2 离子和Cd2 离子的存在都会降低Pb2 离子的吸附量.2种吸附剂对Pb2 离子的吸附都符合Langmuir等温线模型,而对Cd2 离子的吸附都较为符合Freundlich等温线模型.1 mol/L HNO3对吸附有Pb2 离子的黑曲霉和简青霉进行解吸,解吸率分别可达77.4%和92.3%.
MA Man-ying , SHI Zhou , LIU You-shi , WU Xing-jie
Abstract:利用铜绿假单胞菌在以豆油为唯一碳源的培养基中发酵生产鼠李糖脂(RL),采用预处理、酸沉淀和冷冻干燥的新工艺流程从发酵液中提取RL.通过平行及正交试验探讨了用新工艺提取RL的工艺条件.试验结果表明,与传统方法提取的RL相比,新方法提取的RL纯度更高,且产量提高了8.8 g/L.由于传统工艺需要大量氯仿和甲醇等有毒溶剂用于RL的萃取,而新工艺不需要这些有毒物质,因此,本研究提出的新工艺为绿色提取工艺.
CAI Li-jun , LIN Ya-ping , YI Ye-qing , LI Xiao-long , JIANG Lin-bo
Abstract:By using the method of 22 kinds of fluorescence labeling in experiment environment of the basedsurface approach, a DNA computation based algorithm for solving the problem of special integer planning was proposed. We have introduced a method, in which the
Abstract:A new string matching automata was constructed. The automata had the advantage that each of the matching windows always kept the uniform form in which the left part in this window was a prefix of the pattern and the characters of the right part were not c
Abstract:利用Cramer法则和Brouwer不动点定理,通过构造适当的Lyapunov泛函并结合矩阵形式的Halanay微分不等式分析技巧,研究了一类具有连续分布时滞的细胞神经网络模型的动力学性质,获得了该模型的平衡点的存在性和全局指数稳定性的充分条件.改进和推广了已有文献的结论.这些结果对设计全局指数稳定的细胞神经网络具有重要的指导意义.