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1.
吴伟雄 《应用数学和力学(英文版)》1994,(8)
FINITEELEMENTANALYSISFORTHEUNSTEADYNEARSHORECIRCULATIONDUETOWAVE-CURRENTINTER-ACTION(I)——NUMERICALMODELWuWei-xiong(吴伟雄)(Tongj... 相似文献
2.
纳米力学的数值模拟方法 总被引:8,自引:3,他引:8
纳米力学是一支新兴学科,主要研究100nm以下尺度上物质的行
为和变化规律.物质在纳米尺度上所具有的特殊效应如量子效应、微尺
度效应等导致了其特异的性能和行为.人们对纳米力学行为的认识,目
前主要通过试验观测和数值模拟等方法.本文概要回顾了分子动力学模
拟、蒙特卡罗模拟等纳米力学计算方法的研究进展及现状,提出了以
量子力学为基础、多学科交叉、多层次融合发展纳米力学研究方法的构
思,并对纳米力学研究方法所面临的问题及其发展趋势做了初步展望. 相似文献
3.
SYNTHESIS AND CHARACTERIZATION OF SURFACE-HYPERBRANCHED MAGNETITE NANOPARTICLE FOR BOVINE SERUM ALBUMIN IMMOBILIZATION 总被引:1,自引:0,他引:1
BifengPan FengGao HongchenGu 《中国颗粒学报》2004,2(6):261-265
A hyperbranched polyamidoamine polymer was synthesized on the surface of magnetite nanoparticles to enhance bovine serum albumin (BSA) immobilization efficiency. The amount of immobilized bovine serum albumin (BSA) on the surface-hyperbranched magnetite nanoparticle was up to 2.5 times as much as that of magnetite nanoparticle modified with only amino silane. 相似文献
4.
提出了一种新的控制策略——主动多重调谐质量阻尼器(AMTMD).AMTMD控制系统频率呈线性分布.AMTMD保持相同的刚度和阻尼但质量变化.AMTMD的主动控制力采用Roorda(1975)提出的生成模式.基于结构的广义振型模型,导出了设置AMTMD时结构的动力放大系数(DMF).于是AMTMD优化准则选择为结构最大动力放大系数的最小值的最小化.分别使用位移、速度和加速度传感器,通过最优搜寻,研究了反映AMTMD有效性和鲁棒性的参数.这些参数包括:频率间隔、平均阻尼比、调谐频率比、Min.Min.Max.DMF、标准化反馈增益系数和环增益系数.为比较,同时考虑了多重调谐质量阻尼器和主动调谐质量阻尼器.而且,数值结果表明:AMTMD比MTMD具有更高的有效性和鲁棒性且ATMD也有更高的有效性. 相似文献
5.
Zhenghong Bao Kang Xiao Xingzhen Qi Xinxing Wang Liangshu Zhong Kegong Fang Minggui Lin Yuhan Sun 《天然气化学杂志》2013,(1):107-113
Cu-Fe composite oxides were prepared by co-precipitation method and tested for higher alcohol synthesis from syngas. The selectivity to C2+OH and C6+OH in alcohol distribution was very high while the methane product fraction in hydrocarbon distribution was rather low, demonstrating a promising potential in higher alcohols synthesis from syngas. The distribution of alcohols and hydrocarbons approximately obeyed Anderson-Schulz-Flory distribution with similar chain growth probability, indicating alcohols and hydrocarbons derived from the same intermediates. The effects of Cu/Fe molar ratio, reaction temperature and gas hourly space velocity (GHSV) on catalytic performance were studied in detail. The sample with a Cu/Fe molar ratio of 10/1 exhibited the best catalytic performance. Higher reaction temperature accelerated water-gas-shift reaction and led to lower total alcohols selectivity. GHSV showed great effect on catalytic performance and higher GHSV increased the total alcohol selectivity, indicating there existed visible dehydration reaction of alcohol into hydrocarbon. 相似文献
6.
LI HaoJun TANG GuiFeng HE Feng WU Bin HU XiaoGong CHEN YanLing 《中国科学:物理学 力学 天文学(英文版)》2013,(8):1591-1597
A new strategy to realize precise absolute positioning for a single-frequency user is presented. In the presented strategy, the receiver clock and ambiguities are removed using the satelliteand epoch-differenced (SDED) algorithm. As a further development of the SDED algorithm, a regional augmentation network is used to generate the SDED atmospheric delays at the user. The weakened mathematic property due to the epoch-differenced operation is improved by adding the generated atmospheric delays and applying the robust estimation. To test the new approach, the 24-h data at 5 Continuous Operation Reference Station (CORS) stations in Shanghai is processed. The results show a more than 96% success rate, defined as the case where three directions achieve the desired positioning accuracy of 10 cm, when the observation is longer than 20 min. The 20-min static results show that the new method can reach an accuracy of 3.42, 4.76 and 9.26 cm in the North, East and Up directions, respectively. An experiment was carried out to assess the kinematic positioning. The results show that the kinematic positioning accuracy is 4.11, 5.31 and 4.05 cm in the north-south, east-west and height directions,respectively. 相似文献
7.
Two novel,supramolecular,multiferrocenyl rhomboids 5 and 6 have been successfully constructed from newly designed 60 ferrocenyl donor precursor 1 via coordination-driven self-assembly.The structures of all multiferrocenyl rhomboids were characterized by multinuclear NMR(1H and 31P),CSI-TOF-MS, and PM6 semi-empirical molecular simulation,and their electrochemical behaviors have been investigated. 相似文献
8.
Three novel Zn(II) complexes,[Zn4L1Cl4]-3H2O(1),[Zn4L2Cl4]-2DMF(2) and[Zn4L3Cl4]H2O(3),have been synthesized and structurally characterized.In these complexes,interesting 32-membered dodecadentate macrocyclic ligands were generated in situ by ’2 + 2’ type condensation reactions between a tetraamine and various dialdehydes.All the complexes are isostructurally tetranuclear Zn(Ⅱ) complexes,containing endogenous alkoxo and phenoxo bridges.Applications of the macrocyclic ligands as Zn2+ sensors have been investigated.Take H4L1 for example,it exhibits a 4-fold fluorescence enhancement upon the addition of 2 equiv.of Zn2+ in MeOH. 相似文献
9.
10.
材料的动态损伤和失效 总被引:34,自引:0,他引:34
本文对动载荷下材料内部损伤演化过程的研究进行了较为全面、系统的介绍和总结,并对现有的各种动态损伤模型(包括笔者所提出的模型)进行了必要的比较、讨论和评述。 相似文献