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为了有效完成大型铰接单层网壳结构的后屈曲分析,本文采用对杆单元杆端力函数求导的方法推导出了等直杆单元切线刚度矩阵的精确形式。该切线刚度矩阵不受结构小变形限制,适用于结构产生任意大结点位移情况。以六角星桁架、平面圆拱桁架和大跨K8单层网壳结构为算例,采用广义位移控制法进行非线性后屈曲分析,其中预测子采用本文杆单元切线刚度矩阵。算例分析结果表明,本文杆单元切线刚度矩阵在大型铰接单层网壳结构的非线性后屈曲分析中有很强的预测能力。 相似文献
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In this paper, we propose a new method to realize drive-response system synchronization control and parameter identification for a class of generalized Julia sets. By means of this method, the zero asymptotic sliding variables are applied to control the fractal identification. Furthermore, the problems of synchronization control are solved in the case of a drive system with unknown parameters, and the unknown parameters of the drive system can be identified in the asymptotic synchronization process. The results of simulation examples demonstrate the effectiveness of this new method. Particularly, the basic Julia set is also discussed. 相似文献
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The reaction of Ru3(CO)12 with five-membered cyclic SP(S)(Fc)N(Ph)NC(Me) gave two novel trinuclear and tetranuclear ruthenium carbonyl clusters containing capping S atoms in Ru3(CO)8(μ3-S)2[P(Fc)N(Ph)NC(Me)S] 1 and Ru4(CO)7(μ-CO)3(μ4-S)2[P(Fc)N(Ph)NC(Me)S] 2 (Fc=C5H5FeC5H4). During the reaction, the ligand precursor cleaved only in its P=S bond to give the fragments S and [P(Fc)N(Ph)NC(Me)S], and then coordinated to the ruthenium atoms to form the clusters as listed above. The clusters have been characterized by elementary analysis, IR, 1H NMR and MS spectroscopy. The crystal structure of cluster 2 has been determined by X-ary diffraction techniques. The crystal belongs to monoclinic with space group P21/c. The unit cell parameters are as follows: a=1.18744(7) nm, b=1.36041(11) nm, c=2.20026(18) nm, β=104.126(3) °, V=3.4468(5) nm3, Dc=2.175 g·cm-3, Z=4. In the molecule, the three bridging carbonyls and Ru4 are planar and with a pseudo-octahedral Ru4S2 skeleton. The terminal carbonyl of Ru1 was substituted by the cyclic ligand [P(Fc)N(Ph)NC(Me)S]. CCDC: 217076. 相似文献
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Based on Hfickel's molecular orbit theory, the chaos and bifurcation behaviour of a molecular orbit modelled by a nonfinear dynamic system is studied. The relationship between molecular orbit and its energy level in the nonlinear dynamic system is obtained. 相似文献
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Fe~3(CO)~1~2与4个S,N取代的杂环硫代酰胺配前体[SCSC(SR)NNPh(SL~n),其中SL~1:R=Me;SL~2:R=Et;SL~3:R=n-Pr;SL~4:R=i-Bu]反应,合成得到含硫氮杂环卡宾配体的通式为[Fe~3(CO)~8(μ~3-S)~2L]的4个新羰合铁簇合物(1~4)。其配体S原子和杂环卡宾L皆来自配前体SL的劈开。对它们进行了元素分析,IR,^1HNMR和MS表征,并用X射线衍射测定了2的晶体分子结构,表明含硫氮杂环分子片CSC(SR)NNPh(L)的卡宾碳具有sp^2成键特征,其C~卡~宾键长为0.1960nm。2的分子几何构型维持母体物[Fe~3(CO)~9(μ~3-S)~2]的形状,其中卡宾基取代四方锥分子骨架Fe~3S~2基底平面Fe(1)S(1)Fe(3)S(2)的Fe(3)原子上径向位置的一个端羰基CO。 相似文献