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Zhen Yu Yuping Duan Lidong Liu Shunhua Liu Xujing Liu Xiaogang Li 《Surface and interface analysis : SIA》2009,41(5):361-365
Hot‐dipped aluminum copper with plating auxiliary KF is introduced in this work. In this study, the intermetallic layer thickness varies with dipping temperature and time in a linear relationship. The main phases are identified to be CuAl2 and K3AlF6 by means of X‐ray diffraction. The reaction equations are deduced according to the elements concentration gradient in cross section. The copper diffusion rate in liquid Al is calculated to be 1.13 × 10−12 m2/s by Fick's second law in semi‐infinite solid model, and the obtained conductivity is 1.758–1.767 × 10−2 Ω mm2/m. The results indicate that the interfacial bonding is in a good state and plating auxiliary KF aqueous solution. can significantly improve the substrate wettability. The appropriate hot‐dipping condition for the samples is 953–973 K for 4–8 s. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
84.
Hiromichi Fujioka 《Tetrahedron letters》2010,51(15):1945-2017
The first asymmetric total syntheses of the (+)- and (−)-cryptocaryones are described. Removal of the acetal unit of the enone acetal 5, which was obtained in our previous study from the cyclohexadiene acetal 3, afforded the enone acetal 8 in a one-pot procedure. The acylation of 8 with cinnamoyl chloride and subsequent hydrolysis of the resulting acetal gave the lactol 11. Its oxidation with NIS and tetra-n-butylammonium iodide (TBAI) finally furnished the natural (+)-cryptocaryone 2. The same procedure from ent-3 afforded the unnatural one 1. 相似文献
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为了获得sine-Gordon型方程的无穷序列精确解,给出三角函数型辅助方程和双曲函数型辅助方程及其Bäcklund变换和解的非线性叠加公式,借助符号计算系统Mathematica,构造了sine-Gordon方程、mKdV-sine-Gordon方程、(n+1)维双sine-Gordon方程和sinh-Gordon方程的无穷序列新精确解.其中包括无穷序列三角函数解、无穷序列双曲函数解、无穷序列Jacobi椭圆函数解和无穷序列复合型解.
关键词:
sine-Gordon型方程
解的非线性叠加公式
辅助方程
无穷序列精确解 相似文献
88.
Mathew Baxter Robert A. Van Gorder 《Mathematical Methods in the Applied Sciences》2014,37(11):1642-1651
We consider wave solutions to nonlinear sigma models in n dimensions. First, we reduce the system of governing PDEs into a system of ODEs through a traveling wave assumption. Under a new transform, we then reduce this system into a single nonlinear ODE. Making use of the method of homotopy analysis, we are able to construct approximate analytical solutions to this nonlinear ODE. We apply two distinct auxiliary linear operators and show that one of these permits solutions with lower residual error than the other. This demonstrates the effectiveness of properly selecting the auxiliary linear operator when performing homotopy analysis of a nonlinear problem. From here, we then obtain residual error‐minimizing values of the convergence control parameter. We find that properly selecting the convergence control parameter makes a drastic difference in the magnitude of the residual error. Together, appropriate selection of the auxiliary linear operator and of the convergence control parameter is shown to allow approximate solutions that quickly converge to the true solution, which means that few terms are needed in the construction of such solution. This, in turn, greatly improves computational efficiency. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
89.
根据装备质量管理的特点对装备质量管理的风险因素进行了分析,依据指标体系的设计原则建立了装备质量管理风险评估的指标体系,并给出了基于网络层次分析法和粒子群优化算法的的装备质量管理风险评估指标权重值的确定方法.并给出了实例分析. 相似文献
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