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本文综合评述了近年来2-[2-(二环己膦基)苯基]-1-甲基-1H-吲哚(CM-Phos)膦配体及其衍生物在钯催化的交叉偶联反应中的应用, 主要根据不同种类的交叉偶联反应进行系统性分述, 并对该领域的发展前景进行了展望. 相似文献
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设г是直径为d且型为(a 1,3)的距离正则图,其中a≥2.用l(c,a,b)表示交叉阵列ι(г)中列(c,a,6)t的个数,记r=r(г)=l(c1,a1,b1),8=8(г)=l(Cr 1,ar 1,br 1)及t=t(г)=l(cr s 1,ar s 1,br s 1).那末,若Cr 1=3,ar 1=4a或3a 1,则d=r t 2. 相似文献
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In this paper, the Clarkson–Kruskal direct approach is employed to investigate the exact solutions of the2-dimensional rotational Euler equations for the incompressible fluid. The application of the method leads to a system of completely solvable ordinary differential equations. Several special cases are discussed and novel nonlinear exact solutions with respect to variables x and y are obtained. It is of interest to notice that the pressure p is obtained by the second kind of curvilinear integral and the coefficients of the nonlinear solutions are solitary wave type functions like tanh(kt/2)and sech(kt/2) due to the rotational parameter k = 0. Such phenomenon never appear in the classical Euler equations wherein the Coriolis force arising from the gravity and Earth's rotation is ignored. Finally, illustrative numerical figures are attached to show the behaviors that the exact solutions may exhibit. 相似文献
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在通识化学的教学层面上,面向不同背景的学生,以简单有机物完全燃烧的化学方程式的配平为主题,梳理数学方法在化学方程式配平中的应用和特点,采用跨学科的方式,让学生能从不同的角度进行思考和学习,以掌握数学方法在化学中的应用。 相似文献
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By taking into account the two-spin interaction in the transverse Ising model (TIM), the influence of the defect layers (including JB andΩB on the polarization and Curie temperature are calculated numerically, within the framework of the decoupling approximation under Green's function. The numerical results show that the polarization and Curie temperature will both become large sensitively due to the large values ofJB and the small value of ΩB of the defect layers. Meanwhile, the dependence of the crossover values of the exchange interaction JA, the transverse field ΩAof the bulk material on the exchange
interaction JB and the transverse fieldΩB of the defect layers are shown in 3-Dimensional (3-D) figures for the first time. Moreover, the transition features of the ferroelectric thin film with defect layers are presented. 相似文献
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Bivariational methods are presented for nonlinear integral equationsof Ham-merstein type = Kf(). With appropriate conditions onK and f, various upper and lower bounding functionals are derivedfor inner products and associated with the solution . Inthe latter case, suitable choices for g lead to point wise boundson both and its derivative. The methods are tested on a pendulumequation, and encouraging accuracy is obtained using simpletrial vectors. 相似文献