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261.
262.
In this papsr all the known Backlund trans- formations of the Ernst equation are de}tved by ua}ing prolongation: method. As tile nonlinear realizationsp and infinite-dimensional linear realization for the prolongation structure are used, the inverse scattering equation (Lax-pair) is also derived. And the connection between BT and Lax-pair becomes evident. A systematic procedure for deriving the non-Linear realizations of the algebras is sugested based on the prolongation structure. The two knowniBackl and transformations as well as the Lax-pair of the Ernst-Maxwell equations are obtained bu the same method. 相似文献
263.
We discuss the magnetic moment of W± bosons in W-S model. First we assume that there is no spontaneous symmetry broking. starting from the formalism of path integrals and using the gauge invariance requirement, we obtain the Ward-Takahashi identities for the 3-line VIB proper vertex functions and prove that its tensor structure is the same form as that of bare vertex couplings, which indicated the W± bosons have neither anomalous magnetic moment nor electric quadrupole moment. For the realistic case of spontaneous symmetry breaking, we introduce in the Lagrangian an explicit symmetry breaking term. After discussing the problem of analytic continuation for mass of W± bosons, we prove that prove that the above mentioned conclusion is still valid here. 相似文献
264.
In this paper we generalize the definition of Levy flight (LF). With the help of a useful definition for the critical exponents of LF by introducing the concept of cutoff steplength, we calculate analytically the exponents of FDLFs in arbitrary d dimensions, utilizing the generating function method. 相似文献
265.
Numerical techniques for the analysis of wave–body interactions are developed by the combined use of two boundary integral equation formulations. The velocity potential, which is expressed in a perturbation expansion, is obtained directly from the application of Green's theorem (the ‘potential formulation’), while the fluid velocity is obtained from the gradient of the alternative form where the potential is represented by a source distribution (the ‘source formulation’). In both formulations, the integral equations are modified to remove the effect of the irregular frequencies. It is well known from earlier works that if the normal velocity is prescribed on the interior free surface, inside the body, an extended boundary integral equation can be derived which is free of the irregular frequency effects. It is shown here that the value of the normal velocity on the interior free surface must be continuous with that outside the body, to avoid a logarithmic singularity in the source strength at the waterline. Thus the analysis must be carried out sequentially in order to evaluate the fluid velocity correctly: first for the velocity potential and then for the source strength. Computations are made to demonstrate the effectiveness of the extended boundary integral euations in the potential and source formulations. Results are shown which include the added-mass and damping coefficients and the first-order wave-exciting forces for simple three-dimensional bodies and the second-order forces on a tension-leg-platform. The latter example illustrates the importance of removing irregular frequency effects in the context of second-order wave loads. 相似文献
266.
We consider Toeplitz operators Tu with symbol u on the Bergman space of the unit ball,and then study the convergences and summability for the sequences of power... 相似文献
267.
WU Xi-Hong GONG Hai-Fang CHEN Fa-Rong ZHUANG Zhi-Xia SUN Da-Hai WANG Xiao-Ru Frank S. C. LEE 《高等学校化学学报》2000,21(Z1):36
Cinnabar, composed mainly of HgS,is often used in Traditional Chinese Medicines as part of the active ingredients in formulated drugs to treat diseases such as epilepsy,sore throat. To gain understanding on the clinical efficacy, safety and toxicity of these TCMs, information regarding not only the total concentrations of the heavy metals, but also their different chemical species is necessary. Therefore, the development of sample treatment and analytical techniques for the accurate determination and speciation of heavy metals in TCM products are of critical importance. The dual objectives of this work are to:(1) develop a leaching procedure using simulated body fluids for bioavailability and toxicity studies, and (2) investigate the possibility of Cinnabar derived mercury to bind with other constitutes in Tian Wan Bu Xin Wan using a sequential extraction scheme. 相似文献
268.
Implication knowledge is useful for drawing conclusions or confirming hypotheses based on some observed data. The challenge here is where/how to derive such knowledge. Traditional knowledge acquisition methodologies or tools have limited power in that they rely on human knowledge engineers' judgements and are applicable only under controlled situations. It would be desirable as well as imperative if we can demonstrate any automatic means of mining such implication knowledge directly from empirical data-this is because in practical applications,data samples are usually available and most importantly the automatically induced implications are less subjective and mathematically sound. As a response to this challenge, our work has developed and validated a new method of automatically discovering implication knowledge by statistically inducing the implication relationships among the data attributes in empirically-obtained sample data. 相似文献
269.
具有十二元环开放结构磷酸锌的非水合成与表征 总被引:5,自引:1,他引:4
从非水体系中制备了 Zn2 ( HPO4) 3· H3NCH2 CH2 NH3单晶 ,用 X射线测定了晶体结构 ,用红外光谱 ,DTA-TG等方法对化合物进行了表征 .晶体属三斜晶系 ,P1空间群 .晶胞参数 a=0 .82 1 5( 3 ) nm,b=0 .8557( 3 ) nm,c=0 .9760 ( 3 ) nm,α=93 .8( 3 )°,β=95.3 8( 3 )°,γ=1 0 9.75( 3 )°,V=0 .63 94 nm3,Z=2 ,Dc=2 .50 g·cm- 3.结构中的锌和磷均与氧形成四面体配位 ,Zn O4和 HPO4四面体严格交替排列 ,骨架中的氧分为二桥氧和端氧 ,端氧只向 P原子配位 .三维开放式骨架结构中沿 a轴和 b轴方向有十二元环直孔道 ,质子化的有机胺在 a轴方向的十二元环孔道中 相似文献
270.
结构型网格分块生成技术 总被引:6,自引:0,他引:6
构造了一种适用于模拟具有复杂几何特征的流动问题的结构型网格生成方法,该方法应用CAD技术中非均匀有理B样条(NURBS)曲面表达形式,根据给定物体的典型站位截面,首先对物体进行分片表面网格的构造与重构,同时根据物体几何特征及流场特性对绕流流场进行区域分解并构造其块边界,在此基础上再采用数值方法进行相应的分块网格生成,并给出了应用所建立的方法生成的几种天地往返运输系统流场网格. 相似文献