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291.
292.
Based on the statistical fission theory, we have calculated the mass and kinetic energy distributions as well as other physical quantities of 235U fission induced by thermal neutron using microscopical method. That is, the quantum state densities of the fragments at scission point are calculated by means of BCS hamiltonian. The contribution of the collective deformation of fragments to the quantum state density has been taken into consideration. The potential energy of fragment is calculated by means of Strutinski procedure, and the shelling effect, pairing correlation as well as collective deformation have been taken into consideration in calculating the excitation energy at scission point. The scission point distance is treated as an adjustable parameter.Comparing with other statistical fission theories, our results give better agreement with existing experiments. 相似文献
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295.
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
296.
By making use of the technique ofintegration within an ordered product (IWOP) of operators and the bosonic and fermionic coherent states we derive the normally ordered operator realization of U(1/1) supergroup. Its application in calculating the superpartition function of the supersymmetric Jaynes-Cummings model is demonstrated. The antinormally ordered realization of U(1/1) is also obtained. 相似文献
297.
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
298.
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
299.
微波合成碳负载纳米铂催化剂及其对甲醇氧化的电催化性能 总被引:17,自引:1,他引:16
利用微波辐射快速加热含有XC—72碳的H2PtCl6的乙二醇混合液合成了碳负载的纳米铂,铂负载的质量分数在10%~20%,实验结果表明纳米铂粒子具有均匀的尺寸和形状,其平均粒径在3.6nm,并均匀地分散在纳米碳的表面,循环伏安和恒电位极化表明微波合成的Pt/C比以KBH4作为还原剂制备Pt/C和商业得到E-TEK Pt/C催化剂对甲醇的电化学氧化具有更高的催化活性。 相似文献
300.
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