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991.
992.
993.
在Minkowski空间中,定义了定向曲面上的第二类松弛弹性线,推导了在定向曲面上的第二类松弛弹性线的Euler-Lagrange方程.进一步阐明了,这些曲线是否落在曲率线上,最后给出相关的实例. 相似文献
994.
Topological Aspect and Bifurcation of Disclination Lines in Two—Dimensional Liquid Crystals 总被引:2,自引:0,他引:2
Using φ-mapping method and topological current theory,the topological structure and bifurcation of disclination lines in two-dimensional liquid crystals are studied.By introducing the strength density and the topological current of many disclination lines,the total disclination strength is topologically quantized by the Hopf indices and Brouwer degrees at the singularities of the director field when the Jacobian determinant of director field does not vanish.When the Jacobian determinant vanishes,the origin,annihilation and bifurcation processes of disclination lines are studied in the neighborhoods of the limit points and bifurcation points,respectively.The branch solutions at the limit point and the different directions of all branch curves at the bifurcation point are calculated with the conservation law of the topological quantum numbers.It is pointed out that a disclination line with a higher strength is unstable and it will evolve to the lower strength state through the bifurcation process. 相似文献
995.
Based on Fourier-transform intra-cavity laser absorption spectroscopy (FT-ICLAS) setup reported, a signal differential module is introduced to reduce the noise rising from the fluctuation of the laser power and to improve the quality of the interferogram obtained in the experiment. The capability to do quantitative measurement was demonstrated by recording the atmospheric oxygen absorption near 760 nm. The v=6 local mode stretching overtone spectra of phosphine were recorded with different sample pressure. The pressure caused self-broadening and line shift parameters of this band were achieved. 相似文献
996.
The cross-field diffusion coefficient (D_⊥) at the edge in the HT-7 tokamak is close to the Bohm value when the line average electron density ranges from 1.5×10^{19} to 3.0×10^{19}m^{-3}. The energy profile of the particles is derived directly from the H_α(D_α) line shape; the dissociative excitation of molecules is dominating when the local electron temperature is above 10eV. By means of the Monte Carlo method the D_α line shape is also simulated. We find that the molecular dissociation contributes to 57% of neutral atoms and 53% of emission intensity in front of the limiter, and 85% of neutral atoms and 82% of emission intensity in front of the wall. The influence of atomic and molecular processes on the energy balance is discussed for the scrape-off layer (SOL), and the power loss from molecular dissociation is found to be 6×10^4kW at the SOL. The ion Bernstein wave (IBW) can effectively suppress the magnetohydrodynamic behaviour, the fluctuation levels and the turbulence; the D_⊥ in front of the limiter declines from 0.84 to 0.2m^2·s^{-1} and the particle confinement time rises from 9 to 12ms. 相似文献
997.
This paper presents a new theory for calculating the transport of high-energy photons and their secondary charged particles. We call this new algorithm characteristic line method, which is completely analytic. Using this new method we cannot only accurately calculate the transport behaviour of energetic photons, but also precisely describes the transport behaviour and energy deposition of secondary electrons, photoelectrons, Compton recoil electrons and positron-electron pairs. Its calculation efficiency is much higher than that of the Monte Carlo method. The theory can be directly applied to layered media situation and obtain a pencil-beam-modelled solution. Therefore, it may be applied to clinical applications for radiation therapy. 相似文献
998.
HIRFL的辐照治癌终端 总被引:3,自引:0,他引:3
为了进行重离子束流的肿瘤治疗和生物效应的研究,HIRFL正在建造一个辐照治癌终端.主要介绍了该终端的束流制备方法和束流线的布局、性能参数和束流光学设计计算结果. A new experimental terminal is being constructed at HIRFL for research program of proton and heavy ion therapies and irradiation effects of living things . The beam preparation method and the layout, performance and beam optics calculation of the beam line are presented. 相似文献
999.
HUANGWen-Hua ZHANGJie-Fang 《理论物理通讯》2004,42(1):4-8
Using the variable separation approach, many types of exact solutions of the generalized (2 1)-dimensional Nizhnik-Novikov-Veselov equation are derived. One of the exact solutions of this model is analyzed to study the interaction between a line soliton and a y-periodic soliton. 相似文献
1000.
First of all the deformation is considered of two infinitesimal material line elements lying along vectors M,N emanating from a particle at X in a body. For all M,N lying in a given plane, an identity is derived relating the stretches along M,N and the angles of the pair of infinitesimal material line elements before and after deformation. Then, the deformation is
considered of three non-coplanar infinitesimal material line elements lying along vectors M,N,P emanating from a particle at X in a body. An identity is derived relating the stretches along M,N,P and the angles between the three pairs of infinitesimal material line elements before and after deformation. The identity
is factored leading to easy interpretation. The special case of infinitesimal strain is considered.
相似文献