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991.
ZHU Jia-Min MA Zheng-Yi 《理论物理通讯》2006,46(3):393-396
In this paper, using the variable coefficient generalized projected Rieatti equation expansion method, we present explicit solutions of the (2+1)-dimensional variable coefficients Broer-Kaup (VCBK) equations. These solutions include Weierstrass function solution, solitary wave solutions, soliton-like solutions and trigonometric function solutions. Among these solutions, some are found for the first time. Because of the three or four arbitrary functions, rich localized excitations can be found. 相似文献
992.
The incorporation of energy elastic effects in the modeling of flowing polymeric liquids is discussed. Since conformational
energetic effects are determined by structural features much smaller than the end-to-end vector of the polymer chains, commonly
employed single conformation tensor models are insufficient to describe energy elastic effects. The need for a local structural
variable is substantiated by studying a microscopic toy model with energetic effects in the setting of a generalized canonical
ensemble. In order to examine the dynamics of flowing polymeric liquids with energy elastic effects, a thermodynamically admissible
set of evolution equations is presented that accounts for the evolution of the microstructure in terms of a slow tensor, as
well as a fast, local scalar variable. It is demonstrated that the temperature used in the definition of the heat flux is
directly related to the Lagrange multiplier of the microscopic energy in the generalized canonical partition function. The
temperature equation is discussed with respect to, first, the dependence of the heat capacity on the polymer conformation
and, second, the possibility to measure experimentally the effects of the conformational energy.
相似文献
Markus HütterEmail: |
993.
使用主值空间表示的各向同性塑性本构方程 总被引:1,自引:0,他引:1
针对各向同性材料,在内变量为标量的假定下,应用张量函数表示定理给出了其塑性应变增量的不变性表示.它的3个不可约基张量取决于应力张量、相互正交且共主轴.建立3个基张量构成的张量子空间与三维主值空间的对应关系,将共主轴的张量采用笛卡尔坐标系中的矢量描述,矢量在不同坐标系下的分量均为张量的一组不可约不变量.定义塑性应变增量对应的矢量为内变量增量,使用张量函数表示理论得到,内变量演化方程除取决于应力对应的矢量和内变量本身外,还取决于应力增量在张量子空间中的投影,该投影就是应力对应矢量的增量,因此,本构方程归结为确定主值空间中矢量之间的关系.最后表明,三维主值空间与张量子空间中的流动法则是等价的. 相似文献
994.
995.
HUANG Wen-Hua LIU Yu-Lu MA Zheng-Yi 《理论物理通讯》2007,47(3):397-402
Using the variable separation approach, we obtain a general exact solution with arbitrary variable separation functions for the (2+ 1)-dimensional Maccari system. By introducing Jacobi elliptic functions dn and nd in the seed solution, two types of doubly periodic propagating wave patterns are derived. We invest/gate the wave patterns evolution along with the modulus k increasing, many important and interesting properties are revealed. 相似文献
996.
The internal modes of incoherent vector solitons (IVSs) in
photovoltaic photorefractive materials are investigated in the
framework of coupled nonlinear Schr\"{o}dinger equations. It is found
that there is a pair of internal modes corresponding to a
bright--bright IVS. The propagation dynamics of the bright-bright IVS
perturbed by the internal modes is simulated by numerical method. 相似文献
997.
Hong Zhang Ethan Tumarkin Ruby May A. Sullan Gilbert C. Walker Eugenia Kumacheva 《Macromolecular rapid communications》2007,28(5):527-538
Polymer microgels in the size range from several micrometers to hundreds of micrometers are used in the pharmaceutical, cosmetics, nutrition, pesticide, and food industries, as well as in the encapsulation of cells. To date, a broad range of strategies for the generation of polymer microgels exist, however, these methods involve multistage processes, do not utilize biocompatible components or do not allow precise control of the dimensions and internal structure of the microgels. Recently, microfluidic strategies for the production of polymer particles have offered precise control over the shapes, morphologies, and size distributions of polymer colloids. This paper discusses the most recent results obtained by the authors in the area of the microfluidic production of biopolymer microgels. It provides a brief review of the microfluidic methods for the continuous synthesis and fabrication of microgels, sets the criteria for the successful microfluidic generation of biomicrogels, and describes two methods for the preparation of microgels by microfluidic means. The article concludes with a summary and an outlook.
998.
用多极方法数值研究构成六重对称全内反射型光子晶体光纤各种结构参数对基模零色散点的调节.数值结果表明,在相对孔径较大时,包层空气孔柱层数不影响零色散点,在其它结构参数相同的条件下,空气孔直径越大,零色散点波长越短,而在其它结构参数相同的条件下,空气孔孔距越大,零色散点波长越长,当空气孔直径与空气孔孔距都很小时,零色散点出现在长波区域,当空气孔直径与空气孔孔距大到一定程度时,色散曲线在零色散线出现振荡特性,并出现多个零色散点,在包层空气柱层数一定的条件下,中央纤芯缺省空气孔层数对零色散点的调节范围大. 相似文献
999.
By using a Bäcklund transformation and the multi-linear variable separation approach, we find a new general
solution of a (2+1)-dimensional generalization of the nonlinear
Schrödinger system. The new “universal” formula is defined, and then, rich coherent structures can be found by selecting corresponding
functions appropriately. 相似文献
1000.
Bayesian latent variable regression (BLVR) aims to utilize all available information for empirical modeling via a Bayesian framework. Such information includes prior knowledge about the underlying variables, model parameters and measurement error distributions. This paper improves upon the existing optimization‐based BLVR (BLVR‐OPT) method [1] by developing a sampling‐based Bayesian latent variable regression (BLVR‐S) method that relies on Gibbs sampling. Use of the sampling‐based framework not only provides point estimates, but its ability to generate samples that represent the posterior distribution of the unknown variables, also readily provides error bounds. Features and advantages of this method are demonstrated via examples based on simulated data and real Near‐Infrared (NIR) spectroscopy data. Practical aspects of Bayesian modeling such as determining when the extra computation may be worth the effort are addressed by an empirical study of the effects of the amount of training data and signal to noise ratio (SNR). The benefits of BLVR seem to be most significant when the number of measurements is limited and when noise in output variables is relatively large. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献