Discontinuities constitute an integral part of rock mass and inherently affect its anisotropic deformation behavior.This work focuses on the equivalent elastic deformation of rock mass with multiple persistent joint s...Discontinuities constitute an integral part of rock mass and inherently affect its anisotropic deformation behavior.This work focuses on the equivalent elastic deformation of rock mass with multiple persistent joint sets.A new method based on the space geometric and mechanical properties of the modified crack tensor is proposed,providing an analytical solution for the equivalent elastic compliance tensor of rock mass.A series of experiments validate the capability of the compliance tensor to accurately represent the deformation of rock mass with multiple persistent joint sets,based on conditions set by the basic hypothesis.The spatially varying rules of the equivalent elastic parameters of rock mass with a single joint set are analyzed to reveal the universal law of the stratified rock mass.展开更多
贵刊《科技英语学习》1999年第6期登载了广西马轮基同志的《于细微处于求精确)一文,该文末尾提出了FQHE一词的翻译,现就笔者所知,试译及介绍如下: FQHE应为Fraction Quantum Hall Effect的简写,据此应把FQHE译为“分数量子霍尔效应”。...贵刊《科技英语学习》1999年第6期登载了广西马轮基同志的《于细微处于求精确)一文,该文末尾提出了FQHE一词的翻译,现就笔者所知,试译及介绍如下: FQHE应为Fraction Quantum Hall Effect的简写,据此应把FQHE译为“分数量子霍尔效应”。那么是否有“整数量子霍尔效应”呢?答案是肯定的。展开更多
Mating preferences can show extreme variation within and among individuals even when sensory inputs are conserved. This variation is a result of changes associated with evaluative mechanisms that assign positive, neut...Mating preferences can show extreme variation within and among individuals even when sensory inputs are conserved. This variation is a result of changes associated with evaluative mechanisms that assign positive, neutral, or negative hedonic value to stimuli--that is, label them as attractive, uninteresting, or unattractive. There is widespread behavioral evidence for differences in genes, environmental cues, or social experience leading to marked changes in the hedonic value of stimuli. Evaluation is accomplished through an array of mechanisms that are readily modifiable through genetic changes or environmental inputs, and that may often result in the rapid acquisition or loss of behavioral preferences. Reversals in preference arising from ＂flips＂ in hedonic value may be quite common. Incorporating such discontinuous changes into models of preference evolution may illuminate our understanding of processes like trait diversification, sexual conflict, and sympatric speciation.展开更多
With more and more improvements of atmosphere or ocean models,a growing number of physical processes in the form of parameterization are incorporated into the models,which,on the one hand,makes the models capable of d...With more and more improvements of atmosphere or ocean models,a growing number of physical processes in the form of parameterization are incorporated into the models,which,on the one hand,makes the models capable of describing the at-mospheric or oceanic movement more precisely,and on the other hand,introduces non-smoothness in the form of "on-off" switches into the models."On-off" switches enhance the nonlinearity of the models and finally result in the loss of the effec-tiveness of variational data assimilation(VDA) based on the conventional adjoint method(ADJ).This study,in virtue of the optimization ability of a genetic algorithm(GA) for non-smooth problems,presents a new GA(referred to as GA NEW) to solve the problems of the VDA with discontinuous "on-off" processes.In the GA-NEW,adaptive selection and mutation oper-ators,blend crossover operator,and elitist strategy are combined in application.In order to verify the effectiveness and feasi-bility of the GA NEW in VDA,an idealized model of partial differential equation with discontinuous "on-off" switches in the forcing term is adopted as the governing equation.By comparison with the ADJ,it is shown that the GA NEW in VDA is more effective and can yield better assimilation retrievals.In addition,VDA experiments demonstrate that the performance of a GA is greatly related to the configuration of genetic operators(selection,crossover and mutation operators) and much better results may be attained with more proper genetic operations.Furthermore,the robustness of the GA NEW to observational noise,model errors and observation density is investigated,and the results show that the GA NEW has stronger robustness than the ADJ with respect to all the three observation noises,model errors,and sparse observation.展开更多
基金Projects(41172284,51379202) supported by the National Natural Science Foundation of ChinaProject(2013CB036405) supported by the National Basic Research Program of ChinaProject(2013BAB02B01) supported by the National Key Technologies R&D Program of China
文摘Discontinuities constitute an integral part of rock mass and inherently affect its anisotropic deformation behavior.This work focuses on the equivalent elastic deformation of rock mass with multiple persistent joint sets.A new method based on the space geometric and mechanical properties of the modified crack tensor is proposed,providing an analytical solution for the equivalent elastic compliance tensor of rock mass.A series of experiments validate the capability of the compliance tensor to accurately represent the deformation of rock mass with multiple persistent joint sets,based on conditions set by the basic hypothesis.The spatially varying rules of the equivalent elastic parameters of rock mass with a single joint set are analyzed to reveal the universal law of the stratified rock mass.
文摘贵刊《科技英语学习》1999年第6期登载了广西马轮基同志的《于细微处于求精确)一文,该文末尾提出了FQHE一词的翻译,现就笔者所知,试译及介绍如下: FQHE应为Fraction Quantum Hall Effect的简写,据此应把FQHE译为“分数量子霍尔效应”。那么是否有“整数量子霍尔效应”呢?答案是肯定的。
文摘Mating preferences can show extreme variation within and among individuals even when sensory inputs are conserved. This variation is a result of changes associated with evaluative mechanisms that assign positive, neutral, or negative hedonic value to stimuli--that is, label them as attractive, uninteresting, or unattractive. There is widespread behavioral evidence for differences in genes, environmental cues, or social experience leading to marked changes in the hedonic value of stimuli. Evaluation is accomplished through an array of mechanisms that are readily modifiable through genetic changes or environmental inputs, and that may often result in the rapid acquisition or loss of behavioral preferences. Reversals in preference arising from ＂flips＂ in hedonic value may be quite common. Incorporating such discontinuous changes into models of preference evolution may illuminate our understanding of processes like trait diversification, sexual conflict, and sympatric speciation.
基金supported by National Natural Science Foundation of China (Grant Nos.40975063 and 40830955)
文摘With more and more improvements of atmosphere or ocean models,a growing number of physical processes in the form of parameterization are incorporated into the models,which,on the one hand,makes the models capable of describing the at-mospheric or oceanic movement more precisely,and on the other hand,introduces non-smoothness in the form of "on-off" switches into the models."On-off" switches enhance the nonlinearity of the models and finally result in the loss of the effec-tiveness of variational data assimilation(VDA) based on the conventional adjoint method(ADJ).This study,in virtue of the optimization ability of a genetic algorithm(GA) for non-smooth problems,presents a new GA(referred to as GA NEW) to solve the problems of the VDA with discontinuous "on-off" processes.In the GA-NEW,adaptive selection and mutation oper-ators,blend crossover operator,and elitist strategy are combined in application.In order to verify the effectiveness and feasi-bility of the GA NEW in VDA,an idealized model of partial differential equation with discontinuous "on-off" switches in the forcing term is adopted as the governing equation.By comparison with the ADJ,it is shown that the GA NEW in VDA is more effective and can yield better assimilation retrievals.In addition,VDA experiments demonstrate that the performance of a GA is greatly related to the configuration of genetic operators(selection,crossover and mutation operators) and much better results may be attained with more proper genetic operations.Furthermore,the robustness of the GA NEW to observational noise,model errors and observation density is investigated,and the results show that the GA NEW has stronger robustness than the ADJ with respect to all the three observation noises,model errors,and sparse observation.
