The goal of this paper is to research one new characteristic of complex system. Brittleness, which is one new characteritic of complex system, is presented in this paper. The linguistic and qualitative descriptions of...The goal of this paper is to research one new characteristic of complex system. Brittleness, which is one new characteritic of complex system, is presented in this paper. The linguistic and qualitative descriptions of complex system are also given in this paper. Otherwise, the qualitative description of complex system is presented at first. On the basis of analyzing the existing brittleness problems, linguistic description and mathematic description of brittleness are given as well. Three kinds of phenomena to judge brittleness of complex system are also given, based on catastrophe theory. Basic characteristics of brittleness are given on the basis of its mathematic description. Two critical point sets are defined by using catastrophe theory. The definition of brittleness and its related theory can serve the control of complex system, and provide theoretical basis for the design and control of complex system.展开更多
Methods that can efficiently model the effects of rock joints on rock mass behavior can be beneficial in rock engineering. The suitability of equivalent rock mass(ERM) technique based upon particle methods is investig...Methods that can efficiently model the effects of rock joints on rock mass behavior can be beneficial in rock engineering. The suitability of equivalent rock mass(ERM) technique based upon particle methods is investigated. The ERM methodology is first validated by comparing calculated and experimental data of lab triaxial compression test on a set of cylindrical rock mass samples, each containing a single joint oriented in various dip angles. The simulated results are then used to study the stress-strain nonlinearity and failure mechanism as a function of the joint dip angle and confining stress. The anisotropy and size effects are also investigated by using multi-scale cubic ERM models subjected to triaxial compression test. The deformation and failure behavior are found to be influenced by joint degradation, the micro-crack formation in the intact rock, the interaction between two joints, and the interactions of micro-cracks and joints.展开更多
After the emergence of a severe labor shortage in 2004, wage levels for rural migrant workers （hereafter referred to as ＂migrant workers ＂） ceased their long time stagnation and began to rise rapidly. This rise ca...After the emergence of a severe labor shortage in 2004, wage levels for rural migrant workers （hereafter referred to as ＂migrant workers ＂） ceased their long time stagnation and began to rise rapidly. This rise can be attributed to various factors, such as demographics, business cycles, policy, and China＇s economic structure. As the wage-setting mechanism for migrant workers changes from traditional minimum wage to negotiated pricing rules subject to the reservation wage, China＇s economy indicates that it is embracing a new era of rapid wage increases. Changes in China＇s income distribution will bring opportunities to the turning point of Kuznets ＂Inverted-U＂ Curve, and allow China to narrow its significant income gap. These changes will transform China＇s economic growth model from one that is export and investment-dependent to one that is driven by domestic consumption.展开更多
Materials science is an interdisciplinary field applying the properties of matter to various areas of science and engineering. This scientific field investigates the relationship between the structure of materials at ...Materials science is an interdisciplinary field applying the properties of matter to various areas of science and engineering. This scientific field investigates the relationship between the structure of materials at atomic or molecular scales and their macroscopic properties. It incorporates elements of applied physics and chemistry. With significant media attention focused on nanoscience and nanotechnology in recent years, materials science has been propelled to the forefront at many universities. Materials science encompasses various classes of materials, including electronic materials, functional ceramics, magnesium, material and processes for flat-panel displays, eco/environmental materials, sustainable energy materials, transportation materials, electronic packaging materials, etc.展开更多
基金Supported by the Commission of Science Technology and Industry for National Defense (J1600B001)
文摘The goal of this paper is to research one new characteristic of complex system. Brittleness, which is one new characteritic of complex system, is presented in this paper. The linguistic and qualitative descriptions of complex system are also given in this paper. Otherwise, the qualitative description of complex system is presented at first. On the basis of analyzing the existing brittleness problems, linguistic description and mathematic description of brittleness are given as well. Three kinds of phenomena to judge brittleness of complex system are also given, based on catastrophe theory. Basic characteristics of brittleness are given on the basis of its mathematic description. Two critical point sets are defined by using catastrophe theory. The definition of brittleness and its related theory can serve the control of complex system, and provide theoretical basis for the design and control of complex system.
基金Projects(51074014,51174014) supported by the National Natural Science Foundation of China
文摘Methods that can efficiently model the effects of rock joints on rock mass behavior can be beneficial in rock engineering. The suitability of equivalent rock mass(ERM) technique based upon particle methods is investigated. The ERM methodology is first validated by comparing calculated and experimental data of lab triaxial compression test on a set of cylindrical rock mass samples, each containing a single joint oriented in various dip angles. The simulated results are then used to study the stress-strain nonlinearity and failure mechanism as a function of the joint dip angle and confining stress. The anisotropy and size effects are also investigated by using multi-scale cubic ERM models subjected to triaxial compression test. The deformation and failure behavior are found to be influenced by joint degradation, the micro-crack formation in the intact rock, the interaction between two joints, and the interactions of micro-cracks and joints.
文摘After the emergence of a severe labor shortage in 2004, wage levels for rural migrant workers （hereafter referred to as ＂migrant workers ＂） ceased their long time stagnation and began to rise rapidly. This rise can be attributed to various factors, such as demographics, business cycles, policy, and China＇s economic structure. As the wage-setting mechanism for migrant workers changes from traditional minimum wage to negotiated pricing rules subject to the reservation wage, China＇s economy indicates that it is embracing a new era of rapid wage increases. Changes in China＇s income distribution will bring opportunities to the turning point of Kuznets ＂Inverted-U＂ Curve, and allow China to narrow its significant income gap. These changes will transform China＇s economic growth model from one that is export and investment-dependent to one that is driven by domestic consumption.
文摘Materials science is an interdisciplinary field applying the properties of matter to various areas of science and engineering. This scientific field investigates the relationship between the structure of materials at atomic or molecular scales and their macroscopic properties. It incorporates elements of applied physics and chemistry. With significant media attention focused on nanoscience and nanotechnology in recent years, materials science has been propelled to the forefront at many universities. Materials science encompasses various classes of materials, including electronic materials, functional ceramics, magnesium, material and processes for flat-panel displays, eco/environmental materials, sustainable energy materials, transportation materials, electronic packaging materials, etc.
