In this paper a three degrees of freedom autoparametric system with limited power supply is investigated numerically. The system consists of the body, which is hung on a spring and a damper, and two pendulums connecte...In this paper a three degrees of freedom autoparametric system with limited power supply is investigated numerically. The system consists of the body, which is hung on a spring and a damper, and two pendulums connected by shape memory alloy （SMA） spring. Shape memory alloys have ability to change their material properties with temperature. A polynomial constitutive model is assumed to describe the behavior of the SMA spring. The non-ideal source of power adds one degree of freedom, so the system has four degrees of freedom. The equations of motion have been solved numerically and pseudoelastic effects associated with the martensitic phase transformation are studied. It is shown that in this type system one mode of vibrations might excite or damp another mode, and that except different kinds of periodic vibrations there may also appear chaotic vibrations. For the identification of the responses of the system＇s various techniques, including chaos techniques such as bifurcation diagrams and time histories, power spectral densities, Poincare maps and exponents of Lyapunov may be used.展开更多
By comparing China's import of major imported agriculture textile material( cotton and wool),the characteristics of import are concluded. On this basis,a restricted version of source differentiated almost ideal de...By comparing China's import of major imported agriculture textile material( cotton and wool),the characteristics of import are concluded. On this basis,a restricted version of source differentiated almost ideal demand system( RSDAIDS) is used to estimate the income and price elasticity of major imported agriculture textile material from the major sources based on the data from 1992 to 2015. The results are shown as follows.( 1) Although the dependency on imported cotton is lower than wool, the fluctuation of cotton import is much more drastic; China's demand for cotton is relatively price elastic with higher expenditure elasticity compared with wool; besides,the existence of complementarity is proved between imported cotton and wool.( 2) According to the import elasticity of cotton,demand for cotton imported from India shows priority over cotton from other sources; demand for cotton imported from America is the most price-sensitive one; substitution among cotton from different sources is weak.( 3) According to the import elasticity of wool,wool imported from Uruguay has bright market prospects. In addition,wool imported from Australia has irreplaceable advantage than that from New Zealand.展开更多
In this paper, an explicit finite element method to analyze the dynamic responses of three-medium coupled systems with any terrain is developed on the basis of the numerical simulation of the continuous conditions on ...In this paper, an explicit finite element method to analyze the dynamic responses of three-medium coupled systems with any terrain is developed on the basis of the numerical simulation of the continuous conditions on the bounda-ries among fluid saturated porous medium, elastic single-phase medium and ideal fluid medium. This method is a very effective one with the characteristic of high calculating speed and small memory needed because the formulae for this explicit finite element method have the characteristic of decoupling, and which does not need to solve sys-tem of linear equations. The method is applied to analyze the dynamic response of a reservoir with considering the dynamic interactions among water, dam, sediment and basement rock. The vertical displacement at the top point of the dam is calculated and some conclusions are given.展开更多
针对综合能源系统运行方案选优结果区分度低、指标权重确定不合理的问题,提出一种基于改进博弈论组合赋权-逼近理想解排序法(technique for order preference by similarity to an ideal solution,TOPSIS)的综合能源系统运行方案评价方...针对综合能源系统运行方案选优结果区分度低、指标权重确定不合理的问题,提出一种基于改进博弈论组合赋权-逼近理想解排序法(technique for order preference by similarity to an ideal solution,TOPSIS)的综合能源系统运行方案评价方法。首先,建立一种新的博弈论组合赋权模型,解决了组合赋权过程误差较大的问题。其次,引入虚拟正、负理想解对TOPSIS法进行改进,解决了传统TOPSIS法评价结果区分度低的问题。最后,以上海某酒店综合能源系统数据为例进行仿真。结果表明:所提方法减少了组合赋权过程产生的误差,提高了综合能源系统运行方案评价结果的区分度。展开更多
文章在常规TOPSIS(technique for order preference by similarity to ideal solution)模型的基础上提出空间TOPSIS模型,以安徽省休宁县为例,采用地理信息系统(geographic information system,GIS)技术对安徽省休宁县的滑坡易发性进行...文章在常规TOPSIS(technique for order preference by similarity to ideal solution)模型的基础上提出空间TOPSIS模型,以安徽省休宁县为例,采用地理信息系统(geographic information system,GIS)技术对安徽省休宁县的滑坡易发性进行评价。研究表明:基于GIS的空间TOPSIS模型的滑坡易发性评价,能够处理和分析滑坡评价因子以及滑坡易发性的空间变化特征;评价结果与休宁县境内已经发生滑坡的空间分布较为吻合,评价结果较好。基于GIS的空间TOPSIS模型在滑坡易发性评价中具有较好的适用性。展开更多
文摘In this paper a three degrees of freedom autoparametric system with limited power supply is investigated numerically. The system consists of the body, which is hung on a spring and a damper, and two pendulums connected by shape memory alloy （SMA） spring. Shape memory alloys have ability to change their material properties with temperature. A polynomial constitutive model is assumed to describe the behavior of the SMA spring. The non-ideal source of power adds one degree of freedom, so the system has four degrees of freedom. The equations of motion have been solved numerically and pseudoelastic effects associated with the martensitic phase transformation are studied. It is shown that in this type system one mode of vibrations might excite or damp another mode, and that except different kinds of periodic vibrations there may also appear chaotic vibrations. For the identification of the responses of the system＇s various techniques, including chaos techniques such as bifurcation diagrams and time histories, power spectral densities, Poincare maps and exponents of Lyapunov may be used.
基金Industrial Research of National Wool and Csahmere Industry Technology System,China(No.CARS-40-20)
文摘By comparing China's import of major imported agriculture textile material( cotton and wool),the characteristics of import are concluded. On this basis,a restricted version of source differentiated almost ideal demand system( RSDAIDS) is used to estimate the income and price elasticity of major imported agriculture textile material from the major sources based on the data from 1992 to 2015. The results are shown as follows.( 1) Although the dependency on imported cotton is lower than wool, the fluctuation of cotton import is much more drastic; China's demand for cotton is relatively price elastic with higher expenditure elasticity compared with wool; besides,the existence of complementarity is proved between imported cotton and wool.( 2) According to the import elasticity of cotton,demand for cotton imported from India shows priority over cotton from other sources; demand for cotton imported from America is the most price-sensitive one; substitution among cotton from different sources is weak.( 3) According to the import elasticity of wool,wool imported from Uruguay has bright market prospects. In addition,wool imported from Australia has irreplaceable advantage than that from New Zealand.
基金National Natural Scienccs Foundation of China (50178005).
文摘In this paper, an explicit finite element method to analyze the dynamic responses of three-medium coupled systems with any terrain is developed on the basis of the numerical simulation of the continuous conditions on the bounda-ries among fluid saturated porous medium, elastic single-phase medium and ideal fluid medium. This method is a very effective one with the characteristic of high calculating speed and small memory needed because the formulae for this explicit finite element method have the characteristic of decoupling, and which does not need to solve sys-tem of linear equations. The method is applied to analyze the dynamic response of a reservoir with considering the dynamic interactions among water, dam, sediment and basement rock. The vertical displacement at the top point of the dam is calculated and some conclusions are given.
文摘针对综合能源系统运行方案选优结果区分度低、指标权重确定不合理的问题,提出一种基于改进博弈论组合赋权-逼近理想解排序法(technique for order preference by similarity to an ideal solution,TOPSIS)的综合能源系统运行方案评价方法。首先,建立一种新的博弈论组合赋权模型,解决了组合赋权过程误差较大的问题。其次,引入虚拟正、负理想解对TOPSIS法进行改进,解决了传统TOPSIS法评价结果区分度低的问题。最后,以上海某酒店综合能源系统数据为例进行仿真。结果表明:所提方法减少了组合赋权过程产生的误差,提高了综合能源系统运行方案评价结果的区分度。
文摘文章在常规TOPSIS(technique for order preference by similarity to ideal solution)模型的基础上提出空间TOPSIS模型,以安徽省休宁县为例,采用地理信息系统(geographic information system,GIS)技术对安徽省休宁县的滑坡易发性进行评价。研究表明:基于GIS的空间TOPSIS模型的滑坡易发性评价,能够处理和分析滑坡评价因子以及滑坡易发性的空间变化特征;评价结果与休宁县境内已经发生滑坡的空间分布较为吻合,评价结果较好。基于GIS的空间TOPSIS模型在滑坡易发性评价中具有较好的适用性。
