The mathematical model of a 3-element centripetal-turbine hydrodynamic torque converter and analytic description of fluid flow inside the hydrodynamic torque converter are investigated. A new torus coordinate system i...The mathematical model of a 3-element centripetal-turbine hydrodynamic torque converter and analytic description of fluid flow inside the hydrodynamic torque converter are investigated. A new torus coordinate system is proposed so as to quantitatively describe fluid movement inside the hydrodynamic torque converter. The particle movement inside the hydrodynamic torque converter is decomposed into meridional component movement and torus component movement, and a universal meridional streamline equation is derived. According to the relationship between the converter wheel velocity polygon and its blade angle, a torus streamline differential equation is established. The universal meridional streamline equation is approximated with square polynomials. The approximation error curve is given and the percentage error is not greater than 0.86%. Considered as a function of polar angle, the blade angle cotangent of each converter wheel varies linearly with polar angle. By using integral calculus, torus streamline equations are obtained. As a result, the problem of difficult flow description of the hydrodynamic torque converter is solved and a new analytic research system is established.展开更多
The problem of mathematical simulation of motion of dynamic systems characteristics and their coincidence with real experimental data which correspond to these characteristics is investigated in this paper. Mathematic...The problem of mathematical simulation of motion of dynamic systems characteristics and their coincidence with real experimental data which correspond to these characteristics is investigated in this paper. Mathematical description of process will be named as adequate mathematical description if the results of mathematical simulation by the help of this description coincide with experiment with inaccuracy of initial data. The synthesis of such description is very important at mathematical modeling and forecast of motion of real physical phenomena. The specified problem is still poorly investigated and hardly adapted to formalization. The requirements to the adequate mathematical description of dynamic system are considered for the case when mathematical description of dynamic systems is represented by linear system of the ordinary differential equations. In this paper the mathematical model of process is given a priori with inexact parameters and then the models of external loads are being determined for which the results of simulation coincide with experiment. The methods of obtaining of the steady models of external loads are suggested. The example of the adequate description construction of the main mechanical line dynamics of rolling mill is given.展开更多
A new task mode, hardware logic task mode, is presented. Its architecture, schedule and implementation are described with HDI.( Hardware Description Language ), and the validity of the system has been proved by logi...A new task mode, hardware logic task mode, is presented. Its architecture, schedule and implementation are described with HDI.( Hardware Description Language ), and the validity of the system has been proved by logic simulation. It has advantage for real-time applications and overheadsaving for operating .system, so it is profitable for the controller in the embedded system. The relationship among RTOS (Real-Time Operating System), SoC(System on Chip), VIA (Virtual Interface Architecture) and hardware logic task is also discussed in the paper.展开更多
A thermodynamic description of the Ni-Co-Gd system is developed by means of the computer programs THERMO CALC, using models for the Gibbs energy of individual phases. Previous assessments of the three binary systems ...A thermodynamic description of the Ni-Co-Gd system is developed by means of the computer programs THERMO CALC, using models for the Gibbs energy of individual phases. Previous assessments of the three binary systems were incorporated. The system contains ten different compounds and they are all treated as line compounds. Good agreement is obtained between the calculation and experimental results in the ternary system.展开更多
In a structural system reliability analysis that lacks probabilistic information, calculating the numerical characteristics of the state functions, especially the first four moments of the state functions, is necessar...In a structural system reliability analysis that lacks probabilistic information, calculating the numerical characteristics of the state functions, especially the first four moments of the state functions, is necessary. Based on that, the structural system reliability is analyzed with a fourth-order moment method. The reliability sensitivity is required to conduct the differential operation of the numerical characteristic functions. A reliability sensitivity analysis formula is then derived in combination with the relation of the differential operation. Based on the matrix theory and Kronecker algebra, this paper systematically derives a matrix expression of the first four moments of the state functions, and establishes the matrix relation between the first four moments of the state functions and those of the basic random variables. On this basis, a differential operation formula of the first four moments of the state functions is further derived against the first four moments of the basic random variables. The vector relation between the state functions and the multidimensional basic random variables is described by means of the matrix operation to extend the operation method. Finally, a concise and intuitive formula is obtained to explore the inherent essential relation between the numerical characteristics of the state functions and those of the basic random variables, leading to a universal equation for the two kinds of numerical characteristics.展开更多
世界各国都高度重视教育发展,在新时代背景下进行教育活动核算方法的研究有重要的理论与实践意义。本文以联合国教科文组织发布的《国民教育账户方法论》(Methodologyof National Education Accounts 2016,MNEA2016)和联合国《国民账户...世界各国都高度重视教育发展,在新时代背景下进行教育活动核算方法的研究有重要的理论与实践意义。本文以联合国教科文组织发布的《国民教育账户方法论》(Methodologyof National Education Accounts 2016,MNEA2016)和联合国《国民账户体系》(System of National Accounts2008,SNA2008)等为基础,讨论我国教育活动核算体系的理论基础与重要范畴,设计账户与核算表通式,构造教育核算指标体系,探讨我国教育核算体系的数据支撑及其与中国国民经济核算体系(China’s System of National Accounts 2016,CSNA2016)的对接问题,以期形成我国教育核算体系的基本范式。展开更多
协方差分析描述函数法(covariance analysis describing function technique,CADET)在处理系统的随机响应问题上具有求解迅速、仿真精度高等优点.但对于复杂系统,其理论推导过程、求解系统解析响应方程较为复杂繁琐.为进一步推广CADET...协方差分析描述函数法(covariance analysis describing function technique,CADET)在处理系统的随机响应问题上具有求解迅速、仿真精度高等优点.但对于复杂系统,其理论推导过程、求解系统解析响应方程较为复杂繁琐.为进一步推广CADET的应用,依托高斯–埃尔米特积分法,提出了一种通用化的CADET数值算法.作为算法验证,以车辆行驶过程中的随机振动为例,建立了几种不同非线性悬架车辆的二自由度动力学模型,并将CADET通用化数值算法与传统CADET算法及蒙特卡罗法进行了对比分析.仿真结果表明,CADET的通用化数值算法可以达到满足应用要求的计算精度,这验证了所提数值算法的有效性,且具有更强的泛化应用于复杂非线性动力系统的价值.展开更多
基金supported by Henan Provincial Tackle Key Program of China (Grant No. 0424260038)
文摘The mathematical model of a 3-element centripetal-turbine hydrodynamic torque converter and analytic description of fluid flow inside the hydrodynamic torque converter are investigated. A new torus coordinate system is proposed so as to quantitatively describe fluid movement inside the hydrodynamic torque converter. The particle movement inside the hydrodynamic torque converter is decomposed into meridional component movement and torus component movement, and a universal meridional streamline equation is derived. According to the relationship between the converter wheel velocity polygon and its blade angle, a torus streamline differential equation is established. The universal meridional streamline equation is approximated with square polynomials. The approximation error curve is given and the percentage error is not greater than 0.86%. Considered as a function of polar angle, the blade angle cotangent of each converter wheel varies linearly with polar angle. By using integral calculus, torus streamline equations are obtained. As a result, the problem of difficult flow description of the hydrodynamic torque converter is solved and a new analytic research system is established.
文摘The problem of mathematical simulation of motion of dynamic systems characteristics and their coincidence with real experimental data which correspond to these characteristics is investigated in this paper. Mathematical description of process will be named as adequate mathematical description if the results of mathematical simulation by the help of this description coincide with experiment with inaccuracy of initial data. The synthesis of such description is very important at mathematical modeling and forecast of motion of real physical phenomena. The specified problem is still poorly investigated and hardly adapted to formalization. The requirements to the adequate mathematical description of dynamic system are considered for the case when mathematical description of dynamic systems is represented by linear system of the ordinary differential equations. In this paper the mathematical model of process is given a priori with inexact parameters and then the models of external loads are being determined for which the results of simulation coincide with experiment. The methods of obtaining of the steady models of external loads are suggested. The example of the adequate description construction of the main mechanical line dynamics of rolling mill is given.
基金Supported bythe National Basic Research Programof China (973 Program2004CB318201) the National Natural Sci-ence Foundation of China (60273074)
文摘A new task mode, hardware logic task mode, is presented. Its architecture, schedule and implementation are described with HDI.( Hardware Description Language ), and the validity of the system has been proved by logic simulation. It has advantage for real-time applications and overheadsaving for operating .system, so it is profitable for the controller in the embedded system. The relationship among RTOS (Real-Time Operating System), SoC(System on Chip), VIA (Virtual Interface Architecture) and hardware logic task is also discussed in the paper.
文摘A thermodynamic description of the Ni-Co-Gd system is developed by means of the computer programs THERMO CALC, using models for the Gibbs energy of individual phases. Previous assessments of the three binary systems were incorporated. The system contains ten different compounds and they are all treated as line compounds. Good agreement is obtained between the calculation and experimental results in the ternary system.
基金Project supported by the National Natural Science Foundation of China(Nos.51135003 and U1234208)the Major State Basic Research Development Program of China(973 Program)(No.2014CB046303)
文摘In a structural system reliability analysis that lacks probabilistic information, calculating the numerical characteristics of the state functions, especially the first four moments of the state functions, is necessary. Based on that, the structural system reliability is analyzed with a fourth-order moment method. The reliability sensitivity is required to conduct the differential operation of the numerical characteristic functions. A reliability sensitivity analysis formula is then derived in combination with the relation of the differential operation. Based on the matrix theory and Kronecker algebra, this paper systematically derives a matrix expression of the first four moments of the state functions, and establishes the matrix relation between the first four moments of the state functions and those of the basic random variables. On this basis, a differential operation formula of the first four moments of the state functions is further derived against the first four moments of the basic random variables. The vector relation between the state functions and the multidimensional basic random variables is described by means of the matrix operation to extend the operation method. Finally, a concise and intuitive formula is obtained to explore the inherent essential relation between the numerical characteristics of the state functions and those of the basic random variables, leading to a universal equation for the two kinds of numerical characteristics.
文摘世界各国都高度重视教育发展,在新时代背景下进行教育活动核算方法的研究有重要的理论与实践意义。本文以联合国教科文组织发布的《国民教育账户方法论》(Methodologyof National Education Accounts 2016,MNEA2016)和联合国《国民账户体系》(System of National Accounts2008,SNA2008)等为基础,讨论我国教育活动核算体系的理论基础与重要范畴,设计账户与核算表通式,构造教育核算指标体系,探讨我国教育核算体系的数据支撑及其与中国国民经济核算体系(China’s System of National Accounts 2016,CSNA2016)的对接问题,以期形成我国教育核算体系的基本范式。
文摘协方差分析描述函数法(covariance analysis describing function technique,CADET)在处理系统的随机响应问题上具有求解迅速、仿真精度高等优点.但对于复杂系统,其理论推导过程、求解系统解析响应方程较为复杂繁琐.为进一步推广CADET的应用,依托高斯–埃尔米特积分法,提出了一种通用化的CADET数值算法.作为算法验证,以车辆行驶过程中的随机振动为例,建立了几种不同非线性悬架车辆的二自由度动力学模型,并将CADET通用化数值算法与传统CADET算法及蒙特卡罗法进行了对比分析.仿真结果表明,CADET的通用化数值算法可以达到满足应用要求的计算精度,这验证了所提数值算法的有效性,且具有更强的泛化应用于复杂非线性动力系统的价值.