Based on grain yield data of China, the vanation features of grain yield in China in recent 40 years and their relationships with the associated factors were analyzed. Results show that the total grain yield increased...Based on grain yield data of China, the vanation features of grain yield in China in recent 40 years and their relationships with the associated factors were analyzed. Results show that the total grain yield increased gradually, and its interannual variation is influenced principally by unit area crop yield (about 70 percent in average). The influences of agricultural technology, social factors and weather conditions on thet area crop yield can be separated because of their unique variation trends and time scales. The influence of agricultural technology is in a smoothly and gradually incremental trend, and the influence of the social factors is oscillated with three waves in recent 40 years, and the influence of weather conditions is fiuctuated sharply from year to year. Their mean effects on the inter-annual variation of unit area crop yield are about 35 to 40 percent, 10 to 15 percent and 50 percent respectively. In the view point of predictions, the effects of weather conditions are much more important.展开更多
By using the partially ordered methods, the existence problem of solutions formore general implicit varational inequalities of monotone type in Hausdorfftopological linear spaces are considered. As application we uti...By using the partially ordered methods, the existence problem of solutions formore general implicit varational inequalities of monotone type in Hausdorfftopological linear spaces are considered. As application we utilize the results presentedin this paper to study the existence of solutions for Nash equilibrium problem and thesemi-linear elliptic differential equations.展开更多
In this paper. the principle of maximum power losses for the incompressibleviscous fluid proposed by professor Chien Wei-zang is extended to the hydrodynamicproblems of a special class of non-Newtonian fluid-generaliz...In this paper. the principle of maximum power losses for the incompressibleviscous fluid proposed by professor Chien Wei-zang is extended to the hydrodynamicproblems of a special class of non-Newtonian fluid-generalized Newtonian fluid.The constraint condition of variation are eliminated by the method of idetifiedLagrangian multipliers and a generalized variational principle is established.展开更多
In the present paper, we hare mtroduced the random materials. loads. geometricalshapes, force and displacement boundary condition directly. into the functionalvariational formula, by. use of a small parameter perturb...In the present paper, we hare mtroduced the random materials. loads. geometricalshapes, force and displacement boundary condition directly. into the functionalvariational formula, by. use of a small parameter perturbation method, a unifiedrandom variational principle in finite defomation of elastieity and nonlinear randomfinite element method are esiablished, and used.for reliability, analysis of structures.Numerical examples showed that the methods have the advontages of simple andconvenient program implementation and are effective for the probabilistic problems inmechanics.展开更多
文摘Based on grain yield data of China, the vanation features of grain yield in China in recent 40 years and their relationships with the associated factors were analyzed. Results show that the total grain yield increased gradually, and its interannual variation is influenced principally by unit area crop yield (about 70 percent in average). The influences of agricultural technology, social factors and weather conditions on thet area crop yield can be separated because of their unique variation trends and time scales. The influence of agricultural technology is in a smoothly and gradually incremental trend, and the influence of the social factors is oscillated with three waves in recent 40 years, and the influence of weather conditions is fiuctuated sharply from year to year. Their mean effects on the inter-annual variation of unit area crop yield are about 35 to 40 percent, 10 to 15 percent and 50 percent respectively. In the view point of predictions, the effects of weather conditions are much more important.
文摘By using the partially ordered methods, the existence problem of solutions formore general implicit varational inequalities of monotone type in Hausdorfftopological linear spaces are considered. As application we utilize the results presentedin this paper to study the existence of solutions for Nash equilibrium problem and thesemi-linear elliptic differential equations.
文摘In this paper. the principle of maximum power losses for the incompressibleviscous fluid proposed by professor Chien Wei-zang is extended to the hydrodynamicproblems of a special class of non-Newtonian fluid-generalized Newtonian fluid.The constraint condition of variation are eliminated by the method of idetifiedLagrangian multipliers and a generalized variational principle is established.
文摘In the present paper, we hare mtroduced the random materials. loads. geometricalshapes, force and displacement boundary condition directly. into the functionalvariational formula, by. use of a small parameter perturbation method, a unifiedrandom variational principle in finite defomation of elastieity and nonlinear randomfinite element method are esiablished, and used.for reliability, analysis of structures.Numerical examples showed that the methods have the advontages of simple andconvenient program implementation and are effective for the probabilistic problems inmechanics.
