To predict the attitude of satellite during the whole deployment process and evaluate the locking impact, a numerical flexible model of a certain satellite associated with four flexible honeycomb solar panels was esta...To predict the attitude of satellite during the whole deployment process and evaluate the locking impact, a numerical flexible model of a certain satellite associated with four flexible honeycomb solar panels was established. The flexible solar panel was modeled by the finite element analysis (FEA), and the motion equations were derived by Lagrangian formulation. The locking process was based on the method of Hertzian contact, which enables one to predict the locking impact on the satellite and the subsequent oscillation of solar panels. The results reveal that locking operation has great impact on the attitude of the satellite, and the angular acceleration of satellite reaches 22.03°/s2 at the locking moment; the flexible solar panels model is feasible to predict the accurate response of the satellite during deployment and the oscillation of solar panels; the instantly impulsive force occurred during locking process is about 1.5 kN and the changing time is nearly 0.32 s. It provides an effective approach to present the flexible solar panels' deployment process and evaluate the locking impact.展开更多
The thermal switch algebra method and theory, which is used as a power tool of logic analyses of heat transfer process, is discussed in this paper, it was a practical application of pan-logic algebra in the heat scien...The thermal switch algebra method and theory, which is used as a power tool of logic analyses of heat transfer process, is discussed in this paper, it was a practical application of pan-logic algebra in the heat science. As an example of heat switch algebra application, the logic algebra model of interfacial thermal resister between Bi-2223 and AIN were built at the range from 30K to 200K according to the thermal switch algebra theory. The computer simulation results were agreed greatly with experiment data, the error is less that 5%. The design and analyses of digit heat routes can be described by the thermal switch algebra as well.展开更多
When solving a mathematical problem, we sometimes encounter a situation where we can not reach a correct answer in spite of acquiring knowledge and formula necessary for the solution. The reason can be attributed to t...When solving a mathematical problem, we sometimes encounter a situation where we can not reach a correct answer in spite of acquiring knowledge and formula necessary for the solution. The reason can be attributed to the lack in metacognitive abilities. Metacognitive abilities consist of comparing the difficulty of problem with own ability, proper plan of solution process, and conscious monitoring and control of solution process. The role and importance of metacognitive ability in mathematical problem solving of permutations and combinations was explored. Participants were required to solve five practical problems related to permutations and combinations. For each problem, the solution process was divided into： （1） understanding （recognition） of mathematical problem; （2） plan of solution; （3） execution of solution. Participants were also required to rate the anticipation whether they could solve it or not, and to rate the confidence of their own answer. According to the total score of five problems, the participants were categorized into the group of the high test score and the group of the low test score. As a result, at the plan and the execution processes, statistically significant differences were detected between the high and the low score groups. As for the rating on the anticipation of result and the confidence of own answer, no significant differences were found between both groups. Moreover, the relationship between the score of plan process and the score of execution process was statistically correlated. In other words, the more proper the plan process was conducted, the more proper solution the participants reached. In such a way, the importance of metacognitive ability in the solving process, especially the plan ability, was suggested.展开更多
In the development process of human history, music and literature have their own unique characteristics, and also are closely related to each other. Both own a very long history and maintain an interdependent relation...In the development process of human history, music and literature have their own unique characteristics, and also are closely related to each other. Both own a very long history and maintain an interdependent relationship with each other. The dances accompanied by music in China＇ s primitive tribes and the lyric poetry in the ancient Greek times can be said to be the coexistence form of music and literature. Although music and literature have undergone a whole development process from a unified development to an independent development, there are links always maintained between the two art forms. In this paper, the coexistence and fusion between music and literature are specifically introduced from different aspects.展开更多
In this work,for a one-dimensional regime-switching diffusion process,we show that when it is positive recurrent,then there exists a stationary distribution,and when it is null recurrent,then there exists an invariant...In this work,for a one-dimensional regime-switching diffusion process,we show that when it is positive recurrent,then there exists a stationary distribution,and when it is null recurrent,then there exists an invariant measure. We also provide the explicit representation of the stationary distribution and invariant measure based on the hitting times of the process.展开更多
文摘To predict the attitude of satellite during the whole deployment process and evaluate the locking impact, a numerical flexible model of a certain satellite associated with four flexible honeycomb solar panels was established. The flexible solar panel was modeled by the finite element analysis (FEA), and the motion equations were derived by Lagrangian formulation. The locking process was based on the method of Hertzian contact, which enables one to predict the locking impact on the satellite and the subsequent oscillation of solar panels. The results reveal that locking operation has great impact on the attitude of the satellite, and the angular acceleration of satellite reaches 22.03°/s2 at the locking moment; the flexible solar panels model is feasible to predict the accurate response of the satellite during deployment and the oscillation of solar panels; the instantly impulsive force occurred during locking process is about 1.5 kN and the changing time is nearly 0.32 s. It provides an effective approach to present the flexible solar panels' deployment process and evaluate the locking impact.
基金This work was supported by the nature science foundation of China （No. 51076013） and Ph.D. Program Foundation of Education of China （No. 20040487039）.
文摘The thermal switch algebra method and theory, which is used as a power tool of logic analyses of heat transfer process, is discussed in this paper, it was a practical application of pan-logic algebra in the heat science. As an example of heat switch algebra application, the logic algebra model of interfacial thermal resister between Bi-2223 and AIN were built at the range from 30K to 200K according to the thermal switch algebra theory. The computer simulation results were agreed greatly with experiment data, the error is less that 5%. The design and analyses of digit heat routes can be described by the thermal switch algebra as well.
文摘When solving a mathematical problem, we sometimes encounter a situation where we can not reach a correct answer in spite of acquiring knowledge and formula necessary for the solution. The reason can be attributed to the lack in metacognitive abilities. Metacognitive abilities consist of comparing the difficulty of problem with own ability, proper plan of solution process, and conscious monitoring and control of solution process. The role and importance of metacognitive ability in mathematical problem solving of permutations and combinations was explored. Participants were required to solve five practical problems related to permutations and combinations. For each problem, the solution process was divided into： （1） understanding （recognition） of mathematical problem; （2） plan of solution; （3） execution of solution. Participants were also required to rate the anticipation whether they could solve it or not, and to rate the confidence of their own answer. According to the total score of five problems, the participants were categorized into the group of the high test score and the group of the low test score. As a result, at the plan and the execution processes, statistically significant differences were detected between the high and the low score groups. As for the rating on the anticipation of result and the confidence of own answer, no significant differences were found between both groups. Moreover, the relationship between the score of plan process and the score of execution process was statistically correlated. In other words, the more proper the plan process was conducted, the more proper solution the participants reached. In such a way, the importance of metacognitive ability in the solving process, especially the plan ability, was suggested.
文摘In the development process of human history, music and literature have their own unique characteristics, and also are closely related to each other. Both own a very long history and maintain an interdependent relationship with each other. The dances accompanied by music in China＇ s primitive tribes and the lyric poetry in the ancient Greek times can be said to be the coexistence form of music and literature. Although music and literature have undergone a whole development process from a unified development to an independent development, there are links always maintained between the two art forms. In this paper, the coexistence and fusion between music and literature are specifically introduced from different aspects.
基金supported by National Natural Science Foundation of China(Grant No.11301030)Beijing Higher Education Young Elite Teacher Project
文摘In this work,for a one-dimensional regime-switching diffusion process,we show that when it is positive recurrent,then there exists a stationary distribution,and when it is null recurrent,then there exists an invariant measure. We also provide the explicit representation of the stationary distribution and invariant measure based on the hitting times of the process.
