Serious accidents of mine hoists caused by high-speed sliding between friction lining and wire rope are often seen in coal mines.In order to solve this problem,we analyzed the contact characteristics between friction ...Serious accidents of mine hoists caused by high-speed sliding between friction lining and wire rope are often seen in coal mines.In order to solve this problem,we analyzed the contact characteristics between friction lining and wire rope.Then we carried out a dynamic mechanical analysis(DMA) to explain the change in mechanical properties of the friction lining as function of temperature and load frequency and found that temperature has a stronger effect on the mechanical properties than the frequency.We used multiple regression analysis to obtain the thermoviscoelastic constitutive relations of the friction lining.As well we derived the analytic solution for the thermoviscoelastic contact radius and pressure by combining the theory of viscoelastic contact mechanics with thermoviscoelastic constitutive relations.展开更多
The non-linear flux equation, the non-linear Fokker-Planck equation （or Smoluchowski equation）, and the non-linear Langiven equation are the basic equations for describing particle diffusion in non-ideal system subj...The non-linear flux equation, the non-linear Fokker-Planck equation （or Smoluchowski equation）, and the non-linear Langiven equation are the basic equations for describing particle diffusion in non-ideal system subjected to time-dependent external fields. Nevertheless, the exact solution of those equations is still a challenge because of their inherent complexity of the non-linear mathematics. Li et al. found that, based on the defined apparent variables, the nonlinear Fokker-Planck equation and the non-linear flux equation could be transformed to linear forms under the condition of strong friction limit or loeal equilibrium assumption. In this paper, some new features of the theory were found： （i） The linear flux equation for describing non-linear diffusion can be obtained from the irreversible thermodynamic theory; （ii） The linear non-steady state diffusion equation for describing non-linear diffusion of the non-steady state, which was described by the non-linear Fokker-Planek equation, can be derived more consistently from the microscopic molecular statistical theory; （iii） In the theory, the non-linear Langiven equation also bears a linear form; （iv） For some special cases, e.g. diffusion in a periodic total potential system, the local equilibrium assumption or the strong friction limit is not required in establishing the linear theory for describing non-linear diffusion, so the linear theory may be important in the study of Brown motor.展开更多
Based on the crystal plasticity theory and interatomic potential, in this paper a new thermo-elasto-plasticity constitutive model is proposed to study the behavior of metal crystals at finite temperature. By applying ...Based on the crystal plasticity theory and interatomic potential, in this paper a new thermo-elasto-plasticity constitutive model is proposed to study the behavior of metal crystals at finite temperature. By applying the present constitutive model, the stress-strain curves under uniaxial tension at different temperatures are calculated for the typical crystal A1, and the calculated results are compared with the experimental results. From the comparisons, it can be seen that the present theory has the capability to describe the thermo-elasto-plastic behavior of metal crystals at finite temperature through a concise and explicit calculation process.展开更多
A Nash group is said to be almost linear if it has a Nash representation with a finite kernel. Structures and basic properties of these groups are studied.
This paper investigates the impacts of intercultural experience through English as a lingua franca （ELF） on language attitudes, with the focus on Chinese speakers＇ narratives of ELF experience in relation to their ...This paper investigates the impacts of intercultural experience through English as a lingua franca （ELF） on language attitudes, with the focus on Chinese speakers＇ narratives of ELF experience in relation to their views of Englishes. The data retrieved through 769 questionnaires and 35 interviews with Chinese users of English revealed the impacts in four aspects. First, the lack of ELF experience helps to maintain the assumption that conformity to native English is necessary for interactants to understand each other. Second, ELF experience triggers the question about the exclusive connection between nativeness and intelligibility. Third, it raises challenges to the exclusive relevance of native English for successful intercultural communication. Fourth, it helps to develop an awareness of intercultural communication strategies as important for communicative effectiveness in the context of the diversity of English. Attitudes revealed in the four aspects all point to a concern with the issue what is intelligible English. This paper thus discusses intelligibility in relation to （non-） nativeness and the role of intercultural experience in making sense of the issue of intelligibility, which leads to the exploration of pedagogical implications of this study.展开更多
Axial age theory suggests that a major transformation of thought occurred across several civilisations, including ancient Greece, in the period 800-200 BCE. This paper questions whether any such transformation can be ...Axial age theory suggests that a major transformation of thought occurred across several civilisations, including ancient Greece, in the period 800-200 BCE. This paper questions whether any such transformation can be identified in ancient Greece. It focuses on texts associated with ＂mystery religions＂ and the works of Presocratic philosophers as potential evidence for transformation. It demonstrates that there was a continuity of thought throughout the period, and that ＂rationality＂ was never seen to be in conflict with ＂traditional religious ideas＂.展开更多
基金Projects 50875253 supported by the National Natural Science Foundation of China20060290505 by the Research Fund for the Doctoral Program of Higher Education of China+2 种基金107054 by the Key Project of Ministry of Education of ChinaBK2008127 by the Natural Science Foundation of Jiangsu ProvinceCX08B_042Z by the Scientific Innovation Program for Postgraduates in Colleges and Universities of Jiangsu Province
文摘Serious accidents of mine hoists caused by high-speed sliding between friction lining and wire rope are often seen in coal mines.In order to solve this problem,we analyzed the contact characteristics between friction lining and wire rope.Then we carried out a dynamic mechanical analysis(DMA) to explain the change in mechanical properties of the friction lining as function of temperature and load frequency and found that temperature has a stronger effect on the mechanical properties than the frequency.We used multiple regression analysis to obtain the thermoviscoelastic constitutive relations of the friction lining.As well we derived the analytic solution for the thermoviscoelastic contact radius and pressure by combining the theory of viscoelastic contact mechanics with thermoviscoelastic constitutive relations.
基金Supported by the National Natural Science Foundation of China under Grant Nos.40671090 and 40740420660
文摘The non-linear flux equation, the non-linear Fokker-Planck equation （or Smoluchowski equation）, and the non-linear Langiven equation are the basic equations for describing particle diffusion in non-ideal system subjected to time-dependent external fields. Nevertheless, the exact solution of those equations is still a challenge because of their inherent complexity of the non-linear mathematics. Li et al. found that, based on the defined apparent variables, the nonlinear Fokker-Planck equation and the non-linear flux equation could be transformed to linear forms under the condition of strong friction limit or loeal equilibrium assumption. In this paper, some new features of the theory were found： （i） The linear flux equation for describing non-linear diffusion can be obtained from the irreversible thermodynamic theory; （ii） The linear non-steady state diffusion equation for describing non-linear diffusion of the non-steady state, which was described by the non-linear Fokker-Planek equation, can be derived more consistently from the microscopic molecular statistical theory; （iii） In the theory, the non-linear Langiven equation also bears a linear form; （iv） For some special cases, e.g. diffusion in a periodic total potential system, the local equilibrium assumption or the strong friction limit is not required in establishing the linear theory for describing non-linear diffusion, so the linear theory may be important in the study of Brown motor.
基金supported by the National Natural Science Foundation of China(Grant Nos.11021262,11172303 and 11132011)National Basic Research Program of China(Grant No.2012CB937500)
文摘Based on the crystal plasticity theory and interatomic potential, in this paper a new thermo-elasto-plasticity constitutive model is proposed to study the behavior of metal crystals at finite temperature. By applying the present constitutive model, the stress-strain curves under uniaxial tension at different temperatures are calculated for the typical crystal A1, and the calculated results are compared with the experimental results. From the comparisons, it can be seen that the present theory has the capability to describe the thermo-elasto-plastic behavior of metal crystals at finite temperature through a concise and explicit calculation process.
基金supported by the National Natural Science Foundation of China(Nos.11222101,11321101)
文摘A Nash group is said to be almost linear if it has a Nash representation with a finite kernel. Structures and basic properties of these groups are studied.
文摘This paper investigates the impacts of intercultural experience through English as a lingua franca （ELF） on language attitudes, with the focus on Chinese speakers＇ narratives of ELF experience in relation to their views of Englishes. The data retrieved through 769 questionnaires and 35 interviews with Chinese users of English revealed the impacts in four aspects. First, the lack of ELF experience helps to maintain the assumption that conformity to native English is necessary for interactants to understand each other. Second, ELF experience triggers the question about the exclusive connection between nativeness and intelligibility. Third, it raises challenges to the exclusive relevance of native English for successful intercultural communication. Fourth, it helps to develop an awareness of intercultural communication strategies as important for communicative effectiveness in the context of the diversity of English. Attitudes revealed in the four aspects all point to a concern with the issue what is intelligible English. This paper thus discusses intelligibility in relation to （non-） nativeness and the role of intercultural experience in making sense of the issue of intelligibility, which leads to the exploration of pedagogical implications of this study.
文摘Axial age theory suggests that a major transformation of thought occurred across several civilisations, including ancient Greece, in the period 800-200 BCE. This paper questions whether any such transformation can be identified in ancient Greece. It focuses on texts associated with ＂mystery religions＂ and the works of Presocratic philosophers as potential evidence for transformation. It demonstrates that there was a continuity of thought throughout the period, and that ＂rationality＂ was never seen to be in conflict with ＂traditional religious ideas＂.
