For a finite group G, K. W. Gruenberg and O. Kegel defined the prime graph Г(G)of G in 1975: (i) the set of vertices V(Г(G))=π(G), the set of all prime divisors of │G│, (ii)for p, q∈π(G), p, q are joined by an ...For a finite group G, K. W. Gruenberg and O. Kegel defined the prime graph Г(G)of G in 1975: (i) the set of vertices V(Г(G))=π(G), the set of all prime divisors of │G│, (ii)for p, q∈π(G), p, q are joined by an edge if and only if G contains an element of orderpq.展开更多
As the most important performance,compliance of shield tunneling machines(STM) is defined as the capability to accommodate the sudden change of the load induced by the variable geological conditions during excavation....As the most important performance,compliance of shield tunneling machines(STM) is defined as the capability to accommodate the sudden change of the load induced by the variable geological conditions during excavation.Owing to the different requirements of the compliant tasks,the existing methods in the robotic field cannot be utilized in the analysis and design of the mechanical system of shield tunneling machines.In this paper,based on the stiffness of the mechanical system and the equivalent contact stiffness of the tunnel face,the tunneling interface-matching index(IMI) is proposed to evaluate the compliance of the machine.The IMI is defined as a metric to describe the coincidence of the stiffness curves of the mechanical system and the tunnel face.Moreover,a tunneling case is investigated in the paper as an example to expound the validation of IMI and the analytical process.In conclusion,the IMI presented here can be served as an appraisement of the capability in conforming to the load fluctuation,and give instructions for the design of the thrust system of shield tunneling machines.展开更多
中国气候区域分割之演进,要可分为二期,即寇本（Koeppen）期舆竺可桢期是也。寇本时期,对於世界气候之分类,以方法单纯,系统一律为其特色。寇本马东男（Emma de Mortonne）及希孟（J.sion）三氏,无论分割全世界之气候区域,或一洲之气候...中国气候区域分割之演进,要可分为二期,即寇本（Koeppen）期舆竺可桢期是也。寇本时期,对於世界气候之分类,以方法单纯,系统一律为其特色。寇本马东男（Emma de Mortonne）及希孟（J.sion）三氏,无论分割全世界之气候区域,或一洲之气候区域,均取同一标准。展开更多
There are some problems in junior middle school students' listening and speaking ability.The Audiolingual Method,which focuses on how to improve language learners' listening and speaking ability according to s...There are some problems in junior middle school students' listening and speaking ability.The Audiolingual Method,which focuses on how to improve language learners' listening and speaking ability according to some specific training techniques,can improve the students' ability of listening and speaking effectively.展开更多
基金Project partially supported by the National Natural Science Foundation of ChinaPh. D. F. of Southwest China Normal University.
文摘For a finite group G, K. W. Gruenberg and O. Kegel defined the prime graph Г(G)of G in 1975: (i) the set of vertices V(Г(G))=π(G), the set of all prime divisors of │G│, (ii)for p, q∈π(G), p, q are joined by an edge if and only if G contains an element of orderpq.
基金supported by the National Basic Research Program of China ("973" Program) (Grant No. 2007CB714003)the National Natural Science Foundation of China (Grant Nos. 51075259 and 50905108)the Program for New Century Excellent Talents in University (Grant No.NCET-10-0579)
文摘As the most important performance,compliance of shield tunneling machines(STM) is defined as the capability to accommodate the sudden change of the load induced by the variable geological conditions during excavation.Owing to the different requirements of the compliant tasks,the existing methods in the robotic field cannot be utilized in the analysis and design of the mechanical system of shield tunneling machines.In this paper,based on the stiffness of the mechanical system and the equivalent contact stiffness of the tunnel face,the tunneling interface-matching index(IMI) is proposed to evaluate the compliance of the machine.The IMI is defined as a metric to describe the coincidence of the stiffness curves of the mechanical system and the tunnel face.Moreover,a tunneling case is investigated in the paper as an example to expound the validation of IMI and the analytical process.In conclusion,the IMI presented here can be served as an appraisement of the capability in conforming to the load fluctuation,and give instructions for the design of the thrust system of shield tunneling machines.
文摘There are some problems in junior middle school students' listening and speaking ability.The Audiolingual Method,which focuses on how to improve language learners' listening and speaking ability according to some specific training techniques,can improve the students' ability of listening and speaking effectively.
