In the coexisted world of 3G,4G,5G and many other specialized wireless communication systems,billions of connections could be existing for various information transmission types.Unluckily,data show that the increase o...In the coexisted world of 3G,4G,5G and many other specialized wireless communication systems,billions of connections could be existing for various information transmission types.Unluckily,data show that the increase of network capacity is heavily more than the increase of the network energy efficiency in recent years,which could lead to more energy consumption per transmitted bit in the future network.As basic units in mobile communication systems,microwave/RF components and modules play key roles展开更多
The cohesion weakening and friction strengthening(CWFS)model for rock reveals the strength components mobilization process during progressive brittle failure process of rock,which is very helpful in understanding mech...The cohesion weakening and friction strengthening(CWFS)model for rock reveals the strength components mobilization process during progressive brittle failure process of rock,which is very helpful in understanding mechanical properties of rock.However,the used incremental cyclic loading−unloading compression test for the determination of strength components is very complicated,which limits the application of CWFS model.In this paper,incremental cyclic loading−unloading compression test was firstly carried out to study the evolution of deformation and the strength properties of Beishan granite after various temperatures treated under different confining pressures.We found the axial and lateral unloading modulus are closely related to the applied stress and damage state of rock.Based on these findings,we can accurately determine the plastic strain during the entire failure process using conventional tri-axial compression test data.Furthermore,a strength component(cohesive and frictional strength)determination method was developed using conventional triaxial compression test.Using this method,we analyzed the variation of strength mobilization and deformation properties of Beishan granite after various temperatures treated.At last,a non-simultaneous strength mobilization model for thermally treated granite was obtained and verified by numerical simulation,which demonstrated the effectiveness of the proposed strength determination method.展开更多
A new elasto-plastic constitutive model is presented in the framework of plasticity theory. The strength characteristics of a diatomaceous soft rock is investigated. The friction angle and cohesion of soft rock are mo...A new elasto-plastic constitutive model is presented in the framework of plasticity theory. The strength characteristics of a diatomaceous soft rock is investigated. The friction angle and cohesion of soft rock are mobilized as a function of plastic strain. A hyperbolic hardening function for the mobilized friction and a mixed parabolic and exponential equation for the mobilized cohesion are proposed. In view of the unified strength theory and the mobilizations of strength components, a yield function is given. A plastic potential function is determined by using the non-associated plastic flow rule. An elasto-plastic constitutive model is developed and verified. The results indicate that the proposed model can predict the behavior of soft rock accurately. The advantages of the proposed constitutive model are analyzed. The evidences support that the proposed constitutive model is a mixed hardening/softening model. A hump hardening/softening function for mobilized friction is extended to a more generalized condition.展开更多
Study of sapphirine and related mineral association in the high-grade region of the Larsemann Hills, East Antarctica, shows that sapphirine of the area is characterized by its magnesio-, iron- and aluminum-rich, but s...Study of sapphirine and related mineral association in the high-grade region of the Larsemann Hills, East Antarctica, shows that sapphirine of the area is characterized by its magnesio-, iron- and aluminum-rich, but silica-poor feature, and the obvious intra- and intergrain changes in compositions. The change is mainly mani- fested as the Tschermark substitution ( Mg, Fe) + Si =2A1. In the high-grade meta-morphism and anatexis process the multistage crystallization of minerals occurred and resulted in the complexity of the mineral association, such as the differentiation of leuco-and melano-components. Among them, the mafic-rich minerals formed earlier, and the differentiation of magnesio-and iron-components is responsible for the earlier presence of iron-rich minerals and later crystallization of magnesio-rich minerals, thus the successive associations of multistage occurred. The rock composition is an important but not critical factor to the occurrence of sapphirine. It is the mobilization of components that accounts for the formation of sapphirine. The multistage evolution of mineral association to some degree reflects the changing composition and opening of the setting. It is therefore deduced that the protolith from which sapphirine is derived is not necessarily magnesio-rich pelite. The heterogeneity of sapphirine composition is resulted from the various media, not the PT changes. Sapphirine formed at 840-880℃ ,not the so-called ultrahigh temperature condition(〉 1000℃). Its formation is related to both the filtration and diffusion processes in high-grade metamor-phism and anatexis.展开更多
It is discussed with the design and implementation of an architecture for a mobile robot to navigate in dynamic and anknown indoor environments. The architecture is based on the framework of Open Robot Control Softwar...It is discussed with the design and implementation of an architecture for a mobile robot to navigate in dynamic and anknown indoor environments. The architecture is based on the framework of Open Robot Control Software at KTH (OROCOS@KTH), which is also discussed and evaluated to navigate indoor efficiently, a new algorithm named door-like-exit detection is proposed which employs 2D feature oft. door and extracts key points of pathway from the raw data of a laser scanner. As a hybrid architecture, it is decomposed into several basic components which can be classified as either deliberative or reactive. Each component can concurrently execute and communicate with another. It is expansible and transferable and its components are reusable.展开更多
文摘In the coexisted world of 3G,4G,5G and many other specialized wireless communication systems,billions of connections could be existing for various information transmission types.Unluckily,data show that the increase of network capacity is heavily more than the increase of the network energy efficiency in recent years,which could lead to more energy consumption per transmitted bit in the future network.As basic units in mobile communication systems,microwave/RF components and modules play key roles
基金Project(41902301)supported by the National Natural Science Foundation of ChinaProject(20201Y185)supported by the Science and Technology Foundation of Guizhou Province,China+2 种基金Project(Z018023)supported by the Open Research Fund of State Key Laboratory of Geomechanics and Geotechnical Engineering,IRSM,CASProject(201822)supported by the Foundation for Young Talents of Guizhou University,ChinaProject(2017-5402)supported by the Mountain Geohazard Prevention R&D Center of Guizhou Province,China。
文摘The cohesion weakening and friction strengthening(CWFS)model for rock reveals the strength components mobilization process during progressive brittle failure process of rock,which is very helpful in understanding mechanical properties of rock.However,the used incremental cyclic loading−unloading compression test for the determination of strength components is very complicated,which limits the application of CWFS model.In this paper,incremental cyclic loading−unloading compression test was firstly carried out to study the evolution of deformation and the strength properties of Beishan granite after various temperatures treated under different confining pressures.We found the axial and lateral unloading modulus are closely related to the applied stress and damage state of rock.Based on these findings,we can accurately determine the plastic strain during the entire failure process using conventional tri-axial compression test data.Furthermore,a strength component(cohesive and frictional strength)determination method was developed using conventional triaxial compression test.Using this method,we analyzed the variation of strength mobilization and deformation properties of Beishan granite after various temperatures treated.At last,a non-simultaneous strength mobilization model for thermally treated granite was obtained and verified by numerical simulation,which demonstrated the effectiveness of the proposed strength determination method.
基金Projects(5127915551009114)supported by the National Natural Science Foundation of ChinaProject(xjj2014127)supported by the Fundamental Research Funds for the Central Universities,China
文摘A new elasto-plastic constitutive model is presented in the framework of plasticity theory. The strength characteristics of a diatomaceous soft rock is investigated. The friction angle and cohesion of soft rock are mobilized as a function of plastic strain. A hyperbolic hardening function for the mobilized friction and a mixed parabolic and exponential equation for the mobilized cohesion are proposed. In view of the unified strength theory and the mobilizations of strength components, a yield function is given. A plastic potential function is determined by using the non-associated plastic flow rule. An elasto-plastic constitutive model is developed and verified. The results indicate that the proposed model can predict the behavior of soft rock accurately. The advantages of the proposed constitutive model are analyzed. The evidences support that the proposed constitutive model is a mixed hardening/softening model. A hump hardening/softening function for mobilized friction is extended to a more generalized condition.
基金supported by the National Natural Science Foundation of China (No.40572041)the Chinese Geological Survey(Grant No.1212010711509)+3 种基金Programme of Excellent Young Scientists of the Ministry of Land and Resources(MLR)Basic outlay of the Ministry (J0704)The logistic was supported by the Chinese Arctic and Antarctic AdministrationThe anonymous reviewers are thanked for their valuable comments of the early version of the paper.
文摘Study of sapphirine and related mineral association in the high-grade region of the Larsemann Hills, East Antarctica, shows that sapphirine of the area is characterized by its magnesio-, iron- and aluminum-rich, but silica-poor feature, and the obvious intra- and intergrain changes in compositions. The change is mainly mani- fested as the Tschermark substitution ( Mg, Fe) + Si =2A1. In the high-grade meta-morphism and anatexis process the multistage crystallization of minerals occurred and resulted in the complexity of the mineral association, such as the differentiation of leuco-and melano-components. Among them, the mafic-rich minerals formed earlier, and the differentiation of magnesio-and iron-components is responsible for the earlier presence of iron-rich minerals and later crystallization of magnesio-rich minerals, thus the successive associations of multistage occurred. The rock composition is an important but not critical factor to the occurrence of sapphirine. It is the mobilization of components that accounts for the formation of sapphirine. The multistage evolution of mineral association to some degree reflects the changing composition and opening of the setting. It is therefore deduced that the protolith from which sapphirine is derived is not necessarily magnesio-rich pelite. The heterogeneity of sapphirine composition is resulted from the various media, not the PT changes. Sapphirine formed at 840-880℃ ,not the so-called ultrahigh temperature condition(〉 1000℃). Its formation is related to both the filtration and diffusion processes in high-grade metamor-phism and anatexis.
基金The project is supported by European Open Robot Control Software Founda-tion(No.IST-2000-31064), National Natural Science Foundation of China(No.60475031) and the Swedish Foundation for Strategic Research, Sweden.
文摘It is discussed with the design and implementation of an architecture for a mobile robot to navigate in dynamic and anknown indoor environments. The architecture is based on the framework of Open Robot Control Software at KTH (OROCOS@KTH), which is also discussed and evaluated to navigate indoor efficiently, a new algorithm named door-like-exit detection is proposed which employs 2D feature oft. door and extracts key points of pathway from the raw data of a laser scanner. As a hybrid architecture, it is decomposed into several basic components which can be classified as either deliberative or reactive. Each component can concurrently execute and communicate with another. It is expansible and transferable and its components are reusable.