The Philippine Arena Project is a large domed roof structure. The arena volume is significant, with 227 m x 179 m ellipse shaped space standing, which is the largest non-column arena in the world. Reinforced concrete ...The Philippine Arena Project is a large domed roof structure. The arena volume is significant, with 227 m x 179 m ellipse shaped space standing, which is the largest non-column arena in the world. Reinforced concrete is used for the bowl structure and main seismic resisting system is considered as dual system. For the structure above Level 04, steel rakers and columns are applied. To identify seismic resisting performance of steel structure, push over analysis had been carried out. Pre-cast concrete plank is planned for arena seating to meet constructing ability. The roof structure is grid type space frame. Tension trusses are located under the space frame for overall stability of roof structure. Wind tunnel test had been conducted to evaluate accurate wind pressure for both structure and cladding design. LRB （lead rubber bearing） is located under the roof structure to reduce seismic force delivered from sub-structure.展开更多
The seismic behaviors of an integral concreting frame, a light steel storey-adding frame and a storeyadding frame strengthened with carbon fiber reinforced polymer(CFRP)were investigated under low-cycle and repeated l...The seismic behaviors of an integral concreting frame, a light steel storey-adding frame and a storeyadding frame strengthened with carbon fiber reinforced polymer(CFRP)were investigated under low-cycle and repeated load(scale 1∶3). The failure characteristics, hysteretic behavior, rigidity degeneracy, deflection ductility and energy-dissipation capacity of the three specimens were compared. The test results reveal that chemicallybonded rebar technique can meet the requirements of storey-adding engineering. The carrying capacity, the deflection ductility, the energy-dissipating capacity and seismic performance of the light steel storey-adding frame are higher than those of the integral concreting frame, and they are the highest in the storey-adding frame strengthened with CFRP.展开更多
As is generally known, Newton＇s notion of universal gravitation surpassed various theories of particular gravities in the early modem age, as represented mainly by Kepler and Hooke. In his seminal work Hooke and the ...As is generally known, Newton＇s notion of universal gravitation surpassed various theories of particular gravities in the early modem age, as represented mainly by Kepler and Hooke. In his seminal work Hooke and the Law of Universal Gravitation： A Reappraisal of a Reappraisal Richard S. Westfall argues that Hooke could not reach beyond the concept of spatially bounded particular gravities, as he deployed the method of analogy between the material principle of congruity and incongruity and the extension of gravitational spheres and their action at a distance. However, the doctrine of universal gravitation does not exclude the nature of particular gravities; it is predicated on the notion of an infinite expansion of individual-gravitational spheres and their uniform nature, namely the mutual and centripetal attraction. In my treatise 1 attempt to reinvestigate the nature and structure of gravitation, as established historically in the framework of Newtonian Classical Mechanics, by a method of structural intuition. It examines how the structural intuition, as represented in the celestial-mechanical intuitions of Hooke and Kepler, could unfold into an innovative process within the context of early modem mechanical philosophy, attaining thus a historical siglaificance and legitimacy as against the prevailing Newtonian method of geometric-mathematical axiomatization of mechanical principles. It also explores the actual demonstrative features of the tidal phenomenon with regard to its lunar- and solar-gravitational causation, which has been considered to date to be an important piece of empirical evidence for the theory of universal gravitation.展开更多
This paper first introduces the basic principle of seismic risk analysis, and then put forward the basic concept of structures global seismic fragility, aiming at the existing problems of traditional analysis method, ...This paper first introduces the basic principle of seismic risk analysis, and then put forward the basic concept of structures global seismic fragility, aiming at the existing problems of traditional analysis method, combined the method of analytical approximation degree of structure reliability with Performance-Based Seismic Design （PBSD）, put forward the analysis method of structural reliability and the performance of the global seismic fragility, are calculated by using the finite element reliability method of structures global seismic fragility. Taking the maximum interlamination relative deformation as indicators of overall performance, we analyze seismic fragility of five storey RC frame structure, rendering the seismic fragility curves corresponding to different performance requirements and different earthquake action.展开更多
Three new metal organic frameworks,[Mn^(Ⅲ)_(4)Mn^(Ⅱ)_(8)O_(2)(4-thmpy)_(4)(O_(2)CPh)_(10)(OMe)_(2)(H_(2)O)_(2)]·3CH_(3)OH·4H_(2)O(1),[Mn^(Ⅱ)_(4)Co^(Ⅱ)_(6)O(4-thmpy)_(4)(O_(2)CPh)_(6)(H_(2)O)_(4)]·CH...Three new metal organic frameworks,[Mn^(Ⅲ)_(4)Mn^(Ⅱ)_(8)O_(2)(4-thmpy)_(4)(O_(2)CPh)_(10)(OMe)_(2)(H_(2)O)_(2)]·3CH_(3)OH·4H_(2)O(1),[Mn^(Ⅱ)_(4)Co^(Ⅱ)_(6)O(4-thmpy)_(4)(O_(2)CPh)_(6)(H_(2)O)_(4)]·CH_(3)OH·3H_(2)O(2),and[Mn^(Ⅱ)_(4)Ni^(Ⅱ)_(6)O(4-thmpy)_(4)(O_(2)CPh)_(6)(H_(2)O)_(4)]·2CH_(3)OH·2H_(2)O(3),have been successfully synthesized by using 4-[tri-(hydroxymethyl)methyl]pyridine(4-thmpyH_(3))as ligand.Crystal structure analyses show that compound 1 is a disk-like twelve nuclear[Mn^(Ⅲ)_(4)Mn^(Ⅱ)_(8)]0D cluster.Compounds 2 and 3 are isomorphic,and the decanuclear heteronuclear cluster[Mn^(Ⅱ)_(4)Co^(Ⅱ)_(6)]node in compound 2 can be seen as a hyper-tetrahedron of four coboundary cubic alkanes[Mn^(Ⅱ)Co^(Ⅱ)_(3)O_(4)],then each ten-nuclear heteronuclear cluster[Mn^(Ⅱ)_(4)Co^(Ⅱ)_(6)]is connected by six 4-thmpy^(3-)with six adjacent decanuclear clusters[Mn^(Ⅱ)_(4)Co^(Ⅱ)_(6)],forming the NaCl-type 3D topological structure.Magnetic studies showed that there exist antiferromagnetic interactions between metal ions in 1-3.展开更多
Antimony-based materials with high theoretical capacity are known as promising anodes for potassiumion batteries(PIBs). However, they still face challenges from the large ionic radius of the K ion, which has sluggish ...Antimony-based materials with high theoretical capacity are known as promising anodes for potassiumion batteries(PIBs). However, they still face challenges from the large ionic radius of the K ion, which has sluggish kinetics. Much effort is needed to exploit high-performance electrode materials to satisfy the reversible capacity of PIBs. In this paper, nano Sb confined in N-doped carbon fibers(Sb@CN nanofibers)were successfully prepared through an electrospinning method, which was designed to improve potassium storage performances. Sb@CN nanofibers benefit from the fact that the synergy between the porous nanofiber frame structure and the uniformly distributed Sb nano-components in the carbon matrix can effectively accelerate the ion migration rate and reduce the mechanical stress caused by K+insertion/extraction, Sb@CN nanofiber electrodes thus exhibited excellent potassium storage performance, especially long cycle stability, as expected. When utilized as a PIB anode, they delivered high reversible capacity of 360.2 m Ah g-1 after 200 cycles at 50 m A g-1, and a particularly stable capacity of 212.7 m Ah g-1 was also obtained after 1000 cycles even at 5000 m A g-1. Given such outstanding electrochemical performances,this work is expected to provide insight into the development and exploration of advanced alloy-type electrodes for PIBs.展开更多
This paper presents an effective approach for updating finite element dynamic model from incomplete modal data identified from ambient vibration measurements.The proposed method is based on the relationship between th...This paper presents an effective approach for updating finite element dynamic model from incomplete modal data identified from ambient vibration measurements.The proposed method is based on the relationship between the perturbation of structural parameters such as stiffness and mass changes and the modal data measurements of the tested structure such as measured mode shape readings.Structural updating parameters including both stiffness and mass parameters are employed to represent the differences in structural parameters between the finite element model and the associated tested structure.These updating parameters are then evaluated by an iterative solution procedure,giving optimised solutions in the least squares sense without requiring an optimisation technique.In order to reduce the influence of modal measurement uncertainty,the truncated singular value decomposition regularization method incorporating the quasi-optimality criterion is employed to produce reliable solutions for the structural updating parameters.Finally,the numerical investigations of a space frame structure and the practical applications to the Canton Tower benchmark problem demonstrate that the proposed method can correctly update the given finite element model using the incomplete modal data identified from the recorded ambient vibration measurements.展开更多
The problems of ITRF2008,the latest International Terrestrial Reference Frame,are pointed out and analyzed as follows:(1) ITRF is not a mm-level Terrestrial Reference Frame;(2) the origin of ITRF is neither the Earth&...The problems of ITRF2008,the latest International Terrestrial Reference Frame,are pointed out and analyzed as follows:(1) ITRF is not a mm-level Terrestrial Reference Frame;(2) the origin of ITRF is neither the Earth's center of mass (CM) nor the center of figure (CF);(3) the scale of ITRF is not a uniform system in the sense of the gravitational theory of relativity.These problems result from the linear hypothesis used in the establishment and maintenance of ITRF,which includes the linear hypothesis of the coordinates definition of the ITRF reference stations,and the seven coordinate transformation parameters (three translation parameters,three rotation parameters,and one scale parameter) when the ITRF combine solution is constructed.The linear hypothesis of the ITRF construction leads to the current terrestrial reference frame only at the cm-level,which cannot satisfy the requirements of monitoring mm-level crust movements as well as the global environment.This article points out that the construction of a mm-level Terrestrial Reference Frame is actually a leap from linear to nonlinear.Therefore,according to the main characteristics of nonlinear changes of the crust's deformation,the geocenter motion and the overall height fluctuation of the Earth,the new ITRF station coordinates definition and the new observation equations of combined solutions are constructed for the realization of a mm-level nonlinear ITRF,which can solve the problems of the current ITRF.展开更多
文摘The Philippine Arena Project is a large domed roof structure. The arena volume is significant, with 227 m x 179 m ellipse shaped space standing, which is the largest non-column arena in the world. Reinforced concrete is used for the bowl structure and main seismic resisting system is considered as dual system. For the structure above Level 04, steel rakers and columns are applied. To identify seismic resisting performance of steel structure, push over analysis had been carried out. Pre-cast concrete plank is planned for arena seating to meet constructing ability. The roof structure is grid type space frame. Tension trusses are located under the space frame for overall stability of roof structure. Wind tunnel test had been conducted to evaluate accurate wind pressure for both structure and cladding design. LRB （lead rubber bearing） is located under the roof structure to reduce seismic force delivered from sub-structure.
基金Supported by the National Natural Science Foundation of China(No.51379142)
文摘The seismic behaviors of an integral concreting frame, a light steel storey-adding frame and a storeyadding frame strengthened with carbon fiber reinforced polymer(CFRP)were investigated under low-cycle and repeated load(scale 1∶3). The failure characteristics, hysteretic behavior, rigidity degeneracy, deflection ductility and energy-dissipation capacity of the three specimens were compared. The test results reveal that chemicallybonded rebar technique can meet the requirements of storey-adding engineering. The carrying capacity, the deflection ductility, the energy-dissipating capacity and seismic performance of the light steel storey-adding frame are higher than those of the integral concreting frame, and they are the highest in the storey-adding frame strengthened with CFRP.
文摘As is generally known, Newton＇s notion of universal gravitation surpassed various theories of particular gravities in the early modem age, as represented mainly by Kepler and Hooke. In his seminal work Hooke and the Law of Universal Gravitation： A Reappraisal of a Reappraisal Richard S. Westfall argues that Hooke could not reach beyond the concept of spatially bounded particular gravities, as he deployed the method of analogy between the material principle of congruity and incongruity and the extension of gravitational spheres and their action at a distance. However, the doctrine of universal gravitation does not exclude the nature of particular gravities; it is predicated on the notion of an infinite expansion of individual-gravitational spheres and their uniform nature, namely the mutual and centripetal attraction. In my treatise 1 attempt to reinvestigate the nature and structure of gravitation, as established historically in the framework of Newtonian Classical Mechanics, by a method of structural intuition. It examines how the structural intuition, as represented in the celestial-mechanical intuitions of Hooke and Kepler, could unfold into an innovative process within the context of early modem mechanical philosophy, attaining thus a historical siglaificance and legitimacy as against the prevailing Newtonian method of geometric-mathematical axiomatization of mechanical principles. It also explores the actual demonstrative features of the tidal phenomenon with regard to its lunar- and solar-gravitational causation, which has been considered to date to be an important piece of empirical evidence for the theory of universal gravitation.
文摘This paper first introduces the basic principle of seismic risk analysis, and then put forward the basic concept of structures global seismic fragility, aiming at the existing problems of traditional analysis method, combined the method of analytical approximation degree of structure reliability with Performance-Based Seismic Design （PBSD）, put forward the analysis method of structural reliability and the performance of the global seismic fragility, are calculated by using the finite element reliability method of structures global seismic fragility. Taking the maximum interlamination relative deformation as indicators of overall performance, we analyze seismic fragility of five storey RC frame structure, rendering the seismic fragility curves corresponding to different performance requirements and different earthquake action.
基金the National Natural Science Foundation of China(21873018)Foundation of the Education Department of Jilin Province(111099108)Jilin Provincial Research Center of Advanced Energy Materials(Northeast Normal University)for financial support
文摘Three new metal organic frameworks,[Mn^(Ⅲ)_(4)Mn^(Ⅱ)_(8)O_(2)(4-thmpy)_(4)(O_(2)CPh)_(10)(OMe)_(2)(H_(2)O)_(2)]·3CH_(3)OH·4H_(2)O(1),[Mn^(Ⅱ)_(4)Co^(Ⅱ)_(6)O(4-thmpy)_(4)(O_(2)CPh)_(6)(H_(2)O)_(4)]·CH_(3)OH·3H_(2)O(2),and[Mn^(Ⅱ)_(4)Ni^(Ⅱ)_(6)O(4-thmpy)_(4)(O_(2)CPh)_(6)(H_(2)O)_(4)]·2CH_(3)OH·2H_(2)O(3),have been successfully synthesized by using 4-[tri-(hydroxymethyl)methyl]pyridine(4-thmpyH_(3))as ligand.Crystal structure analyses show that compound 1 is a disk-like twelve nuclear[Mn^(Ⅲ)_(4)Mn^(Ⅱ)_(8)]0D cluster.Compounds 2 and 3 are isomorphic,and the decanuclear heteronuclear cluster[Mn^(Ⅱ)_(4)Co^(Ⅱ)_(6)]node in compound 2 can be seen as a hyper-tetrahedron of four coboundary cubic alkanes[Mn^(Ⅱ)Co^(Ⅱ)_(3)O_(4)],then each ten-nuclear heteronuclear cluster[Mn^(Ⅱ)_(4)Co^(Ⅱ)_(6)]is connected by six 4-thmpy^(3-)with six adjacent decanuclear clusters[Mn^(Ⅱ)_(4)Co^(Ⅱ)_(6)],forming the NaCl-type 3D topological structure.Magnetic studies showed that there exist antiferromagnetic interactions between metal ions in 1-3.
基金supported by the National Natural Science Foundation of China(51904342,51622406,and 21673298)the National Postdoctoral Program for Innovative Talents(BX201600192)+4 种基金Central South University Postdoctoral Foundation(140050018)China Postdoctoral Science Foundation(2017 M6203552)the National Key Research and Development Program of China(2017YFB0102000,2018YFB0104200)Hunan Provincial Science and Technology Plan(2017TP1001)the Fundamental Research Funds for the Central Universities of Central South University(2019zzts431,2019zzts433)。
文摘Antimony-based materials with high theoretical capacity are known as promising anodes for potassiumion batteries(PIBs). However, they still face challenges from the large ionic radius of the K ion, which has sluggish kinetics. Much effort is needed to exploit high-performance electrode materials to satisfy the reversible capacity of PIBs. In this paper, nano Sb confined in N-doped carbon fibers(Sb@CN nanofibers)were successfully prepared through an electrospinning method, which was designed to improve potassium storage performances. Sb@CN nanofibers benefit from the fact that the synergy between the porous nanofiber frame structure and the uniformly distributed Sb nano-components in the carbon matrix can effectively accelerate the ion migration rate and reduce the mechanical stress caused by K+insertion/extraction, Sb@CN nanofiber electrodes thus exhibited excellent potassium storage performance, especially long cycle stability, as expected. When utilized as a PIB anode, they delivered high reversible capacity of 360.2 m Ah g-1 after 200 cycles at 50 m A g-1, and a particularly stable capacity of 212.7 m Ah g-1 was also obtained after 1000 cycles even at 5000 m A g-1. Given such outstanding electrochemical performances,this work is expected to provide insight into the development and exploration of advanced alloy-type electrodes for PIBs.
文摘This paper presents an effective approach for updating finite element dynamic model from incomplete modal data identified from ambient vibration measurements.The proposed method is based on the relationship between the perturbation of structural parameters such as stiffness and mass changes and the modal data measurements of the tested structure such as measured mode shape readings.Structural updating parameters including both stiffness and mass parameters are employed to represent the differences in structural parameters between the finite element model and the associated tested structure.These updating parameters are then evaluated by an iterative solution procedure,giving optimised solutions in the least squares sense without requiring an optimisation technique.In order to reduce the influence of modal measurement uncertainty,the truncated singular value decomposition regularization method incorporating the quasi-optimality criterion is employed to produce reliable solutions for the structural updating parameters.Finally,the numerical investigations of a space frame structure and the practical applications to the Canton Tower benchmark problem demonstrate that the proposed method can correctly update the given finite element model using the incomplete modal data identified from the recorded ambient vibration measurements.
基金supported by the National Natural Science Foundation of China (Grant No.10603011)the National High Technology Research and Development Program (Grant No.2009AA12Z307)+1 种基金the Science and Technology Commission of Shanghai Municipality (Grant Nos.05QMX1462 and 08ZR1422400)the Youth Foundation of Knowledge Innovation Project of the Chinese Academy of Sciences,Shanghai Astronomical Observatory (Grant No.5120090304)
文摘The problems of ITRF2008,the latest International Terrestrial Reference Frame,are pointed out and analyzed as follows:(1) ITRF is not a mm-level Terrestrial Reference Frame;(2) the origin of ITRF is neither the Earth's center of mass (CM) nor the center of figure (CF);(3) the scale of ITRF is not a uniform system in the sense of the gravitational theory of relativity.These problems result from the linear hypothesis used in the establishment and maintenance of ITRF,which includes the linear hypothesis of the coordinates definition of the ITRF reference stations,and the seven coordinate transformation parameters (three translation parameters,three rotation parameters,and one scale parameter) when the ITRF combine solution is constructed.The linear hypothesis of the ITRF construction leads to the current terrestrial reference frame only at the cm-level,which cannot satisfy the requirements of monitoring mm-level crust movements as well as the global environment.This article points out that the construction of a mm-level Terrestrial Reference Frame is actually a leap from linear to nonlinear.Therefore,according to the main characteristics of nonlinear changes of the crust's deformation,the geocenter motion and the overall height fluctuation of the Earth,the new ITRF station coordinates definition and the new observation equations of combined solutions are constructed for the realization of a mm-level nonlinear ITRF,which can solve the problems of the current ITRF.
