Based on the analysis of several objective functions,a new method was proposed.Firstly,the feature of the inclination curve was analyzed.On this basis,the soil could be divided into several blocks with different displ...Based on the analysis of several objective functions,a new method was proposed.Firstly,the feature of the inclination curve was analyzed.On this basis,the soil could be divided into several blocks with different displacements and deformations.Then,the method of the soil division was presented,and the characteristic of single soil block was studied.The displacement of the block had two components:sliding and deformation.Moreover,a new objective function was constructed according to the deformation of the soil block.Finally,the sensitivities of the objective functions by traditional method and the new method were calculated,respectively.The result shows that the new objective function is more sensitive to mechanical parameters and the inversion result is close to that obtained by the large direct shear apparatus.So,this method can be used in slope back analysis and its effectiveness is proved.展开更多
Structural and compositional transitions of Datong coal ash and its CaCO3 additional effects were carefully exam- ined at a temperature range of 300 to 1 600℃ by using XRD and solid state NMR. The quantitative estima...Structural and compositional transitions of Datong coal ash and its CaCO3 additional effects were carefully exam- ined at a temperature range of 300 to 1 600℃ by using XRD and solid state NMR. The quantitative estimation of amorphous structures of ashes can be successfully obtained through the analyses of solid state NMR spectra. Viscosity of molten ash and its changes with CaCO3 addition were also evaluated up to 1 700 ℃ by using a rotary type viscometer. Glasses with poor crystalline and amorphous phase were continuously formed through the eutectic reaction of silica above fusing temperature (FT〉1 500 ℃) that caused broadening and shift of 29Si and 27A1 peaks in NMR results. With the additional amount of CaCO3 increasing, the peaks shifted to downfield obviously; the fraction of Si(OA1)0(OSi)4 decreased, while that of Si(OA1)l(OSi)l at 84.3 x 10-6 increased apparently. These transitions indicated the destruction of large alumina-silicate framework into small segments by the addition of Ca ion.展开更多
The chemical ingredients, morphological structure and properties of mulberry fiber have been researched. The results show that the mulberry fiber is cellulose fiber. The crystal structure of mulberry fiber is cellulos...The chemical ingredients, morphological structure and properties of mulberry fiber have been researched. The results show that the mulberry fiber is cellulose fiber. The crystal structure of mulberry fiber is cellulose I and the crystal cell belongs to the monoelinic system. The mulberry fiber crystal degree is 62.9% and orientation degree is 43.7%, the fineness of mulberry fiber is 2.3- 3.9 dtex, the length of the single fiber is 28 - 47 mm, the breaking strength of mulberry fiber is about 2.93 cN/dtex, and the initial modulus is about 76.82 cN/dtex.展开更多
There are many thrust-related structures occurring in the Paleozoic strata of the Niushou Mountain in the central part of Ningxia Hui Autonomous Region. The fault-related folds are the typical structures in this area....There are many thrust-related structures occurring in the Paleozoic strata of the Niushou Mountain in the central part of Ningxia Hui Autonomous Region. The fault-related folds are the typical structures in this area. Based on the analysis about these structures and their relationships, the processes by which these structures of the Miboshan Formation were formed are reconstructed, and the strata underwent about three stages of deformation: (1) horizontal shortening, (2) folding, and (3) thrusting. And the fact that the Niushou Mountain is the leading edge of an old thrust sheet was proved, the Niushou Mountain,the Daluo Mountain and the Xiaoluo Mountain together constitute the front part of this old thrust zone,so the Niushou Mountain and the Ordovician strata in the central and southern parts of Ningxia now are likely allochthons. In the period from middle Ordovician to Devonian, the areas of the central and southern Ningxia belonged to the back-arc foreland basin of North Qilianshan orogen, which was adjacent to the continent in the north. In the later part of the early Paleozoic period, the Niushou Mountain was formed after the closure of the back-arc foreland basin.展开更多
A novel hybrid self-reconfigurable modular robot is designed to finish the morphing action from line shape to hexagon shape. The robot is composed of many basic modules,each of which consists of a master module and a ...A novel hybrid self-reconfigurable modular robot is designed to finish the morphing action from line shape to hexagon shape. The robot is composed of many basic modules,each of which consists of a master module and a slave module in the shape of triangular prism. There are four connection ports on each basic module. For the master module there are two holes on each connection port,and for the slave one there are two pegs on each connection. The docking process between two neighboring basic modules is analyzed with a peg-in-hole mechanical structure. A small motion's method is presented and the contact forces are derived. According to the force/moment,the pose of a motion module should be adjusted to make two neighboring modules align and finish the docking process.Finally,a simulation of 3 basic modules is shown to finish the morphing and docking process effectively. The system can finish the morphing task from the line shape to the hexagon shape.展开更多
Ab-initio molecular dynamics simulation was performed to investigate the local atomic structure of Co55Ta^0B35 alloys. Pair distribution function, coordination number, HA index and Voronoi polyhedra were used to descr...Ab-initio molecular dynamics simulation was performed to investigate the local atomic structure of Co55Ta^0B35 alloys. Pair distribution function, coordination number, HA index and Voronoi polyhedra were used to describe the detailed local structure of this alloy. It was revealed Co7TalB2, Co6TalB2 and CosTa2B4 among the dominant (0 3 6 0), (0 4 4 0), (0 1 10 2) and (0 3 6 4) polyhedra were the basic local structure units in CossTal0B3s amorphous alloy. Furthermore, most of the dominant poly- hedra tended to have Ta atoms involved and these polyhedra may have a critical role during glass formation.展开更多
基金Projects(2013CB036004,2011CB710601)supported by the National Basic Research Program of ChinaProject(51178468)supported by the National Natural Science Foundation of ChinaProject(CX2011B096)supported by Hunan Provincial Postgraduate Innovation Program,China
文摘Based on the analysis of several objective functions,a new method was proposed.Firstly,the feature of the inclination curve was analyzed.On this basis,the soil could be divided into several blocks with different displacements and deformations.Then,the method of the soil division was presented,and the characteristic of single soil block was studied.The displacement of the block had two components:sliding and deformation.Moreover,a new objective function was constructed according to the deformation of the soil block.Finally,the sensitivities of the objective functions by traditional method and the new method were calculated,respectively.The result shows that the new objective function is more sensitive to mechanical parameters and the inversion result is close to that obtained by the large direct shear apparatus.So,this method can be used in slope back analysis and its effectiveness is proved.
文摘Structural and compositional transitions of Datong coal ash and its CaCO3 additional effects were carefully exam- ined at a temperature range of 300 to 1 600℃ by using XRD and solid state NMR. The quantitative estimation of amorphous structures of ashes can be successfully obtained through the analyses of solid state NMR spectra. Viscosity of molten ash and its changes with CaCO3 addition were also evaluated up to 1 700 ℃ by using a rotary type viscometer. Glasses with poor crystalline and amorphous phase were continuously formed through the eutectic reaction of silica above fusing temperature (FT〉1 500 ℃) that caused broadening and shift of 29Si and 27A1 peaks in NMR results. With the additional amount of CaCO3 increasing, the peaks shifted to downfield obviously; the fraction of Si(OA1)0(OSi)4 decreased, while that of Si(OA1)l(OSi)l at 84.3 x 10-6 increased apparently. These transitions indicated the destruction of large alumina-silicate framework into small segments by the addition of Ca ion.
基金Doctorate Foundation of Xi'an Polytechnic University and the 2006 Year Research Project of Shaanxi Educational Bureau , China (No.06JK284)
文摘The chemical ingredients, morphological structure and properties of mulberry fiber have been researched. The results show that the mulberry fiber is cellulose fiber. The crystal structure of mulberry fiber is cellulose I and the crystal cell belongs to the monoelinic system. The mulberry fiber crystal degree is 62.9% and orientation degree is 43.7%, the fineness of mulberry fiber is 2.3- 3.9 dtex, the length of the single fiber is 28 - 47 mm, the breaking strength of mulberry fiber is about 2.93 cN/dtex, and the initial modulus is about 76.82 cN/dtex.
基金supported by National Science Foundation(Grant No.4983402).
文摘There are many thrust-related structures occurring in the Paleozoic strata of the Niushou Mountain in the central part of Ningxia Hui Autonomous Region. The fault-related folds are the typical structures in this area. Based on the analysis about these structures and their relationships, the processes by which these structures of the Miboshan Formation were formed are reconstructed, and the strata underwent about three stages of deformation: (1) horizontal shortening, (2) folding, and (3) thrusting. And the fact that the Niushou Mountain is the leading edge of an old thrust sheet was proved, the Niushou Mountain,the Daluo Mountain and the Xiaoluo Mountain together constitute the front part of this old thrust zone,so the Niushou Mountain and the Ordovician strata in the central and southern parts of Ningxia now are likely allochthons. In the period from middle Ordovician to Devonian, the areas of the central and southern Ningxia belonged to the back-arc foreland basin of North Qilianshan orogen, which was adjacent to the continent in the north. In the later part of the early Paleozoic period, the Niushou Mountain was formed after the closure of the back-arc foreland basin.
基金Supported by the National Natural Science Foundation of China(No.61175069,51075272,51475300)
文摘A novel hybrid self-reconfigurable modular robot is designed to finish the morphing action from line shape to hexagon shape. The robot is composed of many basic modules,each of which consists of a master module and a slave module in the shape of triangular prism. There are four connection ports on each basic module. For the master module there are two holes on each connection port,and for the slave one there are two pegs on each connection. The docking process between two neighboring basic modules is analyzed with a peg-in-hole mechanical structure. A small motion's method is presented and the contact forces are derived. According to the force/moment,the pose of a motion module should be adjusted to make two neighboring modules align and finish the docking process.Finally,a simulation of 3 basic modules is shown to finish the morphing and docking process effectively. The system can finish the morphing task from the line shape to the hexagon shape.
基金supported by the National Natural Science Foundation of China (Grant No. 51101004)the Fundamental Research Funds for the Central Universities
文摘Ab-initio molecular dynamics simulation was performed to investigate the local atomic structure of Co55Ta^0B35 alloys. Pair distribution function, coordination number, HA index and Voronoi polyhedra were used to describe the detailed local structure of this alloy. It was revealed Co7TalB2, Co6TalB2 and CosTa2B4 among the dominant (0 3 6 0), (0 4 4 0), (0 1 10 2) and (0 3 6 4) polyhedra were the basic local structure units in CossTal0B3s amorphous alloy. Furthermore, most of the dominant poly- hedra tended to have Ta atoms involved and these polyhedra may have a critical role during glass formation.