Location of the heavily loaded building on the ground of the small load capacity requires application of the appropriate foundation structure. The required foundation system is most often deep, it is expensive and its...Location of the heavily loaded building on the ground of the small load capacity requires application of the appropriate foundation structure. The required foundation system is most often deep, it is expensive and its cost increases significantly when the building is located in earthquake area or in mining damage sector. The proposed structural system of the combined foundation makes possible to design and to construct a very stable and relative inexpensive foundation structure, which can obtain an extremely large horizontal surface and which can be placed not deeply beneath the terrain level. It can be a very solid support structure for a tall building placed on very weak subsoil and at the same time located in seismic area. This system can be applied not only for new buildings but it can be used for the existing buildings and moreover for straighten of the inclined objects. Due to special arrangement of component parts the combined foundation possesses inherent features of a vibration damper, what is highly desirable if buildings have to be located in earthquake areas. When the aboveground storeys structure has some similar patterns with structural form of the combined foundation then the structural system of the whole building obtains coherent structural characteristics and it is called the combined structural system of the tall building. Suitable application of this system makes possible to design high-rise buildings having interesting and unique architectonic forms, what is presented on a selected example.展开更多
The self-developed taper barrel rheomoulding (TBR) machine for light alloy semi-solid slurry preparation was introduced.The semi-solid slurry was obtained from the intense shearing turbulence of the alloy melt in the ...The self-developed taper barrel rheomoulding (TBR) machine for light alloy semi-solid slurry preparation was introduced.The semi-solid slurry was obtained from the intense shearing turbulence of the alloy melt in the cause of solidification, which was further caused by the relative rotation of the internal and external taper barrel whose surface contained wale and groove.The heat transmission model of TBR process, the flow rules and the shearing model of the alloy melt were deduced.Taking A365 as experimental material, the microstructure evolution rules under different slurry preparation processes were analyzed.The results show that decreasing the pouring temperature of A365 alloy melt properly or increasing the shearing rate helps to obtain ideal semi-solid microstructure with the primary particle size of about 70 μm and the shape factor of above 0.8.展开更多
The effects of semi-solid isothermal process parameters on the microstructure evolution of Mg-Gd rare earth alloy produced by strain-induced melt activation(SIMA)were investigated.The formation mechanism of the partic...The effects of semi-solid isothermal process parameters on the microstructure evolution of Mg-Gd rare earth alloy produced by strain-induced melt activation(SIMA)were investigated.The formation mechanism of the particles in the process of the isothermal treatment was also discussed.The results show that the microstructure of the as-cast alloy consists ofα-Mg solid solution, Mg5RE and Mg24RE5(Gd,Y,Nd)phase.After being extruded with an extrusion ratio of 14:1 at 380℃,the microstructure of Mg-Gd alloy changes from developed dendrites to near-equiaxed grains.The liquid volume fraction of the semisolid slurry gradually increases with elevating isothermal temperature or prolonging isothermal time during the partial remelting.To obtain an ideal semisolid slurry,the optimal process parameters for the Mg-Gd alloy should be 630℃for isothermal temperature and 30 min for the corresponding time,respectively,where the volume fraction of the liquid phase is 52%.展开更多
The relationship between forms and forces is one of the main topics of structural morphology. This harmonious coexisting link is very strong for systems in tensegrity state, commonly called ＂tensegrity systems＂. It ...The relationship between forms and forces is one of the main topics of structural morphology. This harmonious coexisting link is very strong for systems in tensegrity state, commonly called ＂tensegrity systems＂. It is currently apparent that, among the tensegrity systems, there also exist cable-bar cells with a discontinuous network of cables. It is possible to design a separate set of cables inside the cable-bar elementary cell and to establish a self-stress state of equilibrium. In this connection, the author of this paper suggested to assume a new Class-Theta tensegrity systems. Each of the basic tensegrity systems termed Class-Theta possesses an external and internal set of tension components. The shape of Greek capital letter 69 （Theta） reflects two sets of such components （two sets of tendons, cables, etc.）. This notation corresponds to Skelton＇s Class-k tensegrity structure. As shown in this paper, the Class-Theta tensegrity cell can exemplify a geometrically and practically useful form for the lightweight and long-span modular structures, mainly but not only in view of civil engineering and architecture.展开更多
Two new copper coordination polymers [Cu(μ2-4,4?-bipyridine)(NO2)2]n (C10H8- N4O4Cu, Mr = 311.75) 1 and [Cu(μ2-4,4?-bipyridine)2(H2O)2]n?2n(4,4?-bipyridine)?2nClO4?nH2O (C40H38N8O11Cl2Cu, Mr = 941.22) 2 were synthes...Two new copper coordination polymers [Cu(μ2-4,4?-bipyridine)(NO2)2]n (C10H8- N4O4Cu, Mr = 311.75) 1 and [Cu(μ2-4,4?-bipyridine)2(H2O)2]n?2n(4,4?-bipyridine)?2nClO4?nH2O (C40H38N8O11Cl2Cu, Mr = 941.22) 2 were synthesized by hydrothermal reaction and determined by X-ray diffraction method. Compound 1 crystallizes in monoclinic, space group P2/m with a = 4.7740(10), b = 11.039(2), c = 5.6752(14) ?, β = 91.394(9)o, V = 299.00(11) ?3, Z = 1, Dc = 1.731 g/cm3, F(000) = 157 and μ(MoKa) = 0.7107 mm-1. Compound 2 crystallizes in monoclinic, space group P2/n with a = 12.916(2), b = 11.149(1), c = 15.006(2) ?, β =106.642(6)o, V = 2070.3(5) ?3, Z = 2, Dc = 1.510 g/cm3, F(000) = 970 and μ(MoKa) = 0.7107 mm-1. In the structure of compound 1, the metal atom is in a slightly distorted octahedral CuO4N2 geometry surrounded by four O atoms of two NO2 ligands in the equatorial positions and two N atoms from 4,4?-bipyridine ligands in the axial sites, and the 4,4?-bipyridine ligands bridge the neighboring Cu2+ atoms to form polymeric chains in the lattice. Compound 2 has a 2D square-grid network structure. The square grids are superposed on each other to form a channel framework. The square cavity has dimensions of 11.148(2)? ×11.229(3)?. Every two guest 4,4?-bipyridine molecules are clathra- ted in each hydrophobic host cavity and further stabilized by π-π stacking and hydrogen bonding interactions.展开更多
文摘Location of the heavily loaded building on the ground of the small load capacity requires application of the appropriate foundation structure. The required foundation system is most often deep, it is expensive and its cost increases significantly when the building is located in earthquake area or in mining damage sector. The proposed structural system of the combined foundation makes possible to design and to construct a very stable and relative inexpensive foundation structure, which can obtain an extremely large horizontal surface and which can be placed not deeply beneath the terrain level. It can be a very solid support structure for a tall building placed on very weak subsoil and at the same time located in seismic area. This system can be applied not only for new buildings but it can be used for the existing buildings and moreover for straighten of the inclined objects. Due to special arrangement of component parts the combined foundation possesses inherent features of a vibration damper, what is highly desirable if buildings have to be located in earthquake areas. When the aboveground storeys structure has some similar patterns with structural form of the combined foundation then the structural system of the whole building obtains coherent structural characteristics and it is called the combined structural system of the tall building. Suitable application of this system makes possible to design high-rise buildings having interesting and unique architectonic forms, what is presented on a selected example.
基金Project(2006CB605203) supported by the National Basic Research Program of China
文摘The self-developed taper barrel rheomoulding (TBR) machine for light alloy semi-solid slurry preparation was introduced.The semi-solid slurry was obtained from the intense shearing turbulence of the alloy melt in the cause of solidification, which was further caused by the relative rotation of the internal and external taper barrel whose surface contained wale and groove.The heat transmission model of TBR process, the flow rules and the shearing model of the alloy melt were deduced.Taking A365 as experimental material, the microstructure evolution rules under different slurry preparation processes were analyzed.The results show that decreasing the pouring temperature of A365 alloy melt properly or increasing the shearing rate helps to obtain ideal semi-solid microstructure with the primary particle size of about 70 μm and the shape factor of above 0.8.
基金Projects(2006BA104B04-1,2006BAE04B07-3)supported by the National Science and Technology supporting Program of ChinaProject(2007KZ05)supported by the Science and Technology Foundation of Changchun City,China+1 种基金Project supported by"985 Project"of Jilin University,ChinaProject supported by the Open Subject of State Key Laboratory of Rare Earth Resource Utilization(2008)
文摘The effects of semi-solid isothermal process parameters on the microstructure evolution of Mg-Gd rare earth alloy produced by strain-induced melt activation(SIMA)were investigated.The formation mechanism of the particles in the process of the isothermal treatment was also discussed.The results show that the microstructure of the as-cast alloy consists ofα-Mg solid solution, Mg5RE and Mg24RE5(Gd,Y,Nd)phase.After being extruded with an extrusion ratio of 14:1 at 380℃,the microstructure of Mg-Gd alloy changes from developed dendrites to near-equiaxed grains.The liquid volume fraction of the semisolid slurry gradually increases with elevating isothermal temperature or prolonging isothermal time during the partial remelting.To obtain an ideal semisolid slurry,the optimal process parameters for the Mg-Gd alloy should be 630℃for isothermal temperature and 30 min for the corresponding time,respectively,where the volume fraction of the liquid phase is 52%.
文摘The relationship between forms and forces is one of the main topics of structural morphology. This harmonious coexisting link is very strong for systems in tensegrity state, commonly called ＂tensegrity systems＂. It is currently apparent that, among the tensegrity systems, there also exist cable-bar cells with a discontinuous network of cables. It is possible to design a separate set of cables inside the cable-bar elementary cell and to establish a self-stress state of equilibrium. In this connection, the author of this paper suggested to assume a new Class-Theta tensegrity systems. Each of the basic tensegrity systems termed Class-Theta possesses an external and internal set of tension components. The shape of Greek capital letter 69 （Theta） reflects two sets of such components （two sets of tendons, cables, etc.）. This notation corresponds to Skelton＇s Class-k tensegrity structure. As shown in this paper, the Class-Theta tensegrity cell can exemplify a geometrically and practically useful form for the lightweight and long-span modular structures, mainly but not only in view of civil engineering and architecture.
基金This work was supported by the National Natural Science Foundation of China (No. 20173063) the State Key Basic Research and Development Plan of China (001CB108906) and the NSF of Fujian Province (E0020001)
文摘Two new copper coordination polymers [Cu(μ2-4,4?-bipyridine)(NO2)2]n (C10H8- N4O4Cu, Mr = 311.75) 1 and [Cu(μ2-4,4?-bipyridine)2(H2O)2]n?2n(4,4?-bipyridine)?2nClO4?nH2O (C40H38N8O11Cl2Cu, Mr = 941.22) 2 were synthesized by hydrothermal reaction and determined by X-ray diffraction method. Compound 1 crystallizes in monoclinic, space group P2/m with a = 4.7740(10), b = 11.039(2), c = 5.6752(14) ?, β = 91.394(9)o, V = 299.00(11) ?3, Z = 1, Dc = 1.731 g/cm3, F(000) = 157 and μ(MoKa) = 0.7107 mm-1. Compound 2 crystallizes in monoclinic, space group P2/n with a = 12.916(2), b = 11.149(1), c = 15.006(2) ?, β =106.642(6)o, V = 2070.3(5) ?3, Z = 2, Dc = 1.510 g/cm3, F(000) = 970 and μ(MoKa) = 0.7107 mm-1. In the structure of compound 1, the metal atom is in a slightly distorted octahedral CuO4N2 geometry surrounded by four O atoms of two NO2 ligands in the equatorial positions and two N atoms from 4,4?-bipyridine ligands in the axial sites, and the 4,4?-bipyridine ligands bridge the neighboring Cu2+ atoms to form polymeric chains in the lattice. Compound 2 has a 2D square-grid network structure. The square grids are superposed on each other to form a channel framework. The square cavity has dimensions of 11.148(2)? ×11.229(3)?. Every two guest 4,4?-bipyridine molecules are clathra- ted in each hydrophobic host cavity and further stabilized by π-π stacking and hydrogen bonding interactions.
