This article elaborated the characteristics of settlement shape in detail with examples. Aiming at the negative effects on settlement shape by construction, we put forward some measures, such as respect for ecological...This article elaborated the characteristics of settlement shape in detail with examples. Aiming at the negative effects on settlement shape by construction, we put forward some measures, such as respect for ecological environment, selection mode of space development, protection of historical features, and excavation of culture connotation, so as to realize the protection of settlement shape.展开更多
The formability of AA5052/polyethylene/AA5052 sandwich sheets was experimentally studied. Three kinds of AA5052/polyethylene/AA5052 sandwich specimens with different thicknesses of core materials were prepared by the ...The formability of AA5052/polyethylene/AA5052 sandwich sheets was experimentally studied. Three kinds of AA5052/polyethylene/AA5052 sandwich specimens with different thicknesses of core materials were prepared by the hot pressing adhesive method. Then, the uniaxial tensile tests were conducted to investigate the mechanical properties of AA5052/polyethylene/ AA5052 sandwich sheets, and the stretching tests were carried out to investigate the influences of polymer core thickness on the limit dome height of the sandwich sheet. The forming limit curves for three kinds of sandwich sheets were obtained. The experimental results show that the forming limit of the AA5052/polyethylene/AA5052 sandwich sheet is higher than that of the monolithic AA5052 sheet, and it increases with increasing the thickness of polyethylene core.展开更多
[ObJective] The research aimed to determine the geographic distribution map of system of Rana dybowskii. [Method] Four morphologic indices （body length, body weight, forelimb length, hindlimb length） of eight geogra...[ObJective] The research aimed to determine the geographic distribution map of system of Rana dybowskii. [Method] Four morphologic indices （body length, body weight, forelimb length, hindlimb length） of eight geographical populations of R.dybowskii which naturally distribute in Changhai Mountain and Xiaoxing＇an Mountain were measured. Measure results were variance analyzed and cluster analyzed. [Result] Variance analysis showed： the genetic branching among the Dongfanghong male population（ belongs to Wandashan） and Xiaoxing＇an Mountain male population and Changbai Mountain male population were significantly different （P〈0.05） ; the genetic branching between the Hebei female population （belongs to Xiaoxing＇an Mountain） and Changbai Mountain female population was significantly different （P〈0.05 ）. Cluster analysis showed ： male R.dybowskii can be divided into three groups ： the first group included Quanyang, Tianbei, Chaoyang and Ddkouqin, the second group included Tieli and Anshan, the third group included Dongfanghong; and the female R. dybowskii can be divided into three groups ： the first group included Quanyang and Chaoyang, the second group included Tianbei and Dakouqin, the third group included Hebei. [Condusion] The paper deduced that the Sanjiang Plain was the geographical origin center ofR. dybowskii which radiated to Changbai Mountain and Xiaoxing＇an Mountain along the adverse current of Songhua River basin, therefore, the current distribution pattern of R. dybowskii was formed.展开更多
A polymer electro optic modulator has been fabricated with the functional layer acting as a kind of corona poled crosslinkable polyurethane. The three optical layers, namely waveguide, photolithography and oxygen are...A polymer electro optic modulator has been fabricated with the functional layer acting as a kind of corona poled crosslinkable polyurethane. The three optical layers, namely waveguide, photolithography and oxygen are fabricated by spin coating. With the Reactive Ion Etching method, the ridge of the waveguide is constructed. With light at 1 31μm being fiber coupled to waveguide, the mode and the modulation properties of these devices are demonstrated in a micron control system.展开更多
Shaped charge jet formation process is studied under the conditions of different background lights by means of high speed frame photography. In order to shoot true jet appearance, the glass tube in which jet moves is...Shaped charge jet formation process is studied under the conditions of different background lights by means of high speed frame photography. In order to shoot true jet appearance, the glass tube in which jet moves is vacuumized. The experiment results show that observing jet appearance with the double reflecting mirrors system is feasible as long as the vacuum of the glass tube can meet the requirement of experiment.展开更多
The density functional theory on the level of B3LYP/6-31G was empolyed to study the chain growth mechanism in polymerization process of α-linear olefin in TiCl3/AlEt2Cl catalytic system to synthesize drag reduction a...The density functional theory on the level of B3LYP/6-31G was empolyed to study the chain growth mechanism in polymerization process of α-linear olefin in TiCl3/AlEt2Cl catalytic system to synthesize drag reduction agent. Full parameter optimization without symmetry restrictions for reactants, products, the possible transition states, and intermediates was calculated. Vibration frequency was analyzed for all of stagnation points on the potential energy surface at the same theoretical level. The internal reaction coordinate was calculated from the transition states to reactants and products respectively. The results showed as flloes： （i） Coordination compounds were formed on the optimum configuration of TiCl3/AlEt2Cl.（ii） The transition states were formed. The energy di？erence between transition states and the coordination compounds was 40.687 kJ/mol. （iii） Double bond opened and Ti-C（4） bond fractured, and the polymerization was completed. The calculation results also showed that the chain growth mechanism did not essentially change with the increase of carbon atom number of α-linear olefin. From the relationship between polymerization activation energy and carbon atom number of the α-linear olefin, it can be seen that the α-linear olefin monomers with 6-10 carbon atoms had low activation energy and wide range. It was optimum to synthesize drag reduction agent by polymerization.展开更多
Polypyrrole （PPY） microbelts are synthesized via the absorbent cotton template for the first time. PPY microbelts are characterized by Fourier transform infrared spectroscopy.The stability, the morphology and electr...Polypyrrole （PPY） microbelts are synthesized via the absorbent cotton template for the first time. PPY microbelts are characterized by Fourier transform infrared spectroscopy.The stability, the morphology and electrical conductivity of such microbelts are evaluated by means of scanning electron microscope, thermo-gravimetric analysis and four-probe con-ductivity. A possible mechanism for the formation of PPY microbelts are proposed. The conductivity is measured, and the conductivity variation mechanism of the PPY microbelts with the pyrrole monomer concentrations is analyzed.展开更多
A windowed very small aperture laser (VSAL) source for use in high resolution near field optical data storage is fabricated.The windowed regions are introduced to avoid shorting the pn junction with metal coating a...A windowed very small aperture laser (VSAL) source for use in high resolution near field optical data storage is fabricated.The windowed regions are introduced to avoid shorting the pn junction with metal coating and suppress the COD effect.It facilitates producing VSAL by simplified technology and improves the laser performance.A VSAL with 400nm small aperture is demonstrated by focused ion beam (FIB) and the output power is 0 3mW at 31mA.展开更多
基金Supported by the 11th 5-year Scientific Supporting Project Fund of the Ministry of Science and Technology(2006BAJ01A12-06)the 11th 5-years Planning Philosophy and Social Science Project of Sichuan Province(SC06B014)~~
文摘This article elaborated the characteristics of settlement shape in detail with examples. Aiming at the negative effects on settlement shape by construction, we put forward some measures, such as respect for ecological environment, selection mode of space development, protection of historical features, and excavation of culture connotation, so as to realize the protection of settlement shape.
基金Project(HIT.NSRIF.2009033) supported by the Scientific Research Foundation of Harbin Institute of Technology,China
文摘The formability of AA5052/polyethylene/AA5052 sandwich sheets was experimentally studied. Three kinds of AA5052/polyethylene/AA5052 sandwich specimens with different thicknesses of core materials were prepared by the hot pressing adhesive method. Then, the uniaxial tensile tests were conducted to investigate the mechanical properties of AA5052/polyethylene/ AA5052 sandwich sheets, and the stretching tests were carried out to investigate the influences of polymer core thickness on the limit dome height of the sandwich sheet. The forming limit curves for three kinds of sandwich sheets were obtained. The experimental results show that the forming limit of the AA5052/polyethylene/AA5052 sandwich sheet is higher than that of the monolithic AA5052 sheet, and it increases with increasing the thickness of polyethylene core.
文摘[ObJective] The research aimed to determine the geographic distribution map of system of Rana dybowskii. [Method] Four morphologic indices （body length, body weight, forelimb length, hindlimb length） of eight geographical populations of R.dybowskii which naturally distribute in Changhai Mountain and Xiaoxing＇an Mountain were measured. Measure results were variance analyzed and cluster analyzed. [Result] Variance analysis showed： the genetic branching among the Dongfanghong male population（ belongs to Wandashan） and Xiaoxing＇an Mountain male population and Changbai Mountain male population were significantly different （P〈0.05） ; the genetic branching between the Hebei female population （belongs to Xiaoxing＇an Mountain） and Changbai Mountain female population was significantly different （P〈0.05 ）. Cluster analysis showed ： male R.dybowskii can be divided into three groups ： the first group included Quanyang, Tianbei, Chaoyang and Ddkouqin, the second group included Tieli and Anshan, the third group included Dongfanghong; and the female R. dybowskii can be divided into three groups ： the first group included Quanyang and Chaoyang, the second group included Tianbei and Dakouqin, the third group included Hebei. [Condusion] The paper deduced that the Sanjiang Plain was the geographical origin center ofR. dybowskii which radiated to Changbai Mountain and Xiaoxing＇an Mountain along the adverse current of Songhua River basin, therefore, the current distribution pattern of R. dybowskii was formed.
文摘A polymer electro optic modulator has been fabricated with the functional layer acting as a kind of corona poled crosslinkable polyurethane. The three optical layers, namely waveguide, photolithography and oxygen are fabricated by spin coating. With the Reactive Ion Etching method, the ridge of the waveguide is constructed. With light at 1 31μm being fiber coupled to waveguide, the mode and the modulation properties of these devices are demonstrated in a micron control system.
文摘Shaped charge jet formation process is studied under the conditions of different background lights by means of high speed frame photography. In order to shoot true jet appearance, the glass tube in which jet moves is vacuumized. The experiment results show that observing jet appearance with the double reflecting mirrors system is feasible as long as the vacuum of the glass tube can meet the requirement of experiment.
文摘The density functional theory on the level of B3LYP/6-31G was empolyed to study the chain growth mechanism in polymerization process of α-linear olefin in TiCl3/AlEt2Cl catalytic system to synthesize drag reduction agent. Full parameter optimization without symmetry restrictions for reactants, products, the possible transition states, and intermediates was calculated. Vibration frequency was analyzed for all of stagnation points on the potential energy surface at the same theoretical level. The internal reaction coordinate was calculated from the transition states to reactants and products respectively. The results showed as flloes： （i） Coordination compounds were formed on the optimum configuration of TiCl3/AlEt2Cl.（ii） The transition states were formed. The energy di？erence between transition states and the coordination compounds was 40.687 kJ/mol. （iii） Double bond opened and Ti-C（4） bond fractured, and the polymerization was completed. The calculation results also showed that the chain growth mechanism did not essentially change with the increase of carbon atom number of α-linear olefin. From the relationship between polymerization activation energy and carbon atom number of the α-linear olefin, it can be seen that the α-linear olefin monomers with 6-10 carbon atoms had low activation energy and wide range. It was optimum to synthesize drag reduction agent by polymerization.
基金This work was supported by the National Natural Science Foundation of China （No.20571066 and No.20871108）, the Program for the Top Scietutions of Shanxi, and the Program for the Top Young Academic Leaders of Higher Learning Institutions of Shanxi.nce and Technology Inovation Team of Higher Learning Insti
文摘Polypyrrole （PPY） microbelts are synthesized via the absorbent cotton template for the first time. PPY microbelts are characterized by Fourier transform infrared spectroscopy.The stability, the morphology and electrical conductivity of such microbelts are evaluated by means of scanning electron microscope, thermo-gravimetric analysis and four-probe con-ductivity. A possible mechanism for the formation of PPY microbelts are proposed. The conductivity is measured, and the conductivity variation mechanism of the PPY microbelts with the pyrrole monomer concentrations is analyzed.
文摘A windowed very small aperture laser (VSAL) source for use in high resolution near field optical data storage is fabricated.The windowed regions are introduced to avoid shorting the pn junction with metal coating and suppress the COD effect.It facilitates producing VSAL by simplified technology and improves the laser performance.A VSAL with 400nm small aperture is demonstrated by focused ion beam (FIB) and the output power is 0 3mW at 31mA.
