The CuZrAl bulk metallic glass with minor-addition of Fe was prepared by rapid quenching method. The structures were examined by X-ray diffraction (XRD). The effect of Fe on the glass-forming ability was studied by ...The CuZrAl bulk metallic glass with minor-addition of Fe was prepared by rapid quenching method. The structures were examined by X-ray diffraction (XRD). The effect of Fe on the glass-forming ability was studied by differential scanning calorimetry (DSC). The minor-addition of Fe obviously extends the supercooled liquid region ΔTx. The plastic strain of the Cu44Zr48Al7Fe bulk metallic glass is about 1.5%. The microstructures were examined by transmission electron microscopy (TEM). It is found that when 1%-2% Fe (mole fraction) were introduced into the CuZrAl alloy matrix, nanoscale phase separation occurs in the as-prepared Cu44Zr48Al7Fe bulk metallic glass.展开更多
The Ni−MoO_(2) heterostructure was synthesized in suit on porous bulk NiMo alloy by a facile powder metallurgy and hydrothermal method.The results of field emission scanning electron microscopy(SEM),field emission tra...The Ni−MoO_(2) heterostructure was synthesized in suit on porous bulk NiMo alloy by a facile powder metallurgy and hydrothermal method.The results of field emission scanning electron microscopy(SEM),field emission transmission electron microscopy(TEM)and X-ray photoelectron spectroscopy(XPS)reveal that the as-prepared electrode possesses the heterostructure and a layer of Ni(OH)_(2) nanosheets is formed on the surface of Ni−MoO_(2) electrode simultaneously after hydrothermal treatment,which provides abundant interface and much active sites,as well as much active specific surface area.The results of hydrogen evolution reaction indicate that the Ni−MoO_(2) heterostructure electrode exhibits excellent catalytic performance,requiring only 41 mV overpotential to reach the current density of 10 mA/cm^(2).It also possesses a small Tafel slope of 52.7 mV/dec and long-term stability of electrolysis in alkaline medium.展开更多
The Ordos block is a stable tectonic unit since the Cenozoic. Whether low-resistivity layers exist in the middle and lower crust of this kind block is an open question. This work attempts to reveal the entire crustal ...The Ordos block is a stable tectonic unit since the Cenozoic. Whether low-resistivity layers exist in the middle and lower crust of this kind block is an open question. This work attempts to reveal the entire crustal structure of the block based on interpretation of magnetotelluric data collected along the profile across this region. The result shows that a layered structure characterizes the crust of the Ordos block, with a low-resistivity layer at depth of about 20km, presumably associated with fluids there. In contrast, in the areas of active tectonics on the east and west of the block, there are no such layered electric structures in the crust, and the low-resistivity zones may be related to the decollement zones (or ductile shear zones) in the crust. The difference in electric structure of crust between the Ordos Block and neighboring areas is of significance to analyze the movement and deformation of varied blocks in the continent.展开更多
In order to improve the intelligence of the English teaching management, so as to improve the English teaching resource scheduling and sharing ability, a design method of teaching management system is proposed based o...In order to improve the intelligence of the English teaching management, so as to improve the English teaching resource scheduling and sharing ability, a design method of teaching management system is proposed based on Web. The system adopts Web network architecture design, mainly it is divided into MUC main control module, database module, data management module and man-machine interaction module, Network management and online scheduling of English teaching resources are obtained based on C/S framework, data exchange of English teaching resources is realized on client side and server side, the control component of the English teaching resource distribution database uses MBM29LV400BC as the logic decoding controller. The intelligent algorithm is used to analyze the big data to realize the scheduling and access control of the English teaching management system resources. The test results show that the design of the English teaching management system has good resource scheduling and database construction ability, and the overall intelligence of the system is better.展开更多
In this paper new criteria for designing of temporary architectures, which can be used as a uniform coverage for open spaces, are discussed. Frequently temporary architectures use building techniques and materials lig...In this paper new criteria for designing of temporary architectures, which can be used as a uniform coverage for open spaces, are discussed. Frequently temporary architectures use building techniques and materials lightweight. In the case of temporary architectures the theme of sustainability requires that the structure can be reused in different occasions and contexts. The solution to these issues, developed in this paper, makes use of a innovative constructive procedure of prestressed masonry in blocks of natural stone. This procedure is used for the construction of the vertical supports of the cover, consisting of a tensostructure with shape of hyperboloid, obtained by products standard (steel profiles and membrane). The columns with prestressed blocks of natural stone, dry assembled, allow you to have a modular structure, easily assembled and disassembled, with full recovery of all elements; the stone columns, due to their weight, are able to stabilize the whole structure, even to the dynamic stresses, without using any type of foundation structure fixed to the ground. This paper shows the description of all the elements that make up the new type of temporary architecture designed.展开更多
Numerical simulation on conjugate heat transfer of an internal cooled turbine vane was carried out. Numerical techniques employed included the third-order accuracy TVD scheme, multi-block structured grids and the tech...Numerical simulation on conjugate heat transfer of an internal cooled turbine vane was carried out. Numerical techniques employed included the third-order accuracy TVD scheme, multi-block structured grids and the technique of arbitrary curved mesh. Comparison between results of commercial CFD codes with several turbulence models and those of this code shows that it is incorrect of commercial CFD codes to predict the thermal boundary layer with traditional turbulence models, and that turbulence models considering transition lead to more accurate heat transfer in thermal boundary layer with some reliability and deficiency yet. The results of this code are close to those of CFX with transition model.展开更多
In this paper, the TAS-I (Thales Alenia Space-Italy) Test Bench for Robotics and Autonomy (TBRA) is presented. It is based on a flexible and modular software architecture (Framework Engine), in which each functi...In this paper, the TAS-I (Thales Alenia Space-Italy) Test Bench for Robotics and Autonomy (TBRA) is presented. It is based on a flexible and modular software architecture (Framework Engine), in which each functional module (representing the GNC subsystems) implements a key functionality of the GNC (Guidance Navigation and Control). Modules communicate by means of standardised interfaces designed for exchange of necessary information among the modules composing the entire system. This approach permits the interchange-ability of each subsystem without affecting the overall functionalities of the GNC system. In this paper, the TBRA system, together with the implemented functional modules will be described. Tests results will be reported and future development will be discussed.展开更多
Effects of agglomerates on the densification behavior and microstructural evolution during solid-state sintering of a cube of copper particles have been studied with discrete element method (DEM).It is found that the ...Effects of agglomerates on the densification behavior and microstructural evolution during solid-state sintering of a cube of copper particles have been studied with discrete element method (DEM).It is found that the densification of the sintering system decreases as the volume fraction of agglomerates increases.At a given volume fraction of agglomerates,the smaller the size of agglomerates,the poorer the densification and more inhomogeneous the compact is.The morphology and distribution of agglomerates have negligible effects on the densification,especially for the case with a low volume fraction of agglomerates.Agglomerates with a smaller average coordination number would have more restriction on the densification of sintering bodies.To our best knowledge,it is the first time to study the effect of agglomerates on sintering behavior using DEM.This study should be useful for further investigations of the effect of various inhomogeneities of microstructure on the complex sintering process by DEM.展开更多
Deformation of the bulk metallic glasses (BMGs) and the creation and propagation of the shear bands are closely interconnected.Shearing force was loaded on Zr 41.2 Ti 13.8 Cu 12.5 Ni 10.0 Be 22.5 (Vit.1) BMGs by cutti...Deformation of the bulk metallic glasses (BMGs) and the creation and propagation of the shear bands are closely interconnected.Shearing force was loaded on Zr 41.2 Ti 13.8 Cu 12.5 Ni 10.0 Be 22.5 (Vit.1) BMGs by cutting during the turning of the BMG rod.The temperature rise of alloy on the shear bands was calculated and the result showed that it could reach the temperature of the super-cooled liquid zone or exceed the melting point.The temperature rise caused viscous fluid flow and brought about the deformation of BMGs.This suggested that the deformation of BMGs was derived,at least to some extent,from the adiabatic shear temperature rise.展开更多
基金Project (2010ZDJH10) supported by the Nanjing University of Science and Technology Research Funding, ChinaProject (BK2007213) supported by the Natural Science Foundation of Jiangsu Province, China
文摘The CuZrAl bulk metallic glass with minor-addition of Fe was prepared by rapid quenching method. The structures were examined by X-ray diffraction (XRD). The effect of Fe on the glass-forming ability was studied by differential scanning calorimetry (DSC). The minor-addition of Fe obviously extends the supercooled liquid region ΔTx. The plastic strain of the Cu44Zr48Al7Fe bulk metallic glass is about 1.5%. The microstructures were examined by transmission electron microscopy (TEM). It is found that when 1%-2% Fe (mole fraction) were introduced into the CuZrAl alloy matrix, nanoscale phase separation occurs in the as-prepared Cu44Zr48Al7Fe bulk metallic glass.
基金the financial supports from the National Natural Science Foundation of China(Nos.52161040,51862026)the Natural Science Foundation of Jiangxi Province,China(Nos.20202ACBL214011,20192ACBL21048)the Aeronautical Science Foundation of China(No.2017ZF56027)。
文摘The Ni−MoO_(2) heterostructure was synthesized in suit on porous bulk NiMo alloy by a facile powder metallurgy and hydrothermal method.The results of field emission scanning electron microscopy(SEM),field emission transmission electron microscopy(TEM)and X-ray photoelectron spectroscopy(XPS)reveal that the as-prepared electrode possesses the heterostructure and a layer of Ni(OH)_(2) nanosheets is formed on the surface of Ni−MoO_(2) electrode simultaneously after hydrothermal treatment,which provides abundant interface and much active sites,as well as much active specific surface area.The results of hydrogen evolution reaction indicate that the Ni−MoO_(2) heterostructure electrode exhibits excellent catalytic performance,requiring only 41 mV overpotential to reach the current density of 10 mA/cm^(2).It also possesses a small Tafel slope of 52.7 mV/dec and long-term stability of electrolysis in alkaline medium.
基金sponsored by Earthquake Research Project for Public Affair(2008419010)the National Natural Science Foundation of China(40374032, 40534023)+4 种基金the Basic Scientific Research Special Program of the Institute of Geology,CEA(DFIGCEA0607117)the Basic Scientific Research Fund of the State Level Institutes for Commonweal (DF-IGCEA-0607-1-17)the National Basic Research Program(2004CB418402),Chinathe National Key Basic Research Program (95-13-02-02)the Key Program of the Natural Science Foundation of China (40534023)
文摘The Ordos block is a stable tectonic unit since the Cenozoic. Whether low-resistivity layers exist in the middle and lower crust of this kind block is an open question. This work attempts to reveal the entire crustal structure of the block based on interpretation of magnetotelluric data collected along the profile across this region. The result shows that a layered structure characterizes the crust of the Ordos block, with a low-resistivity layer at depth of about 20km, presumably associated with fluids there. In contrast, in the areas of active tectonics on the east and west of the block, there are no such layered electric structures in the crust, and the low-resistivity zones may be related to the decollement zones (or ductile shear zones) in the crust. The difference in electric structure of crust between the Ordos Block and neighboring areas is of significance to analyze the movement and deformation of varied blocks in the continent.
文摘In order to improve the intelligence of the English teaching management, so as to improve the English teaching resource scheduling and sharing ability, a design method of teaching management system is proposed based on Web. The system adopts Web network architecture design, mainly it is divided into MUC main control module, database module, data management module and man-machine interaction module, Network management and online scheduling of English teaching resources are obtained based on C/S framework, data exchange of English teaching resources is realized on client side and server side, the control component of the English teaching resource distribution database uses MBM29LV400BC as the logic decoding controller. The intelligent algorithm is used to analyze the big data to realize the scheduling and access control of the English teaching management system resources. The test results show that the design of the English teaching management system has good resource scheduling and database construction ability, and the overall intelligence of the system is better.
文摘In this paper new criteria for designing of temporary architectures, which can be used as a uniform coverage for open spaces, are discussed. Frequently temporary architectures use building techniques and materials lightweight. In the case of temporary architectures the theme of sustainability requires that the structure can be reused in different occasions and contexts. The solution to these issues, developed in this paper, makes use of a innovative constructive procedure of prestressed masonry in blocks of natural stone. This procedure is used for the construction of the vertical supports of the cover, consisting of a tensostructure with shape of hyperboloid, obtained by products standard (steel profiles and membrane). The columns with prestressed blocks of natural stone, dry assembled, allow you to have a modular structure, easily assembled and disassembled, with full recovery of all elements; the stone columns, due to their weight, are able to stabilize the whole structure, even to the dynamic stresses, without using any type of foundation structure fixed to the ground. This paper shows the description of all the elements that make up the new type of temporary architecture designed.
基金Sponsored by the National Natural Science Foundation of China (Grant No.5047028 and 50476017)
文摘Numerical simulation on conjugate heat transfer of an internal cooled turbine vane was carried out. Numerical techniques employed included the third-order accuracy TVD scheme, multi-block structured grids and the technique of arbitrary curved mesh. Comparison between results of commercial CFD codes with several turbulence models and those of this code shows that it is incorrect of commercial CFD codes to predict the thermal boundary layer with traditional turbulence models, and that turbulence models considering transition lead to more accurate heat transfer in thermal boundary layer with some reliability and deficiency yet. The results of this code are close to those of CFX with transition model.
文摘In this paper, the TAS-I (Thales Alenia Space-Italy) Test Bench for Robotics and Autonomy (TBRA) is presented. It is based on a flexible and modular software architecture (Framework Engine), in which each functional module (representing the GNC subsystems) implements a key functionality of the GNC (Guidance Navigation and Control). Modules communicate by means of standardised interfaces designed for exchange of necessary information among the modules composing the entire system. This approach permits the interchange-ability of each subsystem without affecting the overall functionalities of the GNC system. In this paper, the TBRA system, together with the implemented functional modules will be described. Tests results will be reported and future development will be discussed.
基金supported by the National Natural Science Foundation of China (Grant Nos.10972220,11021262 and 11125211)the National Basic Research Program of China (Grant No.2012CB937500)
文摘Effects of agglomerates on the densification behavior and microstructural evolution during solid-state sintering of a cube of copper particles have been studied with discrete element method (DEM).It is found that the densification of the sintering system decreases as the volume fraction of agglomerates increases.At a given volume fraction of agglomerates,the smaller the size of agglomerates,the poorer the densification and more inhomogeneous the compact is.The morphology and distribution of agglomerates have negligible effects on the densification,especially for the case with a low volume fraction of agglomerates.Agglomerates with a smaller average coordination number would have more restriction on the densification of sintering bodies.To our best knowledge,it is the first time to study the effect of agglomerates on sintering behavior using DEM.This study should be useful for further investigations of the effect of various inhomogeneities of microstructure on the complex sintering process by DEM.
基金supported by the National Basic Research Program of China (Grant No. 2010CB731600)the National Natural Science Foundation of China (Grant Nos. 50731005,50821001 and 51171163)+1 种基金the Doctoral Fund of Ministry of Education of China (Grant No. 20101333110004)the Nature Science Foundation of Hebei (Grant No. E2010001176)
文摘Deformation of the bulk metallic glasses (BMGs) and the creation and propagation of the shear bands are closely interconnected.Shearing force was loaded on Zr 41.2 Ti 13.8 Cu 12.5 Ni 10.0 Be 22.5 (Vit.1) BMGs by cutting during the turning of the BMG rod.The temperature rise of alloy on the shear bands was calculated and the result showed that it could reach the temperature of the super-cooled liquid zone or exceed the melting point.The temperature rise caused viscous fluid flow and brought about the deformation of BMGs.This suggested that the deformation of BMGs was derived,at least to some extent,from the adiabatic shear temperature rise.