From the general formula for calculating the efficiency of planetary geartrains, the efficiency of the double crank ring-plate-type pin-cycloidal gear planetary drive isderived. To prove the theory, an experimental st...From the general formula for calculating the efficiency of planetary geartrains, the efficiency of the double crank ring-plate-type pin-cycloidal gear planetary drive isderived. To prove the theory, an experimental study has been conducted. The tested value of theefficiency of a sample set of the new-type drive in the experiment agrees with the calculated one.It shows that the new-type drive is of not merely high bearing capacity, but also quite highefficiency.展开更多
Based on an analysis of the requirement of network-oriented NC lathe training system, a general framework of web-based training system is established. The key techniques for establishing this system include a three-la...Based on an analysis of the requirement of network-oriented NC lathe training system, a general framework of web-based training system is established. The key techniques for establishing this system include a three-layer web structure in building the general framework, the technique of VRML to model a virtual operating environment, and the access to the database using the ASP technique.展开更多
The change of microstructure with strain was investigated in a Fe-32Mn-5Si austenitic alloy at room temperature by X-raydiffraction profile analysis.The experimental results show that the Fe-32Mn-5Si alloy is deformed...The change of microstructure with strain was investigated in a Fe-32Mn-5Si austenitic alloy at room temperature by X-raydiffraction profile analysis.The experimental results show that the Fe-32Mn-5Si alloy is deformed by the strain—induced γ→εtransformation and the twinning except dislocation slip at room temperature.The amount of strain-induced ε-martensite,thestacking fault probability and the twinning probability all exhibit parabolic relationship with increasing strain.The stackingfault probability is higher than the twinning probability.展开更多
The influences of lattice parameter of austenite, the electron concentration, the yield strength of parent phase on γ→ε martensite start temperature Ms in the Fe-Mn alloys containing C, Al, Ge and Si have been expe...The influences of lattice parameter of austenite, the electron concentration, the yield strength of parent phase on γ→ε martensite start temperature Ms in the Fe-Mn alloys containing C, Al, Ge and Si have been experimentally investigated. The results show that the lattice parameter of austenite is more important than the electron concentration and the yield strength of parent phase in governing the γ→ε martensitic transformation in Fe-Mn based alloys. A relation between the Ms and lattice parameter of austenite in Fe-Mn based alloys is suggested. The elements Mn, C, Al, Ge, which increase the lattice parameter of austenite lower the Ms; while the element Si, which decreases the lattice parameter increases the MS. The depressing effect of antiferromagnetic transition on the γ→ε martensitic transformation may be related to the increase of lattice parameter due to the positive magnetostriction during the antiferromagnetic transition.展开更多
This paper analyses the local behavior of the simple off-diagonal bivariate quadratic function approximation to a bivariate function which has a given power series expansion about the origin.It is shown that the simpl...This paper analyses the local behavior of the simple off-diagonal bivariate quadratic function approximation to a bivariate function which has a given power series expansion about the origin.It is shown that the simple off-diagonal bivariate quadratic Hermite-Padé form always defines a bivariate quadratic function and that this function is analytic in a neighbourhood of the origin.Numerical examples compare the obtained results with the approximation power of diagonal Chisholm approximant and Taylor polynomial approximant.展开更多
This paper generalizes the basic principle of multiplier-enlargement approach to approximating any nonbounded continuous functions with positive linear operators, and as an example, Bernstein polynomial operators are ...This paper generalizes the basic principle of multiplier-enlargement approach to approximating any nonbounded continuous functions with positive linear operators, and as an example, Bernstein polynomial operators are analysed and studied. This paper gives a certain theorem as a general rule to approximate any nonbounded continuous functions.展开更多
Ni-Fe-C filler metal based on WC-30Co/Ni-Fe-C/45 steel is developed using TIGwelding method. The weld joints are studied by means of optical microscope, SEM, EPMA, X-rays andmicro hardness test etc. The results show t...Ni-Fe-C filler metal based on WC-30Co/Ni-Fe-C/45 steel is developed using TIGwelding method. The weld joints are studied by means of optical microscope, SEM, EPMA, X-rays andmicro hardness test etc. The results show that the weld joints of WC-30Co and 45 steel can beobtained by TIG welding using Ni-Fe-C alloys as filler metals. The harmful eta phase formed in thejoints is M_6C, M_(12)C type carbides. The poor carbon content of the W-Co-C system resulted fromthe carbon diffusion and the high ingredient Fe are the two vital factors inducing to eta phaseformation. It could be restricted by the addition of carbon element into Ni-Fe alloys.展开更多
The existing scheme of rational polynomial approximants, defined by multivariate power series, is extended to define approximants with branch points. The existence theorem is obtained. The basic properties used to def...The existing scheme of rational polynomial approximants, defined by multivariate power series, is extended to define approximants with branch points. The existence theorem is obtained. The basic properties used to define the rational approximants can be preserved almost intactly. Especially, the local behavior of the diagonal bivariate quadratic algebraic function approximation is analysed.展开更多
基金This project is supported by National Natural Science Foundation of China (No.50175011).
文摘From the general formula for calculating the efficiency of planetary geartrains, the efficiency of the double crank ring-plate-type pin-cycloidal gear planetary drive isderived. To prove the theory, an experimental study has been conducted. The tested value of theefficiency of a sample set of the new-type drive in the experiment agrees with the calculated one.It shows that the new-type drive is of not merely high bearing capacity, but also quite highefficiency.
文摘Based on an analysis of the requirement of network-oriented NC lathe training system, a general framework of web-based training system is established. The key techniques for establishing this system include a three-layer web structure in building the general framework, the technique of VRML to model a virtual operating environment, and the access to the database using the ASP technique.
基金The project was supported by the National Natural Science Foundation of China(grant No.59601007).
文摘The change of microstructure with strain was investigated in a Fe-32Mn-5Si austenitic alloy at room temperature by X-raydiffraction profile analysis.The experimental results show that the Fe-32Mn-5Si alloy is deformed by the strain—induced γ→εtransformation and the twinning except dislocation slip at room temperature.The amount of strain-induced ε-martensite,thestacking fault probability and the twinning probability all exhibit parabolic relationship with increasing strain.The stackingfault probability is higher than the twinning probability.
文摘The influences of lattice parameter of austenite, the electron concentration, the yield strength of parent phase on γ→ε martensite start temperature Ms in the Fe-Mn alloys containing C, Al, Ge and Si have been experimentally investigated. The results show that the lattice parameter of austenite is more important than the electron concentration and the yield strength of parent phase in governing the γ→ε martensitic transformation in Fe-Mn based alloys. A relation between the Ms and lattice parameter of austenite in Fe-Mn based alloys is suggested. The elements Mn, C, Al, Ge, which increase the lattice parameter of austenite lower the Ms; while the element Si, which decreases the lattice parameter increases the MS. The depressing effect of antiferromagnetic transition on the γ→ε martensitic transformation may be related to the increase of lattice parameter due to the positive magnetostriction during the antiferromagnetic transition.
基金Supported by National Natural Science Foundation of China( 699730 1 0,1 0 2 71 0 2 2 )
文摘This paper analyses the local behavior of the simple off-diagonal bivariate quadratic function approximation to a bivariate function which has a given power series expansion about the origin.It is shown that the simple off-diagonal bivariate quadratic Hermite-Padé form always defines a bivariate quadratic function and that this function is analytic in a neighbourhood of the origin.Numerical examples compare the obtained results with the approximation power of diagonal Chisholm approximant and Taylor polynomial approximant.
文摘This paper generalizes the basic principle of multiplier-enlargement approach to approximating any nonbounded continuous functions with positive linear operators, and as an example, Bernstein polynomial operators are analysed and studied. This paper gives a certain theorem as a general rule to approximate any nonbounded continuous functions.
文摘Ni-Fe-C filler metal based on WC-30Co/Ni-Fe-C/45 steel is developed using TIGwelding method. The weld joints are studied by means of optical microscope, SEM, EPMA, X-rays andmicro hardness test etc. The results show that the weld joints of WC-30Co and 45 steel can beobtained by TIG welding using Ni-Fe-C alloys as filler metals. The harmful eta phase formed in thejoints is M_6C, M_(12)C type carbides. The poor carbon content of the W-Co-C system resulted fromthe carbon diffusion and the high ingredient Fe are the two vital factors inducing to eta phaseformation. It could be restricted by the addition of carbon element into Ni-Fe alloys.
文摘The existing scheme of rational polynomial approximants, defined by multivariate power series, is extended to define approximants with branch points. The existence theorem is obtained. The basic properties used to define the rational approximants can be preserved almost intactly. Especially, the local behavior of the diagonal bivariate quadratic algebraic function approximation is analysed.
