For the motion of a sphere on a rough horizontal plane, in the previous paper[1]the author aimed at providing approximate analytical solutions while the nutation is neglected,In this paper ,the control equations for t...For the motion of a sphere on a rough horizontal plane, in the previous paper[1]the author aimed at providing approximate analytical solutions while the nutation is neglected,In this paper ,the control equations for the sphere with nutation have beendeduced on the basis of paper [1]. Through the medium of solving these equations,the conclusion for the velocity of contact point in paper [1]is still proved true for the case with nutation.What is more ,some interesting results are gained ,for example the ve-locity of centre and contact point is relative to the angular velocity of spin and nuta-tion the direction of velocity of centre and contact point is constant.Under the condi-tion which is supposed to be weak nutation,the approximate analytical solutions are obtained,so that the results of paper [1]is proved to be true.展开更多
The geometries and electronic properties of SnSe/metal contact have been investigated using first-principles calcula- tion. It is found that the geometries of monolayer SnSe were affected slightly when SnSe adsorbs on...The geometries and electronic properties of SnSe/metal contact have been investigated using first-principles calcula- tion. It is found that the geometries of monolayer SnSe were affected slightly when SnSe adsorbs on M （M = Ag,Au,Ta） substrate. Compared with the corresponding free-standing monolayer SnSe, the adsorbed SnSe undergoes a semiconductor- to-metal transition. The potential difference AV indicates that SnSefra contact is the best candidate for the Schottky contact of the three SnSe/M contacts. Two types of current-in-plane （CIP） structure, where a freestanding monolayer SnSe is con- nected to SnSe/M, are identified as the n-type CIP structure in SnSe/Ag contact and p-type CIP structure in SnSe/Au and SnSe/Ta contact. The results can stimulate further investigation for the multifunctional SnSe/metal contact.展开更多
In the paper, we develop the fundamental solutions for a graded half-plane subjected to concentrated forces acting perpendicularly and parallel to the surface. In the solutions, Young’s modulus is assumed to vary in ...In the paper, we develop the fundamental solutions for a graded half-plane subjected to concentrated forces acting perpendicularly and parallel to the surface. In the solutions, Young’s modulus is assumed to vary in the form of E(y)=E0eαy and Poisson’s ratio is assumed to be constant. On the basis of the fundamental solutions, the singular integral equations are formulated for the unknown traction distributions with Green’s function method. From the fundamental integral equations, a series of integral equations for special cases may be deduced corresponding to practical contact situations. The validity of the fundamental solutions and the integral equations is demonstrated with the degenerate solutions and two typical numerical examples.展开更多
为研究织构表面对面接触摩擦副摩擦特性的影响,设计和制造4个表面高度算术平均值相同、表面微凹坑面积占有率分别为7%、14%、21%、28%的试件,选用HDM20端面摩擦磨损试验机,针对油润滑和脂润滑两种润滑剂,在不同载荷、转速等工况和不同...为研究织构表面对面接触摩擦副摩擦特性的影响,设计和制造4个表面高度算术平均值相同、表面微凹坑面积占有率分别为7%、14%、21%、28%的试件,选用HDM20端面摩擦磨损试验机,针对油润滑和脂润滑两种润滑剂,在不同载荷、转速等工况和不同摩擦副配对材料等条件下进行了试验研究,探讨表面形貌对摩擦特性的影响规律,并使用Talysurf CCI Lite非接触式三维光学轮廓仪对试样进行三维表面测量,采用ISO25178定义的体积参数和连通性系数对三维表面形貌进行表征,从而得出表面体积参数及连通性系数与摩擦因数的关系。结果表明:在油润滑条件下表面形貌的微观结构特性对摩擦的影响要比脂润滑条件下的更显著;在钢对铜摩擦副条件下织构表面的摩擦因数变化比较复杂,在钢对钢摩擦副条件下织构表面的摩擦因数变化相对平稳;在不同的条件下,最优的表面微观结构特性也不同;将连通性系数和体积参数结合起来对表面形貌进行表征将更有利于表面微观结构特性的摩擦学设计。展开更多
文摘For the motion of a sphere on a rough horizontal plane, in the previous paper[1]the author aimed at providing approximate analytical solutions while the nutation is neglected,In this paper ,the control equations for the sphere with nutation have beendeduced on the basis of paper [1]. Through the medium of solving these equations,the conclusion for the velocity of contact point in paper [1]is still proved true for the case with nutation.What is more ,some interesting results are gained ,for example the ve-locity of centre and contact point is relative to the angular velocity of spin and nuta-tion the direction of velocity of centre and contact point is constant.Under the condi-tion which is supposed to be weak nutation,the approximate analytical solutions are obtained,so that the results of paper [1]is proved to be true.
基金supported by the National Natural Science Foundation of China(Grant Nos.U1304518 and U1404109)
文摘The geometries and electronic properties of SnSe/metal contact have been investigated using first-principles calcula- tion. It is found that the geometries of monolayer SnSe were affected slightly when SnSe adsorbs on M （M = Ag,Au,Ta） substrate. Compared with the corresponding free-standing monolayer SnSe, the adsorbed SnSe undergoes a semiconductor- to-metal transition. The potential difference AV indicates that SnSefra contact is the best candidate for the Schottky contact of the three SnSe/M contacts. Two types of current-in-plane （CIP） structure, where a freestanding monolayer SnSe is con- nected to SnSe/M, are identified as the n-type CIP structure in SnSe/Ag contact and p-type CIP structure in SnSe/Au and SnSe/Ta contact. The results can stimulate further investigation for the multifunctional SnSe/metal contact.
基金supported by the National Natural Science Foundation of China ( No.10502040)the National Basic Research Program(No.2007CB707705)
文摘In the paper, we develop the fundamental solutions for a graded half-plane subjected to concentrated forces acting perpendicularly and parallel to the surface. In the solutions, Young’s modulus is assumed to vary in the form of E(y)=E0eαy and Poisson’s ratio is assumed to be constant. On the basis of the fundamental solutions, the singular integral equations are formulated for the unknown traction distributions with Green’s function method. From the fundamental integral equations, a series of integral equations for special cases may be deduced corresponding to practical contact situations. The validity of the fundamental solutions and the integral equations is demonstrated with the degenerate solutions and two typical numerical examples.
文摘为研究织构表面对面接触摩擦副摩擦特性的影响,设计和制造4个表面高度算术平均值相同、表面微凹坑面积占有率分别为7%、14%、21%、28%的试件,选用HDM20端面摩擦磨损试验机,针对油润滑和脂润滑两种润滑剂,在不同载荷、转速等工况和不同摩擦副配对材料等条件下进行了试验研究,探讨表面形貌对摩擦特性的影响规律,并使用Talysurf CCI Lite非接触式三维光学轮廓仪对试样进行三维表面测量,采用ISO25178定义的体积参数和连通性系数对三维表面形貌进行表征,从而得出表面体积参数及连通性系数与摩擦因数的关系。结果表明:在油润滑条件下表面形貌的微观结构特性对摩擦的影响要比脂润滑条件下的更显著;在钢对铜摩擦副条件下织构表面的摩擦因数变化比较复杂,在钢对钢摩擦副条件下织构表面的摩擦因数变化相对平稳;在不同的条件下,最优的表面微观结构特性也不同;将连通性系数和体积参数结合起来对表面形貌进行表征将更有利于表面微观结构特性的摩擦学设计。
