Turnouts are in close proximity to each other in the stations of high-speed railway.The stress and deformation of those turnouts which are laid nearby are influenced mutually and therefore those turnouts should be con...Turnouts are in close proximity to each other in the stations of high-speed railway.The stress and deformation of those turnouts which are laid nearby are influenced mutually and therefore those turnouts should be considered together.On the basis of finite element method,according to No.18 jointless turnout with swing nose frog in the ballasted track of high-speed railway,a finite element calculating model of jointless turnout group coupling the longitudinal,lateral and vertical directions is established.The influencing factors,for instance the number of turnouts,connection form,length of intermediate straight line and ballast bed longitudinal resistance,on the mechanical characteristics of turnout,transverse deformation of switch rail and range of rail temperature for laying turnout are analyzed in this paper.The results show that more turnouts result in more obvious interaction between them when the lengths of intermediate straight line are the same;more significant influence between the turnouts with the connection form of head-to-head is produced compared to that of head-to-end;from the perspective of statics,influence between turnouts could be ignored basically if the intermediate straight line is over 50 m;bigger longitudinal resistance of ballast bed leads to less influence between the turnouts.展开更多
We give some sufficient conditions for non-congruent numbers in terms of the Monsky matrices.Many known criteria for non-congruent numbers can be viewed as special cases of our results.
A t-hyperwheel(t≥3) of length l(or W l(t) for brevity) is a t-uniform hypergraph(V,E) ,where E = {e1,e2,. . .,el} and v1,v2,. . .,vl are distinct vertices of V = il=1 ei such that for i = 1,. . .,l,vi,vi+1 ∈ ei and ...A t-hyperwheel(t≥3) of length l(or W l(t) for brevity) is a t-uniform hypergraph(V,E) ,where E = {e1,e2,. . .,el} and v1,v2,. . .,vl are distinct vertices of V = il=1 ei such that for i = 1,. . .,l,vi,vi+1 ∈ ei and ei ∩ ej = P,j ∈/{i-1,i,i + 1},where the operation on the subscripts is modulo l and P is a vertex of V which is different from vi,1 i l. In this paper,we investigate the maximum packing problem of MPλ(3,W 4( 3) ,v) . Finally,the packing number Dλ(3,W 4( 3) ,v) is determined for any positive integers v 5 and λ.展开更多
基金supported by the National Natural Science Foundation-High Speed Railway Joint Fund of China (Grant No. U1234211)the National Natural Science Foundation of China (Grant No. 51108025)the Ministry of Railways Science and Technology Research Development Major Project of China (Grant Nos. 2010G018-D-2 and2011G014-D)
文摘Turnouts are in close proximity to each other in the stations of high-speed railway.The stress and deformation of those turnouts which are laid nearby are influenced mutually and therefore those turnouts should be considered together.On the basis of finite element method,according to No.18 jointless turnout with swing nose frog in the ballasted track of high-speed railway,a finite element calculating model of jointless turnout group coupling the longitudinal,lateral and vertical directions is established.The influencing factors,for instance the number of turnouts,connection form,length of intermediate straight line and ballast bed longitudinal resistance,on the mechanical characteristics of turnout,transverse deformation of switch rail and range of rail temperature for laying turnout are analyzed in this paper.The results show that more turnouts result in more obvious interaction between them when the lengths of intermediate straight line are the same;more significant influence between the turnouts with the connection form of head-to-head is produced compared to that of head-to-end;from the perspective of statics,influence between turnouts could be ignored basically if the intermediate straight line is over 50 m;bigger longitudinal resistance of ballast bed leads to less influence between the turnouts.
基金supported by NSFC(Nos.12231009,11971224,12071209).
文摘We give some sufficient conditions for non-congruent numbers in terms of the Monsky matrices.Many known criteria for non-congruent numbers can be viewed as special cases of our results.
基金supported by National Natural Science Foundation of China (Grant Nos. 10771013, 10831002)
文摘A t-hyperwheel(t≥3) of length l(or W l(t) for brevity) is a t-uniform hypergraph(V,E) ,where E = {e1,e2,. . .,el} and v1,v2,. . .,vl are distinct vertices of V = il=1 ei such that for i = 1,. . .,l,vi,vi+1 ∈ ei and ei ∩ ej = P,j ∈/{i-1,i,i + 1},where the operation on the subscripts is modulo l and P is a vertex of V which is different from vi,1 i l. In this paper,we investigate the maximum packing problem of MPλ(3,W 4( 3) ,v) . Finally,the packing number Dλ(3,W 4( 3) ,v) is determined for any positive integers v 5 and λ.
