For Super Typhoon Maria(2018),the multi-intensity change stages are identified and reproduced by numerical simulation.It is rather difficult to perform a perfect simulation for such a repeatedly reinforced typhoon dur...For Super Typhoon Maria(2018),the multi-intensity change stages are identified and reproduced by numerical simulation.It is rather difficult to perform a perfect simulation for such a repeatedly reinforced typhoon during its long life-cycle and remote path.In this study,the rapid intensification(RI)episode is focused on to investigate the convective burst(CB)characteristics and the relationship between the CBs and the RI of Maria.For Typhoon Maria,1)the spatial pattern of the inner-core CBs in distinct shear-relative quadrants,instead of the overall inner-core CBs frequently used in previous studies,presents cyclonic rotation from downshear to upshear quadrants during RI,producing a higher efficiency for tropical cyclone(TC)spinup,which accelerates the RI process.2)Dual meanings/relationships exist between CBs and RI for Maria,in contrast to the previous argument that CBs might be an indicator or a precursor to RI.The sudden growth of CBs prior to RI provides a precursor for the upcoming RI.Additionally,the appearance of the CB peak soon after RI indicates RI could lead to more intensive deep convections.The overlap of CBs with high inertial stability inside the radius of maximum wind plays a significant role in the RI of TCs.3)The synoptic attributions to CBs are also explored for the entire troposphere,fitting in the bottom-up thinking of convection growth.The CBs might be associated with high convective available potential energy in the boundary layer,a strengthening of the deep-layer secondary circulation,and an enhanced upper-level eddy momentum flux convergence.展开更多
The development of an analytic solution in terms of laminate parameters is presented for contact stresses and joint strength in pin-loaded orthotropic plates. This involved the determination of complex stress function...The development of an analytic solution in terms of laminate parameters is presented for contact stresses and joint strength in pin-loaded orthotropic plates. This involved the determination of complex stress functions required to compute stresses in terms of a set of unknown coefficients for the specified displacement expressions satisfying the prescribed boundary conditions. The assumed Coulomb friction between the plate and the pin was used to provide the solution and iteration was also used to determine the extent of contact region. The results from present study showed good agreement with the available results in literature for all the joint configurations evaluated.展开更多
Dual actions with respect to U(1) gauge fields for the Born-Infeld and Dp-brane theories are reexamined.Taking into account an additional condition,i.e.a corollary to the field equation of the auxiliary metric,one obt...Dual actions with respect to U(1) gauge fields for the Born-Infeld and Dp-brane theories are reexamined.Taking into account an additional condition,i.e.a corollary to the field equation of the auxiliary metric,one obtainsan alternative dual action that does not involve the infinite series in the auxiliary metric given by [M.Abou Zeid andC.M.Hull,Phys.Lett.B 428 (1998) 277],but just picks out the first term from the series formally.New effectiveinteractions of the theories are revealed.That is,the new dual action gives rise to an effective interaction in terms ofone interaction term rather than infinitely many terms of different (higher) orders of interactions physically.However,the price paid for eliminating the infinite series is that the new action is not quadratic but highly nonlinear in the Hodgedual of a (p-1)-form field strength.This non-linearity is inevitable under the requirement that the two dual actionsare equivalent.展开更多
This study presents the determination of the stress intensity factors （SIFs） at the edges of the cracks in an elastic strip weakened by N-collinear cracks. The problem of an orthotropic elastic strip is reduced to a...This study presents the determination of the stress intensity factors （SIFs） at the edges of the cracks in an elastic strip weakened by N-collinear cracks. The problem of an orthotropic elastic strip is reduced to a system of Cauchy type singular integral equations. The system of singular integral equations is approached by a Quadrature technique. Under two different loading conditions, the results are obtained for the different cases of crack numbers. The resistance of the strip is examined by considering the orthotropic properties of the strip material. Finally, the crack interactions are clarified during the analysis.展开更多
基金The authors are supported by the National Natural Science Foundation of China[grant numbers 41575064,41875079,and 41775079]the Open Research Program of the State Key Laboratory of Severe Weather,Chinese Academy of Meteorological Sciences[grant number 2019LASW-A04].
文摘For Super Typhoon Maria(2018),the multi-intensity change stages are identified and reproduced by numerical simulation.It is rather difficult to perform a perfect simulation for such a repeatedly reinforced typhoon during its long life-cycle and remote path.In this study,the rapid intensification(RI)episode is focused on to investigate the convective burst(CB)characteristics and the relationship between the CBs and the RI of Maria.For Typhoon Maria,1)the spatial pattern of the inner-core CBs in distinct shear-relative quadrants,instead of the overall inner-core CBs frequently used in previous studies,presents cyclonic rotation from downshear to upshear quadrants during RI,producing a higher efficiency for tropical cyclone(TC)spinup,which accelerates the RI process.2)Dual meanings/relationships exist between CBs and RI for Maria,in contrast to the previous argument that CBs might be an indicator or a precursor to RI.The sudden growth of CBs prior to RI provides a precursor for the upcoming RI.Additionally,the appearance of the CB peak soon after RI indicates RI could lead to more intensive deep convections.The overlap of CBs with high inertial stability inside the radius of maximum wind plays a significant role in the RI of TCs.3)The synoptic attributions to CBs are also explored for the entire troposphere,fitting in the bottom-up thinking of convection growth.The CBs might be associated with high convective available potential energy in the boundary layer,a strengthening of the deep-layer secondary circulation,and an enhanced upper-level eddy momentum flux convergence.
文摘The development of an analytic solution in terms of laminate parameters is presented for contact stresses and joint strength in pin-loaded orthotropic plates. This involved the determination of complex stress functions required to compute stresses in terms of a set of unknown coefficients for the specified displacement expressions satisfying the prescribed boundary conditions. The assumed Coulomb friction between the plate and the pin was used to provide the solution and iteration was also used to determine the extent of contact region. The results from present study showed good agreement with the available results in literature for all the joint configurations evaluated.
基金Supported by the National Natural Science Foundation of China under Grant No.10675061the Doctoral Foundation of the Ministry of Education of China under Grant No.20060055006
文摘Dual actions with respect to U(1) gauge fields for the Born-Infeld and Dp-brane theories are reexamined.Taking into account an additional condition,i.e.a corollary to the field equation of the auxiliary metric,one obtainsan alternative dual action that does not involve the infinite series in the auxiliary metric given by [M.Abou Zeid andC.M.Hull,Phys.Lett.B 428 (1998) 277],but just picks out the first term from the series formally.New effectiveinteractions of the theories are revealed.That is,the new dual action gives rise to an effective interaction in terms ofone interaction term rather than infinitely many terms of different (higher) orders of interactions physically.However,the price paid for eliminating the infinite series is that the new action is not quadratic but highly nonlinear in the Hodgedual of a (p-1)-form field strength.This non-linearity is inevitable under the requirement that the two dual actionsare equivalent.
文摘This study presents the determination of the stress intensity factors （SIFs） at the edges of the cracks in an elastic strip weakened by N-collinear cracks. The problem of an orthotropic elastic strip is reduced to a system of Cauchy type singular integral equations. The system of singular integral equations is approached by a Quadrature technique. Under two different loading conditions, the results are obtained for the different cases of crack numbers. The resistance of the strip is examined by considering the orthotropic properties of the strip material. Finally, the crack interactions are clarified during the analysis.
