In this paper,we establish a Rosenthal-type inequality of partial sums for ρ~mixing random variables.As its applications,we get the complete convergence rates in the strong laws for ρ^-mixing random variables.The re...In this paper,we establish a Rosenthal-type inequality of partial sums for ρ~mixing random variables.As its applications,we get the complete convergence rates in the strong laws for ρ^-mixing random variables.The result obtained extends the corresponding result.展开更多
The photodetachment of a negative molecular ion is studied theoretically using a two-center model. The detached electron wave function is obtained as a superposition of two coherent waves originating from each center....The photodetachment of a negative molecular ion is studied theoretically using a two-center model. The detached electron wave function is obtained as a superposition of two coherent waves originating from each center. The photo-detached electron flux is evaluated on a screen placed at a large distance from the negative molecular ion. The electron flux on the screen displays strong interferences, the peak positions are related to the distance between the two centers in the negative molecular ion. We a/so obtained a simple analytical formula for the total photodetachment cross section. It approaches one and two times of the cross section for the one-center system in the high and lowphoton energy limits respectively.展开更多
We investigate entanglement transfer from two separate cavities to the excitons in two quantum dots separately placed in the two cavities. The cavity fields and the excitons are treated as two continuous-variable （CV...We investigate entanglement transfer from two separate cavities to the excitons in two quantum dots separately placed in the two cavities. The cavity fields and the excitons are treated as two continuous-variable （CV） subsystems. The time-dependent characteristic functions in the Wigner representation for the two subsystems are analytically obtained. Under the conditions that one of the two CV subsystems is initially prepared in a two-mode squeezed vacuum state and the other in its lowest energy state, we show that the entanglement reciprocation between the cavity fields and the excitons is realizable.展开更多
Although quantum field theory allows the local energy density negative, it also places severe restrictions on the negative energy. One of the restrictions is the quantum energy inequality （QEI）, in which the energy ...Although quantum field theory allows the local energy density negative, it also places severe restrictions on the negative energy. One of the restrictions is the quantum energy inequality （QEI）, in which the energy density is averaged over time, or space, or over space and time. By now temporal QEIs have been established for various quantum fields, but less work has been done for the spacetime quantum energy inequality. In this paper we deal with the free Rarita-Schwinger field and present a quantum inequality bound on the energy density averaged over space and time. Comparison with the QEI for the Rarita-Schwinger field shows that the lower bound is the same with the QEI. At the same time, we find the quantum inequality for the Rarita-Schwinger field is weaker than those for the scalar and Dirac fields. This fact gives further support to the conjecture that the more freedom the field has, the more easily the field displays negative energy density and the weaker the quantum inequality becomes.展开更多
Utilizing primary documents available at the George Bush Presidential Library, this study evaluates the veto record of President Bush using a case study as well as quantitative methods. The case study reviews the back...Utilizing primary documents available at the George Bush Presidential Library, this study evaluates the veto record of President Bush using a case study as well as quantitative methods. The case study reviews the background and fate of the only veto overridden during his term in office. It finds that the Bush White House had tried on several previous occasions to scrap the legislation, only to have it be reintroduced in each succeeding Congress. By 1992, when George Bush was running for reelection and in trouble politically, his team was unable to stave off defeat. The article likewise assesses the success of the Bush administration in its employment of the veto and compares the veto record of President Bush to previous and subsequent chief executives.展开更多
A cylindrical negative Poisson's ratio(CNPR) structure based on two-dimensional double-arrow negative Poisson's ratio(NPR)structure was introduced in this paper. The CNPR structure has excellent stiffness, dam...A cylindrical negative Poisson's ratio(CNPR) structure based on two-dimensional double-arrow negative Poisson's ratio(NPR)structure was introduced in this paper. The CNPR structure has excellent stiffness, damping and energy absorption performances,and can be applied as spring, damper and energy absorbing components. In this study, the CNPR structure was used as a jounce bumper in vehicle suspension, and the load-displacement curve of NPR jounce bumper was discussed. Moreover, the influences of structural parameters and materials on the load-displacement curve of NPR jounce bumper were specifically researched. It came to the conclusion that only the numbers of cells and layers impact the hardening displacement of NPR jounce bumper. And all parameters significantly affect the structure stiffness at different displacement periods. On the other hand, the load-displacement curve of NPR jounce bumper should be in an ideal region which is difficult to be achieved applying mathematical optimization method. Therefore, a parametric design strategy of NPR jounce bumper was proposed according to the parametric analysis results. The design strategy had two main steps: design of hardening displacement and design of stiffness. The analysis results proved that the proposed method is reliable and is also meaningful for relevant structure design problem.展开更多
基金Supported by the National Science Foundation（10661006） Supported by Innovation Project of Guangxi Graduate Education（2007105960812M18）
文摘In this paper,we establish a Rosenthal-type inequality of partial sums for ρ~mixing random variables.As its applications,we get the complete convergence rates in the strong laws for ρ^-mixing random variables.The result obtained extends the corresponding result.
基金The project supported by National Natural Science Foundation of China under Grant No. 90403028
文摘The photodetachment of a negative molecular ion is studied theoretically using a two-center model. The detached electron wave function is obtained as a superposition of two coherent waves originating from each center. The photo-detached electron flux is evaluated on a screen placed at a large distance from the negative molecular ion. The electron flux on the screen displays strong interferences, the peak positions are related to the distance between the two centers in the negative molecular ion. We a/so obtained a simple analytical formula for the total photodetachment cross section. It approaches one and two times of the cross section for the one-center system in the high and lowphoton energy limits respectively.
基金The project supported by National Natural Science Foundation of China under Grant Nos. 10374007 and 60472021
文摘We investigate entanglement transfer from two separate cavities to the excitons in two quantum dots separately placed in the two cavities. The cavity fields and the excitons are treated as two continuous-variable （CV） subsystems. The time-dependent characteristic functions in the Wigner representation for the two subsystems are analytically obtained. Under the conditions that one of the two CV subsystems is initially prepared in a two-mode squeezed vacuum state and the other in its lowest energy state, we show that the entanglement reciprocation between the cavity fields and the excitons is realizable.
基金The project supported by National Natural Science Foundation of China under Grant Nos. 10375023 and 10125521, the Program for New Century Excellent Talents under Grant No. 04-0784, the Key Project of the Ministry of Education under Grant No. 205110, and the 973 State Key Basic Research and Development Program of China under Grant No. G2000077400
文摘Although quantum field theory allows the local energy density negative, it also places severe restrictions on the negative energy. One of the restrictions is the quantum energy inequality （QEI）, in which the energy density is averaged over time, or space, or over space and time. By now temporal QEIs have been established for various quantum fields, but less work has been done for the spacetime quantum energy inequality. In this paper we deal with the free Rarita-Schwinger field and present a quantum inequality bound on the energy density averaged over space and time. Comparison with the QEI for the Rarita-Schwinger field shows that the lower bound is the same with the QEI. At the same time, we find the quantum inequality for the Rarita-Schwinger field is weaker than those for the scalar and Dirac fields. This fact gives further support to the conjecture that the more freedom the field has, the more easily the field displays negative energy density and the weaker the quantum inequality becomes.
文摘Utilizing primary documents available at the George Bush Presidential Library, this study evaluates the veto record of President Bush using a case study as well as quantitative methods. The case study reviews the background and fate of the only veto overridden during his term in office. It finds that the Bush White House had tried on several previous occasions to scrap the legislation, only to have it be reintroduced in each succeeding Congress. By 1992, when George Bush was running for reelection and in trouble politically, his team was unable to stave off defeat. The article likewise assesses the success of the Bush administration in its employment of the veto and compares the veto record of President Bush to previous and subsequent chief executives.
基金supported by the Natural Science Foundation of Jiangsu Province(Grant No.BK20170784)Aeronautical Science Foundation of China(Granted No.2016ZA52003)
文摘A cylindrical negative Poisson's ratio(CNPR) structure based on two-dimensional double-arrow negative Poisson's ratio(NPR)structure was introduced in this paper. The CNPR structure has excellent stiffness, damping and energy absorption performances,and can be applied as spring, damper and energy absorbing components. In this study, the CNPR structure was used as a jounce bumper in vehicle suspension, and the load-displacement curve of NPR jounce bumper was discussed. Moreover, the influences of structural parameters and materials on the load-displacement curve of NPR jounce bumper were specifically researched. It came to the conclusion that only the numbers of cells and layers impact the hardening displacement of NPR jounce bumper. And all parameters significantly affect the structure stiffness at different displacement periods. On the other hand, the load-displacement curve of NPR jounce bumper should be in an ideal region which is difficult to be achieved applying mathematical optimization method. Therefore, a parametric design strategy of NPR jounce bumper was proposed according to the parametric analysis results. The design strategy had two main steps: design of hardening displacement and design of stiffness. The analysis results proved that the proposed method is reliable and is also meaningful for relevant structure design problem.
