The effect of rotation on the shape (figure) and gravitational quadrupole of astronomical bodies is calculated by using an approximate point core model: A point mass at the center of an ellipsoidal homogeneous fluid. ...The effect of rotation on the shape (figure) and gravitational quadrupole of astronomical bodies is calculated by using an approximate point core model: A point mass at the center of an ellipsoidal homogeneous fluid. Maclaurin’s analytical result for homogenous bodies generalizes to this model and leads to very accurate analytical results connecting the three observables: oblateness (ò), gravitational quadrupole (J2), and angular velocity parameter (q). The analytical results are compared to observational data for the planets and a good agreement is found. Oscillations near equilibrium are studied within the model.展开更多
Check Point软件技术有限公司全新的VPN-1 Power Multi—core已经面市。该方案采用了Check Point在2006年5月推出、正在申请专利的CoreXL加速技术，能在安全及性能表现方面取得平衡，确保用户在取得最高水平的整合应用安全保护的同时，...Check Point软件技术有限公司全新的VPN-1 Power Multi—core已经面市。该方案采用了Check Point在2006年5月推出、正在申请专利的CoreXL加速技术，能在安全及性能表现方面取得平衡，确保用户在取得最高水平的整合应用安全保护的同时，不会影响网络的数据传输流畅度而影响最终用户的互联网使用体验。展开更多
Sensing coverage is a fundamental design issue in wireless sensor networks(WSNs),while sensor scheduling ensures coverage degree to the monitored event and extends the network lifetime.In this paper,we address k-cover...Sensing coverage is a fundamental design issue in wireless sensor networks(WSNs),while sensor scheduling ensures coverage degree to the monitored event and extends the network lifetime.In this paper,we address k-coverage scheduling problem in dense WSNs,we maintain a connected k-coverage energy efficiently through a novel Hard-Core based Coordinated Scheduling(HCCS),in which hardcore is a thinning process in stochastic geometry that inhibits more than one active sensor covering any area redundantly in a minimum distance. As compared with existing coordinated scheduling,HCCS allows coordination between sensors with little communication overhead.Moreover,due to the traditional sensing models in k-coverage analysis is unsuitable to describe the characteristic of transmit channel in dense WSNs,we propose a novel sensing model integrating Rayleigh Fading and Distribution of Active sensors(RFDA),and derive the coverage measure and k-coverage probability for the monitored event under RFDA. In addition,we analyze the influence factors,i.e. the transmit condition and monitoring degree to the k-coverage probability. Finally,through Monte Carlo simulations,it is shown that the k-coverage probability of HCCS outperforms that of its random scheduling counterpart.展开更多
Based on the covariant density functional theory,by employing the core–quasiparticle coupling(CQC)model,the nuclear level density of odd-A nuclei at the saddle point is achieved.The total level density is calculated ...Based on the covariant density functional theory,by employing the core–quasiparticle coupling(CQC)model,the nuclear level density of odd-A nuclei at the saddle point is achieved.The total level density is calculated via the convolution of the intrinsic level density and the collective level density.The intrinsic level densities are obtained in the finite-temperature covariant density functional theory,which takes into account the nuclear deformation and pairing self-consistently.For saddle points on the free energy surface in the(β_(2),γ)plane,the entropy and the associated intrinsic level density are compared with those of the global minima.By introducing a quasiparticle to the two neighboring even–even core nuclei,whose properties are determined by the five-dimensional collective Hamiltonian model,the collective levels of the odd-A nuclei are obtained via the CQC model.The total level densities of the^(234-240)U agree well with the available experimental data and Hilaire’s result.Furthermore,the ratio of the total level densities at the saddle points to those at the global minima and the ratio of the total level densities to the intrinsic level densities are discussed separately.展开更多
Using embedded atom method and molecular static relaxation method, the core structure of <100>, <110> edge dislocations, <100> screw dislocation, the interaction between point defects and <100>...Using embedded atom method and molecular static relaxation method, the core structure of <100>, <110> edge dislocations, <100> screw dislocation, the interaction between point defects and <100> edge dislocation in NiAl intermetallics were investigated. The results show that <100>edge dislocation expands along and orientation on the (001) slip plane. The core structure of <100> edge dislocation on (001) plane is like a 'butterfly', while it is very compact when it lies on {110} slip plane. So NiAl will have a <100>{110} slip system in stead of <100>{100} slip system, as experiments showed. <110> edge dislocation has a more expanded core structure and the atoms of dislocation core distort more heavily. None dislocation dissociation was found in the studied dislocations. The outlines of dislocation core structures change very little after a row of point defects are introduced in them, which can be explained by point defects' little effects on the stress field around dislocation core. The results also show that it is hard to change dislocation core structure by decreasing alloy order using the method of introducing limited point defects into the alloy.展开更多
文摘The effect of rotation on the shape (figure) and gravitational quadrupole of astronomical bodies is calculated by using an approximate point core model: A point mass at the center of an ellipsoidal homogeneous fluid. Maclaurin’s analytical result for homogenous bodies generalizes to this model and leads to very accurate analytical results connecting the three observables: oblateness (ò), gravitational quadrupole (J2), and angular velocity parameter (q). The analytical results are compared to observational data for the planets and a good agreement is found. Oscillations near equilibrium are studied within the model.
文摘Check Point软件技术有限公司全新的VPN-1 Power Multi—core已经面市。该方案采用了Check Point在2006年5月推出、正在申请专利的CoreXL加速技术，能在安全及性能表现方面取得平衡，确保用户在取得最高水平的整合应用安全保护的同时，不会影响网络的数据传输流畅度而影响最终用户的互联网使用体验。
基金supported by the National Science Foundation of China under Grant 61271186
文摘Sensing coverage is a fundamental design issue in wireless sensor networks(WSNs),while sensor scheduling ensures coverage degree to the monitored event and extends the network lifetime.In this paper,we address k-coverage scheduling problem in dense WSNs,we maintain a connected k-coverage energy efficiently through a novel Hard-Core based Coordinated Scheduling(HCCS),in which hardcore is a thinning process in stochastic geometry that inhibits more than one active sensor covering any area redundantly in a minimum distance. As compared with existing coordinated scheduling,HCCS allows coordination between sensors with little communication overhead.Moreover,due to the traditional sensing models in k-coverage analysis is unsuitable to describe the characteristic of transmit channel in dense WSNs,we propose a novel sensing model integrating Rayleigh Fading and Distribution of Active sensors(RFDA),and derive the coverage measure and k-coverage probability for the monitored event under RFDA. In addition,we analyze the influence factors,i.e. the transmit condition and monitoring degree to the k-coverage probability. Finally,through Monte Carlo simulations,it is shown that the k-coverage probability of HCCS outperforms that of its random scheduling counterpart.
基金supported by the China Institute of Atomic Energy(No.401Y-FW-GKXJ-21-1496)the Natural Science Foundation of Henan Province(No.202300410480 and 202300410479)+1 种基金the Open Project of Guangxi Key Laboratory of Nuclear Physics and Nuclear Technology(No.NLK2021-01)the National Natural Science Foundation of China(No.U2032141).
文摘Based on the covariant density functional theory,by employing the core–quasiparticle coupling(CQC)model,the nuclear level density of odd-A nuclei at the saddle point is achieved.The total level density is calculated via the convolution of the intrinsic level density and the collective level density.The intrinsic level densities are obtained in the finite-temperature covariant density functional theory,which takes into account the nuclear deformation and pairing self-consistently.For saddle points on the free energy surface in the(β_(2),γ)plane,the entropy and the associated intrinsic level density are compared with those of the global minima.By introducing a quasiparticle to the two neighboring even–even core nuclei,whose properties are determined by the five-dimensional collective Hamiltonian model,the collective levels of the odd-A nuclei are obtained via the CQC model.The total level densities of the^(234-240)U agree well with the available experimental data and Hilaire’s result.Furthermore,the ratio of the total level densities at the saddle points to those at the global minima and the ratio of the total level densities to the intrinsic level densities are discussed separately.
文摘Using embedded atom method and molecular static relaxation method, the core structure of <100>, <110> edge dislocations, <100> screw dislocation, the interaction between point defects and <100> edge dislocation in NiAl intermetallics were investigated. The results show that <100>edge dislocation expands along and orientation on the (001) slip plane. The core structure of <100> edge dislocation on (001) plane is like a 'butterfly', while it is very compact when it lies on {110} slip plane. So NiAl will have a <100>{110} slip system in stead of <100>{100} slip system, as experiments showed. <110> edge dislocation has a more expanded core structure and the atoms of dislocation core distort more heavily. None dislocation dissociation was found in the studied dislocations. The outlines of dislocation core structures change very little after a row of point defects are introduced in them, which can be explained by point defects' little effects on the stress field around dislocation core. The results also show that it is hard to change dislocation core structure by decreasing alloy order using the method of introducing limited point defects into the alloy.
