The transmission upper limit of a double-layer frequency selective surface （FSS） with two infinitely thin metal arrays is pre- sented based on the study of the general equivalent transmission line model of a double-...The transmission upper limit of a double-layer frequency selective surface （FSS） with two infinitely thin metal arrays is pre- sented based on the study of the general equivalent transmission line model of a double-layer FSS. Results of theoretical analyses, numerical simulations and experiments show that this transmis- sion upper limit is independent of the array and the element, which indicates that it is impossible to achieve a transmission upper limit higher than this one under a given incident and dielectric- supporting condition by the design of the periodic array. Both the applicable condition and the possible application of the transmis- sion upper limit are discussed. The results show that the transmis- sion upper limit not only has a good reachability, but also provides a key to effectively improve the transmission performance of a double-layer FSS or more complex frequency selective structures.展开更多
The paper proposes a decentralized concurrent transmission strategy in shared channels based on an incomplete information game in Ad Hoc networks.Based on the nodal channel quality,the game can work out a channel gain...The paper proposes a decentralized concurrent transmission strategy in shared channels based on an incomplete information game in Ad Hoc networks.Based on the nodal channel quality,the game can work out a channel gain threshold,which decides the candidates for taking part in the concurrent transmission.The utility formula is made for maximizing the overall throughput based on channel quality variation.For an achievable Bayesian Nash equilibrium（BNE） solution,this paper further prices the selfish players in utility functions for attempting to improve the channel gain one-sidedly.Accordingly,this game allows each node to distributedly decide whether to transmit concurrently with others depending on the Nash equilibrium（NE）.Besides,to make the proposed game practical,this paper next presents an efficient particle swarm optimization（PSO） model to fasten the otherwise very slow convergence procedure due to the large computational complexity.Numerical results show the proposed approach is feasible to increase concurrent transmission opportunities for active nodes and the convergence can be swiftly obtained with a few of iteration times by the proposed PSO algorithm.展开更多
The problem was found that the nucleation and growth of diamond are different on each side of flaky catalyst in the cubic high pressure diamond synthesis system. Some theories explainning this difference were introduc...The problem was found that the nucleation and growth of diamond are different on each side of flaky catalyst in the cubic high pressure diamond synthesis system. Some theories explainning this difference were introduced in the paper. The synthesis cavity and the forces on flaky ctalyst were analysed. The results show that the stress makes the transmission velocity of carbon different on each side of catalyst slice, which causes the difference of nucleation density of diamond between two sides of the slice.展开更多
文摘The transmission upper limit of a double-layer frequency selective surface （FSS） with two infinitely thin metal arrays is pre- sented based on the study of the general equivalent transmission line model of a double-layer FSS. Results of theoretical analyses, numerical simulations and experiments show that this transmis- sion upper limit is independent of the array and the element, which indicates that it is impossible to achieve a transmission upper limit higher than this one under a given incident and dielectric- supporting condition by the design of the periodic array. Both the applicable condition and the possible application of the transmis- sion upper limit are discussed. The results show that the transmis- sion upper limit not only has a good reachability, but also provides a key to effectively improve the transmission performance of a double-layer FSS or more complex frequency selective structures.
基金supported by the National Natural Science Foundation of China (6120113361172055+6 种基金60832005U083500461072067)the Postdoctoral Science Foundation of China (20100481323)the Program for New Century Excellent Talents (NCET-11-0691)the "111 Project"of China (B08038)the Foundation of Guangxi Key Lab of Wireless Wideband Communication & Signal Processing (11105)
文摘The paper proposes a decentralized concurrent transmission strategy in shared channels based on an incomplete information game in Ad Hoc networks.Based on the nodal channel quality,the game can work out a channel gain threshold,which decides the candidates for taking part in the concurrent transmission.The utility formula is made for maximizing the overall throughput based on channel quality variation.For an achievable Bayesian Nash equilibrium（BNE） solution,this paper further prices the selfish players in utility functions for attempting to improve the channel gain one-sidedly.Accordingly,this game allows each node to distributedly decide whether to transmit concurrently with others depending on the Nash equilibrium（NE）.Besides,to make the proposed game practical,this paper next presents an efficient particle swarm optimization（PSO） model to fasten the otherwise very slow convergence procedure due to the large computational complexity.Numerical results show the proposed approach is feasible to increase concurrent transmission opportunities for active nodes and the convergence can be swiftly obtained with a few of iteration times by the proposed PSO algorithm.
文摘The problem was found that the nucleation and growth of diamond are different on each side of flaky catalyst in the cubic high pressure diamond synthesis system. Some theories explainning this difference were introduced in the paper. The synthesis cavity and the forces on flaky ctalyst were analysed. The results show that the stress makes the transmission velocity of carbon different on each side of catalyst slice, which causes the difference of nucleation density of diamond between two sides of the slice.
