The usual (1+1)-dimensional Schwartz Boussinesq equation is extended to the (1+1)-dimensional space-time symmetric form and the general (n+1)-dimensional space-time symmetric form. These extensions are Painle...The usual (1+1)-dimensional Schwartz Boussinesq equation is extended to the (1+1)-dimensional space-time symmetric form and the general (n+1)-dimensional space-time symmetric form. These extensions are Painleve integrable in the sense that they possess the Painleve property. The single soliton solutions and the periodic travelling wave solutions for arbitrary dimensional space-time symmetric form are obtained by the Painleve-Backlund transformation.展开更多
<div style="text-align:justify;"> Transceiver module and two-dimensional sum difference network are important components of phased array antenna. In this paper, multilayer printed board is used to inte...<div style="text-align:justify;"> Transceiver module and two-dimensional sum difference network are important components of phased array antenna. In this paper, multilayer printed board is used to integrate millimeter wave multi-channel transceiver circuit and sum difference network. The interconnection between them is realized through RF coaxial vertical transition. At the same time, the heat dissipation design and inter channel shielding design of the module are carried out. The RF and low frequency required by the module are completed through the wiring between and within the dielectric plate layers. Finally, 128 arrays are fabricated and verified by multi-channel passive test. The results show that the type transceiver module integrating with two-dimensional sum difference network has good performance, and 128 channels have excellent amplitude and phase characteristics. The integration technology has the characteristics of lightweight, miniaturization, high integration and low manufacturing cost. It can be widely used in miniaturized phased array antennas. </div>展开更多
The possible high dimensional integrable models are studied in three different aspects: (i) starting from a strong symmetry operator of a known (1+1 )-dimensional integrable model,we can construct a type of (n+1)-dime...The possible high dimensional integrable models are studied in three different aspects: (i) starting from a strong symmetry operator of a known (1+1 )-dimensional integrable model,we can construct a type of (n+1)-dimensional integrable models,high dimensional breaking soliton equations; (ii)from every concrete realization of the generalized Virasoro algebra,we can get many high dimensional integrable models in the meaning that the models possess generalized Virasoro symmetry algebra; (iii)starting from the Schwartz equations which possess confor-mal invariance,we can also get various high dimensional integrable models in the meaning that they possess Painleve property. t展开更多
针对航行船舶三维时域水动力分析问题,本文采用多域高阶边界元法(MDHOBEM, Multi-Domain Higher Order Boundary Element Method)开展研究,通过假设控制面,将计算域分为内域和外域两部分,内域采用Rankine面元法,外域使用自由面格林函数...针对航行船舶三维时域水动力分析问题,本文采用多域高阶边界元法(MDHOBEM, Multi-Domain Higher Order Boundary Element Method)开展研究,通过假设控制面,将计算域分为内域和外域两部分,内域采用Rankine面元法,外域使用自由面格林函数法,内外域联立求解。从内域、外域、波浪激励三个层面改进多域法的精度、计算效率,以适应不同工况需求。内域重新推导非线性边界条件,考虑入射波对绕辐射问题计算的影响,提高大幅波浪中运动计算精度;外域采用垂向积分形式自由面格林函数,提高格林函数积分计算的收敛性、稳定性及计算效率;波浪激励采用高阶谱(HOS, High Order Spectral)方法生成演化的波场,考虑波浪自身的非线性,提高对非线性现象的捕捉和模拟能力。以C11船为对象,研究内域非线性改进对船舶大幅运动计算精度的提高;以S175集装箱船为对象,验证外域垂向积分对运动及波阻增加计算效率和稳定性的提高;对比S175在线性波场和非线性波场中的运动,论证考虑非线性波场对运动计算的影响;以某内倾船为对象,研究不同层次改进对参数横摇现象捕捉的影响,验证非线性波浪激励对多域法非线性现象捕捉能力的提升;整体上形成不同层面改进多域法,为不同工况下时域水动力分析提供理论和程序支撑。展开更多
基金supported by the National Natural Science Foundation of China (Grant No 10575087)the Natural Science Foundation of Zhejiang Province,China (Grant No 102053)
文摘The usual (1+1)-dimensional Schwartz Boussinesq equation is extended to the (1+1)-dimensional space-time symmetric form and the general (n+1)-dimensional space-time symmetric form. These extensions are Painleve integrable in the sense that they possess the Painleve property. The single soliton solutions and the periodic travelling wave solutions for arbitrary dimensional space-time symmetric form are obtained by the Painleve-Backlund transformation.
文摘<div style="text-align:justify;"> Transceiver module and two-dimensional sum difference network are important components of phased array antenna. In this paper, multilayer printed board is used to integrate millimeter wave multi-channel transceiver circuit and sum difference network. The interconnection between them is realized through RF coaxial vertical transition. At the same time, the heat dissipation design and inter channel shielding design of the module are carried out. The RF and low frequency required by the module are completed through the wiring between and within the dielectric plate layers. Finally, 128 arrays are fabricated and verified by multi-channel passive test. The results show that the type transceiver module integrating with two-dimensional sum difference network has good performance, and 128 channels have excellent amplitude and phase characteristics. The integration technology has the characteristics of lightweight, miniaturization, high integration and low manufacturing cost. It can be widely used in miniaturized phased array antennas. </div>
基金Project supported by the National Natural Science Foundation of China and the Natural Science Foundation of Zhejiang Province.
文摘The possible high dimensional integrable models are studied in three different aspects: (i) starting from a strong symmetry operator of a known (1+1 )-dimensional integrable model,we can construct a type of (n+1)-dimensional integrable models,high dimensional breaking soliton equations; (ii)from every concrete realization of the generalized Virasoro algebra,we can get many high dimensional integrable models in the meaning that the models possess generalized Virasoro symmetry algebra; (iii)starting from the Schwartz equations which possess confor-mal invariance,we can also get various high dimensional integrable models in the meaning that they possess Painleve property. t
文摘针对航行船舶三维时域水动力分析问题,本文采用多域高阶边界元法(MDHOBEM, Multi-Domain Higher Order Boundary Element Method)开展研究,通过假设控制面,将计算域分为内域和外域两部分,内域采用Rankine面元法,外域使用自由面格林函数法,内外域联立求解。从内域、外域、波浪激励三个层面改进多域法的精度、计算效率,以适应不同工况需求。内域重新推导非线性边界条件,考虑入射波对绕辐射问题计算的影响,提高大幅波浪中运动计算精度;外域采用垂向积分形式自由面格林函数,提高格林函数积分计算的收敛性、稳定性及计算效率;波浪激励采用高阶谱(HOS, High Order Spectral)方法生成演化的波场,考虑波浪自身的非线性,提高对非线性现象的捕捉和模拟能力。以C11船为对象,研究内域非线性改进对船舶大幅运动计算精度的提高;以S175集装箱船为对象,验证外域垂向积分对运动及波阻增加计算效率和稳定性的提高;对比S175在线性波场和非线性波场中的运动,论证考虑非线性波场对运动计算的影响;以某内倾船为对象,研究不同层次改进对参数横摇现象捕捉的影响,验证非线性波浪激励对多域法非线性现象捕捉能力的提升;整体上形成不同层面改进多域法,为不同工况下时域水动力分析提供理论和程序支撑。