O+DC1→OD+Cl反应在~3 A″势能面上的动力学研究(英文)

在~3A″势能面上,在散射能为14～20 kcal/mol的范围内,运用准经典轨线方法对O+DCl→OD+Cl进行了动力学研究.我们发现积分散射截面随着散射能的增加而增大,产物OD的振动分布发生了很强的粒子数的反转现象,且振动激发较弱、转动激发较强.后向散射居于主导地位,碰撞能的变化对产物转动取向的影响不大.     

Allometric scaling of countries

As huge complex systems consisting of geographic regions, natural resources, people and economic entities, countries follow the allometric scaling law which is ubiquitous in ecological, and urban systems. We systematically investigated the allometric scaling relationships between a large number of macroscopic properties and geographic (area), demographic (population) and economic (GDP, gross domestic production) sizes of countries respectively. We found that most of the economic, trade, energy consumption, communication related properties have significant super-linear (the exponent is larger than 1) or nearly linear allometric scaling relations with the GDP. Meanwhile, the geographic (arable area, natural resources, etc.), demographic (labor force, military age population, etc.) and transportation-related properties (road length, airports) have significant and sub-linear (the exponent is smaller than 1) allometric scaling relations with area. Several differences of power law relations with respect to the population between countries and cities were pointed out. First, population increases sub-linearly with area in countries. Second, the GDP increases linearly in countries but not super-linearly as in cities. Finally, electricity or oil consumption per capita increases with population faster than cities.     

金属和Kerr非线性介质界面上表面等离子体激元的色散关系

从麦克斯韦方程组出发,结合边界条件,分别得到TM波和TE波在金属和Kerr非线性介质界面上表面等离子体激元的色散关系.由于非线性的存在,TM波的色散关系变得复杂,与光强、非线性系数有关.和线性情况一样,此界面不存在TE波.     

介质加载折叠波导行波管的线性分析

提出了一种介质加载折叠波导慢波结构,给出了该结构中存在电子注时慢波互作用的热色散方程,在介电常数ε_r=1的特殊情况下该方程即简化为普通折叠波导的小信号工作方程.在给定慢波结构尺寸的基础上,分析比较了介质加载对放大器小信号增益特性的影响,结果表明:"弱加载"(介质厚度d/a<0.1)时,无需重新设计慢波结构的参数,只需适当调整工作电压和电流就可以满足原有设计要求,而且和未加载时相比增益特性更为平坦,降低的电子注阻抗也有利于电子效率的提高.考虑到 关键词： 折叠波导 行波管放大器 介质加载 热色散方程     

X波段重复频率GW级超辐射相对论返波管

运用超辐射机理,通过粒子模拟设计了X波段超辐射相对论返波管,并在小型Tesla脉冲源平台上开展了实验研究。通过空间功率积分和直接对辐射微波时域波形的分析得到实验结果:在束压350 kV、束流4.8 kA、脉宽3.1 ns、引导磁场2.2 T条件下,产生的微波辐射功率1.4 GW,中心频率9.36 GHz,脉宽500~700 ps,辐射模式为TE11,能在重复频率100 Hz下稳定运行。功率转换效率超过80%。实验结果与粒子模拟结果比较吻合,成功实现了在短脉冲条件下产生重复频率、亚纳秒脉宽、GW级微波辐射。     

X波段相对论返波管谐振反射器

基于TPG2000强流电子束加速器和带谐振反射器的相对论返波管振荡器,开展了X波段高功率微波产生实验研究,获得了功率约2.5 GW,脉宽约20 ns的微波输出。理论分析及模拟了不同倒角大小对谐振反射器的表面电场及截止性能的影响,并对不同倒角开展了实验研究。结果表明,对谐振反射器倒角可增加输出微波脉冲宽度,且随着倒角增加,微波脉宽增加,效率略有降低。在谐振反射器倒角5 mm情况下,利用电压900 kV,电流9 kA的强流电子束,实验获得了功率约2.5 GW、脉宽大于25 ns的微波输出。     

Einstein relation in n-i-p-i and microstructures of nonlinear optical, optoelectronic and related materials: Simplified theory, relative comparison and suggestions for an experimental determination

We investigate the Einstein relation for the diffusivity-mobility ratio (DMR) for n-i-p-i and the microstructures of nonlinear optical compounds on the basis of a newly formulated electron dispersion law. The corresponding results for III-V, ternary and quaternary materials form a special case of our generalized analysis. The respective DMRs for II-VI, IV-VI and stressed materials have been studied. It has been found that taking CdGeAs₂, Cd₃As₂, InAs, InSb, Hg_1−xCd_xTe, In_1−xGa_xAs_yP_1−y lattices matched to InP, CdS, PbTe, PbSnTe and Pb_1−xSn_xSe and stressed InSb as examples that the DMR increases with increasing electron concentration in various manners with different numerical magnitudes which reflect the different signatures of the n-i-p-i systems and the corresponding microstructures. We have suggested an experimental method of determining the DMR in this case and the present simplified analysis is in agreement with the suggested relationship. In addition, our results find three applications in the field of quantum effect devices.     

无氧铜等熵卸载路径的实验研究

 采用化爆加载,以黄铜为飞片、无氧铜为靶板,测量了以抗氢钢（HR2）、重玻璃（SiO₂）、铝合金（LY12/LF6）、镁铝合金（MB2）、有机玻璃（PMMA）和空气（Air）为垫块（Anvil）材料中的冲击波速度（上述材料的Hugoniot状态参数C₀、λ均为已知）,由此确定了无氧铜的等熵卸载路径。结果表明：在冲击态（即初始卸载态）高达219 GPa的压力范围内,无氧铜的等熵卸载过程可用Grüneisen状态方程在ργ=ρ₀γ₀近似下作很好的描述;各条卸载路径到一个大气压的终态粒子速度U_S与镜像反演的粒子速度2u的偏差(U_S-2u)/(2u),随冲击波压力的增加而增大。     

In-plane bistatic backward scattering from seabottom with randomly inhomogeneous sediment and rough interface

1 Introduction Backward scattering of sound due to sediment is the main source of shallow waterreverberation. In order to predict the reverberation or detect sediment properties frommeasured reverberation data, a reasonable in-plane bistatic backward scattering (BBS)model is essential. The scattering can be caused by the roughness of water-sediment in-terface or by inhomogeneities within the volume of sediment. A great deal of researchhas been done on sediment backscattering, most of which h…     

快速数值差分递推改进算法在超宽连续谱模拟中的应用研究

对快速数值差分递推公式进行了改进,使之能够求解带有脉冲自陡峭项和脉冲内喇曼散射项的非线性薛定谔方程.通过与传统孤子解析结果及分步傅里叶方法数值结果的对比分析表明,快速数值差分递推改进算法是一种快速而准确的数值计算方法,它不仅能够同步考虑光学媒质中的群速色散作用和非线性克尔作用,而且将所有高阶非线性项对光脉冲传输的影响也...