Beam Coupling due to Self－Pumped Phase Conjugate Reflection in Photorefractive Crystals

ＢｅａｍＣｏｕｐｌｉｎｇｄｕｅｔｏＳｅｌｆ－ＰｕｍｐｅｄＰｈａｓｅＣｏｎｊｕｇａｔｅＲｅｆｌｅｃｔｉｏｎｉｎＰｈｏｔｏｒｅｆｒａｃｔｉｖｅＣｒｙｓｔａｌｓ￥（孙秀冬）（许克彬）（孙万钧）（周忠祥）ＳＵＮＸｉｕｄｏｎｇ；ＸＵＫｅｂｉｎ；ＳＵＮＷａｎｊｕ...     

光折变晶体中双光束耦合时间响应特性的研究

从描述双光束耦合规律的动态方程组出发．在考虑了光栅调制度变化后，给出了包含晶体固有参数、入射总光强、入射夹角、光强比等变量在内的写入响应时间解析表达式，实验结果与理论分析定性符合很好。     

记录光偏振对掺偶氮染料液晶薄膜二波耦合效应的影响

研究了平面型掺偶氮染料(DR1)向列液晶(5CB)薄膜对可见光波段的响应及在二波耦合实验中探测光(633nm)的衍射效率与记录光(488nm)偏振的关系,并进行了相应解释,得到了小角度入射条件下,记录光偏振方向平行于样品摩擦取向方向时的空间变化的介电张量。此结果适用于多数偶氮类染料,很好地解释了光致顺-反异构引起的折射率变化。     

Relativistic Electromagnetic Soliton in Electron-Positron-Ion Plasma

Considering the limiting weak nonlinearity, we obtained the solution of the coupled equations describing the interaction of ultraintense laser with cold transparent multicomponent plasma. It was indicated that the ions tend to accumulate at the center of the soliton and have large velocity when we consider the mobile ions in the multicomponent plasma, which shows that the result is different from that of the Berezhiani＇s analysis. The change of proportion of ions in the plasma has effects on the amplitude of vector potential and the maximum velocity of the soliton.     

电脑测配色在灯芯绒活性染色上的应用

介绍电脑测配色系统及其基础资料的制备;细述在灯芯绒活性染色上的应用及其中的注意点。其中基础资料的精度直接影响使用准确性;建立色库和摸索染料校正系数规律以提高配色处方的可参考性。     

4000 m轮轨+滑轨丛式移运低温钻机的研制

为满足俄罗斯北极圈附近极地低温地区的油气勘探开发需要,研制了4 000 m轮轨+滑轨丛式移运低温钻机。钻机主要运用了低温结构件技术、双模式轨道同时移动的丛式井移运技术、加热及保温等技术,满足极地低温地区丛式井钻井工艺要求。钻机由2移运模块组成,井架、底座和绞车等钻台区部件组成的主机模块整体采用滑动摩擦的滑轨方式移动;钻井液处理、钻井泵、电控和气源等部件组成的配套辅助模块采用滚动摩擦轮轨方式移动,2模块共用钻机机具液压站液压动力同时移动,满足丛式钻井及过井口设备的工艺要求。钻机配套2节套装伸缩式井架,利用液压油缸起升,井架可整体利用半挂车拖挂运输。另外钻机具有钻井液吹扫和棘爪自锁等多项自动化操作功能。钻机在常规试验和联调试验中,各项性能指标均达到了设计要求。该低温钻机性能先进,工作效率和搬家的适用性高,具有广阔的市场推广前景。     

光折变聚合物中生色团取向振荡过程的观察

利用透射椭偏技术测量了光折变聚合物PVK∶5CB∶C60中生色团5CB(4,4′-n-pentylcyanobiphenyl)的动态取向过程.当温度远高于系统的玻璃转化温度时,在很低的外加电场下就可观察到生色团5CB取向振动过程.振动频率与外加电场的大小有关.并且生色团的稳态取向分布是温度的函数.就我们所知,目前的理论模型还无法对这些现象给出合理的解释.(PH9)     

等离子体复合雷达吸波材料的电磁特性

随着现代先进探测技术的不断发展,对隐身技术的要求不断提高.传统的雷达吸波材料隐身技术在6 GHz以上微波频段内有较好的隐身效果,而等离子体隐身技术在低频（6 GHz以下）更易于实现.基于此,文中采用雷达吸波材料和等离子体技术复合,利用同轴网格辉光放电产生等离子体与雷达吸波材料相结合,并进行了隐身性能测试.测试结果表明,复合隐身效果优于单一隐身技术的隐身效果,且通过调节等离子体的放电功率等参数,易于实现隐身效果的控制.本文的研究工作可以为等离子体和雷达吸波材料复合隐身技术相关研究提供一定参考.     

Theoretical research on the transport and ionization rate coefficients in glow discharge dusty plasma

The electron kinetic model for investigating the transport and ionization rate coefficients of argon glow discharge dusty plasma is developed from the Boltzmann equation.Both of the electron-neutral and electron-dust collisions are considered as collision terms in the kinetic equation.The kinetic equation is simplified by employing the local approximation and nonlocal approach under the same discharge conditions,and the corresponding simplified kinetic equations are known as local and nonlocal kinetic equations respectively.Then the electron energy distribution function(EEDF)is obtained by numerically solving the local and nonlocal kinetic equations and the dust charging equations simultaneously.Based on the obtained EEDFs,the effective electron temperature,electron mobility,electron diffusion coefficient and ionization rate coefficient are calculated for different discharge conditions.It is shown that the EEDFs calculated from the local kinetic model clearly differ from the nonlocal EEDFs and both the local and nonlocal EEDFs are also clearly different with Maxwellian distributions.The appearance of dust particles results in an obvious decrease of high energy electrons and increase of low energy electrons when axial electric field is low.With the increase of axial electric field,the influence of dust particles on the EEDFs becomes smaller.The electron mobility and diffusion coefficients calculated on the basis of local and nonlocal EEDFs do not differ greatly to the dust-free ones.While,when dust density nd=10^6 cm^?3,the electron mobility increases obviously compared with the dust-free results at low axial electric field and decreases with the increasing axial electric field until they are close to the dust-free ones.Meanwhile,electron diffusion coefficients for dusty case become smaller and decrease with the increasing axial electric field.The ionization rate coefficients decrease when dust particles are introduced and they approach the dust-free results gradually with the increasing axial electric field.     

Composite wave-absorbing structure combining thin plasma and metasurface

In order to solve the thickness dependence of plasma absorption of electromagnetic waves and further reduce the backward radar scattering cross section(RCS) of the target, we designed a novel composite structure of a metasurface and plasma. A metasurface with three absorption peaks is designed by means of an equivalent circuit based on an electromagnetic resonance type metamaterial absorber. The reflection and absorption of the composite structure are numerically and experimentally verified. The...