摘要：In this review paper, we introduce a self-phase controlled stimulated Brillouin scattering phase conjugate mirror(SCSBS-PCM) and the Kumgang laser. The SC-SBS-PCM was proposed and demonstrated its success at the academic low power level, ~100 mJ@10 Hz. The Kumgang laser is under development to verify whether the SC-SBS-PCM is operable at the k W level. It is a 4 kW beam combination laser combining four 1 k W beams using the SC-SBS-PCM. If the Kumgang laser functions successfully, it will be the most important step towards a Dream laser, a hypothetical laser with unlimited power and a high repetition rate.

摘要：Broadband sound sink/absorber via a structure with deep sub-wavelength thickness is of great and continuing interest in physics and engineering *** intuitive technique extensively used is to combine components(resonators)with quasi-perfect absorption to piece together a broad absorbing band,but the requirement of quasi-perfect absorption substantially places a very strict restriction on the impedance and thickness of the ***,we theoretically and experimentally demonstrate that a compact broadband acoustic sink that quasi-perfectly absorbs broadband arriving sound waves can be achieved with coherently coupled‘‘weak resonances"(resonant sound absorbing systems with low absorption peaks).Although each component exhibits rather low absorption peak alone,via manipulating the coherent coupling effect among the components,they collectively provide a remarkably improved performance over a wide frequency range with a significantly compressed *** illustrate the design principle,a hybrid metasurface utilizing the coaction of parallel and cascade couplings is presented,which possesses an average absorption coefficient of 0.957 in the quasi-perfect band(a>0:9)from 870 to 3224 Hz with a thickness of only 3.9 *** results open new avenues for the development of novel and highly efficient acoustic absorbers against low frequency noise,and more essentially,suggest an efficient approach towards on-demand acoustic impedance engineering in broadband.

摘要：在建的大连自由电子激光(Dalian coherent Light Source,DCLS)是我国第一个开工建设的四代光源,也将是全球唯一可调波极紫外自由电子激光器。本文采用蒙特卡罗程序FLUKA,建立了电子束流线源均匀模型(均匀电子固定角度发射),对DCLS注入器段的主体墙厚度做了屏蔽设计,计算中引入方差减小技巧,以降低计算结果的统计误差;并将基于束流线源模型的蒙特卡罗计算结果与基于经验公式的Shiled11软件的计算结果做了比较。结果表明,基于束流线源模型的蒙特卡罗计算结果与基于经验公式的Shiled11软件的计算结果吻合较好;主体墙外的剂量主要是由中子贡献,95%以上的中子剂量是由巨共振中子贡献。因此,基于电子束流线源模型的蒙特卡罗方法适用于电子直线加速器的主体墙的横向屏蔽设计。

摘要：We generalized an constructing method of noncoherent unitary space time codes (N-USTC) over Rayleigh flat fading channels. A family of N-USTCs with T symbol peroids, M transmit and N receive antennas was constructed by the exponential mapping method based on the tangent subspace of the Grassmann manifold. This exponential mapping method can transform the coherent space time codes (C-STC) into the N-USTC on the Grassmann manifold. We infered an universal framework of constructing a C-STC that is designed by using the algebraic number theory and has full rate and full diversity (FRFD) for t symbol periods and same antennas, where M, N, T, t are general positive integer. We discussed the constraint condition that the exponential mapping has only one solution, from which we presented a approach of searching the optimum adjustive factor αopt that can generate an optimum noncoherent codeword. For different code parameters M, N, T, t and the optimum adjustive factor αopt, we gave the simulation results of the several N-USTCs.

摘要：被动型CPT原子钟是一种可实现微型化和芯片化设计的原子钟。针对微小卫星和地面手持设备的应用需求,提出了一种微型CPT铯原子钟的设计方案。分析了基于^(133)Cs的CPT原子钟物理设计的优点。完成了原理样机的设计实现与测试,原理样机的体积小于100 ml、功耗小于2 W、稳定度指标优于6×10^(-11)τ^(-1/2)(1~100 s)。最后,对芯片化设计及微型CPT原子钟应用进行了展望。

摘要：业主：教友会日期：2011年—2014年面积：2 500平方米 朋友之家是英国教友会（贵格会）之家。它是由休伯特·利德贝特设计的二级建筑,在1927年赢得了英国皇家建筑师协会铜奖。约翰·麦卡兰建筑事务所将大会议厅（1000个座位）翻新改造成为一个多功能的、可进入并可持续发展的地方,以满足不断增长的教友会有关宣传和社会活动的需求。

摘要：常见电信英文缩略词注解ＳＤＨ：同步数字体系，是指微波或光纤传输网所使用的传输体系，它与准同步数字体系（ＰＤＨ）相比，优越性十分明显，可向更高速率更大容量扩展，容易实现兼容，便于进行全网的监控和管理，便于实现上下话路功能，便于统一标准接口，可大大提高通...