脉冲馈入方式改变对束流传输的影响

利用加速器原有的束流传输及检测系统,在单脉冲直线感应加速器上分别对双边馈入和单边馈入情况下强流束的传输情况进行了实验测量。实验结果表明:在改变加速脉冲的馈入方式后,传输过程中电子束在加速段的束心位置发生了明显改变,将对加速器的束流输运产生非常不利的影响。通过对实验数据的比较和分析,提出了传输线延时产生双脉冲可能采用的脉冲馈入方案。     

Enhancement of scale-free network attack tolerance

Despite the large size of most communication and transportation systems,there are short paths between nodes in these networks which guarantee the efficient information,data and passenger delivery;furthermore these networks have a surprising tolerance under random errors thanks to their inherent scale-free topology.However,their scale-free topology also makes them fragile under intentional attacks,leaving us a challenge on how to improve the network robustness against intentional attacks without losing their strong tolerance under random errors and high message and passenger delivering capacity.Here we propose two methods (SL method and SH method) to enhance scale-free network’s tolerance under attack in different conditions.     

Cu_2O particles with ordered pores via electrochemical deposition method

Cu2O particles cube with ordered pores are electrodeposited by using colloidal crystal template method. The shape of Cu2O cube particle is partly determined by its growing habit. Therefore, Cu2O cube particles with ordered pores are fabricated instead of three dimensional inverse opal structures.     

关于几种新的析分解的计算方法

对变形樟度极分解的计算方法进行了分析，给出了极分解计算的四种新方法：（１）增量叠加法；（２）基于伸长张量不变量（近似）计算法；（３）确定主转动轴计算法；（４）坐标变换法。增加叠加极分解计算方法将为建立以伸长张量为变应度量的大变形大转动有限分析方法提供基础。本文还给出了伸长张量物质时间导数的简洁表达式。     

THE SUPERCONDUCTIVITY IN Al-DOPEDY_(1-x)Al_xBa_2Cu_3O_y

本文系统地分析了在Ｙ１－ｘＡｌｘＢａ２Ｃｕ３Ｏｙ（ｘ＝０～０．７）中用Ａｌ替代Ｙ的替代效应．我们发现当ｘ＜０．４时，Ａｌ主要替代在Ｙ位，引起结构畸变，从而导致氧含量的减少和Ｏ－Ｔ相变，转变温度随Ａｌ含量增加而下降．当掺杂量大于０．４，Ａｌ开始占据Ｃｕ（１）和Ｃｕ（２）位，样品变为四方结构，Ｔｃ迅速下降．ＸＰＳ分析表明，Ａｌ的位置依赖于掺杂量，随掺杂浓度的增加Ａｌ依次替代Ｙ，Ｃｕ（１），Ｃｕ（２）．同时我们观察到Ｔｃ和ＣｕＯ２平面间相互作用的正比关系．     

A Stable Ultrashort Pulse Generator Based on EAM and Well-Designed Compressor for Applications in 160 Gbit/s OTDM Networks

A stable 10 GHz ultrashort pulse generator consisted of an electroabsorption modulator （EAM） and a welldesigned fibre-based pulse compressor is proposed and demonstrated experimentally. The obtained short pulse has high extinction ratio, no pedestal, low timing jitter, and FWHM of only 2.4ps. The excellent performance of multiplexing from 10 GHz to 160 GHz confirms the potential of the generator for applications in 160 Gbit/s optical time-division-multiplexing （OTDM） systems.     

聚丙烯／尼龙6原位复合材料的形态与表面,界面特性

以聚丙烯为基体、尼龙６为分散相共混得到分散相成纤的原位复合材料。显微形态观察发现在考察的浓度范围内微纤的直径基本与分散相含量无关。提高拉伸作用和增大剪切作用使微纤变细。当分散相含量越大，纤维数目越多时，水在复合材料表面的接触角越小，材料的吸水率越高。     

非马尔科夫环境中各向异性海森堡自旋链的几何量子失协

本文主要在非马尔科夫环境中,在时变磁场和Dzyaloshinski—Moriya相互作用下,以最大纠缠态■作为信道,研究了具有各种参数的两比特海森堡XYZ模型的几何量子失协.通过在非马尔科夫环境中的量子态扩散方法模拟了系统的几何量子失协随时间的演化关系.根据数值模拟结果显示:环境关联系数γ、自旋耦合系数J和J_z、余弦磁场强度B、以及自旋—轨道相互作用都能影响系统几何量子失协的性质.当环境关联系数γ较小时,几何量子失协呈现出明显的上升趋势,可见非马尔科夫环境对系统的几何量子失协表现出积极的作用.同时较大的自旋耦合系数J和余弦磁场强度B对系统的几何量子失协也有积极的影响.     

High-Energy Rectangular Pulse Dissipative Soliton Generation in a Long-Cavity Sigma-Shaped Configuration Mode-Locked Fiber Laser

The high-energy rectangular pulse dissipative soliton （DS） is achieved in a long-cavity sigma-shaped configuration erbium-doped fiber laser. A long fiber is inserted in the linear arm of the sigma-shaped configuration to extend the resonator length twice, which effectively improves the pulse energy. The nonlinear polarization rotation technique is employed to realize the mode-locked state. Stable rectangular pulses with pulse energy of 421.22 nJ are obtained at the pump power of 620mW. To the best of our knowledge, this high pulse energy is a new record of the rectangular pulse mode-locked DS fiber lasers.     

Pt/Cu(001)-p(2×2)-O表面吸附结构的总能计算

采用密度泛函理论(DFT)研究了氧吸附后Pt/Cu(001)表面合金的原子结构和表面性质. 计算结果表明, 在Pt/Cu(001)-p(2×2)-O表面最稳定结构中, 衬底表面原子层不发生再构, 氧原子吸附于4重对称的Pt原子谷位, 每个氧原子吸附能约为2.303 eV. 吸附结构的Cu—O和Pt—O键键长分别为0.202和0.298 nm, 氧原子的吸附高度ZCu—O约为0.092 nm. 吸附前后Pt/Cu(001)-1ML(monolayer)表面合金的表面功函数分别为4.678和5.355 eV. 吸附表面氧原子和衬底的结合主要来自氧原子2p轨道和衬底金属原子d轨道的杂化作用, 氧原子吸附形成的表面电子态主要位于费米能级以下约-2.7 eV 处.