Scheme for Generalized Quantum State Sharing of a Single-Qubit State in Cavity QED

An experimentally feasible scheme for generalized quantum state sharing of an arbitrary unknown single- qubit state in cavity QED is presented. Using a generalized Greenberger-Horne-Zeilinger （GHZ） state as the quantum channel among the three parties, the quantum information （i.e. the single-qubit state） from the sender can be split in such a way that the information can be recovered if and only if both receivers collaborate. Moreover, the scheme is insensitive to both the effects of thermal field and cavity decay.     

一维非线性光子晶体全光开关的数值研究

在光子晶体的缺陷层内掺入Kerr介质,基于Kerr非线性效应导致的缺陷态迁移原理,设计了两种一维光子晶体全光开关结构.应用时域有限差分（FD-TD）法,编制Matlab计算程序,对全光开关进行数值特性分析.讨论频率混合效应对全光开关的影响.观察光子局域效应增强光子晶体非线性的现象,验证了光子局域效应与光子晶体完整周期结构的层数有关,层数太少光子局域效应不明显.     

The design of a five-cell high-current superconducting cavity

Energy recovery linacs are promising for achieving high average current with superior beam quality. The key component for accelerating such high-current beams is the superconducting radio-frequency cavity. The design of a 1.3 GHz five-cell high-current superconducting cavity has been carried out under cooperation between Peking University and the Argonne National Laboratory. The radio-frequency properties, damping of the higher order modes, multipacting and mechanical features of this cavity have been discussed and the final design is presented.     

方程ü bu~r g(u(t-τ))=p(t)的2π-周期解(英文)

本文对一类不具耗散项的时滞微分方程进行了分析 ,利用重合度理论 ,得到了方程至少存在一个 2 π-周期解的充分条件     

金融市场中经纪人相互竞争和适应性行为的物理模型

金融物理中的争当少数者博奕模型,是一个用来模拟金融市场动力学行为的最简单的模型,可以尝试利用它来对实际金融市场中许多现象提供物理的理解.文章介绍了关于金融物理的争当少数者博奕模型的一些主要研究结果和若干最新的发展方向.     

Improvement of Properties of Pseudomonas sp. Lipase in Resolution of 2-Octanol

IntroductionThe demand for the high purity of chiral com-pounds has led to the increasing use of biocatalystsand the increasing research in order to obtain en-zymes with a higher activity and selectivity.In thisfield the utilization of lipases has been proved to beone of the simplest but most promising techniquesfor the enantioselective conversion of various hy-drophobic acids and alcohols in the last decade.There has been a considerable interestin improvingthe enantioselectivity of lipases an…     

Sn0.5Ti((0.5)O2固溶体的溶胶-凝胶法制备、表征及其热稳定性研究

采用溶胶-凝胶法制备了Sn_0.5Ti_0.5O₂固溶体.用X射线衍射(XRD)、差热分析(DTA)和红外(IR)技术对材料的结构和热稳定性进行了分析表征.固溶体的热稳定性与起始反应温度有关,在40℃水浴温度下制备的凝胶经1000℃烧结,发生了相分解,出现了富Sn和富Ti相,而在80℃水浴温度下制备的凝胶经1200℃烧结也不发生相分解,仍以Sn_0.5Ti_0.5O₂相存在,而且用差热分析也得到了同样的结论.     

Asymmetric Cu-catalyzed Henry reaction using chiral camphor Schiff bases immobilized on a macromolecular chain

Immobilized catalysts have attracted chemists’ attention for long time because of convenient recycling, which is very important for some special catalyst even immobilizations accompanying the decrease of catalytic activity and selectivity. Our group focused on the developing chiral catalysts with camphor framework to catalyze various asymmetric reactions for long time. For easily recycling the unique chiral catalysts, a series of polymer catalysts with chiral camphor unit were synthesized by RAFT polymerization. Herein, the performance of the synthesized polymer chiral catalysts was reported by catalyzing asymmetric Henry reaction. After optimizing the reaction conditions, the synthesized chiral polymer catalyst provides a good yield and enantioselectivity to the reaction of p-nitrobenzaldehyde and nitromethane. In the meantime, the recycles and reused properties of synthesized polymer catalysts were examination by the model asymmetric Henry reaction. The catalyzed activities and enantioselectivities did not show obviously decrease until recycling five times.     

Breaking Parallel Orientation of Rods via a Dendritic Architecture toward Diverse Supramolecular Structures

Self‐assembled nanostructures of rod‐like molecules are commonly limited to nematic or layered smectic structures dominated by the parallel arrangement of the rod‐like components. Distinct self‐assembly behavior of four categories of dendritic rods constructed by placing a tri(hydroxy) group at the apex of dendritic oligo‐fluorenes is observed. Designed hydrogen bonding and dendritic architecture break the parallel arrangement of the rods, resulting in molecules with specific (fan‐like or cone‐like) shapes. While the fan‐shaped molecules tend to form hexagonal packing cylindrical phases, the cone‐shaped molecules could form spherical motifs to pack into various ordered structures, including the Frank–Kasper A15 phase and dodecagonal quasicrystal. This study provides a model system to engineer diverse supramolecular structures by rod‐like molecules and sheds new light into the mechanisms of the formation of unconventional spherical packing structures in soft matter.     

环形扬声器阵列的警报系统设计*

针对工厂车间中局部异常需警报及时提醒的情况,设计一款36通道的环形音频警报系统,实现局部警报声播放的效果,并验证所设计系统的可行性。为达到输入输出实时运算的目的,该基于环形扬声器阵列的警报系统以高性能数字信号处理为核心展开,通过多通道模拟数字转换器、数字模拟转换器及功率放大器等硬件电路,利用最小二乘法将警报信号传递到相应区域。在全消声室环境下,该系统通过PC机产生单频信号,实现了音频的指向性,验证了所设计系统的可行性。