Preparation of the W State of Atoms in a Single Cavity or N Distant Cavities by Photon Interference

We suggest two schemes to generate the W state of N A-type three-level atoms. In the schemes, identical N three-level atoms are trapped in a cavity or N distant cavities. The success or failure of the generation of the W state can be determined by detecting the polarization of photon leaking out of the cavity. The result demonstrates that the W state is free from both the cavity loss and the spontaneous emission due to the fact that the two ground states (left and right) of the three-level atoms are stable states (or metastable states).     

Couchman-Reynolds方程的检验与体积模量及关联系数的计算

本文用回归分析法,系统地检验了57种元素固体对高压下的Couchman-Reynolds方程的显著性;计算和讨论了它们的体积模量和关联系数,其结果与实验一致。     

沉淀还原法制备高性能CO2加氢合成甲醇Cu/ZnO/Al2O3催化剂

由铜基催化剂催化CO2+H2合成甲醇是有效利用CO2的潜在途径[1～5]. 但传统的催化剂对该反应的催化活性及选择性均很低[3～5], 因而寻求具有高活性及高选择性的新型催化剂已成为重要研究课题[4,6]. Cu/ZnO系列催化剂的制备方法和助剂对催化剂的性质及CO2加氢合成甲醇的反应性能有显著影响[6～10], 传统的气相还原活化铜基催化剂的过程常伴随强烈的热效应, 导致催化剂活化过程存在耗时长及还原条件难以控制等问题[11]. 本文采用沉淀-还原法, 用KBH4溶液对新鲜制备的碳酸盐共沉淀进行液相化学还原处理, 直接得到高活性及高选择性的还原态Cu/ZnO/Al2O3甲醇合成催化剂, 并可通过改变催化剂表面Cu+/Cu0活性物种的相对比例来改善催化剂的活性及选择性.     

硫杂冠醚的合成

冠醚化合物对金属离子的络合不仅具有较高的稳定性,而且更重要的是具有良好的选择性。当冠醚环中的氧原子部分或全部被氮或硫原子取代后,它们对碱金属、碱土金属的亲和性能降低,而对过渡金属离子的亲和能力相应提高。硫杂冠醚对亲硫的贵金属、重金属离子具有更强的络合能力和更高的选择性。1974     

Simple Algorithm for Deterministic Entanglement Concentration

We first present the general solution and the simplest special solution of the doubly stochastic matrix used in deterministic entanglement concentration. Then, we give a better scheme to realize deterministic entanglement concentration. Under this scheme, the concentration is realized, and more importantly, two partially entangled pairs concentrate to four-particle Greenberger-Horne-Zeilinger （GHZ） states with a certain probability.     

微乳液的热力学性质 I: 芳烃类的侧链链长对微乳液热力学函数影响

本文研究以非离子型表面活性剂-正辛醇-水-芳烃类所组成的微乳液, 探讨醇从油相转移到界面相时的自由能变化, 以及温度对自由能的影响。计算出熵和焓的变化, 发现在实验范围内, 上述热力学函数的对数值与芳烃侧链的碳原子数(n)呈线性关系。这些关系式对微乳液的构成和稳定性的讨论是重要的, 还对几种芳烃异构体所构成的微乳液的热力学函数进行了实验和讨论。     

新型茼蒿素类似物的合成和抗虫构效关系研究

Twenty-one tonghaosu analogs were synthesized via hydroamination or selective reduction of the endocyclic double bond of the corresponding dienol spiroketals. Structures of all the new compounds were confirmed by ^1H NMR, IR, MS, HREIMS or elemental analysis. Their antifeedant activity against large white butterfly （Pieris brassicae L） and larvicidal activity toward mosquito （Culex quinquefasciatus Say） were examined. Some of them exhibited antifeeding activities comparable to or stronger than tonghaosu Z-1. Based on the activity data, the preliminary structure-activity relationship was also discussed, which might be instructive for finding out lead compounds with better bioactivities in the future.     

Fe81Ga19合金晶体生长取向与磁致伸缩性能

通过区熔定向凝固法,生长出[001]易磁化方向与晶体轴向之间存在不同取向差的Fe₈₁Ga₁₉合金单晶体和Fe₈₁Ga₁₉合金多晶体.极图测试结果显示,Fe₈₁Ga₁₉合金单晶体的[001]方向与轴向取向差分别为12°,5°和3°.采用电阻应变片法测定相应磁致伸缩应变,与外加磁场方向平行的轴向磁致伸缩应变分别为254×10^-6,271×10^{-6< 关键词： 磁致伸缩 81Ga₁₉合金')" href="#">Fe₈₁Ga₁₉合金 晶体取向}     

节律性时间期待和空间期待对听觉目标辨别的影响

合理的推断和预期是加快辨别听觉目标的关键。通过听觉目标辨别的反应时任务,研究了听感知过程中节律性时间期待和空间期待对声音目标辨别的影响。实验中,听觉序列中各声音以规律或不规律的时间节奏、沿有序或随机的空间方位呈现,形成四种期待条件:时间和空间期待兼备、只有时间期待、只有空间期待和没有期待。被试对声音序列末尾随机呈现的听觉目标尽快做按键反应。结果发现:（1）节律性时间期待显著加快被试对目标声音的反应速度;（2）空间期待对目标辨别速度的促进作用仅在时间非规律条件下发生。可见,在辨别听觉目标时,听者优先使用时间期待,并在无有效时间预测信息时使用空间期待,以促成对声音目标的最优知觉加工。      

First-principles research on influence of C dopants on magnetic and electric properties of rocksalt MgS

<正>The 2×2×1 rocksalt C-doped MgS supercells are optimized and their magnetic and electric properties,including the half-metallicity,the conductivity and the supercell magnetic moments,are calculated or analysed by the first-principles researches based on the density functional theory.Results show that the concentration of C-dopants may cause important influence on the magnetic and the electric properties of rocksalt MgS.C dopants are inclined to have a scattering distribution.MgC_(0.0625)S_(0.9375),~aMgC_(0.1250)S_(0.8750) and MgC_(0.1875)S_(0.8125) have evident half-metallicity. They have wide spin energy gaps,thus high Curie temperature possibly.Their supercell magnetic moments are near to integral numbers 2.0,4.0 and 6.0μB.The main reason for spin polarization and half-metallicity of C-doped MgS is that there are sp hybridized orbitals in ligand compound ML_6 caused by covalent interaction between C-ions and Mg-ions.