Kinetic evolutionary behavior of catalysis-select migration

We propose a catalysis-select migration driven evolution model of two-species(A-and B-species) aggregates,where one unit of species A migrates to species B under the catalysts of species C,while under the catalysts of species D the reaction will become one unit of species B migrating to species A.Meanwhile the catalyst aggregates of species C perform self-coagulation,as do the species D aggregates.We study this catalysis-select migration driven kinetic aggregation phenomena using the generalized Smoluchowski rate equation approach with C species catalysis-select migration rate kernel K(k;i,j) = Kkij and D species catalysis-select migration rate kernel J(k;i,j) = Jkij.The kinetic evolution behaviour is found to be dominated by the competition between the catalysis-select immigration and emigration,in which the competition is between JD0 and KC0(D0 and C0 are the initial numbers of the monomers of species D and C,respectively).When JD0 KC0 > 0,the aggregate size distribution of species A satisfies the conventional scaling form and that of species B satisfies a modified scaling form.And in the case of JD0 KC0 < 0,species A and B exchange their aggregate size distributions as in the above JD0 KC0 > 0 case.     

三维横向流体诱发直管振动的数值模拟

基于有限体积法和有限元法,结合动网格控制技术,建立了横向流体作用下三维弹性直管流致振动计算的数值模型,实现了计算结构动力学与计算流体力学之间的联合仿真．首先,通过对刚性管的静止绕流计算,研究了网格离散方式和不同湍流模型对圆柱类结构静止绕流流场特征的影响和预测能力,得到了适用于双向耦合分析的CFD模型;其次,利用基于双向流固耦合方法的流致振动模型,计算并分析了流体力与结构位移间的相位关系,指出流体力与位移间的相位差是由流体力引起的,同时对双向耦合和单向耦合进行了比较分析;最后通过对直管流致振动的数值计算,联合管表面压力、尾流区时均速度、分离角等时均量,分析了尾流区的流场特征.     

DDQ氧化法合成3-溴-1-（3-氯-2-吡啶基）二1H-吡唑-5-甲酸酯类化合物

以DDQ为氧化剂,对3-溴-1-（3-氯-2-吡啶基）-4,5-二氢-1H-吡唑-5-甲酸酯类化合物进行氧化研究,合成了一系列3-溴-1-（3-氯-2-吡啶基）-1H-吡唑-5-甲酸酯类化合物,其结构经氢谱、碳谱和高分辨质谱分析确证,该方法具有操作简便、产率高、适用范围广等优点．     

含铰接杆系结构几何非线性分析子结构方法

将细长杆系结构按长度方向划分为多个子结构,由于在子结构坐标系下的节点位移均是小位移,可以将子结构内部自由度凝聚到边界. 考虑到子结构端面在变形过程中保持为刚性截面,将端面节点自由度进一步凝聚到端面形心点,这样每一个子结构就减缩成形式上只有两个节点的广义梁单元,大大减缩了自由度. 大位移大转动是细长杆系结构产生几何非线性效应的一个重要原因,基于共旋坐标法,建立了随单元一起运动的随动坐标系,推导了子结构单元的节点力平衡方程及其切线刚度阵. 同时,考虑到工程机械中细长杆系结构含有相互铰接的刚体加强块,给出了非独立自由度节点力转换到独立参数下的广义节点力及其导数. 最后,通过履带式起重机的副臂工况算例,给出了其在不同载荷下的臂架结构位移,验证了方法的正确性.      

The Essence of More Nonlocality with Less Entanglement in Bell Tests

In this paper, we will explore the essence of the phenomenon that state with less entanglement may generate greater Bell violation in the two-qubit Bell tests with CH-type inequalities, i.e., more nonlocality with less entanglement. We will show that this interesting but counterintuitive phenomenon is caused by the rotational asymmetry of the nonmaximally entangled state in the measurement plane. This asymmetry allows the both-side detection probabilities and the one-side detection probabilities obtain their maximal values with nonmaximally entangled state. But the maximal Bell violation may not always happen on nonmaximally entangled state, because these probabilities will compete with each other, and the Bell violation behaves differently for various CH-type inequalities.     

Deterministically distinguishing a remote Bell state

It has been proven that, with a single copy provided, the four Bell states cannot be distinguished by local operations and classical communications (LOCC). Traditionally, a Bell basis projective measurement is needed to distinguish the four Bell states, which is usually carried out with a local interference between two particles. This paper presents an interesting protocol that allows two remote parties to distinguish four Bell states deterministically. We prove that our protocol of distinguishing remote Bell states is beyond LOCC.     

The reliability of AlGaN/GaN high electron mobility transistors under step-electrical stresses

In spite of their extraordinary performance, AlGaN/GaN high electron mobility transistors (HEMTs) still lack solid reliability. Devices under accelerated DC stress tests (off-state, V_DS =0 state, and on-state step-stress) are investigated to help us identify the degradation mechanisms of the AlGaN/GaN HEMTs. All our findings are consistent with the degradation mechanism based on crystallographic-defect formation due to the inverse piezoelectric effects in Ref. [1] (Joh J and del Alamo J A 2006 IEEE IDEM Tech. Digest p. 415). However, under the on-state condition, the devices are suffering from both inverse piezoelectric effects and hot electron effects, and so to improve the reliability of the devices both effects should be taken into consideration.     

Parametric down-conversion with local operation and two-way classical communication

The decoy-state quantum key distribution protocol suggested by Adachi et al. (Phys. Rev. Lett. 99 180503 (2007)) is proven to be secure and feasible with current techniques. It owns two attractive merits,i.e.,its longer secure transmission distance and more convenient operation design. In this paper,we first improve the protocol with the aid of local operation and two-way classical communication (2-LOCC). After our modifications,the secure transmission distance is increased by about 20 km,which will make the protocol more practicable.     

环糊精在手性药物分离分析研究中的应用

环糊精由于自身特殊的手性环境和结构特征,已广泛运用于手性化合物的对映体拆分及分析。对近年来环糊精在各种色谱、质谱及核磁等分析方法中的应用进行了归纳总结,综述了环糊精及其衍生物在手性药物的分离分析方面的研究进展。     

三唑类超分子化学与药物研究新进展

三唑环为含有三个氮原子的五元杂环, 唑环具有芳香性和丰富的电子, 易接受质子和络合金属离子, 因而三唑类化合物易通过配位键、氢键、离子-偶极、阳离子-?、?-?堆积、疏水效应以及范德华力等非共价键力形成超分子聚集体, 表现出许多特殊的性能及生物活性, 具有广泛的潜在应用如作为离子受体、材料、医药等. 近些年来, 相关三唑类超分子化学与医药的研究非常活跃, 发展特别迅速, 已成为十分活跃的热点研究领域. 本文结合自己的工作, 参考国内外近五年文献, 首次系统综述了三唑类化合物作为阳离子和阴离子受体以及三唑类超分子作为发光与磁性材料、医药在抗菌、抗真菌、抗癌等方面的研究与开发近况. 希望本综述对三唑类超分子化学与药物的进一步研发有所启迪.