Reaction of Molybdenum Hexa-carbonyl with Mercapto-pyridine （PySH） or Mercapto-pyridine Oxide （PyS→O） and Crystal Structure of [Et4N][Mo2（PyS）3（CO）5]

Introduction Mercapto-pyridine, C5H4NS-(PyS), containing two active atoms, S and N, is a bidentate ligand, which may act as a 3-electron donor or a 5-electron donor and may be a bridging ligand to link two metal atoms to form polynuclear metal clusters or a chelating agent to coor-dinate to a metal atom by S and N atoms. So the mer-capto-pyridine is a very important reagent and its reac-tion with metal compound is very useful for simulating the active center in metal enzymes and syntheses …     

芳氢与配位硫原子之间(sp2C-H…S)的分子内氢键

化合物(Et4N)2[Pd2(mp)2(Hmp)2](1)(H2mp＝2-巯基苯酚)的1H NMR谱中芳氢H16的峰出现在δ 8.79处,与预测值(δ 7.1)相差1.7,这是由于H16与配位硫S2原子之间存在弱相互作用,即新型的sρ2C-H…S之间的氢键作用.原子间距离C16…S2(0.361pm)和H16…S2(0.295pm)分别小于相应原子的范德华半径之和(0.370pm和0.305pm),C16-H16…S2角为128.1°,证明了这种新型氢键的存在.此外,在分子振动光谱中观察到这种氢键的作用使得芳氢υC-H出现在低于3000cm-1处.通过与类似物[Pd2(PPh3)2(Hmp)2Cl2](2)的比较,以及1在DMSO溶剂中仍然保持O-H…O和C-H…S这2种氢键的事实,表明C-H…S之间的作用,对1的配体Hmp中的苯环与Pd2S2平面之间的夹角偏离90°可能是有贡献的.     

Quantum Secure Direct Communication Network with Two-Step Protocol

An efficient quantum secure direct communication network protocol with the two-step scheme is proposed by using the Einstein-Podolsky-Rosen （EPR） pair block as the quantum information carrier. The server, say Alice, prepares and measures the EPR pairs in the quantum communication and the users perform the four local unitary operations to encode their message. Anyone of the legitimate users can communicate another one on the network securely. Since almost all of the instances in this scheme are useful and each EPR pair can carry two bits of information, the efficiency for qubits and the source capacity both approach the maximal values.     

高压容器耐压及气密性试验检测系统的设计

在高压下使用的压力容器、阀门等产品，制成后需进行耐压试验和气密性试验以保证产品在工作压力下不泄漏。为此，研究设计了一套可采取自动和手动两种控制方式，对高压容器等产品安全地进行耐压、气密性试验的充气系统，及可在气密试验压力下检测漏率值的真空检漏系统。     

Exponential synchronization of stochastic impulsive perturbed chaotic Lur''e systems with time-varying delay and parametric uncertainty

This paper is devoted to investigating the scheme of exponential synchronization for uncertain stochastic impulsive perturbed chaotic Lur＇e systems. The parametric uncertainty is assumed to be norm bounded. Based on the Lyapunov function method, time-varying delay feedback control technique and a modified Halanay inequality for stochastic differential equations, several sufficient conditions are presented to guarantee the exponential synchronization in mean square between two identical uncertain chaotic Lur＇e systems with stochastic and impulsive perturbations. These conditions are expressed in terms of linear matrix inequalities （LMIs）, which can easily be checked by utilizing the numerically efficient Matlab LMI toolbox. It is worth pointing out that the approach developed in this paper can provide a more general framework for the synchronization of multi-perturbation chaotic Lur＇e systems, which reflects a more realistic dynamics. Finally, a numerical example is provided to demonstrate the effectiveness of the proposed method.     

羟基硅烷的偶极矩

用溶液法测定三甲基羟基硅烷、三苯基羟基硅烷、二甲基二羟基硅烷和二苯基二羟基硅烷的偶极矩,实验数据按 Guggenheim 法计算得到的结果分别是1.53,1.51,1.94,1.74 D。与 Grubb-Osthoff 所给两种羟基硅烷的偶极矩值相差甚大。而 Malatesta-Pizzotti 的结果是与本工作的结果相协调的。偶极矩数据指出:在二羟基硅烷的结构中,两个羟基的内旋转是受阻的,其择优排布使两个 RSi-OH 基团极矩矢量间约成102°的夹角。     

复合三角柱光子晶体传输特性研究

应用平面波展开法研究了二维复合介质柱光子晶体中引入缺陷和改变其折射率对传输特性的影响,得到了不同尺寸和介电常数下的透射谱,并与无复合介质柱光子晶体的结果进行了比较。结果表明：复合柱越细,禁带越宽,中心频率越高,变化关系与无复合柱的结果相反;复合柱折射率越大,禁带越窄,中心频率越低,与无复合柱的结果相同。     

分散固相萃取-液相色谱-串联质谱法测定水果中19种酸性农药

建立了同时检测葡萄、苹果和桔子等水果中2,4-滴等19种酸性农药的分散固相萃取-液相色谱-串联质谱(HPLC-MS/MS)方法。葡萄、苹果和桔子样品经乙酸-乙腈(1∶99,V/V)提取后,C18分散固相萃取净化,采用反相C18色谱柱分离。以0.1%甲酸和0.1%甲酸-乙腈溶液作为流动相进行梯度洗脱,采用多反应监测离子模式进行定性分析,基质标准曲线外标法进行定量分析,线性范围在0.01~0.2 mg/kg之间。在0.02,0.05和0.1 mg/kg添加水平下,19种酸性农药的回收率为70.3%～105.3%;相对标准偏差为0.37%～10.9%。本方法的定量限为0.005～0.02 mg/kg。     

具有m条切换线的扰动微分系统的极限环

本文研究具有m条切换线的扰动微分系统的极限环个数问题.所用方法的关键点是通过计算一阶Melnikov函数M(h)的生成元得到M(h)的代数结构.本方法可以用来研究其它具有多条切换线的扰动微分系统的极限环分支问题.     

收益共享的寄售契约下供应商生产成本谎报行为分析

在收益共享寄售契约下的两级供应链中,供应商向零售商报告其生产成本;零售商根据供应商报告的生产成本,决定零售商的收益分配比例;供应商决定零售价格和生产数量,并且保持产品的所有权.由于信息不对称,供应商可能谎报其生产成本.作者应用博弈论分析了供应商谎报行为对供应链及其成员决策及绩效的影响.利用解析的方法得出一些理论结果:零售价格在信息对称时小于生产成本信息不对称时;订货数量在信息对称时大于生产成本信息不对称时;零售商的利润分配比例在信息对称时大于生产成本信息不对称时.供应商的谎报行为使其自身利润增加,使零售商和供应链的利润减少.