Copper(II)-acid co-catalyzed intermolecular substitution of electron-rich aromatics with diazoesters

The intermolecular aromatic substitution of N,N-dialkylanilines and alkoxybenzenes with diazoesters is shown to proceed in the presence of catalytic amounts of both copper(II) salt and acid (Lewis or Brønsted). This method is a mild and rare metal-free C-C bond formation reaction between aromatic (sp²) and aliphatic (sp³) carbons.     

Synthesis,crystal structure,and third-order non-linear optical properties of a new Cd(II) polymer constructed from pyrazine-2-carboxylic acid

A new cadmium(II) pyrazine-2-carboxylate coordination polymer, {[Cd(L)(H₂O)₂(SO₄)_0.5]₂·H₂O}_n (1) (HL = pyrazine-2-carboxylic acid), has been synthesized by low-temperature solid-state reaction. Single-crystal X-ray analyses reveal that 1 possesses a 3-D framework structure. The polymer 1 was characterized by elemental analyses, thermogravimetric analyses, X-ray powder diffraction analyses, IR spectra, and UV–visible spectra. The third-order non-linear optical properties were also investigated and they exhibit nice non-linear absorption and self-defocusing performance with modulus of the hyperpolarizability (γ) 1.30 × 10^?30 esu for 1 in a 2.01 × 10^?4 M?dm^?3 DMF solution.     

复合型改性木质素基钻井液用降粘剂的性能研究

以马尾松硫酸盐制浆黑液为原料,经化学改性制备复合型改性木质素基钻井液用降粘剂,并对其在钻井液中的降粘性能进行实验室评价。研究结果表明,该降粘剂既能发挥无机降粘剂良好的降粘作用,又具有木质素系降粘剂良好的抗温、抗盐效果,具有较好的协同作用。加入0.5%降粘剂的淡水基浆,降粘率可达96.7%。     

复合Poisson-Geometric风险模型的预警区问题

应用有别于传统鞅方法的方法,充分利用盈余过程的强马氏性,在一类复合Poisson-Geometric风险模型下讨论预警区问题,得到第一个预警区的一个条件矩母函数所满足的微积分方程,并在指数索赔情形下给出其精确解.     

盐湖镁资源的开发和利用*

我国盐湖镁资源品位高、储量大、易于开采,但目前的开发利用明显滞后,在一定程度上影响了盐湖其它资源的可持续开发和综合利用。本文针对我国盐湖镁资源的特点,综述了和盐湖镁资源开发利用相关的氢氧化镁、氧化镁、金属镁、镁合金、氯氧镁水泥和镁质晶须的开发及研究进展,并对我国盐湖镁资源的开发利用提出了一些建议。     

超分子化合物(C_(12)H_(10)N_4)(C_7H_6O_3)_2的合成、晶体结构及荧光性质

合成了超分子化合物(C_(12)H_(10)N_4)(C_7H_6O_3)_2,并进行了元素分析、红外光谱、紫外光谱表征和单晶X射线衍射分析.构筑单元之间通过多重氢键和π-π堆积作用的协同效应形成超分子化合物,并研究了化合物的固体荧光性能.研究表明:该晶体属于单斜晶系P2_1/c空间群,晶胞参数为:a=0.3974(1) nm,b=2.0330(2) nm,c=1.4343(1) nm, β=94.892(2)°,V=1.15440(19) nm~3,d_c=1.400 g/cm~3,Z = 2,μ= 0.102 mm~(-1),F_((000))=508,R_1=0.0359,wR_2=0.0893 [I>2σ(I)].     

Two dimensional analytical solution for a partially vegetated compound channel flow

The theory of an eddy viscosity model is applied to the study of the flow in a compound channel which is partially vegetated. The governing equation is constituted by analyzing the longitudinal forces acting on the unit volume where the effect of the vegetation on the flow is considered as a drag force item, The compound channel is divided into 3 sub-regions in the transverse direction, and the coefficients in every region＇s differential equations were solved simultaneously. Thus, the analytical solution of the transverse distribution of the depth-averaged velocity for uniform flow in a partially vegetated compound channel was obtained. The results can be used to predict the transverse distribution of bed shear stress, which has an important effect on the transportation of sediment. By comparing the analytical results with the measured data, the analytical solution in this paper is shown to be sufficiently accurate to predict most hydraulic features for engineering design purposes.     

α、ω-双香豆素长链化合物激基缔合物的研究

通过α、ω－双香豆素长链化合物详细研究了香豆素激基缔合物的荧光行办，通过吸收光谱、荧光光谱和激发光谱，考察了香豆素激基缔合物的发光位置与激发波长，借助单光子技术确定了形成的是分子内的激基缔合物，通过1HNMR谱研究了不同双香豆素长链化合物的构象分布，揭示了在水溶液中由于疏水相互作用促进了长链化合物分子内激基缔合物的形成．     

顶空气相色谱法测定化妆品中15种挥发性有机溶剂残留

建立了化妆品中15种挥发性有机溶剂残留的顶空气相色谱测定方法。样品经60 ℃、30 min静态顶空后,采用气相色谱-氢火焰离子化检测器进行检测,外标法定量。加标回收试验结果表明: 15种挥发性有机溶剂残留平均回收率为62.8%～116%,相对标准偏差均小于5%。方法的检出限为0.09～0.68 mg/kg。该方法可有效克服基体干扰,一次进样可同时分离和测定化妆品中15种挥发性有机溶剂,准确灵敏,简单快速,适用于化妆品中挥发性有机溶剂残留的检测。     

Molecular Dynamic Simulation on the Absorbing Process of Isolating and Coating of α-olefin Drag Reducing Polymer

The absorbing process in isolating and coating process of α-olefin drag reducing polymer was studied by molecular dynamic simulation method, on basis of coating theory of α-olefin drag reducing polymer particles with polyurethane as coating material. The distributions of sodium laurate, sodium dodecyl sulfate, and sodium dodecyl benzene sulfonate on the surface of α-olefin drag reducing polymer particles were almost the same, but the bending degrees of them were obviously different. The bending degree of SLA molecules was greater than those of the other two surfactant molecules. Simulation results of absorbing and accu-mulating structure showed that, though hydrophobic properties of surfactant molecules were almost the same, water density around long chain sulfonate sodium was bigger than that around alkyl sulfate sodium. This property goes against useful absorbing and accumulating on the surface of α-olefin drag reducing polymer particles; simulation results of interactions of different surfactant and multiple hydroxyl compounds on surface of particles showed that, interactions of different surfactant and one kind of multiple hydroxyl compound were similar to those of one kind of surfactant and different multiple hydroxyl compounds. These two contrast types of interactions also exhibited the differences of absorbing distribution and closing degrees to surface of particles. The sequence of closing degrees was derived from sim-ulation; control step of addition polymerization interaction in coating process was absorbing mass transfer process, so the more closed to surface of particle the multiple hydroxyl com-pounds were, the easier interactions with isocyanate were. Simulation results represented the compatibility relationship between surfactant and multiple hydroxyl compounds. The isolating and coating processes of α-olefin drag reducing polymer were further understood on molecule and atom level through above simulation research, and based on the simulation, a referenced theoretical basis was provided for practical optimal selection and experimental preparation of α-olefin drag reducing polymer particles suspension isolation agent.