Synthesis,microwave‐promoted catalytic activity in Suzuki–Miyaura cross‐coupling reactions and antimicrobial properties of novel benzimidazole salts bearing trimethylsilyl group

A mixture of benzimidazole salts (2–7), Pd(OAc)₂ and K₂CO₃ in DMF–H₂O catalyzes the Suzuki–Miyaura cross‐coupling reactions promoted by microwave irradiation resulting in high yield within a short time. In particular, the yield of the Suzuki–Miyaura reactions with aryl bromides was found to be nearly quantitative. The synthesized benzimidazole salts (2–7) were identified by ¹H‐¹³C, NMR, IR spectroscopic methods and microanalysis. The molecular structure of 1 was determined by X‐ray crystallography. The antibacterial and antifungal activities of the novel benzimidazole derivatives (1–7) were also tested against standard strains. Copyright © 2011 John Wiley & Sons, Ltd.     

Study on the Crystal Structure of RS-1-(2-methoxyphenyl)-4-〔3-(1-naphthyloxy)-2-hydroxypropyl〕-piperazine

ＩＮＴＲＯＤＵＣＴＩＯＮＮａｆｔｏｐｉｄｉｌ，ＲＳ １ （２ ｍｅｔｈｏｘｙｐｈｅｎｙｌ） ４ 〔３ （１ ｎａｐｈｔｈｙｌｏｘｙ） ２ ｈｙｄｒｏｘｙｐｒｏｐｙｌ〕 ｐｉｐｅｒａｚｉｎｅ，ｉｓａｎｏｖｅｌａｎｔｉｈｙｐｅｒｔｅｎｓｉｖｅｄｒｕｇｃｕ...     

肾性骨病与微量元素铝相关性观察

观察了32例慢性肾功能衰竭(CRF)患者血铝含量,平均为12668±06358,明显高于正常人血铝07286±00826,P<001;血铝与血钙水平呈负相关r=-06235,P<005;肾性骨病(ROD)患者血铝明显高于非骨病患者(P<005)。提出CRF患者有明显铝蓄积,并且与ROD有相关性。对CRF患者应注意血铝的监测,以便进行针对性预防和治疗。     

KrF激光受激布里渊散射反射率稳定性的研究

实验研究发现抽运功率密度（或抽运能量）的波动引起的受激布里渊散射(SBS)反射率的不稳定程度受实验参数（抽运能量、介质气压和透镜焦距）的影响.当抽运能量、介质气压和透镜焦距这三个参数同时满足下列条件时可以获得稳定的输出：抽运能量超过5倍的SBS阈值，介质气压在16×105Pa和透镜焦距在15—50cm的范围内；同时还发现当改变实验参数时SBS反射率与稳定性的变化规律完全一致，反射率越高稳定性越好.通过理论分析得到 SBS反射率的相对稳定度实际上是受GIL因子的影响，理论计算与实验符合得很好. 关键词： KrF激光 受激布里渊散射 反射率 稳定度     

Application of the method of split rigidities to anisotropic laminated shallow shells

In this paper, according to the method stated by Hu Haichang in [3], on the basis of [1], the method of split rigidities is generalized for the purpose of solving the problems of lateral deflection, stability and lateral vibration for anisotropic laminated shallow shells, and a simple and practical approximate method is obtained, in which the errors and computing work are comparatively small.     

ELASTO-PLASTIC COUPLED ANALYSIS OF BURIED STRUCTURE AND SOIL MEDIUM BY PERTURBATIONAL SEMI-ANALYTIC METHOD

I.IntroductionMoreandmoreelasto-plasticanalysesareusedinCivilEngineering.TheMohr-Coulombyieldconditionisoftenappliedtorockandsoilmediumtostudythesituationofdestruction.Theperturbationalmethodwasfirstusedinthestudyofcelestialmechanics,thenithasbeenusedinsolidmechanicstocarryoutthegeometricallyandphysicallynonlinearanalysis[']'12].Forlarge?scalcproblems,thegeneralnumericalmethodsmaynotbeapttothiscomplexcalculation,butsemi-analyticalmethodscandoitwell.Touseanalyticalfunctionsinoneortwodirectio…     

多模式自适应重要抽样法及其应用

针对多模式的可靠性分析，研究了其失效概率计算的自适应重要抽样法，该方法用模拟退火 算法来自动调整每个失效模式的重要抽样函数，使其逐渐趋近于估计方差最小的重要抽样 函数. 对于多个模式系统失效概率的计算，采用混合加权自适应重要抽样的方法, 反映了每个 失效模式对系统失效概率的贡献；对于系统失效模式所含基本变量不全相同的情况，提出了 扩展自适应重要抽样法, 来统一所有失效模式中的基本变量，从而使得混合自适应 重要抽样, 可以方便地求解变量不全相同时的系统失效概率. 对估计值方差和变异系数的计算公 式进行了推导. 验证算例结果, 充分说明方法的合理性与可行性.     

Finite difference method for 2-D and 3-D nonlinear free surface wave problems

A finite difference method is developed for the numerical modelling of the 2-D and 3-D unsteady potential flow generated by transient disturbances on the free surface, on which the nonlinear boundary conditions are fully satisfied. The unknown function is computed with an iteration scheme processing in a transformed time-invariant space. After the velocity is calculated, the location of the free surface is renewed and so is the value of velocity on it. The boundary-value problem of the governing equation is then solved at the next time step. The present method incorporates the FFT. Consequently, a tri-diagonal equation system is obtained which could be readily solved. The feasibility of this method has been demonstrated by 2-D and 3-D examples corresponding to different initial disturbances. This work is supported by the science foundation of Academia Sinica. The paper had been accepted by the XVIth International Congress of IUTAM, Lyngby, Denmark, August, 1984.     

挤压油膜阻尼器-滑动轴承-柔性转子系统的动力响应分析

建立了挤压油膜阻尼器-滑动轴承-柔性转子非线性系统的动力学模型,采用Runge-Kutta法进行求解,进而对系统的稳定性和分叉行为进行了研究。仿真计算结果表明,系统能够在一定范围内保持稳定,随着转速的变化系统将会出现倍周期、准周期及混沌响应,从而为有效地控制转子的稳定运行状态提供了理论依据。     

考虑基本变量模糊与随机性的广义自适应重要抽样法

基于模糊随机广义可靠性分析向随机可靠性分析的转换,提出了模糊随机广义失效概率计算的自适应重要抽样法,该方法利用模拟退火智能优化,在模拟的过程中逐步逼近模糊随机广义设计点,并在模拟过程中自适应地构造重要抽样函数,从而使得模糊随机失效概率的计算效率和精度大为提高。与传统的重要抽样法相比,本文方法无需首先求解失效模式的设计点。对非线性失效区和复杂等价概率密度函数,由于模拟退火智能优化在寻找设计点时比诸如一次二阶矩法(FOSM)更为有效,因而所提方法适合非线性失效区和复杂等价概率密度函数情况下的广义可靠性分析。另外,随着重要抽样密度函数逐步向最优值的自动调整,抽取的样本数逐渐增大,使后续构建的重要抽样函数更能体现对广义失效概率贡献的重要程度,并使失效概率的计算更加准确。文中算例证明了所提方法的合理性。