THE EFFECT OF IONIC STRENGTH ON THE UPTAKE OF TAURINE ON A STRONG-BASIC ANION EXCHANGE RESIN

1. INTRODUCTION Taurine (NH2CH2CH2SO3H) is one of the most important amino acids in the human body, and plays an important role in a variety of physiological functions, pharmacological actions and pathological conditions, such as in controlling epilepsy, hypertension and arrhythmia. It is also often used to recover osmotic pressure and promote cerebrum growth [1,2]. As one of amino acids, taurine had the amphoteric characteristic which can be utilized in the ion-exchange technique to e…     

A New Quaternary Ammonium Heteropolyoxotungstate Catalyst for Propylene Epoxidation to Propylene Oxide

A new quaternary ammonium heteropolyoxotungstant (cat.C) is prepared and characterized. And the cat.C also is an reaction-controlled phase-transfer catalyst. The catalytic system of O2/EAHQ (2-ethylanthrahydroquinone)/cat.c is used for the epoxidation of propylene. Under the optimal conditions, the yield of propylene oxide based on EAHQ is 84.1%, theselectivity for propylene oxide based on propylene is 99.8% and the conversion of propylene based on EAHQ is 84.3%. The cat.c precipitates after the epoxidation reaction for easy separation. The cat. C is stable enough to be recycled three times without any loss in selectivity.     

退化扩散过程小扰动的平均越出时间估计

本文研究了Ｒ＾ｄ上的扩散过程｛Ｘεｔ｝，它是Ｒ＾ｄ上退化扩散过程｝Ｘｔ｝的小随机扰动，其中｛Ｘｔ｝满足随机微分方程ｄＸｔ＝ｂ（Ｘｔ）ｄｔ＋τ（Ｘｔ）ｏｄＷｔ；｛Ｘ＾εｔ｝满足随机微分方程ｄＸ＾εｔ＝ｂ（Ｘεｔ）ｄｔ＋τ（Ｘ＾εｔ）ｏｄＷｔ√εσ（Ｘ＾εｔ）ｄＢｔ，ε〉０。     

SYNTHESIS AND CHARACTERIZATION OF NOVEL SOL-GEL DOPED ORGANIC/INORGANIC HYBRID NONLINEAR OPTICAL MATERIALS

1.INTRODUCTIONInthe21thcentury,thephotoelectrontechnologyisgraduallyreplacingmicroelectronicsone.Todevelopphotoelectronindustryhasbecomethemostcharmingoneinnewcentury,whilenonlinearopticalmaterials(NLO)isjustanimportantphotoelectronicalmedia,andcanbewidelyusedinallfieldsofthephotoelectronindustry.TheopticalpropertiesoftheexistingNLOmaterialsarestillfarfromthenecessaryforthepracticaluseofphotoelectronicdevice.ManypreparationtechnologiesweredevelopedinordertoimprovethequalityofNLOmateria…     

Structural evolution of the intruder band in 118Sn

Excited states of the positive-parity intruder band in~(118) Sn have been studied via the ~(116)Cd(~7Li,lp4n) reaction at ~7Li energy of 48 MeV using techniques of in-beam γ-ray spectroscopy.This intruder band has been observed up to 7187 keV with spin (16~+). The structural evolution of this intruder band with increasing angular momentum has been discussed in terms of the aligned angular momentum and the ratio of the E-Gamma Over Spin (E-GOS) curve.     

Ray-Tracing Simulation on Filamentation of Prefocused and Freely Propagated Laser Pulses in Air

The filamentation mechanisms of prefocused and freely propagated femtosecond laser pulses axe compared using the ray-tracing method. The dynamic spatial replenishment mechanism takes place in the filaments with high electron density, which is generally formed by prefocused laser pulses. The mechanism of long-range filamentation over lOOm distance is analyzed to be the spatiotemporal moving focus.     

关于两个驻波叠加结果的讨论

本文对在一条波线上的两个驻波的叠加结果进行了简明扼要的分析，对进一步理解行波和驻波之间的相互关系有积极的意义。     

用纵横波声时比法测螺栓轴力精度研究

用纵横波测量螺栓轴力的技术已取得较大发展,本文介绍了纵横波比值法原理,通过理论推导,获得比值法计算的简易公式。建立试验平台,用现场用螺栓进行标定和测量,得出比值法在工程实践状态下的测量误差为10%以内,基本能满足工程应用的要求。此外,针对试验结果,本文还初步探讨了误差出现的原因以及提高精度的方法。本文介绍的比值法,无需精确测量标定螺栓长度和纵横波声速,现场应用更加简洁,具有较大的工程应用价值。     

Preparation and conductivity of tungstovanadogermanic heteropoly acid polyethylene glycol (PEG) hybrid material

In this work, the polyethylene glycol (PEG) hybrid material composited with tungstovanadogermanic heteropoly acid was prepared. Infrared (IR) spectrum revealed that the Keggin structure characteristic of the anion was present in PEG hybrid material. At room temperature (20°C), the conductivity of the sample is 4.07×10⁻³ S cm⁻¹. The results indicated that it is a new kind of excellent high-proton conductor. According to the experimental results, we proposed a possible mechanism of the proton conduction of the hybrid materials.