Rh(acac)(CO)2的振动光谱及其简正坐标分析

Rh(acac)(CO)_2是烯烃氢甲酰化、氢硅化及一氧化碳加氢反应重要催化剂.晶体具有红绿二色性·在4000至80cm~(-1)范围测定了其红外和拉曼光谱;采用简化的一般价力场(SGVFF),对观测谱带进行了简正坐标分析。1 实验方法Rh(acac)(C0)_2按文献方法合成,并重结晶。红外光谱:用CsI压片在P-E 983G红外光谱仪上测试了4000～180cm~(-1)范围内的光谱,分辨率2cm~(-1).550～80 cm~(-1)波段在Digilab FTS-20E/D-V真空型傅氏光谱仪上得到。     

双(2,2-二硝基丙基)肼甲硼氢络合物的合成及性能研究

本文报道了双(2,2-二硝基丙基)肼甲硼氢络合物的合成及其性能。实验表明,该络合物在较低温度下(0～5℃)有一定安定性,放置几天后,基本不变,在稍高温度下(20～25℃)放置1～2小时即迅速分解,自燃或自爆。此外,还讨论了可能的机理。     

A New Sesquiterpene Lactone from Scorzonera austriaca

A new guaianolide was isolated from the roots of Scorzonera austriaca. The structurewas elucidated on the basis of spectral methods including 2D NMR.     

PEG-400 as an efficient reaction medium for the synthesis of 2,4,5-triaryl-1H-imidazoles and 1,2,4,5-tetraaryl-1H-imidazoles

An efficient protocol for the one-pot multicomponent synthesis of various 2,4,5-triaryl- IH-imidazoles and 1,2,4,5-tetraaryl-1H-imidazoles using PEG-400 as reaction medium is described. This method has the advantages of good yields, less pollution and simple reaction conditions.     

Synthesis of gibbilimbols B and D by a modified Ramberg-Bcklund reaction

Gibbilimbols B and D were synthesized from the facile rearrangement of sulfone in the presence of dibromodifluoromethane and alumina-supported KOH in dichloromethane,followed by refluxing the rearrangement products in conc.HCl and methanol and then treating with thiophenol in the presence of AIBN.     

A possible proton pygmy resonance in ~(17)Ne

The low-lying electric dipole strengths in proton-rich nuclei 17F and 17Ne, which can be produced at HIRFL-CSR in Lanzhou, are investigated. In the framework of the covariant density functional theory the self-consistent relativistic Hartree Bogoliubov model and the relativistic quasiparticle random phase approximation with the NL3 parameter set and Gogny pairing interaction are adopted in the calculations. A pronounced dipole peak appears below 10 MeV in17Ne, but does not occur in 17F. The prop erties of t...     

预热速率和Mg粒度对MgCNi_3致密度及相成份的影响

用自蔓延高温合成法(SHS)制备了MgCNi_3超导块材,用XRD和SEM对试样进行了表征,理论计算和实验结果表明,如果预热温度太低,自蔓延过程不能进行,当预热温度大于620℃时才能用电弧引燃反应,预热速率越小试样越致密;Mg粒度越小反应后绝热温度越高,成相速率越快,并导致合成产物出现烧结现象,样品所形成的致密度和孔洞尺寸依赖于原始Mg粉的粒度,Mg粒度越小,试样越致密,孔洞越小,但是Mg粒度不同不改变晶粒的形成和生长机理.     

A constitutive model of frozen soil with damage and numerical simulation for the coupled problem

Based on the microcosmic mechanics of composite materials, an elastic constitutive model for frozen soil with damage is presented. For frozen sandy soil with a range of ice contents and under a range of temperature conditions, quantitative results determined by this constitutive model agree with practically measured stress-strain curves. After numerically simulating the coupled water, temperature and stress fields of channel frozen and frozen roadbed using a self-developed finite-element routine, more accur...     

Surface Confined Ionic Liquid—A New Stationary Phase for the Separation of Ephedrines in High-performance Liquid Chromatography

In this article, a new and effective stationary phase based on ionic liquid modified silica is first reported and used for the separation of ephedrines in high-performance liquid chromatography (HPLC). The separation results indicate the high efficiency and reproducibility of the stationary phase. The electrostatic interaction, ion-exchange interaction between the solutes and the stationary phase are considered to attribute the effective separation. Moreover, the free silanols on the surface of the silica are effectively masked by the immobilized ionic liquid, a result of which is to decrease the non-specific absorption.     

The Preparation of Perovskite Nano Powder by Sol-gel from DTPA and the Mechanism of Thermal Decomposition

Dy0.8Sr0.2FeO3 nano powder, a synthetic oxide, is made by sol-gel method from metal nitrate and diethylenetriaminepentaaeetic acid (DTPA), and the processing parameters are optimized.The process of the preparation, thermal decomposition and the property of the powder are studied by TG-DTA, IR, TEM, and XRD. The diameter of the average grain is about 70 nm. This new technique can be used in the preparation and the studying of ha‘no materials in the complex oxide system.