邻位吡啶自由基多通道分解反应的动力学和反应机理研究

Utilizing Gaussian94 program package, all species involved in decomposition reactions of o-pyridyl radical were optimized fully at B3LYP/6-311＋＋G^＊＊ level. Intrinsic reaction coordinate calculations were employed to confirm the connections of the transition states and products, and transition states were ascertained by the number of imaginary frequency （0 or 1）. The reaction mechanism was elucidated by the vibrational mode analysis and electronic population analysis, and the reaction rate constants were calculated with transition state theory.     

非绝热、非周期演化量子相位特征与测量研究

以二能级原子系统为模型, 细致地研究了非绝热演化量子相位特征. 基于量子干涉原理, 提出了一种测量非绝热演化量子相位的新方法. 且阐述了这种测量方法的物理机理, 利用这种方法在原子态布居几率的干涉条纹中可直接获得量子相位的分布信息.     

大底盘双塔结构层间隔震技术的抗震性能分析

大底盘双塔结构在地震时底盘与上部塔楼连接处的薄弱层易遭到破坏。为解决竖向刚度不均匀造成的地震破坏,采用层间隔震技术,在大底盘与上部塔楼之间设置隔震层,减小传入上部结构的地震作用。运用SAP2000有限元分析软件,建立层间隔震结构和非隔震结构模型,对其进行时程分析。结果表明:隔震结构的加速度幅值,层间位移,底部剪力都相应地减小;隔震结构的变形主要由隔震层承担,隔震结构加速度和层间位移在隔震层处达到最大值,层间剪力在隔震层处大幅度减小,起到了相应的隔震效果,为工程实际提供了理论依据。     

Quantum diffraction of wave function in time-domain

The transition of a two-level system driven by a linearly weak chirped pulse is studied. Under the first order perturbation approximation, an analytical expression of the population probability is obtained, which is similar to the one describing Fresnel diffraction by a straight edge. It is shown that the population oscillation results from the diffraction of quantum wave function in time-domain. Supported by the Natural Science Foundation of Shaanxi Province of China (Grant No. 2007A04)     

同多钨酸根柱撑镍铝水滑石的原位合成

采用原位沉积法在γ-Al₂O₃表面原位合成了对苯二甲酸阴离子柱撑的镍铝水滑石,并用同多钨酸根阴离子部分交换了镍铝水滑石中的对苯二甲酸阴离子。用XRD,BET, FT-IR和TG-DTA等测试方法对材料进行表征。结果表明,经过同多钨酸根阴离子的交换以后,垂直于水滑石层板方向的平行层板方向的晶格参数(c)值变小,平行层板方向的晶格参数(a)值不变,(003)、(006)、(009) 衍射峰处的层间距(d)值比为3∶2∶1;交换过程没有改变水滑石的结构,水滑石原位生长在γ-Al₂O₃表面及内孔,比表面积由γ-Al₂O₃载体的219m²/g增加到247m²/g,孔径分布则由原来的2～11nm变化为3～4nm。     

Reaction Mechanism of the Multi-channel Decomposition Reactions of C_(10)H_(14)~+·

n-Butylbenzene cations C10H14^＋ serve as a model compound to investigate the reaction mechanisms of alkylbenzene cations. The reactions of C10H14^＋. decomposition reaction system have been studied extensively at the B3LYP/6-311＋＋G^＊＊ level with Gaussion98 package. The chain reaction of C10H14^＋ dissociation was initiated by C-H bond rupture. All reaction channels initiated by C-H rupture were fully investigated with the vibrational mode analvsis to confirm the transition states and to reveal the reaction mechanism. A theoretical investigation on the reactions of this positive ion free radical can help us fully understand the decomposition processes.     

Squeezing bandwidth controllable twin beam light and phase sensitive nonlinear interferometer based on atomic ensembles

We review our recent experimental progress in quantum technology employing amplification effect of four-wave mixing in a rubidium vapor. We have produced an intensity difference squeezed light source at frequencies as low as 1.5 kHz which is so far the lowest frequency at which squeezing has been observed in an atomic system. Moreover, we find that the bandwidth of our squeezed light source can be controlled with light intensity pumping. Using our non-classical light source, we have further developed a nonlinear Mach-Zehnder (MZ) interferometer, for which the maximum fringe intensity depends quadratically on the intensity of the phase-sensing field at the high-gain regime, leading to much better sensitivity than a linear MZ interferometer in which the beam splitters have the same phase-sensing intensity. The quantum technologies developed by our group could have great potential in areas such as precision measurement and quantum information.     

Study on the α-cyclodextrin/poly(ethylene glycol) self-assembly supramolecular nanoparticles for drug delivery

This paper reports the synthesis and drug delivery properties of a novel supramolecular nanoparticle.α-Cyclodextrins(α-CD) were threaded on cinnamic acid modified poly(ethylene glycol) to form inclusion complex nanoparticles by supramolecular self-assemble.The anti-tumor drug doxorubicin was loaded in the nanoparticles and released in vitro to study the drug release behavior and the anti-tumor effects.The structure and morphology of the nanoparticles were characterized by nuclear magnetic resonance,X-ray di...     

有机化合物中巯基官能团的选择性氧化

本文综述了２０余年来关于有机化合物中巯基官能团的多种选择性氧化剂和氧化方法．     

A Convenient Synthesis of Conjugated Acetylenic Ketones by Copper(l)-Catalyzed under Microwave Irradiation

Alkynyl ketones are useful precursors and intermediates in synthetic organic chemistry1 and has evoked considerable interest. A number of methods for the synthesis of conjugated acetylenic ketones involve the reaction a metal acetylide with an acyl chlorides or another carboxylic acid derivative have been developed 2. Recently, the synthesis of α, β-conjugated acetylenic ketones catalyzed by Pd(Ⅱ) or by copper(Ⅰ)pd(Ⅱ) reaction of 1-alkynes and acyl chlorides have been described. The acylation of terminal alkynes by acyl chlorides in the presence of catalytic amounts copper(Ⅰ) salts leading to α, β-conjugated acetylenic ketones has also been reported. However, many of these reactions suffer from lack of high pressure (17 atm), long reaction time (30 h)and require low temperatures (-78℃). Our work involves the synthesis of conjugated acetylenic ketones via the reaction of terminal alkynes with aroyl chlorides in the presence of cuprous iodide under microwave irradiation conditions.