Electrostatic surface guiding of cold polar molecules with a single charged wire

This paper proposes a scheme to guide cold polar molecules by using a single charged wire half embanked in an insulating substrate and a homogeneous bias electric field, which is generated by a plate capacitor composed of two infinite parallel metal plates. The spatial distributions of the electrostatic field produced by the combination of the charged wire and the plate capacitor and the corresponding Stark potentials (including dipole forces) for metastable CO molecules are calculated, the relationships between the electric field and the parameters of our charged-wire layout are analysed. It also studies the influences of the insulator on the electric field distribution and the discharge effect. This study shows that the proposed scheme can be used to guide cold polar molecules in the weak-field -- seeking states, and to form various molecule-optical elements, such as molecular funnel, molecular beam-splitters and molecule interferometer, even to construct a variety of integrated molecule-optical elements and their molecule chips.     

毛细管区带电泳法同时测定饲料中西马特罗、盐酸克伦特罗和沙丁胺醇

建立了同时测定饲料中西马特罗、盐酸克伦特罗与沙丁胺醇的毛细管区带电泳-紫外检测方法。考察了实验参数对 分离和检测结果的影响。在最佳实验条件下,在60 mmol/L的柠檬酸-柠檬酸钠运行缓冲液(pH 6.29)中,上述3种物质在8 min内完全分离。西马特罗、盐酸克伦特罗和沙丁胺醇的线性响应范围为0.1~1.0 mg/L,最低检测限(以信噪比为3计)分 别为0.02,0.03和0.02 mg/L。所建立的方法直接用于饲料中西马特罗、盐酸克伦特罗和沙丁胺醇的测定,结果令人满意 。     

不同的引导肽对丝状噬菌体基因8蛋白展示外源多肽的影响

为了研究不同的引导肽对在基因8蛋白上展示外源多肽的影响,利用基因工程方法将一短肽插入基因8蛋白的N端,并将引导多肽去除或用基因3蛋白的引导肽序列替代基因8的引导肽序列.采用放射性脉冲追踪技术检测不同的引导肽对在基因8蛋白上展示外源多肽的作用.结果表明,无引导肽序列的引导,蛋白前体无法向成熟蛋白转化.基因3蛋白的引导肽可以引导展示有外源多肽的基因8蛋白,完成从前体向成熟蛋白的转化,但转化率明显下降.研究结果对阐明噬菌体外壳蛋白在大肠杆菌中的跨膜机制具有重要的意义.     

一类推广的带干扰风险模型的条件破产概率

本文首先利用随机时刻变换推广了一类带干扰的风险模型,然后讨论这类风险模型的条件破产概率.研究表明条件破产概率相对于无条件破产概率能提供更多有用信息,这对保险公司及时调整投资和管理策略是很有帮助的.     

染料-示波计时电位法测定天然水中的不同形态铝

槲皮素;羟基喹啉-磺酸;染料-示波计时电位法测定天然水中的不同形态铝     

均聚物结晶与熔融化的稳态和亚稳态转变统计理论

基于多重微晶网络结构模型和分子分凝机制建立了高分子晶体的微晶核-和微晶粒-高分子链组模型,推导出了平衡态下高分子预结晶动力学方程,计算出了平衡态下不同尺寸微晶核-和微晶粒-高分子链组的几率分布函数.建立了非稳态下不同尺寸的微晶核-高分子链组的成核演化方程和微晶粒-高分子链组的增长演化方程,求解一般状态下的两个演化方程后,得到了不同时间和不同尺寸的微晶核-和微晶粒-高分子链组的一般密度分布函数.最后根据成核自由能和增长自由能对晶核和晶粒的尺寸大小的依赖性,提出了微晶核-高分子链组和微晶粒-高分子链组存在稳定性的热力学条件和动力学条件,成功地表征为三个特征区(稳态、亚稳态和非稳态).     

Magnetic guide of cold atoms using a U-shaped current-carrying conductor

We propose a new scheme to magnetically guide cold neutral atoms using a U-shaped current carrying conductor. The spatial magnetic field distribution from the U-shaped current-carrying conductor and the relationship between the magnetic field and parameters of the U-shaped conductor are analysed. Our study shows that U-shaped current-carrying conductor can be used to realize single- or double-channel magnetic guiding of cold atoms in weak-field-seeking states and to construct various atom-optical elements. By using Monte Carlo simulations, the dynamic process of the guided atomic-beam splitting in an atomic-beam splitter composed by the U-shaped current-carrying conductor is studied, and some results are presented.     

毛细管电泳-安培检测法测定生物活性肽的研究

采用毛细管电泳-安培检测法对生物活性肽Tyr-Trg,Tyr-D-Arg和Tyr-Gly-Gly进行了分离检测,获得了较好的结果.     

Quantitative prediction of substituted products based on quantum-chemical parameters and neural network method

The criterion of orientating group of electrophilic aromatic nitration was discussed by means of pattern recognition method with quantum-chemical parameters as features, and the product ratios of the reactions were quantitatively calculated using artificial neural network (ANN) method with the same parameters as inputs, based on the ab initio calculation of quantum chemistry. The quantum-chemical parameters involved orbital energy, orbital electron population, atomic total electron density and atomic net charge. The predicted values are in agreement with experimental results and (he predicted error of the ANN with quantum-chemical parameters for the reaction is the smallest among the all methods.     

Synthesis of two pentaarylated [60]fullerene derivatives Ar_5C_(60)-H (Ar = p-MeC_6H_4, m-MeC_6H_4) and their novel electrochemical properties

Through one pot reaction of C60 with organocopper/magne-sium reagent ( p - MeQ H4 )2 CuMgBr or ( m - MeC6 H )2 -CuMgBr prepared from CuBr-Me2S and p-MeC6H4MgBr or m-MeC6H4MgBr and subsequent quenching with aqueous NH4Cl, two pentaarylated [60] fullerene derivatives (p-MeC6H4)5C60H (1) and (m-MeC6H4)5C60H (2) have been synthesized in 94% and 96% yields, respectively. While known compound 1 prepared via this improved method is unambiguously identified, new compound 2 is fully characterized by elemental analysis, IR, UV-vis, 1H NMR and 13C NMR spectroscopies. Additionally, electrochemical study shows that the two [60] fullerene derivatives 1 and 2 in dichloromethane solution display two sequential one-electron reductions which are shifted by about 0.4V towards more negative potential values with respect to free C60. Such remarkable cathodic shift is attributed to the multiple breakage of the double-bond conjugation within the fullerene core.