Effect of Calix[4]pyrrole as Addition Reagent on Anions Separation in Capillary Zone Electrophoresis (CZE)

Calixpyrroles, as new macrocyclic receptors, have gain increasing interest in host-guest chemistry. Pioneering work in this area by Sessler and co-workers have evidenced that calix[4]pyrroles are effective anion binding agents and have used for anion binding, sensing and new anion separation technologies1, 2. In this letter, we report that calix[4]pyrroles A, B and C3,4 (Scheme 1) can serve as additives in CZE for the separa- tion of halide ions. Scheme 1 A B C When analyzing anions with…     

Design studies on the 4π γ-ray calorimeter for the ETF experiment at HIRFL-CSR

A high detection efficiency calorimeter which is used to detect γ-rays with energies from 1 MeV up to 10 MeV as well as light charged particles has been proposed. Design of the geometry, results of the crystal tests and Monte Carlo simulations are presented in this paper. The simulation results confirm that the calorimeter can obtain high detection efficiency and good energy resolution with the current designed geometry. And the calorimeter is competent for the future External Target Facility (ETF) experiments.     

OXIDATIVE COUPLING OF METHANE OVER Mn_2O_3-Na_2WO_4/SiO_2 CATALYST IN THE ABSENCE OF DILUTE GAS

The oxidative coupling of methane over Mn2O3-Na2WO4/SiO2 catalyst has been investigated in the absence of dilute gas. 16.4% of C2 yield and 80.4% of the selectivity to C2 hydrocarbons were obtained at CH4/O2 = 8.5/1.5. The effect of flow rate on the selectivity to C2 hydrocarbons and CH4 conversion was different under the reaction condition of different ratio of CH4 to oxygen. The flow rate had a more remarkable effect on the selectivity at the lower ratio of methane to oxygen. The addition of steam into the reaction gas can increase C2 yield to some extent, but that of HC1 decrease the selectivity to C2 hydrocarbons.     

A New Guaianolide from Saussurea macrota

A new guaianolide was isolated from Saussurea macrota.Its structure was elucidated by NMR spectroscopic and X-ray diffraction methods.     

同位旋非对称核物质性质与扩展的BHF方法(III)HVH定理与费米能量

在扩展的同位旋相关的Brueckner—Hartree—Fock理论框架内,在整个同位旋自由度范围内研究了质量算子的空穴线展开中不同等级近似下非对称核物质中Hugenholtz—Van Hove定理的满足程度,并计算了中子和质子的费米能量.结果表明为了使Hugenholtz-Van Hove定理达到令人满意的满足程度,需要同时考虑质量算子中的重排贡献和重正修正,从而指出了基态关联对于非对称核物质中单粒子性质的重要性.     

苄基酒石酸甲乙酯的立体选择性合成

本文报道了赤式苄基酒石酸甲乙酯(3)的立体选择性合成,其~1H核磁共振谱、红外光谱和质谱与预期的结构一致。这个方法对合成其它具有赤式酒石酸结构的天然产物有一定的参考价值。     

钠原子团簇的碰撞动力学

采用紧密结合的分子动力学模型，对第一个满壳附近（ｎ＝８）钠原子团簇碰撞Ｎａｎ＋Ｎａｎ的动力学性质进行了系统性研究。对有限温度下的多次模拟事件，在各种碰撞参数与不同轰击能量时，双团簇（Ｎａｎ）２的稳定性进行了研究。并发现，当质心系单原子能量为０．０２５ｅＶ时，对中心碰撞，（Ｎａ８）２能够存在３０００ｆｓ，而对周边碰撞，（Ｎａ８）２能够存在１００００ｆｓ；不管对中心碰撞还是对周边碰撞，在较低的轰击能量下，这种暂态双团簇结构具有较长的寿命；在相同的单原子轰击能量和相同的碰撞参数，（Ｎａ８）２和（Ｎａ９）２的动力学寿命没有差别，只是（Ｎａ８）２比（Ｎａ９）２的温度更低。     

Salen-Mn(III)-Complex-Catalyzed Oxidations of Secondary Alcohols

IntroductionCarbonylgroupsarethemostimportantfunctionalgroupsinorganicsynthesis ,andtheirintroductionbyoxi dationchemistrystartingfromalcoholsisaprocessofmajorimportance .1Earlyprotocolsforthistransformationreliedontheuseofstoichiometricoxidantssuchaschromium(VI)reagentsorMnO2 .2 Withthegoalofimprovingsyn theticefficiencyandavoidingpotentialenvironmentalhaz ards ,prominentsuccessinthisdirectionhasbeenrecentlyachievedbyutilizingmolecularoxygenwithanassistanceofpotenttransitionmetalcompounds.3…     

Synthesis of Gingerenone C and 5-Hydroxy-1-(4′-hydroxy-3-methoxyphenyl)-7-(4′′-hydroxyphenyl)-3-heptanone

Diarylheptanoidsconstituteadistinctgroupofmetabolitesofnaturalplantcharacterizedbytwoaromaticringslinkedbyalinearsevenaliphaticchain.Therehavebeenfewreportsonthebiologicalactivitiesofdiarylheptanoids,mostofwhichappearingintheareasofanti-inflammatory,anti-oxidative,superoxidescavengingandanti-hepatotoxiceffects1,2.SomeofthemareusedastraditionalmedicineinAsia3.Compound1and2werefirstlyisolatedfromtherhizomesofZingiberofficalrespectively4,5.Sofarthesynthesisofthesetwocompoundshavenotbeenreportedy…     

反相液体色谱中溶质保留行为的研究——保留行为与溶质及流动相性质的关系

本文从热力学乎衡的观点出发,导出了在一定的固定相和流动相中,描述保留行为与溶质性质关系的通用式,并通过实验及文献数据验证了该式,获满意结果。当固定相一定时,得出溶质保留值的对数1n k’与二元流动相中有机改性剂的组成呈二次函数关系,亦用实验验证了这种关系。讨论了三元体系中溶质的保留行为与流动相中两种有机改性剂间的关系,以及各种情况下影响色谱体系选择性的因素。