PROGRESS ON ACTIVATED CARBON FIBERS

1. INTRODUCTION The serious environment pollution and natural resources waste is imperiling human existence and development. To counter the exhaustion and dilution of natural resources, and to prevent environment from further pollution, it is their duty …     

Enantiomeric Separation of Epinephrine and Salbutamol by Micellar Electrokinetic Chromatography Using β-Cyclodextrin as Chiral Additive

Enantiomeric separation of epinephrine and salbutamol was investigated by micellar electrokinetic chromatography employing β-cyclodextrin as chiral additive in ammonium chloride-ammonia solution. The analytes were detected by electrochemistry using gold microelectrode at 0.65 V versus SCE reference electrode. The effects of detection potential,concentration of β-cyclodextrin, concentration of sodium dodecyl sulfate, pH value of electrolyte and applied voltage were discussed.     

PREPARATION OF ACTIVATED CARBON FIBER AND THEIR XENON ADSORPTION PROPERTIES (II)-XENON ADSORPTION PROPERTIES

1. INTRODUCTION The adsorption and concentration of xenon has practical application interest in the purification of radioactive waste gas released from nuclear plant operation. Moreover, the monitor of xenon isotopic, derived from nuclear explosion or nu…     

丙烯酸酯共聚物涂膜中钛螯合物的交联作用

用红外光谱、紫外光谱、差示扫描量热等手段表征了掺杂体系内钛螯舍物(Ti-Ac)与丙烯酸酯共聚物的相互作用。测试了Ti-Ac用量对涂膜耐水性、耐热性及复溶性的影响。鲒果表明。当ωTi-Ac=0．015时涂膜的吸水率可下降到1％以下。且涂膜仍保持较好的复溶性(15s)。     

活性碳纤维的结构修饰及其吸附氙性能的研究

活性炭纤维对氙的吸附容量与其孔结构密切相关，为了提高活性炭纤维对氙气的吸附容量，本文分别用亚甲基蓝、对硝基苯酚等有机物，或氯化钠、碘等无机化合物填充的方法修饰活性炭纤维的孔结构；以及利用高锰酸钾或硝酸等氧化处理修饰活性炭纤维的表面化学性质，同时，利用低温氮等温吸附表征了这些改性活性炭纤维的孔结构，以及通过光电子能谱表征了改性活性炭纤维的表面化学结构，上述化合物充填或氧化改性活性炭纤维对氙的吸附性能的研究结果表明，适量化合物填充，或合适浓度硝酸对活性炭纤维的表面处理，可以有效地修饰活性炭纤维的孔结构或改变活性炭纤维表面对氙的亲和力。因而可有效地提高改性活性炭纤维对氙的吸附容量。     

Effect of the Magnetic Field on the Magnetically Stabilized Gliding Arc Discharge and Its Application in the Preparation of Carbon Black Nanoparticles

In this study, a cylindrical plasma generator with an axial magnetic field is constructed to obtain the magnetically stabilized gliding arc discharge (MSGAD). Using high speed photography, voltage waveform analysis and spectral diagnostics, the MSGAD physical characteristics, such as arc voltage, rotation speed, electric field, excitation/rotational temperature, etc., are investigated under different magnetic field. The experimental results reveal that as the magnetic field increases, the arc voltage, rotation speed, electric field and non-equilibrium level increase, and the MSGAD is more stable under the larger magnetic field. Additionally, carbon black nanoparticles with “crumpled paper sheet” structure are prepared by the MSGAD. The results indicate that the enhanced magnetic field can promote the transition from amorphous carbon to crystalline graphite. It is inferred that the transition is likely relevant to the rotation speed and electron energy of the arc plasma.     

Two New Sequiterpenoids from Helicteres angustifolia

A new sesquiterpenoid lactone, 3,6,9-trimethyl-pyrano[2,3,4-de]chromen-2-one (1) and a novel sesquiterpenoid quinone, 6-[2-(5-acetyl-2,7-dimethyl-8-oxo-bicyclo[4.2.0]octa-l,3,5-trien-7-yl)-2-oxo-ethyl]-3,9-dimethylnaphtho[1,8-bc]pyran-7,8-dione (2) together with a known perezone (3) were isolated from the roots of Helicteres angustifolia. The structures were elucidated as mainly on the basis of ID and 2D NMR spectroscopic data.     

带有偏差变元的广义Hamilton系统周期解的存在性

应用变分方法与Morse理论,本文讨论下面含有时滞的广义Hamilton系统的周期解,J*du-dt=g(t,u(t-r1),…,u(t-rs))其中J*是非奇异2n×2n反对称矩阵.在一定条件下,本文得到上述方程至少存在两个非平凡2π-周期解而对于一般的微分系统,本文给出其具有变分结构的判定性准则.     

微波合成的纳米球形CaS∶Ag+荧光体的荧光光谱

在微波场作用下 ,快速合成了CaS∶Ag+荧光体 ,用X射线粉末衍射 (XRD)分析证实了它们是立方晶相。测定了它们的激发光谱和发射光谱 ,发现其发射峰位于 372nm、45 0nm和 5 77nm ,分别是由A′gCa V2 +S 中心的Ag+离子、间隙Ag+离子、A′gCa的Ag+离子和CaS基质自激活产生的 ,随着Ag+的掺杂浓度和助熔剂的改变 ,Ag+离子的几个发光中心互相转化 ,荧光体发出不同颜色的荧光。用扫描电镜 (SEM)观察了它们的晶体形貌和尺寸大小 ,结果表明CaS∶Ag+荧光体的晶体形貌都是球形的 ,但其粒径和晶体的分散性受Ag+的掺杂浓度和助熔剂的影响 ,出现了纳米晶 ( 7～ 10 0nm)和亚微米晶 ( 12 5～ 30 0nm)。