离子液体限域于硅胶纳米孔道中的电化学行为研究(英文)

通过溶胶-凝胶法制备了硅胶包载咪唑类离子液体修饰电极,研究其与体相离子液体不同的伏安行为;另一方面,制备不同离子液体含量为15% ~ 28%的包载离子液体硅胶和涂覆离子液体硅胶,用电化学阻抗研究其在20 ^oC到80 ^oC下电导率的变化情况. 异常的电化学行为主要表现在：1)硅胶包载离子液体导致Fc/Fc⁺电对的半波电位正移63.5 ~ 200 mV;2)当离子液体限域于硅胶纳米孔道中时,离子液体的电化学稳定性变差;3)包载离子液体硅胶的电导率要比涂覆离子液体的电导率高29.6% ~ 136%. 由此推断,可能是由于离子液体充满硅胶孔腔和孔道从而形成了纳米网状的离子液体导电介质. 这些结果表明,硅胶包载离子液体不仅可以作为修饰电极的优良载体,而且也有助于理解离子液体限域于硅胶纳米孔道中的限域效应.     

纳米ZnO的制备及其光催化性能研究

本文以羟丙基纤维素(HPC)作为分散剂,运用沉淀法制备出了粒径均匀的ZnO颗粒.通过透射电子显微镜(TEM),X射线衍射(XRD),紫外可见光吸收光谱,光致发光谱(PL)对ZnO进行了性能表征,并探讨了其形成机理及制备中的影响因素.利用纳米ZnO作为光催化剂对有机染料罗丹明B进行了光降解实验,实验结果表明,此方法制备的ZnO具有良好的光催化性能,有望在治理环境污染等领域具有良好的应用.     

氨基酸的不对称化学合成

氨基酸是具有重要生理活性的物质。用一般化学反应合成的α-氨基酸为外消旋体。使用不对称反应能有效地合成某一对映体过量的氨基酸。本文就近年来氨基酸不对称化学合成的一些新进展作一概述。     

用正电子湮没技术研究加强型交联聚乙烯热收缩制品

用正电子湮没寿命谱方法，对国内外几个主要厂家的加强型热收缩制品进行了对比测试，得到了一些有参考价值的结果． The positron lifetime technique has been used to study heat shrunk products of cross linking PE which came from different factories. Same valuabled results are obtained.     

模拟函数法测定重力加速度

模拟函数法测重力加速度是针对传统的重力加速度测定中没有考虑空气阻力影响而采用的一种新型方法。本文采用此法测定了当地的重力加速度，得到了较满意的效果。     

The effect of cellular aging on the dynamics of spiral waves

Cellular aging can result in deterioration of electrical coupling, the extension of the action potential duration, and lower excitability of the cell. Those factors are introduced into the Greenberg–Hastings cellular automaton model and the effects of the cellular aging on the dynamics of spiral waves are studied. The numerical results show that a 50% reduction of the coupling strength of aging cells has a little influence on spiral waves. If the coupling strength of aging cells equals zero, the ability for the medium to maintain spiral waves will be reduced by approximately 50% when the aging cell ratio increases from 0 to 0.5, where the reduction of cell excitability plays a major role in inducing disappearance of spiral waves. When the relevant parameters are properly chosen, the cellular aging can lead to the meandering of spiral waves,the emergence of the binary spiral waves, and even the disappearance of spiral waves via the stopping rotation or shrinkage of wave. Physical mechanisms of the above phenomena are analyzed briefly.     

Infrared Spectra and Pyrolysis of Selected Molecular Models of Coal: Insight from Density Functional Calculations

Equilibrium structures and infrared spectra of four typical molecular models of coal have been studied by density functional calculations. Combining theoretical calculations on the coal models with experimental FT-IR spectra of selected low rank perhydrous coals, a plausible molecular representation for this kind of coals was proposed, and its predicted IR spectra reasonably match the experimental observation. Calculations indicate that the cleavage of the C-C bridge bond for the coal structures considered here occurs at about 540 ℃ and the C-O ether bridge bond may break under temperature ranging from 500 to 600 ℃ for the aryl-CH2-O-CH2-aryl ether bond or from 200 to 300 ℃ for the aryl-CH2-O-aryl ether bond, showing remarkable effect of the local structural environment. The coal model containing the carboxyl group may release CO2 at about 300 ℃ through the decarboxylation with a barrier of 69 kcal/mol.     

生物模板法常温合成CdS纳米线

采用新型生物模板法常温合成CdS纳米线的新方法,并对其结构和性能进行了表征。SAED分析表明:生物模板表面包覆上了结晶良好的CdS纳米颗粒。TEM照片表明:CdS纳米线长(4±0.6)μm,直径为(400±55)nm,构成纳米线的CdS颗粒尺寸为(5.5±0.3)nm。荧光光谱分析表明:该纳米线具有优异的荧光性质,使其在生物,电子领域有潜在的应用。     

1-苯基-3-甲基-4-苯甲酰基-吡唑酮-5与中性磷(膦)萃取剂协同萃取镧(Ⅲ)

研究了1-苯基-3-甲基- 4-苯甲酰基-吡唑酮-5(HPMBP)和中性有机磷(膦)类萃取剂Cyanex 471X(TIBPS,B)在硝酸介质中对稀土元素La（Ⅲ）的萃取,用斜率法和恒摩尔法探讨了萃取机理,确定了萃合物的组成为La(NO3)2·PMBP·B,计算了萃取平衡常数.比较了HPMBP与Cyanex 471X、Cyanex 921、Cyanex 923、Cyanex 925、DEH/EHP、P350及TBP的单独及混合体系萃取La（Ⅲ）的性能,结果表明所有混合体系对La（Ⅲ）均有协同效应,其中HPMBP与Cyanex 923、Cyanex 921、Cyanex 925的混合体系是萃取La（Ⅲ）的有效体系.