静电纺丝制备碳纳米管基复合纳米纤维的研究进展

碳纳米管(CNTs)作为增强材料与聚合物复合制成纳米纤维,有助于提高纳米纤维性能,扩展其应用领域。本文综述了近年来国内外静电纺丝制备CNTs基复合纳米纤维的研究现状,重点介绍了CNTs/PAN复合纳米纤维、CNTs/PANI/PEO复合纳米纤维、CNTs/PVA复合纳米纤维、CNTs/PA复合纳米纤维、CNTs/TiO2复合纳米纤维的研究进展及其在纳米传感器、电磁干扰、超级电容器、染料敏化太阳能电池(DSSCs)、组织工程支架、药物控制释放等方面的应用潜力,展望了CNTs基复合纳米纤维的发展前景。     

橡胶纳米复合材料的一些新进展

近十年来出现了许多新型的橡胶纳米复合材料体系,这些体系展现出比传统体系更强的可设计性、更丰富的性能表现或者呈现功能性质。本文主要综述了橡胶基纳米复合材料的新体系设计和制备方法。基于目前研究现状,作者展望了橡胶纳米复合材料研究若干个值得关注的方向。     

Catalytic performance of cement clinker supported nickel catalyst in glycerol dry reforming

The paper reports the development of cement clinker-supported nickel （with metal loadings of 5 wt%, 10 wt%, 15 wt% and 20 wt%） catalysts for glycerol dry （CO2） reforming reaction. XRF results showed that CaO constituted 62.0% of cement clinker. The physicochemical characterization of the catalysts revealed 32-folds increment of BET surface area （SBET） with the addition of nickel metal into the cement clinker, which was also corroborated by FESEM images. Significantly, XRD results suggested different types of Ni oxides formation with Ni loading, whilst Ca3SiO5 and Ca2Al0.67Mn0.33FeO5 were the main crystallite species for pure cement clinker. Temperature-programmed reduction analysis yielded three domains of H2 reduction peaks, viz. centered at approximately 750 K referred to as type-Ⅰ peaks, another peaks at 820 K denoted as type-Ⅱ peaks and the highest reduction peaks, type-Ⅲ recorded at above 1000 K. 20 wt% Ni was found to be the best loading with the highest XG and H2 yield, whilst the lowest methanation activity. Syngas with lower H2/CO ratios （0.6 to 1.5） were readily produced from glycerol dry reforming at CO2-to-Glycerol feed ratio （CGR） of unity. Nonetheless, carbon deposit comprised of whisker type （Cv） and graphitic-like type （Cc） species were found to be in majority on 20 wt%Ni/CC catalysts.     

核酸适配体在重金属检测中的应用研究

随着工业化生产的快速发展,由重金属离子带来的环境污染也越来越引起了人们的高度重视.科研人员通过不同的检测方法对重金属离子进行检测.由于核酸适配体对重金属离子的选择性较高,使得其在重金属检测中的应用越来越广.     

水溶性ZnSe量子点在快速灵敏检测牛分枝杆菌表面MPB83蛋白中的应用

本实验以巯基丙酸作为稳定剂,在水相条件下快速合成稳定性好的水溶性硒化锌量子点(ZnSe QDs),采用透射电子显微镜、X射线衍射、红外光谱、荧光以及紫外光谱法等对ZnSe QDs进行了材料表征。将得到的ZnSe QDs通过共价结合方式标记到牛分枝杆菌表面的MPB83蛋白抗体分子上,基于抗体与MPB83蛋白的特异性相互作用,建立了一种检测MPB83蛋白的光谱新方法。研究了pH值及温度对检测的影响,得到pH 8.5,37℃为适宜的体系酸度和温度。在优化的实验条件下,MPB83蛋白浓度在44~528 mg/L范围内,QDs的荧光强度与蛋白浓度间呈现良好的线性关系,此方法对MPB83蛋白的检出限为4.4 mg/L。该方法为实现准确而及时的诊断牛结核病提供一定理论依据。     

自动固相萃取-液相色谱-串联质谱法同时测定血液中5种抗抑郁类药物

建立了血液中5种抗抑郁类药物的自动固相萃取-液相色谱-串联质谱(ASPE-LC-MS/MS)分析方法。样品经HLB固相萃取柱提取后,采用LC-MS/MS进行测定,外标法定量。在Waters AtlantisTM dC18反相柱上分离,梯度洗脱,流动相为甲醇-0.1%甲酸(1∶4,V/V)溶液,质谱采集为电喷雾正离子多反应监测模式。采用基质匹配标准溶液校正,5种目标物在1~500μg/L范围内具有良好的线性关系,相关系数(R)大于0.9975,检出限在0.1~0.6μg/L之间;添加浓度水平为10,100和500μg/L时,方法回收率为70.6%~93.8%,相对标准偏差在3.9%~9.2%之间。本方法可用于血液中5种抗抑郁类药物的法庭与临床毒物分析。     

纤维二糖与葡萄糖催化转化制备乙二醇(英文)

选用纤维二糖作为探针分子,探索纤维素催化转化制备乙二醇过程的反应路径.分别考察了纤维二糖和葡萄糖在双组分催化剂H2WO4和Ru/C下的催化反应活性.结果表明,乙二醇不仅来自于纤维二糖水解产物葡萄糖的逆羟醛缩合作用,同时也可以来自于纤维二糖的直接逆羟醛缩合过程.而且,纤维二糖的直接逆羟醛缩合作用对糖苷键的水解也有一定的促进作用.比较发现,钨基催化剂作用下纤维二糖的逆羟醛缩合反应活性比葡萄糖要低,因此乙醇醛可以缓慢产生并在Ru/C催化剂上迅速加氢生成乙二醇.使得以纤维二糖作为原料比以葡萄糖作为原料时获得更高的乙二醇收率.     

A Theoretical Study on the Photochromic Mechanism of 1-Phenyl-3-methyl-4-（6-hydro-4-amino-5-sulfo-2,3-pyrazine）-pyrazole-5-one

The photochromic mechanism of 1-phenyl-3-methyl-4-（6-hydro-4-amino-5-sulfo-2,3- pyrazine）-pyrazole-5-one has been investigated using the density functional theory（DFT）. The solvent effect is simulated using the polarizable continuum model（PCM） of the self-consistent reaction field theory. According to the crystal structure of the title compound, an intramolecular proton transfer mechanism from enol to keto form was proposed to interpret its photochromism. Bader＇s atom-in-molecule（AIM） theory is used to investigate the nature of hydrogen bonds and ring structures. Time-dependent density functional theory（TDDFT） calculation results show that the photochromic process from enol to keto form is reasonable. The conformation and molecular orbital analysis of enol and keto forms explain why only intramolecular proton transfer is possible. The results from analyzing the energy and dipole moments of enol form, transition state and keto form in the gas phase and in different solvents have been used to assess the stability of the title compound.     

Syntheses,Crystal Structures,and Biological Activities of Two 5-Pyrimidinyl-1,2,4-oxadiazoles

Two 5-pyrimidinyl-1,2,4-oxadiazoles were synthesized through two different routes and their structures were characterized by single-crystal X-ray diffraction, NMR and MS. Compound 3, 5-(2-chloro-4-methyl-6-phenylpyrimidin-5-yl)-3-phenyl-1,2,4-oxadiazole, crystallizes in orthorhombic, space group Pbca with a = 19.1575(11), b = 8.2115(5), c = 21.2035(12), V = 3335.6(3)3 and Z = 4. Compound 6, 5-(2,6-dichloropyrimidin-4-yl)-3-phenyl-1,2,4-oxadiazole, crystallizes in monoclinic space group Pn with a = 8.4275(13), b = 5.4088(8), c = 13.493(2), β = 99.768(3)o, V = 4658.6(6)3 and Z = 8. Preliminary bioassay indicated that the two title compounds had good herbicidal activities.     

Influence of Cell Disruption and Elution on Cellulase Release of Clostridium straminisolvens (CSK1)

Clostridium straminisolvens (CSK1) is a novel cellulolytic bacterium isolated from a cellulose-degrading bacterial community MC1. In this study, the influence of the following cell disruption and elution methods on CSK1cellulase release was investigated: (1) freezing–thawing, (2) ultrasonication, (3) elution, (4) freezing–thawing following elution, (5) ultrasonication following elution, and lastly (6) high-pressure homogenization following elution. The activity of the cellulases CMCase, β-glucosidase, Avicelase, FPase, and xylanase in crude extracts increased 81.5, 23.8, 87.7, 46.3, and 51.7 %, respectively, with an observed optimal treatment method for each cellulase type. The release of protein from CSK1 cells increased following either cell disruption or elution and was highest at 88.3 % in the homogenization high pressure following elution treatment. A newly observed protein was present following cell elution. The performance of cell elution as determined by real time-PCR indicated that the first time cell elution removed more than 90 % of the CSK1 cells from the substrate. These findings demonstrate that cell disruption and elution are effective methods for inducing cellulase release, and elution is the key step for CSK1. To our knowledge, this study presents the first evidence of optimal treatments for induction of cellulase release of Clostridium straminisolvens. This information will be of great value for use in subsequent efforts to better understand the cellulase characteristics of CSK1 and cellulose degradation mechanisms of the MC1 community.