对杂散光测试材料要求的探讨

从分光光度计杂散光测试原理出发,对我国目前在用的几种杂散光测试材料特性进行了分析。通过实验验证,指出了其中的不合理处,并提出了对杂散光测试材料特性的基本要求。 ,     

微乳液法合成LiFePO4 / C正极材料及其电化学性能

本文采用微乳液方法合成了纳米LiFePO₄ / C正极材料。制备样品分别用XRD和SEM进行表征，充放电测试其电化学性能。600 ℃制备样品为单一物相，平均粒径90 nm，在室温2.0～4.0 V (vs Li) 放电电压范围和15 mA·g^-1放电速率下，首次放电容量达到159 mAh·g^-1。制备样品同样展现良好的循环性能。在15 mA·g^-1速率下40次循环后，制备样品放电容量仍保持首次放电容量的98.9%。优异的电化学性能得益于样品颗粒的纳米尺寸、均匀分布以及表面碳层包覆提高了活性材料的电子电导率。     

Mechanochemical Preparation of Water-Soluble Forms of Triterpene Acids

A waste-free technology for mechanochemical processing of fir needles into a biologically active preparation that regulates plant growth was developed. A preparation exhibiting cytokinin activity due to the presence in it of water-soluble forms of triterpene acids can be prepared using the proposed method. The effectiveness of the proposed method was confirmed by instrumental methods and biological tests.     

32Cr2MoVA合金结构钢标准物质的研制

本标准物质系合金钢。主要成份有碳、硅、锰、磷、硫、铬、镍、钼、钒,同时还含有锡、铅、砷、锑、铋等微量元素,每种元素成份都具有良好的线性关系。它可作为量值传递和仲裁分析的依据,同时也可用于校验分析仪器与分析方法的正确性和可靠性。     

石墨烯的制备、功能化及在化学中的应用

石墨烯是最近发现的一种具有二维平面结构的碳纳米材料, 它的特殊单原子层结构使其具有许多独特的物理化学性质. 有关石墨烯的基础和应用研究已成为当前的前沿和热点课题之一. 本文仅就目前石墨烯的制备方法、功能化方法以及在化学领域中的应用作一综述, 重点阐述石墨烯应用于化学修饰电极、化学电源、催化剂和药物载体以及气体传感器等方面的研究进展, 并对石墨烯在相关领域的应用前景作了展望.     

互通多孔碳/二氧化锰纳米复合材料的原位水热合成及电化学性能

以互通多孔碳（IPC）为载体，水热条件下在碳表面原位反应生成纳米结构的二氧化锰（MnO₂），制备互通多孔碳/二氧化锰纳米（IPC/MnO₂）复合电极材料. 采用扫描电镜（SEM），透射电镜（TEM），X射线衍射（XRD），热重分析（TGA）对其结构进行表征；采用循环伏安法、恒流充放电和交流阻抗对其电化学性能进行研究. 结果表明：生成的MnO₂均匀地负载在碳的表面，形成多层次结构，并且随着温度的升高IPC表面负载的MnO₂由纳米颗粒变为纳米片状结构；MnO₂纳米片具有典型的K-Birnessite 型晶体结构；复合物中MnO₂的含量约为34%（w）. 在100 ℃制备的IPC/MnO₂复合材料在三电极系统中最高比电容达到了411 F·g^-1；随着反应温度的升高,比容量先增长后基本保持不变. 以IPC/MnO₂为正极，活性炭（AC）为负极，1 mol·L^-1 Na₂SO₄溶液为电解液组装成IPC/MnO₂//AC 混合超级电容器，发现IPC/MnO₂电极的电容器其电位窗口从1 V扩展到1.8 V，容量可达86F·g^-1，且表现出良好的电容特性和大电流放电性能.     

Electrochemical instability of bis(trifluoromethylsulfonyl)imide based ionic liquids as solvents in high voltage electrolytes for potassium ion batteries

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Effects of pH and Dye Concentration on the Optical and Structural Properties of Coumarin-4 Dye-Doped SiO2-PDMS Xerogels

Optical and structural properties of coumarin-4 dye-doped SiO₂-PDMS xerogels synthesized by acid catalyzed (one-step) and acid-base catalyzed (two-step) sol-gel routes with varying pH (0.6 to 7) and dye content ( 5 × 10^–4 to 5 × 10^–2 mole) are reported. Spectroscopic methods such as photo-luminescence, FT-IR and FT-Raman were used for characterizations. The acid catalyzed xerogels prepared with pH < 2.5 exhibited two fluorescence peaks, I at 390 nm and II at 480 nm. The acid-base catalyzed xerogels synthesized with pH < 2.5 also exhibited two peaks, I at 400 nm and II at 475 nm. Peak II was not observed for the samples with pH 2.5. This phenomenon was attributed to the existence of pH dependent different forms of coumarin-4 molecule. The concentration-quenching phenomenon was observed for the acid catalyzed xerogels prepared with different dye concentration. TheFT-IR spectra indicated the existence of hydrogen bonds between the carbonyl groups of dye molecules and the silanol groups of gel matrix. The hydrogen bonding was the highest for the samples with the extremity pH, 0.6 and 7, resulting in the highest dye/gel matrix interactions, hence, the highest fluorescence peaks. The Raman studies indicated that the samples prepared with pH < 2.5 possessed relatively more number of 3-membered siloxane rings than 4-membered siloxane rings. The ring statistics was reversed for the samples with pH > 2.5. The number of silanol groups was higher for the samples with pH > 2.5.     

氧化共沉淀法制备纳米级掺锑α—Fe2O3气敏陶瓷粉料

氧化共沉淀法制备纳米级掺锑α┐Ｆｅ２Ｏ３气敏陶瓷粉料王忠春＊＊刘尔生陈耐生＊黄金陵（福州大学化学系福州３５０００２）关键词α－Ｆｅ２Ｏ３陶瓷，锑掺杂气敏材料，纳米材料１９９６－１０－０５收稿，１９９７－０４－２２修回福建省科委资助项目＊＊现在上海硅酸...     

手性液晶掺杂剂（S）—4‘—辛氧基—4—（2—酰氧基—丙氧基）联苯的合成

手性液晶掺杂剂（Ｓ）┐４┐辛氧基┐４┐（２┐酰氧基┐丙氧基）联苯的合成马汝建李培荣国斌＊（华东理工大学化学系上海２００２３７）关键词铁电液晶材料，手性液晶掺杂剂，合成，手征性１９９７－０２－０３收稿，１９９７－０８－０７修回铁电液晶显示器所用的材料...