固体氧化物燃料电池La0.7Sr0.3Cr1-xMnxO3-δ阳极性能研究

采用溶胶凝胶法制备了La0.7Sr0.3Cr1-xMnxO3-δ(x=0.3,0.4,0.5,0.6)系列阳极粉体。在1000℃下焙烧后,XRD结果显示粉体物相为单一的钙钛矿相。制备以La0.7Sr0.3Cr1-xMnxO3-δ为阳极,Ce0.8Sm0.2O1.9(SDC)为电解质,Pr0.6Sr0.4Co0.8Fe0.2O3-δ-SDC复合阴极的电解质支撑型固体氧化物燃料单电池。由扫描电子显微镜(SEM)观察表明单电池电解质致密,阳极孔径分布均匀,厚度约为20μm,多孔阴极厚度为10μm。采用直流四电极法测试以La0.7Sr0.3Cr0.5Mn0.5O3-δ为阳极用湿氢气作燃料时在800℃下获得最大输出功率为232.84 mW.cm-2,短路电流为0.92 A.cm-2。     

混合钴源对Co-Pd/TiO2催化剂催化CH4-CO2两步梯阶转化法合成乙酸的性能影响

以混合钴源为前驱体, 采用等体积浸渍法制备了Co-Pd/TiO2催化剂, 考察了其对CH4和CO2梯阶转化直接合成乙酸的催化性能, 采用XRD, XPS, NH3-TPD和BET对催化剂进行了表征. 结果表明, 催化剂具有适宜的表面酸性、 高比表面积和孔结构, 有利于提高催化剂的活性. 在m(CoCl2)∶m=2∶5, m(Co)∶m(Pd)=2∶1, 常压, 150 ℃条件下, 乙酸的生成速率达到6.13 mg·g-1Cat·h-1, 选择性达到 81.6%, 分别比以单一Co源制备的催化剂提高了134%和16%.     

系列磺丁基甜菜碱的表征及表面活性

用FT-IR、1H NMR和元素分析对自制的3种磺丁基甜菜碱(SBm-4)的结构进行了表征,研究了它们的表面性能、泡沫性能和乳化性能。 获得SB12-4的cmc为2.20×10-3 mol/L,γcmc为31.48 mN/m;SB14-4的cmc为2.80×10-4 mol/L,γcmc为29.68 mN/m;SB16-4的cmc为2.30×10-5 mol/L,γcmc为32.06 mN/m。 3种磺丁基甜菜碱的cmc值随着烷基链长增加逐渐减小,γcmc先减小后增加,三者的起泡性随浓度增加而增加,到一定值后保持不变;泡沫稳定性随浓度增加逐渐增强,起泡性随着温度的增加有缓慢增加趋势,泡沫稳定性随温度增加逐渐降低。 3种表面活性剂的乳化能力随浓度增加先增加后降低。     

((吡啶-3-基)甲氧基)芳酸衍生物的合成及抗血小板聚集活性

以具有活血化瘀作用的中药有效成分阿魏酸为先导物,按生物电子等排原理,设计合成了6个((吡啶-3-基)甲氧基)芳酸衍生物,其结构经IR,1H NMR,13C NMR及MS确证.体外药效筛选结果显示,部分((吡啶-3-基)甲氧基)芳酸衍生物对二磷酸腺苷(ADP)诱导的血小板聚集具有较好的抑制活性,其中化合物1a的抑制作用明...     

紧束缚模型方法及其在DNA分子中的应用

近年来,紧束缚模型方法被广泛应用于计算生物大分子体系.本文从第一性原理出发,根据紧束缚近似的思想,推导出生物大分子体系中的单电子运动方程.在此基础上给出了紧束缚模型方法中所涉及参数(在位能和迁移积分)的计算公式,在理论上完善了紧束缚模型方法.我们将所提出的参数化方法应用于理想B型DNA分子,给出了各种序列组合下的在位能和迁移积分.此外,我们还计算了周期性DNA分子poly(A)-poly(T)和poly(G)-poly(C)中空穴在位能和迁移积分随格点间距离的变化,为改进现有的SSH极化子模型提供了新的思路,有助于DNA中电荷输运的极化子机理的研究.     

In situ chemical fabrication of polyaniline/multi-walled carbon nanotubes composites as supports of Pt for methanol electrooxidation

Science China Chemistry - In this study, platinum (Pt)-polyaniline(PANI)/MWNTs catalysts were synthesized by two sequential reactions. First, core-shell structural PANI/MWNTs composites were...     

Trace determination of hexabromocyclododecane diastereomers in water samples with temperature controlled ionic liquid dispersive liquid phase microextraction

A novel temperature controlled ionic liquid dispersive liquid phase microextraction(TCIL-DLPME) coupled with rapid resolution liquid chromatography-electrospray tandem mass spectrometry(RRLC-ESI-MS-MS) has been developed for the enrichment and determination of three hexabromocyclododecane diastereomers(HBCDs) in water samples.Green solvent ionic liquid(IL) was used as extraction solvent instead of toxic organic solvents.This technique also avoided the usage of dispersive solvent.Some important parameters that might affect the extraction efficiency were optimized.Under the optimum conditions,good linear relationship,sensitivity and reproducibility were obtained.All the limits of detection for the three diastereomers were 0.1 ng/ mL.The linear range was obtained in the range of 1-100 ng/mL for the total amount of three HBCD diastereomers.It was satisfactory to analyze real environmental water samples with the recoveries ranging from 77.2%to 99.3%.The main advantage of the method is toxic organic solvent-free.     

具有AWO分子筛结构的磷酸铝[Cu(en)2]0.5[Al3P3O12(OH)]:合成、结构与相转变

利用水热合成方法,以自组装的铜胺配合物为模板剂,合成出具有AWO分子筛结构的磷酸铝微孔化合物[Cu(en)2]0.5[Al3P3O12(OH)],命名为AlPO-CJ53.单晶结构解析表明,其结晶在单斜晶系/P21/n(No.14)空间群,晶胞参数为:a=0.85547(11)nm,b=1.7671(2)nn,c=0....     

高效液相色谱-三重四级杆质谱分析海洋甲壳动物淋巴和肌肉中的20-羟基蜕皮酮

在三疣梭子蟹(Portunus trituberculatus)血淋巴中加入高油菜素内酯作为内标,用乙腈去除蛋白,采用高效液相色谱-三重四级杆质谱(HPLC-QqQ MS)对20-羟基蜕皮酮进行分析;对3种甲壳动物(-三疣梭子蟹、脊尾白虾(PaJaemon carincaua'a Holthuis)和口虾蛄(Orato...     

Graphene-encapsulated iron microspheres on the graphene nanosheets

Graphene nanosheets (GNSs) loading graphene-encapsulated iron microspheres (GEIMs) were fabricated by heat treatment of graphene oxide nanosheets (GONs) with ferric trichloride (FeCl(3)). The special pentagon-hexagonal graphene shells have been produced by precipitation of carbon from metal carbide solutions, thanks to the high reactivity of GONs and ferric nanoparticles dispersing homogeneously between graphene layers. The morphology, structure and elemental composition of GEIMs were investigated by scanning electron microscope, X-ray diffraction and electron energy disperse spectroscope, respectively. The formation mechanism of GEIMs was proposed. Hollow graphene microspheres (HGMs) on the GNSs were obtained with the removal of ferric species in GEIMs. When used as the anode materials for lithium-ion batteries, the almost graphitic HGMs exhibit stable voltage platform at ca. 0.2 V, excellent cycle capability and higher reversible capacity of about 440 mAh g(-1) after 50 cycles and possess great potential application in lithium-ion batteries.