TiO2微粒功能化多孔Al2O3膜的光电化学研究

用恒电位法制备了多孔Al2O3薄膜,通过在Al2O3薄膜孔内水蒸汽水解钛酸异丙酯生成了锐钛矿型TiO2微粒,制备出了Al2O3与TiO2微粒的复合薄膜．用XRD,SEM,光电化学方法进行了研究．实验表明：该复合薄膜具有光电转换特性,在光催化、光电化学太阳能转换中具有应用价值．     

P3HT修饰一维有序壳核式CdS/ZnO纳米棒阵列复合膜的光电化学性能

采用电化学方法在铟锡氧化物(ITO)导电玻璃上制备了高度有序的ZnO纳米棒阵列, 在ZnO纳米棒阵列上先后电化学沉积CdS纳米晶膜及聚3-己基噻吩(P3HT)薄膜得到P3HT修饰的一维有序壳核式CdS/ZnO纳米阵列结构, 并通过扫描电镜(SEM)、透射电镜(TEM)、X射线衍射(XRD)、能量散射X射线(EDX)等表征手段证实了该结构的形成. 以此纳米结构薄膜为光阳极组装新型半导体敏化太阳电池, 研究了CdS纳米晶膜的厚度和P3HT薄膜的沉积对电池光伏性能的影响, 初步探讨了电荷在电池结构中的传输机理, 结果表明, CdS纳米晶膜和P3HT薄膜的沉积有效地拓宽了光阳极的光吸收范围, 实验中电池的光电转换效率最高达到1.08%.     

纳米微晶Fe69.5(CuCrV)9.5Si13B8超铁磁性研究

经813K温度退火后的纳米微晶Fe_(?)(CuCrV)_(9.5)Si_(13)B_8由α-Fe(Si)晶粒和晶界两种磁相组成,温度从10—8l3K的穆斯堡尔研究显示晶粒的超精细场随着温度的变化曲线上有一个转折.用超铁磁性模型进行拟合,结果表明晶界和晶粒间存在强的交换耦合作用,使晶粒的有效磁各向异性常数减小为原来的六分之一. 关键词：     

Liquid chromatography–fluorescence detection for simultaneous analysis of sulfonamide residues in honey

A rapid, accurate LC analytical method has been developed for determination of eight sulfonamides (sulfacetamide, sulfapyridine, sulfamerazine, sulfamethoxypyridazine, sulfameter, sulfachloropyridazine, sulfamethoxazole and sulfadimethoxine) in honey. The sample was dissolved in phosphoric acid solution (pH 2). After filtration, the sample solution was cleaned by use of two solid-phase extraction (SPE) cartridges-an aromatic sulfonic cation-exchange cartridge and an Oasis HLB cartridge. The eight sulfonamides were then derivatized with fluorescamine and the derivatives were determined by LC with fluorescence detection at excitation and emission wavelengths of 405 and 495 nm, respectively. Average recoveries at three fortification levels in the range 0.02-0.50 mg kg(-1) in twelve different kinds of honey were 73.5-94.1% with coefficients of variation of 4.35-16.60%. The limit of detection (LOD) was 0.002 mg kg(-1) for sulfacetamide, sulfapyridine, sulfamerazine, and sulfamethoxypyridazine; that for sulfameter, sulfachloropyridazine, sulfamethoxazole and sulfadimethoxine was 0.005 mg kg(-1). The limit of quantitation (LOQ) was 0.005 mg kg(-1) for sulfacetamide, sulfapyridine, sulfamerazine, and sulfamethoxypyridazine; that for sulfameter, sulfachloropyridazine, sulfamethoxazole, and sulfadimethoxine was 0.010 mg kg(-1). The method is suitable for determination of multiresidue sulfonamides in the various kinds of honey.     

磁偶极和电四极在磁各向异性介质中的辐射功率

在经典电动力学的框架下,研究了磁各向异性介质中的电磁辐射问题,得到了磁偶极和电四极在磁各向异性介质中的辐射功率表达式.进一步地,通过把各向同性介质中的μrii代入所得辐射功率表达式,得到了与文献相符合的结果,验证了所得结果的正确性.研究结果表明磁偶极和电四极在磁各向异性介质中的辐射功率大小与磁各向异性介质的μrii大小有关,对判断磁偶极和电四极在磁各向异性介质中的辐射效果有较大的帮助.     

元素分析-同位素比质谱法测定葡萄酒中乙醇δ 13C值

比较了旋转蒸发仪、全玻璃蒸馏装置和全自动蒸馏控制系统3种蒸馏方法,对葡萄酒乙醇δ13C值的影响,确定了元素分析-同位素比质谱仪(Elementary analysis-isotope ratio mass spectrometer)最佳测定条件,建立了元素分析-同位素比质谱法测定乙醇δ13C值方法。在重复性和再现性条件下,对乙醇标准及葡萄酒乙醇δ13C值进行测定,标准偏差低于0.25‰。检测食品同位素分析技术-能力测试计划(FIT-PTS)两个葡萄酒样品乙醇δ13C值,与给定值相差0.2‰。采用液相色谱-同位素比质谱法(Liquid chromatography-isotope ratio mass spectrometry)与本方法分别对16个国家和地区40个葡萄酒样品的乙醇δ13C值测定,其结果为!23.90‰~28.29‰,且两种检测方法的检测结果差值︳Δδ(EA-LC)max︳<0.3‰,具有较强的相关性(R2=0.9749)。本方法无同位素分馏,适用于葡萄酒中乙醇δ13C值测定。     

Dynamic Coordination Chemistry of Fluorinated Zr-MOFs: Synthetic Control and Reassembly/Disassembly Beyond de Novo Synthesis to Tune the Structure and Property

Known for excellent stability, porosity and functionality, the high-valent Zr⁴⁺ metal–organic frameworks (Zr-MOFs) still meets synthetic challenge in modulating the strength of Zr-O_carboxylate linkage. Herein we explore the unusual coordination dynamics of fluorinated Zr-MOFs by designing two trifluoromethyl modified ligands with distinct geometry preference to form a family of thermodynamic and kinetic products. The low-connecting kinetic Zr-MOFs possess substitutable coordination sites to endow Zr₆-cluster with extra dynamic behaviors, thus opening a post-synthetic pathway to sequential reassembly/disassembly processes. Comprehensive factors, including ligand geometry, Zr₆-cluster connectivity, acid modulator and reaction temperature/concentration, have been studied for controllable syntheses. The stability, hydrophobicity and gas adsorption/separation properties of obtained Zr-MOFs are explored. This work sheds light on the understanding of the dynamic coordination chemistry of Zr-MOFs beyond strong Zr−O bond, which poses a versatile platform for modification and functionalization of Zr-MOFs.     

低温冷冻靶温度动态特性的数值模拟研究

惯性约束聚变点火成功的关键之一在于靶丸内形成均匀的氘氚冰层,靶丸周围的温度场对冰层质量有很大影响.首先通过实验靶系统实验验证了数值计算模型的可靠性,在此模型的基础上,对低温冷冻靶装置的热物理问题特别是温度动态特性问题展开了数值模拟,重点考察冷环温度波动时,温度传递衰减过程的规律以及各影响因素对于温度传递衰减过程的影响.结果显示:冷环温度一定时,填充气体压力降低、填充气体中氦气比例增大,靶丸表面温度均匀性提高;当冷环温度波动时,温度波动的周期减小、振幅减小、填充气体压力升高、填充气体中氦气比例降低有利于控制靶丸表面温度波动;冷环温度波动的周期适中、振幅减小、填充气体压力降低、填充气体中氦气比例提高有利于改善靶丸表面温度均匀性.研究结果对实验中冷冻靶合理配置各参数实现温度控制具有重要参考价值.