大气气溶胶的种类及其对人类的影响分析

依据大气气溶胶的水溶性组分将气溶胶划分出硫酸盐气溶胶、硝酸盐气溶胶、铵盐气溶胶等3种,并对气溶胶对人类的影响进行了分析。     

Mo（Ⅵ）还原产物催化NO2^—的极谱研究

Mo(Ⅵ)在pH 2～3,0.1mol/L KCl溶液中能被还原,其电位为-0.45V(对Ag/AgCl)。还原产物能沉积在滴汞上,它能催化N0_2~-的还原。NO_2~-的还原电位从-0.95V(对Ag/AgCl)正移到-0.81V。NO_2~-还原峰电流的大小正比于它的浓度,NO_3~-在很宽的浓度范围内不干扰。本文对NO_2~-和NO_3~-在Mo存在时的极谱行为作了探讨。     

离子选择电极应用研究——乙醇-水混合溶剂中硝酸根对铅离子的配合平衡

本文用铅离子选择电极测定了乙醇-水混合溶剂中Pb-NO_3配合物的稳定常数.实验证明,铅和硝酸根可以形成PbNO_3~+和Pb(NO_3)_2两种配合物。所计算的热力学稳定常数表明溶剂中乙醇含量直到76%(w/w)lgβ_i°-1/ε都呈直线关系.     

Structure and function of eukaryotic NAD(P)H:nitrate reductase

Pyridine nucleotide-dependent nitrate reductases (NRs; EC 1.6.6.1–3) are molybdenum-containing enzymes found in eukaryotic organisms which assimilate nitrate. NR is a homodimer with an ∼100 kDa polypeptide which folds into stable domains housing each of the enzyme's redox cofactors—FAD, heme-Fe molybdopterin (Mo-MPT) and the electron donor NAD(P)H—and there is also a domain for the dimer interface. NR has two active sites: the nitrate-reducing Mo-containing active site and the pyridine nucleotide active site formed between the FAD and NAD(P)H domains. The major barriers to defining the mechanism of catalysis for NR are obtaining the detailed three-dimensional structures for oxidized and reduced enzyme and more in-depth analysis of electron transfer rates in holo-NR. Recombinant expression of holo-NR and its fragments, including site-directed mutagenesis of key acative site and domain interface residues, are expected to make large contributions to this effort to understand the catalytic mechanism of NR.     

The coordination and function of the redox centres of the membrane-bound nitrate reductases

Under anaerobic conditions and in the presence of nitrate, the facultative anaerobe Escherichia coli synthesises an electron-transport chain comprising a primary dehydrogenase and the terminal membrane-bound nitrate reductase A (NarGHI). This review focuses on recent advances obtained on the structure and function of the three protein subunits of membrane-bound nitrate reductases. We discuss a global architecture for the Mo-bisMGD-containing subunit (NarG) and a coordination model for the four [Fe–S] centres of the electron-transfer subunit (NarH) and for the two b-type haems of the anchor subunit NarI.     

气相色谱法测定乳品中的硝酸盐

本文采用气相色谱法测定乳制品中硝酸盐含量。将样品中的蛋白质分离后,把硝酸盐制备成硝基苯衍生物,用电子捕获检测器测量,以峰高定量,用标准曲线法定量样品中硝酸盐的含量。此法较镉柱法简便、快速、灵敏度高,干扰少,最低可检出乳品中20μg/kg的硝酸盐,线性范围在20～200ppb样品测定结果的变异系数为3.10％(n=7),回收率在95％～116.8％。     

转化法制备硝酸钾的微型实验

设计了一个在试管中利用NaNO3和KCl通过转化法制备KNO3的微型实验．该实验试剂用量仅为常量实验的1／10，反应装置简单．反应时间只需43min，产率达75％以上，产品质量合格．     

五水,三水硝酸镱的制备及其热分解行为的研究

本文制备了稳定的题目化合物,对所得样品进行了表征。采用TG-DTG法研究了它们的热分解行为,通过IR对反应物、中间产物和最终产物进行了鉴别。发现中间产物有低水合物和碱式盐,最终产物是氧化镜。进行了样品一些脱水过程的动力学研究,借助不同升温速率下的TG—DTG曲线,用Kissinger法计算了它们脱水的表观活化能值,利用DSC法求出了它们的脱水焓值。     

硝酸根离子在紫外区吸收光谱的研究

本文研究硝酸根离子在紫外区的吸收光谱,发现一直线区段,并精确测定了谱峰位置。     

硝酸稀土[R(NO_3)_3]和单一稀土(RGl_3)对小麦幼苗氮素代谢以及根系生长的影响

用不同浓度的硝酸稀土和氯化稀土处理小麦幼苗,发现低浓度可以促进干物质累积和根茎生长,高低浓度均对硝酸还原酶活性和氮素吸收有增加的趋势,但两者不是同步的关系。