芒硝、硝酸铵、生石灰制备硝酸钠的工艺研究

本文介绍了以芒硝、硝酸铵、生石灰为原料制备硝酸钠的方法，给出了最佳反应条件以及原料配比。由此所得硝酸钠纯度高，原料利用率在９０％以上。     

渗透胁迫对小麦幼苗硝酸还原酶活性的影响

本文研究了小麦幼苗根部和离体叶切段遭受PEG(MW=6000)渗透胁迫后叶内硝酸还原酶(NR)活性的变化,发现渗透胁迫不仅降低叶片中已有的NR活性,还抑制底物NO_3~-对NR的诱导过程。进一步研究表明,幼苗NR的诱导受抑与渗透胁迫下叶内诱导物不足有关。     

硝酸稀土甘氨酸固体配合物的红外光谱研究

稀土与甘氨酸作用形成固体配合物的研究工作已有许多。但用稀土硝酸盐与甘氨酸作用生成固体配合物的工作尚未见文献报道，而红外光谱的研究也未开展，本工作在水相中制得了Ｌａ、Ｃｅ、Ｐｒ、Ｎｄ、Ｓｍ、Ｅｕ、Ｇｄ、Ｔｂ、Ｙ共９种稀土硝酸盐与甘氨酸固体配合物，测量了配合物的ＦＴ－ＩＲ光谱，对其主要红外吸收带进行了归属，同时也对配合物配位键性质进行了探讨。     

硝酸镨水合物热分解机理的研究

本文采用TG-DTG法研究了Pr(NO_3)3·nH_2O(n=6,4,2)的热分解行为,并通过IR对反应物、中间产物和最终产物进行了鉴别.同时,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,并利用DSC法求得了Pr(NO_3)_3·6H_2O的脱水焓.     

硝酸铈铵氧化体系固态合成双偶氮化合物

报道了一种在固态条件下合成二芳基双偶氮化合物的新方法.用硝酸铈铵(CAN)氧化体系对二芳基卡巴肼进行双侧氧化脱氢反应,共合成了8种二芳基卡巴二腙.这种方法具有条件温和、操作简便、无溶剂、污染少等优点.     

Functional, biochemical and genetic diversity of prokaryotic nitrate reductases

Prokaryotic nitrate reduction can serve a number of physiological roles and can be catalysed by a number of biochemically distinct nitrate reductases. Three distinct nitrate reductase classes can be indentified in prokaryotes, NAS, NAR and NAP. NAS is located in the cytoplasmic compartment and participates in nitrogen assimilation. NAR is usually a three-subunit complex anchored to the cytoplasmic face of the membrane with its active site located in the cytoplasmic compartment and is involved in anaerobic nitrate respiration. NAP is a two-subunit complex, located in the periplasmic compartment, that is coupled to quinol oxidation via a membrane anchored tetraheme cytochrome. It shows considerable functional flexibility by participating in anaerobic respiration or redox energy dissipation depending on the organism in which it is found. The members of all three classes of enzymes bind the bis-molybdopterin guanine dinucleotide cofactor at the active site, but they differ markedly in the number and nature of cofactors used to transfer electrons to this site. Analysis of prokaryotic genome sequences available at the time of writing reveals that the different nitrate reductases are phylogenetically widespread.     

汾河滩七种野菜硝酸盐，Vc及氨基酸含量的研究

测定了汾河滩七种野菜中硝酸盐,亚硝酸盐,维生素C和氨基酸含量,结果表明刺儿菜,藜,碱蓬的硝酸盐,亚硝酸盐含量较高且均超标,不宜食用,苦荬菜的亚硝酸盐含量虽较高, 但其Vc含量极其丰富,若食量作一定限制,还是可以食用的,地肤,车前,苦菜的硝酸盐与亚硝酸盐含量均较低,且Vc及氨基酸含量也较高,可以食用。     

硝酸还原酶和可溶性蛋白对东北三省蒙古栎种源生长性状的影响

本文研究了东北三省25个蒙古栎种源的硝酸还原酶和可溶性蛋白与生长性状的关系．不同生长性状的蒙古栎种源,硝酸还原酶活性和可溶性蛋白含量上都存在着显著的差异,并且同一种源呈现明显的季节变化．试验结果表明生长性状与所研究的两个理化指标之问存在显著的正相关,即高、径生长好的种源,硝酸还原酶活性和可溶性蛋白含量高;硝酸还原酶活性大的种源,可溶性蛋白含量也高,可以为林木育种提供参考．本试验中,集安种源在两项生理指标中含量均最高,可作为优质种源进行推广．     

硝酸稀土与速克灵混配对番茄灰霉病的防病效果及机制的研究

室温下,用1500倍速克灵、3000mg/L硝酸稀土、1500倍速克灵+3000mg/L硝酸稀土、2000倍速克灵+3000mg/L硝酸稀土、2500倍速克灵+3000mg/L硝酸稀土、3000倍速克灵+3000mg/L硝酸稀土的混剂喷施番茄幼苗,间隔不同时间接种番茄灰霉病菌,测定其防病效果及番茄叶片内丙二醛含量和多酚氧化酶活性。结果表明:不同处理在喷施后第15天时,对番茄灰霉病的防病效果最为理想,其中1500倍速克灵+3000mg/L硝酸稀土的混剂的效果最好,防效达96.10%,1500倍速克灵、3000mg/L硝酸稀土和2000倍速克灵+3000mg/L硝酸稀土、2500倍速克灵+3000mg/L硝酸稀土、3000倍速克灵+3000mg/L硝酸稀土的混剂次之。喷施1500倍速克灵+3000mg/L硝酸稀土混剂的植株丙二醛含量最低,为30.54(mmol·g),多酚氧化酶活性最高,为73(0.01A/min)。说明稀土与速克灵混合具有良好的抑菌和增抗作用。     

Effects of ammonium and nitrate on encystment and growth of Scrippsiella trochoidea

To avoid unfavorable environmental condi- tions, Scrippsiella trochoidea is capable of forming a resting cyst in the process of growth. In the present study, we investigated the effects of nitrate and ammonium on the growth and encystment of S. trochoidea. We incubated S. trochoidea in modified f/2 media without nitrogen and silicate in flasks. The flasks were divided into two groups. Nitrate was added as a nitrogen source in the first group, and ammonium was added in the second group. The concentrations of the nitrogen compounds were 0, 10, 30, 60, and 90 μmol/L. The results indicate that NO3--N favors cell growth, and the cultures with a higher concentration of NO3--N were ineffective at forming cysts. In contrast, NH4＋-N promoted cell growth and cyst formation. At similar concentrations as NO3--N, NH4＋-N had a toxic effect on cell growth and increased the cyst formation ratio. Thus, the NH4＋-N concentration is an important factor for controlling encystment. We believe that the impact of NH4＋-N in inducing cyst formation may be a useful feedback mechanism in ecological systems.