亚硝酸铵共存下用尿素代替甲醇作抗干扰剂测定硝酸铵

提出尿素替代甲醇溶液分析亚硝酸铵中硝酸铵含量的测定方法。该方法用无毒尿素代替毒性较大的甲醇溶液,来避免甲醇的毒性对分析人员带来的危害。加入回收率在97％～102％之间,相对标准偏差为1.3％。     

由硝酸铵和氯化钾制取硝酸钾的研究

本文叙述了由硝酸铵和氯化钾制取硝酸钾的原理和方法。对所选定的工艺进行了定量计算,用正交法安排实验,对实验结果进行了讨论。得出了制备硝酸钾的较佳工艺参数。     

结晶成核与生长两阶段的模型识别研究

针对溶液间歇结晶过程的特点,定义并关联了无因次变量K和K^ ,用于对结晶过程中成核和生长两阶段进行定量识别。对于添加晶种的KNO3-H2O间歇结晶过程,模拟分析的结果表明：无因次变量K和K*的数值均随着晶核形成过程而减小,随着晶核生长过程而增大。由实验测定的动态透光率和溶液浓度,即可对结晶过程中的成核和生长两阶段进行定量识别。     

The influence of nitrate reduction strategies on the temporal development of the nitrate pollution of soil and groundwater throughout Germany - a regionally differentiated case study

A GIS-based area-differentiating model has been used to analyze the nitrate pollution of soil and groundwater throughout Germany. The results of the calculations based on the model for the current situation show that a high potential for high nitrate pollution of the soil and groundwater (> 50 mg NO₃/l) is to be expected in all regions of Germany subject to intensive agricultural use. In order to achieve a sustainable use of water resources, effective strategies to reduce the nitrogen surpluses from agriculture must be developed and analyzed with respect to their spatial and temporal impact on the nitrate pollution of soil and groundwater, taking into consideration the various agricultural land usages as well as the different hydrological, hydrogeological and agricultural conditions.The effects of three different nitrate reduction strategies on the resulting N-surpluses and the nitrate concentration in the leachate were investigated: firstly, a stocking rate limitation, secondly, a limitation of both organic and mineral fertilizers and thirdly, a combination of three reduction measures consisting of a stocking rate limitation, an improvement of the nitrogen utilization factor by livestock and a higher utilization factor of nitrogen bound in organic fertilizers by crops. The analysis showed that separate application of each of these nitrogen reduction measures would only lower the nitrogen surpluses in a few regions. In order to achieve a considerable reduction of nitrate concentrations both in leachate from land under agricultural use and in the groundwater a combination of area-covering and regionally effective measures (scenario III) turned out to be most promising.     

Nutrient losses in surface and subsurface flow from pasture applied poultry litter and composted poultry litter

Over application of poultry litter may cause pollution of surface and ground water. Spatial variability in soil characteristics makes predictions difficult. Composting poultry litter could reduce the risk of pollution by creating more stable organic components. Three rates of poultry litter and compost (10 Mg ha^-1 litter, 20 Mg ha^-1 litter and 10 Mg ha^-1 litter combined with 50 Mg ha^-1 compost) to three watersheds under pasture. The watersheds were monitored for surface and subsurface flow. Nitrate-N concentrations in subsurface flow did not exceed the U.S. Environmental Protection Agency drinking water standard of 10 mg L^-1. Soluble phosphorus concentrations in runoff were high, reaching a maximum of 8.5 mg L^-1 under the compost treatment. These concentrations are generally lower than reported on smaller scale studies, which shows the need of studies at the correct scale.     

Fate of nitrogen applied in different fertilizers to the surface of a calcareous soil in Syria

¹⁵N-labelled ammonium sulphate or¹⁵N-labelled urea were each applied in solutionat a rate of 30 kg N ha^-1 to the surface of 20soil cores (52 mm internal diameter × 100 mm deep)located on a field experiment at the ICARDA station,Tel Hadya, Syria. Recovery of ¹⁵N-label in theammonium, nitrate, organic and/or urea-N pools in thesoil was measured on days 0, 1, 2, 5 and 13 afterapplication. Total recovery of ¹⁵N was initially100%, but by day 13 after application it had declinedto 51% with urea and 73% with ammonium sulphate.Ammonium nitrate labelled either as ammonium or asnitrate was also applied to the soil surface of 8other cores at the same time. ¹⁵N recovery in thefour soil N pools was measured only on day 12 afterapplication. Total recovery of ¹⁵N-label was 75%with labelled ammonium and 57% with labelled nitrate.Volatilization of ammonia from this calcareous soil(pH 8.1) is one probable mechanism of N loss fromammonium and urea fertilizers: with nitrate bothleaching beyond the base of the core (i.e. 100 mm) and denitrification were responsible for Nlosses. These large losses of N immediately afterapplication have implications for fertilizermanagement practices.     

复分解法制硝酸钡新工艺研究

简述了硝酸钡的应用前景及国内外生产技术现状,论述了以硫化钡和硝酸铵为原料复分解法制硝酸钡的工艺流程及反应机理。试验结果表明,新工艺可获得符合国家标准ＧＢ－１６１３－７９一级品硝酸钡产品,产品收率在９８％以上,有较好的经济效益。     

La(Ⅲ)、Nd(Ⅲ)、Tb(Ⅲ)、Er(Ⅲ)与二溴水杨醛缩乙二胺配合物的合成与表征及薄层色谱研究

合成了四种稀土双核配合物,其组成为Ｌｎ２Ｌ３（ＮＯ３）６·３Ｈ２Ｏ〔Ｌｎ＝Ｌａ（Ⅲ）、Ｎｄ（Ⅲ）、Ｔｂ（Ⅲ）、Ｅｒ（Ⅲ）;Ｌ＝３,５－二溴水杨醛缩乙二胺〕,并通过元素分析、红外光谱、紫外光谱、差热－热重及摩尔电导分析等手段,对合成的配合物进行了表征,并研究了配合物的薄层色谱行为     

车制乳化炸药溶液制备工艺的安全性

地面站－混装车现场装药的乳化炸药生产方式一般认为是最安全的,但正确 理解和按工艺条件的要求操作,是保证生产安全的先决条件,德兴铜矿乳化炸药地面站溶 液生产制备过程中,曾多次发生硝酸铵溶液自燃现象,给生产带来了不安全隐患,造成了 巨大经济损失。本文通过对地面制备站生产过程中溶液储罐发生燃烧事故的分析研究,初 步找到了硝酸铵溶液发生自燃现象的原因,并提出了解决的技术措施．     

废硝酸制取硝酸钠和硫脲的工艺研究

利用工业废硝酸制取硫化氢同时副产硝酸钠,并合成了硫脲。结果硫脲收率达85％,硝酸钠收率达90％以上。