Nitrogen fertilizer use in rainfed agriculture

Agronomic efficiency (AE) is defined as the increase in economic yield of a crop per unit fertilizer applied. Components of AE are physiological efficiency and apparent recovery fraction. The latter can be further separated into uptake efficiency and availability index. Ways to increase the nitrogen fertilizer use efficiency in rainfed agriculture through fertilizer management are discussed.     

Particle-Substrate Collisions, Particle Rebound and Removal

Recent progress in particle capture and rebound and its effect on the adhesion force is reviewed in this paper. Particles rebound when the incident velocity is greater than a characteristic critical velocity. Lower impaction velocity particles experience elastic and plastic deformation. Recent models for particle rebound and capture are discussed and evaluated in terms of their restrictive assumptions and results. Recent experimental data of particle rebound and capture is also discussed, as is the hydrodynamic removal of captured particles. The removal of particles occurs when the applied hydrodynamic removal force overcomes the adhesion force. The effect of adhesion-induced deformation on the removal of particles is introduced and discussed.     

Reduction of NO2 stored in a commercial lean NO x trap at low temperatures

Isothermal storage of NO₂ and subsequent reduction with different reducing agents (H₂, CO or H₂ + CO) in a lean NO _x trap catalyst was tested by Temperature Programmed Desorption (TPD) and Temperature Programmed Reduction (TPR) experiments at temperatures representative of automotive “cold-start” conditions (<200 °C) using a commercial NO _x trap catalyst. Results from the TPR experiments revealed that no reduction of stored NO₂ to N₂ was observed at 100–180 °C, and at 200 °C 10% reduction only of NO₂ to N₂ was measured. A special affinity of H₂ to form NH₃ was observed during the reduction of stored NO₂. The formation of NH₃ increases with increasing amount of stored NO₂ and decreases with increasing storage temperature. Direct relation exists between the amount of adsorbed and/or stored NO₂ and the formation of H₂O and NH₃.     

玉米黄粉酶解液在黄原胶发酵生产应用的研究

以玉米黄粉酶解液为氮源应用于黄原胶发酵培养基，探讨了蛋白酶种类、玉米黄粉酶解液添加量和酶添加量等因素对其发酵黄原胶粘度和产胶率的影响，并优化了复配氮源的种类及其复配比例。结果表明，碱性蛋白酶水解液作为氮源发酵黄原胶的粘度和产胶率优于其它蛋白酶解液；当酶解液添加量为6%、碱性蛋白酶添加量为8kU时，发酵黄原胶的粘度和产胶率可以达到4235cp和24.4g/L。大豆蛋白与玉米黄粉酶解液复配效果优于与棉籽粉、豆粕粉、花生粉的复配；玉米黄粉酶解液与大豆蛋白复配比为3:7时，发酵黄原胶的粘度和产胶率可以达到5833cp和32.4g/L，与单独以大豆蛋白为氮源无明显差异。本研究为提高玉米黄粉资源利用率、降低黄原胶的发酵生产成本提供了新思路。     

玉米浆为有机氮源的L-乳酸发酵的研究

利用细菌厌氧发酵生产L-乳酸,以降低L-乳酸生产成本为主要目的,实验以玉米浆为有机氮源,以硫酸铵为主要无机氮源,研究了不同接种量对发酵过程的影响;并就以玉米浆替代酵母粉、豆粕水解液、生物素为有机氮源的L-乳酸发酵进行了对比研究实验,实验证明了玉米浆做为有机氮源用于L-乳酸发酵的可行性。在保证生产能力的同时,使用玉米浆为有机氮源对进一步降低L-乳酸生产成本,减少玉米浆对环境的污染进行了探索。     

高产小麦磷钾效应和适宜氮磷钾配比研究

黄泛冲积石灰性土壤在适宜施氮水平下磷钾不同用量及配比对小麦生长的影响表现为:(1)磷肥以中量施用水平(每公顷施用P2O5120kg)增产效果最好,分别比未施磷、低量施用水平(每公顷用P2O548kg)增产30.82%、20.27%,高量施用水平(每公顷施用P2O5192kg),虽然比中量施用水平表现出增产,但增产幅度很小,只有2.85%;(2)钾肥对小麦的增产效应小于磷肥,只有在施用磷肥的基础上配施钾肥,才能使钾的效应得到充分发挥;(3)小麦全生育期氮磷钾施用比例1∶0.5∶0.5为最佳,每公顷施用N240kg、P2O5120kg、K2O120kg效益最高。     

电凝聚方法处理聚氯乙烯工业废水试验

对电凝聚方法处理聚氯乙烯工业废水的效果及影响因素进行了分析研究。现场运 行结果表明,该方法试验装置对聚氯乙烯废水的处理效果较好,出水水质达到综合排放 标准,对COD,BOD和TSS的去除率分别达到95％,91％和90％;对废水流量负荷的变化 具有较好的适应性,保证出水水质稳定;装置的运行成本经济实用。     

Al2O3-SiC-C质主铁沟浇注料的结合相研究

对高炉主出铁沟用Al2O3-SiC-C质浇注料的结合相变化进行了分析，其中涉及到溶胶结合、氮化硅铁为添加物形成的sialon结合、水泥形成的水硬性结合。溶胶结合强度主要来自于化学结合；而sialon结合、水泥结合的强度仍然来自少量水泥形成的水硬性凝固相的作用，因此对烘烤工艺、使用效果的影响不同。     

利用空气氧化NO的技术探讨

本文针对工业废气中NOx治理技术,对氧化NO的方法进行了论述,比较了各种方法的主要技术特征,着重分析了用空气作为氧化剂的可行性,得出了用空气氧化NO有较好的经济性、应用前景广阔的结论。     

渗透汽化汽油脱硫技术研究进展

随着环保法规的日益严格,世界各国对清洁汽油中硫含量做出了严格的规定,汽油的低硫化甚至无硫化已成为一种必然趋势,汽油的深度脱硫技术已成为各石油公司和相关研究者的研究热点。渗透汽化是一种新型高效的膜分离技术,其在汽油深度脱硫技术方面具有独特优势。介绍了渗透汽化汽油脱硫技术的基本原理、工艺特点及国内外有关研究进展情况。