Nitrification and denitrification derived N2O production from a grassland soil under application of DCD and Actilith F2

The relative contribution of nitrification and denitrification to N₂O production was investigated by means of soil incubations with acetylene in a mixed clover/ryegrass sown sward 5 days after application of a mineral fertiliser (calcium ammonium nitrate) or an organic one (cattle slurry) with and without the addition of the nitrification inhibitor dicyandiamide (DCD) and the commercial slurry additive Actilith-F2. At this time, maximum field N₂O emissions were taking place. N₂O production by the slurry amended soil was twice as high as that of the mineral amended one. N₂O came in a greater proportion from nitrification rather than from denitrification in the slurry treatment, while for the mineral fertilisation most N₂O came from denitrification. The addition of DCD to slurry produced a decrease in N₂O production both from nitrification and denitrification. No reduction in N₂O losses was observed from addition of DCD to the mineral fertilisation, although DCD resulted effective in reducing the nitrification rate by 53% both in the slurry and the mineral fertilisation. Actilith F2 induced a high nitrification rate and N₂O production from denitrification was reduced while that from nitrification was not. This revised version was published online in August 2006 with corrections to the Cover Date.     

石油化工装备“后果分析”方法的介绍

石油化工装备的失效,由于所处理的物料常常是易燃易爆的化学品,所以往往导致发生燃烧、爆炸等,还可以波及附近的其它装置和设备发生连锁的失效和爆炸。为了分析这种严重事故可能造成的影响,研究防止这种事故的发生,近年来研究和发展了一种定量估计这种失效后果严重程度的方法,称为后果分析(Consequence Analysis)。通过分析,从这些设备的失效概率、可能发生的失效形式,研究设备内物料的泄漏形式、可能发生的后果、影响范围的大小、对周围装置、环境和人员的危害程度等,从而提出在设备设计、工厂的总图设计中采取的措施,以减轻其危害的程度。     

氨内参比法测定尿素熔融液中缩二脲含量

研究了尿素熔融液中缩二脲含量测定时各种消除氨干扰的方法，确定了氨内参比法可作为消除氨干扰的最佳方法，完善了该法应用时的具体操作步骤，建立了一个适用于尿素合成各工段尿液中缩二脲含量测定的简单、快速、准确的分析方法。     

电沉积紫膜薄膜中菌紫质的光电响应对N-端表面的金属阳离子浓度的依赖性

用不锈钢／电沉积紫膜薄膜／含水胶（电介质）／钢型菌紫质光电池研究了作用于Ｎ－端表面（紫膜外表面）的钾、镁、镧离子对菌紫质光电响应的影响．在所测条件下光电极性均与质子泵方向一致．光电压幅值是离子浓度依赖性的，对钾、镁、镧离子均存在极大值浓度，它们之间有数量级的差异；依赖性曲线趋势和极大值浓度均各自分别与溶液中菌紫质的质子泵效率对阳离子浓度的这种依赖性相一致．不过，光电响应对作用于Ｃ－端表面的这些离子不存在上述的浓度依赖性．上述的两种依赖性成相关性说明：电沉积紫膜薄膜中菌紫质的光电响应主要来自质子泵运而非非质子离子的贡献；存在一合适的离子浓度使菌紫质的光电响应有极大值．用质子泵结构域模型和扩散双电层理论对这种依赖性进行的讨论认为：金属阳离子的结合与屏蔽两种效应可以解释这种依赖性．     

冷冻法硝酸磷肥两段中和料浆黏度变化规律研究

为满足硝酸磷肥生产设备对料浆流动性的要求,从而寻求较佳的工艺条件,对冷冻法硝酸磷肥脱钙母液氨中和时料浆的黏度进行测定,以确定硝酸磷肥两段中和不同条件对料浆黏度的影响。结果表明,磷矿中的镁和钙与料浆黏度成正比,镁的影响大于钙的影响;控制一段中和料浆pH为1.5~2.0、n(N)/n(P)为1~2时料浆黏度≤100 mPa·s,当温度在100~140℃时料浆黏度≤50 mPa·s,满足要求。     

肥料级磷酸一铵料浆提纯制备电池级磷酸一铵研究

介绍利用肥料级磷酸一铵料浆提纯制备电池级磷酸一铵的工艺路线和条件:将肥料级磷酸一铵料浆过滤除去不溶性杂质,滤液用氨水调节pH,并加入除杂剂使杂质沉淀后过滤,再浓缩结晶得到电池级磷酸一铵;结晶母液及滤渣返回化肥系统生产化肥。此法所用原料成本低,工艺简单,得到的磷酸一铵产品纯度高,可用于生产锂电池正极材料磷酸铁及磷酸铁锂,具有较好的社会效益及经济效益。     

湿法磷酸生产中降低磷矿浆水分的研究

由于湿法磷酸产能的提升,磷矿浆细度的提高,导致磷矿浆在浓密机内难沉降,磷矿浆相对密度降低,水分升高,对下游生产带来极大不便,影响其经济效益。分析主要原因,并介绍采取的相应措施,改造后,矿浆w(H_2O)由41%降为40.89%,降低了生产成本,为下游生产带来了良好的效果。     

Consolidation grouting technology for fire prevention in mined‐out areas of working face with large inclined angle and its application

The phenomenon of linear flow of slurry in mined‐out areas of working face with large inclined angle is a crucial issue that hinders grouting for fire prevention. The traditional way of grouting exerts a poor effect on inhibiting coal spontaneous combustion, so it is in urgent need of a suitable grouting technology for fire prevention in mined‐out areas with large inclined angle working face. This paper brings up the consolidation grouting method for fire prevention for the first time and conducts a systematic study on the flow characteristics of slurry and sedimentation characteristics of slurry in mined‐out areas with large inclined angle working face. Consolidation slurry materials and their ratio are optimized by experiments. Test platform has been established, and effectiveness of the consolidation grouting for fire prevention has been simulated. The results show that settling velocity of yellow mud increases at first and then decreases as the concentration of consolidation slurry materials ascends. The optimum mass concentration is 0.2%–0.8%. The flow speed of mud is greatly reduced by laying consolidation slurry materials (The decreasing range is approaching 50%). The retention of yellow mud in mined‐out areas has significantly increased. Finally, technology in working site has been developed; meanwhile, compressed air and spray between frames have been used during the period of working face, and the consolidated way of expansion bags in wood crib to lay consolidation slurry materials has been adopted during the period of stopping work. Field application shows that CO concentration at upper corner decreases significantly and eliminates signs of spontaneous combustion. Besides, the flowing water becomes clearer, and effectiveness of the consolidation grouting is remarkable after laying consolidation slurry material band. Research results can provide theoretical guidance to technology for fire hazard prevention in mined‐out areas with large inclined angle. Copyright © 2016 John Wiley & Sons, Ltd.     

Effect of ambient conditions on drying of herbs in solar greenhouse dryer with integrated heat pump

An even span solar greenhouse dryer was built and applied to dry Java tea (Orthosiphon aristatus) and Sabah snake grass (Clinacanthus nutans Lindau). Findings showed that the solar greenhouse dryer performs satisfactorily during clear weather except at nighttime and rainy day due to product rehydration which is heavily influenced by high relative humidity from ambient air. Integrating of heat pump into the solar greenhouse dryer has successfully reduced the room relative humidity by 10–15%. Also, heat pump has mitigated the product rehydration issue by maintaining room relative humidity at maximum of 65% throughout the drying period. The drying rate of Java tea was improved three to fourfold, i.e., from 0.004–0.008 to 0.018–0.025?g H₂O/g DM min, whereas 10% of drying time was saved for both Java tea leaf and Sabah snake grass leaf with the assistance of heat pump system. Meanwhile, the supply of dry air from the heat pump system with a magnitude of 0.25–0.50?m/s helps in enhancing the drying rate of the herbs as well as minimizing the nonuniformity of drying temperature and relative humidity inside the solar greenhouse dryer.     

最小二乘法在泵试验台数据测量曲线拟合中的作用

为了保证高精度的数据测量,泵试验台所有的测量仪表均由相关检定单位进行了检定,并出具了相应的检定证书,但是一部分检定证书里的检定数据是离散的、未经处理的,这直接导致了检定数据无法应用到测控系统中去。针对这一情况,提出了兼顾整个量程精度的最小二乘法拟合直线的方法来处理这些数据,以方便测控系统应用这些检定数据并保证数据测量足够的精度。在泵试验台,还需要测量试验泵的输入功率即泵配电机的输出功率,这通常需要安装扭矩仪一类的设备,但是这类设备的安装调试工作量太大,针对这一情况,提出了最小二乘法拟合抛物线的方法,仅仅通过分析电机的输入功率就可以得到电机的输出功率。