卤水-氨水法制备氢氧化镁阻燃剂的实验研究

通过卤水-氨水法制备了氢氧化镁阻燃剂,采用络合滴定法标定卤水中钙镁的含量,同时考察了氨水与镁离子物质的量比、反应温度对氢氧化镁阻燃剂产率的影响,对制备出的氢氧化镁进行了红外光谱分析。实验结果表明,当氨水与镁离子物质的量比为3.5∶1、反应温度为20~25℃时制备的氢氧化镁产率较高。     

天然气长输管道氮气隔离法投产置换工艺研究

以长庆气田至呼和浩特天然气管道建设工程为背景，探讨了氮气隔离法置换工艺在天然气长输管道投产中的应用。通过对采用单隔离器和无隔离器的两种天然气置换工艺进行分析比较，得出了无隔离器的氮气隔离置换工艺是目前比较理想的天然气置换工艺。     

Regulating Nitrogen Pollution with Risk Averse Farmers under Hidden Information and Moral Hazard

We consider a model of pollution regulation for a risk averse farmer involving hidden information, moral hazard, and risk-sharing. The representative farmer faces a production risk originating from nitrogen leaching, and privately observes the soil capacity in retaining nitrogen only after the regulation contract is signed. The latter specifies a transfer and a nitrogen quota, whose decomposition by the farmer among different production stages is unknown to the regulator. We first characterize the optimal solution to the regulator's problem. The sequential decision model is estimated on French crop production data, and the results are used to calibrate and simulate the optimal contract.     

石家庄市某制药企业污水处理过程废气排放特征及治理效果研究

为了弄清制药企业污水处理过程废气的排放情况及废气治理工艺的效果,采集制药企业污水处理各工序以及经过废气处理后排放的废气样品,分析每个采样点硫化氢、氨及TVOC的排放特征。结果表明:在各个采样工序中,氨气在水解酸化池排放量最高,达到3 360 mg/m3,TVOC在生物MBR池工序排放量最高,达到11 469 mg/m3,硫化氢在絮凝反应沉淀池排放量最高,达到51 717 mg/m3。治理后的总排放口废气排放量均明显低于其通过废气治理设施前的水平。废气治理设施"碱洗+氧化+水洗"工艺对硫化氢和氨的去除效果好,对TVOC的治理效果较差;生物滴滤床工艺对硫化氢的去除效果较好,对氨及TVOC的去除效果较差,但对TVOC的去除效果优于"碱洗+氧化+水洗"工艺。研究可为污水处理过程寻找有针对性的废气处理工艺、为减少污水处理过程中恶臭气体及挥发性有机物的排放提供参考。     

河北省不同利用方式农田土壤氮磷环境风险分析

弄清不同利用方式农田土壤氮磷养分平衡状况,进而明确其环境风险特征,为进一步指导土壤养分管理及环境政策制定具有重要意义。研究以河北省的粮田、果园和菜地为研究对象,通过分析三种利用方式氮磷的输入、化肥和有机肥的分配比例及氮磷养分的盈余状况,并结合化肥使用环境风险指数,评价三种不同利用方式化肥氮磷的环境风险类型。结果表明,氮总输入量为菜地明显高于果园和粮田,磷总输入量为菜地和果园明显高于粮田,且粮田和菜地氮磷输入主要以化肥为主。三种不同利用方式农田氮磷均呈盈余状态,其中氮盈余率为果园(532.6%)明显高于菜地(61.5%)和粮田(31.6%),磷盈余率为菜地(700.4%)和果园(615.7%)明显高于粮田(66.6%)。化肥氮磷的环境风险指数均为菜地(0.83)明显高于粮田(0.59-0.62),三种不同利用方式下化肥氮磷的环境风险类型均达低度风险及以上,特别是菜地达严重风险。为了农业的可持续发展,河北省粮田应控制氮磷肥的投入,果园和菜地应加大减少氮磷肥化肥投入,以减少对环境的潜在危害。同时为了更好地培肥地力,在控制施肥总量的前提下应加大粮田和菜地有机肥的投入比例。     

Crop Input Response Functions with Stochastic Plateaus

Agronomic research on crop response to nitrogen fertilizer suggests that a plateau function may be appropriate, but the plateau varies across fields and years. Available models that treat the plateau as a stochastic variable are not readily extendable to handle field or year random effects as seems to be appropriate based on the agronomic data. This article develops a method of estimating a response function with a stochastic plateau that can capture random effects. The method is then used to determine economically optimal levels of nitrogen fertilizer for wheat ( Triticum aestivum ).     

简介模具弹性元件的新秀——氮气弹簧

目前常规弹性元件有弹簧、橡皮和气垫,被广泛地应用在工业企业中,满足了工业领域很多弹性储能的需求。氮气弹簧作为模具中的新秀,已得到了广泛的应用,氮气弹簧在模具中的应用使得简化了模具的结构,降低了制造成本,大幅提高了冲压件的质量。     

不同预处理方法对纳氏试剂比色法测定氨氮的影响

纳氏试剂比色法是污水处理厂测定水中氨氮广泛采用的方法。通过试验讨论了纳氏试剂比色法检测污水处理厂污水的氨氮时,使用絮凝沉淀与蒸馏两种不同预处理方法对测定结果的差异,试验结果表明,污水处理厂由于出水浊度大,铁、锰等重金属含量大,对于氨氮的检测宜采用蒸馏预处理方法。     

An accelerating treadmill and an overlooked contradiction in industrial agriculture: Climate change and nitrogen fertilizer

In this article, we explore if and why farmers are responding to the impacts of climate change with practices that increase greenhouse gas emissions. Our examination focuses on heavy rainfall events and Midwestern corn farmers' nitrogen fertilizer management. Due to climate change, the frequency and intensity of heavy rain events is increasing across the Midwest. These events increase nitrogen loss to the environment and introduces economic risks to farmers. Drawing from a theoretical framework that merges O'Connor's second contradiction of capitalism and Schnaiberg's treadmill of production, we argue farmers' responses to these events reflect the second contradiction, increasing contributions to climate change, and are shaped by treadmill‐like political‐economic pressures. We examine this using a qualitative sample of 154 farmers across Indiana, Iowa, and Michigan. Given profit imperatives, adapting farmers in our sample primarily used increased nitrogen application rates to reduce their vulnerability to heavy rains. As nitrogen rate is directly associated with nitrous oxide emissions, this adaptive strategy is effective but increases agricultural contributions to climate change. This preliminarily suggests that the political‐economic structure encourages farmers to respond to climate change in ways that accelerate the environmental contradictions of industrial agriculture.