Gender and inorganic nitrogen: what are the implications of moving towards a more balanced use of nitrogen fertilizer in the tropics?

For agriculture to play a role in climate change mitigation strategies to reduce emissions from inorganic nitrogen (N) fertilizer through a more balanced and efficient use are necessary. Such strategies should align with the overarching principle of sustainable intensification and will need to consider the economic, environmental and social trade-offs of reduced fertilizer-related emissions. However, the gender equity dimensions of such strategies are rarely considered. The case studies cited in this paper, from India, Lake Victoria in East Africa and more broadly from sub-Saharan Africa (SSA), show that the negative externalities of imbalanced inorganic N use in high- and low-use scenarios impact more strongly on women and children. We examine, through a literature review of recent work in SSA, the relative jointness of intra-household bargaining processes in low N use scenarios to assess the degree to which they impact upon N use. We suggest that gender-equitable strategies for achieving more balanced use of N will increase the likelihood of attaining macro-level reductions in GHG emissions provided that they secure equity in intra-household decision-making and address food security. Gender-equitable N use efficiency strategies will help to integrate and assure gender and social equity co-benefits at local scales.     

泡沫剂室内优选及其在调剖工艺中的应用

TFP-1高温发泡剂是以石油磺酸盐为主剂的耐高温泡沫剂。室内试验分别测试在油藏温度(50℃)下发泡剂溶液表面张力、发泡体积、半衰期和阻力因子,以确定发泡剂的最佳浓度。发泡剂浓度在0.5%时泡沫各项性能达到最佳,在高温加热的条件下,发泡剂热稳定性能较好。现场气液比设计优选为1:1,实验证明氮气泡沫能够对高含水层、高渗透层具有较好的封堵能力。针对某区边水淹井现场试验共28井次,泡沫剂浓度按注入蒸汽量的0.5%～0.6%设计,应用后排水期缩短,综合含水下降;同时峰值产油增加,油气比增加。     

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.     

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 ).     

基于非点源污染的密云水源保护区水环境容量核算及其分配

根据密云水库一级保护区内河流、水文、污染物特征,采用输出系数法模型进行研究区非点源污染负荷估算,并以COD、氨氮和总磷为控制因子,建立一维河流水质模型,定量计算研究区水环境容量,在此基础上,对研究区水环境剩余容量及污染排放削减量进行分配。结果表明:研究区非点源污染负荷输出总值分别COD433.84t/a、氨氮47.14t/a和总磷40.75t/a,4种非点源污染类型中畜禽养殖的COD、氨氮和总磷分别占各项总污染负荷的78.6%、60%、87.1%,成为保护区内主要的污染来源,水土流失污染、农村生活污水依次之,民俗旅游的污染负荷贡献率最低;污染源类型中,生活和民俗旅游污水则主要造成COD污染,而水土流失主要引起氨氮和总磷污染。保护区内COD、氨氮和总磷的水环境容量分别为3 170.36t/a、128.20t/a、25.27t/a,相较于污染负荷,水环境容量偏小。其中,总磷的污染风险最大,其环境剩余容量达到负值,应对其进行总量15.48t/a的削减。秉承公平和效益原则,总磷排放量削减分配中,畜禽养殖、生活污水、民俗旅游、水土流失各污染源的削减比例分别为44.26%、10.83%、40.90%、6.15%;氨氮的水环境剩余容量分配中,畜牧养殖的分配量最小、分配比例最低(14.16t、49.85%);畜牧养殖成为研究区内重点削减和控制的污染源。基于非点源污染的水环境容量计算及其分配研究可为保护区水环境控制管理与污染防治提供科学依据与决策支持。对加强密云水库饮水源保护,控制上游污染源,保证水质安全,确保北京市民人体健康和经济发展具有重要意义。     

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。     

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。     

氮素水平对五味子幼苗生长的影响

以2年生五味子苗未为试验材料,在田间条件下,施以不同水平的氮素,分析了叶片可溶性蛋白、叶绿素含量、根系及茎叶中全氮含量、生物量等季节的动态变化规律,探讨了不同氮素水平对五味子苗未生长的影响.结果表明:(1)随着供氮水平的增加五味子茎叶全氮含量、可溶性蛋白、叶绿素含量都呈先升高后下降的变化趋势,不同生长时期表现出的峰值不...     

转炉底吹全程吹氮工艺可行性研究

针对目前抚顺新钢铁的生产工艺的情况,对复吹转炉全程吹氮和氮氩切换两种工艺进行各工序的钢样、气体样进行分析,铸坯和轧材进行金相组织检验,对比分析结果通过得到转炉底吹全程吹氮工艺结论性的结果。