Individualized water source as an indicator of attitudes about water management and conservation in humid regions

Public perceptions about water quantity and water as a common pool resource are understudied in humid regions. As water demand increases, the need to more closely manage water, even in humid areas, will increase, requiring better understanding how people perceive their water supply, how they view paying for water conservation and how water user characteristics influence attitudes. A survey finds correlations between utilizing an individual water source (e.g. well or spring) and attitudes toward water management and conservation. Compared to respondents with a shared water source, those with an individual source believe they are segregated from regional water concerns. They are less willing to pay for water management or conservation measures and less supportive of any government intervention in water management. These results suggest that planners and water managers may face resistance to conservation policies or any policy based on the idea of water as a common pool resource.     

大庆贴不贴泡周边土壤及地下水石油烃污染规律

贴不贴泡是大庆某石油化工总厂生产废水排放场地,其作用相当于一个水面较大的氧化塘.在纳污泡周边分别采集土壤及地下水样品,以研究其对周边土壤及地下水的污染状况.结果显示:纳污泡附近地下水及表层土壤受到不同程度石油烃污染,但除第1个采样点外,其余各采样点污染程度随距离变化不明显;土壤纵向以40～60cm厚度层污染最为严重.说明大庆地区草甸黑土对石油烃滞留能力很强,使石油烃在其中的迁移速度很低,特别是水平迁移速度更小,才使污染近30年的场地地下水受到的石油烃污染不是十分严重.表层土壤的污染主要是由于雨季纳污泡内污水溢出造成的.      

Property rights and grassland degradation: a study of the Xilingol pasture, Inner Mongolia, China

The semi-private property rights arrangement called the Household Production Responsibility System (HPRS) was started in the early 1980s in Xilingol pasture of Inner Mongolia (China), and stimulated the development of stockbreeding. The grassland has been degrading severely with increasing numbers of livestock. Based on a historical review of property rights regimes in Inner Mongolia and empirical surveys in Xilingol pasture during 2001-2003, this paper assesses the implementation of HPRS and its impacts on incomes of households as well as the environmental impact on the grassland. It was found that HPRS does not mitigate the "Tragedy of the Commons", instead it has exacerbated the situation. It was also found that co-management of grassland and livestock among a few households presents a sustainable use of grassland to develop livestock breeding. We conclude with the recommendation that small-scale collective property rights systems should be encouraged in Xilingol pasture of Inner Mongolia.     

A tutorial on learning human welder's behavior: Sensing,modeling, and control

Human welder's experiences and skills are critical for producing quality welds in manual GTAW process. Learning human welder's behavior can help develop next generation intelligent welding machines and train welders faster. In this tutorial paper, various aspects of mechanizing the welder's intelligence are surveyed, including sensing of the weld pool, modeling of the welder's adjustments and this model-based control approach. Specifically, different sensing methods of the weld pool are reviewed and a novel 3D vision-based sensing system developed at University of Kentucky is introduced. Characterization of the weld pool is performed and human intelligent model is constructed, including an extensive survey on modeling human dynamics and neuro-fuzzy techniques. Closed-loop control experiment results are presented to illustrate the robustness of the model-based intelligent controller despite welding speed disturbance. A foundation is thus established to explore the mechanism and transformation of human welder's intelligence into robotic welding system. Finally future research directions in this field are presented.     

大型LNG储罐泄漏事故后果评估

对LNG储罐泄漏事故进行危险分析,选用PHAST软件计算模型,针对LNG储罐不同事故类型选取最大设想事故进行假设模拟,确定了不同条件下LNG储罐泄漏事故的安全距离;对结果进行分析,得出的结论对LNG储罐的安全管理和事故预防提供了一定的参考。     

华北平原冬小麦季化肥氮去向及土壤氮库盈亏定量化探索

为提高华北平原冬小麦种植体系的氮肥利用率、减少氮肥对环境的污染,本研究对前人的试验数据进行整理核算,分析肥料氮、作物氮和土壤氮三者之间的关系,探索冬小麦季化肥氮的去向及土壤氮库的盈亏情况.结果表明:华北平原冬小麦当季化肥氮的吸收量随施氮量的增加而升高,对土壤氮素的吸收随施氮量的增加而降低;在秸秆50%还田和100%还田两种情况下,土壤氮库盈亏量与施氮量之间均呈线性极显著正相关,且土壤氮库达到平衡时的施氮量分别是 N 192和166 kg·hm-2;冬小麦对氮肥的吸收利用率推荐施氮远高于传统施氮,过量施氮不仅不会提高作物产量,还会降低氮肥利用率,增加土壤残留和损失;3种秸秆处理方式下的冬小麦氮肥各去向绝对量与施氮量(N 75~375 kg·hm-2)之间均呈显著线性相关关系,秸秆不还田条件下的地上部吸收率、秸秆吸收率和秸秆50%还田下的地上部吸收率及秸秆100%还田下的0~100 cm土壤残留率均与施氮量(N 75~375 kg·hm-2)之间呈显著相关关系.     

水解酸化-深井曝气-脱气-二沉池工艺处理印染废水工程实例

对某纺织企业污水站进行改造,由于用地紧张,将污水站生物接触氧化工艺改造成深井曝气工艺,大大节约了土地资源,并且有较好的处理效果。深井曝气具有抗冲击能力强、氧利用率高、管理方便、运行稳定、低能耗、占地省等优点,因此越来越多的被应用到印染纺织废水的处理中。但也存在着缺点:污泥龄比较短,硝化效果比较差,导致脱氮能力不强,污泥的稳定程度比低负荷工艺低,钻井技术要求也相对较高等。总之,深井曝气工艺是一种先进的处理工业废水的新工艺,若能扬长避短,将会得到广泛应用。     

庚烷池火多火源燃烧特性的实验研究

多火源燃烧是森林火灾和城市群发性火灾中重要而又特殊的火灾现象,相关研究很少。通过恒定控制液面高度的实验系统,对直径0.1m、0.2m和0.4m的庚烷池火在单个火源、两火源燃烧和三火源线性排列时的火焰高度、火焰体积和燃烧速率等特性进行了实验研究。研究发现,三火源燃烧时中间火源的火焰高度、火焰体积和燃烧速率明显高于两火源燃烧和单火源燃烧,三火源燃烧时边上火源与两火源的燃烧状况难以区分。这些燃烧特性随着火源间距的减小,呈现增大趋势。热量反馈增强和空气卷吸受限这两种火源相互作用机制相互耦合,且随着火源间距的减小而增强,在S/D（S为火源间距,D为油池直径）为2～4时,两种机制强烈竞争,在其他参数范围内热量反馈增强效应占主导作用。研究还发现火焰体积与热释放速率有较好的线性相关关系,单位火焰体积的热释放速率约为1614kW/m3。     

深度处理系统机械搅拌澄清池的特点及运行

山西侯马发电厂城市污水回用工程深度处理,采用石灰处理系统。经过几个月的调试运行,机械搅拌澄清池设计合理,运行正常。     

复配超细粉体三相泡沫的制备与稳定性研究

为改善泡沫灭火剂的高温稳定性和抗复燃性能,将石墨粉、膨润土和空心玻璃微珠按一定比例复配加入泡沫灭火剂中制备防灭火三相泡沫,利用自主设计的实验台架,研究其发泡、稳泡及油面热稳定性等主要性能,分析复配超细粉体对泡沫灭火剂稳定性的影响机理。实验证明,复配粉体的加入可使泡沫灭火剂在高温下的稳定时间延长10倍以上,粉体颗粒会在泡沫表面形成一层致密壳层,增强泡沫的隔热阻燃性能,石墨粉的存在使壳层更加致密且增强了泡沫的流动性,但会对泡沫的发泡性能产生较大的影响,当空心玻璃微珠和石墨粉的添加质量比为5∶2时,整体效果较好。