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排序方式: 共有96条查询结果,搜索用时 31 毫秒
71.
定向致裂爆破法在煤矿瓦斯抽放中的应用研究   总被引:13,自引:0,他引:13  
通过对定向致裂爆破机理的分析和研究,推导出了切缝管装药的爆破参数。经现场应用证明,这种爆破方法可以在煤层中产生定向裂隙,达到提高瓦斯抽放率的目的,对预防爆矿瓦斯爆,保证安全生产具有指导意义。  相似文献   
72.
We consider how the reputation of being socially responsible works as an effective source of motivation in protecting a public good, such as endangered species. This paper investigates the mechanism design for endangered species protection on private land under asymmetric information about reputation and land quality. We examine optimal monetary transfer by designing an efficient mechanism which takes into account the crowding out effect of monetary rewards on socially responsible behavior. We find landowners who have good reputation contribute more than the optimum level. Landowners with poor reputation sacrifices information rent; rather they buy reputation.  相似文献   
73.
It is widely believed that there is strong experimental evidence to support the idea that exogenously imposed regulations crowd out the intrinsic motivations of common pool resource (CPR) users to refrain from over-harvesting. We introduce a novel experimental design that attempts to disentangle potential confounds in previous experiments. A key feature of our experimental design is to have the exact same regulations chosen endogenously as those that are imposed exogenously. When we compare the same regulations chosen endogenously to those externally imposed, we observe no differences in extraction levels among CPR users in a laboratory experiment. We also observe no differences between weak external regulations and no regulations, after controlling for a potential confound. However, when we add communication to our endogenous treatment, we observe significant behavioral differences between endogenous regulations with communication and exogenous regulations without communication. Our results suggest that externally imposed regulations do not crowd out intrinsic motivations in the lab and they confirm that communication facilitates cooperation to reduce extraction.  相似文献   
74.
高职院校在创业教育中存在着创业教育模式、教育方法、创业教育实践缺乏具体指导等问题。在分析国外创业教育的模式及运作基础上,提出了建立教学模式的完整理论基础、建立正式的学校课程体系和高水平的师资队伍、搭建创业实战平台等对策,积极寻找符合高职院校创业教育的路径和方法。  相似文献   
75.
随着经济的快速发展,环境污染问题成为制约我国经济进一步发展的瓶颈之一,严重地阻碍着我国经济与社会可持续发展战略的实施。指出了环境污染问题的特征,分析了以行政干预为主的方法本身所造成的缺陷,提出必须运用适当的环境经济手段来促进环保事业的发展。同时提出了选择环境经济手段的思路,并对其理论渊源、现状和前景等方面进行了分析。  相似文献   
76.
以加权平均抛物线拟合法为例,研究了顾及后期地形曲线光滑模型的采样点布设规则的确定问题.研究表明,对需要光滑拟合处理的地形曲线,除了传统的适当增加冗余采样点(采集质量检测点)外,还需要依据后期的光滑拟合模型,合理规划这些检测点的布点位置,才能有效保障地形曲线的科学采样与高保真重构.  相似文献   
77.
盐析法从锂离子电池正极浸出液中回收钴盐的研究   总被引:6,自引:0,他引:6  
根据电解质溶液的现代理论,探索利用盐析方法从锂离子电池正极浸出液中回收盐的可能性.在从LiCoO2为正极的盐酸浸出液中加入(NH4)2SO4饱和水溶液和无水乙醇,可使浸出液中的Co2 发生盐析,当浸出液、(NH4)2SO4饱和水溶液和无水乙醇的体积比控制为2:1:3时,Co2 的析出率可达到92%以上.所得盐析产品经X射线衍射分析可知为(NH4)2Co(SO4)2和(NH4)Al(SO4)2,且Co2 在Al3 之前从浸出液中析出,分段盐析可使这2种盐分离,得到不同的产品.  相似文献   
78.
东亚地区夏季旱涝分布与南海夏季风爆发时间关系   总被引:1,自引:0,他引:1  
利用东亚地区529个代表站地面历史月降水资料和南海夏季风爆发时间的历史序列资料,对近55年(1951—2005年)南海夏季风爆发时间进行了多时间尺度变化特征分析,并依据夏季降水距平百分率确定了旱涝灾害等级标准,应用合成诊断分析方法研究了南海夏季风爆发时间偏早、偏晚和正常3种典型时态与东亚地区夏季旱涝分布的对应关系。结果表明:(1)在南海夏季风偏早爆发年份,中国长江流域、东北北部、华北局部以及韩国南部、日本南部、蒙古国东部易发生旱灾;中国的华南东部、淮河流域、环渤海北部及中朝边界、韩国北部易发生涝灾;(2)在南海夏季风偏晚爆发年份,中国江南地区、东南沿海、海南岛、东北局部以及日本的东部易发生旱灾;中国华南西部、淮河流域、华北大部、东北东部以及韩国南部、日本南部易发生涝灾;(3)在南海夏季风正常爆发年份,中国的华南南部、江淮地区、中朝边界、中蒙边界以及韩国局部、日本南部易发生旱灾;中国江南西部以及日本大部易发生涝灾。  相似文献   
79.
To counteract global species decline, modern biodiversity conservation engages in large projects, spends billions of dollars, and includes many organizations working simultaneously within regions. To add to this complexity, the conservation sector has hierarchical structure, where conservation actions are often outsourced by funders (foundations, government, etc.) to local organizations that work on‐the‐ground. In contrast, conservation science usually assumes that a single organization makes resource allocation decisions. This discrepancy calls for theory to understand how the expected biodiversity outcomes change when interactions between organizations are accounted for. Here, we used a game theoretic model to explore how biodiversity outcomes are affected by vertical and horizontal interactions between 3 conservation organizations: a funder that outsourced its actions and 2 local conservation organizations that work on‐the‐ground. Interactions between the organizations changed the spending decisions made by individual organizations, and thereby the magnitude and direction of the conservation benefits. We showed that funders would struggle to incentivize recipient organizations with set priorities to perform desired actions, even when they control substantial amounts of the funding and employ common contracting approaches to enhance outcomes. Instead, biodiversity outcomes depended on priority alignment across the organizations. Conservation outcomes for the funder were improved by strategic interactions when organizational priorities were well aligned, but decreased when priorities were misaligned. Meanwhile, local organizations had improved outcomes regardless of alignment due to additional funding in the system. Given that conservation often involves the aggregate actions of multiple organizations with different objectives, strategic interactions between organizations need to be considered if we are to predict possible outcomes of conservation programs or costs of achieving conservation targets.  相似文献   
80.
高浓度氨氮废水处理试验   总被引:4,自引:0,他引:4  
何卿  李峰 《环境科技》1999,12(4):12-13
采用二级吹脱加生化的方法处理高浓度氨氮废水,试验在工况I(气、水温均为4℃)和工况Ⅱ(气温4℃,水温28℃,pH=10.5)条件下分别进行静、动态试验,结果表明在工况Ⅱ条件下,氧化铁废水(浓氨水)的静、动态试验怕氮去除率分别为82.67%和84.19%;综合废水的静、动态试验氨氮去除率一级吹脱分别为62.03%和74.16%,二级吹脱后氨氮浓度降至82.16mg/L和74.32mg/L。再接上后续的生化处理,该废水能达到规定的排放标准。  相似文献   
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