动力扰动作用下充填体的力学响应研究

稳定的充填体是二步骤矿房回采的安全保障。在采矿动力作用下实现充填体的稳定性预测,是二步开采的安全控制关键。为了研究不同扰动幅值下充填体的动力响应规律,以某矿山工程为研究对象,采用Midas/GTS与FLAC3D数值模拟技术,建立了充填体动力稳定性分析的三维数值模型并进行了数值模拟分析。研究结果表明:动力扰动作用下,充填体暴露面的破坏区域由四周逐渐向中心扩展,并随着动力扰动幅值的增加,充填体暴露面破坏区域逐渐增大直至贯通破坏;充填体暴露面质点峰值振动速度随着动力扰动峰值的增加而增加,并得出了适用于该矿充填体暴露面振动峰值速度与动力扰动幅值之间的函数关系。距动力加载面越远,充填体内部质点峰值振动速度越小,且距动力加载面0~12 m处,质点峰值振动速度衰减较慢,从12~20 m质点峰值振动速度下降趋势最为明显。     

乌鲁木齐市大气污染治理成效的综合评估分析

2012~2013年乌鲁木齐采用了以煤改气为主的大气环境治理措施.利用2009~2014年冬季主要污染物浓度、1993~2014年的直接辐射、能见度、霾日数据,并参考相关文献,从大气环境的化学属性、物理属性两个方面评估煤改气等工程措施对乌鲁木齐市大气环境的改善效果.结果表明, 2013~2014年两个冬季乌鲁木齐市主要污染物PM₁₀、SO₂、NO₂浓度比煤改气前期(2009~2011年冬季)各自下降了26.1%、80.2%、11.6%;细颗粒物PM_2.5中水溶性物质的总浓度比例下降了20.57%.煤改气工程前后PM_2.5中可溶性离子浓度排名前三位的均是SO₄^2-、NH₄⁺和NO₃^-,但后期SO₄^2-和NH₄⁺占据PM_2.5质量浓度比例比前期下降近一半,NO₃^-质量浓度比例变化不大.从大气物理特性来看,煤改气等工程之后乌鲁木齐冬季直接辐射量提高,且2014/2015年冬季的直接辐射量是过去23年中第二个峰值;2012/2013年冬季能见度平均增加了5.7km,是1997年以来的最大值.与上年度同期相比,增幅达35.0%;2012/2013年冬季霾日数比上年度同期减少了15d,降幅达50%.上述结果说明乌鲁木齐市的大气环境得到了一定程度的改善.     

Measuring marginal willingness to pay using conjoint analysis and developing benefit transfer functions in various Asian cities

We need a consistent methodology to measure the co-benefits of climate change mitigation across Asian countries. This study chose a strategy of modifying the Japan-specific life-cycle impact assessment method based on endpoint modeling (LIME) for wider application across countries. LIME has two dimensions. First, it is an environmental science that links the cause-and-effect chain. Second, it is an environmental valuation that weighs four endpoint damages in monetary terms through a conjoint analysis that is derived from an Internet-based questionnaire survey. This article describes the modification of the methodology for application of the conjoint analysis to weigh environmental impacts. We approached the investigation as follows. First, we conducted Internet surveys to measure marginal willingness-to-pay (MWTP). We used a sample of 112 respondents in their 20 s to 40 s, divided equally between men and women, in 11 cities across China, India, and Southeast Asia. The results obtained showed clear statistical significance and were comparable across the cities. Second, we attempted to develop functions (called benefit transfer functions) to simplify the measured MWTP in order to apply it across different Asian countries. The functions were derived through a stepwise meta-analytic method, a type of multiple regression analysis whose independent variable was MWTP and dependent variables were attributes of both respondents and surveyed cities. The functions showed that coal consumption and percentage of nature reserve were dependent variables. Then, the MWTPs estimated from the functions were compared with the measured MWTP for transfer error, which is calculated by the absolute value of the difference between the estimated value and the measured value divided by the latter. The transfer error was below 50% in about 90% of the 44 results (a combination of four endpoints and 11 cities), implying that the developed functions were statistically significant.     

The role of weekly high‐activated positive mood,context, and personality in innovative work behavior: A multilevel and interactional model

This article proposed and tested a multilevel and interactional model of individual innovation in which weekly moods represent a core construct between context, personality, and innovative work behavior. Adopting the circumplex model of affect, innovative work behavior is proposed as resulting from weekly positive and high‐activated mood. Furthermore, drawing on the Big Five model of personality and cognitive appraisal theory, openness to experience and support for innovation are proposed as individual and contextual variables, respectively, which interplay in this process. Openness to experience interacts with support for innovation leading to high‐activated positive mood. Furthermore, openness interacts with these feelings leading to greater levels of innovative work behavior. Overall, the model entails a moderated mediation process where weekly high‐activated positive mood represents a crucial variable for transforming contextual and individual resources into innovative outcomes. These propositions were tested and supported using a diary methodology and multilevel structural equation modeling, on the basis of 893 observations of innovative work behavior and moods nested in 10 weekly waves of data. This information was collected from 92 individuals of diverse occupations employed in 73 distinct companies. Theoretical and practical implications are discussed. Copyright © 2013 John Wiley & Sons, Ltd.     

土壤有机碳储量估算的影响因素和不确定性

土壤作为陆地生态系统最大的碳库和碳循环过程的关键环节,其源、汇的变化直接影响全球碳平衡,因此,土壤有机碳储量估算成为生态领域的重要研究内容之一。通过比较不同研究者在不同研究尺度上报道的有机碳储量的研究结果,发现这些研究结果较不一致。分析认为导致土壤有机碳储量评估结果存在较大差异的原因,主要是来自于采样过程中人类干扰以及气候变化等环境要素的波动,特别是研究者所采取的不同估算方法和背景资料。从环境要素（外因）和估算方法（内因）两个角度出发,提出了土壤有机碳储量的研究意义,阐述了造成土壤有机碳储量估算的不确定性和目前研究中存在的问题,并在此基础上,对其未来研究方向和重点进行了展望。     

大断层采动“活化”导水特性研究

煤层回采引起的断层“活化”导水是矿井突水的一种重要形式,具有很高的危险性和隐敝性。依托具体的工程背景,建立简化的力学模型和数值模型,根据弹塑性力学和裂隙介质水动力学理论分析不同推进距离时断层面上的主应力和法向应力变化情况,并通过模拟计算得出回采过程中应力变化与塑性破坏特征。研究结果表明,新集矿区F10大型断层在煤层推进至距断层20 m位置时开始有“活化”趋势,断层带岩体位移值陡增到005 m,距10 m时断层面主应力急剧增大,峰值应力向浅部转移,断层带发生明显位移,孔裂隙扩张。为保证生产安全,需预设30 m防水煤柱,避免煤岩体突水通道沟通主干断层及承压含水层,该研究成果可为矿井生产提供一定的参考价值。     

微波促进无机酸对金属腐蚀速率的研究

为缩短无机酸对金属腐蚀性的检测时间,提高危险性鉴定效率,在联合国《关于危险货物运输的建议书-试验和标准手册》关于化学品对金属腐蚀性检测方法的基础上,以微波辐射装置代替传统的电加热水浴,以20#碳钢和7075-T6铝作为金属试片,研究了不同温度下采用微波法与标准试验方法时稀盐酸和硫酸溶液对金属的腐蚀速率。研究表明,金属的重量损失率随着测试温度的升高而增加,微波法下金属试片的质量损失率显著高于相同腐蚀时间和温度下的标准试验方法。微波法在75℃下40h可与标准试验方法55℃下168h的腐蚀效果进行等效,可以明显提高无机酸对于金属腐蚀性的检测效率。     

一起高压除氧器爆炸事故原因分析

除氧器是火力发电厂给水回热系统中的一个混合式加热器,它的作用是除去锅炉给水中的氧气和其它不凝结气体,以保证锅炉给水的品质,除氧器的安全运行是发电厂安全运行的有效保证。本文对火力发电厂一台20万千瓦机组在正常运行时除氧器突然发生爆炸事故进行分析,找出事故原因提出预防事故的措施。     

上海城市河流生态系统服务的支付意愿

条件价值评估法(CVM)是推导环境资源生态系统服务的支付意愿的标准方法之一.以全国城市河流整治的样板工程--上海浦东张家浜为例,采用支付卡式CVM研究方法,对该城市河流生态系统服务的支付意愿进行了分析.共发放支付卡式CVM问卷800份,回收有效问卷646份.获得张家浜生态系统服务的平均支付意愿为195.07～253.04元/(a·户),将研究结果与国内外部分研究进行了比较.讨论了支付意愿的分布形态和范围,对支付意愿与受访者个人社会经济变量(收入、学历、捐款经历和环境态度等)的回归关系进行了较为详细的分析,并对回归结论进行了环境经济学解释.对支付卡式CVM研究中导致支付意愿产生偏差的部分原因作了一定讨论.最后提出了用CVM推导支付意愿的研究方法面对的批评和争议以及CVM研究结论可靠性的环境决策依据.     

基于CVM的城市大气细颗粒物健康风险的经济评估

运用权变评价法(CVM)调查北京居民对降低PM2.5健康风险的支付意愿,结果表明居民为PM2.5年平均浓度降低30%、45%和60%的平均支付意愿分别71.60元/月、85.66元/月和94.31元/月.基于结构方程模型,以风险特征、风险情绪、风险沟通3个维度衡量风险认知,构建风险认知与支付意愿相关模型,分析表明风险认知对支付意愿的影响系数为0.37;风险认知3个维度中风险情绪反映度最高,负荷量为0.95,且风险情绪中“现实满意度”影响最显著,负荷量为0.71;风险特征中PM2.5健康风险发生可能性、后果严重性影响程度最高,负荷量均为0.85;个人特征能直接或通过风险认知间接影响支付意愿,总影响系数为0.47,且个人特征中受教育程度与收入表现出强共变性,共变系数为0.67.