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1.
循环冷却水复配阻垢缓蚀剂配方的优化   总被引:2,自引:1,他引:2  
阐述了循环冷却水对金属腐蚀的机理、阻垢缓蚀剂作用的原理,提出了复配缓蚀阻垢剂配方优化的原则及评价标准。并对攀钢煤化公司循环冷却水进行了复配缓蚀阻垢剂配方优化试验,通过配方优化试验,筛选出了DS—605型(浓度为100mg/L)的高效低磷有机膦阻垢缓蚀剂。该配方技术先进,其阻垢缓蚀效果优于GB/50050—95规定的指标要求,冷却水磷含量由原先的12mg/L降至6mg/L,年处理费用降低了27%,具有显著的经济效益和环保效益,目前正准备投入实际使用。  相似文献   
2.
Summary This study focuses on discrimination of changes, produced by low-level microwave exposure in intensity and time variability of the human EEG at rest. The power spectral density (PSD) method and nonlinear scaling analysis of the length distribution of low variability periods (LDLVP) were selected for analysis of the EEG signal. During the study, 19 healthy volunteers were exposed to a microwave (450 MHz) of 217 Hz frequency on-off modulation. The field power density at the scalp was 0.16 mW/cm2. The experimental protocol consisted of ten cycles of repetitive microwave exposure. Signals from frontal, temporal, parietal and occipital EEG channels on EEG theta, alpha and beta rhythms were analysed. Exposure to microwave causes average increase of EEG activity. LDLVP analysis discriminated significant effect in time variability for 2 subjects (11%). PSD method detected significant changes in intensity for 4 subjects (21%). The effect of low-level microwave exposure is stronger on EEG beta rhythm in temporal and parietal regions of the human brain.  相似文献   
3.
作为人地关系中"地"对"人"负面作用的核心学科——灾害风险学存在着显著的地理空间尺度差异与尺度效应。本文提出灾害风险尺度耦合的概念与类型,从数据、方法和区划三个方面提出灾害风险研究中的空间降尺度和空间升尺度耦合思路,供同行学者参考。  相似文献   
4.
为预测和判断锅炉故障的发生,完善锅炉故障检测技术,基于锅炉运转具有非线性特点,提出将非线性评价指标应用于锅炉故障诊断。研究特征信号的非线性特性,通过确定延迟时间和嵌入维数来重构相空间;采用混沌分形理论研究非线性评价指标;提取最大Lyapunov指数和关联维数,并为收集的每种特征信号选择最合适的非线性指标。结果表明:蒸汽压力的非线性特征指标应选择关联维数,烟气温度1、烟气温度2、水管温度1和水管温度2的非线性特征指标应当选择最大Lyapunov指数。  相似文献   
5.
Introduction: Heterogeneous driving populations with many different origins are likely to have various sub-cultures that comprise of drivers with shared driver characteristics, most likely with dissimilar traffic safety cultures. An innovative methodology in traffic safety research is introduced which is beneficial for large datasets with multiple variables, making it useful for the multi-variate classification of drivers, driving attitudes and/or (risky) driving behaviours. Method: With the application of multidimensional scaling analysis (MDS), this study explores traffic safety culture in the State of Qatar using a questionnaire and investigates the similarity patterns between the questionnaire items, aiming to classify attitudes towards risky driving behaviours into themes. MDS is subsequently applied to classify drivers within a heterogeneous driving sample into sub-cultures with shared driver characteristics and different risky driving attitudes. Results: Results show that acceptance of speeding is highest among the young Arabic students and acceptance of distraction and drivers’ negligence such as phone use and not wearing a seatbelt is highest among male Arab drivers. Acceptance of extreme risk-taking like intoxicated driving and red-light running is highest among South-Asian business drivers. Conclusion: It is important and practical to understand risky behavioural habits among sub-cultures and thereby focussing on groups of drivers instead of individuals, because groups are easier to approach and drivers within sub-cultures are found to influence each other. By indicating which groups of drivers are most likely to perform specific risky driving themes, it is possible to target these groups and effectively emphasise certain subsets of risky driving behaviours during training or traffic safety education. Practical Applications: This study provides guidance for the improvement of driver education and targeted traffic safety awareness campaigns, intending to make changes to attitudes and habits within specific driver sub-cultures with the aim to improve traffic safety on the longer term.  相似文献   
6.
基于韦伯-费希纳定律的空气质量普适韦伯指数公式   总被引:3,自引:0,他引:3  
在适当设定各项空气污染物浓度"参照值"cj0的基础上,用相应于"参照值"cj0的污染物的"规范值"xj作为基于韦伯-费希纳(W-F)定律空气质量指数公式中的污染刺激量。由于各污染物同级标准的浓度"规范值"xjl差异不大,从而可以认为各污染物的韦伯指数公式等效于一个具有共同适用的韦伯常数α的W-F指数公式,并采用粒子群(PSO)算法优化得出α,得到对7项空气污染物皆适用的空气质量普适韦伯指数公式。该公式应用于多个实例分析,并与多种其它评价方法的评价结果比较表明,空气质量普适韦伯指数公式具有简单、实用和直观的特点。  相似文献   
7.
Urban area expansion is happening at much faster rates in Asian and African cities than elsewhere in the world. This study uses multi-temporal Landsat images to map the urban extent of six small to large cities in West Africa at four different time steps from the early 1970s–2010. The selected cities are Kumasi of Ghana, Daloa of Cote d’Ivoire, Abuja and Kano in Nigeria, Kindia of Guinea, and Ouagadougou of Burkina Faso. All cities revealed significant urban growth in both urban area and population; however, it was apparent that there was a lot of variability in urban area development. Exponential urban growth rates in the cities were measured as ranging between 0.026 and 0.077, with allometric scaling factors matching those of other countries.  相似文献   
8.
根据生态足迹分析方法,建立了水资源生态足迹概念模型,确定了计算水资源帐户生态足迹所需的3个关键参数,即平均水资源产量、均衡因子和地区产量因子,计算了安康市1996—2007年水资源生态足迹和生态承载力。引入水资源生态足迹压力指数、万元GDP水资源生态足迹、累积水资源生态足迹等指标,利用水足迹模型评价水资源可持续发展程度的全面性和对比性。结果表明,计算结果可客观评价安康市水资源可持续发展与利用情况,为地区水资源的可持续利用与管理提供了科学的依据。  相似文献   
9.
ABSTRACT

Ecological democracy confronts a challenge of not only reconciling democracy and ecology, but doing so where human activities and their environmental consequences are increasingly global. Deliberative scholars dealing with these issues emphasise reflexive governance, involving the contestation of discourses, as part of the solution, mostly aimed at high-level institutions and intergovernmental cooperation. However, even at this level democracy demands responsiveness to the citizen. To this end, the paper explores citizen-level deliberation to inform possibilities for ecological democracy writ large, via a growing literature on deliberative governance and polycentrism. Different system levels are connected via ecologically reflexive capacity and the discursive conditions under which it is enhanced, including in small-scale minipublics. This understanding informs mechanisms for ‘scaling up’ deliberative quality to the wider public sphere via regulating the manipulation of public discourse. Minipublic deliberation, properly harnessed, can serve to decontaminate public debate of anti-reflexive strategic arguments and reshape public discourse. Such anti-reflexive strategies seek to shape the public will, specifically by de-emphasising ecology via intuitive arguments that short-cut public reasoning. Acting as discursive regulatory trustees, minipublics can improve reflexivity in the wider system via a nested polycentric approach that discursively connects citizens’ deliberation to the global system both horizontally and vertically.  相似文献   
10.
基于卫星遥感的浙北平原气溶胶光学特性长期变化分析   总被引:1,自引:1,他引:0  
利用MOD04 C051气溶胶产品,以浙江北部平原为主要研究区,开展区域气溶胶光学特性长期(2000年3月—2013年12月)变化分析.长期逐月时间序列显示,区域气溶胶光学特性具有年内周期性变化规律,AOD(Aerosol Optical Depth)峰值多出现在5月或6月;Angstrom Exponent(α指数)峰值多出现在3月或4月.在空间分布上,研究区中部地区气溶胶污染较重且粗粒子成分较高.研究区气溶胶光学特性长期变化特征主要体现在:1气溶胶污染总体减轻但细粒子成分增加,复合污染加重;2008年以来区域AOD年均值总体呈下降趋势;2007—2013年α指数年均值显著高于2000—2006年;区域α指数月均值增长趋势显著,近14年的总倾向率为0.125(p0.05);2AOD和α指数的季节差异呈减小趋势,AOD的季节变化规律由2000年的春夏≈冬秋转变为2013年的春冬秋≥夏;α指数虽仍以夏秋季高于冬春季,但春秋两季α指数相对增大;3以污染较轻的湖州市和污染较重的嘉兴市为例的原因分析显示,AOD变化与SO2排放量具有一定相关性,α指数变化与民用汽车拥有量变化趋势一致,相关性较高.  相似文献   
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