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681.
东三旗台Sacks体应变干扰分析与震例研究 总被引:4,自引:0,他引:4
本文对北京市昌平区东三旗台Sacks体应变观测值与固体潮、气压、水位、降雨关系进行了初步分析。通过干扰因素分析,为提高地震预报的准确性提供了参考依据。同时,进行了有关震例研究,希望通过总结震例,为今后利用Sacks体应变观测探索地震预报实践建立科学的分析处理方法。 相似文献
682.
Bin He Taikan Oki Fubao Sun Daisuke Komori Shinjiro Kanae Yi Wang Hyungjun Kim Dai Yamazaki 《Journal of environmental management》2011
Artificial Neural Network (ANN) is a flexible and popular tool for predicting the non-linear behavior in the environmental system. Here, the feed-forward ANN model was used to investigate the relationship among the land use, fertilizer, and hydrometerological conditions in 59 river basins over Japan and then applied to estimate the monthly river total nitrogen concentration (TNC). It was shown by the sensitivity analysis, that precipitation, temperature, river discharge, forest area and urban area have high relationships with TNC. The ANN structure having eight inputs and one hidden layer with seven nodes gives the best estimate of TNC. The 1:1 scatter plots of predicted versus measured TNC were closely aligned and provided coefficients of errors of 0.98 and 0.93 for ANNs calibration and validation, respectively. From the results obtained, the ANN model gave satisfactory predictions of stream TNC and appears to be a useful tool for prediction of TNC in Japanese streams. It indicates that the ANN model was able to provide accurate estimates of nitrogen concentration in streams. Its application to such environmental data will encourage further studies on prediction of stream TNC in ungauged rivers and provide a useful tool for water resource and environment managers to obtain a quick preliminary assessment of TNC variations. 相似文献
683.
根据2004—2009年大气中SO2污染物的监测数据,通过灰色GM(1,1)模型预测了未来6年秦皇岛市大气中SO2的变化趋势。结果显示,灰色系统GM(1,1)模型合理,精度较高,相对误差为-1.875%~1.228%,与环保部门公布的数据吻合程度较好。 相似文献
684.
The explosion and deflagration-to-detonation transition (DDT) in epoxy propane (E.P.) vapor/air mixture clouds under weak ignition conditions has been studied in an experimental tube of diameter 199 mm and length 29.6 m. E.P. vapor clouds were formed by injecting liquid E.P. into the experimental tube and evaporating of the fine E.P. droplets. The dimension and the evaporating process of the E.P. droplet were measured and analyzed. The E.P. vapor/air mixture clouds were ignited by an electric spark with an ignition energy of 40 J. The characteristics and the stages of the DDT process in the E.P. vapor/air mixtures have been studied and analyzed. A self-sustained detonation wave formed, as was evident from the existence of a transverse wave and a cellular structure. Moreover, a retonation wave formed during the DDT process in the E.P. vapor/air mixture. The influence of the E.P. vapor concentration on the DDT process has been studied. The minimum E.P. vapor concentration for the occurrence of the DDT in the E.P. vapor/air mixture has been evaluated and the variation of DDT distance with E.P. vapor concentration has been analyzed. 相似文献
685.
686.
Hancheng Dai Xinyuan Liu Chaoyi Guo Yazhen Wu Chen Huang Keding Lu Yuanhang Zhang Lei Duan Miaomiao Cheng Fahe Chai Fengqiao Mei 《环境科学学报(英文版)》2023,123(1):140-155
China has put great efforts into air pollution control over the past years and recently committed to its most ambitious climate target. Cost and benefit analysis has been widely used to evaluate the control policies in terms of past performance, future reduction potential,and direct and indirect impacts. To understand the cost and benefit analysis for air pollution control in China, we conducted a bibliometric review of more than 100 studies published over the past two decades, including the cur... 相似文献
687.
Ruobin Dai Hongyi Han Yuting Zhu Xi Wang Zhiwei Wang 《Frontiers of Environmental Science & Engineering》2022,16(4):40
688.
Zhong Jie Ma Yancheng Jiang Shaojun Dai Guangling Liu Zhenyuan Shu Yuehong 《Environmental science and pollution research international》2022,29(59):88630-88643
Environmental Science and Pollution Research - Metal-free biochar to activate persulfate and degrade organic contaminants has attracted great attention in advanced oxidation processes, while the... 相似文献
689.
当前,举国上下都在为构建和谐社会而不懈努力,特别是北京市提出了“人文北京、科技北京、绿色北京”的举措,城市建设得到了快速发展。与此同时,高、大、深、新的建筑工程愈来愈多,施工难度日益增大,生产安全事故的发生也呈上升的趋势,特别是高处坠落事故愈来愈严重。 相似文献
690.
Xie Shouxiang Dai Xichao & Wang Yafen School of Management China University of Mining & Technology Xuzhou China 《中国人口.资源与环境(英文版)》2004,2(3)
Cities based on mining are distinctive from other cities in China. Their heavy dependence on minerals, a relatively undiversified industrial structure, seriously damaged ecological environment and the rather low degree of openness have all reduced their competitiveness, and severely constrained and hindered their sustainable development. In this paper the authors will study mining-based cities from the perspective of sustainable development, first by having a critical review of their features, and then by researching into strategic options to support their sustainable development. 相似文献