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彩虹玻屏厂工业中水网的组建与应用
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作者 王备战 《陕西环境》 2002年第5期32-34,共3页
通过对该企业用水情况的全面调查分析,提出组建工业中水网,提高工业用水回用率的设想,并通过实施和运行分析验证,实现了年节水700,000m3、工业用水回用率从55%提高到89%的行业先进水平。
关键词 中水网 工业 研磨废水 回用率
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青弋江流域下游中片水网圩区水情分析与建议 被引量:1
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作者 丁贤青 《中国防汛抗旱》 2019年第12期52-54,共3页
介绍了靑弋江分洪道工程建设基本情况,提出了靑弋江分洪道投入使用后,下游中片水网圩区水位相关关系发生根本性变化,形成新的中片水网圩区水位平衡关系,在此基础上分析了中片水网圩区水情变化原因,提出了拟定新的设计水位值、在红庙节... 介绍了靑弋江分洪道工程建设基本情况,提出了靑弋江分洪道投入使用后,下游中片水网圩区水位相关关系发生根本性变化,形成新的中片水网圩区水位平衡关系,在此基础上分析了中片水网圩区水情变化原因,提出了拟定新的设计水位值、在红庙节制闸左坝上开设非常泄洪道等规划建议。 展开更多
关键词 青弋江流域 水网圩区 防洪形势 水情分析
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Spatial differentiation in stable isotope compositions of surface waters and its environmental significance in the Issyk-Kul Lake region of Central Asia 被引量:2
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作者 MA Long JILILI Abuduwaili LI Yao-ming 《Journal of Mountain Science》 SCIE CSCD 2018年第2期254-263,共10页
Stable isotope values of oxygen (180) and hydrogen (2H) of surface waters were used to study the origin and environmental significanees in the Issyk-Kul basin of Kyrgyzstan in Central Asia, which is the most impor... Stable isotope values of oxygen (180) and hydrogen (2H) of surface waters were used to study the origin and environmental significanees in the Issyk-Kul basin of Kyrgyzstan in Central Asia, which is the most important intermountain basin in the modern Tien Shan orogen. This study is the first analysis of hydrochemical spatial differentiation in the stable isotopes of surface waters in this watershed. 75 samples were collected from rivers, springs, lakes, rain and snow during the rainy season in July and August of 2o16. Stable isotopes of 180 and 2H were studied for all samples, and cation ratios (Sr/Ca and Mg/Ca) were also determined for lake water samples. Stable isotope values from precipitation scattered around the Local Meteoric Water Line (determined from Urumqi Station of the global network of isotopes in precipitation (GNIP)), together with values of the Deuterium excess parameter (d) from 15.3‰ to 30.5‰, with an average of 19.8‰, indicating that the moisture sources are primarily from regions with low relative humidity. The 8180 and 52H values were significantly different between the river and lake samples, indicating that regional evaporation caused the isotopic enrichment of lake water. Geospatial autocorrelation, measured by Moran's I coefficient, indicated weak spatial autocorrelation within stable isotopes of oxygen and hydrogen in the surface waters of the studied area, which is primarily an effect of climate during the water chemistry evolution. The cation ratios Sr/Ca and Mg/Ca in lake water samples were not correlated with the concentration of total dissolved solids, but did show correlation with stable isotopic values, which is significant for paleoenvironmental reconstruction. 展开更多
关键词 Spatial differentiation Stable isotope Moisture Sources Geospatial autocorrelation IssykKul Lake Central Asia
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Spatiotemporal factors affecting fish harvest and their use in estimating the monthly yield of single otter trawls in Putuo district of Zhoushan, China 被引量:4
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作者 王迎宾 郑基 +1 位作者 王洋 郑献之 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2012年第4期580-586,共7页
We used generalized additive models (GAM) to analyze the relationship between spatiotemporal factors and catch, and to estimate the monthly marine fishery yield of single otter trawls in Putuo district of Zhoushan, Ch... We used generalized additive models (GAM) to analyze the relationship between spatiotemporal factors and catch, and to estimate the monthly marine fishery yield of single otter trawls in Putuo district of Zhoushan, China. We used logbooks from five commercial fishing boats and data in government's monthly statistical reports. We developed two GAM models: one included temporal variables (month and hauling time) and spatial variables (longitude and latitude), and another included just two variables, month and the number of fishing boats. Our results suggest that temporal factors explained more of the variability in catch than spatial factors. Furthermore, month explained the majority of variation in catch. Change in spatial distribution of fleet had a temporal component as the boats fished within a relatively small area within the same month, but the area varied among months. The number of boats fishing in each month also explained a large proportion of the variation in catch. Engine power had no effect on catch. The pseudo-coefficients (PCf) of the two GAMs were 0.13 and 0.29 respectively, indicating the both had good fits. The model yielded estimates that were very similar to those in the governmental reports between January to September, with relative estimate errors (REE) of <18%. However, the yields in October and November were significantly underestimated, with REEs of 36% and 27%, respectively. 展开更多
关键词 generalized additive model (GAM) estimate of catch single otter trawl Zhoushan
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Food web structure and trophic levels in polyculture ricecrab fields 被引量:4
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作者 郭凯 赵文 +3 位作者 李文宽 赵苑淞 张鹏 张晨 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2015年第3期735-740,共6页
Stable carbon and nitrogen isotopes were used to investigate nutrient pathways and trophic relationships from the rice-crab system in Panjin, Liaoning Province, China. Values of 313C ranged from -27.38%±0.44%o to... Stable carbon and nitrogen isotopes were used to investigate nutrient pathways and trophic relationships from the rice-crab system in Panjin, Liaoning Province, China. Values of 313C ranged from -27.38%±0.44%o to -18.34%±0.26%o and δ^15N ranged from 1.10%o4-0.88%o to 9.33%±0.57%. Pseudorasbora parva (Stone moroko) had the highest δ^13C and 8tSN values. The lowest δ^13C values were obtained for the macrophytes and the lowest δ^15N value was found in sediments. Stable carbon and nitrogen isotopes were used to determine the contribution of different food items to the diets of crabs. The δ^13C results indicated that the Pseudorasbora parva made the greatest contribution to the diet of Eriocheir sinensis (Chinese mitten crab), while the δ^15N results indicated that most food items contributed more than 10% to the diet of the crab. There were three trophic levels identified in the system (Levels 0-2). The crab Eriocheir sinensis, fish Pseudorasbora parva and Misgurnus anguillicaudatus (Oriental weatherfish), and the oligochaete Limnodrilus hoffmeisteri (Limnodrilus worm), were at the second level, zooplankton were at the first level and suspended particulate matter and macrophytes were at trophic position 0. 展开更多
关键词 rice-crab culture Eriocheir sinens stable carbon isotope stable nitrogen isotope trophic level
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Equilibrating Pressure with Auto-Control Valve in Water Distribution Networks
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作者 张宏伟 闫晓强 张丽 《Transactions of Tianjin University》 EI CAS 2003年第4期334-339,共6页
This paper probes into the feasibility of equilibrating pressure of water distribution network through (using auto-control valves) in theory and in the economy. An optimal valve control model is designed to minimize t... This paper probes into the feasibility of equilibrating pressure of water distribution network through (using auto-control valves) in theory and in the economy. An optimal valve control model is designed to minimize the sum of squares of residual pressure in the network. Such an analog simulation has been performed on the year 2003 programming network of a certain littoral district in North China, through which this paper confirms that it is feasible to equilibrate pressure with auto-control valves in theory. The research work has brought about a discovery of applicable conditions of valves in economic feasibility, which avoids a great economic loss due to the wild use of auto-control valve. In addition, simulated annealing algorithm is applied to optimize valve settings and shown to identify global optimum or near-optimum. 展开更多
关键词 auto-control valve water distribution networks equilibrating pressure simulated annealing
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Stable isotopes in aquatic food web of an artificial lagoon in the Hangzhou Bay,China
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作者 全为民 施利燕 陈亚瞿 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2010年第3期489-497,共9页
Stable isotope values, δ13C and δ15N, were determined for four primary producers and 19 dominant consumers in a small artificial lagoon located in Hangzhou Bay. Based on these results the major pathways for energy f... Stable isotope values, δ13C and δ15N, were determined for four primary producers and 19 dominant consumers in a small artificial lagoon located in Hangzhou Bay. Based on these results the major pathways for energy flow and trophic structure of the artificial lagoon ecosystem were characterized. The mean δ13C values for the 19 consumers ranged from -22.99‰ to -14.24‰. Apart from so-iny mullet Liza haematocheila, the other 18 consumers had intermediate δ13C values between those of epibenthic microalgae and particulate organic matter (POM). The results of a multiple source linear mixing model (IsoSource model) indicated that 50% or more of the organic carbon in the tissues of most consumers was derived from epibenthic microalgae. This indicated that these primary producers were the main food source fueling the lagoon food web. The mean δ15N values for the 19 consumers varied between 4.93‰ and 12.97‰ and indicated four trophic levels in the lagoon. Four macroinvertebrates and zooplankton represented the primary consumers, whilst the other 14 consumers occupied the secondary and tertiary consumer levels. The 19 consumers were divided into three trophic guilds (detritivores/suspension feeders, omnivores and carnivores). 展开更多
关键词 isotope ^13C ^15N lsoSource model trophic level food web
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Statistic Measurement and Empirical Research on Sustainable Development of China Internet
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作者 HU Yonghong 《Journal of Systems Science & Complexity》 SCIE EI CSCD 2016年第2期336-349,共14页
In this paper,the concepts of green development and coordinated development of the Internet are proposed,and the connotation of sustainable development of the Internet is defined further.Based on these,by using the co... In this paper,the concepts of green development and coordinated development of the Internet are proposed,and the connotation of sustainable development of the Internet is defined further.Based on these,by using the comprehensive evaluation method,the Internet sustainable development index(ISDI) system is created and designed,the sustainable development level of the Internet in China is evaluated and measured systematically,and corresponding policy suggestions are given. 展开更多
关键词 INDEX INTERNET sustainable development.
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