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On-line Measurement of Water-Soluble Ions in Ambient Particles 被引量:5
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作者 温天雪 王跃思 +1 位作者 张士昱 刘广仁 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2006年第4期586-592,共7页
Combining the system of rapid collection of ambient particles and ion chromatography, the system of rapid collection of fine particles and ion chromatography (RCFP-IC) was established to automatically analyze on-lin... Combining the system of rapid collection of ambient particles and ion chromatography, the system of rapid collection of fine particles and ion chromatography (RCFP-IC) was established to automatically analyze on-line the concentrations of water-soluble ions in ambient particles. Here, the general scheme of RCFP-IC is described and its basic performance is tested. The detection limit of RCFP-IC for SO4^2-, NO3^-, NO2^-, Cl^- and F- is below 0.3μg m^-3. The collection efficiency of RCFP-IC increases rapidly with increasing sized particles. For particles larger than 300 nm, the collection efficiency approaches 100%. The precision of RCFP-IC is more than 90% over 28 repetitions. The response of RCFP-IC is very sensitive and no obvious cross-pollution is found during measurement. A comparison of RCFP-IC with an integrated filter measurement indicates that the measurement of RCFP-IC is comparable in both laboratory experiments and field observations. The results of the field experiment prove that RCFP-IC is an effective on-line monitoring system and is helpful in source apportionment and pollution episode monitoring. 展开更多
关键词 RCFP-IC water-soluble ions ON-line basic performance field observation
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Determination of triazine herbicide residues in water samples by on-line sweeping concentration in micellar electrokinetic chromatography 被引量:2
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作者 Shuai Hua Zhang Yuan Yuan Yang Dan Dan Han Chun Wang Xin Zhou Xiao Huan Zang Zhi Wang 《Chinese Chemical Letters》 SCIE CAS CSCD 2008年第12期1487-1490,共4页
A new method for the determination of atrazine, simazine and prometryn in water samples by on-line sweeping concentration technique in micellar electrokinetic chromatography (MEKC) was developed. Various parameters ... A new method for the determination of atrazine, simazine and prometryn in water samples by on-line sweeping concentration technique in micellar electrokinetic chromatography (MEKC) was developed. Various parameters affecting sample enrichment and separation efficiency were systematically studied. Compared with the conventional MEKC method, up to 60-200-fold improvement in concentration sensitivity was achieved in terms of peak height by using this sweeping injection technique. The compound strychnine was used as the internal standard for the improvement of the experimental reproducibility. The limits of detection (S/ N = 3:1) for atrazine, simazine and prometryn were 9, 10 and 0.5 ng mL-1, respectively. This method has been successfully applied to the analysis of atrazine, simazine and prometryn in lake, steam and ground water. 展开更多
关键词 Triazine herbicides On-line concentration MEKC SWEEPING water samples
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Roughness evaluation in shotcrete-lined water tunnels with invert concrete based on cases from Nepal
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作者 Chhatra Bahadur Basnet Krishna Kanta Panthi 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2018年第1期42-59,共18页
Most of the existing roughness estimation methods for water tunnels are related to either unlined or concrete/steel-lined tunnels. With the improvement in shotcrete technology, advancement in tunneling equipment and c... Most of the existing roughness estimation methods for water tunnels are related to either unlined or concrete/steel-lined tunnels. With the improvement in shotcrete technology, advancement in tunneling equipment and cost and time effectiveness, future water tunnels built for hydropower projects will consist of rock support with the extensive use of shotcrete lining in combination with systematic bolting and concrete lining in the tunnel invert. However, very little research has been performed to find out tunnel surface roughness for shotcrete-lined tunnels with invert concrete, which is important in calculating overall head loss along the waterway system to achieve an optimum and economic hydropower plant design. Hence, the main aim of this article is to review prevailing methods available to calculate tunnel wall roughness, and to use existing methods of head loss calculation to back-calculate roughness of the shotcrete-lined tunnels with invert concrete by exploiting measured head loss and actual cross-sectional profiles of two headrace tunnels from Nepal. Furthermore, the article aims to establish a link between the Manning coefficient and the physical roughness of the shotcrete-lined tunnel with invert concrete and to establish a link between over-break thickness and physical roughness. Attempts are also made to find a correlation between over-break thickness and rock mass quality described by Q-system and discussions are conducted on the potential cost savings that can be made if concrete lining is replaced by shotcrete lining with invert concrete. 展开更多
关键词 Shotcrete-lined water tunnels Friction loss Physical and hydraulic roughnesses Tunnel over-break
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Moisture Analysis of a Squall Line Case Based on Precipitable Water Vapor Data from a Ground-Based GPS Network in the Yangtze River Delta 被引量:3
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作者 丁金才 杨引明 +4 位作者 叶其欣 黄炎 马晓星 马雷鸣 Y. R. GUO 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2007年第3期409-420,共12页
A squall line swept eastward across the area of the Yangtze River Delta and produced gusty winds and heavy rain from the afternoon to the evening of 24 August 2002. In this papers the roles of moisture in the genesis ... A squall line swept eastward across the area of the Yangtze River Delta and produced gusty winds and heavy rain from the afternoon to the evening of 24 August 2002. In this papers the roles of moisture in the genesis and development of the squall line were studied. Based on the precipitable water vapor (PWV) data from a ground-based GPS network over the Yangtze River Delta in China, plus data from a Pennsylvania State University/National Atmospheric Center (PSU/NCAR) mesoscale model (MM5) simulation, initialized by three-dimensional variational (3D-VAR) assimilation of the PWV data, some interesting features are revealed. During the 12 hours prior to the squall line arriving in the Shanghai area, a significant increase in PWV indicates a favorable moist environment for a squall line to develop. The vertical profile of the moisture illustrates that it mainly increased in the middle levels of the troposphere, and not at the surface. Temporal variation in PWV is a better precursor for squall line development than other surface meteorological parameters. The characteristics of the horizontal distribution of PWV not only indicated a favorable moist environment, but also evolved a cyclonic wind field for a squall line genesis and development. The "+2 mm" contours of the three-hourly PWV variation can be used successfully to predict the location of the squall line two hours later. 展开更多
关键词 squall line global positioning system (GPS) precipitable water vapor (PWV)
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Adaptability and recovery capability of two maize inbred-line foundation genotypes, following treatment with progressive water-deficit stress and stress recovery 被引量:1
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作者 Xianwei Fan Guiyuan Huang +2 位作者 Liujun Zhang Tao Deng Youzhi Li 《Agricultural Sciences》 2013年第8期389-398,共10页
Two maize inbred lines, the foundation genotype Y478 and its derived line Z58, are widely used to breed novel maize cultivars in China, but little is known about which traits confer Z58 with superior drought tolerance... Two maize inbred lines, the foundation genotype Y478 and its derived line Z58, are widely used to breed novel maize cultivars in China, but little is known about which traits confer Z58 with superior drought tolerance and yield. In the present study, responses in growth traits, photosynthetic parameters, chlorophyll fluorescence and leaf micromorphological characteristics were evaluated in Y478 and Z58 subjected to water-deficit stress induced by PEG 6000. The derived line Z58 showed greater drought tolerance than Y478, which was associated with higher leaf relative water content (RWC), root efficiency, and strong growth recovery. Z58 showed a higher stomatal density and stomatal area under the non-stressed condition;in these traits, both genotypes showed a similar decreasing trend with increased severity of water-deficit stress. In addition, the stomatal size of Y478 declined significantly. These micromorphological differences between the two lines were consistent with changes in physiological parameters, which may contribute to the enhanced capability for growth recovery in Z58. A non-linear response of Fv/Fm to leaf RWC was observed, and Fv/Fm decreased rapidly with a further gradual decline of leaf RWC. The relationship between other chlorophyll fluorescence parameters (photochemical quenching and electron transport rate) and RWC is also discussed. 展开更多
关键词 MAIZE INBRED lines Morphological Response Gas Exchange CHLOROPHYLL Fluorescence water-DEFICIT Stress RECOVERY
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Feasibility of Transferring Drinking Water from the Senegal River in the East (Backel) to the West Center (Fatick) in Senegal
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作者 Ndiouga Camara Alioune Ly +1 位作者 Babacar Diouf Séni Tamba 《Journal of Water Resource and Protection》 CAS 2024年第11期720-729,共10页
Every year, 24 billion m3 of fresh water are thrown into the sea by the Senegal River, while most of the country’s populations do not have permanent access to drinking water. Also, agricultural land, which extends as... Every year, 24 billion m3 of fresh water are thrown into the sea by the Senegal River, while most of the country’s populations do not have permanent access to drinking water. Also, agricultural land, which extends as far as the eye can see, is only used during winter periods, thus slowing down the development of agriculture. It is in this context that this article studies the feasibility of transferring drinking water from the Senegal River in the east of the country to the center-west through a transfer canal to meet the drinking water needs of the populations. In addition, we intend to flood the fossil valleys from this canal and recharge the aquifers. The watershed resulting from the juxtaposition of the two watersheds which dominate central Senegal has a slightly descending profile from Bakel to Fatick. This promotes gravity flow of water over 542 km. This analysis is carried out by the Glabal Mapper software and SRTM1 images. We report that all water needs have been estimated at approximately 70 m3/s based on the ANDS census in 2023, the distribution of arable land and groundwater recharge areas in the country. The waters flowing in the canal have depths (draft) not reaching 4.6 m. These results are obtained by applying the Manning Strickler equation, on a channel with a straight cross-section in the shape of a trapezoid and lined with sand concrete. The canal thus designed will bring water to populations and arid zones in the central and central-western regions of the country where problems persist. However, it will be necessary to overcome a difference in altitude of 96 m over 30 km to raise the water from the river to the threshold of the canal in order to ensure the flow in the latter. We have retained two calculation variants (Canal + Pumping or Single Pumping) whose pumping stations will be powered by solar fields. Due to the heavy investments, the installations upstream of the canal will be modular over time. Consequently, the central canal project will be constructed in six (6) phases of ten (10) years. 展开更多
关键词 Fresh water CANAL Fossil Valleys Aquifers The Dividing line watersheds Gravity Flow Sand Concrete Height Difference Modular Solar Fields
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Environmental Isotopic Characterization of Groundwater and Surface Water in Northeast Missan Province,South Iraq 被引量:4
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作者 Hussein Badr GHALIB Ali Riza SGüT 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2014年第4期1227-1238,共12页
The present work studies the environmental isotopes assess groundwater characteristics of the different parts of the main aquifer in the northeast Missan Province in south of Iraq. Water samples of groundwater and sur... The present work studies the environmental isotopes assess groundwater characteristics of the different parts of the main aquifer in the northeast Missan Province in south of Iraq. Water samples of groundwater and surface water were collected for two dry and wet seasons during the water year of 2011-2012. The study shows that most of the groundwater in the aquifer falls above the global meteoric water line, and all the samples fall below the Mediterranean meteoric water line, indicating that these samples are a mixture of two water types. The tritium content of these samples supports this conclusion. The overall conclusion of this study indicates that there are two sources of groundwater recharge in the studied area: the ephemeral streams (Teeb and Dewerge) and major precipitation sources. According to the tritium levels at or below one tritium unit (TU) obtained from the water, supply wells are highly confined or "not vulnerable". Overall, the 3^H results imply that recent recharge has taken place during the last four to five decades. In the recharge area, the high tritium content in the southern part of the Teeb area suggests that the recharge originates from rapid infiltration of surface runoff. Therefore, the groundwater resources in the study area should be protected from contamination, because it will influence the aquifer in a relatively short period of time if any contamination enters the recharge areas of the aquifer. 展开更多
关键词 Groundwater recharge Tritium environmental isotope meteoric water line Iraq
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台风“暹芭”对湖南影响的分阶段对比分析
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作者 唐明晖 陈龙 +2 位作者 赵恩榕 王强 陈紫妍 《灾害学》 北大核心 2025年第1期102-109,共8页
利用常规观测、再分析和双偏振雷达资料,结合拉格朗日混合单粒子轨迹模式(HYSPLIT),对比分析了2022年台风“暹芭”影响湖南的三个阶段(台前飑线、台风倒槽、台风低压)水汽来源、双偏振特征,并探讨降水特征。结果表明:①台前飑线阶段,水... 利用常规观测、再分析和双偏振雷达资料,结合拉格朗日混合单粒子轨迹模式(HYSPLIT),对比分析了2022年台风“暹芭”影响湖南的三个阶段(台前飑线、台风倒槽、台风低压)水汽来源、双偏振特征,并探讨降水特征。结果表明:①台前飑线阶段,水汽主要源自西太平洋、鄱阳湖,沿东风输送至湘北,与东北风形成辐合;回波表现为积云降水特征,呈带状、质心偏低;Z_(DR)和K_(DP)值高,CC值大,以数浓度高扁平大雨滴为主。②台风倒槽阶段,水汽源自南海和西太平洋,沿槽前偏东南气流向湘中输送;回波表现为层云降水特征,低层Z_(H)、K_(DP)、Z_(DR)偏低,CC偏大,以数浓度低的小雨滴为主;5 km高度出现CC亮带,导致“列车效应”暴雨。③台风低压阶段,水汽源自中南半岛、北部湾和南海,沿低压向湘东南、湘东北输送;回波呈积层混合降水特征,中低层K_(DP)有大值(≥1.7°/km)区,Z_(DR)强度偏弱,以数浓度高小雨滴为主。研究结果有助于理解台风影响下的降水特征。 展开更多
关键词 台风“暹芭” 分阶段分析 水汽输送 台前飑线 雷达双偏振
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Fractionation mechanism of stable isotope in evaporating water body 被引量:7
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作者 ZHANG Xinping TIAN Lide LIU Jingmiao 《Journal of Geographical Sciences》 SCIE CSCD 2005年第3期375-384,共10页
Under Rayleigh equilibrium condition, stable isotopic ratio in residual water increases with the decrease of the residual water proportion f exponentially, and the fractionation rate of stable isotopes is inversely pr... Under Rayleigh equilibrium condition, stable isotopic ratio in residual water increases with the decrease of the residual water proportion f exponentially, and the fractionation rate of stable isotopes is inversely proportional to temperature. However, under kinetic evaporation condition, the fi'actionation of stable isotopes is not only related to the phase temperature but also influenced by the atmospheric humidity and the mass exchange between liquid and vapor phases. The ratio 6 in residual water will not change with f after undergoing evaporation of a long time for great relative humidity. The rate that the evaporating water body reaches isotopic steady state is mainly dependent on the relative humidity in atmosphere. The analysis shows that the actual mean linear variety rates, about -30.0, of the δ^18O in residual water versus the residual water proportion at Nagqu and Amdo stations are consistent with the simulated process under temperature of 20℃ and relative humidity of 50%. The distillation line simulated under Rayleigh equilibrium condition is analogous to the global meteoric water line (MWL) as the temperature is about 20℃. Under non-equilibrium condition, the slope and constant values of distillation line are directly proportional to temperature and relative humidity. According to the basic data, the simulated distillation line is very consistent with the actual distillation line of Qinghai Lake. 展开更多
关键词 stable isotope EVAPORATION kinetic fractionation distillation line water body
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Investigation of the Leaching Behavior of Mortar Pipe Lining in Drinking Water 被引量:1
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作者 高岳毅 张亚梅 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2010年第5期893-896,共4页
The leaching behavior of three types of mortars was investigated using a self-design device which could simulate the field conditions of pipe lining. The results by ICP and ESEM measurement show that the developed sla... The leaching behavior of three types of mortars was investigated using a self-design device which could simulate the field conditions of pipe lining. The results by ICP and ESEM measurement show that the developed slag cement mortar is suitable for the lining of cast iron pipe that is used for delivering drinking water. 展开更多
关键词 LEACHING pipe lining drinking water slag cement
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Numerical storm surge model with higher order finite difference method of lines for the coast of Bangladesh 被引量:2
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作者 Gour Chandra Paul Md. Emran Ali 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2019年第6期100-116,共17页
In this study, the method of lines (MOLs) with higher order central difference approximation method coupled with the classical fourth order Runge-Kutta (RK(4,4)) method is used in solving shallow water equations (SWEs... In this study, the method of lines (MOLs) with higher order central difference approximation method coupled with the classical fourth order Runge-Kutta (RK(4,4)) method is used in solving shallow water equations (SWEs) in Cartesian coordinates to foresee water levels associated with a storm accurately along the coast of Bangladesh. In doing so, the partial derivatives of the SWEs with respect to the space variables were discretized with 5-point central difference, as a test case, to obtain a system of ordinary differential equations with time as an independent variable for every spatial grid point, which with initial conditions were solved by the RK(4,4) method. The complex land-sea interface and bottom topographic details were incorporated closely using nested schemes. The coastal and island boundaries were rectangularized through proper stair step representation, and the storing positions of the scalar and momentum variables were specified according to the rules of structured C-grid. A stable tidal regime was made over the model domain considering the effect of the major tidal constituent, M2 along the southern open boundary of the outermost parent scheme. The Meghna River fresh water discharge was taken into account for the inner most child scheme. To take into account the dynamic interaction of tide and surge, the generated tidal regime was introduced as the initial state of the sea, and the surge was then made to come over it through computer simulation. Numerical experiments were performed with the cyclone April 1991 to simulate water levels due to tide, surge, and their interaction at different stations along the coast of Bangladesh. Our computed results were found to compare reasonable well with the limited observed data obtained from Bangladesh Inland Water Transport Authority (BIWTA) and were found to be better in comparison with the results obtained through the regular finite difference method and the 3-point central difference MOLs coupled with the RK(4,4) method with regard to the root mean square error values. 展开更多
关键词 SHALLOW water equations METHOD of lines higher order finite difference approximation METHOD SURGE nested scheme
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Efficacy of Watercourse Lining in Sindh —A Review Study in Relation with Kohistan Region
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作者 Asadullah Soomro Abdul Latif Qureshi +1 位作者 Nisar Ahmed Memon Zia uddin Abro 《Agricultural Sciences》 2018年第9期1215-1227,共13页
The total number of watercourses in Pakistan is about 110,000 and particularly in Sindh it is about 46,699, out of which 7576 have been lined from 1977 to 1998 and from 2004 to 2015;22,479 have been lined and the rema... The total number of watercourses in Pakistan is about 110,000 and particularly in Sindh it is about 46,699, out of which 7576 have been lined from 1977 to 1998 and from 2004 to 2015;22,479 have been lined and the remaining 16,644 still require improvement. At the current rate of progress, the lining of remaining watercourses would further take about 21 years. As designed life of the improved watercourse is about 25 years. By the time of ending of many watercourse improvement programs, there will again require the rehabilitation on many of the earlier watercourse lining schemes. Generally two types of watercourse lining are practiced in Sindh i.e. Rectangular Lined Watercourses (with single and double brick walls) and Trapezoidal Concrete Lined Watercourses. Because of efficient, effectiveness, easy maintenance and repair work, the Rectangular Lined Watercourse is more frequently practiced in Sindh. It is now suggested that: to renovate the watercourses an accelerated program should be started and the system (with the sense of terms and conditions) for renovation of watercourses program should also be changed. The research work towards different types of lining materials for watercourse should be conducted. Looking to the brief review it is suggested that a fiber glass type plastic material with semi-circular or U-shaped, pre-cast fabricated RCC Trapezoidal or Parabolic in place of brick mortar and concrete could be used for watercourse lining. This methodology, proposed to be used, will enable us to determine cost-benefit ratio, life span and such other parameters for its feasibility under variable climatic conditions of Sindh (North Sindh being dry and hot, while South Sindh semi-humid and warm). 展开更多
关键词 watercourse LINING water Management in Pakistan
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Critical State Sedimentation Line of Soft Marine Clays 被引量:1
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作者 洪振舜 刘汉龙 CHANG Nien-yin 《China Ocean Engineering》 SCIE EI 2003年第4期631-640,共10页
The compression behavior responsible for unity sensitivity is very valuable in quantitative assessment of the effects of soil structure on the compression behavior of soft marine sediments. However, the quantitative a... The compression behavior responsible for unity sensitivity is very valuable in quantitative assessment of the effects of soil structure on the compression behavior of soft marine sediments. However, the quantitative assessment of such effects is not possible because of unavailability of the formula for the compression curve of marine sediments responsible for unit sensitivity. In this study, the relationship between the remolded state and the conventional critical state line is presented in the deviator stress versus mean effective stress plot. The analysis indicates that the remolded state is on the conventional critical state line obtained at a relatively small strain. Thus, a unique critical state sedimentation line for marine sediments of unit sensitivity is proposed. The comparison between the critical state sedimentation line proposed in this study and the existing normalized consolidation curves obtained from conventional oedometer tests on remolded soils or reconstituted soils explains well the 展开更多
关键词 conventional critical state line critical state sedimentation line initial water content liquid limit marine sediments ocean wave action remolded state
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Identification of Potential F<sub>1</sub>Hybrids in Maize Responsive to Water Deficient Condition
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作者 Fahad Masoud Wattoo Muhammad Saleem Muhammad Sajjad 《American Journal of Plant Sciences》 2014年第13期1945-1955,共11页
The assessment of heterotic F1 combinations is a basic requisite for hybrid seed development. A set of 30 F1 hybrids along with their parental inbred lines were evaluated under both normal and water deficit conditions... The assessment of heterotic F1 combinations is a basic requisite for hybrid seed development. A set of 30 F1 hybrids along with their parental inbred lines were evaluated under both normal and water deficit conditions for various physiological and agronomic traits. Highly significant mean squares due to general combining ability, specific combining ability and reciprocal effect were observed for all traits under both water regimes. Components of variation exhibited greater estimates for GCA variance (б2g) than SCA variance (б2s) for majority of the traits under both normal and stress conditions depicting the predominant role of additive genetic component. Inbred lines NCIL-20-20, D-157 and OH-8 were found to be the best general combiner on the basis of performance regarding grain yield per plant under water deficit condition. The F1 combinations namely, NCIL-20-20 × D-109, NCIL-20-20 × OH-8 and D-157 × NCIL-20-20 were out-performers based on yield and yield attributes under water deficit conditions. On the basis of our results, we recommend these hybrids for further exploitation to assess their potential for commercial cultivation under water deficit condition. 展开更多
关键词 MAIZE General COMBINING ABILITY (GCA) Specific COMBINING ABILITY (SCA) water Stress Inbred lines
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Protecting Water Quality and Public Health Using a Smart Grid
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作者 Ken Thompson Raja Kadiyala 《Computational Water, Energy, and Environmental Engineering》 2013年第2期73-80,共8页
After the attacks on September 11, 2001 and the follow-up risk assessments by utilities across the United States, securing the water distribution system against malevolent attack became a strategic goal for the U.S. E... After the attacks on September 11, 2001 and the follow-up risk assessments by utilities across the United States, securing the water distribution system against malevolent attack became a strategic goal for the U.S. Environmental Protection Agency. Following 3 years of development work on a Contamination Warning System (CWS) at the Greater Cincinnati Water Works, four major cities across the United States were selected to enhance the CWS development conducted by the USEPA. One of the major efforts undertaken was to develop a process to seamlessly process “Big Data” sets in real time from different sources (online water quality monitoring, consumer complaints, enhanced security, public health surveillance, and sampling and analysis) and graphically display actionable information for operators to evaluate and respond to appropriately. The most significant finding that arose from the development and implementation of the “dashboard” were the dual benefits observed by all four utilities: the ability to enhance their operations and improve the regulatory compliance of their water distribution systems. Challenge: While most of the utilities had systems in place for SCADA, Work Order Management, Laboratory Management, 311 Call Center Management, Hydraulic Models, Public Health Monitoring, and GIS, these systems were not integrated, resulting in duplicate data entry, which made it difficult to trace back to a “single source of truth.” Each one of these data sources can produce a wealth of raw data. For most utilities, very little of this data is being translated into actionable information as utilities cannot overwhelm their staffs with manually processing the mountains of data generated. Instead, utilities prefer to provide their staffs with actionable information that is easily understood and provides the basis for rapid decision-making. Smart grid systems were developed so utilities can essentially find the actionable needle in the haystack of data. Utilities can then focus on rapidly evaluating the new information, compare it known activities occurring in the system, and identify the correct level of response required. Solution: CH2M HILL was engaged to design, implement, integrate, and deploy a unified spatial dashboard/smart grid system. This system included the processes, technology, automation, and governance necessary to link together the disparate systems in real time and fuse these data streams to the GIS. The overall solution mapped the business process involved with the data collection, the information flow requirements, and the system and application requirements. With these fundamentals defined, system integration was implemented to ensure that the individual systems worked together, eliminating need for duplicate data entry and manual processing. The spatial dashboard was developed on top of the integration platform, allowing the underlying component data streams to be visualized in a spatial setting. Result: With the smart grid system in place, the utilities had a straightforward method to determine the true operating conditions of their systems in real time, quickly identify a potential non-compliance problem in the early stages, and improve system security. The smart grid system has freed staff to focus on improving water quality through the automation of many mundane daily tasks. The system also plays an integral role in monitoring and optimizing the utilities’ daily operations and has been relied on during recovery operations, such as those in response to recent Superstorm Sandy. CH2M HILL is starting to identify the processes needed to expand the application of the smart grid system to include real-time water demands using AMI/AMR and real-time energy loads from pumping facilities. Once the smart grid system has been expanded to include Quality-Quantity-Energy, CH2M HILL can apply optimization engines to provide utility operations staffs with a true optimization tool for their water systems. 展开更多
关键词 Smart Grid ON-line water Quality Monitoring OWQM EVENT Detection System EDS TEVA-SPOT
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Gibbs Density Surface of Water and Steam: 2nd Debate on the Absence of Van Der Waals’ “Critical Point”
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作者 Leslie V. Woodcock 《Natural Science》 2014年第6期411-432,共22页
A revised phase diagram for water shows three distinct fluid phases. There is no continuity of liquid and gas, and no “critical point” on Gibbs’ density surface as hypothesized by van der Waals. A supercritical col... A revised phase diagram for water shows three distinct fluid phases. There is no continuity of liquid and gas, and no “critical point” on Gibbs’ density surface as hypothesized by van der Waals. A supercritical colloidal mesophase bounded by percolation transition loci separates supercritical liquid water and gas-phase steam. The water phase is bounded by a percolation transition (PA) of available volume, whereas steam is bounded by the loci of a percolation transition (PB) at a density whereupon a bonded molecular cluster suddenly percolates large distances. At the respective percolation densities, there is no barrier to nucleation of water to steam (PA) or steam to water (PB). Below the critical temperature, the percolation loci become the metastable spinodals in the two-phase coexistence region. A critical divide is defined by the interception of PA and PB the p-T plane. Critical parameters are obtainable from slopes and intercepts of pressure-density supercritical isotherms within the mesophase. The supercritical mesophase is a fourth equilibrium state besides ice, water and steam. A thermodynamic state function rigidity (dp/dρ)T defines a distinction between liquid and gas, and shows a remarkable symmetry due to an equivalence in number density fluctuations, arising from available volume and molecular clusters, in liquid and gas respectively. Following an earlier debate in these pages [“Fluid phases of argon: A debate on the absence of van der Waals’ critical point” Natural Science 5 (2) 194-206 (2013)], we here report further debate on a science of criticality applied to water and steam (APPENDIX 1). 展开更多
关键词 water STEAM Phase DIAGRAM Critical line PERCOLATION LOCI
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Variation characteristics of stable isotopes in atmospheric precipitation in Adelaide,Australia
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作者 WANG Dizhou ZHANG Xinping +2 位作者 LIU Zhongli LI Guang GUAN Huade 《地球环境学报》 CSCD 2024年第4期641-652,共12页
Background,aim,and scope Stable isotope in water could respond sensitively to the variation of environment and be reserved in different geological archives,although they are scarce in the environment.And the methods d... Background,aim,and scope Stable isotope in water could respond sensitively to the variation of environment and be reserved in different geological archives,although they are scarce in the environment.And the methods derived from the stable isotope composition of water have been widely applied in researches on hydrometeorology,weather diagnosis,and paleoclimate reconstruction,which help well for understanding the water-cycle processes in one region.Here,it is aimed to explore the temporal changes of stable isotopes in precipitation from Adelaide,Australia and determine the influencing factors at different timescales.Materials and methods Based on the isotopic data of daily precipitation over four years collected in Adelaide,Australia,the variation characteristics of dailyδD,δ^(18)O,and dexcess in precipitation and its relationship with meteorological elements were analyzed.Results The results demonstrated the local meteoric water line(LMWL)in Adelaide,wasδD=6.38×δ^(18)O+6.68,with a gradient less than 8.There is a significant negative correlation between dailyδ^(18)O and precipitation amount or relative humidity at daily timescales in both the whole year and wither/summerhalf year(p<0.001),but a significant positive correlation between dailyδ^(18)O and temperature in the whole year and the winter half-year(p<0.001).Discussion The correlation coefficients betweenδ^(18)O and daily mean temperature didn’t show a significant positive correlation,which may be attributed to that the precipitation in Adelaide area in January was mainly influenced by strong convective weather,and the stable isotope values in precipitation were significantly negative.Furthermore,this propose was also evidenced by the results from dexcess of precipitation with larger value in the winter half-year than that in the summer half-year,which may be resulted from the precipitation events in winter are mostly influenced by oceanic water vapor,while the sources of water vapor in summer precipitation events are more complicated and influenced by strong convective weather.On the other hand,the slope and intercept of theδ^(18)O—P regression lines in the summer months(-0.41 and 0.50‰)are larger and smaller than those in the winter months(-0.22 and-2.15‰),respectively,indicating that the precipitation stable isotopes have a relatively stronger rainout effect in the summer months than in the winter months.Besides,the measured values ofδ^(18)O in daily precipitation have a good linear relationship with our simulated values ofδ^(18)O,demonstrating the established regression model could provide a reliable simulation for theδ^(18)O values in daily precipitation in Adelaide area.It’s worth noting that the precipitation events with low precipitation amount,low relative humidity and high temperature,usually had relatively small slope and intercept of MWL,implying that raindrops may be strongly affected by sub-cloud secondary evaporation in the falling process.Conclusions The variation ofδ^(18)O in daily precipitation from Adelaide region was controlled by different factors at different timescales.And the water vapor sources and the meteorological conditions of precipitation events(such as the degree of sub-cloud secondary evaporation)also played an important role on the variation ofδ^(18)O.Recommendations and perspectives Stable isotope in daily precipitation can provide more accurate information about water-cycle and atmosphere circulation,it is therefore necessary to continue to collect and analyze daily-scale precipitation data over a longer time span.The results of this study will provide the basis for the fields of hydrometeorology,meteorological diagnosis and paleoclimate reconstruction in Adelaide,Australia. 展开更多
关键词 Adelaide PRECIPITATION stable isotopes meteoric water line stepwise regression analysis
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Design and Evaluation of Dadu Canal Lining for Sustainable Water Saving
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作者 Ashfaque A. Memon Khalifa Q. Leghari +5 位作者 Agha F. H. Pathan Kanya L. Khatri Sadiq A. Shah Kanwal K. Pinjani Rabia Soomro Kameran Ansari 《Journal of Water Resource and Protection》 2013年第7期689-698,共10页
Pakistan livelihood depends on agriculture and so for this on irrigation system. The irrigation system in Sindh province depends on three barrages. The canals off taking from these three barrages irrigate 5.5 million ... Pakistan livelihood depends on agriculture and so for this on irrigation system. The irrigation system in Sindh province depends on three barrages. The canals off taking from these three barrages irrigate 5.5 million hectares of agriculture land. Sukkur Barrage, which is the oldest one, irrigates more than 2.0 million hectares of land. The Dadu Canal off taking from Sukkur barrage is an earthen canal. A huge amount of irrigation water is lost from the canal in the form of seepage from banks and bed. It is estimated that 40 to 50 per cent of water is lost between the canal head works to the farm-gate. The seepage from the canal creates twin problems of salinity and water logging consequently a large agriculture land has gone out of use, and this process is continued particularly in Sindh. Lining of Canals is considered an effective solution to this problem. But lining of canals in Sindh is a great issue as canals will need to be closed long enough to deprive the farmers at least one crop season and the farmers are unable to pay this price for canal. Therefore, in this study, the Dadu Canal is proposed to be redesigned as an adjacent lined canal which involves design of cross section for various lining options at locations where changes in the hydraulic conditions occur at cross regulators and fall structures. The proposed lining is preferred to be plain cement concrete lining which is selected after investigating local conditions. Quantity and cost estimation at selected RDs (Reduced Distance) proved feasible and significant in long term functioning of Dadu Canal. 展开更多
关键词 Dadu CANAL CONCRETE LINING CANAL Design LINING Evaluation SUSTAINABLE water SAVING
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基于改进水波算法的复杂多人共站装配线平衡研究
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作者 张梅 傅艳霞 +1 位作者 朱金辉 邓率航 《计算机集成制造系统》 EI CSCD 北大核心 2024年第1期129-143,共15页
针对实际装配环境中存在多人协同装配和共站的情况,研究了考虑工序复杂程度与工人能力差异的多人协作共站装配线平衡问题。首先,考虑到装配工序的复杂程度需指派不同规模和类型的工人组,建立了以最小化工作站数量和工人数量为目标函数... 针对实际装配环境中存在多人协同装配和共站的情况,研究了考虑工序复杂程度与工人能力差异的多人协作共站装配线平衡问题。首先,考虑到装配工序的复杂程度需指派不同规模和类型的工人组,建立了以最小化工作站数量和工人数量为目标函数的多目标优化数学模型;在此基础上,提出一种改进的离散水波优化算法,对算子进行了离散化改造,并设计了基于拓扑排序的编码方案和启发式的解码方案,同时引入扰动个体和路径重连的搜索策略来增加解的多样性,进而提高解的质量;最后,通过求解两类测试用例,以线效率和平滑指数作为性能指标,验证了改进离散水波算法在求解复杂多人共站装配线平衡问题上的可行性与有效性,并将算法应用到动车装配线平衡优化中。 展开更多
关键词 多人协作 多人共站 装配线平衡 水波算法 拓扑排序
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充水作用下露天煤矿内排土场边坡稳定性分析
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作者 王来贵 纪宇轩 赵娜 《辽宁工程技术大学学报(自然科学版)》 CAS 北大核心 2024年第3期257-264,共8页
为分析废弃矿坑改造成蓄水湖时充水高度对内排土场边坡稳定性的影响,采用室内相似试验、数值模拟和理论分析的方法对不同水位高度下内排土场边坡稳定性进行研究。研究结果表明:随着充水高度的增加,浸润线运移速度、边坡最大位移、孔隙... 为分析废弃矿坑改造成蓄水湖时充水高度对内排土场边坡稳定性的影响,采用室内相似试验、数值模拟和理论分析的方法对不同水位高度下内排土场边坡稳定性进行研究。研究结果表明:随着充水高度的增加,浸润线运移速度、边坡最大位移、孔隙水压力和边坡土体受到的压力整体呈增长趋势。充水高度越大,边坡倾角越大,边坡稳定系数越低。研究结论为露天煤矿改造成蓄水湖或蓄能水电站项目工程提供参考。 展开更多
关键词 边坡稳定性 条分法 浸润线 孔隙水压 内排土场 充水高度
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