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Measuring the geometry of a developing scour hole in clear-waterconditions using underwater sonar scanning 预览
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作者 Ashley Rogers Costantino Manes Toru Tsuzaki 《国际泥沙研究:英文版》 SCIE 2020年第1期105-114,共10页
A novel scanning technique using a rotating-head sonar profiler attached to a slider mechanism is presented as a means to directly measure the complex erosion and deposition features of local scour holes developing in... A novel scanning technique using a rotating-head sonar profiler attached to a slider mechanism is presented as a means to directly measure the complex erosion and deposition features of local scour holes developing in clear-water conditions around vertical cylinders mimicking bridge piers.Extensive validation shows that the method produces high-density elevation surfaces to within y1.5±2 mm accuracy in a quasi-non-invasive manner.This equates to 0.5±0.7%relative to the flow depth which sonar resolution is well known to scale with.Experimental data from three trials using different cylinder diameters indicate that monitoring of the entire scour hole over time(instead of only the maximum depth as is commonly done in laboratory experiments)can reveal important information about local scour evolution.In particular,results show that the scour-hole volume scales with the maximum scour depth cubed(VOLy3s)through three linear regimes.The transition to the third linear regime was found to represent a step change in the scour evolution process.Following the recent theoretical framework proposed by Manes and Brocchini(2015),this change,termed the crossover point,was interpreted as the point where the production of turbulent kinetic energy plateaus which corresponds to a stabilization in the erosive power of the horseshoe vortex.Scour development beyond the crossover point is characterised by a significant reduction in the rate of volumetric scour,relative to the steadily-increasing maximum scour depth.This overall reduction in volume-development is attributed to a balance between erosion from in-front of the pier and deposition around the sides using topography analysis.It is speculated that the existence of the crossover point may help to identify the characteristic length and time scales describing the evolution of local scour,which may be used for modeling purposes. 展开更多
关键词 Local scour Scour volume Clear water SONAR Scour hole geometry SIMILARITY
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Neonatal ketamine exposure-induced hippocampal neuroapoptosis in the developing brain impairs adult spatial learning ability 预览
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作者 Dan Lyu Ning Tang +2 位作者 Andrew W. Womack Yong-Jin He Qing Lin 《中国神经再生研究:英文版》 SCIE CAS CSCD 2020年第5期880-886,共7页
Ketamine exposure can lead to selective neuroapoptosis in the developing brain.p66ShcA,the cellular adapter protein expressed selectively in immature neurons,is a known pro-apoptotic molecule that triggers neuroapopto... Ketamine exposure can lead to selective neuroapoptosis in the developing brain.p66ShcA,the cellular adapter protein expressed selectively in immature neurons,is a known pro-apoptotic molecule that triggers neuroapoptosis when activated.Sprague-Dawley rats at postnatal day 7 were subcutaneously injected in the neck with ketamine 20 mg/kg,six times at 2-hour intervals.At 0,1,3,and 6 hours after final injection,western blot assay was used to detect the expression of cleaved caspase-3,p66ShcA,and phosphorylated p66ShcA.We found that the expression of activated p66ShcA and caspase-3 increased after ketamine exposure and peaked at 3 hours.The same procedure was performed on a different group of rats.At the age of 4 weeks,spatial learning and memory abilities were tested with the Morris water maze.Latency to find the hidden platform for these rats was longer than it was for control rats,although the residence time in the target quadrant was similar.These findings indicate that ketamine exposure resulted in p66ShcA being activated in the course of an apoptotic cascade during the neonatal period.This may have contributed to the deficit in spatial learning and memory that persisted into adulthood.The experimental protocol was approved by the Institutional Animal Care and Use Committee at the University of Texas at Arlington,USA (approval No.A13.008) on January 22,2013. 展开更多
关键词 caspase-3 DEVELOPMENTAL neuroapoptosis hippocampus KETAMINE MORRIS water MAZE N-METHYL-D-ASPARTATE acid receptors p66ShcA SPATIAL learning
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On Soil and Water,Soil and Water Ecology,and Soil and Water Ecological Conservation 预览
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作者 Sun Fazheng 《气象与环境研究:英文版》 CAS 2019年第3期29-32,共4页
On the basis of discussing the positions and functions of soil and water in terrestrial ecosystem,the concept of soil and water ecology is put forward.It is thought that the integral concept of inseparability between ... On the basis of discussing the positions and functions of soil and water in terrestrial ecosystem,the concept of soil and water ecology is put forward.It is thought that the integral concept of inseparability between vegetation and soil,water is an important feature of soil and water ecology.Meanwhile,a new definition for soil and water ecological conservation is given,and it is divided into four types:ecological,natural,production and construction.At the height of soil and water ecology,it is an active,organic and holistic concept of soil and water conservation,and is deepening and development of the cognitive view on soil and water conservation to understand and control soil and water loss from the source and linkage of elements,which will make soil and water ecological conservation enter a new era. 展开更多
关键词 SOIL and WATER SOIL and WATER ECOLOGY SOIL and WATER ECOLOGICAL CONSERVATION SOIL and WATER CONSERVATION
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Presence, dissemination and removal of antibiotic resistant bacteria and antibiotic resistance genes in urban drinking water system: A review
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作者 Qiaowen Tan Weiying Li +4 位作者 Junpeng Zhang Wei Zhou Jiping Chen Yue Li Jie Ma 《环境科学与工程前沿(英文)》 SCIE EI CAS CSCD 2019年第3期13-27,共15页
Antibiotic resistance in aquatic environment has become an important pollution problem worldwide. In recent years, much attention was paid to antibiotic resistance in urban drinking water systems due to its close rela... Antibiotic resistance in aquatic environment has become an important pollution problem worldwide. In recent years, much attention was paid to antibiotic resistance in urban drinking water systems due to its close relationship with the biosafety of drinking water. This review was focused on the mechanisms of antibiotic resistance, as well as the presence, dissemination and removal of antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) in the urban drinking water system. First, the presence of ARB and ARGs in the drinking water source was discussed. The variation of concentration of ARGs and ARB during coagulation, sedimentation and filtration process were provided subsequently, in which filtration was proved to be a promising technology to remove ARGs. However, biological activated carbon (BAC) process and drinking water distribution systems (DWDSs) could be incubators which promote the antibiotic resistance, due to the enrichment of ARGs and ARB in the biofilms attached to the active carbon and pipe wall. Besides, as for disinfection process, mechanisms of the inactivation of ARB and the promotion of conjugative transfer of ARGs under chlorine, ozone and UV disinfection were described in detail. Here we provide some theoretical support for future researches which aim at antibiotic resistance controlling in drinking water. 展开更多
关键词 Antibiotic resistant BACTERIA Antibiotic resistance genes WATER source DRINKING WATER treatment plant DRINKING WATER distribution SYSTEM Urban DRINKING WATER SYSTEM
江苏农村水厂水碘含量监测结果分析
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作者 夏玉婷 鹿奎奎 +6 位作者 尚莉 叶云杰 王培桦 汪旸 刘茂 徐燕 刘冉 《中华地方病学杂志》 CAS CSCD 北大核心 2019年第10期818-822,共5页
目的进一步了解和掌握江苏省水碘含量分布及影响因素。方法2012-2014年,在江苏省63个县(市、区)的农村集中式供水水厂中抽取半数水厂作为调查点,调查和分析各个调查点的监测类型、水厂类型、水源类型、自检能力、消毒情况、水处理方式... 目的进一步了解和掌握江苏省水碘含量分布及影响因素。方法2012-2014年,在江苏省63个县(市、区)的农村集中式供水水厂中抽取半数水厂作为调查点,调查和分析各个调查点的监测类型、水厂类型、水源类型、自检能力、消毒情况、水处理方式等。每个调查点分别采集1份末梢水水样,测定水碘含量。结果2012-2014年共监测江河水938份,水碘中位数为5.9μg/L;湖泊水57份,水碘中位数为6.8μg/L;水库水228份,水碘中位数为7.1μg/L;沟塘水43份,水碘中位数为6.9μg/L;深井水5474份,水碘中位数为28.2μg/L;浅井水162份,水碘中位数为30.9μg/L,不同水源类型水样水碘中位数比较差异有统计学意义(χ2=844.9,P<0.05)。水源水为湖泊水、水库水、沟塘水、深井水、浅井水水碘中位数在不同水厂监测类型间比较差异有统计学的意义(χ2=9.6、6.3、9.7、121.2、38.1,P均<0.05)。水源水为江河水、水库水、深井水、浅井水水碘中位数在不同水厂类型间比较差异有统计学意义(χ2=109.5、39.0、153.3、7.6,P均<0.05)。水源水为江河水、湖泊水、深井水、浅井水水碘中位数在不同水厂自检能力上比较差异有统计学的意义(χ2=62.5、5.1、29.9、10.1,P均<0.05)。水源水为水库水、深井水、浅井水水碘中位数在不同水厂消毒情况上比较差异有统计学意义(χ2=12.1、12.4、35.7,P均<0.05)。水源水为江河水、水库水、深井水、浅井水水碘中位数在不同水处理方式上比较差异有统计学意义(χ2=9.5、21.2、102.4、46.9,P均<0.05)。结论江苏省农村不同水源类型水样水碘含量不同,水碘含量高低受监测类型、水厂类型、自检能力、消毒情况、水处理方式等因素影响。 展开更多
关键词 水源类型 水处理方式
Analysis of Water Resources Vulnerability Assessment Tools 预览
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作者 Kanga IdéSoumaila Albachir Seydou Niandou +2 位作者 Mustapha Naimi Chikhaoui Mohamed Keith Schimmel 《农业科学与技术:B》 2019年第2期69-86,共18页
Water resources face many pressures and stresses around the world.Assessing the vulnerability of water resources is,therefore,increasingly an essential practice in water resources management.Several studies of water r... Water resources face many pressures and stresses around the world.Assessing the vulnerability of water resources is,therefore,increasingly an essential practice in water resources management.Several studies of water resources vulnerability have been carried out around the world during the last three decades.Thus,the main objective of this study was to analyze water resources vulnerability assessment tools and identify the methodological trend of water resources vulnerability assessment at the local level in existing literature.To achieve this objective,the Preferred Reporting Items for Systematic Reviews and Meta-Analyses(PRISMA)method has been applied to include or exclude articles.Articles on water vulnerability numbering 374 were preselected in the ScienceDirect and the Google Scholar databases.Only 32 out of the 374 articles met the inclusion criteria defined for the analysis.The results show that China(21.9%),U.S.A.(9.4%)and Canada(6.3%)are the most active countries publishing water resources vulnerability assessments.Some 191 vulnerability indicators from the 32 articles were classified into five categories of factors:physical factors(33.5%),socio-economic factors(28.3%),environmental or eco-environmental factors(25.1%),institutions and governance factors(7.3%)and infrastructure factors(5.8%).This study shows that almost half of the studies(47%)considered all five categories of factors,9.4%considered four categories of factors,6.3%considered three categories of factors,28%used two types of factors and 9.4%considered only one category.Researchers have used several methods to assess water resources vulnerability:overlay and index methods(59.4%),process-based models(12.5%),statistical methods(9.4%),overlay and index methods plus process-based model(9.4%),overlay and index methods plus statistical methods(6.3%)and statistical methods plus process-based models(3.1%).Geographic information system(GIS)is an important tool in assessing the vulnerability of water resources with almost 60%of the studies using it at s 展开更多
关键词 WATER VULNERABILITY WATER RESOURCES MANAGEMENT WATER VULNERABILITY ASSESSMENT tools.
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A Systematic Review and Meta-Analysis of Water Quality Indices 预览
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作者 Kanga Idé Soumaila Albachir Seydou Niandou +4 位作者 Mustapha Naimi Chikhaoui Mohamed Keith Schimmel Stephanie Luster-Teasley Naeem Nizar Sheick 《农业科学与技术:B》 2019年第1期1-14,共14页
Water quality indices (WQI) are useful tools for indicating the suitability of water for an expected use. However, they can suffer from some problems. The objective of this paper was to analyze the development of WQI ... Water quality indices (WQI) are useful tools for indicating the suitability of water for an expected use. However, they can suffer from some problems. The objective of this paper was to analyze the development of WQI to determine which parameters are used in water quality assessment and to discuss the characteristics of WQI. To screen articles on WQI, the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) method is applied to include or exclude articles. Four necessary steps are needed to design WQI: parameter selection, standardization, weighting and aggregation. A set of six methods of aggregations of sub-indices are identified: the arithmetic mean, the geometric mean, the root square, the logarithmic function, the fuzzy inference and the minimum operator. The problems encountered for the overall index are different according to the form of aggregation. They are eclipsing, ambiguity, rigidity or flexibility, adaptability and compensation. The chemical parameters (70%) are the most used in the development of WQI with the physical parameters used at 24% and the biological parameters at 6%. Dissolved oxygen (DO, 87%), total coliforms (87%), biological oxygen demand (BOD, 73%), pH (73%), temperature (67%), turbidity (60%), ammonia (53%), ammonium (47%) and total dissolved solids (47%) are the most commonly used parameters for water quality assessment. 展开更多
关键词 WATER QUALITY indices WATER QUALITY PARAMETERS WATER QUALITY assessment REVIEW META-ANALYSIS
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Environmental Ethics of Water Resources Management 预览
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作者 Amad Deen Abdusalam Alghwail 《美中经济评论:英文版》 2019年第1期44-49,共6页
Scarcity and sustainability of water resources are the most important problem amongst the major problems that human faces in the present and will increasingly face in the future. The current water crisis is complex an... Scarcity and sustainability of water resources are the most important problem amongst the major problems that human faces in the present and will increasingly face in the future. The current water crisis is complex and a result of several factors. Sustainable management of water resources is imperative as water scarcity is becoming a development constraint, impeding the economic growth of many countries in the globe. Environmental ethics can be a valuable tool for sustainable resource management in any region in the globe. Recognizing water as finite and vulnerable involves a holistic approach, linking social and economic with ecosystem protection, and should be applied across a whole catchments area or groundwater aquifer. This holistic approach is an important implication of the finite nature of water. 展开更多
关键词 WATER SCARCITY FRESHWATER environmental ETHICS WATER RESOURCES management SUSTAINABILITY of WATER
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Impact of environmental variables on spatial and seasonal internal phosphorus loading in a mesoeutrophic lake 预览
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作者 Katarzyna Kowalczewska-Madura Ryszard Goldyn +1 位作者 Julia Bogucka Katarzyna Strzelczyk 《国际泥沙研究:英文版》 SCIE 2019年第1期14-26,共13页
Strzeszynskie Lake was formerly a slightly eutrophic(meso-eutrophic)water body.The aim of the current research was to define variables on both spatial and seasonal internal phosphorus loading from bottom sediments at ... Strzeszynskie Lake was formerly a slightly eutrophic(meso-eutrophic)water body.The aim of the current research was to define variables on both spatial and seasonal internal phosphorus loading from bottom sediments at five stations located in zones varying in depth,oxygenation,macrophyte presence,and uses of the neighboring catchment area.Ex situ experiments done with the use of intact bottom sediment cores have shown that the highest phosphorus release occurred in the deepest part of the lake and reached 3.6 mg P/m2d under anoxic conditions during summer thermal stratification.In turn,the internal loading from littoral sediments,which were well aerated all year round,was clearly lower.Furthermore,phosphorus accumulation in the bottom sediment was observed to reach a maximum of 1.45 mg P/m2 d in autumn.A comparison of the internal loading intensity in lake zones with different land uses of the neighboring catchment area has shown slightly higher values at stations adjacent to the forest catchment area than those used for recreation.Changes in the land use of the catchment area of Strzeszynskie Lake,especially the increase in impermeable surfaces,have led to an increased inflow of external loads after heavy rains,resulting in deterioration in water quality and a delayed increase in internal loading. 展开更多
关键词 BOTTOM sediments INTERSTITIAL WATER BOTTOM WATER Internal LOADING Sediment-water interface
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水对致密气藏气相渗流能力作用机理研究 预览
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作者 朱维耀 杨西一 《特种油气藏》 CAS CSCD 北大核心 2019年第3期128-132,共5页
为研究边底水和压裂液等流体的侵入对超低含水饱和度气藏气相渗流能力的影响,选取渗透率约为0. 100 mD的致密砂岩岩心,对岩心水驱过程中渗透率变化、气水两相渗流规律进行了实验研究。结果表明:地层水和去离子水引起的岩样渗透率变化模... 为研究边底水和压裂液等流体的侵入对超低含水饱和度气藏气相渗流能力的影响,选取渗透率约为0. 100 mD的致密砂岩岩心,对岩心水驱过程中渗透率变化、气水两相渗流规律进行了实验研究。结果表明:地层水和去离子水引起的岩样渗透率变化模式相似,地层水引起的渗透率下降幅度小于去离子水引起的渗透率下降幅度;束缚水饱和度时,随含水饱和度增加气相渗透率下降明显,渗透率大的岩心下降规律是“先慢后快”,渗透率小的岩心下降规律是“先快后慢”;水的侵入对气相渗流能力影响严重,且随含水饱和度降低,气相渗透恢复率低于10%,渗透率损失高达90%以上。其中,由于气水两相相互作用导致的渗透率损失约为50%;由于微观结构变化导致的渗透率下降约为15%~40%。压裂液的性质对于储层开发具有重要影响,储层开发前,应配备合适的压裂液。 展开更多
关键词 致密砂岩 气相渗流能力 水伤害 超低含水饱和度
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基于实证数学规划模型的农业水价政策效应模拟 预览
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作者 谭倩 王淑萍 张田媛 《农业工程学报》 EI CAS CSCD 北大核心 2019年第16期161-171,共11页
水价政策的合理制定对水资源高效利用意义重大。水价政策的决策过程往往主观性过强,缺乏水价政策效应的量化研究方法。针对多水源多灌溉方式下的农业灌区,基于实证数学规划方法构建农业水价政策效应模拟方法。将建立的方法应用于甘肃省... 水价政策的合理制定对水资源高效利用意义重大。水价政策的决策过程往往主观性过强,缺乏水价政策效应的量化研究方法。针对多水源多灌溉方式下的农业灌区,基于实证数学规划方法构建农业水价政策效应模拟方法。将建立的方法应用于甘肃省民勤县进行实证研究,分别模拟了3种水价政策下用水效益、灌溉用水量、种植占地和节水灌溉工程面积等对水价上涨的响应机制,分析了不同政策下的水价上涨阈值和不同水价水平下的适宜政策。结果表明:在单一水价和两部制水价政策下,民勤县农业水价宜处于0.24~2.10元/m^3之间;在差别水价政策下,水价宜处于0.24~1.50元/m^3之间;当计量部分水价低于2.10元/m^3或高于6元/m^3时,差别水价政策的综合效益最高;当计量部分水价在2.10~6元/m^3之间时,单一水价政策最为理想;实行差别水价政策且计量部分水价为1.50元/m^3时取得的单方水效益最高。该文证实了民勤县目前实行的差别水价政策是适宜的,水价的稳步上涨不会降低用水的综合效益,但应在水价上调的同时考虑当地实际情况,且注意加大对节水灌溉工程的投入和建立配套的农户收入补贴政策。该文建立的农业水价政策效应模拟方法具有较广泛的适用性。 展开更多
关键词 农业 模型 实证数学规划 水价政策 用水效益
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Remote Detection of Varying Water Storage in Relation to Surfacial Temperature of Aral Sea 预览
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作者 MU Guangyi CHEN Li +1 位作者 HU Liangjun SONG Kaishan 《中国地理科学:英文版》 SCIE CSCD 2019年第5期741-755,共15页
Lake monitoring by remote sensing is of significant importance to understanding the lake and ambient ecological and environmental processes. In particular, whether lake water storage variation could predict lake surfa... Lake monitoring by remote sensing is of significant importance to understanding the lake and ambient ecological and environmental processes. In particular, whether lake water storage variation could predict lake surfacial temperature or vice versa has long fascinated the research community, in that it would greatly benefit the monitoring missions and scientific interpretation of the lake change processes. This study attempted to remotely detect the dynamics of the Aral Sea and pursue the relationships between varying lake water storage attributes and surface water temperature by using MODIS LST(Moderate-resolution Imaging Spectroradiometer Land Surface Temperature) 8-day composite products, satellite altimeter data, and actual meteorological measurements. Their associations with lake Surface Water Temperatures(SWT) were then analyzed. Results showed the lake water surface areas and elevations of the North Aral Sea tended to increasing trend from 2001(2793.0 km~2, 13.6 m) to 2015(6997.8 km~2, 15.9 m), while those of the South Aral Sea showed a decreasing trend during 2001(20 434.6 km~2, 3.9 m) and 2015(3256.1 km~2, 0.9 m). In addition, the annual daytime and nighttime lake SWT both decreased in the North Aral Sea, while only the daytime SWT in the South Aral Sea exhibited an increase, indicating a rising deviation of diurnal temperatures in the South Aral Sea during the past 15 yr. Moreover, a lower correlation was found between variations in the daytime SWT and storage capacity in the South Aral Sea(R~2 = 0.33;P < 0.05), no fair correlations were tested between lake water storage and daytime SWT in the North Aral Sea nor between lake water storage and nighttime SWT in either part of the sea. These results implied that climate change, if any at least during the research period, has no significant effects on lake dynamics over the two sectors of the Aral Sea with anthropogenic disturbances. However, climate change and human activities may overlap to explain complex consequences in the lake storage variations. Our r 展开更多
关键词 SURFACE WATER Temperature(SWT) LAKE WATER SURFACE dynamics LAKE WATER storage Moderate-resolution Imaging Spectroradiometer(MODIS) the Aral Sea
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Modelling and development of recycled water conditioning of copper-molybdenum ores processing 预览
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作者 Irina Pestriak Valery Morozov Erdenetuya Otchir 《矿业科学技术学报:英文版》 CSCD 2019年第2期313-317,共5页
Current use of enrichment and processing technologies of ores requires the introduction of closed circuits of water treatment.A decrease in technological properties is caused by accumulations of ion-molecular componen... Current use of enrichment and processing technologies of ores requires the introduction of closed circuits of water treatment.A decrease in technological properties is caused by accumulations of ion-molecular components in the circulating water.The objective of the simulation is to determine the maximum allowable concentrations of ions and molecules as well as the choice of conditions for deposition or adsorption.First of all,our examinations decrease the concentration of copper ions and fatty acids in the circulating water.By pre-mixing water with the highest concentration of these ions,a reduction of copper ion and fatty acid concentrations in the recycled water occurs.The results do not only ensure the achievement of the maximum permitted concentration(MPC)of copper and iron,significantly reducing the amount of oxidized copper,they also make it possible to use the united sewage as current water for the flotation process.Mixing and adding filtrate of tailings,discharges of urban wastewater treatment and effluent of ash pit of thermal power stations(TPS)to recycled water causes an increase in the capacity of the enrichment plant by 15-17%. 展开更多
关键词 TAILINGS RECYCLING WATER Closed cycle Urban waste WATER CONDITIONING FLOTATION of ORE Natural WATER
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The effect of hydrogel particle size on water retention properties and availability under water stress 预览
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作者 Ahmad M.Abdallah 《国际水土保持研究(英文)》 SCIE 2019年第3期275-285,共11页
The use of superabsorbent polymers or hydrogels could increase the water holding capacity (WHC) of sandy soil and reduce water loss by deep percolation.However,hydrogels' retained water availability to plants migh... The use of superabsorbent polymers or hydrogels could increase the water holding capacity (WHC) of sandy soil and reduce water loss by deep percolation.However,hydrogels' retained water availability to plants might be overestimated without taking into consideration the hydrogel particles size.Therefore,the ultimate objective of this study was to address the impacts of hydrogel particles size on hydrogel's retained water availability (plant available water,PAW),daily water consumption (DWC) and survival of Guava seedlings subjected to drought.Moreover,some soil physical properties,i.e.,WHC,water retention properties,and hydraulic conductivity (Ksat) were investigated.Hydrogel (WaterSorb,'WS') application,particularly the WS of small particles,significantly reduced Ksat,and increased WHC and PAW.Therefore,seedlings grown in soil amended with WS fine (0.8-1.0 mm),WS medium (1.0-2.0 mm) and WS large (2-4 mm) survived for 27.0 ± 1.3,24.0 ± 1.1 and 17.0 ± 0.7 days,respectively,compared to 13.0 ± 1.0 days for the control.The water stored in the WS of large particles was less readily available for plant roots.Interestingly,hydrogels,had no effect on the DWC of the seedlings.Utilizing hydrogels as a soil amendment increases WHC PAW,growth and survival of Guava seedlings,while the effect was less pronounced for the large hydrogel particles which had lower specific surface area and swelling rate. 展开更多
关键词 WATER HOLDING capacity SWELLING rate WATER consumption Available WATER capacity SEEDLINGS survival
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Underground coal gasification and its strategic significance to the development of natural gas industry in China 预览
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作者 ZOU Caineng CHEN Yanpeng +3 位作者 KONG Lingfeng SUN Fenjin CHEN Shanshan DONG Zhen 《石油勘探与开发:英文版》 2019年第2期205-215,共11页
Based on the present situation and trend of underground coal gasification in China and overseas, this article puts forward the basic concept, mechanism and mode of underground coal gasification, and presents the chall... Based on the present situation and trend of underground coal gasification in China and overseas, this article puts forward the basic concept, mechanism and mode of underground coal gasification, and presents the challenges, development potential and development path now faced. In China, underground coal gasification which is in accord with the clean utilization of coal can produce "artificial gas", which provides a new strategic approach to supply methane and hydrogen with Chinese characteristics before new energy sources offer large-scale supply. Coal measure strata in oil-bearing basins are developed in China, with 3.77 trillion tons coal reserves for the buried depth of 1000-3 000 m. It is initially expected that the amount of natural gas resources from underground coal gasification to be 272-332 trillion cubic meters, which are about triple the sum of conventional natural gas, or equivalent to the total unconventional natural gas resources. According to the differences of coal reaction mechanism and product composition of underground coal gasification, the underground coal gasification can be divided into three development modes, hydrogen-rich in shallow, methane-rich in medium and deep,supercritical hydrogen-rich in deep. Beyond the scope of underground mining of coal enterprises, petroleum and petrochemical enterprises can take their own integration advantages of technologies, pipeline, market and so on, to develop underground coal gasification business based on their different needs and technical maturity, to effectively exploit a large amount of coal resources cleanly and to alleviate the tight supply of natural gas. It can also be combined with using the produced hydrogen in nearby area and the CO2 flooding and storage in adjacent oil areas to create a demonstration zone for net zero emissions of petroleum and petrochemical recycling economy. It is significant for reserving resources and technologies for the coming "hydrogen economy" era, and opening up a new path for China’s "clean, low carbon, safe a 展开更多
关键词 COAL underground COAL GASIFICATION natural GAS GAS revolution coal-made methane coal-made hydrogen SUPERCRITICAL WATER SUPERCRITICAL WATER GASIFICATION
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纳氏试剂光度法测定氨氮时样品溶液pH值对分析结果的影响 预览
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作者 殷善学 《化工设计通讯》 CAS 2019年第6期150-150,152共2页
用纳氏试剂分光光度法测定氨氮时,样品溶液吸光度的pH值影响分析结果.在某些条件下,当pH>12时,样品溶液的吸光度随pH值的增加而增加.因此,在确定氨氮的过程中,样品溶液的pH值应在颜色必须合理之前进行调节,以确保样品溶液的颜色在pH&... 用纳氏试剂分光光度法测定氨氮时,样品溶液吸光度的pH值影响分析结果.在某些条件下,当pH>12时,样品溶液的吸光度随pH值的增加而增加.因此,在确定氨氮的过程中,样品溶液的pH值应在颜色必须合理之前进行调节,以确保样品溶液的颜色在pH>12之后. 展开更多
关键词 纳氏试剂 氨氮 水检测
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Vietnam Economic Situation and Its Impacts on Three Natural Resources: Air, Water, and Soil 预览
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作者 Le Dieu Linh Nguyen 《管理研究:英文版》 2019年第6期582-587,共6页
The current economic development is the process of improving the physical and spiritual living conditions for people through the production of material wealth and the improvement of social relations as well as the imp... The current economic development is the process of improving the physical and spiritual living conditions for people through the production of material wealth and the improvement of social relations as well as the improvement of cultural quality.In recent years,Vietnam showed robust growth in terms of economic development,along with the fast pace of urbanization and population increase.However,the economic growth has led to serious problems relating to the environment,such as the pollution of the air,water,and soil,which hugely affected the quality of human life.The Environmental Kuznets Curve(EKC)implied that a country with strong economic background shifting to industrialization or mechanization of agriculture will have positive GDP and the environmental damage level will decrease.The analysis and assessment showed that the environmental problems caused by economic activities are:air pollution in the urban area still maintained at high level;water pollution in rivers and limited fresh water supply;and the soil pollution and declining water supply underneath soil are developing. 展开更多
关键词 SOCIO-ECONOMIC development EKC AIR WATER SOIL AIR POLLUTION WATER POLLUTION SOIL POLLUTION
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Tap Water versus Bottled Water: A Pilot Study 预览
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作者 Ryan Knox Rodney McDermott 《水资源与保护(英文)》 2019年第11期1398-1407,共10页
The aim of this exploratory research and comparative numerical pilot study was to investigate any significant differences in the microbiological content of tap and bottled water through the measurement of risk indicat... The aim of this exploratory research and comparative numerical pilot study was to investigate any significant differences in the microbiological content of tap and bottled water through the measurement of risk indicator parameters including Enterococci, Escherichia coli (E. coli) and colony-forming units (CFUs). This study to investigate storage conditions and compare consumer options of public water supply and bottled water using microbiological limits was carried out for public health research. This was a unique pilot study to Northern Ireland with global relevance due to the increase in the bottled water market and the need to address the lack of consumer awareness regarding storage and microbiological content. No E. coli or Enterococci were found in any of the 31 tap or bottled water samples. Three unrefrigerated bottled water samples exceeded the threshold in Colony Counts 22°C & 37°C (degrees Celsius) and failed in line with Drinking Water Directive guidelines. This indicated a link between storage conditions and microbiological quality. No link between prices or microbiological quality was indicated. This research recommends the creation of a regulator for the bottled water industry, the need for clearly labelled microbiological content and daily testing. Water suppliers such as Northern Ireland (NI) Water should promote the quality of tap water. Recommendations are also outlined for consumers. There is no statistically significant difference in the microbiological quality of tap and bottled water in Northern Ireland despite marketing claims. 展开更多
关键词 Water TAP BOTTLED PUBLIC HEALTH Storage MICROBIOLOGICAL Regulation
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Improved Response to Water Shortage: A Discrete Choice Experiment Study in Langata Sub County, Nairobi City-Kenya 预览
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作者 E. A. Ochungo G. O. Ouma +1 位作者 J. P. O. Obiero N. A. Odero 《水资源与保护(英文)》 2019年第9期1161-1187,共27页
This study aimed at identifying the most preferred water quality tracking system (WQTS) for adoption and the determining factors for the same among the Langata sub County households in Nairobi city, Kenya. Perrenial m... This study aimed at identifying the most preferred water quality tracking system (WQTS) for adoption and the determining factors for the same among the Langata sub County households in Nairobi city, Kenya. Perrenial municipal water shortage in this neighborhood has forced the residents to depend on vended water supplication but whose quality is not possible to verify at the moment. Accordingly, a mobile phone quality tracing application running on blockchain technology platform was developed to fill the gap of provenance tracking. A non-market discrete choice experiments (DCEs) model was deployed in which four-option attribute bundles;with one being the “status quo” choice were presented to each of the 382 randomly sampled respondents from the five wards within the area. Results indicated that Option 2;the communally managed WQTS emerged as the most preferred choice at 53.9%. Secondly, the male factor was identified as the major determinant to this decision. In conclusion, the study proposes for the installation of this new WQTS which will trigger a 12% adjustment of the average household’s monthly water bill. In addition, this paper recommends for a city-wide assessment of residents’ willingness to pay (WTP) for this WQTS, which it deems as an improved response to water shortage problem. Finally, the study contributes to the application of DCEs model in technology adoption literature. 展开更多
关键词 Water Alternatives DOUBT TRUST Quality TRACKING System COMMUNAL Action
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Impact of polymer mixtures on the stabilization and erosion control of silty sand slope
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作者 YANG Qing-wen PEI Xiang-jun HUANG Run-qiu 《山地科学学报:英文版》 SCIE CSCD 2019年第2期470-485,共16页
Silty sand can be prone to erosion because it is short of stability cementation materials. In recent years, various emerging soil stabilizers, especially natural organic substance and polymer, have been used to improv... Silty sand can be prone to erosion because it is short of stability cementation materials. In recent years, various emerging soil stabilizers, especially natural organic substance and polymer, have been used to improve soil strength, water stability and ability of erosion resistance. In this study, a new type of soil stabilization additive modified carboxymethyl cellulose(M-CMC), consisting of carboxymethyl cellulose(CMC) and polyacrylamide(PAM), was developed for stabilization treatment of silty sand. A series of laboratory tests were conducted to evaluate the performance of M-CMC application on shear strength, permeability, water susceptibility and microstructure of the silty sand soil treated with additive concentration range of 0%-1.3%. Moreover, rainfall simulation experiments were conducted to evaluate the effect of M-CMC on the erosion control of silty sand which compacted soil in a large-sized runoff(1 m~2) plots. Test plot which treated with 1.1% concentration of soil stabilizer and control plot which treated with same amount of water were cured outdoor for 50 days before rainfall simulation test. Rainfall intensity was applied at 120 mm·h-1 for 60 min. Finally, a field test is performed in order to assess the practical application effect of silty sand with 1.1% M-CMC. In general, the results showed that an increase of the concentration of M-CMC resulted in an improvement in water susceptibility and shear strength but a decrease in the infiltration rate. Internal friction angle of the treated soil remarkably increased under a low M-CMC concentration(less than 0.7%), while cohesion of them sharply increased under a relatively high M-CMC concentration(larger than 0.7%). Water susceptibility of the treated samples was improved remarkably under a relatively high M-CMC concentration(larger than 0.7%). Permeability coefficient of them decreased significantly when the M-CMC concentration was increased from 0 to 0.5% and, then, from 0.9% to 1.3%. Based on the images obtained from a scanning electron microscopy( 展开更多
关键词 Soil STABILIZATION WATER susceptibility permeability EROSION WATER RETENTION CEMENTATION
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