期刊文献+
共找到5,507篇文章
< 1 2 250 >
每页显示 20 50 100
Ordered mesoporous materials for water pollution treatment:Adsorption and catalysis
1
作者 Peng Zhang Mingming He +4 位作者 Wei Teng Fukuan Li Xinyuan Qiu Kexun Li Hao Wang 《Green Energy & Environment》 SCIE EI CAS CSCD 2024年第8期1239-1256,共18页
To meet the growing emission of water contaminants,the development of new materials that enhance the efficiency of the water treatment system is urgent.Ordered mesoporous materials provide opportunities in environment... To meet the growing emission of water contaminants,the development of new materials that enhance the efficiency of the water treatment system is urgent.Ordered mesoporous materials provide opportunities in environmental processing applications due to their exceptionally high surface areas,large pore sizes,and enough pore volumes.These properties might enhance the performance of materials concerning adsorption/catalysis capability,durability,and stability.In this review,we enumerate the ordered mesoporous materials as adsorbents/catalysts and their modifications in water pollution treatment from the past decade,including heavy metals(Hg^(2+),Pb^(2+),Cd^(2+),Cr^(6+),etc.),toxic anions(nitrate,phosphate,fluoride,etc.),and organic contaminants(organic dyes,antibiotics,etc.).These contributions demonstrate a deep understanding of the synergistic effect between the incorporated framework and homogeneous active centers.Besides,the challenges and perspectives of the future developments of ordered mesoporous materials in wastewater treatment are proposed.This work provides a theoretical basis and complete summary for the application of ordered mesoporous materials in the removal of contaminants from aqueous solutions. 展开更多
关键词 water pollution treatment Ordered mesoporous materials Toxic contaminants ADSORPTION CATALYSIS
下载PDF
Formation of Water Quality of Surface Water Bodies Used in the Material Processing
2
作者 Tatyana Lyubimova Anatoly Lepikhin +2 位作者 Yanina Parshakova Irina Zayakina Alibek Issakhov 《Fluid Dynamics & Materials Processing》 EI 2024年第4期815-828,共14页
In the process of production or processing of materials by various methods,there is a need for a large volume of water of the required quality.Today in many regions of the world,there is an acute problem of providing ... In the process of production or processing of materials by various methods,there is a need for a large volume of water of the required quality.Today in many regions of the world,there is an acute problem of providing industry with water of a required quality.Its solution is an urgent and difficult task.The water quality of surface water bodies is formed by a combination of a large number of both natural and anthropogenic factors,and is often significantly heterogeneous not only in the water area,but also in depth.As a rule,the water supply of large industrial enterprises is located along the river network.Mergers are the most important nodes of river systems.Understanding the mechanism of transport of pollutants at the confluence of rivers is critical for assessing water quality.In recent years,thanks to the data of satellite images,the interest of researchers in the phenomenon of mixing the waters of merging rivers has increased.The nature of the merger is influenced by the formation of transverse circulation.Within the framework of this work,a study of vorticity,as well as the width of the mixing zone,depending on the distance from the confluence,the speeds of the merging rivers and the angle of confluence was carried out.Since the consumer properties of water are largely determined by its chemical and physical indicators,the intensity of mixing,determined largely by the nature of the secondary circulation,is of fundamental importance for assessing the distribution of hydrochemical indicators of water quality in the mixing zone.These characteristics are important not only for organizing water intake for drinking and technical purposes with the best consumer properties,but also for organizing an effective monitoring system for confluence zones. 展开更多
关键词 water for material processing water quality formation of transverse circulation
下载PDF
Recentadvancesincarbon‐basedmaterials for solar‐driven interfacial photothermal conversion water evaporation:Assemblies,structures,applications,and prospective 被引量:9
3
作者 Yanmin Li Yanying Shi +4 位作者 Haiwen Wang Tiefeng Liu Xiuwen Zheng Shanmin Gao Jun Lu 《Carbon Energy》 SCIE EI CAS CSCD 2023年第11期101-142,共42页
The shortage of fresh water in the world has brought upon a serious crisis to human health and economic development.Solar‐driven interfacial photothermal conversion water evaporation including evaporating seawater,la... The shortage of fresh water in the world has brought upon a serious crisis to human health and economic development.Solar‐driven interfacial photothermal conversion water evaporation including evaporating seawater,lake water,or river water has been recognized as an environmentally friendly process for obtaining clean water in a low‐cost way.However,water transport is restricted by itself by solar energy absorption capacity's limits,especially for finite evaporation rates and insufficient working life.Therefore,it is important to seek photothermal conversion materials that can efficiently absorb solar energy and reasonably design solar‐driven interfacial photothermal conversion water evaporation devices.This paper reviews the research progress of carbon‐based photothermal conversion materials and the mechanism for solar‐driven interfacial photothermal conversion water evaporation,as well as the summary of the design and development of the devices.Based on the research progress and achievements of photothermal conversion materials and devices in the fields of seawater desalination and photothermal electric energy generation in recent years,the challenges and opportunities faced by carbon‐based photothermal conversion materials and devices are discussed.The prospect of the practical application of solar‐driven interfacial photothermal conversion evaporation technology is foreseen,and theoretical guidance is provided for the further development of this technology. 展开更多
关键词 APPLICATIONS carbon‐based materials EVAPORATOR photothermal conversion water evaporation
下载PDF
MXene-based hybrid materials for electrochemical and photoelectrochemical H_(2) generation
4
作者 Jun Young Kim Seung Hun Roh +2 位作者 Chengkai Xia Uk Sim Jung Kyu Kim 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第6期111-125,I0004,共16页
The conversion of solar energy to produce clean hydrogen fuel through water splitting is an emerging strategy for efficiently storing solar energy in the form of solar fuel.This aligns with the increasing global deman... The conversion of solar energy to produce clean hydrogen fuel through water splitting is an emerging strategy for efficiently storing solar energy in the form of solar fuel.This aligns with the increasing global demand for the development of an ideal energy alternative to fossil fuels that does not emit greenhouse gases.Electrochemical(EC) and photoelectrochemical(PEC) water splitting technologies have garnered significant attention worldwide for advanced hydrogen solar fuel production in recent decades.To achieve sustainable green H_(2) production,it is essential to create efficient catalyst materials that are low-cost and can replace expensive noble metal-based catalysts.These characteristics make them an ideal catalyst material for the process.Two-dimensional MXenes with M_(n+1)X_(n) structure have been identified as a promising option for EC and PEC water splitting due to their superior hydrophilicity,metal-like conductivity,large surface area,and adjustable surface chemistry.Here,we present a summary of recent advancements in the synthesis and performance enhancement methods for MXene hybrid materials in hydrogen production through EC and PEC water splitting.Furthermore,we examine the challenges and insights associated with the rational design of MXene-based hybrid materials to facilitate efficient water splitting for sustainable solar fuel production. 展开更多
关键词 MXene Hybrid materials EC PEC HER OER water splitting
下载PDF
A thermodynamics-based three-scale constitutive model for partially saturated granular materials
5
作者 Jianqiu Tian Enlong Liu Yuancheng Guo 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第5期1813-1831,共19页
A three-scale constitutive model for unsaturated granular materials based on thermodynamic theory is presented.The three-scale yield locus,derived from the explicit yield criterion for solid matrix,is developed from a... A three-scale constitutive model for unsaturated granular materials based on thermodynamic theory is presented.The three-scale yield locus,derived from the explicit yield criterion for solid matrix,is developed from a series of discrete interparticle contact planes.The three-scale yield locus is sensitive to porosity changes;therefore,it is reinterpreted as a corresponding constitutive model without phenomenological parameters.Furthermore,a water retention curve is proposed based on special pore morphology and experimental observations.The features of the partially saturated granular materials are well captured by the model.Under wetting and isotropic compression,volumetric compaction occurs,and the degree of saturation increases.Moreover,the higher the matric suction,the greater the strength,and the smaller the volumetric compaction.Compared with the phenomenological Barcelona basic model,the proposed three-scale constitutive model has fewer parameters;virtually all parameters have clear physical meanings. 展开更多
关键词 Unsaturated granular material Unsaturated porous material GEOmaterialS Multi-scale constitutive model water retention curve PLASTICITY
下载PDF
Effect of Water Absorption on the Mechanical Property and Failure Mechanism of Hollow Glass Microspheres Composite Epoxy Resin Solid Buoyancy Materials
6
作者 DING Yue ZHAI Gang-jun +2 位作者 MA Zhe WEI Zi-hao LI Xin 《China Ocean Engineering》 SCIE EI CSCD 2023年第5期876-884,共9页
To study the water absorption of hollow glass microspheres(HGMs)composite epoxy resin solid buoyancy materials in the marine environment and its effect on the mechanical properties,the water absorption was measured by... To study the water absorption of hollow glass microspheres(HGMs)composite epoxy resin solid buoyancy materials in the marine environment and its effect on the mechanical properties,the water absorption was measured by immersing the material in distilled water for 36 days at ambient temperature and fitted to Fick’s second law.The strength of materials before and after water absorption were tested by uniaxial experiments,and the effects of the filling ratio and water absorption on the mechanical properties of the materials were analyzed and explained.Finally,the failure modes and mechanism of the hollow glass microspheres composite material were explicated from the microscopic level by scanning electron microscope(SEM).This research will help solve the problems of solid buoyancy materials in ocean engineering applications. 展开更多
关键词 solid buoyancy material water absorption mechanical property failure mechanism scanning electron microscope
下载PDF
Effects of Combined Application of Water Retaining Agents and Organic Materials on Water Holding Characteristics of Yellow Brown Soils in Hilly Areas 被引量:1
7
作者 唐玉邦 虞利俊 +4 位作者 徐磊 罗佳 王东升 范如芹 裴勤 《Agricultural Science & Technology》 CAS 2015年第9期1985-1988,共4页
[Objective] The aim was to reduce fertilizer and water losses caused by surface runoffs in rainy season and provide scientific references for soil moisture in arid season. [Method] The application proportion of comple... [Objective] The aim was to reduce fertilizer and water losses caused by surface runoffs in rainy season and provide scientific references for soil moisture in arid season. [Method] The application proportion of complex water-holding organic materials was determined by multi-factor mixture experiment and the curve changes of soil moisture characters were tested to analyze water-holding capacity and water availability of soils. [Result] The initial moisture content of soil with different mixture proportions improved in varying degrees. For example, when water-retention agents reached 0.4% and 0.6% of soil weight, soil moisture contents were 69.0% and70.5%, respectively, which showed significant differences with the control(S0.0). Soil dehydration terms in different treatments all extended, prolonging in the range of4.6-14 d. [Conclusion] The applications of water-retention agent and organic material would improve water-holding capacity of hills and low mountains, and initial moisture content and dehydration cycle tend to be volatile upon mixture proportion. Therefore,it is necessary to adjust soil fertility, crop species, and irrigation to meet crop demands on fertilizer and water. 展开更多
关键词 water retaining agents Organic materials Soils of hilly areas water characteristics
下载PDF
Enhancing fly ash utilization in backfill materials treated with CO_(2)carbonation under ambient conditions 被引量:2
8
作者 Ichhuy Ngo Liqiang Ma +1 位作者 Jiangtao Zhai Yangyang Wang 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2023年第3期323-337,共15页
The environmental concerns resulting from coal-fired power generation that produces large amounts of CO_(2)and fly ash are of great interest.To mitigate,this study aims to develop a novel carbonated CO_(2)-fly ash-bas... The environmental concerns resulting from coal-fired power generation that produces large amounts of CO_(2)and fly ash are of great interest.To mitigate,this study aims to develop a novel carbonated CO_(2)-fly ash-based backfill(CFBF)material under ambient conditions.The performance of CFBF was investigated for different fly ash-cement ratios and compared with non-CO_(2)reacted samples.The fresh CFBF slurry conformed to the Herschel-Bulkley model with shear thinning characteristics.After carbonation,the yield stress of the fresh slurry increased significantly by lowering fly ash ratio due to gel formation.The setting times were accelerated,resulting in approximately 40.6%of increased early strength.The final strength decreased when incorporating a lower fly ash ratio(50%and 60%),which was related to the existing heterogeneous pores caused by rapid fluid loss.The strength increased with fly ash content above 70%because additional C-S(A)-H and silica gels were characterized to precipitate on the grain surface,so the binding between particles increased.The C-S(A)-H gel was developed through the pozzolanic reaction,where CaCO_(3)was the prerequisite calcium source obtained in the CO_(2)-fly ash reaction.Furthermore,the maximum CO_(2)uptake efficiency was 1.39 mg-CO_(2)/g-CFBF.The CFBF material is feasible to co-dispose CO_(2)and fly ash in the mine goaf as negative carbon backfill materials,and simultaneously mitigates the strata movement and water lost in post-subsurface mining. 展开更多
关键词 Fly ash utilization CO_(2)carbonation Ambient conditions water conservative backfill mining Negative carbon backfill materials
下载PDF
Designing high-efficiency light-to-thermal conversion materials for solar desalination and photothermal catalysis 被引量:1
9
作者 Hanjin Jiang Xinghang Liu +5 位作者 Dewen Wang Zhenan Qiao Dong Wang Fei Huang Hongyan Peng Chaoquan Hu 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2023年第4期581-600,共20页
Light-to-thermal conversion materials(LTCMs)have been of great interest to researchers due to their impressive energy conversion capacity and wide range of applications in biomedical,desalination,and synergistic catal... Light-to-thermal conversion materials(LTCMs)have been of great interest to researchers due to their impressive energy conversion capacity and wide range of applications in biomedical,desalination,and synergistic catalysis.Given the limited advances in existing materials(metals,semiconductors,π-conjugates),researchers generally adopt the method of constructing complex systems and hybrid structures to optimize performance and achieve multifunctional integration.However,the development of LTCMs is still in its infancy as the physical mechanism of light-to-thermal conversion is unclear.In this review,we proposed design strategies for efficient LTCMs by analyzing the physical process of light-tothermal conversion.First,we analyze the nature of light absorption and heat generation to reveal the physical processes of light-to-thermal conversion.Then,we explain the light-to-thermal conversion mechanisms of metallic,semiconducting andπ-conjugated LCTMs,and propose new material design strategies and performance improvement methods.Finally,we summarize the challenges and prospects of LTCMs in emerging applications such as solar water evaporation and photothermal catalysis. 展开更多
关键词 Light-to-thermal conversion Solar energy conversion material design Performance improvement Solar water evaporation Photothermal catalysis
下载PDF
Chemical and Isotopic Characteristics of the Water and Suspended Particulate Materials in the Yangtze River and Their Geological and Environmental Implications 被引量:10
10
作者 DING Tiping GAO Jianfei +5 位作者 TIAN Shihong SHI Guoyu CHEN Feng WANG Chengyu LUO Xurong HAN Dan 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2014年第1期276-360,共85页
The chemical and isotopic characteristics of the water and suspended particulate materials(SPM) in the Yangtze River were investigated on the samples collected from 25 hydrological monitoring stations in the mainste... The chemical and isotopic characteristics of the water and suspended particulate materials(SPM) in the Yangtze River were investigated on the samples collected from 25 hydrological monitoring stations in the mainsteam and 13 hydrological monitoring stations in the major tributaries during 2003 to 2007. The water samples show a large variation in both δD( 30‰ to 112‰) and δ18O( 3.8‰ to 15.4‰) values. Both δD and δ18O values show a decrease from the river head to the Jinsha Jiang section and then increase downstream to the river mouth. It is found that the oxygen and hydrogen isotopic compositions of the Yangtze water are controlled by meteoric precipitation, evaporation, ice(and snow) melting and dam building. The Yangtze SPM concentrations show a large variation and are well corresponded to the spatial and temporal changes of flow speed, runoff and SPM supply, which are affected by the slope of the river bed, local precipitation rate, weathering intensity, erosion condition and anthropogenic activity. The Yangtze SPM consists of clay minerals, clastic silicate and carbonate minerals, heavy minerals, iron hydroxide and organic compounds. From the upper to lower reaches, the clay and clastic silicate components in SPM increase gradually, but the carbonate components decrease gradually, which may reflect changes of climate and weathering intensity in the drainage area. Compared to those of the upper crust rocks, the Yangtze SPM has lower contents of SiO2, CaO, K2 O and Na2 O and higher contents of TFe2 O3 and trace metals of Co, Ni, Cu, Zn, Pb and Cd. The ΣREE in the Yangtze SPM is also slightly higher than that of the upper crust. From the upper to lower reaches, the CaO and MgO contents in SPM decrease gradually, but the SiO2 content increases gradually, corresponding to the increase of clay minerals and decrease of the carbonates. The δ30SiSPM values( 1.1‰ to 0.3‰) of the Yangtze SPM are similar to those of the average shale, but lower than those of the granite rocks( 0.3‰ to 0.3‰), reflecting the effect of silicon isotope fractionation in silicate weathering process. The δ30SiSPM values of the Yangtze SPM show a decreasing trend from the upper to the middle and lower reaches, responding to the variation of the clay content. The major anions of the river water are HCO 3, SO 4 2, Cl, NO 3, SiO 4 4 and F and the major cations include Ca2+, Na+, Mg2+, K+ and Sr2+. The good correlation between HCO3-content and the content of Ca2+may suggest that carbonate dissolution is the dominate contributor to the total dissolved solid(TDS) of the Yangtze River. Very good correlations are also found among contents of Cl, SO4 2, Na+, Mg2+, K+and Sr2+, indicating the important contribution of evaporite dissolution to the TDS of the Yangtze River. High TDS contents are generally found in the head water, reflecting a strong effect of evaporation in the Qinghai-Tibet Plateau. A small increase of the TDS is generally observed in the river mouth, indicating the influence of tidal intrusion. The F and NO3 contents show a clear increase trend from the upstream to downstream, reflecting the contribution of pesticides and fertilizers in the Chuan Jiang section and the middle and lower reaches. The DSi shows a decrease trend from the upstream to downstream, reflecting the effect of rice and grass growth along the Chuan Jiang section and the middle and lower reaches. The dissolved Cu, Zn and Cd in the Yangtze water are all higher than those in world large rivers, reflecting the effect of intensive mining activity along the Yangtze drainage area. The Yangtze water generally shows similar REE distribution pattern to the global shale. The δ30SiDiss values of the dissolved silicon vary from 0.5‰ to 3.7‰, which is the highest among those of the rivers studied. The δ30SiDiss values of the water in the Yangtze mainsteam show an increase trend from the upper stream to downstream. Its DSi and δ30SiDiss are influenced by multiple processes, such as weathering process, phytolith growth in plants, evaporation, phytolith dissolution, growth of fresh water diatom, adsorption and desorption of aqueous monosilicic acid on iron oxide, precipitation of silcretes and formation of clays coatings in aquifers, and human activity. The δ34SSO4 values of the Yangtze water range from 1.7‰ to 9.0‰. The SO4 in the Yangtze water are mainly from the SO4 in meteoric water, the dissolved sulfate from evaporite, and oxidation of sulfide in rocks, coal and ore deposits. The sulfate reduction and precipitation process can also affect the sulfur isotope composition of the Yangtze water. The87Sr/86Sr ratios of the Yangtze water range from 0.70823 to 0.71590, with an average value of 0.71084. The87Sr/86Sr ratio and Sr concentration are primary controlled by mixing of various sources with different87Sr/86Sr ratios and Sr contents, including the limestone, evaporite and the silicate rocks. The atmospheric precipitation and anthropogenic inputs can also contribute some Sr to the river. The δ11B values of the dissolved B in the Yangtze water range from 2.0‰ to 18.3‰, which is affected by multifactors, such as silicate weathering, carbonate weathering, evaporite dissolution, atmospheric deposition, and anthropogenic inputs. 展开更多
关键词 Yangtze River stable isotopes water chemistry Suspended Particulate materials(SPM) HYDROLOGY environmental implication
下载PDF
Influence of Composite Phosphate Inorganic Antibacterial Materials Containing Rare Earth on Activated Water Property of Ceramics 被引量:11
11
作者 梁金生 梁广川 +3 位作者 祁洪飞 吴子钊 冀志江 金宗哲 《Journal of Rare Earths》 SCIE EI CAS CSCD 2004年第3期436-439,共4页
Antibacterial ceramic was prepared by doping enamel slurry with composite phosphate inorganic antibacterial materials containing rare earth (inorganic antibacterial additives), and then the mechanisms for activating w... Antibacterial ceramic was prepared by doping enamel slurry with composite phosphate inorganic antibacterial materials containing rare earth (inorganic antibacterial additives), and then the mechanisms for activating water and improving seed germinative property were tested by nuclear magnetic resonance (NMR) and the method of testing oxygen dissolved in activated water. Results show that the half peak width of (()^(17)O-NMR) for tap water activated by the antibacterial ceramic drops from 115.36 to 99.15 Hz, and oxygen concentrations of activated water increase by 20%, germinate rate of horsebean and earthnut seeds increases by 12.5% and 7.5%, respectively. Therefore antibacterial ceramic doped enamel slurry with inorganic antibacterial additives containing rare earth can reduce the volume of clusters of water molecules, improve activation of tap water, and promote plant seeds germinate. 展开更多
关键词 CERAMICS composite materials phosphate antibacterial ceramic nuclear magnetic resonance (NMR) activated water oxygen concentrations rare earths
下载PDF
The application of perovskite materials in solar water splitting 被引量:6
12
作者 Yanbin Huang Jun Liu +8 位作者 Yanchun Deng Yuanyuan Qian Xiaohao Jia Mengmeng Ma Cheng Yang Kong Liu Zhijie Wang Shengchun Qu Zhanguo Wang 《Journal of Semiconductors》 EI CAS CSCD 2020年第1期39-55,共17页
Solar water splitting is a promising strategy for sustainable production of renewable hydrogen,and solving the crisis of energy and environment in the world.However,large-scale application of this method is hampered b... Solar water splitting is a promising strategy for sustainable production of renewable hydrogen,and solving the crisis of energy and environment in the world.However,large-scale application of this method is hampered by the efficiency and the expense of the solar water splitting systems.Searching for non-toxic,low-cost,efficient and stable photocatalysts is an important way for solar water splitting.Due to the simplicity of structure and the flexibility of composition,perovskite based photocatalysts have recently attracted widespread attention for application in solar water splitting.In this review,the recent developments of perovskite based photocatalysts for water splitting are summarized.An introduction including the structures and properties of perovskite materials,and the fundamentals of solar water splitting is first provided.Then,it specifically focuses on the strategies for designing and modulating perovskite materials to improve their photocatalytic performance for solar water splitting.The current challenges and perspectives of perovskite materials in solar water splitting are also reviewed.The aim of this review is to summarize recent findings and developments of perovskite based photocatalysts and provide some useful guidance for the future research on the design and development of highly efficient perovskite based photocatalysts and the relevant systems for water splitting. 展开更多
关键词 solar water splitting perovskite materials PHOTOCATALYST
下载PDF
Chemical and Isotopic Characters of the Water and Suspended Particulate Materials in the Yellow River and Their Geological and Environmental Implications 被引量:5
13
作者 DING Tiping GAO Jianfei +5 位作者 TIAN Shihong WANG Huaibai LI Ming WANG Chengyu LUO Xurong HANG Dan 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2016年第1期285-351,共67页
The chemical and isotopic characteristics of the water and suspended particulate materials (SPM) in the Yellow River were investigated on the samples collected from 29 hydrological monitoring stations in the mainste... The chemical and isotopic characteristics of the water and suspended particulate materials (SPM) in the Yellow River were investigated on the samples collected from 29 hydrological monitoring stations in the mainstem and several major tributaries during 2004 to 2007. The JD and δ^18O values of the Yellow River water vary in large ranges from -32%0 to -91‰ and from -3.1‰ to -12.5‰, respectively. The characters of H and O isotope variations indicate that the major sources of the Yellow River water are meteoric water and snow melting water, and water cycle in the Yellow River basin is affected strongly by evaporation process and human activity. The average SPM content (9.635 g/L) of the Yellow River is the highest among the world large rivers. Compared with the Yangtze River, the Yellow River SPM has much lower clay content and significantly higher contents of clastic silicates and carbonates. In comparison to the upper crust rocks, the Yellow River SPM contains less SiO2, CaO, K2O and Na2O, but more TFe203, Co, Ni, Cu, Zn, Pb and Cd. The abnormal high Cd contents found in some sample may be related to local industrial activity. The REE contents and distribution pattern of the Yellow River SPM are very close to the average value of the global shale. The average δ^30Sisp in the Yellow River (-0.11‰) is slightly higher than the average value (-0.22‰) of the Yangtze River SPM. The major factors controlling the δ^30Si SPM of the Yellow River are the soil supply, the isotopic composition of the soil and the climate conditions. The TDS in the Yellow River are the highest among those of world large rivers. Fair correlations are observed among Cl, Na^+, K^+, and Mg^2+ contents of the Yellow River water, indicating the effect of evaporation. The Ca^2+ and Sr^2+ concentrations show good correlation to the SO42 concentration rather than HCO3-concentration, reflecting its origin from evaporates. The NO3-contents are affected by farmland fertilization. The Cu, Zn and Cd contents in dissolved load of the Yellow River water are all higher than those of average world large rivers, reflecting the effect of human activity. The dissolved load in the Yellow River water generally shows a REE distribution pattern parallel to those for the Yangtze River and the Xijiang River. The δ^30Si values of the dissolved silicon vary in a range from 0.4%0 to 2.9%0, averaging 1.34%o. The major processes controlling the Dsi weathering process of silicate rocks, growth of and δ^30SiDiss of the Yellow River water are the phytolith in plants, evaporation, dissolution of phytolith in soil, growth of fresh water diatom, adsorption and desorption of aqueous monosilicic acid on iron oxide and human activities. The average δ^30^SiDiss value of the Yellow River is significantly lower than that of the Nile River, Yangtze River and Siberia rivers, but higher than those of other rivers, reflecting their differences in chemical weathering and biological activity. The δ^34SSO4 values of the Yellow River water range from -3.8%0 to 14.1%o, averaging 7.97%0. There is some correlation between SO4^2- content and δ^34SSO4. The factors controlling the δ^34SSO4 of the Yellow River water are the SO4 in the meteoric water, the SO4 from gypsum or anhydrite in evaporite rocks, oxidation and dissolution of sulfides in the mineral deposits, magmatic rocks and sedimentary rocks, the sulfate reduction and precipitation process and the sulfate from fertilizer. The ^87Sr/^86Sr ratios of all samples range from 0.71041 to 0.71237, averaging 0.71128. The variations in the ^87Sr/^86Sr ratio and Sr concentration of river water are primarily caused by mixing of waters of various origins with different 87Sr/S6Sr ratios and Sr contents resulting from water-rock interaction with different rock types. 展开更多
关键词 Yellow River stable isotopes water chemistry suspended particulate materials (SPM) HYDROLOGY environmental implication
下载PDF
Influence of Water Content on Conductivity and Piezoresistivity of Cement-based Material with both Carbon Fiber and Carbon Black 被引量:4
14
作者 韩宝国 欧进萍 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2010年第1期147-151,共5页
The influence of water content on the conductivity and piezoresistivity of cement-based material with carbon fiber (CF) and carbon black (CB) was investigated. The piezoresistivity of cement-based material with bo... The influence of water content on the conductivity and piezoresistivity of cement-based material with carbon fiber (CF) and carbon black (CB) was investigated. The piezoresistivity of cement-based material with both CF and CB was compared with that of cement-based material with CF only, and the changes in electrical resistivity of cement-based material with both CF and CB under static and loading conditions in different drying and soaking time were studied. It is found that the piezoresistivity of cement-based material with both CF and CB has better repeatability and linearity than that of cement-based material with CF only. The conductivity and the sensitivity of piezoresistive cement-based material with both CF and CB are enhanced as the water content in piezoresistive cement-based material increases. 展开更多
关键词 cement-based material carbon fiber carbon black water content CONDUCTIVITY PIEZORESISTIVITY
下载PDF
Effects of Specimen Shape and Size on Water Loss and Drying Shrinkage of Cement-based Materials 被引量:4
15
作者 巴明芳 钱春香 WANG Hui 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2013年第4期733-740,共8页
The effects of specimen size and shape on development of water loss and shrinkage of mortar and concrete respectively were investigated. The experimental results showed that the effects of specimen size and shape on w... The effects of specimen size and shape on development of water loss and shrinkage of mortar and concrete respectively were investigated. The experimental results showed that the effects of specimen size and shape on water loss ratio were consistent with those on drying shrinkage strain. It is also indicated that drying shrinkage strain has obvious linear correlation with water loss ratios independent of specimen size and shape. The effects of specimen size and shape on the water loss ratio were embodied in established model of averaged relative humidity improved by considering effects of sequential hydration and calculated by finite difference method. Furthermore, the effects of specimen size and shape on drying shrinkage strain of concrete were experimentally deduced and applied to modify criterion EB-FIP1990. The comparison between experimental and calculated results shows that the modified EB-FIP1990 can be adopted to predict drying shrinkage strain of concrete with reasonable accuracy. 展开更多
关键词 cement-based materials drying shrinkage water loss effective drying thickness
下载PDF
High Water Content Material Based on Ba-Bearing Sulphoaluminate Cement 被引量:3
16
作者 常钧 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2005年第3期88-90,共3页
A new type of high water content material which is made up of two pastes is prepared, one is refute from lime and gypsum, and another is based on Ba-bearing sulphoaluminate cement. It has excellent properties such as ... A new type of high water content material which is made up of two pastes is prepared, one is refute from lime and gypsum, and another is based on Ba-bearing sulphoaluminate cement. It has excellent properties such as slow single paste solidifing ,fust double pustes solidifing ,fast coagulating and hardening, high early strength, good suspeasion property at high W/C ratio and low cost. Meanwhile, the properties and hydration mechanism of the material were analyzed by using XRD, DTA- TG and SEM. The hydrated products of new type of high water content material are Ba-bearing ettringite, BaSO4 , aluminum gel and C-S-H gel. 展开更多
关键词 Ba- bearing sulphoaluminate cement high water content material filling material BAO barium industrial waste residue
下载PDF
Super-absorbent swellable polymer as grouting material for treatment of karst water inrush 被引量:5
17
作者 Shucai Li Chenyang Ma +5 位作者 Rentai Liu Mengjun Chen Jia Yan Zhenjun Wang Shaolong Duan Huasheng Zhang 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2021年第5期753-763,共11页
Grouting is the most commonly used method to control water inrush in underground engineering.Traditional cement-based materials are easy to dilute and hard to coagulate under the influence of large flow and high-veloc... Grouting is the most commonly used method to control water inrush in underground engineering.Traditional cement-based materials are easy to dilute and hard to coagulate under the influence of large flow and high-velocity water inrush.To address these deficiencies,a new type of polymer grouting material with an excellent expansion ratio was synthesised.The material quickly absorbs water and has an expansion ratio of 1:300.The material is composed of a superabsorbent polymer(SAP),glycerol,and ethanol.The effects of water quality on the expansion ratio and expansion rate of the material were examined,and the best solid–liquid ratio for the slurry was determined by fluidity measurements.A karst specially designed pipeline water inrush test device showed that 800 g of SAP can achieve 0.6 m/s water flow blockage in the smooth pipeline,demonstrating that the ability of the SAP slurry to block water inrush is superior to those of other materials.This study provides a reference for water inrush plugging,and has important implications for the reduction and control of karst pipeline-type water inrush disasters,ensuring the safety of construction sites and preventing loss of life and damage to property. 展开更多
关键词 KARST water inrush Model test Grouting material Superabsorbent polymer
下载PDF
Structure Characterization and Dephosphorization Effect Analysis of Oyster Shell-silica Micropowder Waste Water Dephosphorization Materials 被引量:2
18
作者 赖寿莲 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2010年第1期33-38,共6页
In this work,the effects of pH value of waste water and initial concentration of phosphorus on dephosphorization materials were investigated.The materials were prepared by shaping,sintering and hydrothermal reshaping ... In this work,the effects of pH value of waste water and initial concentration of phosphorus on dephosphorization materials were investigated.The materials were prepared by shaping,sintering and hydrothermal reshaping oyster shell and silica micro-powder.Different concentrations of phosphorus-contained waste water were simulated with potassium dihydrogen phosphate solution,the effect of dephosphorization was tested with phosphomolybdenum blue spectrophotometer method,and the crystal phase and microstructure of materials were characterized by XRD and SEM methods. It was indicated that dephosphorization was completed in 6 h when the initial phosphorus concentration in waste water was lower than 15 mg/L, and the dephosphorization time prolonged as the increase of phosphorus concentration. It was observed that the pH value of waste water influenced dephosphorization significantly, and neutral subalkalic environment favored dephosphorization. When the pH value was 11, the efficiency of dephosphozation was the greatest. For waste water with an initial concentration of 20 mg/L, the dephosphozation rate is close to 100% in8 h. 展开更多
关键词 oyster shell silica micro-powder hydrothermal reaction waste water dephosphorization materials environmental-friendly material
下载PDF
Water purification with sintered porous materials fabricated at 400℃ from sea bottom sediments 被引量:2
19
作者 DABWAN Ahmed H A IMAI Daizo +5 位作者 KANECO Satoshi SENMATSU Isamu NAKAHAMA Katsuyuki KATSUMATA Hideyuki SUZUKI Tohru OHTA Kiyohisa 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2008年第2期172-176,共5页
A sintering technology for preparing porous materials from sea bottom sediments was developed for use in water purification. The purpose of the present study was to develop methods for converting the sea bottom sedime... A sintering technology for preparing porous materials from sea bottom sediments was developed for use in water purification. The purpose of the present study was to develop methods for converting the sea bottom sediments dredged from Ago Bay into value-added recycled products. The sintered products fabricated at 400℃ were found to be very effective adsorbents for the removal of heavy metals. 展开更多
关键词 sintering preparation technology porous materials sea bottom sediments water purification heavy metals
下载PDF
Seismic performance evaluation of water supply pipes installed in a full-scale RC frame structure based on a shaking table test 被引量:1
20
作者 Wu Houli Guo Endong +2 位作者 Wang Jingyi Dai Xin Dai Chenxi 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2024年第1期163-178,共16页
As an important part of nonstructural components,the seismic response of indoor water supply pipes deserves much attention.This paper presents shaking table test research on water supply pipes installed in a full-scal... As an important part of nonstructural components,the seismic response of indoor water supply pipes deserves much attention.This paper presents shaking table test research on water supply pipes installed in a full-scale reinforced concrete(RC)frame structure.Different material pipes and different methods for penetrating the reinforced concrete floors are combined to evaluate the difference in seismic performance.Floor response spectra and pipe acceleration amplification factors based on test data are discussed and compared with code provisions.A seismic fragility study of displacement demand is conducted based on numerical simulation.The acceleration response and displacement response of different combinations are compared.The results show that the combination of different pipe materials and different passing-through methods can cause obvious differences in the seismic response of indoor riser pipes. 展开更多
关键词 water supply pipe different materials shaking table test amplification factor seismic fragility
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部