维普中文期刊产品整合服务
122篇 您的检索式:关键字=HYDRATION
    题名 作者 年代 出处 被引量
1EFFECT OF STONE POWDER ON STONE CHIPPINGS CONCRETE显示文摘In this paper,the effect and mechanism of calcareous stone powder with size less than 0. 074mm are investigated in stone chippings concrete. The results show that the stone powder can participate in hydration reaction and acts as crystal nucleus in hydration process, namely. it has hydration activity to an extent. The strength of stone chippings concrete is enhanced and the easy-mixing capacity of the concrete mortar is modified when stone chippings contain a proper amount of stone powder. The stone powder has little effect on the wearability of the concrete.周明凯 彭少明 徐健 朱承华 1996Journal of Wuhan University of Technology(Materials Science)1996,11,4:23
2Experimental study on hydration damage mechanism of shale from the Longmaxi Formation in southern Sichuan Basin, China显示文摘As a serious problem in drilling operation,wellbore instability restricts efficient development of shale gas.The interaction between the drilling fluid and shale with hydration swelling property would have impact on the generation and propagation mechanism of cracks in shale formation,leading to wellbore instability.In order to investigate the influence of the hydration swelling on the crack propagation,mineral components and physicochemical properties of shale from the Lower Silurian Longmaxi Formation(LF)were investigated by using the XRD analysis,cation exchange capabilities(CEC)analysis,and SEM observation,and we researched the hydration mechanism of LF shale.Results show that quartz and clay mineral are dominated in mineral composition,and illite content averaged 67%in clay mineral.Meanwhile,CEC of the LF shale are 94.4 mmol/kg.The process of water intruding inside shale along microcracks was able to be observed through high power microscope,meanwhile,the hydration swelling stress would concentrate at the crack tip.The microcracks would propagate,bifurcate and connect with each other,with increase of water immersing time,and it would ultimately develop into macro-fracture.Moreover,the macrocracks extend and coalesce along the bedding,resulting in the rock failure into blocks.Hydration swelling is one of the major causes that lead to wellbore instability of the LF shale,and therefore improving sealing capacity and inhibition of drilling fluid system is an effective measure to stabilize a borehole.Xiangjun Liu Wei Zeng Lixi Liang Jian Xiong 2016Petroleum2016,2,1:14
3Coupled effect of cement hydration and temperature on hydraulic behavior of cemented tailings backfill显示文摘Cemented tailings backfill(CTB) is made by mixing cement, tailings and water together, thus cement hydration and water seepage flow are the two crucial factors affecting the quality of CTB. Cement hydration process can release significant amount of heat to raise the temperature of CTB and in turn increase the rate of cement hydration. Meanwhile, the progress of cement hydration consumes water and produces hydration products to change the pore structures within CTB, which further influences the hydraulic behavior of CTB. In order to understand the hydraulic behavior of CTB, a numerical model was developed by coupling the hydraulic,thermal and hydration equations. This model was then implemented into COMSOL Multiphysics to simulate the evolutions of temperature and water seepage flow within CTB versus curing time. The predicted outcomes were compared with correspondent experimental results, proving the validity and availability of this model. By taking advantage of the validated model, effects of various initial CTB and curing temperatures, cement content, and CTB's geometric shapes on the hydraulic behavior of CTB were demonstrated numerically. The presented conclusions can contribute to preparing more environmentally friendly CTB structures.吴迪 蔡嗣经 2015Journal of Central South University2015,22,5:9
4Solvation effects on brain uptakes of isomers of ^(99m)Tc brain imaging agents显示文摘Analysis of electrostatic hydration free energies of the isomers of the 99mTc-BAT and 99mTc-DADT complexes is carried out using the computer simulation technique. The results show that not only a correlation exists between the logarithm of the brain uptake and the electrostatic hydration free energy for the isomers of 99mTc-brain radiopharmaceu-ticals, but also a linear relationship exists between the logarithm of the ratio of the brain uptake of the syn isomer to that of the anti one and the difference between the electrostatic hydration free energy of the syn-isomer and that of the anti one. Furthermore, the investigation on the important factors influencing the brain uptakes of 99mTc-radiophar-maceuticals and the reasons of the different biodistribution of the isomers of the 99mTc-complexes is explored at the molecular level. The results may provide a reference for the rational drug design of brain imaging agents.JIA Hongmei, MA Xiaohui, WANG Cunxin & LIU Boli1. Department of Chemistry, Beijing Normal University, Beijing 100875, China 2. Center for Biomedical Engineering, Beijing Polytechnic University, Beijing 100022, China 2002Chinese Science Bulletin2002,47,21:8
5Research on Hydration of Steel Slag Cement Activated with Waterglass显示文摘This paper studied the hydration and strength influence factors of Steel Slag Cement (SSC), such as the quantity of steel slag and slag and the dosage of additive. The results show that: (a) In the process of hydration of SSC,steel slag and slag activate each other; (b) Waterglass's structure forms the preliminary skeleton of SSC,and the hydration products of SSC link or fill in the skeleton; (c) Sodium in waterglass is the catalytic and its concentration does not change in the process of hydration. (d) Structure of activation is a significant factor to the property of SSC.胡曙光 2001Journal of Wuhan University of Technology(Materials Science)2001,16,1:8
6Study on the hardening mechanism of cement asphalt binder显示文摘The hydration and hardening mechanism of cement asphalt binder(CAB) was studied.The early hydration process,hydration products and paste microstructure of CAB made by Portland cement and anionic asphalt emulsion were investigated by calorimetry,X-ray diffraction,and environmental scanning electron microscopy.The early hydration process of CAB can be characterized as 5 stages similar to those of Portland cement.There is no chemical reaction detected between cement and asphalt,hence no new hydration products other than those of Portland cement are produced.The hardening of CAB begins with the hydration of cement.When the hydration of cement comes into the acceleration period and its exothermic rate comes to the maximum,the coalescence of asphalt particles in asphalt emulsion is triggered.In the hardened system of CAB,it was found that the hydration products of cement form the skeleton and are covered by the continuous asphalt film.They formed an interpenetrating network system.The emulsifiers in the asphalt emulsion may retard the hydration process of cement.YANG JinBo,YAN PeiYu,KONG XiangMing & LI Xiang Key Laboratory of Structural Engineering and Vibration of Education Ministry of China,Department of Civil Engineering,Tsinghua University,Beijing 100084,China 2010Science China(Technological Sciences)2010,53,5:7
7Effects of magnetic fields on HCFC-141b refrigerant gas hydrate formation显示文摘Low-pressure refrigerant gas hydrates have brilliant prospects as a cool storage me-dium for air-conditioning systems. Intensive effects of some specific magnetic fields on the forma-tion process of HCFC-141b refrigerant gas hydrate are depicted experimentally. Under influence of these specific magnetic fields, the orientation and growth region of gas hydrate are altered; induc-tion time of hydrate crystallization can be shortened extremely, and it can be shortened to 40 min from 9 h; hydrate formation mass can be enhanced considerably, and hydration rate can arrive at 100% in some instances. Meanwhile, the relations of induction time and hydration rate changed with magnetic field intensity are depicted, and some elementary regulations are found.刘勇 郭开华 梁德青 樊栓狮 2003Science China Chemistry2003,46,4:6
8Hydration-Enhanced Lubricating Electrospun Nanofibrous Membranes Prevent Tissue Adhesion显示文摘Lubrication is the key to efficient function of human tissues and has significant impact on the comfort level.However,the construction of a lubricating nanofibrous membrane has not been reported as yet,especially using a one-step surface modification method.Here,bioinspired by the superlubrication mechanism of articular cartilage,we successfully construct hydration-enhanced lubricating nanofibers via one-step in situ grafting of a copolymer synthesized by dopamine methacrylamide(DMA)and 2-methacryloyloxyethyl phosphorylcholine(MPC)onto electrospun polycaprolactone(PCL)nanofibers.The zwitterionic MPC structure provides the nanofiber surface with hydration lubrication behavior.The coefficient of friction(COF)of the lubricating nanofibrous membrane decreases significantly and is approximately 65%less than that of pure PCL nanofibers,which are easily worn out under friction regardless of hydration.The lubricating nanofibers,however,show favorable wear-resistance performance.Besides,they possess a strong antiadhesion ability of fibroblasts compared with pure PCL nanofibers.The cell density decreases approximately 9-fold,and the cell area decreases approximately 12 times on day 7.Furthermore,the in vivo antitendon adhesion data reveals that the lubricating nanofiber group has a significantly lower adhesion score and a better antitissue adhesion.Altogether,our developed hydration-enhanced lubricating nanofibers show promising applications in the biomedical field such as antiadhesive membranes.Liang Cheng Yi Wang Guoming Sun Shizhu Wen Lianfu Deng Hongyu Zhang Wenguo Cui 2020Research2020,,1:6
9Hydrogen sulfide promotes flowering in heading Chinese cabbage by S-sulfhydration of BraFLCs显示文摘Heading Chinese cabbage(Brassica rapa L.syn.B.campestris L.ssp.chinensis Makino var.pekinensis(Rupr.)J.Cao et Sh.Cao)is a cruciferous Brassica vegetable that has a triplicate genome,owing to an ancient genome duplication event.It is unclear whether the duplicated homologs have conserved or diversi fied functions.Hydrogen sulfide(H_(2)S)is a plant gasotransmitter that plays important physiological roles in growth,development,and responses to environmental stresses.The modification of cysteines through S-sulfhydration is an important mechanism of H_(2)S,which regulates protein functions.H?S promotes flowering in Arabidopsis and heading Chinese cabbage.Here we investigated the molecular mechanisms of H_(2)S used to promote flowering in the latter.Four,five,and four BraFLC,BraSOC I,and BraFT homologs were identi fi ed in heading Chinese cabbage.Different BraFLC proteins were bound to different CArG boxes in the promoter regions of the BraSOC I and BraFT homologs,producing different binding patterns.Thus,there may be functionally diverse BraFLC homologs in heading Chinese cabbage.Exogenous H_(2)S at 100μmol L^(-1) significantly promoted flowering by compensating for insuf fi cient vernalization.BraFLC 1 and BraFLC_(3) underwent S-sulfhydration by H_(2)S,after which their abilities to bind most BraSOC I or BraFT promoter probes weakened or even disappeared.These changes in binding ability were consistent with the expression pattern of the BraFT and BraSOC I homologs in seedlings treated with H_(2)S.These results indicated that H_(2)S signaling regulates flowering time.In summary,H_(2)S signaling promoted plant flowering by weakening or eliminating the binding abilities of BraFLCs to downstream promoters through S-sulfhydration.Xiaoli Ma Liping Zhang Zhuoya Pei Linlin Zhang Zhiqiang Liu Danmei Liu Xuefeng Hao Zhuping Jin Yanxi Pei 2021Horticulture Research2021,8,1:6
10Probing the hydration of composite cement pastes containing fly ash and silica fume by proton NMR spin-lattice relaxation显示文摘Proton NMR spin-lattice relaxation (T1) was used as a prober for observing the hydration process of composite cement pastes blending fly ash and silica fume during the early age.The distribution at initial time,evolution curves and signals intensity of T1 were shown in this paper.Results demonstrate that the T1 distribution curves at initial time exhibit two peaks,which are regarded as two different water phases in the pastes.The evolution curves of T1 are in good agreement with the hydration process of composite pastes and could be roughly divided into four stages:initial period,dormant period,acceleration period and steady period.The hydration mechanism for each stage was discussed.The hydration of the composite cement pastes was retarded by the addition of fly ash and silica fume when compared to that of pure cement.However,the hydration degree of the cement in the blends was promoted.SHE AnMing & YAO Wu Key Laboratory of Advanced Civil Engineering Materials (Tongji University),Ministry of Education,Shanghai 200092,China 2010Science China(Technological Sciences)2010,53,6:6
11Effect of Calcium Silicate Hydrate Seeds on Hydration and Mechanical Properties of Cement显示文摘C-S-H series are synthesized at different temperatures and ages by pozzolanic reaction.The change of particle size distribution,phase composition,morphology and nanostructure of C-S-H with temperatures and ages,and the effects of C-S-H seeds and seeds parameters on the hydration behavior and mechanical properties development of cement were investigated by DLS,XRD,SEM,^(29)Si NMR,TAM-air isothermal calorimeter and mechanical properties test.The results show that the particle size,crystallinity,basal spacing and Q^(2)/Q^(1) ratio of C-S-H increases with the increase of synthesis temperature and age.The addition of synthesized C-S-H seeds to cement pastes results in the strong acceleration effect on cement hydration and significant improvement of the early strength of cement paste and mortar.The 1 day-C-S-H seeds synthesized at room temperature can increase the strength of cement paste by about 30 MPa at 12 h.The effect does not show a very regular change with the increase of the temperature and age of seeds synthesis.Considering the effect of C-S-H seeds on the hydration and mechanical properties of cement,and economy and short cycle of seeds synthesis,the C-S-H seeds synthesized at room temperature for 1 day or 55 ℃ water bath for 12 hours is recommended..王以撒 吕林女 HE Yongjia WANG Fazhou HU Shuguang 2021Journal of Wuhan University of Technology(Materials Science)2021,36,1:5
12Hydration process in Portland cement blended with activated coal gangue显示文摘This paper deals with the hydration of a blend of Portland cement and activated coal gangue in order to determine the relationship between the degree of hydration and compressive strength development.The hydration process was investigated by various means:isothermal calorimetry,thermal analysis,non-evaporable water measurement,and X-ray diffraction analysis.The results show that the activated coal gangue is a pozzolanic material that contributes to the hydration of the cement blend.The pozzolanic reaction occurs over a period of between 7 and 90 d,consuming portlandite and forming both crystal hydrates and ill-crystallized calcium silicate hydrates.These hydrates are similar to those found in pure Portland cement.The results show that if activated coal gangue is substituted for cement at up to 30%(w/w),it does not significantly affect the final compressive strength of the blend.A long-term compressive strength improvement can in fact be achieved by using activated coal gangue as a sup-plementary cementing material.The relationship between compressive strength and degree of hydration for both pure Portland cement and blended cement can be described with the same equation.However,the parameters are different since blended cement produces fewer calcium silicate hydrates than pure Portland cement at the same degree of hydration.Xian-ping LIU Pei-ming WANG Min-ju DING 2011Journal of Zhejiang University-Science A(Applied Physics & Engineering)2011,12,7:4
13Effect of PCEs with Different Functional Groups on the Performance of Cement Paste显示文摘The adsorption behaviors and dispersing properties of polycarboxylate superplasticizer(PCE) with different functional groups were systematically analyzed to reveal the theory and methods of modifying PCE molecular structures and regulating PCE performances. By substituting carboxylic groups with sulfonic groups, ester groups or acylamino groups, respectively, modified PCEs with different functional groups were synthesized. Results show that introducing low amount of ester groups or sulfonic groups into the PCE molecules has no negative effects on the fluidity of cement paste, while introducing acylamino groups into PCE molecules significantly weakens the fluidity of cement paste. At low amount(when the molar ratio of sodium methallyl sulfonate to TPEG is lower than 0.4), the rapid adsorption of sulfonic groups onto the cement particles contributes to the high dispersing performance of the sulfonic group modified PCEs. When the substitution ratio of acrylic acid by sulfonic acid is higher than 0.4, the viscosity and the yield stress of cement paste increases sharply. Redundant sulfonic groups lead to the excessive charge density of the PCE, which contributes to the inhomogeneous adsorption on the cement grains and hence results in the decline of the dispersing performance. Substitution of carboxylic group by acylamino group or ester group slightly changes the viscosity as well as the yield stress of cement paste. Introducing sulfonic group into PCE molecule improves the adsorption behavior of PCEs, while introducing ester group or acylamino group into PCE depresses the adsorption properties.何燕 ZHANG Xiong WANG Yiting KONG Yaning JI Tao SHUI Liangliang WANG Xiaofu WANG Haoren 2019Journal of Wuhan University of Technology(Materials Science)2019,34,5:3
14Effects of lime treatment on the microstructure and hydraulic conductivity of Héricourt clay显示文摘This study aims at evidencing the effects of lime treatment on the microstructure and hydraulic conductivity of a compacted expansive clay,with emphasis put on the effect of lime hydration and modification.For this purpose,evolutions of hydraulic conductivity were investigated for both lime-treated and untreated soil specimens over 7 d after full saturation of the specimens and their microstructures were observed at the end.Note that for the treated specimen,dry clay powder was mixed with quicklime prior to compaction in order to study the effect of lime hydration.It is observed that lime hydration and modification did not affect the intra-aggregate pores but increased the inter-aggregates pores size.This increase gave rise to an increase of hydraulic conductivity.More precisely,the hydraulic conductivity of lime-treated specimen increased progressively during the first 3 d of modification phase and stabilised during the next 4 d which correspond to a short period prior to the stabilisation phase.The microstructure observation showed that stabilisation reactions took place after 7 d.Under the effect of stabilisation,a decreasing hydraulic conductivity can be expected in longer time due to the formation of cementitious compounds.Thanh Danh Tran Yu-Jun Cui Anh Minh Tang Martine Audiguier Roger Cojean 2014Journal of Rock Mechanics and Geotechnical Engineering2014,6,5:3
15Effect of temperature on the hydration process and strength development in blends of Portland cement and activated coal gangue or fly ash显示文摘This paper describes the results of an investigation into the effect of the variation of curing temperatures between 0 and 60 °C on the hydration process,pore structure variation,and compressive strength development of activated coal gangue-cement blend(ACGC) . Hardened ACGC pastes cured for hydration periods from 1 to 360 d were examined using the non-evaporable water method,thermal analysis,mercury intrusion porosimetry,and mechanical testing. To evaluate the specific effect of activated coal gangue(ACG) as a supplementary cementing material(SCM) ,a fly ash-cement blend(FAC) was used as a control. Results show that raising the curing temperature accelerates pozzolanic reactions involving the SCMs,increasing the degree of hydration of the cement blends,and hence increasing the rate of improvement in strength. The effect of curing temperature on FAC is greater than that on ACGC. The pore structure of the hardened cement paste is improved by increasing the curing temperature up to 40 °C,but when the curing temperature reaches 60 °C,the changing nature of the pore structure leads to a decrease in strength. The correlation between compressive strength and the degree of hydration and porosity is linear in nature.Pei-ming WANG Xian-ping LIU 2011Journal of Zhejiang University-Science A(Applied Physics & Engineering)2011,12,2:3
16Effect of Nano Silica on Hydration and Microstructure Characteristics of Cement High Volume Fly Ash System Under Steam Curing显示文摘The influences of nano silica (NS) on the hydration and microstructure development of steam cured cement high volume fly ash (40 wt%, CHVFA) system were investigated. The compressive strength of mortars was tested with different NS dosage from 0 to 4%. Results show that the compressive strength is dramatically improved with the increase of NS content up to 3%, and decreases with further increase of NS content (e g, at 4%). Then X?ray diffraction (XRD), differential scanning calorimetry-thermogravimetry (DSCTG), scanning electron microscope (SEM), energy disperse spectroscopy (EDS), mercury intrusion porosimeter (MIP) and nuclear magnetic resonance (NMR) were used to analyze the mechanism. The results reveal that the addition of NS accelerates the hydration of cement and fly ash, decreases the porosity and the content of calcium hydroxide (CH) and increases the polymerization degree of C-S-H thus enhancing the compressive strength of mortars. The interfacial transition zone (ITZ) of CHVFA mortars is also significantly improved by the addition ofNS, embodying in the decrease of Ca/Si ratio and CH enrichment of ITZ.马保国 梅军鹏 TAN Hongbo LI Hainan LIU Xiaohai JIANG Wenbin ZHANG Ting 2019Journal of Wuhan University of Technology(Materials Science)2019,34,3:3
17Effect of New Hardening Accelerator on the Strength of Segment Concrete显示文摘A novel crystal nucleus-based cement-hardening accelerator was evaluated using various mortar and segment concrete experiments.The mechanism of hardening acceleration was investigated via hydration temperature variation analysis,hydration degree analysis,X-ray diffraction(XRD)and scanning electron microscopy(SEM).In the presence of accelerator,the fluidity loss of mortar was increased after 30 minuites,and a coagulation was also observed.Moreover,based on the image of SEM,the formation of C-S-H gels was enhanced in the early hydration.As a result,the hardening accelerator could significantly boost the early strength of concrete,especially within one day of pouring,and shorten steam curing time to meet the demolding strength.邓最亮 WANG Weishan 路贵民 FU Lefeng ZHENG Baicun 2021Journal of Wuhan University of Technology(Materials Science)2021,36,3:3
18High-temperature transport properties of BaSn_(1−x)Sc_(x)O_(3−δ) ceramic materials as promising electrolytes for protonic ceramic fuel cells显示文摘Protonic ceramic fuel cells(PCFCs)offer a convenient means for electrochemical conversion of chemical energy into electricity at intermediate temperatures with very high efficiency.Although BaCeO_(3)-and BaZrO_(3)-based complex oxides have been positioned as the most promising PCFC electrolytes,the design of new protonic conductors with improved properties is of paramount importance.Within the present work,we studied transport properties of scandium-doped barium stannate(Sc-doped BaSnO_(3)).Our analysis included the fabrication of porous and dense BaSn_(1−x)Sc_(x)O_(3−δ)ceramic materials(0≤x≤0.37),as well as a comprehensive analysis of their total,ionic,and electronic conductivities across all the experimental conditions realized under the PCFC operation:both air and hydrogen atmospheres with various water vapor partial pressures(p(H2O)),and a temperature range of 500–900℃.This work reports on electrolyte domain boundaries of the undoped and doped BaSnO_(3)for the first time,revealing that pure BaSnO_(3)exhibits mixed ionic–electronic conduction behavior under both oxidizing and reducing conditions,while the Sc-doping results in the gradual improvement of ionic(including protonic)conductivity,extending the electrolyte domain boundaries towards reduced atmospheres.This latter property makes the heavilydoped BaSnO_(3)representatives attractive for PCFC applications.Inna A.ZVONAREVA AlexeyМ.MINEEV Natalia A.TARASOVA Xian-Zhu FU Dmitry A.MEDVEDEV 2022Journal of Advanced Ceramics2022,11,7:2
19Effect of polycarboxylate type of super plasticizer on the hydration properties of composite cements显示文摘The work aims to study the effect of polycarboxylate type of super plasticizer on the hydration of composite cements.In this paper we have studied the hydration of 20 wt%fly ash(FA)blended Portland cement in the presence of 0.1 wt%super plasticizer(SP).Water consistency,setting times,non-evaporable water contents,compressive strength,water percolation,and air content measurements were carried out.In addition,Xray diffraction studies were carried out to understand the hydration process.The results indicated the increase in compressive strength of the FA blended Portland cement in the presence of SP and with the increase of the hydration time.Mukesh KUMAR N.P.SINGH Sanjay Kumar SINGH 2011Frontiers of Chemistry in China2011,6,1:2
20Experimental and Numerical Analysis of Restrained Early Age Cracking based on Electrical Resistivity Using Eccentric Sample显示文摘Crack potential and hydration processes of the cement pastes were monitored using an upto-date eccentric steel cracking frame(ESCF), associated with the non-contact electrical resistivity apparatus, independently. The objective of employing the ESCF is to give a new method determining cracks of concrete at early age. The findings indicate that the lowest water-cement ratio paste reveals highest resistivity values, compasses an earlier inflection point and obtained higher stress. The eccentric restrained cracking test exhibited that lower water-cement ratio paste cracked at the earliest time, accordingly confirms cracking tendency is the highest. Tensile strength test and stresses utilizing ABAQUS simulation was performed. The crack initiation ages obtained are consistent with the experimental program results, which indicates that ABAQUS numerical analysis can well be utilized to predict the crack tendency of cement.Maha A Abusogi 魏小胜 2018Journal of Wuhan University of Technology(Materials Science)2018,33,6:2
返回顶部 每页显示:
共7页 首页 上一页 第1页 下一页 末页 /7 跳转

网站首页 | 关于我们 | 联系我们 | 产品服务 | 客服中心 | 广告服务 | 版权声明 | 网站联盟 | 友情链接 | 售卡网点

版权所有© 渝B2-20050021-1 渝公网安备 50019002500403号 违法和不良信息举报中心

互联网出版许可证 新出网证(渝)字10号 全国400电话 - 免长途话费