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Effects of Spherical Light-weight Aggregates Additions on Workability and Mechanical Properties of Al_2O_3-SiO_2 System Castables
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作者 YU Renhong LIU Pengcheng +1 位作者 DONG Gaofeng DONG Hongqin 《China's Refractories》 CAS 2017年第4期1-6,共6页
In order to clarify the effect of spherical light-weight aggregates addition on properties of A12 07 - Si02 system castables, adopting ATO mullite traditional light-weight aggregates and ATO mullite spherical light-we... In order to clarify the effect of spherical light-weight aggregates addition on properties of A12 07 - Si02 system castables, adopting ATO mullite traditional light-weight aggregates and ATO mullite spherical light-weight aggre- gates, bauxite homogenization powder, microsilica , cal- cium aluminate cement as main raw materials, light- weight Al2 03 - SiO2 system castables were prepared by replacing conventional light-weight aggregate with spherical light-weight aggregates. The effects of spheri- cal light-weight aggregates addition on workability, me- chanical properties of castables after heated at different temperatures were researched; the microstructure of the aggregates was analyzed by SEM. The result shows that the introduction of spherical light-weight aggregates can significantly improve the flowability and reduce the water addition of the castables. Water demand of the castable is reduced from 18% with the conventional light-weight aggregates to 14% with spherical light-weight aggre- gates. In addition, light-weight castables prepared by spherical aggregates can keep the same workability with- in a wider range of water addition. Therefore, spherical aggregates are user-friendly. The introduction of spheri- cal light-weight aggregates is favorable to packing densi- ty and mechanical properties of castables, such as cold crushing strength, cold modulus of rupture, hot modulus of rupture at 1 200℃. 展开更多
关键词 spherical light-weight aggregates ability mechanical properties alumina - silica castables work- system
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Effect of Pre-wetted Light-weight Aggregate on Internal RelativeHumidity and Autogenous Shrinkage of Concrete 被引量:3
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作者 叶家军 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2006年第1期134-137,共4页
This research indicates that the gradient of internal relative humidity (IRH) decreases rapidly within 7-day curing age in HPC. The amount of water imported by pre-wetted light-weight aggregate can regulate IRH of ... This research indicates that the gradient of internal relative humidity (IRH) decreases rapidly within 7-day curing age in HPC. The amount of water imported by pre-wetted light-weight aggregate can regulate IRH of concrete. By importing a proper amount of water, the process of the decline of IRH can be delayed and the autogenous shrinkage can be reduced. The relationship among the amount of water imported by pre- wetted lightweight aggregate, IRH and AS was established. The result provides a new method of reducing early AS and enhancing early cracking resistance of HPC. 展开更多
关键词 autogenous shrinkage pre-wetted lightweight aggregate internal relative humidity high performance concrete
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Effect of Aggregate Gradation on the Properties of 3D Printed Recycled Coarse Aggregate Concrete
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作者 DING Yahong TONG Jiaqi +3 位作者 ZHANG Meixiang GUO Shuqi ZHANG Yaqi ZHAO Yu 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS CSCD 2024年第6期1541-1554,共14页
A simplex centroid design method was employed to design the gradation of recycled coarse aggregate.The bulk density was measured while the specific surface area and average excess paste thickness were calculated with ... A simplex centroid design method was employed to design the gradation of recycled coarse aggregate.The bulk density was measured while the specific surface area and average excess paste thickness were calculated with different gradations.The fluidity,dynamic yield stress,static yield stress,printed width,printed inclination,compressive strength and ultrasonic wave velocity of 3D printed recycled aggregate concrete(3DPRAC)were further studied.The experimental results demonstrate that,with the increase of small-sized aggregate(4.75-7 mm)content,the bulk density initially increases and then decreases,and the specific surface area gradually increases.The average excess paste thickness fluctuates with both bulk density and specific surface area.The workability of 3DPRAC is closely related to the average excess paste thickness.With an increase in average paste thickness,there is a gradual decrease in dynamic yield stress,static yield stress and printed inclination,accompanied by an increase in fluidity and printed width.The mechanical performance of 3DPRAC closely correlates with the bulk density.With an increase in the bulk density,there is an increase in the ultrasonic wave velocity,accompanied by a slight increase in the compressive strength and a significant decrease in the anisotropic coefficient.Furthermore,an index for buildability failure of 3DPRAC based on the average excess paste thickness is proposed. 展开更多
关键词 3D printed recycled coarse aggregate concrete aggregate gradation excess paste WORKABILITY mechanical performance
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Underwater Pulse Waveform Recognition Based on Hash Aggregate Discriminant Network
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作者 WANG Fangchen ZHONG Guoqiang WANG Liang 《Journal of Ocean University of China》 SCIE CAS CSCD 2024年第3期654-660,共7页
Underwater pulse waveform recognition is an important method for underwater object detection.Most existing works focus on the application of traditional pattern recognition methods,which ignore the time-and space-vary... Underwater pulse waveform recognition is an important method for underwater object detection.Most existing works focus on the application of traditional pattern recognition methods,which ignore the time-and space-varying characteristics in sound propagation channels and cannot easily extract valuable waveform features.Sound propagation channels in seawater are time-and space-varying convolutional channels.In the extraction of the waveform features of underwater acoustic signals,the effect of high-accuracy underwater acoustic signal recognition is identified by eliminating the influence of time-and space-varying convolutional channels to the greatest extent possible.We propose a hash aggregate discriminative network(HADN),which combines hash learning and deep learning to minimize the time-and space-varying effects on convolutional channels and adaptively learns effective underwater waveform features to achieve high-accuracy underwater pulse waveform recognition.In the extraction of the hash features of acoustic signals,a discrete constraint between clusters within a hash feature class is introduced.This constraint can ensure that the influence of convolutional channels on hash features is minimized.In addition,we design a new loss function called aggregate discriminative loss(AD-loss).The use of AD-loss and softmax-loss can increase the discriminativeness of the learned hash features.Experimental results show that on pool and ocean datasets,which were collected in pools and oceans,respectively,by using acoustic collectors,the proposed HADN performs better than other comparative models in terms of accuracy and mAP. 展开更多
关键词 convolutional channel hash aggregate discriminative network aggregate discriminant loss waveform recognition
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Clinical significance of platelet mononuclear cell aggregates in patients with sepsis and acute respiratory distress syndrome
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作者 Chong-Min Huang Juan-Juan Li Wei-Ke Wei 《World Journal of Clinical Cases》 SCIE 2024年第5期966-972,共7页
BACKGROUND The diagnosis of sepsis combined with acute respiratory distress syndrome(ARDS)has increased owing to the enhanced awareness among medical profes-sionals and the continuous development of modern medical tec... BACKGROUND The diagnosis of sepsis combined with acute respiratory distress syndrome(ARDS)has increased owing to the enhanced awareness among medical profes-sionals and the continuous development of modern medical technologies,while early diagnosis of ARDS still lacks specific biomarkers.One of the main patho-genic mechanisms of sepsis-associated ARDS involves the actions of various pathological injuries and inflammatory factors,such as platelet and white blood cells activation,leading to an increase of surface adhesion molecules.These adhesion molecules further form platelet-white blood cell aggregates,including platelet-mononuclear cell aggregates(PMAs).PMAs has been identified as one of the markers of platelet activation,here we hypothesize that PMAs might play a potential biomarker for the early diagnosis of this complication.METHODS We selected 72 hospitalized patients diagnosed with sepsis as the study population between March 2019 and March 2022.Among them,30 patients with sepsis and ARDS formed the study group,while 42 sepsis patients without ARDS comprised the control group.After diagnosis,venous blood samples were imme-diately collected from all patients.Flow cytometry was employed to analyze the expression of PMAs,platelet neutrophil aggregates(PNAs),and platelet aggregates(PLyAs)in the serum.Additionally,the Acute Physiology and Chronic Health Evaluation(APACHE)II score was calculated for each patient,and receiver operating characteristic curves were generated to assess diagnostic value.RESULTS The study found that the levels of PNAs and PLyAs in the serum of the study group were higher than those in the control group,but the difference was not statistically significant(P>0.05).However,the expression of PMAs in the serum of the study group was significantly upregulated(P<0.05)and positively correlated with the APACHE II score(r=0.671,P<0.05).When using PMAs as a diagnostic indicator,the area under the curve value was 0.957,indicating a high diagnostic value(P<0.05).Furthermore,the optimal cutoff value was 8.418%,with a diagnostic sensitivity of 0.819 and specificity of 0.947.CONCLUSION In summary,the serum levels of PMAs significantly increase in patients with sepsis and ARDS.Therefore,serum PMAs have the potential to become a new biomarker for clinically diagnosing sepsis complicated by ARDS. 展开更多
关键词 SEPSIS Acute respiratory distress syndrome Platelet leukocyte aggregates Platelet mononuclear cell aggregates Biomarker
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The Mechanical and Electrical Properties of the Smart Aggregate Based on the Mixed Cementitious Materials
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作者 WANG Haifeng YAN Handong +2 位作者 XU Yuye MEI Zhen WANG Chen 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS CSCD 2024年第6期1528-1533,共6页
Cement and resin were designed as mixed cementitious materials to study the smart aggregate(SA)of smart concrete.Carbon fiber(CF)and surfactant were taken into consideration to adjust the mechanical and electrical pro... Cement and resin were designed as mixed cementitious materials to study the smart aggregate(SA)of smart concrete.Carbon fiber(CF)and surfactant were taken into consideration to adjust the mechanical and electrical properties of smart aggregate(SA)in this issue.The experimental results indicate that the flexibility and mechanical properties of SA can be improved by using such mixed cementitious materials.It is shows that,although the compressive strength and flexural strength can be enhanced effectively by using resin and CF,the electrical conductivity decreases significantly,which is because the water molecules are difficult to penetrate through the mixture materials so the hydration reaction of cement can not fully carry out.However,the electrical conductivity can be improved by adding the surfactant,and the strength and mechanical electrical properties can be adjusted effectively by the surfactant. 展开更多
关键词 SURFACTANT carbon fiber electrical property mechanical property smart aggregate
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Mechanical Behavior Based on Aggregates Microstructure of Ultra-high Performance Concrete
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作者 丁庆军 ZHOU Changsheng +4 位作者 张高展 GUO Hong LI Yang ZHANG Yongyuan GUO Kaizheng 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS CSCD 2024年第3期673-681,共9页
We developed ultra-high performance concrete(UHPC)incorporating mullite sand and brown corundum sand(BCS),and the quartz sand UHPC was utilized to prepare for comparison.The properties of compressive strength,elastic ... We developed ultra-high performance concrete(UHPC)incorporating mullite sand and brown corundum sand(BCS),and the quartz sand UHPC was utilized to prepare for comparison.The properties of compressive strength,elastic modulus,ultrasonic pulse velocity,flexural strength,and toughness were investigated.Scanning electron microscopy and nanoindentation were also conducted to reveal the underlying mechanisms affecting macroscopic performance.Due to the superior interface bonding properties between mullite sand and matrix,the compressive strength and flexural toughness of UHPC have been significantly improved.Mullite sand and BCS aggregates have higher stiffness than quartz sand,contributing to the excellent elastic modulus exhibited by UHPC.The stiffness and volume of aggregates have a more significant impact on the elastic modulus of UHPC than interface performance,and the latter contributes more to the strength of UHPC.This study will provide a reference for developing UHPC with superior elastic modulus for structural engineering. 展开更多
关键词 ultra-high performance concrete mechanical properties fine aggregates MICROSTRUCTURE NANOINDENTATION
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Hybrid anionic block copolymerization:From organocatalysis-streamlined crossover to internally microphase-separated aggregates
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作者 Lijun Liu Heng Li +3 位作者 Pengfei Zhang Yubo Zhou Junpeng Zhao Guangzhao Zhang 《Aggregate》 EI CAS 2024年第4期226-235,共10页
Polyolefin-b-poly(ethylene oxide)(PEO)represents the most widely investigated amphiphilic block copolymers.So far,one-pot continuous synthesis of such hybrid block copolymers has only been fulfilled by anionic polymeriz... Polyolefin-b-poly(ethylene oxide)(PEO)represents the most widely investigated amphiphilic block copolymers.So far,one-pot continuous synthesis of such hybrid block copolymers has only been fulfilled by anionic polymerization through sequen-tial addition of vinyl monomers and ethylene oxide(EO).It still remains challenging to achieve altogether high block efficiency,high polymerization efficiency,and high molar mass for PEO.Here,we report a one-pot hybrid block copolymerization approach to polyisoprene/polystyrene(PI/PS)-b-PEO,in which PI/PS are formed by sBuLi-initiated anionic vinyl-addition polymerization,then in situ employed as macroinitiators for the anionic ring-opening polymerization(ROP)of EO aided by an organic Lewis pair.The cooperative(dual-ion-complexing)catalytic effect of organobase and triethylborane is proven,for thefirst time,effective for lithium alkoxide initiator system,allowing to achieve at room temperature high ROP activity(complete EO conversion and PEO of 3–64 kg/mol reached in 1–6 h),narrow molar mass distribution,controlled block lengths and composition.Density functional the-ory calculation shows that phosphazene bases are particularly effective,compared with N-heterocyclic bases,for complexing with Li+and enhancing the nucleophilic-ity of oxyanion.The rate of ROP is also affected by Li+-induced aggregation of the chain-end ion pairs,which though can be offset by adequate catalyst loadings.The versatility of this approach is further demonstrated in the one-pot synthesis of tri-/tetrablock ter-/quaterpolymers constituted by PI,PS,PEO,and poly(propylene oxide).Of great interest,PS-b-PI-b-PEO triblock terpolymer with a specific com-position is found to form internally microphase-separated micellar aggregates when dispersed in water. 展开更多
关键词 aggregation anionic polymerization block copolymer ORGANOCATALYSIS ring-opening polymerization
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Straw mulching alters the composition and loss of dissolved organic matter in farmland surface runoff by inhibiting the fragmentation of soil small macroaggregates
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作者 Shanshan Cai Lei Sun +7 位作者 Wei Wang Yan Li Jianli Ding Liang Jin Yumei Li Jiuming Zhang Jingkuan Wang Dan Wei 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2024年第5期1703-1717,共15页
Straw mulching is a widespread practice for reducing the soil carbon loss caused by erosion.However,the effects of straw mulching on dissolved organic matter(DOM)runoff loss from black soil are not well studied.How st... Straw mulching is a widespread practice for reducing the soil carbon loss caused by erosion.However,the effects of straw mulching on dissolved organic matter(DOM)runoff loss from black soil are not well studied.How straw mulching affects the composition and loss of runoff DOM by changing soil aggregates remains largely unclear.Here,a straw mulching treatment was compared to a no mulching treatment(as a control)on sloping farmland with black soil erosion in Northeast China.We divided the soil into large macroaggregates(>2 mm),small macroaggregates(0.25-2 mm),and microaggregates(<0.25 mm).After five rain events,the effects of straw mulching on the concentration(characterized by dissolved organic carbon(DoC)and composition(analyzed by fluorescence spectroscopy)of runoff and soil aggregate DOM were studied.The results showed that straw mulching reduced the runoff amount by 54.7%.Therefore,although straw mulching increased the average DOc concentration in runoff,it reduced the total runoff DOM loss by 48.3%.The composition of runoff DOM is similar to that of soil,as both contain humic-like acid and protein-like components.With straw mulching treatment,the protein-like components in small macroaggregates accumulated and the protein-like components in runoff declined with rain events.Fluorescence spectroscopy technology may help in understanding the hydrological paths of rain events by capturing the dynamic changes of runoff and soil DOM characteristics.A variation partitioning analysis(VPA)indicated that the DOM concentration and composition of microaggregates explained 68.2%of the change in runoff DOM from no mulching plots,while the change in runoff DOM from straw mulching plots was dominated by small macroaggregates at a rate of 55.1%.Taken together,our results demonstrated that straw mulching reduces the fragmentation of small macroaggregates and the loss of microaggregates,thus effecting DOM compositions in soil and reducing the DOM loss in runoff.These results provide a theoretical basis for reducing carbon loss in sloping farmland. 展开更多
关键词 dissolved organic matter black soil surface runoff aggregateS fluorescence spectrum
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Smart multi-functional aggregates reoxygenate tumor microenvironment through a two-pronged strategy to revitalize cancer immunotherapy
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作者 Yan Zhang Luoqi Liang +10 位作者 Hexiang Li Yuqing Cao Du Meng Xinru Li Meichen Wang Jingyuan Wang Yao Yao Shaoqiang Zhang Chao Chen Peng Hou Qi Yang 《Aggregate》 EI CAS 2024年第4期256-268,共13页
PD-1/PD-L1 inhibitors have emerged as standard treatments for advanced solid tumors;however,challenges such as a low overall response rate and systemic side effects impede their implementation.Hypoxia drives the remod... PD-1/PD-L1 inhibitors have emerged as standard treatments for advanced solid tumors;however,challenges such as a low overall response rate and systemic side effects impede their implementation.Hypoxia drives the remodeling of the tumor microenvironment,which is a leading reason for the failure of immunotherapies.Despite some reported strategies to alleviate hypoxia,their individual limitations constrain further improvements.Herein,a novel two-pronged strategy is pre-sented to efficiently address hypoxia by simultaneously adopting atovaquone(ATO,inhibiting oxygen consumption)and oxyhemoglobin(HbO2,directly supplement-ing oxygen)within a multifunctional aggregate termed NPs-aPD-1/HbO2/ATO.In addition to eliminating hypoxia with these two components,this smart aggre-gate also includes albumin and an ROS-responsive cross-linker as a controlled release scaffold,along with PD-1 antibody(aPD-1)for immunotherapy.Intriguingly,NPs-aPD-1/HbO2/ATO demonstrates exceptional tumor targeting in vivo,exhibit-ing≈4.2 fold higher accumulation in tumors than in the liver.Consequently,this aggregate not only effectively mitigates hypoxia and significantly assists aPD-1 immunotherapy but also simultaneously resolves the targeting and systemic toxicity issues associated with individual administration of each component.This study pro-poses substantial implications for drug-targeted delivery,addressing tumor hypoxia and advancing immunotherapy,providing valuable insights for advancing cancer treatment strategies. 展开更多
关键词 HYPOXIA IMMUNOTHERAPY ROS-responsive smart aggregate synergistic therapy tumor targeting
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Unveiling the exceptional evolution of solute aggregates: From micro to trace, solution to interface
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作者 Weili Wang Hao Ma +4 位作者 Qiuting Huang Siheng Luo Bin Ren Zhongqun Tian Guokun Liu 《Aggregate》 EI CAS 2024年第5期394-401,共8页
Existential state of solutes substantially affects the efficiency and direction of vari-ous chemical and biological processes,about which current consensus is still limited at macro and micro levels.At the trace level,... Existential state of solutes substantially affects the efficiency and direction of vari-ous chemical and biological processes,about which current consensus is still limited at macro and micro levels.At the trace level,solutes assume a pivotal role across a spectrum of criticalfields.However,their existential states,especially at inter-faces,remain largely elusive.Herein,an exceptional evolution of solute molecules is unveiled from micro to trace,solution to interface,with the aid of surface-enhanced Raman spectroscopy,extinction,DLS and theoretical simulations.Given predom-inant existence of monomers within the solution,these aggregates dominate the interfacial behavior of solute molecules.Moreover,a universal,aggregate-controlled mechanism is demonstrated that aggregates triggered by cosolvent,which can dra-matically promote efficiency of catalytic reactions.The results provide novel insights into the interaction mechanisms between reactants and catalysts,potentially offering fresh perspectives for the manipulation of multiphase catalysis and related biological processes. 展开更多
关键词 aggregate molecular dynamics surface-enhanced Raman spectroscopy
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Polycrystalline ZSM-5 Aggregates Induced by Seed and Catalytic Performance in Methanol to Hydrocarbon
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作者 WANG Xuchang JIAO Chuyu +5 位作者 JI Zhuo JIAO Qirui QIN Bo DU Yanze ZHENG Jiajun LI Ruifeng 《无机材料学报》 SCIE EI CAS CSCD 北大核心 2024年第8期945-954,I0010-I0013,共14页
Synthesis of ZSM-5 zeolite typically utilizes small molecule polyamines or quaternary ammonium salts as organic structure guiding agent(OSDA).By contrast,the OSDA-free hydrothermal synthesis system eliminates the use ... Synthesis of ZSM-5 zeolite typically utilizes small molecule polyamines or quaternary ammonium salts as organic structure guiding agent(OSDA).By contrast,the OSDA-free hydrothermal synthesis system eliminates the use of organic templates and the subsequent calcination procedure.This not only reduces the cost of synthesis,but also prevents environmental pollution from the combustion of organic templates,representing an eco-friendly approach.Despite this,literature suggests that even so-called template-free synthesis systems often involve trace amount of organic substances like alcohol.In the present work,a calcined commercial ZSM-5 zeolite was served as seed,with sodium aluminate as aluminum source and silica sol as silicon source,ensuring an entirely template-free synthesis system.Polycrystalline ZSM-5 aggregates consisted of rod-like nanocrystals were successfully prepared in the completely OSDA-free system.Effects of the Si/Al ratio in ZSM-5 seed,dosage and crystallization conditions such as crystallization temperature and crystallization time on ZSM-5 synthesis were investigated.The results show that a highly crystallinity ZSM-5 aggregate consisting of primary nano-sized crystals less than 100 nm is produced from a gel precursor with 5.6%(in mass)seed after hydrothermal treatment for 48 h.Furthermore,the Si/Al ratio in ZSM-5 seed has little effect on the topological structure and pore structure of the synthesized samples.However,the seeds with a low Si/Al ratio facilitate faster crystallization of zeolite and enhance the acidity,especially the strong acid centers,of the catalyst.The catalytic performance of the synthesized polycrystalline ZSM-5 was evaluated during dehydration of methanol and compared with a commercial reference ZSM-5r.The results exhibit that as compared with the reference catalyst,the fabricated sample has a longer catalytic lifetime(16 h vs 8 h)attributed to its hierarchical pores derived from the loosely packed primary nanoparticles.Additionally,the prepared polycrystalline catalyst also exhibits a higher aromatics selectivity(28.1%-29.8%vs 26.5%). 展开更多
关键词 ZSM-5 polycrystalline aggregate crystal seed structure guiding agent
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Effect of Modification Treatment on Chloride Ions Permeability and Microstructure of Recycled Brick-mixed Aggregate Concrete
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作者 何子明 申爱琴 +2 位作者 WANG Xiaobin WU Jinhua WANG Lusheng 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS CSCD 2024年第3期728-737,共10页
The modification methods of pozzolan slurry combined with sodium silicate and silicon-based additive were respectively adopted to treat recycled coarse brick-mixed aggregate(RCBA)in this study.The compressive strength... The modification methods of pozzolan slurry combined with sodium silicate and silicon-based additive were respectively adopted to treat recycled coarse brick-mixed aggregate(RCBA)in this study.The compressive strength and chloride permeability resistance of recycled aggregate concrete(RAC)before and after modification treatment were tested,and the microstructure of RAC was analyzed by mercury intrusion porosimetry(MIP)and scanning electron microscopy(SEM).The results show that the physical properties of RCBA strengthened by modification treatment are improved,and the compressive strength and chloride permeability resistance of treated RAC are also significantly improved.The modification treatment optimizes the pore size distribution of RAC,which increases the number of gel pores and transition pores,and decreases the number of capillary pores and macro pores.The surface fractal dimension shows a significant correlation with chloride diffusion coefficient,indicating that the variation of chloride permeability of treated RAC is consistent with the microstructure evolution. 展开更多
关键词 recycled aggregate concrete modification treatment compressive strength chloride permeability resistance MICROSTRUCTURE
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High-efficiency Carbonation Modification Methods of Recycled Coarse Aggregates
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作者 张美香 YANG Xiaolin +3 位作者 丁亚红 SUN Bo ZHANG Xianggang LÜXiuwen 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS CSCD 2024年第2期386-398,共13页
To solve the problem of only surface carbonation and realize high-efficiency carbonation of recycled coarse aggregate,the method of carbonated recycled coarse aggregate with nano materials pre-soaking was first put fo... To solve the problem of only surface carbonation and realize high-efficiency carbonation of recycled coarse aggregate,the method of carbonated recycled coarse aggregate with nano materials pre-soaking was first put forward.The carbonation effect of modified recycled coarse aggregate with three different carbonation methods was evaluated,and water absorption,apparent density and crush index of modified recycled coarse aggregate were measured.Combined with XRD,SEM,and MIP microscopic analysis,the high-efficiency carbonation strengthening mechanism of modified recycled coarse aggregate was revealed.The experimental results show that,compared with the non-carbonated recycled coarse aggregate,the physical and microscopic properties of carbonated recycled coarse aggregate are improved.The method of carbonation with nano-SiO_(2) pre-soaking can realize the high-efficiency carbonation of recycled coarse aggregate,for modified recycled coarse aggregate with the method,water absorption is reduced by 23.03%,porosity is reduced by 44.06%,and the average pore diameter is 21.82 nm.The high-efficiency carbonation strengthening mechanism show that the pre-socked nano-SiO_(2) is bound to the hydration product Ca(OH)_(2) of the old mortar with nano-scale C-S-H,which can improve the CO_(2) absorption rate,accelerate the carbonation reaction,generate more stable CaCO_(3) and nano-scale silica gel,and bond to the dense three-dimensional network structure to realize the bidirectional enhancement of nano-materials and pressurized carbonation.It is concluded that the method of carbonation with nano-SiO_(2) pre-soaking is a novel high-efficiency carbonation modification of recycled coarse aggregate. 展开更多
关键词 recycled coarse aggregate pressurized carbonation high-efficiency carbonation NANO-SIO2 strengthening mechanism
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Prediction Model-based Multi-objective Optimization for Mix-ratio Design of Recycled Aggregate Concrete
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作者 CHEN Tao WU Di YAO Xiaojun 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS CSCD 2024年第6期1507-1517,共11页
The prediction model for mechanical properties of RAC was established through the Bayesian optimization-based Gaussian process regression(BO-GPR)method,where the input variables in BO-GPR model depend on the mix ratio... The prediction model for mechanical properties of RAC was established through the Bayesian optimization-based Gaussian process regression(BO-GPR)method,where the input variables in BO-GPR model depend on the mix ratio of concrete.Then the compressive strength prediction model,the material cost,and environmental factors were simultaneously considered as objectives,while a multi-objective gray wolf optimization algorithm was developed for finding the optimal mix ratio.A total of 730 RAC datasets were used for training and testing the predication model,while the optimal design method for mix ratio was verified through RAC experiments.The experimental results show that the predicted,testing,and expected compressive strengths are nearly consistent,illustrating the effectiveness of the proposed method. 展开更多
关键词 recycled coarse aggregate mix ratio multi-objective optimization prediction model compressive strength
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"Three-in-One" Ecological Development and Efficient Utilization Model of Aggregates
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作者 Yunkai FAN Shichang XU +2 位作者 Qiangjie HUANG Yiyuan LU Ziyi WEI 《Asian Agricultural Research》 2024年第6期13-18,共6页
Green mining and the formation of an effective and efficient development model have become key issues that aggregates enterprises around the world need to solve urgently.On the basis of analyzing the development statu... Green mining and the formation of an effective and efficient development model have become key issues that aggregates enterprises around the world need to solve urgently.On the basis of analyzing the development status of aggregates industry in Xiluodu area,the paper studied the main problems faced in the construction of green aggregates mines at present,and proposed a"three-in-one"ecological,intelligent and efficient green mine construction model for"ecological development","green logistics"and"solid waste recycling"of aggregates.The study has certain theoretical value and practical significance for the construction of green aggregates mine in Xiluodu area. 展开更多
关键词 aggregateS ECOLOGICAL development EFFICIENT UTILIZATION
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Repair of Second-Generation Recycled Fine Aggregate of Waste Concrete from Freeze-Thaw Environment by Carbonation Treatment
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作者 Jie Huang Rongbin Jiang +1 位作者 Xiaobo Sun Yingyong Shuai 《Journal of Renewable Materials》 EI CAS 2024年第1期187-201,共15页
The reuse of waste recycled concrete from harsh environments has become a research hotspot in the field of construction.This study investigated the repair effect of carbonation treatment on second-generation recycled ... The reuse of waste recycled concrete from harsh environments has become a research hotspot in the field of construction.This study investigated the repair effect of carbonation treatment on second-generation recycled fine aggregate(SRFA)obtained from recycled fine aggregate concrete(RFAC)subjected to freeze-thaw(FT)cycles.Before and after carbonation,the properties of SRFA were evaluated.Carbonated second-generation recycled fine aggregate(CSRFA)at five substitution rates(0%,25%,50%,75%,100%)to replace SRFA was used to prepare carbonated second-generation recycled fine aggregate concrete(CSRFAC).The water absorption,porosity and mechanical properties of CSRFAC were tested,and its frost-resisting durability was evaluated.The results showed after carbonation treatment,the physical properties of SRFA was improved and met the requirements of II aggregate.The micro-hardness of the interfacial transition zone and attached mortar in CSRFA was 50.5%and 31.2%higher than that in SRFA,respectively.With the increase of CSRFA replacement rate,the water absorption and porosity of CSRFAC gradually decreased,and the mechanical properties and frost resistance of CSRFAC were gradually improved.Carbonation treatment effectively repairs the damage of SRFA caused by FT cycles and improves its application potential. 展开更多
关键词 Carbonation treatment REPAIR freeze-thaw cycles second-generation recycled fine aggregate
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Impact of wetting-drying cycles and acidic conditions on the soil aggregate stability of yellow‒brown soil
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作者 XIA Zhenyao NI Yuanzhen +2 位作者 LIU Deyu WANG Di XIAO Hai 《Journal of Mountain Science》 SCIE CSCD 2024年第6期2075-2090,共16页
Soil aggregate is the basic structural unit of soil,which is the foundation for supporting ecosystem functions,while its composition and stability is significantly affected by the external environment.This study was c... Soil aggregate is the basic structural unit of soil,which is the foundation for supporting ecosystem functions,while its composition and stability is significantly affected by the external environment.This study was conducted to explore the effect of external environment(wetting-drying cycles and acidic conditions)on the soil aggregate distribution and stability and identify the key soil physicochemical factors that affect the soil aggregate stability.The yellow‒brown soil from the Three Gorges Reservoir area(TGRA)was used,and 8 wetting-drying conditions(0,1,2,3,4,5,10 and 15 cycles)were simulated under 4 acidic conditions(pH=3,4,5 and 7).The particle size distribution and soil aggregate stability were determined by wet sieving method,the contribution of environmental factors(acid condition,wetting-drying cycle and their combined action)to the soil aggregate stability was clarified and the key soil physicochemical factors that affect the soil aggregate stability under wetting-drying cycles and acidic conditions were determined by using the Pearson’s correlation analysis,Partial least squares path modeling(PLS‒PM)and multiple linear regression analysis.The results indicate that wetting-drying cycles and acidic conditions have significant effects on the stability of soil aggregates,the soil aggregate stability gradually decreases with increasing number of wetting-drying cycles and it obviously decreases with the increase of acidity.Moreover,the combination of wetting-drying cycles and acidic conditions aggravate the reduction in the soil aggregate stability.The wetting-drying cycles,acidic conditions and their combined effect imposes significant impact on the soil aggregate stability,and the wetting-drying cycles exert the greatest influence.The soil aggregate stability is significantly correlated with the pH,Ca^(2+),Mg^(2+),maximum disintegration index(MDI)and soil bulk density(SBD).The PLS‒PM and multiple linear regression analysis further reveal that the soil aggregate stability is primarily influenced by SBD,Ca^(2+),and MDI.These results offer a scientific basis for understanding the soil aggregate breakdown mechanism and are helpful for clarifying the coupled effect of wetting-drying cycles and acid rain on terrestrial ecosystems in the TGRA. 展开更多
关键词 Yellow‒brown soil Wetting-drying cycles Acidic conditions Soil aggregate stability Soil disintegration
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Simulation of Fracture Process of Lightweight Aggregate Concrete Based on Digital Image Processing Technology
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作者 Safwan Al-sayed Xi Wang Yijiang Peng 《Computers, Materials & Continua》 SCIE EI 2024年第6期4169-4195,共27页
The mechanical properties and failure mechanism of lightweight aggregate concrete(LWAC)is a hot topic in the engineering field,and the relationship between its microstructure and macroscopic mechanical properties is a... The mechanical properties and failure mechanism of lightweight aggregate concrete(LWAC)is a hot topic in the engineering field,and the relationship between its microstructure and macroscopic mechanical properties is also a frontier research topic in the academic field.In this study,the image processing technology is used to establish a micro-structure model of lightweight aggregate concrete.Through the information extraction and processing of the section image of actual light aggregate concrete specimens,the mesostructural model of light aggregate concrete with real aggregate characteristics is established.The numerical simulation of uniaxial tensile test,uniaxial compression test and three-point bending test of lightweight aggregate concrete are carried out using a new finite element method-the base force element method respectively.Firstly,the image processing technology is used to produce beam specimens,uniaxial compression specimens and uniaxial tensile specimens of light aggregate concrete,which can better simulate the aggregate shape and random distribution of real light aggregate concrete.Secondly,the three-point bending test is numerically simulated.Thirdly,the uniaxial compression specimen generated by image processing technology is numerically simulated.Fourth,the uniaxial tensile specimen generated by image processing technology is numerically simulated.The mechanical behavior and damage mode of the specimen during loading were analyzed.The results of numerical simulation are compared and analyzed with those of relevant experiments.The feasibility and correctness of the micromodel established in this study for analyzing the micromechanics of lightweight aggregate concrete materials are verified.Image processing technology has a broad application prospect in the field of concrete mesoscopic damage analysis. 展开更多
关键词 Digital image processing lightweight aggregate concrete mesoscopic model numerical simulation fracture analysis bending beams
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Lysine aggregates-based nanostructured antimicrobial peptides for cariogenic biofilm microenvironment-activated caries treatment
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作者 Siyuan Li Feng Wang +6 位作者 Yang Chen Wanrui Shi Dashuai Liu Mingyang Lv Bin Zhao Yi Liu Hao Zhang 《Aggregate》 EI CAS 2024年第5期307-319,共13页
Dental caries is one of the most prevalent and costly biofilm-induced oral diseases that causes the deterioration of the mineralized tooth tissue.Traditional antimicro-bial agents like antibiotics and antimicrobial pep... Dental caries is one of the most prevalent and costly biofilm-induced oral diseases that causes the deterioration of the mineralized tooth tissue.Traditional antimicro-bial agents like antibiotics and antimicrobial peptides(AMPs)struggle to effectively eradicate bacteria in biofilms without eliciting resistance.Herein,we demonstrate the construction of FeOOH@Fe-Lysine@Au nanostructured AMPs(nAMPs)dis-tinguished by their AMP-like antibacterial activity and self-producing reactive oxygen species(ROS)capacity for caries treatment.On the one hand,FeOOH@Fe-Lysine@Au nAMPs can catalyze glucose oxidation to generate ROS within the cariogenic biofilm microenvironment,resulting in the disintegration of the extra-cellular polymeric substance matrix and the exposure of bacteria.On the other hand,FeOOH@Fe-Lysine@Au nAMPs can attach to bacterial surfaces via electrostatic attractions,proceeding to damage membranes,disrupt metabolic pathways,and inhibit protein synthesis through the aggregated lysine and the generated ROS.Based on this antibacterial mechanism,FeOOH@Fe-Lysine@Au nAMPs can effectively eradicate Streptococcus mutans and its associated biofilm,significantly impeding the progression of dental caries.Given the straightforward and cost-efficient prepa-ration of FeOOH@Fe-Lysine@Au nAMPs compared to AMPs that require specific sequences,and their minimal adverse impacts on gingival/palatal tissues,major organs,and oral/gut microbiomes,our research may promote the development of novel therapeutic agents in dental health maintenance. 展开更多
关键词 antimicrobial peptides biofilm catalytic cascade reactions dental caries lysine aggregates
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