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Frontiers of Structural and Civil Engineering 2024年第1期18卷 80-88页

作者： wei jiang Wenqian LI xi CHEN School of Materials science and Engineering Tongji UniversityShanghai 200092China School of Civil Engineering Tongji UniversityShanghai 200092China

The first exothermic peak of cement-based material occurs a few minutes after mixing,and the properties of three dimensional(3D)printed concrete,such as setting time,are very sensitive to *** this background,based on the classical Park cement exothermic model of hydration,we propose and construct a numerical model of the first exothermic peak,taking into account the proportions of C_(3)S,C_(3)A and quicklime in *** calculated parameters are calibrated by means of relevant published exothermic test *** is found that this developed model offers a good simulation of the first exothermic peak of hydration for C_(3)S and C_(3)A proportions from 0 to 100% of cement clinker and reflects the effect of quicklime content at 8%-10%.The unique value of this research is provision of an important computational tool for applications that are sensitive to the first exothermic peak of hydration,such as 3D printing.

关键词： 3D printed cement-based materials cement hydration the first exothermic peak liquid quick-setting agent numerical model

Colloid-facilitated release of polybrominated diphenyl ethers at an e-waste recycling site: evidence from undisturbed soil core leaching experiments

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Frontiers of Environmental science & Engineering 2024年第2期18卷 91-101页

作者： Zebin Huo Mengjun xi Lianrui Xu Chuanjia jiang wei Chen college of Environmental science and Engineering Ministry of Education Key Laboratory of Pollution Processes and Environmental CriteriaTianjin Key Laboratory of Environmental Remediation and Pollution ControlNankai UniversityTianjin 300350China

Polybrominated diphenyl ethers (PBDEs), a class of persistent organic pollutants, have been frequently detected in soil at e-waste recycling sites. However, the key factors controlling the transport of PBDEs from surface soil to the vadose zone and groundwater are unclear. Here, colloid-enhanced leaching of PBDEs from undisturbed soil cores collected at an e-waste recycling site in Tianjin, china, is reported. Spatially heterogeneous release of colloids and PBDEs was observed in all the tested soil cores under chemical and hydrodynamic perturbations, indicating the presence of preferential flow paths. Colloid concentration in the effluent significantly increased as ionic strength decreased (from 10 to 0.01 mmol/L), probably due to the stronger electrostatic repulsion between colloidal particles and the soil matrix at lower ionic strength. In contrast, colloid mobilization was not significantly affected by the changes in pH of the influent (from 4.0 to 10.0) and flow rate (from a Darcy velocity of 1.5 to 6.0 cm/h). The concentrations of 2,2′,3,3′,4,4′,5,5′,6,6′-decabromodiphenyl ether (BDE-209), the predominant PBDE congener at the site, detected in the leachate (ranging from 1.09 to 3.43 ng/L) were much lower than previously reported results from packed column leaching tests, and were positively correlated with colloid concentrations. This indicates that remobilization of colloids at e-waste recycling sites can promote the leaching and downward migration of PBDEs from surface soil. The findings highlight the potential risk of surface soil PBDE contamination to groundwater quality and call for further understanding of colloid-facilitated transport for predicting the fate of PBDEs at e-waste recycling sites.

关键词： Polybrominated diphenyl ether Colloid-facilitated transport E-waste recycling site Undisturbed soil core Groundwater quality

Effect of solution treatment on the microstructure,phase transformation behavior and functional properties of NiTiNb ternary shape memory alloys fabricated via laser powder bed fusion in-situ alloying

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International Journal of Extreme Manufacturing 2024年第4期6卷 202-223页

作者： Rui xi Hao jiang Guichuan Li Zhihui Zhang Huiliang wei Guoqun Zhao Jan Van Humbeeck xiebin Wang Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials(Ministry of Education) Shandong UniversityJingshi Road 17923Jinan 250061People's Republic of China Department of Materials Engineering University of Leuven(KU Leuven)Kasteelpark Arenberg 44 bus 2450Heverlee B3001Belgium Key Laboratory of Bionic Engineering(Ministry of Education) Jilin UniversityRenmin Street 5988Changchun 130025People's Republic of China School of Mechanical Engineering Nanjing University of Science and TechnologyXiaolingwei Street 200Nanjing 210094People's Republic of China

Post-heat treatment is commonly employed to improve the microstructural homogeneity and enhance the mechanical performances of the additively manufactured metallic *** this work,a ternary(NiTi)91Nb9(at.%)shape memory alloy was produced by laser powder bed fusion(L-PBF)using pre-alloyed NiTi and elemental Nb *** effect of solution treatment on the microstructure,phase transformation behavior and mechanical/functional performances was *** in-situ alloyed(NiTi)91Nb9 alloy exhibits a submicron cellular-dendritic structure surrounding the supersaturated B2-NiTi *** high-temperature(1273 K)solution treatment,Nb-rich precipitates were precipitated from the supersaturated *** fragmentation and spheroidization of the NiTi/Nb eutectics occurred during solution treatment,leading to a morphological transition from mesh-like into rod-like and *** of theβ-Nb phases occurred with increasing holding *** martensite transformation temperature increases after solution treatment,mainly attributed to:(i)reduced lattice distortion due to the Nb expulsion from the supersaturated B2-NiTi,and(ii)the Ti expulsion from theβ-Nb phases that lowers the ratio Ni/Ti in the B2-NiTi matrix,which resulted from the microstructure changes from non-equilibrium to equilibrium *** thermal hysteresis of the solutionized alloys is around 145 K after 20%pre-deformation,which is comparable to the conventional NiTiNb alloys.A short-term solution treatment(*** 1273 K for 30 min)enhances the ductility and strength of the as-printed specimen,with the increase of fracture stress from(613±19)MPa to(781±20)MPa and the increase of fracture strain from(7.6±0.1)%to(9.5±0.4)%.Both the as-printed and solutionized samples exhibit good tensile shape memory effects with recovery rates>90%.This work suggests that post-process heat treatment is essential to optimize the microstructure and improve the mechanical performances of the L-PBF in-situ allo

关键词： shape memory alloy NiTiNb laser powder bed fusion in-situ alloying heat treatment

Stable carbon isotope composition and intrinsic water use efficiency in plants along an altitudinal gradient on the eastern slope of Yulong Snow Mountain, china

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Ecological Processes 2024年第2期13卷 218-230页

作者： Feng jiang Tao Pu Zi-Jing Xue Yan-wei Ma xiao-Yi Shi Fu-xi Shi college of Geography and Environmental sciences Zhejiang Normal University Yulong Snow Mountain Glacier and Environment Observation and Research Station/State Key Laboratory of Cryospheric sciences Northwest Institute of Eco-Environment and ResourcesChinese Academy of Sciences Key Laboratory of National Forestry and Grassland Administration on Forest Ecosystem Protection and Restoration of Poyang Lake Watershed College of Forestry Jiangxi Agricultural University

Background Stable carbon isotope composition(δ13Cp) can be used to estimate the changes in intrinsic water use efficiency（iWUE） in plants,which helps us to better understand plants' response strategies to climate *** study focused on the variations in δ13Cpand iWUE for the different life-form plants（i.e.,herbs,shrubs,and trees）along an altitudinal gradient（3300,3600,3900,4100,4300,and 4500 m） on the eastern slope of Yulong Snow Mountain,southeastern margin of the Qinghai-Tibet *** response mechanisms of δ13Cpand iWUE for different life-form plants to altitude were thoroughly analyzed in this mountain *** The δ13Cpvalues of plants on the eastern slopes of Yulong Snow Mountain ranged from-30.4‰to-26.55‰,with a mean of-28.02‰,indicating a dominance of *** δ13Cpand iWUE values varied among different life-form plants in the order of herbs> shrubs> trees,particularly in 3600,3900,and 4300 ***δ13Cpand iWUE values for herbs and shrubs increased with altitude and were mainly controlled by air *** two parameters for trees exhibited a trend of initial decrease followed by an increase with *** 3900 m,the δ13Cpand iWUE values decreased with altitude,influenced by soil ***,above 3900 m,the two parameters increased with altitude,mainly regulated by air *** addition,iWUE was positively correlated with leaf P content but negatively correlated with leaf N:P ratio,especially for herbs and trees,suggesting that P plays a key role in modulating iWUE in this *** The diffe rentiated responses of water availability for different life-form plants to a higher altitudinal gradient are regulated by air temperature,soil moisture,and leaf P content in the Yulong Snow *** results provide valuable insights into understanding the wate r-carbon relationships in high-altitude ecosystems.

关键词： Stable carbon isotope Water use efficiency Altitude Life form Yulong Snow Mountain

A Deep Mantle Source for the Late Neoarchean Metamorphosed Basalts in Eastern Hebei,North china Craton:Insights from Whole-Rock Geochemistry and Sm-Nd Isotopes,and Zircon U-Pb-Hf Isotopes

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Journal of Earth science 2024年第1期35卷 29-40页

作者： Zhuang Li Chunjing wei Chuan Yang xi Zhang college of Geosciences China University of PetroleumBeijing 102249China MOE Key Laboratory of Orogenic Belts and Crustal Evolution School of Earth and Space SciencesPeking UniversityBeijing 100871China china Transport Telecommunications and Information Center Beijing 100011China

The basalts within the greenstone belt worldwide serve as an ideal target to decipher the nature of Archean mantle sources and further to extend the understanding of the early stages of Earth's *** provide important insights into the issues,we carried out a detailed investigation of whole-rock geochemistry and Sm-Nd isotopes,and zircon U-Pb-Hf isotopes for the Late Neoarchean metamorphosed basalts in eastern Hebei,North china Craton.U-Pb isotopic dating using the LA-ICPMS on zircons reveals that the basalts in eastern Hebei erupted at ca.2.48-2.51 Ga and subsequently experienced multiple regional metamorphic events at 2477 and 1798 Ma,*** metamorphosed basalts are featured by low SiO_(2),MgO,K_(2)O+Na_(2)O,and high Fe O contents,endowed with the subalkaline and high-Fe tholeiitic *** radiogenic initial Nd and Hf isotope values and correlations among V,Ni and Cr contents strongly imply that the basalts experienced significant clinopyroxene and olivine fractionation and minor crustal contamination during magma *** are also characterized by the relatively low total REE contents and exhibit significant depletions to moderate enrichments in the LREE contents,indicating the derivation from a deep mantle source in an Archean proto-mantle plume setting.

关键词： zircon U-Pb-Hf isotopes geochemistry Late Neoarchean basaltic magmatism North china Craton Archean proto-mantle plume

Antibacterial properties of cerium oxide nanoparticles:Recent progresses and future challenges

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Particuology 2024年第10期93卷 264-283页

作者： Heishu Zheng Jiajing Tang Yanhua wei xi Deng Yingjuan Zhang xiangyu Ma Xudong jiang Zhi Ping Xu Hongbing Liao college&Hospital of Stomatology Guangxi Medical UniversityNanning530021China Guangxi Key Laboratory of Oral and Maxillofacial Rehabilitation and Reconstruction Guangxi Medical UniversityNanning530021China The First Affiliated Hospital of Guangxi Medical university Nanning530021China School of Medicine Guangxi University of Science and TechnologyLiuzhou545005China Institute of Biomedical Health technology and Engineering and Institute of Systems and Physical Biology Shenzhen Bay LaboratoryShenzhen518107China Australian Institute for Bioengineering and Nanotechnology(Bld 75) The University of QueenslandSt LuciaQueensland 4074Australia

Use of cerium oxide nanoparticles(CeO_(2) NPs)to optimize management of resistant microorganisms has received increasing attention due to non-specific activity of inorganic antibacterial *** the mechanism of action is essential to elucidating the antibacterial activity of CeO_(2) NPs against ***,this review aims to summarize the antibacterial mechanisms of CeO_(2) NPs and correlate the structural and physicochemical properties of CeO_(2) NPs to their antibacterial *** further summarize the strategies for the improvement of the antibacterial performance of CeO_(2) NPs and provide our opinions for future challenges as a conclusion.

关键词： Nanoparticles Cerium oxide Antibacterial activity Nanozyme Fenton reaction

Enhancing electrochemical capacity and interfacial stability of lithium-ion batteries through side reaction modulation with ultrathin carbon nanotube film and optimized lithium cobalt oxide particle size

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Nano Research 2024年第8期17卷 7230-7241页

作者： wei xi xiaogang xia Jiacheng Zhu Dehua Yang Sishen xie Beijing National Laboratory for Condensed Matter Physics and Institute of Physics Chinese Academy of SciencesBeijing 100190China School of Physical sciences University of Chinese Academy of SciencesBeijing 100049China Advanced Passivation technology Lab College of Physics Science and TechnologyHebei UniversityBaoding 071002China

Lithium cobalt oxide(LCO),the first commercialized cathode active material for lithium-ion batteries,is known for high voltage and ***,its application has been limited by relatively low capacity and stability at high *** particle size is considered one of the most straightforward and effective strategies to enhance ion transfer,thus increasing the rate ***,side reactions are simultaneously enhanced as the specific surface area ***,we investigate the impact of LCO particles with varying size distributions and optimize the particle *** modulate the side reactions associated with particle size reduction,an ultrathin carbon nanotube film(UCNF)is introduced to coat the cathode *** this simple process and optimized particle size,the rate performance improves significantly,normal commercial LCO achieves 118 mA·h·g^(−1)at 3.0–4.3 V and 20 C(0.72 mA·h·cm^(−2)),corresponding to power density of 8732 W·kg^(−1).This method is applied to high voltage as well,152 mA·h·g^(−1)at 3.0–4.6 V and 20 C(0.99 mA·h·cm^(−2))was achieved with high-voltage LCO(HVLCO),corresponding to power density of 11,552 W·kg^(−1).The cycling stability is also enhanced,with the capacity retention maintaining more than 96%after 100 cycles at 0.1 *** the first time,UCNF is demonstrated to suppress the excessive decomposition of the electrolytes and solvents by blocking electron injection/extraction between LCO and electrolyte *** findings provide a simple method for improving LCO rate performance,especially at high C-rates.

关键词： lithium-ion batteries lithium cobalt oxides carbon nanomaterials side reactions

Multi-source data integration and multi-scale modeling framework for progressive prediction of complex geological interfaces in tunneling

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Underground Space 2024年第2期15卷 1-25页

作者： Jingxiao Wang Peinan Li xiaoying Zhuang xiaojun Li xi jiang Jun Wu Department of Geotechnical Engineering College of Civil EngineeringTongji UniversityShanghai 200092China college of Environmental science and Engineering Donghua UniversityShanghai 201620China Institute of Photonics Department of Mathematics and PhysicsLeibniz University HannoverHannover 30167Germany Department of Civil and Environmental Engineering The Hong Kong Polytechnic UniversityHung HomKowloonHong Kong 100872China college of Civil Engineering Shanghai Normal UniversityShanghai 200233China

A reliable geological model plays a fundamental role in the efficiency and safety of mountain tunnel ***,regional models based on limited survey data represent macroscopic geological environments but not detailed internal geological characteristics,especially at tunnel portals with complex geological *** paper presents a comprehensive methodological framework for refined modeling of the tunnel surrounding rock and subsequent mechanics analysis,with a particular focus on natural space distortion of hard-soft rock interfaces at tunnel *** progressive prediction of geological structures is developed considering multi-source data derived from the tunnel survey and excavation *** improve the accuracy of the models,a novel modeling method is proposed to integrate multi-source and multi-scale data based on data extraction and potential field ***,a regional-scale model and an engineering-scale model are built,providing a clear insight into geological phenomena and supporting numerical *** addition,the proposed framework is applied to a case study,the Long-tou mountain tunnel project in Guangzhou,china,where the dominant rock type is *** results show that the data integration and modeling methods effectively improve model structure *** improved model’s calculation deviation is reduced by about 10%to 20%in the mechanical *** study contributes to revealing the complex geological environment with singular interfaces and promoting the safety and performance of mountain tunneling.

关键词： Mountain tunnel Geological modeling Multi-source data Progressive prediction Tunnel portals

Multiple-dimensioned defect engineering for graphite felt electrode of vanadium redox flow battery

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Carbon Energy 2024年第2期6卷 143-153页

作者： Yingqiao jiang Yinhui Wang Gang Cheng Yuehua Li Lei Dai Jing Zhu wei Meng Jingyu xi Ling Wang Zhangxing He School of Chemical Engineering North China University of Science and TechnologyTangshanChina Tsinghua Shenzhen International Graduate School Institute of Materials ResearchTsinghua UniversityShenzhenChina

The scarcity of wettability,insufficient active sites,and low surface area of graphite felt(GF)have long been suppressing the performance of vanadium redox flow batteries(VRFBs).Herein,an ultra-homogeneous multipledimensioned defect,including nano-scale etching and atomic-scale N,O codoping,was used to modify GF by the molten salt ***_(4)Cl and KClO_(3) were added simultaneously to the system to obtain porous N/O co-doped electrode(GF/ON),where KClO_(3) was used to ultra-homogeneously etch,and O-functionalize electrode,and NH4Cl was used as N dopant,***/ON presents better electrochemical catalysis for VO_(2)+/VO_(2)+ and V3+/V2+ reactions than only O-functionalized electrodes(GF/O)and *** enhanced electrochemical properties are attributed to an increase in active sites,surface area,and wettability,as well as the synergistic effect of N and O,which is also supported by the density functional theory ***,the cell using GF/ON shows higher discharge capacity,energy efficiency,and stability for cycling performance than the pristine cell at 140 mA cm^(−2) for 200 ***,the energy efficiency of the modified cell is increased by 9.7% from 55.2% for the pristine cell at 260 mA cm^(−2).Such an ultra-homogeneous etching with N and O co-doping through“boiling”molten salt medium provides an effective and practical application potential way to prepare superior electrodes for VRFB.

关键词： graphite felt molten salt N O co-doping ultra-homogeneous etching vanadium redox flow battery