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Rebuilding the theory of isotope fractionation for evaporation of silicate melts under vacuum condition

Acta Geochimica 2024年第4期43卷 661-676页

作者： Jie wang Yun Liu Research Center for Planetary Science College of Earth and Planetary SciencesChengdu University of TechnologyChengdu 610059China State Key Laboratory of Ore Deposit Geochemistry Institute of GeochemistryChinese Academy of SciencesGuiyang 550081China CAS Center for Excellence in Comparative Planetology Hefei 230026China

Isotope eff ects are pivotal in understanding silicate melt evaporation and planetary accretion *** on the hertz-Knudsen equation,the current theory often fails to predict observed isotope fractionations of laboratory experiments due to its oversimplified ***,we point out that the hertz-Knudsen-equation-based theory is incomplete for silicate melt evaporation cases and can only be used for situations where the vaporized species is identical to the one in the *** propose a new model designed for silicate melt evaporation under *** model considers multiple steps including mass transfer,chemical reaction,and *** derivations reveal a kinetic isotopic fractionation factor(KIFF orα)αour model=[m(^(1)species)/m(^(2)species)]^(0.5),where m(species)is the mass of the reactant of reaction/nucleation-limiting step or species of diffusion-limiting step and superscript 1 and 2 represent light and heavy isotopes,*** model can eff ectively reproduce most reported KIFFs of laboratory experiments for various elements,i.e.,Mg,Si,K,Rb,Fe,Ca,and ***,the KIFF-mixing model referring that an overall rate of evaporation can be determined by two steps jointly can account for the eff ects of low P_(h2)pressure,composition,and *** addition,we find that chemical reactions,diffusion,and nucleation can control the overall rate of evaporation of silicate melts by using the fitting slope in ln(−ln f)versus ln(t).Notably,our model allows for the theoretical calculations of parameters like activation energy(E_(a)),providing a novel approach to studying compositional and environmental eff ects on evaporation processes,and shedding light on the formation and evolution of the proto-solar and Earth-Moon systems.

关键词： Evaporation Kinetic isotopic fractionation Chemical kinetics hertz-Knudsen equation CAIS

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Europium-bearing organic framework with excellent X-ray scintillating luminescence

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Journal of Rare Earths 2024年第2期42卷 251-255,I0001页

作者： Yugang Zhang Lanhua Chen Xia wang Wei Liu Shu'ao wang State Key Laboratory of Radiation Medicine and Protection School for Radiological and Interdisciplinary Sciences(RAD-X)and Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education InstitutionsSoochow UniversitySuzhou215123China School of Environmental and Materials Engineering Yantai UniversityYantai264005China

Two europium-bearing organic frameworks,termed as EuTPO-1 and EuTPO-2(h_(3)TPO=tris(4-carboxylphenyI)-phosphineoxide),are reported in this work.A series of characterizations of EuTPO-1and EuTPO-2,such as X-ray crystallography and photoluminescence spectroscopy,was performed to expatiate their structure and physicochemical *** of them are constructed by dimers of the europium-oxygen subunit of [Eu_(2)O_(16)] and TPO *** from high X-ray stopping attenuation and excellent luminescence efficiency,they emit sufficient luminescence when irradiated with ***,they possess stable light outputs when exposed to high humidities and strong radiation dose,outperforming the commercial scintillator CsI:*** result paves the way for developing new scintillator and enriches the compound of europium-bearing organic framework with X-ray scintillating luminescence.

关键词： Metal-organic frameworks Scintillating material Luminescence efficiency Rare earths

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Accelerating the Screening of Modified MA2Z4 Catalysts for hydrogen Evolution Reaction by Deep Learning-Based Local Geometric Analysis

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ENERGY & ENVIRONMENTAL MATERIALS 2024年第6期7卷 290-302页

作者： Zheng, Jingnan wang, Shibin Deng, Shengwei Yao, Zihao hu, Junhua wang, Jianguo Zhejiang Univ Technol Inst Ind Catalysis Coll Chem Engn State Key Lab Breeding Base Green Chem Synth Techn Hangzhou 310032 Peoples R China Zhengzhou Univ Sch Mat Sci & Engn Zhengzhou 450001 Peoples R China Zhengzhou Univ State Ctr Int Cooperat Designer Low Carbon & Envir Sch Mat Sci & Engn Zhengzhou 450001 Peoples R China

Machine learning (ML) integrated with density functional theory (DFT) calculations have recently been used to accelerate the design and discovery of single-atom catalysts (SACs) by establishing deep structure-activity relationships. The traditional ML models are always difficult to identify the structural differences among the single-atom systems with different modification methods, leading to the limitation of the potential application range. Aiming to the structural properties of several typical two-dimensional MA(2)Z(4)-based single-atom systems (bare MA(2)Z(4) and metal single-atom doped/supported MA(2)Z(4)), an improved crystal graph convolutional neural network (CGCNN) classification model was employed, instead of the traditional machine learning regression model, to address the challenge of incompatibility in the studied systems. The CGCNN model was optimized using crystal graph representation in which the geometric configuration was divided into active layer, surface layer, and bulk layer (ASB-GCNN). Through ML and DFT calculations, five potential single-atom hydrogen evolution reaction (hER) catalysts were screened from chemical space of 600 MA(2)Z(4)-based materials, especially V-1/hfSn2N4(S) with high stability and activity (Delta G(h*) is 0.06 eV). Further projected density of states (pDOS) analysis in combination with the wave function analysis of the SAC-h bond revealed that the SAC-dz(2) orbital coincided with the h-s orbital around the energy level of -2.50 eV, and orbital analysis confirmed the formation of sigma bonds. This study provides an efficient multistep screening design framework of metal single-atom catalyst for hER systems with similar two-dimensional supports but different geometric configurations.

关键词： graph convolutional neural network hydrogen evolution reaction modified MA(2)Z(4) substrate single atom catalyst MONOLAYER MAChINE

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Study on surface discharge of nonlinear conductive epoxy resin/SrTiO3 composites in 80–300 K temperature zone

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high Voltage 2024年第1期9卷 117-126页

作者： Yunqi Xing Bin wang Mingyang wang Jiakai Chi Peng Jia Rongjin huang State Key Laboratory of Reliability and Intelligence of Electrical Equipment Hebei University of TechnologyTianjinChina Key Laboratory of Electormagnetic Field and Electrical Apparatus Reliability of hebei Province Hebei University of TechnologyTianjinChina Key Laboratory of Special Machine and high Voltage Apparatus(Ministry of Education) Shenyang University of TechnologyShenyangChina State Grid Tianjin high Voltage Company TianjinChina China Energy Engineering Group Tianjin Electric Power Design Institute Co. Ltd.TianjinChina CAS Key Laboratory of Cryogenics Technical Institute of Physics and ChemistryBeijingChina

Bisphenol F epoxy resin(EP)is often used in terminal current lead insulation of superconducting equipment because of its good insulation performance,high mechanical strength,good toughness at cryogenic temperatures,and resistance to cold shock and heat ***,due to the wide temperature range of 80–300 K and the strong electric field,the EP-N_(2)interface is prone to surface flashover,resulting in terminal insulation *** improve the reliability of the current lead insulation,non-linear conductive EP/strontium titanate(SrTiO_(3))composites were prepared by modification with nano *** changes of dielectric,surface discharge,flashover,and trap distribution characteristics of composite materials were studied,and the mechanism of SrTiO_(3)on the surface flashover of composite materials was *** results show that the conductivity of the composite increases with the rise of SrTiO_(3)filling content,and the amplitude of improvement is greater under the strong electric field,showing a more significant *** composite has a lower trap energy level and a greater number of shallow traps compared to pure EP,which accelerates surface charge detrapping and reduces charge accumulation,effectively enhancing the discharge and surface flashover voltage of the composite.

关键词： composites composite insulation

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halogen-bond induced unusual polyhalogen anions formation in hydrogen-bonded frameworks to secure iodine sequestration

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Nano Research 2024年第7期17卷 6766-6772页

作者： Yi Xie Pengling huang Qiang Gao Shiyu wang Jianchen wang Gang Ye Collaborative Innovation Center of Advanced Nuclear Energy Technology Institute of Nuclear and New Energy TechnologyTsinghua UniversityBeijing 100084China

Safe confinement of fission iodine isotopes for long-term radioactive waste disposal remains a formidable challenge,as conventional sorbents provide inherently weak iodine-host *** report here a novel halogen bond(X-bond)directed strategy to sequester volatile iodine in hydrogen-bonded(h-bonded)frameworks with unprecedented ***-assisted hbonded frameworks bearing open halide sites are developed,showing distinctive iodine encapsulation behaviors without compromising the *** crystallographic evidence indicates the formation of X-bonds,i.e.,I–I···Cl^(−) and I–I···Br^(−),within the confined pore *** polyhalogen anions,i.e.,[I_(2)Cl_(2)]^(2−)and[I_(2)Br_(2)]^(2−),sustained in h-bonded frameworks are identified for the first *** X-bond reinforced host-guest interaction affords robust iodine trapping without leaking out even at elevated temperatures up to 180℃.By integrating the halogen-bond chemistry with h-bonded frameworks,this study offers fresh concepts for developing effective host reservoirs to secure fission iodine isotopes from spent fuel reprocessing off-gases.

关键词： halogen-bond chemistry anion coordination chemistry hydrogen-bonded organic frameworks polyhalogen anions iodine confinement

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Universal architecture and defect engineering dual strategy for hierarchical antimony phosphate composite toward fast and durable sodium storage

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Journal of Energy Chemistry 2024年第3期90卷 110-119,I0004页

作者： Jiawei Wu Gaoyu wang Wei Zhang Lixiang wang Jian Peng Qinghua Li Zhixin Liang Wenbo Fan Jiazhao wang Shaoming huang School of Materials and Energy Guangzhou Key Laboratory of Low-Dimensional Materials and Energy Storage DevicesGuangdong University of TechnologyGuangzhou 510006GuangdongChina School of Mechanical and Electrical Engineering Jiaxing Nanhu UniversityJiaxing 314001ZhejiangChina Institute for Superconducting and Electronic Materials Australian Institute for Innovative MaterialsUniversity of WollongongInnovation CampusSquires WayNorth WollongongNSW2522Australia

Antimony(Sb)-ba sed anode materials are feasible candidates for sodium-ion batteries(SIBs) due to their high theoretical specific capacity and excellent electrical ***,they still suffer from volume distortion,structural collapse,and ionic conduction interruption upon ***,a hierarchical array-like nanofiber structure was designed to address these limitations by combining architecture engineering and anion tuning strategy,in which SbPO_(4-x) with oxygen vacancy nanosheet arrays are anchored on the surface of interwoven carbon nanofibers(SbPO_(4-x)@CNFs).In particular,bulky PO_(4)^(3-) anions mitigate the large volume distortion and generate Na_(3)PO_(4) with high ionic conductivity,collectively improving cyclic stability and ionic transport *** abundant oxygen vacancies substantially boost the intrinsic electronic conductivity of SbPO_4,further accelerating the reaction *** addition,hierarchical fibrous structures provide abundant active sites,construct efficient conducting networks,and enhance the electron/ion transport *** from the advanced structural design,the SbPO_(4-x)@CNFs electrodes exhibit outstanding cycling stability(1000 cycles at 1.0 A g^(-1) with capacity decay of 0.05% per cycle) and rapid sodium storage performance(293.8 mA h g^(-1) at 5.0 A g^(-1)).Importantly,systematic in-/ex-situ techniques have revealed the "multi-step conversion-alloying" reaction process and the "battery-capacitor dual-mode" sodium-storage *** work provides valuable insights into the design of anode materials for advanced SIBs with elevated stability and superior rate performance.

关键词： SbPO_(4) anodes hierarchical nanostructures Oxygen vacancy Stress dispersion Sodium-ion batteries

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Surface Coating Enabling Sulfide Solid Electrolytes with Excellent Air Stability and Lithium Compatibility

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ENERGY & ENVIRONMENTAL MATERIALS 2024年第6期7卷 41-49页

作者： Luo, Min wang, Changhong Duan, Yi Zhao, Xuyang wang, Jiantao Sun, Xueliang GRINM Grp Corp Ltd Natl Power Battery Innovat Ctr Beijing 100088 Peoples R China China Automot Battery Res Inst Co Ltd Beijing 100088 Peoples R China Gen Res Inst Nonferrous Met Beijing 100088 Peoples R China Eastern Inst Technol Eastern Inst Adv Study Ningbo 315200 Peoples R China

All-solid-state lithium metal batteries (ASSLMBs) featuring sulfide solid electrolytes (SEs) are recognized as the most promising next-generation energy storage technology because of their exceptional safety and much-improved energy density. however, lithium dendrite growth in sulfide SEs and their poor air stability have posed significant obstacles to the advancement of sulfide-based ASSLMBs. here, a thin layer (approximately 5 nm) of g-C3N4 is coated on the surface of a sulfide SE (Li6PS5Cl), which not only lowers the electronic conductivity of Li6PS5Cl but also achieves remarkable interface stability by facilitating the in situ formation of ion-conductive Li3N at the Li/Li6PS5Cl interface. Additionally, the g-C3N4 coating on the surface can substantially reduce the formation of h2S when Li6PS5Cl is exposed to humid air. As a result, Li-Li symmetrical cells using g-C3N4-coated Li6PS5Cl stably cycle for 1000 h with a current density of 0.2 mA cm(-2). ASSLMBs paired with LiNbO3-coated LiNi0.6Mn0.2Co0.2O2 exhibit a capacity of 132.8 mAh g(-1) at 0.1 C and a high-capacity retention of 99.1% after 200 cycles. Furthermore, g-C3N4-coated Li6PS5Cl effectively mitigates the self-discharge behavior observed in ASSLMBs. This surface-coating approach for sulfide solid electrolytes opens the door to the practical implementation of sulfide-based ASSLMBs.

关键词： anode interface g-C3N4 coating Li6PS5Cl lithium dendrite inhibition solid-state lithium metal batteries METAL BATTERIES IMPROVEMENT FE

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PVDF/6h-SiC composite fiber films with enhanced piezoelectric performance by interfacial engineering for diversified applications

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Journal of Materials Science & Technology 2024年第3期170卷 238-245页

作者： Linlin Zhou Tao Yang Chunyu Guo Kang wang Enhui wang Laipan Zhu hailong wang Sheng Cao Kuo-Chih Chou Xinmei hou Institute for Carbon Neutrality University of Science and Technology BeijingBeijing 100083China Beijing Institute of Nanoenergy and Nanosystems Chinese Academy of SciencesBeijing 101400China School of Materials Science Engineering Zhengzhou UniversityZhengzhou 450001China State Key Laboratory of Featured Metal Materials and Life-cycle Safety for Composite Structures Guangxi UniversityNanning 530004China

Piezoelectric silicon carbide(SiC)has been quite attractive due to its superior chemical and physical properties as well as wide potential ***,the inherent brittleness and unsatisfactory piezoelectric response of piezoelectric semiconductors remain the major obstacles to their diversified ***,flexible multifunctional PVDF/6h-SiC composite fiber films are fabricated and utilized to assemble both piezoelectric nanogenerators(PENGs)and stress/temperature/light *** open cir-cuit voltage(V_(oc))and the density of short circuit current(I_(sc))of the PENG based on the PVDF/5 wt%6h-SiC composite fiber films reach 28.94 V and 0.24μA cm^(-2),showing a significant improvement of 240%and 300%compared with that based on the pure PVDF *** effect of 6h-SiC nanoparticles(NPs)on inducing interfacial polarization and stress concentration in composite fiber films is proved by first-principles calculation and finite element *** stress/temperature/light sensors based on the composite fiber film also show high sensitivity to the corresponding *** study shows that the PVDF/6h-SiC composite fiber film is a promising candidate for assembling high-performance energy harvesters and diverse sensors.

关键词： 6h-SiC PVDF Multifunctional composite fiber film Energy harvester Stress/temperature/light sensor

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Stress relaxation properties of calcium silicate hydrate:a molecular dynamics study

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2024年第2期25卷 97-115页

作者： Zhicheng GENG Shengwen TANG Yang wang hubao A Zhen hE Kai WU Lei wang State Key Laboratory of Water Resources Engineering and Management Wuhan UniversityWuhan430072China Key Laboratory of Advanced Civil Engineering Materials of Ministry of Education School of Materials Science and EngineeringTongji UniversityShanghai200092China College of Materials Science and Engineering Xi’an University of Architecture and TechnologyXi’an710055China

The time-dependent viscoelastic response of cement-based materials to applied deformation is far from fully understood at the atomic *** silicate hydrate(C-S-h),the main hydration product of Portland cement,is responsible for the viscoelastic mechanism of cement-based *** this study,a molecular model of C-S-h was developed to explain the stress relaxation characteristics of C-S-h at different initial deformation states,Ca/Si ratios,temperatures,and water contents,which cannot be accessed *** stress relaxation of C-S-h occurs regardless of whether it is subjected to initial shear,tensile,or compressive deformation,and shows a heterogeneous *** plays a crucial role in the stress relaxation process.A large Ca/Si ratio and high temperature reduce the cohesion between the calcium-silicate layer and the interlayer region,and the viscosity of the interlayer region,thereby accelerating the stress relaxation of *** effect of the hydrogen bond network and the morphology of C-S-h on the evolution of the stress relaxation characteristics of C-S-h at different water contents was elucidated by nonaffine mean squared *** results shed light on the stress relaxation characteristics of C-S-h from a microscopic perspective,bridging the gap between the microscopic phenomena and the underlying atomic-level mechanisms.

关键词： Calcium silicate hydrate(C-S-h) Stress relaxation Ca/Si ratio Temperature Water content Atomic simulation

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Computational design of bimetallic Tm_(2)@g-C_(9)N_(4)electrocatalysts for enhanced CO reduction toward C_(2)products

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Chinese Chemical Letters 2024年第7期35卷 484-490页

作者： Jiajun wang Guolin Yi Shengling Guo Jianing wang Shujuan Li Ke Xu Weiyi wang Shulai Lei Tianjin Key Laboratory of Structure and Performance for Functional Molecules College of ChemistryTianjin Normal UniversityTianjin 300387China Department of Chemical Physics&hefei National Laboratory for Physical Sciences at Microscale University of Science and Technology of ChinaHefei 230026China hubei Key Laboratory of Low Dimensional Optoelectronic Materials and Devices Hubei University of Arts and ScienceXiangyang 441053China hubei Longzhong Laboratory Xiangyang 441053China

Electrochemical CO reduction(ECOR)as a potential strategy for producing valuable chemicals and fuels has captured substantial ***,the currently available electrocatalysts suffer from poor selectivity and low Faradaic efficiency,limiting their industrial ***,we systematically investigate the potential of homonuclear bimetallic electrocatalysts,Tm_(2)@C_(9)N_(4)(TM=Fe,Co,Ni,and Cu),for the ECOR through extensive density functional theory *** findings suggest that all four proposed monolayers exhibit exceptional stability,making them highly suitable for experimental synthesis and practical ***,these transition-metal dual atoms anchored on C_(9)N_(4)monolayers show great potential in facilitating the production of high-value C_(2)products,such as C_(2)h_(5)Oh and C_(2)h_(4),due to the significantly low limiting potentials(-0.06~-0.46 V)and small kinetic energy barriers(0.54–1.08 eV)for the CO coupling ***,with the exception of Ni_(2)@C_(9)N_(4),these bimetallic catalysts demonstrate the impressive suppression of the competitive hydrogen evolution reaction(hER),leading to a high selectivity for C_(2)products in *** predictions would accelerate the development of high-performance C_(9)N_(4)-based dual-atom catalysts for the ECOR.

关键词： C_(9)N_(4)monolayer Double-atom catalysts CO electroreduction Multi-carbon products Density functional theory

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