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Modulated noble metal/2D MOF heterostructures for improved hydrogen storage of MgH2

Rare Metals 2024年第4期43卷 1672-1685页

作者： Zeng-Yi Li Li-Xian Sun Fen Xu Yu-Mei Luo Yong-Peng Xia Sheng Wei Chen-Chen Zhang Ri-Guang Cheng Chao-Feng Ye Meng-Yuan Liu Ju-Lan Zeng zhong cao Hong-Ge Pan School of Material Science and Engineering Guilin University of Electronic Technology School of Chemistry and Chemical Engineering Changsha University of Science and Technology Institute of Science and Technology for New Energy Xi'an Technological University

The conjugation of external species with twodimensional（2D） materials has broad application prospects.In this study,we have explored the potential of noble metal/2D MOF heterostructures in hydrogen storage.Specifically,the MgH2-Ni-MOF@Pd system has shown remarkable hydrogen desorption/sorption performances,starting to liberate hydrogen at 181 0C,which is 230 0C lower than that of pristine MgH2.Under the catalytic effect of Ni-MOF@Pd,the dehydrogenation apparent activation energy of MgH2 is noticeably decreased from（133.5 ± 17.5） to（34.58 ± 1.87） kJ·mol-1,and the hydrogenation apparent activation energy is reduced from（70.41 ± 7.43） to（25.78 ± 4.64） kJ·mol-1,which is lowered by 63.4%.The fully-dehydrogenated MgH2-NiMOF@Pd composite rapidly uptakes hydrogen,with 2.62wt% at 100℃ and 6.06 wt% at 150℃ within 300 s,respectively.The mechanism analysis of MgH2 catalyzed by Ni-MOF@Pd has revealed that the transformation of Mg2Ni and Mg2NiH4could act as a "hydrogen pump",providing numerous channels for fast diffusion and transport of hydrogen atoms.Moreover,in the dehydrogenation process,the element Pd reacts with MgH2to form the MgPd alloy phase,which makes MgH2take precedence to decompose through the Mg-Pd alloy rather than self-decomposition,further reducing thermal stability and improving de/hydrogenation kinetics.The synergistic effect of Mg-Pd,Mg2Ni,and the special ultra-thin 2D sheet structure of the additive is the main reason for the good hydrogen storage property of MgH2-Ni-MOF@Pd.Our findings provide inspiration for designing efficient multifunctional additives with unique morphologies to optimize the hydrogen desorption/sorption behaviors of hydrogen storage materials.

关键词： Hydrogen storage Magnesium hydride 2D metal-organic framework nanosheets Ni/Pd Synergistic catalysis

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Enhanced High-Temperature Cycling Stability of Garnet-Based All Solid-State Lithium Battery Using a Multi-Functional Catholyte Buffer Layer

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Nano-Micro Letters 2024年第7期16卷 59-73页

作者： Leqi Zhao Yijun zhong Chencheng cao Tony Tang Zongping Shao WA School of Mines:Minerals Energy and Chemical EngineeringCurtin UniversityPerthWA 6102Australia

The pursuit of safer and high-performance lithium-ion batteries(LIBs)has triggered extensive research activities on solid-state batteries,while challenges related to the unstable electrode-electrolyte interface hinder their practical implementation.Polymer has been used extensively to improve the cathode-electrolyte interface in garnet-based all-solid-state LIBs(ASSLBs),while it introduces new concerns about thermal stability.In this study,we propose the incorporation of a multi-functional flame-retardant triphenyl phos-phate additive into poly(ethylene oxide),acting as a thin buffer layer between LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM811)cathode and garnet electro-lyte.Through electrochemical stability tests,cycling performance evaluations,interfacial thermal stability analysis and flammability tests,improved thermal stability(capacity retention of 98.5%after 100 cycles at 60℃,and 89.6%after 50 cycles at 80℃)and safety characteristics(safe and stable cycling up to 100℃)are demonstrated.Based on various materials characterizations,the mechanism for the improved thermal stability of the interface is proposed.The results highlight the potential of multi-functional flame-retardant additives to address the challenges associated with the electrode-electrolyte interface in ASSLBs at high temperature.Efficient thermal modification in ASSLBs operating at elevated temperatures is also essential for enabling large-scale energy storage with safety being the primary concern.

关键词： Solid-state battery Cathode electrolyte interlayer Flame-retardant additive Cycling stability Interfacial stability

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A Hybrid Air Quality Prediction Model Based on Empirical Mode Decomposition

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Tsinghua Science and Technology 2024年第1期29卷 99-111页

作者： Yuxuan cao Difei Zhang Shaoqi Ding Weiyi zhong Chao Yan School of Computer Science Qufu Normal UniversityRizhao 276826China School of Mathematical Sciences Qufu Normal UniversityQufu 273165China School of Computer Science Qufu Normal UniversityRizhao 270826China College of Economic and Management Shandong University of Science and TechnologyQingdao 250307China

Air pollution is a severe environmental problem in urban areas.Accurate air quality prediction can help governments and individuals make proper decisions to cope with potential air pollution.As a classic time series forecasting model,the AutoRegressive Integrated Moving Average(ARIMA)has been widely adopted in air quality prediction.However,because of the volatility of air quality and the lack of additional context information,i.e.,the spatial relationships among monitor stations,traditional ARIMA models suffer from unstable prediction performance.Though some deep networks can achieve higher accuracy,a mass of training data,heavy computing,and time cost are required.In this paper,we propose a hybrid model to simultaneously predict seven air pollution indicators from multiple monitoring stations.The proposed model consists of three components:(1)an extended ARIMA to predict matrix series of multiple air quality indicators from several adjacent monitoring stations;(2)the Empirical Mode Decomposition(EMD)to decompose the air quality time series data into multiple smooth sub-series;and(3)the truncated Singular Value Decomposition(SvD)to compress and denoise the expanded matrix.Experimental results on the public dataset show that our proposed model outperforms the state-of-art air quality forecasting models in both accuracy and time cost.

关键词： air quality prediction Empirical Mode Decomposition(EMD) Singular Value Decomposition(SVD) AutoRegressive Integrated Moving Average(ARIMA)

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Microstructure and properties of coarse-grained WC-10Co cemented carbides with different carbon contents during heat treatments

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Rare Metals 2024年第4期43卷 1786-1792页

作者： Yuan-Feng Xie Xing-Cheng Xie zhong-Wu Li Rui-Jun cao zhong-Kun Lin Qing Li Chen-Guang Lin Powder Metallurgy and Special Materials Research Department General Research Institute for Nonferrous Metals

The effects of cryogenic treatment（CT） and tempering-cryogenic treatment（TCT） on the microstructure and properties of coarse-grained WC-10Co cemented carbides with different carbon contents were researched.The binder phase,WC mean grain sizes,W solubility in the binder,relative magnetic s aturation,densities,hardness,wear resistance and second phase precipitation of cemented carbides with different heat treatments were discussed.The results show that there are significant changes of microstructure and properties in the samples with CT and TCT,especially due to the precipitation of metastable nanoparticles WxCoyCzin the binder during the heat treatments of CT and TCT.With the simultaneous combination of microstructure and nanoparticle-reinforced binder,a dramatically improved combination of hardness and wear resistance of the samples after TCT has been achieved.

关键词： Cryogenic treatment Tempering Coarse-grained cemented carbide Carbon content Nanoparticle-reinforced binder

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Nonlinear Impact Damage Evolution of Charpy Type and Analysis of Its Key Influencing Factors

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Chinese Journal of Mechanical Engineering 2024年第1期37卷 254-264页

作者： Jianfeng Mao Qian Xu Jiadong Yang Chi cao Dasheng Wang Fengping zhong Mingya Chen Institute of Process Equipment and Control Engineering Zhejiang University of TechnologyHangzhou 310032China Taizhou Key Laboratory of Advanced Manufacturing Technology Taizhou InstituteZhejiang University of TechnologyTaizhou 318014China State Key Laboratory of Nuclear Power Safety Monitoring Technology and Equipment Shenzhen 518172China Zhejiang Academy of Special Equipment Science Hangzhou 310020China Suzhou Nuclear Power Research Institute Suzhou 215004China

The current research of Charpy impact mainly focuses on obtaining the ductile brittle transition temperature of materials by experiments.Compared with experiments,numerical simulation can study many problems with harsh conditions.However,there are still few studies on the influence of geometric factors such as side grooves.In this paper,the geometry of standard Charpy impact test is designed.Specimens with different widths and side grooves are tested.The finite element model of Charpy impact was established by ABAQUS software.Use test results and simulation results to verify each other.The effects of sample width,side groove depth and side groove bottom fillet on the impact fracture resistance of the sample were studied.The results show that the specimen width is positively correlated with the impact toughness of the specimen.The side groove greatly reduces the impact toughness of the material;the toughness of side groove decreases with the increase of depth;the fracture toughness of side groove decreases with the increase of fillet at the bottom of side groove.The proportion of toughness energy to impact energy of samples was analyzed.The results show that the toughness energy accounts for about 70%of the impact energy of the sample,which has little to do with the geometric characteristics of the sample.This study presents a reliable method for studying Charpy impact tests.The influence of geometric parameters is obtained,which provides a reference method for the study of impact toughness of high toughness materials.

关键词： Johnson-Cook model Impact toughness Charpy impact

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Improved forecasting via physics-guided machine learning as exemplified using“21·7”extreme rainfall event in Henan

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Science China Earth Sciences 2024年第5期67卷 1652-1674页

作者： Qi zhong Zhicha ZHANG Xiuping YAO Shaoyu HOU Shenming FU Yong cao Linguo JING China Meteorological Administration Training Center Beijing 100081China State Key Laboratory of Severe Weather Chinese Academy of Meteorological SciencesBeijing 100081China Zhejiang Meteorological Observatory Hangzhou 310017China Hebei Provincial Weather Modification Center Shijiazhuang 050020China Institute of Atmospheric Physics Chinese Academy of SciencesBeijing 100029China National Meteorological Center Beijing 100081China School of Computer Science Chengdu University of Information TechnologyChengdu 610225China

As a natural disaster,extreme precipitation is among the most destructive and influential,but predicting its occurrence and evolution accurately is very challenging because of its rarity and uniqueness.Taking the example of the“21·7”extreme precipitation event(17–21 July 2021)in Henan Province,this study explores the potential of using physics-guided machine learning to improve the accuracy of forecasting the intensity and location of extreme precipitation.Three physics-guided ways of embedding physical features,fusing physical model forecasts and revised loss function are used,i.e.,(1)analyzing the anomalous circulation and thermodynamical factors,(2)analyzing the multi-model forecast bias and the associated underlying reasons for it,and(3)using professional forecasting knowledge to design the loss function,and the corresponding results are used as input for machine learning to improve the forecasting accuracy.The results indicate that by learning the relationship between anomalous physical features and heavy precipitation,the forecasting of precipitation intensity is improved significantly,but the location is rarely adjusted and more false alarms appear.Possible reasons for this are as follows.The anomalous features used here mainly contain information about large-scale systems and factors which are consistent with the model precipitation deviation;moreover,the samples of extreme precipitation are sparse and so the algorithm used here is simple.However,by combining“good and different”multi models with machine learning,the advantages of each model are extracted and then the location of the precipitation center in the forecast is improved significantly.Therefore,by combining the appropriate anomalous features with multi-model fusion,an integrated improvement of the forecast of the rainfall intensity and location is achieved.Overall,this study is a novel exploration to improve the refined forecasting of heavy precipitation with extreme intensity and high variability,and provides a reference for the deep fusion of

关键词： Extreme precipitation event Refined assessment Anomalous physical features Multi-model fusion Machine learning

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C_(Ar)-Br bond cleavage via cooperative EnT/NHC catalysis: mild access to indolines

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Science China Chemistry 2024年第3期67卷 922-927页

作者： Yi-Xiong Dong cao-Bo Li Ming-Lei Jin zhong-Hua Gao Song Ye Beijing National Laboratory for Molecular Sciences CAS Key Laboratory of Molecular Recognition and FunctionCAS Research/Education Center for Excellence in Molecular SciencesInstitute of ChemistryChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China

The cooperative visible-light mediated and NHC-catalyzed dearomative arylation-acylation of N-(2-bromobenzoyl)indoles with aldehydes was developed, affording the corresponding highly functionalized polycyclic indolines in moderate to good yields with exclusive diastereoselectivities. Mechanism investigations support the activation of CAr-Br bond via visible-light mediated energy transfer(EnT) and the following single-electron-transfer(SET) with Breslow intermediate under NHC catalysis to give key aryl radical and ketyl radical. This protocol demonstrates the cleavage of CAr-Br bond under mild cooperative EnT/NHC catalysis.

关键词： energy transfer N-heterocyclic carbenes photocatalysis aryl radicals indolines

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Effect of lens surgery on health-related quality of life in preschool children with congenital ectopia lentis

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International Journal of Ophthalmology(English edition) 2024年第1期17卷 66-72页

作者： Yan-Qiao Huang Qian-zhong cao Yi-Yao Wang Yi-Jing Zhou Dan-Ying Zheng State Key Laboratory of Ophthalmology Zhongshan Ophthalmic CenterSun Yat-sen UniversityGuangdong Provincial Key Laboratory of Ophthalmology and Visual ScienceGuangdong Provincial Clinical Research Center for Ocular DiseasesGuangzhou 510060Guangdong ProvinceChina

AIM:To evaluate the effect of lens surgery on health-related quality of life(HRQoL)of preschool children with congenital ectopia lentis(CEL).METHODS:A prospective self-controlled study was conducted in zhongshan Ophthalmic Center.Children aged from 5 to 7y whom were diagnosed with CEL and underwent phacoemulsification with scleral-fixated posterior chamber intraocular lens implantation and their parents were enrolled in this study.All of them completed the child and proxy(parental)PedsQL™4.0 before and after the surgery.Their preoperative scores were compared to their postoperative ones.Subgroup analyses were performed based on gender and preoperative bilateral presenting visual acuity of the children.RESULTS:Thirty-two children with CEL successfully underwent surgery without any complications,among whom 8 had monocular surgery and 24 had binocular surgery.Preoperative and postoperative questionnaires were completed by 32 child-parent pairs.Surgical intervention could significantly improve the vision of affected children(P<0.001).The medians of physical,psychosocial and total health scores self-reported by the children were 68.75(62.50,81.25),65.00(60.00,80.00)and 67.39(60.87,78.26)preoperatively and were 93.75(87.50,100.00),90.00(83.33,96.67)and 89.13(85.32,95.65)postoperatively.The preoperative scores of the affected children were significantly lower in all scales than age-matched healthy children(P<0.001).All the postoperative scores were significantly higher than the preoperative scores in affected children and their parents(P<0.001).In the physical functioning evaluation,the preoperative score reported by parents of girls was higher than parents of boys(P=0.041),and the postoperative score of girls was higher than that of boys(P=0.036).CONCLUSION:CEL is associated with significantly worse quality of life in preschool children.Surgical intervention can significantly improve the HRQoL in affected children from both personal and family perspective.

关键词： congenital ectopia lentis surgical intervention health-related quality of life preschool children

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Enhanced gas production and CO_(2) storage in hydrate-bearing sediments via pre-depressurization and rapid CO_(2) injection

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Chinese Journal of Chemical Engineering 2024年第3期67卷 126-134页

作者： Hongnan Chen Yifei Sun Bojian cao Minglong Wang Ming Wang Jinrong zhong Changyu Sun Guangjin Chen State Key Laboratory of Heavy Oil Processing China University of PetroleumBeijing 102249China School of Chemistry and Chemical Engineering Changsha University of Science&TechnologyChangsha 410114China

Carbon emission reduction and clean energy development are urgent demands for mankind in the coming decades.Exploring an efficient CO_(2) storage method can significantly reduce CO_(2) emissions in the short term.In this study,we attempted to construct sediment samples with different residual CH_(4) hydrate amounts and reservoir conditions,and then investigate the potentials of both CO_(2) storage and enhanced CH_(4) recovery in depleted gas hydrate deposits in the permafrost and ocean zones,respectively.The results demonstrate that CO_(2) hydrate formation rate can be significantly improved due to the presence of residual hydrate seeds;However,excessive residual hydrates in turn lead to the decrease in CO_(2) storage efficiency.Affected by the T-P conditions of the reservoir,the storage amount of liquid CO_(2) can reach 8 times that of gaseous CO_(2),and CO_(2) stored in hydrate form reaches 2-4 times.Additionally,we noticed two other advantages of this method.One is that CO_(2) injection can enhance CH_(4) recovery rate and increases CH_(4) recovery by 10%-20%.The second is that hydrate saturation in the reservoir can be restored to 20%-40%,which means that the solid volume of the reservoir avoids serious shrinkage.Obviously,this is crucial for protecting the goaf stability.In summary,this approach is greatly promising for high-efficient CO_(2) storage and safe exploitation of gas hydrate.

关键词： Hydrate Depressurization CO_(2) storage CH_(4) production Reservoir remediation

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High-Efficiency Dynamic Scanning Strategy for Powder Bed Fusion by Controlling Temperature Field of the Heat-Affected Zone

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Chinese Journal of Mechanical Engineering 2024年第1期37卷 203-214页

作者： Xiaokang Huang Xiaoyong Tian Qi zhong Shunwen He Cunbao Huo Yi cao Zhiqiang Tong Dichen Li State Key Laboratory of Manufacturing Systems Engineering Xi’an Jiaotong UniversityXian 710049China

Improvement of fabrication efficiency and part performance was the main challenge for the large-scale powder bed fusion(PBF)process.In this study,a dynamic monitoring and feedback system of powder bed temperature field using an infrared thermal imager has been established and integrated into a four-laser PBF equipment with a working area of 2000 mm×2000 mm.The heat-affected zone(HAZ)temperature field has been controlled by adjusting the scanning speed dynamically.Simultaneously,the relationship among spot size,HAZ temperature,and part performance has been established.The fluctuation of the HAZ temperature in four-laser scanning areas was decreased from 30.85℃to 17.41℃.Thus,the consistency of the sintering performance of the produced large component has been improved.Based on the controllable temperature field,a dynamically adjusting strategy for laser spot size was proposed,by which the fabrication efficiency was improved up to 65.38%.The current research results were of great significance to the further industrial applications of large-scale PBF equipment.

关键词： Powder bed fusion Efficiency Large-scale Spot size Heat-affected zone(HAZ)

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