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Recent Advances in Mechanistic Understanding of Metal-Free Carbon Thermocatalysis and Electrocatalysis with Model Molecules

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Nano-Micro Letters 2024年第7期16卷 74-97页

作者： wei guo Linhui Yu Ling Tang Yan wan Yangming Lin CAS Key Laboratory of Design and Assembly of Functional Nanostructures Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002People’s Republic of China Xiamen Key Laboratory of Rare Earth Photoelectric Functional Materials Xiamen Institute of Rare Earth MaterialsHaixi InstituteChinese Academy of SciencesXiamen 361021People’s Republic of China State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002People’s Republic of China Institute of Urban Environment Chinese Academy of SciencesXiamen 361021People’s Republic of China

Metal-free carbon,as the most representative heterogeneous metal-free catalysts,have received considerable interests in electro-and thermo-catalytic reac-tions due to their impressive performance and sustainability.Over the past decade,well-designed carbon catalysts with tunable structures and heteroatom groups coupled with various characterization techniques have proposed numerous reaction mechanisms.However,active sites,key intermediate species,precise structure-activity relationships and dynamic evolution processes of carbon catalysts are still rife with controversies due to the monotony and limitation of used experimental methods.In this Review,we sum-marize the extensive efforts on model catalysts since the 2000s,particularly in the past decade,to overcome the influences of material and structure limitations in metal-free carbon catalysis.Using both nanomolecule model and bulk model,the real contribution of each alien species,defect and edge configuration to a series of fundamentally important reactions,such as thermocatalytic reactions,electrocatalytic reactions,were systematically studied.Combined with in situ techniques,isotope labeling and size control,the detailed reaction mechanisms,the precise 2D structure-activity relationships and the rate-determining steps were revealed at a molecular level.Furthermore,the outlook of model carbon catalysis has also been proposed in this work.

关键词： Metal-free carbon catalysts Model catalyst Electrocatalysis Active site Reaction mechanisms

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Numerical simulations of FPSO with sloshing tanks in a random freak waves

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Journal of Hydrodynamics 2022年第3期34卷 491-498页

作者： Yuan Zhuang guo wang De-cheng wan Jian-wei Wu Computational Marine Hydrodynamics Lab(CMHL) School of Naval ArchitectureOcean and Civil EngineeringShanghai Jiao Tong UniversityShanghai200240China Marine Design and Research Institute of China Shanghai200011China Wuhan Second Ship Design and Research Institute Wuhan430205China

This paper presents a potential-viscous coupled method to simulate a floating production storage and offloading(FPSO)with two liquefied natural gas(LNG)sloshing tanks in a random freak wave.The potential theory uses high-order-spectral(HOS)method.The random wave is generated by HOS for 2000 s,and a freak wave is observed around 1830 s.The FPSO LNG model was firstly verified in regular waves using HOS-computational fluid dynamics(CFD)coupled method and validated the HOS-CFD coupled method can solve the ship motion coupled with sloshing tanks accurately.The FPSO with LNG tanks are then simulated in the freak wave,showed the coupling effects when the freak wave passes.With the existence of the sloshing tanks,the amplitude of the roll motion decreases and the period of roll motion changed.Wave breaking phenomenon can be observed when the wave crest of the freak wave encounters with the ship.

关键词： Ship motion with sloshing tank high-order-spectral-computational fluid dynamics(HOS-CFD)method naoe-FOAM-SJTU solver freak waves

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AOL4PS:A Large-scale Data Set for Personalized Search

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Data Intelligence 2021年第4期3卷 548-567页

作者： Qian guo wei Chen Huaiyu wan School of Computer and Information Technology Beijing Jiaotong UniversityBeijing 100044China Beijing Key Laboratory of Traflc Data Analysis and Mining Beijing 100044China

Personalized search is a promising way to improve the quality of Websearch,and it has attracted much attention from both academic and industrial communities.Much of the current related research is based on commercial search engine data,which can not be released publicly for such reasons as privacy protection and information security.This leads to a serious lack of accessible public data sets in this field.The few publicly available data sets have not become widely used in academia because of the complexity of the processing process required to study personalized search methods.The lack of data sets together with the difficulties of data processing has brought obstacles to fair comparison and evaluation of personalized search models.In this paper,we constructed a large-scale data set AOL4 PS to evaluate personalized search methods,collected and processed from AOL query logs.We present the complete and detailed data processing and construction process.Specifically,to address the challenges of processing time and storage space demands brought by massive data volumes,we optimized the process of data set construction and proposed an improved BM25 algorithm.Experiments are performed on AOL4 PS with some classic and state-of-the-art personalized search methods,and the experiment results demonstrate that AOL4 PS can measure the effect of personalized search models.

关键词： Personalized search Text data processing Data set construction

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Graph Convolutional Networks Embedding Textual Structure Information for Relation Extraction

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Computers, Materials & Continua 2024年第5期79卷 3299-3314页

作者： Chuyuan wei Jinzhe Li Zhiyuan wang Shanshan wan Maozu guo School of Electrical and Information Engineering Beijing University of Civil Engineering and ArchitectureBeijing102616China

Deep neural network-based relational extraction research has made significant progress in recent years,andit provides data support for many natural language processing downstream tasks such as building knowledgegraph,sentiment analysis and question-answering systems.However,previous studies ignored much unusedstructural information in sentences that could enhance the performance of the relation extraction task.Moreover,most existing dependency-based models utilize self-attention to distinguish the importance of context,whichhardly deals withmultiple-structure information.To efficiently leverage multiple structure information,this paperproposes a dynamic structure attention mechanism model based on textual structure information,which deeplyintegrates word embedding,named entity recognition labels,part of speech,dependency tree and dependency typeinto a graph convolutional network.Specifically,our model extracts text features of different structures from theinput sentence.Textual Structure information Graph Convolutional Networks employs the dynamic structureattention mechanism to learn multi-structure attention,effectively distinguishing important contextual features invarious structural information.In addition,multi-structure weights are carefully designed as amergingmechanismin the different structure attention to dynamically adjust the final attention.This paper combines these featuresand trains a graph convolutional network for relation extraction.We experiment on supervised relation extractiondatasets including SemEval 2010 Task 8,TACRED,TACREV,and Re-TACED,the result significantly outperformsthe previous.

关键词： Relation extraction graph convolutional neural networks dependency tree dynamic structure attention

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Assessment of subgrid-scale models in wall-modeled large-eddy simulations of turbulent channel flows

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水动力学研究与进展B辑:英文版 2023年第3期35卷 407-416页

作者： wei-wen Zhao Fu-chang Zhou guo-qing Fan De-cheng wan Computational Marine Hydrodynamics Lab(CMHL) School of Naval ArchitectureOcean and Civil EngineeringShanghai Jiao Tong UniversityShanghai 200240China Wuhan Second Ship Design and Research Institute Wuhan 430205China

Considering the demanding of grid requirements for high-Reynolds-number wall-bounded flow,the wall-modeled large-eddy simulation(WMLES)is an attractive method to deal with near wall turbulence.However,the effect of subgrid-scale(SGS)models for wall-bounded turbulent flow in combination with wall stress models is still unclear.In this paper,turbulent channel flow at Reτ=1000 are numerically simulated by WMLES in conjunction with four different SGS models,i.e.,the wall-adapting local eddy-viscosity model,the dynamic Smagorinsky model,the dynamic SGS kinetic energy model and the dynamic Lagrangian model.The mean velocity profiles are compared with the law of the wall,and the velocity fluctuations are compared with direct numerical simulation data.The energy spectrum of velocity and wall pressure fluctuations are presented and the role of SGS models on predicting turbulent channel flow with WMLES is discussed.

关键词： Wall-modeled large-eddy simulation(WMLES) subgrid-scale(SGS)model turbulent channel flow energy spectra

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Six-hierarchy model of accident analysis and its application in coal mine accidents

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Journal of Safety Science and Resilience 2022年第1期3卷 61-71页

作者： Qiuju Ma Mengsai wan Juncheng Shao Mingyu Zhong Yuhao guo wei wang School of Emergency Management and Safety Engineering China University of Mining and TechnologyBeijing 100083China Shanghai Fire Science and Technology Research Institute of MEM Shanghai 200032China

Accident analysis models play a significant role in accident investigation and analysis.Most traditional models,usually based on a chain of events,have serious limitations when used for complex systems,especially for coal mine accident.HFACS is a widely accepted accident cause model with complex structure and content.Based on HFACS and accident investigation need in China,a new systemic accident analysis method“Six-hierarchy model”is proposed.And the index database of accident causal factors at each hierarchy of coal mine accidents is established.This model provides clear guidance for the prevention of accidents from six levels,which helps to the targeted rectification after accidents and the improvement of safety management level.The source,ap-plication scope,advantages and disadvantages of HFACS and six-hierarchy model are compared.The“2.14”gas explosion accident in Sunjiawan coal mine is analyzed by using HFACS and six-hierarchy model and the safety management suggestions are put forward.The study shows that the Six-hierarchy model provides a clear guide for the prevention of accidents from six levels.And it benefits the targeted rectification after accidents and the continuous improvement of safety management.

关键词： Accident Accident analysis Six-hierarchy Coal mine accident HFACS

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Effect of die structure parameters on deformation behavior of bent tube in free bending process

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Journal of Iron and Steel Research(International) 2023年第3期30卷 487-503页

作者： wei wang Cheng Cheng Li wan Jie Tao Xun-zhong guo Chun-mei Liu College of Material Science and Technology Nanjing University of Aeronautics and AstronauticsNanjing 211100JiangsuChina State Key Laboratory of Digital Manufacturing Equipment and Technology Huazhong University of Science and TechnologyWuhan 430074HubeiChina Capital Aerospace Machinery Corporation Beijing 100076China

The bending section of tube between the bending die and the guider is in a less constrained state during the free bending process.The free bending dies have the important impact on the plastic deformation behavior and the forming quality of tube.To study the evolution law of the deformation behavior of tube with the die structure parameters and optimize the free bending die parameters,the free bending experiments and the corresponding numerical simulations were carried out.The design principle of free bending die was illustrated.The free bending experiment was conducted to verify the reliability of the numerical simulation method.Based on the numerical simulation results,the influence of the distance between the center point of bending die and the front end of guider on the forming quality of bent tube is more obvious than that of the fillet of guider.However,the fillet of bending die hardly affects the stress and strain distribution and the evolution of the wall thickness.Finally,the free bending experiments with the newly determined free bending dies were conducted.The ultimate bending radius of bent tube is reduced and the forming quality is improved.

关键词： Free bending Die structure parameter Forming quality Numerical simulation Tube

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Preliminary control of the air entrainment in bow wave based on the Liutex force method

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Journal of Hydrodynamics 2022年第3期34卷 483-490页

作者： Yi-ding Hu Jian-wei Wu De-cheng wan guo wang Yi-qian wang Computational Marine Hydrodynamics Lab(CMHL) School of Naval ArchitectureOcean and Civil EngineeringShanghai Jiao Tong UniversityShanghai200240China Wuhan Second Ship Design and Research Institute Wuhan430205China Marine Design and Research Institute of China Shanghai200011China School of Mathematical Science Soochow UniversitySuzhou215006China

Trails induced by air entrainment of bow wave breaking can be observed clearly around an advancing ship,making it prong to be detected and causing reduction in hydrodynamic performance.In breaking bow wave region,different scale of coherent vortex structures related closely to the air entrainment are generated.The formation and evolution of bubble clouds can be accounted partly by the swirling vortex flow of the jet plunging.In this work,high-fidelity simulation of the bow wave breaking around a rectangular thin plate is performed with the in-house code BAMR-SJTU.A Liutex force model is constructed to investigate the interaction between the free surface and vortices,and to explore the possibility of alleviating or controlling the air entrainment.This study is the first attempt to manipulate vortices corresponding to the air entrainment of the bow wave breaking.Some typical vortex structures based on the Liutex vortex identification method and the distribution of the vortex force are presented.Comparison of the vortex structures and the entrapped bubbles is conducted to illustrate the efficiency of Liutex force model in air entrainment control.

关键词： Bow wave breaking air entrainment coherent vortex structures Liutex force field model

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Cytomegalovirus Pneumonia in Patients with Rheumatic Diseases After Immunosuppressive Therapy： A Single Center Study in China

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Chinese Medical Journal 2016年第3期129卷 267-273页

作者： Yu Xue Li Jiang Wei-Guo Wan Yu-Ming Chen Jiong Zhang Zhen-Chun Zhang Department of Rheumatology Huashan Hospital Fudan University Shanghai 200040 China Institute of Rheumatology Immunology and Allergy Fudan University Shanghai 200040 China Department of Rheumatology Linyi People's Hospital Linyi Shandong 276000 China Department of Laboratory Medicine Huashan Hospital Fudan University Shanghai 200040 China

Background： Rheumatic diseases involve multiple organs that are affected by immunological mechanisms.Treatment with corticosteroids and immunosuppressive agents may also increase the frequency of infection.Cytomegalovirus （CMV） is a widespread herpes virus and a well-recognized pathogen, which causes an opportunistic and potentially fatal infection in immunocompromised patients.This retrospective study aimed to investigate the clinical and laboratory characteristics of CMV pneumonia in patients with rheumatic diseases after immunosuppressive therapy in a single center in Shanghai, China.Methods： Eight hundred and thirty-four patients with rheumatic diseases who had undergone CMV-DNA viral load tests were included, and the medical records of 142 patients who were positive for CMV-DNA in plasma samples were evaluated.GraphPad Prism version 5.013 （San Diego, CA, USA） was used to conduct statistical analysis.The correlation between CMV-DNA viral loads and lymphocyte counts was assessed using the Spearman rank correlation coefficient test.Significance between qualitative data was analyzed using Pearson＆#39;s Chi-squared test.The cut-offthresholds for CMV-DNA viral load and lymphocyte count were determined by receiver operating characteristic （ROC） curve analysis.Results： One hundred and forty-two patients had positive CMV viral load tests.Of these 142 patients, 73 patients with CMV pneumonia were regarded as symptomatic, and the other 69 were asymptomatic.The symptomatic group received higher doses ofprednisolone （PSL） and more frequently immunosuppressants than the asymptomatic group （P 〈 0.01）.The symptomatic group had lower lymphocyte counts, especially CD4＋ T-cells, than the asymptomatic group （P 〈 0.01）.By ROC curve analysis, when CD4＋ T-cell count was 〈0.39 ＆#215; 109/L, patients with rheumatic diseases were at high risk for symptomatic CMV infection.The CMV-DNA load was significantly higher in the symptomatic patients than that in asymptomatic patients （P 〈 0.01;threshold viral loads： 1.75 ＆#215; 104 copies/ml）

关键词： Cytomegalovirus Cytomegalovirus Pneumonia Polymerase Chain Reaction Rheumatic Disease Viral Load

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An Innovative Three-Dimensional Method for Identifying a Proper Femoral Intramedullary Entry Point in Total Knee Arthroplasty

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Chinese Medical Journal 2018年第21期131卷 2531-2536页

作者： Lu-Yao Ma Hong-Yu wei Fu-Yin wan wan-Shou guo Jin-Hui Ma 'Department of Orthopaedics Second Hospital of Shanxi Medical University Taiyuan Shanxi 030001 China Department of Orthopaedics China-Japan Friendship Hospital Beijing 100029 China Department of Orthopaedics Peking University China-Japan Friendship School of Clinical Medicine Beijing 100029 China

Background： Identification of the proper femoral intramedullary （IM） access point is an important determinant of final implant position in IM-guided total knee arthroplasty （TKA）. The aim of this study was to identify the optimal entry point in Chinese participants using a new three-dimensional method. Methods： A series of computed tomography scans of 44 femurs in Chinese participants from October 2014 to October 2015 were imported into Mimics 17.0 software to identify the optimal entry point. The apex of the intercondylar notch （AIN） was used as the reference bony anatomical landmark to identify the proper entry point to insert the IM rod. The statistical significance was calculated on the basis of a 5% level （P 〈 0.05） using the Student＇s t-test. Results： For the males, the average ideal entry point was 1.49 mm medial and 13.39 mm anterior to the AIN. The values were 1.77 mm medial and 15.29 mm anterior to the AIN in females. A significant difference was present between males and females （13.39 ±2.46 mm vs. 15.29 ± 3.44 mm, t = 2.124, P = 0.040）. When using the recommended location as the entry point for the IM rod, the mean potential error differed significantly from the femoral trochlear groove （the potential error of IM in males in coronal plane： 0.93~ ±0.24~ vs. 1.27~ ± 0.32~, t = -4.166, P 〈 0.001; the potential error of 1M in males in sagittal plane： 1.40° ± 0.42° vs. 2.79° ± 0.70°, t = -7.155, P 〈 0.001; the potential error oflM in females in coronal plane： 0.73° ± 0.28° vs. 1.15° ± 0.35°, t = -3.940, P 〈 0.001 ： and the potential error of 1M in females in sagittal plane： 1.48° ±0.47° vs. 2.76° ± 0.83°, t = -5.574, P 〈 0.001 ）. A significant difference was present between the recommended point and the point 10 mm anterior to the origin of the posterior cruciate ligament （the potential error of IM in males in coronal plane： 0.93° ± 0.24° vs. 1.53° ±0.43°, t = -5.948, P 〈 0.001 ; the potential error of IM in males in sagittal plane： 1.40° ± 0.42° vs. 2.15°± 0.75°, t = -3.152, P = 0.003; the potential error

关键词： Displacement Femoral lntramedullary Guide Intercondylar Notch Total Knee Arthroplasty

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