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Flow characterization of macroporous W-4.8 vol.%ZrO2 alloy during hot deformation with improved constitutive equation and processing maps

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Tungsten 2024年第3期6卷 610-620页

作者： jia-Hao Ye Liu-jie xu ji-Kang Hu School of Materials Science and Engineering Henan University of Science and Technology National Joint Engineering Research Center for Abrasion Control and Molding of Metal Materials Henan University of Science and Technology

In this work,isothermal compression experiments of macroporous W-4.8 vol.%ZrO2（W-4.8ZrO2） at 1300-1600℃ and strain rate of 0.005-1 s-1were carried out on a Gleeble-1500D thermo-mechanical *** dynamic recovery of W-4.8ZrO2is the main "softening" *** the basis of Arrhenius model,the initial constitutive equation is established by exploring the influence of temperature,strain rate and rheological *** on Arrhenius model,the relationship between flow stress,strain rate and deformation temperature is *** the influence of strain,the improved constitutive equation and the law of material constant changing with the strain are *** that,the hot processing maps were drawn on the basis of the dynamic material model,which is used to analyze the instability mechanism of the W-4.8ZrO2,and determine the appropriate hot working process parameters(temperature:1350-1450℃,strain rate:0.1-1 s-1).

关键词： Tungsten alloy Flow characteristics Constitutive equation Hot processing maps

Span-based joint entity and relation extraction augmented with sequence tagging mechanism

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Science China(Information Sciences) 2024年第5期67卷 84-98页

作者： Bin ji Shasha LI Hao xu jie YU Jun MA Huijun LIU jing YANG College of Computer National University of Defense Technology

Span-based joint extraction simultaneously conducts named entity recognition(NER) and relation extraction(RE) in a text span form. However, since previous span-based models rely on span-level classifications, they cannot benefit from token-level label information, which has been proven advantageous for the task. In this paper, we propose a sequence tagging augmented span-based network(STSN), a spanbased joint model that can make use of token-level label information. In STSN, we construct a core neural architecture by deep stacking multiple attention layers, each of which consists of three basic attention *** the one hand, the core architecture enables our model to learn token-level label information via the sequence tagging mechanism and then uses the information in the span-based joint extraction; on the other hand, it establishes a bi-directional information interaction between NER and RE. Experimental results on three benchmark datasets show that STSN consistently outperforms the strongest baselines in terms of F1,creating new state-of-the-art results.

关键词： joint extraction named entity recognition relation extraction span sequence tagging mechanism

An efficient data-driven global sensitivity analysis method of shale gas production through convolutional neural network

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Petroleum Science 2024年第4期21卷 2475-2484页

作者： Liang xue Shuai xu jie Nie ji Qin jiang-Xia Han Yue-Tian Liu Qin-Zhuo Liao State Key Laboratory of Petroleum Resources and Engineering China University of Petroleum (Beijing) Department of Oil-Gas Field Development Engineering College of Petroleum Engineering China University of Petroleum (Beijing) Chuanqing Drilling Engineering Co.Ltd. China National Petroleum Corporation

The shale gas development process is complex in terms of its flow mechanisms and the accuracy of the production forecasting is influenced by geological parameters and engineering parameters. Therefore, to quantitatively evaluate the relative importance of model parameters on the production forecasting performance, sensitivity analysis of parameters is required. The parameters are ranked according to the sensitivity coefficients for the subsequent optimization scheme design. A data-driven global sensitivity analysis(GSA) method using convolutional neural networks(CNN) is proposed to identify the influencing parameters in shale gas production. The CNN is trained on a large dataset, validated against numerical simulations, and utilized as a surrogate model for efficient sensitivity analysis. Our approach integrates CNN with the Sobol' global sensitivity analysis method, presenting three key scenarios for sensitivity analysis: analysis of the production stage as a whole, analysis by fixed time intervals, and analysis by declining rate. The findings underscore the predominant influence of reservoir thickness and well length on shale gas production. Furthermore, the temporal sensitivity analysis reveals the dynamic shifts in parameter importance across the distinct production stages.

关键词： Shale gas Global sensitivity Convolutional neural network Data-driven

Single-cluster electronics using metallic clusters:Fabrications,regulations,and applications

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Nano Research 2024年第1期17卷 65-78页

作者： Caiyun Wei Wei xu Shurui ji Ruiyun Huang Junyang Liu Wenqiu Su jie Bai jiale Huang Wenjing Hong State Key Laboratory of Physical Chemistry of Solid Surfaces National Engineering Research Centre of Chemicals for Electronic ManufacturingCollege of Chemistry and Chemical Engineering&Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province(IKKEM)Xiamen UniversityXiamen 361005China

Metallic clusters,ranging from 1 to 2 nm in size,have emerged as promising candidates for creating nanoelectronic devices at the single-cluster *** the intermediate quantum properties between metals and semiconductors,these metallic clusters offer an alternative pathway to silicon-based electronics and organic molecules for miniaturized electronics with dimensions below 5 *** progress has been made in studies of single-cluster electronic ***,a clear guide for selecting,synthesizing,and fabricating functional single-cluster electronic devices is still *** review article provides a comprehensive overview of single-cluster electronic devices,including the mechanisms of electron transport,the fabrication of devices,and the regulations of electron transport ***,we discuss the challenges and future directions for single-cluster electronic devices and their potential applications.

关键词： single-cluster junctions electronic properties electron transport metallic clusters structure regulation

Elaborate Design of Two Novel Fluorescent Zinc-based Metal-Organic Frameworks for Highly Efficient Tetracycline Antibiotics Detection

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Chemical Research in Chinese Universities 2024年第3期40卷 499-507页

作者： TAO He ji Chengshan ZHANG jian YIN Yuanyuan jiA Wenwen jiANG Xin xu jie YANG Yulin MIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage School of Chemistry and Chemical EngineeringHarbin Institute of TechnologyHarbin 150001P.R.China

The abuse of tetracycline antibiotics has caused great harm to human health and *** inexpensive,convenient and sensitive methods for the detection of tetracycline antibiotics is highly ***,based on the H_(4)ddp ligand[H_(4)ddp=3-(3,5-dicarboxyphenyl)pyridine-2,6-dicarboxylic acid],two novel zinc-based metal-organic frameworks(MOFs){[Zn_(3)(ddp)_(2)(H_(2)O)_(4)]·3H_(2)O}n(Zn1-ddp)and{[Zn_(3)(ddp)_(2)(H_(2)O)_(4)]·3H_(2)O}n(Zn2-ddp)were successfully designed by delicate structural *** Zn1-ddp and Zn2-ddp exhibited excellent water and chemical stability and showed excellent fluorescence quenching performance for tetracycline ***,the more advanced framework structure and better fluorescent performance make Zn1-ddp more sensitive than Zn2-ddp in fluorescent detection with a detection limit of 0.29µmol/L for tetracycline(TC),0.09µmol/L for doxycycline(DOX),0.10µmol/L for minocycline(MIN)and metacycline(MEL),0.19µmol/L for chlortetracycline(CTC),and 0.67µmol/L for oxytetracycline(OTC)among tetracycline *** fluorescence quenching mechanism of Zn1-ddp and Zn2-ddp for tetracycline antibiotics detection was deeply *** reasons for the superior detection performance of Zn1-ddp over Zn2-ddp were also analyzed in depth through Fourier transform infrared spectrophotometry(FTIR),X-ray photoelectron spectroscopy(XPS)analysis and framework structure *** developed method opens up a new perspective for antibiotics detection based on zinc-based MOFs.

关键词： Water system Metal-organic framework Fluorescent detection Tetracycline antibiotic

Soft coarse-grained particle model for particle-fluid systems

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Particuology 2024年第1期84卷 178-193页

作者： Yanhao Ye ji xu Wei Ge State Key Laboratory of Multiphase Complex Systems Institute of Process EngineeringChinese Academy of SciencesBeijing100190China School of Chemical Engineering University of Chinese Academy of SciencesBeijing100049China Innovation Academy for Green Manufacture Chinese Academy of SciencesBeijing100190China

By modeling a group of neighboring real particles as a single coarse-grained particle(CGP),discrete particle method(DPM)is now capable of simulating industrial-scale particle-fluid ***,a systematic approach to determine the CGP properties and develop their interaction models is still lacking,which casts uncertainty on the predictivity of the *** this study,collisions between predefined particle groups are analyzed to construct kernel functions for modeling the CGPs and then the model parameters are determined by equating the statistical properties of the CGPs and the real particles in the physical process *** approach is implemented for homogeneous cooling of granular gas,then demonstrated effective in simulating experimental fluidized beds.

关键词： Coarse-grain(CG) Discrete particle method(DPM) Fluidized bed Multi-scale simulation

A modern survey method for determining live loads based on multi-source and open-access data on the Internet

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Frontiers of Structural and Civil Engineering 2024年第8期18卷 1135-1147页

作者： Chi xu Jun CHEN jie LI School of Civil Engineering Tongji UniversityShanghai 200092China The State Key Laboratory on Disaster Reduction in Civil Engineering Tongji UniversityShanghai 200092China

Sufficient survey data are required to describe the stochastic behaviors of live ***,due to manual and on-site operation required by traditional survey methods,traditional surveys face challenges like occupant resistance,high costs,and long implementation *** study proposes a new survey method to access live load data online and *** samples are acquired from multi-source,open-access and dynamically updated data on the *** change intervals,geometrical dimensions and object quantities are obtained from transaction information,building attributes and virtual reality models on real estate websites,*** object weights are collected from commodity information on e-commerce *** integration of the aforementioned data allows for the extraction of necessary statistics to describe a live load *** proposed method is applied to a live load survey in China,covering 20040 m^(2),with around 90000 samples acquired for object weights and load *** survey results reveal that about 70%−80%of the amplitude statistics are attributable to 1/6 of the total object types.

关键词： live load online survey method data acquisition data integration

Nanoforming of transferred metal contacts for enhanced twodimensional field effect transistors

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Nano Research 2024年第4期17卷 3210-3216页

作者： Shuoheng xu Zheng Huang jie Guan Yaowu Hu The Institute of Technological Sciences Wuhan UniversityWuhan 430072China School of Power and Mechanical Engineering Wuhan UniversityWuhan 430072China School of Physics Southeast UniversityNanjing 211189China

Two-dimensional transition metal chalcogenides(2D-TMDs)have attracted much attention because of their unique layered structure and physical properties for transistor *** transferred metal contacts on these low-dimensional materials or their homogeneous and heterogeneous multilayers have generated huge interest to avoid deposition *** this paper,we show that there are large physical gaps at both the edge contact and surface contact between the transferred electrodes and the 2D materials.A method called laser shock induced superplastic deformation(LSISD)is proposed to tackle this issue and enhance the performance of the *** enhancement mechanism was investigated by molecular dynamics(MD)simulations of the nanoforming process,atomic force microscopy(AFM),scanning electron microscopy(SEM),transmission electron microscopy(TEM)characterizations of the interfaces,and density functional theory(DFT)*** force effect of laser shock can reduce the contact gap between metals and *** electrical performances of the transistors before and after LSISD,along with MD simulations,are used to find the optimal process *** addition,this paper applies the LSISD method to the short-channel MoS_(2)/graphene vertical transistors to show potential improvement in interface contact and electrical *** paper demonstrates the first report on using mechanical force induced by laser shock to enhance metal–semiconductor interfaces and transistor performances.

关键词： laser shock nanoforming metal-semiconductor contact electronics two-dimensional transistors

Durable Ru Nanocrystal with HfO_(2)Modification for Acidic Overall Water Splitting

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Nano-Micro Letters 2024年第9期16卷 462-477页

作者： Xiangkai Kong jie xu Zhicheng Ju Changle Chen School of Materials and Physics China University of Mining and TechnologyXuzhou 221116JiangsuPeople’s Republic of China Anhui Province Key Laboratory of Pollutant Sensitive Materials and Environmental Remediation Huaibei Normal UniversityHuaibei 235000AnhuiPeople’s Republic of China School of Chemistry and Materials Science University of Science and Technology of ChinaHefei 230026AnhuiPeople’s Republic of China School of Chemistry and Chemical Engineering Nanjing UniversityNanjing 210023JiangsuPeople’s Republic of China

Durable and efficient bi-functional catalyst,that is capable of both oxygen evolution reaction and hydrogen evolution reaction under acidic condition,are highly desired for the commercialization of proton exchange membrane water ***,we report a robust L-Ru/HfO_(2)heterostructure constructed via confining crystalline Ru nanodomains by HfO_(2)*** assembled with a proton exchange membrane,the bi-functional L-Ru/HfO_(2)catalyst-based electrolyzer presents a voltage of 1.57 and 1.67 V to reach 100 and 300 mA cm^(-2)current density,prevailing most of previously reported Ru-based materials as well as commercial Pt/C||RuO_(2)*** is revealed that the synergistic effect of HfO_(2)modification and small crystalline domain formation significantly alleviates the over-oxidation of *** importantly,this synergistic effect facilitates a dual-site oxide path during the oxygen evolution procedure via optimization of the binding configurations of oxygenated *** a result,the Ru active sites maintain the metallic state along with reduced energy barrier for the rate-determining step(^(*)O→^(*)OOH).Both of water adsorption and dissociation(Volmer step)are strengthened,while a moderate hydrogen binding is achieved to accelerate the hydrogen desorption procedure(Tafel step).Consequently,the activity and stability of acidic overall water splitting are simultaneously enhanced.

关键词： Ruthenium Hafnium dioxide Oxygen evolution catalysis Anti-oxidation

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