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Improving photochemical indicators for attributing ozone sensitivities in source apportionment analysis

Journal of Environmental Sciences 2024年第9期143卷 235-246页

作者： Xiaohui Du wei Tang Zhongzhi Zhang yang Yu yang Li Ling Huang Greg Yarwood Fan Meng Atmospheric Environment Institute Chinese Research Academy of Environmental SciencesBeijing 100012China College of Water Sciences Beijing Normal UniversityBeijing 100857China Asia Center for Air Pollution Research United Nations Environment Programme Asia and the Pacific OfficeNishi-kuNiigata-shi 9502144Japan School of Environmental and Chemical Engineering Shanghai UniversityShanghai 200444China Ramboll NovatoCalifornia 94945USA

Comprehensive Air Quality Model with extensions(CAMx)-Decoupled Direct Method(DDM)simulations of first-order ozone(O_(3))sensitivity to nitrogen oxides(NO_(x))and volatile organic compounds(VOCs)emissions were performed and combined with modelled P_(H_(2)O_(2))/P_(HNO_(3))ratios to obtain a range of thresholds for determining O_(3)-sensitivity regimes for different areas of *** the new threshold ranges for photochemical indicators,the method for determining O_(3)formation in the Ozone Source Apportionment Technology(OSAT)module within CAMx was improved by a dynamically varied threshold of P_(H_(2)O_(2))/P_(HNO_(3))*** O_(3)concentration contributions in the newly added transition regime were apportioned to NO_(x)and VOCs emissions in proportion to the relationship between the P_(H_(2)O_(2))/P_(HNO_(3))ratio and first-order O_(3)*** source contributions of O_(3)concentrations from different emission sectors from June to September 2019 were compared using the original and improved *** results showed that the O_(3)concentration contributions changed significantly in the NO_(x)-limited regime,with a maximum decrease of 21.89%,while the contributions increased by up to 7.57%in the VOC-limited regime,and were within 15μg/m^(3)in the transition *** modified OSAT module enabled a more sophisticated attribution of O_(3)to precursor emissions and may have far-reaching implications for informing O_(3)pollution control policy.

关键词： O_(3) modeling O_(3)-sensitivity regimes Ozone source apportionment technology Photochemical indicators

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Dynamic recrystallization behavior and strengthening mechanism of a novel Mo-Ti_(3)AlC_(2) alloy at ultrahigh temperature

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Rare Metals 2024年第8期43卷 3946-3960页

作者： Lu yang Xin-Yuan Zheng yang Zhao Xi-Ran Wang Fang-Nao Xiao Shi-Zhong wei School of Materials Science and Engineering Henan University of Science and TechnologyLuoyang 471023China National Joint Engineering Research Center for Abrasion Control and Molding of Metal Materials Henan University of Science and TechnologyLuoyang 471003China Department of Applied Mechanics Univ.Bourgogne FrancheComteFEMTO-ST InstituteCNRS/UF/ENSMM/UTBM25000BesangonFrance

Increasing the recrystallization temperature to achieve better high-temperature performance is critical in the development of molybdenum alloys for ultrahightemperature applications,such as the newest generation of multitype high-temperature nuclear *** this study,an innovative strategy was proposed to improve the performance of molybdenum alloys at high temperature by using the two-dimensional MAX(where M is an early transition metal,A is an A-group element and X is C or N)ceramic material Ti_(3)AlC_(2).The relationships between flow stress,strain rate and temperature were *** microstructure,distribution of misorientation and evolution of dislocations in the Mo-Ti_(3)AlC_(2) alloy were *** microscopic mechanism of the Ti_(3)AlC_(2) phase in the molybdenum alloy at high temperatures was *** experimental results showed that the peak flow stress of Mo-Ti_(3)AlC_(2) at 1600℃ reached 155 MPa,which was161.8% greater than that of pure *** activation energy of thermal deformation of Mo-Ti_(3)AlC_(2) was as large as537 kJ·mol~(-1),which was 17.6% more than that of pure *** recrystallization temperature reached 1600℃ or even *** topological reaction of the Ti_(3)AlC_(2) phase consumed a large amount of energy at high temperatures,resulting in increases in the deformation activation *** structures of AlTi_3 and Ti-O Magneli-phase oxides(Ti_nO_(2n-1)) were formed in-situ,which relied on kink bands and interlayer slip,resulting in many dislocations during ***,the special two-dimensional of the structure Ti_(3)AlC_(2) ceramic inhibited the recrystallization behavior of the Mo *** results of this study can provide theoretical guidance for the development of a new generation of molybdenum alloys for use in ultrahigh-temperature environments.

关键词： Mo alloy Two-dimensional reinforcement Dynamic recrystallization behavior Hot deformation Mechanical properties

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Does City Shape Affect China's Economic Development?

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China & World Economy 2024年第1期32卷 21-56页

作者： wei Zou Fei yang Economics and Management School Wuhan UniversityChina

This paper constructs a general equilibrium spatial urban model and measures city geometric compactness using the patch-shape index based on evidence from satellite imagery and basic vector maps of *** adopts the ordinary least squares and instrumental variable approaches to examine the effect of city shape on the urban development of 279 Chinese cities at or above the prefecture *** empirical results show that there was a significant negative correlation between city shape and economic ***,every 1 percentage point increase in the patch-shape index led to a decrease in city-scale GDP by 0.009 percent,housing prices by 0.044 percent,and wages by 0.024 *** compact urban layouts attracted an inflow of households and firms,stimulated city economic growth,and were associated with increased housing prices and wage *** paper considers the cities'initial conditions,trends in population changes(expanding,shrinking,and stagnant cities),and geographic factors,and finds that the results are *** array of policy implications can be drawn from the research.

关键词： city footprint compactness economic development urban spatial shape

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A new model simulating the development of gas condensate reservoirs

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Energy Geoscience 2024年第1期5卷 239-248页

作者： yang yang Zengmin Lun Rui Wang Maolei Cui wei Hu Petroleum Exploration and Production Research Institute SINOPECBeijing100083China

A new simulation model for the development of gas condensate reservoirs is introduced based on the influence that phase change,non-Darcy flow,and capillary pressure have on the production of gas *** model predicts well performance,including bottom-hole pressure,oil/gas production rate,oil/gas recovery,gaseoil ratio,and the change in produced fluid *** also calculates dynamic characters,such as the change of pressure field and oil/gas saturation field during the development of gas condensate *** model is applicable to different boundary conditions(both constant-pressure and sealed boundary)and different production modes(both constant-pressure and constant-volume production modes).Model validation attempted using numerical simulation results for sealed boundary conditions with constant-pressure production mode has shown a relatively good match,proving its *** constant-pressure boundary conditions with constant-volume production mode,four stages are defined according to the dynamic behavior of production performance in the development of gas condensate reservoirs.

关键词： Gas condensate reservoir Phase behavior Numerical simulation Pseudo-pressure method

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Learning a Mixture of Conditional Gating Blocks for Visual Question Answering

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Journal of Computer Science & Technology 2024年第4期39卷 912-928页

作者： Qiang Sun Yan-wei Fu Xiang-yang Xue School of Statistics and Information Shanghai University of International Business and EconomicsShanghai 201620China Academy for Engineering and Technology Fudan UniversityShanghai 200433China School of Data Science Fudan UniversityShanghai 200433China School of Computer Science Fudan UniversityShanghai 200433China

As a Turing test in multimedia,visual question answering(VQA)aims to answer the textual question with a given ***,the“dynamic”property of neural networks has been explored as one of the most promising ways of improving the adaptability,interpretability,and capacity of the neural network ***,despite the prevalence of dynamic convolutional neural networks,it is relatively less touched and very nontrivial to exploit dynamics in the transformers of the VQA tasks through all the stages in an end-to-end ***,due to the large computation cost of transformers,researchers are inclined to only apply transformers on the extracted high-level visual features for downstream vision and language *** this end,we introduce a question-guided dynamic layer to the transformer as it can effectively increase the model capacity and require fewer transformer layers for the VQA *** particular,we name the dynamics in the Transformer as Conditional Multi-Head Self-Attention block(cMHSA).Furthermore,our questionguided cMHSA is compatible with conditional ResNeXt block(cResNeXt).Thus a novel model mixture of conditional gating blocks(McG)is proposed for VQA,which keeps the best of the Transformer,convolutional neural network(CNN),and dynamic *** pure conditional gating CNN model and the conditional gating Transformer model can be viewed as special examples of *** quantitatively and qualitatively evaluate McG on the CLEVR and VQA-Abstract *** experiments show that McG has achieved the state-of-the-art performance on these benchmark datasets.

关键词： visual question answering Transformer dynamic network

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Electromagnetic scattering and imaging simulation of extremely large-scale sea-ship scene based on GPU parallel technology

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Journal of Electronic Science and Technology 2024年第2期22卷 16-23页

作者： Cheng-wei Zhang Zhi-Qin Zhao wei yang Li-Lai Zhou Hai-Yu Zhu Southwest China Institute of Electronic Technology Chengdu610036China School of Electronic Science and Engineering University of Electronic Science and Technology of ChinaChengdu611731China Tencent Company Shenzhen518054China

Aiming to solve the bottleneck problem of electromagnetic scattering simulation in the scenes of extremely large-scale seas and ships,a high-frequency method by using graphics processing unit(GPU)parallel acceleration technique is *** the implementation of different electromagnetic methods of physical optics(PO),shooting and bouncing ray(SBR),and physical theory of diffraction(PTD),a parallel computing scheme based on the CPU-GPU parallel computing scheme is realized to balance computing ***,a multi-GPU framework is further proposed to solve the computational difficulty caused by the massive number of ray tubes in the ray tracing *** using the established simulation platform,signals of ships at different seas are simulated and their images are achieved as *** is shown that the higher sea states degrade the averaged peak signal-to-noise ratio(PSNR)of radar image.

关键词： Multi graphics processing unit Radar imaging Sea-ship Shooting and bouncing rays

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Modeling Near-Field Impulsive Waves Generated by Deformable Landslide Using the HBP Model Based on the SPH Method

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Journal of Ocean University of China 2024年第2期23卷 328-344页

作者： WANG wei wei weicheng CHAI Bo XIA Hao WANG yang DU Juan LIU Jizhixian School of Environmental Studies China University of GeosciencesWuhan 430078China Hubei Key Laboratory of yangtze Catchment Environmental Aquatic Science Wuhan 430078China Faculty of Engineering China University of GeosciencesWuhan 430074China Research Center for Geohazards Monitoring and Warning in Three Gorges Reservoir Wanzhou 404000China

Landslide-generated impulsive waves(LGWs)in reservoir areas can seriously threaten waterway safety as well as hu-man life and properties around the two side *** risk reduction and mitigation of such a hazard require the accurate prediction of near-field wave characteristics,such as wave amplitude and ***,near-field LGW involves complicated fluid-solid ***,the wave characteristics are closely related to various aspects,including the geometry and physical features of the slide,river,and body of ***,the empirical or analytical methods used for rough estimation cannot derive accurate results,especially for deformable landslides,due to their significant geometry changes during the sliding *** this study,the near-field waves generated by deformable landslides were simulated by smoothed particle hydrodynamics(SPH)based on multi-phase *** deformable landslides were generalized as a kind of viscous flow by adopting the Herschel-Bulkley-Papanastasiou(HBP)-based nonNewtonian rheology *** HBP model is capable of producing deformable landslide dynamics even though the high-speed sliding process is *** this study,an idealized experiment case originating from Lituya LGW and a practical case of Gongjiafang LGW were reproduced for verification and *** simulation results of both cases show satisfactory consistency with the experiment/investigation data in terms of landslide movement and near-field impulsive wave characteristics,thus indicating the applicability and accuracy of the proposed ***,the effects of the HBP model’s rheological parameters on the landslide dynamics and near-field wave characteristics are discussed,providing a parameter calibration method along with sug-gestions for further applications.

关键词： deformable landslide impulsive waves near-field SPH nonNewtonian fluids

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Micromechanism and mathematical model of stress sensitivity in tight reservoirs of binary granular medium

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Petroleum Science 2024年第3期21卷 1780-1795页

作者： Jian-Bang Wu Sheng-Lai yang Qiang Li Kun yang Can Huang Dao-Ping Lv wei Zhou State Key Laboratory of Petroleum Resources and Engineering China University of Petroleum(Beijing)Beijing2249China Laboratoire de G eologie Ecole Normale Sup erieure/CNRS UMR8538PSL Research UniversityParis75005France Research Institute of Exploration and Development Xinjiang Oilfield CompanyKaramay834000XinjiangChina

Research on reservoir rock stress sensitivity has traditionally focused on unary granular structures,neglecting the binary nature of real reservoirs,especially tight *** the stresssensitive behavior and mathematical characterization of binary granular media remains a challenging *** this study,we conducted online-NMR experiments to investigate the permeability and porosity evolution as well as stress-sensitive control mechanisms in tight sandy conglomerate *** results revealed stress sensitivity coefficients between 0.042 and 0.098 and permeability damage rates ranging from 65.6%to 90.9%,with an average pore compression coefficient of 0.0168—0.0208 MPa ***-scale compression occurred in three stages:filling,compression,and compaction,with matrix pores playing a dominant role in pore *** stress sensitivity of binary granular media was found to be influenced by the support structure and particle *** stress sensitivity was associated with small fine particle size,high fines content,high uniformity coefficient of particle size,high plastic deformation,and low Young's ***-supported samples exhibited a high irreversible permeability damage rate(average=74.2%)and stress sensitivity coefficients(average=0.089),with pore spaces more *** contrast,grain-supported samples showed low stress sensitivity coefficients(average=0.021)at high stress *** on the experiments,we developed a mathematical model for stress sensitivity in binary granular media,considering binary granular properties and nested interactions using Hertz contact deformation and Poiseuille *** describing the change in activity content of fines under stress,we characterized the non-stationary state of compressive deformation in the binary granular structure and classified the reservoir into three *** model was applied for production prediction using actual data from the Mahu reservoir in China,showing that the e

关键词： Stress sensitivity Binary granular medium Tight reservoir Online-NMR Reservoir energy retention rate

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Genetic mechanism of body size variation in groupers:Insights from phylotranscriptomics

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Zoological Research 2024年第2期45卷 314-328页

作者： wei-wei Zhang Zhuo-Ying Weng Xi Wang yang yang Duo Li Le Wang Xiao-Chun Liu Zi-Ning Meng State Key Laboratory of Biocontrol Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory of Aquatic Economic AnimalsSchool of Life SciencesSun Yat-sen UniversityGuangzhouGuangdong 510275China Southern Laboratory of Ocean Science and Engineering(Zhuhai) ZhuhaiGuangdong 519000China Area of Ecology and Biodiversity School of Biological SciencesUniversity of Hong KongHong Kong SAR 999077China Molecular Population Genetics Group Temasek Life Sciences LaboratorySingapore City 117604Singapore

Animal body size variation is of particular interest in evolutionary biology,but the genetic basis remains largely *** studies have shown the presence of two parallel evolutionary genetic clusters within the fish genus Epinephelus with evident divergence in body size,providing an excellent opportunity to investigate the genetic basis of body size variation in ***,we performed phylotranscriptomic analysis and reconstructed the phylogeny of 13 epinephelids originating from the South China *** genetic clades with an estimated divergence time of approximately 15.4 million years ago were correlated with large and small body size,respectively.A total of 180 rapidly evolving genes and two positively selected genes were identified between the two *** enrichment analyses of these candidate genes revealed distinct enrichment categories between the two *** pathways and genes may play important roles in body size variation in groupers through complex regulatory *** on our results,we speculate that the ancestors of the two divergent groups of groupers may have adapted to different environments through habitat selection,leading to genetic variations in metabolic patterns,organ development,and lifespan,resulting in body size divergence between the two locally adapted *** findings provide important insights into the genetic mechanisms underlying body size variation in groupers and species differentiation.

关键词： Phylotranscriptomics Grouper Body size Rapidly evolving genes(REGs) Positively selected genes(PSGs)

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A review of structural modification and biological activities of oleanolic acid

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Chinese Journal of Natural Medicines 2024年第1期22卷 15-30页

作者： yang Huali DENG Minghui JIA Hongwei ZHANG Kaicheng LIU yang CHENG Maosheng XIAO wei State Key Laboratory of New-tech for Chinese Medicine Pharmaceutical Process Jiangsu Kanion Pharmaceutical Co.Ltd.Lianyungang 222001China Key Laboratory of Structure-Based Drug Design&Discovery of Ministry of Education School of Pharmaceutical EngineeringShenyang Pharmaceutical UniversityShenyang 110016China

Oleanolic acid(OA),a pentacyclic triterpenoid,exhibits a broad spectrum of biological activities,including antitumor,antiviral,antibacterial,anti-inflammatory,hepatoprotective,hypoglycemic,and hypolipidemic *** its initial isolation and identification,numerous studies have reported on the structural modifications and pharmacological activities of OA and its *** this,there has been a dearth of comprehensive reviews in the past two decades,leading to challenges in subsequent research on *** on the main biological activities of OA,this paper comprehensively summarized the modification strategies and structureactivity relationships(SARs)of OA and its derivatives to provide valuable reference for future investigations into OA.

关键词： Oleanolic acid Derivatives Pentacyclic triterpenoid Structural modification Biological activities

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