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Acta Mathematicae Applicatae Sinica 2024年第2期40卷 539-546页

作者： Wen wang Da-peng XIE Hui zhou School of Mathematics and Statistics Hefei Normal UniversityHefei 230601China

In this paper,we prove a local Hamilton type gradient estimate for positive solution of the nonlinear parabolic equation ut(x,t)=Δu(x,t)+au(x,t) ln u(x,t)+bu^(α)(x,t),on M×(-∞,∞) with α∈R,where a and b are *** ... 详细信息

关键词： nonlinear parabolic equation gradient estimate Harnack inequality

Towards robustness and generalization of point cloud representation:A geometry coding method and a large-scale object-level dataset

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Computational Visual Media 2024年第1期10卷 27-43页

作者： Mingye Xu Zhipeng zhou Yali wang Yu Qiao Guangdong-Hong Kong-Macao Joint Laboratory of Human-Machine Intelligence-Synergy Systems Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhen518000China University of Chinese Academy of Sciences Beijing065001China Shanghai AI Laboratory Shanghai200001China SIAT Branch Shenzhen Institute of Artificial Intelligence and Robotics for SocietyShenzhen518000China Alibaba DAMO Academy Hangzhou242332China

Robustness and generalization are two challenging problems for learning point cloud *** tackle these problems,we first design a novel geometry coding model,which can effectively use an invariant eigengraph to group points with similar geometric information,even when such points are far from each *** also introduce a large-scale point cloud dataset,*** consists of 184 categories and 51,915 synthetic objects,which brings new challenges for point cloud classification,and provides a new benchmark to assess point cloud cross-domain ***,we perform extensive experiments on point cloud classification,using ModelNet40,ScanObjectNN,and our PCNet184,and segmentation,using ShapeNetPart and *** method achieves comparable performance to state-of-the-art methods on these datasets,for both supervised and unsupervised *** and our dataset are available at https://***/MingyeXu/PCNet184.

关键词： geometry coding self-supervised learning point cloud classification segmentation 3D analysis

Record-breaking summer-autumn drought in southern China in 2022:Roles of tropical sea surface temperature and Eurasian warming

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Science China Earth Sciences 2024年第2期67卷 420-431页

作者： Yuepeng HU Botao zhou Huijun wang Dapeng ZHANG Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters/Key Laboratory of Meteorological Disaster Ministry of Education/Joint International Research Laboratory of Climate and Environment ChangeNanjing University of Information Science and TechnologyNanjing210044China School of Atmospheric Sciences Nanjing University of Information Science and TechnologyNanjing210044China

From summer to autumn in 2022,a severe drought lasted in southern China,posing serious effects on economic growth and ecological *** study explored the atmospheric circulations accounting for this persistent drought *** shows that the drought in southern China during the summer of 2022 was strongly linked to the divergence of water vapor flux and descending motions,which were respectively caused by the anomalous anticyclone over the western North Pacific and the northward movement of the East Asian subtropical jet(EASJ).Differently,the atmospheric background responsible for the sustained drought in autumn is manly featured by a cyclonic circulation anomaly over the region from the Bay of Bengal to the South China Sea,which led to decreased moisture and descending motions in southern *** investigation suggests that the rarely strong surface warming over northern Eurasia and the extreme La Nina-like pattern over the tropical Pacific jointly resulted in the anomalous anticyclone over the western North Pacific and the northward shift of the EASJ in the summer of 2022,while the cyclonic circulation anomaly prevailing over the region from the Bay of Bengal to the South China Sea in autumn was largely attributed to the extremely negative anomalies of the tropical Indian Ocean sea surface temperature.

关键词： Summer-autumn drought Southern China Tropical sea surface temperature Eurasian warming

Feature-Grounded Single-Stage Text-to-Image Generation

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Tsinghua Science and Technology 2024年第2期29卷 469-480页

作者： Yuan zhou Peng wang Lei Xiang Haofeng Zhang School of Artificial Intelligence Nanjing University of Information Science and TechnologyNanjing 210044China School of Computer Science and Engineering Nanjing University of Science and TechnologyNanjing 210094China

Recently,Generative Adversarial Networks(GANs)have become the mainstream text-to-image(T2I)***,a standard normal distribution noise of inputs cannot provide sufficient information to synthesize an image that approaches the ground-truth image ***,the multistage generation strategy results in complex T2I ***,this study proposes a novel feature-grounded single-stage T2I model,which considers the“real”distribution learned from training images as one input and introduces a worst-case-optimized similarity measure into the loss function to enhance the model's generation *** results on two benchmark datasets demonstrate the competitive performance of the proposed model in terms of the Frechet inception distance and inception score compared to those of some classical and state-of-the-art models,showing the improved similarities among the generated image,text,and ground truth.

关键词： text-to-image(T2I) feature-grounded single-stage generation Generative Adversarial Network(GAN)

Acetylacetone effectively controlled the secondary metabolites of Microcystis aeruginosa under simulated sunlight irradiation

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Journal of Environmental Sciences 2024年第1期135卷 285-295页

作者： Xiaomeng wang Yixin Luo Shujuan Zhang Lixiang zhou Department of Environmental Engineering College of Resources and Environmental SciencesNanjing Agricultural UniversityNanjing 210095China The State Key Laboratory of Pollution Control and Resource Reuse School of the EnvironmentNanjing UniversityNanjing 210023China

Inactivation of cyanobacterial cells and simultaneous control of secondary metabolites is of significant necessity for the treatment of cyanobacteria-laden ***(AcAc)has been reported a specific algicide to inactivate Microcystis aeruginosa(***)and an effective light activator to degrade *** study systematically investigated the photodegradation ability of AcAc under xenon(Xe)irradiation on the secondary metabolites of ***,mainly algal organic matter(AOM),especially toxic microcystin-LR(MC-LR).Results showed that AcAc outperformed H_(2)O_(2)in destructing the protein-like substances,humic acid-like matters,aromatic proteins and fulvic-like substances of *** MC-LR(250μg/L),0.05 mmol/L AcAc attained the same degradation efficiency(87.0%)as 0.1mmol/L H_(2)O_(2).The degradation mechanism of Xe/AcAc might involve photo-induced energy/electron transfer and formation of carbon center *** conditions(pH>9.0)were detrimental to the photoactivity of AcAc,corresponding to the observed degradation rate constant(k_(1)value)of MC-LR drastically decreasing to 0.0013 min^(-1)as solution pH exceeded *** PO_(4)^(3-)and HCO_(3)^(-)ions had obvious inhibition effects,whereas NO_(3)^(-)slightly improved k_(1)value from 0.0277 min^(-1)to 0.0321 min^(-1).The presence of AOM did not significantly inhibit MC-LR degradation in Xe/AcAc *** addition,the biological toxicity of MC-LR was greatly reduced after *** results demonstrated that AcAc was an alternative algicidal agent to effectively inactivate algal cells and simultaneously control the secondary metabolites after cell ***,the concentration and irradiation conditions should be further optimized in practical application.

关键词： Microcystis aeruginosa Photodegradation Acetylacetone Secondary metabolites Microcystin

Grading of products utilizing bamboo as a substitute for plastic based on environmental effects

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Science China Earth Sciences 2024年第9期67卷 2989-2998页

作者： Meng ZHANG Guomo zhou Lei GU Wenshuo wang College of Forestry Beijing Forestry UniversityBeijing 100083China Key Laboratory of Carbon Cycling in Forest Ecosystems and Carbon Sequestration of Zhejiang Province Zhejiang A&F UniversityHangzhou 311300China

To achieve sustainable development goals,mitigate plastic pollution,and promote eco-friendly products,it is crucial to identify key products in the bamboo as a substitute for plastic(BSP)industry and assess their environmental *** study proposed a novel evaluation method for the environmental effect of bamboo as a substitute for plastic(EBSP).It focused on the contributions of BSP products in reducing plastic pollution and greenhouse gas *** established a set of EBSP evaluation indicators and developed a grading model,evaluating 30 typical BSP products across six *** results showed that the EBSP evaluation model,based on the emission reduction rate of substitution(ERRS),substitution rate of material(SRM),and product renewal ratio(PRR),can accurately quantify the environmental benefits of BSP *** model has successfully facilitated precise quantification of the EBSP and established a rational and effective grading system for BSP *** results also demonstrated that the average EBSP ranking across the six categories of BSP products,in descending order,is:disposable bamboo products,bamboo household goods,bamboo packaging products,bamboo engineering materials,bamboo furniture products,and bamboo craft ***,disposable bamboo products scored an EBSP 1.96 times the overall average,indicating significant environmental *** PRR emerged as a critical factor influencing *** BSP products with the same lifespan,those with higher substitution emission reduction efficiency offered more pronounced environmental ***,the BSP industry should strategically prioritize disposable bamboo products,such as bamboo toothbrushes,cutlery,and lunch *** products should be the primary focus of policy support and central to efforts in product development,design innovation,and market promotion.

关键词： Bamboo as a substitute for plastic Bamboo products Substitution emission reduction Environmental benefits Gradingevaluation

Structural parameter optimization of a furrow opener based on EDEM software

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International Journal of Agricultural and Biological Engineering 2024年第3期17卷 115-120页

作者： Longjie wang Bin zhou Chang Wan Ling zhou College of Mechanical and Electrical Engineering Tarim UniversityAlar 843300XinjiangChina Modern Agricultural Engineering Key Laboratory at Universities of Education Department of Xinjiang Uygur Autonomous Region Alar 843300XinjiangChina Xinjiang Production and Construction Corps(XPCC)Key Laboratory of Utilization and Equipment of Special Agricultural and Forestry Products in Southern Xinjiang Alar 843300XinjiangChina

To reduce the ditching resistance of a furrow opener during operation,single-factor and multiple-factor combinations were used to explore the influence of the furrow opener’s advance speed,blade opening angle,and width on the ditching resistance based on the discrete element method(DEM).A DEM simulation of the furrow opener was *** changing these influencing factors,the parameters with the least resistance to operation were *** openers were fabricated according to the optimized results,and soil trench tests were carried *** and soil groove tests showed that the minimum ditching resistance was 58.54 N when the current advance speed was 4.47 m/s,the blade opening angle was 32.02°,and the furrow opener width was 51.45 *** error between the simulated value of the ditching resistance and the soil trench test was within 10%,and the trends of resistance change were essentially the same,indicating that it is feasible to optimize the structural parameters of a trench furrow opener using *** research results can provide a reference for the parameter optimization of furrow openers.

关键词： furrow opener discrete element optimization ditching resistance

Computational Experiments for Complex Social Systems:Integrated Design of Experiment System

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IEEE/CAA Journal of Automatica Sinica 2024年第5期11卷 1175-1189页

作者： Xiao Xue Xiangning Yu Deyu zhou Xiao wang Chongke Bi Shufang wang Fei-Yue wang College of Intelligence and Computing Tianjin UniversityTianjin 300350China School of Software Shandong UniversityJinan 250101China School of Artificial Intelligence Anhui UniversityHefei 230601China School of Geographic and Environmental Sciences Tianjin Normal UniversityTianjin 300387China Institute of Automation Chinese Academy of Sciences Beijing 100190China

Powered by advanced information industry and intelligent technology,more and more complex systems are exhibiting characteristics of the cyber-physical-social systems(CPSS).And human factors have become crucial in the operations of complex social *** mechanical analysis and social simulations alone are powerless for analyzing complex social *** this backdrop,computational experiments have emerged as a new method for quantitative analysis of complex social systems by combining social simulation(e.g.,ABM),complexity science,and domain ***,in the process of applying computational experiments,the construction of experiment system not only considers a large number of artificial society models,but also involves a large amount of data and *** a result,how to integrate various data,model and knowledge to achieve a running experiment system has become a key *** paper proposes an integrated design framework of computational experiment system,which is composed of four parts:generation of digital subject,generation of digital object,design of operation engine,and construction of experiment ***,this paper outlines a typical case study of coal mine emergency management to verify the validity of the proposed framework.

关键词： artificial system operations

Broadening environmental research in the era of accurate protein structure determination and predictions

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Frontiers of Environmental Science & Engineering 2024年第7期18卷 169-178页

作者： Mingda zhou Tong wang Ke Xu Han wang Zibin Li Wei-xian Zhang Yayi wang State Key Laboratory of Pollution Control and Resources Reuse Shanghai Institute of Pollution Control and Ecological SecurityCollege of Environmental Science and EngineeringTongji UniversityShanghai 200092China Translational Research Institute of Brain and Brain-Like Intelligence Shanghai Fourth People's HospitalSchool of MedicineTongji UniversityShanghai 200434China

The deep-learning protein structure prediction method AlphaFold2 has garnered enormous attention beyond the realm of structural biology,for its groundbreaking contribution to solving the"protein foiding problem"In this perspective,we explore the connection between protein structure studies and environmental research,delving into the potential for addressing specific environmental *** are promising for environmental applications because of the functional diversity endowed by their structural ***,structural studies on proteins with environmental significance remain ***,we present the opportunity to study proteins by advancing experimental determination and deep-learning prediction ***,the latest progress in environmental research via cryogenic electron microscopy is *** allows us to determine the structure of protein complexes in their native state within cells at molecular resolution,revealing environmentally-associated structural *** the remarkable advancements in computational power and experimental resolution,the study of protein structure and dynamics has reached unprecedented depth and *** advancements will undoubtedly accelerate the establishment of comprehensive environmental protein structural and functional *** opportunities for protein engineering exist to enable innovative solutions for environmental applications,such as the degradation of persistent contaminants,and the recovery of valuable metals as well as rare earth elements.

关键词： Environmental proteins Protein structure Cryogenic electron microscopy Protein structure prediction Protein engineering Artificial Intelligence

METTL3 regulates glucose transporter expression in placenta exposed to hyperglycemia through the mTOR signaling pathway

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Chinese Medical Journal 2024年第13期137卷 1563-1575页

作者： Jie Ning Jing huai Shuxian wang Jie Yan Rina Su Muqiu Zhang Mengtong Liu Huixia Yang Department of Obstetrics and Gynaecology Peking University First HospitalBeijing 100034China Beijing Key Laboratory of Maternal Foetal Medicine of Gestational Diabetes Mellitus Beijing 100034China Peking University Beijing 100034China

Background:Alterations in the placental expression of glucose transporters(GLUTs),the crucial maternal-fetal nutrient transporters,have been found in women with hyperglycemia in pregnancy(HIP).However,there is still uncertainty about the underlying effect of the high-glucose environment on placental GLUTs expression in ***:We quantitatively evaluated the activity of mammalian target of rapamycin(mTOR)and expression of GLUTs(GLUT1,GLUT3,and GLUT4)in the placenta of women with normal pregnancies(CTRL,n=12)and pregnant women complicated with poorly controlled type 2 diabetes mellitus(T2DM,n=12)by *** addition,BeWo cells were treated with different glucose concentrations to verify the regulation of ***,changes in the expression of GLUTs following the activation or suppression of the mTOR pathway were also assessed using MHY1485/rapamycin(RAPA)treatment or small interfering RNA(siRNA)-mediated silencing ***,we further explored the alteration and potential upstream regulatory role of methyltransferase-like 3(METTL3)when exposed to ***:mTOR,phosphorylated mTOR(p-mTOR),and GLUT1 protein levels were upregulated in the placenta of women with T2DM compared with those *** BeWo cells,mTOR activity increased with increasing glucose concentration,and the expression of GLUT1,GLUT3,and GLUT4 as well as GLUT1 cell membrane translocation were upregulated by hyperglycemia to varying *** the drug-mediated and genetic depletion of mTOR signaling in BeWo cells suppressed GLUTs expression,whereas MHY1485-induced mTOR activation upregulated GLUTs ***,high glucose levels upregulated METTL3 expression and nuclear translocation,and decreasing METTL3 levels suppressed GLUTs expression and mTOR activity and vice ***,in METTL3 knockdown BeWo cells,the inhibitory effect on GLUTs expression was eliminated by activating the mTOR signaling pathway using ***:High-g

关键词： Glucose transporters Hyperglycemia Type 2 diabetes mellitus Pregnancy Mammalian target of rapamycin Methyltransferase-like 3