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Channel pruning on frequency response

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Science China(Information Sciences) 2025年第1期68卷 159-170页

作者： Hang lin Yifan PENG lin BIE Chenggang YAN Xibin ZHAO Yue GAO School of Software Tsinghua University School of Automation Hangzhou Dianzi University

Network pruning has a significant role in reducing network parameters and accelerating the inference time of the network. Some existing methods prune the network based on the frequency of the data, and finally obtain a sub-network with high accuracy. However, according to our experimental analysis, different frequencies of information in the data contribute differently to the accuracy of the model, and using this information directly for pruning without making a selection will lead to incorrect results. We believe that pruning should retain the convolutional kernels in the network that process important information, while those kernels that process unimportant information should be removed. In this paper, we first investigate the meaning of each frequency band information in the spectrum and their contribution to the prediction accuracy of the network,and according to these results, we propose a new pruning method based on frequency response(PFR). Our PFR finds and removes the convolutional kernels in the network that specialize in processing unimportant information, resulting in a compact neural network model. PFR obtains significant experimental results on different datasets, for example, a 56.0% raduction of float points operations(FlOPs) on Res Net-50 and only 0.37% of Top-1 accuracy degradation on the Image Net dataset.

关键词： deep learning model compression filter pruning channel pruning frequency response

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New progresses of fine-grained sediment gravity-flow deposits and their importance for unconventional shale oil and gas plays

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Petroleum Science 2025年第1期22卷 1-15页

作者： Tian Yang Ying-lin liu State Key laboratory of Oil and Gas Reservoir Geology and Exploitation (Chengdu University of Technology) Institute of Sedimentary Geology Key laboratory of Deep-time Geography and Environment Reconstruction and Applications of Ministry of Natural Resources Chengdu University of Technology

Fine-grained sediments are widely distributed and constitute the most abundant component in sedimentary systems, thus the research on their genesis and distribution is of great significance. In recent years, fine-grained sediment gravity-flows(FGSGF) have been recognized as an important transportation and depositional mechanism for accumulating thick successions of fine-grained sediments. Through a comprehensive review and synthesis of global research on FGSGF deposition, the characteristics,depositional mechanisms, and distribution patterns of fine-grained sediment gravity-flow deposits(FGSGFD) are discussed, and future research prospects are clarified. In addition to the traditionally recognized low-density turbidity current and muddy debris flow, wave-enhanced gravity flow, lowdensity muddy hyperpycnal flow, and hypopycnal plumes can all form widely distributed FGSGFD. At the same time, the evolution of FGSGF during transportation can result in transitional and hybrid gravityflow deposits. The combination of multiple triggering mechanisms promotes the widespread development of FGSGFD, without temporal and spatial limitations. Different types and concentrations of clay minerals, organic matters, and organo-clay complexes are the keys to controlling the flow transformation of FGSGF from low-concentration turbidity currents to high-concentration muddy debris flows. Further study is needed on the interaction mechanism of FGSGF caused by different initiations, the evolution of FGSGF with the effect of organic-inorganic synergy, and the controlling factors of the distribution patterns of FGSGFD. The study of FGSGFD can shed some new light on the formation of widely developed thin-bedded siltstones within shales. At the same time, these insights may broaden the exploration scope of shale oil and gas, which have important geological significances for unconventional shale oil and gas.

关键词： Fine-grained sediment gravity-flow Depositional mechanism Transportation and evolution Distribution pattern Shale oil and gas

Upper Bounds on the Multicolor Ramsey Numbers r_(k)(C_(4))

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Acta Mathematicae Applicatae Sinica 2025年第1期41卷 286-294页

作者： Tian-yu lI Qi-zhong lin Center for Discrete Mathematics Fuzhou UniversityFuzhou 350108China

The multicolor Ramsey number r_(k)(C_(4))is the smallest integer N such that any k-edge coloring of KN contains a monochromatic C_(4).The current best upper bound of r_(k)(C_(4))was obtained by Chung(1974)and independently by Irving(1974),i.e.,r_(k)(C_(4))≤k^(2)+k+1 for all k≥*** is no progress on the upper bound since *** this paper,we improve the upper bound of r_(k)(C_(4))by showing that r_(k)(C_(4))≤k^(2)+k-1 for even k≥*** improvement is based on the upper bound of the Turan number ex(n,C4),in which we mainly use the double counting method and many novel ideas from Firke,Kosek,Nash,and Williford[***,Ser.B 103(2013),327-336].

关键词： Multicolor Ramsey number Turan number 4-cycle

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Corrosion resistance and antibacterial properties of Ti−3Cu alloy prepared by selective laser melting

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中国有色金属学报 2025年第1期35卷 143-156页

作者： Meng-zhen ZHU Jing-lei MIAO Xiong-wen ZHOU Er-lin ZHANG Zhi-lin lIU Hai-lin YANG State Key laboratory of Powder Metallurgy Central South UniversityChangsha 410083China The Third Xiangya Hospital Central South UniversityChangsha 410013China Department of Prosthodontics Centre of StomatologyXiangya HospitalCentral South UniversityChangsha 410008China Key laboratory for Anisotropy and Texture of Materials Ministry of EducationSchool of Materials Science and EngineeringNortheastern UniversityShenyang 110819China light Alloy Research Institute College of Mechanical and Electrical EngineeringCentral South UniversityChangsha 410083China

The corrosion resistance and antibacterial properties of Ti−3Cu alloy prepared by selective laser melting were evaluated using electrochemical experiments and a variety of antibacterial *** is found that the charge transfer resistance of Ti−3Cu alloy was 4.89×10^(5)Ω∙cm^(2),which was doubled the data obtained by CP-Ti *** antibacterial rates of Ti−3Cu alloy against *** and *** were 45.0%and 54.5%.And the antibacterial rates increased with the prolongation of cultivation time,reaching up to 62.8%and 68.6%,*** in-situ nano Ti_(2)Cu precipitates were homogeneously distributed in the matrix of the Ti−3Cu alloy,which was the key reason of increasing the corrosion ***,the microscale electric fields between theα-Ti matrix and the Ti_(2)Cu was responsible for the enhancement of the antibacterial properties.

关键词： selective laser melting Ti−3Cu alloy microstructure corrosion resistance antibacterial properties

The profound review of Fenton process:What’s the next step?

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Journal of Environmental Sciences 2025年第1期147卷 114-130页

作者： Yimin lin Junlian Qiao Yuankui Sun Hongyu Dong State Key laboratory of Pollution Control and Resources Reuse College of Environmental Science and EngineeringTongji UniversityShanghai 200092China Department of Environmental Science School of Ecological and Environmental SciencesEast China Normal UniversityShanghai 200241China

Fenton and Fenton-like processes,which could produce highly reactive species to degrade organic contaminants,have been widely used in the field of wastewater ***,the chemistry of Fenton process including the nature of active oxidants,the complicated reactions involved,and the behind reason for its strongly pH-dependent performance,is the basis for the application of Fenton and Fenton-like processes in wastewater ***,the conflicting views still exist about the mechanism of the Fenton *** instance,reaching a unanimous consensus on the nature of active oxidants(hydroxyl radical or tetravalent iron)in this process remains *** review comprehensively examined the mechanism of the Fenton process including the debate on the nature of active oxidants,reactions involved in the Fenton process,and the behind reason for the pH-dependent degradation of contaminants in the Fenton ***,we summarized several strategies that promote the Fe(Ⅱ)/Fe(Ⅲ)cycle,reduce the competitive consumption of active oxidants by side reactions,and replace the Fenton reagent,thus improving the performance of the Fenton ***,advances for the future were proposed including the demand for the high-accuracy identification of active oxidants and taking advantages of the characteristic of target contaminants during the degradation of contaminants by the Fenton process.

关键词： Advanced oxidation process Fenton Hydroxyl radical Fe(IV) Wastewater treatment

Profiles,exposure assessment and expanded screening of PAHs and their derivatives in one petroleum refinery facility of China

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Journal of Environmental Sciences 2025年第1期147卷 550-560页

作者： Ning Wang Fengjiao Jiang lin Xu Yaqi Cai School of Municipal and Environmental Engineering Shandong Jianzhu UniversityJinan 250101China Resource and Environmental Innovation Institute Shandong Jianzhu UniversityJinan 250101China State Key laboratory of Environmental Chemistry and Ecotoxicology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China School of Environment Hangzhou Institute for Advanced StudyUCASHangzhou 330106China Hubei Key laboratory of Environmental and Health Effects of Persistence Toxic Substances Institute of Environment and HealthJianghan UniversityWuhan 430056China

This study investigated environmental distribution and human exposure of polycyclic aromatic hydrocarbons(PAHs)and their derivatives in one Chinese petroleum refinery *** was found that,following with high concentrations of 16 EPA PAHs(∑Parent-PAHs)in smelting subarea of studied petroleum refinery facility,total derivatives of PAHs[named as XPAHs,including nitro PAHs(NPAHs),chlorinated PAHs(Cl-PAHs),and brominated PAHs(Br-PAHs)]in gas(mean=1.57×10^(4)ng/m^(3)),total suspended particulate(TSP)(mean=4.33×10^(3) ng/m^(3))and soil(mean=4.37×10^(3) ng/g)in this subarea had 1.76-6.19 times higher levels than those from other subareas of this facility,surrounding residential areas and reference areas,indicating that petroleum refining processes would lead apparent derivation of ***,compared with those in residential and reference areas,gas samples in the petrochemical areas had higher∑NPAH/∑PAHs(mean=2.18),but lower∑Cl-PAH/∑PAHs(mean=1.43×10^(-1))and∑Br-PAH/∑PAHs ratios(mean=7.49×10^(-2)),indicating the richer nitrification of PAHs than chlorination during petrochemical *** occupational exposure to PAHs and XPAHs in this petroleum refinery facility were 24-343 times higher than non-occupational exposure,and the IlCR(1.04×10^(-4))for petrochemical workers was considered to be potential high ***,one expanded high-resolution screening through GC Orbitrap/MS was performed for soils from petrochemical area,and another 35 PAHs were found,including alkyl-PAHs,phenyl-PAHs and other species,indicat-ing that profiles and risks of PAHs analogs in petrochemical areas deserve further expanded investigation.

关键词： Polycyclic aromatic hydrocarbons(PAHs) Derivatives Petroleum refinery Human exposure Non-targeted screening

Soil colloids can significantly enhance spreading of polybromodiphenyl ethers in groundwater by serving as an effective carrier

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Journal of Environmental Sciences 2025年第1期147卷 93-100页

作者： lin Duan Min li Jiameng liu Wei Chen College of Environmental Science and Engineering Ministry of Education Key Laboratory of Pollution Processes and Environmental CriteriaTianjin Key Laboratory of Environmental Remediation and Pollution ControlNankai UniversityTianjin 300350China

Polybromodiphenyl ethers(PBDEs),the widely used flame retardants,are common contaminants in surface soils at e-waste recycling *** association of PBDEs with soil colloids has been observed,indicating the potential risk to groundwater due to colloid-facilitated ***,the extent to which soil colloidsmay enhance the spreading of PBDEs in groundwater is largely ***,we report the co-transport of decabromodiphenyl ester(BDE-209)and soil colloids in saturated porous *** colloids released froma soil sample collected at an e-waste recycling site in Tianjin,China,contain high concentration of PBDEs,with BDE-209 being the most abundant conger(320±30 mg/kg).The colloids exhibit relatively high mobility in saturated sand columns,under conditions commonly observed in groundwater ***,under all the tested conditions(i.e.,varying flow velocity,pH,ionic species and ionic strength),the mass of eluted BDE-209 correlates linearly with that of eluted soil colloids,even though the mobility of the colloids varies markedly depending on the specific hydrodynamic and solution chemistry conditions ***,the mass of BDE-209 retained in the columns also correlates strongly with themass of retained ***,the PBDEs remain bound to soil colloids during transport in porous *** in this study indicate that soil colloidsmay significantly promote the transport of PBDEs in groundwater by serving as an effective *** might be the reason why the highly insoluble and adsorptive PBDEs are found in groundwater at some PBDE-contaminated sites.

关键词： Polybromodiphenyl ethers Soil colloids E-waste recycling sites Groundwater Facilitated transport

Projective Hilbert modules and sequential approximations

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Science China Mathematics 2025年第1期68卷 137-168页

作者： lawrence G.Brown Huaxin lin Department of Mathematics Purdue UniversityWest LafayetteIN 47907-2067USA Department of Mathematics East China Normal UniversityShanghai 200062China Department of Mathematics University of OregonEugeneOR 97405USA

We show that when A is a separable C^(*)-algebra,every countably generated Hilbert A-module is projective(with bounded module maps as morphisms).We also study the approximate extensions of bounded module *** the case where A is aσ-unital simple C^(*)-algebra with strict comparison,and every strictly positive lower semicontinuous affine function on quasitraces can be realized as the rank of an element in the Cuntz semigroup,we show that the Cuntz semigroup is equivalent to unitarily equivalent classes of countably generated Hilbert A-modules if and only if A has stable rank one.

关键词： projective Hilbert modules simple C^(*)-algebras sequential approximations

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Evaluating complementaries among urban water,energy,infrastructure,and social Sustainable Development Goals in China

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Journal of Environmental Sciences 2025年第3期149卷 585-597页

作者： Ke Yu Yifan Song Jin lin Shen Qu School of Management and Economics Beijing Institute of TechnologyBeijing 100081China Center for Energy&Environmental Policy Research Beijing Institute of TechnologyBeijing 100081China

Urban areas’performance in water,energy,infrastructure,and socio-economic sectors is intertwined and measurable through Sustainable Development Goals(SDGs)6–*** synergy among these is critical for *** study constructs an indicator framework that reflects progress towards these urban SDGs in *** indicate underperformance in SDGs 8–11,suggesting the need for transformative *** network analysis,the research reveals complementarities among these ***,the SDG space divides into socio-economic and ecological clusters,with SDG 6(Clean Water and Sanitation)central to ***,SDG 8(Decent Work and Economic Growth)and SDG 9(Industry,Innovation,and Infrastructure)act as bridges,while greater synergies exist between SDG 12(Responsible Consumption and Production)and SDG 13(Climate Action).An in-depth view at the indicator-level shows a core-periphery structure,emphasizing indicators like SDG 6.2(Wastewater Treatment Rate)and SDG 6.6(Recycled Water Production Capacity per capita)as *** study confirms the urban SDG space’s stability and predictiveness,underscoring its value in steering well-aligned policy decisions for sustainable growth.

关键词： Sustainable development goals Synergy Urban development Policy decisions