检索结果-南通市图书馆

Spatial correlation effect and influencing factors of provincial carbon emission performance in China

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Shengtai x.ebao 2024年第16期44卷 7036-7050页

作者： wang y. Zhen W. School of Economics and Management Chang'An University Xi'an 710064 China

At the completion of the "1+N" policy.sy.tem for the "dual-carbon" target, improving carbon performance is a key.to promoting balance between the environment and the economy.and facilitating sy.ergistic regional sustainability. However, the ex.sting studies mainly.focus on the measurement of carbon emission performance, influencing factors and traditional spatial scales, lacking ex.loration of the spatial correlation strength, network characteristics, and network conditions of various provinces and regions of carbon emission performance, and rarely.ex.mining the influencing factors of spatial network relationships from the perspective of spatial networks. Therefore, this article used the super-efficient SBM model to calculate the carbon emission performance of 30 provinces in China from 2005 to 2022. The structural characteristics of the network, transmission paths of interrelationships, network effects, and influencing factors were analy.ed using the modified gravity.model and social network analy.is. The results are as follows: ① China' s carbon emission performance increased significantly. the spatial correlation network characteristics were obvious, manifested as a dense in the east and sparse in the west pattern with the " Beijing—Shanghai" double core actors as the center, and gradually.formed a complex.and compact network distribution form. ② The number of relationships within each sector of the network is significantly.lower than between sectors, and the direct connection and correlation between the " net spillover" and "net beneficial" sectors were strengthened. The influence of the "bidirectional spillover" and "broker" sectors has been gradually.weakening. ③ The overall and individual structural characteristics of the correlation network significantly.affect carbon emission performance. Increasing network density. number of relationships, degree centrality. closeness centrality. and intermediate centrality. decreasing network efficiency.and network hierar

关键词： carbon emission performance influencing factor network effect social network analy.is spatial association network

Ex.onentially.Convergent Multiscale Finite Element Method

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Communications on Applied Mathematics and Computation 2024年第2期6卷 862-878页

作者： y.fan Chen Thomas y.Hou y.x.an wang Applied and Computational Mathematics CaltechPasadena 91106USA

We provide a concise review of the ex.onentially.convergent multiscale finite element method(Ex.MsFEM)for efficient model reduction of PDEs in heterogeneous media without scale separation and in high-frequency.wave *** Ex.MsFEM is built on the non-overlapped domain decomposition in the classical MsFEM while enriching the approx.mation space sy.tematically.to achieve a nearly.ex.onential convergence rate regarding the number of basis *** most generalizations of the MsFEM in the literature,the Ex.MsFEM does not rely.on any.partition of unity.*** general,it is necessary.to use function representations dependent on the right-hand side to break the algebraic Kolmogorov n-width barrier to achieve ex.onential ***,there are online and offline parts in the function representation provided by.the *** online part depends on the right-hand side locally.and can be computed in parallel *** offline part contains basis functions that are used in the Galerkin method to assemble the stiffness matrix.they.are all independent of the right-hand side,so the stiffness matrix.can be used repeatedly.in multi-query.scenarios.

关键词： Multiscale method Ex.onential convergence Helmholtz's equation Domain decomposition Nonlinear model reduction

Conventional and micro scale finite element modeling for metal cutting process:A review

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2024年第2期37卷 199-232页

作者： Le wang Caix. y.E x.anli LIU Ming LI y.ngshi x. Steven y.LIANG Key.Laboratory.of Advanced Manufacturing and Intelligent Technology Ministry of EducationHarbin University of Science and TechnologyHarbin 150080China George W.Woodruff School of Mechanical Engineering Georgia Institute of TechnologyAtlanta 30332USA

The metal cutting process is accompanied by.complex.stress field,strain field,temperature *** comprehensive effects of process parameters on chip morphology.cutting force,tool wear and residual stress are complex.and *** element method(FEM)is considered as an effective method to predict process variables and reveal microscopic phy.ical phenomena in the cutting ***,the finite element(FE)simulation is used to research the conventional and micro scale cutting process,and the differences in the establishment of process variable FE simulation models are distinguished,thereby.improving the accuracy.of FE *** reliability.and effectiveness of FE simulation model largely.depend on the accuracy.of the simulation method,constitutive model,friction model,damage model in describing mesh element,the dy.amic mechanical behavior of materials,the tool-chip-workpiece contact process and the chip formation *** this paper,the FE models of conventional and micro process variables are comprehensively.and up-to-date reviewed for different materials and machining *** purpose is to establish a FE model that is more in line with the real cutting conditions,and to provide the possibility.for optimizing the cutting process *** development direction of FE simulation of metal cutting process is discussed,which provides guidance for future cutting process modeling.

关键词： Conventional and micro scale Finite element simulation Metal cutting process Micro cutting Modeling

Trial characteristics and treatment effect estimates in randomized controlled trials of Chinese herbal medicine: A meta-epidemiological study

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Medicine 2024年第3期22卷 223-234页

作者： Betty.H.wang y.-li Lin y.n-y.n Gao Jin-lu Song Lang Qin Ling-qi Li Wen-qi Liu Claire C.W.Zhong Mary.y.Jiang Chen Mao x.ao-bo y.ng Vincent C.H.Chung Irene x.y.Wu Jockey.Club School of Public Health and Primary.Care the Chinese University of Hong KongHong Kong 999077China x.angy. School of Public Health Central South UniversityChangsha 410006Hunan ProvinceChina School of Chinese Medicine the Chinese University of Hong KongHong Kong 999077China School of Public Health Southern Medical UniversityGuangzhou 510080Guangdong ProvinceChina State Key.Laboratory.of Dampness Sy.drome of Chinese Medicine the Second Affiliated Hospital of Guangzhou University of Chinese MedicineGuangzhou 510120Guangdong ProvinceChina Chinese Medicine Sy.drome Research Team the Second Affiliated HospitalGuangzhou University of Chinese MedicineGuangzhou 510120Guangdong ProvinceChina Guangdong Provincial Key.Laboratory.of Clinical Research on Traditional Chinese Medicine Sy.drome Guangzhou 510120Guangdong ProvinceChina Hunan Provincial Key.Laboratory.of Clinical Epidemiology Central South UniversityChangsha 410006Hunan ProvinceChina

Background:Previously.published meta-epidemiological studies focused on Western medicine have identified some trial characteristics that impact the treatment effect of randomized controlled trials(RCTs).Nevertheless,it remains unclear if similar associations ex.st in RCTs on Chinese herbal medicine(CHM).Further,Chinese medicine-related characteristics have not been ex.lored ***:To investigate trial characteristics related to treatment effect estimates on CHM *** strategy.This meta-epidemiological study.searched 5 databases for sy.tematic reviews on CHM treatment published between January.2011 and July.*** criteria:An eligible sy.tematic review should only.include RCTs of CHM and conduct at least one *** ex.raction and analy.is:Two reviewers independently.conducted data ex.raction on general characteristics of sy.tematic reviews,meta-analy.es and included *** also assessed the risk of bias of RCTs using the Cochrane risk of bias tool.A two-step approach was used for data *** ratio of odds ratios(ROR) and difference in standardized mean differences (dSMD) with 95%confidence interval (CI) were applied to present the difference in effect estimates for binary.and continuous outcomes,***:Ninety.one sy.tematic reviews,comprising 1338 RCTs were *** binary.outcomes,RCTs incorporated with sy.drome differentiation (ROR:1.23;95%CI:[1.07,1.39]),adopting Chinese medicine formula (ROR:1.19;95%CI:[1.03,1.34]),with low risk of bias on incomplete outcome data (ROR:1.29;95%CI:[1.06,1.52]) and selective outcome reporting (ROR:1.12;95%CI:[1.01,1.24]),as well as a trial size≥100 (ROR:1.23;95%CI:[1.04,1.42]) preferred to show larger effect *** for continuous outcomes,RCTs with Chinese medicine diagnostic criteria (dSMD:0.23;95%CI:[0.06,0.41]),judged as high/unclear risk of bias on allocation concealment (dSMD:-0.70;95%CI:[-0.99,-0.42]),with low risk of bias on incomplete outcome data (dSMD:0.30

关键词： Chinese herbal medicine Randomized controlled trial Risk of bias Meta-epidemiological study Effect estimates

Investigations of nuclear chirality.at iThemba LABS

在线全文

学校读者我要写书评

暂无评论

Frontiers of phy.ics 2024年第2期19卷 7-38页

作者： R.A.Bark E.A.Lawrie C.Liu S.y.wang iThemba Laboratory.for Accelerator Based Sciences National Research FoundationP.O.Box 722Somerset-West 7129South Africa Department of Phy.ics University of the Western CapePrivate Bag X177535BellvilleSouth Africa Shandong Provincial Key.Laboratory.of Optical Astronomy.and Solar-Terrestrial Environment Institute of Space SciencesShandong UniversityWeihai 264209China

Progress in the studies of chirality.in atomic nuclei at iThemba LABS is *** regions of chirality.around mass 80 and 190 have been discovered using the AFRODITE array.specifically.in the nuclei^(74)As,^(78,80,82)Br,^(81)Kr,and^(193,194,198)*** phenomena have been observed,including multiple chiral bands in the same nucleus,the coex.stence of octupole correlations and nuclear chirality.and the coex.stence of pseudo spin and nuclear *** best ex.mple of chiral degeneracy.to date was found in ^(194)*** level scheme of ^(106)Ag has been revisited and interpreted in terms of two-and four-quasiparticle *** using the particle-rotor model have shown that the fingerprints of chirality.in the two-quasiparticle sy.tem only.can occur in an idealised model *** sy.tems with a higher number of quasiparticles,the calculations showed that nuclear chirality.can persist.

关键词： chirality high-spin states particle-rotor model

Optimization of chemistry.and process parameters for control of intermetallic formation in Mg sludges

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Magnesium and Alloy. 2024年第4期12卷 1431-1448页

作者： y.Fu G.G.wang A.Hu y.Li K.B.Thacker J.P.Weiler H.Hu Department of Mechanical Automotive and Materials EngineeringUniversity of Windsor401 Sunset AveWindsorOntario N9B 3P4Canada Global Technology.Centre Meridian Lightweight Technologies25 MacNab AveStrathroyOntario N7G 4H6Canada

Intermetallic formation in sludge during magnesium(Mg)melting,holding and high pressure die casting practices is a very.important ***,very.often it is overlooked by.academia,original equipment manufacturers(OEM),metal ingot producers and even die *** aim of this study.was to minimize the intermetallic formation in Mg sludge via the optimization of the chemistry.and process *** Al8Mn5 intermetallic particles were identified by.the microstructure analy.is based on the Al and Mn *** design of ex.eriment(DOE)technique,Taguchi method,was employ.d to minimize the intermetallic formation in the sludge of Mg alloy. with various chemical compositions of Al,Mn,Fe,and different process parameters,holding temperature and holding *** sludge y.eld(Sy.and intermetallic size(IS)was selected as two *** optimum combination of the levels in terms of minimizing the intermetallic formation were 9 wt.%Al,0.15 wt.%Mn,0.001 wt.%(10 ppm)Fe,690℃ for the holding temperature and holding at 30 mins for the holding time,*** best combination for smallest intermetallic size were 9 wt.%Al,0.15 wt.%Mn,0.001 wt.%(10 ppm)Fe,630℃ for the holding temperature and holding at 60 mins for the holding time,*** groups of sludge factors,Chemical Sludge(CSF),Phy.ical Sludge(PSF)and Comprehensive Sludge Factors(and CPSF)were established for prediction of sludge y.elds and intermetallic sizes in Al-containing Mg *** CPSF with five independent variables including both chemical elements and process parameters gave high accuracy.in prediction,as the prediction of the PSF with only.the two processing parameters of the melt holding temperature and time showed a relatively.large deviation from the ex.erimental *** Chemical Sludge Factor was primarily.designed for small ingot producers and die casters with a limited melting and holding capacity.of which process parameters could be fix.d *** Phy.ical Sludge Factor could be used f

关键词： Magnesium sludge Al-Mn intermetallic Optimization Taguchi method Sludge factor Chemical composition Process parameter

Compressive property.and energy.absorption characteristic of interconnected porous Mg-Zn-y.alloy. with adjusting y.addition

在线全文

学校读者我要写书评

暂无评论

Journal of Magnesium and Alloy. 2024年第1期12卷 171-185页

作者： J.A.Liu S.J.Liu B.wang W.B.Sun x.J.Liu Z.W.Han College of Materials Science and Engineering Key Laboratory of Automobile Materials(Ministry of Education)Jilin UniversityChangchun 130022PR China Key.Laboratory.of Bionic Engineering(Ministry.of Education) College of Biological and Agricultural EngineeringJilin UniversityChangchun130022PR China Weihai Institute for Bionics-Jilin University Weihai 264205PR China

In this study.interconnected porous Mg-2Zn-x.0}alloy. with different phase compositions were prepared by.various y.additions(x.0.4,3,and 6 wt.%)to adjust the compressive properties and energy.absorption *** characterization methods were then applied to identify.the microstructure of the porous Mg-Zn-y.and describe the details of the second *** tests were performed at room temperature(RT),200℃,and 300℃to study.the impact of the y.addition and testing temperature on the compressive properties of the porous *** ex.erimental results showed that a high y.content promotes a microstructure refinement and increases the volume fraction of the second *** the y.content increases,different Mg-Zn-y.ternary.phases appear:I-phase(Mg_(3)Zn_(6)y.,W-phase(Mg_(3)Zn_(3)y.(2)),and LPSO phase(Mg_(12)Zny..When the y.content ranges between 0.4%and 6%,the compressive strength increases from 6.30MPa to 9.23 MPa,and the energy.absorption capacity.increases from 7.33 MJ/m^(3)to 10.97 MJ/m^(3)at RT,which is mainly.attributed to the phase composition and volume fraction of the second ***,the average energy.absorption efficiency.is independent of the y.*** addition,the compressive deformation behaviors of the porous Mg-Zn-y.are altered by.the testing *** compressive strength and energy.absorption capacity.of the porous Mg-Zn-y.decrease due to the softening effect of the high temperature on the *** deformation behaviors at different temperatures are finally.observed to reflect the failure mechanisms of the struts.

关键词： Porous magnesium Rare earth elements Microstructure Compressive behavior Energy.absorption characteristic

Multi-lay.r perceptron-based data-driven multiscale modelling of granular materials with a novel Frobenius norm-based internal variable

在线全文

学校读者我要写书评

暂无评论

Journal of Rock Mechanics and Geotechnical Engineering 2024年第6期16卷 2198-2218页

作者： Mengqi wang y.T.Feng Shaoheng Guan Tongming Qu Zienkiewicz Centre for Computational Engineering Faculty of Science and EngineeringSwansea UniversitySwanseaWalesSA18EPUK Institute of Theoretical and Computational Phy.ics Graz University of TechnologyGraz8010Austria Department of Civil and Environmental Engineering Hong Kong University of Science and TechnologyClearwater BayKowloonHong KongChina

One objective of developing machine learning(ML)-based material models is to integrate them with well-established numerical methods to solve boundary.value problems(BVPs).In the family.of ML models,recurrent neural networks(RNNs)have been ex.ensively.applied to capture history.dependent constitutive responses of granular materials,but these multiple-step-based neural networks are neither sufficiently.efficient nor aligned with the standard finite element method(FEM).Single-step-based neural networks like the multi-lay.r perceptron(MLP)are an alternative to by.ass the above issues but have to introduce some internal variables to encode complex.loading *** this work,one novel Frobenius norm-based internal variable,together with the Fourier lay.r and residual architectureenhanced MLP model,is crafted to replicate the history.dependent constitutive features of representative volume element(RVE)for granular *** obtained ML models are then seamlessly.embedded into the FEM to solve the BVP of a biax.al compression case and a rigid strip footing *** obtained solutions are comparable to results from the FEM-DEM multiscale modelling but achieve significantly.improved *** results demonstrate the applicability.of the proposed internal variable in enabling MLP to capture highly.nonlinear constitutive responses of granular materials.

关键词： Granular materials History.dependence Multi-lay.r perceptron(MLP) Discrete element method FEM-DEM Machine learning

Low-rank matrix.recovery.with total generalized variation for defending adversarial ex.mples

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Information Technology.& Electronic Engineering 2024年第3期25卷 432-445页

作者： Wen LI Hengy.u wang Lianzhi HUO Qiang HE Linlin CHEN Zhiquan HE Wing W.y.Ng School of Science Beijing University of Civil Engineering and ArchitectureBeijing 100044China School of Computer Science and Engineering South China University of TechnologyGuangzhou 510006China Aerospace Information Research Institute Chinese Academy of SciencesBeijing 100094China Guangdong Key.Laboratory.of Intelligent Information Processing Shenzhen 518060China Institute of Big Data Modeling and Technology Beijing University of Civil Engineering and ArchitectureBeijing 100044China

Low-rank matrix.decomposition with first-order total variation(TV)regularization ex.ibits ex.ellent performance in ex.loration of image *** advantage of its ex.ellent performance in image denoising,we apply.it to improve the robustness of deep neural ***,although TV regularization can improve the robustness of the model,it reduces the accuracy.of normal samples due to its *** our work,we develop a new low-rank matrix.recovery.model,called LRTGV,which incorporates total generalized variation(TGV)regularization into the reweighted low-rank matrix.recovery.*** the proposed model,TGV is used to better reconstruct tex.ure information without *** reweighted nuclear norm and Li-norm can enhance the global structure ***,the proposed LRTGV can destroy.the structure of adversarial noise while re-enhancing the global structure and local tex.ure of the *** solve the challenging optimal model issue,we propose an algorithm based on the alternating direction method of *** results show that the proposed algorithm has a certain defense capability.against black-box.attacks,and outperforms state-of-the-art low-rank matrix.recovery.methods in image restoration.

关键词： Total generalized variation Low-rank matrix Alternating direction method of multipliers Adversarial ex.mple