检索结果-南通市图书馆

Formation of carbon and oxygen rich surface layer on high purity magnesium by atmospheric carbon dioxide plasma

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Magnesium and Alloys 2023年第1期11卷 88-99页

作者： Gyoung G.Jang Sinchul Yeom Jong K.Keum Mina Yoon Harry III Meyer yi-feng su Jiheon Jun Manufacturing Science Division Oak Ridge National Laboratory(ORNL)One Bethel Valley RoadPO Box 2008MS6054Oak RidgeTN 37831United States Material Science and Technologies Division Oak Ridge National Laboratory(ORNL)One Bethel Valley RoadOak RidgeTN 37831United States Neutron Scattering Division&Center for Nanophase Materials Sciences ORNLOne Bethel Valley RoadOak RidgeTN 37831United States Chemical Sciences Division ORNLOne Bethel Valley RoadOak RidgeTN 37831United States

Carbon and oxygen-rich corrosion barrier layer formed on Mg by a simple and scalable CO_(2) atmospheric plasma(CO_(2)-AP)*** reactive CO_(2)-AP interacts with the Mg surface and forms a unique layered structure with the top MgCO_(3)/MgO-intermixed particulates pillars and the bottom dense *** surface features were simultaneously formed on the nano-/micro-structured MgO layer by carbonate molecules,plasma-active CO_(2) molecules,and/or other volatile organic compounds on the nano-/micro-structured MgO particle *** resulting surfaces after CO_(2)-AP were either hydrophobic or hydrophilic and exhibited lower anodic current or high resistance for Mg *** the hydrophobic surfaces of CO_(2)-AP treated Mg,molecular dynamic simulations were performed to understand the origin of hydrophobicity and identified that the amorphous carbon layers formed on the Mg surface are the *** environmentally benign abundant-gas-based process enables the cost reduction associated with waste treatment,generation of by-product,and supply of raw material.

关键词： Atmospheric plasma Magnesium Corrosion protection surface modification

Behaviour recognition based on the integration of multigranular motion features in the Internet of Things

在线全文

学校读者我要写书评

暂无评论

Digital Communications and Networks 2024年第3期10卷 666-675页

作者： Lizong Zhang yiming Wang Ke Yan yi su Nawaf Alharbe Shuxin feng School of Computer Science and Engineering University of Electronic Science and Technology of ChinaChengdu611731China Beijing Institute of Remote Sensing Equipment Beijing100039China Applied College Taibah UniversityMedina42353Saudi Arabia

With the adoption of cutting-edge communication technologies such as 5G/6G systems and the extensive development of devices,crowdsensing systems in the Internet of Things(IoT)are now conducting complicated video analysis tasks such as behaviour *** applications have dramatically increased the diversity of IoT ***,behaviour recognition in videos usually requires a combinatorial analysis of the spatial information about objects and information about their dynamic actions in the temporal *** recognition may even rely more on the modeling of temporal information containing short-range and long-range motions,in contrast to computer vision tasks involving images that focus on understanding spatial ***,current solutions fail to jointly and comprehensively analyse short-range motions between adjacent frames and long-range temporal aggregations at large scales in *** this paper,we propose a novel behaviour recognition method based on the integration of multigranular(IMG)motion features,which can provide support for deploying video analysis in multimedia IoT crowdsensing *** particular,we achieve reliable motion information modeling by integrating a channel attention-based short-term motion feature enhancement module(CSEM)and a cascaded long-term motion feature integration module(CLIM).We evaluate our model on several action recognition benchmarks,such as HMDB51,Something-Something and *** experimental results demonstrate that our approach outperforms the previous state-of-the-art methods,which confirms its effective-ness and efficiency.

关键词： Behaviour recognition Motion features Attention mechanism Internet of things Crowdsensing

Hybrid Block Diagonalization Precoding for Multi-User Weighted sum-Rate Maximization

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

China Communications 2024年第8期21卷 127-141页

作者： su Xiaofeng Jiang yi Key Laboratory for Information Science of Electromagnetic Waves(MoE) Department of Communication Science and EngineeringFudan UniversityShanghai 200433China

This paper studies large-scale multi-input multi-output(MIMO)orthogonal frequency division multiplexing(OFDM)communications in a broadband frequency-selective channel,where a massive MIMO base station(BS)communicates with multiple users equipped with *** develop a hybrid precoding design to maximize the weighted sum-rate(WSR)of the users by optimizing the digital and the analog precoders *** the digital part,we employ block-diagonalization to eliminate inter-user interference and apply water-filling power allocation to maximize the *** the analog part,the optimization of the PSN is formulated as an unconstrained problem,which can be efficiently solved by a gradient descent *** results show that the proposed block-diagonal hybrid precoding algorithm can outperform the existing works.

关键词： block-diagonal gradient descent hybrid precoding iterative optimization MIMO-OFDM multi-user water-filling power allocation weighted sum-rate maximization

A Geometric Based Connection between Fractional Calculus and Fractal Functions

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2024年第2期40卷 537-567页

作者： Yong Shun LIANG Wei yi su School of Mathematics and Statistic Nanjing University of Science and TechnologyNanjing 210094P.R.China Department of Mathematics Nanjing UniversityNanjing 210023P.R.China

Establishing the accurate relationship between fractional calculus and fractals is an important research content of fractional calculus *** the present paper,we investigate the relationship between fractional calculus and fractal functions,based only on fractal dimension *** dimension of the Riemann-Liouville fractional integral of continuous functions seems no more than fractal dimension of functions *** fractal dimension of the Riemann-Liouville fractional differential of continuous functions seems no less than fractal dimension of functions themselves when they *** further discussion,fractal dimension of the Riemann-Liouville fractional integral is at least linearly decreasing and fractal dimension of the Riemann-Liouville fractional differential is at most linearly increasing for the Holder continuous *** about other fractional calculus,such as the Weyl-Marchaud fractional derivative and the Weyl fractional integral has also been given *** work is helpful to reveal the mechanism of fractional calculus on continuous *** the same time,it provides some theoretical basis for the rationality of the definition of fractional *** is also helpful to reveal and explain the internal relationship between fractional calculus and fractals from the perspective of geometry.

关键词： Fractional calculus fractal functions fractal dimension fractional calculus equation relationship

Numerical study of the influence of the atmospheric pressure on the thermal environment in the passenger cabin

在线全文

学校读者我要写书评

暂无评论

Building Simulation 2024年第2期17卷 253-265页

作者： Xin su Yu Guo Zhengwei Long yi Cao Tianjin Key Lab.of Indoor Air Environmental Quality Control School of Environmental Science and EngineeringTianjin UniversityTianjin300072China Shanghai Aircraft Design and Research Institute Jinke RoadPudong DistrictShanghai201210China

The cabin air pressure remains lower than the horizontal atmospheric pressure when the airplane is in *** pressure is one of the parameters that must be taken into consideration while studying the thermal environment of an airplane *** are still no reference values for aircraft cabins despite the fact that numerous studies on low pressure heat transfer have demonstrated the connection between convective heat transfer coefficient(CHTC)and air *** this paper,a correction method for CHTC under low pressure conditions was established by using the dummy heat dissipation in the low-pressure cabin *** this basis,a thermal environment simulation model was developed,then was applied to the simulation of a seven-row aircraft cabin containing 42 passengers,and the CHTC and heat loss of dummy surface in the cabin were ***,the results of PMV calculated by using heat dissipation and air parameters at sampling points were *** results show that the modified CHTC can accurately reflect the cabin thermal environment under low pressure conditions,and the correction of CHTC can be realized by adjusting the turbulent Prandtl number,which is nonlinear correlated with the *** simulation results of the thermal environment in the seven-row cabin show that the CHTC changes by about 42%before and after *** air pressure decreases during take-off,which reduces the average CHTC of the crew surface from 5.09 W/(m^(2)·K)to 4.56 W/(m^(2)·K),but the air temperature rises by about 0.2°C as a *** deviation of PMV results calculated by using simulated heat loss data and using air parameters of measuring points in space is up to 0.5,but the latter is representative for calculating the thermal comfort level of the whole cabin.

关键词： low pressure aircraft cabin simulation heat dissipation convective heat transfer coefficient

Molecular evolution of Toll-like receptors in rodents

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Integrative Zoology 2024年第3期19卷 371-386页

作者： Qianqian su yi CHEN Hongxuan HE College of Forestry Central South University of Forestry and TechnologyChangshaChina National Research Center for Wildlife-Borne Diseases Institute of ZoologyChinese Academy of SciencesBeijingChina

Toll-like receptors(TLRs),the key sensor molecules in vertebrates,trigger the innate immunity and prime the adaptive immune *** TLR family of rodents,the largest order of mammals,typically contains 13 TLR ***,a clear picture of the evolution of the rodent TLR family has not yet emerged and the TLR evolutionary patterns are unclear in rodent ***,we analyzed the natural variation and the evolutionary processes acting on the TLR family in rodents at both the interspecific and population *** results showed that rodent TLRs were dominated by purifying selection,but a series of positively selected sites(PSSs)primarily located in the ligand-binding domain was also *** numbers of PSSs differed among TLRs,and nonviralsensing TLRs had more PSSs than those in viral-sensing ***-conversion events were found between TLR1 and TLR6 in most rodent *** genetic analyses showed that TLR2,TLR8,and TLR12 were under positive selection in Rattus norvegicus and ***,whereas positive selection also acted on TLR5 and TLR9 in the former species,as well as TLR1 and TLR7 in the latter ***,we found that the proportion of polymorphisms with potentially functional change was much lower in viral-sensing TLRs than in nonviral-sensing TLRs in both of these rat *** findings revealed the first thorough insight into the evolution of the rodent TLR genetic variability and provided important novel insights into the evolutionary history of TLRs over long and short timescales.

关键词： adaptive evolution gene conversion positive selection rodents Toll-like receptors

Dynamic COVID Zero Strategy triggered a significant increase of chlorine-based disinfectant

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 Environmental Science & Engineering 2024年第8期18卷 73-80页

作者： Xuhao Wang Mai su Chunyan Wang yi Liu School of Environment Tsinghua UniversityBeijing 100084China

Chlorine-based disinfectants(CBDs)have been widely used to prevent and control the spread of the COVID-19,which may lead to the formation of carcinogenic *** China,strict disinfection strategies by local governments/communities or volunteering by residents have been implemented to meet the Dynamic COVID Zero(DCZ)***,the amount of CBDs used has not been *** author proposed an urban-scale disinfectant consumption estimation(ALICE)model to quantify weekly CBD *** results show that the CBD consumption for the urban region of Beijing during the DCZ strategy was 3704.0 t(0.43 kg/(cap-yr)),equivalent to a monthly increase of 15 g/cap(70.5%)in CBD consumption compared with that in *** to the scenario analysis,a stricter strategy with a shorter response time toward new cases will decrease the total CBD consumption by 1.2% compared with the baseline estimation.A more precise prevention strategy with a smaller delineation of risk area and a less stringent strategy with a longer response time will lower the total CBD consumption by 0.42% and 0.35%,***,the more precise prevention strategy will reduce CBD consumption of close off and lockdown area(COLD area)by 16.9%,and the stricter strategy will reduce this consumption by 37.7%.This study highlights the impact of pandemic prevention and control strategies on chlorine-based disinfectant consumption and some implications for future environmental pollution and risk assessments.

关键词： COVID-19 Dynamic COVID Zero Strategy Disinfectants consumption Bottom-up approach Scenario analysis

Multiple-quantum-coherence dynamics of spin-1 Bose–Einstein condensate during quantum phase transitions

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2024年第1期76卷 105-110页

作者： Fulin Deng Peng Xu su yi Wenxian Zhang Key Laboratory of Artificial Micro-and Nano-structures of Ministry of Education School of Physics and TechnologyWuhan UniversityWuhanHubei 430072China School of Physics Zhengzhou UniversityZhengzhou 450001China CAS Key Laboratory of Theoretical Physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing 100190China CAS Center for Excellence in Topological Quantum Computation&School of Physical Sciences University of Chinese Academy of SciencesBeijing 100049China Wuhan Institute of Quantum Technology WuhanHubei 430206China

Multiple quantum coherences are often employed to describe quantum many-body dynamics in nuclear spin systems and recently,to characterize quantum phase transitions in trapped *** we investigate the multiple-quantum-coherence dynamics of a spin-1 Bose–Einstein *** adjusting the quadratic Zeeman shift,the condensate exhibits three quantum *** numerical results show that the spectrum of multiple quantum coherence does indeed catch the quantum critical *** importantly,with only a few low-order multiple quantum coherences,the spin-1 condensate exhibits rich signals of the many-body dynamics,beyond conventional *** experimental implementation of such multiple quantum coherence protocol is also discussed.

关键词： Bose-Einstein condensate spin-mixing dynamics quantum phase transitions multiple-quantum-coherences quantum entanglement

An overview of potential cardioprotective benefits of xanthophylls in atherosclerosis:an evidence-based review

在线全文

学校读者我要写书评

暂无评论

Food Science and Human Wellness 2024年第4期13卷 1739-1755页

作者： Yuting su feng Chen Jiehua Chen Mingfu Wang Shenzhen Key Laboratory of Marine Microbiome Engineering Institute for Advanced StudyShenzhen UniversityShenzhen 518060China Institution for Innovative Development of Food Industry Shenzhen UniversityShenzhen 518060China College of Civil and Transportation Engineering Shenzhen UniversityShenzhen 518060China Shenzhen Key Laboratory of Food Nutrition and Health Shenzhen UniversityShenzhen 518060China

Atherosclerosis,as the most prevalent form of cardiovascular disease,is characterized by oxidized lowdensity lipoprotein(ox-LDL)accumulation in the vascular wall,increased inflammation of the large arteries,dysfunction of the endothelial cells(ECs)and vascular smooth muscle cells(VSMCs),which may eventually lead to the formation of ***,one of the main groups of carotenoids,have been proposed as preventive agents or adjunct therapies to prevent and slow the progression of atherosclerosis due to their cardioprotective ***,the underlying preventive mechanism of action of xanthophylls on the pathogenesis of atherosclerosis remains unclear,and clinical evidence of the effect of xanthophylls on atherosclerosis have not yet been summarized and critically *** this regard,we conducted a comprehensive literature search in four scientific databases(Pub Med,Google Scholar,Science Direct and Web of Science)and carefully analyzed the existing evidence to provide meaningful insights on the association between xanthophylls and atherosclerosis from various *** on the evidence from in vitro and in vivo studies,we explored several potential mechanisms,including antioxidant effect,anti-inflammatory effect,regulation of lipid metabolism,and modulation of ECs and VSMCs dysfunction,and we found that a clear picture of regulatory pathways of xanthophylls on atherosclerosis prevention and treatment is still *** addition,epidemiological studies suggested the possible relationship among high dietary intake of xanthophylls,high plasma/serum xanthophylls and a reduced risk of *** evidence from interventional studies investigating the effect of xanthophylls on atherosclerosis is very sparse,whilst indirect clinical evidence was only limited to astaxanthin and ***,well-designed long-term randomized controlled trials(RCTs)are highly recommended for future studies to investigate the effective dose of different

关键词： Atherosclerosis Xanthophylls Antioxidant Anti-inflammation Lipid metabolism