检索结果-南通市图书馆

npj Computational Materials 2023年第1期9卷 314-321页

作者： zhuoling Jiang Kah-Meng Yam Yee Sin ang Na Guo Yongjie z.ang Hao Wang Chun z.ang Department of Physics and Centre for Advanced 2D Materials National University of SingaporeSingapore 117551Singapore Science Mathematics and Technology(SMT)ClusterSingapore University of Technology and DesignSingapore 487372Singapore Department of Chemistry National University of SingaporeSingapore 117543Singapore National University of Singapore Chongqing Research Institute 401123 ChongqingChina

Precise manipulation and monitoring spin transport in one-dimensional (1D) systems is a long-sought goal in the field of nano-spintronics. Based on first-principles calculations, we report the observation of half-integer conductance quantization in the Cobalt-fulvalene sandwich nanowire. Compared with a pure monatomic Cobalt wire, the introduction of fulvalene molecules leads to threeimportant features: Firstly, the strong coupling between the fulvalene and the Cobalt prevents the contamination of the ambientair, ensuring both chemical and physical stabilities;Secondly, the fulvalene symmetry-selectively filters out most of the d-typeorbitals of the Cobalt while leaving a single d-type orbital to form an open spin channel around the Fermi level, which offers amechanism to achieve the observed half-integer conductance;Thirdly, it maintains a superexchange coupling between adjacent Coatoms to achieve a high Curie temperature. Spin transport calculations show that this half-metallic nanowire can serve as a perfectspin filter or a spin valve device, thus revealing the potential of Cobalt-fulvalene sandwich nanowire as a promising building blockof high-performance spintronics technology.

关键词： sandwich coupling transport

Microstructure and mechanical behavior of laser aided additive manufactured low carbon interstitial Fe_(49.5)Mn_(30)Co_(10)Cr_(10)C_(0.5)multicomponent alloy

维普期刊数据库评论

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 Materials Science & Technology 2021年第18期77卷 38-46页

作者： Y.Chew z.G.zhu F.Weng S.B.Gao F.L.Ng B.Y Lee G.J.Bi Singapore Institute of Manufacturing Technology 73 Nanyang Drive637662Singapore School of Mechanical Aerospace Engineering Nanyang Technological University50 N any ang Avenue639798Singapore

Laser aided additive manufacturing(LAAM)was used to fabricate bulk Fe_(49.5)Mn_(30)Co_(10)Cr_(10)C_(0.5)interstitial multicomponent alloy using pre-alloyed *** room temperature yield strength(σ_y),ultimate tensile strength(σ_(UTS))and elongation(ε_(UTS))were 645 MPa,917 MPa and 27.0%*** asbuilt sample consisted of equiaxed and dendritic cellular structures formed by elemental *** cellular structures together with oxide particle inclusions were deemed to strengthen the *** other contributing components include dislocation strengthening,friction stress and grain boundary *** highε_(UTS)was attributed to dislocation motion and activation of both twinning and transformation-induced plasticity(TWIP and TRIP).Tensile tests performed at-40℃and-130℃demonstrated superior tensile strength of 1041 MPa and 1267 MPa ***,almost no twinning was observed in the fractured sample tested at-40℃and-130℃.Instead,higher fraction of strain-induced hexagonal close-packed(HCP)εphase transformation of 21.2%were observed for fractured sample tested at-40℃,compared with 6.3%in fractured room temperature sample.

关键词： Multicomponent alloys Laser aided additive manufacturing Additive manufacturing Microstructure Mechanical property

Learners’motivational response to the Science,PE,&Me!curriculum:A situational interest perspective

在线全文

学校读者我要写书评

暂无评论

Journal of Sport and Health Science 2021年第2期10卷 243-251页

作者： Senlin Chen Haichun Sun Xihe zhu ang Chen Catherine D.Ennis(Posthumous) School of Kinesiology Louisiana State UniversityBaton RougeLA 70803USA Department of Teaching and Learning University of South FloridaTampaFL 33620USA Department of Human Movement Sciences Old Dominion UniversityNorfolkVA 23529USA Department of Kinesiology University of North Carolina at GreensboroGreensboroNC 27402USA

Background:The Science,PE,&Me!(SPEM)curriculum is a concept-based physical education curriculum that offers students coherent educational experiences for constructing health-related fitness knowledge through movement *** purpose of this study was to evaluate students’motivational response to the SPEM curriculum from the situational interest ***:The study used a cluster randomized controlled design in which 30 elementary schools in one of the largest metropolitan areas in the eastern United States were randomly assigned to an experimental or comparison *** all students in the 3rd,4th,and 5th grades in the targeted schools were eligible to participate in the study,a random sample of students from the experimental(n=1749;15 schools)and comparison groups(n=1985;15 schools)provided ***’motivational response to the SPEM curriculum or comparison curriculum was measured using the previously validated Situational Interest *** were analyzed using structural mean ***:The results demonstrated that the experimental group(as reference group)showed significantly higher enjoyment(z=-2.01),challenge(z=-6.54),exploration(z=-12.195),novelty(z=-8.80),and attention demand(z=-7.90)than the comparison ***:The findings indicate that the SPEM curriculum created a more situationally interesting context for learning than the comparison physical education curriculum.

关键词： Constructivist learning theory Curriculum intervention Elementary physical education Learner motivation Structural mean modeling

Key emergency response technologies for abrupt air pollution accidents in China

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2023年第1期123卷 235-254页

作者： Jun Duan Shushuai Mao Pinhua Xie Jianlei Lang ang Li Jingjing Tong Min Qin Jin Xu zeya Shen Key Laboratory of Environmental Optics and Technology Anhui Institute of Optics and Fine MechanicsHFIPSChinese Academy of SciencesHefei 230031China Key Laboratory of Beijing on Regional Air Pollution Control Faculty of Environment and LifeBeijing University of TechnologyBeijing 100124China School of Environmental Science and Optoelectronic Technology University of Science and Technology of ChinaHefei 230026China CAS Center for Excellence in Regional Atmospheric Environment Institute of Urban EnvironmentChinese Academy of SciencesXiamen 361021China University of Chinese Academy of Sciences Beijing 100049China Institutes of Physical Science and Information Technology Anhui UniversityHefei 230601China

Abrupt air pollution accidents can endanger people’s health and destroy the local ecological *** appropriate emergency response can minimize the harmful effects of accidents and protect people’s lives and *** paper provides an overview of the key emergency response technologies for abrupt air pollution accidents around the globe with emphasis on the major achievements that China has obtained in recent *** decades of effort,China has made significant progress in emergency monitoring technologies and equipment,source estimation technologies,pollutant dispersion simulation technologies and *** effective domestic emergency monitoring instruments(e.g.,portable DOAS/FT-IR systems,portable FID/PID systems,portable GC-MS systems,scanning imaging remote sensing systems,and emergency monitoring vehicles)had been developed which can meet the demands for routine emergency response activities.A monitoring layout technique combining air dispersion simulation,fuzzy comprehensive evaluation,and a post-optimality analysis was proposed to identify the optimal monitoring layout scheme under the constraints of limited monitoring *** source estimation technologies,including the forward method and the inversion method,have been established and evaluated under various ***-scale dynamic pollution dispersion simulation systems with high temporal and spatial resolution were further developed.A comprehensive emergency response platform integrating database support,source estimation,monitoring schemes,fast monitoring of pollutants,pollution predictions and risk assessment was developed based on the technical idea of"source identification-model simulation-environmental monitoring"dynamic interactive *** is expected that the emergency response capability for abrupt air pollution accidents will gradually improve in China.

关键词： Air pollution accidents Emergency response Emergency monitoring Source estimation Pollutant dispersion simulation

Understanding the structural evolution of Au/WO_(2.7) compounds in hydrogen atmosphere by atomic scale in situ environmental TEM

在线全文

学校读者我要写书评

暂无评论

Nano Research 2020年第11期13卷 3019-3024页

作者： Fei Hui Chong Li Yanhui Chen Chunhui Wang Jingping Huang ang Li Wei Li Jin zou Xiaodong Han Key Lab of Microstructure and Property of Advanced Materials Beijing University of TechnologyBeijing100124China International Laboratory for Quantum Functional Materials of Henan School of Physics and MicroelectronicsZhengzhou UniversityZhengzhou450001China School of Mechanical and Mining Engineering and Centre for Microscopy and Microanalysis The University of QueenslandSt LuciaQLD4072Australia

Hydrogen energy is a resuscitated clean energy source and its sensitive detection in air is crucial due to its very low explosive *** oxide decorated with noble metal nanoparticles has been used for the enhancement of gas detection and exhibits superior *** the intrinsic mechanism of the detection and the enhancement mechanism is thus becoming a fundamental issue for the further development of novel metal/oxide compound gas-sensing ***,the correlation between the microstructural evolution,the charge transport and the complex sensing process has not yet been directly revealed and its atomic mechanism is still *** this study,an Au/WO_(2.7) compound was synthesized and exhibited a strongly enhanced gas sensitivity to many reductive gases,especially ***-corrected environmental transmission electron microscopy was used to investigate the atomic-scale microstructural evolution in situ during the reaction between H_(2) and Au/WO_(2.7) *** and sintering processes of the Au particles on the WO_(2.7) surface were observed under heating and gaseous environments,and no injection of hydrogen atoms was *** principle calculations verified the swing and sintering processes,and they can be explained by the enhancement of H2 sensitivity.

关键词： in situ environmental TEM H2 sensing Au/WO_(2.7) gas-solid interface

A multiobjective evolutionary optimization method based critical rainfall thresholds for debris flows initiation

维普期刊数据库评论

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 Mountain Science 2020年第8期17卷 1860-1873页

作者： YAN Yan z.ang Yu HU Wang GUO Xiao-jun MA Chao Wang zi-ang z.ang Qun Key Laboratory of High-Speed Railway Engineering MOE/School of Civil EngineeringSouthwest Jiao tong UniversityChengdu 610031China Institute of Geographic Sciences and Natural Resources Research Chinese Academy of SciencesBeijing 100101China School of Computer Science and Engineering University of Electronic Science and Technology of ChinaChengdu 611731China Key Laboratory of Mountain Surface Process and Hazards/Institute of Mountain Hazards and Environment Chinese Academy of SciencesChengdu 610041China School of Soil and Water Conservation Beijing Forestry UniversityBeijing 100083China Sichuan Institute of Land and Space Ecological Restoration and Geological Hazard Prevention Chengdu 610081China

At present,most researches on the critical rainfall threshold of debris flow initiation use a linear model obtained through *** relatively weak fault tolerance,this method not only ignores nonlinear effects but also is susceptible to singular noise samples,which makes it difficult to characterize the true quantization relationship of the rainfall ***,the early warning threshold determined by statistical parameters is susceptible to negative samples(samples where no debris flow has occurred),which leads to uncertainty in the reliability of the early warning results by the regression *** overcome the above limitations,this study develops a data-driven multiobjective evolutionary optimization method that combines an artificial neural network(ANN)and a multiobjective evolutionary optimization implemented by particle swarm optimization(PSO).Firstly,the Pareto optimality method is used to represent the nonlinear and conflicting critical thresholds for the rainfall intensity I and the rainfall duration *** ANN is used to construct a dual-target(dual-task)predictive surrogate model,and then a PSO-based multiobjective evolutionary optimization algorithm is applied to train the ANN and stochastically search the trained ANN for obtaining the Pareto front of the I-D surrogate prediction model,which is intended to overcome the limitations of the existing linear regression-based threshold ***,a double early warning curve model that can effectively control the false alarm rate and negative alarm rate of hazard warnings are proposed based on the decision space and target space *** study provides theoretical guidance for the early warning and forecasting of debris flows and has strong applicability.

关键词： Debris flow Critical rainfall thresholds Multiobjective evolutionary optimization Artificial neural network Pareto optimality

Second-harmonic generation using d(33)in periodically poled lithium niobate microdisk resonators

在线全文

学校读者我要写书评

暂无评论

Photonics Research 2020年第3期8卷 311-317页

作者： zHENzHONG HAO LI z.ang WENBO MAO ang GAO XIAOMEI GAO FENG GAO Fang BO GUOQUAN z.ang JINGJUN XU MOE Key Laboratory of Weak-Light Nonlinear Photonics TEDA Institute of Applied Physics and School of PhysicsNankai UniversityTianjin 300457China Collaborative Innovation Center of Extreme Optics Shanxi UniversityTaiyuan 030006China

A fabrication process allowing for the production of periodically poled lithium niobate(PPLN)photonic devices with any domain pattern and unit size down to 200 nm is developed by combining semiconductor fabrication techniques and piezo-force-microscopy tips *** on this fabrication process,PPLN microdisk resonators with quality factors of 8×10~4 were fabricated from a z-cut lithium niobate ***-harmonic generation(SHG)utilizing d(33)in the whole cavity was demonstrated in a PPLN microdisk with a 2μm-spatialperiod radial domain *** SHG conversion efficiency was measured to be 1.44×10^(-5)m W^(-1).This work paves the way to fabricate complex PPLN photonic devices and to obtain efficient nonlinear optical effects that have wide applications in both classical and quantum optics.

关键词： lithium harmonic niobate

Optimization Analysis of Sustainable Solar Power System for Mobile Communication Systems

在线全文

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2022年第5期71卷 3243-3255页

作者： Mohammed H.Alsharif Raju Kannadasan Amir Y.Hassan Wael z.Tawfik Mun-Kyeom Kim Muhammad Asghar Khan Ahmad A.A.Solyman Department of Electrical Engineering College of Electronics and Information EngineeringSejong University209 Neungdong-roGwangjin-guSeoul05006Korea Department of Electrical and Electronics Engineering Sri Venkateswara College of EngineeringSriprumbudurChennai602117India Department of Power Electronics and Energy Conversion Electronics Research InstituteGiza12622Egypt Department of Physics Faculty of ScienceBeni-Suef UniversityBeni-Suef62511Egypt Department of Energy System Engineering Chung-Ang University84 Heukseok-roDongjak-guSeoul156-756Korea Department of Electrical Engineering Hamdard University Islamabad44000Pakistan Department of Electrical and Electronics Engineering Istanbul Gelisim UniversityAvcılar34310Turkey

Cellular mobile technology has witnessed tremendous growth in recent *** of the challenges facing the operators to extend the coverage of the networks to meet the rising demand for cellular mobile services is the power sources used to supply cellular towers with energy,especially in ***,switch from the conventional sources of energy to a greener and sustainable power model became a target of the academic and industrial sectors in many fields;one of these important fields is the telecommunication ***,this study aims to find the optimum sizing and technoeconomic investigation of a solar photovoltaic scheme to deploy cellular mobile technology infrastructure cleanly and *** optimal solarpowered system is designed by employing the energy-balance procedures of the HOMER software *** problem objective is considered in terms of cost,but the energy system is constrained to meet the power demand *** simulations were performed to determine the optimum sizing,performance and monetary cost of the power system,using long-term meteorological datasets for a case study site with defined longitude(31◦25E)and latitude(30◦06N).From the observed results,the total net present cost(NPC)of the proposed system is$28,***,these outcomes can provide profound economic,technical,and ecological benefits to cellular *** also ensures a sizeable reduction in greenhouse gas that supports sustainable green wireless network(WN)deployment in remote areas.

关键词： Wireless networks green wireless networks green communications sustainability OPEX

Mandible exosomal ssc-mir-133b regulates tooth development in miniature swine via endogenous apoptosis

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Bone Research 2018年第4期6卷 408-417页

作者： Ye Li Xinxin Wang Jiali Ren Xiaoshan Wu Guoqing Li zhipeng Fan Chunmei z.ang ang Li Songlin Wang Molecular Laboratory for Gene Therapy and Tooth Regeneration Beijing Key Laboratory of Tooth Regeneration and Function Reconstruction School of Stomatology Capital Medical University Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research College of Stomatology Xi'an Jiaotong University Laboratory of Molecular Signaling and Stem Cell Therapy Beijing Key Laboratory of Tooth Regeneration and Function Reconstruction School of Stomatology Capital Medical University Department of Biochemistry and Molecular Biology Capital Medical University School of Basic Medical Sciences

Signal transduction between different organs is crucial in the normal development of the human body. As an important medium for signal communication, exosomes can transfer important information, such as microRNAs(miRNAs), from donors to *** are known to fine-tune a variety of biological processes, including maxillofacial development; however, the underlying mechanism remains largely unknown. In the present study, transient apoptosis was found to be due to the expression of a miniature swine maxillofacial-specific miRNA, ssc-mir-133b. Upregulation of ssc-mir-133b resulted in robust apoptosis in primary dental mesenchymal cells in the maxillofacial region. Cell leukemia myeloid 1(Mcl-1) was verified as the functional target, which triggered further downstream activation of endogenous mitochondria-related apoptotic processes during tooth *** importantly, mandible exosomes were responsible for the initial apoptosis signal. An animal study demonstrated that ectopic expression of ssc-mir-133 b resulted in failed tooth formation after 12 weeks of subcutaneous transplantation in nude mice. The tooth germ developed abnormally without the indispensable exosomal signals from the mandible.

关键词： In As