检索结果-南通市图书馆

Graphene： Nanostructure engineering and applications

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 physics 2017年第1期12卷 1-22页

作者： tingting zhang Shuang Wu Rong Yang Guangyu zhang 1Institute of Physics Chinese Academy of Sciences Beijing 100190 China School of Physical Sciences University of Chinese Academy of Sciences Beijing 100190 China Beijing Key Laboratory for Nanomaterials and Nanodevices Beijing 100190 China Collaborative Innovation Center of Quantum Matter Beijing 100190 China

Graphene has attracted extensive research interest in recent years because of its fascinating physical properties and its potential for various applications. The band structure or electronic properties of graphene are very sensitive to its geometry, size, and edge structures, especially when the size of graphene is below the quantum confinement limit. Graphene nanoribbons （GNRs） can be used as a model system to investigate such structure-sensitive parameters. In this review, we examine the fabrication of GNRs via both top-down and bottom-up approaches. The edge-related electronic and transport properties of GNRs are also discussed.

关键词： graphene nanoribbons (GNRs) microfabrication top-down bottom-up electronic transport zigzag mobility edge state

Ultra-Wideband Millimeter-Wave Vortex Beam Generation Based on Reflective Pancharatnam-Berry Phase Metasurface

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 Communications and Information Networks 2023年第4期8卷 349-356页

作者： tingting zhang Xuehong Sun Yanpeng zhang Liping Liu Ningxia Key Laboratory of Intelligent Sensing of Desert Information School of Information EngineeringElectronics and Electrical EngineeringNingxia UniversityYinchuan 750021China School of Physics Ningxia UniversityNingxia 750021China

Due to the gradual scarcity of spectrum resources,orbital angular momentum(OAM)technology has been proposed and developed continuously to broaden channel *** solve this problem,some ultra-wideband reflective phase metasurface antennas working in millimeter band are designed to generate high purity vortex waves which carry *** on the Pancharatnam-Berry(PB)phase concept,the unit cell is composed of a metasurface,dielectric,metal grounding *** the optimization design of the unit structure parameters,the reflected wave efficiency can be as high as 95%when covering 2元rotating phase,which realizes the basic requirements of PB phase concept and the relative bandwidth of 116%.Then the metasurface arrays are arranged according to vortex wave generation formula and phase compensation *** the 25 GHz to 35 GHz frequency wide band,integer(l=±1,±2,±3)decimal(l=±1.5)and high-mode(l=±8)OAM vortex beams are generated,*** OAM purity analysis shows that the antennas can generate millimeter wave OAM beams with high purity in a wide band range,and with a maximum gain of up to 23.6 dBi.

关键词： Orbital angular momentum(OAM) millimeter wave ultra-wideband metasurface Pancharatnam-Berry(PB)phase

基于网络(ANP)的口袋公园服务水平研究——以安宁市昆钢口袋公园为例

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

科学技术创新 2025年第2期 155-160页

作者：孙允聪张婷婷昆明工业职业技术学院云南昆明

在我国城市建设过程中,城市角落遗弃的小空间可改造成为口袋公园,口袋公园为市民增加了城市绿地。通过选取代表性口袋公园建设资料研究,综合运用多种分析方法,研究口袋公园的综合服务水平。研究表明,口袋公园选址的小区人口密度,尤其是... 详细信息

在我国城市建设过程中,城市角落遗弃的小空间可改造成为口袋公园,口袋公园为市民增加了城市绿地。通过选取代表性口袋公园建设资料研究,综合运用多种分析方法,研究口袋公园的综合服务水平。研究表明,口袋公园选址的小区人口密度,尤其是道路网络的通达性对服务水平影响较大。

关键词：口袋公园网络数据集网络分析方法缓冲区分析叠合分析

Insights from metagenomic,metatranscriptomic,and molecular ecological network analyses into the effects of chromium nanoparticles on activated sludge system

在线全文

学校读者我要写书评

暂无评论

Frontiers of Environmental Science & Engineering 2020年第4期14卷 53-63页

作者： Quan Zheng Minglu zhang tingting zhang Xinhui Li Minghan Zhu Xiaohui Wang Beijing Engineering Research Center of Environmental Material for Water Purification College of Chemical EngineeringBeijing University of Chemical TechnologyBeijing 100029China Key Laboratory of Cleaner Production and Integrated Resource Utilization of China National Light Industry Beijing Technology and Business UniversityBeijing 100048China

The objectives of this study were to investigate the influence of chromium nanoparticles(Cr NPs)on the nitrogen and phosphorus removal performance and the bacterial structures of an activated sludge(AS)***,we through molecular ecological networks(MENs)discussed the bacterial *** last we researched the change of the functional genes and their expression patterns related to nitrogen and phosphorus removaT in an AS *** results showed that long-term exposure to 1 mg/L Cr NPs significantly promoted the denitrifying process and phosphorus removal in the AS *** relative abundance of denitrifying and phosphorus removal microorganisms,such as Denitratisoma,Thauera,Dechloromonas,and Defluviicoccus,increased *** Accumulibacter,well-known as polyphosphate-accumulating organisms(PAOs),increased significantly;the relative abundance of Candidatus Competibacter,known as glycogen-accumulating organisms(GAOs),decreased ***,metagenomic and metatranscriptomic analysis revealed that most of the genera related to denitrifying and phosphorus removal had greatly increased,according to the quantities of denitrifying and phosphorus genes,and the corresponding transcription likewise greatly ***,MENs analysis showed that although the overall network became smaller and looser in the presence of Cr NPs,the microbial connections among members related to nitrogen and phosphorus removal were *** abundance increases of denitrifiers and PAOs,and their increased transcription of functional genes,together with the enhanced interactions may be associated with the promotion of the denitrifying process and phosphorus removal.

关键词： Chromium nanoparticles(Cr NPs) Metagenomic analysis Metatranscriptomic analysis Molecular ecological networks(MENs) Nitrogen and phosphorus removal

A review on analytical methods for pharmaceutical and personal care products and their transformation products

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 Environmental Sciences 2021年第3期33卷 260-281页

作者： Yuan Meng Weiyi Liu Xiaohui Liu Jinlan zhang Meng Peng tingting zhang Department of Environmental Science and Engineering Beijing Environmental Pollution Control and Resource Engineering Research CenterBeijing University of Chemical TechnologyBeijing 100029China National Engineering Laboratory for Lake Pollution Control and Ecological Restoration State Key Laboratory of Environmental Criteria and Risk AssessmentChinese Research Academy of Environmental SciencesBeijing 100012China School of Environment Tsinghua UniversityBeijing 100084China

Pharmaceutical and personal care products(PPCPs)and corresponding transformation products have caused widespread concern due to their persistent emissions and potential *** have wide octanol-water partition coefficients(K_(ow))and different ionization constants(pK_(a))resulting in a poor analysis accuracy and efficiency.A suitable analytical method is the first prerequisite for further research on their environmental behavior to prioritize the *** study reviewed a full-scale analytical protocol for environmental samples in the recent ten years:from sampling to instrumental *** sampling techniques were compared and recommended for long-term continuous and scientific observation.A quick and effective sample extraction and clean-up method are highly *** methods coupled to mass spectrometry for determining PPCPs with a wide range of logK_(ow)(-7.53 to 10.80)were summed ***-resolution mass spectrometry was confirmed to be a promising strategy for screening unknown transformation products,which would provide a nanogram level of detection limits and more accurate mass *** strategies and mass change principles were summarized in *** recovery rate was important in multiple contaminants analysis identification and factors affecting the recovery rate of PPCPs were also discussed in this review,including sample matrix,target compounds characteristics,extraction method and solid-phase *** review provides useful information for the selection of appropriate analytical methods and future development directions.

关键词： Pharmaceutical and personal care products Transformation products Passive sampling Extraction High-resolution mass spectrometry

Distributed Real-time State Estimation for Combined Heat and Power Systems

在线全文

学校读者我要写书评

暂无评论

Journal of Modern Power Systems and Clean Energy 2021年第2期9卷 316-327页

作者： tingting zhang Wen zhang Qi Zhao Yaxin Du Jian Chen Junbo Zhao the Key Laboratory of Power System Intelligent Dispatch and Control Ministry of EducationShandong UniversityJinan 250061China the Department of Electrical and Computer Engineering Mississippi State UniversityStarkvilleMS 39762USA

This paper proposes a distributed real-time state estimation(RTSE)method for the combined heat and power systems(CHPSs).First,a difference-based model for the heat system is established considering the dynamics of heat *** heat system model is further used along with the power system steady-state model for holistic CHPS state estimation.A cubature Kalman filter(CKF)-based RTSE is developed to deal with the system nonlinearity while integrating both the historical and present measurement ***,a multi-timescale asynchronous distributed computation scheme is designed to enhance the scalability of the proposed method for largescale *** distributed implementation requires only a small amount of information exchange and thus protects the privacy of different energy *** carried out on two CHPSs show that the proposed method can significantly improve the estimation efficiency of CHPS without loss of accuracy compared with other existing models and methods.

关键词： Combined heat and power system(CHPS) cubature Kalman filter(CKF) heat dynamics multi-time-scale asynchronous distributed scheme real-time state estimation(RTSE)

Performance improvement of the stochastic-resonance-based tri-stableenergy harvester under random rotational vibration

在线全文

学校读者我要写书评

暂无评论

Theoretical & Applied Mechanics Letters 2022年第5期12卷 326-331页

作者： tingting zhang Yanfei Jin Yanxia zhang Department of Mechanics Beijing Institute of TechnologyBeijing 100081China Department of Mathematics Xi’an University of Science and TechnologyXi’anShaanxi 710054China

In this paper,the stochastic-resonance-based tri-stable energy harvester(TEH)is proposed to enhance harvesting performance under random rotational *** electromechanical coupled system interfaced with a standard rectifier circuit driven by colored noise is *** stationary probability density function(SPDF)of the harvester is obtained by the improved stochastic ***,with the adiabatic approximation theory,the analytical expression of signal-to-noise ratio(SNR)for the TEH is deduced to characterize stochastic resonance(SR).To enhance direct current(DC)power delivery from a rotational TEH,the influences of system parameters on SR is *** obtained results suggest that there are damping-induced resonance and noise-intensity-induced SR in the tri-stable *** TEH has higher harvesting performance under the optimal *** is,the optimal parameter combinations can induce optimal SR and maximize harvesting ***,the stochastic-resonance-based TEH can be optimized to enhance energy harvesting through choosing the optimal parameter.

关键词： Tri-stable energy harvesting Stochastic resonance Random rotational vibration Signal-to-noise ratio

Probabilistic analysis of tunnel face seismic stability in layered rock masses using Polynomial Chaos Kriging metamodel

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7期16卷 2678-2693页

作者： Jianhong Man tingting zhang Hongwei Huang Daniel Dias Department of Geotechnical Engineering Key Laboratory of Geotechnical and Underground Engineering of Ministry of EducationCollege of Civil EngineeringTongji UniversityShanghai200092China Grenoble Alpes 3SR LabCNRS UMR 5521Grenoble38000France

Face stability is an essential issue in tunnel design and *** rock masses are typical and ubiquitous;uncertainties in rock properties always *** view of this,a comprehensive method,which combines the Upper bound Limit analysis of Tunnel face stability,the Polynomial Chaos Kriging,the Monte-Carlo Simulation and Analysis of Covariance method(ULT-PCK-MA),is proposed to investigate the seismic stability of tunnel faces.A two-dimensional analytical model of ULT is developed to evaluate the virtual support force based on the upper bound limit *** efficient probabilistic analysis method PCK-MA based on the adaptive Polynomial Chaos Kriging metamodel is then implemented to investigate the parameter uncertainty *** input parameters,including geological strength indices,uniaxial compressive strengths and constants for three rock formations,and the horizontal seismic coefficients,are treated as random *** effects of these parameter uncertainties on the failure probability and sensitivity indices are *** addition,the effects of weak layer position,the middle layer thickness and quality,the tunnel diameter,the parameters correlation,and the seismic loadings are investigated,*** results show that the layer distributions significantly influence the tunnel face probabilistic stability,particularly when the weak rock is present in the bottom *** efficiency of the proposed ULT-PCK-MA is validated,which is expected to facilitate the engineering design and construction.

关键词： Tunnel face stability Layered rock masses Polynomial Chaos Kriging(PCK) Sensitivity index Seismic loadings

Deterministic and probabilistic analysis of great-depth braced excavations:A 32 m excavation case study in Paris

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 Rock Mechanics and Geotechnical Engineering 2024年第5期16卷 1505-1521页

作者： tingting zhang Julien Baroth Daniel Dias Khadija Nejjar Université Grenoble Alpes CNRSGrenoble INP3SRGrenoble38000France Antea Group Antony92160France School of Automotive and Transportation Engineering Hefei University of TechnologyHefei23009China Terrasol 42-52 Quai de la RapéeParis75012France

The Fort d’Issy-Vanves-Clamart(FIVC)braced excavation in France is analyzed to provide insights into the geotechnical serviceability assessment of excavations at great depth within deterministic and probabilistic *** FIVC excavation is excavated at 32 m below the ground surface in Parisian sedimentary basin and a plane-strain finite element analysis is implemented to examine the wall deflections and ground surface settlements.A stochastic finite element method based on the polynomial chaos Kriging metamodel(MSFEM)is then proposed for the probabilistic *** with field measurements and former studies are carried *** academic cases are then conducted to investigate the great-depth excavation stability regarding the maximum horizontal wall deflection and maximum ground surface *** results indicate that the proposed MSFEM is effective for probabilistic analyses and can provide useful insights for the excavation design and construction.A sensitivity analysis for seven considered random parameters is then *** soil friction angle at the excavation bottom layer is the most significant one for *** soil-wall interaction effects on the excavation stability are also given.

关键词： Braced deep excavation Soil-wall interaction Stochastic finite element method Horizontal wall deflection Settlement Failure probability