检索结果-南通市图书馆

Machine Intelligence Research 2024年第5期21卷 983-992页

作者： Mengle Peng Xiaoyong Jiang Langyue Huang Zhongyi Li Haiteng Wu Xiaotang Geng Zhejiang university of Science and technology Hangzhou310023China Zhejiang Key Laboratory of Intelligent Operation and Maintenance Robot Hangzhou311100China

With the increasing demand for power in society,there is much live equipment in substations,and the safety and standardization of live working of workers are facing *** at these problems of scene complexity and object diversity in the real-time detection of the live working safety of substation workers,an adaptive multihead structure and lightweight feature pyramid-based network(AHLNet)is proposed in this study,which is based on ***,we take AH-Darknet53 as the backbone network of YOLOV3,which can introduce an adaptive multihead(AMH)structure,reduce the number of network parameters,and improve the feature extraction ability of the backbone ***,to reduce the number of convolution layers of the deeper feature map,a lightweight feature pyramid network(LFPN)is proposed,which can perform feature fusion in advance to alleviate the problem of feature imbalance and gradient ***,the proposed AHLNet is evaluated on the datasets of 16 categories of substation safety operation scenarios,and the average prediction accuracy MAP_(50)reaches 82.10%.Compared with YOLOV3,MAP_(50)is increased by 2.43%,and the number of parameters is 90 M,which is only 38%of the number of parameters of *** addition,the detection speed is basically the same as that of YOLOV3,which can meet the real-time and accurate detection requirements for the safe operation of substation staff.

关键词： Adaptive multihead structure lightweight feature pyramid substation feature imbalance multiobject detection

Syngas to ethanol on MoCu(211)surface:Effect of promoter Mo on C-O bond breaking and C-C bond formation

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 Chemical Engineering 2022年第5期35卷 78-89页

作者： Lijuan He Cuimei Zhi Lixia Ling Riguang Zhang Baojun Wang State Key Laboratory of Clean and Efficient Coal Utilization Taiyuan University of TechnologyTaiyuan 030024China Key Laboratory of Coal Science and technology(taiyuan university of technology) Ministry of Education and Shanxi ProvinceTaiyuan 030024China College of Chemistry and Bioengineering Taiyuan University of Science and TechnologyTaiyuan 030024China College of Chemistry and Chemical Engineering Taiyuan University of TechnologyTaiyuan 030024China

The mechanism of syngas to ethanol on MoCu(211)surface has been researched by density functional theory(DFT)calculation,and the effects of Mo as a promoter on C-O bond breaking and C-C bond formation have been *** show that Cu-Mo atoms constitute the active sites on MoCu(211)surface after Mo atom being served as a promoter of Cu *** with Cu(211),MoCu(211)has two ***,CH_(3) is the most advantageous monomer on the MoCu(211)surface,which provides abundant CH_(3) intermediate for syngas to ***,the C-C bond is formed mainly by inserting CHO into the abundant CH_(3),and the generated CH_(3)CHO through multiple steps of hydrogenation to generate C_(2)H_(5)*** key of the promoter Mo on the MoCu(211)surface also has been verified by the analysis of its electronic *** charge density shows that the massive electron transfer from Mo to Cu,projected density of states(pDOS)shows that the electron transfer from Mo to Cu makes the d-band center of MoCu(211)nearer to the Fermi level,these indicate that the MoCu(211)catalytic capacity *** addition of Mo in the Cu-based catalyst not only can effectively solve the problem of C-O bond breaking,but also promote C-C bond *** the influence of Mo content on C-O bond breaking and C-C bond formation,compared with MoCu(211),the DFT results and the d-band center of Mo_(2)Cu(211)show that the increase of Mo content could not promote the synergistic effect of Cu/Mo on the generation of ethanol more effectively.

关键词： Syngas Ethanol DFT Cu catalyst Promoter Mo

Carbon Fiber Breakage Mechanism in Aluminum(Al)/Carbon Fibers(CFs) Composite Sheet during Accumulative Roll Bonding(ARB) Process

在线全文

学校读者我要写书评

暂无评论

Journal of Wuhan university of technology(Materials Science) 2024年第1期39卷 167-173页

作者：胡淑芬 SUN Zhenzhong SHEN Fanghua DENG Jun 杨卫平杨浩坤 School of Engineering Jiangxi Agricultural UniversityNanchang 330045China School of Mechanical Engineering Dongguan University of TechnologyDongguan 510730China Guangdong-Hong Kong-Macao Joint Laboratory for Neutron Scattering Science and technology Dongguan 510730China Smart Manufacturing Division Hong Kong Productivity Council78 Tat Chee AvenueHong Kong 5999075China

We put forward a method of fabricating Aluminum(Al)/carbon fibers(CFs) composite sheets by the accumulative roll bonding(ARB) method. The finished Al/CFs composite sheet has CFs and pure Al sheets as sandwich and surface layers. After cross-section observation of the Al/CFs composite sheet, we found that the CFs discretely distributed within the sandwich layer. Besides, the tensile test showed that the contribution of the sandwich CFs layer to tensile strength was less than 11% compared with annealed pure Al sheet. With ex-situ observation of the CFs breakage evolution with-16%,-32%, and-45% rolling reduction during the ARB process, the plastic instability of the Al layer was found to bring shear damages to the CFs. At last, the bridging strengthening mechanism introduced by CFs was sacrificed. We provide new insight into and instruction on Al/CFs composite sheet preparation method and processing parameters.

关键词： Al/CFs composite sheet accumulative roll bonding tensile strength plastic instability carbon fiber breakage

Robust Segmentation Method for Noisy Images Based on an Unsupervised Denosing Filter

在线全文

学校读者我要写书评

暂无评论

Tsinghua Science and technology 2021年第5期26卷 736-748页

作者： Ling Zhang Jianchao Liu Fangxing Shang Gang Li Juming Zhao Yueqin Zhang College of Software Taiyuan University of TechnologyTaiyuan 030024China College of Information and Computer Taiyuan University of TechnologyTaiyuan 030024China Information technology Department Shanxi Tizones Technology Co.LtdTaiyuan 030024China

Level-set-based image segmentation has been widely used in unsupervised segmentation *** have recently alleviated the influence of image noise on segmentation results by introducing global or local statistics into existing *** existing methods are based on the assumption that the distribution of image noise is known or ***,real-time images do not meet this *** bridge this gap,we propose a novel level-set-based segmentation method with an unsupervised denoising ***,a denoising filter is acquired under the unsupervised learning ***,the denoising filter is integrated into the level-set framework to separate noise from the noisy image ***,the level-set energy function is minimized to acquire segmentation *** experiments demonstrate the robustness and effectiveness of the proposed method when applied to noisy images.

关键词： image segmentation noisy image level set autoencoder

Graded Heterojunction Improves Wide-Bandgap Perovskite for Highly Efficient 4-Terminal Perovskite/Silicon Tandem Solar Cells

在线全文

学校读者我要写书评

暂无评论

Research 2024年第2期2023卷 181-190页

作者： Wenming Chai Lindong Li Weidong Zhu Dazheng Chen Long Zhou He Xi Jincheng Zhang Chunfu Zhang Yue Hao State Key Discipline Laboratory of Wide Band Gap Semiconductor technology&Shaanxi Joint Key Laboratory of Graphene School of MicroelectronicsXidian UniversityXi'anShaanxi 710071China Xi'an Baoxin Solar technology Co. Ltd.Xi'an710071China

Wide-bandgap(WBG)perovskite solar cells(PSCs)are essential for highly efficient and stable silicon/perovskite tandem solar *** this study,we adopted a synthetic strategy with lead thiocyanate(Pb(SCN)_(2))additive and methylammonium chloride(MACl)posttreatment to enhance the crystallinity and improve the interface of WBG perovskite films with a bandgap of 1.68 *** excessive PbI_(2)was formed at grain boundaries and converted into MAPbI_(3-x)Cl_(x)perovskites,which are utilized to form the graded heterojunction(GHJ)and compressive *** is beneficial for passivating nonradiative recombination defects,suppressing halide phase segregation,and facilitating carrier ***,the device with GHJ delivered a champion efficiency of 20.30%and superior stability in ambient air and under 85℃.Finally,we achieved a recorded efficiency of 30.91%for 4-terminal WBG perovskite/TOPCon tandem silicon solar *** findings demonstrate a promising approach for fabricating efficient and stable WBG PSCs through the formation of GHJ.

关键词： perovskite Graded Highly

α-decay properties of superheavy nuclei with 117 ≤ Z ≤ 120 from the systematics of decay chains and isotopic chains

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 Physics C 2024年第3期48卷 118-125页

作者：万涛唐树林钱以斌 Department of Applied Physics and MIIT Key Laboratory of Semiconductor Microstructure and Quantum Sensing Nanjing University of Science and TechnologyNanjing 210094China

Recently, the synthesis of new elements above Z = 118 has been a hot topic in nuclear physics. Meanwhile, the α-decay chain is expected to be the unique tool to identify these heaviest nuclei. We have systematically calculated the α-decay energies and half-lives on the same footing for superheavy nuclei (SHN) within the cluster model along with a slightly modified Woods-Saxon (W.S.) potential as the nuclear potential. Based on the available experimental data, the key radius parameter (R) in the α-core potential is determined via the systematic trend from the α-decay and isotopic chains. The α-decay energy (Qα) values and half-lives are then obtained simultaneously for those unknown SHN in the range of 117 ≤ Z ≤ 120, during which the decay width is obtained using a new treatment for the asymptotic behavior of the α-core wave function. The theoretical values and experimental data are found to be in excellent agreement for the nuclei ^(293,294)117 and ^(294)118 regardless of the method used to determine the R parameter. Predicting the α-decay chains for new elements Z = 119 and Z = 120 can be useful in ongoing or forthcoming experiments.

关键词： superheavy nuclei αdecay decay chains isotopic chains

Pedestrian wind flow prediction using spatial-frequency generative adversarial network

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 319-334页

作者： Pengyue Wang Maozu Guo Yingeng Cao Shimeng Hao Xiaoping Zhou Lingling Zhao School of Architecture and Urban Planning Beijing University of Civil Engineering and ArchitectureBeijing100044China Beijing Key Laboratory of Intelligent Processing for Building Big Data Beijing100044China School of Electrical and Information Engineering Beijing University of Civil Engineering and ArchitectureBeijing100044China School of Computer Science and technology Harbin Institute of TechnologyHarbin150001China

Pedestrian wind flow is a critical factor in designing livable residential environments under growing complex urban *** pedestrian wind flow during the early design stages is essential but currently suffers from inefficiencies in numerical *** learning,particularly generative adversarial networks(GAN),has been increasingly adopted as an alternative method to provide efficient prediction of pedestrian wind ***,existing GAN-based wind flow prediction schemes have limitations due to the lack of considering the spatial and frequency characteristics of wind flow *** study proposes a novel approach termed SFGAN,which embeds spatial and frequency characteristics to enhance pedestrian wind flow *** the spatial domain,Gaussian blur is employed to decompose wind flow into components containing wind speed and distinguished flow edges,which are used as the embedded spatial *** information of wind flow is obtained through discrete wavelet transformation and used as the embedded frequency *** spatial and frequency characteristics of wind flow are jointly utilized to enforce consistency between the predicted wind flow and ground truth during the training phase,thereby leading to enhanced *** results demonstrate that SFGAN clearly improves wind flow prediction,reducing Wind_MAE,Wind_RMSE and the Fréchet Inception Distance(FID)score by 5.35%,6.52%and 12.30%,compared to the previous best method,*** also analyze the effectiveness of incorporating the spatial and frequency characteristics of wind flow in predicting pedestrian wind *** reduces errors in predicting wind flow at large error intervals and performs well in wake regions and regions surrounding *** enhanced predictions provide a better understanding of performance variability,bringing insights at the early design stage to improve pedestrian wind *** proposed spatial-frequen

关键词： pedestrian wind flow prediction generative adversarial network Gaussian kernel wavelet transform objective function

Wideband Circularly Polarized Substrate-Integrated Waveguide Aperture-Coupled Metasurface Antenna Array for Millimeter-Wave 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

Chinese Journal of Electronics 2024年

作者： Jiwei LIAN Chun GENG Xue LU Dazhi DING School of Microelectronics (School of Integrated Circuits) Nanjing University of Science and Technology State Key Laboratory of Millimeter Waves Southeast University Qian Xuesen College Nanjing University of Science and Technology

A wideband circularly polarized(CP) aperture-coupled metasurface antenna operating at millimeterwave frequency spectrum in substrate-integrated waveguide(SIW) technology is proposed. Such a proposed metasurface antenna is composed of two substrates. The first substrate contains an end-shorted SIW section with a slot etched. The introduced metasurface is printed on the top of the second substrate. The metasurface is comprised of3 × 3 unit cells, each of which contains two interconnected patches and two parasitic patches. The working mechanism of the proposed metasurface antenna is illustrated in details. The proposed metasurface antenna has wide impedance bandwidth and axial ratio(AR) bandwidth, which are 66.7% and 40%, respectively. Using the proposed metasurface antenna, a 4 × 4 CP metasurface antenna array with an impedance bandwidth of 24%, an AR bandwidth of 30%, and a peak gain of 18.7 dBic in simulation is developed in this paper for millimeter-wave applications.

关键词：

Small but mighty:Empowering sodium/potassium-ion battery performance with S-doped SnO_(2) quantum dots embedded in N,S codoped carbon fiber network

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Carbon Energy 2024年第5期6卷 186-200页

作者： Shengnan He Hui Wu Shuang Li Ke Liu Yaxiong Yang Hongge Pan Xuebin Yu Institute of Science and technology for New Energy Xi'an Technological UniversityXi'anChina Department of Materials Science Fudan UniversityShanghaiChina Wanxiang A123 Systems Corporation HangzhouChina School of Material Science and Engineering Shanghai UniversityShanghaiChina

SnO_(2) has been extensively investigated as an anode material for sodium-ion batteries(SIBs)and potassium-ion batteries(PIBs)due to its high Na/K storage capacity,high abundance,and low ***,the sluggish reaction kinetics,low electronic conductivity,and large volume changes during charge and discharge hinder the practical applications of SnO_(2)-based electrodes for SIBs and *** rational structures with fast charge/ion transfer and robust stability is important to overcoming these ***,S-doped SnO_(2)(S-SnO_(2))quantum dots(QDs)(≈3 nm)encapsulated in an N,S codoped carbon fiber networks(S-SnO_(2)-CFN)are rationally fabricated using a sequential freeze-drying,calcination,and S-doping *** analysis and density functional theory calculations reveal that the integration of S-SnO_(2) QDs with N,S codoped carbon fiber network remarkably decreases the adsorption energies of Na/K atoms in the interlayer of SnO_(2)-CFN,and the S doping can increase the conductivity of SnO_(2),thereby enhancing the ion transfer *** synergistic interaction between S-SnO_(2) QDs and N,S codoped carbon fiber network results in a composite with fast Na+/K+storage and extraordinary long-term ***,the S-SnO_(2)-CFN delivers high rate capacities of 141.0 mAh g^(−1) at 20 A g^(−1) in SIBs and 102.8 mAh g^(−1) at 10 A g^(−1) in ***,it delivers ultra-stable sodium storage up to 10,000 cycles at 5 A g^(−1) and potassium storage up to 5000 cycles at 2 A g^(−1).This study provides insights into constructing metal oxide-based carbon fiber network structures for high-performance electrochemical energy storage and conversion devices.

关键词： carbon fiber network heteroatom doping potassium-ion battery sodium-ion battery S-SnO_(2)quantum dot

A multi-scale framework for life reduction assessment of turbine blade caused by microstructural degradation

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1期37卷 186-200页

作者： Xiaoguang YANG Menglei WANG Duoqi SHI Zhenlei LI Yongsheng FAN School of Energy and Power Engineering Beihang UniversityBeijing 102206China Research Institute of Aero-Engine Beihang UniversityBeijing 102206China National Key Laboratory of Science and technology on Aero-Engine Aero-Thermodynamics Beihang UniversityBeijing 102206China

The prolonged thermal exposure with centrifugal load results in microstructural degradation,which ultimately leads to a reduction in the fatigue and creep resistance of the turbine *** present work proposes a multi-scale framework to estimate the life reduction of turbine blades,which combines a microstructural degradation model,a two-phase constitutive model,and a microstructure-dependent fatigue and creep life reduction *** framework with multi-scale models is validated by a Single Crystal(SC)Ni-based superalloy at the microstructural length-scale and is then applied to calculate the microstructural degradation and the fatigue and creep life reduction of turbine blades under two specific service *** simulation results and quantitative analysis show that the microstructural degradation and fatigue and creep life reduction of the turbine blade are heavily influenced by the variations in the proportion of the intermediate state,namely,the maximum rotor speed status,in the two specific service *** intermediate state accelerates the microstructural degradation and leads to a reduction of the life,especially the effective fatigue life reserve due to the higher temperature and rotational speed than that of the 93%maximum rotor speed status marked as the reference *** proposed multi-scale framework provides a capable approach to analyze the reduction of the fatigue and creep life for turbine blade induced by microstructural degradation,which can assist to determine a reasonable Time Between Overhaul(TBO)of the engine.

关键词： Creep Fatigue Life reduction Microstructural degradation Multi-scale modeling Turbine blades