检索结果-南通市图书馆

Feasibility study of a large-scale tuned mass damper with eddy current damping mechanism

Earthquake Engineering and Engineering Vibration 2012年第3期11卷 391-401页

作者： wang zhihao Chen Zhengqing wang Jianhui Wind Engineering Research Center Hunan UniversityChangsha 410082China School of Civil Engineering and Communication North China University of Water Resources and Electric PowerZhengzhou 450011China

Tuned mass dampers （TMDs） have been widely used in recent years to mitigate structural vibration. However, the damping mechanisms employed in the TMDs are mostly based on viscous dampers, which have several well-known disadvantages, such as oil leakage and difficult adjustment of damping ratio for an operating TMD. Alternatively, eddy current damping （ECD） that does not require any contact with the main structure is a potential solution. This paper discusses the design, analysis, manufacture and testing of a large-scale horizontal TMD based on ECD. First, the theoretical model of ECD is formulated, then one large-scale horizontal TMD using ECD is constructed, and finally performance tests of the TMD are conducted. The test results show that the proposed TMD has a very low intrinsic damping ratio, while the damping ratio due to ECD is the dominant damping source, which can be as large as 15% in a proper configuration. In addition, the damping ratios estimated with the theoretical model are roughly consistent with those identified from the test results, and the source of this error is investigated. Moreover, it is demonstrated that the damping ratio in the proposed TMD can be easily adjusted by varying the air gap between permanent magnets and conductive plates. In view of practical applications, possible improvements and feasibility considerations for the proposed TMD are then discussed. It is confirmed that the proposed TMD with ECD is reliable and feasible for use in structural vibration control.

关键词： tuned mass damper eddy current damping permanent magnets conductive plate modal damping ratio

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

How could imperfect device properties influence the performances of spiking neural networks?

引用

Science China(Information Sciences) 2023年第8期66卷 233-242页

作者： Jingyang CHEN zhihao wang Tong wang Heming HUANG Zheyuan SHAO Zhe wang Xin GUO State Key Laboratory of Material Processing and Die & Mould Technology School of Materials Science and EngineeringHuazhong University of Science and Technology

Spiking neural networks(SNNs) provide an efficient way to apply artificial intelligence systems on edge devices. Memristive devices with tunable conductance states can be used to emulate the functions of biological neurons and synapses and to build SNNs. In this work, fully-connected SNNs based on various memristive devices are constructed, and a hardware-compatible spike-timing-dependent plasticity(STDP)learning rule is applied to train the SNNs. Strategies are designed to suppress the overfitting problem and improve the performance of the SNNs in the case of a small training set. However, the properties of memristive devices are never perfect. The effects of imperfect device properties, e.g., asymmetric weight update, insufficient number of conductance states, and low on/off ratio, on the performance of the SNNs are elaborated.

关键词： oxides memristive devices device properties spiking neural networks neuromorphic computing

来源：

同方期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A Robust Superhydrophobic Smart Coating with Reversible Thermochromic and Photochromic Property

引用

Journal of Bionic Engineering 2022年第6期19卷 1589-1600页

作者： Peng wang Xuesong Zhang zhihao wang Tao Chen Honglian Zhang Wei Duan Huilong Han School of Energy Power and Mechanical EngineeringNorth China Electric Power UniversityBaoding071000China Hebei Key Laboratory of Electric Machinery Health Maintenance and Failure Prevention North China Electric Power UniversityBaoding071003China

Both thermochromic and photochromic coating have attracted many attentions due to their widely applications,but the low stability is a big *** by the lotus leaf,to endow the chromic coating with superhydrophobicity is a possible *** this research,a dual response coating was prepared by adding photochromic and thermochromic particles *** prepared sample demonstrated at least four-state color switching,which can be successfully used in tactile imaging,multi-color fabric,erasable record,and security *** superhydrophobicity was achieved by introducing vinyl-terminated polydimethylsiloxane,which not only offers low surface energy but also can cross-link with the particles to increase the ***,the prepared sample maintained superhydrophobicity after various kinds of destruction(such as sandpaper abrasion,corrosive liquid attack,ultrasonic treatment,UV irradiation,and high-speed drops/turbulent jets impact).Even though the superhydrophobicity can be destroyed by plasma etching,it can be recovered after 12 h at room temperature.

关键词： Bionic coating Superhydrophobic Thermochromic Photochromic Robust

来源：

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

Investigation of Out-Phase Electromagnetic Casting of Aluminum Alloy

引用

稀有金属材料与工程 2009年第A03期38卷 73-77页

作者： Zhao zhihao Zhu Qingfeng wang Xiangjie Cui Jianzhong Key Laboratory of Electromagnetic Processing of Materials Ministry of Education Northeastern University Shenyang 110004 China

The influences of out-phase electromagnetic field on the as-cast structure of horizontal direct chill casting aluminum alloy ingot were experimental by and numerical by studied. The results of numerical analysis show that the interaction of the out-phase electromagnetic field and the melt can generate an electromagnetically induced forced flow in the melt, which, in turn, changes flow pattern and temperature field in the mold. The as-cast structure of the ingot can be greatly improved by the changes of flow pattern and temperature field. The results of experimental analysis show that with application of out-phase electromagnetic field, temperature distribution in the melt is more uniform, grain morphology changes from columnar grains to equiaxed grains and grain size decreases.

关键词：铝合金异相电磁场电磁感应温度

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Sunlight-activated AlFeO_3/TiO_2 photocatalyst

引用

Science China Chemistry 2006年第1期49卷 67-74页

作者： YUAN zhihao wang Yuhong SUN Yongchang wang Jing BIE Lijian DUAN Yueqing Nanomaterials & Nanotechnology Research Center School of Materials Science & Engineering Tianjin University of Technology Tianjin 300191 China Nanomaterials & Nanotechnology Research Center School of Materials Science & Engineering Tianjin University of Technology Tianjin 300191 China Nanomaterials & Nanotechnology Research Center School of Materials Science & Engineering Tianjin University of Technology Tianjin 300191 China Nanomaterials & Nanotechnology Research Center School of Materials Science & Engineering Tianjin University of Technology Tianjin 300191 China Nanomaterials & Nanotechnology Research Center School of Materials Science & Engineering Tianjin University of Technology Tianjin 300191 China Nanomaterials & Nanotechnology Research Center School of Materials Science & Engineering Tianjin University of Technology Tianjin 300191 China

A nanocomposite photocatalyst composed of AlFeO3 and TiO2 is prepared, and charac-terized through X-ray diffraction. Application of the nanocomposite for the photodegradations of eosin dye and methyl orange gives an improved photoactivity compared with TiO2-only nanomaterials. The optimal concentration of AlFeO3 in the composite is about 1.0 wt% under UV excitation, and 9.0 wt% under sunlight excitation for the improved photoactivity. Furthermore, this nanocomposite is more active for eosin photodegradation if natural sunlight rather than UV is used. This may be due to the reason that adding AlFeO3 nanoparticles into TiO2 matrix can promote the separation of photogener-ated charge carriers, and extend the photoresponse of TiO2 toward visible region, which results in an increase in the solar energy utilization efficiency.

关键词： nanocomposite, photocatalysis, titania, aluminum ferrite.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A Topic-Triggered Translation Model for Statistical Machine Translation

引用

Chinese Journal of Electronics 2017年第1期26卷 65-72页

作者： SU Jinsong wang zhihao WU Qingqiang YAO Junfeng LONG Fei ZHANG Haiying Software School Xiamen University Provincial Key Laboratory for Computer Information Processing Technology Soochow University Automation Department Xiamen University

Translation model containing translation rules with probabilities plays a crucial role in statistical machine translation. Conventional method estimates translation probabilities with only the consideration of cooccurrence frequencies of bilingual translation units, while ignoring document-level context information. In this paper, we extend the conventional translation model to a topic-triggered one. Specifically, we estimate topic-specific translation probabilities of translation rules by leveraging topical context information, and online score selected translation rules according to topic posterior distributions of translated sentences. As compared with the conventional model, our model allows for more fine-grained distinction among different translations. Experiment results on large data set demonstrate the effectiveness of our model.

关键词： Statistical machine translation Topictriggered translation model Topical context information

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

The influence of pore structures and Lewis acid sites on selective hydrogenolysis of guaiacol to benzene over Ru/TS-1

引用

Green Energy & Environment 2022年第5期7卷 1014-1023页

作者： Yingying Xin Zhaoxia Zheng Zhicheng Luo Chengzhen Jiang Shaofeng Gao zhihao wang Chen Zhao Shanghai Key Laboratory of Green Chemistry and Chemical Processes School of Chemistry and Molecular EngineeringEast China Normal UniversityShanghai200062China Jinan Shengquan Group Share Holding Co. Ltd.Jinan250204China

Here,we report a Ru/TS-1 catalyst for selective hydrogenolysis of guaiacol to benzene in the aqueous phase at conditions of 240℃ and 0.2 MPa H2,achieving a benzene yield of 86% with a hydrogenolysis rate of 103.1 mmol g^(-1) h^(-1).It was found that Silicalite-1(MFI type) with suitable pore sizes supported Ru nanoparticles(NPs) favored for hydrogenolysis of guaiacol,whereas de-aluminated Ru/HBEA,Ru/HY and Ru/MWW(without acidic sites) accelerated the parallel reactions of hydrogenation of *** addition,Ru NPs located at the orifice of Silicalite-1 was proved to be more electron-deficient and active than Ru NPs on the outer surface,as evidenced by CO-IR characterization and activity tests on Ru/Silicalite-1(with and without templates).Moreover,Br?nsted acid sites(BAS) on Ru/MFI highly promoted the hydrogenation rates of aromatics,while Lewis acid sites(LAS) on Ru/TS-1 and Ru/MFI led to a linear increase of guaiacol hydrogenolysis rate to benzene,probably due to the enhanced absorbance capability of guaiacol and phenol on the LAS of ***,pore structure properties of MFI coupled with abundant LAS(TS-1) as well as Ru NPs on the orifice of pores of TS-1 construct a promising catalyst for achieving efficient aromatic hydrocarbons from selective hydrogenolysis of lignin.

关键词： benzene hydrogenation catalyst

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A Potential Global Standard Stratotype-Section and Point of the Moscovian Stage(Carboniferous)

引用

Acta Geologica Sinica(English Edition) 2011年第2期85卷 366-372页

作者： wang Xiangdong QI Yuping Lance LAMBERT wang zhihao wang Yue HU Keyi LIN Wei CHEN Bo State Key Laboratory of Palaeobiology and Stratigraphy Nanjing Institute of Geology and Palaeontologythe Chinese Academy of Sciences Nanjing Jiangsu 210008 China Department of Geological Sciences University of Texas at San Antonio San Antonio Texas 78249-0663 USA

Conodonts and fusulinids are the two most widely used biotic groups for subdividing and correlating Bashkirian and Moscovian strata. The definition of the base of the Global Moscovian Stage is undecided because there are many disagreements among existing boundary definition proposals,each of which has disadvantages. Declinognathodus donetzianus is easily recognized but somewhat limited in its paleogeographic distribution. Idiognathoides postsulcatus is slightly more widespread, but it is less easily identified and its occurrences may be diachronous from region to region. Diplognathodus ellesmerensis is easily recognized and even more widespread, but it is usually rare and its ancestry is not adequately known. The Naqing Section of South Guizhou, South China contains diverse conodont evolutionary lineages among different taxa, including Idiognathoides, Idiognathodus, Diplognathodus,Neognathodus, Gondolella and Mesogondolella. There are numerous transitional forms in almost every lineage of the Naqing section, which shows that the prospects for South China to play a critical role in determining the basal Moscovian Stage definition are good.

关键词： Bashkirian-Moscovian Boundary Global Standard Stratotype-Section and Point conodont fusulinid the Naqing Section of South Guizhou China

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

The influence of solute atom ordering on the deformation behavior of hexagonal close packed Ti-Al alloys

引用

Journal of Materials Science & Technology 2020年第17期52卷 235-242页

作者： Hao Wu Yunlei Xu zhihao wang Zhenhua Liu Qinggang Li Jinkai Li Junyan Wu School of Materials Science and Engineering University of JinanJinan 250022China School of Material Science and Engineering Qilu University of Technology(Shandong Academy of Sciences)Jinan 250353China Technical Division Sinomach Foundry and Metal Forming Co.Ltd.Jinan 250306China Shandong Provincial Key Laboratory of Preparation and Measurement of Building Materials Jinan 250022China

A framework of compositionally graded Ti-Al alloys was proposed to elucidate the Al alloying dependent deformation mechanism at room *** trace analysis demonstrated low-alloyed Ti-Al model materials were plastically deformed by prismatic slip,pyramidal slip,stacking faults,and deformation *** Al concentration promoted chemical ordering,thus suppressing the dislocation motion and deformation *** mechanism behind such a kind of composition-mediated deformation physics was *** findings are expected to be applicable in the design of next-generation high-performance structural materials through the tailoring of the chemical ordering of solute atoms in substitutional solid solution.

关键词： Titanium alloys Diffusion Alloying Electron microscopy

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Traffic Anomaly DetectionMethod Based on Improved GRU and EFMS-Kmeans Clustering

引用

Computer Modeling in Engineering & Sciences 2021年第3期126卷 1053-1091页

作者： Yonghua Huo Yi Cao zhihao wang Yu Yan Zhongdi Ge Yang Yang Science and Technology on Communication Networks Laboratory The 54th Research Institute of CETCShijiazhuangChina Department of Military Representative Office of General Military Equipment Development Shijiazhuang ShijiazhuangChina State Key Laboratory of Networking and Switching Technology Beijing University of Posts and TelecommunicationsBeijing100876China

In recent years,with the continuous development of information technology and the rapid growth of network scale,network monitoring and management become more and more *** traffic is an important part of network *** order to ensure the normal operation of the network,improve the availability of the network,find network faults in time and deal with network attacks;it is necessary to detect the abnormal traffic in the *** traffic detection is of great significance in the actual network ***,in order to improve the accuracy and efficiency of network traffic anomaly detection,this paper proposes a comprehensive anomaly detection method based on improved GRU traffic prediction and improved K-means clustering,and cascade the traffic prediction and clustering to achieve the purpose of anomaly ***,an improved highway-GRU algorithm HS-GRU(An improved Gate Recurrent Unit neural network based on Highway network and STL algorithm,HS-GRU)is proposed,which combines STL decomposition algorithm with highway GRU neural network and uses this improved algorithm to predict *** then,we proposed the EFMS-Kmeans algorithm(An improved clustering algorithmthat combined Mean Shift algorithmbased on electrostatic force with K-means clustering)to solve the shortcoming of the traditional K-means clustering which cannot automatically determine the number of *** sum of the squared errors(SSE)method and the contour coefficient method were used to double test the clustering *** determining the clustering center,the potential energy gradient was directly used for anomaly detection by using the threshold method,which considered the local characteristics of the data and ensured the accuracy of anomaly *** simulation results show that the anomaly detection algorithm based on HS-GRU and EFMS-Kmeans clustering proposed in this paper can effectively improve the accuracy of flow anomaly detection and has impo

关键词： Anomaly detection gated recurrent unit clustering mean shift K-means

来源：

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

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：