检索结果-南通市图书馆

Journal of Iron and Steel Research International 2024年第8期31卷 1900-1913页

作者： Jin-wen song wen Yan Zhe Chen Ying Liu Shao-song Hong The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan 430081HubeiChina National-provincial Joint Engineering Research Center of High Temperature Materials and Lining Technology Wuhan University of Science and TechnologyWuhan 430081HubeiChina Jiangsu Sheng Nai New Materials Co. Ltd.Taizhou 225503JiangsuChina

The effect of nano-carbon black content(O,8 and 12 wt.%)on the wettability of molten steel on Al_(2)O_(3)-C substrates was investigated by the sessile drop wetting method at 1500℃ under argon *** the beginning of the wetting experiment,the contact angle decreased with the increase in nano-carbon black *** the wetting experiment progressed,FeAl_(2)0_(4) layer and sheet Al_(2)O_(3) layer were found at the interface between the molten steel and the Al_(2)O_(3)-C substrates with O and 8 wt.% nano-carbon black content,and the contact angle deceased with *** the content of nano-carbon black was 12 wt.%,a large number of nano-Al_(2)O_(3) whiskers were observed,which made the contact angle between the molten steel and Al_(2)O_(3)-C substrate become *** on the scanning electron microscope and energy dispersive spectrometry results,the formation mechanism of FeAl2O4 layer and Al_(2)O_(3) layer and the interfacial reaction mechanism were proposed.

关键词： Contact angle Nano-carbon black Al_(2)O_(3)-C substrate Molten steel Interfacial reaction

Low profile cavity-embedded ultra-wideband UHF array antenna with end-fire beams

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 Electronic Science and Technology 2024年第2期22卷 24-35页

作者： Huan He wen-song Wang Southwest China Institute of Electronic Technology Chengdu610036China School of Electrical and Electronic Engineering Department Nanyang Technological UniversitySingapore639798Singapore

A low-profile,vertically polarized,ultra-wideband array antenna with end-fire beams operating in an ultra-high frequency(UHF)band is developed in this *** array antenna consists of 1×16 log-periodic top-hat loaded monopole antenna arrays and is feasible to embed into a shallow cavity to further reduce the array *** is introduced in the proposed antenna element to reduce profile height and the rectangular top hats are carefully designed to minimize the transverse *** results show that when the antenna array operates in a frequency range of 300 MHz-900 MHz,the end-fire radiation pattern achieves±45°scanning range in the horizontal *** prototypes of the proposed end-fire antenna element and a uniformly spaced linear array(1×2)are fabricated and *** end-fire antenna array should be suitable for airborne applications where low-profile and conformal scanning phased antenna arrays with end-fire radiations are *** design is attractive for airborne platform applications that are used to search,discover,identify,and scout the aerial target with vertically polarized beams.

关键词： End-fire radiation Low-profile Vertical polarization Log-periodic array

Band gap analysis of periodic structures based on cell experimental frequency response functions(FRFs)

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Mechanica Sinica 2019年第1期35卷 156-173,I0005页

作者： Li-Jie Wu Han-wen song School of Aerospace Engineering and Applied Mechanics Tongji UniversityShanghai 200092China

An approach is proposed to estimate the transfer function of the periodic structure, which is known as an absorber due to its repetitive cells leading to the band gap phenomenon. The band gap is a frequency range in which vibration will be inhibited. A transfer function is usually performed to gain band gap. Previous scholars regard estimation of the transfer function as a forward problem assuming known cell mass and stiffness matrices. However, the estimation of band gap for irregular or complicated cells is hardly accurate because it is difficult to model the cell exactly. Therefore, we treat the estimation as an inverse problem by employing modal identification and curve fitting. A transfer matrix is then established by parameters identitled through modal analysis. Both simulations and experiments have been performed. Some interesting conclusions about the relationship between modal parameters and band gap have been achieved.

关键词： Band gap Modal analysis Parameter identification Periodic structure Transfer matrix

L(1, 2)-edge-labelings for lattices

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Applied Mathematics(A Journal of Chinese Universities) 2014年第2期29卷 230-240页

作者： HE Dan LIN wen-song Department of Mathematics Southeast University

For a graph G and two positive integers j and k, an m-L（j, k）-edge-labeling of G is an assignment on the edges to the set {0, 1, 2,..., m}, such that adjacent edges which receive labels differ at least by j, and edges which are distance two apart receive labels differ at least by k. The λj,k-number of G is the minimum m such that an m-L（j, k）-edge-labeling is admitted by G. In this article, the L（1, 2）-edge-labeling for the hexagonal lattice, the square lattice and the triangular lattice are studied, and the bounds for λj,k-numbers of these graphs are obtained.

关键词： L(j k)-edge-labeling line graph triangular lattice square lattice hexagonal lattice.

Mapping the spatial and temporal patterns of fallow land in mountainous regions of China

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

International Journal of Digital Earth 2022年第1期15卷 2148-2167页

作者： wen song Alexander V.Prishchepov Wei song Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijingPeople’s Republic of China School of Geomatics and Urban Spatial Informatics Beijing University of Civil Engineering and ArchitectureBeijingPeople’s Republic of China Department of Geosciences and Natural Resource Management (IGN) University of CopenhagenKøbenhavn KDenmark Department of Theoretical Cybernetics and Applied Mathematics Altai State UniversityBarnaulRussia

The rapid growth of the global population has resulted in a continuous increase in cropland intensity and a shortening of the fallow period as part of the cropland rotation ***,there is a lack of systematic knowledge on the extent of fallow lands,particularly in complex landscapes,such as the mountainous regions of *** fill this knowledge gap,taking Yuanyang County(YYC),Yunnan Province,China,as a case study,we tested a method to identify the spatial-temporal distribution of fallow land by mapping cropland with Landsat *** overall accuracy of land cover classification,including cropland,ranged between 90.1%and 95.8%from 1998 to *** average accuracy of fallow plots was 75.7%from 2001 to *** annual fallow rate varied between 8.3%and 54.3%,with an average of 20.7%.Kernel density estimated with the probability density function showed that fallow varied between 5 and 13 blocks per km2,gradually decreasing from the central area to the *** elevation,the low value of regional domestic products,and the increased distance to rural settlements were closely related to the higher proportions of fallow *** approach presented here can be applied to map fallow land in other regions.

关键词： Remote sensing fallow land kernel density time series China

Structure, biochemical function, and signaling mechanism of plant NLRs

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Molecular Plant 2023年第1期16卷 75-95页

作者： Jizong Wang wen song Jijie Chai State Key Laboratory of Protein and Plant Gene Research School of Advanced Agricultural SciencesPeking UniversityBeijing 100871China Tsinghua-Peking Joint Center for Life Sciences Center for Plant BiologySchool of Life SciencesTsinghua UniversityBeijing 100084China Institute of Biochemistry University of Cologne50674 CologneGermany Max Planck Institute for Plant Breeding Research 50829 CologneGermany Peking University Institute of Advanced Agricultural Sciences Shandong Laboratory of Advanced Agricultural Sciences at WeifangWeifangShandong 261000China

To counter pathogen invasion,plants have evolved a large number of immune receptors,including membrane-resident pattern recognition receptors(PRRs)and intracellular nucleotide-binding and leucine-rich repeat receptors(NLRs).Our knowledge about PRR and NLR signaling mechanisms has expanded significantly over the past few *** NLRs form multi-protein complexes called resistosomes in response to pathogen effectors,and the signaling mediated by NLR resistosomes converges on Ca2+-permeable ***2+-permeable channels important for PRR signaling have also been *** findings highlight a crucial role of Ca2+in triggering plant immune *** this review,we first discuss the structural and biochemical mechanisms of non-canonical NLR Ca2+channels and then summarize our knowledge about immune-related Ca2+-permeable channels and their roles in PRR and NLR *** also discuss the potential role of Ca2+in the intricate interaction between PRR and NLR signaling.

关键词： plant immunity PRR NLR resistosome Ca2+-permeable channels Ca2+signaling second messenger

Stochastic Variational Inference-Based Parallel and Online Supervised Topic Model for Large-Scale Text Processing

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 Computer Science & Technology 2018年第5期33卷 1007-1022页

作者： Yang Li wen-Zhuo song Bo Yang College of Computer Science and Technology Jilin University Changchun 130012 China Key Laboratory of Symbolic Computation and Knowledge Engineering Ministry of Education Jilin University Changchun 130012 China Aviation University of Air Force Changchun 130062 China

Topic modeling is a mainstream and effective technology to deal with text data, with wide applications in text analysis, natural language, personalized recommendation, computer vision, etc. Among all the known topic models, supervised Latent Dirichlet Allocation （sLDA） is acknowledged as a popular and competitive supervised topic model. How- ever, the gradual increase of the scale of datasets makes sLDA more and more inefficient and time-consuming, and limits its applications in a very narrow range. To solve it, a parallel online sLDA, named PO-sLDA （Parallel and Online sLDA）, is proposed in this study. It uses the stochastic variational inference as the learning method to make the training procedure more rapid and efficient, and a parallel computing mechanism implemented via the MapReduce framework is proposed to promote the capacity of cloud computing and big data processing. The online training capacity supported by PO-sLDA expands the application scope of this approach, making it instrumental for real-life applications with high real-time demand. The validation using two datasets with different sizes shows that the proposed approach has the comparative accuracy as the sLDA and can efficiently accelerate the training procedure. Moreover, its good convergence and online training capacity make it lucrative for the large-scale text data analyzing and processing.

关键词： topic modeling, large-scale text classification, stochastic variational inference, cloud computing online learning

The First-Order Necessary Conditions for Sparsity Constrained Optimization

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 the Operations Research Society of China 2015年第4期3卷 521-535页

作者： Xue Li wen song School of Mathematical Sciences Harbin Normal UniversityHarbin 150025China

In this paper,we study optimization problems with the sparsity *** we give the expressions of the Mordukhovich(the limiting)normal cone of sparsity constraint and its intersection with a polyhedral set,and then based ... 详细信息

关键词： Sparsity constrained optimization Mordukhovich normal cone First-order necessary conditions

A GENERALIZATION OF CLARKE'S FIXED POINT THEOREM

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Applied Mathematics(A Journal of Chinese Universities) 1995年第4期10卷 463-466页

作者： song wen Department of Mathematics Harbin Normal University Harbin

This paper proposes a formally stronger set-valued Clarke's fixed point theorem. By this theorem we can improve a fixed point theorem for weakly inward contraction set-valued mapping of D. Dowing and W.A. Kirk.

关键词： Contraction mapping fixed point weakly inward metric spaces.

Acyclic Edge Coloring of Triangle-free 1-planar Graphs

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

Acta Mathematica Sinica,English Series 2015年第10期31卷 1563-1570页

作者： wen Yao song Lian Ying MIAO Institute of Mathematics China University of Mining and TechnologyXuzhou

A proper edge coloring of a graph G is acyclic if there is no 2-colored cycle in G. The acyclic chromatic index of G, denoted by X＇a（G）, is the least number of colors such that G has an acyclic edge coloring. A graph is 1-planar if it can be drawn on the plane so that each edge is crossed by at most one other edge. In this paper, it is proved that X＇a（G） ≤△ A（G）＋ 22, if G is a triangle-free 1-planar graph.

关键词： Acyclic chromatic index acyclic edge coloring 1-planar graph