检索结果-南通市图书馆

Adiabatic Invariant for Dynamic Systems on Time Scale

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

Transactions of Nanjing University of Aeronautics and Astronautics 2019年第4期36卷 680-685页

作者： song Chuanjing School of Mathematics and Physics Suzhou University of Science and TechnologySuzhou 215009P.R.China

Perturbation to Noether symmetry and adiabatic invariants for Birkhoffian system,Hamiltonian system and Lagrangian system with delta derivative are investigated,***,the definition and some related properties of time scale calculus are listed simply as ***,the Birkhoffian system with delta derivative is *** on the differential equation of motion as well as Noether symmetry and conserved quantity,perturbation to Noether symmetry and adiabatic invariant are ***,adiabatic invariants for the Hamiltonian system and the Lagrangian system are presented through some *** finally,an example is given to illustrate the methods and results.

关键词： perturbation to Noether symmetry adiabatic invariant dynamic system time scale

Current Situation and Prospect of High Performance Refractories for Iron and Steel Industry in China

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 1997年第2期4卷 3-8页

作者： song Shentai CISRI Journal of Iron and Steel Research

The development,physicochemical properties and application effectiveness of new high performance refractory products used in iron and steel industry in recent years are summarizedThe new products include carbon-containing oxides,non-oxides,functional refractories,low cement and ultra-low cement castables *** is pointed out that quality of refractory products needs to be improved and high performance varieties be ***,research should be done on composite materials and composite structures,equipment techniques and optimization control of refractory production should be strengthened as well.

关键词： high performance refractory physicochemical properly application effectiveness iron and steel industry

同方期刊数据库

Insight into the mode of action of 2,4-dichlorophenoxyacetic acid(2,4-D) as an herbicide

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Plant Biology 2014年第2期56卷 106-113页

作者： Yaling song Key Laboratory of Tropical Plant Resource and Sustainable Use Xishuangbanna Tropical Botanical Garden the Chinese Academy of Sciences

2,4-Dichlorophenoxyacetic acid （2,4-D） was the first synthetic herbicide to be commercially developed and has commonly been used as a broadleaf herbicide for over 60 years. It is a selective herbicide that kills dicots without affecting monocots and mimics natural auxin at the molecular level. Physiological responses of dicots sensitive to auxinic herbicides include abnormal growth, senescence,and plant death. The identification of auxin receptors, auxin transport carriers, transcription factors response to auxin, and cross-talk among phytohormones have shed light on the molecular action mode of 2,4-D as a herbicide. Here, the molecular action mode of 2,4-D is highlighted according to the latest findings, emphasizing the physiological process, perception, and signal transduction under herbicide treatment.

关键词： 2,4-D (2,4-dichlorophenoxyacetic acid) abscisic acid auxin ethylene herbicide metabolism

Representation learning in discourse parsing:A survey

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2020年第10期63卷 1921-1946页

作者： song Wei LIU LiZhen College of Information Engineering and Academy for Multidisciplinary Studies Capital Normal UniversityBeijing 100056China

Neural network based deep learning methods aim to learn representations of data and have produced state-of-the-art results in many natural language processing(NLP)*** parsing is an important research topic in discourse analysis,aiming to infer the discourse structure and model the coherence of a given *** survey covers text-level discourse parsing,shallow discourse parsing and coherence *** first introduce the basic concepts and traditional approaches,and then focus on recent advances in discourse structure oriented representation *** also introduce a trend of discourse structure aware representation learning that is to exploit discourse structures or discourse objectives for learning representations of sentences and documents for specific applications or for general ***,we present a brief summary of the progress and discuss several future directions.

关键词： discourse analysis discourse parsing discourse relation coherence assessment representation learning

A More Efficient Approach for Remote Sensing Image Classification

在线全文

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2023年第3期74卷 5741-5756页

作者： Huaxiang song School of Geography Science and Tourism Hunan University of Arts and ScienceChangde415000China

Over the past decade,the significant growth of the convolutional neural network(CNN)based on deep learning(DL)approaches has greatly improved the machine learning(ML)algorithm’s performance on the semantic scene classification(SSC)of remote sensing images(RSI).However,the unbalanced attention to classification accuracy and efficiency has made the superiority of DL-based algorithms,e.g.,automation and simplicity,partially *** ML strategies(e.g.,the handcrafted features or indicators)and accuracy-aimed strategies with a high trade-off(e.g.,the multi-stage CNNs and ensemble of multi-CNNs)are widely used without any training efficiency optimization involved,which may result in suboptimal *** address this problem,we propose a fast and simple training CNN framework(named FST-EfficientNet)for RSI-SSC based on an EfficientNetversion2 small(EfficientNetV2-S)CNN *** whole algorithm flow is completely one-stage and end-to-end without any handcrafted features or discriminators *** the implementation of training efficiency optimization,only several routine data augmentation tricks coupled with a fixed ratio of resolution or a gradually increasing resolution strategy are employed,so that the algorithm’s trade-off is very *** performance evaluation shows that our FST-EfficientNet achieves new state-of-the-art(SOTA)records in the overall accuracy(OA)with about 0.8%to 2.7%ahead of all earlier methods on the Aerial Image Dataset(AID)and Northwestern Poly-technical University Remote Sensing Image Scene Classification 45 Dataset(NWPU-RESISC45D).Meanwhile,the results also demonstrate the importance and indispensability of training efficiency optimization strategies for RSI-SSC by *** fact,it is not necessary to gain better classification accuracy by completely relying on an excessive trade-off without ***,these findings are expected to contribute to the development of more efficient CNN-based approaches in RSI-SSC.

关键词： FST-EfficientNet efficient approach scene classification remote sensing deep learning

Multiplicity one theorems, S-version

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

Science China Mathematics 2015年第2期58卷 233-256页

作者： WANG song The Morningside Center of Mathematics Academy of Mathematics and Systems ScienceChinese Academy of Sciences HUA Loo-Keng Key Laboratory of Mathematics Chinese Academy of Sciences

It is well known by the strong multiplicity one thatπis uniquely determined by the Satake parameter c(π,v)for almost all ***,it suffices for us to test only finitely many *** proved some S-effective version of multiplicity one *** speaking,ifπandπ′are not equivalent,then there is also a bound N(S)which is some expression in terms of K,d and max(N(π),N(π′)),which are analytic conductor ofπandπ′,respectively(will be defined soon),such that there is a v/∈S withπv～=π′vand N pv<*** also proved S-effective multiplicity one for the Chebotarev Density Theorem,and for GL(1).

关键词： multiplicity one theorem S-version automorphic form L-function

Multivariate Refinement Equations and Convergence of Cascade Algorithms in L_(p)(0

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2003年第1期19卷 97-106页

作者： song LI Department of Mathematices Zhejiang UniversityHangzhou 310027P.R.China Institute of Mathematics Academy of Mathematics and System sciencesChinese Academy of SciencesBeijing 100080P.R.China

We consider the solutions of refinement equations written in the form$$\varphi \left( x \right) = \sum\limits_{\alpha \in \Zopf^s} {a\left( \alpha \right)\varphi \left( {Mx - \alpha } \right) + g\left( x \right),\,\,\,x \in \Ropf^s} $$where the vector of functions } = (}1, ..., }r)T is unknown, g is a given vector of compactly supported functions on A^s, a is a finitely supported sequence of r 2 r matrices called the refinement mask, and M is an s 2 s dilation matrix with m = |detM|. Inhomogeneous refinement equations appear in the construction of multiwavelets and the constructions of wavelets on a finite interval. The cascade algorithm with mask a, g, and dilation M generates a sequence }n, n = 1, 2, ..., by the iterative process$$\varphi _n \left( x \right) = \sum\limits_{\alpha \in \Zopf^s} {a\left( \alpha \right)\varphi _{n - 1} \left(Mx - \alpha \right) + g\left( x \right),\,\,\,x \in \Ropf^s} $$from a starting vector of function }0. We characterize the Lp-convergence (0 < p < 1) of the cascade algorithm in terms of the p-norm joint spectral radius of a collection of linear operators associated with the refinement mask. We also obtain a smoothness property of the solutions of the refinement equations associated with the homogeneous refinement equation.

关键词： Inhomogeneous refinement equation Joint spectral radius Cascade algorithm L_(p)(R^(s))(0

Elliptic genera of homogeneous spin manifolds and theta functions identities

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

Science China Mathematics 2005年第12期48卷 1637-1645页

作者： song Ruifang Department of Mathematical Sciences Tsinghua UniversityBeijing 100084China

By Witten rigidity theorem and the Atiyah-Bott-Segal-Singer Lefschetz fixed point formula, the elliptic genus of a homogeneous spin manifold G/H can be expressed as a sum of theta functions quotients over the Weyl gro... 详细信息

关键词： fixed point formula,Witten rigidity theorem,elliptic genus,Jacobi theta functions.

Electrochemical behavior of gold and its associated minerals in alkaline thiourea solutions

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2018年第7期25卷 737-743页

作者： he zhou yong-sheng song wen-juan li kun song national engineering laboratory of biohydrometallurgy grimat engineering institute co.ltdbeijing 101407China school of chemical&environmental engineering china university of mining&technologybeijing 100083China

Electrochemical measurements were conducted to study the electrochemical behavior of gold （Au） and its commonly associated minerals in alkaline thiourea solutions. The results indicated that without addition of any stabilizer, selective dissolution of Au from stibnite and pyrite was only possible at relatively low thiourea concentrations. As Na2SiO3 was added, pyrite started to become active and an oxida- tion peak appeared; the oxidation peaks of axsenopyrite and chalcocite appeared earlier thaxl that of Au. The chalcocite peak shifted in the positive direction and the peak current increased. Stibnite did not show an oxidation peak and its current was nearly zero. Adding Na2SiO3 favored the selective dissolution of Au when its minerals were associated with chalcocite and stibinte. At pH 12, the Au anode dissolution peak current increased with stabilizer concentration. At 0.38 and 0.42 V and for Na2SiO3 concentration below 0.09 M, the current density continuously increased with Na2SiO3 concentration. The Na2SiO3 concentration had to be adequate to stabilize thiourea. When the potential was higher than 0.42 V, the surface of the Au electrode started to passivate. With an additional increase in potential, the presence of Na2SiO3 could not stop the inevitable decomposition of thiourea.

关键词： alkaline daiourea Au associated mineral Na2SiO3 electrochemical behavior