检索结果-南通市图书馆

A Sufficient Condition on 3-colorable Plane Graphs Without 5- and 6-circuits

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Acta Mathematicae Applicatae Sinica 2014年第3期30卷 765-772页

作者： Bao-gang xu Institute of Mathematics School of Mathematical SciencesNanjing Normal University

In 2003, Borodin and Raspaud proved that if G is a plane graph without 5-circuits and without triangles of distance less than four, then G is 3-colorable. In this paper, we prove that if G is a plane graph without 5- ... 详细信息

关键词： plane graph circuit coloring

Volatiles in the mantle transition zone and their effects on big mantle wedge systems

在线全文

学校读者我要写书评

暂无评论

National Science Review 2024年第6期11卷 15-18页

作者： Yu Wang Yi-gang xu State Key Laboratory of Isotope Geochemistry Guangzhou Institute of Geochemistry Chinese Academy of Sciences Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou)

The mantle transition zone (MTZ), located between the upper and lower mantle, is characterized by sudden seismicvelocity discontinuities at depths of 410 and 660 km where significant change in mineralogical composition occurs. As a link between the upper and lower mantle,the MTZ is a layer of special significance in Earth’s deep structure, and a critical interface in geodynamics and material circulation.

关键词： systems effects mantle their transition volatiles wedge zone

Higher pressure differentiation of arc magmas under thicker crust

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

National Science Review 2023年第3期10卷 100-101页

作者： Yi-gang xu State Key Laboratory of Isotope Geochemistry Guangzhou Institute of Geochemistry Chinese Academy of Sciences Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou)

The formation of continental crust is pivotal to understanding the evolution of the earth and its *** average intermediate or’andesitic’bulk composition and characteristic depletion of niobium of the continental crust are strikingly matched by convergent margin magmas [1].This has led to the inference that most continental crust is derived from igneous,arc ***,continental crust has characteristically higher Mg#(>0.5) than most oceanic arc andesites (<0.5).

关键词：

A 3-color Theorem on Plane Graphs without 5-circuits

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2007年第6期23卷 1059-1062页

作者： Bao gang xu School of Math. & Computer Science Nanjing Normal University Nanjing 210097 P. R. China

In this paper, we prove that every plane graph without 5-circuits and without triangles of distance less than 3 is 3-colorable. This improves the main result of Borodin and Raspaud [Borodin, O. V., Raspaud, A.： A sufficient condition for planar graphs to be 3-colorable. Journal of Combinatorial Theory, Ser. B, 88, 17-27 （2003）], and provides a new upper bound to their conjecture.

关键词： plane graph circuit coloring

Seismic resilient shear wall structures:A state-of-the-art review

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2023年第6期66卷 1640-1661页

作者： xu gang GUO Tong LI AiQun Key Laboratory of Concrete and Prestressed Concrete Structures of the Ministry of Education Southeast UniversityNanjing 211189China Multi-Functional Shaking Tables Laboratory Beijing University of Civil Engineering and ArchitectureBeijing 100044China

The ductile design principle has been widely adopted in seismic design of structures,so the main structural components are designed to have the dual functions of bearing and energy dissipation under the *** recent years,the intensity of major earthquakes occurred in China,Chile,New Zealand,and Japan had reached or exceeded the design level of the maximum credible *** most cases,the designed structures did not collapse and the casualties were ***,many structures were seriously damaged and must be overhauled or rebuilt,resulting in huge economic ***,researchers have paid more attention to the seismic resilient *** shear wall can provide an efficient lateral force resisting capacity and has a wide range of applications in building *** review firstly summarized the research advances of seismic resilient shear wall structures,mainly from three aspects:high-performance materials,replaceable components,and hybrid structural systems;then,the development of seismic performance analysis,design methods,and engineering applications of seismic resilient shear wall structures were presented;finally,the key issues that need to be explored in the future research were discussed,which was helpful for the wide application of seismic resilient shear wall structures.

关键词： seismic resilience shear wall self-centering structure seismic design engineering application

同方期刊数据库

On the Existence and Stability of a Global Subsonic Flow in a 3D Infinitely Long Cylindrical Nozzle

在线全文

学校读者我要写书评

暂无评论

Chinese Annals of Mathematics,Series B 2010年第2期31卷 163-190页

作者： gang xu Huicheng YIN Faculty of Science Jiangsu University Zhenjiang 212013 Jiangsu China Department of Mathematics ＆ IMS Nanjing University Nanjing 210093 China. Department of Mathematics ＆ IMS Nanjing University Nanjing 210093 China.

This paper is concerned with the problem on the global existence and stability of a subsonic flow in an infinitely long cylindrical nozzle for the 3D steady potential flow equation. Such a problem was indicated by Courant-Friedrichs in [8, p. 377]： A flow through a duct should be considered as a cal symmetry and should be determined steady, isentropic, irrotational flow with cylindriby solving the 3D potential flow equations with appropriate boundary conditions. By introducing some suitably weighted HSlder spaces and establishing a priori estimates, the authors prove the global existence and stability of a subsonic potential flow in a 3D nozzle when the state of subsonic flow at negative infinity is given.

关键词： Subsonic flow Potential flow equation Bessel function Weighted HSlder space Global existence

Nonexistence of a Globally Stable Supersonic Conic Shock Wave for the Steady Supersonic Isothermal Euler Flow

在线全文

学校读者我要写书评

暂无评论

Chinese Annals of Mathematics,Series B 2013年第4期34卷 557-574页

作者： Yuchen LI gang xu Department of Mathematics & IMS Nanjing University Corresponding author. Department of Mathematics Jiangsu University

In this paper, for the full Euler system of the isothermal gas, we show that a globally stable supersonic conic shock wave solution does not exist when a uniform supersonic incoming flow hits an infinitely long and cu... 详细信息

关键词： Supersonic flow Conic shock Full Euler system Isothermal gas Nonexistence

A High-Accuracy Single Patch Representation of Multi-Patch Geometries with Applications to Isogeometric Analysis

在线全文

学校读者我要写书评

暂无评论

Computer Modeling in Engineering & Sciences 2020年第8期124卷 627-642页

作者： Jinlan xu Ningning Sun gang xu School of Computer Science and Technology Hangzhou Dianzi UniversityHangzhou310018China

This paper presents a novel approximating method to construct highprecision single-patch representation of B-spline surface from a multi-patch representation for isogeometric *** isogeometric analysis,multi-patch structure is not easy to achieve high continuity between neighboring patches which will reduce the advantage of isogeometric analysis in a *** proposed method can achieve high continuity at surface stitching region with low geometric error,and this technique exploits constructing the approximate surface with several control points are from original surfaces,which guarantees the local feature of the surface can be well-preserved with high *** the proposed approximating method,isogeometric analysis results using the new single-patch can be obtained efficiently compared with the original multi-patch *** examples are presented to illustrate the effectiveness,accuracy and efficiency of the proposed method.

关键词： Isogeometric analysis patch merging multi-patch structure computational efficiency

Forecasting China’s natural gas consumption based on a combination model

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

Journal of Natural Gas Chemistry 2010年第5期19卷 493-496页

作者： gang xu Weiguo W ang .DalianInstituteofChemicalPhysics ChineseAcademyofSciencesDalian116023LiaoningChina CollegeofQuantitativeEconomics DongbeiUniversityofFinance＆EconomicsDalian116025LiaoningChina

Ensuring a sufficient energy supply is essential to a country. Natural gas constitutes a vital part in energy supply and therefore forecasting natural gas consumption reliably and accurately is an essential part of a country＇s energy policy. Over the years, studies have shown that a combinative model gives better projected results compared to a single model. In this study, we used Polynomial Curve and Moving Average Combination Projection （PCMACP） model to estimate the future natural gas consumption in China from 2009 to 2015. The new proposed PCMACP model shows more reliable and accurate results： its Mean Absolute Percentage Error （MAPE） is less than those of any previous models within the investigated range. According to the PCMACP model, the average annual growth rate will increase for the next 7 years and the amount of natural gas consumption will reach 171600 million cubic meters in 2015 in China.

关键词： natural gas consumption forecasting combination model