检索结果-南通市图书馆

Strong Convergence Theorems for Strictly Asymptotically Pseudocontractive Mappings in Hilbert Spaces

Acta Mathematica Sinica,English Series 2011年第7期27卷 1367-1378页

作者： shi sheng ZHANG Department of Mathematics Yibin University Yibin 644007 P. R. China

The purpose of this paper is by using CSQ method to study the strong convergence problem of iterative sequences for a pair of strictly asymptotically pseudocontractive mappings to approximate a common fixed point in a Hilbert space. Under suitable conditions some strong convergence theorems are proved. The results presented in the paper are new which extend and improve some recent results of Acedo and Xu [Iterative methods for strict pseudo-contractions in Hilbert spaces. Nonlinear Anal., 67（7）, 2258-2271 （2007）], Kim and Xu [Strong convergence of modified Mann iterations for asymptoti- cally nonexpansive mappings and semigroups. Nonlinear Anal., 64, 1140-1152 （2006）], Martinez-Yanes and Xu [Strong convergence of the CQ method for fixed point iteration processes. Nonlinear Anal., 64, 2400-2411 （2006）], Nakajo and Takahashi pings and nonexpansive semigroups. J. Math [Strong convergence theorems for nonexpansive map- Anal. Appl., 279, 372-379 （2003）], Marino and Xu [Weak and strong convergence theorems for strict pseudocontractions in Hilbert spaces. J. Math. Anal. Appl., 329（1）, 336-346 （2007）], Osilike et al. [Demiclosedness principle and convergence theorems for k-strictly asymptotically pseudocontractive maps. J. Math. Anal. Appl., 326, 1334-1345 （2007）], Liu [Convergence theorems of the sequence of iterates for asymptotically demicontractive and hemicontractive mappings. Nonlinear Anal., 26（11）, 1835-1842 （1996）], Osilike et al. [Fixed points of demi-contractive mappings in arbitrary Banach spaces. Panamer Math. J., 12（2）, 77-88 （2002）], Gu [The new composite implicit iteration process strictly pseudocontractive mappings. J. Math with errors for common fixed points of a finite family of Anal. Appl., 329, 766-776 （2007）].

关键词： Strictly asymptotically pseudocontractive mapping strictly pseudocontractive mapping of Browder Petryshyn type CSQ methods common fixed point

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

Unicyclic Graphs of Minimal Spectral Radius

引用

Acta Mathematica Sinica,English Series 2013年第2期29卷 281-286页

作者： Ling sheng shi Department of Mathematical Sciences Tsinghua University

It was conjectured by Li and Feng in 1979 that the unicyclic graph formed by a cycle of order g linking to an endvertex of a path of length k minimizes the spectral radius of all unicyclic graphs of order g ＋ k and girth g. In 1987, Cao proved that this conjecture is true for k ≥ g（g - 2）/8 and false for k = 2 and sufficiently large g. In this note, we show that g 〉12 suffices for the counterexample and give more counterexamples with large girth for any integer k 〉 1.

关键词： Extremal graph Li-Feng's conjecture spectral radius unicyclic

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

Weak Convergence Theorem for Lipschizian Pseudocontraction Semigroups in Banach Spaces

引用

Acta Mathematica Sinica,English Series 2010年第2期26卷 337-344页

作者： shi sheng ZHANG Department of Mathematics Yibin University Yibin 644007 Sichuan P. R. China

The purpose of this paper is to study the weak convergence problems of the irnplicity iteration process for Lipschitzian pseudocontraction semigroups in general Banach spaces. The results presented in this paper extend and improve the corresponding results of Zhou [Nonlinear Anal., 68, 2977-2983 （2008）], Chen, et ah [J. Math. Anal. Appl., 314, 701 709 （2006）], Xu and Ori [Numer. Funct. Anal. Optim, 22, 767-773 （2001）] and Osilike [J. Math. Anal. Appl., 294, 73-81 （2004）]. Keywords

关键词： Lipschitzian pseudocontraction semigroup demi-closed principle common fixed point Opial condition strongly pseudocontractive mapping implicit iteration process

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

Microstructure and mechanical properties of high-strength low alloy steel by wire and arc additive manufacturing

引用

International Journal of Minerals,Metallurgy and Materials 2020年第7期27卷 933-942页

作者： Yi-li Dai sheng-fu Yu An-guo Huang Yu-sheng shi State Key Laboratory of Material Processing and Die&Mould Technology Huazhong University of Science and TechnologyWuhan 430074China

A high-building multi-directional pipe joint(HBMDPJ)was fabricated by wire and arc additive manufacturing using high-strength low-alloy(HSLA)*** microstructure characteristics and transformation were observed and *** results show that the forming part includes four *** solidification zone solidifies as typical columnar crystals from a molten *** complete austenitizing zone forms from the solidification zone heated to a temperature greater than 1100℃,and the typical columnar crystals in this zone are difficult to *** partial austenitizing zone forms from the completely austenite zone heated between Ac1(austenite transition temperature)and1100℃,which is mainly equiaxed *** several thermal cycles,the partial austenitizing zone transforms to the tempering zone,which consistes of fully equiaxed *** the solidification zone to the tempering zone,the average grain size decreases from 75 to20μ*** mechanical properties of HBMDPJ satisfies the requirement for the intended application.

关键词： wire and arc additive manufacturing high strength low alloy steel microstructure inclusions fine grain ferrite mechanical properties

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

Conditional Connectivity of Bubble Sort Graphs

引用

Acta Mathematicae Applicatae Sinica 2017年第4期33卷 933-944页

作者： Ling-sheng shi Peng WU Department of Mathematical Sciences Tsinghua University Beijing 100084 China

A subset F V（G） is called an Rk-vertex-cut of a graph G if G - F is disconnected and each vertex of G - F has at least k neighbors in G - F. The Rk-vertex-connectivity of G, denoted by κk（G）, is the cardinality of a minimum Rk-vertex-cut of G. Let Bn be the bubble sort graph of dimension n. It is known that κk（Bn） = 2k（n - k - 1） for n _〉 2k and k = 1,2. In this paper, we prove it for k =3 and conjecture that it is true for all k ∈ N. We also prove that the connectivity cannot be more than conjectured.

关键词： bubble sort graph connectivity cut

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

Baicalin Reduces Early Brain Injury after Subarachnoid Hemorrhage in Rats

引用

Chinese Journal of Integrative Medicine 2020年第7期26卷 510-518页

作者： ZHANG Hua-bin TU Xian-kun SONG shi-wei LIANG Ri-sheng shi Song-sheng Department of Neurosurgery Fujian Medical University Union HospitalNeurosurgery Research Institute of Fujian ProvinceFuzhou(350001)China

Objective: To evaluate the effect of baicalin on subarachnoid hemorrhage(SAH) in rats and explore the potential mechanisms. Methods: Sprague-Dawley rats underwent experimental SAH and received treatment with baicalin at 10 or 50 mg/kg after 2 and 12 h of SAH. Neurological scores, brain water content, Evans-blue extravasation, and levels of glutathione peroxidase(GSH-Px), superoxide dismutase(SOD), myeloperoxidase(MPO), and malondialdehyde(MDA) were measured 24 h after SAH. Expression of nuclear factor erythroid-related factor 2(Nrf2), NAD(P)H: quinone oxidoreductase 1(NQO1), matrix metalloproteinase-9(MMP-9), aquaporin 4(AQP4), occludin, and zonulaoccludens-1(ZO-1) were detected in the brain by Western blot. Heme oxygenase-1(HO-1) was detected by quantitative polymerase chain reaction, and tumor necrosis factor-α(TNF-α) and interleukin-1β(IL-1β) were assessed by enzyme-linked immunosorbent assay. Results: Baicalin attenuated EBI 24 h after SAH in rats(P<0.05). Baicalin elevated neurological scores, GSH-Px, SOD, and increased the expression of Nrf2, NQO1, HO-1, occludin, and ZO-1 in SAH rats(P<0.05 or P<0.01). Baicalin reduced MPO, MDA, and the expression of MMP-9, AQP4, TNF-α, and IL-1β(P<0.05 or P<0.01). Conclusion: Baicalin reduced SAH-induced EBI, partially via activation of the Nrf2/HO-1 pathway and inhibition of MMP-9 and AQP4.

关键词： aquaporin 4 baicalin Chinese medicine early brain injury matrix metalloproteinase-9 subarachnoid hemorrhage

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

SOME CONVERGENCE PROBLEM OF ITERATIVE SEQUENCESFOR ACCRETIVE AND PSEUDO-CONTRACTIVETYPE MAPPING IN BANACH SPACES

引用

Applied Mathematics and Mechanics(English Edition) 2002年第4期23卷 394-408页

作者： ZHANG shi-sheng(张石生) Department of Mathematics Sichuan University Chengdu 610064 P R China

Some necessary and sufficient conditions for convergence of Ishikawa Mann and steepest descent iterative sequence for accretive and pseudo-contractive type mapping in Banach spaces were obtained. The results improve, ... 详细信息

关键词： accretive mapping pseudo-contractive mapping hemi-accretive mapping hemi-pseudo-contractive mapping Ishikawa iterative sequence Mann iterative sequence steepest descent sequence

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

Influence of high-temperature oxidation of SiC powders on curing properties of SiC slurry for digital light processing

引用

Journal of Advanced Ceramics 2023年第1期12卷 169-181页

作者： Zhang-Ao shi Jia-Min WU Zhi-Qiang FANG Yu-sheng shi State Key Laboratory of Materials Processing and Die&Mould Technology School of Materials Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074China Engineering Research Center of Ceramic Materials for Additive Manufacturing Ministry of EducationWuhan 430074China

Fabrication of silicon carbide(SiC)ceramics by digital light processing(DLP)technology is difficult owing to high refractive index and high ultraviolet(UV)absorptivity of SiC *** surface of the SiC powders can be coated with silicon oxide(SiO_(2))with low refractive index and low UV absorptivity via high-temperature oxidation,reducing the loss of UV energy in the DLP process and realizing the DLP preparation of the SiC ***,it is necessary to explore a high-temperature modification process to obtain a better modification effect of the SiC ***,the high-temperature modification behavior of the SiC powders is thoroughly investigated in this *** results show that nano-scale oxide film is formed on the surface of the SiC powders by short-time high-temperature oxidation,effectively reducing the UV absorptivity and the surface refractive index(nʹ)of the SiC *** the oxidation temperature is 1300℃,compared with that of unoxidized SiC powders,the UV absorptivity of oxidized SiC powders decreases from 0.5065 to 0.4654,and a curing depth of SiC slurry increases from 22±4 to 59±4μ***,SiC green bodies are successfully prepared by the DLP with the the oxidized powders,and flexural strength of SiC sintered parts reaches 47.9±2.3 MPa after 3 h of atmospheric sintering at 2000℃without any sintering aid.

关键词： silicon carbide(SiC)powders oxidation modification digital light processing(DLP) ultraviolet(UV)absorptivity curing depth

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

Study of the deformed halo nucleus^(31)Ne with Glauber model based on microscopic self-consistent structures

引用

Science China(Physics,Mechanics & Astronomy) 2022年第6期65卷 67-75页

作者： shi-Yi Zhong shi-sheng Zhang Xiang-Xiang Sun Michael S.Smith School of Physics Beihang UniversityBeijing 100191China School of Nuclear Science and Technology University of Chinese Academy of SciencesBeijing 100049China Physics Division Oak Ridge National LaboratoryOak Ridge 378^(31)-6354USA

The exotic deformed nucleus^(31)Ne is studied with an approach that combines self-consistent structure and reaction *** deformed relativistic Hartree-Bogoliubov theory in continuum(DRHBc)is utilized to demonstrate that deformation and pairing correlations give rise to a halo structure with a large-amplitude p-wave configuration in^(31)*** the valence nucleon wave functions and angle-averaged density distributions of ^(30)Ne from this theory are used as input for the Glauber reaction model to study the observables of neutron-rich neon isotopes to search halo *** NL1 effective interaction,our predictions of the reaction cross sections for these exotic neon isotopes on a carbon target can better reproduce the experimental data than those from the relativistic mean field model for a spherical shape with resonances and pairing correlation contributions,and are roughly 3.3%(∼50 mb)larger than those with Gaussian function-fitted densities of the core *** calculated one-neutron removal cross section at 240 MeV/nucleon,and the inclusive longitudinal momentum distribution of the 30Ne residues from the^(31)Ne breakup reaction are largely improved over previous theoretical predictions and agree well with *** reaction evalu-ations indicate a dilute density distribution in coordinate space and are a canonical signature of a halo ***,our predictions with the NL3 and PK1 effective interactions give slightly better descriptions of reaction observables for exotic neon isotopes.

关键词： halo relativistic model Glauber model reaction cross section momentum distribution

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

Microstructure and properties of silica-based ceramic cores by laser powder bed fusion combined with vacuum infiltration

引用

Journal of Materials Science & Technology 2023年第26期157卷 71-79页

作者： Jie Zhang Jia-Min Wu Heng Liu Wen Zheng Chun-sheng Ye shi-Feng Wen Chun-Ze Yan Yu-sheng shi State Key Laboratory of Materials Processing and Die&Mould Technology School of Materials Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074China Engineering Research Center of Ceramic Materials for Additive Manufacturing Ministry of EducationWuhan 430074China

The silica-based ceramic core has attracted much attention in the preparation of hollow blades due to its great *** this paper,the silica-based ceramic cores reinforced with ZrSiO_(4) were prepared by laser powder bed fusion(LPBF)combined with vacuum infiltration(VI).To enhance the infiltration effect,the pre-sintered bodies with high porosity and hydrophilicity were obtained by pre-sintering at 1100℃.Results showed that a large number of silica particles infiltrated into the pre-sintered *** infiltrated silica promoted the generation of liquid phase in sintering,thereby promoting the removal of pores and the connection of ***,the dispersed ZrSiO_(4) grains prevented the viscous flow of the liquid phase,thereby increasing the ***_(4) grains could hinder the propagation of cracks due to their high *** the addition of ZrSiO_(4) was 10 wt.%,room-temperature flexural strength of silica-based ceramic cores infiltrated with slurry S1(the mass ratio of silica sol to silica powder was 10:1)reached 17.21 MPa due to the reinforcement of sintering ***,high-temperature flexural strength reached 13.90 ***,the pre-sintering process could greatly improve the mechanical properties of silica-based ceramic cores prepared by LPBF-VI technology.

关键词： Silica-based ceramic cores Laser powder bed fusion ZrSiO_(4) Pre-sintering Vacuum infiltration

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：