检索结果-南通市图书馆

Probing the Bardeen-Kiselev black hole with the cosmological constant caused by Einstein equations coupled with nonlinear electrodynamics using quasinormal modes and greybody bounds

引用

Communications in Theoretical Physics 2024年第6期76卷 102-119页

作者： s R Wu B q Wang Z W Long College of Physics Guizhou UniversityGuiyang 550025China College Pharmacy Guizhou University of Traditional Chinese MedicineGuiyang 550025China

In this work,we investigate a static and spherically symmetric Bardeen-Kiselev black hole(BH)with the cosmological constant,which is a solution of the Einstein-non-linear Maxwell field *** compute the quasinormal frequencies for the Bardeen-Kiselev BH with the cosmological constant due to electromagnetic and gravitational *** varying the BH parameters,we discuss the behavior of both real and imaginary parts of the BH quasinormal frequencies and compare these frequencies with the Reissner-Nordström-de sitter BH surrounded by quintessence(RN-dsq).Interestingly,it is shown that the responses of the Bardeen-Kiselev BH with the cosmological constant and the RN-dsq under electromagnetic perturbations are different when the charge parameter q,the state parameter w and the normalization factor c are varied;however,for the gravitational perturbations,the responses of the Bardeen-Kiselev BH with the cosmological constant and the RN-dsq are different only when the charge parameter q is ***,compared with the gravitational perturbations,the electromagnetic perturbations can be used to understand nonlinear and linear electromagnetic fields in curved spacetime *** interesting observation is that,due to the presence of Kiselev quintessence,the electromagnetic perturbations around the Bardeen-Kiselev BH with the cosmological constant damps faster and oscillates slowly;for the gravitational perturbations,the quasinormal mode decays slowly and oscillates *** also study the reflection and transmission coefficients along with the absorption cross section in the Bardeen-Kiselev BH with the cosmological constant;it is shown that the transmission coefficients will increase due to the presence of Kiselev quintessence.

关键词： quasinormal modes greybody factors Bardeen-Kiselev black hole with cosmological constant

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

THERMAL sTREssEs RELAXATION DEsIGN OF Ni/NiFe_(2)O_(4) sYsTEM FUNCTIONALLY GRADED CERMET INERT ANODE

引用

Acta Metallurgica sinica(English Letters) 2005年第5期18卷 635-641页

作者： J. Li q.s. Zhang Y.q. Lai s.L. Ye Y.X. Liu school of Metallurgy science and Engineering Central South University Changsha 410083 China

The thermal stresses relaxation of Ni/NiFe2O4 system functionally graded cermet inert anode for aluminum electrolysis was optimally designed. The transient thermal stresses of the inert anode under complex boundary condition during high-temp （955℃） electrolysis were calculated using the finite-element software ANsYs, the influence of different parameters on the distribution of the thermal stresses were analyzed. The results showed that, during the process of thermal shock, the thermal hoop tensile stress on the surface of the anode is very large, which is possibly the major cause of anode crack; when the radius of the anode is between 0.05-0.15m, a range that can be realized by recent manufacturing technology, the optimum composition distribution exponent p is 0.25; The hoop tensile stresses reduce with the decrease of anode scale and also decrease with the decrease of the convection coefficient between the electrolyte and the anode.

关键词： functionally graded material (FGM) transient thermal stresses ANsYs inert anode aluminum electrolysis

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 six-variable quasi-3D isogeometric approach for free vibration of functionally graded graphene origami-enabled auxetic metamaterial plates submerged in a fluid medium

引用

Applied Mathematics and Mechanics(English Edition) 2025年第1期 157-176页

作者： Wei CHEN Zhihong tang Yufen LIAO Linxin PENG College of Civil Engineering University of South China College of Civil Engineering and Architecture Guangxi University Key Laboratory of Disaster Prevention and structural safety of Ministry of Education Guangxi University

This paper presents, for the first time, an effective numerical approach based on the isogeometric analysis(IGA) and the six-variable quasi-three dimensional(3D)higher-order shear deformation theory(HsDT) to study the free vibration characteristics of functionally-graded(FG) graphene origami(GOri)-enabled auxetic metamaterial(GOEAM) plates submerged in a fluid medium. The plate theory incorporates the thickness stretching and the effects of transverse shear deformation without using any shear correction factors. The velocity potential function and Bernoulli's equation are used to derive the hydrodynamic pressure acting on the plate surface. Both horizontally and vertically immersed plate configurations are considered here in the form of inertia *** plates are composed of multilayer GOEAMs, with the GOri content varying through the plate's thickness in a layer-wise manner. This design results in graded auxetic *** material properties are evaluated by mixing rules and a genetic programming(GP)-assisted micromechanical model. The governing equations of motion for the FG-GOEAM plates immersed in a fluid medium are derived by Hamilton's principle. After validating the convergence and accuracy of the present model, a comprehensive parametric study is carried out to examine the effects of the GOri content, GOri distribution pattern, GOri folding degree, fluid level, immersed depth, and geometric parameter on the natural frequencies of the FG-GOEAM plates. The results show that the natural frequencies for the four GOri distribution patterns increase with the increase in the layer number when the lay number is fewer than 10, and then stabilize after the layer number reaches ***, in general, the natural frequency of the FG-GOEAM plate in a vacuum or fluid increases when the GOri content increases, while decreases when the GOri folding degree increases. some additional findings related to the numerical results are presented in the conclusions. It is belie

关键词：

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

TiZr-base Bulk Metallic Glass with over 50 mm in Diameter

引用

Journal of Materials science & Technology 2010年第6期26卷 481-486页

作者： M. q. tang H.F. Zhang Z. W. Zhu H.M. Fu A.M. Wang H. Li Z.q. Hu shenyang National Laboratory for Materials science Institute of Metal Research Chinese Academy of Sciences 72Wenhua Road Shenyang 110016 China

Low-cost TiZr-base bulk metallic glasses （BMGs）（Ti36.1Zr33.2Ni5.8Be24.9）100-xCux （x=5, 7 and g） with a maximum size of over 50 mm in diameter were developed by optimizing the alloy composition. The idea is initiated by selecting a particular microstructure comprising primary β-Ti dendrite and amorphous phase. Afterwards, based on this composition of amorphous phase, a class of TiZr-base bulk metallic glasses was designed step by step to reach the optimum composition range. The glass transition temperature （Tg）, initial crystallization temperature （Tx） and width of supercooled region （AT） of （***33.2Nis.8Be24.9）91Cu9 BMG are 611, 055 and 44 K, respectively. The （Ti36.1Zr33.2Ni5.8Be24.9）91Cu9 BMG exhibits low density of 5.541 g·cm-3 and high compressive fracture strength of 1800 MPa, which promises the potential application as structural materials.

关键词： TiZr-base alloy Bulk metallic glass (BMG) Fracture strength

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 novel friction stir diffusion bonding process using convex-vortex pin tools

引用

Journal of Materials science & Technology 2020年第13期47卷 23-30页

作者： s.D.Ji q.Wen Z.W.Li College of Aerospace Engineering Shenyang Aerospace UniversityShenyang 110136China state Key Laboratory of Advanced Welding and Joining Harbin Institute of TechnologyHarbin 150001China

In this work,a novel friction stir diffusion bonding(FsDB)method was proposed to eliminate hook when joining thin *** tools,with several convex-vortex pins were innovatively designed to improve the diffusion bonding effect of the lap *** showed that sound joints,excellently bonded at the lap interface and without hook,were *** lap interfaces on the joints welded using the T-tool and F-tool almost remained intact,thereby indicating that they were formed by diffusion *** material flow behavior was also simulated by FLUENT software and the results showed that the material flow along thickness was significantly enhanced by increasing the pin *** joint welded by the T-tool showed shear fracture *** bonding was formed at the lap interface when using the F-tool and thus the joint showed tensile fracture.

关键词： Friction stir diffusion bonding Convex-vortex pin Hook Material flow Failure

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 Fe Addition on Products of self-Propagating High-Temperature synthesis Reaction in 3Ti-si-2C system

引用

稀有金属材料与工程 2009年第A03期38卷 113-118页

作者： Guan q L Wang H Y Li s L si W P Jiang q C Key Laboratory of Automobile Materials of Ministry of Education Jilin University Changchun 130025 China

Influence of Fe addition on products of self-propagating high-temperature synthesis (sHs) reaction in 3Ti-si-2C system was investigated in the present study. Without Fe addition, Ti5si3 and TiC are the dominant phases along with a small amount of Ti3siC2 phase and unreacted C left in the final products. As Fe content ranges from 10% to 30%, the products consist of TiC, Ti5si3, Fe2Ti and unreacted C, but no trace of Ti3siC2 phase is detected. Furthermore, the amounts of both Fe2Ti and C phases increase with Fe content increasing. Addition of Fe has a great effect on the reaction route and significantly restrains the formation of Ti3siC2 during the combustion synthesis process, and therefore, the sHs is not an effective fabrication technique to synthesize the ternary Ti3siC2 ceramic in either 3Ti-si-2C or Fe-3Ti-si-2C system. Besides, without Fe addition, Ti5si3 presents as the coarse irregular appearance with an obviously sintered morphology. In contrast, the shape of Ti5si3 exhibits more and more spherical (cobblestone-like) and the surface becomes increasingly smooth, because the amount of liquids formed during the sHs reaction increases with the increase of Fe content. On the other hand, with Fe content increasing from 0 to 30 wt.%, the particulate size of TiC decreases from more than 5 μm to 1 μm or less, mainly due to the fact that the combustion temperature decreases with the increase of Fe content in the preforms.

关键词：复合材料铁含量燃烧过程物理性能

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

Two loop low temperature corrections to electron self energy

引用

Chinese Physics C 2011年第7期35卷 608-611页

作者： Mahnaz q. Haseeb samina s. Masood Department of Physics COMSATS Institute of Information Technology Islamabad Pakistan Department of Physics University of Houston Clear Lake Houston TX 77058

We recalculate the two loop corrections in the background heat bath using real time formalism. The procedure of the integrations of loop momenta with dependence on finite temperature before the momenta without it has been followed. We determine the mass and wavefunction renormalization constants in the low temperature limit of qED, for the first time with this preferred order of integrations. The correction to electron mass and spinors in this limit is important in the early universe at the time of primordial nucleosynthesis as well as in astrophysics.

关键词： renormalization finite temperature field theory electron self energy two-loop corrections

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

A reliability assessment method based on support vector machines for CNC equipment

引用

science China(Technological sciences) 2009年第7期52卷 1849-1857页

作者： WU Jun DENG Chao sHAO XinYu XIE s q school of Naval Architecture and Ocean Engineering Huazhong University of Science and TechnologyWuhan 430074China state Key Laboratory of Digital Manufacturing Equipment&Technology Huazhong University of Science and TechnologyWuhan 430074China Department of Mechanical Engineering University of AucklandAucklandNew Zealand

With the applications of high technology,a catastrophic failure of CNC equipment rarely occurs at normal operation *** it is difficult for traditional reliability assessment methods based on time-to-failure distributions to deduce the reliability *** paper presents a novel reliability assessment methodology to estimate the reliability level of equipment with machining performance degradation data when only a few samples are *** least squares support vector machines(Ls-sVM) are introduced to analyze the performance degradation process on the equipment.A two-stage parameter optimization and searching method is proposed to improve the Ls-sVM regression performance and a reliability assessment model based on the Ls-sVM is built.A machining performance degradation experiment has been carried out on an OTM650 machine tool to validate the effectiveness of the proposed reliability assessment methodology.

关键词： reliability assessment least squares support vector machines performance degradation radial basis function parameter optimization

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

EMBRITTLEMENT OF A Cr-Mo LOW-ALLOY sTEEL DUE TO LOW-TEMPERATURE NEUTRON IRRADIATION

引用

Acta Metallurgica sinica(English Letters) 2006年第1期19卷 20-26页

作者： s.H. song L. q. Weng Department of Materials science and Engineering Shenzhen Graduate School HarbinInstitute of Technology Shenzhen 518055 China

Embrittlement of a Cr-Mo2.25CrlMo steel stemming from neutron irradiation at 270℃ is studied by virtue of small punch testing in conjunction with scanning electron microscopy. The ductile-brittle transition temperature determined by the small punch test is much lower than that determined by the standard Charpy test. There is some irradiation-induced embrittlement effect after the steel is irradiated for 46 days with a neutron dose rate of 1.05×10^18dpa/s （displacement per atom per second）.

关键词： irradiation embrittlement segregation low alloy steels pressure vessel

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

Active{1121}and{1012}extension twinning in a WE43 Mg alloy

引用

Journal of Materials science & Technology 2023年第13期144卷 93-101页

作者： W.q.Chen s.Deng X.J.Zhao s.N.Luo Key Laboratory of Advanced Technologies of Materials Ministry of EducationSouthwest Jiaotong UniversityChengdu 610031China The Peac Institute of Multiscale sciences Chengdu 610031China

Deformation twinning in a WE43 alloy subjected to uniaxial compression at room temperature is ***{1121}and{1012}extension twinning is *** activation of{1121}twinning in a certain grain is influenced not only by its own schmid factor,but also by that of the basal ***-twin interactions of the co-zone{1121}twin variants are commonly observed and systematically studied,including the crystallographic characteristics of the four typically observed twin-twin junctions(TTJs)and the associated twin-twin *** the quilted-looking TTJs formed by the interaction of co-zone{1012}twin variants,crossing-like TTJs of co-zone{1121}twin variants are observed and their formation mechanisms are ***-like TTJs are also formed by the interaction of{1121}and{10¯12}*** morphology and thickening rate of{1121}and{1012}twins vary markedly due to the difference in twinning *** needle-like{1121}twins thicken more slowly than the lenticular{1012}*** nucleation is observed on the previously formed{1121}twin boundary due to the relatively large strain concentration on such interface,while twin nucleation on{1012}twin boundary is rarely observed.

关键词： Mg alloy Plastic deformation Twinning Twin-twin interaction Twin-twin junction

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：