检索结果-南通市图书馆

Correlation of surface features with corrosion behaviors of interstitial free steel processed by temper rolling

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 Materials Science & Technology 2020年第1期36卷 37-44页

作者： heng Chen Zebang He lin Lu Institute for Advanced Materials and Technology University of Science and Technology BeijingBeijing100083China State Key Laboratory of Metal Material for Marine Equipment and Application Anshan114000China

Temper rolling,as a final manufacturing procedure,brings the change of surface features and hence affects the corrosion behaviors of interstitial-free(IF)*** study investigates changes in residual stress,microstructure,and surface topography of IF steel using X-ray diffraction,electron backscatter diffraction,and optical interferometric *** the synthetic influence of surface features on the corrosion process of the steel was evaluated by damp heat tests and electrochemical *** showed that low tensile and compressive residual stresses are introduced to the surface of the IF *** grains had a grain orientation spread(GOS)value greater than 0.50 after temper ***,temper rolling caused a slight change in the surface profile of the IF *** compressive residual stress had an overwhelming role at the macroscopic level,in retarding the corrosion evolution process of IF steel,as well as in decreasing the average corrosion *** corrosion was more likely to initiate and propagate in matrices with a high GOS value,which played the determinant role at the microscopic ***,the depth of valley in the surface profile could affect the diffusion process involved in the electrode reactions,which was more likely to exert an extra influence on the corrosion rate of IF steel.

关键词： Temper rolling Surface feature Corrosion behavior Interstitial-free steel

Double-lined M dwarf eclipsing binaries from Catalina Sky Survey and LAMOST

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2017年第2期17卷 29-34页

作者： chien-Hsiu Lee chien-Cheng lin Subaru Telescope National Astronomical Observatory of Japan Shanghai Astronomical Observatory Chinese Academy of Sciences

Eclipsing binaries provide a unique opportunity to determine fundamental stellar properties. In the era of wide-field cameras and all-sky imaging surveys, thousands of eclipsing binaries have been reported through light curve classification, yet their basic properties remain unexplored due to the ex- tensive efforts needed to follow them up spectroscopically. In this paper we investigate three M2-M3 type double-lined eclipsing binaries discovered by cross-matching eclipsing binaries from the Catalina Sky Survey with spectroscopically classified M dwarfs from the Large Sky Area Multi-Object Fiber Spectroscopic Telescope survey data release one and two. Because these three M dwarf binaries are faint, we further acquire radial velocity measurements using GMOS on the Gemini North telescope with R ~4000, enabling us to determine the mass and radius of individual stellar components. By jointly fitting the light and radial velocity curves of these systems, we derive the mass and radius of the primary and secondary components of these three systems, in the range between 0.28-0.42 MQ and 0.29-0.67 R, respectively. Future observations with a high resolution spectrograph will help us pin down the uncertainties in their stellar parameters, and render these systems benchmarks to study M dwarfs, providing inputs to improving stellar models in the low mass regime, or establishing an empirical mass-radius relation for M dwarf stars.

关键词： (stars) binaries eclipsing

Analysis of Two-sample Censored Data Using a Semiparametric Mixture Model

在线全文

学校读者我要写书评

暂无评论

Acta Mathematicae Applicatae Sinica 2009年第3期25卷 389-398页

作者： Gang Li chien-tai lin Department of Biostatistics University of California Los Angeles CA 90095 U.S.A. Department of Mathematics Tamkang University Tamsui 251 Taiwan

In this article we study a semiparametric mixture model for the two-sample problem with right censored data. The model implies that the densities for the continuous outcomes are related by a parametric tilt but otherwise unspecified. It provides a useful alternative to the Cox （1972） proportional hazards model for the comparison of treatments based on right censored survival data. We propose an iterative algorithm for the semiparametric maximum likelihood estimates of the parametric and nonparametric components of the model. The performance of the proposed method is studied using simulation. We illustrate our method in an application to melanoma.

关键词： Biased sampling EM algorithm maximum likelihood estimation mixture model semiparametric model

New finite strain elastoplastic equations for accurately and explicitly simulating pseudoelastic-to-plastic transition effects of shape memory alloys

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2020年第10期41卷 1583-1596页

作者： Siyu WANG lin ZHAN Huifeng XI heng XIAO School of Mechanics and Construction Engineering MOE Key Lab of Disaster Forecast and Control in EngineeringJinan University601 West Huangpu AvenueGuangzhou 510632China Shanghai Institute of Applied Mathematics and Mechanics Shanghai Key Laboratory of Mechanics in Energy EngineeringSchool of Mechanics and Engineering ScienceShanghai UniversityShanghai 200072China

A new finite strain elatoplastic J2-flow model with coupling effects of both isotropic and anisotropic hardening is proposed with the co-rotational logarithmic *** terms of certain single-variable shape functions representing uniaxial loading and unloading curves,explicit multi-axial expressions for the three hardening quantities incorporated in the new model proposed are derived in unified forms for the purpose of automatically and accurately simulating complex pseudoelastic-to-plastic transition effects of shape memory alloys(SMAs)under multiple loading-unloading *** examples show that with only a single parameter of direct physical meaning for each cycle,accurate and explicit simulations may be achieved for extensive data from multiple cycle tests.

关键词： shape memory alloy(SMA) finite deformation pseudo-elasticity plasticity cyclic loading transition effect elastoplastic equation explicit and accurate approach

Which sectors should be covered by the EU Carbon Border Adjustment Mechanism?

在线全文

学校读者我要写书评

暂无评论

Advances in Climate Change Research 2023年第6期14卷 952-962页

作者： Bo-Qiang lin heng-Song ZHAO School of Management China Institute for Studies in Energy PolicyXiamen UniversityXiamen 361005China

The European Union(EU)is developing the Carbon Border Adjustment Mechanism(CBAM)to address carbon leakage in international ***,the EU has paid inadequate attention to input-output linkages,specifically those in the steel,aluminum,and fertiliser *** study aims to identify priority sectors eligible for initial regulation within the emissions-intensive trade-exposed(EITE)industries based on input-output linkages and compare its impacts with the current CBAM sector *** study constructs a Global Production Network(GPN)and Carbon Flow Network(CFN)to present the input trade and embodied carbon flows for the EITE *** study highlights the role of the EITE industries as influential nodes in the production network and how the EITE industries in the EU contribute to carbon *** improve the economy and political acceptability,CABM should cover four priority sectors with low economic impacts but a crucial role in reducing emissions,such as plastics,phosphorus fertiliser,aluminum,and copper industry.

关键词： Carbon Border Adjustment mechanism Input-output analysis Hypothetical extraction method Production network Embodied carbon emissions

Connes distance of 2D harmonic oscillators in quantum phase space

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

Chinese Physics B 2021年第11期30卷 170-179页

作者： Bing-Sheng lin Tai-Hua heng School of Mathematics South China University of TechnologyGuangzhou 510641China Laboratory of Quantum Science and Engineering South China University of TechnologyGuangzhou 510641China School of Physics and Material Science Anhui UniversityHefei 230601China

We study the Connes distance of quantum states of two-dimensional(2D)harmonic oscillators in phase *** the Hilbert–Schmidt operatorial formulation,we construct a boson Fock space and a quantum Hilbert space,and obtain the Dirac operator and a spectral triple corresponding to a four-dimensional(4D)quantum phase *** on the ball condition,we obtain some constraint relations about the optimal *** construct the corresponding optimal elements and then derive the Connes distance between two arbitrary Fock states of 2D quantum harmonic *** prove that these two-dimensional distances satisfy the Pythagoras *** results are significant for the study of geometric structures of noncommutative spaces,and it can also help us to study the physical properties of quantum systems in some kinds of noncommutative spaces.

关键词： Connes distance noncommutative geometry harmonic oscillator

Effects of marine sediment on the response of a submerged floating tunnel due to p- wave incidence

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Sinica 2019年第4期35卷 773-785页

作者： heng lin Yiqiang Xiang Zhengyang Chen Ying Yang Department of Civil Engineering College of Civil Engineering and ArchitectureZhejiang University Hangzhou 310058 China

Submerged floating tunnel (SFT) is a novel type traffic structure for crossing long strait and deep lakes. To investigate the dynamic pressure acting on an SFT under compression (P) wave incidence, a theoretical analysis model considering marine sediment effect has been proposed. Based on displacement potential functions, the reflection and refraction coefficients of P wave in different media are derived. Numerical examples are employed to illustrate the effects of the thickness of sediment layer, the incident P wave angle, the tether stiffness and spacing, and the permeability of the sediment on the dynamic pressure loading on the SFT. The results show that dynamic pressure is related to the saturation of sediment and affected by the thickness of sediment. The partially saturated sediment will amplify the dynamic pressure loading on the SFT, and the resonance frequency increases a little with the fully saturated sediment. Besides, increasing the tether stiffness and decreasing in the tether spacing will lead to a dynamic pressure falling. Deepening the SFT position and reducing the permeability of the sediment are effective measures to reduce dynamic pressure acting on the SFT.

关键词： Submerged floating tunnel Dynamic pressure Porous medium P-wave Displacement potential function

Two-Dimensional Fin Efficiency of Plate Fin-Tube Heat Exchangers Under Partially and Fully Wet Conditions

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 Thermal Science 2002年第3期11卷 249-254页

作者： Jiin-Yuh Jang chien-Nan lin Natl Cheng Kung Univ Dept Mech Engn Tainan 70101 Taiwan

This paper presents the two-dimensional analysis for the efficiency of continuous plate fin-tube heat exchangers in staggered and in-lined arrangements under the dry, partially wet, and fully wet conditions for different heat transfer coefficient (h = 20 W/m2K to h = 80 W/m2K) and air relative humidity over the full range from φ= 0 % to φ= 100%. It is shown that the fin efficiencies of the staggered arrangement are higher than those for the in-lined arrangement, and the fully wet fin efficiency is 10~20% lower than that for a dry fin. The conventional 1-D sector method underestimates the fin efficiency up to 4 % as compared to the 2-D analysis.

关键词： fin efficiency plate fin-tube partially and fully wet.

Preparation and oxygen permeation properties of SrFe(Cu)O_(3-δ) dense ceramic membranes

在线全文

学校读者我要写书评

暂无评论

Journal of Natural Gas Chemistry 2009年第1期18卷 45-49页

作者： heng Zhang Tingting Wang Xinfa Dong Weiming lin School of Chemistry and Chemical Engineering Qufu Normal University Qufu 273165 Shandong China School of Chemical and Energy Engineering South China University of Technology Guangzhou 510640 Guangdong China

Mixed oxygen-ionic and electronic conducting membranes of SrFe（Cu）O3-δ were prepared by solid-state reaction method. The crystal structure, oxygen nonstoichiometry, and phase stability of the materials were studied by TGA and XRD. Oxygen permeation fluxes through these membranes were studied at operating temperature ranging from 750 to 950 ℃. Results showed that doping Cu in SrFeO3-δ compound had a significant effect on the formation of single-phased perovskite structure. For SrFe1-xCu2O3-δ series materials, the oxygen nonstoichiometry and the oxygen permeation flux increased considerably with the increase of Cu-doping content （x = 0.1-0.3）. The sintering property of the membrane decreased significantly when the Cu substitution amount reached 40%. SrFe0.7Cu0.3O3-δ showed high oxygen permeation flux, but SrCuO2 and Sr2Fe2O5 phases formed in the compound after oxygen permeation test induced cracks in the membrane.

关键词： perovskite mixed conductor oxygen permeation phase stability