检索结果-南通市图书馆

Effect of cerium addition on non-metallic inclusions in a high-carbon chromium bearing steel

Journal of Iron and Steel Research International 2023年第11期30卷 2254-2266页

作者： Hao Li Qiang Ren Li-feng zhang State Key Lab of Metastable Materials Science and Technology Yanshan UniversityQinhuangdao066004HebeiChina School of Mechanical Engineering Yanshan UniversityQinhuangdao066004HebeiChina School of Mechanical and Materials Engineering North China University of TechnologyBeijing100144China

Effects of varied levels of cerium(28×10-6,65×10^(-6) and 150×10^(-6))on inclusions in a high-carbon chromium bearing steel at different stages(before adding cerium,after adding cerium for 1,5,10 min and ingot)were studied using laboratory *** automatic scanning electron microscope system with energy-dispersive spectroscopy was used to analyze the amount,composition,size and morphology of inclusions in the steel at different *** the cerium content in the molten steel increased from 0 to 150×10^(-6),the evolution sequence of inclusions was as follows:Al_(2)O_(3)→CeAl11O18→CeAlO_(3)→Ce_(2)O_(2)*** 28×10^(-6) cerium was added,Al_(2)O_(3) inclusions were modified into CeAl_(11)O_(18) inclusions in the molten steel and then were further transformed into Al2O3 and CeAlO3 inclusions in the solid steel during *** the addition of 65×10^(-6) cerium,inclusions in the molten steel were modified into CeAlO_(3) and a small number of Ce2O2S *** the addition amount of cerium increased to 150×10^(-6),inclusions were transformed to Ce_(2)O_(2)*** size of inclusions in the molten steel decreased obviously with cerium *** the other hand,the size of inclusions increased during the cooling process in solid steels of No.1 steel(with 28×10^(-6) cerium)and No.2 steel(with 65×10^(-6) cerium).During the cooling process,unmodified MnS inclusions were precipitated in the solid steel of No.1 steel and wrapped outside the Al2O3 and CeAlO_(3) inclusions to form large complex *** the cooling process of No.2 steel,the inclusion size of CeAlO_(3) increased due to the collision and *** the No.3 steel(with 150×10^(-6) cerium),the average size of inclusions decreased rapidly and remained at a lower size during the cooling process,which was beneficial to improving the fatigue life of the steel.

关键词： Cerium Inclusion Transformation High-carbon chromium bearing steel Modification

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

Dynamics of a Reaction-diffusion-ODE System in a Heterogeneous Media

引用

Acta Mathematicae Applicatae Sinica 2024年第2期40卷 275-301页

作者： Cong-hui zhang Hai-feng zhang Mei-rong zhang School of Science Beijing University of Civil Engineering and ArchitectureBeijing 102616China Institute of Applied System Analysis Jiangsu UniversityZhenjiang 212013China Department of Mathematical Sciences Tsinghua UniversityBeijing 100084China

The existence and stability of stationary solutions for a reaction-diffusion-ODE system are investigated in this *** first show that there exist both continuous and discontinuous stationary *** a good understanding of the stability of discontinuous stationary solutions is gained under an appropriate *** addition,we demonstrate the influences of the diffusion coefficient on stationary *** results we obtained are based on the super-/sub-solution method and the generalized mountain pass ***,some numerical simulations are given to illustrate the theoretical results.

关键词： reaction-diffusion-ODE system discontinuous stationary solutions stability asymptotic behavior monotone solutions

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 magnetic properties of Ti/Ni/Ti in dependence on Ni layer thickness

引用

Rare Metals 2006年第z1期25卷 592-595页

作者： zhang Hanwei feng Shunzhen zhang Yujie SUN Huiyuan College of Physics Science and Information Engineering Hebei Normal University Shijiazhuang 050016 China College of Physics Science and Information Engineering Hebei Normal University Shijiazhuang 050016 China College of Physics Science and Information Engineering Hebei Normal University Shijiazhuang 050016 China College of Physics Science and Information Engineering Hebei Normal University Shijiazhuang 050016 China

The films of Ti(15 nm)/Ni(t nm)/Ti(15 nm)(t=20, 30, 40, 50) were prepared by dc magnetron sputtering at room temperature and subsequent annealing at 400 ℃ for 30 min. Scanning probe microscope (SPM), vibrating sample magnetometer (VSM) and X-ray diffraction (XRD) were applied to study the magnetic properties and microstructure. AFM images show that small and uniform grains and some clusters appear with the increase of Ni thickness, also MFM images show that the size of domain first decreases and then increases. The coercivity reaches the maximum 48 kA·m-1 at t=30 nm. The XRD profiles show stronger fcc (111) orientation peak of Ni and weak hcp structure peaks of Ni3Ti. This results reveal that the crystal lines have the prefer orientation and achieve the ordered.

关键词： magnetic recording magnetron sputtering coercivity annealing

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

Multi-year monitoring of paddy rice planting area in Northeast China using MODIS time series data

引用

Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2013年第10期14卷 934-946页

作者： Jing-jing SHI Jing-feng HUANG feng zhang Institute of Agricultural Remote Sensing and Information Application Zhejiang University Key Laboratory of Agricultural Remote Sensing and Information System of Zhejiang Province Ministry of Education Key Laboratory of Environmental Remediation and Ecological Health Zhejiang University

e The objective of this study was to investigate the tempo-spatial distribution of paddy rice in Northeast China using moderate resolution imaging spectroradiometer （MODIS） data. We developed an algorithm for detection and estimation of the transplanting and flooding periods of paddy rice with a combination of enhanced vegetation index （EVI） and land surface water index with a central wavelength at 2130 nm （LSW12130）. In two intensive sites in Northeast China, fine resolution satellite imagery was used to validate the performance of the algorithm at pixel and 3x3 pixel window levels, respectively. The commission and omission errors in both of the intensive sites were approximately less than 20%. Based on the algorithm, annual distribution of paddy rice in Northeast China from 2001 to 2009 was mapped and analyzed. The results demonstrated that the MODIS-derived area was highly correlated with published agricultural statistical data with a coefficient of determination （R^2） value of 0.847. It also revealed a sharp decline in 2003, especially in the Sanjiang Plain located in the northeast of Heilongjiang Province, due to the oversupply and price decline of rice in 2002. These results suggest that the approaches are available for accurate and reliable monitoring of rice cultivated areas and variation on a large scale.

关键词： Paddy rice Moderate resolution imaging spectroradiometer(MODIS) Northeast China Enhanced vegetation index Land surface water index

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

Recyclable hydrolyzed polymers of intrinsic microporosity-1/Fe_(3)O_(4) magnetic composites as adsorbents for selective cationic dye adsorption

引用

Frontiers of Chemical Science and Engineering 2024年第2期18卷 113-125页

作者： feng zhang Shuainan Xu Xiumei Geng Meixia Shan Yatao zhang School of Chemical Engineering Zhengzhou UniversityZhengzhou 450001China

Polymers of intrinsic microporosity shows great potential for dye adsorption and magnetic Fe_(3)O_(4) are easy to be *** this work,hydrolyzed polymers of intrinsic microporosity-1/Fe_(3)O_(4) composite adsorbents were prepared by phase inversion and hydrolysis process for cationic dye *** chemical structure and morphology of the composite adsorbents were systematically characterized by several characterization *** methylene blue as the target dye,the influences of solution pH,contact time,initial dye concentration,and system temperature on the methylene blue adsorption process were *** incorporation of Fe_(3)O_(4) particle into hydrolyzed polymers of intrinsic microporosity-1 endow the adsorbent with high magnetic saturation(20.7 emu·g^(–1))which allows the rapid separation of the ***,the adsorption process was simulated by adsorption kinetics,isotherms and thermodynamics to gain insight onto the intrinsic adsorption *** addition,the composite adsorbents are able to selectively adsorb cationic dyes from mixed dyes *** polymers of intrinsic microporosity/Fe_(3)O_(4) shows only a slight decrease for methylene blue adsorption after 10 adsorption/regeneration cycles,demonstrating the outstanding regeneration *** high adsorption capacity,outstanding regeneration ability,together with simple preparation method,endow the composite adsorbents great potential for selective removal of cationic dyes in wastewater system.

关键词： polymers of intrinsic microporosity magnetic adsorbent cationic dye adsorption

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

Production of p-rich nuclei with Z = 20-25 based on radioactive ion beams

引用

Nuclear Science and Techniques 2022年第5期33卷 30-38页

作者： Bing Li Na Tang Yu-Hai zhang feng-Shou zhang Key Laboratory of Beam Technology of the Ministry of Education College of Nuclear Science and TechnologyBeijing Normal UniversityBeijing 100875China Institute of Radiation Technology Beijing Academy of Science and TechnologyBeijing 100875China Center of Theoretical Nuclear Physics National Laboratory of Heavy Ion Accelerator of LanzhouLanzhou 730000China

Within the framework of isospin-dependent Boltzmann-Langevin model,the production cross sections of proton-rich nuclei with Z=20-25 are *** to the reaction results for different isospin of projectiles^(48)Ni,^(49)Ni,and^(50)Ni,proton-rich fragments tend to be more easily produced in reactions with the protonrich projectile^(48)*** production cross sections of the unknown nuclei in the vicinity of the projectile are sensitive to incident *** is observed that incident energy of 345 MeV/u is appropriate for producing proton-rich nuclei with Z=*** projectile fragmentation reactions based on the radioactive ion beam of48Ni at 345MeV/u,several unknown proton-rich nuclei near the proton drip line are generated in the *** these new nuclei are near-projectile elements near Z=*** production cross sections of the new nuclei^(34)Ca,37,38Sc,^(38)Ti,^(40,41,42)V,^(40,41)Cr,and^(42,43,44,45)Mn are in the range of ***,projectile fragmentation of radioactive ion beams of Ni is a potential method for generating new proton-rich nuclei with Z=20-25.

关键词： Production cross sections Radioactive ion beams Isospin-dependent Boltzmann-Langevin model

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

Dynamical Behavior of SEIR-SVS Epidemic Models with Nonlinear Incidence and Vaccination

引用

Acta Mathematicae Applicatae Sinica 2022年第2期38卷 282-303页

作者： Xiao-mei feng Li-li LIU feng-qin zhang School of Mathematics and Informational Technology Yuncheng UniversityYuncheng 044000China School of Mathematics and Informational Sciences Shaanxi Normal UniversityXi'an 710062China Complex Systems Research Center Shanxi UniversityTaiyuan 030006China Shanxi Key Laboratory of Mathematical Techniques and Big Data Analysis on Disease Control and Prevention Shanxi UniversityTaiyuan 030006China

For some infectious diseases such as mumps,HBV,there is evidence showing that vaccinated individuals always lose their immunity at different rates depending on the inoculation *** this paper,we propose an age-structured epidemic model using a step function to describe the rate at which vaccinated individuals lose immunity and reduce the age-structured epidemic model to the delay differential *** the age-structured model,we consider the positivity,boundedness,and compactness of the semiflow and study global stability of equilibria by constructing appropriate Lyapunov ***,for the reduced delay differential equation model,we study the existence of the endemic equilibrium and prove the global stability of ***,some numerical simulations are provided to support our theoretical results and a brief discussion is given.

关键词： vaccination age-structured epidemic model delay differential equation model stability Lyapunov functional

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

Control of Ultra Low Titanium in Ultra Low Carbon Al-Si Killed Steel

引用

Journal of Iron and Steel Research International 2013年第4期20卷 20-25页

作者： zhang feng LI Guang-qiang Silicon Steel Department Baoshan Iron and Steel Co.Ltd. Key Laboratory forFerrous Metallurgy and Resources Utilization of Ministry of Education Wuhan University of Science and Technology

Titanium is the impurity in some special steel *** existence of titanium decreases the grain size,depresses the yield strength,and results in the low quality of these steels in various ***,titanium should be removed to the *** on the industrial production of ultra low carbon Al-Si killed steel,the physical-chemical behavior of titanium was investigated in vacuum degassing refining（RH）process with and without *** influences of titanium content in hot metal,ladle slag composition,and ladle slag quantity,etc,on titanium content of refined liquid steel were *** results showed that the partition ratio of titanium between ladle slag and liquid steel is in inverse proportion to the 4/3square of aluminum *** maximum partition ratio of titanium between top slag and liquid steel can be obtained by adjusting an optimum slag composition including contents of FeOxand Al2O3and the slag basicity,and the suitable range of them should be controlled higher than 6%,less than 20%,and within 1.5to 3.0,***,desulfurization refining by RH decreases the partition ratio of titanium between ladle slag and liquid steel *** ensure the titanium content stably less than 15×10-6 in a 300tladle,the titanium content in hot metal must be less than 500×10-6 and the thickness of basic oxygen furnace（BOF）slag carrying over must be less than 50mm.

关键词： titanium desulfurization RH refining ultra low carbon steel Al-Si killed steel

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

Samarium( II )-electrocatalyzed chemoselective reductive alkoxylation of phthalimides

引用

Organic Chemistry Frontiers 2022年第5期9卷 1308-1314页

作者： Yu-feng zhang Mohamed Mellah Universite Paris-Saclay CNRSInstitut de Chimie Moleculaire et des Materiaux d’OrsayBatiment 42091405 OrsayFrance

The unprecedented samarium electrocatalyzed reductive alkoxylation of phthalimides in a single step is *** mild conditions,using electrogenerated Sm(II)with TMSCl(trimethyl chlorosilane),N-substituted 3-alkoxyl isoind... 详细信息

关键词： catalyzed reductive substituted

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

The Solutions of the Coupled Einstein-Maxwell Equations and Dilaton Equations

引用

Acta Mathematicae Applicatae Sinica 2018年第3期34卷 485-492页

作者： Rui-feng zhang Ya GU Institute of Contemporary Mathematics Henan University Kaifeng 475004 China School of Mathematics and Statistics Henan University Kaifeng 475004 China

In this paper, we consider extremely charged static perfect fluid distributions with a dilaton field in the framework of general relativity. By using calculus of variations, we establish the existence theorem for the solutions of this important gravitational system. We show that there is a continuous family of smooth solutions realizing asymptotically flat space metrics.

关键词： nonlinear elliptic equations the variational method the asymptotic estimates.

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

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：