检索结果-南通市图书馆

Journal of Iron and Steel Research International 2015年第10期22卷 885-891页

作者： jian-hong dong Min CHEN Nan WANG School of Materials and Metallurgy Northeastern University

A novel-type delivery system consisting of a special feeding device and delivery device was developed and applied to a φ600 mm× 1 000 mm twin-roll casting system for producing the steel strip of 2 mm in thickness, and the characteristics of fluid flow and temperature field in the casting pool were investigated by mathematical simulation. The results showed that the melt from the novel-type delivery system was distributed to the casting pool along the width direction smoothly and uniformly. At the casting speed of 80 m/min, the difference of minimum residence time （groin） and actual average residence time （tave） among different ports of the delivery device was less than 0.18 s and 0.26 s respectively, and the average amplitude of level fluctuation was 0.3 mm to 0.6 mm on the free surface of casting pool. In addition, the difference of temperature on the free surface of the pool was below 20 K and the difference across the width direction of roll in different pool depths was less than 13 K, which indicates that the uniformity of temperature distribution was obtained in the casting pool to maintain the casting process and the defect-free steel strip can also be obtained.

关键词： twin-roll strip casting novel-type delivery system fluid flow temperature field mathematical simulation

Growth Rate,Microstructure and Phase Composition of Oxide Scales for Three Typical Steels in Simulated Continuous Casting Process

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2014年第12期21卷 1065-1072页

作者： Nan WANG jian-hong dong Wei-jun HUANG Bo LI Min CHEN School of Materials and Metallurgy Northeastern University

C-rowth rate, microstructure and phase composition of scale layer formed during oxidation in 56 % H2O9%O2 N2 and following continuous cooling in ambient air were experimentally investigated by means of optical microscopy, scanning electron microscopy （SEM）, energy-dispersive spectroscopy （EDS） and X-ray diffraction （XRD） for 45, 20CrMnTi and TTS443M steels respectively, to examine the effects of strand surface temperature and steel composition on the scale formation in simulated continudus casting process. The growth rates were found to be ap proximately parabolic and the calculated activation energy of TTS443M steel is much higher than those of the two other steels. For 45 and 20CrMnTi steels, the scale layers were looser and a distinct gap formed at the scale-sub strate interface at higher strand surface temperature. The dominant phases within the scale were iron oxides except for FeO · Cr2O3 phase simuhaneously existing in the oxide scale of 20CrMnTi steel. On the other hand, the scale layer formed on TTS443M steel was compact and tightly attached to the steel surface. At both lower and higher strand surface temperature, iron oxide was main phase in external layer of the scale, while chromia was dominant in inner layer with an appreciable Cr enrichment.

关键词： oxide scale growth rate microstructure phase composition continuous casting

Recovery rates of iron, nickel, and chromium via iron-bath reduction of stainless steel dust briquettes based on corundum crucible erosion balance analysis

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2018年第3期25卷 320-329页

作者： Fei Yuan Hui-ning Zhang Hui Li jian-hong dong Hui-hui Xiong An-jun Xu School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083 China School of Metallurgy and Chemical Engineering Jiangxi University of Science and TechnologyGanzhou 341000 Jiangxi China China Metallurgical Industry Planning and Research Institute Beijing 100083 China

The leaching of chromium from stainless steel dust （SSD） is deleterious to the environment. To address this issue, the reduction of SSD briquettes can be employed to effectively extract chromium. The recovery rates of iron, chromium, and nickel via ironbath reduction of SSD briquettes were determined using X-ray fluorescence spectroscopy, X-ray diffraction, and scanning electron microscopy measurements. First, the effects of basicity and contents of silicon, iron, CaF2, and carbon on the recovery rates of the three metals were analyzed using the slag amount prediction model, which was originally established from the A1203 balance of corundum crucible erosion behavior. Second, the effect of feeding mode, i.e., whether steel scrap and SSD briquettes were simultaneously added, on the recovery rates was discussed in detail. Third, the iron-bath reduction of SSD briquettes was thermodynamically analyzed. The results indicated that the recovery rates of the three metals are greater than 95% those of using a basicity of 1.5 and 6.0% CaF2, 15% carbon, and 7% ferrosilicon. The recovery rate of chromium increases twofold with the addition of ferrosilicon. The feeding mode of adding briquettes and steel scrap simultaneously is better for recovery of metals and separation of the metal and slag than the feeding mode of adding steel scrap firstly and then briquettes.

关键词： Stainless steel dust Erosion model Ferrosilicon Iron Nickel-Chromium Recovery Iron-bath reduction

Kinetic triplet from low-temperature carburization and carbon deposition reactions

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 Iron and Steel Research International 2022年第10期29卷 1545-1558页

作者： Wei Zhang Kui Li jian-hong dong Cheng-zhi Li Ai-hua Liu Ju-hua Zhang Zheng-liang Xue The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan430081HubeiChina Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education Wuhan University of Science and TechnologyWuhan430081HubeiChina Hanshan Normal University Chaozhou521041GuangdongChina Key Laboratory of Ecological Utilization of Multi-Metallic Mineral of Education Ministry Northeastern UniversityShenyang110819LiaoningChina

Carbon deposition reaction is unfavorable for smooth operation of blast furnace,while the product of carburization reaction is a superior iron-bearing raw material in non-blast furnace *** kinetic triplet of these two reactions was obtained based on non-isothermal kinetic *** to the Sharp–Wentworth method,the activation energy of the carburization reaction is 397.77 kJ/mol,and the activation energies of the carbon depositions on hematite and magnetite are 188.92 and 100.89 kJ/mol,*** carburization reaction is controlled by the Jander mechanism,and the carbon depositions on hematite and magnetite are both controlled by the mechanism of Zhuravlev–Lesokhin–*** on Coats–Redfern method,the activation energies of the above three reactions are 360.65,149.29,and 102.36 kJ/mol,*** carburization reaction is a first-order reaction,while the carbon depositions on hematite and magnetite are both third-order *** particular,the negative activation energy is obtained if considering the anti-Arrhenius circumstance in the Sharp-Wentworth *** on above results,it is feasible to adopt non-isothermal kinetic method to study the kinetic triplet of a *** to the obtained activation energies and reaction mechanism functions,the simulated kinetic data are in good agreement with the experimental values even using the negative activation energy.

关键词： Kinetic triplet Carburization reaction Carbon deposition Non-isothermal kinetic Magnetite Hematite

Thermodynamic analysis on synthesis process of diamond

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 Central South University 2001年第3期13卷 156-160页

作者： YI jian-hong, PENG Yuan-dong (State Key Laboratory for Powder Metallurgy, Central South University, Changsha 410083, China) State Key Laboratory for Powder Metallurgy Central South University Changsha China

Based upon the thermodynamic analysis of the nucleation of d iamond crystal, the effects of synthesis temperature and pressure on the nucleat ion of diamond crystal, diamond growth and output of diamond crystal, particle s ize and strength were discussed. The results show that the excess pressure has a n important effect on the critical radius of nucleation and thermodynamic b a rrier in the formation of a critical nucleus. Considering the excess pressure, t he expression of diamond nucleation rate was obtained.

关键词： diamond synthesis pressure temperature nucleation growth

Programmable repulsive potential for tight-binding from Chen-Möbius inversion theorem

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2024年第1期67卷 71-83页

作者： jian-Gao Li Jin-Kun Tang hong-Quan Song Gotthard Seifert dong-Bo Zhang College of Nuclear Science and Technology Beijing Normal UniversityBeijing 100875China Department of Physics Beijing Normal UniversityBeijing 100875China College of Physics and Telecommunication Engineering Zhoukou Normal UniversityZhoukou 466001China Theoretische Chemie Technische Universität DresdenDresden D-01062Germany

An accurate total energy calculation is essential in materials *** date,many tight-binding(TB)approaches based on parameterized hopping can produce electronic structures comparable to those obtained using first-principles ***,TB approaches still have limited applicability for determining material properties derived from the total *** is,the predictive power of the TB total energy is impaired by an inaccurate evaluation of the repulsive *** complexity associated with the parametrization of TB repulsive potentials is the weak link in this *** this study,we propose a new method for obtaining the pairwise TB repulsive potential for crystalline materials by employing the Chen-Möbius inversion *** show that the TB-based phonon dispersions,calculated using the resulting repulsive potential,compare well with those obtained by first-principles calculations for various systems,including covalent and ionic bulk materials and twodimensional *** present approach only requires the first-principles total energy and TB electronic band energy as input and does not involve any *** striking feature enables us to generate repulsive potentials programmatically.

关键词： tight binding first-principles calculation total energy repulsive potential phonon dispersion

Poles Extraction Based LiDAR Localization for Autonomous Robot Systems

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 Systems Science & Complexity 2024年第4期37卷 1413-1424页

作者： hong Xin dong Yi College of Electronic and Information Engineering Tongji UniversityShanghai 201800China

With the development of intelligent technology,the problem of Li DAR-based localization has played an increasingly important role in the localization of robots in unmanned *** the dense point clouds from the environment requires a large amount of memory,specific and stable structural features,such as pole-like objects in the environment,can serve as the ideal landmarks for localization in unmanned systems,which can effectively reduce the memory usage and mitigate the effects of dynamic environment *** this paper,the authors propose a pole-like objects extraction approach and then,it is applied into the localization system of mobile *** the same experimental conditions,the proposed method can extract more pole-like objects and achieve better long-term localization accuracy than some existing methods in different urban environmental datasets.

关键词： Pole-like landmark extraction robot localization

Steel-refractory reactions in lanthanum-,cerium-,and ytrium-added steels

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2024年第6期31卷 1473-1485页

作者： jian Kang hong-po Wang Yu Wang College of Materials Science and Engineering Chongqing UniversityChongqing 400044China The State Key Laboratory of Mechanical Transmissions Chongqing UniversityChongqing 400044China

A systematic experimental study was conducted on the similarities and differences in the reactions between commonly used rare earth elements(REEs)and frequently used refractories in the steelmaking *** results indicate that the reaction behaviors of La,Ce,and Y with MgO,Al_(2)O_(3),and MgO·Al_(2)O_(3) crucibles differed *** consumption rates of La,Ce,and Y in the molten steel were in descending order of La>Ce>Y for smelting with all three kinds of *** the REEs reacted with the crucible,the contents of Mg and Al showed a trend of first increasing and then *** laboratory-scale smelting conditions,the reactions related to REEs were dominated by steel-crucible reactions,and the contact area between the unit mass of molten steel and refractory materials mainly determined the consumption rates of ***-and Ce-crucible reactions generated loose and porous reaction interfaces;however,Y-crucible reactions generated a dense Y_(2)O_(3) layer,dramatically suppressing the consumption rate of *** calculation indicated that the reactions between rare earth and different refractory materials were first-order *** crucible materials significantly affected the product type and morphology of the steel-crucible reaction interfaces,thereby influencing the consumption rate of *** reactions between REEs and refractories must be seriously considered,especially for small-scale smelting.

关键词： Rare earth Inclusion Refractory Thermodynamics Dynamics

Adjuvant therapy for hepatocellular carcinoma:Dilemmas at the start of a new era

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2024年第8期30卷 806-810页

作者： jian-hong Zhong Department of Hepatobiliary Surgery Guangxi Medical University Cancer HospitalNanning 530021Guangxi Zhuang Autonomous RegionChina

Approximately 50%-70%of patients with hepatocellular carcinoma experience recurrence within five years after curative hepatic resection or *** a result,many patients receive adjuvant therapy after curative resection or ablation in order to prolong recurrence-free *** therapy recommended by national guidelines can differ,and guidelines do not specify when to initiate adjuvant therapy or how long to continue *** and other unanswered questions around adjuvant therapies make it difficult to optimize them and determine which may be more appropriate for a given type of *** questions need to be addressed by clinicians and researchers.

关键词： Adjuvant therapy Hepatocellular carcinoma Tumor recurrence Unanswered questions

Grain refinement of 5A06 aluminum alloy welds caused by tungsten inert gas welding arc characteristics under Ar-He alternating gas supply conditions:a coupled method of water-cooled copper plate test/numerical simulation

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 Iron and Steel Research International 2024年第3期31卷 767-777页

作者： hong-bin Dai jian Miao Jia-xin Lin School of Materials Science and Engineering Harbin University of Science and TechnologyHarbin 150040HeilongjiangChina

The welding arc,as a carrier for the conversion of electrical energy to thermal energy,has a direct impact on the quality of welding by its properties and *** the tungsten inert gas(TIG)welding process under the condition of Ar-He alternating gas supply,the arc is alternately converted between Ar arc and He arc with an alternating gas supply cycle,which has obvious arc change *** FLUENT software was used to numerically simulate the characteristics of the TIG arc under the condition of alternating gas supply,and the arc temperature field,arc pressure,electric potential and current density distribution under the condition of alternating gas supply were *** with the real-time data of arc pressure measured by the water-cooled copper plate with holes,it is proved that the TIG arc has obvious dynamic characteristics under the condition of Ar-He alternating gas *** unique dynamic TIG arc acts on the 5A06 aluminum alloy weld,causing the molten pool to stir,resulting in uniform microstructure and grain refinement at the weld,and thereby improving the mechanical properties of the welded joint.

关键词： Alternating gas supply Grain refinement Numerical simulation Tungsten argon arc morphology Microstructure Mechanical property