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Comparison study on hot state modification of converter slag by adding Al_(2)O_(3) or SiO_(2)

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Journal of Iron and Steel Research International 2024年第11期31卷 2684-2692页

作者： yu-feng Tian Guang-qiang Li Yong-qian Li yu Liu 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 Hubei Provincial Key Laboratory for New Processes of Ironmaking and Steelmaking Wuhan University of Science and TechnologyWuhan 430081HubeiChina China Baowu Steel Group Corporation Limited Shanghai201900China

The value-added utilization of converter steel slag is crucial, with China’s annual production having reached 100 million tons. The utilization of converter slag in the construction materials sector is limited as it undergoes volume expansion during the aging process, mainly caused by the hydration reaction of free calcium oxide present in the slag. The influence of alumina addition on the mineral transformation of typical industrial converter slag was investigated. Different quantities of alumina were introduced into the slag, and the original and modified slags were remelted under argon atmosphere, followed by quenching. The experimental results were compared with thermodynamic simulation calculations for further analysis. As the alumina content increases, it reacts with the free calcium oxide in slag, leading to the formation of low-melting-point calcium aluminoferrite. Additionally, alumina addition effectively reduces slag viscosity. Finally, an assessment of the energy consumption for alumina-modified and silica-modified converter slags was presented.

关键词： Converter slag Free calcium oxide Alumina addition Viscosity Energy consumption

First-Principle Calculations for Transition Phase and Elastic Properties of SrS

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Communications in Theoretical Physics 2008年第6期49卷 1611-1614页

作者： CHENG Yan LU Lai-yu JIA Ou-He gou Qing-Quan School of Physical Science and Technology Sichuan University Chengdu 610064 China Institute of Atomic and Molecular Physics Sichuan University Chengdu 610065 China Laboratory for Shock Wave and Detonation Physics Research Institute of Fluid Physics Chinese Academy of Engineering Physics Mianyang 621900 China

The transition phase and elastic properties of SrS from NaCl structure （B1） to CsCl structure （B2） are investigated by ab initio plane-wave pseudopotential density functional theory method and by the quasi-harmonic Debye model. The transition pressure varies non-linearly with temperature, and the pressure of the mechanical instability increases linearly with increasing temperature. It is shown that the B1 structure SrS is a most elastically anisotropic minerat any pressure. The Debye temperature, the heat capacity, thermal expansion and Gruneisen parameter over a wide range of pressures and temperatures are also obtained.

关键词： elastic constants generalized gradient approximation quasi-harmonic Debye model SrS

Altered 3D genome reorganization mediates precocious myeloid differentiation of aged hematopoietic stem cells in inflammation

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Science China Life Sciences 2025年

作者： Xinyu Cui yu Dong qiang Zhan Yixin Huang Qianshu Zhu Zihao Zhang Guang Yang Liping Wang Shijun Shen Jia Zhao Zhiyi Lin Jiatong Sun Zhongqu Su Yihan Xiao Chuyu Zhang yuwei Liang Lu Shen Lichen Ji Xuguang Zhang Jiqing Yin Hong Wang Zhiyang Chen Zhenyu Ju Cizhong Jiang Rongrong Le Shaorong Gao Clinical and Translational Research Center of Shanghai First Maternity & Infant Hospital Frontier Science Center for Stem Cells School of Life Sciences and Technology Tongji University Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration of Ministry of Education Orthopaedic Department of Tongji Hospital School of Life Sciences and Technology Tongji University Key Laboratory of Regenerative Medicine of Ministry of Education Institute of Aging and Regenerative Medicine Department of Developmental & Regenerative Medicine College of Life Science and Technology Jinan University Shandong Key Laboratory of Animal Bioengineering and Disease Prevention College of Animal Science and Technology Shandong Agricultural University Department of Joint Surgery Shanghai East Hospital Tongji University School of Medicine Shanghai Institute of Nutrition and Health Chinese Academy of Sciences

Inflammation is a driving force of hematopoietic stem cells(HSCs) aging, causing irreversible exhaustion of functional HSCs. However, the underlying mechanism of HSCs erosion by inflammatory insult remains poorly understood. Here, we find that transient LPS exposure primes aged HSCs to undergo accelerated differentiation at the expense of self-renewal, leading to depletion of HSCs. Meanwhile, the central regulator nuclear factor kappa B(NF-κB) mediating functional impairment by inflammation insult induces differential transcriptional response in aged HSCs compared with young HSCs, with precocious activation of myeloid lineage genes. Altered compartmentalization and chromatin loop formation are associated with aging-related differential transcriptional response in HSCs upon lipopolysaccharide(LPS)stimulation. Mechanistically, enhancer and promoter regions of myeloid lineage genes in aged HSCs are more accessible and display more rapid and prominent CTCF occupancy upon LPS stimulation. Our study provides comprehensive resources for the three-dimensional(3D)genome structure of HSCs and sheds light into the ordered genome organization and the associated transcriptome signature underlying HSCs aging.

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Agrobacterium-mediated delivery of CRISPR/Cas reagents for genome editing in plants enters an era of ternary vector systems

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Science China(Life Sciences) 2020年第10期63卷 1491-1498页

作者： yu Zhang qiang Zhang Qi-Jun Chen State Key Laboratory of Plant Physiology and Biochemistry College of Biological SciencesChina Agricultural UniversityBeijing 100193China Center for Crop Functional Genomics and Molecular Breeding China Agricultural UniversityBeijing 100193China

Lack of appropriate methods for delivery of genome-editing reagents is a major barrier to CRISPR/Cas-mediated genome editing in ***-mediated genetic transformation(AMGT)is the preferred method of CRISPR/Cas reagent delivery,and researchers have recently made great improvements to this *** this article,we review the development of AMGT and AMGT-based delivery of CRISPR/Cas *** give an overview of the development of AMGT vectors including binary vector,superbinary vector,dual binary vector,and ternary vector *** also review the progress in Agrobacterium genomics and Agrobacterium genetic engineering for optimal *** focus in particular on the ternary vector system and the resources we *** summary,it is our opinion that Agrobacterium-mediated CRISPR/Cas genome editing in plants is entering an era of ternary vector systems,which are often integrated with morphogenic *** new vectors described in this article are available from Addgene and/or MolecularCloud for sharing with academic investigators for noncommercial research.

关键词： genome editing CRISPR/Cas ternary vector system delivery Agrobacterium-mediated transformation

Production scheduling problems of steelmaking-continuous casting process in dynamic production environment

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Journal of Iron and Steel Research International 2017年第6期24卷 586-594页

作者： Zhong Zheng Jian-yu Long Xiao-qiang Gao College of Materials Science and Engineering Chongqing University Chongqing 400045 China College of Economics and Business Administration Chongqing University Chongqing 400044 China

A concept of production scenario for the steelmaking continuous casting production process and the mathe- matical description of such concept were proposed. The production scenario was described with the varia- tion of the equipment status and the production material properties based on the executing production schedule. Then, the dynamic characteristics of the production process could be described with the evolu tion process of production scenario. Through analyzing the influence of the dynamic production scenario on production scheduling, three key points about the scheduling problems were identified： the problem for integrating the schedules of different batches that is non-neglected when making a schedule, the problem for matching the material flow with the schedule that should be solved when implementing a schedule, and the problem for eliminating the deviations between the initial schedule and implemented schedule that should be solved when rescheduling in a disturbed environment. Finally, a set of experiments were con- ducted, and the results demonstrated that making the production schedule and solving the rescheduling problem for steelmaking continuous casting process with addressing the above three problems improve the adaptability of the schedule in dynamic environment.

关键词： SchedulingReschedulingSteelmakingContinuous castingDisturbanceProduction scenario

Application of Computational Fluid Dynamics and Fluid Structure Interaction Techniques for Calculating the 3D Transient Flow of Journal Bearings Coupled with Rotor Systems

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Chinese Journal of Mechanical Engineering 2012年第5期25卷 926-932页

作者： LI qiang yu Guichang LIU Shulian ZHENG Shuiying Institute of Chemical Machinery Zhejiang University Hangzhou 310027 China Department of Electro-mechanical Engineering Zhejiang University of Science & Technology Hangzhou 310023 China

Journal bearings are important parts to keep the high dynamic performance of rotor machinery. Some methods have already been proposed to analysis the flow field of journal bearings, and in most of these methods simplified physical model and classic Reynolds equation are always applied. While the application of the general computational fluid dynamics （CFD）-fluid structure interaction （FSI） techniques is more beneficial for analysis of the fluid field in a journal bearing when more detailed solutions are needed. This paper deals with the quasi-coupling calculation of transient fluid dynamics of oil film in journal bearings and rotor dynamics with CFD-FSI techniques. The fluid dynamics of oil film is calculated by applying the so-called ＂dynamic mesh＂ technique. A new mesh movement approacb is presented while the dynamic mesh models provided by FLUENT are not suitable for the transient oil flow in journal bearings. The proposed mesh movement approach is based on the structured mesh. When the joumal moves, the movement distance of every grid in the flow field of bearing can be calculated, and then the update of the volume mesh can be handled automatically by user defined function （UDF）. The journal displacement at each time step is obtained by solving the moving equations of the rotor-bearing system under the known oil film force condition. A case study is carried out to calculate the locus of the journal center and pressure distribution of the journal in order to prove the feasibility of this method. The calculating results indicate that the proposed method can predict the transient flow field of a journal bearing in a rotor-bearing system where more realistic models are involved. The presented calculation method provides a basis for studying the nonlinear dynamic behavior of a general rotor-bearing system.

关键词： mesh movement transient flow computational fluid dynamics (CFD) fluid-structure interaction (FSI) journal bearing

Finite Element Simulation of Flexible Roll Forming with Supplemented Material Data and the Experimental Verification

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Chinese Journal of Mechanical Engineering 2016年第2期29卷 342-350页

作者： YAN yu WANG Haibo LI qiang GUAN Yanzhi School of Mechanical and Material Engineerin North China University of Technology

Flexible roll forming is a promising manufacturing method for the production of variable cross section products. Considering the large plastic strain in this forming process which is much larger than that of uniform deformation phase of uniaxial tensile test, the widely adopted method of simulating the forming processes with non-supplemented material data from uniaxial tensile test will certainly lead to large error. To reduce this error, the material data is supplemented based on three constitutive models. Then a finite element model of a six passes flexible roll forming process is established based on the supplemented material data and the original material data from the uniaxial tensile test. The flexible roll forming experiment of a B pillar reinforcing plate is carried out to verify the proposed method. Final cross section shapes of the experimental and the simulated results are compared. It is shown that the simulation calculated with supplemented material data based on Swift model agrees well with the experimental results, while the simulation based on original material data could not predict the actual deformation accurately. The results indicate that this material supplement method is reliable and indispensible, and the simulation model can well reflect the real metal forming process. Detailed analysis of the distribution and history of plastic strain at different positions are performed. A new material data supplement method is proposed to tackle the problem which is ignored in other roll forming simulations, and thus the forming process simulation accuracy can be greatly improved.

关键词： 3D Flexible roll forming constitutive model material data supplementation finite element method experiment verification

SCC investigation of low alloy ultra-high strength steel 30CrMnSiNi2A in 3.5wt% NaCl solution by slow strain rate technique

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Chinese Journal of Aeronautics 2014年第5期27卷 1327-1333页

作者： Liu Jianhua Guo qiang yu Mei Li Songmei Key Laboratory of Aerospace Materials & Performance (Ministry of Education) School of Materials Science and Engineering Beihang University

To evaluate stress corrosion cracking（SCC） mechanism of low alloy ultra-high strength steel 30CrMnSiNi2 A in environment containing NaCl, SCC behavior of the steel in 3.5wt% NaCl solution is investigated by slow strain rate technique（SSRT） with various strain rates and applied potentials, surface analysis technique, and electrochemical measurements. SCC susceptibility of the steel increases rapidly with strain rate decreasing from 1 · 10 5s 1to 5 · 10 7s 1, and becomes stable when strain rate is lower than 5 · 10 7s 1. SCC propagation of the steel in the solution at open circuit potential（OCP） needs sufficient hydrogen which is supplied at a certain strain *** surface at OCP has similar characteristics with that at cathodic polarization 1000 mVSCE, which presents characteristic fractography of hydrogen induced cracking（HIC）.All of these indicate that SCC behavior of the steel in the solution at OCP is mainly controlled by HIC rather than anodic dissolution（AD）.

关键词： Hydrogen NaCl solution Stress corrosion cracking Slow strain rate technique Ultra-high strength steel

Study on positive temperature coefficient of resistivity of co-doped BaTiO_3 with Curie temperature in room temperature region

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Science China(Technological Sciences) 2019年第5期62卷 811-819页

作者： yu AiMei LI qiang FAN DeSong ZHANG HongLiang MIIT Key Laboratory of Thermal Control of Electronic Equipment School of Energy and Power EngineeringNanjing University of Science & Technology

As a temperature self-regulating heater material, the doped BaTiO_3 exhibits an attractive application perspective in the thermal management of electrical devices. However, the high Curie temperature does not meet the requirement in the thermal control application. In this work,(Ba_(0.997-x)Ce_(0.003)Sr_x)(TiNb_(0.002))O_3(x=0.2, 0.3, 0.35, abbreviated as BCSTNs) ceramics were prepared by the solid-state reaction method. The purpose of doping different content of strontium is to shift the Curie temperature of BaTiO_3-based ceramic to the ambient temperature region, maintaining excellent PT_C effect and low room-temperature resistivity by codoped cation ions in Ba-and Ti-site. The influences of sintering temperature and soak time on the microstructure as well as electrical properties of BCSTNs ceramics have been studied. The X-ray diffraction reveals that the composition with x=0.35 exhibits the coexistence of tetragonal and cubic lattice symmetries, confirmed by the Rietveld structure refinement. The dense microstructure with average grain sizes 0.84–7.87 μm was observed for BCSTN ceramics. Temperature-resistivity measurements demonstrate that T_C of the ceramics with x=0.35 shifted to the room temperature region. Additionally, the BCSTN ceramic with heavy doping Sr exhibits relative low room-temperature resistivity and the resistance jump greater than 2.0 orders of magnitude.

关键词： electrical heating Co-doped BaTiO3 curie temperature positive temperature coefficient of resistivity