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Research status of inclusions in bearing steel and discussion on non-alloy deoxidation process

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Journal of Iron and Steel Research International 2023年第1期30卷 1-20页

作者： Lei Cao li-guang Zhu Zhi-hong Guo School of Metallurgy and Ecological Engineering University of Science and Technology BeijingBeijing 100083China Materials Engineering Department Hebei Vocational University of Industry and TechnologyShijiazhuang 050091HebeiChina Department of Materials Science and Engineering Hebei University of Science and TechnologyShijiazhuang 050090HebeiChina

Non-metallic inclusion in steel is a very key factor affecting the fatigue life and quality stability of high-quality bearing *** mainly affect the fatigue life and toughness of the material by affecting the continuity of the steel matrix,thereby endangering the safety and stability of the *** research progress of inclusion formation,removal and modification was *** on the current research status of Al deoxidation or Si deoxidation process,the feasibility of non-alloy deoxidation process for high-quality bearing steel was proposed and discussed.C or H_(2) is used as non-alloy deoxidizer,and the deoxidation products are CO and H_(2)O gases,which are easy to be removed from the molten *** are few studies on the non-alloy deoxidation process,especially the research and application of C or H_(2) deoxidation for high-quality bearing ***,the non-alloy deoxidation process is of great significance for reducing oxygen content and improving cleanliness of high-quality bearing ***,it is necessary to study the mechanism and kinetics of C and H_(2) deoxidation and analyze the factors affecting deoxidation effect systematically,so as to provide a solid theoretical basis for the practice of non-alloy deoxidation process for high-quality bearing steel.

关键词： High-quality bearing steel Non-metallic inclusion Non-alloy deoxidation C deoxidation H_(2)deoxidation

三臂凿岩台车臂架机械与液压系统优化与仿真分析

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液压气动与密封 2025年第2期45卷 9-17页

作者：李光朋阮利超李皓楠常威中铁工程装备集团隧道设备制造有限公司河南新乡453000

三臂凿岩台车是硬岩隧道钻爆法施工的专用设备,其臂架系统是末端钻机大范围作业的关键。针对三臂凿岩台车臂架系统易抖动、变形大的难题,提出优化臂架机械结构强度与一阶谐振频率,开发一套臂架高稳态电液驱动系统,实现三臂凿岩台车臂架... 详细信息

三臂凿岩台车是硬岩隧道钻爆法施工的专用设备,其臂架系统是末端钻机大范围作业的关键。针对三臂凿岩台车臂架系统易抖动、变形大的难题,提出优化臂架机械结构强度与一阶谐振频率,开发一套臂架高稳态电液驱动系统,实现三臂凿岩台车臂架系统稳定性与可靠性的提升。首先,在分析传统臂架结构应力应变分布与模态特征基础上,提出优化设计伸缩臂内部肋板与大臂外部肋板结构,在不影响总体结构尺寸的前提下,将大臂(伸缩臂完全伸出)最大变形由32.1 mm降至19.6 mm,一阶固有频率由2.36 Hz提升至3.03 Hz。在此基础上,开发了一套新型高稳态臂架电液驱动系统,建立电液驱动系统的仿真分析模型,并提出优化设置平衡阀弹簧刚度、平衡阀控制口与回油口阻尼阀过流面积、主油路阻尼阀过流面积等参数提升电液系统的稳定性,通过仿真建模分析探明了不同液压系统参数对臂架控制系统稳定性与动态特性的影响规律。通过臂架机械与液压系统的优化,实现臂架系统稳定性的提升,对未来三臂凿岩台车的设计与调试提供了重要参考。

关键词：三臂凿岩台车臂架系统臂架结构电液驱动系统稳定性与动态特性

Effects of additives on the phase transformation, occurrence state, and the interface of the Ti component in Ti-bearing blast furnace slag

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International Journal of Minerals,Metallurgy and Materials 2016年第9期23卷 1029-1040页

作者： li Zhang Wu Zhang Ju-hua Zhang guang-qiang li School of Materials and Metallurgy Northeastern University School of Materials Science and Engineering Shenyang Ligong University School of Materials and Metallurgy Wuhan University of Science and Technology

The influences of additives on the phase transformation, occurrence state, and the interface of the Ti component in Ti-bearing blast furnace slag were investigated. After oxidation, most of the Ti component in the slag was enriched into the perovskite phase, which served as the Ti-rich phase during the crystallization process. The phase transformation, occurrence state, and the interface of the Ti component were observed to be affected by the addition of different types of agents. During the oxidation process, titanaugite and Ti-rich diopside phases gradually transformed into non-Ti phases（anorthite： CaMgSi2O6 and CaAl2Si2O8） in the form of dendrites or columns, which were observed to be distributed at the surface of the perovskite phase. Several more cracks appeared along the grain boundaries of the perovskite phase after the addition of P2O5, facilitating the liberation of the perovskite phase. Composite additives combining both an acid and a base, such as CaO ＋ CaF2 or P2O5 ＋ CaF2, were used. We observed that the disadvantages of using single additives were successfully overcome.

关键词： blast furnace slag titanium additives phase transformation interfaces

Auto-ignition and stabilization mechanism of diluted H_2 jet flame

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2011年第2期12卷 154-161页

作者： Wei FENG Zhi-jun WU Jun DENG li-guang li Key Laboratory for Power Machinery and Engineering of Ministry of Education Shanghai Jiao Tong University Shanghai 200030 China School of Automotive Studies Tongji University Shanghai 200092 China

The controllable active thermo-atmosphere combustor(CATAC) has become a utilizable and effective facility because it benefits the optical diagnostics and modeling. This paper presents the modeling research of the auto-ignition and flames of the H2/N2(H2/CH4/N2,or H2/H2O2/N2) mixture on a CATAC,and shows curves varying with temperatures of auto-ignition delay,the height of the site of auto-ignition of lifted flames,and flame lift-off height. The results of auto-ignition delay and the lift-off height are compared the experimental results to validate the model. A turning point can be seen on each curve,identified with criterion temperature. It can be concluded that when the co-flow temperature is higher than the criterion temperature,the auto-ignition and lifted flame of the mixture are not stable. Conversely,below the criterion temperature,the mixture will auto-ignite in a stable fashion. Stabilization mechanisms of auto-ignition and lifted flames are analyzed in terms of the criterion temperature.

关键词： Simulation Combustor Auto-ignition Jet flame Stabilization mechanism

Wear Mechanism of Cemented Carbide Tool in High Speed Milling of Stainless Steel

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Chinese Journal of Mechanical Engineering 2018年第6期31卷 177-186页

作者： guang-Jun liu Zhao-Cheng Zhou Xin Qian Wei-Hai Pang guang-Hui li guang-Yu Tan School of Mechanical Engineering Tongji University College of Environmental Science and Engineering Tongji University School of Mechanical and Power Engineering Guangdong Ocean University

Adhesion of cutting tool and chip often occurs when machining stainless steels with cemented carbide tools. Wear mechanism of cemented carbide tool in high speed milling of stainless steel 0Cr13Ni4 Mo was studied in this work. Machining tests on high speed milling of 0Cr13Ni4 Mo with a cemented carbide tool are conducted. The cutting force and cutting temperature are measured. The wear pattern is recorded and analyzed by high?speed camera, scanning electron microscope(SEM) and energy dispersive X?ray spectroscopy(EDS). It is found that adhesive wear was the dominant wear pattern causing tool failure. The process and microcosmic mechanism of the tool’s adhesive wear are analyzed and discussed based on the experimental results. It is shown that adhesive wear of the tool occurs due to the wear of coating, the a nity of elements Fe and Co, and the grinding of workpiece materials to the tool material. The process of adhesive wear includes both microcosmic elements di usion and macroscopic cyclic process of adhe?sion, tearing and fracture.

关键词： Cemented carbide tool High speed milling Stainless steel Wear mechanism

Scheduling Jobs with Release and Delivery Times Subject to Nested Eligibility Constraints

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Journal of the Operations Research Society of China 2021年第1期9卷 63-77页

作者： Yu-Zhong Zhang Shu-guang li Institute of Operations Research Qufu Normal UniversityRizhao 276826ShandongChina Key Laboratory of Intelligent Information Processing in Universities of Shandong(Shandong Institute of Business and Technology) Yantai 264005ShandongChina College of Computer Science and Technology Shandong Institute of Business and TechnologyYantai 264005ShandongChina

The problem of scheduling jobs with release and delivery time subject to machine eligibility constraints is *** eligible sets of the jobs are nested,and pre-emptions are not *** goal is to minimize the maximum delivery completion time,i.e.,the time by which all jobs are *** the special case of equal release time,a 2-approximation algorithm is presented whose running time depends linearly on the number of *** the general case of unequal release time,a polynomial time approximation scheme is derived.

关键词： Scheduling Nested eligibilityconstraints Release time Deliverytime Polynomial timeapproximationscheme

Difference in Organic Carbon Contents and Distributions in Particle-size Fractions between Soil and Sediment on the Southern Loess Plateau, China

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Journal of Mountain Science 2014年第3期11卷 717-726页

作者： li guang-lu PANG Xiao-ming College of Resources and Environment Northwest A&F University Tianshui Soil and Water Conservation Experiment Station of YRCC

The purpose of this study was to assess the effect of long-term cultivation and water erosion on the soil organic carbon （OC） in particle-size fractions. The study site is located at Nihegou Watershed in the Southern Loess Plateau, China. The soil at this site is loess with loose and silty structure, and contains macropores. The results showed that the OC concentrations in sediments and in the particle-size fractions of sediments were higher than those in soils and in the particle-size fractions of soils. The OC concentration was highest in the clay particles and was lowest in the sand particles. Clay particles possessed higher OC enrichment ability than silt and sand particles. The proportions of OC in the silt fractions of soil and sediment were the highest （mean value of 53.87% and 58.48%, respectively）, and the total proportion of OC in the clay and silt fractions accounted for 96% and 98% of the total OC in the soil and sediment, respectively. The loss of OC was highest in silt particles, with an average value of 0.16 Mg ha^-1 y^-1, and was lowest in the sand （0.003 Mg ha^-1 y^-l）. This result suggests that the fine particle-size fraction in the removed sediment may be an important indicator to assess soil OC losses.

关键词： Soil organic carbon Loess Plateau Enrichment ratio Water erosion Particle fraction

Electrospun composites of PHBV/pearl powder for bone repairing

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Progress in Natural Science:Materials International 2015年第4期25卷 327-333页

作者： Jingjing Bai Jiamu Dai guang li College of Material Science and Engineering Donghua University

Electrospun fi ber has highly structural similarity with natural bone extracelluar matrix(ECM). Many researches about fabricating organic–inorganic composite materials have been carried out in order to mimic the natural composition of bone and enhance the biocompatibility of materials. In this work, pearl powder was added to the poly(3-hydroxybutyrate-co-3-hydroxyvalerate)(PHBV) and the composite nano fi ber scaffold was prepared by electrospinning. Mineralization ability of the composite scaffolds can be evaluated by analyzing hydroxyapatite(HA)formation on the surface of nano fi ber scaffolds. The obtained composite nano fi ber scaffolds showed an enhanced mineralization capacity due to incorporation of pearl powder. The HA formed amount of the composite scaffolds was raised as the increase of pearl powder in composite scaffolds. Therefore, the prepared PHBV/pearl composite nano fi ber scaffolds would be a promising candidate as an osteoconductive composite material for bone repairing.

关键词： Hydroxyapatite Pearl PHBV Mineralization Composite nano fi bers scaffolds

Locally-primitive Arc-transitive lO-Valent Graphs of Square-free Order

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Algebra Colloquium 2018年第2期25卷 243-264页

作者： guang li Zaiping Lu Xiaoyuan Zhang Center for Combinatorics LPMC-TJKLC Nankai University Tianjin 300071 China

In this paper, we present a complete classification for locally-primitive arctransitive graphs which have square-free order and valency 10. The classification involves nine graphs and three infinite families of graphs.

关键词： arc-transitive graph locally-primitive graph normal quotient vertexstabilizer (almost) simple group