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Preparation and characterization of calcium aluminate by chemical synthesis

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Journal of University of Science and Technology Beijing 2006年第1期13卷 82-86页

作者： Feng Chen Yanruo Hong jialin sun Jinglong Bu Materials Science and Engineering School University of Science and Technology Beijing Beijing 100083 China Hebei Physical and Engineering Institute Tangshan 063009 China

Saturated Ca（OH）2 and AlCl3 solutions were used to synthesize calcium aluminate hydrate precipitates at room temperature; high purity calcium aluminate powders with stable phases were made by calcination of the precursors at a temperature as low as 1100℃. PSD and BET analysis revealed the particles with sizes ranging from submicrometer to several micrometers and with a specific area of 13 m^2/g. The measurement of hydraulic exotherm revealed that the exothennal rate is in peak for about 2 h. The exothermal quantities are 449.24 J/g at 12 h and 488.38 J/g at 24 h. Its strength development is quick and the 1 day curing strength is almost equal to 100% of the 3 days curing strength in the mortar test.

关键词： calcium aluminate preparation characterization chemical synthesis

Microstructure, mechanical properties and toughening mechanism of directional Fe2B crystal in Fe-B alloy with trace Cr addition

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Journal of Materials Science & Technology 2020年第22期54卷 172-179页

作者： Yongxin Jian Zhifu Huang Xiaoting Liu jialin sun Jiandong Xing State Key Laboratory for Mechanical Behavior of Materials Xi'an Jiaotong UniversityXian710049China

Exploring the effective way to improve Fe2 B's toughness has always been the hot topic in the researches of Fe-B wear resistant *** the present work,the effects of Cr on the microstructure,mechanical properties and lattice structure of directional Fe2 B have been *** affecting mechanism of Cr addition has been discussed according to the experimental and first-principle calculation *** results show Cr addition can improve the toughness of directional Fe2 B on the longitudinal sections perpendicular to(002) crystal plane,without sacrificing the hardness *** toughening mechanism by Cr substitution has been revealed:Cr addition enriches the electron density between the B atoms along [002] direction,contributing to the shrinkage of the bond length and the enhancement of the bond strength of B-B *** obtained results provide insight into the intrinsic reason for toughening Fe2 B by Cr doping.

关键词： Directional Fe2B Cr addition Lattice evolution Toughening mechanism

PAI-1和TLR4在烧伤后增生性瘢痕组织中的表达水平及意义

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安徽医药 2025年第1期29卷 79-83,I0005页

作者：孙佳琳郑伟才樊磊河南科技大学第一附属医院烧伤整形外科河南洛阳471000

目的探究纤溶酶原激活物抑制剂-1(PAI-1)和Toll样受体4(TLR4)在烧伤后增生性瘢痕(HS)组织中的表达水平及临床意义。方法选取河南科技大学第一附属医院2020年7月至2022年7月收治的94例HS病人为研究对象,术中取病人HS组织为HS组,并选取HS... 详细信息

目的探究纤溶酶原激活物抑制剂-1(PAI-1)和Toll样受体4(TLR4)在烧伤后增生性瘢痕(HS)组织中的表达水平及临床意义。方法选取河南科技大学第一附属医院2020年7月至2022年7月收治的94例HS病人为研究对象,术中取病人HS组织为HS组,并选取HS病人正常皮肤组织为对照组。实时荧光定量逆转录聚合酶链反应(qRT-PCR)法对组织中PAI-1、TLR4 mRNA表达水平进行测定;免疫组化法对组织中PAI-1、TLR4阳性表达情况进行测定;采用蛋白质印迹法测定PAI-1、TLR4的蛋白表达水平;使用温哥华瘢痕量表(VSS)对瘢痕组织严重情况进行评价,使用跨皮水分丢失(TEWL)对HS病人的表皮屏障功能进行评估;Pearson相关性分析病人HS组织中PAI-1、TLR4表达水平与VSS及TEWL净丧失量之间的关系。结果HS组PAI-1表达水平1.54±0.32、TLR4 mRNA表达水平1.61±0.38高于对照组1.11±0.24、1.06±0.21,HS组PAI-1、TLR4阳性表达率及蛋白表达水平也显著高于对照组(P<0.05);病人HS组织VSS评分为(12.01±3.48)分,HS组织TEWL值显著高于对照组(P<0.05),TEWL净丧失量为(7.87±2.37)g·m^(−2)·h^(−1);Pearson相关性分析结果表明,HS组织中PAI-1、TLR4表达水平分别与VSS及TEWL净丧失量呈显著正相关(P<0.05)。结论烧伤后病人HS组织中PAI-1、TLR4 mRNA表达水平、阳性表达率及蛋白表达水平均显著升高,且PAI-1、TLR4与HS组织严重程度,表皮屏障功能障碍有关,因此PAI-1、TLR4有望成为临床治疗HS的新靶点。

关键词：纤溶酶原激活物抑制物 Toll样受体4 烧伤增生性瘢痕临床意义

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Research on the Fe-silicon nitride material self-producing N_2 at high temperature

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Journal of University of Science and Technology Beijing 2006年第1期13卷 78-81页

作者： Junhong Chen Xueda Wang jialin sun Huasheng Zhan Wen Song Department of Inorganic and Nonmetallic Materials University of Science and Technology Beijing Beijing 100083 China School of Material Science and Technology Anshan University of Science and Technohology Anshan 114002 China

The Fe silicon nitride synthesized by flashing combustion process was studied to determine the reaction temperature between Fe and silicon nitride, the account of N2 given out in the course of the reaction, and the change of the microstructure during calcination. The results showed that at 1127.2℃ the Fe-silicon nitride self-reacts and releases N2 and under 101.3 kPa the volume of N2 given out in the course of the reaction is 20 times more than that of the starting material. N2 is produced quickly, and completes in several decade seconds. With the producing of N2, the structure of Silicon Nitride around Fe becomes loose and porous, or cracks are formed by the reaction between Fe and silicon nitride. So if it is made use of that Fe-silicon nitride self-producing N2 at the high temperature, the performance of the material on a base of Fe-silicon nitride could be greatly improved.

关键词： synthesis by flashing combustion process Fe-Silicon Nitride Nitrogen

Evolution of resistive switching polarity in Au/Ar^+ bombarded SrTi_(0.993)Nb_(0.007)O_3/In sandwiches

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Chinese Science Bulletin 2012年第1期57卷 20-24页

作者： XIE GuanLin WANG YuHang REN TianLing ZHU jialin sun jialin ZHANG LiuWan Laboratory of Advanced Materials State Key Laboratory of Low-Dimensional Quantum PhysicsDepartment of PhysicsTsinghua UniversityBeijing 100084China Institute of Microelectronics Tsinghua UniversityBeijing 100084China

We investigated the resistive switching characteristics of Au/Ar+bombarded SrTi 0.993 Nb0.007O3/In *** evolution of the resistive switching polarity with sweeping voltage was *** experiments showed that under a macroscopic electrode the homogeneous trapping-detrapping-type conduction and filament-type conduction coexist and compete with each *** a large sweeping voltage range,the trapping-detrapping-type conduction ***,for a small range the latter dominates. If the bias voltage is too large,the filament conduction could be *** results will help deepen the understanding of the resistive switching polarity,and will aid in future device design.

关键词：开关特性三明治电阻极性 AR 演变轰炸金

Phase Evolution and Microstructure of C-AI System in Carbon-embedded Atmosphere

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China's Refractories 2014年第3期23卷 15-18页

作者： WEI Juncong sun jialin School of Materials Science and Technology University of Science and Technology Beijing Hebei Province Key Laboratory of Inorganic Nonmetallic Materials Hebei United University

n order to investigate the phase evolution and microstructure of aluminum containing carbon composites,- 195 graphite flake and ≤0. 074 mm aluminum powders（ Al 99%,in mass,the same hereinafter） were used as main starting materials. The mixture with 1 ∶ 1of graphite and aluminum was well mixed with additional 15% phenolic resin and then shaped in a hydraulic machine. The specimens were first dried at 250 ℃ for12 h,and then graphite-embedded fired at 800,1 000,1 200,1 400,and 1 600 ℃ for 3 h,respectively. XRD and SEM were used to characterize the phase compositions and section microstructure. The results show that at800 ℃ aluminum powder melts and reacts with carbon in resin forming granular Al4C3 at the edge of graphite;at 1 000 ℃,Al4C3 increases in amount and grows in volume,and AlN commences to form; at 1 200 ℃,some Al4C3 grows to tabular shape,and other Al4C3 nitridizes forming fibrous AlN; at 1 400 ℃,Al4C3 decreases because it is nitridized or oxidized forming fibrous AlN or Al2O3; at 1 600 ℃,Al4C3 disappears,AlN or Al2O3 gets big and coarse.

关键词： carlton composite aluminum powder aluminum carbide aluminum nitride alumina

Progress in densification and toughening of high entropy carbide ceramics

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Journal of Materials Science & Technology 2023年第30期161卷 10-43页

作者： Zhennan Cao jialin sun Lingtao Meng Keguo Zhang Jun Zhao Zhifu Huang Xialun Yun School of Mechanical Electrical&Information EngineeringShandong University(Weihai)Weihai 264209China State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China Shenzhen Research Institute of Shandong University Shenzhen 518057China Key Laboratory of High Efficiency and Clean Mechanical Manufacture of MOE School of Mechanical EngineeringShandong UniversityJinan 250061China State Key Laboratory for Mechanical Behavior of Materials School of Materials Science and EngineeringXi’an Jiaotong UniversityXi’an 710049China State Key Laboratory for Manufacturing System Engineering School of Mechanical EngineeringXi’an Jiaotong UniversityXi’an 710049China

High entropy carbide ceramics(HECC)are solid solution of inorganic compounds with five or more prin-cipal metal *** interests in HECC are dramatically sparked by the enormous possibilities in composition-microstructure-property *** widely acknowledged,HECCs enjoy higher hardness and oxidation/corrosion/wear resistance,as well as lower thermal conductivity than conventional engi-neering carbide ceramics,making them the most potential candidates for state-of-the-art structural and functional applications in extreme service *** the advantages,however,the poor den-sification coupled with low fracture toughness significantly limited the practical applications of *** to the difficulty,the literature available for toughening HECC is woefully *** considera-tion of this insufficiency,we apply towards offer a comprehensive,critical review of the mechanical be-havior of HECC,highlighting the densification enhancing strategies(carbon content,sintering techniques,grain size,sintering aids,etc.)as well as toughening methods including particle toughening,whisker/fiber toughening,synergistic toughening,graphene-carbon nanotube toughening,to further the service reliabil-ity of HECC in practical industrial ***,despite some significant successes,important directions for further development of HECC are given as multi-dimensional gradient HECC,additive man-ufacturing of HECC,processing-composition-microstructure-property relationship prediction and genomes of HECC based on machine learning,and high-throughput computing,etc.

关键词： High entropy carbide ceramic Densification Toughening Mechanical properties

High-performance multifunctional(Hf^(0.2)Nb_(0.2)Ta_(0.2)Ti_(0.2)Zr_(0.2))C high-entropy ceramic reinforced with low-loading 3D hybrid graphene–carbon nanotube

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Journal of Advanced Ceramics 2023年第2期12卷 341-356页

作者： jialin sun Jun ZHAO Yonghui ZHOU Peng ZHAI Xialun YUN Zhifu HUANG Hui ZHANG Guohua ZHANG School of Mechanical Electrical&Information EngineeringShandong University(Weihai)Weihai 264209China State Key Laboratory for Mechanical Behavior of Materials School of Materials Science and EngineeringXi’an Jiaotong UniversityXi’an 710049China Key Laboratory of High Efficiency and Clean Mechanical Manufacture of Ministry of Education School of Mechanical EngineeringShandong UniversityJinan 250061China State Key Laboratory for Manufacturing System Engineering School of Mechanical EngineeringXi’an Jiaotong UniversityXi’an 710049China State Key Laboratory of High Performance Ceramics and Superfine Microstructure Shanghai Institute of CeramicsChinese Academy of SciencesShanghai 200050China State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China

There has been growing interest in the high-entropy ceramic(HEC)recently owing to its tailorable compositions and microstructures,versatile properties,together with promising structural and functional ***,inferior fracture toughness(KIC)and damage tolerance restricted many practical applications of the ***,we addressed this challenge by incorporating a threedimensional graphene–carbon nanotube(3D G–CNT)as toughening agent in(Hf_(0.2)Nb_(0.2)Ta_(0.2)Ti_(0.2)Zr_(0.2))*** resulting enhanced 3D G–CNT/(Hf_(0.2)Nb_(0.2)Ta_(0.2)Ti_(0.2)Zr_(0.2))C featured an outstanding toughness of 8.23 MPa·m^(1/2),while remaining superior strength(763 MPa)and hardness(24.7 GPa).An ultralow friction coefficient(0.15)coupled with an ultralow wear rate(w,2.6×10^(−7) mm^(3)/(N·m))in the 3D G–CNT/(Hf_(0.2)Nb_(0.2)Ta_(0.2)Ti_(0.2)Zr_(0.2))C was obtained primarily as a function of lubricating scrolls,in which two-dimensional(2D)graphene acted as a tribolayer,and one-dimensional(1D)carbon nanotubes acted as nano ball bearings embedded ***,the 3D G–CNT/(Hf_(0.2)Nb_(0.2)Ta_(0.2)Ti_(0.2)Zr_(0.2))C exhibited rather low thermal conductivity(κ)yet excellent electrical conductivity(σ,1.3×10^(6) S/m)in comparison with the pure(Hf_(0.2)Nb_(0.2)Ta_(0.2)Ti_(0.2)Zr_(0.2))*** study provided great potential for maximizing the physical and functional properties of the HEC for various applications.

关键词： high-entropy ceramic(HEC) three-dimensional graphene-carbon nanotube(3D G-CNT) toughening lubricating thermal conductivity(κ)/electrical conductivity(σ)

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重载铁路道岔区轨道刚度的分布及均匀化

中国铁道科学 2017年第3期38卷 19-24页

作者：孙加林中国铁道科学研究院铁道科学技术研究发展中心北京100081

针对重载铁路道岔区因轨道刚度分布不均匀而造成的轮轨动力冲击作用过大的问题,运用MIDAS软件建立75kg·m^(-1)钢轨12号固定辙叉道岔全长范围内的三维全尺寸有限元模型,研究道岔区全长范围内轨道整体刚度的分布。结果表明:道岔区里轨刚... 详细信息

针对重载铁路道岔区因轨道刚度分布不均匀而造成的轮轨动力冲击作用过大的问题,运用MIDAS软件建立75kg·m^(-1)钢轨12号固定辙叉道岔全长范围内的三维全尺寸有限元模型,研究道岔区全长范围内轨道整体刚度的分布。结果表明:道岔区里轨刚度的最大值为285kN·mm^(-1),较区间线路轨道刚度最大相差165kN·mm^(-1);道岔区基本轨刚度最大值为178kN·mm^(-1),较区间线路轨道刚度最大相差57kN·mm^(-1)。为实现岔区轨道刚度的均匀化,提出调整铁垫板下长大胶垫刚度的技术解决方案。现场试验表明,该方案可以使道岔区的里轨刚度最大降低约17%,基本轨刚度最大降低约16%,实现岔区的轨道刚度基本与区间线路的轨道刚度在同一水平上,基本消除了道岔区的轨道固有刚度不平顺,有效减少了轮轨动力作用。

关键词：重载铁路道岔轨道刚度分布均匀化