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Microstructure and properties of a wear resistant Al-25Si-4Cu-1Mg coating prepared by supersonic plasma spraying

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International Journal of Minerals,Metallurgy and Materials 2020年第9期27卷 1287-1294页

作者： Tian-shun Dong Ming Liu Yang Feng Guo-lu Li xiao-bing Li School of Materials Science and Engineering Hebei University of TechnologyTianjin 300130China Key Laboratory for New Type of Function Material in Hebei Province Hebei University of TechnologyTianjin 300130China National Key Laboratory for Remanufacturing Academy of Armored Forces EngineeringBeijing 100072China

A high content silicon aluminum alloy(Al-25Si-4Cu-1Mg)coating was prepared on a 2A12 aluminum alloy by supersonic plasma *** morphology and microstructure of the coating were observed and *** hardness,elastic modulus,and bonding strength of the coating were *** wear resistance of the coating and 2A12 aluminum alloy was studied by friction and wear *** results indicated that the coating was compact and the porosity was only 1.5%.The phase of the coating was mainly composed ofα-Al andβ-Si as well as some hard particles(Al9Si,Al3.21Si0.47,and CuAl2).The average microhardness of the coating was HV 242,which was greater than that of 2A12 aluminum alloy(HV 110).The wear resistance of the coating was superior to 2A12 aluminum *** wear mechanism of the 2A12 aluminum alloy was primarily adhesive wear,while that of the coating was primarily abrasive ***,it is possible to prepare a high content silicon aluminum alloy coating with good wear resistance on an aluminum alloy by supersonic plasma spraying.

关键词： coating high silicon aluminum alloy microstructure mechanical properties wear resistance

Effect of oxide inclusions on MnS precipitates and tensile mechanical property of high-strength low-alloy steel

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Journal of Iron and Steel Research International 2024年第5期31卷 1210-1220页

作者： xiao-yong Gao Hong Wei Li-feng Zhang School of Mechanical Engineering Yanshan UniversityQinhuangdao066004HebeiChina School of Materials Science and Engineering Yanshan UniversityQinhuangdao066004HebeiChina School of Mechanical and Materials Engineering North China University of TechnologyBeijing100144China

The key role of oxide inclusions on the microstructure and mechanical property of a high-strength low-alloy steel was *** field emission scanning electron microscope equipped with energy-dispersive spectrometry was used to characterize MnS *** inclusions play an important role in the shape control of MnS *** oxides fovored to decrease the size and the aspect ratio of MnS *** less oxide inclusions in the steel,approximately over 16.7%MnS precipitates were with aspect ratio a>5 and pure MnS precipitates accounted for 75.9%in ***,with more oxide inclusions in the steel,only 7.4%MnS precipitates were with a>5 and pure MnS precipitates accounted for 60.1%in *** of MnS by oxide inclusions improved the strength and inhibited the *** oxide inclusions in the steel increased the yield strength and tensile strength of the steel in both longitudinal and transverse directions,and lowered the anisotropy of the mechanical property.

关键词： High-strength low-alloy steel MnS Oxide inclusion Mechanical property Anisotropy

miR-26a regulates mouse hepatocyte proliferation via directly targeting the 3' untranslated region of CCND2 and CCNE2

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Hepatobiliary & Pancreatic Diseases International 2016年第1期15卷 65-72页

作者： Jian Zhou Wei-Qiang Ju xiao-Peng Yuan xiao-Feng Zhu Dong-Ping Wang xiao-shun He Organ Transplant Center the First Affiliated HospitalSun Yat-Sen University

BACKGROUND： The deficiency of liver regeneration needs to be addressed in the fields of liver surgery, split liver transplan- tation and living donor liver transplantation. Researches of microRNAs would broaden our understandings on the mecha- nisms of various diseases. Our previous research confirmed that miR-26a regulated liver regeneration in mice; however, the relationship between miR-26a and its target, directly or in- directly, remains unclear. Therefore, the present study further investigated the mechanism of miR-26a in regulating mouse hepatocyte proliferation. METHODS： An established mouse liver cell line, Nctc-1469, was transfected with Ad5-miR-26a-EGFP, Ad5-anti-miR-26a- EGFP or AdS-EGFP vector. Cell proliferation was assessed by MTS, cell apoptosis and cell cycle by flow cytometry, and gene expression by Western blotting and quantitative real-time PCR. Dual-luciferase reporter assays were used to test targets of miR-26a. RESULTS： Compared with the Ad5-EGFP group, Ad5-anti- miR-26a-EGFP down-regulated miR-26a and increased prolif- eration of hepatocytes, with more cells entering the G1 phase of cell cycle （82.70%＋1.45% vs 75.80%＋_3.92%）, and decreased apoptosis （5.50%＋0.35% vs 6.73%_＋0.42%）. CCND2 and CCNE2 were the direct targeted genes of miR-26a, miR-26a down- regulation up-regulated CCND2 and CCNE2 expressions and down-regulated p53 expression in Nctc-1469 cells. On the con- trary, miR-26a over-expression showed the opposite results. CONCLUSIONS： miR-26a regulated mouse hepatocyte pro- liferation by directly targeting the 3＇ untranslated regions of cyclin D2/cyclin E2; miR-26a also regulated p53-mediated apoptosis. Our data suggested that miR-26a may be a promis- ing regulator in liver regeneration.

关键词： microRNA miR-26a gene expression hepatocyte proliferation regulation

Effects of Alloy Element and Microstructure on Corrosion Resistant Property of Deposited Metals of Weathering Steel

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Journal of Iron and Steel Research International 2016年第2期23卷 171-177页

作者： xiao-ming xiao Yun PENG Cheng-yong MA Zhi-ling TIAN State Key Laboratory of Advanced Steel Processes and Products Central Iron & Steel Research Institute

Alloy element and microstructure are key factors that dominate mechanical and corrosion resistant properties of weathering steel. The effect of Mo on microstructure, mechanical properties and corrosion resistant property of depos ited metal was investigated. Experimental results show that with the increase of Mo content in deposited metals, the phase transformation temperature decreases, and the ferrite zone in CCT diagram moves rightward, resulting in en larged bainite zone and reduced ferrite and pearlite zone. The addition of 0.24 mass% Mo in deposited metal results in the increase of tensile strength, more M-A constituent and less high angle grain which reduce the low temperature toughness. It is found that Mo can raise the weathering resistance of deposited metal in industrial atmosphere. Analy sis indicates that Mo may enrich in the inner rust layer, produce MoO3, enhance the formation of compact rust film and impede the anode dissolution reaction. Granular bainite in deposited metals displays better corrosion resistance than acicular ferrite during the initial corrosion stage, but its long-term influence on the corrosion resistance is limited.

关键词： weathering steel deposited metal Mo microstructure mechanical property corrosion resistance

Induced circularly polarized luminescence of perovskite nanocrystals by self-assembly chiral gel

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Nano Research 2023年第1期16卷 1459-1464页

作者： Rui Cao Xuekang Yang yong Wang Yin xiao School of Science Tianjin UniversityTianjin 300350China School of Chemical Engineering and Technology Tianjin UniversityTianjin 300350China National Center for Nanoscience and Technology Beijing 100190China

Perovskites nanocrystals(NCs)with circularly polarized light(CPL)activity have drawn much attention due to the fascinating photoelectric properties of perovskite NCs as well as the abundant applications of CPL in three-dimensional(3D)displays,nonlinear optics,spintronics devices,CPL lasers,and so ***,bio-inspired by life,we designed and synthesized a simple amphiphilic molecule which could self-assemble into chiral gel with helix chirality in non-polar *** co-assembly of the CsPbX3 NCs with the chiral gel,CPL at the first excitation band of CsPbX3 NCs is induced in the whole visible spectrum with a maximum glum of 8.2×10−*** induced CPL arises from the selective CPL-absorption of the CsPbX3 NCs’luminesce by the chiral gel,which provides a facile and practical approach to induce CPL in perovskite NCs and other nanocrystals.

关键词： circularly polarized light(CPL) chiral gel CsPbX3 perovskite nanocrystal selective CPL-absorption

Research and development on hypervelocity impact protection using Whipple shield:An overview

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Defence Technology（防务技术） 2021年第6期17卷 1864-1886页

作者： Ken Wen xiao-wei Chen yong-gang Lu State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing100081China Institute of Systems Engineering China Academy of Engineering PhysicsMianyangSichuan621999China

Whipple shield,a dual-wall system,as well as its improved structures,is widely applied to defend the hypervelocity impact of space debris(projectile).This paper reviews the studies about the mechanism and process of protection against hypervelocity impacts using Whipple ***-based experiment and numerical simulation for hypervelocity impact and protection are introduced *** steps of the Whipple shield protection are discussed in order,including the interaction between the projectile and bumper,the movement and diffusion of the debris cloud,and the interaction between the debris cloud and rear *** improvements of the protection performance focusing on these three steps are *** works in the last decade are mentioned *** prospects and suggestions for future studies are put forward.

关键词： Space debris Hypervelocity impact Debris cloud Whipple shield Ballistic limit

Multi-robot hunting strategy based on FIS and artificial immune algorithm

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High Technology Letters 2019年第1期25卷 57-64页

作者： Duan yong Huang xiao Shenyang University of Technology

data is gathered to describe the relative location and relative motion state of the robots, which in turn forms the beginning stage of the fuzzy rule. The artificial immune algorithm optimizes and generates the rule data base and adaptive design considers factors in measuring the hunting efficiency. The optimized rules are applied to the hunting task and the results show that the algorithm can effectively actualize hunting of multiple mobile robots.

关键词： multi-robot hunting fuzzy inference system(FIS) artificial immunity fuzzy rule database

Scaffold-hopping strategy toward calanolides with nitrogen-containing heterocycles

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Chinese Chemical Letters 2013年第4期24卷 295-298页

作者： xiao-yong Guo Gang Liu Beijing Key Laboratory of Active Substance Discovery and Druggability Evaluation Institute of Materia MedicoChinese Academy of Medical Sciences and Peking Union Medical College Beijing Key Laboratory of Active Substance Discovery and Druggability Evaluation Institute of Materia MedicaChinese Academy of Medical Sciences and Peking Union Medical College Tsinghua-Peking Center for Life Sciences and Department of Pharmacology and Pharmaceutical Sciences School of MedicineTsinghua University

（~）-Calanolide A was the first natural product identified as an active agent against HIV-1 and Mycobacterium tuberculosis （Mtb）. In devising a scaffold-hopping strategy of structure modification of （＋）-calanolide A, we focused on the synthesis of calanolides by replacing ring D with various five or six membered nitrogen-containing heterocycles, hoping to get further understanding of the structure- activity relationship.

关键词： CalanolidesScaffold hoppingNitrogen-containing heterocycles

Acetylcholine receptor pathway in lung cancer: New twists to an old story

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World Journal of Clinical Oncology 2014年第4期5卷 667-676页

作者： xiao-Min Niu shun Lu Department of Shanghai Lung Cancer Center Shanghai Chest Hospital Shanghai Jiao Tong University

Genome-wide association studies revealed that allelic variation in the α5-α3-β4 nicotine acetylcholine receptor(n ACh R) cluster on chromosome 15q24-15q25.1 was associated with lung cancer risk. n ACh Rs are membrane ligand-gated cation channels whose activation is triggered by the binding of the endogenous neurotransmitter acetylcholine(ACh) or other biologic compounds including nicotine. n ACh Rs have been found on lung cancer cells, underscoring the idea that the non-neuronal n ACh R pathway has important implications for lung cancer. Several studies focusing on the treatment with n ACh R antagonists with improved selectivity might trigger novel strategies for the intervention and prevention of lung cancer. Here we review the genetic risk factors for lung cancer in the n ACh R gene cluster, the roles of nicotine receptors, and the molecular mechanisms of acetylcholine receptor pathways to lead to more opportunities for intervention and prevention of lung cancer.

关键词： Acetylcholine receptor Pathway CHRNA Nicotine Pulmonary carcinoma