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Mechanical behavior and response mechanism of porous metal structures manufactured by laser powder bed fusion under compressive loading

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International Journal of Minerals,Metallurgy and Materials 2024年第4期31卷 737-749页

作者： Xuanming Cai yang Hou Wei Zhang Zhiqiang Fan Yubo Gao Junyuan Wang Heyang Sun Zhujun Zhang wenshu yang School of Aerospace Engineering North University of ChinaTaiyuan 030051China School of Materials Science and Engineering North University of ChinaTaiyuan 030051China School of Astronautics Harbin Institute of TechnologyHarbin 150080China School of Mechanical Engineering North University of ChinaTaiyuan 030051China Shijiazhuang Campus Army Engineering University of PLAShijiazhuang 050003China 65589 Unit 91 Detachment Daqing 163411China School of Materials Science and Engineering Harbin Institute of TechnologyHarbin 150080China

Al Si10Mg porous protective structure often produces different damage forms under compressive loading,and these damage modes affect its protective function.In order to well meet the service requirements,there is an urgent need to comprehensively understand the mechanical behavior and response mechanism of AlSi10Mg porous structures under compressive loading.In this paper,Al Si10Mg porous structures with three kinds of volume fractions are designed and optimized to meet the requirements of high-impact,strong-energy absorption,and lightweight characteristics.The mechanical behaviors of AlSi10Mg porous structures,including the stress-strain relationship,structural bearing state,deformation and damage modes,and energy absorption characteristics,were obtained through experimental studies at different loading rates.The damage pattern of the damage section indicates that AlSi10Mg porous structures have both ductile and brittle mechanical properties.Numerical simulation studies show that the AlSi10Mg porous structure undergoes shear damage due to relative misalignment along the diagonal cross-section,and the damage location is almost at 45°to the load direction,which is the most direct cause of its structural damage,revealing the damage mechanism of AlSi10Mg porous structures under the compressive load.The normalized energy absorption model constructed in the paper well interprets the energy absorption state of Al Si10Mg porous structures and gives the sensitive location of the structures,and the results of this paper provide important references for peers in structural design and optimization.

关键词： AlSi10Mg additive manufacture energy absorption characteristics damage by deformation mechanical behavior

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Liposomalα-cyperone targeting bone resorption surfaces suppresses osteoclast differentiation and osteoporosis progression via the PI3K/Akt axis

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Nano Research 2024年第4期17卷 2949-2959页

作者： Lin yang Xueying An Wang Gong wenshu Wu Bin Liu Xiaoyan Shao Yansi Xian Rui Peng Baosheng Guo Qing Jiang Division of Sports Medicine and Adult Reconstructive Surgery Department of Orthopedic SurgeryNanjing Drum Tower Hospital Clinical College of Nanjing Medical University321 Zhongshan RoadNanjing 210008China Branch of National Clinical Research Center for Orthopedics Sports Medicine and RehabilitationNanjing 210008China State Key Laboratory of Pharmaceutical Biotechnology Medical SchoolNanjing University&Division of Sports Medicine and Adult Reconstructive SurgeryDepartment of Orthopedic SurgeryNanjing Drum Tower HospitalThe Affiliated Hospital of Nanjing University Medical SchoolNanjing 210008China

Osteoporosis is a metabolic dysregulation of bone that occurs mainly in postmenopausal women,and the hyperfunction of osteoclasts is the primary contributor to postmenopausal osteoporosis.However,the development of effective therapeutic drugs and precise delivery systems remains a challenge in the field of anti-absorption therapy.Here,we reported theα-cyperone(α-CYP)for anti-osteoporosis and developed a liposome-based nano-drug delivery system ofα-CYP,that specifically targets the bone resorption interface.Firstly,we found that theα-CYP,one of the major sesquiterpenes of Cyperus rotundus L.,attenuated the progression of osteoporosis in ovariectomized(OVX)mice and down-regulated the expression of phosphorylated proteins of phosphoinositide 3-kinase(PI3K)and protein kinase B(Akt),causing down-regulation of osteoclast-related genes/proteins and curbing osteoclast differentiation.Furthermore,α-CYP reversed the activation of osteoclastic differentiation and enhanced osteoporosis-related proteins expression caused by PI3K/Akt agonist(YS-49).More importantly,we adopted the osteoclastic resorption surface targeting peptide Asp8 and constructed the liposome(lipαC@Asp8)to deliverα-CYP to osteoclasts and confirmed its anti-osteoporosis effect and enhanced osteoclast inhibition by blocking PI3K/Akt axis.In conclusion,this study demonstrated thatα-CYP inhibits osteoclast differentiation and osteoporosis development by silencing PI3K/Akt pathway,and the liposome targeting delivery systems loaded withα-CYP might provide a novel and effective strategy to treat osteoporosis.

关键词： osteoporosis α-cyperone osteoclast phosphoinositide 3-kinase/protein kinase B(PI3K/Akt) liposome

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Hot deformation behavior and microstructure evolution of Be/2024Al composites

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International Journal of Minerals,Metallurgy and Materials 2023年第11期30卷 2245-2258页

作者： Yixiao Xia Zeyang Kuang Ping Zhu Boyu Ju Guoqin Chen Ping Wu wenshu yang Gaohui Wu School of Materials Science and Engineering Harbin Institute of TechnologyHarbin 150001China Key Laboratory of Advanced Structure-Function Integrated Materials and Green Manufacturing Technology School of Materials Science and EngineeringHarbin Institute of TechnologyHarbin 150001China Key Laboratory of Advanced Science and Technology on High Power Microwave Xi'an 710024China Northwest Institute of Nuclear Technology Xi'an 710024China

The high temperature compression test of Be/2024Al composites with 62wt%Be was conducted at 500–575℃ and strain rate of0.003–0.1 s^(-1).The strain-compensated Arrhenius model and modified Johnson–Cook model were introduced to predict the hot deformation behavior of Be/2024Al composites.The result shows that the activation energy of Be/2024Al composites was 363.364 k J·mol^(-1).Compared with composites reinforced with traditional ceramics,Be/2024Al composites can be deformed with ultra-high content of reinforcement,attributing to the deformable property of Be particles.The average relative error of the two models shows that modified Johnson–Cook model was more suitable for low temperature condition while strain-compensated Arrhenius model was more suitable for high temperature condition.The processing map was generated and a hot extrusion experiment was conducted according to the map.A comparation of the microstructure of Be/2024Al composites before and after extrusion shows that the Be particle deformed coordinately with the matrix and elongated at the extrusion direction.

关键词： Be/Al composites hot deformation behavior constitutive model hot extrusion

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Photocatalytic oxidative of Keggin-type polyoxometalate ionic liquid for enhanced extractive desulfurization in binary deep eutectic solvents

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Chinese Journal of Chemical Engineering 2022年第4期35卷 205-211页

作者： Linlan Wu Zhengxin Jiao Suhang Xun Minqiang He Lei Fan Chao Wang wenshu yang wenshuai Zhu Huaming Li School of Chemistry and Chemical Engineering Institute for Energy ResearchJiangsu UniversityZhenjiang 212013China School of Environment and Safety Engineering Institute of Environmental Health and Ecological SecurityJiangsu UniversityZhenjiang 212013China School of Chemistry and Chemical Engineering Yangzhou UniversityYangzhou 225002China

A series of novel binary deep eutectic solvents(DESs)composed of choline chloride(ChCl)and formic acid(HCOOH)with different molar ratios have been successfully synthesized and applied in extractive desulfurization(EDS).Keggin-type polyoxometallate ionic liquid[TTPh]_(3)PW_(12)O_(40) was prepared and used as catalyst to enhance the EDS capacity by means of photocatalytic oxidative process.Both of the DESs and[TTPh]_(3)PW_(12)O_(40) ionic liquid catalyst were characterized in detail by Fourier transform infrared spectroscopy spectra(FT-IR),elemental analysis,and X-ray photoelectron spectroscopy(XPS).It was found that the molar ratios of Ch Cl:HCOOH had a major impact on desulfurization performance,and the optimal desulfurization capacity 96.5%was obtained by ChCl/5 HCOOH.Besides dibenzothiophene(DBT),the desulfurization efficiencies of 4-methylbenzothiophene(4-MDBT)and 4,6-dimethyldibenzothiophene(4,6-DMDBT),two kinds of DBT derivatives,were also investigated under the same experimental conditions.Moreover,the free radical scavenging experiments manifested that superoxide radical(·O_(2)^(-)) and hole(h^(+)) played important roles in the desulfurization system.After further analysis of the oxidation products by gas chromatography-mass spectrometry(GC–MS),the possible reaction mechanism was proposed.Thus,photocatalytic oxidative has been proved to be one of the efficient approaches for enhancing the extractive desulfurization performance in DES.

关键词： Deep eutectic solvents Extractive desulfurization Ionic liquid Photocatalytic oxidative Aerobic Fuel

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包容性终身学习内涵、意义与实践策略——基于《巴厘宣言:拥抱包容——全民终身学习路线图》解析

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比较教育研究 2024年第5期46卷 95-104页

作者：李文淑山东建筑大学法学院山东济南250101

面对气候、人口变化及数字化转型的挑战,包容性终身学习的价值进一步彰显。为此,2023年7月3日至6日,联合国教科文组织终身学习研究所协同印度尼西亚政府在巴厘岛召开“如何实现终身学习包容性”的主题会议,发布《巴厘宣言:拥抱包容——... 详细信息

面对气候、人口变化及数字化转型的挑战,包容性终身学习的价值进一步彰显。为此,2023年7月3日至6日,联合国教科文组织终身学习研究所协同印度尼西亚政府在巴厘岛召开“如何实现终身学习包容性”的主题会议,发布《巴厘宣言:拥抱包容——全民终身学习路线图》,旨在将教育转型峰会和《马拉喀什行动框架》概述的包容性终身学习愿景转化为切实可行的实践方略。该宣言呼吁从包容性学习环境、包容性社会结构、包容性终身教育政策和包容性学习方式四个维度构建包容性终身学习生态系统,完善融通且贯穿终身的包容性技能培育机制,建立协调一致且负责任的治理机制,健全监测、问责及公共投资。

关键词：包容性终身学习巴厘宣言技能培育数字技术

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Microstructure and Mechanical Properties of 45 vol.%SiC_p/7075Al Composite

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Journal of Materials Science & Technology 2015年第9期31卷 930-934页

作者： Ziyang Xiu wenshu yang Ronghua Dong Murid Hussain Longtao Jiang YongXing Liu Gaohui Wu State Key Laboratory of Advanced Welding and Joining Harbin Institute of Technology Department of Material Science and Engineering Harbin Institute of Technology Department of Chemical Engineering COMSATS Institute of Information Technology

Microstructure and mechanical behavior of high volume content SiCp/7xxxAl composites have not been explored yet. Therefore, in the present work, 45 vol.% SiCp/7075Al composite has been prepared by pres- sure infiltration method. High density dislocations were found around SiC/Al interface in SiCp/7075Al composite after water-quenching and aging treatment. Fine dispersed nano-η＇ phases were observed after the aging treatment. Adverse to other SiCp/Al composites prepared by the pressure infiltration method, an interface layer was observed between SiC particles and AI matrix. Furthermore, high-resolution trans- mission electron microscopy （HRTEM） observation indicated that this interface layer was coherent/semi- coherent with that of the SiC particles. 45 vol.% SiCp/7075Al composite demonstrated high tensile strength （630 MPa） and micro-ductility. Compared to aged SiCp/2024Al composite, the aged SiCp/7075Al com- posite showed an increase of about 200% in the tensile strain and 90% in the tensile strength, respectively. It is speculated that nano-η＇ phases in the Al matrix significantly contributed to the strengthening effect while the interface layer between SiC and AI matrix might be beneficial to the strength and plasticity of SiCp/7075Al composite.

关键词： Metal matrix composite7075Al InterfaceNano precipitationMechanical properties

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增值评价中的天花板和地板效应分析

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中国考试 2024年第3期 87-97页

作者：骆文淑陈方丁佛山科学技术学院广东佛山528225 广东省教育考试院广州510635

天花板和地板效应是增值评价中经常会涉及的问题。其不仅与测验本身的天花板和地板效应相联系,还与增值评价模型的选择有关。残差增分模型和学生成长百分等级模型是增值评价中常用的条件状态模型,其所估计的个体成长是与同等水平学术伙... 详细信息

天花板和地板效应是增值评价中经常会涉及的问题。其不仅与测验本身的天花板和地板效应相联系,还与增值评价模型的选择有关。残差增分模型和学生成长百分等级模型是增值评价中常用的条件状态模型,其所估计的个体成长是与同等水平学术伙伴比较的相对成长,在一定程度上可以破解天花板和地板效应问题。基于两组考生的中、高考数据进行分析比较,残差增分模型和学生成长百分等级模型在解决天花板和地板效应问题上的有效性得到了验证。研究结果为研究者和教育评价工作者选择增值模型提供了参考。

关键词：增值评价增值模型天花板效应地板效应

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Scalable and facile synthesis of V_(2)O_(5) nanoparticles via ball milling for improved aerobic oxidative desulfurization

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Green Energy & Environment 2021年第2期6卷 169-175页

作者： Yiru Zou Chao Wang Hanxiang Chen Haiyan Ji Qian Zhu wenshu yang Linlin Chen Zhigang Chen wenshuai Zhu School of Materials Science and Engineering Jiangsu UniveriyZhenjiang212013China Institute of Enmironmental Health and Ecological Security School of the Envirorment and Safery EngineeringJiangsu UniversityZhenjiang212013China Schood of Chemistry and Chemical Engineering Jiangsu UniversityZhenjiang 212013China Jiangsu University Jingjiang College Zhenjiang212114China

In recent years, transition-metal oxides(TMOs) have been long employed for aerobic oxidative desulfurization. However, the inherent bottlenecks, such as the low explosion of active sites, limit the application of bulk TMOs catalyst. In this study, V_(2)O_(5) nanoparticles with oxygen vacancies were prepared in large-scale via facile ball milling strategy with adding oxalic acid as a reducing agent. The as-prepared catalysts exhibit remarkable sulfur removal for oils with different initial S-concentrations and different substrates. Sulfur removal could reach up to 99.7%(< 2 ppm) under the optimized reaction conditions. This work provides a feasible desulfurization strategy for fuel oils.

关键词： Ball milling V_(2)O_5 nanoparticles Oxygen vacancies Aerobic oxidative desulfurization

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仿刺参(Apostichopus japonicus)肠道源植物乳杆菌(Lactobacillus plantarum)HY21的生长及益生特性分析

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微生物学报 2024年第3期64卷 840-853页

作者：李忠琴王泽楠黄文树杨求华邹文政集美大学水产学院福建厦门361021 福建省水产研究所福建厦门361021 鳗鲡现代产业技术教育部工程研究中心福建厦门361021 华中农业大学动物科学技术学院·动物医学院湖北武汉430070

【目的】在仿刺参(Apostichopus japonicus)健康养殖中为了寻找具有良好耐受性、益生性、安全性的益生菌,本研究从仿刺参肠道内容物中分离获得一株植物乳杆菌(Lactobacillus plantarum)HY21,对其益生潜能进行评价。【方法】利用摇瓶发... 详细信息

【目的】在仿刺参(Apostichopus japonicus)健康养殖中为了寻找具有良好耐受性、益生性、安全性的益生菌,本研究从仿刺参肠道内容物中分离获得一株植物乳杆菌(Lactobacillus plantarum)HY21,对其益生潜能进行评价。【方法】利用摇瓶发酵培养、应用环境因子模拟试验、抗生素药敏测试等方法,分析L.plantarum HY21的生长特性、产酸性能、发酵液的抗氧化性质和对水产致病菌的抑制作用;检测菌体的疏水性、自聚性和共聚性、黏附力和药物敏感性,以及对应用环境因子的耐受性。【结果】L.plantarum HY21摇瓶发酵培养温度30°C、初始pH 8.0,于2–10 h为对数生长期,发酵18 h后pH达到最低3.6;发酵液对溶藻弧菌的抑菌直径达到(13.96±0.30)mm,对1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2-trinitrophenylhydrazine,DPPH)自由基清除率达到95.45%±1.56%;L.plantarum HY21的疏水率为60.42%±2.78%、自聚率为22.69%±1.36%,与溶藻弧菌共聚率为27.98%±1.45%;对体表和肠道黏液蛋白的黏附量分别达到(1.66±0.01)×10^(6)CFU/mL和(1.23±0.15)×10^(6)CFU/mL;对13种常见的抗菌药物均表现敏感;菌体在模拟胃肠液(pH 3.0,pH6.8)中孵育3 h存活率均可达99%以上,在10%鱼胆汁溶液中孵育3 h存活率达到68.11%±7.98%,在3%海盐溶液中孵育16h存活率达到97.58%±7.14%。【结论】L.plantarum HY21具有良好的定殖作用、抑菌作用、抗氧化作用等益生特性,而且在应用环境中具有高存活率和高安全性,可以作为一株新的水产益生菌,为开发水产益生菌制剂提供科学理论依据。

关键词：植物乳杆菌耐受性黏附性抑菌作用抗氧化作用

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企业数字化转型、人力资本与内部薪酬差距

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北京工商大学学报（社会科学版） 2024年第2期39卷 31-44页

作者：高文书万诗婕中国社会科学院大学应用经济学院北京102488

企业是推动数字技术发挥经济效应的重要微观主体,也是平衡资本和劳动分配关系的关键所在。基于2009—2019年中国A股上市公司的数据,运用Python爬虫技术评估了上市公司的数字化转型程度,实证研究了数字化转型对企业内部薪酬差距的影响及... 详细信息

企业是推动数字技术发挥经济效应的重要微观主体,也是平衡资本和劳动分配关系的关键所在。基于2009—2019年中国A股上市公司的数据,运用Python爬虫技术评估了上市公司的数字化转型程度,实证研究了数字化转型对企业内部薪酬差距的影响及其作用机制。实证分析发现,数字化转型对企业高管与员工之间的收入差距具有显著的扩大效应。机制分析结果表明,数字化转型会通过提升员工人力资本水平缩小企业内部收入差距,也会通过提升管理层人力资本水平扩大企业内部薪酬差距。异质性分析发现,数字化转型对低议价能力企业与非技术密集型企业内部薪酬差距的影响更大。进一步分析表明,企业数字化转型产生超额薪酬差距的原因在于员工薪酬涨幅小于管理层。因此,数字经济时代,为实现企业数字化转型与收入分配的相对公平,政府应推动劳动力知识技能升级,优化劳动力结构,充分发挥人力资本在推动企业内部收入分配公平方面的作用,进而缩小企业内部收入差距。

关键词：数字化转型数字技术内部薪酬差距收入分配人力资本

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