检索结果-南通市图书馆

A Nitride-Reinforced NbMoTaWHfN Refractory High-Entropy Alloy with Potential Ultra-High-Temperature Engineering Applications

在线全文

学校读者我要写书评

暂无评论

Engineering 2023年第11期30卷 110-120页

作者： Yixing Wan Yanhai Cheng Yongxiong Chen Zhibin Zhang Yanan Liu haijun gong Baolong Shen Xiubing Liang School of Mechanical and Electrical Engineering China University of Mining and TechnologyXuzhou 221116China Defense Innovation Institute Academy of Military ScienceBeijing 100071China School of Materials Science and Engineering Southeast UniversityNanjing 211189China

Refractory high-entropy alloys(RHEAs)have promising applications as the new generation of hightemperature alloys in hypersonic vehicles,aero-engines,gas turbines,and nuclear power *** study focuses on the microstructures and mechanical properties of the NbMoTaW(HfN)_(x)(x=0,0.3,0.7,and 1.0)*** alloys consist of multiple phases of body-centered cubic(BCC),hafnium nitride(HfN),or multicomponent nitride(MN)*** the x contents increase,the grain size becomes smaller,and the strength gradually *** compressive yield strengths of the NbMoTaWHfN RHEA at ambient temperature,1000,1400,and 1800℃ were found to be 1682,1192,792,and 288 MPa,*** high-temperature strength of this alloy is an inspiring result that exceeds the high temperature and strength of most known alloys,including high-entropy alloys,refractory metals,and *** HfN phase has a significant effect on strengthening due to its high structural stability and sluggish grain coarsening,even at ultra-high *** superior properties endow the NbMoTaWHfN RHEA with potential for a wide range of engineering applications at ultra-high *** work offers a strategy for the design of high-temperature alloys and proposes an ultra-high-temperature alloy with potential for future engineering applications.

关键词： Refractory high-entropy alloy High temperature Mechanical property Microstructure Strengthening mechanism

Microstructure and properties of ZL205 Alloy

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

China Foundry 2008年第1期5卷 24-27页

作者： Mi Guofa Wang Kuangfei gong haijun Wang Hongwei Zeng Songyan School of Materials Science and Engineering Henan Polytechnic University Jiaozuo 454000 China School of Materials Science and Engineering Harbin Institute of Technology Harbin 150001 China

The microstructure, precipitate type, precipitate distribution and tensile strength of a ZL205 alloy, beforeand after ageing treatment, have been studied by means of optical microscopy and transmission electron *** results showed that the as-cast microstructure of the alloy was made up of α-Al and eutectic phase distributedat the grain boundaries. During ageing treatment, the tensile strength increased at first and then reduced with time,and the highest ultimate tensile strength was found to be around 488.2 MPa.

关键词： Al-Cu alloy grain refinement mechanical property microstructure

在线全文

学校读者我要写书评

暂无评论

铸钢机车车钩精密铸造工艺及其凝固组织研究

特种铸造及有色合金 2024年第9期44卷 1291-1296页

作者：龚海军郭志启李福军钟发勇高正源孙鹏飞重庆交通大学机电与车辆工程学院重庆400074 天长市兴宇交通装备科技有限公司滁州239300

为获得致密组织和良好性能、防止产生裂纹,设计了精密铸造车钩的正交试验,确定了最优参数,即浇注温度为1570℃、型壳预热温度为425℃、浇注时间为29 s。通过铸造仿真分析了最优参数下铸件温度场、应力场对于缩孔缩松及裂纹形成的影响,... 详细信息

为获得致密组织和良好性能、防止产生裂纹,设计了精密铸造车钩的正交试验,确定了最优参数,即浇注温度为1570℃、型壳预热温度为425℃、浇注时间为29 s。通过铸造仿真分析了最优参数下铸件温度场、应力场对于缩孔缩松及裂纹形成的影响,同时通过KGT模型对铸件关键部位进行组织模拟。最后对试制车钩进行X射线探伤,未发现内部存在裂纹及孔隙,各部位金相组织与组织仿真结果基本一致,车钩经热处理后其平均抗拉强度可达1020 MPa。结果表明,正交优化后获得了合理的车钩铸造工艺参数,晶粒较细,性能高于标准要求。

关键词：机车车钩精密铸造应力组织模拟力学性能

维普期刊数据库博看期刊

Numerical simulation of flow and heat transfer of continous cast steel slab under traveling magnetic field

在线全文

学校读者我要写书评

暂无评论

China Foundry 2013年第2期10卷 92-98页

作者： gong haijun Li Xinzhong Fan Xueyi Qie Juhong Xu Daming Guo Jingjie School of Materials Science and Engineering Harbin Institute of Technology

A unified numerical model for simulating solidification transport phenomena (STP) of steel slab in electromagnetic continuous casting (EMCC) process was developed. In order to solve the multi-physics fields coupled problem conveniently, the complicated bidirectional coupled process between EM and STP was simplified as a unidirectional one, and a FEM/FVM-combined numerical simulation technique was adopted. The traveling magnetic fields (TMFs) applied to the EMCC process were calculated using the ANSYS11.0 software, and then the EM-data output by ANSYS were converted to FVM-format using a data-format conversion program developed previously. Thereafter, the governing equations were solved using a pressure-based Direct-SIMPLE algorithm. The simulation results of the STP in CC-process show that, due to the influences of Lorentz force and Joule heat, the two strong circulating flows and the temperature field can be obviously damped and changed once TMF with one pair of poles (1-POPs) or 2-POPs is applied, which would accordingly improve the quality of casting. It was found in the present research that the integrated actions of 2-POPs TMF are superior to 1-POPs. All the computations indicate that the present numerical model of EM-STP as well as the FEM/FVM-combined technique is successful.

关键词： continuous casting flow field electromagnetic field ANSYS Direct-SIMPLE algorithm FEM/FVM

Effects of the fertilizer and water management on amino acids and volatile components in Cabernet Sauvignon grapes and wines

在线全文

学校读者我要写书评

暂无评论

International Journal of Agricultural and Biological Engineering 2024年第1期17卷 69-79页

作者： Kui Zhang Wenhuai Kang Weihua Han haijun Ma Daozhi gong Ling Qin College of Food Science and Biology Hebei University of Science and TechnologyShijiazhuang 050018China Institute of Environment and Sustainable Development in Agriculture Chinese Academy of Agricultural SciencesBeijing 100081China College of Biological Science and Engineering North Minzu UniversityYinchuan 750021China

The amino acids and the volatile substances in grapes and wines play important roles in their quality,and the concentrations of these substances can be changed by how a vineyard is managed,e.g.,irrigation and fertigation *** study aimed to evaluate the effect of fertilizer and water management on the distribution of amino acids,the volatile component profiles,and the sensory characteristics of Cabernet Sauvignon grapes and *** results showed that the amino acid concentration in grape berries was the highest under the 100%local fertilizer rate(HF)and 100%water irrigation quota(HW)treatment,and the volatile component concentration in wine was the highest under HF and 80%water irrigation quota(MW)*** effect of irrigation on the amino acid content in grapes was greater than that of *** synergistic effect of fertilizer and water on arginine,serine,and glutamine in grape berries was *** interactive effect of fertigation and irrigation on the volatile substance in grapes was greater than that of fertigation and irrigation *** influence of irrigation on volatile substances in wines was greater than that of *** addition,there was also a correlation between the concentrations of multiple amino acids in grapes and volatile components in *** component analysis showed that the wine from the HFMW treatment had the best quality among all treatments.

关键词： fertilizer and water management grape ine amino acids volatile components

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

熔模铸造机车车钩工作应力与疲劳寿命仿真

轨道交通装备与技术 2024年第1期32卷 1-7页

作者：郭志启龚海军李福军高正源孙鹏飞钟发勇重庆交通大学机电与车辆工程学院重庆400047 天长市兴宇交通装备科技有限公司安徽滁州239300

为快速评估熔模铸造机车车钩性能,先对车钩材料取样测试获取材料性能参数;然后在ANSYS Workbench中分别对车钩3种典型受力和2种载荷谱下的静力及疲劳进行有限元分析。结果表明,机车启、停时车钩内最大应力分别为482.7 MPa和603.4 MPa,... 详细信息

为快速评估熔模铸造机车车钩性能,先对车钩材料取样测试获取材料性能参数;然后在ANSYS Workbench中分别对车钩3种典型受力和2种载荷谱下的静力及疲劳进行有限元分析。结果表明,机车启、停时车钩内最大应力分别为482.7 MPa和603.4 MPa,满足使用要求;采用重庆地铁3号线和大秦线载荷谱模拟,绘制出了重庆地铁3号线车钩的脉冲循环应力-疲劳寿命曲线,分析结果可以满足寿命要求。文章基于车钩材料性能测试和仿真分析,为熔模铸造车钩应力分布状态和疲劳寿命快速评估提供了便捷有效的方法。

关键词：机车车钩熔模铸造 E级钢微观组织疲劳仿真

在线全文

学校读者我要写书评

暂无评论

混有着色剂的光敏树脂光固化技术研究

华中科技大学学报（自然科学版） 2007年第S1期35卷 121-124页

作者：宫海军王扬哈尔滨工业大学机械制造及其自动化系黑龙江哈尔滨150001

研究了混入不同着色剂的液态光敏树脂在激光扫描照射下树脂单层固化厚度的变化规律,比较了不同着色剂对树脂固化程度的影响.进一步研究了经表面改性的着色剂加入液态树脂后对树脂固化程度的影响.实验结果表明:随着色剂种类和加入量的变... 详细信息

研究了混入不同着色剂的液态光敏树脂在激光扫描照射下树脂单层固化厚度的变化规律,比较了不同着色剂对树脂固化程度的影响.进一步研究了经表面改性的着色剂加入液态树脂后对树脂固化程度的影响.实验结果表明:随着色剂种类和加入量的变化,树脂固化程度发生明显变化.使用表面改性的方法,可以改善着色剂在液态树脂中的分散性以及着色树脂的固化程度.使用MTS Nano Indenter XP型纳米硬度计对固化树脂进行力学性能检测,结果显示混入改性着色剂的固化树脂的表面可承受的压力和弹性模量有显著提高.

关键词：光固化立体造型着色剂表面改性力学性能

甘肃积石山县地震伤员紧急医疗后送转运89例分析

在线全文

学校读者我要写书评

暂无评论

中国急救复苏与灾害医学杂志 2024年第7期19卷 863-866页

作者：练亚鹏龚海军岳志泉周刚井旭东甘文辉张晓琴王映珍甘肃省紧急医疗救援中心甘肃兰州730030 兰州大学第二医院重症医学科甘肃兰州730030

目的分析甘肃积石山县6.2级地震后伤员紧急医疗转运情况和流行病学特征,为震区伤员医疗转运提供经验及参考。方法回顾性分析2023年12月19日—2023年12月26日转运89例积石山县地震伤员情况,调查伤员的年龄、性别、受伤部位、救援转入... 详细信息

目的分析甘肃积石山县6.2级地震后伤员紧急医疗转运情况和流行病学特征,为震区伤员医疗转运提供经验及参考。方法回顾性分析2023年12月19日—2023年12月26日转运89例积石山县地震伤员情况,调查伤员的年龄、性别、受伤部位、救援转入时间、伤情严重程度、转运情况等。采用Excel软件建立数据库,使用SPSS 21.0统计软件进行描述性统计分析。结果地震发生后共89例伤员转运至省级三甲医院,其中男性36例(40.45%),女性53例(59.55%),平均年龄(46.9±23.8)岁。转运高峰期为震后第3天和第4天,分别转运26例和25例伤员。89例伤员中多发伤53例,占59.55%。依据ISS评分系统将损伤程度分为轻、重、危重3个等级,89例伤员中危重伤54例(60.67%),重伤32例(13.96%),轻伤3例(3.37%)。在转运过程中86例(96.63%)伤员进行心电监护,12例(13.48%)伤员使用呼吸机辅助通气,1例(1.12%)患者转运至医院后救治无效死亡,其余患者均平稳转运至省级三甲医院继续治疗,病情平稳。结论积石山县地震伤员伤情重,且多为多发伤,在转运过程中需根据伤情特点及转运高峰时间合理配备相关急救物资和调配医护人员,以提高伤员的救治率。

关键词：地震转运伤员

A case study of using an efficient CRISPR/Cas9 system to develop variegated lettuce

在线全文

学校读者我要写书评

暂无评论

Vegetable Research 2021年第1期1卷 26-35页

作者： Chi D Nguyen Juncheng Li Baiquan Mou haijun gong Heqiang Huo Mid-Florida Research and Education Center IFAS-University of Florida2725 South Binion RoadApopkaFL 32703United States Department of Environmental Horticulture IFAS-University of Florida2550 Hull RdGainesvilleFL 32611United States Fruit Tree Research Institute Guangdong Academy of Agricultural SciencesNo.80Dafeng Second StreetTianhe DistrictGuangzhou 510640China ARS/USDA 1636 E Alisal StSalinasCA 93905United States College of Horticultural Sciences Northwest Agriculture and Forestry University3 Taicheng RoadYangling 712100China

The clustered,regularly interspaced,short palindromic repeat associated endonuclease 9(CRISPR/Cas9)system has emerged as a powerful approach for precision breeding to create plants with desirable ***,the CRISPR/Cas9 system relies heavily on an efficient plant transformation system that is usually time-consuming and ***,we have constructed a CRISPR-Cas9 vector with neomycin phosphotransferase II and green fluorescent protein(eGFP-NPTII),where the high expression of GFP during plant regeneration allowed us to minimize the positional effect on T-DNA expression and facilitate screening T-DNA-free *** gene editing using CRISPR/Cas9 has been illustrated in different plant species,but an important aesthetic characteristic of leaf variegation remained *** the newly designed construct,we have targeted the variegation gene LsVAR2 in *** results indicated that LsVAR2 is closely related to both AtFtsH2 and AtFtsH8,in which homozygous mutations lead to an albino phenotype while a variegated phenotype was induced by CRISPR/Cas9 de novo gene *** conclusion,the unique design of our CRISPR/Cas9 construct could efficiently edit the target gene and ease the screening of non-TDNA mutants through detecting GFP signals during plant regeneration and progeny ***,the success of gene-editing of LsVAR2 in lettuce demonstrates proof in this method to develop novel plant breeding materials for valuable horticultural plant species.

关键词： system breeding consuming