检索结果-南通市图书馆

Natural gas density under extremely high pressure and high temperature: Comparison of molecular dynamics simulation with corresponding state model

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2021年第3期34卷 2-9页

作者： luchao Jin Yongming He Guobing Zhou Qiuhao Chang Liangliang Huang Xingru Wu Alchemy Sciences Inc. 6002 Rogerdale RdSte 125HoustonTX 77072USA College of Energy Chengdu Science and Technology UniversityChengdu 610059China University of Oklahoma 100 East Boyd stSarkeys Energy Center 1210NormanOK 73019USA

This work applied molecular dynamics(MD)simulation to calculate densities of natural gas mixtures at extremely high pressure(>138 MPa)and high temperature(>200℃)conditions(x HPHT)to bridge the knowledge and technical gaps between experiments and classical *** experimental data are scarce at these conditions which are also out of assumptions for classical predictive correlations,such as the Dranchuk&Abou-Kassem(DAK)equation of state(EOS).Force fields of natural gas components were carefully chosen from literatures and the simulation results are validated with experimental *** largest relative error is 2.67%for pure hydrocarbons,2.99%for C1/C3 mixture,7.85%for C1/C4 mixture,and 8.47%for pure *** satisfactory predictions demonstrate that the MD simulation approach is reliable to predict natural-and acid-gases thermodynamic *** validated model is further used to generate data for the study of the EOS with pressure up to 276 MPa and temperature up to 573 *** results also reveal that the Dranchuk&Abou-Kassem(DAK)EOS is capable of predicting natural gas compressibility to a satisfactory accuracy at x HPHT conditions,which extends the confidence range of the DAK EOS.

关键词： High-pressure high temperature Z-factor Molecular dynamics simulation Natural gas density Correlations

Crystal structure determination of nanolaminated Ti_(5)Al_(2)C_(3) by combined techniques of XRPD,TEM and ab initio calculations

在线全文

学校读者我要写书评

暂无评论

Journal of Advanced Ceramics 2012年第4期1卷 268-273页

作者： Hui ZHANG Xiaohui WANG Yonghui MA luchao SUN Liya ZHENG Yanchun ZHOU Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of Sciences72 Wenhua RoadShenyang 110016China Graduate School of Chinese Academy of Sciences Beijing 100039China Science and Technology on Advanced Functional Composite Laboratory Aerospace Research Institute of Materials&Processing TechnologyNo.1 South Dahongmen RoadBeijing 100076China

Crystal structure of Ti_(5)Al_(2)C_(3)was determined by means of X-ray powder diffraction(XRPD),transmission electron microscopy(TEM)and ab initio *** contrast to the already known P63/mmc space group that the MAX phases crystallize,it was demonstrated that the R3_m space group could better satisfy the experimental *** lattice parameters are a=0.30564 nm,c=4.81846 nm in a hexagonal unit cell.

关键词： Ti_(5)Al_(2)C_(3) crystal structure layered carbides transmission electron microscopy(TEM)

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

无人机作业参数对苹果树雾滴沉积分布的影响

农机化研究 2024年第4期46卷 183-187页

作者：张亚莉白禄超陈鹏超兰玉彬于保宏华南农业大学工程学院广州510642 华南农业大学电子工程学院/人工智能学院广州510642 国家精准农业航空施药技术国际联合研究中心广州510642 北京韦加无人机科技股份有限公司北京100176

为了研究植保无人飞机在苹果果树雾滴分布的情况,选用韦加JF01-20电动八旋翼四轴植保无人机作为测试平台,探讨飞行速度和喷雾助剂对于苹果果树雾滴分布的影响。试验设定了6组试验处理,以水敏纸为雾滴分布测试工具,分别布置在果树的上中... 详细信息

为了研究植保无人飞机在苹果果树雾滴分布的情况,选用韦加JF01-20电动八旋翼四轴植保无人机作为测试平台,探讨飞行速度和喷雾助剂对于苹果果树雾滴分布的影响。试验设定了6组试验处理,以水敏纸为雾滴分布测试工具,分别布置在果树的上中下冠层,统计果树立体冠层的雾滴分布数据。研究结果表明:果树相同冠层水平面的雾滴分布差异性较大,雾滴分布的变异系数值范围在49.1%~227.6%之间变化;雾滴的分布数值结果在果树冠层从上至下逐步降低,雾滴分布的数值结果随着飞行速度的增加而降低,各雾滴测试指标的变化趋势相同;添加助剂后,各个试验处理以及冠层间的雾滴分布结果具有显著的提升。研究结果可为植保无人飞机应用于苹果果树的喷洒提供数据支持。

关键词：雾滴沉积分布植保无人飞机飞行速度喷雾助剂

Mechanical properties of foamed polyurethane solidified ballasted track

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

High-Speed Railway 2023年第2期1卷 120-129页

作者： Yang Xu luchao Qie Hong Wang Wenying Yu Railway Engineering Research Institute China Academy of Railway Sciences Corporation LimitedBeijing 100081China

Foamed Polyurethane Solidified Ballasted Track(FPSBT),an innovative railway track,is formed by solidifying ballast bed with foamed *** with the traditional Discrete Ballasted Track(DBT),FPSBT does not require regular maintenance such as tamping and ***,limited studies exist on the mechanical properties of *** this study,Laboratory experiments are conducted on polyurethane samples to investigate the effects of polyurethane density on the mechanical properties of ***,the performance of DBT and FPSBT with different polyurethane densities are compared,and the recommended polyurethane density is *** exhibited negligible accumulation of deformation under cyclic loads,indicating excellent performance of FPSBT owing to the anti-deformation properties of ***,a track load vehicle test is *** exhibited better load-transmitting ability than ***,the construction and application of FPSBT in China are *** study is expected to contribute to realizing a more extensive application of FPSBT.

关键词： Ballasted track Foamed polyurethane Solidified track Track load vehicle

High entropy ultra-high temperature ceramic thermal insulator(Zr_(1/5)Hf_(1/5)Nb_(1/5)Ta_(1/5)Ti_(1/5))C with controlled microstructure and outstanding properties

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2022年第24期119卷 190-199页

作者： Zhuojie Shao Zhen Wu luchao Sun Xianpeng Liang Zhaoping Luo Haikun Chen Junning Li Jingyang Wang Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaHefei 230026China Science and Technology on Advanced Functional Composites Laboratory Aerospace Research Institute of Materials and Processing TechnologyBeijing 100076China

due to advancements of hypersonic vehicles,ultra-high temperature thermal insulation materials are urgently requested to shield harsh environment with superhigh heat *** this target,ultra-high temperature ceramics(UHTCs)are the only choice due to their excellent capability at ultra-high *** herein report a novel highly porous high entropy(Zr_(1/5)Hf_(1/5)Nb_(1/5)Ta_(1/5)Ti_(1/5))C fabricated by foam-gelcasting-freeze drying technology combined with in-situ pressureless reaction *** porous(Zr_(1/5)Hf_(1/5)Nb_(1/5)Ta_(1/5)Ti_(1/5))C exhibited ultra-high porosity of 86.4%-95.9%,as well as high strength and low thermal conductivity of 0.70–11.77 MPa and 0.164–0.239 W/(m·K),***,Si C sintering additive only locates at the pit of the surface of sintering neck between UHTC grains,and there is no secondary phase or intergranular film at the grain ***,the oxidation resistance of high entropy carbide powders is greatly improved compared with that of the mixed five carbide *** work clearly highlights the merits of highly porous high entropy(Zr_(1/5)Hf_(1/5)Nb_(1/5)Ta_(1/5)Ti_(1/5))C as an ultra-high temperature thermal insulation material.

关键词： High entropy UHTCs High porosity High strength Low thermal conductivity Oxidation resistance

Abnormal interfacial bonding mechanisms of multi-material additive-manufactured tungsten-stainless steel sandwich structure

在线全文

学校读者我要写书评

暂无评论

International Journal of Extreme Manufacturing 2022年第2期4卷 113-128页

作者： Chao Wei Heng Gu Yuchen Gu luchao Liu Yihe Huang Dongxu Cheng Zhaoqing Li Lin Li Laser Processing Research Centre Department of MechanicalAerospace and Civil EngineeringThe University of ManchesterManchester M139PLUnited Kingdom School of Mechanical Engineering Jiangsu UniversityZhenjiangPeople’s Republic of China College of Engineering Swansea UniversitySwansea SA18ENUnited Kingdom

Tungsten(W)and stainless steel(SS)are well known for the high melting point and good corrosion resistance *** W-SS structures would offer potential applications in extreme *** this study,a SS→W→SS sandwich structure is fabricated via a special laser powder bed fusion(LPBF)method based on an ultrasonic-assisted powder deposition *** characterization of the SS→W interface and W→SS interface was conducted,including microstructure,element distribution,phase distribution,and nano-hardness.A coupled modelling method,combining computational fluid dynamics modelling with discrete element method,simulated the melt pool dynamics and solidification at the material *** study shows that the interface bonding of SS→W(SS printed on W)is the combined effect of solid-state diffusion with different elemental diffusion rates and grain boundary *** keyhole mode of the melt pool at the W→SS(W printed on SS)interface makes the pre-printed SS layers repeatedly remelted,causing the liquid W to flow into the sub-surface of the pre-printed SS through the keyhole cavities realizing the bonding of the W→SS *** above interfacial bonding behaviours are significantly different from the previously reported bonding mechanism based on the melt pool convection during multiple material *** abnormal material interfacial bonding behaviours are reported for the first time.

关键词： multi-material additive manufacturing laser powder bed fusion interfacial bonding element diffusion keyhole mode

柔性Pb_(0.99)Sm_(0.01)(Mg_(1/3)Nb_(2/3))_(0.68)Ti_(0.32)O_(3)弛豫铁电薄膜储能特性

在线全文

学校读者我要写书评

暂无评论

硅酸盐学报 2024年第4期52卷 1301-1309页

作者：吕盼盼石长清辛乐战行张书志王佳李瑞航李存成任路超杨长红张明伟程新山东理工大学材料科学与工程学院山东淄博255000 山东理工大学分析测试中心山东淄博255000 淄博师范高等专科学校数理系山东淄博255130 济南大学山东省建筑材料制备与测试技术重点实验室济南250022

弛豫铁电薄膜电容器因具有细长电滞回线和高能量转化效率成为介电储能应用的理想选择。本工作采用溶胶凝胶法在沉积有LaNiO3缓冲层的云母基底上直接制备了柔性Pb_(0.99)Sm_(0.01)(Mg_(1/3)Nb_(2/3))_(0.68)Ti_(0.32)O_(3)(PSMNT)薄膜,... 详细信息

弛豫铁电薄膜电容器因具有细长电滞回线和高能量转化效率成为介电储能应用的理想选择。本工作采用溶胶凝胶法在沉积有LaNiO3缓冲层的云母基底上直接制备了柔性Pb_(0.99)Sm_(0.01)(Mg_(1/3)Nb_(2/3))_(0.68)Ti_(0.32)O_(3)(PSMNT)薄膜,系统研究了柔性PSMNT膜的微观结构、介电、铁电和储能性能。X射线衍射结果表明薄膜样品为单一钙钛矿相。扫描电子显微镜结果显示薄膜的晶粒尺寸均匀且致密。在极化特性方面,所制备的柔性PSMNT薄膜因具有弛豫性,其电滞回线呈现出纤细束腰特征,在外加电场2468 kV/cm下,其最大饱和极化为74.5μC/cm^(2),剩余极化为16.4μC/cm^(2)。薄膜电容器击穿前最大可释放能量密度和储能效率分为40.7 J/cm^(3)和70%,并且表现出较好的频率(1~20 kHz)和温度(25~120℃)稳定性。此外,样品借助云母衬底可实现优异的可弯折性,在弯曲半径R低至2 mm和弯曲疲劳循环1000次(R=4 mm)后,其储能性能仍可保持。此研究表明以云母为基底的PSMNT弛豫薄膜在柔性储能领域具有很大的应用潜力。

关键词：铌镁酸铅钛酸铅基薄膜弛豫铁电体介电储能柔性

UAV-Assisted Dynamic Avatar Task Migration for Vehicular Metaverse Services: A Multi-Agent Deep Reinforcement Learning Approach

在线全文

学校读者我要写书评

暂无评论

Advances on strategies for searching for next generation thermal barrier coating materials

自动化学报（英文版） 2024年第2期

作者： Jiawen Kang Junlong Chen Minrui Xu Zehui Xiong Yutao Jiao luchao Han dusit Niyato Yongju Tong Shengli Xie

来源：博看期刊评论

在线全文

博看期刊

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2019年第5期35卷 833-851页

作者： Bin Liu Yuchen Liu Changhua Zhu Huimin Xiang Hongfei Chen luchao Sun Yanfeng Gao Yanchun Zhou School of Materials Science and Engineering Shanghai University Shanghai 200444 China Science and Technology on Advanced Functional Composite Laboratory Aerospace Research Institute of Material & Processing Technology Beijing 100076 China High-performance Ceramics Division Shenyang National Laboratory for Materials Science Institute of Metal Research Chinese Academy of Sciences Shenyang 110016 China

Thermal barrier coating(TBC) materials play important roles in gas turbine engines to protect the Nibased super-alloys from the high temperature airflow damage. High melting point, ultra-low thermal conductivity, large thermal expansion coefficient, excellent damage tolerance and moderate mechanical properties are the main requirements of promising TBC materials. In order to improve the efficiency of jet and/or gas turbine engines, which is the key of improved thrust-to-weight ratios and the energysaving, significant efforts have been made on searching for enhanced TBC materials. Theoretically, density functional theory has been successfully used in scanning the structure and properties of materials, and at the same time predicting the mechanical and thermal properties of promising TBC materials for high and ultrahigh temperature applications, which are validated by subsequent experiments. Experimentally,doping and/or alloying are also widely applied to further decrease their thermal conductivities. Now, the strategy through combining theoretical calculations and experiments on searching for next generation thermal insulator materials is widely adopted. In this review, the common used techniques and the recent advantages on searching for promising TBC materials in both theory and experiments are summarized.

关键词： Thermal barrier coatings Oxide First principles calculation Thermal properties Mechanical properties