检索结果-内蒙古大学图书馆

Lightweight and large-scale rGO reinforced SiBCN aerogels with hierarchical cellular structures exposed to high-temperature environments

引用

Journal of Materials science & technology 2024年第12期179卷 145-154页

作者： Huijie Wang Zhiwei Chen Dong Su Key Laboratory of Advanced Ceramics and Machining Technology of Ministry of Education School of Materials Science and EngineeringTianjin UniversityTianjin 300350China

SiBCN ceramic aerogel is an ideal potential candidate for ultra-high temperature thermal insulation due to its unique microscopic pore structure combined with the excellent thermal stability of SiBCN ***,reduced graphene oxide(rGO)modified SiBCN aerogels(rGO/SiBCN)were prepared through solvothermal,freeze-casting and pyrolysis,and the dimension of the aerogel is up toΦ130 mm×28 *** density of the rGO/SiBCN aerogel is as low as 0.024 g/cm^(3) and the microstructural regulation is achieved by controlling the rGO content in the *** hierarchical cellular structure endows the aerogel with a high specific surface area(148.6 m^(2)/g)and low thermal conductivity(0.057 W m^(-1) K^(-1)).The 10 mm-thick sample exhibits excellent thermal insulation and ablation resistance,as evidenced by its ability to reduce the temperature from~1100℃to~180℃under the intense heat of a butane ***,benefiting from the ultrahigh-temperature stability of SiBCN,the rGO/SiBCN aerogel exhibits good thermal stability up to 1200℃in argon and short-oxidation resistance at 800℃in ***-fore,the rGO/SiBCN aerogel with superior overall performance could expand its practical application in high-temperature thermal insulation under extreme environments.

关键词： rGO/SiBCN Lightweight Large size Hierarchical cellular structure Thermal insulation

来源：评论

学校读者我要写书评

暂无评论

Numerical simulation on directional solidification and heat treatment processes of turbine blades

引用

China Foundry 2024年第5期21卷 476-490页

作者： Ye-yuan Hu Ju-huai Ma Qing-yan Xu School of Materials Science and Engineering Tsinghua UniversityKey Laboratory for Advanced Materials Processing TechnologyMinistry of EducationBeijing 100084China

Study on turbine blades is crucial due to their critical role in ensuring the efficient and reliable operation of aircraft ***-based single crystal superalloys are extensively used in the hot manufacturing of turbine blades due to their exceptional high-temperature mechanical *** hot manufacturing of single crystal blades involves directional solidification and heat *** manufacturing of these blades is time-consuming,capital-intensive,and often insufficient to meet industrial *** simulation techniques have gained widespread acceptance in blade manufacturing research due to their low energy consumption,high efficiency,and rapid turnaround *** article introduces the modeling and simulation of hot manufacturing in single crystal *** discussion outlines the prevalent mathematical models employed in numerical simulations related to blade hot *** encapsulates the advancements in research concerning macro to micro-level numerical simulation techniques for directional solidification and heat treatment ***,potential future trajectories for the numerical simulation of single crystal blade hot manufacturing are also discussed.

关键词： single crystal blades Ni-based superalloy directional solidification heat treatment numerical simulation

来源：评论

学校读者我要写书评

暂无评论

Vibration-assisted material damage mechanism:From indentation cracks to scratch cracks

引用

Chinese Journal of Aeronautics 2024年第8期37卷 527-546页

作者： Bingrui LV Bin LIN Tianyi SUI Chunyan LIU Jinshuo ZHANG Longfei WANG Xuhui CHEN Jingguo ZHOU Key Laboratory of Advanced Ceramics and Machining Technology Ministry of EducationTianjin UniversityTianjin 300072China Key Laboratory of Mechanism Theory and Equipment Design of Ministry of Education Tianjin UniversityTianjin 300072China Science and Technology of Advanced Functional Composite Laboratory Aerospace Research Institute of Materials and Processing TechnologyBeijing 100076China

Vibration-assisted grinding is one of the most promising technologies for manufacturing optical components due to its efficiency and quality ***,the damage and crack propagation mechanisms of materials in vibration-assisted grinding are not well *** order to elucidate the mechanism of abrasive scratching during vibration-assisted grinding,a kinematic model of vibration scratching was *** influence of process parameters on the evolution of vibration scratches to indentation or straight scratches is revealed by displacement metrics and velocity ***,scratch and vibration scratch experiments were performed on quartz glass,and the results showed that the vibration scratch cracks are a combination of indentation cracks and scratch *** scratch cracks change from indentation cracks to scratch cracks as the indenter moves from the entrance to the exit of the workpiece or as the vibration frequency changes from high to low.A vertical vibration scratch stress field model is established for the first time,which reveals that the maximum principal stress and tensile stress distribution is the fundamental cause for inducing the transformation of the vibration scratch cracking *** model provides a theoretical basis for understanding of the mechanism of material damage and crack propagation during vibration-assisted grinding.

关键词： Vibration assisted grinding Indentation Vibration scratch Material removal mechanism Stress field model Crack propagation mechanism

来源：评论

学校读者我要写书评

暂无评论

Review of rolling bearings performance degradation trend prediction

引用

Noise and Vibration Worldwide 2024年第11期55卷 585-604页

作者： Wang, Yaping Lu, Kaiting Dong, Renquan Fan, Yuqi Jiang, Xudong Key Laboratory of Advanced Manufacturing and Intelligent Technology Ministry of Education Harbin University of Science and Technology Harbin China

Rolling bearings are widely used in rotating machinery in modern industry, and ensuring their stability during operation is one of the prerequisites for the overall safety of the equipment. Predicting performance degradation can play a key role in preventing accidents and extending equipment life. With the development of big data and deep learning, more trend prediction methods are emerging in the field of performance degradation prediction of rolling bearings. Therefore, this paper reviews the evaluation indicators and performance degradation prediction models for rolling bearing performance degradation prediction. The advantages and disadvantages of physical degradation indicators, and virtual degradation indicators are analyzed. It is presented to utilize the powerful feature self-extraction ability and nonlinear function characterization ability of deep learning methods to construct bearing evaluation indicators. It also analyzes the research progress of traditional performance degradation prediction models and deep learning prediction models. In this review, future developments in rolling bearing performance degradation prediction are summarized in this paper as deep learning-based, digital twin correlation, high dimensionality, and adaptive, which guide researchers and practitioners to effectively identify suitable performance degradation prediction models. © The Author(s) 2024.

关键词： Prediction models

来源：评论

学校读者我要写书评

暂无评论

Rheological Behaviors of Polymers with Nanoparticles Tethered at Each End

引用

Chinese Journal of Polymer science 2024年第3期42卷 400-406,I0009页

作者： Song-Qi Zhang Wen-Qing Wang Jia-Ping Lin Li-Quan Wang Shanghai Key Laboratory of Advanced Polymeric Materials Key Laboratory for Ultrafine Materials of Ministry of EducationSchool of Materials Science and EngineeringEast China University of Science and TechnologyShanghai 200237China

The polymer with nanoparticles tethered at each end is a unique model for unraveling the effect of chain ends on the polymer dynamics. We investigated the rheological behavior of this kind of polymer by using nonequilibrium molecular dynamics simulation. The effect of polymer lengths and nanoparticle radii on the complex moduli and viscosity was examined. The dependence of complex moduli on the frequency becomes less pronounced as the polymer is short or the nanoparticle is large. The shear thinning behavior was revealed for these systems, and the scaling exponent of complex viscosity with respect to the frequency was found to change from-1/2 to-3/4 as the polymer shortens or the nanoparticle enlarges. The rheological behavior was further explained by analyzing the mean square distance of nanoparticles. The simulation results were compared with the existing experimental finding, showing an agreement. The work provides information for understanding the chain end effect on polymer rheology.

关键词： Polymer rheology Modulus Viscosity Molecular dynamics

来源：评论

学校读者我要写书评

暂无评论

New strategy for efficient manufacturing of bulk anisotropic nanocrystalline Nd-Fe-B permanent magnets

引用

Journal of Materials science & technology 2024年第34期201卷 119-129页

作者： Qian Li Lingqi Liu Yuqing Li Ming Yue Yuan Teng Weiqiang Liu Dongtao Zhang School of Materials Science and Engineering Key Laboratory of Advanced Functional MaterialsMinistry of Education of ChinaBeijing University of TechnologyBeijing 100124China

The application of bulk nanocrystalline Nd-Fe-B permanent magnets manufactured by hot deformation methods was severely limited by production ***,this work proposed an efficient prepa-ration method combining hot rolling and *** the melt-spun Nd-Fe-B magnetic powders as original materials,dense,large-sized,and well-uniform precursors for deformation can be obtained through cold pressing and hot *** large-sized hot-rolled magnet can be cut into small pieces and subjected to hot *** deformed magnet exhibits obvious crystallographic anisotropy,and the optimal maximum energy product can reach 35.7 ***,the mechanism of defor-mation and texture formation has been systematically studied,according to the microstructure and tex-ture characterization of different height reduction *** results indicated that there was a typical heterogeneous structure in the hot-rolled and hot-deformed Nd-Fe-B *** precipitation,grain growth,and regular grain arrangement were the main reasons for deformation and texture forma-tion during the deformation *** strategy of replacing traditional hot-pressing with large-sized hot-rolling can produce massively deformed precursors at once,greatly improving production efficiency,which is crucial for promoting the application of bulk nanocrystalline anisotropic Nd-Fe-B permanent magnets.

关键词： Anisotropic Nd-Fe-B magnet Hot rolling Hot deformation Deformation behavior Magnetic properties

来源：评论

学校读者我要写书评

暂无评论

Phase-field simulation of precipitation kinetics and creep properties of Ni-Al-Cr/Ta superalloys

引用

science China(Technological sciences) 2024年第4期67卷 1139-1150页

作者： YANG ShuaiGe ZHANG Zan ZHUO JiCheng LONG HongLi LI YongSheng National Key Laboratory of Advanced Casting Technologies MIIT Key Laboratory of Advanced Metallic and Intermetallic Materials TechnologyEngineering Research Center of Materials Behavior and DesignMinistry of EducationNanjing University of Science and TechnologyNanjing 210094China

The precipitation kinetics ofγ'-Ni_(3)(Al,Ta)phase and creep properties of Ni-15Al-x Ta at.%superalloys are investigated by the crystal plasticity phase-field *** results show that the high Ta content brings a lower creep strain for the deceleration and steady creep stage,while the creep lifetime is *** large external strain intensifies the creep damage and shortens the creep life of Ni-15Al-3Ta at.%*** kinetics evolution and elements distribution are revealed in the quaternary Ni-10Al-8.5Cr-xT a(x=1.5 at.%,2.0 at.%,2.5 at.%)superalloys by the multi-component phase-field *** anti-phase boundary(APB)changes the coarsening mechanism ofγ'phase,and Ta promotes the precipitation ofγ'phase with an increasing volume fraction and particle *** composition difference betweenγ'andγphases increases with the rising of Ta content,the strong partitioning of Ta toγ'phase strengthens the partitioning of Ni and Cr toγmatrix,and Ta shows a superiority than Al in the lattice site occupation of L1_(2)-Ni_(3)(Al,X)*** an importantγ'phase forming element,the optimization of Ta content is essential for improving the mechanical properties of Ni-based superalloys.

关键词： Ni-Al-Ta alloys creep properties kinetics phase-field

来源：评论

学校读者我要写书评

暂无评论

Present Situation and Future Prospects of Motor Cooling System

引用

Recent Patents on Engineering 2024年第7期18卷 103-115页

作者： Hou, Jinting Xie, Baocheng Key Laboratory of Advanced Manufacturing and Intelligent Technology Ministry of Education Harbin University of Science and Technology Harbin150080 China

Background: The motor cooling system is mainly used in aerospace, automotive, and marine fields, where the motor system is cooled to extend the service life and safety of the motor. The running power of motors rises too fast, which leads to the failure of heat dissipation as ex-pected and shortens the service life of motors. Therefore, it is necessary to choose an appropriate cooling mode for motors to improve their cooling structure, reduce their temperature rise, and improve their reliability and service life. The internal motor cooling system can perform fixed-point heat dissipation, but the overall heat dissipation is poor. The external motor cooling system can perform overall heat dissipation but has high requirements on the structure. Over the years, the application and development of motor cooling systems have gained more and more attention. Objective: This paper discusses the structural characteristics, advantages, and development trends of the motor cooling system in order to reduce the temperature rise of the motor and improve its reliability and service life. This paper aims to provide an overview and systematic guidance for future designs of the motor cooling system. Methods: According to the structural characteristics of the motor cooling system and the requirements of the motor application field, the most typical internal cooling system and external cooling system in the motor cooling system are summarized. Results: By analyzing the causes and hazards of motor heating, the limited requirements of the motor system in use are summarized. The motor system is classified and compared based on the struc-ture, heat dissipation principle, and use of the motor heat dissipation system. The characteristics of small volume and strong heat dissipation ability are also summarized. Based on the analysis of the internal and external cooling system, the problems of complex structure and poor cooling effect are summarized, and the future development trend and direction

关键词： Cooling systems

来源：评论

学校读者我要写书评

暂无评论

Recent research on magnetic machinery

引用

Recent Patents on Engineering 2024年第3期18卷 1-12页

作者： Lu, Zikang Xie, Baocheng Key Laboratory of Advanced Manufacturing and Intelligent Technology Ministry of Education Harbin University of Science and Technology Harbin150080 China

As a clean energy source, magnetic energy is a significant power source of mechanical equipment, which affects the direction of control mode and mechanical structure of mechanical equipment. Magnetic machinery is widely used in industrial power systems and automatic control systems as the power source of mechanical equipment transmission parts or actuators. Magnetic machinery is essential to make mechanical equipment easy to control, energy saving and environmental protection, simple structure, and so on. In order to innovate the control mode of mechanical equipment and optimize the types of traditional mechanical systems, magnetic machinery developed magnetic coupling, magnetic gear, magnetic spring, and other magnetic machinery. The characteristics of magnetic machines with different functions are analyzed based on the types of magnetic machines. Therefore, this aspect's development and application are getting more attention in recent years. To innovate the control mode of mechanical equipment and optimize the types of traditional mechanical structures, magnetic types of machinery, such as magnetic coupling, magnetic gear, and magnetic spring, are making continuous progress. New magnetic machines are also being developed. This paper summarizes the typical patents on three kinds of magnetic machinery: Magnetic coupling, magnetic gear and magnetic spring. In addition, the advantages of existing magnetic machinery are summarized, the current situation of magnetic machinery is analyzed, and the development of magnetic machinery is summarized. Through the analysis of enormous patents of magnetic coupling, magnetic gear, and magnetic spring, it is concluded that although there are many kinds of magnetic machinery, there are no systematic and mature design theories and methods. The development trend of magnetic machinery is also discussed. The research on magnetic machinery helps innovate mechanical equipment's control mode and optimize the types of traditional mechanica

关键词： Magnetic couplings

来源：评论

学校读者我要写书评

暂无评论

A multi-functional MgF_(2)/polydopamine/hyaluronan-astaxanthin coating on the biodegradable ZE21B alloy with better corrosion resistance and biocompatibility for cardiovascular application

引用

Journal of Magnesium and Alloys 2024年第3期12卷 1102-1116页

作者： Yachen Hou Xueqi Zhang Jingan Li Liguo Wang Shaokang Guan School of Materials Science and Engineering and Henan Key Laboratory of Advanced Magnesium Alloy and Key Laboratory of Materials Processing and Mold Technology(Ministry of Education) Zhengzhou UniversityZhengzhou 450001China

The cardiovascular diseases(CVD)continue to be the major threat to global public health over the years,while one of the effective methods to treat CVD is stent *** magnesium(Mg)alloys have great potential applications in cardiovascular stents benefit from their excellent biodegradability and ***,excessive degradation rate and the delayed surface endothelialization still limit their further *** this study,we modified a Mg-Zn-Y-Nd alloy(ZE21B)by preparing MgF_(2) as the corrosion resistance layer,the dopamine polymer film(PDA)as the bonding layer,and hyaluronic acid(HA)loaded astaxanthin(ASTA)as an important layer to directing the cardiovascular cells *** electrochemical test results showed that the MgF_(2)/PDA/HA-ASTA coating improved the corrosion resistance of *** cytocompatibility experiments also demonstrated that this novel composite coating also selectively promoted endothelial cells proliferation,inhibited hyperproliferation of smooth muscle cells and adhesion of *** with the HAloaded rapamycin(RAPA)coating,our MgF_(2)/PDA/HA-ASTA coating showed better blood compatibility and cytocompatibility,indicating stronger multi-functions for the ZE21B alloy on cardiovascular application.

关键词： Biodegradable ZE21B alloy Reendothelialization Surface modification Hyaluronic acid Astaxanthin.

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：