检索结果-内蒙古大学图书馆

A comparative study on design standards of screw conveyors in China,Germany,and the USA-Part Ⅱ:Discrete element method

引用

Particuology 2024年第9期92卷 113-125页

作者： Yuan Tan Michael Rackl Weijie Yang Johannes Fottner Wenjun Meng Stephan Kessler Technical University of Munich Chair for Materials HandlingMaterial FlowLogisticsGarchingGermany Ibracon–Ingenieurbüro Dr.-Ing.Rackl ZornedingGermany School of Mechanical Engineering Taiyuan University of Science and TechnologyTaiyuanChina

This part of the study aims to evaluate the advantages and disadvantages of technical standards of screw conveyors in China,Germany,and the USA for industrial *** source or determination method of empirical coefficients as well as the theoretical foundation of dimensioning-relevant diagrams in these standards is not explicitly documented in the ***,instead of less efficient on-site tests,the numerical simulation by discrete element method is *** on the geometrical and operational designs determined in three standards for horizontal,slightly inclined,and vertical conveyance of three representative bulk solids(barley,lignite,and sand),the potential influencing factors are *** constant particle and contact parameters,the potential deviations caused by particle models are ***,the accuracy of power consumption calculation of each standard and the divergence between accessible and required mass flows is comprehensively assessed based on the analysis of simulated *** main conclusions are drawn:(1)Particle fall back is barely considered by all three standards and leads to overestimated mass throughput;(2)The decrease in mass throughput caused by an increasing degree of filling can be compensated by slowing down the rotational speed.

关键词： Discrete element method Design standard Screw conveyor Screw auger Bulk solid

来源：评论

学校读者我要写书评

暂无评论

Observation of the spatial Goos–Hänchen shift due to low-loss dielectrics

引用

Optics Letters 2025年第11期50卷 3533-3536页

作者： Operaña, Jared Joshua Simon, Niña Zambale Hermosa, Nathaniel Material Science and Engineering Program University of the Philippines-Diliman Diliman Quezon City1101 Philippines National Institute of Physics University of the Philippines-Diliman Diliman Quezon City1101 Philippines

In this paper, we present the first, to the best of our knowledge, measurement of spatial Goos–Hänchen (GH) shifts for low-loss dielectrics (φ0 = Εi/|Εr| 1). The observed resonant shifts are up to 100λ. Because of this sharp resonance, measuring the shift is challenging. We argue that it might be possible to use these simple materials for the many proposed applications of the GH shift. Moreover, we show that by using the GH shifts, we can discriminate materials with almost similar values of the real permittivity (Εr) but of different imaginary values (Εi), in our case, the bulk gallium arsenide (GaAs) versus silicon (Si). This allows us to put forth a method to measure the complex permittivity of low-loss dielectrics through the GH shifts. Using this method, the measured permittivity values for Si and GaAs differ from standard values by as little as 0.2% for the real Ε component and 7% for the imaginary Ε component. Further precise and accurate measurement of GH shift will result in an alternative method to measure the permittivity of materials with almost similar real permittivities. © 2025 Optica Publishing Group. All rights are reserved.

关键词： Permittivity measurement

来源：评论

学校读者我要写书评

暂无评论

In situ regulating intimately connected heterostructure by decomposition of solid solution oxides toward high-efficient water oxidation

引用

Rare Metals 2024年第4期43卷 1557-1569页

作者： Shao-Fei Zhang Xiao-Lu Yin Jin Wang Jian-Li Kang Tian-Tian Li Jin-Feng Sun Yong-Qiang Meng Jian-Jiang Wang Dian-Long Wang Kai-Qiang Qin Hebei Key Laboratory of Flexible Functional Materials/Hebei Key Laboratory of Material Near-Net Forming Technology School of Materials Science and EngineeringHebei University of Science and TechnologyShijiazhuang050018China Key Laboratory of Advanced Ceramics and Machining Technology/Ministry of Education School of Materials Science and EngineeringTianjin UniversityTianjin300072China Electrochemical Engine Center Department of Mechanical EngineeringPennsylvania State UniversityUniversity ParkPA16802USA

Heterogeneous interfaces produced by interdomain interactions on a nanoscale performs a crucial role in boosting the properties of an electrocatalyst toward oxygen evolution reaction(OER)***,a series of dual-phase electrodes with intimately connected heterointerfaces are prepared by in situ decomposing solid solution oxide of Ni_(x)Co_(y)Fe_(100-x-y)O,which grew on Ni foam massively via an ultrafast combustion ***,with high-reaction kinetics caused by the reduction treatment at 450℃,the less electronegative Fe and Co are more oxyphilic than Ni,which facilitated their co-exsolution and formation of CoFe_2O_4/NiO oxide with enriched oxygen *** from the nanoporous framework,heterojunction structure,and oxygen defects,the self-supporting electrodes present rapid charge/mass transmission and provide abundant active sites for *** optimized sample(R-SNCF4.5)shows low overpotentials of 226 and 324 mV at 10 and100 mA·cm^(-2),a small Tafel slope(46.7 mV·dec^(-1)),and excellent *** assembled R-SNCF4.5//Pt/C/NF electrolyzer demonstrates continuous electrolysis over 50 h at a current density of 10 mA·cm^(-2),under 1.51 *** functional theory(DFT)calculations verify that the strong electronic modulation plays a critical part in the CoFe_2O_4/NiO hybrid by lowering the energy barriers for the ratedetermining steps,and Fe sites are the most active OER sites.

关键词： Rapid combustion Decomposition of solid solution oxide Dual-phase heterostructure Oxygen evolution reaction Theoretical calculation

来源：评论

学校读者我要写书评

暂无评论

Entropy-modulated and interlayer-doped transition metal layered oxides enable high-energy-density sodium-ion capacitors

引用

Nano Research 2024年第10期17卷 8785-8793页

作者： Tiansheng Wang Yadong Li Zhengyuan Chen Qingshan Liu Jian Lang Langyuan Wu Wendi Dong Zhengyu Ju Hongsen Li Xiaogang Zhang Guihua Yu College of Physics Qingdao UniversityQingdao 266071China Jiangsu Key Laboratory of Materials and Technologies for Energy Storage College of Materials Science and TechnologyNanjing University of Aeronautics and AstronauticsNanjing 210016China Materials Science and Engineering Program and Walker Department of Mechanical Engineering The University of Texas at AustinAustin 78712USA

In recent years,sodium-ion capacitors have attracted attention due to their cost-effectiveness,high power density and similar manufacturing process to lithium-ion ***,the utilization of oxide electrodes in traditional sodium-ion capacitors restricts their further advancement due to the inherent low operating voltage and electrolyte consumption based on their energy storage *** address these challenges,we incorporated Zn,Cu,Ti,and other elements into Na_(0.67)Ni_(0.33)Mn_(0.67)O_(2) to synthesize P2-type Na_(0.7)Ni_(0.28)Mn_(0.6)Zn_(0.05)Cu_(0.02)Ti_(0.05)O_(2) with a modulated entropy and pillaring *** the synergistic interplay between the interlayer pillar and the entropy modulation within the layers,the material exhibits exceptional toughness,effectively shielding it from detrimental phase transitions at elevated voltage *** a result,the material showcases outstanding kinetic properties and long-term cycling stability across the voltage *** integrating these materials with hierarchical porous carbon nanospheres to form a"rocking chair"sodium-ion capacitor,the hybrid full device delivers a high energy density(171 Wh·kg^(-1))and high power density(5245 W·kg^(-1)),as well as outstanding cycling stability(77% capacity retention after 3000 cycles).This work provides an effective material development route to realize simultaneously high energy and power for next-generation sodium-ion capacitors.

关键词： sodium-ion capacitors entropy modulation high power density long-term cycling layered oxide

来源：评论

学校读者我要写书评

暂无评论

Hot Deformation Behavior and Microstructures Evolution of GNP-Reinforced Fine-Grained Mg Composites

引用

Acta Metallurgica Sinica(English Letters) 2024年第3期37卷 407-424页

作者： Hengrui Hu Jiayu Qin Yunpeng Zhu Jinhui Wang Xiaoqiang Li Peipeng Jin Qinghai Provincial Key Laboratory of New Light Alloys Qinghai UniversityXining 810016China Qinghai Provincial Engineering Research Center of High Performance Light Metal Alloys and Forming Qinghai UniversityXining 810016China Department of Mechanical Engineering Tsinghua UniversityBeijing 100084China School of Material Science and Engineering Lanzhou University of TechnologyLanzhou 730050China

Graphene nanoplates(GNPs)-reinforced magnesium matrix composites have been attracted great ***,knowledge is lack for the hot deformation behavior of GNP-reinforced magnesium(GNPs/Mg)*** this study,the fine-grained GNPs/Mg composite was fabricated by powder metallurgy process followed by *** hot deformation behavior,microstructure evolution and dynamic recrystallization(DRX)mechanism of fine-grained GNPs/Mg composite were investigated by hot compression test and electron back-scatter diffraction(EBSD).The hot compression tests of the composite were conducted at temperatures between 423 and 573 K with the strain rates from 0.001 to 1 s^(-1).The strain compensated power law equation was established to describe the hot deformation behavior of the *** stress exponent and activation energy of the composite are 7.76 and 83.23 kJ/mol,respectively,suggesting that the deformation mechanism is grain boundary slip controlled dislocation climb *** abnormally high stress exponent and activation energy are unattainable in the composite due to the fine grain size of the composites and the absence of Zener pinning and Orowan effects of GNPs *** grain size increases with the decrease in Zener-Hollomn(Z)parameter,which can be well fitted by power-law *** the increase in grain size and decrease in Z parameter,the geometrically necessary dislocation density decreases,which shows the approximately power-law relationship.A random and weak texture was formed after hot *** discontinuous dynamic recrystallization and continuous dynamic recrystallization mechanism dominated the DRX behavior at 473 K/0.001 s^(-1) and 573 K/0.001 s^(-1),respectively.

关键词： GNPs Mg composite Hot deformation behavior Constitutive equations Microstructure evolution Dynamic recrystallization

来源：评论

学校读者我要写书评

暂无评论

The Influence of Silicon Dioxide as a Fuel Additive in a Diesel Engine Fuelled by Pure Palm Oil 4

The Influence of Silicon Dioxide as a Fuel Additive in a Die...

引用

4th International Symposium on Advances and Innovation in mechanical engineering, ISAIME 2023

作者： Prahmana, Rico Aditia Darmanto, Prihadi Setyo Reksowardojo, Iman Kartolaksono Prakoso, Tirto Juangsa, Firman Bagja Doctoral Program of Mechanical Engineering Faculty of Mechanical and Aerospace Engineering Institut Teknologi Bandung Bandung40132 Indonesia Program Study of Mechanical Engineering Faculty of Industrial Technology Institut Teknologi Sumatera South Lampung35365 Indonesia Thermal Science and Engineering Research Group Faculty of Mechanical and Aerospace Engineering Institut Teknologi Bandung Bandung Indonesia Department of Chemical Engineering Faculty of Industrial Technology Institut Teknologi Bandung Bandung40132 Indonesia Program Study of Mechanical Engineering Faculty of Industrial Technology Universitas Pertamina Jakarta12220 Indonesia

In the last decade, the Indonesian government has implemented a program to use biodiesel as a substitute for fossil diesel to reduce dependence on fossil fuels. On the other hand, the development of biodiesel as an alternative fuel to replace fossil diesel has several challenges, one of which is the production of biodiesel, which is more complicated and requires a long process. However, the direct use of crude palm oil (CPO) in diesel engines is not recommended because it has many drawbacks. Research recently shows that fuel additives in diesel engines have promising prospects. Therefore, to solve the problem, this study used pure palm oil (PPaO) as the primary fuel, with the addition of silicon oxide (SiO2) as a fuel additive in diesel engines. The results showed that using SiO2 additive in PPaO can increase thermal efficiency by 18.8% at 60% load compared to diesel fuel (DF). Nevertheless, using this fuel increased specific fuel consumption (SFC) by 3.9% on average and increased the opacity by 153% compared to diesel fuel. These results indicate that SiO2 has the potential to be developed as an effective additive to PPaO fuel that can improve the efficiency and performance of diesel engines. © 2025 Institute of Physics Publishing. All rights reserved.

关键词： Biodiesel

来源：评论

学校读者我要写书评

暂无评论

Interlayer interaction mechanism and its regulation on optical properties of bilayer SiCNSs

引用

Frontiers of physics 2023年第4期18卷 227-238页

作者：孔双双刘卫凯于晓霞李亚林杨留柱马昀房晓勇 Key Laboratory for Microstructural Material Physics of Hebei Province School of ScienceYanshan UniversityQinhuangdao 066004China School of Mechanical Engineering Yanshan UniversityQinhuangdao 066004China

Silicon carbide nanosheets(SiCNSs)have a very broad application prospect in the field of new two-dimensional(2D)*** this paper,the interlayer interaction mechanism of bilayer SiCNSs(BL-SiCNSs)and its effect on optical properties are studied by first *** the charge and dipole moment of the layers as parameters,an interlayer coupling model is constructed which is more convenient to control the photoelectric *** results show that the stronger the interlayer coupling,the smaller the band gap of *** interlayer coupling also changes the number of absorption peaks and causes the red or blue shift of absorption *** strong interlayer coupling can produce obvious dispersion and regulate the optical transmission *** larger the interlayer distance,the smaller the permittivity in the vertical ***,the permittivity of the parallel direction is negative in the range of 150-300 nm,showing obvious *** is expected that the results will provide a meaningful theoretical basis for further study of SiCNSs optoelectronic devices.

关键词： SiC nanosheets bilayer nanosheets interlayer coupling model bandgap structure optical properties

来源：评论

学校读者我要写书评

暂无评论

Temperature-modulated crystallographic orientation and electrical properties of BiFeO_(3) thick films sputtered on LaNiO_(3)/Pt/Ti/SiO_(2)/Si for piezo-MEMS applications

引用

Journal of Advanced Ceramics 2024年第12期13卷 1943-1954页

作者： Hongyu Luo Miaomiao Niu Hanfei Zhu Li Li Hongbo Cheng Chao Liu Jianting Li Yuyao Zhao Chenxi Zhang Xiaojie Cao Isaku Kanno Qingguo Chi Jun Ouyang School of Chemistry and Chemical Engineering Qilu University of Technology(Shandong Academy of Sciences)Jinan 250353China School of Mechanical Electrical&Information EngineeringShandong UniversityWeihai 264209China Key Laboratory of Engineering Dielectrics and Its Application(Ministry of Education) Harbin University of Science and TechnologyHarbin 150080China School of Mechanical Engineering Qilu University of Technology(Shandong Academy of Sciences)Jinan 250353China State Key Laboratory of Metal Matrix Composites School of Material Sciences and EngineeringShanghai Jiao Tong UniversityShanghai 200240China Department of Mechanical Engineering Kobe UniversityKobe 657-8501Japan Key Laboratory of Key Film Materials&Application for Equipments(Hunan Province) Hunan Provincial Key Laboratory of Thin Film Materials and DevicesSchool of Material Sciences and EngineeringXiangtan UniversityXiangtan 411105China

In this work,thick BiFeO_(3)films(~1μm)were prepared on LaNiO_(3)-buffered(111)Pt/Ti/SiO_(2)/(100)Si substrates via radio-frequency magnetron sputtering without post-growth *** effects of the substrate temperature on the film’s crystallinity,defect chemistry,and associated electrical properties were *** contrast to the poorly crystallized BiFeO_(3)film deposited at 300℃and the randomly-oriented and(111)-textured films deposited at 500 and 650℃,respectively,a(001)-preferred orientation was achieved in the BiFeO_(3)film deposited at 350℃.This film not only showed a dense,fine-grained morphology but also displayed enhanced electrical properties due to the(001)texture and improved defect *** properties include a reduced leakage current(J≈2.4×10^(−5)A/cm^(2)@200 kV/cm),a small dielectric constant(ε_(r)≈243–217)with a low loss(tanδ≤0.086)measured from 100 Hz to 1 MHz,and a nearly intrinsic remnant polarization(Pr)of~60μC/cm^(2).A detailed TEM analysis confirmed the R3c symmetry of the BFO films and hence ensured good stability of their electrical *** particular,single-beam cantilevers fabricated from BiFeO_(3)/LaNiO_(3)/Pt/Ti/SiO_(2)/Si heterostructures showed excellent electromechanical performance,including a large transverse piezoelectric coefficient(e_(31,f))of~−2.8 C/m^(2),a high figure of merit(FOM)parameter of~4.0 GPa,and a large signal-to-noise ratio of~1.5 C/m^(2).An in-depth analysis revealed the intrinsic nature of the e_(31,f)piezoelectric coefficient,which is well fitted along a straight line of e_(31,f)ratio=(ε_(r)P_(r))ratio with the reported representative *** high-quality lead-free piezoelectric films processed with a reduced thermal budget can open many possibilities for the integration of piezoelectricity into Si-based microelectro–mechanical systems(MEMSs).

关键词： BiFeO_(3) film ferroelectric piezoelectric micro-electro-mechanical system(piezo-MEMS) low thermal budget crystallographic orientation magnetron sputtering

来源：评论

学校读者我要写书评

暂无评论

Effect of Polymer/Fiber Affinity on the Performance of Silk Composite Laminates 38

Effect of Polymer/Fiber Affinity on the Performance of Silk ...

引用

38th Technical Conference of the American Society for Composites, ASC 2023

作者： Hamidi, Youssef K. Mechanical Engineering Program College of Science and Engineering University of Houston-Clear Lake United States

ISBN: (纸本)9781605956916

Aerospace industry is intensely shifting towards the usage of composite materials, as the new Airbus and Boeing aircrafts, among others, comprise increasing percentages of these materials. Beyond their higher specific mechanical properties, fiber reinforced polymer composites are non-magnetic, and thus do not interfere with the magnetic compass of the aircraft, making them particularly suitable for the aircraft's skin. Recent sustainability concerns and environmental awareness has led to the popularity of natural fibers as eco-friendly reinforcements in polymer composites. Among natural fibers with established potential applications, silk fibers have recently received considerable attention from researchers due to their remarkable properties. Strong, lightweight and flexible, silk is a viable natural reinforcement that can be repurposed for composite industrial use. However, silk composite laminates are hardly used in aerospace products due, in part, to a lack of affinity between the silk fibers and epoxy, the polymeric resin often used to manufacture silk composites. This paper investigates the effect of polymer/fiber affinity on the performance of silk composite laminates. To this effect, the silk/resin contact angle is measured for different resins, and correlated with the mechanical properties of the silk composite laminates fabricated by vacuum assisted resin transfer molding (VARTM). The ability of the resin to impregnate the woven silk fiber preform is observed to affect the mechanical performance of these laminates as well as their overall quality. © 2023 by DEStech Publications, Inc. and American Society for Composites. All rights reserved.

关键词： Aerospace industry

来源：评论

学校读者我要写书评

暂无评论

Impact of Artificial Compressibility on the Numerical Solution of Incompressible Nanofluid Flow

引用

Computers, materials & Continua 2023年第3期74卷 5123-5139页

作者： Tohid Adibi Shams Forruque Ahmed Seyed Esmail Razavi Omid Adibi Irfan Anjum Badruddin Syed Javed Department of Mechanical Engineering University of BonabBonabIran Science and Math Program Asian University for WomenChattogram4000Bangladesh School of Mechanical Engineering University of TabrizTabrizIran Energy Management Group Energy and Environment Research CenterNiroo Research InstituteTehranIran Mechanical Engineering Department College of EngineeringKing Khalid UniversityAbha61421Saudi Arabia

The numerical solution of compressible flows has become more prevalent than that of incompressible *** the help of the artificial compressibility approach,incompressible flows can be solved numerically using the same methods as compressible *** artificial compressibility scheme is thus widely used to numerically solve incompressible Navier-Stokes *** numerical method highly depends on its accuracy and speed of *** the artificial compressibility approach is utilized in several numerical simulations,the effect of the compressibility factor on the accuracy of results and convergence speed has not been investigated for nanofluid flows in previous ***,this paper assesses the effect of this factor on the convergence speed and accuracy of results for various types of *** improve the stability and convergence speed of time discretizations,the fifth-order Runge-Kutta method is applied.A computer program has been written in FORTRAN to solve the discretized equations in different Reynolds and Grashof numbers for various *** results demonstrate that the artificial compressibility factor has a noticeable effect on the accuracy and convergence rate of the *** optimum artificial compressibility is found to be between 1 and *** findings can be utilized to enhance the performance of commercial numerical simulation tools,including ANSYS and COMSOL.

关键词： Navier-Stokes equations incompressible flow artificial compressibility convergence rate convection flow

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：