检索结果-南通市图书馆

magnetic probe diagnostics of nonlinear standing waves and bulk ohmic electron power absorption in capacitive discharges

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

Plasma Science and Technology 2021年第11期23卷 74-83页

作者： Kai ZHAO Yongxin LIU Quanzhi ZHANG Demetre j ECONOmOU Younian WANG Key Laboratory of materials modification by Laser Ionand Electron Beams(Ministry of Education)School of PhysicsDalian University of TechnologyDalian 116024People's Republic of China Plasma Processing Laboratory William A.Brookshire Department of Chemical and Biomolecular EngineeringUniversity of HoustonHoustonTexas 77204-4004United States of America

It is recognized that standing wave effects appearing in large-area,very-high-frequency capacitively coupled plasma(CCP)reactors cause center-high plasma *** a high-frequency magnetic probe,we present a direct experimental diagnostic of the nonlinear standing waves and bulk ohmic electron power absorption dynamics in low pressure CCP discharges for different driving frequencies of 13.56,30,and 60 *** design,principle,calibration,and validation of the probe are described in *** structures of the harmonics of the magnetic field,determined by the magnetic probe,were used to calculate the distributions of the harmonic current and the corresponding ohmic electron power deposition,providing insights into the behavior of nonlinear *** a low driving frequency,i.e.13.56 mHz,no remarkable nonlinear standing waves were identified and the bulk ohmic electron power absorption was observed to be *** harmonic magnetic field/current was found to increase dramatically with the driving frequency,due to decreased sheath reactance and more remarkable nonlinear standing waves at a higher driving frequency,leading to the enhancements of the ohmic heating and the plasma density in the bulk,specifically at the electrode *** a high driving frequency,i.e.60 mHz,the high-order harmonic current density and the corresponding ohmic electron power absorption exhibited a similar node structure,with the main peak on axis,and one or more minor peaks between the electrode center and the edge,contributing to the center-high profile of the plasma density.

关键词： capacitively coupled plasmas magnetic probe nonlinear standing waves ohmic heating

Performance study of jute-epoxy composites/sandwiches under normal ballistic impact

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2020年第4期16卷 947-955页

作者： Sangamesh Rajole K.S.Ravishankar S.m.Kulkarni Department of mechanical Engineering National Institute of Technology KarnatakaSurathkalMangalore 575025India Department of metallurgical and materials Engineering National Institute of Technology KarnatakaSurathkalMangalore 575025India

This study is undertaken to explore the use of natural fiber jute-epoxy(jE),jute-epoxy-rubber(jRE)sandwich composite for ballistic energy *** absorbed and residual velocities for these composites are evaluated analytically and through Finite Element Analysis(FEA).FE analysis of jE plates is carried out for different thicknesses(3,5,10 and 15 mm).jE plates and jRE sandwiches having the same thickness(15 mm) are fabricated and tested to measure residual velocity and energy *** analytical results are found to agree well with the results of FE analysis with a maximum error of 9%.The study on jE composite plate reveals that thickness influences the energy *** and FE analysis study showed that jRE sandwiches have better energy absorption than jE *** absorption of a jRE sandwich is about 71% greater than jE *** obtained from FEA and testing are in good agreement,SEm analysis confirms composites failed by fiber rupture and fragmentation.

关键词： Energy absorption Composites Polymer composites Ballistic impact High velocity impact

Interpretable modeling of metallurgical responses for an industrial coal column flotation circuit by XGBoost and SHAP-A “conscious-lab” development

在线全文

学校读者我要写书评

暂无评论

International journal of mining Science and Technology 2021年第6期31卷 1135-1144页

作者： S.Chehreh Chelgani H.Nasiri m.Alidokht minerals and metallurgical Engineering Dept.of CivilEnvironmental and Natural Resources EngineeringLuleåUniversity of TechnologySE-97187 LuleåSweden Department of Computer Engineering Amirkabir University of TechnologyTehranIran Tabas Parvardeh Coal Company(TPCCO) BirjandIran

Surprisingly,no investigation has been explored relationships between operating variables and metallurgical responses of coal column flotation(CF) circuits based on industrial databases for under operation *** a novel approach,this study implemented a conscious-lab "CL" for filling this *** this approach,for developing the CL dedicated to an industrial CF circuit,SHapley Additive explanations(SHAP) and extreme gradient boosting(XGBoost) were powerful unique machine learning systems for the first time *** explainable artificial intelligence models could effectively convert the dataset to a basis that improves human capabilities for better understanding,reasoning,and planning the *** could provide precise multivariable correlation assessments between the CF dataset by using the Tabas Parvadeh coal plant(Kerman,Iran),and showed the importance of solid percentage and washing water on the metallurgical responses of the coal CF *** could predict metallurgical responses(R-square> 0.88) based on operating variables that showed quite higher accuracy than typical modeling methods(Random Forest and support vector regression).

关键词： SHAP XGBoost Explainable AI Coal flotation Separation efficiency

Numerical study on dynamic properties of rubberised concrete with different rubber contents

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2023年第6期24卷 228-240页

作者： Lei Pan Hong Hao jian Cui Thong m.Pham Guangzhou University-Curtin University joint Research Centre for Structural monitoring and Protection Against multi-Dynamic Hazards School of Civil EngineeringGuangzhou UniversityChina Guangzhou University-Curtin University joint Research Centre for Structural monitoring and Protection Against multi-Dynamic Hazards School of Civil and Mechanical EngineeringCurtin UniversityAustralia School of Civil Engineering Tianjin UniversityChina Centre for Infrastructural monitoring and Protection School of Civil and Mechanical EngineeringCurtin UniversityAustralia

As a green environmentally-friendly material,rubberised concrete(Ru C),which has the characteristics of low elastic modulus,large deformation capacity,high damping,good energy dissipation and good crack resistance,has attracted extensive attention and research in the civil engineering ***,most of existing studies are based on experimental tests on Ru C material properties,and there has been no numerical study based on meso-scale modelling of Ru C *** more comprehensively investigate the Ru C dynamic material properties without conducting intensive experimental tests,this study developed a high-fidelity meso-scale model considering coarse and fine aggregates and rubber crumbs to numerically investigate the mechanical properties of rubberised concrete under different strain *** meso-scale model was verified against both quasi-static compressive testing data and Split Hopkinson Pressure Bar(SHPB)dynamic testing *** the verified numerical model,the dynamic properties of rubberised concrete with various rubber content(0%-30%)under different strain rates were *** numerical results show that the developed meso-scale model can use to predict the static and dynamic properties of rubberised concrete with high *** dynamic compressive strength of the rubberised concrete increases with the increment of the strain rate,and the strain rate sensitivity increases with the rubber content ranging from 0 to 30%.Based on intensive numerical simulation data,empirical DIFs is used as a function of strain rate and rubber content to predict the dynamic strength of rubberised concrete.

关键词： Rubberised concrete meso-scale model Numerical simulation Strain rate effect Dynamic increase factor

Coal mine entry rating system:A case study

在线全文

学校读者我要写书评

暂无评论

International journal of mining Science and Technology 2021年第1期31卷 145-151页

作者： mark A.Van Dyke Ted m.Klemetti Craig Compton National Institute for Occupational Safety and Health Pittsburgh Mining Research DivisionPittsburghPA 15236USA

Coal mines are continuously seeking to determine the performance of entries with different ground control products and installation *** are many factors that impact how an entry will perform which include but are not limited to geology,overburden,bolting type and pattern,and mine *** the National Institute for Occupational Safety and Health(NIOSH),research has been instituted to examine the relationship of the parts of a coal mine entry as a system and not as individual *** study this relationship,the first step in this study was to create a numeric rating system that accurately reflects visual observations of the mine entry and is easy to *** researchers devised this rating system to improve upon previous ideas,offering increased flexibility which can be incorporated into an overall entry condition that offers different levels of confidence based on the user’s time devoted to the *** new entry rating system was implemented at three different mines over varying periods of time to evaluate the ground response to the geology,bolt installation pattern,stress changes by mining,overburden,and time dependency.

关键词： Coal Geology Rating system Support

A Study of Eruca vesicaria, Bromelia hemisphaerica and Erythrina americana as Green Corrosion Inhibitors for Carbon Steel in Sulfuric Acid

在线全文

学校读者我要写书评

暂无评论

Advances in materials Physics and Chemistry 2016年第2期6卷 9-20页

作者： m. j. Garcia-Ramirez G. F. Dominguez Patiño j. G. Gonzalez-Rodriguez m. L. Dominguez-Patiño j. A. Dominguez-Patiño Centre for Engineering and Applied Science Morelos State Autonomous University Cuernavaca Mexico Faculty of Biological Sciences Morelos State Autonomous University Cuernavaca Mexico Faculty of Chemistry and Engineering Morelos State Autonomous University Cuernavaca Mexico

A study of Eruca vesicaria, Bromelia hemisphaerica and Erythrina americana as eco-friendly corrosion inhibitors for 1018 carbon steel in 0.5 m H2SO4 has been carried out by using weight loss tests, potentiodynamic polarization curves and electrochemical impedance spectroscopy measuremnts. Results have shown that the three extracts performed as good corrosion inhibitors, but the Eruca vesicaria exhibited the best performance followed by Erythrina americana. The three inhibitors formed a protective, passive film which protected the steel from corrosion. This was because they contain antioxidants present in their molecular structure with heteroatoms such as N, C and O like phenols, amino acids, etc., which react with metal and environment to form the protective film.

关键词： Acid Corrosion Green Inhibitors Electrochemical Techniques

STUDIES ON THE HEAT TRANSFER BEHAVIOUR OF THE INTERFACE BETWEEN WORKPIECE AND mEDIA IN THE QUENCHING PROCESS

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

Acta metallurgica Sinica(English Letters) 1997年第6期10卷 479-484页

作者： m. Cheng j. Cheng S.Q. Yuan and F. Zhao(North China Institute of Technology, Taiyuan 030051, China)

On the basis of experimental studies, a program dealing with the boundary condition in the quenching process has been developed. In this program the method of Beck nonlinear estimation (inverse heat conduction method) was adopted so that the problem of the heat transfer coefficient varying significantly and complicatedly in the quenching process, has been effectively solved. Calculation result shows that the heat transfer coefficient between quenching workpiece and media boundary has a peak value, and this value and the temperature interval in which the peak value occurs vary with the cross section dimensions of workpiece, the types of the quenching media, the temperature and the surface position.

关键词： quenching interface heat transfer

Hardening and toughening effects of intermediate nanosized structures in a confined amorphous alloy film

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23期118卷 44-53页

作者： Z.Q.Chen m.C.Li X.Tong Y.Zhao j.Y.Xie S.W.Guo P.Huang F.Wang H.B.Ke B.A.Sun W.H.Wang Songshan Lake materials Laboratory Dongguan 523808China Institute of Physics Chinese Academy of SciencesBeijing 100190China Xinjiang Key Laboratory of Solid State Physics and Devices and School of Physical Science and Technology Xinjiang UniversityXinjiangUrumqi 830046China Key Laboratory of LCR materials and Devices of Yunnan Province School of Materials and EnergyYunnan UniversityKunming 650091China State-Key Laboratory for mechanical Behavior of material Xi’an Jiaotong UniversityXi’an 710049China State Key Laboratory for Strength and Vibration of mechanical Structures Xi’an Jiaotong UniversityXi’an 710049China National Demonstration Center for Experimental mechanics Education Xi’an Jiaotong UniversityXi’an 710049China

The plastic deformation of amorphous alloys is well known to be localized into shear bands(SBs),which are believed to stem from the atomic-scale flow defects,i.e.,shear transformation zones(STZs).Yet,the bridge between the mesoscopic SBs and the atomic-scale STZs remains poorly *** this work,through thermally activating pronouncedβrelaxations in the well-designed crystalline-layer confined amorphous(CLCA)Ni W alloy films,we experimentally captured and observed an intermediate nanosized structure termed as“nano shear bands”(NSBs)with a typical size of 1–2 nm in thickness and5–10 nm in *** influences of such NSB structures on the macroscale deformation behavior were systematically *** was found that NSBs lead to both hardening and toughening effects for the CLCA films,as they promote multiple and controlled shear banding deformation,which results in enhanced *** intermediate NSB structure could connect the microstructural characteristics and macroscopic plasticity in amorphous alloys and may provide new insights for understanding the microscopic deformation mechanism of amorphous alloys as well as tuning/designing their properties.

关键词： Amorphous alloys Nano shear band Hardening Toughening Crystallization

multi-layered plate finite element models with node-dependent kinematics for smart structures with piezoelectric components

在线全文

学校读者我要写书评

暂无评论

Chinese journal of Aeronautics 2021年第8期34卷 164-175页

作者： Guohong LI Erasmo CARRERA Yuliang HOU Gennady m.KULIKOV mUL2 Group Department of Mechanical and Aerospace EngineeringPolitecnico di TorinoTorino 10129Italy Laboratory of Intelligent materials and Structures Tambov State Technical UniversityTambov 392000Russia School of mechanical and Power Engineering Zhengzhou UniversityZhangzhou 450001China

This article presents a type of plate Finite Element(FE)models with adaptive mathematical refinement capabilities for modeling laminated smart structures with piezoelectric layers or distributed *** p-version shape functions are used in combination with the higher-order Layer-Wise(LW)kinematics adopting hierarchical Legendre ***-Dependent Kinematics(NDK)is employed to implement local LW models in the regions with piezoelectric components and simulate the global substrate structure with the Equivalent Single-Layer(ESL)*** the proposed NDK FE models,the electro-mechanical behavior of smart structures can be predicted with high fidelity and numerical efficiency,and various patch configurations can be conveniently modeled through one set of mesh ***,the effectiveness and efficiency of the NDK FE approach are assessed through numerical examples and its application is demonstrated.

关键词： Finite element Laminated composites Piezoelectric Refined plate theory Smart structures