检索结果-南通市图书馆

Solutions of the Duffin-kemmer-Petiau equation in the presence of Hulthn potential in(1+2) dimensions for unity spin particles using the asymptotic iteration method

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2013年第6期22卷 193-198页

作者： z.Molaee M.k.Bahar F.Yasuk H.Hassanabadi Department of Basic Sciences Garmsar BranchIslamic Azad UniversityGarmsarIran Department of Physics Erciyes University38039KayseriTurkey Department of Physics Karamanoglu Mehmetbey University70100KaramanTurkey Department of Basic Sciences Shahrood BranchIslamic Azad UniversityShahroodIran

The relativistic Duffin-kemmer-Petiau equation in the presence of Hulthen potential in （1 ＋2） dimensions for spin-one particles is studied. Hence, the asymptotic iteration method is used for obtaining energy eigenv... 详细信息

关键词： Duffin-kemmer-Petiau equation Hulthen potential asymptotic iteration method

WAVE RESISTANCE OF WAVE-PIERCING CATAMARANS

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2000年第4期12卷 88-98页

作者： Lu, X.P. Huang, Y. Shi, z.k. Coll. of Traffic Sci. and Eng. Huazhong Univ. of Sci. and Technol. Wuhan 430074 China

Present paper researches the theoretical method for calculating the wave resistance of wave-piercing catamaran. As an example the wave resistance of a wave-piercing catamaran is calculated. The comparison among the theoretical calculation results, the model test results and the graphic evaluation results shows the efficiency of present theoretical method. Finally the wave resistance regulation of wave-piercing catamarans is investigated based on the theoretical method.

关键词： Ships

THEORETICAL ANALYSIS FOR THE MOTION AND TEMPERATURE OF MELT DROPLETS IN SPRAY DEGASSING PROCESS

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2007年第3期20卷 193-198页

作者： R.z. Wu z.k. Qu B.D. Sun D. Shu J. Wang College of Materials Science ＆ Chemical Engineering Harbin Engineering University Harbin 150001 China State key Laboratory of Metal Matrix Composites Shanghai Jiao Tong University Shanghai 200030 China Department of Chemistry Harbin Normal University Harbin 150025 China

The motion of melt droplets in spray degassing process was analyzed theoretically. The height of the treatment tank in spray degassing process couM be determined by the results of theoretical calculation of motion of melt droplets. To know whether the melt droplets wouM solidify during spraying process, the balance temperature of melt droplets was also theoretically analyzed. Then proof experiments for theoretical results about temperature of melt droplets were carried. In comparison, the experimental results were nearly similar to the calculation results,

关键词： spray degassing hydrogen removal aluminum melt motion temperature

Twisted Pair Cable Fault Diagnosis via Random Forest Machine Learning

在线全文

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2022年第6期71卷 5427-5440页

作者： N.B.Ghazali F.C.Seman k.Isa k.N.Ramli z.z.Abidin S.M.Mustam M.A.Haek A.N.z.Abidin A.Asrokin Faculty of Electrical and Electronic Engineering Universiti Tun Hussein Onn MalaysiaBatu PahatJohor TM Research&Development CyberjayaMalaysia

Applying the fault diagnosis techniques to twisted pair copper cable is beneficial to improve the stability and reliability of internet access in Digital Subscriber Line(DSL)Access Network *** network performance depends on the occurrence of cable fault along the copper ***,most of the telecommunication providers monitor the network performance degradation hence troubleshoot the present of the fault by using commercial test gear on-site,which may be resolved using data analytics and machine learning *** paper presents a fault diagnosis method for twisted pair cable fault detection based on knowledge-based and data-driven machine learning *** DSL Access Network is emulated in the laboratory to accommodate VDSL2 Technology with various types of cable fault along the cable distance between 100 m to 1200 ***,the line operation parameters and loop line testing parameters are collected and used to ***,the feature transformation,a knowledge-based method,is utilized to pre-process the fault ***,the random forests algorithms(RFs),a data-driven method,are adopted to train the fault diagnosis classifier and regression algorithm with the processed fault ***,the proposed fault diagnosis method is used to detect and locate the cable fault in the DSL Access Network *** results show that the cable fault detection has an accuracy of more than 97%,with less minimum absolute error in cable fault localization of less than 11%.The proposed algorithm may assist the telecommunication service provider to initiate automated cable faults identification and troubleshooting in the DSL Access Network System.

关键词： Twisted pairs random forest machine learning cable fault DSL

An Implicit Block LU-SGS Algorithm-Based Lattice Boltzmann Flux Solver for Simulation of Hypersonic Flows

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

Advances in Applied Mathematics and Mechanics 2019年第1期11卷 72-90页

作者： z.X.Meng S.z.Li k.Peng W.H.zhang College of Aerospace Science and Engineering National University of Defense TechnologyChangsha 410073China National Innovation Institute of Defense Technology Academy of Military ScienceBeijing 100091China

This paper proposes a stable and efficient implicit block Lower-Upper Symmetric-Gauss-Seidel(LU-SGS)algorithm-based lattice Boltzmann flux solver(LBFS)for simulation of hypersonic *** this method,the finite volume method(FVM)is applied to discretize the Navier-Stokes equations,and the LBFS is utilized to evaluate the numerical flux at the cell *** LBFS,the local solution of discrete velocity Boltzmann equation(DVBE)with the non-free parameter D1Q4 lattice Boltzmann model is adopted to reconstruct the inviscid flux across the cell interface,and the viscous flux is approximated by conventional smooth function *** order to improve the robustness and convergence rate of the simulation for hypersonic flows,especially for problems with complex geometry,the implicit block LU-SGS algorithm is introduced to solve resultant discrete governing equations.A double cone model at Mach number of Ma=9.86 is firstly simulated to validate the proposed scheme,and a hypersonic flight vehicle with wings and rudders at Mach number of Ma=5.56 is then calculated to extend the application in practical engineering *** results show that the proposed scheme could offer a more accurate and effective prediction for hypersonic flows.

关键词： Hypersonic flows lattice Boltzmann flux solver implicit block LU-SGS finite volume method

Mechanical properties of Al/a-C nanocomposite thin films synthesized using a plasma focus device

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

Chinese Physics B 2014年第2期23卷 353-358页

作者： z.A.Umar R.S.Rawat R.Ahmad A.k.kumar Y.Wang T.Hussain z.Chen L.Shen z.zhang NSSE National Institute of EducationNanyang Technological University Department of Physics GC University Center for Advanced Studies in Physics (CASP) GC University School of Materials Science and Engineering Nanyang Technological University Institute of Materials Research and Engineering ASTAR (Agency for ScienceTechnology and Research)3 Research Link

The Al/a-C nanocomposite thin films are synthesized on Si substrates using a dense plasma focus device with alu- minum fitted anode and operating with CH4/Ar admixture. X-ray diffractometer results confirm the formation of metallic crystalline Al phases using different numbers of focus shots. Raman analyses show the formation of D and G peaks for all thin film samples, confirming the presence of a-C in the nanocomposite thin films. The formation of Al/a-C nanocomposite thin films is further confirmed using X-ray photoelectron spectroscopy analysis. The scanning electron microscope results show that the deposited thin films consist of nanoparticles and their agglomerates. The sizes of th agglomerates increase with increasing numbers of focus deposition shots. The nanoindentation results show the variations in hardness and elastic modulus values of nanocomposite thin film with increasing the number of focus shots. Maximum values of hardness and elastic modulus of the composite thin film prepared using 20 focus shots are found to be about 10.7 GPa and 189.2 GPa, respectively.

关键词： dense plasma focus X-ray photoelectron spectroscopy field emission scanning electron micro- scope elastic modulus

Evaluating instrumented Charpy impact strain signals using curve fitting equations

在线全文

学校读者我要写书评

暂无评论

Journal of Central South University 2014年第2期21卷 600-609页

作者： M.B.Ali S.Abdullah M.z.Nuawi A.k.Ariffin z.M.Nopiah Department of Mechanical and Materials Engineering Faculty of Engineering and Built EnvironmentUniversiti Kebangsaan Malaysia Department of Structure and Material Faculty of Mechanical EngineeringUniversiti Teknikal Malaysia Melaka

An effective and simple way to develop equations from impact strain signals was *** research has been performed in this area,but this equation is very important for evaluating input signals in finite element analysis impact tests and for obtaining additional information on material deformation and fracture processes under impact *** this purpose,dynamic impact responses were examined through signals obtained from a strain gauge installed on an impact striker connected to a data acquisition *** 6061-T6 was used to extract strain responses on the striker during Charpy impact *** analysis was performed using the I-kaz method,and curve fitting equations based on the equation for vibration response under a non-periodic force were used to evaluate the Charpy impact *** I-kaz coefficients and curve fitting equations were then compared and discussed with related parameters,such as velocities and *** and thickness were found to be related to the strain signal patterns,curve fitting equations and I-kaz *** equations developed using this method had R2 values greater than 97.7%.Finally,the constructed equations were determined to be suitable for evaluating Charpy impact strain signal patterns and obtaining additional information on fracture processes under impact loading.

关键词： charpy impact curve fitting I-kaz signal and strain

RESEARCH ON LASER DIRECT DEPOSITION PROCESS OF Ti-6Al-4V ALLOY

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2007年第3期20卷 171-180页

作者： S.Y. Gao Y.z. zhang L.k. Shi B.L. Du M.z. Xi H.z. Ji Mechanical Engineering College Yanshan University O~mhuangdao 066004 China Beijing General Research Institute for Nonferrous Metals Beijing 100088 China

Laser direct deposition （LDD） of metallic components is an advanced technology of combining CAD/CAM （computer aided design/computer aided manufacturing）, high power laser, and rapid prototyping. This technology uses laser beam to melt the powders fed coaxiaUy into the molten pool by the laser beam to fabricate fuUy dense metallic components. The present article mainly studies the LDD of Ti-6Al-4V alloy, which can be used to fabricate aircraft components. The mechanical properties of the Ti-6Al-4V alloy, fabricated by LDD, are obtained using the tension test, and the oxygen content of used powders and deposited specimens are measured. In the present article, it can be seen that the mechanical properties obtained using this method are higher than the ones obtained by casting, and equal to those got by wrought anneal. One aircraft part has been made using the LDD process. Because of this aircraft part, with sophisticated shape, the effect of the laser scanning track on the internal soundness of the deposited part was discussed.

关键词： laser direct deposition Ti-6Al-4V alloy mechanical property depositing process aircraft component

Investigation of Microstructure, Microhardness and Thermal Properties of Ag-In Intermetallic Alloys Prepared by Vacuum Arc Meltings

在线全文

学校读者我要写书评

暂无评论

Journal of Wuhan University of Technology(Materials Science) 2024年第1期39卷 182-187页

作者： ÇELİk Erçevik ATA ESENER Pınar ÖzTÜRk Esra AkSÖz Sezen Nevşehir HacıBektaşVeli University Department of Physics50300NevşehirTurkey Erciyes University Graduate School of Natural and Applied Sciences38039KayseriTurkey kocaeli University Department of Physics41380KocaeliTurkey

Ag-In intermetallic alloys were produced by using vacuum arc furnace. Differential Scanning Calorimetry(DSC) and Energy Dispersive X-Ray Spectrometry(EDX) were used to determine the thermal properties and chemical composition of the phases respectively. Microhardness values of Ag-In intermetallics were calculated with Vickers hardness measurement method. According to the experimental results, Ag-34 wt%In intermetallic system generated the best results of energy saving and storage compared to other intermetallic systems. Also from the microhardness results, it was observed that intermetallic alloys were harder than pure silver and Ag-26 wt%In system had the highest microhardness value with 143.45 kg/mm^(2).

关键词： thermal properties microstructure characterization microhardness alloys material characterization