检索结果-南通市图书馆

Effect of high-Frequency Electric Field on Propagation of Electrostatic Wave in a Non-Uniform Relativistic Plasma Waveguide

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 2008年第3期10卷 278-283页

作者： kh.h.EL-shORBAGY Plasma Physics and Nuclear Fusion Department Nuclear Research Center Atomic Energy Authority Cairo Egypt

The effect of a high frequency （hF） electric field on the propagation of electrostatic wave in a 2D non-uniform relativistic plasma waveguide is investigated. A variable separation method is applied to the two-fluid plasma model. An analytical study of the reflection of electrostatic wave propagation along a magnetized non-uniform relativistic plasma slab subjected to an intense hF electric field is presented and compared with the case of a non relativistic plasma. It is found that, when the frequency of the incident wave is close to the relativistic electron plasma frequency, the plasma is less reflective due to the presence of both an hF field and the effect of relativistic electrons. On the other hand, for a low-frequency incident wave the reflection coefficient is directly proportional to the amplitude of the hF field. Also, it is shown that the relativistic electron plasma leads to a decrease in the value of reflection coefficient in comparison with the case of the non relativistic plasma.

关键词： electrostatic wave relativistic plasma waveguide reflection coefficient separation method

Electrical characterization of the organic semiconductor Ag/CuPc/Au schottky diode

在线全文

学校读者我要写书评

暂无评论

Journal of semiconductors 2011年第4期32卷 52-56页

作者： Mutabar shah M.h.sayyad kh.s.Karimov Ghulam Ishaq khan Institute of Engineering sciences and Technology physical Technical Institute of Academy of sciences

This paper reports on the fabrication and investigation of a surface-type organic semiconductor copper phthalocyanine（CuPc） based diode.A thin film of CuPc of thickness 100 nm was thermally sublimed onto a glass substrate with preliminary deposited metallic electrodes to form a surface-type Ag/CuPc/Au schottky *** current-voltage characteristics were measured at room temperature under dark *** barrier height was calculated as 1.05 *** values of mobility and conductivity was found to be 1.74×10;cm;/（V·s） and 5.5×10;Ω;·cm;,*** low voltages the device showed ohmic conduction and the space charge limited current conduction mechanisms were dominated at higher voltages.

关键词： schottky diode copper phthalocyanine thin film organic semiconductor mobility

CuPc based organic-inorganic hetero-junction with Au electrodes

在线全文

学校读者我要写书评

暂无评论

Journal of semiconductors 2010年第7期31卷 22-25页

作者： Zubair Ahmad Muhammad h.sayyad kh.s.Karimov Ghulam Ishaq khan Institute of Engineering sciences and Technology TopiNWFP23460Pakistan Department of Mechanical Engineering 20 Symond Street AucklandUniversity of AucklandNew Zealand

A hetero-junction of n-silicon（n-si） and copper phthalocyanine（CuPc） has been *** current -voltage characteristics were investigated to explain the rectification and conduction *** effect of temperature and humidity on the electrical properties of n-si/CuPc hetero-junction has also been *** characteristics of the junction have been observed to be temperature and humidity dependent,so it is suggested that this junction can be used as a temperature and humidity sensor.

关键词： inorganic-organic hetero-junction n-si CuPc

Effects of magnetic field,porosity,and wall properties for anisotropically elastic multi-stenosis arteries on blood flow characteristics

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2011年第8期32卷 1047-1064页

作者： kh.s.MEkhEIMER M.h.hAROUN M.A.ELKOT Department of Mathematics Faculty of science Al-Azhar University Department of Mathematics Faculty of Education ain shams University Department of Mathematics Faculty of science suez Canal University

A mathematical model for blood flow through an elastic artery with multistenosis under the effect of a magnetic field in a porous medium is presented. The considered arterial segment is simulated by an anisotropically elastic cylindrical tube filled with a viscous incompressible electrically conducting fluid representing blood. An artery with mild local narrowing in its lumen forming a stenosis is analyzed. The effects of arterial wall parameters represent viscoelastic stresses along the longitudinal and circumferential directions T t and T θ , respectively. The degree of anisotropy of the vessel wall γ, total mass of the vessel, and surrounding tissues M and contributions of the viscous and elastic constraints to the total tethering C and K respectively on resistance impedance, wall shear stress distribution, and radial and axial velocities are illustrated. Also, the effects of the stenosis shape m, the constant of permeability κ, the hartmann number ha and the maximum height of the stenosis size δ on the fluid flow characteristics are investigated. The results show that the flow is appreciably influenced by surrounding connective tissues of the arterial wall motion, and the degree of anisotropy of the vessel wall plays an important role in determining the material of the artery. Further, the wall shear stress distribution increases with increasing T t and γ while decreases with increasing T θ , M, C, and K. Transmission of the wall shear stress distribution and resistance impedance at the wall surface through a tethered tube are substantially lower than those through a free tube, while the shearing stress distribution at the stenosis throat has inverse characteristic through totally tethered and free tubes. The trapping bolus increases in size toward the line center of the tube as the permeability constant κ increases and decreases with the hartmann number ha increased. Finally, the trapping bolus appears, gradually in the case of non-symmetric stenosis, and disap

关键词： stenosis degree of anisotropy free tube tethered tube trapping bolus

Machine learning-enhanced Monte Carlo and subset simulations for advanced risk assessment in transportation infrastructure

在线全文

学校读者我要写书评

暂无评论

Journal of Mountain science 2024年第2期21卷 690-717页

作者： Furquan AhMAD Pijush sAMUI s.s.MIshRA Department of Civil Engineering National Institute of TechnologyPatna 800006India

The maintenance of safety and dependability in rail and road embankments is of utmost importance in order to facilitate the smooth operation of transportation *** study introduces a comprehensive methodology for soil slope stability evaluation,employing Monte Carlo simulation(MCs)and subset simulation(ss)with the"UPss 3.0 Add-in"in *** on an 11.693-meter embankment with a soil slope(inclination ratio of 2h:1V),the investigation considers earthquake coefficients(kh)and pore water pressure ratios(ru)following Indian zoning *** chance of slope failure showed a considerable increase as the Coefficient of Variation(COV),seismic coefficients(kh),and pore water pressure ratios(ru)experienced an *** ss approach showed exceptional efficacy in calculating odds of failure that are notably *** computational modeling,the study optimized the worst-case scenario using ANFIs-GA,ANFIs-GWO,ANFIs-PsO,and ANFIs-BBO *** ANFIs-PsO model exhibits exceptional accuracy(training R2=0.9011,RMsE=0.0549;testing R2=0.8968,RMsE=0.0615),emerging as the most *** study highlights the significance of conducting thorough risk assessments and offers practical insights into evaluating and improving the stability of soil slopes in transportation *** findings contribute to the enhancement of safety and reliability in real-world situations.

关键词： Monte Carlo simulation subset simulation Machine Learning seismic coefficient

Evaluation of Al and some of Its Alloys as Anode Materials vs γ-MnO_2 as Cathode Material and Ore Produced γ-MnO_2 vs Zn Anode in KOh solution

在线全文

学校读者我要写书评

暂无评论

Journal of Materials science & Technology 2006年第1期22卷 25-30页

作者： A.M.A.hashem kh.s.Abou-El-sherbini s.Zein El Abedin h.Abbas Inorganic Chemistry Department National Research CentreBehoes StreetDokkiCairoEgypt Physical Chemistry Department National Research CentreBehoes StreetDokkiCairoEgypt

In this study electrochemical performance of Al and some of its alloys （Al-Zn, Al-rvlg and Al-rvln） anodes vs MnO2 cathode were carried out in alkaline solution. The results show that the Al-Zn alloy anode has the best cell capacity among the other alloys. Cell capacity values go in the order Al-Zn〉Al-Mg〉Al〉Al-Mn. This result is probably related to the nature of passive films formed on the surface of the alloys which examined by scanning electron microscopy （sEM）. sEM morphologies of Al and its alloys showed coarse grains of passive films formed on the surface of these anode materials while Al-Mn morphology shows a needle-like structure. Electrolytic manganese dioxide （EMD） produced by electrodepositing on platinum anode from liquor resulting from reduction of low grade pyrolusite ore （β-MnO2） by sulfur slag was characterized as cathode in alkaline Zn-MnO2 batteries. Ore produced sample （EMD1） was performed well in comparison with EMD standard （EMD2）（commercial battery grade electrolytic manganese dioxide, TOsOh-hellas Gh-s）. sEM morphology of Zn anode after cell reaction was carried out and showed that Zn anode has fine grains of passive film on its surface.

关键词： Electrolytic MnO2 Zn Al Alkaline batteries

Optimization Task scheduling Using Cooperation search Algorithm for heterogeneous Cloud Computing systems

在线全文

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2023年第1期74卷 2133-2148页

作者： Ahmed Y.hamed M.kh.Elnahary Faisal s.Alsubaei hamdy h.El-sayed Department of Computer science Faculty of Computers and Artificial IntelligenceSohag UniversitySohag82524Egypt Department of Cybersecurity College of Computer Science and EngineeringUniversity of JeddahJeddah21959Saudi Arabia

Cloud computing has taken over the high-performance distributed computing area,and it currently provides on-demand services and resource polling over the *** a result of constantly changing user service demand,the task scheduling problem has emerged as a critical analytical topic in cloud *** primary goal of scheduling tasks is to distribute tasks to available processors to construct the shortest possible schedule without breaching precedence *** and schedules of tasks substantially influence system operation in a heterogeneous multiprocessor *** diverse processes inside the heuristic-based task scheduling method will result in varying makespan in the heterogeneous computing *** a result,an intelligent scheduling algorithm should efficiently determine the priority of every subtask based on the resources necessary to lower the *** research introduced a novel efficient scheduling task method in cloud computing systems based on the cooperation search algorithm to tackle an essential task and schedule a heterogeneous cloud computing *** basic idea of thismethod is to use the advantages of meta-heuristic algorithms to get the optimal *** assess our algorithm’s performance by running it through three scenarios with varying numbers of *** findings demonstrate that the suggested technique beats existingmethods NewGenetic Algorithm(NGA),Genetic Algorithm(GA),Whale Optimization Algorithm(WOA),Gravitational search Algorithm(GsA),and hybrid heuristic and Genetic(hhG)by 7.9%,2.1%,8.8%,7.7%,3.4%respectively according to makespan.

关键词： heterogeneous processors cooperation search algorithm task scheduling cloud computing

A study on the Wear Behaviour of Dual Phase steels

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

Journal of Materials science & Technology 2007年第1期23卷 107-110页

作者： V.Abouei h.saghafian sh.kheirandish kh.Ranjbar Department of Metallurgy and Materials Engineering Iran University of Science and TechnologyIran shahid Chamran University Iran

Dual phase （DP） steels containing four different amounts of martensite ranging from 43 vol. pct to 81 vol. pct have been developed from 0.2 wt pct carbon steel by intercritical heat treatment at a fixed temperature of 780℃ with varying holding times followed by water quenching. Dry sliding wear tests have been conducted on DP steels using a pin- on-disk machine under different normal loads of 61.3, 68.5, 75.7 and 82.6 N and at a constant sliding speed of 1.20 m/s. At these loads, the mechanism of wear is primarily delamination, which has been confirmed by sEM micrographs of subsurface and wear debris of samples. Wear properties have been found to improve with the increase in martensite volume fraction in dual phase steels.

关键词： Wear Dual phase steel Microstructure

Influence of monovalent cations and CuO nanoparticles on X-nanozeolite in uranium anionic species separation from contaminated drinking water

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2017年第6期25卷 782-792页

作者： h.R. shakur kh. Rezaee Ebrahim saraee M.R. Abdi G. Azimi Department of Nuclear Engineering Faculty of Advance Sciences and Technologies University of lsfahan Isfahan 81746-73441 lran Department of Physics Faculty of science University of lsfahan lsfahan 81747-73441 Iran Department of Chemistry University of lsfahan lsfahan 81747-73441 Iran

The main purpose of this work was the modification of NaX nanozeolite using copper oxide nanoparticles and various monovalent cations such as K^+, Cs^+, and Ag^+in order to make the negatively charged zeolite surface accessible for anionic forms of uranium which are the most dominant species of uranium in the contaminated radioactive waters at natural p h. Various methods such as the X-ray fluorescence(XRF), X-ray powder diffraction(XRD), field emission scanning electron microscopy(FE-sEM), transmission electron microscopy(TEM), Fourier transform infrared spectroscopy(FT-IR), and atomic absorption spectroscopy(AAs) were used to characterize the final synthesized absorbents. Batch technique was used to study the adsorption behavior of uranium ions from polluted drinking water by Na X nanozeolite and its modified forms. In order to better understand the performance of them, the results were compared with those that were obtained for synthesizing bulk NaX zeolite and Na-form of clinoptilolite natural zeolite. Preliminary results indicated that uranium sorption increased as the loading level of CuO nanoparticles on NaX nanozeolite increased from 2.1 wt% to 11.2 wt%. In addition,from the obtained data, an increase in uranium removal efficiency resulted as charge/ionic radius ratio of exchanged cation decreased. Also, the effect of contact time, solid–liquid ratio, initial concentration and temperature on the adsorption process was studied. It is worth mentioning that, in this study, the sorption of uranium was performed under natural conditions of ph and the presence of competing cations and anions which are available in drinking waters.

关键词： Zeolite Monovalent cation NaX/CuO nanocomposite Uranium anions separation Waste water