检索结果-南通市图书馆

mechanical and magneto-electronic properties of europium lanthanide-based cubic perovskites EuYO_(3)(Y=Cr, mn, Fe): An ab initio study

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 2024年第3期42卷 562-569,I0005页

作者： Hayat Ullah Azra Sarwar Sajad ali Rabah Khenata Abdelmadjid Bouhemadou Saad Bin-Omran Department of Physics Women University of Azad Jammu&Kashmir Bagh 10250Pakistan Department of Physics Abdul Wali Khan UniversityMardan23200KPPakistan LPQ3m Laboratory Institute of Science and TechnologyUniversity of Mascara29000MascaraAlgeria Laboratory for Developing New materials and Their Characterization Farhat Abbas University Setif l19000SetifAlgeria Department of Physics and Astronomy College of ScienceKing Saud UniversityP.O.Box 2455Riyadh11451Saudi Arabia

Computational calculations using density functional theory(DFT) were performed for the first time using the full potential linearized augmented plane wave plus local orbital method(FP-LAPW + LO) to determine the structural, elastic, electronic and magnetic properties of europium-based cubic perovskites EuYO_(3)(Y=Cr, mn, Fe). The exchange correlation potentials of GGA along with some analytical methods were adopted for the computation of structural and elastic properties. moreover, the GGA + U formalism was also added for obtaining more precise electronic and magnetic properties, particularly to address the Eu-4f and Y-3d orientations in the spin-polarized double cell symmetry. The observed lattice parameters of these compounds are consistent with experiment. The observed bulk moduli predict that EuCrO_(3) is harder and less compressible than EumnO_(3) and EuFeO_(3). The calculated tolerance factors of these compounds are within the cubic symmetry range. Our computed critical radius of EuCrO_(3) shows that EuCrO_(3) has a larger migration energy. Based on their elastic properties, these compounds are ductile in nature. We also computed the thermal properties of these compounds. The band structures and density of states show that these compounds are metallic in character. The lowest ground state energy and magnetic moments of these compounds expose their ferromagnetic nature. The metallic nature and strong ferromagnetism of these compounds make them promising applicants for application in spintronic.

关键词： Perovskites GGA+U Elastic constants Band structure magnetic moments Rare earths

Frequency and temperature dependent electrical characteristics of CaTiO_(3) nano-ceramic prepared by high-energy ball milling

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Journal of Advanced Ceramics 2013年第3期2卷 291-300页

作者： Subhanarayan SAHOO Umasankar DASH S.K.S.PARASHAR S.m.ali School of Electrical Engineering KIIT UniversityBhubaneswar 751024India Center for Nanotechnology KIIT UniversityBhubaneswar 751024India School of Applied Sciences KIIT UniversityBhubaneswar 751024India

Nanocrystalline calcium titanate(CT)ceramic has been synthesized by a combination of solid-state reaction and high-energy ball *** nano-ceramic is characterized by X-ray diffraction(XRD),dielectric study and impedance *** XRD pattern shows single phase ceramic of orthorhombic *** frequency-dependent dielectric study shows that the dielectric constant is maximized at low frequencies and decreases with an increase in *** spectroscopy analyses reveal a non-Debye type relaxation phenomenon.A significant shift in impedance loss peaks toward the higher-frequency side indicates conduction in the material favoring the long-range motion of mobile charge *** grain conduction effect is observed from the complex impedance spectrum by the appearance of one semicircular arc in Nyquist *** is also observed that the resistance decreases with an increase in temperature showing a negative temperature coefficient of resistance(NTCR).Various thermistor parameters have been calculated by fitting with Steinhart-Hart *** modulus plots represent the presence of temperature-dependent electrical relaxation phenomenon with the *** frequency-dependent AC conductivity at different temperatures indicates that the conduction process is thermally *** activation energy has been calculated from an Arrhenius plot of DC conductivity and relaxation frequency.

关键词： high-energy ball milling dielectric study impedance spectroscopy thermistor conductivity

Optimization of cultural conditions for thermostable β-1,3-1,4-glucanase production by Bacillus subtilis ZJF-IA5

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 Zhejiang University Science 2003年第6期4卷 719-726页

作者：何国庆汤兴俊 mUKHTARA.m.ali 陈启和 CollegeofBiosystemEngineeringandFoodScience ZhejiangUniversityHangzhou310029China

The optimization of cultural conditions for β-glucanase production by Bacillus subtilis ZJF-1A5 was investigated in flask trials. Temperature had great effect on β-glucanasc production which maximized atoptimal temperature of 37℃ and decreased significantly when temperature was over 37℃ . Charge quantity affected β-glucanasc production significantly. Adding oxygen vector N-dodecanc or acetic ether benefited β-glucanasc production, but it depended on the concentration and charge quantity. The results of fractional factorialdesign showed that age and size of inoculum and shaking speed were the key factors affecting β-glueanase production and the cultivation time span to reach the highest β-glucanasc activity. The optimal cultural conditionsfor p-glucanase production obtained with CCD were as follows: inoculum age and size (16 h, 3.82% (v/v)),shaking speed 210 r/rain, charge quantity of 30 mL in 250 mL flask and initial pH 7.0, cultured at 37℃ for 50 h. Repeated experimental results accorded with those predicted by a second-order polynomial model. The amount of p-glucanase, a-amylase and neutral protease produced by B subtills ZJF-1A5 was associated partially with cell growth. Those three enzymes' activities increased following the cell growth and increased signifi-cantly when cells entered the stationary phase.

关键词： β-1,3-1,4-葡聚糖酶枯草杆菌表面响应方法热稳定性发酵生产最优条件

The new types of wave solutions of the Burger’s equation and the Benjamin-Bona-mahony equation

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 Ocean Engineering and Science 2018年第1期3卷 1-10页

作者： md.Azmol Huda m.ali Akbar Shewli Shamim Shanta mathematics Discipline Khulna UniversityBangladesh Department of Applied mathematics University of RajshahiBangladesh Department of mathematics University of RajshahiBangladesh

In this article,we suggest the two variable(G/G,1/G)-expansion method for extracting further general closed form wave solutions of two important nonlinear evolution equations(NLEEs)that model one-dimensional internal waves in deep water and the long surface gravity waves of small amplitude propagating *** method can be regarded as an extension of the(G/G)-expansion *** ansatz of this extension method to obtain the solution is based on homogeneous balance between the highest order dispersion terms and nonlinearity which is similar to the(G/G)method whereas the auxiliary linear ordinary differential equation(LODE)and polynomial solution *** applied this method to find explicit form solutions to the Burger’s and Benjamin-Bona-mahony(BBm)equations to examine the effectiveness of the method and tested through mathematical computational software *** new exact travelling wave solutions in more general form of these two nonlinear equations are derived by this extended *** method introduced here appears to be easier and faster comparatively by means of symbolic computation system.

关键词： Travelling wave solution Soliton Burger’s equation Benjamin-Bona-mahony equation.

Abundant general solitary wave solutions to the family of KdV type equations

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 Ocean Engineering and Science 2017年第1期2卷 47-54页

作者： md.Azmol Huda m.ali Akbar Shewli Shamim Shanta mathematics Discipline Khulna UniversityKhulnaBangladesh Department of Applied mathematics University of RajshahiRajshahiBangladesh Department of mathematics University of RajshahiRajshahiBangladesh

This work explores the construction of more general exact traveling wave solutions of some nonlinear evolution equations(NLEEs)through the application of the(G/G,1/G)-expansion *** method is allied to the widely used(G/G)-method initiated by Wang et *** can be considered as an extension of the(G/G)-expansion *** effectiveness,the method is applied to the family of KdV type *** general form solitary wave solutions as well as periodic solutions are successfully obtained through this ***,in the obtained wider set of solutions,if we set special values of the parameters,some previously known solutions are *** approach of this method is simple and elegantly *** been computerized it is also powerful,reliable and effective.

关键词： Nonlinear evolution equation Solitary wave solution Potential KdV equation Complex modified KdV equation

A study on the compatibility of the generalized Kudryashov method to determine wave solutions

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Propulsion and Power Research 2021年第1期10卷 95-105页

作者： Hemonta Kumar Barman md.Ekramul Islam m.ali Akbar Department of Applied mathematics University of RajshahiRajshahi6205Bangladesh Department of mathematics Pabna University of Science and TechnologyPabna6600Bangladesh

In this article,we establish solitary wave solutions to the Estevez-mansfieldClarkson(EmC)equation and the coupled sine-Gordon equations which are model equations to analyze the formation of shapes in liquid drops,surfaces of negative constant curvature,*** contriving the generalized Kudryashov *** extracted results introduce several types’solitary waves,such as the kink soliton,bell-shape soliton,compacton,singular soliton,peakon and other sort of soliton for distinct valuation of the unknown *** achieved analytic solutions are interpreted in details and their 2D and 3D graphs are *** obtained solutions and the physical structures explain the soliton phenomenon and reproduce the dynamic properties of the front of the travelling wave deformation generated in the dispersive *** shows that the generalized Kudryashov method is powerful,compatible and might be used in further works to found novel solutions for other types of nonlinear evolution equations ascending in physical science and engineering.

关键词： The nonlinear evolution equations(NLEEs) The Estevez-mansfieldClarkson(EmC)equation The coupled sineGordon equations The generalized Kudryashov method Solitons Analytic solutions

machine Learning Approach for COVID-19 Detection on Twitter

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computers, materials & Continua 2021年第8期68卷 2231-2247页

作者： Samina Amin m.Irfan Uddin Heyam H.Al-Baity m.ali Zeb m.Abrar Khan Institute of Computing Kohat University of Science and TechnologyKohat26000Pakistan Department of Information Technology College of Computer and Information SciencesKing Saud UniversityRiyadh11543Saudi Arabia

Social networking services(SNSs)provide massive data that can be a very influential source of information during pandemic *** study shows that social media analysis can be used as a crisis detector(e.g.,understanding the sentiment of social media users regarding various pandemic outbreaks).The novel Coronavirus Disease-19(COVID-19),commonly known as coronavirus,has affected everyone worldwide in *** Twitter data have revealed the status of the COVID-19 outbreak in the most affected *** study focuses on identifying COVID-19 patients using tweets without requiring medical records to find the COVID-19 pandemic in Twitter messages(tweets).For this purpose,we propose herein an intelligent model using traditional machine learning-based approaches,such as support vector machine(SVm),logistic regression(LR),naïve Bayes(NB),random forest(RF),and decision tree(DT)with the help of the term frequency inverse document frequency(TF-IDF)to detect the COVID-19 pandemic in Twitter *** proposed intelligent traditional machine learning-based model classifies Twitter messages into four categories,namely,confirmed deaths,recovered,and *** the experimental analysis,the tweet data on the COVID-19 pandemic are analyzed to evaluate the results of traditional machine learning approaches.A benchmark dataset for COVID-19 on Twitter messages is developed and can be used for future research *** experiments show that the results of the proposed approach are promising in detecting the COVID-19 pandemic in Twitter messages with overall accuracy,precision,recall,and F1 score between 70%and 80%and the confusion matrix for machine learning approaches(i.e.,SVm,NB,LR,RF,and DT)with the TF-IDF feature extraction technique.

关键词： Artificial intelligence coronavirus COVID-19 pandemic social network Twitter machine learning natural language processing

Experimental Design Technique on Removal of Hydrogen Sulfide using CaO-eggshells Dispersed onto Palm Kernel Shell Activated Carbon：Experiment,Optimization,Equilibrium and Kinetic Studies

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 Wuhan University of Technology(materials Science) 2017年第2期32卷 305-320页

作者： OmAR Abed Habecb RAmESH Kanthasamy GOmAA A. m. ali ROSLI bin mohd Yunus Faculty of Chemical & Natural Resources Engineering Universiti Malaysia Pahang Gambang 26300 Kuantan Malaysia Faculty of Industrial Sciences and Technology Universiti Malaysia Pahang Gambang 26300 Kuantan Malaysia Chemistry Department Faculty of Science Al-Azhar University Assiut 71524 Egypt Al-Azhar Center of Nanoscience and Applications (ACNA) Al-Azhar University Assiut 71524 Egypt.

This study presents the use of chicken eggshells waste utilizing palm kernel shell based activated carbon（PKSAC） through the modification of their surface to enhance the adsorption capacity of H2S. Response surface methodology technique was used to optimize the process conditions and they were found to be： 500 mg/L for H2S initial concentration, 540 min for contact time and 1 g for adsorbent mass. The impacts of three arrangement factors（calcination temperature of impregnated activated carbon（IAC）, the calcium solution concentration and contact time of calcination） on the H2S removal efficiency and impregnated AC yield were investigated. Both responses IAC yield（IACY, %） and removal efficiency（RE, %） were maximized to optimize the IAC preparation conditions. The optimum preparation conditions for IACY and RE were found as follows： calcination temperature of IAC of 880 ℃, calcium solution concentration of 49.3% and calcination contact time of 57.6 min, which resulted in 35.8% of IACY and 98.2% RE. In addition, the equilibrium and kinetics of the process were investigated. The adsorbent was characterized using TGA, XRD, FTIR, SEm/EDX, and BET. The maximum monolayer adsorption capacity was found to be 543.47 mg/g. The results recommended that the composite of PKSAC and Ca O could be a useful material for H2S containing wastewater treatment.

关键词： water treatment hydrogen sulfide response surface methodology optimization activated carbon adsorption isotherm kinetics calcium oxide

The closed form solutions of simplified mCH equation and third extended fifth order nonlinear equation

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Propulsion and Power Research 2019年第2期8卷 163-172页

作者： A.K.m.Kazi Sazzad Hossain m.ali Akbar md.Abul Kalam Azad Department of mathematics Begum Rokeya UniversityRangpur 5400Bangladesh Department of Applied mathematics University of RajshahiRajshahi 6200Bangladesh

The investigation of closed form solutions for nonlinear evolution equations(NLEEs)is being an attractive subject in the different branches of mathematical and physical *** this article,the enhanced(G'=G)-expansion method has been applied to find the closed form solutions for NLEEs,such as the simplified mCH equation and third extended fifth order nonlinear equations which are very important in mathematical *** closed form solutions with arbitrary parameters are successfully obtained by this method which are expressed in terms of hyperbolic and trigonometric *** is shown that the obtained solutions are more general and fresh and can be helpful to analyze the NLEES in mathematical physics and engineering problems.

关键词： The enhanced(G'/G)-expansion method Simplified mCH equation Third extended fifth order nonlinear equation Nonlinear evolution equation(NLEEs) Closed form wave solutions