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Journal of Materials Science & technology 2011年第10期27卷 944-950页

作者： Hakan olak Orhan trkoglu Department of Chemistry Faculty of ScienceUniversity of Erciyes

this paper reported the synthesis, crystal structure and electrical conductivity properties of Ni-doped ZnO powders （i.e. Zn1-xNixO binary system, X=0, 0.0025, 0.005, 0.0075 and in the range 0.01≤X〈0.15）. I- phase samples, which were indexed as single phase with a hexagonal （wurtzite） structure in the Zn1-xNixO binary system, were determined by X-ray diffraction （XRD）. the widest range of the I-phase was determined as 0≤X≤0.03 at 1200℃; above this range the mixed phase was observed. the impurity phase was determined as NiO when compared with standard XRD data, using the PDF program. We focused on single f-phase ZnO samples which were synthesized at 1200℃ because of the widest range of solubility limit at this temperature. It was observed that the lattice parameters a and c of the I-phase decreased with Ni doping concentration. the morphology of the I-phase samples was analyzed with a scanning electron microscope. the electrical conductivity of the pure ZnO and single I-phase samples were studied by using the four-probe dc method at temperatures between 100 and 950℃ in air atmosphere. the electrical conductivity values of pure ZnO and 3 mol% Ni-doped ZnO samples at 100℃C were 2×10^-6 and 4.8×10^-6 Ω-***^-1, and at 950℃ they were 1.8 and 3.6 Ω-1cm-1, respectively. In other words, electrical conductivity increased with Ni doping concentration.

关键词： Ⅱ-Ⅵ semiconductors Zinc oxide and doped zinc oxide Four point probe method

Predicting the strength properties of slurry infiltrated fibrous concrete using artificial neural network

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Frontiers of Structural and Civil Engineering 2018年第4期12卷 490-503页

作者： t.Chandra Sekhara REDDY Civil Engineering G.P.R.Engineering CollegeKurnool 518002Andhra PradeshIndia

this paper is aimed at adapting Artificial Neural Networks (ANN) to predict the strength properties of SIFCON containing different minerals admixture. the investigations were done on 84 SIFCON mixes, and specimens were cast and tested after 28 days curing. the obtained experimental data are trained using ANN which consists of 4 input parameters like Percentage of fiber (PF), Aspect Ratio (AR), type of admixture (tA) and Percentage of admixture (PA). the corresponding output parameters are compressive strength, tensile strength and flexural strength. the predicted values obtained using ANN show a good correlation between the experimental data. the performance of the 4-14-3 architecture was better than other architectures. It is concluded that ANN is a highly powerful tool suitable for assessing the strength characteristics of SIFCON.

关键词： artificial neural networks root mean square error SIFCON silica fume metakaolin steel fiber

Graphene-driving novel strain relaxation towards AlN film and DUV photoelectronic devices

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Light(Science & Applications) 2022年第7期11卷 1318-1319页

作者： Hieu.P.t.Nguyen New Jersey Institute of technology Department of Electrical&Computer EngineeringNewarkNJ 07102USA

Graphene-driving strain-pre-store engineering enables the epitaxy of strain-free AlN film with low dislocation density for DUV-LED and the unique mechanism of strain-relaxation in QvdW epitaxy was demystified.

关键词： driving relaxation strain

Synthesis,Crystal Structural and Electrical Conductivity Properties of Fe-Doped Zinc Oxide Powders at High temperatures

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Journal of Materials Science & technology 2012年第3期28卷 268-274页

作者： Hakan Çolak Orhan tÜrkoglu Department of Chemistry Science of FacultyUniversity of ErciyesKayseri38039Turkey Deparment of Chemistry Science of FacultyUniversity of C ank r KaratekinBall ca CampusC ank r18200Turkey

the synthesis,crystal structure and electrical conductivity properties of Fe-doped ZnO powders（in the range of 0.25-15 mol%） were reported in this paper.I-phase samples,which were indexed as single phase with a hexagonal（wurtzite） structure in the Fe-doped ZnO binary system,were determined by X-ray diffraction（XRD）.the solubility limit of Fe in the ZnO lattice is 3 mol% at 950℃.the above mixed phase was *** the impurity phase was determined as the cubic-ZnFe 2 O 4 phase when compared with standard XRD data using the PDF *** study focused on single I-phase ZnO samples which were synthesized at 950℃ because the limit of the solubility range is the widest at this *** lattice parameters a and c of the I-phase decreased with Fe-doping *** morphology of the I-phase samples was analyzed with a scanning electron *** grain size of the I-phase samples increased with heat treatment and doping *** electrical conductivity of the pure ZnO and single I-phase samples was investigated using the four-probe dc method at 100-950℃ in air *** electrical conductivity values of pure ZnO,0.25 and 3 mol% Fe-doped ZnO samples at 100℃ were 2×10-6,1.7×10-3 and 6.3×10-4 ***-1,and at 950℃ they were 3.4,8.5 and 4 ***-1,respectively.

关键词： II-VI semiconductors Zinc oxide and doped zinc oxide Four point probe method

Biodegradation of methanol vapor in a biofilter

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Journal of Environmental Sciences 2003年第5期15卷 691-696页

作者： Durai Arulneyam t.Swaminathan BiotechnologyResearchCentre BiotechnologyResearchCentre DepartmentofChemicalEngineeringIndianInstituteofTechnologyMadrasChennai600036IndiaDepartmentofChemicalEngineeringIndianInstituteofTechnologyMadrasChennai600036India

Volatile organic compounds (VOCs) are a new class of air pollutants posing threat to the environment. Newer technologies are being developed for their control among which biofiltration seem to be most attractive. Biofiltration of methanol vapor from air stream was evaluated in this study. Experimental investigations were conducted on a laboratory scale biofilter, containing mixture of compost and polystyrene inert particles as the filter materials. Mixed consortium of activated sludge was used as an inoculum. the continuous performance of biofilter for methanol removal was monitored for different concentrations and flow rates. the removal efficiencies decreased at higher concentrations and higher gas flow rates. A maximum elimination capacity of 85 g/(m 3·h) was achieved. the response of biofilter to upset loading operation showed that the biofilm in the biofilters was quite stable and quickly adapted to adverse operational conditions.

关键词： biofilter methanol removal efficiency elimination capacity degradation

temperature-dependent dielectric properties of Au/Si_3N_4/n-Si (metal insulator semiconductor) structures

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Chinese Physics B 2013年第11期22卷 541-546页

作者： t.Ataseven A.tataroglu Physics Department Faculty of Sciences Gazi University Teknikokullar

the dielectric properties of Au/Si3N4/n-Si （MIS） structures are studied using the admittance measurements （C–V and G/ω–V） each as a function of temperature in a range from 80 K to 400 K for two frequencies （100 kHz and 1 MHz）. Experimental results show that both the dielectric constant （ε’） and the dielectric loss （ε＂） increase with temperature increasing and decrease with frequency increasing. the measurements also show that the ac conductivity （σac） increases with temperature and frequency increasing. the lnσac versus 1000/t plot shows two linear regions with different slopes which correspond to low （120 K–240 K） and high （280 K–400 K） temperature ranges for the two frequencies. It is found that activation energy increases with frequency and temperature increasing.

关键词： Au/Si3N4/n-Si (metal-insulator-semiconductor) structure admittance measurements dielectricproperties ac conductivity

Effects of varying Alx moles on structure and luminescence properties of ZnAl_(x)O_(1.5x+1):0.1 mol%tb^(3+)nanophosphors prepared using citrate sol-gel method

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Journal of Rare Earths 2023年第3期41卷 358-364,I0002页

作者： V.M.Maphiri L.t.Melato M.R.Mhlongo t.t.Hlatshwayo t.E.Motaung L.F.Koao S.V.Motloung Department of Physics Sefako Makgatho Health Science UniversityP.O.Box 94Medunsa0204South Africa Department of Mathematics Non Destructive Testing and PhysicsVaal University of TechnologyAndries Potgieter BlvdVanderbijlpark1900South Africa Department of Physics University of PretoriaPretoria0002South Africa Department of Chemistry School of Science in the College of Science Engineering and TechnologyUniversity of South AfricaPreller StreetMuckleneuk RidgeCity of TshwaneP.O Box 392UNISA 0003South Africa Department of Chemistry Sefako Makgatho Health Science UniversityP.O.Box 94Medunsa0204South Africa Department of Physics University of the Free State(Qwaqwa Campus)Private Bag X13Phuthaditjhaba 9866South Africa Department of Chemical and Physical Sciences Walter Sisulu UniversityMthathaSouth Africa

Un-doped and ZnAl_(x)O_(1.5x+1):0.1 mol%tb^(3+)(ZAOt)nano-powders were synthesized via citrate sol-gel *** AIx moles were varied in the range of 0.25≤x≤*** X-ray powder diffraction(XRD)data reveal that for xthe prepared samples crystal structure consists of mixed phases of the cubic ZnAl_(2)O_(4) and hexagonal ZnO phases,while for x>1.5 the structure consists of single phase of cubic ZnAl_(2)O_(4).the Raman and Fourier-trans form infrared(FtIR)vibrational spectroscopy show the presence of vibrations emanating ZnAl_(2)O_(4) *** electron microscopy(SEM)and transmission electron microscopy(tEM)show the presence of irregular sphere at x>2.0 attributed to ZnAl_(2)O_(4).the photoluminescence(PL)spectroscopy reveals emissions from both the host and tb^(3+)*** from tb^(3+)are observed at 382,414,439,458 nm and 489,545,585,621 nm,which were attributed to the^(5)D_(3)→^(7)F_(6,5,4,2) and ^(5^)D_(4)→^(7)F_(6,5,4,3),*** results confirm that the tb^(3+)occupation site depends on the Alx *** International Commission on Illumination(CIE)colour chromaticity shows that the emission colour can be tuned from blue to green by varying the AIx moles.

关键词： Citrate sol-gel ZnAl_(2)O_(4)/ZnO tb^(3+)-doped Al_(x)moles Photoluminescence Rare earths

Higher Order Multipole Potentials and Electrostatic Screening Effects on Cohesive Energy and Bulk Modulus of Metallic Nanoparticles

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Communications in theoretical Physics 2011年第12期56卷 1125-1129页

作者： t.Barakat Physics Department King Saud UniversityP.O.Box 2455Riyadh 11451Saudi Arabia

Higher order rnultipole potentials and electrostatic screening effects are introduced to incorporate the dan gling bonds on the surface of a metallic nanopaticle and to modify the coulornb like potential energy terms, respectively. the total interaction energy function for any rnetallic nanoparticle is represented in terms of two- and three-body potentials. the two-body part is described by dipole-dipole interaction potential, and in the three-body part, triple-dipole （DDD） and dipole-dipole-quadrupole （DDQ） terrns are included. the size-dependent cohesive energy and bulk modulus are observed to decrease with decreasing sizes, a result which is in good agreement with the experimental values of Mo and W nanoparticles.

关键词： higher order multipole potentials electrostatic screening effect size-dependent cohesive energy size-dependent bulk modulus metallic nanoparticles

Beta-lactam antibiotic resistance among Escherichia coli isolates from patients with urinary tract infections in Vietnam:A systematic review and meta-analysis

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Asian Pacific Journal of tropical Medicine 2024年第6期17卷 243-255,I0001-I0003页

作者： Dat t Nguyen Princess Margaret Cancer Centre University Health NetworkTorontoOntarioCanada

Objective:to investigate the evolving patterns of antimicrobial resistance against beta-lactam antibiotics in Escherichia coli isolates from urinary tract infection patients in Vietnam,covering the period from 2005 to ***:29 Descriptive studies published between 2010 and 2022 in English and Vietnamese were included in the *** on resistance rates to beta-lactam antibiotics,including cephalosporins and carbapenems,were extracted and *** pooled resistance rates were calculated using random-effects *** trends in resistance were assessed using linear regression ***:Among the beta-lactam antibiotics studied,Escherichia coli exhibited varying levels of resistance,with cephalosporins showing higher resistance rates compared to *** pooled resistance rates were 66%for cefotaxime,65%for ceftriaxone,54%for ceftazidime,and 56%for *** contrast,carbapenems demonstrated lower resistance rates,with weighted pooled resistance rates ranging from 3%to 4%for meropenem,ertapenem,and *** rates were also observed for amoxicillin/clavulanate(35%),ticarcillin/clavulanate(26%),and piperacillin/tazobactam(12%).Significant annual increases in resistance were noted for imipenem(0.56%,Pthis study highlights the critical issue of antimicrobial resistance in urinary tract infections in Vietnam and emphasizes the importance of prudent antibiotic use and the regular monitoring of resistance *** insights are useful for guiding healthcare professionals in optimizing treatment strategies and for policymakers in formulating evidence-based clinical guidelines to combat antibiotic resistance effectively.

关键词： Antimicrobial resistance Urinary tract infection Vietnam

Physics prospects at J-PARC

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Chinese Physics C 2010年第9期34卷 1259-1262页

作者： t.Nagae Kyoto University Department of Physics

We have held an inauguration ceremony of the Japan Proton Accelerator Research Complex （JPARC） on July 6,2009,celebrating the completion of its ***,the beam commissioning of the 50 GeV main proton synchrotron is in progress to improve the beam intensity and quality.A lot of important experimental programs in Nuclear Physics are waiting for the *** this report,I introduce some examples.

关键词： hypernuclei J-PARC hadron kaon