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DFT studies of thermoelectric properties of R-Au intermetallics at 300 K

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Journal of Rare Earths 2018年第2期36卷 197-202页

作者： sardar ahmad Rashid ahmad Muhammad Bilal Najeeb Ur Rehman Center for Computational Materials science University of Malakand Department of Chemistry University of Malakand Department of Physics University of Malakand

Thermoelectric and electronic properties of cubic bi-intermetallics R-Au（R = Tb, Ho. Er. Tm and Yb）compounds were explored. electronic properties i.e. density of states and band structure were computed using first principles calculations which proved the metallic nature of these compounds. Post-DFT（BoltzTraP） calculations were carried out to explore their thermoelectric properties like electrical conductivities. seebeck coefficient, electronic thermal conductivities and figure of merit. The highest seebeck coefficient and figure of merit were found for YbAu among these compounds which are 105 μV/K and 0.285 respectively. All the calculations were carried out at 300 K. Large values of figure of merit obtained for these compounds at room temperature indicate that these materials can be used for thermoelectric devices however need experimental verification.

关键词： DFT seebeck coefficient Figure of merit Thermal conductivity electrical conductivity R-Au

Effect of physiographic factors on qualitative and quantitative charac-teristics of Cornus mas L. natural stands in Arasbaran forests, Iran

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Journal of Forestry Research 2013年第1期24卷 69-74页

作者： ahmad Alijanpour Faculty of Natural Resources Urmia UniversityPardis-e-NazlooSero RoodZip code ***UrmiaI. R. Iran

Arasbaran forests are located in East Azerbaijan （northwest Iran）. Increasing of socio-economic problems in this area causes destruction of biodiversity and structure of these forests. Using multipurpose trees such as cornelian cherry （Cornus mas L） to encourage villagers to produce forest by-products is a basic approach for preserving these forests. This species grows naturally in Arasbaran forests and the fruit is annually exploited using traditional harvest methods. This study aims to assess the ecological requirements of cornelian cherry and the important factors affecting its distribution. For this purpose, 40 circular sampling plots （300 m2） on various slope aspects were demarcated for sampling the occurrence of cornelian cherry in forest stands. DBH and crown cover percentage on north aspects were significantly greater than on other aspects and 4.5% of all trees were cornelian cherry in mature forest stands. North aspects had more seed-origin trees （standards） of cornelian cherry than coppiced trees, while west facing aspects had more coppiced than standard trees. This species had the highest regeneration rate in the sapling stage of 0–2.5 cm DBH. Thus, I recommend cultivation and development of cornelian cherry as a multi-purpose tree in the Arasbaran region on degraded forest lands on north and west aspects.

关键词： Arasbaran forests aspect physiographical factors comelian cherry (Cornus mas L.)

Remediation of sulfidic wastewater by catalytic oxidation with hydrogen peroxide

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Journal of Environmental sciences 2009年第12期21卷 1735-1740页

作者： Naveed ahmad saikat Maitra Binay Kanti Dutta Farooq ahmad Department of Chemical Engineering Universiti Teknologi PETRONAS Department of Chemical Engineering The Petroleum Institute

Oxidation of sulfide in aqueous solution by hydrogen peroxide was investigated in the presence of hydrated ferric oxide catalyst. The ferric oxide catalyst was synthesized by sol gel technique from ferric chloride and ammonia. The synthesized catalyst was characterized by Fourier transform infrared spectroscopy, X-Ray diffraction analysis, scanning electrom microscope and energy dispersive X-ray analysis. The catalyst was quite effective in oxidizing the sulfide by hydrogen peroxide. The effects of sulfide concentration, catalyst loading, H2O2 dosing and temperature on the kinetics of sulfide oxidation were investigated. Kinetic equations and activation energies for the catalytic oxidation reaction were calculated based on the experimental results.

关键词： catalytic oxidation wastewater kinetic equation hydrogen peroxide sodium sulfide remediation

Interactive Effects of silicon and Potassium Nitrate in Improving salt Tolerance of Wheat

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Journal of Integrative Agriculture 2014年第9期13卷 1889-1899页

作者： ahmad Bybordi East Azerbaijan Research Center for Agriculture and Natural Resources Tabriz 53555-141 Iran

Adequate regulation of mineral nutrients might be effective to ameliorate the deleterious effects of salts and help to sustain crop productivity, particularly in glycophytes, under salt stress. In this study, laboratory and greenhouse experiments were carried out at Agricultural and Natural Resources Research Centre in East Azerbaijan, Iran, to investigate the interactive effects of silicon and potassium nitrate in alleviating NaCl induced injuries in wheat（Triticum aestivum L.）. In the laboratory experiment, three winter wheat cultivars Pishgam, Afagh and Alvand were grown on sterile filter paper moistened with 20, 40, 60, 80, and 100 mmol L-1 NaCl solution. Results revealed that wheat cultivars were significantly different in their growth response to different concentrations of NaCl and Pishgam was found to be the most tolerant to NaCl stress, and used in the second part of study. In the greenhouse experiment, Pishgam was grown in a hydroponic system subjected to different NaCl levels（20, 60 and 100 mmol L-1） and treated by silicon（0, 2 and 4 mmol L-1, final concentration in nutrient solution using K2siO3） and potassium nitrate（0, 0.5, 1, and 2 mmol L-1, foliar application）. The experimental design was factorial based on a completely randomized design with three replications. It was found that NaCl stress significantly increased proline accumulation and sodium content in the plant tissues while decreased potassium uptake and accumulation by plants. Moreover, plant weight, 100-seed weight, relative water content, chlorophyll content, and photosynthesis were also significantly affected by varying levels of NaCl. However, exogenous application of silicon and potassium nitrate reduced sodium uptake, increased potassium and consequently improved plant weight, 100-seed weight, seed yield, ear length, and photosynthesis rate. This study suggested that utilization of the salt-tolerant cultivar（Pishgam） combined with proper foliar application of potassium nitrate（2 mmol L-

关键词： germination grain yield foliar application photosynthesis proline relative water content

Deep image retrieval using artificial neural network interpolation and indexing based on similarity measurement

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CAAI Transactions on Intelligence Technology 2022年第2期7卷 200-218页

作者： Faiyaz ahmad Department of Computer Engineering Jamia Millia IslamiaNew DelhiIndia

In content-based image retrieval(CBIR),primitive image signatures are critical because they represent the visual *** signatures,which are algorithmically descriptive and accurately recognized visual components,are used to appropriately index and retrieve comparable *** differentiate an image in the category of qualifying contender,feature vectors must have image information's like colour,objects,shape,spatial *** methods such as sketch-based image retrieval by salient contour(sBIR)and greedy learning of deep Boltzmann machine(GDBM)used spatial information to distinguish between image *** requires interest points and also feature analysis emerged image detection ***,a proposed model to overcome this issue and predict the repeating pattern as well as series of pixels that conclude similarity has been *** this study,a technique called CBIR-similarity measure via artificial neural network interpolation(CBIR-sMANN)has been *** collecting datasets,the images are resized then subject to Gaussian filtering in the pre-processing stage,then by permitting them to the Hessian detector,the interesting points are *** on skewness,mean,kurtosis and standard deviation features were extracted then given to ANN for *** results are stored in a database for *** the testing stage,the query image was inputted that is subjected to pre-processing,and feature extraction was then fed to the similarity measurement ***,ANN helps to get similar images from the ***-sMANN have been implemented in the python tool and then evaluated for its *** show that CBIR-sMANN exhibited a high recall value of 78%with a minimum retrieval time of 980 *** showed the supremacy of the proposed model was comparatively greater than the previous ones.

关键词： Gaussian filtering Hessian detector image retrieval interpolation and similarity measurement repeating pattern

Tunable passively Q-switched ytterbium-doped fiber laser with mechanically exfoliated Gase saturable absorber

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Chinese Optics Letters 2018年第2期16卷 93-97页

作者： H.ahmad s.N.Aidit s.I.Ooi Z.C.Tiu Photonics Research Centre University of Malaya

A tunable passively Q-switched ytterbium-doped fiber laser using few-layer gallium selenide（Gase） as a saturable absorber（sA） is *** few-layer Gase sA,which is fabricated by the mechanical exfoliation method,is able to generate a Q-switched fiber laser that has a maximum repetition rate of 92.6 kHz and a minimum pulsed width of 2.3 μ*** highest pulse energy exhibited by the generated pulse is 18.8 nJ with a signal to noise ratio of ~40 *** tunability of the proposed laser covers from 1042 to 1082 nm,giving a tuning range of 40 nm.

关键词： Tunable passively Q-switched ytterbium-doped fiber laser with mechanically exfoliated Gase saturable absorber sA

Evaluation of liquefaction-induced lateral displacement using Bayesian belief networks

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Frontiers of structural and Civil Engineering 2021年第1期15卷 80-98页

作者： Mahmood ahmad Xiao-Wei TANG Jiang-Nan QIU Feezan ahmad state Key Laboratory of Coastal and Offshore Engineering Dalian University of TechnologyDalian 116024China Department of Civil Engineering University of Engineering and Technology Peshawar(Bannu Campus)Bannu 28100Pakistan Faculty of Management and Economics Dalian University of TechnologyDalian 116024China Department of Civil Engineering Abasyn UniversityPeshawar 25000Pakistan

Liquefaction-induced lateral displacement is responsible for considerable damage to engineered structures during major ***,an accurate estimation of lateral displacement in liquefaction-prone regions is an essential task for geotechnical experts for sustainable *** paper presents a novel probabilistic framework for evaluating liquefaction-induced lateral displacement using the Bayesian belief network(BBN)approach based on an interpretive structural modeling *** BBN models are trained and tested using a wide-range casehistory records *** two BBN models are proposed to predict lateral displacements for free-face and sloping ground *** predictive performance results of the proposed BBN models are compared with those of frequently used multiple linear regression and genetic programming *** results reveal that the BBN models are able to learn complex relationships between lateral displacement and its influencing factors as cause-effect relationships,with reasonable *** study also presents a sensitivity analysis to evaluate the impacts of input factors on the lateral displacement.

关键词： Bayesian belief network seismically induced soil liquefaction interpretive structural modeling lateral displacement

Nanocomposite superstructure of zinc oxide mesocrystal/reduced graphene oxide with effective photoconductivity

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Journal of semiconductors 2024年第11期45卷 81-88页

作者： ahmad A.ahmad Qais M.Al-Bataineh ahmad B.Migdadi Department of Physical sciences Jordan University of Science&TechnologyP.O.Box 3030Irbid-22110Jordan

Metal oxide mesocrystals are the alignment of metal oxide nanoparticles building blocks into the ordered superstructure,which have potentially tunable optical,electronic,and electrical properties suitable for practical ***,we report an effective method for synthesizing mesocrystal zinc oxide nanorods(ZnONRs).The crystal,surface,and internal structures of the zinc oxide mesocrystals were fully *** zinc oxide nanorods/reduced graphene oxide(ZnONRs/rGO)nanocomposite superstructure were synthesized also using the hydrothermal *** crystal,surface,chemical,and internal structures of the ZnONRs/rGO nanocomposite superstructure were also fully *** optical absorption coefficient,bandgap energy,band structure,and electrical conductivity of the ZnONRs/rGO nanocomposite superstructure were investigated to understand its optoelectronic and electrical ***,the photoconductivity of the ZnONRs/rGO nanocomposite superstructure was explored to find the possibilities of using this nanocomposite superstructure for ultraviolet(UV)photodetection ***,we concluded that the ZnONRs/rGO nanocomposite superstructure has high UV sensitivity and is suitable for UV detector applications.

关键词： mesocrystals superstructure mesocrystal zinc oxide nanorods(ZnONRs) meduced graphene oxide(rGO) ZnONRs/rGO nanocomposite superstructure UV photodetection

Intelligence Way from Eco-friendly synthesis strategy of New Heterocyclic Pyrazolic Carboxylic a-Amino Esters

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Chemical Research in Chinese Universities 2020年第6期36卷 1183-1189页

作者： EI Houssine MABROUK Nadia ARROUssE Adil KORCHI Mohammed LACHGAR ahmad OUBAIR Abdelrhani elACHQAR Mohamed JABHA Mohammed LACHKAR Fadoua el HAJJAJI Zakia RAIs Mustapha TALEB Laboratory of Materials Engineering for the Environment&Natural Resources Department of ChemistryFaculty of Sciences and TechnicsBP 509 BoutalamineErrachidiaMoulay Ismail University MeknesMorocco Laboratory of Engineering OrganometallicMolecular and Environment(LlMMOME)Faculty of SciencesUniversity Sidi Mohamed Ben AbdellahB.P.1796FezMorocco Faculty of sciences and Technologies University Sidi Mohamed Ben AbdellahFezMorocco Department of Chemistry Faculty of Sciences Dhar El MahrazUniversity Sidi Mohamed Ben AbdellahB.P.1796FezMorocco Natural Resources and Environment Team(RN&E) Faculty of Sciences and TechnicsErrachidiaMoulay Ismail UniversityMorocco

The a-amino acid derivatives constitute a class of compounds of particular medicinal and synthetic attention and considerable interest has been devoted to their synthesis in recent *** the present work,we develop the computational study of the synthesis reaction of new pyrazolyl a-amino esters derivatives using the Gaussian 09based on the DET/B3LYP density functional theorv method,with the base 6-31G(d.p)to ensure the possibility of carrying out these reactions within the laboratory of ***,this research has encouraged us to establish an economical synthesis strategy of these products in overall vields of 73.5%to 87%to have access to new active biomolecule through the O-alkvlation reaction between methyl a-azidoglycinate N-benzoylated and primary pyrazole alcohols(3,5-dimethyl-1 H-pyrazol-1-yl)methanol,(1H-pyrazol-1-yl)methanol and(3-ethoxy-5-methyl-1H-pyrazol-1yl)methanoll under different operating *** structure of the prepared heterocyclic systems was characterized by conventional spectroscopic techniques,like H NMR.I3℃NMR,and *** results revealed that the experimental study is in good correlation with the computational one.

关键词： a-Pyrazolyl amino ester Methyl a-azido glycinate N-benzoylated O-Alkylation DFT/B3LYP/6-31G(d,p)