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Removal of organic pollutants by lanthanide-doped mIL-53(Fe) metal-organic frameworks:Effect of dopant type in magnetite precursor

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Journal of Rare Earths 2023年第1期41卷 140-148页

作者： Shimaa m.Ali Khadija m.Emran Fedaa m.m.Alrashedee Department of Chemistry Faculty of ScienceCairo University.Giza12613Egypt Department of Chemistry Faculty of ScienceTaibah UniversityMadinah30002Saudi Arabia

A series of undoped and lanthanide doped mIL-53(Fe)/Ln-Fe_(3)O_(4)(Ln=La,Nd,or Gd) metal-organic frameworks(mOFs) were prepared by the solvothermal *** prepared samples were characterized by X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FT-IR),Brunauer-Emmett-Teller(BET) measurements,scanning electron microscopy(SEm),and thermal *** and FT-IR results ascertain the successful mOF formation for all prepared ***-53(Fe)/La-Fe_(3)O_(4) has the smallest particle size of 8.6 nm,the largest BET surface area of 54.2 m^(2)/g,and the highest *** and different lanthanide doped mIL-53(Fe) we re employed as sorbents for the removal of methylene blue(mB)dye from aqueous solutions to examine the doping benefit and the effect of the dopant size on the sorption *** causes mOFs to act as pH-independent sorbents,which make it applicable at any *** follows pseudo-second-order kinetic model,and doped sorbents attain equilibrium *** isotherms are followed,except for mIL-53(Fe)/La-Fe_(3)O_(4).The adsorption capacity increases with increasing the dopant ion size,100.5 mg/g for La-doped mOF,which is about four times higher than that of undoped *** adsorption mechanism involves chemical interactions between Lewis acid in magnetite mIL-53(Fe) series and Lewis base in mB.

关键词： Lanthanide metal organic framework Adsorption Doping Organic dyes Rare earths

Dye-sensitized solar cells based on Cr-doped TiO2 nanotube photoanodes

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Rare metals 2017年第11期36卷 865-871页

作者： m. m. momeni Department of Chemistry Isfahan University of TechnologyIsfahan 84156-83111 Iran

The effect of chromium doping on the photo- voltaic efficiency of dye-sensitized solar cells （DSSCs） with anodized TiO2 nanotubes followed by an annealing process was investigated. Cr-doped TiO2 nanotubes （CrTNs） with different amounts of chromium were obtained by anodizing of titanium foils in a single-step process using potassium chro- mate as the chromium source. Film features were investigated by scanning electron microscopy （SEm）, X-ray diffraction （XRD）, energy-dispersive X-ray spectroscopy （EDX）, and ultraviolet-visible （UV-Vis） spectroscopy. It is clearly seen that highly ordered TiO2 nanotubes are formed in an anodizing solution free of potassium chromate, and with a gradual increase in the potassium chromate concentration, these nanotube structures change to nanoporous and compact films without porosity. The photovoltaic efficiencies of fabricated DSSCs were characterized by a solar cell measurement sys- tem via the photocurrent-voltage （l-V） curves. It is found that the photovoltaic efficiency of DSSCs with CrTNsl sample is improved by more than three times compared to that of DSSCs with undoped TNs. The energy conversion efficiency increases from 1.05 % to 3.89 % by doping of chromium.

关键词： Dye-sensitized solar cell Photoanodes Nanotubes Anodization

New ordered mAX phase mo_2 TiAlC_2: Elastic and electronic properties from first-principles

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Chinese Physics B 2016年第10期25卷 323-329页

作者： m A Hadi m S Ali Department of Physics University of Rajshahi Department of Physics Pabna University of Science and Technology

First-principles computation on the basis of density functional theory(DFT) is executed with the CASTEP code to explore the structural, elastic, and electronic properties along with Debye temperature and theoretical Vickers’ hardness of newly discovered ordered mAX phase carbide mo2TiAlC2. The computed structural parameters are very reasonable compared with the experimental results. The mechanical stability is verified by using the computed elastic constants. The brittleness of the compound is indicated by both the Poisson’s and Pugh’s ratios. The new mAX phase is capable of resisting the pressure and tension and also has the clear directional bonding between atoms. The compound shows significant elastic anisotropy. The Debye temperature estimated from elastic moduli(B, G) is found to be 413.6 K. The electronic structure indicates that the bonding nature of mo2TiAlC2is a mixture of covalent and metallic with few ionic characters. The electron charge density map shows a strong directional mo–C–mo covalent bonding associated with a relatively weak Ti–C *** calculated Fermi surface is due to the low-dispersive mo 4d-like bands, which makes the compound a conductive *** hardness of the compound is also evaluated and a high value of 9.01 GPa is an indication of its strong covalent bonding.

关键词： new ordered mAX phase density functional theory calculations Debye temperature Vickers hardness

Realtime Object Detection Through m-ResNet in Video Surveillance System

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Intelligent Automation & Soft Computing 2023年第2期35卷 2257-2271页

作者： S.Prabu J.m.Gnanasekar Department of Computer Science&Engineering Karpaga Vinayaga College of Engineering and TechnologyChengalpattuTamilnadu603308India Department of Computer Science&Engineering Sri Venkateshwara College of Engineering&TechnologyChennai602001TamilnaduIndia

Object detection plays a vital role in the video surveillance *** enhance security,surveillance cameras are now installed in public areas such as trafﬁc signals,roadways,retail malls,train stations,and ***,monitor-ing the video continually at a quicker pace is a challenging *** a consequence,security cameras are useless and need human *** primary difﬁculty with video surveillance is identifying abnormalities such as thefts,accidents,crimes,or other unlawful *** anomalous action does not occur at a high-er rate than usual *** detect the object in a video,ﬁrst we analyze the images pixel by *** digital image processing,segmentation is the process of segregating the individual image parts into *** performance of segmenta-tion is affected by irregular illumination and/or low *** factors highly affect the real-time object detection process in the video surveillance *** this paper,a modiﬁed ResNet model(m-Resnet)is proposed to enhance the image which is affected by insufﬁcient *** results provide the comparison of existing method output and modiﬁcation architecture of the ResNet model shows the considerable amount improvement in detection objects in the video *** proposed model shows better results in the metrics like preci-sion,recall,pixel accuracy,etc.,andﬁnds a reasonable improvement in the object detection.

关键词： Object detection ResNet video survilence image processing object quality

mF-DFA Analysis of Turbulent Transport measured by a multipurpose Probe

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Chinese Physics Letters 2015年第10期32卷 76-79页

作者： Lafouti m Ghoranneviss m Department of Physics Damavand Branch Islamic Azad University Damavand Iran Plasma Physics Research Center Science and Research Branch Islamic Azad University Tehran Iran

The effect of time of applied bias on the edge turbulent transport is analyzed by the multi-fractal detrend fluctu- ation analysis （mF-DFA） method in the IR-Tl tokamak. The generalized Hurst exponents and the multifractal spectrum are computed by this method. The mF-DFA method is applied to the fluctuation of gradient of float- ing potential time series collected by a multipurpose probe. Tile monofractality or multifractality of the time series can be detected by generalized exponent. The multifractal spectrum describes the singularity content of the process. The results show that with applying bias to the plasma at different times （t = 15 ms, 18ms and 22ms）, the degree of multifractality changes. It reaches the minimum when the bias is applied at t = 18 ms. The multifractality source of data is investigated by the surrogate method （phase randomization techniques）. The surrogate method can destroy the different types of correlations in all the sizes of fluctuations. The results show that the long-range correlation contributes more to multifractality than the fat tail distribution.

关键词： TURBULENCE mULTIFRACTALS RANDOmIZATION (Statistics) CORRELATION (Statistics) TImE series analysis

Study of magnetic and optical properties of Zn1-xTmxTe(Tm = mn,Fe,Co,Ni) diluted magnetic semiconductors：First principle approach

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Chinese Physics B 2017年第2期26卷 452-460页

作者： Q mahmood m Hassan m A Faridi Department of Physics University of the Punjab Quaid-e-Azam Campus-54590 Lahore Pakistan Centre for High Energy Physics University of the Punjab Lahore Pakistan

We present structural,magnetic and optical characteristics of Zn_（1-x）Tm_xTe（Tm = mn,Fe,Co,Ni and x = 6.25%）,calculated through Wien2 k code,by using full potential linearized augmented plane wave（FP-LAPW） *** optimization of the crystal structures have been done to compare the ferromagnetic（Fm） and antiferromagnetic（AFm） ground state energies,to elucidate the ferromagnetic phase stability,which further has been verified through the formation and cohesive ***,the estimated Curie temperatures T_c have demonstrated above room temperature ferromagnetism（RTFm） in Zn_（1-x）Tm_xTe（Tm =mn,Fe,Co,Ni and x= 6.25%）.The calculated electronic properties have depicted that mn- and Co-doped ZnTe behave as ferromagnetic semiconductors,while half-metallic ferromagnetic behaviors are observed in Fe- and Ni-doped *** presence of ferromagnetism is also demonstrated to be due to both the p-d and s-d hybridizations between the host lattice cations and Tm *** calculated band gaps and static real dielectric constants have been observed to vary according to Penn＇s *** evaluated band gaps lie in near visible and ultraviolet regions,which make these materials suitable for various important device applications in optoelectronic and spintronic.

关键词： magnetic semiconductors density functional theory optical and dielectric properties electron density of states and band structure of crystalline solids

INVESTIGATION OF THE THICKNESS VARIABILITY AND mATERIAL HETEROGENEITY EFFECTS ON FREE VIBRATION OF THE VISCOELASTIC CIRCULAR PLATES

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Acta mechanica Solida Sinica 2013年第1期26卷 83-98页

作者： m.Shariyat A.A.Jafari m.m.Alipour Faculty of mechanical Engineering K.N.Toosi University of Technology

The present study deals with free vibration analysis of variable thickness viscoelastic circular plates made of heterogeneous materials and resting on two-parameter elastic foundations in addition to their edge conditions. It is assumed that the viscoelastic material properties vary in the transverse and radial directions simultaneously. The complex modulus approach is employed in conjunction with the elastic-viscoelastic correspondence principle to obtain the solution. The governing equations are solved by means of a power series solution. Finally, a sensitivity analysis including evaluation of effects of various edge conditions, thickness variations, coefficients of the elastic foundation, and material loss factor and heterogeneity on the natural frequencies and modal loss factors is accomplished.

关键词： viscoelastic variable thickness circular plate natural frequencies elastic foundation material heterogeneity power series solution

Application of Nanocrystalline LaNi_5-type Hydrogen Absorbing Alloys in Ni-mH_x Batteries

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Journal of Rare Earths 2004年第5期22卷 596-599页

作者： Jurczyk m Nowak m Institute of materials Science and Engineering Poznan University of Technology 60-965 Poznan PolandInstitute of Materials Science and Engineering Poznan University of Technology 60-965 Poznan Poland

The structure and electrochemical properties of nanocrystalline LaNi_5-type alloys were studied. These materials were prepared by mechanical alloying (mA) followed by annealing. The properties of hydrogen host materials can be modified substantially by alloying to obtain the desired storage characteristics. It was found that the partial substitution of Ni by Al or mn in LaNi_(5-x)m_x alloy leads to an increase in discharge capacity. The alloying elements such as Al, mn and Co greatly improved the cycle life of LaNi_5 material. For example, in the nanocrystalline LaNi_(3.75)mn_(0.75)Al_(0.25)Co_(0.25) powder, discharge capacity up to 258 mAh·g^(-1) was measured (at 40 mA·g^(-1) discharge current). Furthermore, the effect of the graphite coating on the structure of some nanocrystalline alloys and the electrodes characteristics were investigated. The mechanical coating with graphite effectively reduced the degradation rate of the studied electrode materials. The combination of a nanocrystalline LaNi_5-type hydride electrodes and a nickel positive electrode to form a Ni-mH battery, was successful.

关键词： hydrogen absorbing materials electrode materials nanocrystalline materials Ni-mH_x batteries rare earths

Giant magnetoresistance Effect of [bcc-Fe(m)/Cu](m=Co,Ni) multilayers

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Journal of materials Science & Technology 2000年第2期16卷 186-190页

作者： m.matsui, m.Doi and N.Shimizu (Department of Crystalline materials Science and Engineering, Nagoya University, Chikusa-ku, Nagoya 464-8603, Japan Department of Crystalline materials Science and Engineering Nagoya University Chikusa-ku Nagoya 464-8603 Japan

GmR effect of multilayers of bcc-Fe(m)(m=Co, Ni) alloy and Cu layers has been investigated. The maximum mR ratio is found at 1.1 nm Fe(Co) and 1.3～1.4 nm Cu layer thickness in [Fe(Co)/CuJ, and at 1.6 nm Fe(Ni) and 1.4 nm Cu layer thickness in [Fe(Ni)/Cu]. Under the optimum annealing condition, the mR ratio increases up to 50% and 38% for Fe(Co) and Fe(Ni) systems, respectively. The origin of the increase of GmR is discussed, taking the progress of preferred orientation of Fe(Co)[100] or Fe(Ni)[100] by anneahng into account.

关键词： Giant magnetoresistance Effect of m=Co,Ni multilayers Cu bcc-Fe