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HIGHLY TRANSPARENT AND CONDUCTING ZINC-OXIDE FILMS DEPOSITED BY ACTIVATED REACTIVE EVAPORATION

JOURNAL OF ELECTRONIC materials 1987年第3期16卷 141-149页

作者： LAU, WS FONASH, SJ 1. Center for Electronic Materials and Devices Engineering Science Program The Pennsylvania State University 16802 University Park PA

Highly transparent and conducting undoped zinc oxide films have been obtained with a best resistivity of ～1.1 × 10-3 Ω cm, a carrier density of ～1.5 × 1020 cm?3 and a mobility of ～38 cm2V?1s ?1. These we... 详细信息

Highly transparent and conducting undoped zinc oxide films have been obtained with a best resistivity of ～1.1 × 10^-3 Ω cm, a carrier density of ～1.5 × 10²⁰ cm^?3 and a mobility of ～38 cm²V^?1s ^?1. These were produced by activated reactive evaporation at a deposition rate of 2 to 8?/s with a substrate temperature ≤200° C. The films deposited by this process were found to have resistivities that were thickness independent and also were relatively insensitive to deposition parameters. In terms of conductivity, it was found that films deposited at higher temperatures (T > 300°+ C) were always inferior to the films deposited below 200° C. High temperature vacuum annealing (350° C) significantly degraded the resistivity of the undoped films deposited at low temperature; this was attributable to a drop in both the electron concentration and the mobility. Aluminum doping was found to be able to stabilize the electron concentration while the drop in mobility was found to be related to the choice of substrate.

关键词： Zinc oxide films highly transparent films conducting films high temperature stability

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Thermo-optical properties of luminescent carbon dots produced from biomass of Orbignya speciosa (babassu coconut)

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Journal of Molecular Liquids 2025年 423卷

作者： Oliveira, Maykol Christian Damasceno Silva, Adriano Almeida Silva-Silva, Tânia Patrícia Silva, Jhaemely Gabrielly Vieira da Silva Júnior, José Ferreira Sanchez, David Bell, Maria José Valenzuela Garcia, Hans Anderson Viana, Bartolomeu Cruz Terrones, Mauricio Costa, Rubens Silva Santos, Francisco Eroni Paz Physics Department Federal University of Piauí PI 64049550 Brazil Postgraduate Program in Engineering and Materials Science Federal University of 64049550 PI Teresina Brazil Department of Physics and Center for 2-Dimensional and Layered Materials The Pennsylvania State University University ParkPA16802 United States Federal University of Juiz de Fora Institute of Exact Sciences Department of Physics University Campus - UFJF/ ICE/ Department of Physics Martelos MG Juiz de Fora36036330 Brazil Federal Institute of Piauí Paranaíba Campus PI Parnaíba64211145 Brazil

Exploring materials with high nonlinearities derived from organic and biological sources has become a significant focus within the scientific community. Among these materials, carbon dots (CDs) synthesized from biomass have emerged as promising candidates due to their sustainable and cost-effective production methods. This study synthesized CDs from Orbignya speciosa (babassu coconut) biomass via a hydrothermal route. UV–visible absorption and Infrared spectrum analysis revealed characteristic bands associated with the formation of dots and the electronic transitions π–π* from aromatic C=C bonds in the CDs’ core and n–π* transitions of surface carboxylate groups, photoluminescence as a function of temperature and lifetime decay measurements show that the photoluminescence mechanisms in these materials due this transitions comes from electronic indirect transitions from primary sources of the core and carbonyl boundings in the surface of the material, additionally, to this the Dynamic Light Scattering (DLS) and Transmission Electronic Microscopy (TEM) give the structural properties of the dots, amorphous and with a large size distribution with a mean size of (21 ± 1) nm. Thermal lens spectroscopy (TLS) was employed to determine the material's thermal diffusivity, reaching a maximum value of 2.03 × 10−7 m2/s as a function of dilution. The Z-scan technique under continuous wave (CW) excitation at 532 nm investigated nonlinear optical properties, yielding a maximum thermal nonlinear refractive index (n2(th)) value of −5.87 × 10−5 esu. Furthermore, the photothermal efficiency of the CDs was quantified at 505 nm, demonstrating a high absorption efficiency of 94.9 %, suggesting their potential application in photothermal therapies. These findings contribute to understanding babassu coconut CDs’ thermo-optical behavior, highlighting their promise for various practical applications, particularly in biomedicine. © 2025 Elsevier B.V.

关键词： Refractive index

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Subband electron densities of Si delta-doped pseudomorphic In0.2Ga0.8As/GaAs heterostructures

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APPLIED PHYSICS LETTERS 1997年第26期70卷 3582-3584页

作者： Li, G Babinski, A Jagadish, C Department of Electronic Materials Engineering Research School of Physical Science and Engineering Institute of Advanced Studies Australian National University Canberra ACT 0200 Australia

Magnetotransport properties of Si delta-doped pseudomorphic In0.2Ga0.8As/GaAs heterostructures grown by metalorganic vapor phase epitaxy have been investigated in magnetic fields up to 12 T in the dark at 1.7 K. Different delta-doping configurations, in which the same Si delta-doped layer was placed at different positions with respect to the In0.2Ga0.8As well, have been studied to clarify their effect on subband electron densities in the well. Very high electron densities of >4x10(12) cm(-2) were obtained when placing a Si delta-doped layer at the well center or the well-barrier interface. We found that one subband was occupied in the well-center-doped structure, but when the Si delta-doped layer was at the well-barrier interface, the second subband in the well became occupied. The electron density of Si delta-modulation-doped In0.2Ga0.8As/GaAs heterostructures, in which the cap barrier or the buffer barrier was Si delta doped, was in the order of <1.2x10(12) cm(-2). The Si delta doping in both of the barriers led to an increase of the electron density by almost a factor of 2, Owing to an incomplete transfer of the electrons from the Si delta-doped layers to the well, parallel conduction was observed in the Si delta-modulation-doped structures. (C) 1997 American Institute of Physics.

关键词： indium compounds gallium arsenide III-V semiconductors semiconductor doping silicon semiconductor heterojunctions electron density interface states magnetoresistance vapour phase epitaxial growth semiconductor growth impurity states

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Hybridization between microstructure and magnetization improvement in lead and RE co-doped BiFeO_3

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Journal of Rare Earths 2016年第5期34卷 495-506页

作者： M.A.Ahmed S.F.Mansour S.I.El-Dek M.M.Karamany Materials Science Lab.(1) Physics Dept.Faculty of ScienceCairo University Physics Department Faculty of ScienceZagazig University Materials Science and Nanotechnology Dept. Faculty of Post Graduate Studies for Advanced SciencesBeni-Suef University Basic Science Dept. Faculty of EngineeringBritish University in Egypt

The crystal structure,magnetic and electrical properties of Bi（0.96）Pb（0.04） FeO3 and Bi（0.92）Pb（0.04）RE（0.04）FeO3（RE=La,Sm,Dy and Yb）polycrystalline samples were prepared by the flash autocombustion technique.X-ray diffraction（XRD）measurements show that the rare-earth doped compositions crystallized in rhombohedral symmetry of space group R3 *** undoped sample consisted needle shape particles while rare earth substitution preferred platelet like particles as clarified from high resolution transmission electron microscopy（HRTEM）.Morphological features were examined using field emission scanning electron microscopy（FESEM）.Magnetization measurements showed that Yb^3＋ samples possessed the highest room temperature saturation magnetization while when Bi^3＋ ions were substituted by La^3＋ ions,a smaller MS（0.28 emu/g）was *** coexistence of ferroelectric and magnetic transitions was detected using DSC and χM,indicating the multiferroic characteristics of Bi（0.92）Pb（0.04）RE（0.04）FeO3 *** Néel temperature shifted upwards with decreasing the ionic radius of rare earth *** correlation was established between microstructure,morphology and magnetic properties in view of the contribution of magnetocrystalline and shape anisotropy in the magnetic parameters values.

关键词： BiFeO3 multiferroic rare earths anisotropy dielectric conductivity Neel temperature

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Cascaded diffusion-driven self-reinforced adhesive hydrogels for hydrophobic tissue closure

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Composites Part B: engineering 2025年 303卷

作者： Xie, Wenyue Tian, Zhuoling Xue, Rui Duan, Xiaocen Yuan, Zuoying Wan, Zhuo Su, Xing Feng, Yuting Jiang, Ying Wang, Hao Zhang, Long Liu, Xiaozhi Huang, Jianyong Department of Mechanics and Engineering Science College of Engineering Peking University Beijing100871 China Academy for Advanced Interdisciplinary Studies Peking University Beijing100871 China School of Materials Science and Engineering Beijing Institute of Technology Beijing100871 China Department of Interventional Radiology and Vascular Surgery and Wound Healing Center Peking University Third Hospital Beijing100191 China Tianjin Key Laboratory of Epigenetics for Organ Development of Premature Infants Fifth Central Hospital of Tianjin Tianjin 300450 China Tianjin Binhai Huangnan Plateau Medical Research Institute Huangnan Tibetan Autonomous Prefecture People's Hospital Huangnan Prefecture Qinghai Province 811399 China

Adipose tissue adhesion remains challenging due to the difficulty in breaking through hydrophobic energy barriers created by fatty acids and other hydrophobic compounds to form effective adipose tissue closure. Here, we developed a cascaded diffusion-driven adhesive hydrogel capable of achieving the closure of subcutaneous adipose tissues through a competitive multi-hydrogen-bonded network, which was modulated by the controllable spatiotemporal diffusion of gelatin, tea polyphenols, and nicotinamide at the adhesion interfaces. We showed that nicotinamide-triggered cascade diffusion could promote the penetration of tea polyphenols and gelatin networks into adjacent adipose tissues in a topologically entangled manner, achieving self-reinforced interfacial adhesion with a peak adhesion strength greater than 100 kPa. Further, we demonstrated that the hydrogel could effectively close subcutaneous adipose tissues in pig models and activate immune and lipid metabolism-related pathways to prevent fat liquefaction, thereby promoting wound healing and inhibiting excessive adipose tissue fibrosis. This work not only presents a new solution for clinical closure of adipose tissues, but also provides innovative ideas for developing bioactive materials with hydrophobic interface adhesion functions. © 2025 Elsevier Ltd

关键词： Tissue regeneration

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A COMPARISON OF DIFFERENT METHODS FOR THE CALCULATION OF THE CHEMICAL-POTENTIALS OF POLYMER SYSTEMS

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MAKROMOLEKULARE CHEMIE-MACROMOLECULAR SYMPOSIA 1993年第1期65卷 39-47页

作者： KUMAR, SK Department of Materials Science and Engineering Polymer Science Program Pennsylvania State University University Park PA 16802 USA

In an earlier publication we had presented a Monte Carlo method to calculate the incremental chemical potential between a chain of length nu and one of length nu+1 at any density. (Ref.9) In this paper we begin by formally proving that the chemical potential of a whole chain of length nu can be obtained by sequentially summing the incremental chemical potentials of all chains whose lengths are smaller than nu under the same conditions. We then compare the numerical value of chain chemical potentials computed in this fashion to those obtained by inserting whole chains into the simulation cell following the configurational bias procedure proposed by Smit and Frenkel. (Ref.5) It is found, for the two cases considered here, that die results obtained from the two different calculations agree within simulation uncertainty, thus verifying the validity of the proposed arguments.

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Transfer or blockage:Unraveling the interaction between deformation twinning and grain boundary in tantalum under shock loading with molecular dynamics

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Journal of materials science & Technology 2023年第25期156卷 118-128页

作者： Z.C.Meng M.M.Yang A.H.Feng S.J.Qu F.Zhao L.Yang J.H.Yao Y.Yang Q.B.Fan H.Wang Interdisciplinary Centre for Additive Manufacturing (ICAM) School of Materials and ChemistryUniversity of Shanghai for Science and TechnologyShanghai 200093China Institute of Metal Research Chinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China School of Materials Science and Engineering Tongji UniversityShanghai 201804China Academy for Advanced Interdisciplinary Studies Southern University of Science and TechnologyShenzhen 518055China National Key Laboratory of Science and Technology on Materials Under Shock and Impact School of Materials Science and EngineeringBeijing Institute of TechnologyBeijing 100081China Beijing Institute of Technology Chongqing Innovation Center Chongqing 401135China

The interaction between{112}deformation twinning and grain boundary in coaxial polycrystalline tantalum under shock compression was studied with molecular dynamics simulation under different grain pair misorientation ... 详细信息

The interaction between{112}<111>deformation twinning and grain boundary in coaxial polycrystalline tantalum under shock compression was studied with molecular dynamics simulation under different grain pair misorientation angles(MA)and geometric compatibility factor(m’).Generally,in the coaxial polycrystal,the value of MA determines the occurrence of twin transfer(TT)or twin blockage(TB),i.e.,twin transfer occurs at MA≤29°with twin blockage *** TT,the value of m’affects the selection of twin variants.,i.e.,the twin system with a larger m’is easier to *** morphology of twin pairs is ruler-shaped and lenticular under TT and TB,respectively,with different thickening mechanisms,including grain boundary dislocation emission.

关键词： Plasticity Grain boundary Twin Atomistic simulation Tantalum

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EFFECT OF ACID TREATMENT ATMOSPHERE ON THE THERMOPLASTICITY OF A LOW-VOLATILE BITUMINOUS COAL

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ENERGY & FUELS 1989年第6期3卷 703-706页

作者： LEE, CW JENKINS, RG The Pennsylvania State University Fuel Science Program Department of Materials Science and Engineering University Park Pennsylvania 16802 United States The University of Cincinnati College of Engineering Cincinnati OH 45221 United States

A strongly caking low-volatile bituminous coal was treated with HC1 and HF under air and N2 atmospheres. The thermoplastic properties of the raw and treated coals were examined in N2 (1 atm) by use of a microdilatomet... 详细信息

A strongly caking low-volatile bituminous coal was treated with HC1 and HF under air and N₂ atmospheres. The thermoplastic properties of the raw and treated coals were examined in N₂ (1 atm) by use of a microdilatometer. It was found that coals treated with the acids in air exhibited the lowest maximum swelling parameter (V₈, vol %) and weight loss during the dilatometry measurements. The above measured values were significantly restored for the coal acid treated under N₂. The results indicate that acid treatment of this coal in air promotes low-temperature air oxidation of the coal, consequently reducing its thermoplastic properties. It is shown that the acids may be important in catalyzing low-temperature coal oxidation. The significance of the acid treatment atmosphere and its implication for the reaction behavior of acid-treated coals are also discussed. © 1989, American Chemical Society. All rights reserved.

关键词： Coal

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DIFFUSION DURING ELECTRON-BEAM-INDUCED REDUCTION OF TUNGSTEN TRIOXIDE

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PHILOSOPHICAL MAGAZINE LETTERS 1989年第1期60卷 31-36页

作者： SINGH, SR MARKS, LD Center for Surface Radiation Damage Studies Department of Materials Science Engineering Northwestern University Evanston IL 60208 United States

We report experimental results on the kinetics of the electron-beam-induced reduction of WO3byin situhigh-resolution electron microscopy. Electron-beam irradiation of WO3results in complete reduction to W. The process is surface-initiated through desorption of oxygen from the crystal surface, and the subsequent growth of tungsten was found to be a diffusion-controlled process. The damage rate follows a para-linear curve, that is, an initially parabolic damage rate degenerating into a linear rate. The epitaxial relationship between WO3and W was found to be (001)wo3//(110)w. The WO3lattice has a critical nucleus size of about 2·6 nm.

关键词： Tungsten Compounds

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Various types of A.C conduction mechanism models for solid polymer electrolytes (SPE): A review

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Journal of Power Sources 2025年 645卷

作者： Yong, Jacky Winie, Tan Khandaker, Mayeen Uddin Chen, Yuncai Woo, Haw Jiunn Centre for Ionics University of Malaya Department of Physics Faculty of Science University of Malaya Kuala Lumpur50603 Malaysia Center for Functional Materials and Nanotechnology Institute of Science Universiti Teknologi MARA Selangor Shah Alam Malaysia Faculty of Applied Sciences Universiti Teknologi MARA Selangor Shah Alam Malaysia Applied Physics and Radiation Technologies Group CCDCU School of Engineering and Technology Sunway University Selangor Bandar Sunway47500 Malaysia Faculty of Graduaate Studies Daffodil International University Daffodil Smart City Birulia Savar Dhaka1216 Bangladesh Department of Physics College of Science Korea University 145 Anam-ro Seongbuk-gu Seoul02841 Korea Republic of Shenzhen Technology University Future Technology School Guangdong Shenzhen518118 China

This review explores the various AC conduction mechanism models for solid polymer electrolytes (SPEs), which are critical for advancing electrochemical devices like batteries and fuel cells. SPEs are considered promising alternatives to conventional liquid electrolytes due to their enhanced safety and flexibility. However, their relatively low ionic conductivity, especially at room temperature, remains a challenge. To address this, the paper discusses four key AC conduction models: Correlated Barrier Hopping (CBH), Quantum Mechanical Tunnelling (QMT), Small Polaron Hopping (SPH), and Overlapping Large Polaron Tunnelling (OLPT). Each model provides insights into different charge transport processes, such as thermally activated ion hopping and quantum tunnelling. The study highlights how factors like temperature and frequency influence conduction mechanisms, with each model describing distinct behaviours for charge carriers. For example, CBH and SPH rely on hopping mechanisms, while QMT and OLPT focus on tunnelling. By understanding these mechanisms, researchers can optimize the SPE system to enhance ionic conductivity. The paper concludes that selecting the appropriate model depends on the specific SPE material and environmental conditions, emphasizing the need for continued research to further refine these models and explore new SPE formulations for improved performance in practical applications. © 2025 Elsevier B.V.

关键词： Electron tunneling

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