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Structural,morphological,optical and photoluminescent properties of spray-deposited ZnSe thin film

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journal of Semiconductors 2014年第11期35卷 5-9页

作者： G.M.Lohar S.K.Shinde v.j.fulari Holography and Material Research Laboratory Department of PhysicsShivaji University

ZnSe thin films are successfully deposited by spray pyrolysis deposition technique. Deposited thin films are characterized by X-ray diffraction study, and it reveals that spray-deposited ZnSe thin films are polycrystalline with hexagonal crystal structure. Surface morphology is carried out by scanning electron microscopy. It shows cotton-like morphology, and optical properties, such as absorbance, transmittance, reflectance, band gap, refrac- tive index, extinction coefficient are studied. Photoluminescence shows strong emission at 497 nm. Also, spray- deposited ZnSe thin films are hydrophilic in nature, which is shown by contact angle meter.

关键词： spray pyrolysis technique photoluminescence hydrophilicity ZnSe

The influence of monomer concentration on the optical properties of electrochemically synthesized polypyrrole thin films

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journal of Semiconductors 2013年第10期34卷 13-18页

作者： j.v.Thombare M.C.Rath S.H.Han v.j.fulari Holography and Material Research Laboratory Department of PhysicsShivaji UniversityKolhapur-416 004India Radiation and Photochemistry Division BARCMumbaiIndia Department of Chemistry Hanyang UniversitySeoulSouth Korea

Polypyrrole （PPy） thin films were deposited on stainless steel and ITO coated glass substrate at a constant deposition potential of 0.8 v versus saturated calomel electrode （SCE） by using the electrochemical polymerization method. The PPy thin films were deposited at room temperature at various monomer concentrations ranging from 0.1 M to 0.3 M pyrrole. The structural and optical properties of the polypyrrole thin films were investigated using an X-ray diffractometer （XRD）, FTIR spectroscopy, scanning electron microscopy （SEM）, and ultravioletvisible （Uv-vis） spectroscopy. The XRD results show that polypyrrole thin films have a semi crystalline structure. Higher monomer concentration results in a slight increase of crystallinity. The polypyrrole thin films deposited at higher monomer concentration exhibit high visible absorbance. The refractive indexes of the polypyrrole thin films are found to be in the range of 1 to 1.3 and vary with monomer concentration as well as wavelength. The extinction coefficient decreases slightly with monomer concentration. The electrochemically synthesized polypyrrole thin film shows optical band gap energy of 2.14 ev.

关键词： polypyrrole electrochemical polymerization method structure optical properties

The effects of electron irradiation on the optical properties of the organic semiconductor polypyrrole

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journal of Semiconductors 2013年第9期34卷 11-15页

作者： j.v.Thombare M.C.Rath S.H.Han v.j.fulari Holography and Materials Research Laboratory Department of PhysicsShivaji University Radiation and Photochemistry Division BARC Department of Chemistry Hanyang University

The optical properties of polypyrrole （Ppy） thin films upon 2 Mev electron beam irradiation changes with different doses. The induced changes in the optical properties for Ppy thin films were studied in the visible range 300 to 800 nm at room temperature. The optical band gap of the pristine Ppy was found to be 2.19 cv and it decreases up to 1.97 ev for a 50 kGy dose of 2 Mev electron beam. The refractive index dispersion of the samples obeys the single oscillator model. The obtained results suggest that electron beam irradiation changes the optical parameters of Ppy thin films.

关键词： polypyrrole electron beam irradiation optical band gap

Optical properties of electrochemically synthesized polypyrrole thin films:the electrolyte effect

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journal of Semiconductors 2014年第6期35卷 1-4页

作者： j.v.Thombare S.K.Shinde G.M.Lohar U.M.Chougale S.S.Dhasade H.D.Dhaygude B.P.Relekar v.j.fulari Holography and Materials Research Laboratory Department of PhysicsShivaji University Department of Physics Vidnyan MahavidyalyaSangola

Polypyrrole thin films are prepared by the potentiostatic mode of electrodeposition at ＋0.7 v versus a saturated calomel electrode （SCE）. The polypyrrole films are prepared in the presence of different electrolytes such as： p-toluene sulphonic acid （PTS）, oxalic acid and H2SO4. The prepared films are characterized by Uv- vis absorption spectroscopy and normal reflectance measurements. The electrochemically synthesized films are semiconductor in nature. The band gap energy ofpolypyrrole thin films is found to be 1.95, 1.92 and 1.79 ev for H2 SO4, oxalic acid and p-toluene sulphonic acid, respectively. The normal reflectance spectroscopy of polypyrrole films shows that the maximum reflectance is in the presence of p-toluene sulphonic acid; this is may be due to a more distinct microstructure than the others. The optical constants such as the extinction coefficient, refractive index, optical conductivity, etc. are calculated and studied with various electrolytes.

关键词： electrodeposition polypyrrole extinction coefficient refractive index

Thermoluminescence characterization of natural and synthetic irradiated Ce-monazites

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journal of Rare Earths 2024年第4期42卷 643-650页

作者： v.Correcher C.Boronat j.Garcia-Guinea j.F.Benavente T.Rivera-Montalvo CIEMAT Av.Complutense 4028040MadridSpain MNCN-CSIC J.Gutierrez Abascal 228006MadridSpain Instituto Politécnico Nacional CICATA-IPNAv.Legaria 694Mexico City11500Mexico

The thermoluminescence(TL)emission of synthetic and natural Ce-monazites was characterized here to determine the potential application in the identification of microscopic defects from a qualitative point of view trying to link each TL peak to a chemical-physical *** kinetic parameters that lead the luminescence processes were calculated by means of variable heating rate and computing glow curve deconvolution methods and allow identifying three groups of components at~90,130 and 290℃(for the mineral sample)and~90,170,220,270 and 320℃(for the synthetic CePO_(4):Nd_(0.20),La_(0.25)).The main differences appreciated in these complex TL curves are mainly due to(i)the content of impurities(natural sample contains lanthanides as well as U 0.60%and Th 5.22%)and(ii)the degree of crystallinity of the samples which is directly related to the type of impurities(synthetic monazite relies only on Nd and La).The behavior of the dose response in the range of 1-8 Gy is similar for both samples;the TL intensity increases linearly as the dose increases without changes in the position of the maxima,denoting first-order kinetic luminescence *** peak could be mostly associated with structural defects(i.e.,phase transitions),chemical reactions(i.e.,Ce3+?Ce4+redox reaction,dehydration or dehydroxylation processes)or intrinsic defects(i.e.,Frenkel defects,ODCs or NBOHCs).

关键词： Thermoluminescence Kineticparameters Phosphate Ce-monazite Defects Rare earths

Stand dynamics of old-growth hemlock forests in central Bhutan are shaped by natural disturbances

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Forest Ecosystems 2024年第4期11卷 434-447页

作者： Karma Tenzin Craig R.Nitschke Kathryn j.Allen Raphael Trouve Thiet v.Nguyen Patrick j.Baker School of Agriculture Foodand Ecosystem SciencesUniversity of Melbourne500 Yarra BlvdRichmondVictoriaAustralia School of Geography Planningand Spatial SciencesUniversity of TasmaniaSandy BayTasmaniaAustralia Forest Science Institute of South vietnam 1 Pham Van Hai StreetTan Binh DistrictHo Chi Minh CityViet Nam

Understanding how past disturbances have influenced the development of forests is critical for deciphering their current structure and composition and forecasting future *** this study,dendrochronological methods were applied to uncover the disturbance history of old-growth hemlock-dominated forests in central *** of tree-ring samples from two old-growth hemlock stands,located in two different topographic settings,identified the importance of gap-phase dynamics in facilitating recruitment and growth releases and producing complex,multi-aged structure s over *** site showed evidence of a near stand-replacing disturbance in the late 1700s,while the other showed no evide nce of high-severity disturbance at any time over the last 400 *** both sites low-to medium-severity disturbances,some of which appear to be associated with cyclones originating in the Bay of Bengal,dominated the disturbance *** hemlock stands exhibited a significant positive association between cyclone occurrence and growth release events and between recruitment pulses and growth release *** 1800 to 1970 there was an increase in recruitment of angiosperm tree species at most sites and a corresponding decline in conifer *** the past 50 years there has been little new recruitment;this may be due to light limitation in the understory from shade-tolerant angiosperms and bamboo in the lower strata of these *** variations in disturbance dynamics and recruitment were observed across the study sites,suggesting that other factors,such as topography and climate,may be influencing long-term stand development *** study highlights the complex interplay between historical disturbance regimes and tree recruitment in shaping the age and size structures of old-growth hemlock forests in central *** also provides new insights into the dynamics of these forests that can be used to support effective forest conservation and management i

关键词： Forest structure Hemlock forest Himalaya Natural disturbance

In situ digital testing method for quality assessment of soft soil improvement with polyurethane

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journal of Rock Mechanics and Geotechnical Engineering 2024年第5期16卷 1732-1748页

作者： X.F.Wang C.j.Wang W.v.Yue Z.j.Zhang Z.Q.Yue Department of Civil Engineering China University of Geosciences (Beijing)BeijingChina Department of Water Science and Engineering Zhengzhou UniversityZhengzhouChina Department of Geotechnical Engineering Tongji UniversityShanghaiChina Department of Civil Engineering The University of Hong KongChina

This study purposes an in situ testing method on quality assessment of soil *** drilling data includes the spatial distribution and in situ strength of untreated and treated soil along three different drillholes measured by on-site drilling monitoring *** factual drilling data can characterize the degree of soil improvement by penetration injection with permeable *** from on-site drilling monitoring shows that the linear zones represent constant drilling speeds shown in the plot of drill bit advancement *** drilling time,which indicates the spatial distributions of soil *** soil profile at the study site is composed of four layers,which includes fill,untreated silty clay,treated silty clay,and mucky *** results of soil profile are verified by the parallel site *** constant drilling speeds profile the coring-resistant strength of drilled *** comparing with the untreated silty clay,the constant drilling speeds of the treated silty clay have been decreased by 13.0-62.8%.Two drilling-speed-based indices of 61.2%and 65.6%are proposed to assess the decreased average drilling speed and the increased in situ strength of treated silty *** tests,*** compressive strength(UCS)test,have been performed with core sample to investigate and characterize in situ strength by comparing that with drilling *** show that the average predicted strengths of treated silty clay are 2.4-6.9 times higher than the average measured strength of untreated silty *** UCS-based indices of 374.5%and 344.2%verified the quality assessment(QA)results by this new in situ *** method provides a cost-effective tool for quality assessment of soil improvement by utilizing the digital drilling data.

关键词： Drilling process monitoring system Hydraulic rotary drilling process Constant drilling speed Soil improvement Quality assessment

Role of lysosomal trafficking regulator in autophagic lysosome reformation in neurons:a disease perspective

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Neural Regeneration Research 2024年第5期19卷 957-958页

作者： Prashant Sharma jenny Serra-vinardell Wendy j.Introne May Christine v.Malicdan NIH Undiagnosed Diseases Program Common FundOffice of the DirectorNational Institutes of HealthBethesdaMDUSA Human Biochemical Genetics Section Medical Genetics BranchNational Human Genome Research InstituteNational Institutes of HealthBethesdaMDUSA(Serra-Vinardell JIntrone)

Lysosomes are discrete organelles that act as recycling centers for extracellular and intracellular materials,playing a pivotal role in maintaining cellular *** acidic environment,maintained by numerous hydrolytic enzymes,facilitates substrate *** in lysosomal processes can lead to abnormal substrate degradation,significantly impacting cellular *** energy-demanding cells,such as post-mitotic neurons,are especially vulnerable to these changes,often resulting in neurological ***,a conserved catabolic process,requires extensive lysosomal *** plays a key role in removing unnecessary intracellular components,ensuring cellular homeostasis,and promoting cell survival during stress conditions such as starvation,infection,or cellular damage.

关键词： homeostasis lysosomal removing

Synchronized off-harmonic probe laser with highly variable pulse duration for laser-plasma interaction experiments

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High Power Laser Science and Engineering 2024年第1期12卷 99-107页

作者： j.Hornung Y.Zobus H.Lorenté C.Brabetz B.Zielbauer v.Bagnoud GSI Helmholtzzentrum für Schwerionenforschung GmbH DarmstadtGermany Institut d’Optique UniversitéParis-SaclayPalaiseauFrance Institut für Angewandte Physik Technische Universität DarmstadtDarmstadtGermany

This paper presents the development and experimental utilization of a synchronized off-harmonic laser system designed as a probe for ultra-intense laser±plasma interaction experiments. The system exhibits a novel seed-generation design,allowing for a variable pulse duration spanning over more than three orders of magnitude, from 3.45 picoseconds to 10 nanoseconds. This makes it suitable for various plasma diagnostics and visualization techniques. In a side-view configuration, the laser was employed for interferometry and streaked shadowgraphy of a laser-induced plasma while successfully suppressing the self-emission background of the laser±plasma interaction, resulting in a signal-to-self-emission ratio of 110 for this setup. These properties enable the probe to yield valuable insights into the plasma dynamics and interactions at the PHELIX facility and to be deployed at various laser facilities due to its easy-to-implement design.

关键词： interferometry laser-plasma interaction off-harmonic probe laser streaked shadowgraphy