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Modeling OH transport phenomena in cold plasma discharges using the level set method

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Plasma Science and Technology 2019年第5期21卷 121-131页

作者： Wei HAn k n YU Department of Physics City University of Hong KongTat Chee AvenueKowloon TongHong KongPeople's Republic of China Center of Medical Physics and Technology Hefei Institutes of Physical SciencesChinese Academy of SciencesHefei 230031People's Republic of China Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions and School for Radiological and Interdisciplinary Sciences(RAD-X) Soochow UniversitySuzhou 215006People's Republic of China

Cold atmospheric plasmas(CAPs)have attracted considerable interest in the field of plasma *** reactive species such as hydroxyl(OH)species play an important role in applications of *** of OH species towards the target and distribution of these OH species in the plasma plume play an important role in the applications of plasma *** the present work,a computational model was built to simulate the transportation and distribution of OH species in CAP discharges,which was based on the level set method to dynamically track the propagation of plasma carrier gas in air.A reaction term was incorporated for the OH *** OH species tended to diffuse around the main stream of the carrier gas,and thus covered larger radial and axial distances.A CAP discharge onto a skin layer led to the largest accumulation of OH species at the central part of the exposed *** distribution of OH species on the skin was asymmetric,which agreed with *** computational model itself and the obtained results would be useful for future development of plasma medicine.

关键词： cold atmospheric plasmas plasma medicine two-phase flow diffusion level set method

Combustion synthesis of Ce^(3+), Eu^(3+) and Dy^(3+) activated naCaPO_4 phosphors

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Journal of Rare Earths 2011年第6期29卷 527-535页

作者： k n Shinde S J Dhoble Animesh kumar Department of Physics RTM Nagpur University national Environmental Engineering Research Institute

The preparation of naCaPO4 doped with rare earth （RE） ions Ce3＋, Eu3＋ and Dy3＋ by combustion method was described. Under UV excitation （251 nm） of naCaPO4：Ce3＋ showsd emission （367 nm） in UV range. When naCaPO4：Dy3＋ phosphor was excited at 349 nm, the emission spectrum showed intense bands at 482 nm （blue） and 576 nm （yellow）. In Eu activated naCaPO4 phosphor, the emission spectrum showed a dominant peak at 594 nm （orange） while others were at 614 and 621 nm （red） when excited at 393 nm. The prepared phosphor was characterized by X-ray diffraction （XRD）, scanning electron microscope （SEM） and photoluminescence （PL） measurement. Thus, the photoluminescence behavior of naCaPO4：Ce3＋ was strongly suggested for scintillator. Likewise, Eu3＋ and Dy3＋ activated naCaPO4 phosphors were recommended for near-UV white light-emitting diodes （LEDs）.

关键词： combustion synthesis photoluminescence phosphor scintillator solid state lighting rare earths

Investigation into machining performance of microstructurally engineered in-situ particle reinforced magnesium matrix composite

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Journal of Magnesium and Alloys 2023年第3期11卷 916-935页

作者： S.k.Sahoo B.n.Sahoo S.k.Panigrahi Department of Mechanical Engineering Indian Institute of Technology MadrasChennai 600036India Applied Magnesium Research Group Center of Excellence in Materials and Manufacturing for Futuristic MobilityIndian Institute of Technology MadrasChennai 600036India Department of Mechanical Engineering Sardar Vallabhbhai National Institute of TechnologySurat 395007India

Magnesium and magnesium in-situ composites have significant potential in the application of design and manufacturing for automotive and aerospace industries because of their high specific strength and reduced fuel *** there are many challenges for machining of Mg based alloys and composites because of the high tendency of fire and *** challenges can be minimized through microstructural *** this present study,the machining performances of AZ91 Mg alloy and in-situ hybrid TiC+TiB_(2)reinforced AZ91 metal matrix composite was *** effectβ-Mg_(17)Al_(12)phases and grain refinement with and without in-situ particles on machinability were studied through microstructural engineering via aging and friction stir *** end milling operation was carried out at different cutting speeds ranging from 25 mm/min to 90 mm/min under dry environment by using an AlTin-coated tungsten carbide *** optimum cutting speed for machining was found to be 75 mm/min based on the surface roughness values of all conditioned *** base material with dendritic microstructure was found to have poor machinability in terms of inadequate surface finish and edge-burrs *** combined effect of in-situ TiC+TiB_(2)particles addition and grain refinement enhanced the machining performance of the material with superior surface finish,negligible edge-burr formation and better tool wear *** influence of in-situ TiC+TiB_(2)particles,β-Mg_(17)Al_(12)phases and grain refinement on machining characteristics are explained based on the tool wear mechanisms,chip behavior and machining induced affected zone.

关键词： Magnesium In-situ composite End-milling Tool wear Chip morphology

Efficient blue perovskite LEDs from quantum confined structures

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Science China Chemistry 2020年第1期63卷 3-4页

作者： Mahesh k.Gangishetty Daniel n.Congreve Rowland Institute Harvard University

Lead halide perovskites have been leading the optoelectronic field for the last several years,with exceptional progress in photovoltaics and rapid improvement in light emitting diodes(LEDs).LEDs are limited by outcoupling and waveguiding to approximately 20%external quantum efficiency(EQE),and infrared and green perovskite LEDs have already reached this threshold[1-3].For most applications,however,blue light is also required,and blue perovskite LEDs have been left behind,with a maximum EQE of 5.7%at 480 nm[4],and〜2%at wavelengths less than 470 nm[5].These lower efficiencies are due to both challenges inherent in blue(i.e.,wide band gap)materials as well as stability and defect problems specific to blue perovskites.

关键词： optoelectronic quantum perovskite

Combustion synthesis and luminescence characteristic of rare earth activated LiCaBO_3

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Journal of Rare Earths 2012年第10期30卷 1005-1008页

作者： n.S. Bajaj S.k. Omanwar Department of Physics SGB Amravati University Amravati-444602 (M.S.)

Lithium calcium borate （LiCaBO3） polycrystalline thermoluminescence （TL） phosphor doped with rare earth （Tb3＋ and Dy3＋） elements was synthesized by novel solution combustion synthesis. The reaction produced very stable crystalline LiCaBO3：D（D=Tb3＋ and Dy3＋） phosphors. These rare earth doped phosphors material showed maximum TL sensitivity with favorable glow curve shape. TL glow curve of X-ray irradiated that LiCaBO3：Tb3＋ and LiCaBO3：Dy3＋ samples showed two major well-separated glow peaks. The TL sensitivity of these phosphors to X-ray radiation was comparable with that of TLD-100（Harshaw）. Photoluminescence spectra of LiCaBO3：Tb3＋ and LiCaBO3：Dy3＋ showed the characteristic Tb3＋ and Dy3＋ peaks respectively. TL response to X-ray radiation dose was linear up to 25 Gy.

关键词： luminescence LiCaBO3 combustion synthesis rare earths kinetics

Brain-derived neurotrophic factor signaling in the neuromuscular junction during developmental axonal competition and synapse elimination

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neural Regeneration Research 2025年第2期20卷 394-401页

作者： Josep Tomàs Víctor Cilleros-Mañé Laia Just-Borràs Marta Balanyà-Segura Aleksandra Polishchuk Laura nadal Marta Tomàs Carolina Silvera-Simón Manel M.Santafé Maria A.Lanuza Unitat d’Histologia i neurobiologia(UHneurob) Facultat de Medicina i Ciències de la SalutUniversitat Rovira i VirgiliReusSpain

During the development of the nervous system,there is an overproduction of neurons and *** competition between neighboring nerve endings and synapses performing different activity levels leads to their elimination or *** have extensively studied the involvement of the brain-derived neurotrophic factor-Tropomyosin-related kinase B receptor neurotrophic retrograde pathway,at the neuromuscular junction,in the axonal development and synapse elimination process versus the synapse *** purpose of this review is to describe the neurotrophic influence on developmental synapse elimination,in relation to other molecular pathways that we and others have found to regulate this *** particular,we summarize our published results based on transmitter release analysis and axonal counts to show the different involvement of the presynaptic acetylcholine muscarinic autoreceptors,coupled to downstream serine-threonine protein kinases A and C(PkA and PkC)and voltage-gated calcium channels,at different nerve endings in developmental *** dynamic changes that occur simultaneously in several nerve terminals and synapses converge across a postsynaptic site,influence each other,and require careful studies to individualize the mechanisms of specific *** describe an activity-dependent balance(related to the extent of transmitter release)between the presynaptic muscarinic subtypes and the neurotrophin-mediated TrkB/p75nTR pathways that can influence the timing and fate of the competitive interactions between the different axon *** downstream displacement of the PkA/PkC activity ratio to lower values,both in competing nerve terminals and at postsynaptic sites,plays a relevant role in controlling the elimination of supernumerary ***,calcium entry through L-and P/Q-subtypes of voltage-gated calcium channels(both channels are present,together with the n-type channel in developing nerve terminals)contributes to red

关键词： acetylcholine release adenosine receptors axonal competition brain-derived neurotrophic factor calcium channels motor end-plate muscarinic acetylcholine receptors postnatal synapse elimination serine kinases tropomyosin-related kinase receptorB

Aldo-keto synthesis effect on Eu^(3+) fluorescence in YBO3 compared with solid state diffusion

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Journal of Rare Earths 2015年第5期33卷 486-490页

作者： k.A.koparkar n.S.Bajaj S.k.Omanwar Department of Physics Sant Gadge Baba Amravati University

The red-orange emitting phosphor YBO3：Eu3＋was prepared by aldo-keto method and solid state diffusion. Aldo-keto method implied to decrease the processing time and heating temperature. The red-orange emitting phosphor was characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, as well as emission and excitation photoluminescence spectra re-corded at room temperature. The result of aldo-keto method showed that the phosphor YBO3：Eu3＋could be obtained at 900 °C in less time^60%as compared to solid state diffusion （SSD）. The material showed that the strongest emission peak at 595 nm under excitation at 233 nm was only due to forced magnetic dipole 5D0→7F1 transition of Eu3＋ions. Significantly, the emission inten-sity of YBO3：Eu3＋phosphor prepared by aldo-keto method was relatively higher as compared to that obtained by the solid state diffusion.

关键词： aldo-keto method yttria europium optical materials photoluminescence (PL) rare earths

Drop weight impact analysis of GFRP tubes with hollow glass particle-filled matrix

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Defence Technology（防务技术） 2023年第11期29卷 1-9页

作者： Daniel Paul R.Velmurugan n.k.Gupta Department of Aerospace Engineering Indian Institute of Technology MadrasChennaiIndia Department of Applied Mechanics Indian Institute of Technology DelhiNew DelhiIndia

Protecting occupants or payloads in crashes and blasts is of utmost importance in both moving and immobile *** way of achieving this is by using a sacrificial energy *** tubes have been studied as potential energy absorbers due to their ability to fail progressively under axial *** this study,the energy absorption capability of these tubes is enhanced by adding hollow glass particles to the ***-weight tests are performed on composite tubes,and a digital image correlation(DIC)-based technique is used to capture their load-displacement *** eliminates the use of electronic data acquisition systems,load cells,and *** load-displacement curves of the tubes are obtained from the DIC-based technique and examined to understand their crushing *** the mean crush load shows a drop,an increase in crush length is *** specific energy absorbed by the tubes improves with an increase in GMB volume *** addition of 0.1,0.2,0.3 and 0.4 vol fractions of GMB results in the specific energy absorption increasing by6.6%,14.7%,24%and 36.6%,respectively,compared to neat glass fibre-epoxy *** examination of the tubes and comparison with tubes subject to quasi-static compression is also performed.

关键词： Composite tubes Syntactic foam Impact Axial compression Digital image correlation

Models and form factors for stand volume estimation in natural forest ecosystems: a case study of katarniaghat Wildlife Sanctuary (kGWS), Bahraich District, India

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Journal of Forestry Research 2013年第2期24卷 217-226页

作者： V. A. J Adekunle k. n. nair A. k. Srivastava n. k. Singh Federal University of Technology Dept of Forestry & Wood Technology national Botanical Research Institute (Council for Scientific & Industrial Research) Plant Diversity Systematics & Herbarium Division Rana Pratap Marg Department of Forests Sidhauli Forest Division

In view of the difficulties in stand volume estimation in natural forests, we derived real form factors and models for volume estimation in these types of forest ecosystems, using katarniaghat Wildlife Sanctuary as a case study. Tree growth data were obtained for all trees （dbh 〉10 cm） in 4 plots （25 × 25 m） randomly located in each of three strata selected in the forest. The form factor calculated for the stand was 0.42 and a range of 0.42 0.57 was estimated for selected species （density 〉10）. The parameters of model variables were consistent with general growth trends of trees and each was statistically significant. There was no significant difference （p〉0.05） between the observed and predicted volumes for all models and there was very high correlation between observed and predicted volumes. The output of the performance statistics and the logical signs of the regression coefficients of the models demonstrated that they are useful for volume estimation with minimal error. Plotting the biases with respect to considerable regressor variables showed no meaningful and evident trend of bias values along with the independent variables. This showed that the models did not violate regression assumptions and there were no heteroscedacity or multiculnarity problems. We recommend use of the form factors and models in this ecosystem and in similar ones for stand and tree volume estimation.

关键词： natural forest tree volume Estimation biodiversity tree height forest inventory