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Comparative study of Sm^(3+) ions doped phosphate based oxide and oxy-fluoride glasses for solid state lighting applications

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Journal of Rare Earths 2019年第4期37卷 374-382页

作者： M.Shoaib G.Rooh R.Rajaramakrishna n.Chanthima n.Kiwsakunkran H.J.kim J.Kaewkhao S.Tuscharoen Department of Physics Abdul Wali Khan University Center of Excellence in Class Technology and Materials Science (CEGM) Nakhon Pathom Rajabhat University Physics Program Faculty of Science and TechnologyNakhon Pathom Rajabhat University Department of Physics Kyungpook National University

The physical and luminescent properties of Sm^(3+)-doped oxide and oxy-fluoride phosphate glasses were investigated. The glass samples with chemical composition of 69 P_2 O_5-10 BaO-10 ZnO-10 Gd_2 O_3-1 Sm_2 O_3 and 69 P_2 O_5-10 BaO-10 ZnO-10 GdF_3-1 Sm_2 O_3 were prepared by conventional melt quenching technique. The prepared glass samples were characterized with density, molar volume, refractive index,FTIR, UV-Vis-nIR, photo luminesce nce, radio luminescence, decay time profile and CIE diagram. The density and refractive index of the oxide glass have higher values as compared to the oxy-fluoride *** FTIR spectra show the reduction of O-H group in oxy-fluoride glass. The characteristic peaks of Sm^(3+)are observed at 360,372,402,438,419,473,944,1077,1227,1373,1474,1529 and 1585 nm in UV-VIS-nIR spectra. These peaks are related respectively to the transitions from ground state ~6 H_(5/2) to ~4 D_(3/2), ~6 P_(7/2),6 P3/2, ~4 I_(11/2), ~6 F_(11/2), ~6 F_(9/2), ~6 F_(7/2),~6 F_(5/2),~6 F_(3/2), ~6 H_(15/2) and ~6 F_(1/2) excited states. From photoluminescence and radio-luminesce nce it is observed that the oxy-fluoride glass samples show better emission intensity than the oxide glass. The Judd-Ofelt theory(J-0 theory) was used to find J-O intensity Ω_λ(λ = 2,4 and 6)parameters and radiative properties such as transition probability, stimulated emission cross section and branching ratios for titled glasses. The trend observed in the J-O parameters is Ω_4 >Ω_2 >Ω_6. The transition probability,emission cross section and branching ratio have the highest values for the ~4 G_(5/2)→~6 H_(7/2)transition. The CIE coordinates of the prepared glass samples are positioned in the orange region and the CCT value is 3776.105 for oxide and oxyfluoride glass. The oxy-fluoride glass has shorter decay time as compared to the oxide glass and it is recorded to be 1.62 and 1.32 ms for oxide and oxy-fluoride respectively. According to the results obtained in this work, it is obvious t

关键词： Oxy-fluoride glass Photoluminescence Judd-Ofelt theory CIE coordinates Rare earths

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Invasive plant rhizome production and competitiveness vary based on neighbor identity

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Journal of Plant Ecology 2021年第4期14卷 638-647页

作者： Alyssa Laney Smith Daniel Z.Atwater Wonjae kim David C.Haak Jacob n.Barney School of Plant and Environmental Sciences Virginia TechBlacksburgVAUSA Department of Biology Earlham CollegeRichmondINUSA Present address:Department of Ecology and Evolutionary Biology University of ArizonaTucsonAZUSA

Aims Within-species genetic and phenotypic variation have well-known effects on evolutionary processes,but less is known about how within-species variation may influence community-level *** meaningful intraspecific variation might be particularly important in the context of anthropogenic impacts on natural systems,such as agriculture and species invasion,because human actions can cause strong selection *** In a greenhouse study,we explored intraspecific(30 accessions)and ecotypic variation(representing agricultural and nonagricultural habitats)in biomass and rhizome production in response to inter-and intraspecific competition and soil fertility of Johnsongrass(Sorghum halepense),a widespread invasive species and agricultural *** Findings Contrary to our expectations and previous results,we did not find variation in biomass production among Johnsongrass ecotypes at this early life ***,we did find that Johnsongrass biomass varied substantially depending on competitor identity,soil fertility treatments and among *** were 11%larger in the agricultural ecotype and up to 3-fold larger in fertilized treatment;while rhizome biomass increased by~50%when fertilized,but did not differ among ***,in competition,Johnsongrass produced 32%less biomass and 20%less rhizome mass with a conspecific than when competing interspecifically with *** results indicate species-specific competitive responses and changes in rhizome allocation in response to neighbor identity;suggesting the possibility of adaptation by Johnsongrass to shift allocation under competition.

关键词： adaptation agriculture competition exotic invasion Johnsongrass selection Sorghum halepense

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Dealing with Imbalanced Dataset Leveraging Boundary Samples Discovered by Support Vector Data Description

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Computers, Materials & Continua 2021年第3期66卷 2691-2708页

作者： Zhengbo Luo Hamïd Parvïn Harish Garg Sultan noman Qasem kim-Hung Pho Zulkefli Mansor Graduate School of Information Production and SystemsWaseda UniversityTokyoJapan Institute of Research and Development Duy Tan UniversityDa Nang550000Vietnam Faculty of Information Technology Duy Tan UniversityDa Nang550000Vietnam Department of Computer Science Nourabad Mamasani BranchIslamic Azad UniversityMamasaniIran School of Mathematics Thapar Institute of Engineering and TechnologyDeemed UniversityPatialaPunjab147004India Computer Science Department College of Computer and Information SciencesAl Imam Mohammad Ibn Saud Islamic UniversityRiyadhSaudi Arabia Computer Science Department Faculty of Applied ScienceTaiz UniversityTaizYemen Fractional Calculus Optimization and Algebra Research GroupFaculty of Mathematics and StatisticsTon Duc Thang UniversityHo Chi Minh CityVietnam Fakulti Teknologi dan Sains Maklumat Universiti Kebangsaan MalaysiaSelangorMalaysia

These days,imbalanced datasets,denoted throughout the paper by ID,(a dataset that contains some(usually two)classes where one contains considerably smaller number of samples than the other(s))emerge in many real world problems(like health care systems or disease diagnosis systems,anomaly detection,fraud detection,stream based malware detection systems,and so on)and these datasets cause some problems(like under-training of minority class(es)and over-training of majority class(es),bias towards majority class(es),and so on)in classification process and ***,these datasets take the focus of many researchers in any science and there are several solutions for dealing with this *** main aim of this study for dealing with IDs is to resample the borderline samples discovered by Support Vector Data Description(SVDD).There are naturally two kinds of resampling:Under-sampling(U-S)and oversampling(O-S).The O-S may cause the occurrence of over-fitting(the occurrence of over-fitting is its main drawback).The U-S can cause the occurrence of significant information loss(the occurrence of significant information loss is its main drawback).In this study,to avoid the drawbacks of the sampling techniques,we focus on the samples that may be *** data points that can be misclassified are considered to be the borderline data points which are on border(s)between the majority class(es)and minority class(es).First by SVDD,we find the borderline examples;then,the data resampling is applied over *** the next step,the base classifier is trained on the newly created ***,we compare the result of our method in terms of Area Under Curve(AUC)and F-measure and G-mean with the other state-of-the-art *** show that our method has betterresults than the other state-of-the-art methods on our experimental study.

关键词： Imbalanced learning classification borderline examples

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Optimal Reordering Trace Files for Improving Software Testing Suitcase

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Computers, Materials & Continua 2021年第4期67卷 1225-1239页

作者： Yingfu Cai Sultan noman Qasem Harish Garg Hamïd Parvïn kim-Hung Pho Zulkefli Mansor School of Measurement and Communication Harbin University of Science&TechnologyHarbinChina Computer Science Department College of Computer and Information SciencesAl Imam Mohammad Ibn Saud Islamic University(IMSIU)RiyadhSaudi Arabia Department of Computer Science Faculty of Applied ScienceTaiz UniversityTaizYemen School of Mathematics Thapar Institute of Engineering and TechnologyDeemed UniversityPatiala147004India Institute of Research and Development Duy Tan UniversityDa Nang550000Vietnam Faculty of Information Technology Duy Tan UniversityDa Nang550000Vietnam Department of Computer Science Nourabad Mamasani BranchIslamic Azad UniversityMamasaniIran Fractional Calculus Optimization and Algebra Research GroupFaculty of Mathematics and StatisticsTon Duc Thang UniversityHo Chi Minh CityVietnam Fakulti Teknologi dan Sains Maklumat Universiti Kebangsan MalaysiaUKM BangiSelangor43600Malaysia

An invariant can be described as an essential relationship between program *** invariants are very useful in software checking and *** tools that are used to detect invariants are invariant *** are two types of invariant detectors:dynamic invariant detectors and static invariant *** software is an available computer program that implements a special case of a dynamic invariant detection *** proposes a dynamic invariant detection algorithm based on several runs of the tested program;then,it gathers the values of its variables,and finally,it detects relationships between the variables based on a simple statistical *** method has some *** of its biggest drawbacks is its overwhelming time *** is observed that the runtime for the Daikon invariant detection tool is dependent on the ordering of traces in the trace file.A mechanism is proposed in order to reduce differences in adjacent trace *** is done by applying some special techniques of mutation/crossover in genetic algorithm(GA).An experiment is run to assess the benefits of this *** findings reveal that the runtime of the proposed dynamic invariant detection algorithm is superior to the main approach with respect to these improvements.

关键词： Dynamic invariant detection software testing genetic algorithm

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Sandwich-type ordered mesoporous carbon/graphene nanocomposites derived from ionic liquid

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nano Research 2016年第9期9卷 2696-2706页

作者： Ho Seok kim Young Hwan kim Kwang Chul Roh Kwang-Bum kim Lab of Energy Storage Materials Department of Material Science & EngineeringYonsei UniversitySeou1120749Republic of Korea Energy & Environmental Division Korea Institute of Ceramic Engineering & TechnologyJinju 52851Republic of Korea

Sandwich-type ordered mesoporous carbon/graphene nanocomposites were successfully synthesized using 2D ordered mesoporous silica/graphene nanocomposites as the hard template and an ionic liquid as a n-rich carbon source. We used an ionic liquid of 1-(3-cyanopropyl)-3-methylimidazolium dicyanamide containing nitrile groups (–Cn) in the cation and anion as a carbon precursor for the preparation of the nanocomposites. nitriles do not decompose under thermal treatment in an inert gas atmosphere, but leave significant amounts of n-rich carbon materials. The nanocomposites had a large surface area (1,316 m2·g–1), an average pore diameter of 5.9 nm, and high electrical conductivity. The nanocomposite electrode showed a high specific capacitance of 190 F·g–1at 0.5 A·g–1in 1 M TEABF4/An electrolyte and a good rate capability between 0 and 2.7 V for supercapacitor (or ultracapacitor) applications. [Figure not available: see fulltext.] © 2016, Tsinghua University Press and Springer-Verlag Berlin Heidelberg.

关键词： ionic liquid-derived carbon ordered mesoporous carbon/graphene nanocomposite 2D graphene nanocomposite supercapacitor

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n-doped carbon-embedded Tin nanowires as a multifunctional separator for Li–S batteries with enhanced rate capability and cycle stability

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Journal of Energy Chemistry 2021年第6期30卷 10-18,I0001页

作者： Yoongon kim Yuseong noh Jaejin Bae Hyunwoo Ahn Minho kim Won Bae kim Department of Chemical Engineering Pohang University of Science and Technology(POSTECH)77 Cheongam-roNam-guPohang 37673South Korea

Lithium-sulfur(Li-S)batteries have attracted considerable attention as next-generation energy storage devices owing to their high theoretical specific capacity and ***,the commercialization of Li-S batteries is hindered by critical issues,including the migration of the dissolved lithium polysulfides(LiPSs)from the sulfur electrode to the lithium metal anode,resulting in poor cycling ***,we report a multifunctional interlayer configured with an n-doped carbon framework and titanium nitride nanowires on a polypropylene separator(nC/Tin nWs@PP)to suppress the polysulfide shuttling ***/Tin nWs@PP can be obtained by electrospinning and the subsequent scalable solution-based vacuum *** one-dimensional structure of the Tin nWs can shorten the Li-ion diffusion distance with large electrode/electrolyte ***,the n-doped carbon framework in the nWs enables facile electron transportation and allows the suppression of the shuttle effect to improve the electrochemical reaction *** Li-S battery with a nC/Tin nWs@PP separator exhibited enhanced cycling stability and rate capability,indicating that this could be a new research direction for Li-S batteries.

关键词： Li-S battery Shuttle effect Interlayer Separator Tin n-doped carbon 1D nanowire

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Longitudinal trajectories of physical activity in women using latent class growth analysis:The WIn Study

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Journal of Sport and Health Science 2016年第4期5卷 410-416页

作者： Youngdeok kim Minsoo Kang Anna M.Tacón James R.Morrow Jr Department of Kinesiology and Sport Management Texas Tech University Department of Health and Human Performance Middle Tennessee State University Department of Kinesiology Health Promotionand RecreationUniversity of North Texas

Purpose：This study aimed（1） to examine the longitudinal trajectories in objectively measured physical activity（PA）;（2） to identify unknown（i.e.,latent） subgroups with distinct trajectories;and（3） to examine the correlates of latent subgroups among community dwelling ***：The study sample included a total of 669 women from the Women＇s Injury Study,a 5-year prospective cohort study conducted from2007 in the Southwest Central region of the ***-based step-count data across 18 consecutive months were fitte to a latent growth model（LGM） and a latent class growth model（LCGM）.Baseline characteristics were regressed on latent class ***：The longitudinal change in PA was best fi to a piecewise LGM with seasonal *** y increased and decreased levels of PA were observed during the spring,fall,and winter,respectively（p〈0.001）.Three latent subgroups with distinct PA trajectories were identifie（low-active（46.8%）,somewhat-active（41.3%）,and active（11.9%））.Age and body fat percentage at the baseline significant y explained the likelihoods of being in low-active ***：Seasonal variations in PA among women were observed but may not be practically significant A relatively large portion of the sample showed low levels of PA for long *** strategies should be considered for women who are overweight or obese,and aged 〉40 years old to promote PA during the life course.

关键词： Female Pedometer Prospective cohort Season Step-count

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Phase-pure na3V2(PO4)2F3 embedded in carbon matrix through a facile polyol synthesis as a potential cathode for high performance sodium-ion batteries

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nano Research 2019年第4期12卷 911-917页

作者： Sohyun Park Jinju Song Seyeon kim Balaji Sambandam Vinod Mathew Sungjin kim Jeonggeun Jo Seokhun kim Jaekook kim Department of Materials Science and Engineering Chonnam National University 300 Ybngbong-dong Buk-gu Gwangju 500-757 Republic of Korea Gwangju Bio/Energy R&D Center Korea Institute of Energy Research (KIER) 270-25 Samso-ro Buk-gu Gwangju 61003 Republic of Korea

In this study,a pseudo-layered na super-ionic conductor of na3V2(PO4)2F3 (nVPF)/C cathode for sodium-ion batteries is prepared successfully using a facile polyol refluxing process without any impurity *** X-ray diffraction and Rietveld refinement results confirm that nVPF possesses tetragonal nASICOn-type lattice with a space group of P42/*** this preparative method,polyol is utilized as a solvent as well as a carbon *** presence of nanosized nVPF particles in the carbon network is confirmed by field-emission scanning electron microscopy (FE-SEM) and high-resolution transmission electron microscopy (HR-TEM).The existence of carbon is analyzed by Raman scattering and elemental *** applied as a na-storage material in a potential window of 2.0-4.3 V,the electrode exhibits two flat voltage plateaus at 3.7 and 4.2 V with an electrochemically active V^3+/V^4+ redox *** addition,na3V2(PO4)2F3/C composite achieved a retention capacity of ~ 88% even after 1,500 cycles at 15 ***,at high current densities of 30 and 50 C,na3V2(PO4)2F3/C cathode retains the specific discharge capacities of 108.4 and 105.9 mAh·g-1,respectively,revealing the structural stability of the material prepared through a facile polyol refluxing method.

关键词： fluorophosphate na3V2(PO4)2F3 polyol process sodium ion batteries long life stability

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Internal Flow Simulation of High-Performance Solid Rockets using a k-ω Turbulence Model

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Journal of Thermal Science 2005年第2期14卷 114-119页

作者： V.R.SAnAL KUMAR H.D.kim B.n.RAGHUnAnDAn T.SETOGUCHI S.RAGHUnATHAn Andong national University Andong 760-749 KoreaAndong National University Andong 760-749KoreaIndian Institute of Science Bangalore-560 012IndiaSaga University Honjo-machiSaga 840-8502JapanThe Oueen's University of Belfast Northern IrelandUK

For technological reasons many high-performance solid rocket motors are made from segmented propellant grains with non-uniform port geometry. In this paper parametric studies have been carried out to examine the geometric dependence of transient flow features in solid rockets with non-uniform ports. numerical computations have been carried out in an inert simulator of solid propellant rocket motor with the aid of a standard k-ω turbulence model. It was seen that the damping of the temperature fluctuation is faster in solid rocket with convergent port than with divergent port geometry. We inferred that the damping of the flow fluctuations using the port geometry is a meaningful objective for the suppression and control of the instability and/or pressure/thrust oscillations during the starting transient of solid rockets.

关键词： solid rockets pressure spike instability thrust oscillation turbulent separation.

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Silicon nanowire CMOS nOR logic gates featuring onevolt operation on bendable substrates

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nano Research 2018年第5期11卷 2625-2631页

作者： Jeongje Moon Yoonjoong kim Doohyeok Lim Sangsig kim Department of Electrical Engineering Korea University 145 Anam-ro Seongbuk-gu Seoul 02841 Republic of Korea LED PKG Development Group Samsung Electronics Co. Ltd. 1 Samsung-ro Yongin-si Gyeonggi-do 17113 Republic of Korea

In this study, we propose complementary metal-oxide-semiconductor （CMOS） nOR logic gates consisting of silicon nanowire （nW） arrays on bendable substrates. A circuit consisting of two p-channel nW field-effect transistors （nWFETs） in series and two n-channel nWFETs in parallel is constructed to operate a two- input CMOS nOR logic gate. The nOR logic gates operate at a low supply voltage of 1 V with a rail-to-rail logic swing and a high voltage gain of approximately -3.0. The exact nOR logic functionality is achieved owing to the superior electrical characteristics of the well-aligned p- and n-nWFETs, which are obtained using conventional Si-based CMOS technology. Moreover, the nOR logic gates exhibit stable characteristics and have good mechanical properties. The proposed bendable nW CMOS nOR logic gates are promising building blocks for future bendable integrated electronics.

关键词： field-effect transistor silicon nanowire nOR logic gate bendable substrate

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