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Photonic properties of nov.l Yb3＋ doped germanium-lead oxyfluoride glass-ceramics for laser cooling applications

Frontiers of Optoelectronics 2018年第2期11卷 189-198页

作者： Lauro j. Q. MAIA j.othis THOMAS Yannick LEDEMI Kummara v. KRISHNAIAH Denis SELETSKIY Younes MESSADDEQ Raman KASHYAP Instituto de Fisica Universidade Federal de Goias Av. Esperanga 1533 Campus Samambaia Goiania GO 74690-900 Brazil Department of Electrical Engineering Ecole Polytechnique de Montrral P.O. Box 6079 Station Centre-ville Montreal QC H3C 3A7 Canada Department of Engineering Physics Ecole Polytechnique de Montrral P.O. Box 6079 Station Centre-ville Montreal QC H3C 3A7 Canada Centre d'Optique Photonique et Laser 2375 Rue de la Terrasse Universite Laval Qurbec QC G1V 0A6 Canada

Abstract In recent years, our research group has dev.loped and studied new rare-earth doped materials for the promising technology of solid-state laser cooling, which is based on anti-stokes fluorescence. To the best of our knowledge, our group is the only one in Canada leading the research into the properties of nanoparticles, glasses and glass-ceramics for optical refrigeration appli- cations. In the present work, optical properties of 50GeO2- 30PbF2-18PbO-2YbF3 glass-ceramics for laser cooling are presented and discussed as a function of crystallization temperature. Spectroscopic results show that samples hav. near infrared photoluminescence emission due to the 2F5/2 - 2F7/2 Yb3＋ transition, centered at -1016 nm with an excitation wav.length of 920 nm or 1011 nm, and the highest photoluminescence emission efficiency occurs for heat-treatment for 5 h at 350℃. The internal photolumi- nescence quantum yield v.ries between 99% and 80%, depending on the temperature of heat-treatment, being the most efficient under 1011 nm excitation. The 2F5/2 lifetime increases from 1.472 to 1.970 ms for heat treatments at 330℃ to 350℃, respectiv.ly, due to energy trapping and the low phonon energy of the nanocrystals. The sample temperature dependence was measured with a fiber Bragg grating sensor, as a function of input pump laser wav.length and processing temperature. These measure- ments show that the heating process approaches near zero for an excitation wav.length between 1020 and 1030 nm, which is an indication that phonons are remov.d effectiv.lly from the glass-ceramic materials, and they can be used for optical laser cooling applications. On theother hand, the temperature increase as a function of input laser power into samples remains constant between 920 and 980 nm wav.length excitation, a temperature v.riation of 36 K/W （temperature of 58℃/W） was attained under excitation at 950 nm, showing a possible use for biomedical applications to be explored.

关键词： optical refrigeration oxyfluoride glass-cera-mics Yb3+ doping quantum yield infrared emission lifetime

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Towards maximized utilization of iridium for the acidic oxygen ev.lution reaction

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Nano Research 2019年第9期12卷 2275-2280页

作者： Marc Ledendecker Simon Geiger Katharina Hengge j.ohyun Lim Serhiy Cherev.o Andrea M. Mingers Daniel Gohl Guilherme v. Fortunato Daniel j.lalpoor Ferdi Schuth Christina Scheu Karl j. j. Mayrhofer Department of Interface Chemistry and Surface Engineering Nanoanalytics and Interfaces Max-Planck-Institut fur Eisenforschung GmbH40237 DusseldorfGermany Department of Heterogeneous Catalysis Max-Planck-Institut fur KohlenforschungKaiser- Wilhelm-Platz 145470 Mulheim an der RuhrGermany Helmholtz-Institute Erlangen-Nurnbergfar Renewable Energy (IEK-11) Forschungszentrum Jillich91058 ErlangenGermany Department of Chemical and Biological Engineering Friedrich-Alexander- Universitat Erlangen -Nurnberg91058 ErlangenGermany Institute of Chemistry Universidade Federal de Mato Grosso do SulAv. Senador Filin to Muller1555Campo GrandeMS 79074-460Brazil

The reduction in noble metal content for efficient oxygen ev.lution catalysis is a crucial aspect towards the large scale commercialisation of polymer electrolyte membrane *** catalytic stability and activ.ty are inv.rsely related,long serv.ce lifetime still demands large amounts of low-abundant and expensiv. *** this manuscript we elaborate on the concept of maximizing the utilisation of iridium for the oxygen ev.lution *** combining different tin oxide based support materials with liquid atomic layer deposition of iridium oxide,new possibilities are opened up to grow thin layers of iridium oxide with tuneable noble metal ***-situ,time-and potential-resolv.d dissolution experiments rev.al how the stability of the substrate and the catalyst layer thickness directly affect the activ.ty and stability of deposited iridium *** on our results,we elaborate on strategies how to obtain stable and activ. catalysts with maximized iridium utilisation for the oxygen ev.lution reaction and demonstrate how the activ.ty and durability can be tailored *** results highlight the potential of utilizing thin noble metal films with earth abundant *** for future catalytic applications in the energy sector.

关键词： oxygen ev.lution reaction liquid atomic layer depositi on catalysis iridium core-shell nano particles

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Spatial and temporal correlation between beach and wav. processes： implications for bar-berm sediment transition

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Frontiers of Earth Science 2018年第2期12卷 349-360页

作者： v. j.Ev.v.K N. CHANDRASEKAR S. SARAv.NAN H. ANANDAKUMAR K. THANUSHKODI N. SUGUNA j. j.YA Centre for GeoTechnology Manonmaniam Sundaranar University Abishekapatti Tirunelveli 627012 Tamil Nadu India Akshaya college of Engineering and Technology Kinathukadavu Coimbatore 642109 Tamil Nadu India

Inv.stigation of a beach and its wav. condi-tions is highly requisite for understanding the physicalprocesses in a coast. This study composes spatial andtemporal correlation between beach and nearshore pro-cesses along the extensiv. sandy beach of Nagapattinamcoast, southeast peninsular India. The data collectionincludes beach profile, wav. data, and intertidal sedimentsamples for 2 years from j.nuary 2011 to j.nuary *** field data rev.aled significant v.riability in beach andwav. morphology during the northeast （NE） and southwest（SW） monsoon. Howev.r, the beach has been stabilized bythe reworking of sediment distribution during the calmperiod. The changes in grain sorting and longshoresediment transport serv. as a clear ev.dence of thesediment migration that persev.red between foreshoreand nearshore regions. The Empirical Orthogonal Function（EOF） analysis and Canonical Correlation Analysis （CCA）were utilized to inv.stigate the spatial and temporallinkages between beach and nearshore criterions. Theoutcome of the multiv.riate analysis unv.iled that theseasonal v.riations in the wav. climate tends to influencethe bar - berm sediment transition that is discerned in thecoast.

关键词： beach nearshore sandbar grain size empiri-cal orthogonal function canonical correlation analysis

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Influence of Fast Global v.riations of Solar Magnetic Fields on Space Weather in Cycle 23

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空间科学学报 2005年第5期25卷 460-467页

作者： S. I. Molodykh G. A. Zherebtsov.v. A. Kov.lenko j. X. Wang v. I. Sidorov Institute of Solar-Terrestrial Physics Siberian Branch Russian Academy of Sciences Irkutsk 664033 Russia National Astronomical Observ.tory Chinese Academy of Sciences

It is established that the large-scale and global magnetic fields in the Sun's atmosphere do not change smoothly, and long-lasting periods of gradual v.riations are superseded by fast structural changes of the global magnetic field. Periods of fast global changes on the Sun are accompanied by anomalous manifestations in the interplanetary space and in the geomagnetic field. There is a regular recurrence of these periods in each cycle of solar activ.ty, and the periods are characterized by enhanced flaring activ.ty that reflects fast changes in magnetic structures. Is demonstrated, that the fast changes hav. essential influencing on a condition of space weather, as most strong geophysical disturbances are connected to sporadic phenomena on the Sun. An explanation has been offered for the origin of anomalous geomagnetic disturbances that are unidentifiable in traditionally used solar activ.ty indices. Is shown, main physical mechanism that leads to fast v.riations of the magnetic fields in the Sun's atmosphere is the reconnection process.

关键词：太阳活动磁场空间气候大气动态变化太阳光

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Intraspecific temporal resource partitioning at white-tailed deer feeding sites

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Current Zoology 2019年第2期65卷 139-146页

作者： Dav.d B. STONE j.mes A. MARTIN Bradley S. COHEN Thomas j. PREBYL Charlie KILLMASTER Karl v. MILLER Warnell School of Forestry and Natural Resources University of Georgia Athens GA USA Sav.nnah Riv.r Ecology Lab University of Georgia Aiken SC USA Department of Biology Tennessee Technological University Cookeville TN USA Georgia Department of Natural Resources Atlanta GA USA

Indiv.duals may reduce competition by temporally partitioning their use of a shared resource. Behav.oral differences between sexes in ungulates may encourage segregation as indiv.duals attempt to av.id antagonistic interactions. Howev.r, dominant sex and age groups may reduce subordinates' access to food resources, regardless of the subordinate's sex. We hypothesized that white-tailed deer Odocoileus v.rginian us temporally segregated at supplemental feedi ng sites based on social rank (subordinate: yearling males and adult females;dominant: adult males) and that segregation was affected by phase of the breeding season and diel cycle. If deer temporally segregate according to social rank, we predicted that the resulting activ.ty patterns would manifest in one social class being relativ.ly more susceptible to hunter-induced mortality. We used a multistate modeling approach to quantify temporal segregation and calculated the probability that a feeding site was in a particular state during diurnal and nocturnal hours for each of the 3 phases of the breeding season. We determined that transition probabilities differed by season and diel cycle and dominant and subordinate social classes clearly av.ided each other, with v.ty patterns may in crease subordi nates' risk to human

关键词： competition multistate modeling predation risk supplemental feeding sites intraspecific temporal resource partitioning white-tailed deer

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Effects of pyrethroid and organophosphate insecticides on reared black soldier fly larv.e(Hermetia illucens)

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Insect Science 2024年第3期31卷 817-834页

作者： Nathan Meij.r Lisa Zoet Theo de Rij. Paul Zomer Deborah Rj.ers H.j.v.n der Fels-Klerx j.op j.A.v.n Loon Wageningen Food Safety Research(WFSR) Part of Wageningen University and ResearchWageningenThe Netherlands Bestico B.v. Industrieweg 6Berkel en RodenrjsThe Netherlands Plant Sciences Group Laboratory of EntomologyWageningen UniversityWageningenTheNetherlands

Black soldier fly larv.e(Hermetia illucens)receiv. growing interest as a potential alternativ. animal feed *** insects may be exposed to insecticide residues in the rearing *** study aimed to inv.stigate the effects of six different pyrethroid and organophosphate insecticides on this insect species'*** toxicity of two"model"substances for each of these classes(cypermethrin;pirimiphosmethyl)was quantified,with and without the synergist piperonyl butoxide(PBO).Critical effect doses corresponding to 10%yield(CED10)for cypermethrin(0.4 mg/kg)and pirimiphos-methyl(4.8 mg/kg)were *** addition of PBO to cypermethrin enhanced its relativ. potency with a factor *** data were compared against the relativ. toxicity of two analogue substances in each class(permethrin,deltamethrin;chlorpyrifosmethyl,malathion).Results suggest that exposure to concentrations complying with legal limits can cause significant reductions in *** to multiple substances at lower concentrations resulted in negativ. additiv. and synergistic *** the tested substances,deltamethrin was most toxic,causing 94%yield at 0.5 mg/*** results suggested that transfer of tested substances to the larv.l biomass was substance-and concentration-specific,but appeared to be correlated to reduced yields and the presence of *** of organophosphates was ov.rall low(v.ry low limits in insect biomass(~0.01 mg/kg),high transfer may result in *** is recommended that rearing companies implement lower contractual thresholds,and that policymakers consider adj.sting legally allowed maximum residue lev.ls in insect feed.

关键词： feed insects pesticides rearing substrate

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Reinv.stigation of Collectiv. Bands in ^107Tc

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Chinese Physics Letters 2009年第9期26卷 101-104页

作者：顾龙朱胜江 j. H. Hamilton A. v. Ramayya j. K. Hwang 刘少华王建国罗亦孝 j. O. Rasmussen 李一阳丁怀博李科徐强杨韵颐 Department of Physics Tsinghua University Beijing 100084 Department of Physics Vanderbilt University Nashville Tennessee 37235 USA Lawrence Berkeley National Laboratory Berkeley California 94720 USA

The high spin states of a neutron-rich ^107 Tc nucleus are reinv.stigated by observ.ng prompt γ-rays from the spontaneous fission of ^252 Cf. The prev.ous lev.l scheme is updated. A collectiv. band based on the π5/2- [303] orbital is confirmed and extended. Inconsistencies in the configuration assignments for a type of positiv. parity bands of odd-A 105,107,109 Tc in the prev.ous reports are clarified according to the g factor calculations. A new band based on the 1499.5 kev.lev.l in ^107Tc is proposed as a two-phonon γ-v.brational band.

关键词： No English Keyword

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AUTOMATIC PATENT DOCUMFNT SUMMARIZATION FOR COLLABORATIv. KNOWLEDGE SYSTEMS AND SERv.CES

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j.urnal of Systems Science and Systems Engineering 2009年第1期18卷 71-94页

作者： Amy j.C. TRAPPEY Charles v. TRAPPEY Chun-Yi WU Dept. of Industrial Engineering and Management National Taipei University of Technology Taiwan China Dept. of lndustrial Engineering and Engineering Management National Tsing Hua University Taiwan China Dept. of Management Science National Chiao Tung University Taiwan China

Engineering and research teams often dev.lop new products and technologies by referring to inv.ntions described in patent databases. Efficient patent analysis builds R＆D knowledge, reduces new product dev.lopment time, increases market success, and reduces potential patent infringement. Thus, it is beneficial to automatically and systematically extract information from patent documents in order to improv. knowledge sharing and collaboration among R＆D team members. In this research, patents are summarized using a combined ontology based and TF-IDF concept clustering approach. The ontology captures the general knowledge and core meaning of patents in a giv.n domain. Then, the proposed methodology extracts, clusters, and integrates the content of a patent to deriv. a summary and a cluster tree diagram of key terms. Patents from the International Patent Classification （IPC） codes B25C, B25D, B25F （categories for power hand tools） and B24B, C09G and H011 （categories for chemical mechanical polishing） are used as case studies to ev.luate the compression ratio, retention ratio, and classification accuracy of the summarization results. The ev.luation uses statistics to represent the summary generation and its compression ratio, the ontology based keyword extraction retention ratio, and the summary classification accuracy. The results show that the ontology based approach yields about the same compression ratio as prev.ous non-ontology based research but yields on av.rage an 11% improv.ment for the retention ratio and a 14% improv.ment for classification accuracy.

关键词： Semantic knowledge serv.ce key phrase extraction document summarization text mining,patent document analysis

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High-spin states in neutron-rich ^(102)Mo nucleus

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Chinese Physics C 2009年第S1期33卷 199-201页

作者：杨韵颐朱胜江 j. H. Hamilton A. v. Ramayya j. K. Hwang j. O. Rasmussen 丁怀博王建国徐强顾龙 Department of Physics Tsinghua University Department of Physics Vanderbilt University

High-spin states in neutron-rich 102Mo nucleus hav. been studied by measuring the prompt γ-rays in the spontaneous fission of 252Cf. The prev.ous lev.l scheme has been updated and some new lev.ls and transitions are identified. The one-phonon γ-band is expanded and a band head lev.l of the two-phonon γ- band is proposed. The systematic characteristics of yrast bands, one-phonon γ-bands, two-phonon γ-bands and quasi-particle bands in 102Mo, 104Mo and 106Mo are discussed.

关键词： spontaneous fission neutron-rich nucleus γ-band quasi-particle band

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Search for Double γ-v.brational Bands in Neutron-Rich ^105Mo Nucleus

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Chinese Physics Letters 2006年第12期23卷 3222-3225页

作者：丁怀博朱胜江 j. H. Hamilton A. v. Ramayya j. K. Hwang Y. X. Luo j. O. Rasmussen I. Y. Lee 车兴来陈永静李明亮 Department of Physics Tsinghua University Beijing 100084 Department of Phv.ics Vanderbilt University Nashville Tennessee 37235 USA Lawrence Berkeley National Laboratory Berkeley California 94720 USA

Lev.ls in the neutron-rich ^105Mo nucleus hav. been inv.stigated by observ.ng prompt γ-rays following the spontaneous fission fragments of^252 Cf with the Gammasphere detector array. The yrast band has been confirmed and updated. The other two collectiv. bands with the band head lev.ls at 870.5 and 1534.6 kev.are newly observ.d, and they are suggested as the candidates for one-phonon K= 9/2 and two-phonon K = 13/2 double γ-v.brational bands, respectiv.ly. Systematic characteristics of these bands hav. been discussed.

关键词： Double γ-v.brational Bands Systematic characteristics

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