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EXAfS study of cation reordering in NaYf_4:Yb^(3+),Tb^(3+) up-conversion luminescence materials

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Journal of Rare Earths 2014年第3期32卷 226-229页

作者： h.f.brito J.hls T.Laamanen T.Laihinen M.Lastusaari L.Pihlgren L.C.V.Rodrigues T.Soukka Instituto de Química Universidade de S?o Paulo Department of Chemistry University of Turku Turku University Centre for Materials and Surfaces (MatSurf) Department of Chemistry University of Turku FI-20014 Turku Finland Turku University Centre for Materials and Surfaces (MatSurf) Turku Finland University of Turku Graduate School (UTUGS) Doctoral Programme in Physical and Chemical Sciences Graduate School of Materials Research (GSMR) Department of Biochemistry University of Turku

The NaYf4：yb3＋,Tb3＋（Xyb： 0.20, XTb： 0.04） materials were prepared using the co-precipitation method, lne as-preparea material was washed either with or without water in addition to ethanol and thereafter annealed for 5 h at 500℃. This resulted in materials with moderate or very high up-conversion luminescence intensity, respectively. The structural study carried out with X-ray powder diffraction revealed microstrains in the rare earth （R） sublattice that were relaxed for the material with very high up-conversion intensity thus decreasing energy losses. The local structural details were investigated with R LⅢ and Y K edge ex- tended X-ray absorption fine structure （EXAfS） using synchrotron radiation. Around 10 tool.% of the Yb3＋ ions were found to occupy the Na site in the material with very high up-conversion intensity. These Yb species formed clusters with the Tb3＋ ions occupying the regular Na/R sites. Such clustering enhanced the energy transfer between Yb3＋ and Tb3＋ thus intensifying the up-conversion emission.

关键词： EXAfS up-conversion ytterbium terbium cation reordering

Risk factors for running-related injuries:An umbrella systematic review

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Journal of Sport and health Science 2024年第6期13卷 793-804页

作者： Clara Knierim Correia Jean Marlon Machado fabio hech Dominski Marcelo Peduzzi de Castro heiliane de brito fontana Caroline Ruschel College of health and Sport Science State University of the Santa CatarinaFlorianopolis 88080-350Brazil fisiolab Institut Florianopolis 88015-310Brazil Biological Sciences Centre Federal University of Santa CatarinaFlorianopolis 88040-900Brazil

Purpose:This umbrella systematic review(SR) of SRs and meta-analysis seeks to comprehensively synthesize existing literature to identify and consolidate the diverse range of risk factors contributing to running-related injuries(RRIs).Methods:Systematic searches were conducted on June 28,2023,across Web of Science,SPORTDiscus,Scopus,PubMed,and Cochrane *** included SRs,whether accompanied by meta-analyses or not,that focused on investigating risk factors for RRIs within observational *** methodological quality of the SRs was evaluated using the Assessing the Methodological Quality of Systematic Reviews Ⅱ.To assess the extent of overlap across reviews,the corrected covered area metric was ***:from 1509 records retrieved,13 SRs were *** degree of overlap between SRs was low(4%),and quality varied from critically low(n=8) to low(n=5).Two hundred seven outcomes assessed in 148 primary studies were identified as being associated with the occurrence of *** effect sizes of the associations for which risk measures were reported(n=131) were classified as large(n=30,23%),medium(n=38,29%),small(n=48,37%) or no effect(n=15,11%).Running/training characteristics,health and lifestyle factors,along with morphological and biomechanical aspects,exhibit large effect sizes in increasing the risk for ***:Drawing from the outcomes of the low-quality SRs and associations with large effect sizes,our findings indicate that running/training characteristics and health and lifestyle factors,as well as morphological and biomechanical aspects,are all implicated in elevating the risk of RRIs,emphasizing the multifactorial basis of injury incidence in *** the low quality and heterogeneity of SR,individual findings warrant cautious interpretation.

关键词： Umbrella review Runners Injury Risk factor

ENSO impacts on litter stocks and water holding capacity in secondary forests in eastern Amazonia

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Journal of forestry Research 2024年第1期35卷 83-89页

作者： Julia Isabella de Matos Rodrigues Walmer Bruno Rocha Martins Victor Pereira de Oliveira Myriam Suelen da Silva Wanzerley hélio brito dos Santos Júnior francisco de Assis Oliveira Graduate Program in forestry Sciences Av.Presidente Tancredo Neves2501BelémPará66077-530Brazil federal Rural University of Amazonia Av.Presidente Tancredo Neves2501BelémPará66077-530Brazil federal Rural University of Amazonia Tv.Pau-AmareloCapitão PoçoPará68650-000Brazil National Institute of Amazonia Research Av.Constelação Cruzeiro do SulManausAmazonas 69060-062Brazil

Among the impacts of climate change,there is the intensification of phenomena such as the El Niño South-ern Oscillation(ENSO)responsible for El Niño and La Niñ***,understanding their effects on the functional pro-cesses of forests is ***,this study evaluated the effects of ENSO on litter stock and water holding capac-ity(WhC)in a successional forest in eastern *** occurred in periods with the most rainfall in El Niño(2019)and least in La Niña(2021)*** permanent plots were used to sample *** effects were evident for WhC,higher during El Niñ***,this influence was not clear for litter,as only in the rainy season effects were *** was a positive correlation of WhC with precipitation and humidity,while litter stocks were negatively correlated with temperature and wind *** the subject of this study requires long-term assessments,preliminary results suggests that,depending on the intensity of ENSO,forest functional processes can be strongly impacted and *** conclusion reinforces warnings by the scientific community about the impacts of climate change on the maintenance of litter stocks,decomposition and,consequently,the biogeochemical cycle and essential ecosystem services for the maintenance of Amazonia *** need to develop long-term research to understand the effects of climatic change on litter stocks and water holding capacity is highlighted,especially in Amazonia.

关键词： Seasonality Climate change Succession ecosystem Biogeochemical cycle Amazonia biodiversity

Organizational ambidexterity, open innovation and innovation outputs: how do followers and low-flyer EU countries innovate?

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International Journal of Innovation Studies 2024年第2期8卷 186-235页

作者： Joao Leitao Sonia de brito Dina Pereira faculty of Social and human Sciences NECE-Research Unit in Business SciencesUniversity of Beira Interior6200-001CovilhaPortugal Research Unit in Business Sciences(NECE) University of Beira InteriorCovilhaPortugal Centre for Management Studies of Instituto Superior Tecnico(CEG-IST) University of Lisbon1649-004LisboaPortugal Instituto de Ciencias Sociais ICsUniversity of Lisbon1649-004LisboaPortugal

This study analyses the role played by organizational ambidexterity and open innovation in innovation outputs,considering business units with different levels of technological intensity(medium-high and high tech,and medium-low and low tech)for countries with different inno-vation *** countries considered in this paper are i)Estonia and Slovenia as innovation followers;i)Slovakia,hungary,Spain,Czech Republic,Italy,Portugal,Norway,and Croatia as moderate innovators;and ii)Bulgaria,Lithuania and Romania as modest *** the empirical approach,the research hypotheses arise from the literature review and are tested using secondary data collected from the Community Innovation Survey(CIS)*** conceptual model is tested using the logistic regression method,which indicates suitable accuracy and reliability for empirical testing *** evidence reveals that for innovation followers,ambidexterity has a greater influence on the practice of eco-innovation,marketing innovation,and product *** moderate innovators,ambidexterity has a greater influence on the practice of product innovation,process innovation,and *** modest in-novators,ambidexterity has a greater influence on the practice of product innovation,process innovation,and *** regard to open innovation,for innovation followers,this has a negative influence on product innovation in medium-high and high-tech *** moderate innovators,open innovation has a greater influence in process,organizational,and *** the case of modest innovators,open innovation is more significant for innovation outputs in product,organizational,and marketing *** is not always positively related to innovation outputs.

关键词： Organizational ambidexterity CIS Cooperation Open innovation Public innovation policies

Making bridges between preclinical and clinical insights into age-related cognitive decline

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Neural Regeneration Research 2025年第8期20卷 2321-2322页

作者： David VC brito Clévio Nóbrega Algarve Biomedical Center-Research Institute(ABC-RI) Campus GambelasFaroPortugal Algarve Biomedical Center-(ABC) Campus GambelasFaroPortugal faculty of Medicine and Biomedical Sciences(fMCB) University of AlgarveGambelas CampusFaroPortugal

With people living longer,the societal impact of age-related cognitive decline is becoming more pronounced(Crimmins,2015).Thus,it is increasingly important to comprehend the cognitive shifts linked to aging-whether th... 详细信息

关键词： bridges becoming insight

A Comprehensive Review on Charging Topologies and Power Electronic Converter Solutions for Electric Vehicles

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Journal of Modern Power Systems and Clean Energy 2024年第3期12卷 675-694页

作者： Abdelfatah Ali hossam h.h.Mousa Mostafa f.Shaaban Maher A.Azzouz Ahmed S.A.Awad the Department of Electrical Engineering American University of Sharjah26666 SharjahUnited Arab Emirates the Department of Electrical Engineering South Valley University83523 QenaEgypt the Department of Electrical and Computer Engineering University of WindsorWindsorON N9B 3P4 Canada Electrical Engineering Department Qatar UniversityDoha 2713Qatar Department of Electrical and Computer Engineering Sultan Qaboos UniversityMuscat123Oman

Electric vehicles(EVs)are becoming more popular worldwide due to environmental concerns,fuel security,and price *** performance of EVs relies on the energy stored in their batteries,which can be charged using either AC(slow)or DC(fast)***,EVs can also be used as mobile power storage devices using vehicle-to-grid(V2G)*** electronic converters(PECs)have a constructive role in EV applications,both in charging EVs and in ***,this paper comprehensively investigates the state of the art of EV charging topologies and PEC solutions for EV *** examines PECs from the point of view of their classifications,configurations,control approaches,and future research prospects and their impacts on power *** can be classified into various topologies:DC-DC converters,AC-DC converters,DC-AC converters,and AC-AC *** address the limitations of traditional DC-DC converters such as switching losses,size,and high-electromagnetic interference(EMI),resonant converters and multiport converters are being used in high-voltage EV ***,power-train converters have been modified for high-efficiency and reliability in EV *** paper offers an overview of charging topologies,PECs,challenges with solutions,and future trends in the field of the EV charging station applications.

关键词： Charging station charging topology electric vehicle power electronic converter vehicle-to-grid

Microstructure evolution and shape memory behaviors of Ni_(47)Ti_(44)Nb_(9)alloy subjected to multistep thermomechanical loading with different prestrain levels

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Journal of Materials Science & Technology 2024年第4期171卷 80-93页

作者： Y.h.Zhang h.Li Z.W.Yang X.Liu Q.f.Gu State Key Laboratory of Solidification Processing School of Materials Science and EngineeringNorthwestern Polytechnical UniversityXi’an 710072China Shaanxi Key Laboratory of high-Performance Precision forming Technology and Equipment Northwestern Polytechnical UniversityXi’an 710072China

Ni_(47)Ti_(44)Nb_(9)shape memory alloy(SMA)is a promising material in the aerospace field due to its wide transformation *** application of shape memory effect depends on multistep thermomechan-ical loading,viz.,low-temperature deformation and subsequent heating to ***-temperature deformation prestrain plays a pivotal role in shape memory properties tailoring of SMA ***,microstructure evolution and deformation mechanisms of Ni_(47)Ti_(44)Nb_(9)SMA subjected to vari-ous prestrain levels are still *** this end,microstructure evolution and shape memory behaviors of Ni_(47)Ti_(44)Nb_(9)alloy subjected to multistep thermomechanical loading with prestrain levels of 8%-16%at-28℃(M_(s)+30℃)were *** results demonstrate that the stress-strain curve of the specimen exhibits four distinct stages at a maximal prestrain of 16%.Whereas stageⅡand stageⅢend at prestrains of∼8%and∼12%,*** stageⅡ,the stress-induced martensitic transformation is accompanied by the dislocation slip of the NiTi matrix andβ-Nb *** stageⅢ,in addition to the higher density of dislocations and further growth of stress-induced martensite variants(SIMVs),(001)compound twins are introduced as a result of the(001)deformation twinning in stress-induced ***{20-1}martensite twins are gradually introduced in stageⅣ.Correspondingly,after subsequent unloading and heating,a higher density of{114}austenite twins form in the specimen with a larger prestrain of 16%.With increasing prestrain from 8%to 16%,the recoverable strainε_(re)^(T)upon heating increases first and then ***ε_(re)^(T)obtains a maximum of 7.03%at 10%prestrain and de-creases to 6.17%at 16%*** increase ofε_(re)^(T)can be attributed to the formation of new SIMVs,the further growth of existing SIMVs,and the recoverable(001)compound *** the decrease ofε_(re)^(T)is mainly associated with the irrecoverable strain by{20−1}martensite *** effe

关键词： Ni_(47)Ti_(44)Nb_(9)shape memory alloy Wide transformation hysteresis Thermomechanical loading Microstructure evolution Shape memory behaviors Stress-induced martensitic transformation Deformation twinning

Connections Between Induction Generator Effect and Open-loop Modal Proximity to Cause Sub-synchronous Oscillations in Series-compensated Power System

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CSEE Journal of Power and Energy Systems 2024年第3期10卷 963-973页

作者： Wenjuan Du Yang Wang h.f.Wang Tao Zhao Tim Littler College of Electrical Engineering Sichuan UniversityChengduChina School of Electrical Engineering the Queen’s University of BelfastBelfastUK IEEE

The induction generator effect(IGE)and the openloop modal proximity(OLMP)are two different reasons why subsynchronous oscillations(SSOs)in a series-compensated power system(SCPS)may *** IGE attributes the growing SSOs to negative resistance,while the OLMP explains the SSO mechanism from the standpoint of modal *** this paper,we investigate the connections between the IGE and the OLMP through equivalent RLC circuit and open-loop modal *** investigation is conducted for two types of seriescompensated power systems where either a synchronous generator or a DfIG is connected at the sending *** investigation reveals the conditions,in which the IGE and the OLMP may jointly cause the growing SSOs,i.e.,both the IGE and the OLMP can explain why the growing SSOs ***,the investigation indicates that the IGE and the OLMP may be totally irrelevant and lead to growing SSOs *** implies that it is possible that in a SCPS,the growing SSOs are only due to the IGE,and the OLMP is non-existent,and vice ***,when the growing SSOs occurs in a SCPS,examination based on both the IGE and the OLMP should be carefully conducted in order to find if the oscillatory instability is due to the IGE,or the OLMP,or both of them.

关键词： Induction generator effect open-loop modal proximity series compensation sub-synchronous oscillations

Spalling characteristics of high-temperature treated granitic rock at different strain rates

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第4期16卷 1280-1288页

作者： L.f.fan Q.h.Yang X.L.Du The Key Laboratory of Urban Security and Disaster Engineering of Ministry of Education Beijing University of TechnologyBeijing100124China

The dynamic spalling characteristics of rock are important for stability analysis in rock *** paper presented an experimental investigation on the dynamic spalling characteristics of granite with different temperatures and strain rates.A series of dynamic spalling tests with different impact velocities were conducted on thermally treated granite at different *** dynamic spalling strengths of granite with different temperatures and strain rates were determined.A model was proposed to correlate the dynamic spalling strength of granite,high temperature and strain *** results show that the spalling strength of granite decreases with increasing ***,the spalling strength of granite with a higher strain rate is larger than that with a lower strain *** proposed model can describe the relationship among dynamic spalling strength of granite,high temperature and strain rate.

关键词： Dynamic spalling characteristics high temperature Strain rate Dynamic loading Granite