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Rietveld refinement and optical properties of SrWO_4:Eu^(3+) powders prepared by the non-hydrolytic sol-gel method

Journal of Rare Earths 2015年第2期33卷 113-128页

作者： P.F.S.Pereira i.c.nogueira E.Longo E.J.Nassar i.L.V.Rosa L.S.cavalcante chemistry institute University of the State of Sao Paulo Julio de Mesquita Filho-UNESP Francisco DegniAraraquara-SP 14800-900 Brazil LiEc-chemistry Department Federal University of Sao Carlos Via Washington Luis Km 235Sao Carlos-SP 13565-905 Brazil University of Franca-UNiFRAN Via Dr.Armando Sales de OliveiraNo.201 Franca-SP 14404-600 Brazil ccN-DQ-GERATEc University of the State of Piauí Joao Cabral 2231 P.O.Box 391Terezina PI 64002-150 Brazil

We investigated the effect of annealing time on the structure and optical properties of Sr WO4：Eu^3＋ powders prepared by the non-hydrolytic sol-gel method and heat treated at 800 ℃ for 2,4,8 and 16 *** and differential thermal analyses revealed that Sr WO4：Eu^3＋ powders were obtained at about 800 ℃.X-ray diffraction patterns and Rietveld refinement data confirmed that all powders had a scheelite-type tetragonal ***-Raman and Fourier transform infrared spectra indicated structural order at short range and anti-symmetric stretching vibrations of O-W-O bonds associated with tetrahedral[WO4]*** properties were investigated by ultraviolet-visible（UV-vis）diffuse reflectance,and photoluminescence（PL）data which provided the evolution of quantum efficiency（η）and lifetime（τ）.UV-vis spectroscopy evidenced intermediate energy levels within the band gap of Sr WO4：Eu^3＋ *** properties validated that the Eu^3＋ electric-dipole（^5D0→^7F2）transition in PL emission spectra was dominant which proved that Eu^3＋ ions were positioned in a site without an inversion center.[（^5D0→^7F2）/（^5D0→^7F1）]band ratios showed that Eu^3＋ ions were located in a low symmetry *** PL emission,ηandτproved the dependence on the annealing time in the behavior of Sr WO4：Eu3＋powders with a higher relative emission PL intensity as well as higherηandτvalues related to other samples when heat treated at 800℃ for 8 h.

关键词： SrWO4 Rietveld refinement optical band gap Eu^(3+) +-rare earth luminescence

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creation of an oxygen-enriched environment during synthesis as an effective way to improve luminescent properties of Y_(2)O_(3):Eu^(3+)

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Journal of Rare Earths 2025年第1期43卷 21-29,I0001页

作者： Aleksandr A.Nashivochnikov Anton i.Kostyukov Mariana i.Rakhmanova Lidiya S.Kibis Svetlana V.cherepanova Evgenii A.Suprun Novosibirsk State University Pirogova Str.2630090NovosibirskRussia Boreskov institute of catalysis SB RAS 5 Lavrentiev Ave630090NovosibirskRussia Nikolaev institute of inorganic chemistry SB RAS 3 Lavrentiev Ave630090NovosibirskRussia

The growing demand for luminescent nanomaterials intended for various applications increases the necessity to develop and improve approaches to the creation of highly efficient nanosized *** current study,an approach to enhancing the efficiency of red luminescence of monoclinic Y_(2)O_(3):Eu^(3+)with the particle size of~20 nm by creating the oxygen-enriched environment during the gas-phase synthesis was *** investigate the effect of oxygen amount during the synthesis on characteristics of the phosphor,a series of nano structured Y_(2)O_(3):Eu^(3+)with the addition of 0-40 vol%O_(2) to the main buffer gas Ar was synthesized by laser *** is shown that the amount of added O_(2) exerts virtually no effect on the phase composition and particle size,but significantly improves the luminescent characteristics of Y_(2)O_(3):Eu^(3+).Thus,the addition of 30 vol%O_(2) leads to virtually a 20-fold growth in the photoluminescence(PL)intensity caused by ^(5)D_(0)→^(7)F_(0-4) transitions in Eu^(3+)and an increase in the absolute PL quantum yield from 3%to 53%(λex=395 nm)compared to the sample synthesized without O_(2).The addition of oxygen also improves the emission color coordinates from(0.571,0.320)to(0.630,0.322)due to the removal of a considerable fraction of oxygen *** synthesized nanopowders are shown to be highly stable:upon storage under ambient conditions for two *** yield(QY)of the samples decreases by less than 2%.it is expected that the key features underlying the proposed approach will be useful for various methods used to synthesize oxide nanophosphors.

关键词： Photoluminescence Quantum yield Laservaporization Y_(2)0_(3):Eu^(3+) Monoclinic Y_(2)0_(3) Rareearths

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Status and prospects for symmetric organic redox flow batteries

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Journal of Energy chemistry 2025年第1期100卷 125-143页

作者： Md Al Raihan c.Adam Dyker Department of chemistry University of New BrunswickFrederictonNB E3B 5A3Canada

As environmental concerns from fossil fuel consumption intensify,large-scale energy storage becomes imperative for the integration of renewable sources like wind,hydro,and solar with the electrical *** flow batteries,particularly those employing organic molecules,are positioned as a key technology for this *** review explores the growing field of symmetric organic redox flow batteries(ORFBs)within this *** traditional asymmetric designs based on unique active materials for each electrode,symmetric ORFBs involve a single bipolar species for both *** review highlights the benefits of a symmetric design,and categorizes five distinct classes of organic bipolar molecules used in both aqueous and non-aqueous *** providing a comprehensive overview of their cell cycling and performance characteristics,the strengths and weaknesses of the diverse categories of bipolar molecules are highlighted for both solvent systems,as are opportunities for future *** should guide new research directions and advance the development of practical symmetric ORFBs.

关键词： Redox flow battery Symmetric battery Organic battery Aqueous electrolyte Non-aqueousel ectrolyte

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Arctic sea-ice extent: No record minimum in 2023 or recent years

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Atmospheric and Oceanic Science Letters 2025年第1期18卷 52-55页

作者： Ola M.Johannessen Tor i.Olaussen Nansen Scientific Society BergenNorway Nansen Environmental and Remote Sensing center BergenNorway

Arctic sea-ice extent reaches its minimum each year in September. On 11 September 2023 the minimum was 4.969 million square kilometers(***^(2)). This was not a record low, which occurred in 2012, when the minimum was 4.175 ***^(2), 0.794 ***^(2) less than the minimum in 2023. However, the ice extent had decreased by 0.432 ***^(2) compared with 2022. Nevertheless, the summer melting in 2023 was remarkably less than expected when considering the strong heat waves in the atmosphere and ocean, with record temperatures set around the world. in general, there is a high correlation between the long-term decrease in sea-ice extent and the increasing cO_(2) in the atmosphere, where the increase of cO_(2) in recent decades explains about 80% of the decrease in sea ice in September, while the remainder is caused by natural variability.

关键词： Sea ice Arctic Minimum ice climate

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A comparative study on emergent pollutants photo-assisted degradation using ruthenium modified titanate nanotubes and nanowires as catalysts

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Journal of Environmental Sciences 2020年第6期32卷 38-51页

作者： Beatriz Barrocas M.conceicao Oliveira Helena i.S.nogueira Sara Fateixa Olinda c.Monteiro centro de Química Estrutural Faculdade de CienciasUniversidade de LisboaLisboa 1749-016Portugal centro Química Estrutural Instituto Superior TécnicoUniversidade de LisboaLisboa 1049-001Portugal Department of chemistry CICECO-Aveiro Institute of MaterialsUniversity of AveiroAveiro 3810-193Portugal

Several methods have been used to tailor nanomaterials structure and ***,slight changes in the structure outcomes expressive improvements in the optical and photocatalytic properties of semiconductor *** this context,the influence of the metal doping and the morphology on a catalyst performance was studied in this ***,ruthenium doped titanate nanotubes(RuTNT)were synthesised for the first time using an amorphous Ru-containing ***,the photocatalytic performance of this sample was compared to the one obtained for ruthenium titanate nanowires(RuTNW),recently *** samples,RuTNW and RuTNT,were produced using the same Ru-containing precursor but distinct hydrothermal *** powders were structural,morphological and optical characterized by X-ray diffraction and fluorescence,transmission electron microscopy,Raman,X-ray photoelectron and photoluminescence *** variations on the structural and optical properties of the RuTNT and RuTNW nanoparticles,due to ruthenium incorporation were *** potential use as photocatalysts was evaluated on the hydroxyl radical photo-assisted *** samples were catalytic for this reaction,presenting better performances than the pristine counterparts,being RuTNT the best ***,the degradation of two emergent pollutants,caffeine and sulfamethazine,was *** demonstrated to be better photocatalyst than RuTNW for caffeine but identical performances were obtained for *** both catalysts,the degradation mechanism of the pollutants was explored through the identification and quantification of the intermediate compounds produced and several differences were *** indicates the importance of the structural and morphological aspects of a material on its catalytic performance.

关键词： Titanate nanotubes and nanowires Ruthenium doping Ru-Ti replacement Emergent pollutants Photocatalytic degradation

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Acquired sensorineural hearing loss,oxidative stress,and microRNAs

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Neural Regeneration Research 2025年第9期20卷 2513-2519页

作者： Desmond A.Nunez Ru c.Guo Division of Otolaryngology–Head&Neck Surgery Department of SurgeryFaculty of MedicineThe University of British ColumbiaVancouverBCCanada Division of Otolaryngology–Head&Neck Surgery Gordon&Leslie Diamond Health Care CentreVancouver General HospitalVancouverBCCanada Faculty of Medicine–The University of British columbia VancouverBCCanada

Hearing loss is the third leading cause of human ***-related hearing loss,one type of acquired sensorineural hearing loss,is largely responsible for this escalating global health ***-induced,ototoxic,and idiopathic sudden sensorineural are other less common types of acquired hearing *** etiology of these conditions is complex and multi-fa ctorial involving an interplay of genetic and environmental *** stress has recently been proposed as a likely linking cause in most types of acquired sensorineural hearing *** non-coding RNA sequences known as microRNAs(miRNAs)have increasingly been shown to play a role in cellular hypoxia and oxidative stress responses including promoting an apoptotic *** hair cell death is a central histopathological finding in sensorineural hearing *** these cells do not regenerate in humans,it underlies the irreversibility of human age-related hearing *** EMBASE,Ovid MEDLiNE,Web of Science core collection,and *** databases over the period August 1,2018 to July 31,2023 were searched with"hearing loss,""hypoxamiRs,""hypoxia,""microRNAs,""ischemia,"and"oxidative stress"text words for English language primary study publications or registered clinical *** red clinical trials known to the senior author we re also assessed.A total of 222studies were thus *** excluding duplicates,editorials,retra ctions,secondary research studies,and non-English language articles,39 primary studies and clinical trials underwent full-text *** resulted in 11 animal,in vitro,and/or human subject journal articles and 8 registered clinical trial database entries which form the basis of this narrative *** miR-34a and miR-29b levels increase with age in *** miRNAs were demonstrated in human neuroblastoma and murine cochlear cell lines to target Sirtuin 1/peroxisome proliferato r-activated receptor gamma coactivator-1-alpha(SiRT1/P Gc-1α),SiRT

关键词： hearing loss hypoxia microRNAs oxidative stress sensorineural

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Recent progress on elemental tellurium and its devices

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Journal of Semiconductors 2025年第1期46卷 91-106页

作者： Jiachi Liao Zhengxun Lai You Meng Johnny c.Ho Department of Materials Science and Engineering City University of Hong KongKowloonHong Kong 999077China changsha Semiconductor Technology and Application innovation Research institute College of Semiconductors(College of IntegratedC ircuits)Hunan UniversityChangsha 410082China institute for Materials chemistry and Engineering Kyushu UniversityFukuoka 8168580Japan State Key Laboratory of Terahertz and Millimeter Waves City University of Hong KongKowloonHong Kong 999077China

The rapid advancement of information technology has heightened interest in complementary devices and *** p-type semiconductors often lack sufficient electrical performance,thus prompting the search for new materials with high hole mobility and long-term *** tellurium(Te),featuring a one-dimensional chiral atomic structure,has emerged as a promising candidate due to its narrow bandgap,high hole mobility,and versatility in industrial applications,particularly in electronics and renewable *** review highlights recent progress in Te nanostructures and related devices,focusing on synthesis methods,including vapor deposition and hydrothermal synthesis,which produce Te nanowires,nanorods,and other *** applications in photodetectors,gas sensors,and energy harvesting devices are discussed,with a special emphasis on their role within the internet of things(ioT)framework,a rapidly growing field that is reshaping our technological *** prospects and potential applications of Te-based technologies are also highlighted.

关键词： elemental tellurium photodetector field-effect transistor gas sensor energy harvesting device

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Bacteria and host: what does this mean for sepsis bottleneck?

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World Journal of Emergency Medicine 2025年第1期16卷 10-17页

作者： Azzah S Alharbi Raghad Hassan Sanyi Esam i Azhar Department of clinical Microbiology and immunology Faculty of MedicineKing Abdulaziz UniversityJeddah 21362Saudi Arabia Special infectious Agent Unit King Fahad Medical Research CenterKing Abdulaziz UniversityJeddah 21362Saudi Arabia college of Health and Medical Technology Middle Technical UniversityBaghdad 10047Iraq Department of Medical Laboratory Sciences Faculty of Applied Medical SciencesKing Abdulaziz UniversityJeddah 21362Saudi Arabia

BAcKGROUND: Sepsis is a life-threatening inflammatory condition in which the invading pathogen avoids the host's defense mechanisms and continuously stimulates and damages host cells. consequently, many immune responses initially triggered for protection become harmful because of the failure to restore homeostasis, resulting in ongoing hyperinflammation and immunosuppression. METHODS: A literature review was conducted to address bacterial sepsis, describe advances in understanding complex immunological reactions, critically assess diagnostic approaches, and emphasize the importance of studying bacterial bottlenecks in the detection and treatment of ***: Diagnosing sepsis via a single laboratory test is not feasible;therefore, multiple key biomarkers are typically monitored, with a focus on trends rather than absolute values. The immediate interpretation of sepsis-associated clinical signs and symptoms, along with the use of specific and sensitive laboratory tests, is crucial for the survival of patients in the early stages. However, long-term mortality associated with sepsis is now recognized, and alongside the progression of this condition, there is an in vivo selection of adapted ***: Bacterial sepsis remains a significant cause of mortality across all ages and societies. While substantial progress has been made in understanding the immunological mechanisms underlying the inflammatory response, there is growing recognition that the ongoing host-pathogen interactions, including the emergence of adapted virulent strains, shape both the acute and long-term outcomes in sepsis. This underscores the urgent need for novel high-throughput diagnostic methods and a shift toward more pre-emptive, rather than reactive, treatment strategies in sepsis care.

关键词： Sepsis Bacteria Bottleneck inflammation

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Multiple sclerosis is at a checkpoint: advancing the program

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Neural Regeneration Research 2025年第3期20卷 811-812页

作者： Brandon c.Smith Jessica L.Williams Department of Neurosciences Lerner Research InstituteCleveland ClinicClevelandOHUSA Department of Biological Geologicaland Environmental SciencesCleveland State UniversityClevelandOHUSA

Multiple sclerosis(MS) is a chronic inflammatory and demyelinating disease of the central nervous system(cNS). Patients with MS experience sensory and motor function loss due to myelin and/or axon damage perpetuated b... 详细信息

关键词： Hauser sclerosis damage

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Multisensory mechanisms of gait and balance in Parkinson’s disease:an integrative review

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Neural Regeneration Research 2025年第1期20卷 82-92页

作者： Stiven Roytman Rebecca Paalanen Giulia carli Uros Marusic Prabesh Kanel Teus van Laar Nico i.Bohnen Department of Radiology University of MichiganAnn ArborMIUSA Department of Neurology University of MichiganAnn ArborMIUSA Morris K.Udall center of Excellence for Parkinson’s Disease Research University of MichiganAnn ArborMIUSA institute for Kinesiology Research Science and Research Centre KoperKoperSlovenia Department of Health Sciences Alma Mater Europaea–ECMMariborSlovenia Parkinson’s Foundation Research center of Excellence University of MichiganAnn ArborMIUSA Department of Neurology University of GroningenUniversity Medical Center GroningenGroningenThe Netherlands Neurology Service and GREcc VA Ann Arbor Healthcare SystemAnn ArborMIUSA

Understanding the neural underpinning of human gait and balance is one of the most pertinent challenges for 21st-century translational neuroscience due to the profound impact that falls and mobility disturbances have on our aging *** and gait control does not happen automatically,as previously believed,but rather requires continuous involvement of central nervous *** effectively exert control over the body,the brain must integrate multiple streams of sensory information,including visual,vestibular,and somatosensory *** mechanisms which underpin the integration of these multisensory signals are the principal topic of the present *** multisensory integration theories focus on how failure of cognitive processes thought to be involved in multisensory integration leads to falls in older *** emphasis,however,has been placed on specific contributions of individual sensory modalities to multisensory integration processes and cross-modal interactions that occur between the sensory modalities in relation to gait and *** the present work,we review the contributions of somatosensory,visual,and vestibular modalities,along with their multisensory intersections to gait and balance in older adults and patients with Parkinson’s *** also review evidence of vestibular contributions to multisensory temporal binding windows,previously shown to be highly pertinent to fall risk in older ***,we relate multisensory vestibular mechanisms to potential neural substrates,both at the level of neurobiology(concerning positron emission tomography imaging)and at the level of electrophysiology(concerning electroencephalography).We hope that this integrative review,drawing influence across multiple subdisciplines of neuroscience,paves the way for novel research directions and therapeutic neuromodulatory approaches,to improve the lives of older adults and patients with neurodegenerative diseases.

关键词： aging balance encephalography functional magnetic resonance imaging gait multisensory integration Parkinson’s disease positron emission tomography somatosensory vestibular visual

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