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21-Component compositionally complex ceramics: Discovery of ultrahigh-entropy weberite and fergusonite phases and a pyrochlore–weberite transition

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Journal of Advanced Ceramics 2022年第4期11卷 641-655页

作者： Mingde QIN Heidy vega Dawei ZHANG Sarath ADAPA Andrew J.WRIGHT Renkun CHEN Jian LUO Department of Nano Engineering University of California San DiegoLa Jolla 92093USA Department of Chemistry and Biochemistry University of California San DiegoLa Jolla 92093USA Program of Materials Science and Engineering University of California San DiegoLa Jolla 92093USA Department of Mechanical and Aerospace Engineering University of California San DiegoLa Jolla 92093USA

Two new high-entropy ceramics(HECs)in the weberite and fergusonite structures,along with the unexpected formation of ordered pyrochlore phases with ultrahigh-entropy compositions and an abrupt pyrochlore–weberite transition,are discovered in a 21-component oxide *** the Gibbs phase rule allows 21 equilibrium phases,9 out of the 13 compositions examined possess single HEC phases(with ultrahigh ideal configurational entropies:~2.7kB per cation or higher on one sublattice in most cases).Notably,(15RE_(1/15))(Nb_(1/2)Ta_(1/2))O_(4) possess a single monoclinic fergusonite(C2/c)phase,and(15RE_(1/15))_(3)(Nb_(1/2)Ta_(1/2))_(1)O_(7) form a single orthorhombic(C222_(1))weberite phase,where 15RE_(1/15) represents Sc_(1/15)y_(1/15)La_(1/15)Pr_(1/15)Nd_(1/15)Sm_(1/15)Eu_(1/15)Gd_(1/15)Tb_(1/15)Dy_(1/15)Ho_(1/15)Er_(1/15)Tm_(1/15) yb_(1/15)Lu_(1/15).Moreover,a series of eight(15RE_(1/15))_(2+x)(Ti_(1/4)Zr_(1/4)Ce_(1/4)Hf_(1/4))_(2−2x)(Nb_(1/2)Ta_(1/2))_(x)O_(7) specimens all exhibit single phases,where a pyrochlore–weberite transition occurs within 0.75y appreciably,as the amorphous limit may have already been achieved in the ultrahigh-entropy 21-component *** discoveries expand the diversity and complexity of HECs,towards many-component compositionally complex ceramics(CCCs)and ultrahigh-entropy ceramics.

关键词： compositionally complex ceramics high-entropy ceramics(HECs) weberite pyrochlore fergusonite ultrahigh-entropy ceramics many-component ceramics

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MXene multi-functionalization of polyrotaxane based PCMs and the applications in electronic devices thermal management

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Nano Materials Science 2024年第5期6卷 495-503页

作者： Guangzhong yin Alba Marta Lopez Ignacio collado Antonio Vazquez-Lopez Xiang Ao Jose Hobson Silvia G.Prolongo Deyi Wang Escuela Politecnica Superior Universidad Francisco de VitoriaCtra.Pozuelo-Majadahonda Km 1.80028223 Pozuelo de AlarconMadridSpain IMDEA Materials Institute C/Eric Kandel228906GetafeMadridSpain Materials Science and Engineering Area Escuela Superior de Ciencias Experimentales y TecnologíaUniversidad Rey Juan CarlosC/Tulipan s/n28933MadridSpain Universidad Carlos III de Madrid Departamento de Ciencia e Ingeniería de Materiales e Ingeniería QuímicaIAAB.Avda.Universidad3028911LeganesMadridSpain Instituto de Tecnologías para la Sostenibilidad Universidad Rey Juan CarlosC/Tulipan s/n28933MadridSpain

The aim of this work was to improve the thermal conductivity and electromagnetic shielding of the leakage proof phase change materials(PCMs),in which a polyrotaxane(PLR)was used as a support material to encapsulate PEG 1k or PEG 6k and MXene as multi-functional *** PCMs can be processed conveniently by a hot press and the PEG 1k containing samples showed excellent *** conducted a systematic evaluation of the phase transition behavior of the material,thermal conductivity and electromagnetic shielding performance ***,the PCMs achieved a high enthalpy values(123.9–159.6 J/g).The PCMs exhibited an increase of 44.3%,and 137.5%in thermal conductivity values with higher MXene content(5 wt%)for PLR-PEG6k and PLR-PEG1k,respectively,and show high shape stability and no leakage during and after phase *** introduction of MXene can significantly improve the electromagnetic shielding performance of PCM ***,higher conductive samples(samples which contain high MXene contents)offer a higher EMI SE shielding,reaching a maximum of 4.67 dB at 5.6 GHz for *** improvements solve the main problems of organic PEG based PCMs,thus making PLR-PEG-MXene based PCMs good candidates for thermoregulators of both solid-state disks and smart *** is worth pointing out that the sample PLR-1k-MX5 can decrease 4.3C of the reference temperature during cellphone ***,the temperature of the protecting sheet in the simulated solid state disk with PCM was significantly lower(showing a decreasing of 7.9℃)compared with the blank sample.

关键词： Phase change materials Thermal regulation MXene Polyrotaxane Nanocomposites

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Technosols Made of Wastes to Improve Physico-Chemical Characteristics of a Copper Mine Soil

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Pedosphere 2013年第1期23卷 1-9页

作者： V.ASENSIO F.A.vega M.L.ANDRADE E.F.COVELO Department de Bioloxía Vexetal e Ciencia do Solo Facultade de Bioloxia Universidade de VigoLagoas Marcosende 36310 Vigo Pontevedra (Spain)

Mine tailing soils created from the copper extraction in Touro Mine （Northwest Spain） are very degraded both physically and chemically. Three plots in this mine tailing were amended with Technosols in different proportions in each one to know if this mixture improved the physico-chemical characteristics of the mine soil and contaminated it with heavy metals. The Technosols were made of organic wastes, including mussel residues, wood fragments, sewage sludges and paper mill ashes. An unamended area was used as a control soil. Pseudototal and diethylenetriaminepentaacetic acid （DTPA）-extractable contents of A1, Cr, Cu, Fe, Mn, Ni, Pb and Zn were determined in soil samples. The untreated soil had significant limitations for vegetation growth. All the Technosols improved the properties of the mine soil by increasing organic carbon and pH value, but they added Ni, Pb or Zn to the soil. It is advisable to check whether the heavy metal concentrations of the wastes are hazardous or not before adding to soils. It is also necessary to study the effect of these wastes over time and in more areas to conclude if they are actually favourable to restore degraded mine soils.

关键词： heavy metals mine tailing vegetation growth waste amendment

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Lid scrubbing with a gel combining natural extracts for dry eye treatment

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International Journal of Ophthalmology(English edition) 2023年第7期16卷 1053-1059页

作者： Blanca Diaz-vega Carlos Rodriguez-Fabuel Sofia Vitores-Mate Carlos Carpena-Torres Gran Visión Oftalmología Madrid 28026Spain e-Health Vision Department of OphthalmologyMadrid 28232Spain Gran Óptica Madrid Department of Dry EyeMadrid 28026Spain Ocupharm Research Group Department of Optometry and VisionFaculty of Optics and OptometryComplutense University of MadridMadrid 28037Spain

AIM:To evaluate the effect of lid scrubbing using a gel combining different natural extracts on ocular signs and symptoms of dry eye ***:A retrospective study was performed on 19 dry eye patients(51.1±16.0y).Non-invasive tear break-up time,tear meniscus height,meibomian gland loss,lipid layer thickness,conjunctival redness,corneal staining,ocular surface disease index(OSDI),and ocular pain intensity were measured before(baseline),1wk,and 2mo after lid scrubbing with a gel containing different natural extracts(okra extract,aloe vera leaf juice,hydrolysed soy protein,caffeine,citrus unshiu peel extract,and raspberry seed oil).RESULTS:Compared with the baseline,there was a statistically significant improvement in both first(P=0.048)and average(P=0.026)non-invasive tear break-up time 2mo after treatment,as well as in corneal staining(P=0.043,0.012),OSDI(Py(Py,corneal damage,and ocular symptoms,which is the reason why this therapeutic procedure is proposed as an alternative for dry eye ***,it is not possible to attribute this beneficial effect solely to the presence of the natural extracts in the gel,primarily due to the absence of a negative control group.

关键词： lid hygiene natural extracts okra aloe vera soy dry eye

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Retention and Mobility of Copper and Lead in Soils as Influenced by Soil Horizon Properties

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Pedosphere 2011年第5期21卷 603-614页

作者： B.CERQUEIRA E.F.COVELO M.L.ANDRADE F.A.vega Department of Plant Biology and Soil Science University of Vigo

The mobility and bioavailability of heavy metals in soils is largely governed by sorption and desorption ***2+ and Pb2+ are among the most potentially toxic heavy metals and they are present,often concomitantly,in many polluting spills and in *** objective was to assess and compare the competitive sorption and desorption capacities and sorption hysteresis of Cu2+ and Pb2+,as well as their migration through the profiles of four natural soils:a Humic Umbrisol,an Umbric Cambisol,an Endoleptic Luvisol and a Humic *** all horizons Pb2+ was invariably sorbed and retained to a greater extent than Cu2+.The sorption and retention of Cu2+ were most in?uenced by pH,e?ective cation exchange capacity(CECe) and Mn oxide *** the other hand,the fixation capacity of Pb2+ was most in?uenced by pH,CECe,and Mn oxide and organic matter *** and CECe were the individual soil properties most markedly in?uencing Cu2+ and Pb2+ sorption and *** all the horizons Pb2+ exhibited greater hysteresis than Cu2+.In each soil the hysteresis in the A horizon was greater than that in the B horizon,except in the Bt horizon of the Endoleptic Luvisol,due to its high pH and vermiculite *** on migration indices,Pb2+ was less mobile than Cu2+ in the studied soils.

关键词： desorption heavy metal hysteresis migration sorption

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Hadronic spectra from deformed AdS backgrounds

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Chinese Physics C 2020年第6期44卷 109-122页

作者： Eduardo Folco Capossoli Miguel Angel Martín Contreras Danning Li Alfredo vega Henrique Boschi-Filho Instituto de Física Universidade Federal do Rio de Janeiro21.941-972-Rio de Janeiro-RJ-Brazil Departamento de Física/Mestrado Profissional em Práticas da Educação Básica(MPPEB) Colégio Pedro II20.921-903-Rio de Janeiro-RJ-Brazil Instituto de Física y Astronomía Universidad de ValparaísoA.Gran Bretaña 1111ValparaísoChile Department of Physics and Siyuan Laboratory Jinan UniversityGuangzhou 510632China

Because of the presence of modified warp factors in metric tensors,we use deformed AdS5 spaces to apply the AdS/CFT correspondence to calculate the spectra for even and odd glueballs,scalar and vector mesons,and baryons with different *** the glueball cases,we derive their Regge trajectories and compare them with those related to the pomeron and the *** the scalar and vector mesons,as well as baryons,the determined masses are compatible with the *** particular,for these hadrons we found Regge trajectories compatible with another holographic approach as well as with the hadronic spectroscopy,which present an universal Regge slope of approximately 1.1 GeV^2.

关键词： hadronic spectra AdS/QCD model Regge trajectories

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Vibrational Stabilization by Reshaping Arnold Tongues: A Numerical Approach

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Applied Mathematics 2016年第16期7卷 2005-2020页

作者： Joaquin collado Hildeberto Jardón-Kojakhmetov Automatic Control Department CINVESTAV-IPN Mexico City Mexico Engineering and Technology Institute University of Groningen Groningen The Netherlands

This paper presents two contributions to the stability analysis of periodic systems modeled by a Hill equation: The first is a new method for the computation of the Arnold Tongues associated to a given Hill equation which is based on the discretization of the latter. Using the proposed method, a vibrational stabilization is performed by a change in the periodic function which guarantees stability, given that the original equation has unbounded solutions. The results are illustrated by some examples.

关键词： Vibrational Stabilization Hill Equation Periodic Systems Arnold Tongues

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Snapshot Survey of the Presence of Perfluoroalkyl Substances in Products, Articles, and the Environment in Ecuador

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Engineering 2024年第6期37卷 49-61页

作者： Heidelore Fiedler Luis vega-Bustillos Jenny Arias-Pastrano Lander Vinicio Pérez-Aldás Jose Castro-Díaz MTM Research Centre School of Science and TechnologyÖrebro UniversityÖrebro 70182Sweden Undersecretariat of Environmental Quality Ministry of EnvironmentWater and Ecological Transition of EcuadorQuito 170525Ecuador Department of Environmental Chemistry The Technical University of AmbatoHuachi CampusAmbato 180207Ecuador Alternativavision Ambiental Cia.Ltda. Mexico 03100Mexico

The Stockholm Convention on Persistent Organic Pollutants(POPs)is a legally binding instrument for 186 Parties(status:April 2023).Accordingly,among other responsibilities,countries are obliged to report the production,import,or export of the POPs listed in Annexes A,B,or C;provide information to registers;maintain inventories;and monitor the presence of POPs in the *** the broader context of international chemicals and waste management,producer responsibilities,harmonized reporting,and compliance with national and international regulations,Ecuador has addressed the newly listed group of perfluorinated alkyl substances(PFAS)in its national implementation plan and sent selected products from its national market for PFAS *** products analyzed came from the initially listed fields of specific exemptions and acceptable purposes,including:fire-fighting foams;photographic aids;greasers/degreasers;various kinds of paper/packaging;textiles;and leather,coatings,cleaners,metal plating,and *** results showed that the three PFAS presently listed in the Stockholm Convention could be quantified in only a few samples;additional PFAS,not yet listed in the Convention also had low detection *** the number of samples was limited,the samples covered a large spectrum of sample matrices,making it possible to conclude that—once these products become waste and are regulated under the Basel Convention—they would not constitute a disposal ***,verification of the presence of PFAS in products on the market is expected to pose an analytical challenge for both,developed and developing countries.

关键词： Emerging or newly listed POPs Stockholm Convention Products and articles PFAS analysis Developing countries

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Biodegradable stents in gastrointestinal endoscopy

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World Journal of Gastroenterology 2014年第9期20卷 2212-2217页

作者： Vicente Lorenzo-Zú?iga Vicente Moreno-de-vega Ingrid Marín Jaume Boix Endoscopy Unit Department of Gastroenterology Hospital Universitari Germans Trias i Pujol 08916 Badalona Spain Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBEREHD) 08916 Badalona Spain

Biodegradable stents(BDSs)are an attractive option to avoid ongoing dilation or surgery in patients with benign stenoses of the small and large *** experience with the currently the only BDS for endoscopic placement,made of Poly-dioxanone,have shown promising *** some aspects should be improved as are the fact that BDSs lose their radial force over time due to the degradable material,and that can cause stent-induced mucosal or parenchymal *** complication rate and modest clinical efficacy has to be carefully considered in individual patients prior to placement of ***,the price of these stents therefore it is nowadays an important limitation.

关键词： Biodegradable stents Strictures Endoscopy Endoscopic placement Stenoses

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Secondary male hypogonadism： a prevalent but overlooked comorbidity of obesity

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Asian Journal of Andrology 2018年第6期20卷 531-538页

作者： Maria Molina-vega Araceli Mufioz-Garach Miguel Damas-Fuentes JosO Carlos Fernfindez-Garcia Francisco J inahones Department of Endocrinology and Nutrition Virgen de la Victoria Universitary HospitalMalaga 29010Spain Institute of Biomedical Research in Malaga（IBIMA） Virgen de la Victoria Universitary HospitalMalaga 29010Spain CIBER Pathophysiology of Obesity and Nutrition（CB06/003） Institute of Health Carlos III（ISClII）Madrid 28029Spain.

Male hypogonadism associated with obesity is a very prevalent condition and is increasing in parallel with the epidemic prevalence of obesity. Low testosterone levels promote higher fat mass with reduced lean mass. Male hypogonadism is related to an increase in associated cardiometabolic complications, such as hypertension, type 2 diabetes mellitus, the metabolic syndrome, and cardiovascular disease. Its influence as a comorbidity of obesity is becoming more evident and should be evaluated and treated in at-risk patients. Mechanisms involved in this relationship include body composition changes, the presence of adipokines, insulin resistance, and other factors, some of which are still unknown. Weight loss and treatment to replace testosterone levels improve the metabolic profile and quality of life in patients with obesity and hypogonadism; these beneficial effects depend on treatment modality and duration of therapy. The use of testosterone replacement therapy may be indicated, as it has not been shown to increase cardiovascular risk, and retrospective studies suggest a reduction in events in men with metabolic syndrome and type 2 diabetes.

关键词： adipose tissue male hypogonadism obesity testosterone

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