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Direct microwave leaching conditions of rare earth elements in fluorescent wastes

Journal of Rare Earths 2024年第6期42卷 1165-1174,I0007页

作者： A.Bilen B.Birol m.N.Saridede S.S.Kaplan m.S.Sonmez Department of metallurgical and materials Engineering Yildiz Technical UniversityIstanbulTurkey Department of Chemical Engineering and materials Science Stevens Institute of TechnologyNew JereyUSA Department of metallurgical and materials Engineering Istanbul Technical UniversityIstanbulTurkey

The luminescent phosphor powder in the fluorescent lamp constitutes 2%of the lamp’s *** can be mentioned that fluorescent wastes are a crucial raw material to produce rare earth *** the present study,microwave leaching process was conducted to dissolve rare earth elements yttrium(Y),europium(Eu),and remaining rare earth elements(REEs)present in the phosphor powder of the fluorescent *** the yields were *** the microwave leaching process,the effects of the temperature(80-160℃),acid type(hydrochloric acid(HCl),nitric acid(HNO_(3)),sulphuric acid(H_(2)SO_(4))),acid concentration(0.5-6 mol/L),solid to liquid ratio(0.1:10-0.5:10)and reaction time(5-90 min)parameters on leaching efficiencies of varying rare earth elements and calcium were *** highest yield was obtained in the direct microwave leaching of fluorescent waste with the experimental conditions of 6 mol/L HCl,160℃,0.1:10 solid-to-liquid ratio(S:L),and 90 *** energy calculations were made,and kinetic models of the reactions were obtained,and it is observed that Y and Eu dissolution is diffusion-controlled,on the other hand,lanthanum(La),cerium(Ce),and terbium(Tb)were examined to be chemical reaction ***,calcium(Ca)and gadolinium(gd)seem coherent with the mixed ***,mathematical models of all experimental studies are created with the response surface Box-Behnken method and the correlation coefficients of all the models are over 90%.

关键词： Rare earth elements(REEs) Direct microwave leaching Fluorescent waste Kinetic models Response surface method

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Retinoblastoma: The Situation in Burkina Faso over Ten Years

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Open Journal of Ophthalmology 2024年第3期14卷 175-195页

作者： Amadou Ouattara Anicet Corneille Beremwidougou Paté Sankara mariam Traore Dolo Tierinyê Armand meda Windinmanégdé Pierre Djiguimde Rolande Kabore Chantal Gabrielle Bouda Gertrude Augustine meda Hien Jerome Sanou Jean Wenceslas Diallo Ahgbatouhabeba Zabsonre Ahnoux Ophthalmology Department Regional University Hospital of Ouahigouya Ouahigouya Burkina Faso Regional University Hospital of Ouahigouya Ouahigouya Burkina Faso National Center for the Fight against Blindness Ouagadougou Burkina Faso University Hospital of Sour Sanou Bobo-Dioulasso Burkina Faso Nouna District Hospital Nouna Burkina Faso University Hospital of Bogodogo Ouagadougou Burkina Faso University Hospital of Yalgado Ouedraogo Ouagadougou Burkina Faso

Context: In Burkina Faso, there is only one retinoblastoma treatment center located in the capital. Nowadays, the treatment of retinoblastoma has benefited from the contribution of scientific progress. Objective: The aim was to take stock of the situation of retinoblastoma in the pediatric oncology department from January 1, 2010 to December 31, 2019. materials and methods: This was a descriptive cross-sectional study with retrospective data collection over a 10-year period, based on records of patients admitted to pediatric oncology department of CHU-YO. Data were analysed using CS Pro version 7.2 software. Categorical variables were compared using Pearsons Chi-square test at the 5% significance level. Overall survival was estimated using the Kaplan-meier method. Operational definitions were used for lost to follow-up, consultation and diagnosis delays. Results: We collected a total of 204 cases in 10 years, i.e. an annual average of 20.4 cases/year. The mean age at diagnosis was 37.5 months for unilateral cases and 26.4 months for bilateral cases. male predominance was noted, with a sex ratio of 1.31. The majority of patients came from disadvantaged backgrounds (72% farming fathers and 91% housewives). Clinically, leukocoria and exophthalmos were the main presenting features. The average time to consultation was long (8.73 months) and unilateral localization was predominantly unilateral at 77%. In terms of treatment, 102 patients were eligible for curative treatment and 80 for palliative treatment. The prognosis was poor, with 41% death and numerous cases of lost to follow-up (18%). Overall survival was estimated at 32%. The factor associated with the lethality of retiniblastoma was the extension of the tumor to other organs. Conclusion: Recognition of the early clinical signs of retinoblastoma can anticipate the occurrence of this cancer. Health professionals should be encouraged to perform the Buckner test every time they come into contact with children aged 0 t

关键词： Retinoblastoma Prognosis Pediatric Oncology CHU-YO Burkina Faso

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In situ TEm investigation of electron irradiation and aging-induced high-density nanoprecipitates in an mg-10gd-3Y-1Zn-0.5Zr alloy

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Journal of magnesium and Alloys 2024年第5期12卷 1841-1853页

作者： m.Lv H.L.Ge Q.Q.Jin X.H.Shao Y.T.Zhou B.Zhang X.L.ma Shenyang National Laboratory for materials Science Institute of Metal ResearchChinese Academy of Sciences72 Wenhua RoadShenyang 110016China School of materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China materials Science and Engineering Research Center Guangxi University of Science and TechnologyLiuzhou 545006China

In-situ electron irradiation and aging are applied to introduce high-density precipitates in an mg-10gd-3Y-1Zn-0.5Zr(GWZ1031K,wt.%)alloy to improve the *** results show that the hardness of the mg alloy after irradiation for 10 h and aging for 9 h at 250℃ is 1.64 GPa,which is approximately 64% higher than that of the samples before being *** is mainly attributed to γ'precipitates on the basal plane after irradiation and the high-density nanoscale β'precipitates on the prismatic plane after aging,which should be closely related to the irradiation-induced homogenous *** latter plays a key role in precipitation *** result paves a way to improve the mechanical properties of metallic materials by tailoring the precipitation through irradiation and aging.

关键词： mg alloy Electron beam irradiation Hardening Precipitates In-situ TEm

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Preliminary studies on the ionic pulse of snowmelt runoff in the Urumqi River, Xinjiang, Northwest China

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Chinese Science Bulletin 1997年第19期42卷 1643-1646页

作者： Liu, FJ Williams, m Cheng, gd Yang, DQ The State Key Laboratory of Frozen Soil Engineering Chinese Academy of Sciences Lanzhou China Lanzhou Institute of Glaciology and Geocryology Chinese Academy of Sciences Lanzhou China Department of Geography and Institute of Arctic and Alpine Research University of Colorado Boulder USA

IONIC pulse of snowmelt and its runoff in seasonally snow-covered alpine catchments was de-fined by Johannessen et al. When a snowpack begins melting, the first meltwater drainingthrough the pack carries a large fraction of the soluble ions with it, an ionic pulse. 10％ of thefirst meltwater may drain 80％ of the soluble contents out of the snowpack within severalhours or days. In other words, an ionic pulse designates a peak in ionic concentration duringthe initial melting process of a snowpack. The peak has been proved by a plot test 10 times

关键词： snowmelt runoff ionic pulse Urumqi River.

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BaTiO3 solid solutions co-doped with gd3+ and Eu3+:Synthesis,structural evolution and dielectric properties

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Journal of Rare Earths 2024年第10期 1920-1926页

作者： R.martínez-López m.Pérez-Labra J.A.Romero-Serrano F.R.Barrientos-Hernández m.Reyes-Pérez m.I.Valenzuela-Carrillo G.Urbano-Reyes V.E.Reyes-Cruz G.I.Dávila-Pulido Academic Area of Earth Sciences and materials Autonomous University of Hidalgo State metallurgy and materials Department ESIQIE-IPNUPALM Autonomous University of Coahuila Boulevard Adolfo López Mateos S/n

In this paper,the synthesis,structural evolution,and dielectric properties of BaTiO3solid solutions codoped with rare earth elements(gd3+and Eu3+) prepared using the solid-state reaction method are *** pure precursor powders of BaCl3,TiO2,gd2O3,and Eu2O3were mixed in stoichiometric proportions,ground in an agate mortar before being uniaxially pressed at 250 mPa and sintered at 1300℃ in air atmosphere for 6 h to obtain Ba1-3xgd2xTi1-3xEu4xO3（x=0,0.0015,0.01 and0.1）.X-ray diffraction（XRD） and Rietveld's refinement results reveal the crystal phase ferroelectric tetragonal BaTiO3for the samples with x=0,0.0015 and 0.01, as well as a consistent increment in the lattice parameters caused by the *** solubility limit of gd3+and Eu3+in the BaTiO3structure is reached for the sample with x>0.01,and the orthorhombic Eu2TiO5and monoclinic BaTi2O5secondary phases were *** Raman results show the characteristic peaks of ferroelectric tetragonal BaTiO3around 716 cm-1（LO of A1 symmetry）,515 cm-1（TO of A1 symmetry）,and 305 cm-1（B1）.The maximum relative permittivity measured at 1 kHz was recorded to be 6151.8 for the sample with x=0.0015,and a decrease in the Curie temperature to 105℃ with respect to the undoped sample was *** punctual microanalysis for the samples with x=0.0015,0.01,and 0.1 reveals grains composed of Ba,Ti,O,gd,and Eu homogeneously distributed in the *** Ba/Ti ratios for samples with x=0.0015,0.01 and 0.1 are 2.86,2.91,and 0.68,respectively,indicating substitution at the Ti site for samples with x=0.0015 and 0.01 and a substitution at the Ba site for the sample with x=0.1.

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A New method for the Synthesis of C/D Ring Synthon of Vitamin D

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Chinese Chemical Letters 1998年第3期9卷 259-260页

作者： Gao, LJ Zhao, TZ Han, gd Henan Acad Sci Inst Chem Zhengzhou 450003 Peoples R China Chinese Acad med Sci Inst Mat Med Peking Union Med Coll Beijing 100050 Peoples R China

A C/D ring synthon of vitamin D is readily obtained from cholesteryl acetate via oxidation, elimination of acetoxy group and Norrish type II photochemical reaction.

关键词： C/D ring synthon vitamin D cholesteryl acetate photochemical degradation

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Rare earth-doped mixed Ni-Cu-Zn ferrites as an effective photocatalytic agent for active degradation of Rhodamine B dye

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Journal of Rare Earths 2024年第3期42卷 488-496,I0003页

作者： Swapnil A.Jadhav Sandeep B.Somvanshi Sudarshan S.Gawali Kranti Zakde K.m.Jadhav Department of Physics Dr.Babasaheb Ambedkar Marathwada UniversityAurangabad431004MaharashtraIndia School of materials Engineering Purdue UniversityWest Lafayette 47906USA University Department of Basic and Applied Sciences MGM UniversityAurangabad431003MaharashtraIndia

In this study, a series of gd^(3+)-doped mixed Ni-Cu-Zn ferrites with composition of Zn_(0.5)Ni_(0.3)Cu_(0.2)Fe_(2-x)gd_(x)O_(4)(x = 0, 0.025, 0.05, 0.075, 0.1) was prepared using self-ignition sol-gel method. The prepared nanoparticles with an average size ranging from 22 to 26 nm show a single-phase cubic structure belonging to the spinel matrix. A rise in the gd^(3+)concentration leads to an increase in crystallite size and lattice parameter. In Fourier transform infrared spectra, two main absorption bands belonging to the spinel structure are observed. The high-frequency bands(v_(1)) represent the tetrahedral complex, while the lowfrequency bands(v_(2)) signify the octahedral complex. The optical bandgap of the nanoferrites is found within the range of 2.91 to 2.41 eV, depending on their size. The magnetic characteristics of the material,such as saturation magnetization and coercivity are significantly altered with the concentration of gd^(3+)in the solution. Using Rhodamine B(RhB) as a model organic pollutant, an in-depth investigation of the photocatalytic activity of the compounds was carried out. The present outcomes show that adding an adequate amount of gd^(3+)significantly enhances the number of hydroxyl radicals produced by the ferrite,in turn, increasing the photocatalytic activity of the material. mechanism elucidated by scavenger studies reveals that ·OH and holes are the primary reactive radicals responsible for the degradation *** photocatalysts show an insignificant performance loss in five consecutive cycles. Thus, it is concluded that these photocatalysts are highly suitable for the remediation of dye-contaminated wastewater.

关键词： gd^(3+)substitution Spinel ferrite Structural properties magnetic properties Photocatalysis Rare earths

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Tectonic framework of China and its relation with mineral resources——Cognition from geophysical data

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Chinese Science Bulletin 1997年第2期42卷 89-95页

作者： Liu, gd Hao, TY Liu, Y Institute of Geophysics Chinese Academy of Sciences Beijing 100101 China

TECTONIC and its evolution are theoretical basis of geology and summation in geosciences from investigation of the earth’s structure, composition, motion and history. Therefore, they are of great importance to the industrial activities. Various geological maps have been compiled in different scales after long-time observation of rock outcrops in mountains and torrents. These tectonic maps, which are obtained based upon the cognition and judgment of tectonic movements in different ages, are summarization regarding the regularity of geological phenomenon in terms of theory, and provide service of exploration and references for environmental protection and prevention and control of disaster.

关键词： tectonic geophysics macroscopic framework.

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Radiative decays D*(s)→ D(s)γ in covariant confined quark model

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Chinese Physics C 2024年第2期48卷 45-56页

作者： C.T.Tran m.A.Ivanov P.Santorelli Q.C.Vo Department of Physics HCMC University of Technology and EducationVo Van Ngan 1700000 Ho Chi Minh CityVietnam Bogoliubov Laboratory of Theoretical Physics Joint Institute for Nuclear Research141980 DubnaRussia Dipartimento di Fisica"E.Pancini" Universitàdi Napoli Federico ⅡComplesso Universitario di Monte S.AngeloVia CintiaEdificio 680126 NapoliItaly Istituto Nazionale di Fisica Nucleare Sezione di Napoli80126 NapoliItaly University of Science 700000 Ho Chi Minh CityVietnam

Radiative decays D((s))*→D((s))γare revisited in light of new experimental data from the BaBar and BESⅢ*** radiative couplings gd*Dγencoding nonperturbative QCD effects are calculated in the framework of the covariant confined quark model developed by *** compare our results with other theoretical studies and experimental *** couplings(in GeV-1)|g(D*+D+γ)|=0.45(9)and|g(D*0D0γ)|=1.72(34)calculated in our model agree with the corresponding experimental data|g(D*+D+γ)|=0.47(7)and|g(D*0D0γ)|=1.77(16).The most interesting case is the decay Ds*→Dsγ,for which a recent prediction based on light-cone sum rules at next-to-leading order|gds*Dsγ|=0.60(19)deviates from the first(and only to date)lattice QCD result|gds*Dsγ|=0.11(2)at nearly3σ.Our calculation yields|gds*Dsγ|=0.29(6),which falls somehow between the two mentioned results,although it is larger than those predicted in other studies using quark models or QCD sum rules.

关键词： covariant quark model radiative decay charmed meson

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Epidemiology of insertional and midportion Achilles tendinopathy in runners:A prospective cohort study

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Journal of Sport and Health Science 2024年第2期13卷 256-263页

作者： Wenbo Chen Kyra L.A.Cloosterman Sita m.A.Bierma-Zeinstra marienke van middelkoop Robert-Jan de Vos Department of Orthopaedic Surgery and Sports medicine Erasmus MC University Medical CenterRotterdam 3015GDthe Netherlands Department of General Practice Erasmus MC University Medical CenterRotterdam 3015GDthe Netherlands Department of Sports medicine Huashan HospitalFudan UniversityShanghai 200040China

Background:Achilles tendinopathy(AT)is a common problem among *** is only limited evidence for risk factors for AT,and most studies have not defined the AT *** study has compared the incidence and risk factors between insertional AT and midportion AT,though they are considered *** study aimed to assess incidence and risk factors of AT based on data from a large prospective *** secondary aim was to explore differences in risk factors between insertional and midportion ***:Participants were recruited from among registered runners at registration for running *** were completed at baseline,1 month before the event,1 week before the event,and 1 month after the *** concerning demographics,training load,registered events,and running-related injuries were collected at *** follow-up questionnaires collected information about new injuries.A pain map was used to diagnose midportion and insertional *** primary outcome was the incidence of *** logistic regression analysis was applied to identify risk factors for the ***:We included 3379 participants with a mean follow-up of 20.4 *** incidence of AT was 4.2%.The proportion of insertional AT was 27.7%and of midportion AT was 63.8%;the remaining proportion was a combined type of insertional and midportion *** had a significantly higher incidence(5%,95%confidence interval(95%CI):4.1%-6.0%)than women(2.8%,95%CI:2.0%-3.8%).AT in the past12 months was the most predominant risk factor for new-onset AT(odds ratio(OR)=6.47,95%CI:4.27-9.81).This was similar for both subcategories of AT(insertional:OR=5.45,95%CI:2.51-11.81;midportion:OR=6.96,95%CI:4.24-11.40).Participants registering for an event with a distance of 10/10.55 km were less likely to develop a new-onset AT(OR=0.59,95%CI:0.36-0.97)or midportion AT(OR=0.47,95%CI:0.23-0.93).Higher age had a significant negative association with insertional AT(OR=0.97,95%CI:0.9

关键词： Achilles tendon injury Incidence Risk factor Running-related injury

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