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Erbium photoluminescence response related to nanoscale heterogeneities in sol-gel silicates

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Journal of Rare Earths 2013年第1期31卷 18-26页

作者： H.c.Vasconcelos M.G.Meirelles f.Rivera-López Department of Technological Sciences and Development Azores University cEfITEc-centre of Physics and Technological Research Physics Department of FCT/UNL Department of fundamental and Experimental Physics Electronics and SystemsUniversity of La Laguna

Sol-gel glassy films of the SiO2-TiO2-PO2.5-ErO2.5 system containing nanocrystallites of ErPO4, were obtained through suitable heat treatments. Variations in the shape and intensity of the Er3＋ photoluminescent signal around 1500 nm were linked to the nature of the host environment of the active ions; the specific features of the photoluminescent emission spectrum of the erbium 4113/2 metastable level were interpreted in terms of structural changes in the glassy films. The photoluminescent spectrum was found to be sensitive to the order （crystalline） or disorder （amorphous） of the Er3＋ ions neighbour within the glassy matrix. An amorphous envi- ronment led to a broadening of Er3＋ PL emission band while a crystalline one was responsible for a drastic photoluminescent band- width narrowing. The presence of nanoscale heterogeneities caused a drastic photoluminescence intensity decrease. changes in the shape of the decay curve of fluorescence lifetime were found also structurally dependent on volumetric defects, occurrence of phase separation and Er3＋-Er3＋ clustering effects as well.

关键词： sol-gel Er3+ optical probe nanoscale heterogeneities photoluminescence ErPO4 rare earths

Assessing reservoir connectivity with pressure/rate surveillance data

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Petroleum Science 2023年第2期20卷 1077-1086页

作者： G.f.J.Al-Khmaysawee Z.Reza c.S.Kabir Missouri University of Sci.&Tech. RollaMOUSA University of Oklahoma NormanOKUSA Incendium Technologies Round RockTXUSA

Estimating reservoir connectivity is critical for assessing infill-drilling prospects and initiating fluid injection in enhanced oil recovery operations. Several methods have appeared in the literature over decades to meet these business needs, given that all tools, including seismic imaging, have limitations. Besides imaging, geochemical fingerprinting constitutes a powerful tool to gauge the compartmentalization question. However, real-time pressure/rate surveillance data allows assessing interwell connectivity vis-à-vis the overall drainage *** study presents a simplified approach to using the reciprocal-productivity index (RPI) vs. the total-material-balance time (tTMB) plot. This tool exhibits the same slope for those wells in the same compartment beyond the start of the boundary-dominated flow (BDf) period. The wells showing different slopes imply that they are in separate drainage volumes. The early-time transient period remains muted to minimize confusion on this cartesian plot. We validated the proposed tool's efficacy with 2D and 3D models with increased degrees of reservoir complexity, followed by the verification phase with four field examples. The use of other analytical tools complemented our findings.

关键词： Reservoir compartmentalization Reciprocal-productivity index Total material-balance time Analysis of boundary-dominated flow period

NUMERIcAL SIMULATION Of MAcRO-SEGREGATION IN STEEL INGOT DURING SOLIDIfIcATION

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Acta Metallurgica Sinica(English Letters) 2004年第3期17卷 288-294页

作者： c.W.Ma H.f.Shen T.Y.Huang B.c.Liu Department of Mechanical Engineering Tsinghua University Beijing 100084 ChinaDepartment of Mechanical Engineering Tsinghua University Beijing 100084 ChinaDepartment of Mechanical Engineering Tsinghua University Beijing 100084 ChinaDepartment of Mechanical Engineering Tsinghua University Beijing 100084 China

A mathematical model coupling the momentum, energy and species conservation equa-tions was proposed to calculate the macro--segregation of fe--c alloy ingot during solid-ification. The corresponding simulation software which concurrently solves the macro-scopic mass, momentum, energy and species conservation equations has been developedby applying the SIMPLE algorithm.The thermo--solutal convection in a NH_4 cl--H_2O ingot is verified and the result showsgood agreement with that reported. Then macro--segregation in a steel ingot is simu-lated by using the developed program. The steel ingot is in a rectangular mold with ariser. The fluid flow is mainly induced by the temperature field and the solid fraction.The macro--segregation pattern is mainly affected by the thermo--induced convectionin the mushy zone. The negative segregation forms along the walls of the casting.The positive segregation forms at the top center of the casting into the riser. Thespecies concentration reaches the peak in the center of the ingot where solidificationends lastly.

关键词： macro-segregation thermo-solutal convection steel ingot numerical simulation

Investigation on the effectiveness of pretreatment in stormwater management technologies

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Journal of Environmental Sciences 2014年第9期26卷 1824-1830页

作者： Marla c.Maniquiz-Redillas franz Kevin f.Geronimo Lee-Hyung Kim Dept.of civil and Environmental Engineering Kongju National UniversityCheonanChungnamdoSouth Korea

The effectiveness of presettling basins as component of stormwater best management practice （BMP） technologies was investigated. Storm event monitoring and sediment collection were conducted from May 2009 to November 2012 on the presettling basins of the three BMP technologies designed to capture and treat stormwater runoff from highly impervious roads and parking lots. Data on captured runoff and sediment, total suspended solids （TSS） loadings, rainfall and runoff rate, sediment accumulation rate, as well as particle distribution and pollutant concentrations of sediment were gathered and analyzed along with the physical design characteristics of the presettling basins such as surface area and storage volume. Regression models were generated to determine significant relationships between design parameters. Results revealed that the storage volume ratio （ratio of storage volume of presettling basin to BMP） was an important parameter in designing the presettling basin of the BMP. for practicality, optimizing the design of the presetfling basin means that the storage volume ratio should be determined based on the desired captured amount of runoff and sediment from runoff to limit the frequency of maintenance caused by the accumulation of sediment. It was recommended that pretreatment of runoff should be employed when the site in which the BMP is to be sited has high TSS loading and runoff rate, and is subjected to high intensity rainfall.

关键词： Best management practicePresettling basinPretreatmentSedimentStormwater runoff

Synthesis and characterization of caAl_xO_y:Eu^(2+) phosphors prepared using solution-combustion method

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Journal of Rare Earths 2010年第S1期28卷 272-276页

作者： f.B.Dejene D.B.Bem H.c.Swart Department of Physics University of the Free State(Qwaqwa Campus)Private Bag X13Phuthaditjhaba9866South Africa Department of Physics University of the Free StateP.O.Box 339Bloemfontein9300South Africa

Europium-doped calcium aluminate(caAlxOy:Eu2+) phosphors were obtained at low temperatures(500 oc) by the solution-combustion of corresponding metal nitrate-urea solution *** particle size and morphology and the structural and luminescent properties of the as-synthesized phosphors were examined by means of scanning electron microscopy(SEM),X-ray diffraction(XRD),Auger spectroscopy,transmission electron spectroscopy(TEM) and photoluminescence(PL).It was found that the ca:Al molar ratios showed greatly influence not only on the particle size and morphology,but also on their PL spectra and *** the ca:Al molar ratios increasing from 6:100 to 26:100,the structure of as-synthesized phosphor changed from caAl12O19 to monoclinic caAl2O4 and the dominant emitting light from red to blue,implying that the oxidation state of doped europium ions changed from trivalent to divalent due to the structure variation of host lattice.A blue phosphor with almost pure phase can be easily prepared by solution combustion method with suitable ca:Al molar ratio.

关键词： caAlxOy:Eu2+ solution-combustion molar ratio structure luminescence rare earths

Genetic diversity of the hepatitis c virus: Impact and issues inthe antiviral therapy

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World Journal of Gastroenterology 2007年第17期13卷 2416-2426页

作者： H Le Guillou-Guillemette S Vallet c Gaudy-Graffin c Payan A Pivert A Goudeau f Lunel-fabiani Laboratory of Virology University Hospital of Angers France and Laboratory HIFI UPRES EA 3859 University of Angers France Department of Microbiology EA 3882 CHU Morvan University Hospital of Brest France Université francois Rabelais INSERM ERI 19 et CHRU de Tours Tours France

The hepatitis c Virus (HcV) presents a high degree of genetic variability which is explained by the combination of a lack of proof reading by the RNA dependant RNA polymerase and a high level of viral replication. The re- sulting genetic polymorphism defines a classification in clades, genotypes, subtypes, isolates and quasispecies. This diversity is known to reflect the range of responses to Interferon therapy. The genotype is one of the pre- dictive parameters currently used to define the antiviral treatment strategy and the chance of therapeutic suc- cess. Studies have also reported the potential impact of the viral genetic polymorphism in the outcome of antivi- ral therapy in patients infected by the same HcV geno- type. Both structural and non structural genomic regions of HcV have been suggested to be involved in the Inter- feron pathway and the resistance to antiviral therapy. In this review, we first detail the viral basis of HcV diversity. Then, the HcV genetic regions that may be implicated in resistance to therapy are described, with a focus on the structural region encoded by the E2 gene and the non- structural genes NS3, NS5A and NS5B. Both mechanisms of the Interferon resistance and of the new antiviral drugs are described in this review.

关键词： Hepatitis c virus Genetic diversity Therapyresistance E2 NS3 NSSA NSSB

fAcTORS ON VIScOSITY STABILITY Of MOLD fLUXES

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Acta Metallurgica Sinica(English Letters) 2004年第2期17卷 175-180页

作者： c.Y.Zhu c.J.Liu M.f.Jiang Z.D.Yang NortheasternUniversity Shenyang110004China Ji＇nanIronandSteelGroupco. Ji＇nan250101China

Viscosity stability indexes of mold flux at high temperature and low temperature havebeen introduced and the effects of flux compositions on viscosity stability indexeshave been studied. Two mold fluxes have been developed by analyzing the effects offlux viscosity stability on the process and the condition of continuous casting slab ofmedium carbon steel. The results show that the fluxes are suitable for the process.

关键词： mold flux viscosity stability index high temperature low temperature

Hepatocellular carcinoma recurrence after liver transplant:An Australian single-centre study

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World Journal of Transplantation 2025年第1期15卷 105-114页

作者： Matthew G Garas Luis calzadilla-Bertot Briohny W Smith Luc Delriviere Byron Jaques Lingjun Mou Leon A Adams Gerry c MacQuillan George Garas Gary P Jeffrey Michael c Wallace Medical School University of Western AustraliaNedlands 6009Western AustraliaAustralia Department of Hepatology Sir Charles Gairdner HospitalNedlands 6009Western AustraliaAustralia Department of Surgery Sir Charles Gairdner HospitalNedlands 6009Western AustraliaAustralia

BAcKGROUND Hepatocellular carcinoma(Hcc)is a leading cause of cancer-related deaths *** transplantation(LT)offers the most effective *** recurrence is the strongest risk factor that decreases post-LT survival in patients transplanted for *** rate of Hcc recurrence is generally reported as 8%-20%in the *** predictors of Hcc have already been researched,however,to our knowledge there are no published studies on this topic using Australian *** To determine the rate and identify predictors of Hcc recurrence in a contemporary Western Australian LT *** We performed a retrospective cohort study of all liver transplants in patients with Hcc at Sir charles Gairdner Hospital between 2006 and *** was collected from various health record databases and included recipient demographics,serum biochemistry,radiology,operation notes,explant histopathology and details of *** survival of Hcc patients post-LT,stratified for recurrence,was calculated by Kaplan Meier *** and multivariate cox regression was used to determine predictors of Hcc recurrence *** Between 1/1/2006 and 12/31/2021,119 patients were transplanted with Hcc.8.4%of subjects developed recurrent Hcc after LT with median follow-up time of 5.4 *** median time to recurrence was 2.9 years±0.75 *** comparing baseline characteristics,a greater proportion of subjects with recurrence had common characteristics on explant histopathology,including>3 viable nodules(P=0.001),vascular invasion(P=0.003)and poorly differentiated Hcc(P=0.03).Unadjusted survival curves showed lower 1-year,3-year,5-year and 10-year survival rates in subjects with Hcc recurrence compared to those without Hcc recurrence(90%vs 92%,70%vs 88%,42%vs 80%,14%vs 76%,respectively;log rank PcONcLUSION Hcc recurrence was low at 8.4%in this contemporary Australian cohort,however it significantly impacted post-LT *** studies are requir

关键词： Liver cancer Recurrence Liver transplantation Hepatocellular carcinoma Predictors Post-transplant survival Australian data

ISOPERIMETRIc PROBLEMS Of THE cALcULUS Of VARIATIONS WITH fRAcTIONAL DERIVATIVES

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Acta Mathematica Scientia 2012年第2期32卷 619-630页

作者： Ricardo Almeida Rui A.c.ferreira Delfim f.M.Torres center for Research and Development in Mathematics and Applications Department of MathematicsUniversity of Aveiro3810-193 AveiroPortugal Department of Mathematics Faculty of Engineering and Natural SciencesLusophone University of Humanities and Technologies1749-024 LisbonPortugal

In this article, we study isoperimetric problems of the calculus of variations with left and right Riemann-Liouville fractional derivatives. Both situations when the lower bound of the variational integrals coincide a... 详细信息

关键词： calculus of variations fractional derivatives isoperimetric problems