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Journal of Advanced Dielectrics 2015年第3期5卷 65-73页

作者： Venkata Sreenivas Puli Patrick Li Shiva Adireddy douglas b.chrisey Department of Physics and Engineering Physics Tulane University New OrleansLA 70118USA Department of Mechanical Engineering University of Texas at El PasoTX 78869USA

Polycrystalline La-doped baTiO_(3)(ba_(1-x)La_(x)TiO_(3))[x¼0;0:0005;0:001;0:003]ceramics(denoted as bTO,bLT1,bLT2,bLT3)were synthesized by conventional solid-state reaction method and characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),and Raman *** and Raman spectra revealed single-phase tetragonal perovskite crystalline ***-saturated polarization–electric field(P–E)hysteresis loops were observed with the measurement frequency of 50Hz at room temperature and confirmed ferroelectric nature of these ceramics and a high recoverable electrical energy storage density of 0.350J/cm^(3) with energy efficiency(n)-9%,which is useful in energy storage capacitor *** studies revealed anomalies around 415–420K and near the Curie *** latter is attributed to the ferroelectric to paraelectric phase *** dielectric performances were obtained for La-doped samples sintered at 1350℃ for *** growth is inhibited with lanthanum(La)incorporation into the bTO *** temperature semiconducting behavior with positive temperature coefficient of resistivity(PTCR)behavior at TC is attributed to electron compensation mechanism.

关键词： baTiO_(3) doping ferroelectric energy storage semicoductor PTCR

Low temperature sintered giant dielectric permittivity CaCu_(3)Ti_(4)O_(12) sol-gel synthesized nanoparticle capacitors

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Journal of Advanced Dielectrics 2017年第3期7卷 14-23页

作者： Venkata Sreenivas Puli Shiva Adireddy Manish Kothakonda Ravinder Elupula douglas b.chrisey Department of Physics and Engineering Physics Tulane University New OrleansLA 70115USA Department of Chemistry Tulane UniversityNew OrleansLA 70115USA

This paper reports on synthesis of polycrystalline complex perovskite CaCu_(3)Ti_(4)O_(12)(as CCTO)ceramic powders prepared by a sol–gel auto combustion method at different sintering temperatures and sintering times,*** effect of sintering time on the structure,morphology,dielectric and electrical properties of CCTO ceramics is *** the electrical properties via different sintering times is demonstrated for ceramic samples.X-ray diffraction(XRD)studies confirm perovskite-like structure at room *** grain growth is observed for ceramic *** dielectric permittivity was realized for CCTO *** dielectric permittivity was attributed to the internal barrier layer capacitance(IbLC)model associated with the Maxwell–Wagner(MW)polarization mechanism.

关键词： CCTO cubic giant dielectric permittivity IbLC grain growth.

Synthesis and characterization of lead-free ternary component bST-bCT-bZT ceramic capacitors

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Journal of Advanced Dielectrics 2014年第2期4卷 51-59页

作者： Venkata Sreenivas Puli Dhiren K.Pradhan brian C.Riggs Shiva Adireddy Ram S.Katiyar douglas b.chrisey Department of Physics and Engineering Physics Tulane University New Orleans-LA 70118USA Department of Physics University of Puerto Rico San Juan-00936PRUSA

Polycrystalline sample of lead-free 1/3(ba_(0.70)Sr_(0.30)TiO_(3))+1/3(ba_(0.70)Ca_(0.30)TiO_(3))+1/3(baZr_(0.20)Ti_(0.80)O_(3))(bST-bCT-bZT)ceramic was synthesized by solid state reaction *** purity and crystal structure of as-synthesized materials was confirmed by X-ray diffraction(XRD).Temperature-dependent dielectric permittivity studies demonstrated frequency independent behavior,indicating that the studied sample has typical diffuse phase transition behavior with partial thermal hysteresis.A ferroelectric phase transition between cubic and tetragonal phase was noticed near room temperature(~330 K).bulk P-E hysteresis loop showed a saturation polarization of 20.4μC/cm^(2) and a coercive field of~12.78 kV/cm at a maximum electric field of~115 kV/*** dielectric constant(ε~5773),low dielectric loss(tanδ~0.03)were recorded at room *** energy density of 0.44 J/cm^(3) and charge energy density of 1.40 J/cm^(3) were calculated from nonlinear ferroeletric hysteresis loop at maximum electric *** constant at variable temperatures and electric fields,ferroeletric to paraelectric phase transition and energy storage properties were thoroughly discussed.

关键词： Crystal structure dieletric properties energy storage electrical properties

Locally advanced pancreatic cancer: staging, operability, and the importance of multimodality therapy

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Hepatobiliary Surgery and Nutrition 2020年第4期9卷 497-500页

作者： Rebecca Y.Kim douglas b.Evans Kathleen K.Christians Department of Surgery and the Labahn Pancreatic Cancer Program Medical College of WisconsinMilwaukeeWIUSA

The role for surgery in the management of locally advanced pancreatic cancer(LAPC)is nicely discussed in the manuscript by Gemenetzis et *** in the Annals of Surgery(1).As the authors acknowledge,therapeutic selection... 详细信息

关键词： Surgery cancer al.

Hermitian geometry on the resolvent set(Ⅱ)

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Science China Mathematics 2021年第2期64卷 385-398页

作者： Ronald G.douglas Rongwei Yang Department of Mathematics Texas A&M UniversityCollege StationTX 77843USA School of Mathematical Sciences Tianjin Normal UniversityTianjin 300387China Department of Mathematics and Statistics State University of New York at AlbanyAlbanyNY 12222USA

For an element A in a unital C^(*)-algebra b,the operator-valued 1-formωA(z)=(z-A)^(-1) dz is analytic on the resolvent setρ(A),which plays an important role in the functional calculus of *** paper defines a class of Hermitian metrics onρ(A)through the coupling of the operator-valued(1,1)-formΩA=-ωA^(*)∧ωA with tracial and vector *** main goal is to study the connection between A and the properties of the metric concerning curvature,arc length,completeness and singularity.A particular example is when A is quasi-nilpotent,in which case the metric lives on the punctured complex plane C\{0}.The notion of the power set is defined to gauge the"blow-up"rate of the metric at 0,and examples are given to indicate a likely link with A’s hyper-invariant subspaces.

关键词： C^(*)-algebra Hermitian metric curvature arc length Fuglede-Kadison determinant quasi-nilpotent operator power set

Increasing dietary fiber intake for type 2 diabetes mellitus management: A systematic review

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World Journal of Diabetes 2024年第5期15卷 1001-1010页

作者： douglas Nitzke Juliana Czermainski Carolina Rosa Chaline Coghetto Sabrina Alves Fernandes Randhall b Carteri Department of Nutrition Centro Universitário CESUCACachoeirinha 94935-630Brazil Department of Hepatology Universidade Federal de Ciências da Saúde de Porto AlegrePorto Alegre 90430-080Brazil Postgraduate Program in Hepatology Universidade Federal de Ciências da Saúde de Porto AlegrePorto Alegre 90050-170Brazil Postgraduate Program in Hepatology Federal University of Health Sciences of Porto Alegre(UFCSPA)Porto Alegre 90050-170Brazil

bACKGROUND Type 2 diabetes is a chronic,non-communicable disease with a substantial global impact,affecting a significant number of *** etiology is closely tied to imbalanced dietary practices and sedentary ***,increasing die-tary fiber(DF)intake has consistently demonstrated health benefits in numerous studies,including improvements in glycemic control and weight *** To investigate the efficacy of DF interventions in the management of type 2 diabetes mellitus(T2DM).METHODS A systematic literature review was conducted to explore the association between DF intake and the management of *** the inclusion and exclusion criteria,a total of 26 studies were included in this *** The main strategies implied to increased DF intake were:High DF diet plus acarbose(2 studies);DF supplements(14 studies);and high DF diets(10 studies).Overall,most studies indicated that increased DF intake resulted in im-provements in glycemic control and weight management in T2DM *** DF represents a valuable strategy in the treatment of type 2 diabetes,improving health *** intake offers the potential to improve quality of life and reduce complications and mortality associated with ***,through supplements or enriched foods,DF contributes significantly to the control of several markers such as HbA1c,blood glucose,triglycerides,low-density lipoprotein,and body weight.

关键词： Type 2 diabetes mellitus Soluble fibers Insoluble fibers Probiotics blood glucose Nutrition

ANALYSIS OF THE IMPACT OF SAMPLE SIZE, ATTRIbUTE VARIANCE AND WITHIN-SAMPLE CHOICE DISTRIbUTION ON THE ESTIMATION ACCURACY OF MULTINOMIAL LOGIT MODELS USING SIMULATED DATA

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Journal of Systems Science and Systems Engineering 2018年第6期27卷 771-789页

作者： Minhui Zeng Ming Zhong John douglas Hunt Engineering Research Center for Transportation safety ofMOE Wuhan University of Technology Wuhan China School of Traffic and Transportation Engineering Changsha University of Science & Technology China National Engineering Research Center for Water Transportation Safety China Department of Civil and Environmental Engineering University of Waterloo Ontario Canada Department of Civil Engineering University of Calgary Alberta Canada

Literature review indicates that sample size, attribute variance and within-sample choice distribution of alternatives are important considerations in the estimation of multinomial logit （MNL） models, but their impacts on the estimation accuracy have not been systematically studied. Therefore, the objective of this paper is to provide an empirical examination to the above issues through a set of simulated discrete choice preference and rank ordered preference datasets. In this paper, the utility coefficients, alternative specific constants （ASCs）, and the mean and standard deviation of the four attributes for a set of seven hypothetical alternatives are specified as a priori. Then, synthetic datasets, with varying sample size, attribute variance and within-sample choice distribution are simulated. based on these datasets, the utility coefficients and ASCs of the specified MNLs are re-estimated and compared with the original values specified as the priori. It is found that （1） the estimation accuracy of utility parameters increases as the sample size increases; （2） the utility coefficients can be re-estimated with reasonable accuracy, but the estimates of the ASCs are confronted with much larger errors; （3） as the variances of the alternative attributes increase, the estimation accuracy improves significantly; and （4） as the distribution of chosen choices becomes more balanced across alternatives within sample datasets, the hit-ratio decreases. The results indicate that （a） under a similar setting presented in this paper, a large sample consisting of a few thousand observations （3000 - 4000） may be needed in order to provide reasonable estimates for utility coefficients, particularly for ASCs; （b） a larger, but realistic attribute space is preferred in the stated preference survey design; and （c） choice datasets with unbalanced ＂chosen＂ choice frequency distribution is preferred, in order to better capture the elasticity between the ＂perceived utility＂ associated wit

关键词： Sample size attribute variance within-sample choice distribution simulated data

The effect of wilderness and medical training on injury and altitude preparedness among backcountry hikers in Rocky Mountain National Park

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World Journal of Emergency Medicine 2018年第3期9卷 172-177页

作者： Michael D.T.Yue David W.Spivey Daniel b.Gingold douglas G.Sward University of Maryland School of Medicine BaltimoreMarylandUSA Department of Emergency Medicine University of Maryland School of MedicineBaltimoreMarylandUSA Division of Hyperbaric Medicine Program in TraumaUniversity of Maryland Medical CenterBaltimoreMarylandUSA

bACKGROUND:The purpose of this study was to document the correlation between medical and wilderness training with levels of preparedness for acute mountain sickness(AMS),illness,and injury among backcountry ***:We conducted a cross-sectional,convenience survey in Rocky Mountain National Park in July and August *** study group consisted of 380 hikers who completed a written survey that collected information about demographics,wilderness experience,altitude experience,hiking equipment,communications devices,and trip ***:Factors such as wilderness training(wilderness first aid[WFA],wilderness first responder[WFR],or wilderness emergency medical technician[WEMT]),wilderness experience,and altitude experience all affected hikers’emergency *** with medical training were more prepared to avoid or respond to AMS(62.3%vs.34.3%[Pbe prepared to avoid or respond to AMS(52.3%vs.36.8%[P=0.025])but not significantly more likely to be prepared to manage illness/injury(31.8%vs.22.0%[Pbe prepared to avoid or manage AMS,medical emergencies,and injuries than their non-medically trained *** training increased hikers’preparedness for AMS but did not significantly alter preparedness for illness/injury.

关键词： Hiking wilderness Acute mountain illness Injury Training

Current issues in endoscope reprocessing and infection control during gastrointestinal endoscopy

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World Journal of Gastroenterology 2006年第25期12卷 3953-3964页

作者： douglas b Nelson Lawrence F Muscarella Staff Physician in Gastroenterology Minneapolis VA Medical Center University of MinnesotaMinneapolisMN 55417United States Director Research and Development ChiefInfection ControlCustom UltrasonicsInc

The purpose of this article is to review the evidence regarding transmission of infection during gastrointestinal endoscopy, factors important in endoscope reprocessing and infection control, areas to focus on to impr... 详细信息

关键词： Endoscopy Infection Disinfection Reprocessing Infection control

HYERS-ULAM STAbILITY OF SECOND-ORDER LINEAR DYNAMIC EQUATIONS ON TIME SCALES

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Acta Mathematica Scientia 2021年第5期41卷 1809-1826页

作者： douglas R.ANDERSON Masakazu ONITSUKA Department of Mathematics Concordia CollegeMoorheadMN 56562 USA Department of Applied Mathematics kayama University of ScienceOkayama700-0005Japan

We investigate the Hyers-Ulam stability(HUS)of certain second-order linear constant coefficient dynamic equations on time scales,building on recent results for first-order constant coefficient time-scale *** particular,for the case where the roots of the characteristic equation are non-zero real numbers that are positively regressive on the time scale,we establish that the best HUS constant in this case is the reciprocal of the absolute product of these two *** for instability are also given.

关键词： stability second order Hyers-Ulam time scales