检索结果-南通市图书馆

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

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

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

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

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

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

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

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

Seasonal variation and host sex affect bat–bat fly interaction networks in the Amazonian savannahs

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Integrative Zoology 2024年第3期19卷 400-416页

作者： Paulo MEJIA Gustavo Lima URbIETA bruna da Silva XAVIER IsaíJorge de CASTRO JoséJúlio DE TOLEDO Gustavo GRACIOLLI Lucio AndréVIANA DIAS William douglas CARVALHO Programa de Pós-Graduação em biodiversidade Tropical Universidade Federal do Amapá(UNIFAP)MacapáAPBrazil Programa de Pós-Graduação em Ecologia Instituto de BiologiaCentro de Ciências da SaúdeUniversidade Federal do Rio de Janeiro(UFRJ)Rio de JaneiroRJBrazil Laboratório de Mamíferos Instituto de Pesquisas Científicas e Tecnológicas do Estado do Amapá(IEPA)MacapáAPBrazil Programa de Pós-Graduação em biologia Animal Laboratório de SistemáticaEcologia e Evolução(LSEE)Instituto de BiociênciasUniversidade Federal de Mato Grosso do Sul(UFMS)Campo GrandeMTBrazil Terrestrial Ecology Group(TEG-UAM) Departamento de EcologíaFacultad de CienciasUniversidad Autónoma de MadridMadridSpain Centro de Investigación en biodiversidad y Cambio Global(CIbC-UAM) Universidad Autónoma de MadridMadridSpain

bats are the second-most diverse group of mammals in the world,and bat flies are their main ***,significant knowledge gaps remain regarding these antagonistic interactions,especially since diverse factors such as seasonality and host sex can affect their network ***,we explore the influence of such factors by comparing species richness and composition of bat flies on host bats,as well as specialization and modularity of bat–bat fly interaction networks between seasons and adult host *** captured bats and collected their ectoparasitic flies at 10 sampling sites in the savannahs of AmapáState,northeastern region of the brazilian *** female bats being more parasitized and recording greater bat fly species richness in the wet season,neither relationship was statistically *** pooled network could be divided into 15 compartments with 54 links,and all subnetworks comprised>12 *** total number of links ranged from 27 to 48(for the dry and wet seasons,respectively),and female and male subnetworks had 44 and 41 links,*** values were very low for the pooled network and for all *** results revealed higher bat fly species richness and abundance in the wet season,whereas specialization and modularity were higher in the dry ***,the subnetwork for female bats displayed higher specialization and modularity than the male ***,both seasonality and host sex contribute in different ways to bat–bat fly network *** studies should consider these factors when evaluating bat–bat fly interaction networks.

关键词： Amapá Amazon biome bat flies bats interaction networks

Current issues in endoscope reprocessing and infection control during gastrointestinal endoscopy

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

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

Circulating microRNA expression and nonalcoholic fatty liver disease in adolescents with severe obesity

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2024年第4期30卷 332-345页

作者： Yi-Jie Li brittney O baumert Nikos Stratakis Jesse A Goodrich Hao-Tian Wu Jing-Xuan He Yin-Qi Zhao Max T Aung Hong-Xu Wang Sandrah P Eckel douglas I Walker Damaskini Valvi Michele A La Merrill Justin R Ryder Thomas H Inge Todd Jenkins Stephanie Sisley Rohit Kohli Stavra A Xanthakos Andrea A baccarelli Rob McConnell David V Conti Lida Chatzi Department of Population and Public Health Sciences Keck School of MedicineUniversity of Southern CaliforniaLos AngelesCA 90032United States barcelona Institute of Global Health Barcelona Institute of Global HealthBarcelona 08036Spain Department of Environmental Health Sciences Mailman School of Public HealthColumbia UniversityNew YorkNY 10032United States Gangarosa Department of Environmental Health Rollins School of Public HealthEmory UniversityAtlantaGA 30329United States Department of Environmental Medicine and Public Health Icahn School of Medicine at Mount SinaiNew YorkNY 10029United States Department of Environmental Toxicology University of CaliforniaDavisCA 95616United States Department of Surgery Lurie Children’s Hospital of ChicagoChicagoIL 60611United States Northwestern University Feinberg School of Medicine Northwestern UniversityChicagoIL 60611United States Division of biostatistics and Epidemiology Cincinnati Children's Hospital Medical CenterCincinnatiOH 45229United States Department of Pediatrics University of Cincinnati College of MedicineCincinnatiOH 45229United States Department of Pediatrics Children’s Nutrition Research Center USDA/ARSBaylor College of MedicineHoustonTX 77030United States Department of Gastroenterology Children’s Hospital Los AngelesLos AngelesCA 90027United States Division of Gastroenterology Hepatology and NutritionCincinnati Children's Hospital Medical CenterCincinnatiOH 45229United States

bACKGROUND Nonalcoholic fatty liver disease(NAFLD)is one of the most common chronic liver diseases in children and *** ranges in severity from isolated hepatic steatosis to nonalcoholic steatohepatitis(NASH),wherein hepatocellular inflammation and/or fibrosis coexist with *** microRNA(miRNA)levels have been suggested to be altered in NAFLD,but the extent to which miRNA are related to NAFLD features remains *** analysis tested the hypothesis that plasma miRNAs are significantly associated with histological features of NAFLD in *** To investigate the relationship between plasma miRNA expression and NAFLD features among adolescents with *** This study included 81 adolescents diagnosed with NAFLD and 54 adolescents without NAFLD from the Teen-Longitudinal Assessment of bariatric Surgery ***-operative core liver biopsies were collected from participants and used to characterize histological features of *** samples were collected during surgery for miRNA profiling.A total of 843 plasma miRNAs were profiled using the HTG EdgeSeq *** examined associations of plasma miRNAs and NAFLD features using logistic regression after adjusting for age,sex,race,and other key *** Pathways Analysis was used to identify biological functions of miRNAs that were associated with multiple histological features of *** We identified 16 upregulated plasma miRNAs,including miR-193a-5p and miR-193b-5p,and 22 downregulated plasma miRNAs,including miR-1282 and miR-6734-5p,in adolescents with ***,52,16,15,and 9 plasma miRNAs were associated with NASH,fibrosis,ballooning degeneration,and lobular inflammation,***,16 miRNAs were associated with two or more histological features of *** those miRNAs,miR-411-5p was downregulated in NASH,ballooning,and fibrosis,while miR-122-5p,miR-1343-5p,miR-193a-5p,miR-193b-5p,and miR-7845-5p were consistently and posi

关键词： MicroRNA Nonalcoholic fatty liver disease Non-alcoholic steatohepatitis Liver fibrosis Lobular inflammation ballooning degeneration

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

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

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)

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

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

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

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

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