检索结果-南通市图书馆

A comparative assessment of empirical and lattice Boltzmann method-based drag models for simulation of gas-solid flow hydrodynamics in a bubbling fluidized bed

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Particuology 2017年第4期15卷 129-137页

作者： Carlos M. Romero luna Luis R. Carrocci Gretta L.A.F. Arce Ivonete Avila UNESP - Sflo Paulo State University School of Engineering Department of Energy Laboratory of Combustion and Carbon Capture (LC3) CEP 12.516-410 Guaratinguetd SP Brazil INPE - Brazilian Space Research Institute Combustion and Propulsion Associated I.aboratory CEP 12.630-000 Cachoeira Paulista SP Brazil UNJFSC -Jose Faustino Sanchez Carrion National University Faculty of Chemical and Metallurgical Engineering Advanced Materials and Nanotechnology Research Group Huacho Lima Peru

In simulations of fluidized beds using computational fluid dynamics （CFD）, the description of gas-solid flow hydrodynamics relies on a drag model to account for the momentum transfer between gas and solid phases. Although several studies of drag models have been published, there have been few investigations of the application of lattice Boltzmann method （LBM）-based drag models to bubbling fluidized bed simu- lations. In the present study, a comprehensive comparison of empirical and LBM-based drag models was carried out to assess the performance of these models during simulations of gas-solid flow hydrodynam- ics in a bubbling fluidized bed. A CFD model using the MFIX code based on the Eulerian-Eulerian approach and the kinetic theory of granular flow was used to simulate a 2D bubbling fluidized bed with Geldart B particles. The simulation results were validated by comparison with experimental data. Statistical anal- ysis of the results shows that LBM-based drag models can reliably model gas-solid flow hydrodynamics in a bubbling fluidized bed.

关键词： CFD Drag model Gas-solid flow hydrodynamics Bubbling fluidized bed

Alcoholism and liver disease in Mexico:Genetic and environmental factors

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 2013年第44期19卷 7972-7982页

作者： Sonia Roman Eloy Alfonso Zepeda-Carrillo Laura Eugenia Moreno-luna Arturo Panduro Department of Molecular Biology in Medicine Civil Hospital of Guadalajara "Fray Antonio Alcalde" and Health Sciences Center University of GuadalajaraGuadalajara Jalisco 44280 Mexico Universidad Autónoma de Nayarit and Hospital Civil Tepic "Antonio González Guevara" Tepic Nayarit 63000 Mexico

Alcoholism and cirrhosis,which are two of the most serious health problems worldwide,have a broad spectrum of clinical *** diseases are influenced by genetic susceptibility and cultural traits that differ globally but are specific for each *** contrast to other regions around the world,Mexicans present the highest drinking score and a high mortality rate for alcoholic liver disease with an intermediate category level of per capita alcohol *** has a unique history of alcohol consumption that is linked to profound anthropological and social *** Mexican population has an admixture genome inherited from different races,Caucasian,Amerindian and African,with a heterogeneous distribution within the ***,genes related to alcohol addiction,such as dopamine receptor D2 in the brain,or liver alcoholmetabolizing enzymes,such as alcohol dehydrogenase classⅠpolypeptide B,cytochrome P450 2E1 and aldehyde dehydrogenase class 2,may vary from one individual to ***,they may be inherited as risk or non-risk haplogroups that confer susceptibility or resistance either to alcohol addiction or abusive alcohol consumption and possibly liver ***,in this era of genomics,personalized medicine will benefit patients if it is directed according to individual or population-based *** association studies will be required to establish novel strategies for the prevention,care and treatment of liver disease in Mexico and worldwide.

关键词： Alcohol Genes Alcoholism Alcohol dependence Alcohol addiction Alcohol abuse Alcoholic liver cirrhosis Anthropology

CpG island methylator phenotype in adenocarcinomas from the digestive tract:Methods,conclusions,and controversies

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 Gastrointestinal Oncology 2017年第3期9卷 105-120页

作者： Francisco Sánchez-vega Valer Gotea Yun-Ching Chen Laura Elnitski Genomic Functional Analysis Section National Human Genome Research InstituteNational Institutes of HealthRockvilleMD 20852United States

Over the last two decades, cancer-related alterations in DNA methylation that regulate transcription have been reported for a variety of tumors of the gastrointestinal tract. Due to its relevance for translational research, great emphasis has been placed on the analysis and molecular characterization of the CpG island methylator phenotype(CIMP), defined as widespread hypermethylation of CpG islands in clinically distinct subsets of cancer patients. Here, we present an overview of previous work in this field and also explore some open questions using crossplatform data for esophageal, gastric, and colorectal adenocarcinomas from The Cancer Genome Atlas. We provide a data-driven, pan-gastrointestinal stratification of individual samples based on CIMP status and we investigate correlations with oncogenic alterations, including somatic mutations and epigenetic silencing of tumor suppressor genes. Besides known events in CIMP such as BRAF V600 E mutation, CDKN2 A silencing or MLH1 inactivation, we discuss the potential role of emerging actors such as Wnt pathway deregulation through truncating mutations in RNF43 and epigenetic silencing of WIF1. Our results highlight the existence of molecular similarities that are superimposed over a larger backbone of tissue-specific features and can be exploited to reduce heterogeneity of response in clinical trials.

关键词： CpG island methylator phenotype CpG island Promoter DNA methylation Hypermethylation Gastrointestinal cancer

Pancreatic cancer,autoimmune or chronic pancreatitis,beyond tissue diagnosis:Collateral imaging and clinical characteristics may differentiate them

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 Gastrointestinal Oncology 2023年第6期15卷 925-942页

作者： Ana I Tornel-Avelar Jose Antonio Velarde Ruiz-Velasco Mario Pelaez-luna Department of Gastroenterology Hospital Civil of Guadalajara“Fray Antonio Alcalde”Guadalajara 44340JaliscoMexico Research Division School of Medicine/Department of Gastroenterology Universidad Nacional Autonoma de México/National Institute of Medical Sciences and Nutrition“Salvador Zubiran”Tlalpan 14000Mexico CityMexico

Pancreatic ductal adenocarcinoma(PDAC)is one of the most lethal malignancies and is developing into the 2nd leading cause of cancer-related ***,the clinical and radiological presentation of PDAC may be mirrored by other inflammatory pancreatic masses,such as autoimmune pancreatitis(AIP)and massforming chronic pancreatitis(MFCP),making its diagnosis *** AIP and MFCP from PDAC is vital due to significant therapeutic and prognostic *** diagnostic criteria and tools allow the precise differentiation of benign from malignant masses;however,the diagnostic accuracy is *** pancreatic resections have been performed in AIP cases under initial suspicion of PDAC after a diagnostic approach failed to provide an accurate *** is not unusual that after a thorough diagnostic evaluation,the clinician is confronted with a pancreatic mass with uncertain *** those cases,a re-evaluation must be entertained,preferably by an experienced multispecialty team including radiologists,pathologists,gastroenterologists,and surgeons,looking for disease-specific clinical,imaging,and histological hallmarks or collateral evidence that could favor a specific *** aim is to describe current diagnostic limitations that hinder our ability to reach an accurate diagnosis among AIP,PDAC,and MFCP and to highlight those disease-specific clinical,radiological,serological,and histological characteristics that could support the presence of any of these three disorders when facing a pancreatic mass with uncertain diagnosis after an initial diagnostic approach has been unsuccessful.

关键词： Pancreas cancer Chronic pancreatitis Autoimmune pancreatitis Pancreas mass Endoscopic ultrasound Diagnosis

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

市政工程常用支护桩及桩基的经济指标分析

工程技术研究 2024年第9期9卷 111-113页

作者：曹万铖卞小溪蒋佳静刘露娜中国市政工程中南设计研究总院有限公司湖北武汉430010

市政工程通常具有项目跨度长、深度大等特点,为保证项目在有限施工空间中安全作业并具备足够承载力,基坑支护及地基处理造价往往较高。文章总结几种常用桩的工艺特点和经济指标,并分析其造价指标的关键影响因素,有利于经济人员对基坑及... 详细信息

市政工程通常具有项目跨度长、深度大等特点,为保证项目在有限施工空间中安全作业并具备足够承载力,基坑支护及地基处理造价往往较高。文章总结几种常用桩的工艺特点和经济指标,并分析其造价指标的关键影响因素,有利于经济人员对基坑及地基处理进行快速测算,并为设计人员提供合理的投资建议。

关键词：支护桩桩基经济指标

Conditional coherent risk measures and regime-switching conic pricing

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

Probability, Uncertainty and Quantitative Risk 2021年第4期6卷 267-300页

作者： Engel John C Dela vega Robert J Elliott UniSA Business University of South AustraliaSA 5000 AdelaideAustralia Haskayne School of Business University of CalgaryCalgaryAlbertaT2N 1N4Canada

This paper introduces and represents conditional coherent risk measures as essential suprema of conditional expectations over a convex set of probability measures and as distorted expectations given a concave distortion function.A model is then developed for the bid and ask prices of a European-type asset by a conic *** price process is governed by a modified geometric Brownian motion whose drift and diffusion coefficients depend on a Markov *** bid and ask prices of a European-type asset are then characterized using conic quantization.

关键词： Conditional coherent risk measures Markov chains Regime-switching Conic finance European options Distortion functions Conic quantization

Expanding beyond endoscopy: A review of non-invasive modalities in Barrett’s esophagus screening and surveillance

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 2022年第32期28卷 4516-4526页

作者： Dariush Shahsavari Praneeth Kudaravalli John Erikson L Yap Kenneth J vega Division of Gastroenterology and Hepatology Augusta University-Medical College of GeorgiaAugustaGA 30912United States

Barrett’s esophagus(BE)is a condition that results from replacement of the damaged normal squamous esophageal mucosa to intestinal columnar mucosa and is the most significant predisposing factor for development of esophageal *** guidelines recommend endoscopic evaluation for screening and surveillance based on various risk factors which has limitations such as invasiveness,availability of a trained specialist,patient logistics and ***-nasal endoscopy is a less invasive modality but still has similar limitations such as limited availability of trained specialist and ***-endoscopic modalities,in comparison,require minimal intervention,can be done in an office visit and has the potential to be a more ideal choice for mass public screening and surveillance,particularly in patents at low risk for *** include newer generations of esophageal capsule endoscopy which provides direct visualization of BE,and tethered capsule endomicroscopy which can obtain high-resolution images of the *** cell collection devices coupled with biomarkers have been used for BE ***,in combination with TFF3,as well as EsophaCap and EsoCheck have shown promising results in various studies when used with various *** modalities including circulatory microRNAs and volatile organic compounds that have demonstrated favorable *** of these cell collection methods for BE surveillance is a potential area of future research.

关键词： Barrett’s esophagus Screening Surveillance Non-endoscopic Cytosponge Esophacap Esocheck

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

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 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 0.75

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

Grid-connected Converters with Virtual Electromechanical Characteristics:Experimental Verification

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

CSEE Journal of Power and Energy Systems 2017年第3期3卷 286-295页

作者： Weiyi Zhang Daniel Remon Ignacio Candela Alvaro luna Pedro Rodriguez Electrical Engineering Department Technical University of CataloniaBarcelona 08222Spain Department of Engineering University Loyola Andaluc´ıaSeville 41014Spain

Grid-connected power converters,which are frequently used to link renewable generation plants with the grid,are required to provide a better functionality for large scale integration of *** are expected to be gridfriendly,or even grid-supportive,instead of simply grid-feeding or *** paper designs a synchronous power controller for grid-connected converters in detail,emulating the electromechanical characteristics of synchronous machines and improving even its actual performance,as it is based on a virtual *** on this design,the grid-interfacing units are capable of showing inertia,damping,and droop characteristics as synchronous machines and presenting thus a grid-supporting *** detailed control design and experimental validation on a 10 kW laboratory setup acts as the main contribution of this paper,compared with the existing studies on generator emulation controls.

关键词： DC-AC power conversion power generation control synchronous power controller virtual electromechanical characteristics