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Relativistic Landau quantization in the spiral dislocation spacetime

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Communications in Theoretical Physics 2021年第2期73卷 68-72页

作者： A V D M maia K Bakke Departamento de Fisica Universijade Federal da ParaibaCaixa Postal 500858051-900Joao PessoaPBBrazil

We analyse the interaction of a relativistic electron with a uniform magnetic field in the spiral dislocation *** show that analytical solutions to the Dirac equation can be obtained,where the spectrum of energy corresponds to the relativistic Landau *** also analyse the influence of the spiral dislocation on the relativistic Landau levels by showing that there exists an analogue of the Aharonov–Bohm effect for bound states.

关键词： spiral dislocation spacetime relativistic Landau quantization Aharonov-Bohm effect relativistic wave equations Dirac equation

Novel experimental techniques to assess the time-dependent deformations of geosynthetics under soil confinement

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Journal of Rock Mechanics and Geotechnical Engineering 2021年第2期13卷 410-419页

作者： Carina maia Lins Costa Jorge Gabriel Zornberg Department of Civil Engineering Federal University of Rio Grande do NorteAv.Senador Salgado Filho 3000NatalRio Grande do Norte59078-970Brazil Department of Civil Architectural and Environmental Engineering The University of Texas at Austin301 E.Dean KeetonAustinTX78712-0280USA

A new experimental approach to assess the impact of soil confinement on the long-term behavior of geosynthetics is presented in this *** experimental technique described herein includes a novel laboratory apparatus and the use of different types of tests that allow generation of experimental data suitable for evaluation of the time-dependent behavior of geosynthetics under soil *** soil-geosynthetic interaction equipment involves a rigid box capable of accommodating a cubic soil mass under plane strain conditions.A geosynthetic specimen placed horizontally at the mid-height of the soil mass is subjected to sustained vertical pressures that,in turn,induce reinforcement axial loads applied from the soil to the *** previously reported studies on geosynthetic behavior under soil confinement,the equipment was found to be particularly *** minor setup modifications,not only interaction tests but also in-isolation geosynthetic stress relaxation tests and soil-only tests under a constant strain rate can be conducted using the same ***,the time histories of the reinforcement loads and corresponding strains are generated throughout the *** from typical tests conducted using sand and a polypropylene woven geotextile are presented to illustrate the proposed experimental *** testing procedure was found to provide adequate measurements during tests,including good repeatability of test *** soilegeosynthetic interaction tests were found to lead to increasing geotextile strains with time and decreasing reinforcement tension with *** test results highlighted the importance of measuring not only the time history of displacements but also that of reinforcement loads during *** approach of using different types of tests to analyze the soilegeosynthetic interaction behavior is an innovation that provides relevant insight into the impact of soil confinement on the time-dependent deformations of geos

关键词： Geosynthetics Geotextile Creep Stress relaxation Reinforced soil Long-term deformation

Global Stability for a Heroin Model with Age-Dependent Susceptibility

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Journal of Systems Science & Complexity 2015年第6期28卷 1243-1257页

作者： FANG Bin LI Xuezhi MARTCHEVA maia CAI Liming Department of Mathematics Xinyang Normal University Beijing Institute of Information and Control Department of Mathematics University of Florida

This paper considers global asymptotic properties for an age-structured model of heroin use based on the principles of mathematical epidemiology where the incidence rate depends on the age of susceptible individuals. The basic reproduction number of the heroin spread is obtained. It completely determines the stability of equilibria. By using the direct Lyapunov method with Volterra type Lyapunov function, the authors show that the drug-free equilibrium is globally asymptotically stable if the basic reproduction number is less than one, and the unique drug spread equilibrium is globally asymptotically stable if the basic reproduction number is greater than one.

关键词： Age-structured basic reproduction number equilibrium global stability heroin model

Intestinal ultrasound as a non-invasive tool to monitor inflammatory bowel disease activity and guide clinical decision making

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World Journal of Gastroenterology 2023年第15期29卷 2272-2282页

作者： Michael T Dolinger maia Kayal Department of Pediatric Gastroenterology Icahn School of Medicine at Mount SinaiNew YorkNY 10029United States Department of Medicine Division of GastroenterologyIcahn School of Medicine at Mount SinaiNew YorkNY 10029United States

Intestinal ultrasound(IUS)is a non-invasive,real-time,cross-sectional imaging tool that can be used at the point-of-care to assess disease activity in patients with Crohn’s disease or ulcerative *** promotes quick and impactful treatment decisions that can modify disease progression and enhance patient *** review will summarize the technical aspects of IUS,the evidence to support the use of IUS in disease activity monitoring,the comparison of IUS to current standard of care monitoring modalities such as colonoscopy and calprotectin,and the optimal positioning of IUS in a tight-control monitoring strategy.

关键词： Crohn’s disease Ulcerative colitis Disease monitoring Intestinal ultrasound

Numerical modeling of local scour of non-uniform graded sediment for two arrangements of pile groups

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International Journal of Sediment Research 2023年第4期38卷 597-614页

作者： Saeid Okhravi Saeed Gohari Mahdi Alemi Rodrigo maia Institute of Hydrology Slovak Academy of Sciences Department of Water Engineering College of Agriculture Bu-Ali Sina University Departamento de Engenharia Civil Faculdadede Engenharia Universidade do Porto CIIMAR-Interdisciplinary Centre of Marine and Environmental Research University of Porto

A three-dimensional(3D) non-hydrostatic numerical model is established to investigate local scour around four aligned circular piles in uniform and non-uniform sediment mixtures and to provide information for improving scour countermeasures design. In the current study, unsteady Reynolds averaged Navier-Stokes(URANS) equations along with a Re-normalization Group(RNG) k-ε model were applied to simulate the flow field. A non-uniform sediment transport model was applied to estimate the bedload transport. The simulations lasted up to 8 h. The laboratory results of a reference single pile case in uniform and non-uniform sediment were utilized to validate the simulation results of bed elevation changes and time evolution of scour depth and reflected a good agreement. The influence of pile spacing for two arrangements of pile groups, one column(tandem) and two columns(nontandem) of four aligned piles, on spatial/temporal variations of the bed surface in both sediment bed configurations are discussed in detail. The results reveal the significant effects of the pile spacing on the flow field and patterns of scour hole formation and sediment deposition. In general, lower pile spacing results in more scour upstream of the front pile(s) and shifts deposition more downstream due to the existence of higher energy in the wake region of the piles for both sediment types. Side scouring dominates for non-uniform sediment around each pile due to flow deviating because of the presence of relatively larger particles in front of the pile(s). For non-uniform sediment, deposition begins to develop at the exit area of the scour hole and enhances boundary resistance to scour. The knowledge gained from this study is suitable for the accurate determination of riprap dimensions around the front pile(s)and rear piles in a pile group.

关键词： Local bridge pier scour Non-uniform sediment Numerical modeling Pile groups Pile spacing Sediment transport

Stability and convergence of the variable directions difference scheme for one nonlinear two-dimensional model

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International Journal of Biomathematics 2015年第5期8卷 31-51页

作者： Temur Jangveladze Zurab Kiguradze Mikheil Gagoshidze maia Nikolishvili Ilia Vekua Institute of Applied Mathematics of Ivane Javakhishvili Tbilisi State University2 University Street 0186 Tbilisi Georgia Ilia Vekua Institute of Applied Mathematics of Ivane Javakhishvili Tbilisi State University 2 University Street 0186 Tbilisi Georgia Sokhumi State University12 Politkovskaya Street 0186 Tbilisi Georgia Ivane Javakhishvili Tbilisi State University 2 University Street 0186 Tbilisi Georgia

The system of two-dimensional nonlinear partial differential equations is considered. This system describes the vein formation in meristematic tissues of young leaves. Variable directions difference scheme is constructed and investigated. Absolute stability regarding space and time steps of scheme is shown. The convergence statement for the constructed scheme is proved. Rate of convergence is given. Various numerical experiments are carried out and results of some of them are considered in this paper. Comparison of numerical experiments with the results of the theoretical investigation is given too.

关键词： Variable directions difference scheme nonlinear partial differential equations stability convergence vein formation.

Elastically restrained Bernoulli-Euler beams applied to rotary machinery modelling

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Acta Mechanica Sinica 2011年第1期27卷 56-62页

作者： Tiago A.N.Silva Nuno M.M.maia ISEL Polytechnic Institute of LisbonDepartment of Mechanical EngineeringRua Conselheiro Emídio Navarro IDMEC-IST Technical University of LisbonDepartment of Mechanical Engineering

Facing the lateral vibration problem of a machine rotor as a beam on elastic supports in bending,the authors deal with the free vibration of elastically restrained Bernoulli-Euler beams carrying a finite number of concentrated elements along their *** on Rayleigh’s quotient,an iterative strategy is developed to find the approximated torsional stiffness coefficients,which allows the reconciliation between the theoretical model results and the experimental ones,obtained through impact *** mentioned algorithm treats the vibration of continuous beams under a determined set of boundary and continuity conditions, including different torsional stiffness coefficients and the effect of attached concentrated masses and rotational inertias, not only in the energetic terms of the Rayleigh’s quotient but also on the mode shapes,considering the shape functions defined in *** loading cases are examined and examples are given to illustrate the validity of the model and accuracy of the obtained natural frequencies.

关键词： Transverse vibration of beams · Elastic supports · Torsional stiffness coefficients

Epidemiology of functional gastrointestinal disorders in infants and toddlers: A systematic review

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World Journal of Gastroenterology 2016年第28期22卷 6547-6558页

作者： Ana Paula Ferreira-maia Alicia Matijasevich Yuan-Pang Wang Institute and Department of Psychiatry (LIM-23) University of S?o Paulo Medical School Department of Preventive Medicine University of S?o Paulo Medical School

AIM: To assess the functional gastrointestinal disorders(FGID) prevalence in infants and toddlers. METHODS: Pub Med, EMBASE, and Scopus were searched for original articles from inception to February 2016. The literature search was made in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses(PRISMA). For inclusion, each study had to report epidemiological data of FGID on children up to 4 years old and contain standardized outcome Rome Ⅱ or Ⅲ criteria. The overall quality of included epidemiological studies was evaluated in accordance to Loney's proposal for prevalence studies of health literature. Two reviewers assessed each study for inclusion and extracted data. Discrepancies were reconciled through ***: It was identified a total of 101 articles through the databases and two through the manual search. A total of 28 articles fulfilled the eligibility criteria. After reading the full articles, 13 of them were included in the present review. Twelve studies were written in English and one in Chinese, and published between 2004 and 2015. Eight articles(61.5%) were performed in Europe, three(23.1%) in America and two(15.4%) in Asia. Sample size varied between 45 and 9660 subjects. Cross-sectional frequency was reported in majority of studies(k = 9) and four studies prospectively followed the subjects. 27.1% to 38% of participants have met any of Rome's criteria for gastrointestinal syndromes, of those 20.8% presented two or more FGID. Infant regurgitation and functional constipation were the most common FGID, ranging from less than 1% to 25.9% and less than 1% to 31%, respectively. Most included studies were of moderate to poor data quality with respect to absence of confidential interval for prevalence rate and inadequate sampling ***: The scarcity and heterogeneity of FGID data call for the necessity of well-designed epidemiological research in different levels of pediatric practice and refinement of diagnosti

关键词： Infant Functional gastrointestinal disorders Epidemiology Prevalence Toddler

Isolation, Characterization And Identification of Probiotic Bacteria from Chinese Soft-shell Turtle(Trionyx Sinensis)

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Isolation, Characterization And Identification of Probiotic ...

作者： Claudia Rodrighero maia 宁波大学

学位级别：硕士

中华鳖是中国和东南亚国家养殖最为普遍的养殖鳖种,中国是世界中华鳖养殖产量最高的国家,中华鳖养殖年产量达7000吨,全国有各类龟鳖养殖场数千个,重要分成在长江以南各省。随着中华鳖集约化养殖的快速发展,养殖中华鳖各类疾病发生频繁,... 详细信息

中华鳖是中国和东南亚国家养殖最为普遍的养殖鳖种,中国是世界中华鳖养殖产量最高的国家,中华鳖养殖年产量达7000吨,全国有各类龟鳖养殖场数千个,重要分成在长江以南各省。随着中华鳖集约化养殖的快速发展,养殖中华鳖各类疾病发生频繁,主要包括气单胞菌、爱德华菌、变形杆菌等各类细菌。抗生素由于存在诱发耐药性等种类弊病,在水产上的使用受到诸种限制。近年来,各类有益微生物制剂作为疾病控制和预防的替代手段,日益受到重视。本文拟从养殖中华鳖体内分离和鉴定天然栖息的有益菌,以期为中华鳖疾病防控提供新的途径。从养殖中华鳖中分离到73株不同菌株,用嗜水气单胞菌ATCC 7966和BSK10作为指示菌,用于筛选抗病原菌的颉抗菌。共分离到18株对气单胞菌有明显抑菌效果的菌株,对嗜水气单胞菌的抑菌圈大于6mm,用纸片法测定阳性菌培养上清的抑菌力,抑菌圈均为6 mm以上(纸片直径4mm)。对18个阳性菌株用16s r RNA通用引物进行了PCR克隆,经序列分析,鉴定了上述菌株,共分到假单胞菌杆菌(Pseudomonas sp)、黄杆菌(Flavobacterium sp)、紫色杆菌(Janthinobacterium sp.)、波单胞菌(Brevundimonas vesicularis)、芽孢杆菌(Bacillus sp),滕黄微球菌(Micrococcus luteus)、,梭菌(Clostridiales bacterium)、微球菌(Micrococcaceae bacterium)、肠球菌(Enterococcus sp)、土壤杆菌(Agrobacterium sp)、金黄杆菌(Chryseobacterium sp)等。上述有抑菌活性菌株中,有17株可在营养肉汤中快速生长,20小时的菌浓度可达105-108 CFU.m L-1,表明这些菌株适合大量培养,具备规模化培养和作为生产应用的可能性。这些从中华鳖体内分离的天然栖息菌有望作为中华鳖养殖中的有益菌使用,提高中华鳖养殖健康水平、减少病害发生、提高免疫力。此外,从中华鳖体内分离到蜡样微球菌(Micrococcus cereus),该菌对革兰阳性菌和阴性菌均有较强的抑菌力,计划对该菌进行进一步研究,并摸索蜡样微球菌在中华鳖室内和养殖疾病防控中应用条件。.

关键词：中华鳖有益菌筛选 16srRNA 鉴定