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Journal of forestry Research 2014年第3期25卷 591-596页

作者： Gopal Shukla Rajib Biswas A. p. Das Sumit Chakravarty Department of forestry Uttar Banga Krishi Viswavidyalaya Pundibari-736165 (Cooch Behar) West Bengal India Department of Botany University of North Bengal

from March 2007 to March 2009 we quantified plant diversity at Chilapatta Reserve forest in Terai Duars in the Indian eastern Himala-yas. We sampled stratified random nested quadrats. Species richness was 311, representing 167 genera and 81 families. The species diversity index and concentration of dominance of the forest were 2.20 and 0.0072, respectively. Shannon-Wiener index and evenness indices were 4.77 and 1.44, respectively. The Importance Value Index （IVI） of species ranged from 0.13 to 37.94. The estimated diversity indices indicated heterogene-ity of the forest in its composition, structure, function and dynamics. Rich forest plant diversity supports the need for continued conservation of tropical forests.

关键词： Terai Duars phyto-sociology plant diversity diversity indices

Nonexistence and Existence of Multiple positive Solutions for Superlinear Three-point Boundary Value problems via Index Theory

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Acta Mathematicae Applicatae Sinica 2008年第4期24卷 529-540页

作者： Bao-qiang Yan Donal O'Regan Ravi p. Agarwal Department of Mathematics Shandong Normal University Jinan 250014 China Department of Mathematics National University of Ireland Galway Ireland Department of Mathematical Science Florida Institute of Technology Melbourne Florida 32901 USA

This paper discusses both the nonexistence of positive solutions for second-order three-point boundary value problems when the nonlinear term f（t, x, y） is superlinear in y at y = 0 and the existence of multiple positive solutions for second-order three-point boundary value problems when the nonlinear term f（t, x,y） is superlinear in x at ＋∞.

关键词： Three-point boundary value problems cone fixed point index

The importance of source positions during radio fine structure observations

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Research in Astronomy and Astrophysics 2014年第7期14卷 831-842页

作者： Guennadi p.Chernov Yi-Hua Yan Qi-Jun fu Key Laboratory of Solar Activity National Astronomical ObservatoryChinese Academy of Sciences pushkov Institute of Terrestrial Magnetism Ionosphere and Radio Wave PropagationRussian Academy of Sciences (IZMIRAN)TroitskMoscow region142190Russia

The measurement of positions and sizes of radio sources in the observations of the fine structure of solar radio bursts is a determining factor for the selection of the radio emission mechanism. The identical parameters describing the radio sources for zebra structures（ZSs） and fiber bursts confirm there is a common mechanism for both structures. It is very important to measure the size of the source in the corona to determine if it is distributed along the height or if it is point-like. In both models of ZSs（the double plasma resonance（DpR） and the whistler model） the source must be distributed along the height, but by contrast to the stationary source in the DpR model, in the whistler model the source should be moving. Moreover, the direction of the space drift of the radio source must correlate with the frequency drift of stripes in the dynamic spectrum. Some models of ZSs require a local source, for example,the models based on the Bernstein modes, or on explosive instability. The selection of the radio emission mechanism for fast broadband pulsations with millisecond duration also depends on the parameters of their radio sources.

关键词： solar flare -- radio emission -- zebra-pattern -- spike-bursts

Macrobioerosion and Microbioerosion in Marine Molluscan Shells from Holocene and Modern Beaches (39°-40°S, South of Buenos Aires province, Argentina)

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Acta Geologica Sinica(English Edition) 2017年第4期91卷 1215-1230页

作者： Melisa p. CHARO Jose L. CAVALLOTTO Guillermo ACENOLAZA Instituto Superior de Correlacion Geologica (INSUGEO/CONICET-UNT) Miguel Lillo 205 4000 Tucuman Argentina Servicio de Hidrografia Naval Av. Montes de Oca 2124 C1270ABWBuenos Aires Argentina

The marine sediments of the area of Verde peninsula - Jabali Island （39°28＇S/62°19%V-40°28＇ S/62°11＇W） Holocene in age （3-2 ky）, and modern beaches contain a significant amount of bioeroded mollusc shells. fifteen sites were analyzed, in which 20.11% of the mollusc shells （2168 valves） presented bioerosion traces, in 54 species （30 bivalves and 24 gastropods）. fourteen ichnogenera were reported： Entobia, Maeandropolydora, Iramena, Caulostrepsis, pennatichnus, pinaceocladichnus, Trypanites, and Gastrochaenolites （Domichnia）, Gnathichnus and Radulichnus （pascichnia）, finichnus and Centrichnus （fixichnia）, Oichnus （praedicnia）（macrobioerosion）, y Semidendrina （microbioerosion）, the latter is first reported in mollusc shells in Argentina. Eleven ichnospecies were identified finichnus peristroma, Maeandropolydora sulcans, Gnathichnus pentax, pinaceocladichnus onubensis, Caulostrepsis taeniola, Centrichnus eccentricus, Radulichnus inopinatus, Oichnus simplex, Oichnus paraboloides, Oichnus gradatus, and Gastrochaenolites torpedo （lithic remains）. The dominant ichnogenera in the Holocene deposits are Iramena, Entobia and Oichnus. The same ichnogenera are constant with different abundance in the modern beaches, and increasing representation of pinaceocladichnus and pennatichnus. The dominant ichnofacies in the Holocene deposits is Trypanites, revealing a benthonic marine community composed of cheilostome bryzoans, clionaid sponges, predator gastropods, regular echinoids, polychaete annelids, bivalves, thallophytas and fungi. Generally, the area was described as a sublittoral, low-energy, stable environment with high rate of oxygenation, and sandy bottoms, with rocky bottoms at Villalonga locality.

关键词： molluscan bioerosion Holocene south of Buenos Aires province

Evaluation of the heat transfer performance of helical coils of non-circular tubes

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Journal of Zhejiang University-Science A(Applied physics & Engineering) 2011年第1期12卷 63-70页

作者： Jundika C.KURNIA Agus p.SASMITO Arun S.MUJUMDAR Department of Mechanical Engineering National University of Singapore Mineral Metal and Material Technology CentreNational University of Singapore

This study addresses heat transfer performance of various configurations of coiled non-circular tubes, e.g., in-plane spiral ducts, helical spiral ducts, and conical spiral ducts. The laminar flow of a Newtonian fluid in helical coils made of square cross section tubes is simulated using the computational fluid dynamic approach. The effects of tube Reynolds number, fluid prandtl number, coil diameter, etc., are quantified and discussed. Both constant wall temperature and constant heat flux conditions are simulated. The effect of in-plane coil versus a cylindrical design of constant coil, as well as a conical coil design is discussed. Results are compared with those for a straight square tube of the same length as that used to form the coils. Advantages and limitations of using coiled tubes are discussed in light of the numerical results.

关键词： Coil Non-circular tube Heat transfer performance Mathematical model

Do we really understand the role of the oesophagogastric junction in disease?

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World Journal of Gastroenterology 2009年第2期15卷 144-150页

作者： Barry p McMahon Blair A Jobe John E pandolfino Hans Gregersen Department of Medical physics & Clinical Engineering Adelaide & Meath Hospital Tallaght Dublin 24 Ireland Associate professor of Surgery Director of Esophageal Diagnostics & Therapeutic Endoscopy Heart Lung and Esophageal Surgery Institute University of Pittsburgh Medical Centre Shadyside Medical Building Suite 715 Pittsburgh PA 15232 United States Division of Gastroenterology Northwestern Memorial University Hospital 676 N. St. Clair St. Suite 1400 Chicago IL 60611 United States professor of Biomechanics Director of Research Mech-Sense Aalborg Hospital Science and Innovation Centre Sφndre Skovvej 15 9000 Aalborg Denmark

The role of the oesophago-gastric junction (OGJ) in gastro-oesophageal reflux disease is still not completely understood, and there is no clinically used method to assess the OGJ function in patients. Only indirect methods such as pH studies are carried out. The OGJ acts a valve controlling the flow of solids, liquids and gases between the oesophagus and the stomach. Manometry can determine if a sphincter is toned or relaxed; but, it cannot confirm that the sphincter region is actually open. Distension is a new technique for measuring function in the OGJ. By measuring the cross-sectional area through the narrow region in the junction during distension of a catheter mounted bag, much more information on the opening and closing patterns of the junction can be determined. This technique has already been demonstrated to show changes in the OGJ after surgical treatments for reflux disease. New measurement ideas around the concept of distending the OGJ offer new hope that a clinically useable test for compliance at the junction can be developed and could potentially help in determining appropriate therapy.

关键词： Achalasia Distensibility Impedance planimetry Intraluminal impedance manometry Oesophago-gastric junction

Dynamic behavior of sandwich beams with different compositions of magnetorheological fluid core

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International Journal of Smart and Nano Materials 2021年第1期12卷 88-106页

作者： Subash Acharya Vipin J Allien puneet N p Hemantha Kumar Department of Mechanical Engineering NITK SurathkalMangaloreKarnatakaIndia

Magnetorheological fluid(MRf)sandwich beams belong to a class of adaptive beams that consists of MRf sandwiched between two or more face layers and have a great prospective for use in semi-active control of beam vibrations due to their superior vibration suppression *** composition of MRf has a strong influence on the MRf properties and hence affects the vibration characteristics of the *** this work,six MRf samples(MRfs)composed of combination of two particle sizes and three weight fractions of carbonyl iron pow-der(CIp)were prepared and their viscoelastic properties were *** MRfs were used to fabricate different MRf core sandwich ***,a sandwich beam with commer-cially available MRf 132DG fluid as core was *** modal parameters of the cantilever MRf sandwich beams were determined at different magnetic ***,sinusoidal sweep excitation tests were performed on these beams at different magnetic fields to investigate their vibration suppres-sion *** having larger particle size and higher weight fraction of CIp resulted in higher damping ratio and vibration ***,optimal particle size and weight fraction of CIp were determined based on the maximization of damping ratio and minimization of weight of MRf.

关键词： Smart materials adaptive sandwich beam damping ratio vibration suppression complex shear modulus

Radiopaque nano and polymeric materials for atherosclerosis imaging, embolization and other catheterization procedures

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Acta pharmaceutica Sinica B 2018年第3期8卷 360-370页

作者： Li Tian Linfeng Lu James feng Marites p.Melancon Department of Interventional Radiology The University of Texas MD Anderson Cancer Center Duke University Graduate School of Biomedical Sciences University of Texas Health Science Center at Houston

A review of radiopaque nano and polymeric materials for atherosclerosis imaging and catheterization procedures is presented in this paper. Cardiovascular diseases(CVDs) are the leading cause of death in the US with atherosclerosis as a significant contributor for mortality and morbidity. In this review paper, we discussed the physics of radiopacity and X-ray/CT, clinically used contrast agents,and the recent progress in the development of radiopaque imaging agents and devices for the diagnosis and treatment of CVDs. We focused on radiopaque imaging agents for atherosclerosis, radiopaque embolic agents and drug eluting beads, and other radiopaque medical devices related to catheterization procedures to treat CVDs. Common strategies of introducing radiopacity in the polymers, together with examples of their applications in imaging and medical devices, are also presented.

关键词： Radiopaque contrast nanoparticles and materials X-ray CT Vascular diseases Atherosclerosis plaque Stenosis Embolization Inferior vena cava filters

An Interacting Gauge field Theoretic Model for Hodge Theory: Basic Canonical Brackets

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Communications in Theoretical physics 2014年第6期61卷 715-728页

作者： R.Kumar S.Gupta R.p.Malik Department of physics Centre of Advanced Studies Banaras Hindu University DST Centre for Interdisciplinary Mathematical Sciences Faculty of Science Banaras Hindu University

We derive the basic canonical brackets amongst the creation and annihilation operators for a two(1 + 1)-dimensional(2D) gauge field theoretic model of an interacting Hodge theory where a U(1) gauge field(Aμ) is coupled with the fermionic Dirac fields(ψ andˉψ). In this derivation, we exploit the spin-statistics theorem, normal ordering and the strength of the underlying six infinitesimal continuous symmetries(and the concept of their generators) that are present in the theory. We do not use the definition of the canonical conjugate momenta(corresponding to the basic fields of the theory) anywhere in our whole discussion. Thus, we conjecture that our present approach provides an alternative to the canonical method of quantization for a class of gauge field theories that are physical examples of Hodge theory where the continuous symmetries(and corresponding generators) provide the physical realizations of the de Rham cohomological operators of differential geometry at the algebraic level.

关键词： continuous symmetries 2D QED with fermionic Dirac fields symmetry principles basic canoni-cal (anti)commutators creation and annihilation operators conserved charges as generators deRham cohomological operators Hodge theory

Effect of anisotropy on thermoelastic contact problem

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Applied Mathematics and Mechanics(English Edition) 2008年第4期29卷 501-510页

作者： Sakti pada Barik M.Kanoria p.K.Chaudhuri Departmemt of Mathematics Gobardanga Hindu CollegeKhantura24-Parganas(N)West BengalIndia Department of Applied Mathematics University of Calcutta92A.P.C.RoadKolkata-700009India

This paper is concerned with the stationary plane contact of an insulated rigid punch and a half-space which is elastically anisotropic but thermally conducting. The frictional heat generation inside the contact region due to the sliding of the punch over the half-space surface and the heat radiation outside the contact region are taken into account. With the help of fourier integral transform, the problem is reduced to a system of two singular integral equations. The equations are solved numerically by using Gauss-Jacobi and trapezoidal-rule quadratures. The effects of anisotropy and thermal effects are shown graphically.

关键词： transversely isotropic medium fourier transform frictional heating punch heat radiation singular integral equation fredholm integral equation