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Construction of Vertical Wind Profile from Satellite-derived Winds for Objective Analysis of Wind Field

Advances in Atmospheric Sciences 1992年第2期9卷 237-246页

作者： P.N.Mahajan d.r.talwalkar S.Nair S.rajamani Indian Institute of Tropical Meteorology Pune-411008Indian Institute of Tropical Meteorology Pune-411008Indian Institute of Tropical Meteorology Pune-411008Indian Institute of Tropical Meteorology Pune-411008

during summer Monex-79, a variety of observing systems viz. research ships, research aircrafts, constant pressure balloons and geostationary satellite etc. were deployed, besides the regular conventional observations. The purpose of these additional systems was to make the best possible data for the studies on various aspects of monsoon circulation. The present study is aimed at the construction of vertical wind profile using cloud motion vectors obtained from GOES (I-O) satellite and to examine whether the constructed wind profiles improves the representation of the monsoon system, flow pattern etc. in the objective analysis. For this purpose, climatological normals of the wind field are considered as the initial guess and the objective analyses of the wind field are made with, first using only data from conventional observations over land areas, subsequently including the constructed winds from cloud motion vectors. These analyses are then compared with the standard analyses of wind field obtained from Quick Look Atlas by T. N. Krishnamurti et al. (1979).It is inferred that satellite estimated mean wind profiles show good agreement with the mean wind profiles of the research ships with rMS errors less than 5 mps below 500 hPa and less than 8 mps above 500 hPa. It is further inferred that the inclusion of constructed winds shows a positive impact on the objective analysis and improvement is seen to be more marked in the data-sparse region of the Arabian sea. Analyses which include the constructed winds show better agreement with the standard analysis, than the analyses obtained using only conventional winds. Thus, results of our study suggest that the wind profiles constructed using cloud motion vectors are of potential use in objective analysis to depict the major circulation features over the Indian region.

关键词： Construction of Vertical Wind Profile from Satellite-derived Winds for Objective Analysis of Wind Field Wind

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Analysis-Prediction Experiments over Indian region Using Primitive Equation Barotropic Model

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Advances in Atmospheric Sciences 1992年第4期9卷 477-482页

作者： M.Y.Totagi d.r.talwalkar S.rajamani S.S.Singh Indain Institute of Tropical Meteorology Pune-411008 IndiaIndain Institute of Tropical Meteorology Pune-411008 IndiaIndain Institute of Tropical Meteorology Pune-411008 IndiaIndain Institute of Tropical Meteorology Pune-411008 India

The impact of initial guess and grid resolutions on the analysis and prediction has been investigated over the Indian region. For this purpose, an univariate objective analysis scheme and a primitive equation barotrop... 详细信息

关键词： over Analysis-Prediction Experiments over Indian region Using Primitive Equation Barotropic Model

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Some Experiments with Multivariate Objective Analysis Scheme of Heights and Winds Using Optimum Interpolation

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Advances in Atmospheric Sciences 1992年第4期9卷 431-440页

作者： S.K.Sinha S.G.Narkhedkar d.r.talwalkar S.rajamani Indian Institute of Tropical Meteorology Pune 411008 IndiaIndian Institute of Tropical Meteorology Pune 411008 IndiaIndian Institute of Tropical Meteorology Pune 411008 IndiaIndian Institute of Tropical Meteorology Pune 411008 India

A two-dimensional, multitvariate objective analysis scheme for simultaneous analysis of geopotential height and wind fields has been developed over Indian and adjoining region for use in numerical weather prediction. The height-height correlations calculated using daily data of four July months (1976-1979), are used to derive the other autocorrelations and cross-correlations assuming geostropic relationship. A Gaussian function is used to model the autocorrelation function. Since the scheme is multivariate the regression coefficients (weights) are *** the equator, the geostrophic approximation relating mass and wind is decoupled in a way similar to Bergman (1979). The objective analyses were made over Indian and adjoining region for 850, 700, 500, 300 and 200 hPa levels for the period from 4 July to 8 July 1979, 12 GMT. The analyses obtained using multivariate optimum interpolation scheme depict the synoptic situations satisfactorily. The analyses were also compared with the FGGE analyses (from ECMWF) and also with the station observations by computing the root mean square (rMS) errors and the rMS errors are comparable with those obtained in other similar studies.

关键词： In Some Experiments with Multivariate Objective Analysis Scheme of Heights and Winds Using Optimum Interpolation

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Use of Surface Observations to Estimate Upper Air Humidity for the Objective Analysis of relative Humidity over Indian region

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Advances in Atmospheric Sciences 1990年第4期7卷 491-501页

作者： S.K.Sinha d.r.talwalkar S.G.Narkhedkar P.L.Kulkarni S.Nair S.rajamani Indian Institute of Tropical Meteorology Pune-411008 India Indian Institute of Tropical Meteorology Pune-411008 IndiaIndian Institute of Tropical Meteorology Pune-411008 IndiaIndian Institute of Tropical Meteorology Pune-411008 IndiaIndian Institute of Tropical Meteorology Pune-411008 IndiaIndian Institute of Tropical Meteorology Pune-411008 India

In the present study objective analyses of relative humidity (rH) at surface and at the levels of 850, 700 and 500 hPa have been made using Gandin's (1963) optimum interpolation scheme. As the horizontal resolution of the radiosonde stations is rather inadequate for upper air humidity analysis, a scheme has been developed, following rasmussen (1982) to estimate the upper air rH from the surface observations like surface rH, present weather and cloud cover. The relative humidities at the levels 850, 700 and 500 hPa were related to the surface observations through three separate regression relations. The rH values at 850, 700 and 500 hPa levels were estimated from the surface rH, cloud coverage and present weather using the above regression relations and subsequently the objective analyses at 00 GMT for the period from 4 July to 8 July 1979, were made using these estimated data along with the observed radiosonde data. Objective analyses were also made for the same period using only the radiosonde data for comparison to study the impact of those estimated data. root mean square errors were computed for all the five days by interpolating rH at the observing stations from the objectively analysed field and comparing them with the actually observed rH to examine how best the analyses (with and without estimated data) fitted the observations. Lastly they were compared with satellite cloud pictures. This study shows that the estimated upper air rH values have positive impact on the analysis of upper air rH and could be used over radiosonde data sparse region and even over oceanic regions.

关键词： In rH over

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Simple collective model for nuclear chiral mode

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Frontiers of physics 2024年第2期19卷 1-5页

作者： r.V.Jolos E.A.Kolganova d.r.Khamitova Joint Institute for Nuclear research 141980 DubnaMoscow regionRussia dubna State University 141982 DubnaMoscow RegionRussia

A simple semi-analytical collective model that takes into account the limitations of the variation interval of the collective variable is suggested to describe the chiral dynamics in triaxial odd−odd nuclei with a fixed particle−hole *** collective Hamiltonian is constructed with the potential energy obtained using the postulated ansatz for the wave function symmetric with respect to chiral *** diagonalizing the collective Hamiltonian the wave functions of the lowest states are obtained and the evolution of the energy splitting of the chiral doublets in transition from chiral vibration to chiral rotation regime is demonstrated.

关键词： collective model nuclear chiral

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Ion heat transport in electron cyclotron resonance heated L-mode plasma on the T-10 tokamak

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Plasma Science and Technology 2024年第4期26卷 52-60页

作者： V.A.KrUPIN M.r.NUrGALIEV A.r.NEMETS I.A.ZEMTSOV S.d.SUNTSOV T.B.MYALTON d.S.SErGEEV N.A.SOLOVEV d.V.SArYCHEV d.V.rYJAKOV S.N.TUGArINOV N.N.NAUMENKO National research Centre“Kurchatov Institute” Moscow 123182Russia Bauman Moscow State Technical University Moscow 105005Russia Institution“Project Center ITEr” Moscow 123098Russia JSC“SOLAr” Minsk 220034Belarus

Anomalous ion heat transport is analyzed in the T-10 tokamak plasma heated with electron cyclotron resonance heating(ECrH) in second-harmonic extra-ordinary mode. Predictive modeling with empirical scaling for Ohmical heat conductivity shows that in ECrH plasmas the calculated ion temperature could be overestimated, so an increase of anomalous ion heat transport is required. To study this effect two scans are presented: over the EC resonance position and over the ECrH power. The EC resonance position varies from the high-field side to the low-field side by variation of the toroidal magnetic field. The scan over the heating power is presented with on-axis and mixed ECrH regimes. discharges with high anomalous ion heat transport are obtained in all considered regimes. In these discharges the power balance ion heat conductivity exceeds the neoclassical level by up to 10 times. The high ion heat transport regimes are distinguished by three parameters: the ratio Te/Ti, the normalized electron density gradient r/■, and the ion–ion collisionality νii~*. The combination of high Te/Ti, high νii~*, and r/■=6-10 results in values of normalized anomalous ion heat fluxes up to 10 times higher than in the low transport scenario.

关键词： tokamak L-mode electron cyclotron resonance heating ion heat transport

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The magnetosheath at high spectral resolution

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Earth and Planetary Physics 2024年第1期8卷 234-246页

作者： K.d.Küntz d.Koutroumpa W.r.dunn A.Foster F.S.Porter d.G.Sibeck B.Walsh The Henry A.rowland department of Physics and Astronomy Johns Hopkins University3701 San Martin DriveBaltimoreMD21218USA NASA Goddard Space Flight Center 8800 Greenbelt RoadGreenbeltMD 20771USA LATMOS-OVSQ CNRSUVSQ Paris-SaclaySorbonne Université11 Boulevard d’Alembert78280GuyancourtFrance department of Physics and Astronomy University College LondonLondonUK The Centre for Planetary Science at UCL/Birkbeck Gower StreetLondon WC1E 6BTUK Center for Astrophysics Harvard University&Smithsonian Institution60 Garden StreetCambridgeMA 02138USA Center for Space Physics Boston University110 Cummington MallBostonMAUSA

While we eagerly anticipate SMILE’s(Solar wind Magnetosphere Ionosphere Link Explorer)unprecedented X-ray observations of the Earth’s magnetosheath and the initiation of a new era of magnetospheric research,it seems appropriate to look ahead to the abilities of the next generation of astrophysics *** these,the Line Emission Mapper(LEM),a large aperture micro-calorimeter based mission,is currently planned to be able to observe the magnetosheath at high spectral resolution(~2 eV).With a field of view of~30′,LEM will allow higher spatial resolution and higher cadence measurement of the motion of a very small portion of the magnetopause over relatively short periods of time(multiple hours),complementing SMILE’s global ***’s strength is its spectral *** will be able to measure the abundance of a broad range of elements and ionization states,many of which are inaccessible to current in situ instruments,and will be able to separate the emission from the magnetosheath from the emission from the cosmic X-ray background using the difference in their relative velocities.

关键词： magnetosheath charge exchange solar wind abundances

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Uncovering Microstructure-Property relationship in Ni-Alloyed Fe-Mn-Al-C Low-density Steel Treated by Hot-rolling and Air-Cooling Process

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Acta Metallurgica Sinica(English Letters) 2024年第4期37卷 713-725页

作者： Xiaoliang Jia Guhui Gao Xiaolu Gui Chun Feng r.d.K.Misra Bingzhe Bai School of Mechanical Electronicand Control EngineeringBeijing Jiaotong UniversityBeijing100044China CNPC Tubular Goods research Institute Xi’an710077China Laboratory for Excellence in Advanced Steel research University of Texas at El PasoEl PasoTX79968-0521USA School of Material Science and Engineering Key Laboratory of Advanced Materials of Ministry of EducationTsinghua UniversityBeijing100084China

This paper focuses on the relationship between the microstructure and tensile properties of Fe-Mn-Al-C low-density high-strength steel processes by hot-rolling and air-cooling process. The microstructure analysis reveals that the combination of hot-rolling and air-cooling results in the formation of heterogeneous structures comprising different-sized γ and B_(2) phases in the low-density steel with the addition of nickel (Ni). The addition of Ni promotes the formation of the B_(2) phase and induces the pinning of B_(2) phase particles at the γ grain boundaries. This pinning effect effectively hinders the growth of the γ grains, leading to grain refinement. The tensile test results demonstrate that LdS-5Ni (low-density steel, LdS) exhibits excellent high strength and ductility combination, e.g., a tensile strength of 1535 MPa, yield strength of 1482 MPa, and elongation of 23.3%. These remarkable mechanical properties are primarily attributed to the combined strengthening contributions of grain refinement and duplex nano-sized second-phase precipitation hardening.

关键词： Low-density steel Microstructure B_(2)phase κ-Carbide Tensile properties

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Influence of Component Size on the Corrosion Behavior of Ti6Al4V Alloy Fabricated by Electron Beam Powder Bed Fusion

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Acta Metallurgica Sinica(English Letters) 2024年第1期37卷 159-168页

作者： Hongyu Zheng Xin Gai Yun Bai Wentao Hou Shujun Li Yulin Hao r.d.K.Misra rui Yang Institute of Metal research Chinese Academy of SciencesShenyang110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang110016China Nuclear Power Institute of China Chengdu610213China department of Metallurgical Materialsand Biomedical EngineeringThe University of Texas at El Paso500WUniversity AvenueEl PasoTX79968USA

The electrochemical behavior of Ti-6Al-4V with 1 mm and 16 mm thickness prepared by electron beam powder bed fusion(EB-PBF)was investigated in phosphate buffered *** results showed that EB-PBF Ti-6Al-4V with a larger component size was more resistant to corrosion compared to the smaller component,because of less acicularαʹphase content and moreβphase *** a non-equilibrium phase in the“high-energy state”,αʹphase has a greater susceptibility to corrode and reduces the corrosion resistance of the material,whileβphase improves corrosion resistance of titanium *** results show that the phase composition has a more significant effect on the corrosion performance than the grain size.

关键词： Electron beam powder bed fusion Ti6Al4V alloy Corrosion resistance Component size Polarisation

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Spatiotemporal dynamics in butterfly hybrid zones

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Insect Science 2024年第2期31卷 328-353页

作者： Ananda r.Pereira Martins Natalie B.Warren W.Owen McMillan rowan d.H.Barrett redpath Museum McGill University859 Sherbrooke Street WestMontrealQuebecCanada Smithsonian Tropical researchInstitute GamboaPanama CityPanama

Evaluating whether hybrid zones are stable or mobile can provide novelinsights for evolution and conservation biology. Butterflies exhibit high sensitivity to envi-ronmental changes and represent an important model system for the study of hybrid zoneorigins and maintenance. Here, we review the literature exploring butterfly hybrid zones,with a special focus on their spatiotemporal dynamics and the potential mechanisms thatcould lead to their movement or stability. We then compare different lines of evidenceused to investigate hybrid zone dynamics and discuss the strengths and weaknesses ofeach approach. Our goal with this review is to reveal general conditions associated withthe stability or mobility of butterfly hybrid zones by synthesizing evidence obtained us-ing different types of data sampled across multiple regions and spatial scales. Finally, wediscuss spatiotemporal dynamics in the context of a speciation/divergence continuum, therelevance of hybrid zones for conservation biology, and recommend key topics for futureinvestigation.

关键词： butterflies human impacts hybrid zones movement spatiotemporaldynamics stability

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