检索结果-南通市图书馆

Evaluating grant proposals:lessons from using metrics as screening device

在线全文

学校读者我要写书评

暂无评论

Journal of Data and Information Science 2023年第2期8卷 66-92页

作者： Katerina Guba alexey Zheleznov Elena Chechik Center for Institutional Analysis of Science and Education European University at Saint PetersburgGagarinskaya 6/1A Saint Petersburg 191178Russian Federation

Purpose:This study examines the effects of using publication-based metrics for the initial screening in the application process for a project *** key questions are whether formal policy affects the allocation of funds to researchers with a better publication record and how the previous academic performance of principal investigators is related to future project ***/methodology/approach:We compared two competitions,before and after the policy raised the publication threshold for the principal *** analyzed 9,167 papers published by 332 winners in physics and the social sciences and humanities(SSH),and 11,253 publications resulting from each funded ***:We found that among physicists,even in the first period,grants tended to be allocated to prolific authors publishing in high-quality *** contrast,the SSH project grantees had been less prolific in publishing internationally in both periods;however,in the second period,the selection of grant recipients yielded better results regarding awarding grants to more productive authors in terms of the quantity and quality of *** was no evidence that this better selection of grant recipients resulted in better publication records during grant ***:This study contributes to the discussion of formal policies that rely on metrics for the evaluation of grant *** Russian case shows that such policy may have a profound effect on changing the supply side of applicants,especially in disciplines that are less suitable for metric-based *** spite of the criticism given to metrics,they might be a useful additional instrument in academic systems where professional expertise is corrupted and prevents allocation of funds to prolific researchers.

关键词： Grant funding Research evaluation Publication-based metrics Funding allocation

Low-frequency laboratory measurements of the elastic properties of solids using a distributed acoustic sensing system

在线全文

学校读者我要写书评

暂无评论

Journal of Rock Mechanics and Geotechnical Engineering 2023年第9期15卷 2330-2338页

作者： Vassily Mikhaltsevitch Maxim Lebedev Roman Pevzner alexey Yurikov Konstantin Tertyshnikov Curtin University GPO Box U1987PerthWA 6845Australia Centre for Sustainable Energy and Resources Edith Cowan University270 Joondalup DrJoondalupWA 6027Australia

In recent decades,low-frequency(LF)experiments based on the forced-oscillation(FO)method have become common practice in many rock physics laboratories for measuring the elastic and anelastic properties of ***,the use of the electronic displacement sensors in traditional acquisition systems of FO devices such as conventional capacitive transducers or strain gauges seriously limits both the efficiency and productivity of LF measurements,and,due to the limited contact area of the displacement sensors with a sample under test,increases the requirements for sample *** this paper,we present the first results obtained in the development of a new laboratory method elaborated to measure the elastic properties of *** method is a further development of the FO method where traditional data acquisition is replaced by acquisition based on fiber-optic distributed acoustic sensing(DAS)*** new method was tested in a laboratory study using two FO setups designed for measurements under uniaxial and confining *** study was carried out on a sample made from polymethyl methacrylate(PMMA)and an aluminium standard,first under uniaxial pressure at FO frequencies of 1,10,30,60 and 100 Hz,and then under confining pressure at an FO frequency of 1 *** uniaxial and confining pressures were equal to 10 MPa,and the strain in the PMMA sample in all measurements did not exceed 4×10^(-8).The performance of DAS acquisition was compared with the measurements conducted at a strain of 1×10^(-6) using the traditional FO method based on the use of semiconductor strain gauges and the ultrasonic *** results of the DAS measurements are in good agreement with the FO measurements carried out using semiconductor strain gauges and with the literature data.

关键词： Elasticity and anelasticity Acoustic properties Fourier analysis Wave propagation

Late Paleozoic alkaline magmatism in Western Transbaikalia,Russia:Implications for magma sources and tectonic settings

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Geoscience Frontiers 2020年第4期11卷 1289-1303页

作者： Ivan Izbrodin Anna Doroshkevich Mikhail Rampilov alexey Elbaev German Ripp Geological Institute Siberian Branch of the Russian Academy of SciencesRussia V.S.Sobolev Institute of Geology and Mineralogy Siberian Branch of the Russian Academy of SciencesRussia

This paper presents the results of geochronological(40Ar-39Ar,U-Pb SHRIMP Ⅱ),petrological and geochemical studies of the Late Paleozoic complexes of alkaline rocks(Zimovechinsky,Tuchinsky and Koma) located within the Vitim Plateau(the western part of the Mongol-Okhotsk Orogenic Belt).The rocks were formed at 310-280 *** is coeval with Late Paleozoic magmatism within the Central Asian Orogenic *** εNd(T) values show large variations from-2.1 to +3.3 as well as the initial Sr(I) isotopic ratios from 0.7042 to 0.7138,that demonstrate strong isotopic heterogeneity of the magmatic *** geochemical characteristics of the rocks show pronounced positive Pb and negative Ti,Zr-Hf anomalies that can be explained by involvement of the subducted component in primary *** rocks intruded in a setting of extension at the active continental margin of the Siberian Craton during subduction of Mongol-Okhotsk oceanic crust under the Siberian Craton.

关键词： Nepheline-bearing and nepheline-free syenites Geochronological and isotope data Late paleozoic magmatism Sources Central Asian orogenic belt

Authigenic titanite in weathered basalts: Implications for paleoatmospheric reconstructions

在线全文

学校读者我要写书评

暂无评论

Geoscience Frontiers 2020年第6期11卷 2183-2196页

作者： alexey A.Novoselov Dailto Silva Carlos Roberto de Souza Filho Institute of Applied Economic Geology Universidad de ConcepcionConcepcionChile Institute of Geosciences University of CampinasCampinasSPBrazil

The stability of titanite is sensitive to temperature and partial pressure of *** finding of authigenic titanite grains in weathering regolith formed on Parana basalts,Brazil,under tropical climatic conditions,reveals the thermodynamically-driven conversion from calcite to titanite at elevated ambient *** unusual nowadays,this phase transition provides important implications for the understanding of silicate weathering in earlier geological *** types of secondary titanites were identified in the weathering profile of the study *** tiny grains of 10 μm are forming in the microscopic voids in the ***,large fractures filled with Fe-rich clay minerals contain bigger specimens of up to 170μ*** titanites of second type often coexist with chalcedony and *** carbonate minerals were found in the weathering *** sphene can be discriminated from other titanite types by its strong positive Eu anomaly,increased Al2 O3 content and low content of trace *** specific chemical composition and reactive transport modeling link this secondary mineral with dissolution of *** titanite precipitation is controlled by slow diffusion in poorly-aerated,highly-alkaline pore *** subaerial weathering of basaltic rocks provides a significant reservoir for atmospheric ***,the deposition of carbonate minerals is thermodynamically avoided at the stability field of *** demonstrate a complex feedback between CO2 and soil *** rise in pCO2 triggers the precipitation of calcite in the weathering regolith,but the greenhouse effect increasing the temperature can cease carbonate *** titanites were found in several paleosols and at least a part of them can be of weathering origin.

关键词： Titanite Sphene Calcite Paleosols Weathering Paleoclimates

Exploiting the quantum mechanically derived force field for functional materials simulations

在线全文

学校读者我要写书评

暂无评论

npj Computational Materials 2021年第1期7卷 1405-1413页

作者： alexey Odinokov Alexander Yakubovich Won-Joon Son Yongsik Jung Hyeonho Choi Samsung R&D Institute Russia(SRR) Samsung Electronics12 Dvintsev StreetMoscow 127018Russia Data and Information Technology Center Samsung ElectronicsHwaseong 18448Korea Samsung Advanced Institute of Technology(SAIT) Samsung Electronics130 Samsung-roYeongtong-guSuwon 16678Korea

The computational design of functional materials relies heavily on large-scale atomistic *** simulations are often problematic for conventional classical force fields,which require tedious and time-consuming parameterization of interaction *** problem can be solved using a quantum mechanically derived force field(QMDFF)—a system-specific force field derived directly from the first-principles *** present a computational approach for atomistic simulations of complex molecular systems,which include the treatment of chemical reactions with the empirical valence bond *** accuracy of the QMDFF is verified by comparison with the experimental properties of liquid *** illustrate the capabilities of our methodology to simulate functional materials in several case studies:chemical degradation of material in organic light-emitting diode(OLED),polymer chain packing,material morphology of organometallic *** presented methodology is fast,accurate,and highly automated,which allows its application in diverse areas of materials science.

关键词： functional field quantum

Production of the X(4014)as the Spin-2 Partner of X(3872)in e^(+)e^(-)Collisions

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics Letters 2024年第3期41卷 30-36页

作者： Pan-Pan Shi Vadim Baru Feng-Kun Guo Christoph Hanhart alexey Nefediev CAS Key Laboratory of Theoretical Physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing 100190China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100049China Departamento de F′ısica Te′orica and IFIC Centro Mixto Universidad de Valencia-CSIC Institutos de Investigaci′on de PaternaAptdo.2208546071 ValenciaSpain Institut fur Theoretische Physik II Ruhr-Universitat BochumD-44780 BochumGermany Peng Huanwu Collaborative Center for Research and Education Beihang UniversityBeijing 100191China Institute for Advanced Simulation Institut fur Kernphysik and Julich Center for Hadron PhysicsForschungszentrum JulichD-52425 JulichGermany Jozef Stefan Institute Jamova 391000LjubljanaSlovenia CeFEMA Center of Physics and Engineering of Advanced MaterialsInstituto Superior T′ecnicoAvenida Rovisco Pais 11049-001 LisboaPortugal

In 2021,the Belle collaboration reported the first observation of a new structure in theψ(2S)γfinal state produced in the two-photon fusion *** the hadronic molecule picture,this new structure can be associatedwith the shallow isoscalar D*D* bound state and as such is an excellent candidate for the spin-2 partner of the X(3872)with the quantum numbers J^(PC)=2^(++)conventionally named X_(2).

关键词： process X(3872) Collisions

Open-data-driven embeddable quality management services for map-based web applications

在线全文

学校读者我要写书评

暂无评论

Big Earth Data 2018年第4期2卷 395-422页

作者： alexey Noskov Alexander Zipf Institute of Geography Heidelberg UniversityHeidelbergGermany

Various map-centered web services facilitate citizens’*** applications exist for many years *** to simplification and improvement of technologies supporting WebGIS,mapbased services become more popular and important *** quality assurance for such services is a significant *** many of such applications intensively use open data,approaches focused on open solutions are *** work proposes a data-quality concept,which is based on intrinsic and comparable ***(OSM)allows intrinsic data ***,it is used as a reference dataset for quality assessment of public-sector-information Open Data *** point(EDP)-based statistics enables to filter out lowquality Open Data features.A data-type model carries out the inventory of OSM *** comparison of raster web-map tile file sizes and calculation of a simplified data quality indicator make it possible to specify acceptable data quality *** instances of quality assurance web services incorporate data features with acceptable *** work provides all required software and data for the deployment of such services under liberal *** instructions allow users to adopt the proposed solutions for their *** generic use cases illustrate the advantages of the introduced shared web services.

关键词： Data quality big spatial data WebGIS REST API computer vision

Thermal state calculation of chamber in small thrust liquid rocket engine for steady state pulsed mode

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2019年第2期32卷 253-262页

作者： alexey Gennadievich VOROBYEV Svatlana Sergeevna VOROBYEVA Lihui ZHANG Evgeniy Nikolaevich BELIAEV Department of Rocket Engines Moscow Aviation Institute School of Astronautics Beihang University

This paper presents a method of thermal state calculation of combustion chamber in small thrust liquid rocket engine. The goal is to predict the thermal state of chamber wall by using basic parameters of engine: thrust level, propellants, chamber pressure, injection pattern, film cooling parameters, material of wall and their coating, etc. The difficulties in modeling the startup and shutdown processes of thrusters lie in the fact that there are the conjugated physical processes occurring at various parameters for non-design conditions. A mathematical model to predict the thermal state of the combustion chamber for different engine operation modes is developed. To simulate the startup and shutdown processes, a quasi-steady approach is applied by replacing the transient process with time-variant operating parameters of steady-state processes. The mathematical model is based on several principles and data commonly used for heat transfer modeling: geometry of flow part, gas dynamics of flow, thermodynamics of propellants and combustion spices, convective and radiation heat flows, conjugated heat transfer between hot gas and wall, and transient approach for calculation of thermal state of construction. Calculations of the thermal state of the combustion chamber in single-turn-on mode show good convergence with the experimental results. The results of pulsed modes indicate a large temperature gradient on the internal wall surface of the chamber between pulses and the thermal state of the wall strongly depends on the pulse duration and the interval.

关键词： Combustion chamber Film cooling Mathematical model Nonstationary thermal mode Small thrust liquid rocket engine Steady pulse mode Thermal state

Asymmetry ratio as a parameter of Eu^3＋ local environment in phosphors

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 2018年第5期36卷 474-481页

作者： Ilya E. Kolesnikov alexey V. Povolotskiy Daria V. Mamonova Evgeny Yu. Kolesnikov alexey V. Kurochkin Erkki Lahderanta Mikhail D. Mikhailov Saint Petersburg State University 7/9 Universitetskaya nab. 199034 St.petersburg.Russia Lappeenranta University of Technology LUT Skinnarilankatu 34 53850 Lappeenranta Finland Scientific and Technological Institute of Optical Material Science VNTs S. I. Vavilov State Optical Institute Babushkina 36-1 192171 St. Petersburg Russia Volga State University of Technology Lenin Sq. 3 424000 Yoshkar-Ola Russia

Study of the local environment of certain ion is quite a complex problem. Due to the unique luminescent properties, Eu^3＋ ions can be used as a structural probe. In this paper, effect of doping concentration,excitation wavelength and excitation mechanism on asymmetry ratio was systematically studied using Y3Al5O12：Eu^3＋, YVO4：Eu^3＋ and Y2O3：Eu^3＋nanophosphors. The asymmetry ratio gives information about the local surrounding and environmental changes around the Eu^3＋ ions. Asymmetry ratios of YAG：Eu^3＋and YVO4：Eu^3＋ nanopowders were calculated using standard technique and the obtained average values were found to be 0.75 and 8.2, respectively. However, it is found that standard method of asymmetry ratio calculation is suitable only for samples where all Eu^3＋ ions occupy one site. The ＂multisite model＂ of asymmetry ratio calculation was developed and used for Y2O3：Eu^3＋ nanocrystalline powders. Average value of asymmetry ratio for Eu^3＋ ions occupied ＂normal＂ sites is 6.0 and for Eu^3＋ ions occupied ＂defect＂sites is 2.3.

关键词： Eu3+ Oxide powders Luminescence Asymmetry ratio Structural probe Rare earths