Photometric and spectroscopic analysis of YY CrB     

A. Essam  S.M. Saad  M.I. Nouh  A. Dumitrescu  M.M. El-Khateeb  A. Haroon 《New Astronomy》2010,15(2):227-233

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ROCADA: a gridded daily climatic dataset over Romania (1961–2013) for nine meteorological variables     

Alexandru Dumitrescu  Marius-Victor Birsan 《Natural Hazards》2015,78(2):1045-1063

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The study of binary systems with pulsating components using the frequency-modulation theory     

Alexandru Pop  Vlad Turcu 《Astrophysics and Space Science》1993,204(2):233-241

The effect of the orbital motion on the light curve of a pulsating star has been evaluated by means of the amplitude and phase spectra synthesis based on the instantaneous pulsation phase concept. The role of the binary system's geometry (circular or eccentric orbit) and the possibility of binarity diagnosis are also emphasized.  相似文献   

Publisher's announcement     

Alexandru Baltag  Lawrence Moss 《Surveys in Geophysics》1990,11(4):iii-iii

Publisher's announcement  相似文献   

Air temperature trend and the impact on winter wheat phenology in Romania   总被引：4，自引：0，他引：4  

Adina-Eliza Croitoru  Iulian-Horia Holobaca  Catalin Lazar  Florin Moldovan  Alexandru Imbroane 《Climatic change》2012,111(2):393-410

Air temperature variability and trends in Romania were analysed using monthly, seasonal, and annual datasets. Temperature data of winter wheat season were also analysed. The Mann-Kendall test, Sen’s slope estimate, the sequential version of the Mann-Kendall test, the Pettitt test and spatial and temporal hierarchical cluster analyses were used. First, the datasets were checked for changing points. The 106-year period was divided into two long periods of 100 years each to verify the importance of a very short interval in changing of general trends; after that it was divided into three shorter periods of 35–36 years each. The main conclusions are as follows: the 6 years making up the difference between the two long periods are very important in the context of the recent global warming; the three shorter periods analysis indicate some fluctuations rather than continuous warming. The latest short period is the most relevant for global warming. Spatial hierarchical cluster analysis indicated the existence of two distinctive groups. One of them, which includes stations in the south-east part of the country, seems to be influenced by the Black Sea surface temperature. Temporal hierarchical cluster analysis reveals that annual data series have the closest relation with the summer data series. Further, the impact of temperature changes on winter wheat phenology was determined using a phenology simulation performed with the model from the Decision Support System for Agrotechnology Transfer v. 4.0.2.0 platform. Earlier occurrences of anthesis and maturity were noticed for several regions in the country.  相似文献   

Neogene-Quaternary Volcanic forms in the Carpathian-Pannonian Region: a review   总被引：1，自引：0，他引：1  

Jaroslav Lexa  Ioan Seghedi  Karoly Németh  Alexandru Szakács  Vlastimil Koneĉny  Zoltan Pécskay  Alexandrina Fülöp  Marinel Kovacs 《Central European Journal of Geosciences》2010,2(3):207-270

Neogene to Quaternary volcanic/magmatic activity in the Carpathian-Pannonian Region (CPR) occurred between 21 and 0.1 Ma with a distinct migration in time from west to east. It shows a diverse compositional variation in response to a complex interplay of subduction with rollback, back-arc extension, collision, slab break-off, delamination, strike-slip tectonics and microplate rotations, as well as in response to further evolution of magmas in the crustal environment by processes of differentiation, crustal contamination, anatexis and magma mixing. Since most of the primary volcanic forms have been affected by erosion, especially in areas of post-volcanic uplift, based on the level of erosion we distinguish: (1) areas eroded to the basement level, where paleovolcanic reconstruction is not possible; (2) deeply eroded volcanic forms with secondary morphology and possible paleovolcanic reconstruction; (3) eroded volcanic forms with remnants of original morphology preserved; and (4) the least eroded volcanic forms with original morphology quite well preserved. The large variety of volcanic forms present in the area can be grouped in a) monogenetic volcanoes and b) polygenetic volcanoes and their subsurface/intrusive counterparts that belong to various rock series found in the CPR such as calc-alkaline magmatic rock-types (felsic, intermediate and mafic varieties) and alkalic types including K-alkalic, shoshonitic, ultrapotassic and Na-alkalic. The following volcanic/subvolcanic forms have been identified: (i) domes, shield volcanoes, effusive cones, pyroclastic cones, stratovolcanoes and calderas with associated intrusive bodies for intermediate and basic calclkaline volcanism; (ii) domes, calderas and ignimbrite/ash-flow fields for felsic calc-alkaline volcanism and (iii) dome flows, shield volcanoes, maars, tuffcone/tuff-rings, scoria-cones with or without related lava flow/field and their erosional or subsurface forms (necks/ plugs, dykes, shallow intrusions, diatreme, lava lake) for various types of K- and Na-alkalic and ultra-potassic magmatism. Finally, we provide a summary of the eruptive history and distribution of volcanic forms in the CPR using several sub-region schemes.  相似文献   

The July urban heat island of Bucharest as derived from modis images   总被引：2，自引：1，他引：1  

S. Cheval  A. Dumitrescu 《Theoretical and Applied Climatology》2009,96(1-2):145-153

The urban heat island (UHI) of the city of Bucharest (Romania) is analyzed in terms of its extension, geometry, and magnitude using the surface thermal data provided by the moderate resolution imaging spectroradiometer (MODIS) sensors. An objective method is developed that allows to delineate the UHI. The study focuses on the months of July from the 2000–2006 time interval. The average surface temperatures obtained for each pixel (1 km resolution) were analyzed on cross-profiles that helped us to determine the outline of the UHI. The shifting points identified by the Rodionov test in the temperature series of each profile were considered as possible limits of the UHI. Seemingly, the land cover has a major influence on the extension and the geometry of the Bucharest UHI in July. The magnitude of the heat island was calculated by comparing the average temperature inside its limits and the average temperature of the 5 km (a) and of the 10 km (b) buffers around it. The thermal difference between the UHI and the surrounding area of Bucharest is higher and more variable during the daytime, and is noticeably related to the land cover.  相似文献   

Post-collisional Tertiary–Quaternary mafic alkalic magmatism in the Carpathian–Pannonian region: a review     

Ioan Seghedi  Hilary Downes  Orlando Vaselli  Alexandru Szakcs  Kadosa Balogh  Zoltn Pcskay 《Tectonophysics》2004,393(1-4):43

Mafic alkalic volcanism was widespread in the Carpathian–Pannonian region (CPR) between 11 and 0.2 Ma. It followed the Miocene continental collision of the Alcapa and Tisia blocks with the European plate, as subduction-related calc-alkaline magmatism was waning. Several groups of mafic alkalic rocks from different regions within the CPR have been distinguished on the basis of ages and/or trace-element compositions. Their trace element and Sr–Nd–Pb isotope systematics are consistent with derivation from complex mantle-source regions, which included both depleted asthenosphere and metasomatized lithosphere. The mixing of DMM-HIMU-EMII mantle components within asthenosphere-derived magmas indicates variable contamination of the shallow asthenosphere and/or thermal boundary layer of the lithosphere by a HIMU-like component prior to and following the introduction of subduction components.Various mantle sources have been identified: Lower lithospheric mantle modified by several ancient asthenospheric enrichments (source A); Young asthenospheric plumes with OIB-like trace element signatures that are either isotopically enriched (source B) or variably depleted (source C); Old upper asthenosphere heterogeneously contaminated by DM-HIMU-EMII-EMI components and slightly influenced by Miocene subduction-related enrichment (source D); Old upper asthenosphere heterogeneously contaminated by DM-HIMU-EMII components and significantly influenced by Miocene subduction-related enrichment (source E). Melt generation was initiated either by: (i) finger-like young asthenospheric plumes rising to and heating up the base of the lithosphere (below the Alcapa block), or (ii) decompressional melting of old asthenosphere upwelling to replace any lower lithosphere or heating and melting former subducted slabs (the Tisia block).  相似文献   

What Ångström—Prescott equation tells us about the cloud and clear-sky climatologies?     

Paulescu  Marius  Badescu  Viorel  Budea  Sanda  Dumitrescu  Alexandru 《Theoretical and Applied Climatology》2022,147(1-2):239-250

Theoretical and Applied Climatology - The Ångström–Prescott equation defines generically the relationship between solar energy available at ground level and sunshine duration. From...  相似文献   

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Jan‐Hendrik May  He‐Qing Huang  Toshiyuki Fujioka  David Fink  Alexandru Codilean  Guo‐An Yu  Yuanxu Ma  Gerwin Wulf  Jing Gu 《地球表面变化过程与地形》2018,43(3):i-i

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