Quantification of Hydrogen in Natural Diamond by Secondary Ion Mass Spectrometry (SIMS)     

Kaminsky  F. V.  Shilobreeva  S. N.  Ber  B. Ya.  Kazantsev  D. Yu. 《Doklady Earth Sciences》2020,494(1):699-703

Doklady Earth Sciences - The volumetric concentration of hydrogen in two Brazilian diamonds is determined using secondary ion mass spectrometry and implantation of hydrogen into an external...  相似文献   

Configurations of community in flood risk management     

Aleksi Räsänen  Vera Kauppinen  Sirkku Juhola  Gunhild Setten  Haakon Lein 《Norsk geografisk tidsskrift. Norwegian journal of geography》2020,74(3):165-180

ABSTRACT

Despite a notable increase in the literature on community resilience, the notion of ‘community’ remains underproblematised. This is evident within flood risk management (FRM) literature, in which the understanding and roles of communities may be acknowledged but seldom discussed in any detail. The purpose of the article is to demonstrate how community networks are configured by different actors, whose roles and responsibilities span spatial scales within the context of FRM. Accordingly, the authors analyse findings from semi-structured interviews, policy documents, and household surveys from two flood prone areas in Finnish Lapland. The analysis reveals that the ways in which authorities, civil society, and informal actors take on multiple roles are intertwined and form different types of networks. By implication, the configuration of community is fuzzy, elusive and situated, and not confined to a fixed spatiality. The authors discuss the implications of the complex nature of community for FRM specifically, and for community resilience more broadly. They conclude that an analysis of different actors across scales contributes to an understanding of the configuration of community, including community resilience, and how the meaning of community takes shape according to the differing aims of FRM in combination with differing geographical settings.  相似文献   

The Dudica Epithermal Cu–Au Deposit (Republic of North Macedonia)     

Tasev  G.  Serafimovski  D.  Volkov  A. V.  Boev  B.  Djordjevic  T.  Kolitsch  U.  Serafimovski  T. 《Geology of Ore Deposits》2020,62(5):419-431

Geology of Ore Deposits - The Dudica deposit is located in the southern part of the Republic of North Macedonia (RNM), not far from the border with Greece in the Kozuf–Aridean volcanic...  相似文献   

The Structure of Potential Amur Tiger (Panthera tigris altaica) Habitats and Evaluation of Its Prey in Taipingou National Reserve (China) Based on Remote Sensing Data     

Shibing Zhu  Qu  Yi  Liu  Yingzhu  Dobrynin  D. V.  Sukhova  O. V.  Kotlov  I. P.  Sandlersky  R. B.  Yachmennikova  A. A.  Rozhnov  V. V. 《Izvestiya Atmospheric and Oceanic Physics》2020,56(9):1107-1126

Izvestiya, Atmospheric and Oceanic Physics - The population of the Amur tiger (Panthera tigris altaica) in the Russian Far East is currently being restored; young individuals are being spread...  相似文献   

The Oldest Vendian (Ediacaran) Fossils of Eurasia: U–Pb Isotope Age of the Basa Formation (Asha Group,Southern Urals)     

Razumovskiy  A. A.  Novikov  I. A.  Ryazantsev  A. V.  Rud’ko  S. V.  Kuznetsov  N. B.  Yashunskiy  Yu. V. 《Doklady Earth Sciences》2020,495(2):867-871

Doklady Earth Sciences - U–Th–Pb (SHRIMP II) isotopic dating of accessory zircons from Vendian (Ediacaran) ash tuffs of the Basa formation section (Asha Group, Southern Ural) was...  相似文献   

Mercury cycling during acid rain recovery at the forested Lesní potok catchment,Czech Republic     

Tomáš Navrátil  James B. Shanley  Jan Rohovec  Irena Dobešová  Šárka Matoušková  Michal Roll  Tereza Nováková  Filip Oulehle 《水文研究》2021,35(6):e14255

From 2011 to 2019, mercury (Hg) stores and fluxes were studied in the small forested catchment Lesní potok (LES) in the central Czech Republic using the watershed mass balance approach together with internal measurements. Mean input fluxes of Hg via open bulk deposition, beech throughfall and spruce throughfall during the periodwere 2.9, 3.9 and 7.6 μg m⁻² year⁻¹, respectively. These values were considerably lower than corresponding deposition Hg fluxes reported in the early years of the 21st century from catchments in Germany. Current bulk precipitation inputs at unimpacted Czech mountainous sites were lower than those in Germany. The largest Hg inputs to the catchment were via litterfall, averaging 22.6 and 17.8 μg m⁻² year⁻¹ for beech and spruce stands. The average Hg input, based on the sum of mean litterfall and throughfall deposition, was 23.0 μg m⁻² year⁻¹, compared to the estimated Hg output in runoff of 0.5 μg m⁻² year⁻¹, which is low compared to other reported values. Thus, only ~2% of Hg input is exported in stream runoff. Stream water Hg was only weakly related to dissolved organic carbon (DOC) but both concentrations were positively correlated with water temperature. The estimated total soil Hg pool averaged 47.5 mg m⁻², only 4% of which was in the O-horizon. Thus Hg in the O-horizon pool represents 72 years of deposition at the current input flux and 3800 years of export at the current runoff flux. Age-dating by ¹⁴C suggested that organic soil contains Hg from recent deposition, while mineral soil at 40–80 cm depth contained 4400-year old carbon, suggesting the soil had accumulated atmospheric Hg inputs through millennia to reach the highest soil Hg pool of the soil profile. These findings suggest that industrial era intensification of the Hg cycle is superimposed on a slower-paced Hg cycle during most of the Holocene.  相似文献   

Partitioning of Nb,Ta, Ti,Ce, and La between Granitoid Magmatic Melts and Minerals     

Chevychelov  V. Yu.  Viryus  A. A.  Shapovalov  Yu. B. 《Doklady Earth Sciences》2020,495(1):816-820

Doklady Earth Sciences - Experimental data on the Nb, Ta, Ti, Ce, and La concentrations in felsic magmatic melts of various alkalinity and alumina content upon dissolving ilmenorutile,...  相似文献   

Micromechanical approach to effective viscoelastic properties of micro‐fractured geomaterials          下载免费PDF全文

Cássio B. Aguiar  Samir Maghous 《国际地质力学数值与分析法杂志》2018,42(16):2018-2046

The aim of this paper is to formulate a micromechanics‐based approach to non‐aging viscoelastic behavior of materials with randomly distributed micro‐fractures. Unlike cracks, fractures are discontinuities that are able to transfer stresses and can therefore be regarded from a mechanical viewpoint as interfaces endowed with a specific behavior under normal and shear loading. Making use of the elastic‐viscoelastic correspondence principle together with a Mori‐Tanka homogenization scheme, the effective viscoelastic behavior is assessed from properties of the material constituents and damage parameters related to density and size of fractures. It is notably shown that the homogenized behavior thus formulated can be described in most cases by means of a generalized Maxwell rheological model. For practical implementation in structural analyses, an approximate model for the isotropic homogenized fractured medium is formulated within the class of Burger models. Although the approximation is basically developed for short‐term and long‐term behaviors, numerical applications indicate that the approximate Burger model accurately reproduce the homogenized viscoelastic behavior also in the transient conditions.  相似文献   

On the Contribution of the Eddy Transport to the Annual Mean Heat Budget of the Upper Layer in the North Atlantic     

A. B. Polonsky  P. A. Sukhonos 《Izvestiya Atmospheric and Oceanic Physics》2018,54(5):507-514

According to Ocean Re-Analysis System 3 (ORA-S3) data, all components of the annual mean heat budget of the upper quasi-homogeneous ocean layer (UQL) in the North Atlantic for the period of 1959–2011 have been calculated and errors of these estimates have been determined. It has been shown that the contribution of the horizontal eddy diffusivity (estimated as a residual term of the UQL heat balance equation) to changes in the UQL annual mean temperature is significantly overestimated. This takes place mainly due to neglecting the covariances of seasonal fluctuations of current velocity vector components and UQL temperature gradients in calculations carried out with the use of annual average values. These covariances play an important role in the annual mean heat budget in some regions of the North Atlantic, especially in tropical latitudes. Changes in the annual average UQL temperature in the central and eastern parts of the North Atlantic are significantly affected by errors related to an inaccuracy of estimates of annual average heat fluxes on the ocean surface. The maximum contribution of the horizontal eddy diffusivity to the interannual variability of the UQL temperature is observed in the northwestern part of the North Atlantic and the region of the Subpolar Gyre.  相似文献   

Determination of the optimal conditions for inclination maneuvers using a Swing-by     

O. MouraJr.  C. C. Celestino  A. F. B. A. Prado 《Astrophysics and Space Science》2018,363(5):91

The search for methods to reduce the fuel consumption in orbital transfers is something relevant and always current in astrodynamics. Therefore, the maneuvers assisted by the gravity, also called Swing-by maneuvers, can be an advantageous option to save fuel. The proposal of the present research is to explore the influence of some parameters in a Swing-by of an artificial satellite orbiting a planet with one of the moons of this mother planet, with the goal of changing the inclination of the artificial satellite around the main body of the system. The fuel consumption of this maneuver is compared with the required consumption to perform the same change of inclination using the classical approach of impulsive maneuvers.  相似文献