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101.
102.
Fabio R. Marin James W. Jones Abraham Singels Frederick Royce Eduardo D. Assad Giampaolo Q. Pellegrino Flávio Justino 《Climatic change》2013,117(1-2):227-239
This study evaluated the effects of climate change on sugarcane yield, water use efficiency, and irrigation needs in southern Brazil, based on downscaled outputs of two general circulation models (PRECIS and CSIRO) and a sugarcane growth model. For three harvest cycles every year, the DSSAT/CANEGRO model was used to simulate the baseline and four future climate scenarios for stalk yield for the 2050s. The model was calibrated for the main cultivar currently grown in Brazil based on five field experiments under several soil and climate conditions. The sensitivity of simulated stalk fresh mass (SFM) to air temperature, CO2 concentration [CO2] and rainfall was also analyzed. Simulated SFM responses to [CO2], air temperature and rainfall variations were consistent with the literature. There were increases in simulated SFM and water usage efficiency (WUE) for all scenarios. On average, for the current sugarcane area in the State of São Paulo, SFM would increase 24 % and WUE 34 % for rainfed sugarcane. The WUE rise is relevant because of the current concern about water supply in southern Brazil. Considering the current technological improvement rate, projected yields for 2050 ranged from 96 to 129 t?ha?1, which are respectively 15 and 59 % higher than the current state average yield. 相似文献
103.
Driving factors for forest fire occurrence in Durango State of Mexico: A geospatial perspective 总被引:1,自引:2,他引:1
Diana Avila-Flores Marin Pompa-Garcia Xanat Antonio-Nemiga Dante A Rodriguez-Trejo Eduardo Vargas-Perez Javier Santillan-Perez 《中国地理科学(英文版)》2010,20(6):491-497
Forest fire is one of the major causes of forest loss and therefore one of the main constraints for sustainable forest management
worldwide. Identifying the driving factors and understanding the contribution of each factor are essential for the management
of forest fire occurrence. The objective of this study is to identify variables that are spatially related to the occurrence
and incidence of the forest fire in the State of Durango, Mexico. For this purpose, data from forest fire records for a five-year
period were analyzed. The spatial correlations between forest fire occurrence and intensity of land use, susceptibility of
vegetation, temperature, precipitation and slope were tested by Geographically Weighted Regression (GWR) method, under an
Ordinary Least Square estimator. Results show that the spatial pattern of the forest fire in the study area is closely correlated
with the intensity of land use, and land use change is one of the main explanatory variables. In addition, vegetation type
and precipitation are also the main driving factors. The fitting model indicates obvious link between the variables. Forest
fire was found to be the consequence of a particular combination of the environmental factors, and when these factors coexist
with human activities, there is high probability of forest fire occurrence. Mandatory regulation of human activities is a
key strategy for forest fire prevention. 相似文献
104.
M. S. Babushkina V. L. Ugolkov Yu. B. Marin L. P. Nikitina A. G. Goncharov 《Doklady Earth Sciences》2018,479(2):456-459
Using IR–Fourier spectrometry (FTIR) and simultaneous thermal analysis combined with quadrupole mass spectrometry of thermal decomposition products (STA + QMS), olivines and clinopyroxene from xenolites of spinel and garnet lherzolites contained in kimberlites and alkaline basalts were studied to confirm the occurrence of hydrogen and carbon within the structure of the minerals, as well as to specify the forms of H and C. The presence of hydroxyl ions (OH–) and molecules of crystal hydrate water (H2Ocryst) along with CO2, CH, CH2, and CH3 groups was detected, which remained within the structures of mantle minerals up to 1300°C (by the data of both techniques). The total water (OH–and H2Ocryst) was the prevailing component of the C–O–H system. 相似文献
105.
Wolframoixiolite and niobian ferberite from zinnwaldite granitic rocks of the Chukchi Peninsula 总被引:1,自引:0,他引:1
The finding of wolframoixiolite with inclusions of niobian ferberite is described from zinnwaldite granite and ongonite of
the Severny pluton of the Chukchi Peninsula. The optical, morphological, and chemical properties of minerals are characterized
and compared with their analogues from other regions. The petrologic and mineragenic index implications of the minerals are
discussed with allowance for our contemporary mineralogical knowledge on W-bearing Ta-Nb minerals. 相似文献
106.
A review of the current state of genetic mineralogy in the field of the chemical heterogeneity of mineral individuals is presented. Due to advances in the local analysis of matter, the ontogenetic approach is now being focused on the chemical anatomy of minerals. A new line of research, microgeochemistry, deals with the migration of chemical elements in natural crystals caused by defects in the crystal lattice. It becomes evident that structural and chemical heterogeneity is an intrinsic property of mineral individuals. Phenomenological laws of this heterogeneity and the interaction of atoms with lattice defects are stated. 相似文献
107.
108.
Horia Mitrofan Constantin Marin Dorel Zugrvescu Alin Tudorache Lucian Beu?iu Mihaela Radu 《地学学报》2008,20(2):87-94
The Na, K, Mg and Ca contents of certain deep‐origin groundwater discharges have been used by Giggenbach (1988) to define a series of ‘geoindicators’, which may provide hints on the up‐flow depth of origin, on the duration of the fluid ascent to the ground surface and on the associated CO2 flux. On occurrence of a Mw = 6.0 Vrancea earthquake, significant fluctuations of Giggenbach’s geoindicators have been recorded in a saline spring, some 50 km away from the epicentre. A pre‐seismic overall anomaly was monitored for 1 year and a half, the sharpest variations occurring about 3 months before the earthquake. Processes controlling the geoindicator fluctuations assumedly took place at 7–8 km depth, while the earthquake hypocenter depth was about 100 km. This could be an evidence for a mechanical coupling still existing between the seismogenic body in the lithosphere and the overlying crust. 相似文献
109.
R. C. Nichol R. K. Sheth Y. Suto A. J. Gray I. Kayo R. H. Wechsler † F. Marin G. Kulkarni M. Blanton A. J. Connolly J. P. Gardner B. Jain C. J. Miller A. W. Moore A. Pope J. Pun D. Schneider J. Schneider A. Szalay I. Szapudi I. Zehavi N. A. Bahcall I. Csabai J. Brinkmann 《Monthly notices of the Royal Astronomical Society》2006,368(4):1507-1514
110.
Marin F. D. Greenwood 《Estuaries and Coasts》2007,30(3):537-542
Organisms tend to inhabit predictable portions of estuaries along salinity gradients between the ocean inlets (salinity >
35 psu) and the freshwater tributaries (salinity = 0). Previous studies have suggested that the continuous change in biological
community structure along this gradient is relatively rapid at certain salinities. This is the basis for estuarine salinity
zonation schemes similar to the classic Venice System (i.e., 0–0.5, 0.5–5, 5–18, 18–30, 30–40, > 40). An extensive database
(n > 16,000 samples) of frequency of occurrence of nekton was used to assess evidence for estuarine salinity zones in two
southwest Florida estuaries: Tampa Bay and Charlotte Harbor. Rapid change in nekton community structure occurred at each end
of the estuarine salinity gradient, with comparatively slow (but steady) change in between. There was little strong evidence
for estuarine salinity zones at anything other than low salinities (0.1–1). As previously suggested by other authors, estuaries
may be regarded as ecoclines, because they form areas of relatively slow but progressive ecological change. The ends of the
estuarine salinity gradient appear to be ecotones (areas of rapid change) at the interfaces with adjacent freshwater and marine
habitats. This study highlights the rapid change that occurs in nekton community structure at low salinities, which is of
relevance to those managing freshwater inflow to estuaries. 相似文献