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1.
Constantino Tsallis Constantino Tsallis Domingo Prato Angel R. Plastino Angel R. Plastino 《Astrophysics and Space Science》2004,290(3-4):259-274
A variety of astronomical phenomena appear to not satisfy the ergodic hypothesis in the relevant stationary state, if any. As such, there is no reason for expecting the applicability of Boltzmann–Gibbs (BG) statistical mechanics. Some of these phenomena appear to follow, instead, nonextensive statistical mechanics. In the same manner that the BG formalism is based on the entropy S BG=?k∑ i p i ln p i, the nonextensive one is based on the form S q=k(1 ?∑ i p i q)/(q? 1) (with S 1=S BG). The stationary states of the former are characterized by an exponential dependence on the energy, whereas those of the latter are characterized by an (asymptotic) power law. A brief review of this theory is given here, as well as of some of its applications, such as the solar neutrino problem, polytropic self-gravitating systems, galactic peculiar velocities, cosmic rays and some cosmological aspects. In addition to these, an analogy with the Keplerian elliptic orbits versus the Ptolemaic epicycles is developed, where we show that optimizing S q with a few constraints is equivalent to optimizing S BG with an infinite number of constraints. 相似文献
2.
Carlos Augusto Ramos e Silva Pablo Bezerra Dávalos Leonel da Silveira Lobo Sternberg Flavo Elano Soares de Souza Maria Helena Constantino Spyrides Paulo Sérgio Lucio 《Estuarine, Coastal and Shelf Science》2010
We evaluated the physical–chemical properties and nutrient concentrations in two shrimp ponds under conventional management, intensive (I-P) and semi-intensive (SI-P), and one under organic management (O-P), three days after loading and before stoking. The mean’s total alkalinity concentrations were 2.26 ± 0.04 mM, 2.28 ± 0.01 mM and 2.59 ± 0.01 mM, respectively for I-P, SI-P and O-P. Bicarbonate and carbonate accounted for 62% and 37% in I-P, 64% and 36% in SI-P and 83–17% in O-P, respectively. Aragonite and calcite were oversaturated around Ω = 5. Mean total phosphate (TP) concentrations were 441.37 ± 92.06 μg/L, 449 ± 48 μg/L and 473.64 ± 84.17 μg/L, under I-P SI-P and O-P management respectively. Following this sequence, NO3− concentration was 2.98 ± 0.7 μg/L, 1.16 ± 0.16 μg/L and 0.32 ± 0.12 μg/L, under I-P, SI-P and O-P management respectively. Thus, the data suggest that different management of farm organic waste leads to different chemical water quality. 相似文献
3.
Francisco Herv Robert J. Pankhurst Robert Drake Myrl E. Beck Jr. Constantino Mpodozis 《Earth and Planetary Science Letters》1993,120(3-4):375-386
A stock of biotite-muscovite-garnet leucogranite crops out in the lower course of Río Cisnes as an unusual minor lithology within the predominantly dioritic to tonalitic North Patagonian Batholith. Foliated and unfoliated varieties are present—the former are nearer to the main lineament of the Liquin˜e-Ofqui Fault Zone (LOFZ). Two-feldspar thermometry indicates equilibration temperatures above 600°C, for pressures probably not over 3 kbar, as suggested by the Mn-rich garnet composition. A Rb-Sr whole-rock isochron age of 9.6 ± 0.4 Ma (1σ error) probably indicates the time of magma crystallization. 40Ar-39Ar ages of 6.6 ± 0.3 Ma on muscovite and 5.5 ± 0.4 Ma on biotite are cooling ages from which a moderate average uplift/denudation rate ( 1 mm/yr) may be calculated. Paucity of occurrence, distribution close to the LOFZ and a near minimum-melt composition all suggest that the leucogranite magma was derived by partial melting of the lower crust, perhaps by decompression melting at a time when uplift/denudation rates were high (4 mm/yr or more are required). Regional evidence for rapid Holocene uplift in the immediate vicinity of the LOFZ substantiates the feasibility of the proposed petrogenetic model, which may be valid in other strike-slip orogenic environments. 相似文献
4.
Exhumation history and timing of supergene copper mineralisation in an arid climate: New thermochronological data from the Centinela District,Atacama, Chile 总被引：1，自引：0，他引：1 
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下载免费PDF全文 Caroline Sanchez Stéphanie Brichau Rodrigo Riquelme Sébastien Carretier Thomas Bissig Cristopher Lopez Constantino Mpodozis Eduardo Campos Vincent Regard Gérard Hérail Carlos Marquardt 《地学学报》2018,30(1):78-85
Supergene copper mineralisation (SCM) processes occur during the unroofing of porphyry copper deposits. However, the geomorphological stage during which the main mineralisation occurs is still under debate. Here, we present 24 new thermochronological data from Cenozoic intrusives and compare them with the evolution of supergene mineralisation from the Centinela Mining District in the Atacama Desert. Our results indicate a two‐step cooling path: a rapid Late Eocene exhumation followed by a slow denudation. Previously published supergene mineralisation ages cluster after the main Upper Oligocene exhumation period. Ours is the first study that establishes the relationship between exhumation and supergene processes on the scale of a single mining district. It confirms that SCM took place during pediplanation, likely a required condition for efficient SCM under arid climatic conditions, in contrast to wet tropical environments where SCM occurs during rapid relief growth but has limited preservation potential. 相似文献
5.
R. Constantino M.B. Gaspar J. Tata-Regala S. Carvalho J. Cúrdia T. Drago R. Taborda C.C. Monteiro 《Marine environmental research》2009,67(2):89-99
This study aimed to assess the potential effects of clam dredging and the subsequent recovery of the benthic environment. Two experimental areas located at 6 and 18 m depth were established in order to analyse whether impacts and recovery of benthic environment are depth-related. Study areas were located within an area closed to dredging and two different plots were established at both depths. One of the plots was subjected to intense clam dredge-fishing, while the other was undisturbed and therefore used as control. Sampling followed a BACI design, with samples for macrobenthic, meiobenthic and sediment particle size analysis being taken by SCUBA divers from both areas before and after fishing stress. For both depths, impacts on the benthic environment were very low resulting in high recovery rates. Nevertheless, at shallower depths communities demonstrated a faster recovery. It was shown that depending on the faunal component used as a bioindicator, different results can be observed. Generally deposit-feeding organisms with scales or chitinous plates and vermiform shape (mainly crustaceans, polychaetes and ophiuroids), without external protection, were the most affected by dredging, while some polychaetes without external protection and with a carnivorous feeding mode seemed to be enhanced by fishing. The low level of perturbations induced by the dredging activities was comparable to the impact of surface waves on the bottom, as experiments were undertaken in wave-dominated environments. The coexistence of storm events during the study period proved to have similar or even more deleterious effects on the benthic environment. It appears that communities from hydrodynamic fishing grounds that are well adapted to natural physical stress are not highly affected by dredging. 相似文献
6.
Constantino Tsallis 《Astrophysics and Space Science》2006,305(3):261-271
The cornerstones of Boltzmann-Gibbs and nonextensive statistical mechanics respectively are the entropies S
BG
≡ −k ∑
i = 1
W
p
i
ln p
i
and S
q
≡ k (1−∑
i = 1
W
p
i
q
)/(q−1) (q∊ℜ S
1 = S
BG
). Through them we revisit the concept of additivity, and illustrate the (not always clearly perceived) fact that (thermodynamical) extensivity has a well defined sense only if we specify the composition law that is being assumed for the subsystems (say A and B). If the composition law is not explicitly indicated, it is tacitly assumed that A and B are statistically independent. In this case, it immediately follows that S
BG
(A+B) = S
BG
(A)+S
BG
(B), hence extensive, whereas S
q
(A+B)/k = [S
q
(A)/k]+[S
q
(B)/k]+(1−q)[S
q
(A)/k][S
q
(B)/k], hence nonextensive for q ≠ 1. In the present paper we illustrate the remarkable changes that occur when A and B are specially correlated. Indeed, we show that, in such case, S
q
(A+B) = S
q
(A)+S
q
(B) for the appropriate value of q (hence extensive), whereas S
BG
(A+B) ≠ S
BG
(A)+S
BG
(B) (hence nonextensive). We believe that these facts substantially improve the understanding of the mathematical need and physical origin of nonextensive statistical mechanics, and its interpretation in terms of effective occupation of the W
a priori available microstates of the full phase space. In particular, we can appreciate the origin of the following important fact. In order to have entropic extensivity (i.e., lim
N→∞
S(N)/N < ∞, where N≡ numberof
elements
of
the
system), we must use (i) S
BG
, if the number W
eff of effectively occupied microstates increases with N like W
{{eff}}∼ W ∼ μ
N
(μ ≥ 1); (ii) S
q
with q = 1−1/ρ, if W
{{eff}}∼ N^ρ < W (ρ ≥ 0). We had previously conjectured the existence of these two markedly different classes. The contribution of the present paper is to illustrate, for the first time as far as we can tell, the derivation of these facts directly from the set of probabilities of the W microstates. 相似文献
7.
Chris Jesinkey Randall D. Forsythe Constantino Mpodozis John Davidson 《Earth and Planetary Science Letters》1987,85(4)
Paleomagnetic results are reported from three formations of late Paleozoic age from the northern Chilean Andes of the Atacama Desert. For the first time primary NRM components are resolved for Paleozoic units along the western flank of the central Andes. Pole positions are calculated for the formations, and compared with APW data for cratonic South America. These comparisons reveal that the collecting sites in the northern Domeyko and Almeida Ranges of the central Andes have undergone no paleomagnetically defined rotations or translation with respect to cratonic South America since the time of NRM acquisition, which is likely to have been in the lower parts of the Kiaman Reverse Interval. If growth of the South American lithosphere has involved accretion of exotic microplates they are either likely to be substantially older than units sampled here, or be restricted to more coastal terranes. The results, taken together with other paleomagnetic data from northern Chile and southern Peru which have showed a wide range of discordance in their declinations when compared to each other or APW data, lead to the conclusion that this region of the Andes during the Mesozoic or Cenozoic has not been affected by simple processes of clockwise oroclinal bending from Peru to Chile, nor regionally consistent patterns of block rotations. 相似文献
8.
dos Santos Junior Edimar Pereira Xavier Ana Carolina Freitas Martins Letícia Lopes da Rocha Sobierajski Graciela Blain Gabriel Constantino 《Theoretical and Applied Climatology》2022,148(3-4):1199-1216
Theoretical and Applied Climatology - The Standardized Precipitation Index (SPI) is a worldwide used probability-based drought index. Considering that the two-parameter gamma distribution (gam) is... 相似文献
9.
Constantino Tsallis 《Acta Geophysica》2012,60(3):502-525
The celebrated Boltzmann-Gibbs (BG) entropy, S BG = ?kΣ i p i ln p i , and associated statistical mechanics are essentially based on hypotheses such as ergodicity, i.e., when ensemble averages coincide with time averages. This dynamical simplification occurs in classical systems (and quantum counterparts) whose microscopic evolution is governed by a positive largest Lyapunov exponent (LLE). Under such circumstances, relevant microscopic variables behave, from the probabilistic viewpoint, as (nearly) independent. Many phenomena exist, however, in natural, artificial and social systems (geophysics, astrophysics, biophysics, economics, and others) that violate ergodicity. To cover a (possibly) wide class of such systems, a generalization (nonextensive statistical mechanics) of the BG theory was proposed in 1988. This theory is based on nonadditive entropies such as \(S_q = k\frac{{1 - \sum\nolimits_i {p_i^q } }}{{q - 1}}\left( {S_1 = S_{BG} } \right)\). Here we comment some central aspects of this theory, and briefly review typical predictions, verifications and applications in geophysics and elsewhere, as illustrated through theoretical, experimental, observational, and computational results. 相似文献
10.
Tommy Gärling Anders Böök Erik Lindberg Constantino Arce 《The Professional geographer》1991,43(2):143-149
Two groups of subjects with varying amounts of experience with the city in which they lived judged from memory distances between familiar locations. The distance judgments were processed by a multidimensional scaling algorithm (MULTISCALE) that estimates the parameters of a power function transformation of the response scale and the coordinates of the locations in k-dimensional euclidean space. The results for both subject groups suggested that inaccuracies of distance cognition do not reflect the noneuclidean nature of urban cognitive maps but are caused by response bias. 相似文献