The dynamics of desertification in the Horqin Sandy Land between 2000 and 2005 were analyzed using Landsat TM/ETM images and
the data-processing function of geographical information software. The results showed that the extent of desertified land
decreased at a rate of slightly more than 0.1 km2 year−1, from 22,423.1 km2 in 2000 to 22,422.4 km2 in 2005, indicating that desertification has been controlled in this area and that desert areas may be approaching a steady
state. The dynamics of desertification differed among land types. Desertification decreased most obviously in areas of previous
desert land. The area in which desertification was ameliorated was higher than the area that underwent further degradation,
but non-desertified land (113.3 km2) deteriorated at a rate of 22.7 km2 year−1 during this period. This significant change requires careful attention by managers in the study area. 相似文献
Devonian strata in the Guizhong region, Guangxi, China consist mainly of marine deposition carbonates (limestones and dolomites) as well as restricted clastic rocks. The strata thickness is measured as 2041m and classified into 14 formations. An integrated field geological, petrographic, sedimentological, palaeobiological, and geochemical study of these strata reveals that the depositional paleoenvironments were carbonate tidal flat, restricted platform, open platform, shelf, platform margin slop, and algal herm. The total organic carbon (TOC) of sedimentary organic matter ranges between 0.07% and 1.96% with average of 0.21%. The organic matter types are Type I and Type III. The vitrinite reflectance (R0) of kerogen ranges between 0.99% and 2.03%, indicating the maturated and highly maturated stages. The analytical results of the representative samples collected from shelf and subtidal facies show that the differences of organic matter type and biological diagnostic compounds are related to the types of source rocks deposited in different paleoenvironments.
By a natural nonextensive generalization of the conservation of energy in the q-kinetic theory, we study the nonextensivity and the power-law distributions for the many-body systems with the self-gravitating
long-range interactions. It is shown that the power-law distributions describe the long-range nature of the interactions and
the non-local correlations within the self-gravitating system with the inhomogeneous velocity dispersion. A relation is established
between the nonextensive parameter q≠1 and the measurable quantities of the self-gravitating system: the velocity dispersion and the mass density. Correspondingly,
the nonextensive parameter q can be uniquely determined from the microscopic dynamical equation and thus the physical interpretation of q different from unity can be clearly presented. We derive a nonlinear differential equation for the radial density dependence
of the self-gravitating system with the inhomogeneous velocity dispersion, which can correctly describe the density distribution
for the dark matter in the above physical situation. We also apply this q-kinetic approach to analyze the nonextensivity of self-gravitating collisionless systems and self-gravitating gaseous dynamical
systems, giving the power-law distributions the clear physical meaning.
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The application of modern bulk emulsion explosive systems at an underground gold mine resulted in a 57% improvement in gold dilution. While this improvement is impressive and could be expected to be achieved at other sites, the work required to assess and demonstrate the benefits is painstaking. Forty-eight rings involving a total of approximately 50 000 tonnes of ore were monitored using various modern surveying instruments over a 6-month period. The geometric data included blasthole locations and deviation, and the cavity monitoring of stopes. Implementation of a bulk emulsion system not only provided logistical benefits but it also has the desirable explosive properties associated with reducing the effects of blast damage and blast dilution. 相似文献