Integrated radio luminosities of pulsars     

I. F. Malov  O. I. Malov 《Astronomy Reports》2006,50(6):483-495

The integrated radio luminosities of 311 long-period (P > 0.1 s) and 27 short-period (P < 0.1 s) pulsars have been calculated using a new compilation of radio spectra. The luminosities are in the range 10²⁷ ? 10³⁰ erg/s for 88% of the long-period pulsars and 10²⁸ ? 10³¹ erg/s for 88% of the short-period pulsars. We find a high correlation between the luminosity L and the estimate L ₁ = S ₄₀₀ d ² from the catalog of Taylor et al. The factor η for the transformation of the rotational energy of the neutron star into radio emission increases-decreases with increasing period for long-period and short-period pulsars. The mean value of η is ?3.73 for the long-period and ?4.85 for short-period pulsars. No dependence was found between L and the pulsar’s kinematic age t _k = |z|/〈v _z〉, where |z| and 〈v _z〉 = 300 km/s are the pulsars’ height above the plane of the Galaxy and mean velocity. A dependence of L on the rate of rotational energy losses ? was found for both groups of pulsars. It is shown that L ∝ ? ^1/3 for the entire sample. The pulsar luminosity function is constructed, and the total number and birth rate of pulsars in the Galaxy are calculated.  相似文献   

CO₂ exchange in the ocean-atmosphere system on the Chukchi Sea shelf     

I. I. Pipko  I. P. Semiletov  S. P. Pugach 《Doklady Earth Sciences》2006,411(8):1244-1248

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A Solution to the Problem of Predicting the Suitability of Silty–clayey Materials for Cement-stabilization     

Evangelos I. Stavridakis 《Geotechnical and Geological Engineering》2006,24(2):379-398

Major geotechnical problems in construction involving silty–clayey soils are due to their low strength, durability and high compressibility of soft soils, and the swell–shrink nature of the overconsolidated swelling soils. Confronted with these problems, a suitable ground improvement technique is needed, for deep excavations in soft clays, for stability, durability and deformation control. Cement-stabilization is one of the alternatives. An increase in strength and durability, reduction in deformability are the main aims of this method. Conventional cement-stabilization methods are used mainly for surface treatment. However, the use of cement has recently been extended to a greater depth in which cement columns were installed to act as a type of soil reinforcement (deep cement–soil mixing and cement jet grouting). In situ engineering properties of these silty–clayey soils are often variable and difficult to predict. For this reason cement-stabilization methods have a basic target to control the aforementioned engineering properties of these clays so that the properties of a silty–clayey soil become more like the properties of a soft rock such as clayey shale or lightly cemented sandstone. So cement-stabilization of these soils is essential to control their engineering properties and to predict their engineering behaviour for construction. In an effort to predict, classify and study the suitability of silty–clayey soils for cement-stabilization both slaking and unconfined compressive strength tests were carried out on clayey–sand mixtures consisted of two types of clays, kaolin and bentonite. Finally diagrams were prepared to study the variation of slaking and strength due to compaction, curing time and cement percentage and also to predict areas of efficient cement-stabilization.  相似文献   

Proton-stimulated redistribution of Fe atoms in quartz: Experimental modeling of the space radiation effect     

S. N. Shilobreeva  L. L. Kashkarov  M. Yu. Barabanenkov  A. N. Pustovit  V. I. Zinenko  Yu. A. Agafonov 《Doklady Earth Sciences》2006,411(9):1466-1469

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Melt inclusions in minerals of scapolite-bearing granulite (lower crustal xenoliths from diatremes of the Pamirs)     

V. P. Chupin  D. V. Kuz&#;min  I. A. Madyukov 《Doklady Earth Sciences》2006,407(3):507-511

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The correlation of Mesozoic gold ore districts at the Sino-Korean and Aldan-Stanovoi shields     

V. I. Kazansky  V. M. Yanovsky 《Geology of Ore Deposits》2006,48(1):43-60

The geological structure and gold ore potential of the activized Aldan-Stanovoi and Sino-Korean shields of East Asia are compared. These two regions show similar tendencies in their geological evolution during the Archean, Proterozoic, and Phanerozoic epochs but differ in types of tectonic structure and associations of ore deposits. According to recent studies by Russian and Chinese geologists, the Mesozoic complexes of these shields possess higher gold ore potential than was suggested before. As a result of these studies, the amount of conditions favoring the formation of large gold districts and deposits in the activized shields has strongly increased. Some of these deposits are polychronic and polygenetic (the Bam deposit), others are associated with J-K alkaline magmatism (the Central Aldan district), a third group of deposits are related to granites of the same age (the East Shandong district), and a fourth group includes stratiform deposits in the lower part of the udokan series (Ugui district). The various Mesozoic hydrothermal ore deposits of the northern framework of the Sino-Korean Shield are especially interesting. The study of problems of gold metallogeny was initiated in Russian geological science by Yu.A. Bilibin (1935–1940) in the central part of the Aldan Shield. Some new data concerning the gold ore potential of the Sino-Korean Shield extend our knowledge of gold ore districts in East Asia and make clear the necessity of more careful and systematic study of the gold ore potential of the Aldan-Stanovoi Shield.  相似文献   

Petrogenesis of gold-bearing Dioritoids of the Ketkap-Yuna magmatic province, Aldan Shield     

V. F. Polin  A. I. Khanchuk  S. I. Dril  G. P. Sandimirova  L. S. Tsurikova 《Doklady Earth Sciences》2006,409(5):824-830

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Effect of heat treatment on tourmaline from Brazil   总被引：4，自引：0，他引：4  

Cristiane Castañeda  Sigrid G. Eeckhout  Geraldo Magela da Costa  Nilson F. Botelho  Eddy De Grave 《Physics and Chemistry of Minerals》2006,33(3):207-216

The crystal-chemical behaviour of tourmaline from Araçuaí, Minas Gerais state, Brazil, when subjected to heating in air atmosphere has been studied by several techniques, including EMPA, UV–Vis, TGA, and Mössbauer spectroscopy. The tourmaline samples are typically intermediate members of the elbaite-schorl series. The origin of colour and of its change after treatment has been discussed in terms of local disorder, presence of metal transition elements, oxidation of ferrous iron at the octahedral site, and simultaneous trap of the excess electron. These findings may be used to enhance the colour in tourmaline crystals or generate wanted colour changes.  相似文献   

Isotopic signatures of deposition and transformation of Lower Cambrian saliferous rocks in the Irkutsk amphitheater: Communication 1. Sulfur isotopic composition     

V. I. Vinogradov  G. A. Belenitskaya  M. I. Bujakaite  V. N. Kuleshov  M. A. Minaeva  B. G. Pokrovskii 《Lithology and Mineral Resources》2006,41(1):85-97

New isotope data on Lower Cambrian rocks of the Irkutsk amphitheater are reported in three communications. The first communication is devoted to the sulfur isotopic composition, which is most sensitive to ostsedimentary geochemical transformations of sulfate rocks in saliferous formations. It is shown that δ³⁴S values in Bel’sk and Zhigalovo boreholes are within 22–35‰ The lowest values are close to the sulfur isotopic composition of a halogenic basin, while the highest values are related to epigenetic sulfate reduction. This process was responsible for the elimination of 100 m of anhydrites from the Lower Cambrian section.  相似文献   

Regional model assessments of fire risks under global climate changes     

I. I. Mokhov  A. V. Chernokulsky  I. M. Shkolnik 《Doklady Earth Sciences》2006,411(9):1485-1488

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