Theoretical and methodological problems of experimental determination of the initial gradient     

M. M. Burakov 《Water Resources》2010,37(4):446-454

Theoretical and methodological problems of experimentally evaluating the main parameter of nonlinear flow in porous medium at low pressure (or head) gradients—the initial gradient—based on results of pumping tests are considered. Approaches to assessing the reliability of such evaluation are analyzed.  相似文献   

Great Silk Road on the Territory of Kazakhstan: From Past to Future     

Akhmetkal MEDEU  Maulken ASKAROVA  Roman PLOKHIKH  Irina SKORINTSEVA  Aruzhan BEKKULIYEVA 《资源与生态学报(英文版)》2015,6(2):114-118

The Great Silk Road is a trade route linking the East and West which gave impetus to the development of ancient society, and Kazakhstan is the heart of the trade route. At the initial stage, intensive transaction of goods took place between the West and East through The Great Silk Road. This paper reviewed the history of development of the Silk Road and suggested that today to construct the "New Silk Road", Kazakhstan should face many issues, and take many steps to become a Eurasian hub through taking full of advantages. Above all, developing mechanisms of integration and sustainable development is our urgent need.  相似文献   

Six intermediate-mass stars with far-infrared excess: a search for evolutionary connections     

Anatoly S. Miroshnichenko  Christopher L. Mulliss  Karen S. Bjorkman  Nancy D. Morrison  Kenesken S. Kuratov  John P. Wisniewski 《Monthly notices of the Royal Astronomical Society》1999,302(3):612-624

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Solar Activity Predictability Horizons     

Volobuev  D. M.  Makarenko  N. G. 《Geomagnetism and Aeronomy》2020,60(8):1017-1022

Geomagnetism and Aeronomy - The chaotic component in solar-activity variations, the limited amount of observational statistics, and the use of proxy data impose limitations on long-term...  相似文献   

An unfolding method for X-ray spectro-polarimetry     

《Astroparticle Physics》2015

X-ray polarimetry has great scientific potential and new experiments, such as X-Calibur, PoGOLite, XIPE, and GEMS, will not only be orders of magnitude more sensitive than previous missions, but also provide the capability to measure polarization over a wide energy range. However, the measured spectra depend on the collection area, detector responses, and, in case of balloon-borne experiments, the absorption of X-rays in the atmosphere, all of which are energy dependent. Combined with the typically steep source spectra, this leads to significant biases that need to be taken into account to correctly reconstruct energy-resolved polarization properties. In this paper, we present a method based on an iterative unfolding algorithm that makes it possible to simultaneously reconstruct the energy spectrum and the polarization properties as a function of true photon energy. We apply the method to a simulated X-Calibur data set and show that it is able to recover both the energy spectrum and the energy-dependent polarization fraction.  相似文献   

The Detached Binary TW Coronae Borealis     

《New Astronomy》2021

New radial velocity and photometric data for TW CrB have been obtained, and Roche-based simultaneous analysis of RV and light curve data for the system has been accomplished for the first time, using the 2003 version of the Wilson-Devinney code. Values for the masses and radii have been obtained: M₁ = 1.31 (6) M_ʘ, M₂ = 1.22 (4) M_ʘ, and R₁ = 1.50 (1) R_ʘ, R₂ = 1.42 (1) R_ʘ. For the luminosities the most likely values are L₁ = 2.78 (5) L_ʘ and L₂ = 2.01 (4) L_ʘ. Both stars are likely unevolved. There is general agreement with earlier photometric values for Zhang and Zhang (2003) with the exception of their masses and mass ratio. Because the values in this paper for the latter quantities are based on radial velocities, they are to be preferred.  相似文献   

On the applicability of Benford law to exoplanetary and asteroid data     

《New Astronomy》2021

In this article we investigate the masses, orbital periods, semimajor axis, eccentricities and radii of the existing exoplanets by comparing the first and second digit probabilities with Benford laws’s predictions. It is found that the masses, orbital periods and semimajor axis conform to Benfordós law quite well, but radii fail. It is also investigated the first digits occurrence corresponding to a given order of magnitude. We introduce a top function which can estimate all the probabilities of the first digit order-to-order.  相似文献   

The Tekeli earthquake of 2009 in Kazakhstan: Source and effects     

N. N. Mikhailova  N. N. Poleshko 《Seismic Instruments》2011,47(2):180-190

The article investigates parametrization issues of the main shock from the earthquake of June 13, 2009, m _b = 6.3 felt in Tekeli town with intensity 7. Spatial characteristics of the source, mechanism and CMT, aftershock activity regularities were studied. Rupture plane in the source was defined with high probability. Information and pictures about destructions and damages of buildings on the territory of Tekeli town as well as isoseismal map are shown. In 1993 almost at the same place the earthquake with the same focal parameters and processes occurred. Very close parameters of seismic effects on the territory of Almaty having two almost the same sources were noted.  相似文献   

From intra-oceanic subduction to arc accretion and arc-continent collision: Insights from the structural evolution of the Río San Juan metamorphic complex,northern Hispaniola     

《Journal of Structural Geology》2013

The Río San Juan metamorphic complex exposes a segment of a high-pressure subduction-accretionary complex built during Caribbean island arc-North America continental margin convergence. It is composed of accreted arc- and oceanic-derived metaigneous rocks, serpentinized peridotites and minor metasediments forming a structural pile. Combined detailed mapping, structural and metamorphic analysis, and geochronology show that the deformation can be divided into five main events (D1–D5). An early subduction-related D1 deformation and M1 metamorphism produced greenschist (mafic rocks of the Gaspar Hernández peridotite-tectonite), blueschist and eclogite (metamafic blocks in the Jagua Clara mélange), high-P epidote-amphibolite and eclogite (Cuaba unit), and lower blueschist and greenschist-facies conditions (Morrito unit). This was followed by M2 decompression and cooling in the blueschist, greenschist and low-P amphibolite-facies conditions. The shape of the retrograde P-T path, the age of the exhumation-related D2 structures, and the tectonic significance of D2 deformation are different in each structural unit. Published U–Pb and ⁴⁰Ar/³⁹Ar plateau ages and T-t/P-t estimations reveal diachronic Turonian-Coniacian to Maastrichtian retrograde M2 metamorphism in the different structural units of the complex, during a consistent D2 top-to-the-NE/ENE tectonic transport. Regionally, a similar top-to-the-ENE tectonic transport also took place in the metasedimentary nappes of the Samaná complex during the Eocene to earliest Miocene. This kinematic compatibility indicates a general northeastward progradation of deformation in the northern Caribbean convergent margin, as the successive tectonic incorporation of arc, oceanic and continental-derived terrains to the developing Caribbean subduction-accretionary complex took place. D3–D5 deformations are discontinuous and much less penetrative, recording the evolution from ductile to brittle conditions of deformation in the complex. The D3 event substantially modified the nappe-stack and produced open folds with amplitudes up to kilometer-scale. The Late Paleocene-Eocene D4 structures are ductile to ductile–brittle thrusts and inverse shear bands. D5 is a Tertiary, entirely brittle deformation that had considerable influence in the geometry of the whole complex. From the Miocene to the Present, it has been cut and laterally displaced by a D5 sinistral strike-slip fault system associated with the Septentrional fault zone.  相似文献   

Characteristics and Causes of Changes in Water Quality in the Syr Darya River,Kazakhstan     

Sanim Bissenbayeva  Abuduwaili  Jilili  Issanova  Gulnura  Samarkhanov  Kanat 《Water Resources》2020,47(5):904-912

Water Resources - The water quality parameters, like major ions, have been monitored at three stations located along the Syr Darya River. The trend analysis was performed on annual timescales using...  相似文献