慕课在远程网络教师教育领域的应用探析

随着近年来慕课浪潮的兴起,我国现行远程网络教师教育所存在的授课思想落后、授课形式枯燥单一以及评价方式重量轻质等问题逐渐凸显。现阶段我国慕课平台虽然提供了许多国外高校开设的有关教师教育的课程,但对于我国慕课学习者而言,还存在着一定的学习障碍。未来我国远程网络教师教育可以吸取慕课先进经验,在课程平台、教师角色以及教学流程等方面进行有效变革,从而促进我国远程网络教师教育健康发展。     

Formation conditions of the chemistry of Tersinskie carbonic-acid mineral water

Data on the ion-salt, microcomponent, gas, microbiological, and isotopic composition of water and the results of studies of the equilibriums in the water-rock system are used to analyze the formation processes of the composition of Tersinskie carbonic-acid mineral water and their genesis.     

Diagnostic modelling of within-water processes in reservoirs

The objectives of diagnostic calculations using mathematical models of reservoirs are formulated. The structure of a box hydrological model GMV-MGU is described, and the results of calculation of daily water balance, internal heat exchange structure, and heat balance of individual areas in the Mozhaisk and Rybinsk reservoirs are given. First results of calculation of variations in mean daily phytoplankton biomass in the near-dam pool of a weakly eutrophic water body in period of spring (diatoms) and summer (blue-green) blooming are presented.     

The Effect of Aggregation of Impurity Nitrogen on Diamond X-Ray Luminescence

Two samplings of 65 diamond crystals divided by the intensity of a slow X-ray luminescence component are studied from the Arkhangel’skaya and Karpinskogo-1 pipes. IR and EPR spectroscopies revealed a relationship between the nitrogen A and P2 centers of the diamonds and the presence of a slow X-ray luminescence component. Its absence in most diamonds with high content of P1 (C) centers is explained by the low number of A and P2 centers.     

Minimum on the light curve of the classical symbiotic star AS 338 in 1999

We present our UBVRI photometry and spectroscopy of AS 338 performed in 1999–2000. Another eclipse of the hot component in this symbiotic binary system, the deepest one ever observed, occurred in September 1999. The U brightness declined by ～2^m, the Hβflux decreased by a factor of ～2.3, and the [O III]γ5007 flux did not change. The hot component is eclipsed at orbital phases ?≈0.045–0.057. The U-B color index begins to appreciably fluctuate during an eclipse of the hot component and its circumstellar envelope. About 100 days after a strong outburst of 1995, the mean UBV brightness of AS 338 declined linearly in the ensuing five years at the same rate in all bands (ΔU/Δt≈10^?3 mag/day). The brightness of the outer, uneclipsed parts of the circumstellar envelope also decreased, which is attributable to a reduction in the luminosity of the hot component against the rise in its temperature. The appearance of He II lines has not yet been recorded, though the optical brightness of AS 338 has already dropped by ～2^m after the outburst.     

Reconstructions of the Mesozoide structures in the eastern Amur-Okhotsk fold system, Far East

The late Jurassic reconstruction for the Ul’ban synclinorium was proposed based on the lithological and structural similarity of the Upper Permian and Mesozoic complexes of the Yankan-Dzhagdy and Ul’ban lithotectonic zones of the Amur-Okhotsk fold system. It was suggested that the Un’ya-Bom subzone of the Yankan-Dzhagdy LTZ is a fragment of the Ul’ban synclinorium (including its eastern centroclinal closure) that was detached and westward displaced (for 400–600 km) in the first half of the Cretaceous.     

Mathematical modeling of membrane polarization occurring in rocks due to applied electrical field

Membrane polarization occurs in sediments with different surface area of capillaries (pores) and is regarded as a slow type of polarization. This phenomenon is the foundation of the well known methods of induced polarization (IP): time domain and frequency domain induced polarization. The characteristic parameters of induced polarization which are required for studying physical properties of rocks are measured in the laboratory. Data measured in the laboratory confirmed the distinctions of IP processes at time-on and time-off. Additionally linear dependence of voltage and applied current is not always observed. This paper presents the first step of studying: theoretical consideration for time-on and mathematical modeling of membrane polarization, ion concentrations of electrolyte in the pores of different models of pores space, and arising voltage. The problem of concentration of ions along the pores can be solved using the diffusion equation with specified initial and boundary conditions. Reduced boundary conditions for time-on show that transient concentrations at the boundaries are linear with time. It allows obtaining the analytical solution for this equation. Mathematical modeling has been performed for different combinations of pores. It is shown that if electrical current flows from the pores with greater transfer numbers to the pores with smaller transfer numbers, an excess of ions will be observed at this boundary. If the difference of transfer numbers is negative, there is a decrease in the concentration of ions at the vicinity of the boundary. This decrease will continue until the concentration at this boundary reaches zero. In this case the galvanic chain will be interrupted and electrical current flowing through the sample does not penetrate to this cell. The duration of the process of ions distribution in the pore and time of blockage t ₀ is proportional to the radii of contacted pores and inversely proportional to the transfer number difference and square of the current flowing through this cell. It was shown by both laboratory measurement and field processes that induced polarization relates to low porous rocks with small transfer number differences.