The analysis of ballistic capabilities for countering disturbances associated with temporary emergency electric propulsion shutdown

The paper analyzes the possibility for countering ballistic perturbations of the interplanetary transfer trajectory of the spacecraft with electric propulsion (EP) associated with the temporary impossibility of the normal use of the EP in phases of the heliocentric transfer. The main result of the present study is the method for the determination of a new nominal trajectory, at any point of which the allowed duration of the emergency shutdown of electric propulsion is large enough. The numerical analysis is given for one of the possible scenarios of spacecraft injection into the operational heliocentric orbit for solar research.     

Computer Expert System for Epithermal Gold-Silver Deposit Prognostication (Okhotsk–Chuckchee Volcanic Belt,Northeast Russia)

The Okhotsk–Chuckchee volcanic belt (OCVB) represents a world class gold–silver province, being a well-studied part of the Circum-Pacific Rim. Extensive research, preceding the system compilation, included collection of various data on major gold–silver, silver–lead–zinc, and tin–silver ore fields (with some data on minor gold–quartz, gold–sulfide, and gold–rare-metal sites). The database consists of 129 ore fields of the OCVB and comprises 433 geological, mineralogical, geochemical, and geophysical indicators. Using the original pattern recognition programs (accounting the frequencies and correlation of the indicators), the most informative indicators were selected, their weights (both positive and negative) were identified, and an expert system (solution tree) was compiled. The computer system is intended to be an assistance to an expert in the ore field potential evaluation. The system includes several blocks of questions with a goal of classifying the geochemical type and size of the analyzed ore field. The questions have an indirect character, so they could be answered by an expert at early stages of exploration (before drilling). The level of recognition of sizes of the ore sites in the control populations is 95% or higher. The aim of the expert system is to reestimate a large number of known ore sites in a relatively brief period of time with the aid of the personal computer. The revealed patterns could be used in other less studied parts of the Circum-Pacific belt.     

Modeling optical contrast for thin organic films on the sea surface

A continuation of the work dedicated to the study of slicks and film formations on the sea surface is presented. A vector model for the calculation of reflected radiation by the wavy sea surface with respect to the contribution of upwelling radiation from under the sea surface (the second type of waters) is described briefly in [5]. This work contains an analysis of numerical calculations according to the developed procedure and the search for optimal conditions of slick detection. The best conditions for detecting slicks on the sea surface are reached when a P-polarization component of reflected radiation is recorded. In this case, the value of contrast between a slick and a clean surface is 30% higher on average than in recording a contrast without using a polarization filter and is 50% higher than in the case of recording a contrast with a filter oriented to the maximum transmission of S polarization component of reflected radiation. It is shown that, under clear sky conditions, the optimal condition for recording slicks on a sea surface is videotaping in the plane of solar vertical at viewing angles sliding towards the sea surface and when a polarization filter that identifies the Р polarization component of sea radiation is used. In contrast, under overcast sky conditions, it is best to perform observations in the plane that has a wind velocity vector.     

Gamma-ray bursts and the production of cosmogenic radionuclides in the Earth’s atmosphere

An explanation is offered for the impulsive increase in the concentration of cosmogenic radiocarbon in annual tree rings (Δ¹⁴C ～ 12‰) from AD ?775. A possible cause of such an increase could be the high-energy emission from a Galactic gamma-ray burst. It is shown that such an event should not lead to an increase in the total production of ¹⁰Be in the atmosphere, as distinct from the effect of cosmic-ray fluxes on the atmosphere. At the same time, the production of an appreciable amount of ³⁶Cl, which can be detected in Greenland and Antarctica ice samples of the corresponding age, should be expected. This allows the effects caused by a gamma-ray burst and anomalously powerful proton events to be distinguished.     

Some shifts in the population of the USSR

Using the preliminary results of the 1979 census, the authors analyze trends in the distribution of the population of the USSR. Topics considered include the role of natural increase in the redistribution of the population, the relationship between economic development and the rate of population growth in Siberia, the effects of increasing rural-urban migration, and changes in the number and distribution of large cities.     

Economic-Geological Estimation of Gold and Ore Deposits Using Information-Analytical System for the Selection of Analogues

The computer system is developed for evaluation of gold deposits over the world using data collected by experts in the field of gold deposit geology. With the system in use, gold object of interest can be described on the basis of selected groups of tags. The similarity of the considered object to an object from the database is estimated by designed algorithms on the basis of available information characterizing the considered object. These algorithms allow to apply mathematical methods for analysis of the problem what improves quality and reliability of the results. By the method of analogue determination, user can always evaluate unknown properties of the considered object, as for example, ore formation type, economic geological estimate of the deposit on the basis of known properties of the determined analogue.The software equipped by an intuitive graphical interface is developed with use of GIS technologies and modern methods of object-oriented programming.     

Stage boundaries of the Triassic in Northeast Asia

The International Union of Geological Science approved the stage boundaries suggested by the international working groups for the Tethyan Triassic. In this work we estimate the possibility of their establishment and correlation in the Boreal sections of Northeast Asia, based on the analyzed distribution of ammonoids and conodonts. As the conodonts of the Induan Stage have not been identified for sure in the region under study, the lower boundary of the Triassic System is defined here at the base of the Otoceras concavum Zone of the ammonoid scale. In addition to the ammonoids Hedenstroemia hedenstroemi (Keyserling), the first occurrence of the conodonts Pseudogondolella nepalensis (Kozur et Mostler) is suggested to be the biomarker of the Olenekian Stage base. The lower boundaries of the Anisian and Ladinian stages, defined respectively at the basal levels of the Paracrochordiceras-Japonites Beds in Northern Dobrogea and the Eoprotrachyceras curionii Zone in the Brescian Prealps are recognizable, though with some reservations, at the base of the Grambergia taimyrensis and Eonathorstites oleshkoi zones in Northeast Asia. According to the priority principle and similarity between the ammonoid faunas of the Daxatina cf. canadensis Subzone and Frankites regoledanus Zone, the lower boundary of the Carnian Stage is defined at the base of the Alpine Trachyceras aon Zone. In Northeast Asia, this boundary is established at the base of the “Protrachyceras” omkutchanicum Zone, as we take into account the fact that the Daxatina and Stolleyites ammonoid genera occur in sections of British Columbia below the stratigraphic level of the Trachyceras forms. The lower boundary of the Norian Stage is concurrent with the base of the Guembelites jandianus Zone in the Alps and equivalent Stikinoceras kerri Zone in North America and Striatosirenites kinasovi Zone in Northeast Asia. The conodont species Norigondolella navicula (Huckriede) that is most important for the Boreal-Tethyan correlation cannot be used as a biomarker of the Norian lower boundary because of its problematic diagnosis and rare occurrence in the Boreal sections. The Rhaetian Stage base is defined at the appearance level of the Misikella conodont genus in the Hallstatt region, Austria, that is simultaneously the disappearance level of the characteristic Norian bivalves (Monotis) and ammonoids (Metasibirites). In Northeast Asia, this boundary is established at the top of the Monotis ochotica Zone. The correlation between the biostratigraphic units of the Middle-Upper Triassic conodont scale established in Northeast Asia and standard ammonoid zonation is verified.     

Response of permafrost landscapes of Central Yakutia to current changes of climate,and anthropogenic impacts

We discuss the state of permafrost landscapes of Central Yakutia under the influence of current changes of climate and anthropogenic impacts. This study uses the data from the monitoring stations operated by the Permafrost Institute SB RAS, and from the Yakutsk and Pokrovsk meteorological stations. It is found that there is a rather good correlation between the data from the monitoring stations and from the Pokrovsk meteorological station. The last decade saw a considerable rise in temperatures of earth materials. The most sensitive to cliate change are the disturbed landscapes, primarily treeless landscapes such as anthropogenic complexes, and burned-out forests.     

Detailed spatial modeling of temperature in Moscow

A computer complex is described developed for the detailed temperature forecasting in large megalopolises. It consists of the global and microclimatic models implementing the modeling of the thermal regime within Moscow. To increase the modeling quality, an improved technique is proposed of computation of temperature characteristics within the urban canyon. A spatial resolution of output modeling data reaches 500 m. A comparison with the station data demonstrates that the accuracy of air temperature simulation in Moscow and in its nearest vicinities is quite satisfactory.