首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   13篇
  免费   0篇
地球物理   3篇
地质学   1篇
海洋学   2篇
天文学   5篇
综合类   2篇
  2016年   1篇
  2014年   1篇
  2013年   1篇
  2012年   1篇
  2009年   2篇
  2004年   1篇
  2003年   1篇
  1999年   1篇
  1983年   1篇
  1977年   1篇
  1969年   1篇
  1968年   1篇
排序方式: 共有13条查询结果,搜索用时 15 毫秒
1.
The DPLIS and the results of the solar activity cycle No. 20 forecast with the help of it are described briefly.  相似文献   
2.
The results of annual parasitological monitoring in the coastal area near the Abram-mys (Kola Bay, Barents Sea) are presented. The studies were performed in 2006–2007 and included complex examination of the intermediate hosts (mollusks and crustaceans) and definitive hosts (marine fish and birds) of the helminths. The biodiversity of the parasite fauna, seasonal dynamics, and functioning patterns of the parasite systems were investigated. The basic regularities in parasite circulation were assessed in relation to their life cycle strategies and the ecological features of the intermediate and definitive hosts. The factors affecting the success of parasite circulation in the coastal ecosystems were revealed through analysis of parasite biodiversity and abundance dynamics.  相似文献   
3.
Present-day conditions of the Lake Kenon ecosystem are determined by a combination of natural and anthropogenic factors.We have estimated the effects of a complex of factors on the condition of the abiotic environment and on specific biological components in the lake ecosystem.Change in biogenic load has caused an increase in the role of phytoplankton in the general balance of organic matter during the high-water period.Charophytes are the main dominants of bottom vegetation.Anthropogenic load has caused a decrease in both fish species and fish capacity.The lake application as a water reservoir-cooler has influenced the average annual water mineralization(from 420 mg/L to 530.0 mg/L with a maximum 654 mg/L in 1993) and fluctuations in its hydrochemical composition.The present composition of the lake is sulfate-hydrocarbonate-chloride calcium-sodic-magnesium in character.SO 4 – content is twice as much as the maximum permissible concentration in fishery waters.Water drainage from an ash disposal area to the lake has caused an increase in chemical-element concentrations including the heavy metals.Hg concentration in Perca fluviatilis muscles is 0.5 μg/g dry wt.Thus,understanding directions in the ecosystem of the water reservoir-cooler under changing hydrological conditions will let us forecast the consequences of new combined heat and power plant operation.  相似文献   
4.
We study the anomalies of some hydrometeorological fields in the Atlantic-European sector and on the South Coast of Crimea (SCC) in the years of decrease in solar activity in its even and odd 11-year cycles. It is shown that, in the first half of summer, the values of the sea level and surface temperature at the SCC averaged over the years of decrease of an even cycle are lower than for the same years of an odd cycle. As a result, we make a conclusion that there exists a tendency to the formation of quasi-22-year variability of some hydrometeorological characteristics near the SCC. We also discover a trend to the antiphase variability of the number of upwellings and the surface temperature at the SCC in the years of decrease in solar activity in its even and odd 11-year cycles.  相似文献   
5.
6.
The structure and a possible practical application of the portable generator with extremely and super low frequency (ELF-SLF) range (0.1–200 Hz) and power of 2 kW are described. The generator is designed for deep sounding of the Earth’s crust for the purposes of mineral exploration and electromagnetic monitoring of source zones of earthquakes in seismically active regions. Computational and theoretical works, as well as numerical simulation for optimizing the generator’s parameters and element base, are carried out. The main constructive elements of the generator, namely, the power factor corrector, the driver control circuit for power transistors, the inverter of the high-frequency decoupling converter, the multichannel pulse power converter, the output inverter, and etc., are consistently described. The generator’s weight does not exceed 10 kg, and, therefore, the generator may be easily delivered to a testing site using any kind of transport, including planes. The generator is powered by the single-phase network with a voltage of 220 V. The full-scale testing of the generator is performed at the territory of the Yamalo-Nenets autonomous okrug via the connection to the high-voltage transmission line Urengoi-Pangody with a length of 114 km. The maximum current in the line is 12 A. The maximum distance of reliable signal recording is 110 km.  相似文献   
7.
On the basis of a review of data on the effective cross-sections of particle interactions, computations of the effective electron-neutron interaction, of the cross-section values for H, H2 and He were carried out in the range 0.8 1.7 and 2.5 logP g 6.5. The mean cross-sections for the solar mixture used by Zwaan were computed (see Table II). Using these results, the values of the electric conductivity and of its anisotropy coefficient were computed (see Tables VII and VIII), as well as other auxiliary quantities. The conductivity values obtained are in the range from 5 × 109 to 5 × 1012 CGSE units for the assumed physical conditions.On leave from the Astronomical Institute of the Czechoslovak Academy of Sciences, Ondejov, Czechoslovakia.  相似文献   
8.
This article presents the results ofhydrochemical and hydrobiological studies of shallow saline lakes of the Borzya group (Zabaikalsky K_rai, Russia) at the initial filling phase. The lake-margin ecosystems of the studied lakes are characterized by varying degrees of salinity from polyhaline to brine water. Cyclical variations of meteorological conditions and high salinity determined that the compositions of the aquatic organisms are specific, mostly between stenohaline and euryhaline species, the quantities are low, and the community structures are simple.  相似文献   
9.
The results of observations of the umbral flashes in two sunspots are reported. The sunspots differ in their morphological properties (evolution rates and activity levels) and in observation conditions (heliocentric distances). The oscillation parameters of the two sunspots do not coincide. The most significant differences are pronounced in the phase relations and amplitudes of observed oscillations.  相似文献   
10.
Mordvinov  A.V.  Kuklin  G.V. 《Solar physics》1999,187(1):223-226
A hierarchy of cyclic changes in solar activity is studied based on energetic and phase wavelet analyses. The phase wavelet spectrum of yearly number of sunspot groups shows fork-like bifurcations. Separate 11-yr cycles are combined in pairs and wave trains to make up complete magnetic cycles with complex synergies. The phase spectrum also indicates the existence of different regimes in solar activity cyclic changes. This variability seems to be controlled by changes in the solar dynamo regime.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号