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971.
The report presents some results on the cosmic radiation intensity research carried out with the high-altitude balloons for the period of 1977–1979. The intensity of gamma-radiation with the energy above 40 MeV was measured in two balloon flights at an altitude of 4–7 g/cm2 of residual atmosphere in the vicinity of the geomagnetic equator. A temporal analysis of the intensity to discover fluctuations with periods in the range of 4–60 min was made. Quasi-periodic fluctuations of gamma-radiation intensity with 5 min periods, amplitude ~20% and duration of several hours were discovered. Possible mechanisms of such fluctuation appearance are discussed.The report gives the results of measuring downward, upward and horizontal electron fluxes in the vicinity of the equator. The obtained data and the data provided by satellites are compared. The report discusses the prospects of further joint Soviet-Indian research of cosmic gamma-radiation.  相似文献   
972.
Force-field theory is studied in 3-dimension using the full diffusion tensor incorporating drift effects. An analytical approximate solution is deduced under some assumptions which include a flat neutral sheet and a non-uniform density distribution at the outer boundary. By contrast with the usual force-field theory, our solution gives a large and charge dependent latitudinal gradient and near perfect isotropy, even corotation disappears. The results are in general agreement with the numerical calculations of Jokipii and Kopriva.  相似文献   
973.
Digitally coded radar waveforms can be used to obtain large time-bandwidth products (pulse compression ratios). It is demonstrated that periodic radar waveforms with zero sidelobes or almost zero sidelobes can be defined. A perfect periodic code is a periodic code whose autocorrelation function has zero sidelobes and whose amplitude is uniform (maximum power efficiency=1). An asymptotically perfect periodic code has the property that as the number of elements in the code goes to infinity the autocorrelation function of the code has zero sidelobes and its power efficiency is one. The authors introduce a class of radar waveforms that are either perfect or asymptotically perfect codes. These are called reciprocal codes because they can be derived through a linear transformation of known codes. The aperiodic performance of the reciprocal code is examined  相似文献   
974.
A Retarding Potential Analyzer (RPA) is designed using a micro-channel plate in front of the collector as a flow amplifier, which makes it possible to detect ion species with very low concentration (<0,5 cm.?3). A technique is described for using the micro-channel plate at abnormally high pressure (>0.01 N/m2). This allows the precise determination of the mass composition of the low ionosphere. An adaptive retarding potential consisting of 2048 steps is used to increase the sensitivity. This retarding potential is applied in the range where dI/dU ≠ 0. The sensor is hermetically sealed and opens on command.  相似文献   
975.
Measurements of the precipitation of electrons and positive ions (in the keV to MeV range) detected aboard eight rockets launched from Northern Scandinavia are reported together with corresponding satellite data. The downgoing integral fluxes indicate the temporal fluctuations during each flight. Height profiles of the energy deposition into the atmosphere at different levels of geomagnetic disturbance are given.  相似文献   
976.
The environmental advantages of ovonic NiH2 batteries, due to the nontoxicity of ovonic alloys, are briefly discussed, and their general performance is described. Commercial progress in their development is summarized. Their use in electric vehicles is examined  相似文献   
977.
A satellite has been designed for application to radar calibration. Electromagnetic and mechanical characteristics of the satellite and their influence on the selection of shape and other parameters are discussed. Theoretical and experimental scattering data are included.  相似文献   
978.
The application of digital onboard computers for flight control of high-performance aerospace vehicles is desirable, with respect to hardware effort and reliability, as well as operational flexibility. Up to now, digital computers have not been used for the control of short periodic angular oscillations. This task can be solved with the capability of digital computers now available. A good vehicle for the realization of appropriate control equations is the ?frequency transformation?. Using the simplified dynamics of a supersonic aircraft as an example, a procedure for synthesis of a digital control filter is presented. After a first evaluation in the s domain, the design is checked for validity in the frequency domain. If necessary, the original design is corrected appropriately.  相似文献   
979.
980.
Given the need for a light source, cyanobacteria and other photosynthetic microorganisms can be difficult and expensive to grow in large quantities. Lighted growth chambers and incubators typically cost 50-100% more than standard microbiological incubators. Self-shading of cells in liquid cultures prevents the growth of dense suspensions. Growing liquid cultures on a shaker table or lighted shaker incubator achieves greater cell densities, but adds considerably to the cost. For experiments in which gases other than air are required, the cost for conventional incubators increases even more. We describe an apparatus for growing photosynthetic organisms in exotic atmospheres that can be built relatively inexpensively (approximately 100 dollars U.S.) using parts available from typical hardware or department stores (e.g., Wal-mart or K-mart). The apparatus uses microfiltered air (or other gases) to aerate, agitate, and mix liquid cultures, thus achieving very high cell densities (A750 > 3). Because gases are delivered to individual culture tubes, a variety of gas mixes can be used without the need for enclosed chambers. The apparatus works with liquid cultures of unicellular and filamentous species, and also works with agar slants.  相似文献   
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