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1.
L O Bjorn S Widell T Wang 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2002,30(6):1557-1562
Plants have evolved under the influence of UV-B radiation and have acquired systems for monitoring it and investing appropriate resources for protection against it, i.e., filters, quenchers of radicals and reactive oxygen species, and repair systems. An hypothesis for how plants monitor radiation has been presented. 相似文献
2.
S I Bartsev V V Mezhevikin V A Okhonin 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1996,18(1-2):201-204
Any attempt to create LSS for practical applications must take into account the possibility of castastrophic consequences if the problem of LSS reliability and stability is not solved. An integrated conception of CELSS studies development as a possible way to increase its reliability is considered. The BIOS-4 facility project is developed in the context of the conception. Three principles of highly effective experimental CELSS facility design are proposed. Some details of BIOS-4 design and its exploitation features are presented. 相似文献
3.
T Berger M Hajek L Summerer N Vana Y Akatov V Shurshakov V Arkhangelsky 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2004,34(6):1414-1419
The Atominstitute of the Austrian Universities has conducted various space research missions in the last 12 years in cooperation with the Institute for Biomedical Problems in Moscow. They dealt with the exact determination of the radiation hazards for cosmonauts and the development of precise measurement devices. Special emphasis will be laid on the last experiment on space station MIR the goal of which was the determination of the depth distribution of absorbed dose and dose equivalent in a water filled Phantom. The first results from dose measurements onboard the International Space Station (ISS) will also be discussed. The spherical Phantom with a diameter of 35 cm was developed at the Institute for Biomedical Problems and had 4 channels where dosimeters can be exposed in different depths. The exposure period covered the timeframe from May 1997 to February 1999. Thermoluminescent dosimeters (TLDs) were exposed inside the Phantom, either parallel or perpendicular to the hull of the spacecraft. For the evaluation of the linear energy transfer (LET), the high temperature ratio (HTR) method was applied. Based on this method a mean quality factor and, subsequently, the dose equivalent is calculated according to the Q(LET infinity) relationship proposed in ICRP 26. An increased contribution of neutrons could be detected inside the Phantom. However the total dose equivalent did not increase over the depth of the Phantom. As the first Austrian measurements on the ISS dosimeter packages were exposed for 248 days, starting in February 2001 at six different locations onboard the ISS. The Austrian dosimeter sets for this first exposure on the ISS contained five different kinds of passive thermoluminescent dosimeters. First results showed a position dependent absorbed dose rate at the ISS. 相似文献
4.
The problem of target motion analysis (TMA) has been the subject of an important literature. However, present methods use data estimated by a short time analysis (azimuths, Dopplers, etc.). For far sources, the nonstationarities of the array processing outputs, induced by the sources motion, may be simply modeled. This model leads one to consider directly a spatio-temporal TMA. Then new (spatio-temporal) data can be estimated. These estimates correspond to a long time analysis. Further, note that they are estimated independently of the (classical) bearings. In this general framework, the concept of source trajectory replaces the classical instantaneous bearings. Corresponding TMA algorithms are then studied. Then the study of statistical performance is carefully studied 相似文献
5.
The results of the experimental studies of damping characteristics of a composite torsion bar in the helicopter main rotor
hingeless hub are presented. A variant of their improvement is considered. 相似文献
6.
We present an algorithm for calculating the shells of revolution with the branching meridian using the triangular finite elements, the rigidity matrices of which are formed based on the vector method of displacement interpolation [1]. The correct kinematic and static conditions of shell conjugation on the line of their coupling have been developed. The shell structure consisting of a cylinder and adjacent shells is calculated under various conditions of support. 相似文献
7.
I. S. Akhmed’yanov 《Russian Aeronautics (Iz VUZ)》2009,52(4):383-389
The application of the quadrature method [1] to analyzing the shells of revolution under symmetrical loading relative to the
zero meridian is considered. The method can be treated as a generalization of the method presented in [2] to solve the Volterra
integral equation of the second kind. 相似文献
8.
The problem of optimal data fusion in multiple detection systems is studied in the case where training examples are available, but no a priori information is available about the probability distributions of errors committed by the individual detectors. Earlier solutions to this problem require some knowledge of the error distributions of the detectors, for example, either in a parametric form or in a closed analytical form. Here we show that, given a sufficiently large training sample, an optimal fusion rule can be implemented with an arbitrary level of confidence. We first consider the classical cases of Bayesian rule and Neyman-Pearson test for a system of independent detectors. Then we show a general result that any test function with a suitable Lipschitz property can be implemented with arbitrary precision, based on a training sample whose size is a function of the Lipschitz constant, number of parameters, and empirical measures. The general case subsumes the cases of nonindependent and correlated detectors. 相似文献
9.
L. V. Zasova V. I. Moroz V. M. Linkin I. V. Khatuntsev B. S. Maiorov 《Cosmic Research》2006,44(4):364-383
The goal of this paper is to summarize the experimental data on the atmosphere of Venus obtained after 1985, when the VIRA (Venus International Reference Atmosphere) or COSPAR model was published. Among the most important results that have appeared since then are the following: measurements of the vertical temperature profile by the VEGA spacecraft with high precision and high altitude resolution; measurements made with balloons of the VEGA spacecraft; radio occultation measurements of Magellan, Venera-15, and Venera-16; and temperature profiles derived from the data of infrared spectrometry obtained by Venera-15. The new result as compared to VIRA is the creation of a model of the atmosphere in the altitude range 55 to 100 km dependent on local time. This model is presented in our paper in tabulated form. 相似文献
10.
Microbial processes in frozen food 总被引:2,自引:0,他引:2
O Geiges 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1996,18(12):109-118
Deep freezing of food and storage at −19°C is a standard conservation procedure in food technology. The lower limit of growth of bacteria in food is from about −5°C to about −8°C, whereas the reproduction limit of yeasts is 2 to 3°C lower. Storage temperatures above −10°C should therefore not be used. At −18°C, a commonly used storage temperature, no growth of microorganisms will occur. The microorganisms mainly found at the lower growth limit are Pseudomonas sp. and basidiomycete yeasts. The reduction in the number of microorganisms due to freezing, storage, and thawing is not of practical importance. Microbial enzymes, in particular lipases and proteases, are still active at −18°C. Therefore, the quality of raw products and good hygiene at the production site are most important. 相似文献