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991.
Y Kitaya A Tani M Kiyota I Aiga 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1994,14(11):281-284
In order to obtain basic data for construction of a plant cultivation system incorporating a mushroom cultivation subsystem in the CELSS, plant growth and atmospheric CO2 balance in the system were investigated. The plant growth was promoted by a high level of CO2 which resulted from the respiration of the mushroom mycelium in the system. The atmospheric CO2 concentration inside the system changed significantly due to the slight change in the net photosynthetic rate of plants and/or the respiration rate of the mushroom when the plant cultivation system combined directly with the mushroom cultivation subsystem. 相似文献
992.
P Chagvardieff T d'Aletto M Andre 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1994,14(11):269-275
Experiments in growth chambers with controlled atmosphere were performed to compare the effects on the productivity of two treatments stimulating photosynthesis: the doubling of CO2 concentration, the doubling of irradiance; the combining of both was also tested. A large effect of light was noticed: (i) the accumulation of carbon was, contrarily to CO2 effect, amplified within time, and led to the most important dry matter production. (ii) the specific leaf weight was about two-fold increased. (iii) the nitrate content was 2-3 fold less. A significant positive effect of CO2 was detected on the fresh biomass production and the iron content of lettuce. A synergy was observed on dry matter production by the interaction of the two factors. 相似文献
993.
C S Dyer F Lei S N Clucas D F Smart M A Shea 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2003,32(1):81-93
Solar particle events can give greatly enhanced radiation at aircraft altitudes, but are both difficult to predict and to calculate retrospectively. This enhanced radiation can give significant dose to aircrew and greatly increase the rate of single event effects in avionics. Validation of calculations is required but only very few events have been measured in flight. The CREAM detector on Concorde detected the event of 29 September 1989 and also four periods of enhancement during the events of 19-24 October 1989. Instantaneous rates were enhanced by up to a factor ten compared with quiet-time cosmic rays, while flight-averages were enhanced by up to a factor six. Calculations are described for increases in radiation at aircraft altitudes using solar particle spectra in conjunction with Monte Carlo radiation transport codes. In order to obtain solar particle spectra with sufficient accuracy over the required energy range it is necessary to combine space data with measurements from a wide range of geomagnetically dispersed, ground-level neutron monitors. Such spectra have been obtained for 29 September 1989 and 24 October 1989 and these are used to calculate enhancements that are compared with the data from CREAM on Concorde. The effect of cut-off rigidity suppression by geomagnetic activity is shown to be significant. For the largest event on record on 23 February 1956, there are no space data but there are data from a number of ground-level cosmic-ray detectors. Predictions for all events show very steep dependencies on both latitude and altitude. At high latitude and altitude (17 km) calculated increases with respect to cosmic rays are a factor 70 and 500 respectively for 29 September 1989 and 23 February 1956. The levels of radiation for high latitude, subsonic routes are calculated, using London to Los Angeles as an example, and can exceed 1 mSv, which is significantly higher than for Concorde routes from Europe to New York. The sensitivity of the calculations to spectral fitting, geomagnetic activity and other assumptions demonstrates the requirement for widespread carriage of radiation monitors on aircraft. 相似文献
994.
Observations carried out from the coronagraphs on board space missions (LASCO/SOHO, Solar Maximum and Skylab) and ground-based facilities (HAO/Mauna Loa Observatory) show that coronal mass ejections
(CMEs) can be classified into two classes based on their kinematics evolution. These two classes of CMEs are so-called fast
and slow CMEs. The fast CME starts with a high initial speed that remains more or less constant; it is also called the constant-speed CME. On the other hand, the slow CME starts with a low initial speed, but shows a gradual acceleration; it is also called
the accelerated and slow CME. Low and Zhang [Astrophys. J. 564, L53–L56, 2002] suggested that these two classes of CMEs could be a result of a difference in the initial topology of the
magnetic fields associated with the underlying quiescent prominences. A normal prominence magnetic field topology will lead
to a fast CME, while an inverse quiescent prominence results in a slow CME, because of the nature of the magnetic reconnection
processes. In a recent study given by Wu et al. [Solar Phys. 225, 157–175, 2004], it was shown that an inverse quiescent prominence magnetic topology also could produce a fast CME. In this
study, we perform a numerical MHD simulation for CMEs occurring in both normal and inverse quiescent prominence magnetic topology.
This study demonstrates three major physical processes responsible for destabilization of these two types of prominence magnetic
field topologies that can launch CMEs. These three initiation processes are identical to those used by Wu et al. [Solar Phys. 225, 157–175, 2004]. The simulations show that both fast and slow CMEs can be initiated from these two different types of magnetic
topologies. However, the normal quiescent prominence magnetic topology does show the possibility for launching a reconnection island (or secondary O-line) that might be thought of as a “CME’’. 相似文献
995.
D.K. Haggerty E.C. Roelof G.M. Simnett 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2003,32(12):2673-2678
Processes in the solar corona are prodigious accelerators of energetic ions, and electrons. The angular distribution, composition, and spectra of energetic particles observed near Earth gives information on the acceleration mechanisms. A class of energetic particle observations particularly useful in understanding the solar acceleration is the near-relativistic impulsive beam-like electron events. During five years of operation the Advanced Composition Explorer (ACE) has measured well over 400 electron events. Approximately 25% of these electron events are impulsive beam-like events that are released onto interplanetary field lines predominantly from western solar longitudes. We extend our initial 3 year study during the rise to solar maximum (Haggerty and Roelof, 2002; Simnett et al., 2002) to a five year statistical analysis of these beam-like energetic electron events in relationship to optical flares, microwave emission, soft X-ray emission, metric and decametric type-III radio bursts, and coronal mass ejections. 相似文献
996.
Ramachandra K.V. Division R.C. 《IEEE transactions on aerospace and electronic systems》1987,(5):705-708
A one-dimensional tracking filter based on the Kalman filtering techniques for tracking of a dynamic target such as an aircraft is discussed. The target is assumed to be moving with constant acceleration and is acted upon by a plant noise which perturbs its constant acceleration motion. The plant noise accounts for maneuvers and/or other random factors. Analytical results for estimating optimum steady state position, velocity, and acceleration of the target are obtained. 相似文献
997.
Wiesław M. Macek 《Space Science Reviews》2006,122(1-4):329-337
The question of multifractality is of great importance because it allows us to investigate interplanetary hydromagnetic turbulence.
The multifractal spectrum has been investigated with Voyager (magnetic field) data in the outer heliosphere and with Helios
(plasma) data in the inner heliosphere. We use the Grassberger and Procaccia method that allows calculation of the generalized
dimensions of the solar wind attractor in the phase space directly from the cleaned experimental signal. We analyze time series
of plasma parameters of the low-speed streams of the solar wind measured in situ by Helios in the inner heliosphere. The resulting spectrum of dimensions shows a multifractal structure of the solar wind
attractor. In order to quantify that multifractality, we use a simple analytical model of the dynamical system. Namely, we
consider the generalized self-similar baker’s map with two parameters describing uniform compression and natural invariant
measure on the attractor of the system. The action of this map exhibits stretching and folding properties leading to sensitive
dependence on initial conditions. The obtained solar wind singularity spectrum is consistent with that for the multifractal
measure on the weighted baker’s map. 相似文献
998.
N.M. Ashok R.K. Manchanda D.P.K. Banerjee S. Farrell R.K. Sood 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2006,38(12):2777-2778
We present near-infrared spectroscopy of the massive X-ray binary 2S 0114+650. These observations covering the spectral range 1.08–2.35 μm span the region where Paschen and Brackett series recombination lines of hydrogen are expected to be seen, namely, Paβ , Brγ and Br 10–17 lines. The absence of any of these lines in emission supports earlier inferences that the optical component in 2S 0114+650 is unlikely to be a Be star but rather a B type supergiant. Near-IR photometry gives J = 8.78, H = 8.53 and K = 7.96; these values show marginal variations from earlier reported measurements. 相似文献
999.
T. Muoz-Darias I.G. Martínez-Pais J. Casares T.R. Marsh R. Cornelisse D. Steeghs V.S. Dhillon P.A. Charles 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2006,38(12):2762-2764
We present preliminary results of a simultaneous X-ray/optical campaign of the prototypical LMXB Sco X-1 at 1–10 Hz time resolution. Lightcurves of the high excitation Bowen/HeII emission lines and a red continuum at λc 6000 Å were obtained through narrow interference filters with ULTRACAM, and these were cross-correlated with simultaneous RXTE X-ray lightcurves. We find evidence for correlated variability, in particular when Sco X-1 enters the Flaring branch. The Bowen/HeII lightcurves lag the X-ray lightcurves with a light travel time which is consistent with reprocessing in the companion star while the continuum lightcurves have shorter delays consistent with reprocessing in the accretion disc. 相似文献
1000.
In developing radio-electronic devices (RED) of spacecraft operating in the fields of ionizing radiation in space, one of the most important problems is the correct estimation of their radiation tolerance. The “weakest link” in the element base of onboard microelectronic devices under radiation effect is the integrated microcircuits (IMC), especially of large scale (LSI) and very large scale (VLSI) degree of integration. The main characteristic of IMC, which is taken into account when making decisions on using some particular type of IMC in the onboard RED, is the probability of non-failure operation (NFO) at the end of the spacecraft’s lifetime. It should be noted that, until now, the NFO has been calculated only from the reliability characteristics, disregarding the radiation effect. This paper presents the so-called “reliability” approach to determination of radiation tolerance of IMC, which allows one to estimate the probability of non-failure operation of various types of IMC with due account of radiation-stimulated dose failures. The described technique is applied to RED onboard the Spektr-R spacecraft to be launched in 2007. 相似文献