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841.
T. Aramaki S.E. Boggs W.W. Craig H. Fuke F. Gahbauer C.J. Hailey J.E. Koglin N. Madden K. Mori R.A. Ong T. Yoshida 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2010
The General AntiParticle Spectrometer (GAPS) is a novel approach for indirect dark matter searches that exploits cosmic antideuterons. GAPS complements existing and planned direct dark matter searches as well as other indirect techniques, probing a different and unique region of parameter space in a variety of proposed dark matter models. The GAPS method involves capturing antiparticles into a target material with the subsequent formation of an excited exotic atom. The exotic atom decays with the emission of atomic X-rays and pions from the nuclear annihilation, which uniquely identifies the captured antiparticle. This technique has been verified through the accelerator testing at KEK in 2004 and 2005. The prototype flight is scheduled from Hokkaido, Japan in 2011, preparatory for a long duration balloon flight from the Antarctic in 2014. 相似文献
842.
A. N. Kusyumov E. V. Romanova A. S. Batrakov R. R. Nurmukhametov G. N. Barakos 《Russian Aeronautics (Iz VUZ)》2012,55(3):263-268
We consider a problem of a stationary incompressible viscous fluid flow around a flat circular cylinder. In the vicinity of the critical Reynolds number Re cr a stepwise drop of the cylinder drag takes place, which is called the drag crisis. 相似文献
843.
This paper presents the results of three-dimensional numerical studies of hydrodynamics and heat exchange on the models of flat plates in the jet airflow. These results are compared with the experimental data. A three-dimensional model for determining the thermal condition of the nozzle clusters in the conjugated formulation is proposed. Also presented are the data on optimization of the system used for the jet airflow around the duct platforms of the nozzle clusters. 相似文献
844.
The Dawn science operations team has designed the Vesta mission within the constraints of a low-cost Discovery mission, and will apply the same methodology to the Ceres mission. The design employs proactive mapping mission strategies and tactics such as functional redundancy, adaptability to trajectory uncertainties, and easy sequence updates to deliver reliable and robust sequences. Planning tools include the Science Opportunity Analyzer and other multi-mission tools, and the Science time-ordered listings. Science operations are conducted jointly by the Science Operations Support Team at the Jet Propulsion Laboratory (JPL) and the Dawn Science Center at the University of California, Los Angeles (UCLA). The UCLA Dawn Science Center has primary responsibility for data archiving while the JPL team has primary responsibility for spacecraft and instrument operations. Constraints and uncertainties in the planning and sequencing environment are described, and then details of the science plan are presented for each mission sub-phase. The plans indicate that Dawn has a high probability of meeting its science objectives and requirements within the imposed constraints. 相似文献
845.
G. Clément D. Hamilton L. Davenport B. Comet 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2010
This paper reviews the medical operations performed on six European astronauts during seven space missions on board the space station Mir. These missions took place between November 1988 and August 1999, and their duration ranged from 14 days to 189 days. Steps of pre-flight medical selection and flight certification are presented. Countermeasures program used during the flight, as well as rehabilitation program following short and long-duration missions are described. Also reviewed are medical problems encountered during the flight, post-flight physiological changes such as orthostatic intolerance, exercise capacity, blood composition, muscle atrophy, bone density, and radiation exposure. 相似文献
846.
R. Govind J.J. Valette F.G. Lemoine 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2010
The Lambert–Amery System is the largest glacier–ice shelf system in East Antarctica, draining a significant portion of the ice sheet. Variation in ice sheet discharge from Antarctica or Greenland has an impact on the rate of change in global mean sea level; which is a manifestation of climate change. In conjunction with a measure of ice thickness change, ice sheet discharge can be monitored by determining the absolute velocities of these glaciers. 相似文献
847.
V. A. Sorokin N. N. Zakharov M. S. Sharov L. S. Yanovskii 《Russian Aeronautics (Iz VUZ)》2010,53(3):295-302
The results of experimental investigations of gasodynamic characteristics of a combustion chamber model in the integrated
power plant (IPP) with an asymmetric air intake are presented. The influence of an angle of air supply into the chamber model
on hydraulic losses and the flow structure is shown at different air flowrates, relative values of the minimal flow section
area of the feeding air intake pipes, under changes of the flowrate of gas simulating gas generation products and geometric
model parameters. A technique for measuring the concentration of carbon dioxide simulating IPP gas generation products in
the combustion chamber air flow and the results of experimental investigations of a mixture formation process in the combustion
chamber model are described. 相似文献
848.
Malini Aggarwal H.P. Joshi K.N. Iyer Y.S. Kwak 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2013
In this paper, response of low latitude ionosphere to a moderate geomagnetic storm of 7–8 May 2005 (SSC: 1920 UT on 7 May with Sym-H minimum, ∼−112 nT around 1600 UT on 8 May) has been investigated using the GPS measurements from a near EIA crest region, Rajkot (Geog. 22.29°N, 70.74°E, Geomag.14°), India. We found a decrease in total electron content (TEC) in 12 h after the onset of the storm, an increase during and after 6 h of Sym-H deep minimum with a decrease below its usual-day level on the second day during the recovery phase of the storm. On 8 May, an increase of TEC is observed after sunset and during post-midnight hours (maximum up to 170%) with the formation of ionospheric plasma bubbles followed by a nearly simultaneous onset of scintillations at L-band frequencies following the time of rapid decrease in Sym-H index (−30 nT/h around 1300 UT). 相似文献
849.
A mission template for exploration and damage mitigation of potential hazard of Near Earth Asteroids
D. C. Hyland H. A. Altwaijry R. Margulieux J. Doyle J. Sandberg B. Young N. Satak J. Lopez S. Ge X. Bai 《Cosmic Research》2010,48(5):437-442
The Apophis Exploratory and Mitigation Platform (AEMP) concept was developed as a prototype mission to explore and potentially
deflect the Near Earth Asteroid (NEA) 99942 Apophis. Deflection of the asteroid from the potential 2036 impact will be achieved
using a gravity tractor technique, while a permanent deflection, eliminating future threats, will be imparted using a novel
albedo manipulation technique. This mission will serve as an archetypal template for future missions to small NEAs and could
be adapted to mitigate the threat of collision with other potential Earth-crossing objects. 相似文献
850.
Approaches in the determination of plant nutrient uptake and distribution in space flight conditions. 总被引:2,自引:0,他引:2
A G Heyenga A Forsman L S Stodieck A Hoehn M Kliss 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2000,26(2):299-302
The effective growth and development of vascular plants rely on the adequate availability of water and nutrients. Inefficiency in either the initial absorption, transportation, or distribution of these elements are factors which impinge on plant structure and metabolic integrity. The potential effect of space flight and microgravity conditions on the efficiency of these processes is unclear. Limitations in the available quantity of space-grown plant material and the sensitivity of routine analytical techniques have made an evaluation of these processes impractical. However, the recent introduction of new plant cultivating methodologies supporting the application of radionuclide elements and subsequent autoradiography techniques provides a highly sensitive investigative approach amenable to space flight studies. Experiments involving the use of gel based 'nutrient packs' and the radionuclides calcium-45 and iron-59 were conducted on the Shuttle mission STS-94. Uptake rates of the radionuclides between ground and flight plant material appeared comparable. 相似文献