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排序方式: 共有321条查询结果,搜索用时 15 毫秒
271.
J. Kleczek H. Nussbaumer K. A. van der Hucht J. P. de Greve G. Ooms R. J. Rutten H. van der Laan F. W. Jäger G. C. M. Reijnen w. Bijleveld J. Kistemaker C. de Jager E. R. Mustel Y. Ne'eman E. R. Priest H. Stiller W. Seifert O. Namba M. Kuperus Roel Hoekstra F. L. H. M. Stumpers S. Frank J. T. F. Zimmerman C. de Loore R. Gendrin J. Schrijver P. S. Mulder K. A. Pounds R. S. Young L. Houziaux O. Engvold B. J. Bok W. de Graaff 《Space Science Reviews》1983,36(4):415-432
272.
O. Ooms Hans Van Der Woerd Henny J. G. L. M. Lamers Josip Kleczek J. Kovalevsky R. Gathier T. Jarzebowski J. P. Swings K. A. van der Hucht O. Namba R. Mewe D. Lynden-Bell Jan Kuijpers M. van der Klis D. de Hoop H. Wittenberg W. Iwanowska P. S. Thé J. Schrijver S. R. Pottasch 《Space Science Reviews》1984,38(3-4):385-387
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Space Science Reviews - 相似文献
276.
基于运动嵌套网格的前飞旋翼绕流N-S方程数值计算 总被引:6,自引:3,他引:6
通过求解 Navier-Stokes方程数值模拟了直升机旋翼前飞非定常流场。为了模拟包括旋转、周期性变距和周期性挥舞的非定常运动,采用了一种能够快速完成重叠网格间流场信息交换的运动嵌套网格方法。空间上采用中心平均的有限体积法进行离散,时间方向应用含隐式子迭代的双时间法推进求解。为了验证程序的正确性,数值计算了一有升力悬停流场,旋翼桨叶表面压力分布的计算值与实验值吻合很好。 相似文献
277.
R. de Jesus Y. Sahai F.L. Guarnieri P.R. Fagundes A.J. de Abreu F. Becker-Guedes C. Brunini M. Gende T.M.F. Cintra V.A. de Souza V.G. Pillat W.L.C. Lima 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2010
This investigation presents observations related to the generation of equatorial ionospheric irregularities (also known as equatorial spread F (ESF)) including ionospheric plasma bubbles and dynamic behavior of the ionospheric F-region in the South American sector during an intense geomagnetic storm in December 2006 (a period of low solar activity). In this work, ionospheric sounding observations and GPS data obtained between 13 and 16 December 2006 at several stations in the South American sector are presented. On the geomagnetically disturbed night of 14 and 15 December, ionospheric plasma bubbles were observed after an unusual uplifting of the F-region during pre-reversal enhancement (PRE) period. The unusual uplifting of the F-region during PRE was possibly associated with prompt penetration of electric field of magnetospheric origin. During the geomagnetic disturbance night of 14 and 15 December, strong oscillations due to the propagation of traveling ionospheric disturbances (TIDs) by the Joule heating in the auroral region were observed in the F-region at São José dos Campos (SJC, 23.2°S, 45.9°W; dip latitude 17.6°S), Brazil, and Port Stanley (PST, 51.6°S, 57.9°W; geom. latitude 41.6°S). The VTEC-GPS observations presented on the night of 14 and 15 December 2006 show both positive and negative storm phases in the South American sector, possibly due to changes in the large-scale wind circulation and changes in the O/N2 ratio in the southern hemisphere, respectively. 相似文献
278.
T. Visser G. March E. Doornbos C. de Visser P. Visser 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2019,63(10):3139-3153
Thermospheric wind measurements obtained from linear non-gravitational accelerations of the Gravity field and steady-state Ocean Circulation Explorer (GOCE) satellite show discrepancies when compared to ground-based measurements. In this paper the cross-wind is derived from both the linear and the angular accelerations using a newly developed iterative algorithm. The two resulting data sets are compared to test the validity of wind derived from angular accelerations and quantify the uncertainty in accelerometer-derived wind data. In general the difference is found to be less than 50?m/s vertically after high-pass filtering, and 100?m/s horizontally. A sensitivity analysis reveals that continuous thrusting is a major source of uncertainty in the torque-derived wind, as are the magnetic properties of the satellite. The energy accommodation coefficient is identified as a particularly promising parameter for improving the consistency of thermospheric cross-wind data sets in the future. The algorithm may be applied to obtain density and cross-wind from other satellite missions that lack accelerometer data, provided the attitude and orbit are known with sufficient accuracy. 相似文献
279.
Julio E. Valdivia-Silva Rafael Navarro-González José de la Rosa Christopher P. McKay 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2012
The organic compounds on the Martian surface are still undetectable by the previous Viking mission that has been sent to Mars even though they are expected to be there by exogenous and/or endogenous synthesis. The high abiotic reactivity has been the most acceptable explanation for the apparently absence of organic matter in the regolith. 相似文献
280.
Where does the stone go when we drop it? Development of French schoolchildren’s knowledge of gravity
Sören Frappart Valérie Frède 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2010
In this study, we explored children’s knowledge of gravity at different ages (5–6, 7–8, and 9–10 years), by asking the same question (“Where does a stone go when we drop it?”) in three different contexts (on Earth, in a spaceship orbiting the Earth, and on the Moon). We tested the influence of context and children’s age on both the answers and the justifications they provided. We expected that children of all ages would find it easier to make correct predictions in the Earth context than in the other two contexts. We were also interested in the kinds of justification children construct and how these justifications change during ontogenesis. Seventy-two French children were individually interviewed at their school. None of them had received any direct teaching about gravity. Results showed that children found it easier to predict the fall of the stone on Earth than its behaviour in the other two contexts, but that the younger children predicted the fall of the stone on the Moon more accurately than the older children. This unusual developmental effect only occurred for the Moon context. We also found that the categories of justifications changed with age, with a move away from intuitive considerations towards mechanistic ones. 相似文献