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1.
周爱华 《中国天文和天体物理学报》1994,(3)
本文根据１９８０年２月至１９８９年１１月期间ＳＭＭ卫星的硬Ｘ射线（ＨＸＲ）暴观测和ＧＯＥＳ卫星的行星际质子积分流量观测，证认出４８个共同样品，统计发现ＨＸＲ暴的寿命Ｔｄ（ｓ）、峰值记数率Ｆｘ（ｃ／ｓ）和爆发期间发射的总光子数ｃ的对数值，与行星际质子积分流量（被归一到耀斑本地）值Ｆｐ的对数值之间，均具有特别显著的线性关系，其中以ｌｏｇＦｐ与ｌｏｇＣ的线性关系为最好，其拟合方程是ｌｏｇＦｐ（＞１０ＭｅＶ）＝一０．６０４＋０．５３８ｌｏｇＣ，相关系数ｒ为０．７０，相对标准误差为０．２８．文中对质子积分流量的预测精度也作了讨论，并给出了置信区间。 相似文献
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本文根据１９８０年２月至１９８９年１１月期间ＳＭＭ卫星的硬Ｘ射线暴观测和ＧＯＥＲ卫星珠卫星际质子积分流量Ｆｐ观测，证认出４８个共同样品，统计发现ＨＸＲ暴的寿命ＴＤ，峰值记数率Ｆｘ和爆发期间射的总光子数Ｃ的对数值，与行星际质子积分流量（初归一到耀斑本地）值Ｆｐ的对数值之间，均具有特别显著的线性关系，其中以ｌｏｇＦｐ与ｌｏｇＣ的线性关系的最好，其拟合方程是ｌｏｇＦｐ＝－６．０４＋０．５３８ｌｏｇＣ，相 相似文献
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根据近年来地面和空间观测资料的统计分析指出：（１）太阳质子事件（或质子耀斑）的发生同起伏剧烈的强微波爆发（包括脉冲和ＩＶμ型爆发）或短分米波ＩＶ型爆发存在着紧密的共生关系（共生率趋近１００％）；（２）约有２４％—３０％的质子事件没有对应的ＩＩ型爆发。这一结果否定了以前认为ＩＩ型爆发中的激波加速是产生质子事件必要条件的看法，进而论证了产生强微波（脉冲或ＩＶ＿μ型）爆发的相对论性电子（≥５００ｋｅｖ）与质子耀斑中的高能质子（＞１０ＭｅＶ）都是在耀斑脉冲相的磁环中受到随机ＭＨＤ湍动加速作用而产生的。那些逃逸到行星际空间的质子流就构成了太阳质子事件。 相似文献
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第22周中最强烈的太阳活动区 总被引：2，自引：2，他引：0
本文根据观测资料，选取五个指标：活动区中黑子群面积，Ｘ级Ｘ射线耀斑指数，１０．７ｃｍ射电爆发峰值流量，太阳总辐射流量短期大跌落以及质子事件流量，从第２２周的３９６６个活动区中综合评估筛选出ＡＲ５３９５，ＡＲ６５５５和ＡＲ６６５９等１３个最强烈的活动区，供太阳物理和日地物理研究人员进一步研究。本文还简要分析了这１３个活动区的时空分布的不均匀性和相对集中性等特点。 相似文献
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太阳射电爆发与高能质子加速过程 总被引：3，自引：0，他引：3
根据近年来地面和空间观测资料的统计分析指出：（１）太阳质子事件（或质子耀斑）的发生同起伏剧烈的强微波爆发（包括脉冲和ＩＶμ型爆发）或短分米波ＩＶ型爆发存在着紧密的共生关系（共生率趋近１００％）；（２）约有２４％－３０％的质子事件没有对应的ＩＩ型爆发。这一结果否定了以前认为ＩＩ型爆发中的激波加速是产生质子事件必要条件的看法，进而论证了产生强微波（脉冲或ＩＶμ型）爆发的相对论性电子（≥５００ｋｅＶ）与 相似文献
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本文收集了ＳＭＭ运行期间（１９８０．２－１９８９．１１）与地面观测相对应的太阳白光耀斑ＨＸＲＢＳ和ＧＲＳ观测资料，就白光耀斑与硬Ｘ－射线发射及伽玛射线发射之产的关系进行了初步的统计研究，结果表明：白光耀斑与伽玛射线发射之间不存在对应关系；白光耀斑也并非全具有强硬Ｘ－射线发射，对那些只具有对较弱的硬Ｘ－射线发射的白光耀斑，我们发现低能粒子具有足够的能量驱动连续发射，因而它们可能起源于色球，而对那些具 相似文献
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太阳微波爆发中精细结构的统计研究 总被引：1，自引：0，他引：1
本总结了北京天台１９９１年的２８４０ＭＨｚ波段微波爆发中精细结构（ＦＳ）事件的观测。从ＦＳ的时间标度、强度、共生的微波爆发的峰值流量、ＦＳ发生在微波爆发的相位和ＦＳ与Ｈ。耀斑的关系等关系作了统计分子。发现约６７％以上的ＦＳ其持续时间为几十毫秒到几百毫秒，８５％以上的ＦＳ幅度小于２００ｓｆｕ，讨论了ＦＳ的时标、强度及２２周太阳峰年期与２１周ＦＳ出现率的差别。 相似文献
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分析了与日冕物质抛射(CME)有关的太阳微波爆发(SMB)的特征,包括持 续时间、峰值流量、爆发类型、谱指数等．选取了从1999年11月至2003年9月的136 个事件,包括60个部分晕状CME(120°<宽度<360°)／晕状CME(宽度=360°)和 76个正常CME(20°<宽度<120°)／窄CME(0°<宽度<20°)． 研究发现: (1)与正常CME／窄CME有关的微波爆发持续时间较短,与部分晕状 ／晕状CME有关的微波爆发持续时间有长有短; (2)与慢CME有关的微波爆发持续时 间较短,与快CME有关的微波爆发持续时间可长可短;(3)与正常／窄CME有关的微 波爆发峰值辐射流量比较小,与部分晕状／晕状CME有关的微波爆发峰值辐射流量有大 有小;(4)与慢CME有关的微波爆发峰值辐射流量较小,与快CME有关的微波爆发峰 值辐射流量可长可短; (5)与正常／窄CME有关的微波爆发绝大多数为简单(simple) 型,与晕状CME有关的微波爆发绝大多数为复杂(C)／大爆发(GB)型; (6)与CME 有关的事件在频率,f相似文献
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《中国天文和天体物理学报》2014,(10)
正Research in Astronomy and Astrophysics publishes original research papers and reviews on all branches of astronomy and astrophysics.Reviews are by invitation only.Important new results that require rapid publication can be submitted as a Letter(Letters must be restricted in length to 6 printed pages).Authors who submit a paper are expected to be able to certify that the paper is original work, 相似文献
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Laura Schaefer 《Icarus》2005,173(2):454-468
We use chemical equilibrium calculations to model the speciation of alkalis and halogens in volcanic gases emitted on Io. The calculations cover wide temperature (500-2000 K) and pressure (10−6 to 10+1 bars) ranges, which overlap the nominal conditions at Pele (T=1760 K, P=0.01 bars). About 230 compounds of 11 elements (O, S, Li, Na, K, Rb, Cs, F, Cl, Br, I) are considered. The elemental abundances for O, S, Na, K, and Cl are based upon observations. CI chondritic elemental abundances relative to sulfur are used for the other alkalis and halogens (as yet unobserved on Io). We predict the major alkali species in Pele-like volcanic gases and the percentage distribution of each alkali are LiCl (73%), LiF (27%); NaCl (81%), Na (16%), NaF (3%); KCl (91%), K (5%), KF (4%); RbCl (93%), Rb (4%), RbF (3%); CsCl (92%), CsF (6%), Cs (2%). Likewise the major halogen species and the percentage distribution of each halogen are NaF (88%), KF (10%), LiF (2%); NaCl (89%), KCl (11%); NaBr (89%), KBr (10%), Br (1%); NaI (61%), I (30%), KI (9%). We predict the major halogen condensates and their condensation temperatures at P=0.01 bar are NaF (1115 K), LiF (970 K); NaCl (1050 K), KCl (950 K); KBr (750 K), RbBr (730 K), CsBr (645 K); and solid I2 (200 K). We also model disequilibrium chemistry of the alkalis and halogens in the volcanic plume. Based on this work and our prior modeling for Na, K, and Cl in a volcanic plume, we predict the major loss processes for the alkali halide gases are photolysis and/or condensation onto grains. Their estimated photochemical lifetimes range from a few minutes for alkali iodides to a few hours for alkali fluorides. Condensation is apparently the only loss process for elemental iodine. On the basis of elemental abundances and photochemical lifetimes, we recommend searching for gaseous KCl, NaF, LiF, LiCl, RbF, RbCl, CsF, and CsCl around volcanic vents during eruptions. Based on abundance considerations and observations of brown dwarfs we also recommend a search of Io's extended atmosphere and the Io plasma torus for neutral and ionized Li, Cs, Rb, and F. 相似文献
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《中国天文和天体物理学报》2014,(9)
正Research in Astronomy and Astrophysics publishes original research papers and reviews 011 all liranchcs of astronoiriy and astrophysics.Reviews arc by invitation only.Important new results that require rapid publication can be submitted as a Letter(Letters must be restricted in length 相似文献
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Li Xin-nan Zhang Hai-ying Cui Xiang-qun Jiang Zi-bo Zheng Yi Liu Xing-tao Ni Hou-kun 《Chinese Astronomy and Astrophysics》2012
A special stressed annular polishing technique is proposed to mill the off-axis aspheric sub-mirrors of a large segmented mirror with an annular polishing machine. Based on the basic principle of stressed annular polishing technique, a set of special stressing mechanisms are designed to convert milling the aspheric surfaces of sub-mirrors with different off-axis distances into milling the spherical surfaces with identical radii of curvature, so that they can be pol- ished simultaneously on a continuous polishing machine. It took about contin- uous 40 hours to polish a scaled-down mirror of the planning Chinese Future Giant Telescope (CFGT) using this technique. This mirror has the 330 mm di- ameter, 3.6 m off-axis distance, and the 21.6 m radius of curvature, and its max- imum asphericity is 16 micron. The experiment shows that this method has a high effciency, suits batch manufacturing, especially the batch manufacturing of aspheric sub-mirrors of the segmented primary mirror of an extremely large aperture telescope. 相似文献
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Yehouda Enzel Rivka Amit Uri Dayan Onn Crouvi Ron Kahana Baruch Ziv David Sharon 《Global and Planetary Change》2008,60(3-4):165-192
Modern-day synoptic-scale eastern Mediterranean climatology provides a useful context to synthesize the diverse late Pleistocene (60–12 ka) paleohydrologic and paleoenvironmental indicators of past climatic conditions in the Levant and the deserts to its south and east. We first critically evaluate, extract, and summarize paleoenvironmental and paleohydrologic records. Then, we propose a framework of eastern Mediterranean atmospheric circulation features interacting with the morphology and location of the southeast Mediterranean coast. Together they strongly control the spatial distribution of rainfall and wind pattern. This cyclone–physiography interaction enforces the observed rainfall patterns by hampering rainfall generation south and southeast of the latitude of the north Sinai coast, currently at 31°15′.The proposed framework explains the much-increased rains in Lebanon and northern Israel and Jordan as deduced from pollen, rise and maintenance of Lake Lisan, and speleothem formation in areas currently arid and semiarid. The proposed framework also accounts for the southward and eastward transition into semiarid, arid, and hyperarid deserts as expressed in thick loess accumulation at the deserts' margins, dune migration from west to east in the Sinai and the western Negev, and the formation of hyperarid (< 80 mm yr− 1) gypsic–salic soils in the southern Negev and Sinai. Our climatic synthesis explains the hyperarid condition in the southern Negev, located only 200–250 km south of the much-increased rains in the north, probably reflecting a steeper rainfall gradient than the present-day gradient from the wetter Levant into its bordering southern and eastern deserts.At present, the rainiest winter seasons in Lebanon and northern and central Israel are associated with more frequent (+ 20%), deeper Cyprus Lows traversing the eastern Mediterranean at approximately the latitude of southern Turkey. Even these wettest years in northern Israel do not yield above average annual rainfall amounts in the hyperarid southern Negev. This region is mainly influenced by the Active Red Sea Troughs that produce only localized rains. The eastern Mediterranean Cyprus Lows also produce more dust storms and transport higher amounts of suspended dust to the loess area than any other atmospheric pattern. Concurrent rainfall and dust are essential to the late Pleistocene formation of the elongated thick loess zone along the desert northern margin. Even with existing dust storms, the lack of rain and very sparse vegetation account for the absence of late Pleistocene loess sequences from the southern Negev and the formation of hyperarid soils.When the north Sinai coast shifted 30–70 km northwest due to last glacial global sea level lowering, the newly exposed coastal areas supplied the sand and dust to these active eastern Mediterranean cyclones. This enforced the latitude of the northern boundary of the loess zone to be directly due east of the LGM shoreline. This shift of coast to the northwest inhibited rainfall in the southern Levant deserts and maintained their hyperaridity. Concurrently, frequent deep eastern Mediterranean Cyprus Lows were funneled along the northern Mediterranean increasing (probably doubling) the rains in central and northern Israel, Lebanon, southwestern Syria and northern Jordan. These storms and rains formed lakes, forests, and speleothems only a short distance north of the deserts in the southern Levant. 相似文献
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Philippe Stee 《Astrophysics and Space Science》2003,286(1-2):225-236
Interferometry in the visible provides milliarcsecond spatial resolution and thus has been used for studying the circumstellar
environment of active hot stars. In this paper I will illustrate how the visibility modulus and phase can be used to better
constrain the physics of Be disks through results from the VLA, the MkII and the GI2T interferometers. I will insist on the
importance and the potential of coupling high angular resolution with high spectral resolution to the study of Be shells.
Finally I will present a possible study of the circumstellar disk of Be stars using the VLTI.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
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The central compact object for some gamma-ray bursts (GRBs) may be a strongly magnetized millisecond pulsar. It can inject energy to the outer shock of the GRB by through the magnetic dipole radiation, and therefore causes the shallow decay of the early afterglow. Recently, from a large number of GRB X-ray afterglows observed by Swift/XRT(X-ray telescope), it is revealed that many of them exhibit the shallow decay about 102∼104 s after the burst prompt emission. We have fitted the X-ray afterglow light curves of 11 GRBs by using the energy injection model of a magnetar with the rotation period in the millisecond order of magnitude. The obtained result shows the validity and universality of the magnetar energy injection model in explaining the shallow decay of afterglows, and simultaneously provides some constraints on the magnetic field strength and rotation period of the central magnetar. 相似文献