Paleoproterozoic Extensional Structure and Its Controlling on Mineralization in the East of Liaoning Province     

Yang Zhongzhu  Chen Shuliang  Li Xiandong  Wang Zhongjiang  Qu Hongxiang  Gang Jiang 《东北亚地学研究》2001,(1)

IntroductionThe area of eastern Liaoning is an importantmetal and nonmetal metallogenetic district in China,and the Liaohe group is one of the most importantstrata that hosts Pb, Zn, Au, B and Mg etcstratabound deposits. Up to now many geo1ogistssuch as Z…  相似文献   

An Early Investigation Of The Striated Tail Of Comet Hale-Bopp (C/1995 O1)     

Pittichovâ  J.  Sekenina  Z.  Birkle  K.  Boehnhardt  J.  Engels  D.  Keller  P. 《Earth, Moon, and Planets》1997,78(1-3):329-338

The Sekanina-Farrell particle fragmentation model for the striated tails of dust comets is successfully applied to two images of comet Hale-Bopp to study the motions of 12 striae in a time span of March 12–15, 1997. There is evidence for recurring outbursts with a periodicity of 11^h21^m, consistent with results based on analysis of dust jets. The ejecta in all the striae appear to have been released from one source on the nucleus between the end of January and the second half of February 1997, some 60 to 40 days before perihelion. The parent particles were subjected to a radiation pressure acceleration of β_p ≃ 0.55 and their fragmentation lifetimes in 11 of the 12 striae were practically constant and equal to 13–15 days, when normalized to 1 AU from the Sun. Brief analysis of Watanabe et al.'s measurements of striae on their images from March 5–9, 1997 shows even shorter fragmentation lifetimes for the parent particles, mostly about 7–11 days at1 AU. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

A Linear Dependence between the Magnitude and the Logarithm of the Length of the Time the Quasars OJ287 and 3C345 Stay below this Magnitude     

Jin He  G.Z. Xie 《Astrophysics and Space Science》1997,254(2):223-232

We have studied the optical historical light curves of two Active Galactic Nuclei (AGNs): OJ287 and 3C345. We find a linear dependence between the magnitude and the logarithm of the length of the time the objects stay below this magnitude. The relation may originate from a fractal structure of the light curve. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

富碳拱星IRC＋10216和CIT6的CO J=1—0转动谱的观测     

裴春传  陈亚峰 《紫金山天文台台刊》1997,16(4):226-231

使用中国科学院紫金山天文台青海站13.7米射电望远镜于1996年12月至1997年1月对富碳拱星IRC 10216和CIT6的CO J=1-0跃迁(115GHz)进行了观测。在观测谱线的基础上得到了IRC 10216的视向速度和膨胀速度分别为一26.1km s~(-1)和14.8km s~(-1),CIT6的视向速度和膨胀速度分别为0.6km s~(-1)和13.8kms~(-1)。并对望远镜的射束及指向精度进行了研究。  相似文献   

    

Pei-Shan Chen 《地震学报(英文版)》1996,9(3):531-534

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High-temperature geothermal reservoir possibilities in Hungary     

L. Stegena  F. Horváth  K. Landy  Z. Nagy  J. Rumpler 《地学学报》1994,6(3):282-288

Theoretical studies have shown the possibility of high-temperature ('high enthalpy') geothermal reservoirs in the pre-Tertiary rocks at 4–5 km depth range within the Pannonian Basin. This expectation was proven by the hotwater/steam blowout of Fábiánsebestyén-4 borehole (16.12.85–31.1.86). Exploration efforts carried out during 1987–88 in the broad vicinity of the borehole proved that reservoirs of this type can be found with the combination of seismic reflection, silica-thermometry and magnetotelluric sounding methods. Deliberate prospection should be continued in all suitable areas within the basin, since high enthalpy reservoirs promise profitable operation of geothermal power stations.  相似文献   

Remarks on dynamical ellipticity at the Earth's     

C. Z. Zhang  Y. F. Xia 《Earth, Moon, and Planets》1994,65(3):269-276

In this paper, two factors — the redistribution of the density and the variation in the angular velocity of the Earth rotation, that affect the adopted value of the flattening for equidensity surface within the Earth, are discussed. The computational results show that the contribution of the redistribution of the density in the Earth interior (especially in the core) on the change of the flattening at the core-mantle boundary (CMB) is marginal, and that the calculated value of the flattening at the CMB can be in good agreement with the VLBI observed value so long as the fact that the angular velocity of the Earth rotation has undergone the tidal evolution is taken into account. As a result, this paper presents a set of recommended values of the dynamical parameters of the Earth (see Table III) for computing Earth's forced nutation series.  相似文献   

Prediction in Real Time of the 2000 July 14 Heliospheric Shock Wave and its Companions During the `Bastille' Epoch*     

Dryer  M.  Fry  C.D.  Sun  W.  Deehr  C.  Smith  Z.  Akasofu  S.-I.  Andrews  M.D. 《Solar physics》2001,204(1-2):265-284

Prediction of solar-generated disturbances and their three-dimensional propagation through interplanetary space continues to present a vitally important operational space weather forecasting objective. This paper presents the first successful real-time prediction of a series of major heliospheric shock waves at Earth, including the one from the 14 July 2000 (`Bastille Day') flare. An ensemble of three models and their predictions were distributed to a world-wide group of interested scientists as part of an informal Internet space weather forecast research program. Two of the models, STOA (Shock Time of Arrival) and ISPM (Interplanetary Shock Propagation Model), presently in operation by the US Air Force Weather Agency, provided predictions of shock arrival time (SAT) that were, respectively, 0.5 hours after and 3.7 hours before the observed arrival. The third model, HAFv.2 (Hakamada–Akasofu–Fry version 2.0) predicted a time 0.3 hours after the observed shock arrival time (14:37 UT, 15 July 2000). Of primary interest to this study is the third model, firstly in terms of its capability of propagating shocks through non-uniform solar wind conditions, and secondly, in terms of its ability to integrate multiple solar events and display them graphically along with the background solar wind. This latter capability was brought to bear on ten real-time-reported flares, some with CMEs (coronal mass ejections) that took place as companions to the Bastille flare during the period 7–15 July 2000. Some limited statistics are given regarding the three models' shock arrival prediction capability at Earth, as an extension of our earlier studies with this three model ensemble in the prediction of SAT. HAFv.2, however, was able to describe not only the ten events and their interaction as measured at Earth, but also at the spacecraft NEAR (orbiting the asteroid, Eros, at 1.8 AU), and CASSINI (en route, at 4.0 AU, to Saturn). Several important points are noted: (1) this epoch represents a small statistical sample that should be expanded; and (2) the three models, based on theory, empiricism, and simulations represent the state of the art that should presage a similar community process. This paper was presented earlier as an Invited Talk at the American Geophysical Union Fall Meeting, December 14–19, 2000, in San Francisco, CA, U.S.A.toward space weather objectives in the Sun-Earth domain. Supplementary material to this paper is available in electronic form at http://dx.doi.org/10.1023/A:1014200719867  相似文献   

Preliminary observations of oxygen and carbon dioxide of the wintertime Bering Sea marginal ice zone     

Chen-Tung A. Chen 《Continental Shelf Research》1985,4(4):465-483

Wintertime oxygen and pH profiles across the marginal ice zone of the central and southeastern Bering Sea shelf are analyzed and compared with summer data. During the winter, at water depths shallower than 75 m, the water column is homogeneous and near freezing. Between the 75- and 200-m isobaths the structure is essentially two-layered, a cool and fresh upper layer overlying a warmer, more saline bottom layer. The oxygen concentration in the surface mixed layer is higher than the summer values, but the degree of saturation is lower because of the lower temperature in winter. The oxygen degree of saturation in the bottom mixed layer on the shelf in winter are higher than in the surface water in winter and the bottom water in summer.In summer the oxygen and carbon dioxide data show extreme variability governed primarily by biological processes. Winter oxygen and pH data, however, do not scatter as much as the summer data and indicate conservative mixing of several sub-surface water masses. The surface water is undersaturated in both oxygen and carbon dioxide and seems to absorb oxygen, but little carbon dioxide, from the atmosphere.Two stations were occupied in the Aleutian Basin. The homogeneous surface layer has the same oxygen and pH values as in the minimum temperature layer observed in the summer by other investigators at the same location. The result substantiates the hypothesis of early investigators that the summer minimum temperature layer is the remnant local winter water. All winter surface waters sampled are undersaturated with respect to oxygen, suggesting that the input of oxygen through the air-sea exchange does not keep up with the rate of upwelling and cooling, which reduces the degree of oxygen saturation. Surface carbon dioxide is also undersaturated because of cooling. The maximum temperature layer at these two Aleutian Basin stations is warmer, fresher, and contains more oxygen, but less carbon dioxide, than in the summer, suggesting advective input of some nonlocal seawater.  相似文献   

Spectrophotometric Variability of Mira     

A. A. Arkharov  E. I. Hagen-Torn  T. U. Puzakova  E. V. Ruban 《Astrophysics》2005,48(2):143-155

Data from the Pulkovo spectrophotometric data base on the absolute quasimonochromatic fluxes from oCet in the 320–1080 nm range are used to determine the physical parameters of this star in different phases of its light curve. The continuum emission layer is found to expand between the phases of the cycle corresponding to the rising and falling branches of the light curve. The average expansion velocity is 32 km/s. By the time the star’s brightness has fallen by roughly three magnitudes, its radius has increased by almost a factor of three. Over this same time the temperature of the layer has fallen from 3000 K to 2200 K. For this expansion velocity, the calculated mass rate loss is ⊙ M /year.__________Translated from Astrofizika, Vol. 48, No. 2, pp. 175–189 (May 2005).  相似文献