The Effect of Solar Activity on the Annual Precipitation in the Beijing Area   总被引：3，自引：0，他引：3  

Juan Zhao  Yan-Ben Han  Zhi-An LiDepartment of Astronomy  Beijing Normal University Beijing  zj@bnu.edu.cnNational Astronomical Observatories  Chinese Academy of Sciences  Beijing 《中国天文和天体物理学报》2004,4(2):189-197

Using continuous wavelet transform, we examine the relationship between solar activity and the annual precipitation in the Beijing area. The results indicate that the annual precipitation is closely related to the variation of sunspot numbers, and that solar activity probably plays an important role in influencing the precipitation on land.  相似文献   

Polar fields for AB Doradus     

T. McIvor  M. Jardine  A. Collier Cameron  K. Wood  J.-F. Donati 《Monthly notices of the Royal Astronomical Society》2003,345(2):601-608

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Hα Photometry of Two Contact Binaries     

Szilárd Csizmadia  Zsolt Kővári  Péter Klagyivik 《Astrophysics and Space Science》2006,304(1-4):355-357

We carried out optical and Hα photometry of two contact binaries (V861 Herculis, EQ Tauri). The light curve modeling revealed stellar spots in both contact systems and strong Hα excess in the position of the observed stellar spots. A correlation was found between the V−R and R−H_α colour indices of V861 Her.  相似文献   

Observation of, and temporal variations in, solar p-mode multiplet frequency asymmetries at  ℓ= 2      

W. J. Chaplin  Y. Elsworth  G. R. Isaak  B. A. Miller  R. New  S. Thiery  P. Boumier  A. H. Gabriel 《Monthly notices of the Royal Astronomical Society》2003,343(1):343-352

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Observational Test of an Accretion Model of Star Formation in Galactic Clusters     

J. N. Pramanik  S. K. Bhattacharjee 《Astrophysics and Space Science》2006,306(4):241-248

Theoretical predictions of an accretion model of star formation in galactic clusters, published quite long ago, which is found to have some relevance with the current picture of star formation have been tested with observation of seven clusters of young and intermediate ages. It is found that the agreement between the theory and observation is very good.  相似文献   

Strong asymmetry in stellar dynamos     

P. J. Bushby 《Monthly notices of the Royal Astronomical Society》2003,338(3):655-664

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Shear and objective stress rates in hypoplasticity     

D. Kolymbas  I. Herle 《国际地质力学数值与分析法杂志》2003,27(9):733-744

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三峡地区地形变监测与区域地壳稳定性分析     

张众服 《大地测量与地球动力学》1996,(4)

利用三峡地区多年的地形变观测资料，分析了该区的地形变特征。结果表明，各断层活动性甚微或基本不活动，区域地壳相对稳定  相似文献   

Impact of land use covers upon karst processes in a typical Fengcong depression system of Nongla, Guangxi, China   总被引：2，自引：0，他引：2  

Cheng Zhang  Jianguo Pei  Yunqiu Xie  Jianhua Cao  Lanling Wang 《Environmental Geology》2008,55(8):1621-1626

The direction and intensity of karst processes can be deeply affected by soil physical and chemical variations which were resulted from land use. Taking Nongla Fengcong depression area, Mashan County, Guangxi as an example, authors discussed the impact of land use on karst processes based on the data of field limestone tablet. The results showed that the corrosional rates at varied soil depth are quite different. Corrosional rate in woodland and orchard is mostly bigger than 20 mg/a, which is much higher than that in tilled land and shrub. Generally, corrosional rate decreased from orchard, woodland, tilled land, fallow land and shrub successively, in which soil organic matter (OM) and soil pH are two major controlling factors: corrosion process is controlled remarkably by soil OM in woodland and orchard. The higher the organic matter content is and the less the pH value is, the higher the corrosional rate is. Owing to lower organic matter content, the corrosional rate is mainly affected by soil CO₂ in tilled land and shrub.  相似文献   

Natural radioactivity in sediment of Wei River,China   总被引：1，自引：0，他引：1  

Xinwei Lu  Xiaolan Zhang  Fengling Wang 《Environmental Geology》2008,53(7):1475-1481

The concentrations of natural radionuclides in sediment of Wei River of China were measured using γ-ray spectrometry with the aim of estimating the radiation hazard as establishing a database for radioactivity levels of river sediment of China. The activity concentrations of ²²⁶Ra, ²³²Th and ⁴⁰K in sediment samples ranged from 10.4 to 39.9 Bq kg⁻¹, 15.3 to 54.8 Bq kg⁻¹ and 514.8 to 1,175.5 Bq kg⁻¹, respectively. The concentrations of these radionuclides were compared with the typical world values and the average activities of Chinese soil and Shaanxi soil. Radium equivalent activity (Ra_eq), external hazard index (H _ex) and representative level index (I _γr) were calculated for the samples to assess the radiation hazards arising due to the use of these sediment samples in the construction of dwellings. All the sediment samples have Ra_eq lower than the limit of 370 Bq kg⁻¹, H _ex less than unity and I _γr close to 1 Bq kg⁻¹. The overall mean outdoor terrestrial gamma dose rate is 64.8 nGy h⁻¹ and the corresponding outdoor annual effective dose is 0.079 mSv. None of the studied location is considered a radiological risk and sediment can be safely used in construction.  相似文献