Early-fusion based pulsar identification with smart under-sampling

The discovery of pulsars is of great significance in the field of physics and astronomy.As the astronomical equipment produces a large number of pulsar data,an ...     

香港地区活动断裂的初步探讨

香港地区的断裂构造颇为发育,主要有北东、北东东和北西向三组断裂。在现今构造应力场作用之下,北东东和北西向断裂组成共轭断裂系统。由于本地区地震活动水平不高,尚难确定哪组断裂与地震活动密切相关。断层泥的热释光资料表明,断裂的最新活动应在晚更新世,断裂的复发周期应在１０万年左右。目前尚不能肯定哪条断裂为活动断裂。     

Geothermal potential evaluation and development prioritization based on geochemistry of geothermal waters from Kangding area,western Sichuan,China

Kangding geothermal area is located in the western Sichuan, belonging to southeastern margin of Tibetan Plateau. Similar to world-renowned south Tibetan and western Yunnan geothermal belt, western Sichuan has intensive surface thermal manifestations including boiling and hot springs. The emerging temperature of thermal waters ranges from 47 to 79 °C with total dissolved solids lying between 899 and 2550 mg/L. δ²H–δ¹⁸O isotopes indicate a meteoric source for the thermal waters and a significant positive oxygen-18 shift in the southern region. It is suggested that southern thermal waters experienced stronger water–rock interaction and are closer to thermodynamic equilibrium, which is also proved by the water type classification. The reservoir temperature calculated by empirical and theoretical chemical thermometry is 180–225 °C for the north and 225–310 °C for the south. Evidences of hydrogeochemistry, stable isotopes, geothermometry and radiocarbon dating indicate that southern region of Kangding area shows greater geothermal potential than the northern region. In addition, based on the hydrogeochemical modeling of mineral saturation, underlying problem of scaling is likely to occur in the study area. According to the results of reservoir temperature, south Kangding sub-district has greater potential in geothermal power generation and development than northern Kangding. Therefore, further exploration and drilling work should give priority to the south Kangding area.     

Distribution and source of heavy metals in the surface sediments from the near-shore area,north Jiangsu Province,China

Samples of surface sediment and vibrocore were collected in the near-shore area of north Jiangsu Province for grain size, elements, ²¹⁰Pb_excess and ¹³⁷Cs analyses. In our study area, the diversity of metal concentration was controlled not by the grain size, but by the source. The element content of the old Yellow River Delta was used as baseline for our study area. Geoaccumulation indexes indicate that no station was polluted by Cu, Pb, Zn and As, but the I_geo values of As were close to zero in some stations. Slight pollution caused by Cd was observed in some stations. Correlation and enrichment factors suggest that Cu, Pb and Zn are lithogenic in origin, while As and Cd are mixed in origin. Especially, in some polluted stations Cd was obviously anthropogenic in origin.     

基于星载GPS的HY-2卫星高精度精密定轨模拟研究(英文)

HY-2卫星是我国第一颗测高卫星,其径向定轨精度要求厘米量级,搭载了星载GPS接收机。目前HY-2还处于测试阶段,没有公布观测数据。为了确定基于星载GPS的HY-2精密定轨流程及其定轨精度,本文模拟了HY-2卫星星载GPS观测数据,结果表明HY-2星载GPS天线每个历元至少观测7颗GPS卫星。给出了基于星载GPS的精密定轨流程,分别采用简化动力学方法和动态几何法进行了精密定轨实验。对于相位1mm和3mm随机误差的相位观测数据,简化动力学法和动态几何法定轨都能够实现厘米量级的径向精密定轨,几何法定轨精度略低于简化动力定轨。地球重力场模型是影响HY-2卫星精密定轨的重要因素,本文对不同阶次的重力场模型EIGEN2、EGM96、TEG4和GEMT3进行了简化动力学定轨实验,高于50阶次的重力场模型都能够实现厘米级径向精密定轨,主要原因在于大量的高精度星载GPS观测数据和重力场模型精度的提高。     

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贵州省毕节地区煤矸石特征及综合利用分析

研究分析了毕节地区部分矿区煤矸石的特征,指出该区煤矸石总的特点是SiO2、Fe2O3、CaO含量偏高,Al2O3偏低,但不同矿区有一定的差异。根据煤矸石的成分特征,指出了毕节地区煤矸石的利用方向,如制作水泥、新型墙体材料、空心砌块、陶粒（轻骨料、多孔骨料）、铸石,回收铝产品,生产肥料,利用矸石发电及用作筑路材料等。对其在综合利用方面存在的问题进行了分析,认为毕节地区煤矸石的综合利用具有广阔前景。     

影响或控制平昌县地质灾害发育的因素分析

通过对四川平昌县滑坡、崩塌等地质灾害发育发育情况的介绍,分析了影响或控制该县地质灾害发育的因素。     

The interaction and eruption of two adjacent filaments

We present a case study of two successive filament eruptions at the southeast limb of the Sun observed by Solar Dynamics Observatory (SDO) on 2012 April 19. At the initial stage of the first filament (F1) eruption, one leg of the F1 moved toward the second filament (F2) and swept the F2. The interaction between two filaments occurred. After the leg of the F1 swept the F2, it returned from northeast to southwest following the F1 expansion. During the F1 eruption, the middle of the F1 exhibited an obvious twisted structure. The rising speed of the F1 was 85.6 km/s. The partial material of the F1 fell back to the surface along the other leg of the F1 after the F1 eruption and the falling speed was 311.6 km/s. A CME was observed by SOHO/LASCO after the F1 eruption. One of the bright flare ribbons and the dimming regions formed after the F1 eruption were found to move toward the F2. The propagation speeds of the flare ribbons were 4.7 km/s and 4.1 km/s and the propagation speeds of the dimmings were 3 km/s and 6.3 km/s. The small active region was emerging in the northern flank of the F2. The ejection and the falling plasma in the small active region produced the disturbance to the right part of the F2. When the F1 erupted, the large-scale overlying coronal loops of the F1 were pushed out toward the southeast of the Sun by its expanding. During the F1 eruption, the large-scale overlying coronal loops of the F2 began to open toward the southeast. Following the opening of the large-scale overlying coronal loops, the F2 became instable and began to erupt. The rising speed of the F2 was 300.1 km/s. A two-ribbon flare and a weak CME were formed after the F2 eruption. These observations evidenced that the interaction of two filaments and the opening of the large-scale overlying coronal loops caused by the F1 eruption are the most important reason that led to the F2 eruption. Our observations also support the standard solar flare model.