A Chandra detection of the radio hotspot of 3C 123

Chandra X-ray Observatory observations of the powerful, peculiar radio galaxy 3C 123 have resulted in an X-ray detection of the bright eastern hotspot, with a 1-keV flux density of ∼5 nJy. The X-ray flux and spectrum of the hotspot are consistent with the X-rays being inverse-Compton scattering of radio synchrotron photons by the population of electrons responsible for the radio emission ('synchrotron self-Compton emission') if the magnetic fields in the hotspot are close to their equipartition values. 3C 123 is thus the third radio galaxy to show X-ray emission from a hotspot which is consistent with being in equipartition. Chandra also detects emission from a moderately rich cluster surrounding 3C 123, with L _X(2–10 keV)=2×10⁴⁴ erg s⁻¹ and kT ∼5 keV, and absorbed emission from the active nucleus, with an inferred intrinsic column density of 1.7×10²² cm⁻² and an intrinsic 2–10 keV luminosity of 10⁴⁴ erg s⁻¹.     

晚型星HR5553,εEri和70 Oph的活动性,金属丰度和磁场的测定

对１９９５年１１月和１９９６年３、４月间观测获得的ＨＲ５５５３、７０Ｏｐｈ和εＥｒｉ给出了高分辨率,高信噪比的阶梯光栅光谱资料。确定了这３颗晚型活动星的大气参数,采用谱线细致分析方法求出了铁、锂、钙、钪、钛、钒、铬、锰、钴、镍、钇、锆和钡１３种金属元素的丰度。采用多重线统计方法测定了这３颗晚型活动星的磁场和磁场覆盖因子。     

Influence of 2008 Wenchuan earthquake on earthquake occurrence trend of active faults in Sichuan-Yunnan region

The Wenchuan earthquake coseismic deformation field is inferred from the coseismic dislocation data based on a 3-D geometric model of the active faults in Sichuan-Yunnan region. Then the potential dislocation displacement is inverted from the deformation field in the 3-D geometric model. While the faults' slip velocities are inverted from GPS and leveling data, which can be used as the long-term slip vector. After the potential dislocation displacements are projected to long-term slip direction, we have got the influence of Wenchuan earthquake on active faults in Sichuan-Yunnan region. The results show that the northwestern segment of Longmenshan fault, the southern segments of Xianshuihe fault, Anninghe fault, Zemuhe fault, northern and southern segments of Daliangshan fault, Mabian fault got earthquake risks advanced of 305, 19, 12, 9.1 and 18, 51 years respectively in the eastern part of Sichuan and Yunnan. The Lijiang-Xiaojinhe fault, Nujiang fault, Longling-Lancang fault, Nantinghe fault and Zhongdian fault also got earthquake risks advanced in the western part of Sichuan-Yunnan region. Whereas the northwestern segment of Xianshuihe fault and Xiaojiang fault got earthquake risks reduced after the Wenchuan earthquake.     

一种电离层活跃期的三频TECR周跳处理算法

针对电离层活跃期现有三频周跳处理方法难以正确探测与修复周跳和阈值设定不合理的问题,借鉴双频TECR算法,提出一种能够削弱电离层延迟影响的三频TECR算法。三频TECR组合与三频码相无几何无电离层组合均能有效削弱电离层延迟对周跳探测的影响,并能自适应地确定合理阈值。利用三频实测数据对算法进行验证的结果表明,该方法能够有效消除电离层延迟影响,实现电离层活跃期周跳的动态探测与修复。     

垃圾体内部与衬里界面组合破坏稳定分析方法研究

垃圾填埋场沿底坡和背坡衬里界面发生平移破坏的工程实例较多,也有破坏面沿垃圾体内部和底坡的组合破坏形式,相应的计算分析方法有待完善。对组合破坏,根据垃圾体内部破坏面为库仑主动破坏面和组合破坏面上各点安全系数相同的假设,由刚体极限平衡条件,建立组合破坏的稳定计算方法。运用双楔体和组合破坏稳定分析方法对算例和Kettleman Hills填埋场工程实例进行计算分析。结果表明：双楔体法计算得到的最危险平移滑动破坏安全系数大于组合破坏最小安全系数;最危险破坏面是组合破坏面;对Kettleman Hills填埋场,组合滑动面也是可能的滑动破坏面。由此可见,组合破坏是垃圾填埋场可能的破坏形式之一,在进行垃圾填埋体滑动稳定分析计算时应进行组合破坏形式的计算分析。     

A high-resolution radio study of neutral gas in the starburst galaxy NGC 520

We present subarcsec angular resolution observations of the neutral gas in the nearby starburst galaxy NGC 520. The central kpc region of NGC 520 contains an area of significantly enhanced star formation. The radio continuum structure of this region resolves into ∼10 continuum components. By comparing the flux densities of the brightest of these components at 1.4 GHz with published 15-GHz data we infer that these components detected at 1.4 and 1.6 GHz are related to the starburst and are most likely to be collections of several supernova remnants within the beam. None of these components is consistent with emission from an active galactic nuclei. Both neutral hydrogen (H  i ) and hydroxyl (OH) absorption lines are observed against the continuum emission, along with a weak OH maser feature probably related to the star formation activity in this galaxy. Strong H  i absorption  ( N _H∼ 10²² atoms cm⁻²)  traces a velocity gradient of 0.5 km s⁻¹ pc⁻¹ across the central kpc of NGC 520. The H  i absorption velocity structure is consistent with the velocity gradients observed in both the OH absorption and in CO emission observations. The neutral gas velocity structure observed within the central kpc of NGC 520 is attributed to a kpc-scale ring or disc. It is also noted that the velocity gradients observed for these neutral gas components appear to differ with the velocity gradients observed from optical ionized emission lines. This apparent disagreement is discussed and attributed to the extinction of the optical emission from the actual centre of this source hence implying that optical ionized emission lines are only detected from regions with significantly different radii to those sampled by the observations presented here.     

Sr isotope diversity of hot spring and volcanic lake waters from Zao volcano,Japan

The ratio of ⁸⁷Sr/⁸⁶Sr was measured from different water samples of thermal/mineral (hot spring as well as crater lake) and meteoric origins, in order to specify the location and to verify the detailed model of a volcano-hydrothermal system beneath Zao volcano. The ratio showed a trimodal distribution for the case of thermal/mineral water: 0.7052–0.7053 (Type A, Zao hot spring), 0.7039–0.7043 (Type B, Okama crater lake and Shin-funkiko hot spring), and 0.7070–0.7073 (Type C, Gaga, Aone, and Togatta hot springs), respectively. However, in comparison, the ratio was found to be higher for meteoric waters (0.7077–0.7079). The water from the central volcanic edifice (Type B) was found to be similar to that of nearby volcanic rocks in their Sr isotopic ratio. This indicates that the Sr in water was derived from shallow volcanic rocks. The ⁸⁷Sr/⁸⁶Sr ratio for water from the Zao hot spring (Type A) was intermediate between those of the pre-Tertiary granitic and the Quaternary volcanic rocks, thus suggesting that the water had reacted with both volcanic and granitic rocks. The location of the vapor–liquid separation was determined as the boundary of the pre-Tertiary granitic and the Quaternary volcanic rocks by comparing the results of this strontium isotopic study with those of Kiyosu and Kurahashi [Kiyosu, Y., Kurahashi, M., 1984. Isotopic geochemistry of acid thermal waters and volcanic gases from Zao volcano in Japan. J. Volcanol. Geotherm. Res. 21, 313–331.].     

河北省及邻区地震活动时间间隔的一些特征

介绍了地震活动时间间隔的研究历史和定义，对河北省及邻近地区地震活动时间间隔分布的统计点图、间隔一频次统计图进行了分析，分析时结合不同的震级层次、不同的统计时段（长段不同）、不同的活动水平以及地震活动的丛集与孤立。统计结果显示地震活动时间间隔对数一频次统计结果与G－L关系式的统计结果类似，地震活动时间间对数一频镒也呈指数分布。最后对预测中存在的不足进行了一些简单说明。     

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滦河流域碳、水循环和能量平衡遥感综合试验总体设计

始于20世纪80年代的系列大型遥感试验开始系统研究地表物质和能量交换过程,对遥感与地球系统科学研究的结合起到重要作用,但是尚无综合利用多源遥感数据解决碳、水、能量循环问题的有效方案.遥感科学国家重点实验室于滦河上游地区组织开展基础性、多学科、多尺度的"碳、水循环和能量平衡遥感综合试验".本次试验面向地球系统科学对遥感观...