X-ray variability of the pulsar Vela X-1 as observed with ART-P/Granat

Observations of the X-ray pulsar Vela X-1 with the ART-P telescope onboard the Granat Observatory are presented. Variability on a time scale of several thousand seconds was detected; intensity variations are shown to be accompanied by changes in the source’s spectrum. The hardness was also found to be highly variable on a scale of one pulsation period. The source’s spectrum exhibits an absorption feature at energy ～7 keV, which is apparently attributable to cyclotron scattering/absorption in the neutron-star magnetic field. Weak persistent emission was detected during an X-ray eclipse, which probably resulted from the scattering of pulsar emission in the stellar wind from an optical star.     

Energy release on the surface of a rapidly rotating neutron star during disk accretion: A thermodynamic approach

The total energy E of a star as a function of its angular momentum J and mass M in the Newtonian theory, E=E(J, M) [in general relativity, the gravitational mass of a star as a function of its angular momentum J and rest mass m, M=M(J, m)], is used to determine the remaining parameters (angular velocity, chemical potential, etc.) in the case of rigid rotation. Expressions are derived for the energy release during accretion onto a cool (with constant entropy), rapidly rotating neutron star (NS) in the Newtonian theory and in general relativity. A separate analysis is performed for the cases where the NS equatorial radius is larger and smaller than the radius of the marginally stable orbit in the disk plane. An approximate formula is proposed for the NS equatorial radius for an arbitrary equation of state, which matches the exact equation of state at J=0.     

Spectral variability of the X-ray pulsar Hercules X-1

We present the results of our comparative timing and spectral analysis of the high and low (off) states in the X-ray pulsar Her X-1 based on data from the ART-P telescope onboard the Granat observatory. A statistically significant (several mCrab) persistent flux with a simple power-law spectrum was detected during the low state. The spectral slope changed from observation to observation by almost a factor of 2. Pulsations were detected only during the high state of the source, when its flux was a factor of ～25 larger than the low-state flux. The spectral shape of Her X-1 in its high state was complex, with the parameters depending on pulse phase.     

曹妃甸浅滩表层砂体插桩深度研究

曾妃甸浅滩原为古滦河三角洲,三角洲废弃后,海底表层沉积物在波浪潮流的簸选及自重应力作用下,沉积物颗粒粗化,粒度单一,且堆积紧密,工程强度较高。平台在该海医插桩时往往难以贯穿该层,其实际插桩深度较预定深度存在较大偏差。本文对此类砂体的形成机制、插桩过程中土体的压实作用对砂体强度的影响进行了分析,在对砂体力学参数做出适当调整后,运用太沙基地基极限荷载公式进行计算,得到了与实际情况较为一致的结果。     

电感耦合等离子体质谱-X射线衍射法研究云南玉溪和美国内华达地区黏土型锂资源矿物学特征

中国云南玉溪和美国内华达均已发现大量黏土型锂资源,目前关于两地区样品矿物学特征的研究相对不足,而对黏土型锂资源进行充分的矿物学特征研究是锂提取工作开展的重要前提.本文采用X射线荧光光谱、电感耦合等离子体质谱、X射线粉晶衍射、扫描电镜等分析技术,从化学组成、矿物组成、微观形貌等角度对云南玉溪的两个黏土型锂资源样品(YM-...     

短波红外光谱、X射线荧光光谱、黄铁矿热电性分析在胶东新城金矿田深部找矿中的应用

胶东半岛是我国最重要的金矿集区之一,其矿床是典型受北东向断裂构造(焦家断裂带、三山岛断裂带和招平断裂带),以及次生断裂构造(如望儿山断裂和灵北断裂等)控制的矿床类型.前人在该区域做了大量研究,但主要集中在地表和浅层成矿段,对于深部成矿规律与预测的研究相对较少.新城金矿田是胶东半岛的特大型金矿之一,由新城矿床、曲家矿床和...     

石家庄大气污染与沙尘天气的关系分析

利用2002—2006年石家庄市逐时气象资料和环境监测资料,分析了8次典型沙尘天气对空气污染的影响。结果表明:沙尘天气的首要污染物均是可吸入颗粒物,春季中度以上污染日平均出现在沙尘日当日或次日;造成石家庄沙尘天气污染源分外来型、本地型以及二者共同影响型3种;其中,本地型沙尘污染多受冷锋影响,PM10浓度与风速呈正相关。而外来型污染多处于弱气压场控制,PM10浓度与南风呈反相关,而当风向转偏北时则利于污染物积累。     

秦岭主峰太白山北麓降水化学特征分析

利用太白山北麓2011年12月-2013年7月共39次降水样品数据资料, 定量分析了该区域降水化学的特征和时间变化规律. 结果表明: 太白山北麓地区降水中, 除常量离子Na⁺、NH₄⁺、K⁺、Mg²⁺、Ca²⁺、F^-、Cl^-、SO₄^2-、NO₃^-外, CO₃^2-、HCO₃^-、PO₄^3-及低分子有机酸也占有相当比例. 研究区降水常量离子浓度的顺序依次为: NH₄⁺ > SO₄^2- > Ca²⁺ > NO₃^- > Na⁺ > Cl^- > Mg²⁺ > K⁺ > F^-, 离子总浓度表现出明显的季节变化: 夏季(轻度污染) < 秋季(中等污染) < 春季(严重污染) < 冬季(极重污染). 利用因子分析法得出太白山北麓地区降水组分主要有三种来源; Na⁺、Cl^-、Mg²⁺、Ca²⁺主要来自地壳源, SO₄^2-、NO₃^-、NH₄⁺主要来自人为源, K⁺和F^-主要由海盐源和人为源共同贡献. 根据Hysplit 后向气流轨迹分析, 得出不同路径气团降水离子组分不同: 受地形等因素影响, 北方路径的气团比南方路径气团离子总浓度较高; 受土壤类型影响, 西北方向气团降水Na⁺、Mg²⁺、Ca²⁺浓度较高; 受人为活动影响, 东北方向SO₄^2-、NO₃^-、NH₄⁺浓度较高.     

沉积岩中蒙脱石-伊利石混层矿物的SEM/EDAX分析

本文利用扫描电子显微镜与X射线能量色散分析联合法,对沉积岩中蒙脱石-伊利石混层矿物进行系统微区成分分析,求出混合层中伊利石的百分含量。     

攀西地区长石的X射线研究

本文对四川攀枝花—西昌（即攀西裂谷）地区各个不同时期、不同产状、不同岩类中的斜长石、碱性长石进行了X射线研究,配合单矿物化学分析、电子探针成分分析,结合红外光谱、光学测定,精确地计算了42个斜长石,60个碱性长石的晶胞参数,求出其四个四面体的Al含量,确定长石的成分和结构态。为探索攀西地区岩浆活动演化规律,研究攀西裂谷形成、发展及其消亡历史提供了客观依据。