虚拟天文台数据访问系统(VO-DAS)任务调度设计与实现

为解决异地、异构、海量天文数据无缝透明地统一访问,中国虚拟天文台(China-VO)研究小组自主设计并开发了一套解决方案——虚拟天文台数据访问系统(VO-DAS)。着重从执行流程、设计模式、Session机制、生命周期、资源销毁、异常处理等模块详细阐述了该系统的任务调度设计。为了验证该系统的可行性和性能,最后描述了多个天文科学范例。     

太阳目标哈特曼波前探测研究

分别对Hinode光学望远镜SOT观测太阳黑子的本影和半影图像以及太阳米粒组织图像进行了空间频谱计算和相关计算,分析了太阳不同结构区域图像的时域和空域特性对哈特曼波前探测精度的影响。计算和分析结果表明,在子孔径波面倾斜小于0.25″情况下,米粒组织图像采样时间在2 min内、本影和半影采样时间在4 min内,对子孔径波面倾斜探测精度的影响极小;并且由太阳目标特性引起的哈特曼波面探测误差随波面畸变量的增大而增大。这些研究结果可为太阳望远镜哈特曼波前探测器研制和应用提供依据和参考。     

兴隆1m光学望远镜杂散光效应研究

兴隆1m光学望远镜采取了加装挡板等基于经验和定性分析的杂散光抑制措施。用Tracepro光学分析软件对圆顶内1m望远镜的杂散光传播路径做了计算和分析,提出了对1m望远镜的杂散光抑制的改进措施,通过在Tracepro中计算的系统杂散光"归一化点源辐照度透过率(PSNIT)"函数对改进措施进行了评价。计算结果表明:对于有效视场外30°范围的杂散源,改进措施可使得1m望远镜的PSNIT全部下降到10-10;模拟1m望远镜在满月条件下对偏月25°的天体观测(R波段、15等星、t=15~150s),1m望远镜观测信噪比可提高约147%。     

Influence of magnetic fabric anisotropy on seismic wave velocity in paramagnetic granites from NW Himalaya: Results from preliminary investigations

Anisotropy of Magnetic Susceptibility (AMS) and seismic wave velocity studies of some paramagnetic Himalayan granitoids show good correlation between magnetic fabric anisotropy and P wave velocity (Vp). Vp shows strong positive correlation with magnetic lineation (L) and degree of magnetic anisotropy (P′) having correlation coefficient (r) values of 0.93 and 0.89 respectively. Both Vp and Vs show positive correlation with the SiO₂ content of Proterozoic and Paleozoic granitoids. Velocity of S wave (Vs) shows negative correlation with mean magnetic susceptibility (K_m) having ‘r’ value of 0.86. The correlation between Vs-K_m, V_p-P′, V_p-L also shows >95% probability in Spearman’s rank correlation. Based on the results from the present sample size it is suggested that, in paramagnetic granites, V_p is proportional to intensity of deformation and preferred orientation of minerals as well as the mineralogy. On the other hand, Vs is more dependent on the mineralogy alone.     

Structural and magnetic fabric studies of recess structures in the western Himalaya: Implications for 1905 Kangra earthquake

Kinematic information from deformation structures and magnetic fabrics are used to infer recent tectonics around Kangra and Dehradun recesses, western Himalaya. Three types of magnetic fabrics (Type I & II, III, and IV) are identified based on the angle between K3 axis and bedding pole. It was observed that Kangra recess shows more mature fabric type IV as compared to Dehradun recess, where orientation of K3 axes and tectonic fabric reveals dominance of superposed deformation. In the vicinity of Dehradun recess, normal faults occur in un-indurated Quaternary fan deposits confirming their recent formation. The observations are in conformity with earlier studies that during the 1905 Kangra earthquake, the Main Boundary Thrust (MBT) (or one of its subsidiary thrusts) near Kangra showed thrusting whereas the MBT near Dehradun underwent either normal faulting or post seismic adjustments characteristic of normal faulting. The thrusting could be a result of subsurface processes whereas the normal faulting was a result of prevailing surface strains.     

Influence of magnetic fabric anisotropy on seismic wave velocity in paramagnetic granites from NW Himalaya: Results from preliminary investigations

Anisotropy of Magnetic Susceptibility (AMS) and seismic wave velocity studies of some paramagnetic Himalayan granitoids show good correlation between magnetic fabric anisotropy and P wave velocity (Vp). Vp shows strong positive correlation with magnetic lineation (L) and degree of magnetic anisotropy (P′) having correlation coefficient (r) values of 0.93 and 0.89 respectively. Both Vp and Vs show positive correlation with the SiO₂ content of Proterozoic and Paleozoic granitoids. Velocity of S wave (Vs) shows negative correlation with mean magnetic susceptibility (K_m) having ‘r’ value of 0.86. The correlation between Vs-K_m, V_p-P′, V_p-L also shows >95% probability in Spearman’s rank correlation. Based on the results from the present sample size it is suggested that, in paramagnetic granites, V_p is proportional to intensity of deformation and preferred orientation of minerals as well as the mineralogy. On the other hand, Vs is more dependent on the mineralogy alone.     

基于PSO-PP的围岩稳定性评价

围岩的稳定性评价是一个复杂的不确定系统问题。结合投影寻踪方法、粒子群算法和逻辑斯谛曲线函数,建立了围岩稳定性评价的粒子群优化投影寻踪(projection pursuit based on particle swarm optimization,PSO-PP)模型。该模型一方面采用粒子群算法优化投影指标函数及逻辑斯谛曲线函数参数,确保了模型的准确性;另一方面利用逻辑斯谛曲线函数建立投影值与经验等级之间的非线性关系。模型的测试结果显示了良好的精度,实例分析结果与实际状态完全一致,表明该模型在围岩稳定性评价中的可行性和有效性。     

Geochemical signatures of Mesoproterozoic siliciclastic rocks of the Kaimur Group of the Vindhyan Supergroup,Central India

The Upper Kaimur Group of the Vindhyan Supergroup in Central India, primarily consists of three rock types-DhandraulSandstone, Scarp Sandstone and Bijaigarh Shale. Mineralogically and geochemically, they are quartz arenite, sublitharenite to litharenite and litharenite to shale in composition, respectively. The A-CN-K ternary plot and CIA and ICV values suggest that the similar source rocks suffered severe chemical weathering, under a hot-humid climate in an acidic environment with higher P _{CO 2}, which facilitated high sediment influx in the absence of land plants. Various geochemical discriminants, elemental ratios like K₂O/Na₂O, Al₂O₃/TiO₂, SiO₂/MgO, La/Sc, Th/Sc, Th/Cr, Gd_N/Yb_N and pronounced negative Eu anomalies indicate the rocks to be of post-Archean Proterozoic granitic source, with a minor contribution of granodioritic input, in a passive margin setting. The sediments of the Upper Kaimur Group were probably deposited in the interglacial period in between the Paleoproterozoic and Neoproterozoic glacial epochs.     

吉林延边地区浅成热液金(铜)矿床的~(40)Ar/~(39)Ar激光探针测年与成矿时代讨论

延边地区是中国东北部陆缘浅成热液金铜矿床发育的地区之一,广泛发育着浅成热液金矿床、中温热液金(铜)矿床和中深成中高温热液富金铜矿床(类斑岩型);富金铜矿床的成矿时代发生在105～102 Ma,为了进一步确定浅成热液金矿床与中深成中高温热液富金铜矿床的成矿动力学背景,采用流体包裹体的~(40)Ar/~(39)Ar激光探针定年法,对该区典型浅成热液金矿床进行了精细的年代学测定,获得刺猬沟金矿床、五星山金矿床和杜荒岭金矿床的脉石矿物石英流体包裹体的~(40)Ar/~(39)Ar等时线年龄分别为(141±7)Ma、(123±7)Ma和(107±6)Ma,其中刺猬沟金矿床((141±7)Ma)和五星山金矿床((123±7)Ma)的脉石矿物石英流体包裹体含有过剩放射性成因~(40)Ar,而杜荒岭金矿床((107±6)Ma)的脉石矿物石英流体包裹体几乎不含或含极少量过剩放射性成因~(40)Ar。结合最新获得的相关地质体的精细年代学成果,认定该区浅成热液金矿床成矿作用均发生在早白垩世晚期,或发生在早白垩世晚期火山喷发、浅成岩浆就位之后,其形成环境与富金铜矿床一致,为古太平洋板块向亚洲大陆正北向俯冲转入Izanagi-Farallon板块西向俯冲的构造转换期。     

强烈气洗作用导致原油成分变化的定量计算:以库车坳陷天然气藏为例

库车坳陷以产天然气为主,同时产出少量原油和凝析油,油气充注不同步,普遍具有"油早气晚"的特点,晚期大量天然气的侵入,必然对早期聚集的油藏发生改造作用。对气藏中原油成分变化的定量计算和讨论,可为天然气的注入强度定量评价提供直接证据。未遭受气洗的原油,正构烷烃摩尔浓度的对数与相应的碳数呈线性关系,而气洗作用可使轻组分的正构烷烃最先溶解于干气中,并随着天然气继续向前运移,原始油藏中的轻组分正构烷烃大大减少。以此为理论基础,建立了正构烷烃损失的定量计算模型。结果表明克拉2构造原油正构烷烃损失程度最高,平均可达70%左右,大北构造带原油正构烷烃损失程度差异较大,与该地区断块发育有关。气洗作用导致原油正构烷烃减少,而金刚烷、多环芳烃等在天然气中溶解度较低的化合物得以浓缩富集,相对含量大大增加。轻芳烃含量也会随之而增加,原油芳香度增加,石蜡度降低。在模拟实验基础上对气洗程度进行了定量评价,初步估算表明,克拉2构造原油遭受的气洗作用最强,是其他构造带的2～5倍。