与火山—潜火山作用有关的浅成热液金(铜银)矿床流体成矿系统

与火山—潜火山作用有关的浅成热液金(铜银)矿床可以分为低硫型和高硫型两个亚类,所对应的流体成矿系统分别为贵金属(地热)成矿系统和火山热液成矿系统。由于成矿位置和流体成矿过程不同,形成了各具特色的成矿元素组合、围岩蚀变特征和成矿类型。     

北太平洋波浪输运和西边界流的季节变化

西边界流输运可以用Sverdrup理论推算出来.本文首先利用ECMWF再分析风场数据,计算了44年的月平均的风应力旋度及Sverdrup体积输运,在北太平洋3条纬度上对Sverdrup体积输运进行积分,得到Sverdrup体积输运的季节变化,从中发现,在向赤道流动的方向上,Sverdrup体积输运在冬季存在最大值,夏季存在最小值;同样利用ECMWF再分析波浪数据,计算了44a的月平均的Stokes体积输运,在相同纬度上对Stokes体积输运进行积分,得到Stokes体积输运的季节变化,从结果中发现,在向赤道流动的方向上,Stokes输运在冬季存在最大值,在夏季存在最小值.在本文中设定R=T_(st)/T_(sv)×100%,T_(st)为Stokes体积输运,T_(sv)为Sverdrup体积输运,发现Stokes输运和Sverdrup输运存在同位相的季节变化,并且(-R)冬季平均值在5%以上,年平均值在2%～3%左右,从而推断出波浪诱导的输运对Sverdrup输运,既对西边界流有不可忽视的贡献.     

SAGE测光巡天数据处理方法研究

元素丰度与星系演化(Stellar Abundance and Galactic Evolution,SAGE)是自主设计的能够准确计算恒星大气参数以及消光的新测光系统。对北天除银盘外共计约12 000 deg2的天区开展了SAGE系统测光巡天,计划获取约5亿颗恒星的高精度测光数据。单次曝光条件下100σ完备星等uSC～17. 3,vSAGE～16. 8(AB星等),这些为研究银河系提供宝贵的测光资料。介绍了巡天专用的数据处理程序的研究和开发,主要研究了针对单幅图像的快速自动化处理过程,重点介绍数据改正、天体测量校正、测光和流量定标过程,以及数据结果和数据质量检测等。     

Transcriptome profile of Dunaliella salina in Yuncheng Salt Lake reveals salt-stress-related genes under different salinity stresses

Journal of Oceanology and Limnology - Salt stress is an abiotic stress to plants in especially saline lakes. Dunaliella, a halophilic microalga distributed throughout salt lakes and seas, can...     

The Potential Vertical Distribution of Bigeye Tuna ( Thunnus obesus ) and Its Influence on the Spatial Distribution of CPUEs in the Tropical Atlantic Ocean

Understanding the potential vertical distribution of bigeye tuna(Thunnus obesus) is necessary to understand the catch rate fluctuations and the stock assessment of bigeye tuna. To characterize the potential vertical distribution of this fish while foraging and determine the influences of the distribution on longline efficiency in the tropical Atlantic Ocean, the catch per unit effort(CPUE) data were compiled from the International Commission for the Conservation of Atlantic Tunas and the Argo buoy data were downloaded from the Argo data center. The raw Argo buoy data were processed by data mining methods. The CPUE was standardized by support vector machine before analysis. We assumed the depths with the upper and lower limits of the optimum water temperatures of 15℃ and 9℃ as the preferred swimming depth, while the lower limit of the temperature(12℃) associated with the highest hooking rate as the preferred foraging depth(D12) of bigeye tuna during the daytime in the Atlantic Ocean. The preferred swimming depth and foraging depth range in the daytime were assessed by plotting the isobath based on Argo buoy data. The preferred swimming depth and vertical structure of the water column were identified to investigate the spatial effects on the CPUE by using a generalized additive model(GAM). The empirical cumulative distribution function was used to assess the relationship between the spatial distribution of CPUE and the depth of 12℃ isolines and thermocline. The results indicate that 1) the preferred swimming depth of bigeye tuna in the tropical Atlantic is from 100 m to 400 m and displays spatial variation; 2) the preferred foraging depth of bigeye tuna is between 190 and 300 m and below the thermocline; 3) the number of CPUEs peaks at a relative depth of 30 –50 m(difference between the 12℃ isolines and the lower boundary of the thermocline); and 4) most CPUEs are within the lower depth boundary of the thermocline levels(LDBT) which is from 160 m to 230 m. GAM analysis indicates that the general relationship between the nominal CPUE and LDBT is characterized by a dome shape and peaks at approximately 190 m. The oceanographic features influence the habitat of tropical pelagic fish and fisheries. Argo buoy data can be an important tool to describe the habitat of oceanic fish. Our results provide new insights into how oceanographic features influence the habitat of tropical pelagic fish and fisheries and how fisheries exploit these fish using a new tool(Argo profile data).     

东海北部黑潮区浮游动物的多样性研究

由于浮游动物在海洋生态系统中处于主导地位及其对生物地球化学循环和全球变化的重要影响,浮游动物与环境间相互作用的研究已成为现代海洋生态学研究的一个核心问题[1].     

Interacting effects of multiple factors on the morphological evolution of the meandering reaches downstream the Three Gorges Dam

Elucidating the influence of dams on fluvial processes can inform river protection and basin management. However, relatively few studies have focused on how multiple factors interact to affect the morphological evolution of meandering reaches. Using hydrological and topographical data, we analyzed the factors that influence and regulate the meandering reaches downstream the Three Gorges Dam (TGD). Our conclusions are as follows. (1) The meandering reaches can be classified into two types based on their evolution during the pre-dam period: G1 reaches, characterized by convex point bar erosion and concave channel deposition (CECD), and G2 reaches, characterized by convex point bar deposition and concave channel erosion (CDCE). Both reach types exhibited CECD features during the post-dam period. (2) Flow processes and sediment transport are the factors that caused serious erosion of the low beaches located in the convex point bars. However, changes in the river regime, river boundaries and jacking of Dongting Lake do not act as primary controls on the morphological evolution of the meandering reaches. (3) Flood discharges ranging from 20,000 to 25,000 m³/s result in greater erosion of convex point bars. The point bars become scoured if the durations of these flows, which are close to bankfull discharge, exceed 20 days. In addition, the reduction in bedload causes the decreasing of point bar siltation in the water-falling period. (4) During the post-dam period, flood abatement, the increased duration of discharges ranging from 20,000 to 25,000 m³/s, and a significant reduction in sediment transport are the main factors that caused meandering reaches to show CECD features. Our results are relevant to other meandering reaches, where they can inform estimates of riverbed change, river management strategies and river protection.     

山东地磁台网受宁东高压直流输电干扰预处理质量分析

为进一步提高山东地磁台网受高压直流输电干扰的预处理质量,通过中国地震前兆数据处理系统中相对差值检测和预处理检测功能,对山东地磁台网多年来受宁东高压直流输电干扰预处理情况进行了总结分析。结果表明,经过数据预处理,宁东高压直流输电干扰基本被去除,但仍然存在高压直流输电干扰误判、起止时间错判、干扰幅度计量不精确等问题。针对上述问题,对数据进行复核和校对,应用"缓变台阶"功能重新处理,并加强对H、D分量干扰特征的研究。     

长白山天池火山——多成因中央式火山

长白山天池火山属新生代多成因中央式火山,也是我国最大的一座具潜在危险的活火山。火山主体由早期玄武岩盾、中期粗面岩锥和晚期伊格尼姆岩席组成。天池火山布里尼喷发柱高度最高达25 km,柱体最大宽度为半径12～13 km。天池破火山口塌陷过程可以分为四期,分别位于造锥喷发阶段和造伊格尼姆岩喷发阶段。本文对天池火山未来可能的火山灾害类型及范围也作了初步预测。     

煤岩构造变形与动力变质作用

煤岩是一种对温度、压力等地质环境因素十分敏感的有机岩,地质演化过程中的各种构造-热事件必然导致煤岩发生一系列物理与化学结构的变化,并形成不同类型的构造煤。在构造应力作用下,煤岩不仅发生脆性和韧性变形,而且还产生不同程度的动力变质作用。因而,关于煤岩构造变形与动力变质作用的研究不仅具有重要的科学意义,而且在煤层气资源评价以及煤与瓦斯突出危险性预测方面也具有重要的实际意义。文中在已有研究成果基础上,通过对构造煤系列Ro,max、XRD和NMR(CP/MAS+TOSS)等测试和实验方法的对比研究,深入分析了煤岩不同构造变形和动力变质特征,进一步探讨了构造应力下煤岩动力变质作用的机理。研究成果表明,在构造应力作用下,煤岩脆性变形主要是通过破裂面上快速机械摩擦转化为热能而引起煤岩化学结构与其成分的改变;而韧性变形煤主要是通过局部区域应变能的积累而引起煤岩化学结构的破坏,从而发生不同机制的动力变质作用。