超慢速扩张环境下超镁铁质岩系统的热液硫化物成矿机理以及启示     

曹红  孙治雷  刘昌岭  姜学钧  何拥军  黄威  尚鲁宁  王利波  张喜林  耿威  施美娟  李东义 《海洋学报》2018,40(4):61-75

西南印度洋63.5°E热液区是在超慢速扩张洋脊发现的首个超镁铁质岩热液系统。对取自该区的热液硫化物样品进行了系统的矿物学和地球化学分析，矿物学分析结果表明:该热液区硫化物为富Fe型高温硫化物，且经历了较深程度的氧化蚀变，大量中间态的Fe氧化物充填在硫化物矿物间的孔隙及内部解理中；这些硫化物相以白铁矿为主，其次是等轴古巴矿和少量铜蓝，缺乏黄铁矿、闪锌矿。据推断，该区的热液成矿作用分为4个阶段:低温白铁矿阶段→高温等轴古巴矿阶段→自形白铁矿阶段→后期海底风化阶段（少量铜蓝以及大量的Fe的羟氧化物）。与之相对应，地球化学分析结果表明这些硫化物的Fe含量较高（31.57%~44.59%），Cu含量次之（0.16%~7.24%），而Zn含量普遍较低（0.01%~0.11%）；微量元素较为富集Co（328×10-6~2 400×10-6）和Mn（48.5×10-6~1 730×10-6）。该区硫化物中较高含量的Fe、Co与超镁铁质岩热液系统相似，明显高于镁铁质岩热液系统。独特的热液硫化物矿物学特征和元素组成可能与该区普遍出露的地幔岩、橄榄岩蛇纹石化作用以及拆离断层的广泛发育的环境有关。  相似文献   

Local Oceanic Vertical Deflection Determination with Gravity Data Along a Profile     

Jianbo Wang  Xin Liu  Yi Shen  Qiaoli Kong 《Marine Geodesy》2018,41(1):24-43

Deflections of the vertical (DOVs) over oceans cannot be directly measured, which restricts their applications. A local covariance function of anomalous potential is put forward in this paper in conjunction with the least-squares collocation (LSC) method to compute the oceanic DOVs utilization of oceanic gravity data along a profile. The covariance functions of gravity field quantities have been derived directly as functions of x, y and z without the need to introduce coordinate transformations corresponding to along- or cross-profile components. In the proposed methodology, gravity data along a profile were used to calculate the residual gravity anomaly using the remove-compute-restore technique. The residual gravity anomaly was used to calculate the parameters of the proposed covariance function of the local anomalous gravity field, which was used in the LSC to compute the residual DOVs along the profile. The residual DOVs added model DOVs to recover the DOVs along the profile. The results of a simulation experiment prove that the proposed methodology is feasible and effective.  相似文献   

珠江口淇澳岛滨海湿地沉积环境演化及其对人类活动的响应   总被引：1，自引：1，他引：0  

叶翔  李靖  王爱军 《海洋学报》2018,40(7):79-89

滨海湿地作为人类活动和全球变化反应最为敏感的区域，其沉积记录可以反映出周边地区环境变化及人类活动信息。珠江口淇澳岛滨海湿地钻孔分析结果表明，在中全新世期间淇澳岛附近海域为河口湾环境，在风化层以上开始出现淤积，但在4 200 a BP前后受极冷气候的影响，沉积物粗化；自2 500 a BP以来，沉积环境相对稳定，在小冰期期间略有变化。沉积速率计算结果显示:淇澳岛附近海域自中全新世高海面以来的平均沉积速率为0.29 cm/a，4 160~2 500 a BP、2 500 a BP-1488年、1488-1893年、1893-1986年、1990-2007年期间的平均沉积速率分别为:0.17 cm/a、0.23 cm/a、0.35 cm/a、1.37 cm/a和5.94 cm/a，沉积速率逐渐增大，反映了珠江三角洲演化过程中沉积相与沉积环境的变化；1986-1990年期间的海堤建造极大地扰动了该钻孔上部的沉积过程，在工程施工期间共沉积了厚度约112 cm的沉积层，而在海堤建成后，沉积速率也显著增大。沉积物总有机碳、总氮和C/N值的垂向分布表明，在4 160~2 500 a BP期间受海洋环境影响较大，沉积物中有机碳以海源为主，2 500 a BP以来沉积物中碳、氮含量明显增大，C/N也相应变大，有机碳主要来源于陆源输入，但在小冰期期间海源有机碳贡献略有所增大；近百年来由于受人类活动影响显著，陆源有机碳的贡献快速增加。  相似文献   

Porosity Distribution Characteristics and Geological Analysis of Brine Storage Medium in the Qaidam Basin,Western China     

Shuya Hu  Changlai Xiao  Xiujuan Liang  Quansheng Zhao  Guangcai Wang  Jianwei Zhang  Juan Feng 《中国地理科学(英文版)》2018,28(4):707-716

Underground brine is an unusual water resource that contains abundant mineral resources. It is distributed widely in the Qaidam Basin, western China, a hyperarid inland basin located in the northern Tibetan Plateau. Pores in the brine storage medium act as storage space and transmission channels of underground brine. Therefore, the porosity of brine storage medium determines its ability to store brine. In this study, Mahai Salt Lake was used as the research area as a modern saline lake located in the north area of the Qaidam Basin. A total of 100 porosity samples were collected from eight sampling points in two profiles of the research area at sampling depths of 1.30–314.78 m. The porosity distribution characteristics and influencing factors in brine storage medium were analysed according to the measured porosity data. Based on analysis of the pore structure characteristics, the brine storage medium contains intercrystalline pores, unlike conventional freshwater storage mediums. Moreover, the primary salt rock is susceptible to dissolution by lighter brine, facilitating the formation of secondary porosity. Due to the formation of secondary pores, a porosity greater than 20% remains even at buried depths greater than 100 m. Based on the geological statistical analysis, due to the geographic location, salt formation time, and depositional environment, the porosity values of Mahai Salt Lake do not exhibit a wider distribution, but also show more extreme values than a nearby salt lake. Based on the porosity characteristics by depth, due to the presence of secondary pores, flooding, stratigraphic static pressure, and other factors, porosity shows fluctuations with increasing depth.  相似文献   

2016年中国沿海海平面上升显著成因分析及影响   总被引：1，自引：0，他引：1  

王慧  刘克修  范文静  冯建龙  王国松  张建立  王爱梅  李琰 《海洋学报》2018,40(2):43-52

使用中国沿海及西北太平洋区域的水位、海温、气温、气压和风等水文气象资料，详细分析了2016年中国沿海海平面显著升高的成因及影响。分析结果表明:（1）2012-2016年，中国沿海海平面处于准2 a、4 a、准9 a和准19 a周期振荡的高位，几个周期振荡高位叠加，对该时段海平面上升起了一定的作用；（2）2016年，中国沿海气温和海温较1993-2011年的平均值分别高0.7℃与0.5℃，均处于1980年以来高位；气压较1993-2011年的平均值低0.2 hPa；（3）2016年4月、9月、10月和11月，中国沿海海平面均达到1980年以来同期高位，这4个月的风场距平值在东海以南均明显偏大，且以偏南向和向岸风为主，风生流使得海水向岸堆积，沿海长时间以增水为主，对当月局部海平面上升的贡献率达到40%~80%；（4）2016年，中国沿海降水总体偏多，局部区域降水量达到历史同期最高，加上沿海径流量的增加，对沿海局部海平面升高有一定贡献；（5）2016年9-10月，有5个台风相继影响我国南部沿海，持续的风暴潮增水导致台风影响期间的海平面高于当月平均海平面70~360 mm，风暴潮和洪涝灾害给当地造成直接经济损失超过30亿元。  相似文献   

无人化时代反水雷装备体系构想          下载免费PDF全文

赵治平  官红  艾艳辉  王久法 《数字海洋与水下攻防》2018,1(1):1-6

根据我国海洋方向面临的战略安全环境、建设“海上丝绸之路”的要求，我国的反水雷作战范围将延伸到第一岛链以外的海域，反水雷任务除了传统的近岸/ 近海反水雷任务，还增加了海峡反水雷、交通线反水雷以及海外基地反水雷等任务。 为了满足我国反水雷作战需求，结合国际上反水雷技术装备发展方向，用信息化改造、无人化拓展现有反水雷装备，构建无人化时代反水雷装备体系，形成能够在近岸、近海、中远海实施快速、安全、高效的反水雷作战能力。  相似文献   

Comparison of the spatio-temporal dynamics of vegetation between the Changbai Mountains of eastern Eurasia and the Appalachian Mountains of eastern North America     

Xiao-yi Guo  Hong-yan Zhang  Ye-qiao Wang  Hong-shi He  Zheng-fang Wu  Ying-hua Jin  Zheng-xiang Zhang  Jian-jun Zhao 《山地科学学报》2018,15(1):1-12

The Changbai Mountains and the Appalachian Mountains have similar spatial contexts. The elevation, latitude, and moisture gradients of both mountain ranges offer regional insight for investigating the vegetation dynamics in eastern Eurasia and eastern North America. We determined and compared the spatial patterns and temporal trends in the normalized difference vegetation index (NDVI) in the Changbai Mountains and the Appalachian Mountains using time series data from the Global Inventory Modeling and Mapping Studies 3rd generation dataset from 1982 to 2013. The spatial pattern of NDVI in the Changbai Mountains exhibited fragmentation, whereas NDVI in the Appalachian Mountains decreased from south to north. The vegetation dynamics in the Changbai Mountains had an insignificant trend at the regional scale, whereas the dynamics in the Appalachian Mountains had a significant increasing trend. NDVI increased in 55% of the area of the Changbai Mountains and in 95% of the area of the Appalachian Mountains. The peak NDVI occurred one month later in the Changbai Mountains than in the Appalachian Mountains. The results revealed a significant increase in NDVI in autumn in both mountain ranges. The climatic trend in the Changbai Mountains included warming and decreased precipitation, and whereas that in the Appalachian Mountains included significant warming and increased precipitation. Positive and negative correlations existed between NDVI and temperature and precipitation, respectively, in both mountain ranges. Particularly, the spring temperature and NDVI exhibited a significant positive correlation in both mountain ranges. The results of this study suggest that human actives caused the differences in the spatial patterns of NDVI and that various characteristics of climate change and intensity of human actives dominated the differences in the NDVI trends between the Changbai Mountains and the Appalachian Mountains. Additionally, the vegetation dynamics of both mountain ranges were not identical to those in previous broader-scale studies.  相似文献   

参附注射液建立自发性高血压病大鼠肝阳上亢证模型的研究          下载免费PDF全文

周梦  杨文丽  刘晓庆 《应用海洋学学报》2018,34(12):120-122

目的：探讨参附注射液建立自发性高血压大鼠（SHR）模型的可能性。方法：将30只3月龄SPF级健康雄性自发性高血压大鼠称重，随机分为SHR组，附子汤组，参附注射液低、中、高剂量组，每组6只。各组采用对应药物灌胃进行模型制备，另取同品系同周龄雄性魏-凯二氏大鼠（WKY）6只作为正常对照组（WKY组）。观察参附注射液对SHR大鼠24h饮水量、易激惹程度、痛阈、睑结膜充血及收缩压的影响。结果：附子汤组及参附注射液中、高剂量组造模后均出现了易激惹程度增高、睑结膜充血程度增高、饮水量增多、痛阈降低、收缩压升高等肝阳上亢的表现，与WKY组及SHR组比较，差异有统计学意义（P<0.05)，表明造模成功。结论：参附注射液可以制备新型高血压肝阳上亢证模型，但是具体造模机制以及造模药物用量需待进一步探讨确定。  相似文献   

The First Solar Seeing Profile Measurement with Two Apertures and Multiple Guide Regions     

Deqing Ren  Gang Zhao  Xin Wang  Christian Beck  Robert Broadfoot 《Solar physics》2018,293(1):1

The sky brightness is a critical parameter for estimating the coronal observation conditions for a solar observatory. As part of a site-survey project in Western China, we measured the sky brightness continuously at the Lijiang Observatory in Yunnan province in 2011. A sky brightness monitor (SBM) was adopted to measure the sky brightness in a region extending from 4.5 to 7.0 apparent solar radii based on the experience of the Daniel K. Inouye Solar Telescope (DKIST) site survey. Every month, the data were collected manually for at least one week. We collected statistics of the sky brightness at four bandpasses located at 450, 530, 890, and 940 nm. The results indicate that aerosol scattering is of great importance for the diurnal variation of the sky brightness. For most of the year, the sky brightness remains under 20 millionths per airmass before local Noon. On average, the sky brightness is less than 20 millionths, which accounts for 40.41% of the total observing time on a clear day. The best observation time is from 9:00 to 13:00 (Beijing time). The Lijiang Observatory is therefore suitable for coronagraphs investigating the structures and dynamics of the corona.  相似文献   

MicroRNAs identification and bioinformatics analysis in large yellow croaker Larimichthys crocea using an integrated comparative and ab initio approach     

房路京  肖世俊  韩兆方  王志勇 《中国海洋湖沼学报》2018,36(5):1707-1719

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