陕西勉略阳区铜厂矿田矿床（化）类型及其特征   总被引：9，自引：3，他引：6  

韩润生  金世昌 《地质与勘探》2000,36(4):11-15,40

铜厂铜矿田位于我国著名的勉略阳地区中,是重要的铜金多金属矿田。在将矿床（化）类型系统划分为三大类６个亚类基础上,详述了各类型矿床（化）的地质特征,讨论了其矿床成因。认为铜厂矿田矿床为同位多期－多矿化阶段－多来源的多因素成矿床。  相似文献   

多介质反循环复合钻探技术的研究   总被引：4，自引：1，他引：3       下载免费PDF全文

张永勤  靳玉生  刘辉  尚月成  咸丰刚  张星明 《探矿工程》2000,(4):38-41

多介质反循环复合钻探技术是一种将空气反循环连续取样和水力反循环取心钻探技术有效结合起来的全新地质钻探方法。对该钻探技术的特点,研究过程,生产应用试验情况等进行了详细论述。  相似文献   

Injury in trapped Dungeness crabs (Cancer magister)     

Barber  Julie S.; Cobb  J. Stanley 《ICES Journal of Marine Science》2007,64(3):464-472

  相似文献   

福建湄洲岛对台客运码头淤积分析   总被引：1，自引：0，他引：1  

高智勇  蔡锋和转 《海洋工程》2004,22(3):102-106

以岸滩固定剖面观测、沉积物搬运趋势模型、沙粒捕沙器现场观测为基础，分析造成湄洲岛台客运码头淤积的主要原因。分析结果表明，由于风、浪、流共同作用，码头建成后，在其前缘形成一个淤积区，致使码头的使用受到影响。  相似文献   

氢化物冷阱捕集法原子吸收测定海水中无机锡     

陆贤昆  赵丽英  高兴梅 《中国海洋大学学报(自然科学版)》1990,(4)

采用硼氢化纳还原法将海水中无机锡还原为挥发性锡化氢,氮为载气将锡化氢从反应器吹出,并于液氮冷阱中捕集,捕集后将锡化氢载入氢焰原子化器进行原子吸收测定。对该还原反应、氢化物转移、捕集及原子化实验条件进行了详细研究。实验结果表明:该法中可氢化元素As、Sb、Se等超过被测物浓度200倍时亦无明显干扰,检出限为0.0060μg/dm~3,对0.050μg/dm~3 Sn浓度的样品变异系数为±8％。标准曲线表明,在0—0.050μg/dm~3 Sn浓度范围内有理想的线性关系。对海水介质测定,该法所作校准曲线与蒸馏水介质具有相同的斜率,采用NaOH共沉淀预富集可提高灵敏度5—10倍,便于海水样品保存,总回收率95％以上。  相似文献   

The Sea of Okhotsk: A Window on the Ice Age Ocean     

James D. Hays  Joseph J. Morley 《Deep Sea Research Part I: Oceanographic Research Papers》2003,50(12):1481-1506

The modern Sea of Okhotsk and the high-latitude glacial ocean share similar radiolarian faunas suggesting they also share environmental similarities. This sea favors deep- (>200 m) over shallow-living species as evidenced by collections of sediment traps set at 258 and 1061 m in the central part of the Sea. Of the twelve dominant polycystine radiolarian species, four live above and eight below 258 m. The shallow-living species’ productivity maxima coincide with spring and fall phytoplankton blooms while deep-living species’ annual production, nearly twice that of the shallow-living species, is concentrated in fall. Previous workers have shown that summer plankton tows collect higher concentrations of polycystine Radiolaria below than above 200 m and that Radiolaria, fish and zooplankton have unusual concentration maxima between 200 and 500 m. The paucity of Radiolaria and other consumers above 200 m coincides with an upper (0–150 m) cold (−1.5°C to 1.5°C), low salinity layer while higher concentrations below 200 m occur within warmer saltier water. This unusual biological structure must produce a lower ratio of shallow (<200 m) to deep carbon remineralization than elsewhere in the world ocean.Deep-living radiolarian species, similar to those of the modern Sea of Okhotsk, dominate glacial high-latitude deep-sea sediments. If the hydrographic and biological structures that produced these glacial faunas were like those of the modern Sea of Okhotsk, then glacial high-latitude oceans would have differed from today's in at least two respects. Surface waters were less saline and more stable enhancing the spread of winter sea ice. This stability, combined with a deepening of nutrient regeneration, reduced surface water nutrients contributing to a reduction of atmospheric carbon dioxide.  相似文献   

杏林虾池综合养殖系统主要环境因子的变化   总被引：8，自引：0，他引：8  

方志山  杨圣云  许振祖 《台湾海峡》2001,20(4):496-501

根据1999年10月至2000年7月在厦门市杏林虾池综合养殖系统进行水质（水温、透明度、比重、氨氮、亚硝酸氮、硝酸氮、无机磷、pH值、化学需氧量）和沉积物（有机质、硫化物）的跟踪调查，分析结果表明：该养殖系统的水质和沉积物的各项指标较稳定，基本上符合水产养殖的要求，实际生产效益也表明该虾池综合养殖效益较显著。  相似文献   

Study on the slope break belts in the Jurassic down-warped lacustrine basin in western-margin area, Junggar Basin, northwestern China   总被引：1，自引：0，他引：1  

Liu Hao  Wang Yingmin  Xin Renchen  Wang Yuan 《Marine and Petroleum Geology》2006,23(9-10):913-930

The Junggar Basin is one of the large-scale petroliferous basins in northwestern China. During the Jurassic Age it was a down-warped continental basin. Different types of slope break belts with different origins have been identified in the basin, including the fracture, flexure, erosional and depositional slope break belts. Fracture and flexure slope break belts were mainly developed in the western-margin area of the Junggar Basin. Slope break belts can be further divided into two types, which are basin margin and inner basin according to their geographical locations. Tectonic movements are the important origin mechanisms controlling the development of the slope break belts, such as deep-seated thrust structure, inherited paleouplift and secondary fracture movement in the basin. Obviously slope break belts are developed in episodes, developed in multi-stages and are differential in movements and can be inherited and transformed due to the changes of tectonic movements in different periods and different areas. Detailed studies indicate that slope break belts obviously control the strata onlap, the vertical lithologic succession and the vertical and lateral distribution of depositional systems. Slope break belts can control the distribution of different non-structural traps.  相似文献   

拉伸与扭转载荷作用下LNG低温复合软管的力学性能研究          下载免费PDF全文

张进  安晨  武昌旭  高强  魏代锋 《海洋工程》2022,40(4):168-179

LNG低温复合软管结构复杂,且在运行时受风、浪、流等多种载荷联合作用,其在超低温环境下的力学性能直接关系到其能否安全运行。首先参考江苏某软管公司生产的4英寸LNG低温复合软管,建立软管精细化有限元模型,接着对软管在拉伸、扭转两种轴对称载荷作用下的力学性能进行研究,最后就软管结构尺寸对其力学性能的影响展开分析。结果表明：在拉伸及扭转载荷作用下,不同层芳纶布以及同层芳纶布不同材料主方向在对应波峰、波谷处的受力情况不同。芳纶布铺设角度、芳纶布铺设层数、钢丝螺距以及钢丝直径对复合软管力学性能影响显著,分析相应的灵敏度规律从而对结构尺寸做出调整。研究成果可以为LNG低温复合软管的结构设计提供参考。  相似文献   

黏土中防沉板—桩复合基础地震反应特性研究          下载免费PDF全文

关盛杰  孔德森  王晓敏  巩越 《海洋工程》2022,40(1):116-124

为了研究海底防沉板—桩复合基础在地震荷载作用下的动力反应特性,以我国南海深水工程实例为研究对象,利用Flac3D有限差分仿真软件建立了计算模型,土体采用Mohr-Coulomb本构模型,模型底部输入EL Centro地震波,对不同桩长的复合基础进行分析计算.在该特定工程背景下,研究结果表明:随着桩长的增加,防沉板顶部加速度放大系数呈减小趋势;地震荷载下,复合基础发生震陷,沉降量在地震波加速度峰值过后趋于稳定;当桩长为6m时,复合基础的水平振动程度和震陷量最小;由于桩基础把震动能量传输到深部土层中,复合基础周围土体的加速度响应值小于远场土体.在动力时域内,防沉板与桩连接处弯矩最大,需要在此处增设加固装置.  相似文献