出访关岛、文莱和新加坡的水文气象保障分析     

李颜  杨亮  闫明  毛可修  修义瑞 《海洋预报》2004,21(4):69-74

2003年10月中旬到11月中旬,舰艇编队出访关岛、文莱和新加坡期间,多次遇有台风、冷空气等灾害性天气。保障中通过分析西太平洋海域的船舶报资料、卫星云图和日本传真图资料以及编队发回的海上实况资料等信息,结合南海海域和菲律宾海域10—11月份多年的水文气象平均资料,对出访过程中所要航行的海区做了整体的掌握和重点的分析,为编队航行提供了及时准确的天气海洋预报,使编队能及时规避冷空气和台风等灾害性天气,圆满完成了出访期间的水文气象保障工作。  相似文献   

智利外海南极褶柔鱼的形态学及部分生物学特征     

刘必林  陈新军  钱卫国  田思泉 《广东海洋大学学报》2008,28(6)

描述了智利外海南极褶柔鱼Todarodes filippovae的形态特征,并参考前人研究资料,确定了其分类地位,同时对其作了初步分析。鉴定认为:该种系柔鱼科、褶柔鱼亚科、褶柔鱼属的南极褶柔鱼;其最北分布可到27°57′S,比原先文献报道的35°S偏北;渔获物的调查期间的胴长为157～366mm,体重为65～960g,性腺成熟度以Ⅰ、Ⅱ期为主,占总样本的71%。同时,还建立了胴长与体重、胴长与角质额喙长的关系式。  相似文献   

青藏高原-天山地区岩石层构造运动的地幔动力学机制   总被引：31，自引：11，他引：20       下载免费PDF全文

傅容珊  黄建华 《地球物理学报》1998,41(5):658-668

利用全球重力大地水准面异常、板块绝对运动及全球地震层析成像数据,计算了青藏高原-天山地区岩石层下部地幔大尺度对流格局以及此种尺度对流驱动下岩石层内应力场分布;同时,利用区域均衡重力异常数据反演青藏高原中、北部到天山地区上地幔小尺度对流模型．结果表明,大尺度的地幔物质运移过程可能驱动着中国大陆岩石层整体从西部以南北方向为主的运动转向东部地区以北东和南东方向的运动;而该区域上地幔小尺度上升流动支持了现代青藏高原和天山地区的抬升运动．提出和讨论了青藏高原隆升的“断离隆升-挤压隆升-对流隆升”三阶段模式,并探讨了大陆岩石层构造运动的地幔深部动力学背景．  相似文献   

电子烟纸打孔机中断纸控制机构的设计与实现     

潘建寿  祝轩  楚岩 《地球科学与环境学报》1998,(Z1)

本文分析了电子烟纸打孔机断纸控制的作用和意义,并根据对ＬＭ３３１特点的研究,设计并实现了一种用ＬＭ３３１构成的断纸处理方案。实际应用表明,这种方案是一种有效、经济的处理方法。  相似文献   

Parametric Analysis and Experimental Study on Local Flexibility of TY-Type Tubular Joints     

XuHantao Chen Bozhen HuYuren Pan Hao 《中国海洋工程》1996,(1)

Loal flexibility of tubular joints has important effect on the static and dynamic behaviour of offshore platforms, therefore, the determination of it becomes an important research subject in the field of offshore engineering. In this paper, the local flexibility of TY-type tubular joints, which are widely used in offshore platforms, is calculated by using semi- analytical method. Based on the calculated results, parametric formulae for evaluating element in the local joint flexibility matrix of TY- type tubular joints are derived by regression. A test on PVC models of TY-type tubular joints to measure the local joint flexibility is also reported. A comparison of the results calculated from the parametric formulae presented in this paper with those measured from the model test shows that the parametric formulae are reliable. It is recommended that these formulae be used in the global structural analysis of offshore platforms.  相似文献   

东海高密水环流的演变及其对长江口外混合水扩散的影响   总被引：2，自引：1，他引：2  

潘玉球  梁湘三 《海洋学研究》1997,15(2):15-24

本文依据多年的东海水文观测资料，进一步分析了东海高密水核心及其上层环流的形成、演变特点和它对长江口外混合水扩散的影响。获得如下结果：１．东海高密水的形成是具有高温、高盐特性的台湾暖流水北上降温的必然结果。增密方程可以反映这一特点。２．东海高密水核心及其上层环流的形成与由台湾暖流发展引起的水团挤压有关。３．在春、夏季，东海高密水核心区上层环流的发展可对长江口外混合水（盐度为２３～３３）的扩散产生很大影响。这个环流可导致近岸盐度锋松弛，长江口外混合水沿具有低密特性的台湾暖流水和东海高密水之间的密度锋向外扩展。密度锋是长江口外混合水扩散的通道  相似文献   

Seasonal Variations in the Sea off Sanriku Coast, Japan     

Sachiko Oguma  Toru Suzuki  Yutaka Nagata 《Journal of Oceanography》2002,58(6):825-835

The temperature and salinity data obtained by the Iwate Fisheries Technology Center for the 25-year period from 1971 to 1995 were analyzed to clarify the seasonal variations in the sea off Sanriku, Japan. The variations of three typical waters found in this region, the Tsugaru Current water, the Oyashio water, and the Kuroshio water are discussed in terms, of a T-S scatter diagram referring to the water mass classification proposed by Hanawa and Mitsudera (1986). The mean temperature and salinity fields averaged for each month show clear seasonal variation. Distributions of the Tsugaru Current water and the Oyashio water can barely be distinguished in the fields deeper than 200 m since the Tsugaru Current has a shallow structure; however, the fields at 100 m depth indicate remarkable seasonal variation in the area of the Tsugaru Current. At 100 m depth, the temperature and salinity fronts between the Tsugaru Current water and the Oyashio water gradually disappear in January through April, appear again in May, then become clearest in September. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

Application of the WEPP model to determine sources of run‐off and sediment in a forested watershed          下载免费PDF全文

Bahram Saghafian  Amin Reza Meghdadi  Somayeh Sima 《水文研究》2015,29(4):481-497

This study investigates critical run‐off and sediment production sources in a forested Kasilian watershed located in northern Iran. The Water Erosion Prediction Project (WEPP) watershed model was set up to simulate the run‐off and sediment yields. WEPP was calibrated and validated against measured rainfall–run‐off–sediment data. Results showed that simulated run‐off and sediment yields of the watershed were in agreement with the measured data for the calibration and validation periods. While low and medium values of run‐off and sediment yields were adequately simulated by the WEPP model, high run‐off and sediment yield values were underestimated. Performance of the model was evaluated as very good and satisfactory during the calibration and validation stages, respectively. Total soil erosion and sediment load of the study watershed during the study period were determined to be 10 108 t yr^?1 and 8735 t yr^?1, respectively. The northern areas of the watershed with dry farming were identified as the critical erosion prone zones. To prioritize the subwatersheds based on their contribution to the run‐off and sediment production at the watershed's main outlet, unit response approach (URA) was applied. In this regard, subwatersheds close to the main outlet were found to have the highest contribution to sediment yield of the whole watershed. Results indicated that depending on the objective of land and water conservation practices, particularly, for controlling sediment yield at the main outlet, critical areas for implementing the best management practices may be identified through conjunctive application of WEPP and URA. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   

Hillslope run‐off thresholds with shrink–swell clay soils          下载免费PDF全文

Ryan D. Stewart  Majdi R. Abou Najm  David E. Rupp  John W. Lane  Hamil C. Uribe  José Luis Arumí  John S. Selker 《水文研究》2015,29(4):557-571

Irrigation experiments on 12 instrumented field plots were used to assess the impact of dynamic soil crack networks on infiltration and run‐off. During applications of intensity similar to a heavy rainstorm, water was seen being preferentially delivered within the soil profile. However, run‐off was not observed until soil water content of the profile reached field capacity, and the apertures of surface‐connected cracks had closed >60%. Electrical resistivity measurements suggested that subsurface cracks persisted and enhanced lateral transport, even in wet conditions. Likewise, single‐ring infiltration measurements taken before and after irrigation indicated that infiltration remained an important component of the water budget at high soil water content values, despite apparent surface sealing. Overall, although the wetting and sealing of the soil profile showed considerable complexity, an emergent property at the hillslope scale was observed: all of the plots demonstrated a strikingly similar threshold run‐off response to the cumulative precipitation amount. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   

Provenance of Cored Sediments from Active Margin off Southwestern Taiwan Deduced from Geochemical Constraints   总被引：1，自引：0，他引：1  

HUANG Shaowei  CHEN Juchin  LO Chienying  LEE Yungtan  JIANG Weiteh  WANG Yunshuen  CHUNG Sanhsiung 《《地质学报》英文版》2014,88(1):128-141

The cored sediments sampled by R/V Marion Dufrense in the active margin off southwestern Taiwan on the east side of the Manila Trench are mostly muds consisting mainly of quartz, feldspar, illite, chlorite ＋ kaolinite with a trace amount of montmorillonite. The cored sediments have higher Fe, Ti, Cr, Cs, Li, Ni, and V but lower Ca, Na, Mn, Hf, Nb, Sr, Ta, U and Zr contents when compared with the upper continental crust（UCC, Taylor and McLennan, 1985）. The Eu/Eu＊ ratios of the sediments averaging 0.69 indicate that the recycling effect on the Eu anomaly may be minor and the contribution of mafic source rock was unimportant, which can also be depicted in the La-Th-Sc plot（Cullers, 1994） showing a ＂mixed origin＂ close to the felsic end member. The chemistry of the cored sediment can be explained by a mixing model designed by Ho and Chen（1996） with four end members i.e., greywacke, shale, quartzite and limestone, which are widely distributed in the Cenozoic formations of southern Taiwan with greywacke as the dominant contributor followed by shale.  相似文献