印度洋热含量在南海夏季风爆发中的作用     

于乐江  冯俊乔 《热带海洋学报》2011,(4)

利用Scripps海洋研究所0—400m上层海洋热含量资料和美国环境监测中心/国家大气研究中心(National Centers for Environmental Prediction/National Center for Atmospheric Research,NCEP/NCAR)的再分析资料,运用经验正交分解(empirical orthogonal function,EOF)等统计方法,研究在有ENSO影响和去除ENSO影响的情况下,前期春季印度洋热含量如何影响南海夏季风爆发。结果表明,在没有扣除ENSO信号的情况下,热带印度洋热含量EOF分解第一模态呈东西相反变化的空间分布。印度洋东部热含量为正(负)异常、西部为负(正)异常时,南海夏季风爆发较早(晚),印度洋上层热含量主要通过影响热带印度洋上空大气的垂直运动和高低层辐散辐合,进而影响季风纬向环流的强弱,来影响南海夏季风爆发的早晚。在扣除ENSO信号的情况下,印度洋热含量CEOF(conditional EOF)第一模态的空间分布类似于EOF第一模态的空间分布;第二模态表现为除小部分海区外,热带印度洋热含量呈一致变化的海盆模态。这两个模态对南海夏...  相似文献   

新生代亚洲形变与海陆相互作用   总被引：26，自引：0，他引：26  

汪品先 《地球科学》2005,30(1):1-18

在现今各个大陆中, 亚洲经历的新生代形变最强. 白垩纪到老第三纪时的亚洲大陆, 不仅面积较今为小, 而且形态偏瘦"; 自从始新世印度与亚洲碰撞之后, 亚洲的面积与高度急剧增大. 随着青藏高原隆升和边缘海的张裂, 东亚原来西倾的地势发生倒转, 形成了从大陆中央隆升区向周围辐射的亚洲大河流系. 亚洲隆升有可能是北极冰盖形成与发展的重要因素, 因为隆升不仅改变大气环流、加剧风化作用, 而且还使西伯利亚河系改向北流, 通过注入北冰洋的淡水促使海水结冰、导致冰盖形成. 新生代亚洲形变, 也使得亚洲季风系统在早中新世形成, 又在约8 Ma与约3 Ma时强化. 同时, 西太平洋边缘海系列的形成, 也改变了亚洲大陆与太平洋之间的物质与能量的交换. 流经边缘海的太平洋西部边界流, 对于洋面升降和构造运动极为敏感, 在冰期低海面时边界流位于边缘海之外, 使大洋输向大陆的热量和水分大为减少. 今天, 亚洲与太平洋之间的能流与物流最为活跃, 可惜亚洲在全球气候环境演变中的重要性至今未能获得学术界的充分认识.   相似文献   

南海晚渐新世滑塌沉积指示的地质构造事件   总被引：21，自引：0，他引：21  

李前裕  郑洪波  钟广法  汪品先 《地球科学》2005,30(1):19-24

南海北部ODP1148站晚渐新世至早中新世沉积以滑塌堆积和长时间沉积缺失为主要特征.由构造活动引起的沉积间断始于渐新世中期28.5 Ma至早中新世23 Ma左右结束.主间断面位于25 Ma, 亦即滑塌沉积层的底界.4次沉积间断总共造成至少3 Ma沉积记录的缺失.综合岩性、古生物年代测定、地球化学等分析结果, 表明南海晚渐新世的海底扩张模式呈多次跳跃式, 并以“25 Ma事件”为型变高峰.这一系列构造活动是欧亚、澳大利亚、菲律宾-太平洋板块相互作用的结果, 直接导致南海向前期裂谷更发育, 红河大断裂左擦拉张更强的南部扩张的转型.1148站的滑塌沉积为此次南海扩张转型提供了直接的证据.   相似文献   

地震调制比及其在华北地震中短期预报中的应用   总被引：1，自引：0，他引：1  

王炜  宋先月  谢端  王 《地震研究》2001,24(3):202-207

对调制比预报地震方法进行了改进，并使用改进的地震调制比rm10对华北地区进行空间扫描，结果表明中强地震前1年左右的中短期阶段，未来震中周围的rm10中期异常区出现明显的收缩或消失，一些震例在临震前数月还再次出现rm10异常区。本方法具有较好的中短期预报效果，中还就rm10进行中短期预报的有关问题进行了讨论。  相似文献   

岩石破裂时电磁辐射的机理研究   总被引：21，自引：6，他引：21  

朱元清  罗祥麟 《地球物理学报》1991,34(5):594-601

本文提出了岩石破裂时的电磁辐射是裂纹尖端电荷随着裂纹加速扩展运动所产生的假说.应用断裂力学方法推导了岩石破裂时初始裂纹长度与裂纹扩展加速度的关系,并计算了其速度和加速度值.根据破裂岩石的电子发射理论,解释了裂纹尖端带电荷的现象.利用岩石在单轴压缩致裂过程中记录到的近场电磁辐射的实验结果,计算了裂纹扩展时裂纹尖端的电荷量和远场电磁辐射强度.通过对电磁辐射波谱分析的研究,得到岩石破裂时电磁辐射频率上限的估计值.最后对岩石破裂时出现的声光电磁现象在理论上作了统一的定性的解释.  相似文献   

A Ring Model for Limit Analysis of Spatial XX Tubular Joints     

Chen Tieyun  Liu Pu  Wang Deyu Professor  Shanghai Jiaotong University  Shanghai . Postdoctor  Shanghai Jiaotong University  Shanghai 《中国海洋工程》1994,(3)

-A ring model is developed to investigate the ultimate strength of tubular X and XX joints in the case that the brace is compressed. In the present analysis, the tubular joint is made of elasto-perfectly-plastic material, and the arch element of the chord section intersecting with the brace is assumed to be rigid. It is found that when 6 plastic hinges for X joint and 8 plastic hinges Tor XX joint appear in the ring, the limit state is reached, and by means of the equivalent ring width Be formula proposed in a previous paper by the authors, the ultimate strength of tubular X and XX joints subjected to compression can be obtained.  相似文献   

Manned Testing of the Diver Gas Recovery Installation     

Mao Fangguan  Lu Shunchang Luo Ruiren Senior Engineer  Naval Medical Research Institute  P. L. A. of China  Shanghai  Senior Engineer  Navigation Guarantee 《中国海洋工程》1995,(4)

The Diver Gas Recovery Installation (DGRI) was evaluated at 80 msw saturation - 100 msw excursion diving on HeO2 in the Naval Medical Research Institute (NMRI) of China in April, 1995. The diving depth, lockout time, breathing gas flow rate and consumption, inspired oxygen partial pressure (PO2) and carbon dioxide partial pressure (PCO2) were monitored. The results indicated that PO2 was controlled to fluctuate from 64.3 to 84.0 kPa and PCO2 went up from 0.01 kPa up to O.I kPa during 4 hours excursion diving; recovery of breathing gas reached 95%; three divers felt well and breathed comfortably during simulating heavy work. The test showed that it met desired performance goals. The DGRI is a kind of important equipment for long duration deep dive. It enables the gases exhaled by the divers to be re-cycled, and therefore it has great social, military and economic significance for diving operation and submarine rescue.  相似文献   

Buckling Propagation in Marine Pipelines     

Lin Zhongqin  Shen Huishen Chen Tieyun Dr. Associate Professor  Dept. of Mechanical Eng.  Shanghai Jiao Tong University  Shanghai Professor  Dept. of Civil Engineering  Shanghai Jiao Tong University  Shanghai Professor  Dept. of Naval Arch  and Ocean Eng.  Shanghai Jiao Tong University  Shanghai 《中国海洋工程》1993,(1)

The buckling propagation in marine pipelines is studied by means of the cylindrical shell model in this paper. Several parameters including geometrical parameter D/ T, L/ D, physical parameter E and σy are discussed. The computed results are compared with the available experimental data and other computed results, it is found that the present results are closer to the experimental results than other computed results.  相似文献   

A Study on Crack Detection with Modal Parameters of A Jacket Platform   总被引：1，自引：0，他引：1  

张兆德  王德禹 《中国海洋工程》2004,18(1):1-10

Crack detection procedures by different modal parameters are analyzed for identitying a crack and its location and magnitude in a jacket plafform. The first ten natural frequencies and modal shapes of the jacket models are obtained by numerical experiments based on NASTRAN Code. A crack at different locations and of different magnitudes is imposed in the model at the underwater beams. Then, the modal evaluation parameters are calculated numerically, to illustrate the evaluation of modal parameter criteria used in jacket crack detection. The sensitivities of different modal parameters to different cracks are analyzed. A new technique is presented for predicting the approximate location of a breakage in the absence of the data of an intact model. This method can be used to detect a crack in underwater menbers by use of incomplete mode shapes of the top members of the jacket.  相似文献   

Simulation of the Whole Process of Ship-Bridge Collision   总被引：6，自引：0，他引：6  

LIU  Jiancheng 《中国海洋工程》2002,16(3):369-382

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