Nonlinear Coupled Motions for a Given Two-Point Tension Mooring System

—The nonlinear behaviors of plane coupled motions for a given two-point tension mooring sys-tem,are discussed in the present paper.For a cylinder moored by two taut lines under the action ofgravity,buoyance and forces due to wave-current and mooring lines,a mathematical model of motionswith three degrees of freedom is established.The steady solution and stability are analyzed.By integratingthe equations of motions,history,phase map and Poincare map are obtained.The Liapunov exponentsare also computed.The numerical results show that:the horizontal movement will increase,and stabilitywill also increase as the steady force increases.The amplitude of responses will decrease as time-dependentforces decrease.Because of the geometric nonlinearity,there exist many windows bifurcating to pseudo-pe-riodic or multi-periodic solution.The bifurcating patterns may be different.The behaviors are very com-plex.Under wave excitation alone,the motions are nonsymmetrical but still symmetrical statistically.     

基于北斗卫星的预警信息发布技术研究及实现

利用北斗卫星短报文通信功能,以广播方式发布预警信息,可提高预警信息的覆盖范围和时效性, 填补我国海洋及陆地边远地区预警信息发布空白。但北斗卫星预警信息发布存在传输速率低、冗余信息量大、长预警信息发布成功率低的问题。该文对北斗卫星预警信息发布系统的系统结构、协议体系和关键问题开展研究,通过指挥机并联、预警信息编码、影响区域识别、联合补包等方法,解决了北斗卫星预警信息发布系统建设的关键问题。在此基础上,该文设计了预警信息网络发布协议、预警信息北斗发布协议和预警信息北斗传输协议,并开发了原型系统。     

V-3θ图的结构与"98.6"暴雨过程预测分析

V-3θ图是成都气象学院欧阳首承教授设计出来的运用图像结构来预测天气的结构预测方法。主要利用大气中的压、湿、湿、风的垂直分布,判断大气滚流对天气演变的影响来预报天气转折性变化。利用V-3θ图对桂林站1998年6月份的暴雨过程作一个综合分析。结果几次特强的降水都在V-3θ图上有较好的反映。该方法对无明显降水的天气也能作定性的判断。     

MAPGIS在水文地质制图中的应用

利用功能强大的ＭＡＰＧＩＳ系统,根据水文地质图的编制特点,笔者利用ＶｉｓｕａｌＦｏｘｐｒｏ开发了ＭＡＰＧＩＳ数据接口程序ＭＡＰＨＹＤＲＯ,成功地编制了矿井综合水文地质图,为机助编制各类水文地质图提供了一条可行的途径。     

浅谈对“混合土”的认识及其地基处理

“混合土”是一种特殊性土,成分复杂,粒径悬殊,力学性质变化较大。本文以株洲市南华花园地区“混合土”为例,剖析了勘察中应注意的事项,阐述了动力触探是对“混合土”勘察的有效手段,并结合工程实际情况,提出了相应的地基处理措施。     

内蒙古东部半干旱草原残丘景观区铜多金属元素表生地球化学异常特征及其评价指标体系的构建

分析了研究区内钙积层、风成沙等制约因素对铜多金属元素表生地球化学异常发育的影响,总结了该类特殊景观条件下铜多金属元素表生地球化学异常特征及其在垂向和侧向上的迁移规律。在此基础上,构建了该类景观区铜多金属元素的表生地球化学异常评价指标体系     

The study on the interannual variation and the mechanism of the south china sea monsoon

l.Intr0ductionTheonset0ftheSouthChinaSea(SCS)monsoonisasignofthecomingoftheAsianmonsoon.Inaverage,theonsetoftheSCSmonsoonisinthemiddleofMay,butitsstrengthandtheonsetdatediffergreatlyfromoneyeartoanother.TheanomaliesoftheSCSmon-soonhighlydePendonnotonIytheprecipitationinSCS,butalsotheanomaliesofthecircu-lationintheworld.WhyisthemonsoononsetearliestinSCS?Whatisthemechanismoftheonsetanditsvariation?Thisisascientificproblemthatisinterestedinbymeteorologistsbothathomeandabroad.TaoandChen…     

塔中地区中上奥陶统台地镶边体系分析

塔里木盆地塔中地区中上奥陶统碳酸盐岩台地边缘以发育良好的多种粒屑滩和生物礁组成的镶边沉积体系为特征。通过精细的单井相分析,识别出砂屑滩、砾屑滩、生屑滩以及鲕粒滩等,并且区分出3种不同类型的生物礁：①隐藻灰泥丘;②主要由枝状苔藓虫、海绵或（和）珊瑚建造的障积礁;③由石质海绵、托盘类、层孔虫、珊瑚、管孔藻等建造的骨架礁。在面向深水盆地的台缘外带,以发育中～高能粒屑滩和骨架礁组合为特征。在背靠开阔海台地的台缘内带,主要表现为中低能粒屑滩、隐藻灰泥丘以及障积礁的组合。这个台缘镶边沉积体系总体上沿塔中1号断层西侧呈北西-南东向长带状展布,长度100多公里,是本区重要的油气聚集带之一。储层质量台缘外带总体上优于台缘内带,其中骨架礁礁核和粒屑滩灰岩最好,礁间海和滩间海沉积物较差。     

Precise dating of the Dansgaard-Oeschger event 4 and its sub-cycles: Evidence from a stalagmite from Xianyun Cave in Longyan City,Fujian Province

The Dansgaard-Oeschger event 4(DO4 event) is a significant warming event that occurred in the late Marine Isotope Stage 3. At present,there are different understandings about the detailed characteristics and internal structures of the DO4 event. Based on 6 precisely-dated ²³⁰Th ages and 188 oxygen isotope data of a stalagmite(No.XYⅢ-28)from the Xianyun Cave,Fujian Province,we present δ¹⁸O time series with an average resolution of 7 yr from 29.13 to 27.94 kyr B.P. Our new stalagmites δ¹⁸O records uncover the detailed processes of the DO4 event. The onset and end time of the DO4 event recorded by the stalagmite δ¹⁸O is 28.83±0.06 and 28.46±0.06 kyr B.P.,respectively, and the duration is 0.37±0.06 kyr. Differential with abrupt change of NGRIP ice core δ¹⁸O record at the onset of DO4 based on the GICC05 layer count time scale,the Xianyun Cave δ¹⁸O shows a relatively slow change. The Xianyun stalagmite δ¹⁸O values negatively shift by 0.4‰ within 145±60 yr,which indicates that the Xianyun Cave was likely affected by the ocean-atmosphere coupling of the tropical. In addition,the Xianyun stalagmite δ¹⁸O reveals a series of sub-million-scale summer monsoon enhancement events in and around the DO4 event,corresponding to the NGRIP ice core δ¹⁸O record and the Arabian Sea basin record. Our results suggest that the East Asian summer monsoon is related to the north-high latitude temperature and the ITCZ position changes on the sub-millennium-scale event.     

凹坑地形风流结构对污染物散布的模拟研究

利用建立的三维非静力高分辨率高阶湍流闭合模式与随机游动扩散模式研究了一个深凹露天矿区污染物散布的规律,同时在风洞中进行了示踪实验。结果表明,由于凹坑内复环流结构的存在,使得坑内污染物浓度较大,且浓度最大值出现在源的上风侧。数值试验与风洞试验结果吻合较好。