THE TRIGGERING EFFECT OF NEAR-EQUATORIAL CYCLONES ON EL NIO

The relationship between tropical cyclones developing in the Northwest Pacific and El Nino is analysed and the triggering mechanism of the near-equatorial cyclones on El Nino is proposed. It is pointed out that the near-equatorial tropical cyclones developing equatorward of 10°N can intensify equatorial westerlies and produce Kelvin waves, which propagate to the South American Coasts in about 2-3 months, inducing SST to rise there. The near-equatoral cyclones play an essential role in El Nino. The beginning period of El Nino ranges from January to May. The number of near-equatorial cyclones developing in this period determines whether El Nino can be generated or not. The persistence period is from June to September. El Nino can not continue developing unless there are adequate near-equatorial cyclones. If there are not, the developed El Nino will be broken down. The period from October to December is called the developing period. During this period El Nino may approach its culmination only when adequat     

NONLINEAR ELASTIC STABILITY OF CIRCULAR TUBE UNDER COMBINED BENDING AND EXTERNAL PRESSURE

On the basis of S. Kyriakides' findings, the assumption considering that the mid-surface of the tube is inextensible is abandoned in this paper and the nonlinear elastic stabittty of long circular tube under combined bending and external pressure is further investigated. This paper provides more refined results than S. Kyriakides' work. Through a lot of numerical calculations, the beading moment-pressure diagram at critical state is obtained.     

面向地理教学的熔岩流过程可视化

本文为学习理解熔岩流过程提供了一个可视化的解决方案,利用深度相机传感器采集可塑地形的基础高程数据,以流体动力学的浅水方程刻画计算熔岩流过程,并通过投影仪实时投影展示在可塑地形表面,最终实现不同影响因素下熔岩流过程的可视化。     

风蚀事件中农田土壤PM10释放特征

地表风蚀导致的粉尘释放涉及全球变化研究的热点。自然条件下对粉尘释放的观测可以为风洞试验结果提供验证并为开发预测模型提供数据支撑与关键参数。本研究在河北坝上风蚀区,通过观测风蚀事件中农田近地表PM₁₀浓度、垂直通量与流失通量,以及风速和风沙流强度的变化,探讨农田风蚀过程中的粉尘释放特征。结果表明：地表风蚀释尘对近地表粉尘浓度的影响随高度增大而逐渐减弱,各高度的粉尘浓度变化趋势与摩阻风速、输沙率变化趋势相同;粉尘垂直通量和流失通量与摩阻风速呈幂函数关系,与输沙率呈线性关系;农田土壤跃移颗粒的轰击效率α数量级为10^-7m^-1。     

藏东南地区复杂下垫面能量收支特征分析

利用公益性行业（气象）科研专项项目＂藏东南地区复杂下垫面地气交换观测研究＂在藏东南地区进行的地气交换观测实验数据,分析典型晴天和阴天条件下不同下垫面能量过程的特征及其差异。结果表明：在典型晴空状态下,不同下垫面的地表净辐射均具有明显的日变化特征,在典型阴天的情况下,不同下垫面地表净辐射日均值显著减小;在典型晴空天气下,4种类型下垫面上潜热均随着净辐射的增加而表现为增加的趋势,在典型阴天的情况下,潜热通量明显比晴空天气小;不同下垫面感热通量的日变化存在显著的差异,不同下垫面感热的变化特征在典型晴空和阴天条件下的差异不明显;不同下垫面土壤热通量与净辐射的变化趋势基本一致,阴天夜晚土壤热流的交换与晴天夜晚的差异不大,四种下垫面土壤均存在能量损失,土壤处于降温状态。     

银额盆地查干凹陷原油地化特征及油源对比

银额盆地东部查干凹陷首次发现轻质低硫成熟原油，其饱和径含量在90％以上，成熟度相当于镜煤反射率Ro1．0％左右，是生油高峰阶段的产物；原油全碳同位素δ^13C值－31．1‰。原油生物标志物中类异戊二烯含量较高，植烷与姥皖烷均势；三环萜烷含量高于五环萜烷；含有较高的TS C29、Ts、C30重排藿烷、伽马蜡烷；藿烷中以C50藿烷为主，C32以上升藿烷含量极低；孕甾烷含量高；甾烷中以C29甾烷为主，C27甾烷含量也较高，异胆甾烷含量高于胆甾烷；重排甾烷含量低；甾烷的含量与萜烷含量相当，是典型的湖相原油。已发现的天然气中甲烷含量达80％，为湿气。原油和源岩生物标志物组成特征分析对比表明下白垩统巴音戈壁组源岩是主要油源岩。生物标志物特征示原油具有一定的运移效应。     

新型规则混层的七埃绿泥石—膨胀绿泥石和绿泥石—叶蛇纹石的发现

笔者在四川石棉县广元堡蛇纹岩中,发现一个以绿泥石、蛇纹石为主的晚期热液透镜体,长约一米,宽7—8厘米。从中采选了四种不同形态的绿色矿物,分别做了x光衍射(在各种条件下计100次分析),油浸法,化学     

国家测震台MSDP单台数据处理软件常见故障排除

从国家测震台日常观测角度出发,对MSDP单台数据处理软件系统在波形保存、地震定位、报告产出等方面存在的缺陷或容易出现的不当操作加以归纳总结,给出解决方法或提出注意事项,为测震单台用户提供参考。