大尺度海气异常关系的主振荡型分析

简要介绍了主振荡型(POP)分析的原理及方法.用它分析了热带太平洋海表温度异常,得到的主振荡型 P_1、P_2及其周期 T,描述了 El Nino 与 La Nina 事件交替出现的时空特征.分析了热带太平洋区域月平均海温与风场的伴随相关型(ACP),得到了与 El Nino 事件相关的、物理意义清楚的环流异常图像.而对东亚夏季降水、气温的 ACP 分析给出了 El Nino 事件与我国夏季长期天气异常联系的接近实际的结果.     

South Australian rainfall variability and climate extremes

Rainfall extremes over South Australia are connected with broad-scale atmospheric rearrangements associated with strong meridional sea surface temperature (SST) gradients in the eastern Indian Ocean. Thirty-seven years of winter radiosonde data is used to calculate a time series of precipitable water (PW) and convective available potential energy (CAPE) in the atmosphere. Principle component analysis on the parameters of CAPE and PW identify key modes of variability that are spatially and seasonally consistent with tropospheric processes over Australia. The correlation of the leading principle component of winter PW to winter rainfall anomalies reveal the spatial structure of the northwest cloudband and fronts that cross the southern half of the continent during winter. Similarly the second and third principle components, respectively, reveal the structures of the less frequent northern and continental cloudbands with remarkable consistency. 850 hPa-level wind analysis shows that during dry seasons, anomalous offshore flow over the northwest of Australia inhibits advection of moisture into the northwest, while enhanced subsidence from stronger anticyclonic circulation over the southern half of the continent reduces CAPE. This coincides with a southward shift of the subtropical ridge resulting in frontal systems passing well to the south of the continent, thus producing less frequent interaction with moist air advected from the tropics. Wet winters are the reverse, where a weaker meridional pressure gradient to the south of the continent allows rain-bearing fronts to reach lower latitudes. The analysis of SSTs in the Indian Ocean indicate that anomalous warm (cool) waters in the southeast Indian Ocean coincide with a southward (northward) shift in the subtropical ridge during dry (wet) seasons.     

气候可行性论证工作浅析

根据建设项目需要和气候可行性论证发展特点,提出了气候可行性论证的指导原则及要求,从工程建设的合理布局和保护气候环境的基点出发,对气候可行性论证的范围、内容,以及气候可行性论证分析与评价进行了探讨。     

地震散射波模拟成像在金属矿勘探中的应用

由于金属矿地质模型一般具有强非均匀性,造成金属矿地震勘探中采集到的信号杂乱,应用常规的反射地震处理技术难以获得可靠的成像效果.而基于惠更斯一菲涅尔原理的散射成像方法能充分利用地震信号中的全波场信息,例如反射波、绕射波、回转波、直达波、转换波等,它们都是散射波的一种表现形式,从而可以获得较好的成像效果.结合中国东部典型铜矿-铜陵冬瓜山铜矿与中国西部典型锡矿-云南个旧锡矿的地质模型,我们模拟了散射波地震记录,并通过散射成像方法获得了高质量的偏移结果,从数值模拟角度证明了散射成像在金属矿地震勘探中具有较好的应用前景.     

震级离散下的震级频度关系

运用最大熵原理,研究震级离散条件下震级频度关系,得到震级离散条件下震级概率分布函数,结果表明:(1)震级大于等于某一震级的地震次数应通过离散求和的方式得到,而不应通过积分的方式得到;(2)震级上限取为∞的情况下,古登堡意义和里克特意义两种震级频度关系式的b值相等;震级上限有限的情况下,里克特意义震级频度关系式可能不是直...     

气象服务效益特征及其建模原则

分析气象服务效益的一般特征，阐明气象服务宏观与微观两方面的意义，确立构建气象服务效益评估模型的原则。     

The Gravitational “Plane Waves” of Liu & Zhou and the Nonexistence of Dynamic Solutions for Einstein’s Equation

Although both the electromagnetic wave and the gravitational wave can be produced approximately from Maxwell-type equations, there are subtle differences in their respective exact equations. Since gravitational wave carries energy-momentum, the exact field equation of a gravitational wave must have a nonzero source term along its path, whereas a field equation for an electromagnetic wave does not. This explains that there is no weak wave solution of Einstein equation. Historically, neither Einstein & Rosen nor the Physical Review was aware that the nonexistence of gravitational wave solutions is due to a violation of the principle of causality. It is pointed out that the criterion of Liu & Zhou on plane-waves is valid since the principle of causality requires the existence of weak limits. However, due to the influence of the popular but unverified assumption of the existence of dynamic solutions, they made careless errors in their calculations and incorrectly concluded that their plane-waves have weak limits. It is shown that “plane-waves” of Liu & Zhou, is actually unbounded in amplitude, and have no weak limit. Therefore, Liu & Zhou provide additional evidence in supporting the nonexistence of dynamic solutions. PAC Number: 04.20.-q, 04.20.Cv, 04.30.-w     

辽西肖家营子地区金矿遥感信息提取及成矿预测

对TM图像作比值及主成分分析,选择能突出金矿蚀变的高特征向量值所在的主分量进行彩色合成,通过空间滤波及非监督分类处理,图像上显示出似晕圈状的彩色异常区。经野外验证,部分彩色异常区与化探异常分布范围相叠合,新发现的3处金矿点金品位分别达到2.74×10^-6、9.61×10^-6和9.6×10^-6。结合图像上的彩色异常信息和取样分析结果,在进行成矿条件分析后,提出了三处金(银铜)遥感综合成矿预测区。     

自然地理区划问题探讨

本文从较新的角度探讨了自然地理区划的对象和原则等问题。文章指出,地球内能与太阳辐射能都是地表自然综合体演化的外部条件;高度地带性也是地理地带性规律的主要内容。并强调了水热对比关系是各级自然综合体差异的主要根源。     

在“GPS原理与应用”课程中实践研究型教学探讨

通过多年的“GPS原理与应用”课程教学实践,总结出面向研究型教学的几点体会：一是从大量知识的陈述到3个重要原理的凝练;二是从复杂数学模型的推演到简单框图原理的表达;三是从晦涩的学术讲解到与有趣的仪器操作结合;四是从简单的校园实习到野外的实战测网。通过研究型的教学方法使学生们增加学习本课程的兴趣,提高学生理解原理、掌握应用的能力,为以后的工作打下良好的基础。