辽宁义县红石火山岩型金矿床地质特征及其找矿意义

红石金矿是新发现的火山岩型金矿床.辽宁省地质矿产局第四地质大队做了初步详查.在前人工作的基础上,本文概述了矿床地质特征,分析了矿床成因,提出了找矿标志.燕辽地区火山岩分布广泛,找寻该类型矿床有其重要现实意义.     

非静力平衡大气非线性层结对称运动的稳定性和突变

在假定了环境地转风具有水平和垂直的线性切变的情况下,考虑大气层结的线性和非线性切变的作用,建立了一个非线性常微分方程组,然后构造了一个Hamilton函数,通过讨论Hamilton函数的凸凹性,得到了非线性层结对称运动的不稳定判据,同时讨论了非线性层结对称运动产生突变的条件。     

大气中非线性Rossby波包的传播

本文研究了纬向基本气流具有弱切变而不是缓变的情况下的正压非线性Rossby波包,在仅考虑纬向波数k是tx的缓变函数时,可以得到一个描述非线性Rossby波包的推广的非线性Schrodinger方程,并指出,(1)当纬向波数k是t,x的一次缓变(即Z,X的函数)时,非线性Rossby波的波作用密度和能量密度是守恒的。(2)而当纬向波数k是t,x的二次缓变(即Τ,ξ的函数)时,非线性Rossby波包的波作用密度和能量密度并不是守恒的,而且我们还指出在纬向波数k不变的情况下,其波包振幅就变为典型的非线性Schrodinger方程,其流场具有阻塞结构。     

Impact of Greenland blocking on midlatitude extreme cold weather: Modulation of Arctic sea ice in western Greenland

In this study, we analyzed 1979–2019 daily ERA-Interim reanalysis data in winter and performed atmospheric circulation experiments to examine the modulation of Arctic sea ice in western Greenland(Baffin Bay, Davis Strait, and the Labrador Sea, BDL) on winter Greenland blockings. It is found that low BDL sea ice and high BDL surface temperature favor frequent, long-lived, westward-moving Greenland blockings in winter, which cause frequent and strengthening cold surges over the mid-eastern United States. In contrast, high BDL sea ice and low BDL surface temperature favor short-lived, less frequent and quasi-stationary Greenland blockings, mainly leading to cold anomalies in North Europe. Low wintertime BDL sea ice reduces the background potential vorticity meridional gradient(PVy) and zonal wind over the mid-high latitudes of the North Atlantic, which enhances the nonlinearity of Greenland blocking, accelerates the phase speed of its westward movement, and weakens its energy dispersion, thus favoring the occurrence and persistence of Greenland blocking. High BDL sea ice strengthens the background PVyand zonal wind in the mid-high latitudes of the North Atlantic, which weakens the nonlinearity and movement of Greenland blocking, enhances its energy dispersion, and thus suppresses the occurrence and persistence of Greenland blocking and its retrogression. A set of atmospheric circulation experiments supports the above results based on the reanalysis dataset.     

汶川大地震绵竹市回澜立交桥震害调查

绵竹市回澜立交桥跨越绵竹货运火车站,包括主桥及4个平面为圆形的曲线匝道桥,匝道桥为连续箱梁结构.5.12汶川大地震中,回澜立交桥遭到严重破坏,通过对震害的现场调查及分析发现,圆形匝道桥破坏严重,每个匝道桥破坏集中于1-2个抗弯刚度较大的低矮桥墩并引起上部箱梁横向断裂,其余桥墩发生轻度或中度破坏,主要为桥墩混凝土保护层脱落、混凝土开裂及墩顶橡胶支座的滑移,且总体来看,匝道桥破坏沿切向更为明显.主桥破坏相对较轻,主要包括桥墩顶部的支座滑移及主桥与匝道桥间的碰撞破坏.     

BDS基线解算不同时段精度差异分析

北斗导航卫星系统(BDS)已投入运行并完全覆盖我国区域,验证和评估BDS定位精度成为当前的研究热点。本文在河北和四川地区进行了当天内分时段的BDS基线解算,比较结果显示,BDS系统具有良好的稳定性,外符合精度在0.2 m之内,计算基线弦长中误差满足10 mm+5×10^-6D的国家C级控制网的精度要求,同一基线多天分时段解算结果呈现规律性变化,不同时段的结果差异较大,凌晨及傍晚时段的结果精度较高,下午时段的结果精度较差。     

平均误差控制下的频率域矢量数据压缩方法

矢量数据压缩对于受网络带宽限制的WebGIS有着重要意义,其可减少数据存储空间,提高网络传输与处理效率。传统的矢量数据压缩方法主要从空间关系的角度出发,根据原始矢量数据点之间的距离、角度等指标,判断如何对矢量线要素或面要素进行化简,略去冗余的端点。而本文则利用已在图像压缩领域被广泛应用的变换编码的频率域压缩技术,利用能实现能量保持的离散余弦变换和特殊的量化方法,以及无损熵编码,对矢量数据实现了能控制压缩后平均误差的有损压缩。该方法无需事先根据不同的误差限值设计量化表,且能处理指定过大平均误差限值时所出现的问题,有很强的适应能力。最后,使用C#实现了该方法,并验证了方法的可靠性,完成了方法的性能测试。实验结果表明,本文提出的矢量数据压缩方法能获得较大的压缩比,且能较好地保持原始矢量数据所具有的地理形态结构特征。     

土地变更调查数据库质量评价及其错误空间自相关分析——以河北省为例

评价土地变更调查数据库质量,研究数据库错误产生的原因是变更调查工作中的关键问题。本文采用对比分析法定量分析3年间数据库质量变化,并运用全局Moran's I系数、局部Moran's I系数,从县域尺度分析数据库错误的空间自相关格局,揭示数据库错误空间分布变化和局部异常特征。研究结果表明：(1)从错误数量、缺陷等级、错误分布图层和空间分布方面进行评估,河北省2012年数据库质量相较于2010年和2011年得到明显改善;(2)河北省各区县错误分布保持高度自相关,聚集程度波动变化,而局部显著性异常区域的出现主要源于人为误操作。通过研究数据库质量3年间变化情况及空间分布格局,能客观地评价数据库质量状况,有效地分析错误产生的原因,为新一轮土地变更调查工作提供建设性意见。     

The optimization algorithm for the pathfinder sea surface temperature in the East China Seas

Based on the analysis of the quality level in a Pathfinder 4km daily nighttime Sea Surface Temperature product (PFSST) in the East China Seas (ECS) from 1985 to 2004, the proportion of high-quality data was lower than that in the global level. Additionally, the PFSST maps showed clearly the void and anomaly data impacted by atmospheric contamination. In order to solve the above problem, an optimal algorithm was established through introducing the structure function, setting up the daily first-guess sea surface temperature (SST) field and taking PFSST product of the highest quality as reference points. Comparisons were done between this optimally interpolated SST and the selected original PFSST and the simultaneous in situ measurements. It illustrated it was possible to exactly estimate the SST values in the ECS during the recent two decades. The mean bias error and the root mean square error between data sets optimally evaluated and in situ observed were lower than those between the previous global estimations and in situ measurnments.     

Bifurcation of Nonlinear Kelvin Wave-CISK with Conditional Heating in a Truncated Spectral Model:A Possible Mechanism of 30-60-Day Oscillation at the Equator

1.IntroductionSincethe40--50--dayoscillationinthetropicalPacificwasfirstfoundbyMaddenandJulian(1971,1972),ithaslongbeenanimportantresearchtopic.Inobservationalstudies,LauandChan(1985,1986),GhilandMo(1991)showedthattheintraseasonaloscillationsinthetro...