基于计算机视觉的专题图读取系统

本文提出了一种基于计算机视觉的专题图读取系统方案。该系统用CCD相机获取专题图影象,通过线划跟踪、弧段矢量化、拓扑结构形成、数据压缩、几何纠正与拼接等步骤,实现专题图的自动读取,继而进行各种几何量算和统计,建立专题信息库     

Monthly summaries of merchant ship surface marine observations and implications for climate variability studies

We compute the interannual fluctuations of the surface heat budget of the North Atlantic using the trimmed monthly summaries of the Comprehensive Ocean-Atmosphere DataSet (COADS) for the period 1950–1979. The presence of long-period trends in the heat budget imply large variations of the northward cross-equatorial heat transport over the years. To assess the reliability of these variations, we compare the COADS climate signal to that derived from the ocean weather stations (OWSs) of the North Atlantic. The sea surface temperature, air temperature and sea level pressure show good correlation between the anomaly time series derived from the merchant ship monthly summaries of COADS, and those derived from OWS monthly summaries, except for northernmost locations during winter. In contrast, the sensible and latent heat parameters, which require simultaneous measurements of various variables, have merchant ships and ocean weather stations anomaly time series that are poorly correlated. Only in heavily travelled latitudes and during winter, when the air-sea heat exchange anomalies are large, are the merchant ship measurements able to reproduce the interannual fluctuations of the heat fluxes. The long-period trends in the surface heat budget of North Atlantic equatorward of 40° N implied by COADS thus appear unrepresentative of true climate trends. The COADS trends result from a gradual increase in the magnitude of the reported winds over the years due probably to variations in the ratio of measured to estimated winds, as well as from long period fluctuations in the near surface vertical temperature and humidity gradients. Offprint requests to: R Michaud     

长期预报的相空间近邻等距法

考虑到确定性系统的外在随机因素和内在随机性(浑沌)所造成的长期预报的不准确性,本义将有关浑沌的理论和数理统计理论结合起来,提出了d维相空间距平符号传播的“正、反规则”假说和近邻等距模式.实例检验表明,经调试后距平符号的报准率一般为66％—80％,而相对误差一般不大于8％.     

西安市地裂缝CO2异常特征及异常机理初步研究

本文论述了西安地裂缝0.5m和2.0m深处CO_2异常特征,并对其异常机理进行了初步探讨。结果表明,0.5m深处CO_2异常范围较大,与地裂缝造成的破坏范围基本一致,其CO_2主要来源于生物作用;2.0m深处CO_2异常范围窄,与主地裂缝的位置有很好的对应关系,其CO_2主要来源于断裂活动造成的碳酸盐岩破裂释气。     

Soil amplification based on seismometer array and microtremor observations in Chiba,Japan

Soil amplification characteristics of earthquake ground motion were investigated in terms of peak ground acceleration and transfer function based on the Chiba array observation records. The amplification of peak ground acceleration occurred mostly at the top soft layer and was similar for the three components. The effects of non-linear response of soil deposits on the transfer function were examined. Transfer functions calculated by ensemble average were close for the two horizontal components while those obtained from a smoothing operation were generally different. Both the transfer functions from the ensemble average and the smoothing operation underestimated the gain factor around the natural frequencies. A two-step smoothing procedure was proposed and a rotary spectrum was used to improve the estimation of the transfer function. Microtremors were observed at the locations of the boreholes where seismometers are buried. The power spectrum and spatial coherency of the microtremors were compared with those of the earthquake ground motion. Emphasis was placed on the wavetypes which dominated the peaks in the power spectra.     

Orientation error estimation of buried seismographs in array observation

Array observation is an efficient tool to investigate various characteristics of earthquake ground motion. However, seismographs used in arrays may involve unexpected errors in their orientations. Methods of orientation error estimation were developed in three-dimensional space by comparing recorded ground motions at a reference point with those at a checking point. A maximum cross-correlation method and a maximum coherence method were proposed and their accuracy was demonstrated. The earthquake ground motions recorded in the Chiba array and in two other arrays were used in numerical examples. Non-trivial orientation errors were detected for all these arrays. The cross-correlation coefficients and the coherence values between two points increased significantly by correcting the estimated orientation errors.     

南极陨石研究的启示Ι:早期太阳星云连续化学分馏作用的岩石化学证据

球粒陨石金属相的 Ir、Os、Co等亲铁元素的浓度随氧化程度的升高而显著增大 ,其浓度以及铁纹石 Co含量和橄榄石 Fa值均反映了球粒陨石的氧化 -还原程度具有连续变化的特征。根据铁纹石 Co含量、橄榄石 Fa值、低 Ca辉石 Fs值、金属相的 Ir、Os、Co浓度以及其他球粒陨石分类参数 ,可能存在介于 E与 H、H与 L、L与 L L以及 L L与 C之间的球粒陨石过渡型 ,即E/H、H/L、L/L L和 LL/C化学群 ,从而将原有的 9个球粒陨石化学群增加到 1 3个。球粒陨石氧化 -还原程度的变化特征以及球粒陨石过渡型的发现都表明早期太阳星云的化学分馏作用具有连续变化的特点。     

黄海粘土沉积物的来源与分布

本文根据区域自然地理原理,划分黄海粘土沉积物的补给区,在粘土矿物鉴定的基础上,用法方程定量探明黄海粘土沉积物的来源与分布,绘出黄海粘土沉积物分布图。图示:黄海来源于长江的粘土沉积物的分布面积,占其总面积的56.5%,来源于黄河的占43.5%。粘土沉积物的分布同洋流、海流的分布相吻合。     

龙岩梅花山自然保护区环境水文特征*

龙岩梅花山自然保护区位于闽江、九龙江、汀江三江发源地,本文阐述保护区环境水文特征,并提出保护利用水资源的措施。