成都数字遥测地震台网地震速报几个定位软件的比较与讨论

应用成都数字遥测地震台网数据,通过对震中距大于300千米的55次地震重新定位,对比研究成都数字遥测地震台网数据处理软件提供的几种地震定位程序以及原模拟台网使用的地震定位程序,初步认为震中距在300千米<Δ≤10°时,Genetic、Gerlor-P、Gelor-I程序优于Front和loc212程序,而Telloc、loc312程序基本不能用;震中距在10°<Δ≤20°和20°<Δ≤50°时的地震定位,Front优于loc212程序,而Telloc程序不能用.     

土高压三轴仪数据采集和处理系统的改进

较详细介绍了土高压三轴仪数据采集和处理系统的改进，新编测量软件的功能、特点。改进后该设备系统在恢复、扩大仪器功能和实验自动化方面得到进一步的完善。     

Predicting soil organic carbon stocks under commercial forest plantations in KwaZulu-Natal province,South Africa using remotely sensed data

ABSTRACT

Commercial forest plantations are increasing globally, absorbing a large amount of carbon valuable for climate change mitigation. Whereas most carbon assimilation studies have mainly focused on natural forests, understanding the spatial distribution of carbon in commercial forests is central to determining their role in the global carbon cycle. Forest soils are the largest carbon reservoir; hence soils under commercial forests could store a significant amount of carbon. However, the variability of soil organic carbon (SOC) within forest landscapes is still poorly understood. Due to limitations encountered in traditional systems of SOC determination, especially at large spatial extents, remote sensing approaches have recently emerged as a suitable option in mapping soil characteristics. Therefore, this study aimed at predicting soil organic carbon (SOC) stocks in commercial forests using Landsat 8 data. Eighty-one soil samples were processed for SOC concentration and fifteen Landsat 8 derived variables, including vegetation indices and bands were used as predictors to SOC variability. The random forest (RF) was adopted for variable selection and regression method for SOC prediction. Variable selection was done using RF backward elimination to derive three best subset predictors and improve prediction accuracy. These variables were then used to build the RF final model for SOC prediction. The RF model yielded good accuracies with root mean square error of prediction (RMSE) of 0.704 t/ha (16.50% of measured mean SOC) and 10-fold cross-validation of 0.729 t/ha (17.09% of measured mean SOC). The results demonstrate the effectiveness of Landsat 8 bands and derived vegetation indices and RF algorithm in predicting SOC stocks in commercial forests. This study provides an effective framework for local, national or global carbon accounting as well as helps forest managers constantly evaluate the status of SOC in commercial forest compartments.     

LOCT近震综合处理程序的原理与应用

ＬＯＣＴ是针对遥测地震台网对近震（△≤１０００ｋｍ）进行综合性处理工作而编写的ＢＡＳＩＣ优化程序．主体程序由数字化仪输入（含人工输入和文件输入）地震波数据．用交切法、偶台中线与Ｓ－Ｐ联合测定法、虚波走时迭代法测定地震参数，震级ＭＬ的计算，地震目录和报告数据的文件输出等部分组成．具有使用方便，灵活可靠，程序自身保护性好，地震参数的测定速度快、精度高，各种功能既相互独立，又统一于一体，互相补充，功能全面等特点．是进行近震速报和生成目录及报告的理想的实用程序．     

非线性科学在地球物理学和地震学中的应用研究

本文作者承担了国家地震局科技监测司“八五”地震科技信息研究规划：国外非线性科学研究现状与发展专题，现已完成１９９４年度计划内容，取得了初步成果。基于这些成果，本文作者编写了“非线性科学在地球物理学和地震学中的应用研究专辑”，较系统地介绍了前苏联及俄罗斯有关非线性科学在地球物理学和地震学中的应用研究情况，主要内容包括：前苏联及俄罗斯非线性科学在地球物理学和地震学中的应用研究计划，研究进展及深入研究的方向。     

多目标规划理论识别岩溶水系统核函数模型的应用实例

本文在研究核函数理论的基础上,建立了岩溶水系统线性、非线性核函数模型,运用多目标线性、非线性规划识别核函数模型,并编制了相应的程序,把这一理论及模型运用到赵各庄矿坑涌水量预测中,获得了较满意的模拟,预测结果。     

陕西渭北岩溶热水赋存及开发利用研究

隶属于渭北岩溶水系统的岩溶热水,是受控于岐山—富平—韩城深断裂带的深循环水热型热储,其可采资源322.4Mm~3/a。本文旨在论述岩溶热水赋存规律,并结合开发实践,从科学规划角度探讨合理开发利用的有关问题。     

Computation of travel times and rays in a medium of two-dimensional velocity distribution

A ray-tracing computer program is described for a two-dimensional velocity distribution defined by the local wave velocitiesv _{i, j} in points at arbitrary depthv _{i, j} below the surface points with the horizontal coordinatesx _i . The velocity variation is assumed to be linear in the triangles formed by three neighbouring points. Travel times and rays are then calculated after the exact analytic formulae for any position of the source within the model. No assumptions other than of a piecewise linear velocity structure are made. A first-order discontinuity can be approximated by a thin layer with a strong velocity gradient and refracted waves or wide-angle reflections obtained in this way. As an example,P-wave rays were computed for section No. 05 of the Alpine Longitudinal Profile. The model includes a low-velocity channel which is cut off on the eastern side, first-order discontinuities and a sediment basin.Paper presented at the ESC-Workshop Meeting Seismic Waves in Laterally Inhomogeneous Media, Liblice, 1978.     

气象部门电子政务探讨

一套电视天气预报节目的成功制作与播出，与节目的前期精心策划是密不可分的。本文通过对山西电视台公共频道天气预报节目的策划过程进行分析，旨在提高大家对节目策划重要性的认识和理解，同时提高电视气象节目的策划水平，更好地打造精品栏目。     

战略环境评价的若干理论问题的探讨

战略环境评价(简称SEA)是环境影响评价(简称EIA)研究领域的前沿课题。中国对SEA的研究始于20世纪90年代，起步较晚。在了解SEA的概念、特点的基础上，阐述了SEA与项目EIA在评价方法、评价内容上是有所差异的，在评价程序和步骤上是有共同点的。SEA是项目EIA的深化和提高。目前在中国进行EIA的过程中，EIA的局限性和所反映出的问题日益明显，为了提高中国EIA的针对性、科学性和有效性，应积极开展SEA的研究和实践。