763地震仪水平向拾震器抗干扰性能的探索

通过对攀枝花台、成都台763仪调试架设的实践,结合H763仪结构特点,分析了仪器零漂出现的原因和提高仪器抗干扰性能的方法;同时,提出了H763仪安装架设的技术指标及仪器密封方式改善的方法。     

调整核旋仪的一种数值方法

应用数值理论对核旋仪调整的原理进行推导,得到一种简便可行的方法。通过多次实验,结果与理论推导相符。     

近期华北地震大形势的统计分析

文章在３－５年较长时间尺度概率估计的前提下，力争对未来较短时期（１－２年）各区，带地震活动趋势进行定量分析，特别着重于地震总活动水平的比较及年量大震级的预测。     

陕西近期地震活动的周期规律及其意义

随着近年来地震台网监测能力的改善，发现陕西存在ＭＬ≥１．９地震活动的双周年周期的变化规律，该现象对陕西地震预报和地震规律研究有重要意义。     

RILL INITIATION AND EROSION ON HILLSLOPES IN THE HILLY LOESS REGION,WESTERN SHANXI PROVINCE

I. INTRODUCTIONSumming up recent research achievements, Huang (1993) pointed out that the capaciucs ordetachment and transport by rill now were much greater than tboso by rain drop impact and sheet now. soil erosion by water on upper slope area is frcquenhy discussed interms of interrill and rill erosional sub--processes. Compared with rill erosion, interrlll erosion contributes a very small proportion to the sediment transported downwards (Foster,1982). Field experiments conducted by Ca…     

阿尔金断裂带中段的古地震研究

阿尔金断裂带是中国西部最著名的巨型活动深大断裂带,它构成了青藏高原的西北边界,总体呈北70~0—80~0东向展布,绵延1600余公里,影响到地壳深部,在中国西部大地构造演化中占有重要地位。由青海西北角的茫崖镇往东,沿青新界山经索尔库里、拉配泉至当金山口长达400余公里的范围,属该断裂带的中段。沿带形成的断层谷、断层崖、三角面、陡坎以及切错第三系和第四系的情形比比皆是,表明断裂带新生代以来有十分强烈的活动性。阿尔金断裂带中段全新世以来的活动非常明显,沿带发育有由大地震造成的地震鼓包、凹坑、沟槽、陡坎、断错冲沟水系和崩塌等古地震形变现象,分布十分广泛,类型众多齐全。通过1986——1987年两年详细的野外地震地质考察,确定有6次7级以上古地震事件和5条保存较好的地震破裂形变带,表明阿尔金断裂带全新世以来,具有以左旋走滑运动占主导的强烈活动的特点。     

CT在脾破裂中的诊断价值——(附34例分析)

本文通过对34例脾破裂患者伤后不同时间CT平扫、增强扫描、扩大扫描范围和CT监测结果的分析表明:CT在脾破裂的诊断中不仅安全、迅速、敏感、客观、准确、可靠,同时对复合伤的发现,腹腔积血的形成速度和成伤的判断均具有重要价值,是目前最好的检查方法。值得大力推广应用。     

地震地电阻率前兆异常特征及其机理研究

本文在全面整理我国大陆二十余年来的地电阻率观测资料的基础上,分析了地电阻率前兆异常特征及其与地震三要素之间的关系,给出地震强度(震级)与异常时间和震中距乘积的对数呈线性关系的实用结果,研究了不同类型地震地电阻率短临前兆特征及其在地震预报中的应用,探讨了地电阻率前兆变化的机理。     

怀来4井水汞前兆异常特征分析

本文介绍了１９９８年张北６．２级地震前水汞的异常变化;多点突跳、变化幅度大和持续时间长是震前水汞异常的特点。同时还根据以往水汞的多次震例,归纳出怀来４井水汞具有形态的多样性,对应距离为９０～２８０ｋｍ,异常出现后１５～４７天内发震等特点。从而加深了对该井水汞异常与地震关系的认识,有助于今后水汞预测地震水平的提高     

Research on Earthquake Precursor Attractor and Its Predictability

Based on the body strain observation data at Liyang and Xuzhou stations, the Correlation Dimension D2 and the second-order Renyi entropy K2 of the attractor are calculated and studied. In addition, a new method of evaluating the longest predictable time of precursor attractor is advanced under the condition of a certain anomalous criterion rule. The conclusion indicates that the body strain precursor attractor is one of the chaotic attractors and it has some determinate change rules such as the dimension declines before an earthquake and the number of the independent factors on which the variation of the system depends is within the range of 5 - 12. The conclusion also indicates that the longest evaluated predictable time of the body strain attractor is 213 days at the Liyang station and 342 days at the Xuzhou station. It is clear that this research can be of great reference value for recognizing the nonlinear behavior of precursor attractors and for evaluating the predictability of different precursor