中长期地震预测方案综合信度评价的层次分析法

由于存在各种复杂的不确定因素的影响，正确合理地评价地震观测结果的可信度，具有一定的难度。本文首先引入具有广泛应用途的层次分析法，并以华北北部为例，结合Ｄｅｌｐｈｉ专家咨询结果，给出了反映各个预测方案结果的可信度及具有满意一致性的相对重要性权系数。其结果可作为综合各种预测方案，确定该地区中长期地震危险区的参考依据。     

ANALYSIS OF SPHERICAL FUNCTION SPECTRAL STRUCTURE OF THE NORTHERN HEMISPHERE 500 HPA MONTHLY MEAN HEIGHT*

Study is undertaken of spherical function spectral structures of long-term mean and anomaly patterns of the Northern Hemisphere 500 hPa monthly mean geopotential height together with the seasonal and interannual variations investigated.Results show that they are marked by low dimensions and low orders,and the mean and anomaly fields can be described in terms of 20 and 50 spherical function components,respectively.     

福建岭头坪铅锌金银多金属矿地质特征及远景分析

岭头坪铅锌金银多金属矿产于南园组第二、三段中酸-酸性火山碎屑岩的夹层中,矿体呈似层状,受断裂构造及层间破碎带控制.成矿与中生代火山活动紧密相关,可能为中低温火山热液矿床.从成矿地质条件和金土壤异常分析,岭头坪矿区的周围及南、东侧以及石笋歧一带有很好的找矿前景.     

A century of inequality in England and Wales using standardized geographical units

This paper analyses geographical trends in relative poverty in England and Wales over the last century by comparing key quantitative indicators from key dates. The comparison is made possible by interpolating all the datasets onto a single standardized geography. Results suggest rising inequality in spite of the decline in absolute poverty.     

基于改进的Elman神经网络的中长期径流预报

径流中长期预报长期以来一直都是人们关注的热点研究问题。现行的径流预报方法很多,传统的有时间序列法,多元回归分析法等,这些方法虽然简单易用,但是如果预报对象提供的样本容量偏小或者因子选择不够合理,都会造成预报精度偏差过大,难于有效的指导工程应用。鉴于此,本文提出一种改进的采用局部回归的Elman神经网络方法。并应用到凤滩水库优化调度的径流预报中。结果表明,与回归分析法、BP网络相比较,该方法不仅提高了算法的效率,而且提高了预报的精度,在径流预报中具有有效性和优越性。     

长江三角洲地区对流层臭氧的变化趋势

Analysis of tropospheric ozone residual (TOR) data from satellite measurements indicates an increasing trend of tropospheric ozone over the Yangtze Delta region of China. The increasing trend can be derived both from the annual mean TOR and from the monthly mean TOR except for January and March. The increase rate of the decadal mean TOR was 0.82 DU during 1978-2000. The impact of this long-term trend on the climate and atmospheric oxidizing capacity over the region should be further studied. Data comparison shows a significant correlation between the TOR and surface ozone data collected at Lin'an background station in the Yangtze Delta region, suggesting an internal connection between both quantities.     

冻结粉土动强度的荷载效应及长期极限动强度

荷载效应包括速率效应和疲劳效应两部分．速率效应使冻土的动强度和退荷回弹动弹模随应变速率加快而提高;疲劳效应使冻土的动强度随振频增加而下降,但在低应变速率下却使动强度略有提高．在高应变速率下动强度大于静强度,在低应变速度下动强度小于静强度,其间存在一个临界应变速率．通过动强度－破坏振次关系,可确定长期极限动强度．     

江苏-南黄海地区未来地震形势的统计分析

根据１５００年以来的地震资料,应用数理统计、灰色预测、干支６０周期分析等多种方法,对江苏—南黄海地区未来３～５年地震形势进行分析和预测,结果表明：该区目前处于本世纪第２活跃幕中后期,未来几年内依然存在５～６级地震的危险性,至２０００年７月,累积发震概率将达到０．７～０．８,１９９９—２０００年、２００２—２００３年均有可能发生５级以上中强地震。     

就张北地震谈谈地震监测预报中的几个技术性问题

１９９８年１月１０日河北省张北县发生６．２级地震,作为对这次地震的一次反思,就地震监测预报中的长、中、短临预报、地震速报、震害预测等各项工作中的技术问题、改进方向提出了一些具体意见,以供同行们参考。     

Interannual and Decadal Variations of Surface Solar Radiation over East China in the First Half of the 20th Century

Variability and long-term trends of sunshine duration(SSD) and total cloud cover(TCC) were studied based on surface observations from 10 meteorological stations over East China in the first half of the 20 th century. The correlation coefficients between SSD and diurnal temperature range(DTR), as well as TCC, were analyzed. SSD experienced a significant increasing trend(0.16 h d-1 per decade) from 1908 to 1936, and the maximum brightening was in autumn(0.33 h d-1 per decade). The good agreement between the variability of SSD and DTR, supported by the correlation coefficient between them of 0.72, implies that the SSD measurements were reliable. TCC showed a decreasing trend(-0.93% per decade) and was significantly inversely related to SSD(-0.74), indicating the variation of SSD was attributable to changes in cloud cover. The result was obviously different to that since the 1960 s, when clouds could not account for the decadal trend of surface solar radiation in China.