EXPERIMENTAL AND FIELD STUDY ON MINING-PIT MIGRATION

1 INTRODUCTION Because of the large quantity of sand and gravel in their beds, rivers have always been considered as a major source of sand and gravel for civil works. Acceptable quality, ease of extraction and economy are some of the reasons could be mentioned. Unfortunately, specific laws and regulations regarding the safe in-stream mining have not been provided for users and officials. What should be taken into account are the effects of over-mining of sand and gravel, which can cause …     

Reconstruction of the diagenesis of the fluvial-lacustrine- deltaic sandstones and its influence on the reservoir quality evolution-- Evidence from Jurassic and Triassic sandstones, Yanchang Oil Field, Ordos Basin

The reservoir quality of Jurassic and Triassic fluvial and lacustrine-deltaic sandstones of the Yanchang Oil Field in the Ordos Basin is strongly influenced by the burial history and facies-related diagenetic events. The fluvial sandstones have a higher average porosity (14.8%) and a higher permeability (12.7×10?3 ?m2) than those of the deltaic sandstones (9.8% and 5.8 ×10?3 ?m2, respectively). The burial compaction, which resulted in 15% and 20% porosity loss for Jurassic and Triassic sandstones, respectively, is the main factor causing the loss of porosity both for the Jurassic and Triassic sandstones. Among the cements, carbonate is the main one that reduced the reservoir quality of the sandstones. The organic acidic fluid derived from organic matter in the source rocks, the inorganic fluid from rock-water reaction during the late diagenesis, and meteoric waters during the epidiagenesis resulted in the formation of dissolution porosity, which is the main reason for the enhancement of reservoir-quality.     

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20 0 0年 4月 2 0日 ,乌兹别克斯坦卡什卡达林斯克区的岳尔捷帕发生了 M=5.4级强烈地震。对这次地震前后 (1 999年 1 0月 3 1日— 2 0 0 0年 4月 2 2日 )的地震序列进行了初步分析 ,并结合震区附近的《舒尔奇》和《朱玛巴扎尔》等综合预报台地下水观测参数 (流量、湿度、Eh值、p H值等 )的变化和震源机制解 ,分析了应力场的变化和迁移特征。最后认为 k≤ 1 2的地震可以引起应力场的变化 ,这种变化可通过综合观测台来跟踪研究 ;观测点彼此间距不应超过1 0 0— 1 50 km;每个观测点必须选配自己的一组最有信息量的观测方法     

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利用1990－1998年本站天气资料，对影响焦作市的高温天气系统进行分析，以期把握高温天气系统的演变特征，从而提高其预报准确率。     

日本数值预报产品降水预报效果检验

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服务器IIS5．0的虚拟站点配置技术

介绍了微软Windows2000Server集成的IIS5．0Web服务器的虚拟站点配置技术。     

西北低涡下的暴雨过程对比分析

从天气形势、冷空气路径、物理量场等方面对2001年7月下旬鹤壁市受西北低涡影响出现的两场暴雨以上量级降水过程进行对比分析，提出了该类型暴雨过程的预报着眼点。     

FHD—1型质子磁力仪的改进与完善

根据FHD－1型质子磁力仪在实际作用过程中存在的一些问题，以及一些用户提出的建议和要求，对FHD－1型质子磁力仪的实时时钟、标定方法、通用性与适应性、抗干扰能力方面进行了改进和完善，本文对此作介绍。