X-ray afterglow of GRB 050712: multiple energy injections into the external shock

As indicated by observed X-ray flares,a great amount of energy can be intermittently released from the postburst central engine of gamma-ray bursts(GRBs).As a natural consequence,the GRB’s external shock could be repeatedly energized.With such a multiple energy injection model,we explore the unique X-ray afterglow light curve of GRB 050712,which exhibits four shallow decay plateaus.Together with three early X-ray flares,the central engine of GRB 050712 is believed to have released energy at least seven times after the burst.Furthermore,we find that the energies released during the four plateaus are all on the same order of magnitude,but the luminosity significantly decreased with time.These results may provide some interesting implications for the GRB central engine.     

Modelling mechanical behaviour of limestone under reservoir conditions

High porosity and low permeability limestone has presented pore collapse. As fluid is withdrawn from these reservoirs, the effective stresses acting on the rock increase. If the strength of the rock is overcome, pore collapse may occur, leading to irreversible compaction of porous media with permeability and porosity reduction. It impacts on fluid withdrawal. Most of reservoirs have been discovered in weak formations, which are susceptible to this phenomenon. This work presents a study on the mechanical behaviour of a porous limestone from a reservoir located in Campos Basin, offshore Brazil. An experimental program was undergone in order to define its elastic plastic behaviour. The tests reproduced the loading path conditions expected in a reservoir under production. Parameters of the cap model were fitted to these tests and numerical simulations were run. The numerical simulations presented a good agreement with the experimental tests. Copyright © 2006 John Wiley & Sons, Ltd.     

Comparative application of two mathematical models to predict sedimentation in Yermasoyia Reservoir,Cyprus

The Yermasoyia Reservoir is located northeast of the town of Limassol, Cyprus. The storage capacity of the reservoir is 13·6 × 10⁶ m³. The basin area of the Yermasoyia River, which feeds the reservoir, totals 122·5 km². This study aims to estimate the mean annual deposition amount in the reservoir, which originates from the corresponding basin. For the estimate of the mean annual sediment inflow into the reservoir, two mathematical models are used alternatively. Each model consists of three submodels: a rainfall‐runoff submodel, a soil erosion submodel and a sediment transport submodel for streams. In the first model, the potential evapotranspiration is estimated for the rainfall‐runoff submodel, and the soil erosion submodel of Schmidt and the sediment transport submodel of Yang are used. In the second model, the actual evapotranspiration is estimated for the rainfall‐runoff submodel, and the soil erosion submodel of Poesen and the sediment transport submodel of Van Rijn are used. The deposition amount in the reservoir is estimated by means of the diagram of Brune, which delivers the trap efficiency of the reservoir. Daily rainfall data from three rainfall stations, and daily values of air temperature, relative air humidity and sunlight hours from a meteorological station for four years (1986–89) were available. The computed annual runoff volumes and mean annual soil erosion rate are compared with the respective measurement data. Copyright © 2006 John Wiley & Sons, Ltd.     

对二郎坪群火神庙组物质组成的质疑与再认识

经研究证明，前人建立的二郎坪群火神庙组确有少量的亚碱性双峰式火山岩。这些火山岩零星地分布在几个地区，走向不连续，出露宽度一般为数百米。构成该组主体的是一条规模宏伟的侵入岩带，其岩石组合为辉长岩－闪长岩－石英闪长岩－斜长花岗岩－花岗岩，总体上表现为正序岩浆演化序列。这些侵入岩普遍经历了三个阶段的变形变质作用，即第一阶段为韧性变形；第二阶段为静态重结晶；第三阶段为带状褶劈理，表现了复杂而漫长的构造演化史。     

Diagenetic Sequences Analysis of Fuyu Reservoir in Qijia - Gulong Depression, Northern Songliao Basin

Five paragenetic associations are recognized in Fuyu reservoir of Qijia - gulong depression of Daqing oil field: 1 )detrital illite permeation, glauconite and pyrite precipitation; 2 ) feldspar dissolution, kaolinite precipitation and the incipient quartz overgrowths; 3 ) early calcite cements; 4 ) postdate quartz overgrowths and pore - filling quartz, authigenetic illite and chlorite formation, feldspar overgrowths, petroleum injections, K - feldspar and calcite cement dissolution; 5) pore - filling calcite and calcite replacement.     

井中地震用于陆相储层分析的几项技术

中国陆相储层分布广泛，类型复杂，横向变化大，勘探开发成本高，进行储层分析要求采用高新技术和综合利用多种方法。本文总结了在我国几个油区进行陆相储层分析的几项地震技术即：垂直地震剖面（ＶＳＰ）技术，多偏移距和井间层析成象技术以及多参数分析和综合解释技术，在适应我国经济发展的水平和现状的条件下，用以解决我国复杂的陆相油气储层分析的问题。     

Problems of reservoir sedimentation in China

As there are many heavily sediment-laden rivers in China, with high sediment concentration and a large quantity of sediment load, the sedimentation problems of the reservoirs built on those rivers are so serious that the amount of sediment deposited in the reservoirs is great and the rate of sedimentation is accelerated. According to the statistics, up to the end of 1981, a total amount of 11.5×10⁹m³ of sediment were accumulated in those reservoirs, i.e. 14.2% of the total designed capacity were lost. The average annual loss in storage capacity reached 2.3 percent, being the highest in the world. Silting of impounding lakes not only has an effect on the benefits of the reservoirs and seriously threatens the life of reservoirs, but also results in many environmental problems which were not fully estimated in the planning of the reservoirs. In this paper, the situation of reservoir deposition in China are described from the following aspects: 1) the characteristics of hydrology and sediment of the rivers; 2) the seriousness of reservoir sedimentation in China; 3) problems caused by reservoir deposition; 4) the methods of minimizing sediment deposition, etc.     

辽西南天门断裂及其与北票组发育的关系

通过对辽西地区ＴＭ图像地质解译和对南天门断裂的研究表明，虽然南天门断裂现今在地形地貌上表现为其西的北票、朝阳、建昌盆地和其东的金羊盆地的区域性分隔断裂，但是实际上在早侏罗世末以前，则是一个统一盆地内的潜伏（基底）断裂，即非现今的盆地边缘断裂。由于盆地内普遍发育含有油气性良好的下侏罗统北票组，因此，辽西地区应具有良好的油气勘探开发前景。     

Searches for bright-rimmed clouds with IRAS point sources

We have carried out systematic surveys for small bright-rimmed clouds associated with IRAS point sources in/around HII regions. They are candidate sites for star formation due to radiation-driven implosion.     

Facies-controlled volcanic reservoirs of northern Songliao Basin, NE China

Volcanic rocks of the late Mesozoic are very important reservoirs for the commercial natural gases including hydrocarbon, carbon dioxide and rare gases in the northern Songliao Basin. The reservoir volcanic rocks include rhyolite, andesite, trachyte, basalt and tuff. Facies of the volcanic rocks can be classified into 5 categories and 15 special types. Porosity and permeability of the volcanic reservoirs are facies-controlled. Commercial reservoirs were commonly found among the following volcanic subfacies: volcanic neck (I1) , underground-explosive breccia (I3), pyroclastic-bearing lava flow (II3), upper effusive (III3) and inner extrusive ones (IV1). The best volcanic reservoirs are generally evolved in the interbedded explosive and effusive volcanics. Rhyolites show in general better reservoir features than other types of rocks do.