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中国华北地区壳内低速高导层(体)成因模式的探讨   总被引:5,自引:0,他引:5  
高平 《中国地震》1997,13(3):223-231
依据高温高压下华北地区地壳主要岩石的物理性质-波速,电性测定的结果,提出了华北地区低速高导层可能的成因模式以及不同模式的适应范围。认为;碳酸盐岩在深部一定温度,压力和氧逸度条件下碳的析出会导致高导层体的出现;深部韧性剪切带组成矿物的定向排列,可使岩石的波速,电生产生各向异性行为,导致低速高导层的产生;绿片岩相和角闪岩相石中含水矿物的脱水作用会导致上,中地壳岩石物理力学性质的突变,这可能是该地区低速  相似文献   
43.
植物地球化学找矿方法,是利用植物体对环境(土壤、岩石、水等)中微量元素特殊的吸收积累特性,通过对植物样品灰分的分析来发现地球化学异常的一种找矿方法.由于影响植物地球化学异常形成的因素较复杂,给异常的发现和解释评价工作带来许多困难,致使该方法在矿产勘查中的应用仍处于试验研究阶段,很少应用于普查找矿实践  相似文献   
44.
田梦  林海  孙跃武  徐衍彬  高平 《世界地质》2003,22(3):279-283
头台油田是构造—岩性油藏。裂缝型、特低渗透是其显著特点,常规注水开发后经常出现严重的油井水淹,造成油田开发低效。本文以头台油田研究为例,认为对于裂缝型特低渗透油田,采用注水吞吐采油技术,通过套管直接向地层注水,利用储层毛管力作用,进行油水置换,实现单井自注自采吞吐采油,可以改善油田开发效果,减缓产量递减。适合注水吞吐采油基本条件是岩石润湿性为弱亲水和岩石饱和非润湿相。影响注水吞吐采油效果的主要因素是储层吸水状况、微缝发育状况、储层非均质性、注入体积和关井压力等。吞吐采油技术可作为改善裂缝型特低渗透油藏开发效果的一种新的模式来研究和推广。  相似文献   
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The long-term effects of the sea lice treatment products Excis and Slice on zooplankton communities in a Scottish sea loch were investigated at a commercially operating salmon farm over 31 months. Cypermethrin and emamectin benzoate are the active ingredients in Excis and Slice respectively, which are widely used to control ectoparasitic sea lice on farmed salmon. Excis and Slice treatments did not cause basin-wide effects on the zooplankton community. For both formulations, no adverse affects on zooplankton were detected, instead observed changes in zooplankton abundance and community composition displayed natural seasonal cycles of abundance. Water column concentrations of cypermethrin and emamectin benzoate following sea lice treatments at the fish farm were predicted using models. Cypermethrin concentrations of 3000 ng/l were predicted for short periods immediately after each cage treatment assuming no particle adhesion. The 3-h and 24-h Environmental Quality Standards (EQS) were exceeded for 10 h and 32 h respectively on the second day when five cages were treated. However, cypermethrin concentrations higher than 0.5 ng/l (24-h EQS) were predicted to occur over <2% of the total basin area on each treatment day. The 3-h EQS (16 ng/l) was exceeded in <0.3% of the basin on each treatment day. The concentration of soluble emamectin benzoate present in the water column was predicted from modelled deposition footprints and sediment concentrations to be of order 10(-3) ng/l. Predicted concentrations of both chemicals were generally lower than those causing toxicity to copepods in previous laboratory studies and further support the results of this field study that environmental concentrations of Excis and Slice do not adversely impact zooplankton communities.  相似文献   
47.
自从莱河矿作为一个富含Fe~(3+)的正硅酸盐新矿物被研究以来,已有可能将铁橄榄石-莱河矿,看成一个新的矿物系列。在这个系列中已报道的有铁橄榄石、变铁铁橄榄石,高铁铁橄榄石和莱河矿。 此组矿物除铁橄榄石外,热力学性质目前还没有实验资料。为此本文运用了一些近似计算的方法对该组矿物(重点是莱河矿)的热力学参数作了估算,对莱河矿的可能成因和生成条件提出了一些初步看法。  相似文献   
48.
We describe a measurement of the angular power spectrum of anisotropies in the cosmic microwave background (CMB) at scales of 0&fdg;3 to 5 degrees from the North American test flight of the Boomerang experiment. Boomerang is a balloon-borne telescope with a bolometric receiver designed to map CMB anisotropies on a long-duration balloon flight. During a 6 hr test flight of a prototype system in 1997, we mapped more than 200 deg(2) at high Galactic latitudes in two bands centered at 90 and 150 GHz with a resolution of 26&arcmin; and 16&farcm;5 FWHM, respectively. Analysis of the maps gives a power spectrum with a peak at angular scales of 1 degrees with an amplitude 70 μK(CMB).  相似文献   
49.
Observations obtained with the Midcourse Space Experiment (MSX) satellite reveal for the first time the complex mid-infrared morphology of the entire Carina Nebula (NGC 3372). On the largest size scale of approximately 100 pc, the thermal infrared emission from the giant H ii region delineates one coherent structure: a (somewhat distorted) bipolar nebula with the major axis perpendicular to the Galactic plane. The Carina Nebula is usually described as an evolved H ii region that is no longer actively forming stars, clearing away the last vestiges of its natal molecular cloud. However, the MSX observations presented here reveal numerous embedded infrared sources that are good candidates for sites of current star formation. Several compact infrared sources are located at the heads of dust pillars or in dark globules behind ionization fronts. Because their morphology suggests a strong interaction with the peculiar collection of massive stars in the nebula, we speculate that these new infrared sources may be sites of triggered star formation in NGC 3372.  相似文献   
50.
东海初级生产力遥感反演及其时空演化机制   总被引:1,自引:0,他引:1  
According to calculation results of ocean chlorophyll concentration based on SeaWiFS data by SeaBAM model and synchronous ship-measured data, this research set up an improved model for Case I and Case Ⅱ water bodies respectively. The monthly chlorophyll distribution in the East China Sea in 1998 was obtained from this improved model on calculation results of SeaBAM. The euphotic depth distribution in 1998 in the East China Sea is calculated by using remote sensing data of K490 from SeaWiFS according to the relation between the euphotic depth and the oceanic diffuse attenuation coefficient. With data of ocean chlorophyll concentration, euphotic depth, ocean surface photosynthetic available radiation (PAR), daily photoperiod and optimal rate of daily carbon fixation within a water column, the monthly and annual primary productivity spatio-temporal distributions in the East China Sea in 1998 were obtained based on VGPM model. Based on analysis of those distributions, the conclusion can be drawn that there is a clear bimodality character of primary productivity in the monthly distribution in the East China Sea. In detail, the monthly distribution of primary productivity stays the lowest level in winter and rises rapidly to the peak in spring. It gets down a little in summer, and gets up a little in autumn. The daily average of primary productivity in the whole East China Sea is 560.03 mg/m^2/d, which is far higher than the average of subtropical ocean areas. The annual average of primary productivity is 236.95 g/m^2/a. The research on the seasonal variety mechanism of primary productivity shows that several factors that affect the spatio-temporal distribution may include the chlorophyll concentration distribution, temperature condition, the Yangtze River diluted water variety, the euphotic depth, ocean current variety, etc. But the main influencing factors may be different in each local sea area.  相似文献   
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