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四维地震监测是一种以时间推移方式,在一套产油储层上获得并分析重复的三维地震勘探结果的过程,四维地震技术在储层产油造成的流体和饱度,压力和温度变化方面具有直接成象能力,虽然四维地震的原理及概念比较简单,但是用其来解决实际问题却是很复杂的。利用Ｃｈｅｖｒｏｎ公司在墨西哥湾,北海,西非和印度尼西业等地四维地震项目的几个野外实例,讨论了５个主要的实用问题,促使四维地震发展的商业因素包括,通过作出所遗漏的石 相似文献
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自从发现地中海存在蒸发岩之后，有关盐危机期间地中海出现的环境变化发生了引人注目的科学争论．特别是，在两种模式之间“深盆一浅水”模式、（许靖华，1973）以及“浅盆地一浅水”模式（Nesteroff1973）存在明显的对立．“深干化盆地”模式预测地中海海面下降至少达1500m，有3种证据支持这一观点：（1）地球物理资料，表明在地中海西部之下存在海洋地壳（Montaclert等，1978），（2）米辛尼亚期前地层的生物记录，验证存在深水环境（许靖华等，1978），（3）地中海边缘形成的峡谷（Clauzon，1973，1982；等）．但是，某些资料支持在整… 相似文献
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Distribution of persistent organic pollutants in bivalves from the northeast coast of China 总被引：1，自引：0，他引：1
To assess the levels of organochlorine compounds (OCs) in the Chinese coastal environment, monitoring study using bivalves was conducted in 2005. A total of 21 bivalve samples covering the northeastern coast of China were collected and analyzed. Organochlorine compounds were widely distributed in the Chinese coastal environment, with dichlorodiphenyltrichloroethane (DDT) contamination being particularly prevalent. The overall concentrations of PCBs, DDTs, HCHs, chlordane compounds (CHLs), dieldrin, and endosulfans in bivalves were in the ranges of 3.27-25.4, 54.8-2680, 1.42-25.5, n.d. (not detected)-2.28, n.d.-4.02, and n.d.-9.55 ng g(-1) on a dry weight basis, respectively. The concentrations of DDT and HCH compounds are relatively higher than those from the coastal areas of other Asian countries. DDT metabolites were predominant, suggesting that the degradation of DDT is in progress in the Chinese coastal environment. Still, however, DDTs of high concentration exceeding 1000 ng g(-1) were observed at 19% of the stations surveyed. Among HCH compounds, beta-HCH, which is an isomer with strong persistency, was observed predominantly. Compositions of DDT and HCH compounds imply that fresh input of the two compounds into the Chinese coasts is possibly low. 相似文献
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Karenia mikimotoi is one of the most important harmful algal species in the Chinese coastal waters, and which produce hemolytic toxins and ichthyotoxins, resulting in devastating economic losses. Previous studies demonstrated that the increase of nitrate concentration could promote the growth and reproduction of K. mikimotoi. However, the intrinsic mechanisms regarding the effects of nitrate on the K. mikimotoi photosynthesis, nucleic acid replication and differential protein expression remain to be elucidated. Our study demonstrated that nitrate stress inhibited growth of K. mikimotoi (p < 0.01). Algal chlorophyll fluorescence intensity varied slightly while algal cell cycle succession was significantly retarded by nitrate stress (p < 0.05). Sixteen proteins were detected only in nitrate-limited cultures which related to nitrate transport, signal transduction, amino acid metabolism, DNA repair and hemolysin manufacture. Eleven proteins were detected only in nitrate-replete sample and were related to photorespiration, reproduction and growth, assistance of protein modification, cytoskeleton stability and signal transduction. Based on analysis of differential proteomic functional annotations, we hypothesized a proteomic response mechanism of K. mikimotoi to environmental nitrate stress. 相似文献
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The concentrations of ten trace metals were determined in the gills, muscles, hepatopancreas, and exoskeleton tissues of Xenograpsus testudinatus that lives around shallow and acidic hydrothermal vents off Kueishan Island, northeastern Taiwan. The analytical results demonstrate that the metal concentrations vary significantly with the type of crab tissue. The concentrations of Al, Cd, Co, Cu, Fe, Ni, and Zn are highest in the gills, whereas the concentration of Mn is highest in the exoskeleton. Cr and Pb concentrations are similar across the different tissues. The enhanced accumulation of most metals in the gills suggests the metal accumulation via the respiration pathway rather than the uptake of food. The results also reveal that the distribution patterns of metals in tissues are similar in the hepatopancreas and muscles, but very different in both the gills and the exoskeleton, perhaps because of the different pathways of metal utilization in the different crab tissues. 相似文献
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