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501.
502.
基于黔西六盘水煤田和织纳煤田16口井36层次的试井资料, 采用地质统计分析等方法, 探讨了黔西地区煤储层渗透性的展布规律与地应力特征, 论证了煤层埋深与地应力对其渗透性的控制机制.研究表明, 研究区煤储层以特低渗-低渗透率储层(<0.1×10-9m2)为主, 中渗透率储层(0.1×10-9~1.0×10-9m2)也占有相当大比例; 应力场类型在浅部表现为大地动力场型, 一定深度可能转化为准静水压力状态.煤储层渗透率及其埋深的负幂指数关系较为离散, 但在不同深度渗透率转折点与地应力场类型转变一致; 单井煤储层试井渗透率差异较大, 随地应力增大和埋深增加而降低, 平面展布受地应力强度控制由SW-NE具"低-高-低"发育规律.埋深对渗透率的控制实质是地应力的控制, 区域构造位置及其所处高应力场作用下的煤体形变与破碎致使孔裂隙压缩或闭合是该区渗透性差异的主要控制机制. 相似文献
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In this paper, we have analysed the major marine research strategies, programs and projects and the overall layout on marine research of the United Kingdom in recent years and found several characteristics: The United Kingdom increased emphasis on the national top-level design of marine research; The marine research infrastructures of the United Kingdom will be given long-term support in the future; Priority areas on marine research in the future will be determine and identified according to the national science and technology status and national needs of national economy; The United Kingdom will focus on ocean acidification, marine renewable energy development and coastal hazards research in the future. Then we gave out some recommendations on our courtry’ development on marine science and technology: Establishing a long-term national marine science and technology strategic plan; strengthening the investment in the important marine research infrastructure; setting several reasonable research priorities according to China’s national strategic needs. 相似文献
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李林森 《中国天文和天体物理学报》1988,(4)
S.Karakula等人根据Ostriker等人的脉冲星产生的宇宙线能谱依赖脉冲星年龄的理论模型,利用脉冲星发射宇宙线的最大能量: 相似文献
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In the United States, both scholars and practitioners have repeatedly emphasized the importance of “issue framing” for garnering public support for climate change policy. However, the debate frequently overlooks the importance of counter frames. For every framing attempt by advocates of climate policy, there will be a counter frame by the opponents of climate policy. How do counter frames influence the effectiveness of issue framing as a communication strategy? To answer this question, we report results from a survey experiment on a nationally representative sample of 1000 Americans on clean energy policy, a key policy issue in the public debate on climate change in the United States. Overall, we find that different combinations of positive and negative frames have remarkably little effect on support for clean energy policy. A follow-up on-line survey experiment with a convenience sample of 2000 Americans suggests that the counter frames are responsible for undermining the effects of the original frames. 相似文献
510.
Effects of the Soil Heat Flux Estimates on Surface Energy BalanceClosure over a Semi-Arid Grassland
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Soil heat flux is important for surface energy balance (SEB), and inaccurate estimation of soil heat flux
often leads to surface energy imbalance. In this paper, by using observations of surface radiation fluxes
and soil temperature gradients at a semi-arid grassland in Xilingguole, Inner Mongolia, China from June
to September 2008, the characters of the SEB for the semi-arid grassland were analyzed. Firstly, monthly
averaged diurnal variations of SEB components were revealed. A 30-min forward phase displacement of soil
heat flux (G) observed by a fluxplate at the depth of 5-cm below the soil surface was conducted and its effect
on the SEB was studied. Secondly, the surface soil heat flux (Gs) was computed by using harmonic analysis
and the effect of the soil heat storage between the surface and the fluxplate on the SEB was examined.
The results show that with the 30-min forward phase displacement of observed G, the slope of the ordinary
linear regression (OLR) of turbulent fluxes (H+LE) against available energy (Rn–G) increased from 0.835
to 0.842, i.e., the closure ratio of SEB increased by 0.7%, yet energy imclosure of 15.8% still existed in the
SEB. When Gs, instead of G was used in the SEB equation, the slope of corresponding OLR of (H+LE)
against (Rn–Gs) reached 0.979, thereby the imclosure ratio of SEB was reduced to only 2.1%. 相似文献