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21.
山区公路软基病害研究 总被引:2,自引:0,他引:2
随着高等级公路建设规模的扩大,山区公路所面临的路基病害特别是软土路基病害问题也逐渐增多。结合对陕南勉(县)一宁(强)高速公路工程实例分析,对山区软土成因及其特性进行了初步分析,认为山区软土属以坡洪积、湖积和冲积为主的软土,也有少量是由坡残积物堆积而形成。山区软土的特殊性表现在成分的复杂性、分布的不均匀性、隐蔽性和物理力学性质的特殊性。根据其特性以及中国山区公路软基普遍存在的病害问题,总结了山区公路软基的主要病害类型为剪切拉裂破坏、浸水沉陷破坏、剥蚀坍塌破坏、推挤滑动破坏。还提出了相应的软基处理方法及建议。 相似文献
22.
应用地壳波浪与镶嵌构造学说对富氏谱分析法提取地壳垂直形变信息的科学性做了地质学意义上的阐释 ,并提出了根据多期形变资料提取特定波段上构造策应力的数学模型 相似文献
23.
In order to understand the process of surface erosion and acquire basic data of conditions on hillslope without vege tation, a sprinkling experiment is conducted on a bare slope in Mt. Tanakami in the central part of Japan. Based on the mea surements of runoff, mean soil erosion depth, and sediment yield, etc. , the results suggest the following characteristics in the process of surface erosion in the experimental area. (1) The occurrence of sediment discharge is interrupted; (2) Surface runoff is a saturated overland flow; (3) The mean soil erosion depth is thick compared with other areas in Mt. Tanakami;(4) Sediment discharge process is detachment- limited. 相似文献
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应用显微光度术、显微傅立叶红外光谱(Micro-FT.IR)和飞行时间二次离子质谱(TOF-SIMS)等原位微分析技术并结合均一温度测量对胜利油气区下第三系沙河街组沙三段中有机包裹体进行了研究。区分出两类有机包裹体,即原生有机包裹体和次生有机包裹体。结果表明两类有机包裹体特征不同,二者物质组成、有机质成分及化学结构、热演化程度等差别也较大。结合地质分析表明原生有机包裹体是沙三段烃源岩生成烃类运移产物,具“自生自储”特点,而次生有机包裹体是沙四段烃源岩生成的烃类二次运移的产物。沙三段是沙河街组油气运移和聚集的主要层位,因而是寻找油气资源的主要目标层。研究表明,有机包裹体是研究油气生成、运移、聚集和演化等成藏系统最有效的手段之一,在油气勘探中有重要的应用意义。 相似文献
26.
In recent years,scholars at home and abroad have method,and that vanous disasters would be analyzed assynthetically studied natural dlsaste‘theoretically and an Integral.SHI Peilun(1991)putforwad a scientificmethodologlcally,as well as its cases analys。s(CND,term—regional disaster system,which Indicates that1987; MA et al,1990; MARBLE,1990; NE et al,the situation of a disaster(calamity loss)results from1999; PATAK et al,1982; SHI,1991;VAN et al,h… 相似文献
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28.
Hemant K. Badola Jitendra S. Butola 《山地科学学报》2005,2(2):173-180
This paper examines the effect of ploughing depths (A -- 60 cm, B -- 45 cm and C -- 30 cm) on the growth and yield of Heracleum candicans Wall (Apiaceae), a threatened medicinal herb of the Himalayan region. This less-explored plant is being suggested as a potential crop for the mountain agriculture. The study was carried out in an orchard in Himachal Pradesh, India at 2500 m altitude, for two successive growth years. During the first year, all plants remained in juvenile state; in the second year, nearly 65 % plants produced flowers only under 60cm ploughing depth. Among its morphological traits, plant height, collar diameter and aboveground flesh weight were found to be strongly correlated (P 〈 0.01) with the belowground biomass during the first year (r =0.968, 0.925 and 0.973, respectively) and during the second year (r=0.945, 0.928 and 0.775, respectively). Increase in the ploughing depth was significantly correlated (P〈0.01) with all growth parameters, including the belowground dry weight, marketable portion of the produce. The belowground biomass (commercial yield; 16.28 Qt/hec) at depth A was about 2.6 and 4.7 times higher than those recorded at depths B and C, respectively. The results clearly justify the importance of deep ploughing and this paper strongly recommends it for economically sustainable cropping. 相似文献
29.
月日潮汐摩擦和地球惯量矩变化是日长长期变化的主要原因.在本文中,利用最新的地球物理和古生物钟数据,对过去15亿年以来的月日潮汐摩擦、地球惯量矩变化和日长长期变化等作了数值对比研究.由此得到二个重要结论:一是仅利用地球的自转形变不能解释J2的变化,这说明地球的重力分异现象至今仍存在着;其二是在几亿年前的潮汐摩擦比现在大得多,若取潮汐耗散与距离的立方成反比时,理论结果与由古生物钟得到的回归年日数和朔望月日数数据较为符合。 相似文献
30.
Report of the International Astronomical Union Division I Working Group on Precession and the Ecliptic 总被引:1,自引:0,他引:1
J. L. Hilton N. Capitaine J. Chapront J. M. Ferrandiz A. Fienga T. Fukushima J. Getino P. Mathews J.-L. Simon M. Soffel J. Vondrak P. Wallace J. Williams 《Celestial Mechanics and Dynamical Astronomy》2006,94(3):351-367
The IAU Working Group on Precession and the Equinox looked at several solutions for replacing the precession part of the IAU
2000A precession–nutation model, which is not consistent with dynamical theory. These comparisons show that the (Capitaine
et al., Astron. Astrophys., 412, 2003a) precession theory, P03, is both consistent with dynamical theory and the solution most compatible with the IAU 2000A
nutation model. Thus, the working group recommends the adoption of the P03 precession theory for use with the IAU 2000A nutation.
The two greatest sources of uncertainty in the precession theory are the rate of change of the Earth’s dynamical flattening,
ΔJ2, and the precession rates (i.e. the constants of integration used in deriving the precession). The combined uncertainties
limit the accuracy in the precession theory to approximately 2 mas cent−2.
Given that there are difficulties with the traditional angles used to parameterize the precession, zA, ζA, and θA, the working group has decided that the choice of parameters should be left to the user. We provide a consistent set of parameters
that may be used with either the traditional rotation matrix, or those rotation matrices described in (Capitaine et al., Astron.
Astrophys., 412, 2003a) and (Fukushima Astron. J., 126, 2003).
We recommend that the ecliptic pole be explicitly defined by the mean orbital angular momentum vector of the Earth–Moon barycenter
in the Barycentric Celestial Reference System (BCRS), and explicitly state that this definition is being used to avoid confusion
with previous definitions of the ecliptic.
Finally, we recommend that the terms precession of the equator and precession of the ecliptic replace the terms lunisolar precession and planetary precession, respectively. 相似文献