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71.
Geotechnical Properties of Low Calcium and High Calcium Fly Ash 总被引:1,自引:0,他引:1
In this paper, a comparative study has been made for physical and engineering properties of low calcium and high calcium Indian
fly ash. The grain size distribution of fly ash is independent of lime content. Fly ash particles of size >75 μm are mostly irregular in shape whereas finer fractions are spherical for low calcium fly ash. For high calcium fly ash, chemical
and mineralogical differences have been observed for different size fractions. Compared to low calcium fly ash, optimum moisture
content is low and maximum dry density is high for high calcium fly ash. Optimum moisture content is directly proportional
and maximum dry density is inversely proportional to the carbon content. The mode and duration of curing have significant
effect on strength and stress–strain behavior of compacted fly ash. The gain in strength with time for high calcium fly ash
is very high compared to that of low calcium fly ash due to presence of reactive minerals and glassy phase. 相似文献
72.
73.
74.
韧性剪切变形对岩石地球化学行为的制约——以北阿尔金巴什考供韧性剪切带为例 总被引:6,自引:0,他引:6
韧性剪切变形对岩石地球化学行为的制约一直是地质学家们探讨的课题。本文以构成北阿尔金红柳沟——拉配泉俯冲碰撞杂岩带与北阿尔金地块边界的巴什考供斜向逆冲型韧性剪切带为例,通过对韧性剪切带内花岗岩变形前后不同变形强度构造岩的地球化学组成进行对比,确定等比线斜率,探讨韧性变形对岩石体积和成分变异的影响。计算结果表明,在糜棱岩化过程中,糜棱岩化花岗岩体积亏损21%,花岗质糜棱岩体积亏损31%。质量平衡计算结果和等比线图表明,韧;陛剪切作用导致SiO2,流失量最大,A12O3、K2O及Ba、Rb、Sr等都有不同程度的丢失,显示出较强的活动性,MnO、P2O5、Sc位于等比线上或附近,表现出相对的稳定性。岩石中活动组分的变异是流体渗滤作用引起的,不活动组分的变异是体.积亏损造成的。 相似文献
75.
K. V. Sanil Kumar P. V. Hareesh Kumar 《Journal of the Indian Society of Remote Sensing》2005,33(1):137-146
Eddies and planetary waves are identified as one of the important factors that control the dynamics of the Arabian Sea. During
10–14 January 1990, Ignat, Paulyuchenkov (USSR ship) conducted an experiment in the central Arabian Sea and of late TOPEX/POSEIDON
satellites collected data on sea surface height (SSH) anomalies of the Arabian Sea. These data sets give an opportunity to
understand the characteristic of eddies and planetary waves in this region during winter. The geostrophic flow revealed three
anticyclonic and two cyclonic eddies of diameters ranging from 75 to more than 150 km from surface to subsurface levels. Current
speeds around different eddies were maximum at surface and varied from 9 cm/s to 25 cm/s (at the middle point between the
center and periphery). The occurrence of eddies were further investigated with the TOPEX/POSEIDON altimetry for the years
1993–97. The analysis revealed multiple eddies of diameter 100 to 550 km occur every year with maximum number of eddies during
1997 and minimum during 1995. The calculated speed varied between 8–30 cm/s around various eddies.
Longitude-Time plots showed annual Rossby waves generating at the eastern Arabian Sea and propagating westwards with a phase
speed of ~ 10 cm/s along 16° N. Further, it was observed that these waves arrived in the study area by January. In addition,
another positive anomaly of SSH was found generating at the western Arabian Sea simultaneously and extended up to the study
region by April–June. Time series of SSH at selected locations along 16°N revealed many small-scale oscillations and their
spatial variability. These oscillations were delineated using the FFT analysis. Other than the Rossby wave, the major components
at the study region were 40–60 and 26–32 day oscillations. The implications of these long period waves associated with eddies
are discussed. 相似文献
76.
S. Nakamoto S. Prasanna Kumar J. M. Oberhuber H. Saito K. Muneyama R. Frouin 《Journal of Earth System Science》2002,111(3):339-349
Western tropical Indian Ocean, Arabian Sea, and the equatorial Pacific are known as regions of intense bio-chemical-physical
interactions: the Arabian Sea has the largest phytoplankton bloom with seasonal signal, while the equatorial Pacific bloom
is perennial with quasi-permanent upwelling. Here, we studied three dimensional ocean thermodynamics comparing recent ocean
observation with ocean general circulation model (OPYC) experiment combined with remotely sensed chlorophyll pigment concentrations
from the Coastal Zone Color Scanner (CZCS). Using solar radiation parameterization representing observations that a higher
abundance of chlorophyll increases absorption of solar irradiance and heating rate in the upper ocean, we showed that the
mixed layer thickness decreases more than they would be under clear water conditions. These changes in the model mixed layer
were consistent with Joint Global Ocean Flux Study (JGOFS) observations during the 1994-1995 Arabian Sea experiment and epi-fluorescence
microscopy (EFM) on samples collected during Equatorial Pacific Ocean Climate Study (EPOCS) in November, 1988. In the Arabian
Sea, as the chlorophyll concentrations peak in October (3 mg/m3) after the summer plankton bloom induced by coastal upwelling, the chlorophyll induced biological heating enhanced the sea
surface temperature (SST) by as much as 0.6‡C and sub-layer temperature decreases and sub-layer thickness increases. In the
equatorial Pacific, modest concentrations of chlorophyll less than 0.3 mg/m3 is enough to introduce a meridional differential heating, which results in reducing the equatorial mixed layer thickness
to more than 20 m. The anomalous meridional tilting of the mixed layer bottom enhances off equatorial westward geostrophic
currents. Consequently, the equatorial undercurrent transports more water from west to east. We proposed that these numerical
model experiments with use of satellite andin situ ocean observations are consistent under three dimensional ocean circulation theory combined with solar radiation transfer
process. 相似文献
77.
Static deformation of two monoclinic elastic half-spaces in welded contact due to a long inclined strike-slip fault situated
in one of the half-spaces is studied analytically and numerically. Closed-form algebraic expressions for the displacement
at any point of the medium are obtained. The variation of the displacement at the interface with the horizontal distance from
the fault is studied. The effect of anisotropy on the displacement field is examined. It is found that while the anisotropy
of the source half-space has a significant effect on the displacement at the interface, the anisotropy of the other half-space
has only a marginal effect. 相似文献
78.
新时期我国区域经济地理学发展问题初探 总被引:4,自引:0,他引:4
我国新时期的区域经济地理学在取得全面发展的同时,在理论体系,研究方法和实践领域等方面还需要进一步的发展,文章根据学习和实践区域经济地理学的体会,初步提出基础理论和应用理论,思维方法和技术方法等方面发展见解,并指出区域创新系统和国际经济技术合作等学科应注意拓展的重要实践领域,最后提出我国区域经济地理学科发展的建议。 相似文献
79.
80.
成都市民消费结构与休闲活动关系研究 总被引:6,自引:0,他引:6
城市居民消费水平,消费结构会影响其休闲消费能力,消费意愿,消费方式,消费态度和休闲时空结构,文章以成都市7个城区歌舞,茶棋牌,电影及城市公园休闲活动调查为基础,探讨了城市居民消费结构及其变化与休闲活动特征的关系。研究结果表明,城市居民消费结构的改变对歌舞,茶棋牌娱乐活动影响最大。 相似文献