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1.
铀矿床类型的历史沿革研究是铀成矿学研究中的重要内容之一,为铀矿地学者所关注.中国铀矿床类型研究从引进到发展已走过近60年的历程,积累了大量的资料有待总结.笔者自20世纪60年代初至今一直关注铀矿床类型的研究,并积累了国内外铀矿床分类80余例,其中我国铀矿床类型方案约50例,从中获得了许多启示.通过对我国铀矿床类型研究小结、反思,提出新的分类方案构想,分（一）、（二）两部分进行简要论叙. 相似文献
2.
In the present paper, soil-structure interaction analysis of an infinite beam resting on extensible geosynthetic reinforced
earth beds has been carried out for an applied load moving with constant velocity. The viscous damping of the soil-foundation
system has been given due consideration in the analytical procedure. The infinite beam has been treated as resting on a granular
fill layer overlying the naturally occurring weak soil layer. Geosynthetic layer has been provided in the granular fill layer
and has been considered as extensible. This extensible nature has been incorporated with the help of no slip and the compatibility
conditions at the interface between reinforcing layer and the neighboring soil. These conditions help in eliminating the two
interfacial shear stress parameters and in considering the tensile modulus of geosynthetic layer in the analysis. The influence
of various parameters, like magnitude and velocity of applied moving load, viscous damping, relative stiffness of granular
fill and tensile modulus of geosynthetic layer, on the response of soil-foundation system has been studied. It has been observed
that all these parameters affect the response significantly, however, the effect of velocity of moving load and viscous damping
has been found to be more significant especially at higher velocities. 相似文献
3.
中国第四纪孢粉学研究进展 总被引：29，自引：1，他引：28
随着全球变化研究的不断深入,中国第四纪孢粉学研究已取得的长足的发展。化石样品的时间分辨率不断提高,在黄土高原１０万年尺度的孢粉记录分析已达到了小于千年的分辨率,在内蒙古调角海子钻孔的研究已达到百年分辨率。其次,为了准确解译化石孢粉的生态意义,开展了大量表土花粉研究,在中国北方建立了花粉－气候转换函数、气候－花粉响应面模型;系统地开展了表土花粉模拟生物群区的研究,并取得了良好的结果;开展了华北平原不 相似文献
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Swami Saran Surendra Kumar K.G. Garg Arvind Kumar 《Geotechnical and Geological Engineering》2007,25(1):123-137
In the present paper, a method of analysis for calculating the pressure intensity corresponding to a given settlement for
eccentrically and obliquely loaded square and rectangular footings resting on reinforced soil foundation has been presented.
The process has been simplified by presenting non-dimensional charts for the various terms used in the analysis, which can
be directly used by practicing engineers. An approximate method has been suggested to find out the ultimate bearing capacity
of such footings on reinforced soil. The results have been validated with the model test results. The procedure has been made
clear by giving an illustrative example. 相似文献
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《Geomechanics and Geoengineering》2013,8(3):185-194
In this paper, a model for the analysis of footings having finite flexural rigidity resting on a granular bed on top of stone columns improved saturated soft (clayey) soil has been proposed. Soft soil has been modeled as a Kelvin–Voigt body to represent its time dependent behavior. Pasternak shear layer has been used to represent the granular layer and the stone columns have been idealized by means of nonlinear Winkler springs. Nonlinear behavior of granular fill, soft soil and stone columns has been invoked by means of hyperbolic constitutive relationships. Governing differential equations for the soil–foundation system have been obtained and finite difference method has been adopted for solving these, using the Gauss-elimination iterative scheme. Detailed parametric study for a combined footing has been carried out to study the influence of parameters, like magnitude of applied load, flexural rigidity of footing, diameter of stone column, spacing of stone column, ultimate bearing capacity of granular fill, poor foundation soil and stone column, relative stiffness of stone columns and degree of consolidation, on flexural response of the footing. 相似文献
8.
D. Dragovich 《Geoforum》1980,11(2):147-156
An important proportion of Australian dairy production has been destined for export markets, where prices are below those received on the home market. This degree of dependence on international prices has adversely affected dairy farm incomes and thereby influenced both Government responses to the industry's problems and dairymen's decisions about levels of production and farm viability. Examination of the spatial impact on the now declining Australian dairy industry of Government-funded subsidies and of schemes for reconstruction of non-viable dairy farms, has indicated that withdrawal of farmers from the industry has not been areally uniform at the national level; but study of a major dairying region whose industry has undergone substantial decline suggests that this uneven pattern reflects industry and regional characteristics more than the deliberate or inadvertent results of Government intervention. Although Government policy has been broadly directed towards reducing the numbers of dairymen, and hence dependence on overseas prices for production surpluses, industry change has been greatest in regions where viable economic alternatives have been available for low-income dairymen. 相似文献
9.
中国区域地质志项目实施8年以来,已启动24个省级和2个区级地质志的编纂工作,其中11个省级地质志已经完成并通过验收,即将出版面世。通过编纂地质志,对编志地区以及全国地质进行了大综合、大集成,取得若干创新性成果:前寒武纪地质研究获重大突破;重新厘定了一些地区和全国地层系统;分析总结了岩浆岩时空分布规律;进行了构造区划,深化了中国地质构造的认识;发现典型的洋盆地层系统;成功进行了三维立体地质图的编图试点。志书的编纂完成,将为中国地质工作和国家经济社会发展提供一套具有宏观影响的基础地质系列丛书。 相似文献
10.
P. S. Meenu S. Sowmya R. Asha Latha B. S. Shashank D. N. Singh 《Geotechnical and Geological Engineering》2017,35(2):607-614
Dependence of soil suction on factors such as formation of the soil, its particle size, mineralogy, pore-size distribution characteristics, water content, fabric, stress history and presence of salts has been extensively investigated by researchers. However, the influence of the microbial presence and its activity on the soil suction has not yet received researchers’ attention. With this in view, a methodology that facilitates investigation regarding the presence of ‘soil-microbial interface’, which has been termed as ‘bio-geo interface’, has been proposed in this study. Furthermore, the influence of this ‘interface’ on suction characteristics of such soils has also been investigated and the utility of the proposed methodology in addressing such issues, successfully, has been demonstrated. 相似文献
11.
以新疆西准噶尔包古图Ⅴ号岩体为例,系统论述了包古图Ⅴ号含矿岩体的围岩蚀变分带和蚀变期次。结合ETM+数据的特征,选择多种遥感图像预处理方法组合,建立了基于典型蚀变矿物的特征光谱拟合技术的多光谱遥感蚀变信息提取模型,即遥感数据的归一化处理(Calibration )+掩膜(Mask)+混合像元分解(Endmember Unmixing)+波谱拟合(Spectral Feature Fitting)+ SAM+分类(分割)的CES模型。据此模型对岩体进行信息提取,并与化探资料叠加验证了该方法的可行性,取得了较满意的效果。 相似文献
12.
Bearing capacity of rectangular footing on reinforced soil 总被引：2，自引：4，他引：2
In the present paper, a method of analysis for calculating the pressure intensity corresponding to a given settlement for
a rectangular footing resting on reinforced soil foundation has been presented. The process has been simplified by presenting
non-dimensional charts for the various terms used in the analysis, which can be directly used by practicing engineers. An
empirical method has been suggested to find out the ultimate bearing capacity of footing on reinforced soil. The results have
been validated with large-scale model tests also. The procedure has been made clear by giving an illustrative example.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
13.
本文用边界元法解决非稳定系统中水质预测的计算问题,建立了三维水质预测问题的边界元法计算模型,为简化计算手续、提高计算精度,讨论了Laplace变换边界元法,推广了Laplace变换边界元法中的Schapery方法。 相似文献
14.
岩石渗透率与其应力的关系及应用 总被引：6，自引：0，他引：6
根据岩石成岩过程中岩石结构和受力变化,分析了岩岩渗透率和应力的指数关系,并且认为它受岩性和岩石结构的影响,通过多种常用和新式应力模型及岩心样品渗透率的研究,证明了上述关系的存在。将渗透率和应力的关系用于油报储层和煤层气储层的实际应用中显示,油气储层测试用最能描述岩石力学性质受泥质影响的是自然伽玛测井曲线,以此消除和降低岩性的影响,从而改善 力计算的准确性,通过提取分离率高的测井方法－微球型聚信 井 相似文献
15.
The mass balance of the Antarctic Ice Sheet has been calculated based on instrumental estimates of the grounded ice discharge
and snow accumulation data. The boundaries and sectional areas of the main ice catchment basins in West and East Antarctica
have been determined, and the data on the grounded ice discharge and snow accumulation in these basins have been systematized.
The intensity of accumulation and ablation processes in Antarctica has noticeably increased over the last 50 years. The mass
balance of the ice sheet in East Antarctica has been and remains positive, while in West Antarctica it was positive in the
middle of the last century and has become negative by now. The mass balance of the entire Antarctic Ice Sheet has been and
remains positive, while the mass growth has noticeably decreased over the last 50 years. 相似文献
16.
J. Martínez Martínez R. Alvarez Espejo I. Alonso Bilbao M.D. del Rosario Cabrera 《Engineering Geology》1990,29(4):377-386
The sedimentary dynamics of a sandy beach located on the North coast of the Island of Gran Canaria has been studied in relation to physical processes.
The morphodynamic behaviour of the beach has been established and interpreted. Special emphasis has been placed on the characterization of erosive and accretionary processes by means of sediment transport calculations. Two sedimentary indices have been used to define these processes qualitatively and quantitatively. These indices are of importance for management. 相似文献
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地表沉降的研究工作大都集中在地铁隧道盾构法施工的情况,而对于矿山法城市双连拱隧道施工引起地表沉降的研究几乎没有。本文以重庆彭家花园双连拱隧道为工程背景,就矿山法双连拱隧道施工引起的地表变形进行研究。在不同施工方法条件下,针对不同埋深、断面大小进行回归分析,从理论上弄清地表沉降的规律,根据实测资料,提出矿山法施工条件下地表沉降的预测公式。并结合三维数值模拟验证了回归效果 相似文献
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