Effect of saturation on dynamic properties of compacted clay in a resonant column test     

Troyee Tanu Dutta  Maheshbabu Jallu 《Geomechanics and Geoengineering》2017,12(3):181-190

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披针形蜈蚣藻(Grateloupia lanceolata)的早期发育及其生活史     

田伊林  刘雨薇  王宏伟 《海洋与湖沼》2017,48(1):113-121

在实验室培养条件下,详细观察了披针形蜈蚣藻(Grateloupia lanceolata)早期发育过程及生活史,研究了温度与光周期、温度与光照强度的交互作用对其盘状体发育及幼苗生长的影响。结果表明:(1)披针形蜈蚣藻孢子发育类型为"间接盘状体"类型;(2)披针形蜈蚣藻生活史由单倍体的雌、雄配子体,二倍体的果孢子体和四分孢子体组成,配子体与四分孢子体形态一致,为典型的同型世代交替;(3)温度与光周期、温度与光照强度的交互作用对披针形蜈蚣藻盘状体发育及幼苗生长均有极显著影响(P0.01)。其中由温度与光周期交互实验得出:适宜披针形蜈蚣藻生长发育的温度范围为10—25°C,在温度15°C、光周期16L︰8D的条件下,盘状体相对生长速率最大[RGR=(9.902%±0.51%)/d],幼苗的相对生长速率最大[RGR=(9.569%±0.48%)/d]。温度与光照强度交互实验得出:在温度15°C、光照强度80μmol/(m~2·s)条件下,盘状体相对生长速率最大[RGR=(10.113%±0.51%)/d],幼苗的相对生长速率最大[RGR=(8.839%±0.44%)/d]。本研究为披针形蜈蚣藻的种质保存、人工育苗、规模化栽培以及可持续开发利用提供了理论依据和技术支撑。  相似文献   

不同驱替方式下岩石电阻率与饱和度的关系   总被引：7，自引：0，他引：7  

杨春梅  李洪奇  陆大卫  张方礼  高原  邵英超 《吉林大学学报(地球科学版)》2005,35(5):667-671

针对高含水期老区调整井饱和度评价过程中存在的问题,通过模拟油田开发过程的岩石物理实验,研究水驱油方式下电阻率与含水饱和度之间的关系。与油驱水不同,水驱油方式下电阻增大率与含水饱和度在双对数坐标系中的关系不再是一条直线,而呈现出明显的与高、低含水饱和度区间相关的两段式;岩石的润湿特征不同,两段式拐点所对应的含水饱和度S_wp不同,水驱方式下所能达到的最终采收率也不同。水驱油方式下的I－S_w曲线特征表明,用勘探阶段及开发初期油驱水实验得到的饱和度公式对开发中后期的饱和度进行评价不太合适,尤其是在高含水期,电阻率对高含水饱和度反映能力的局限性严重制约了这一阶段水淹层的评价精度。  相似文献   

基于ANSYS/APDL语言的黄壁庄水库土坝渗流稳定分析     

赵晓西  张保雷  王宗敏 《岩土力学》2005,26(Z2):219-221

根据基本方程及定解条件的比较分析,将ANSYS软件的温度场分析功能应用于渗流场的分析,利用APDL语言实现了渗流参数化建模,采用死活单元技术,通过迭代算法计算浸润线位置,解决了黄壁庄水库土坝渗流稳定问题的求解,为今后该大坝的工程管理及安全提供了理论依据。  相似文献   

三峡工程库水位降与红层岸坡稳定性变化的响应关系研究     

宋琨  刘镇  王磊  杨举  晏鄂川 《岩土力学》2006,27(Z2):306-310

三峡工程水库运营中,库水位在145～175 m间周期性变化必将引起岸坡地下水位的波动,从而导致岸坡稳定性的响应变化。为此,根据布辛涅斯克非稳定渗流微分方程,采用多项式拟合初始浸润线,求得了库水位匀速下降和定幅度下降时岸坡的浸润线方程;在运用剩余推力法求解岸坡稳定性时考虑了对应的渗透力。以千将坪滑坡北东侧的红层岸坡为实例,分别考虑库水位由156 m匀速下降至145 m和库水位由156 m定幅度下降时岸坡的稳定性。结果表明：库水位以不同速度匀速下降时,降速越大,稳定性系数下降速率越大;地下水的时间滞后效应随降速的增大而明显延迟,但随着库水位的下降,滞后效应将达到一个最大值;库水位定幅度下降时,降幅与岸坡稳定性系数关系曲线呈现下降速率不同的3段;对于千将坪滑坡北东侧的红层岸坡在库水位匀速下降时,其临界降速为1.2 m/d,在库水位定幅度下降时,其临界单次降幅不超过6.0 m。研究结果对三峡工程库区类似岸坡地质灾害预警预报具有一定的指导意义。  相似文献   

Soil saturation patterns in steep,convergent hill-slopes under forest and pasture vegetation     

R. A. Petch 《水文研究》1988,2(1):93-103

The relationships between hillslope form and the development of zones of hillslope saturation are central to studies of process hydrology. These relationships are examined in two small, steep (30°) first-order basins under forest and pasture vegetation. Hillslope saturation patterns are described using a probability analysis of observations of peak water table elevations made at individual sites in each basin. In both first-order basins, the effects of topographic convergence on the spatial variability of hillslope saturation zones are most pronounced on shallow slopes and in steeper areas where hillslope form is strongly concave. The implications of vegetation type on the formation and variation of hillslope saturation are also examined. The differences in hillslope saturation patterns in each vegetation type are attributed primarily to differences in net rainfall and not soil physical properties or other features of topography.  相似文献   

Spectral Aerosol Transmittance in the Ultraviolet and Visible Spectra in Athens,Greece     

H. D.?KambezidisEmail author  A. D.?Adamopoulos  D.?Zevgolis 《Pure and Applied Geophysics》2005,162(3):625-647

This work investigates the spectral atmospheric transmittance due to aerosols in the urban environment of Athens during a period of one year. The spectral transmittance due to aerosols is derived using measurements of spectral direct-beam solar irradiance in the 310–575 nm spectral band. This derivation is accomplished by using a radiative transfer model for estimating the partial spectral atmospheric transmittance functions due to Rayleigh scattering, and absorption by ozone, nitrogen dioxide and water vapor. The seasonal and diurnal variation of the aerosol transmittance is investigated and the results are discussed with a view to air pollution sources, meteorological factors and topographic characteristics of the Athens basin.  相似文献   

Hydrogeological and geochemical assessments of the Gediz Graben geothermal areas, western Anatolia, Turkey   总被引：1，自引：0，他引：1  

Gültekin Tarcan  Ünsal Gemici  Niyazi Aksoy 《Environmental Geology》2005,47(4):523-534

Gediz Graben is an important area for geothermal activity in Turkey. Menderes Massif rocks consisting of gneisses, schists, marbles and granodiorite, comprise the aquifers of the geothermal systems. Neogene terrestrial sediments made up mainly of sandy and clayey conglomerates cap the systems. Gediz Graben geothermal areas are physically divided into seven main groups: Turgutlu-Urganl, Sart-Çamur, Caferbeyli, Üfürük, Kurunlu, Kavakldere-Sazdere and Alaehir geothermal areas. The third highest aquifer in Turkey temperature (182 ^°C) after Kzldere (242 ^°C) and Germencik (232 ^°C) was discovered in the Kavakldere-Sazdere area. The thermomineral waters of the Gediz Graben geothermal areas have outlet temperatures of 25^–95 ^°C and an electrical conductivity of 874–6020 S/cm. Mineralization is mostly dominated by Na⁺ (188–2027 ppm) and HCO₃^– (544–2950 ppm). Kavakldere-Sazdere area shows the highest boron content among the entire geothermal aquifers of Turkey. Major geochemical processes for thermomineral waters are carbonate and silicate dissolution and mixing.  相似文献   

Thermo-hydro-mechanical behaviour of two heavily overconsolidated clays   总被引：4，自引：0，他引：4  

E. Romero  M.V. Villar 《Engineering Geology》2005,81(3):255-268

An experimental study on the thermo-hydro-mechanical behaviour of two heavily overconsolidated clays is presented. Laboratory tests have been conducted on a Spanish bentonite (FEBEX bentonite) and a Belgian kaolinitic/illitic clay (Boom clay), statically compacted at different initial dry densities and water contents. Volume change behaviour of the soils during suction reduction paths at different temperatures and during heating-cooling cycles at constant water content or suction have been investigated through the use of suction and temperature controlled oedometer cells. In addition, the volume change response under unconfined conditions and constant water content has been measured to determine thermal expansion coefficients. The results show similarities and differences between the observed behaviour of the two types of clays that have been interpreted on the basis of their different structures and regarding their proportion of intra-aggregate water.  相似文献   

Activation energy for diffusion of helium in water-saturated, compacted Na-montmorillonite     

Tomohiro Higashihara  Tamotsu Kozaki 《Engineering Geology》2005,81(3):365-370

It is important to clarify the migration behavior of hydrogen gas dissolved in water-saturated, compacted bentonite, which is a promising material for geologic disposal of high-level waste and TRU waste disposal. The diffusion coefficients of helium, which can be detected under extremely low background conditions, in water-saturated, compacted Na-montmorillonite were determined as a function of temperature by a transient diffusion method. The activation energies for diffusion of helium were then obtained. The activation energies were from 6.9 ± 4.8 to 19 ± 2.8 kJ mol^− 1 and were regarded to be independent of dry density. The activation energies of helium in water-saturated Na-montmorillonite were roughly equal to those in bulk water, 14.9 kJ mol^− 1, and in ice, from 11 to 13 kJ mol^− 1. It is possible that helium diffuses not only in pore water but also in interlayer water.  相似文献