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81.
柿竹园夕卡岩中有早、晚形成的两种产状石榴子石。本文为查明其形成物理化学条件及与矿化的关系,采用矿区天然花岗岩、灰岩和夕卡岩化早期形成的石榴子石为试样进行了模拟实验研究。实验结果表明:夕卡岩化早期石榴子石是在温度400—750℃,压力500—1000bar,pH=5—8条件下,由富含Si、Al、Fe、Cl、F等组分的热液与上泥盆统佘田桥组灰岩交代反应形成的;晚期石榴子石是在温度250—700℃,压力500—1000bar,pH=5—14条件下,由富含Si、Al、F等组分的带钨溶液与早期石榴子石交代反应产生重结晶作用形成的。 相似文献
82.
B. H. Briz-Kishore 《Journal of Earth System Science》1982,91(3):219-234
The use of digital models has increased significantly in recent years with the accessibility of fast computing machines. A
variable dimensioned digital model was constructed for the Shadnagar granite basin using SPECTRUM-7 micro computer to integrate
various hydrogeological characteristics and for their quantitative evaluation. The basin has an areal extent of 437 sq km
and is demarcated with clear water divides in all directions. Transmissivity, recharge and discharge at each cell of the basin
area were estimated by trial and error simulation of the hydrogeological phenomenon under steady state condition. Dynamic
simulation at representative nodes facilitated the estimation of storage coefficient. The capability of the constructed model
was established by the conformance of the simulated hydrographs with the actual behaviour of the ground water system. The
entire studies ammended the earlier arrived estimates of various input/output hydrogeological parameters and evolved a methodology
for efficient processing of aquifer simulation data 相似文献
83.
84.
In this paper a spatially distributed model of the hillslope sediment delivery processes, named the sediment delivery distributed (SEDD) model, is initially reviewed; the model takes into account the sediment delivery processes due to both the hillslope sediment transport and the effects of slope curvature. Then the rainfall and sediment yield events measured at the experimental SPA2 basin, in Sicily, are used both to calibrate the SEDD model and to verify the predictive capability of the distributed sediment delivery approach at event scale. For the SPA2 basin discretized into morphological units and stream tubes, the SEDD model is calibrated at event scale using the measurements carried out at the outlet of the experimental basin in the period December 2000–January 2001. The model calibration is used to determine a relationship useful for estimating the unique coefficient βe of the model by rainfall erosivity factor Re at event scale. To test the predictive capability of the βe = f(Re) relationship, 20 events measured in the period September 2002–December 2005 are used; the comparison between measured sediment yield values and calculated ones for all monitored events shows that the sediment delivery distributed approach has a good predictive ability at event scale. The analysis also shows that estimating βe by the relationship βe = f(Re) gives a better agreement between measured and calculated sediment yields than obtained with the median value βe,m of all 27 calculated βe values. Finally the analysis at annual scale, for the period 2000–2005, allows the estimation of the median value βa,m representative of the annual behaviour. This analysis shows that the sediment delivery distributed approach also has a good predictive ability at annual scale. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
85.
Giada Iacono Marziano Burkhard C. Schmidt Daniela Dolfi 《Journal of Volcanology and Geothermal Research》2007
Equilibrium and disequilibrium degassing of a volatile phase from a magma of K-phonolitic composition was investigated to assess its behavior upon ascent. Decompression experiments were conducted in Ar-pressurized externally heated pressure vessels at superliquidus temperature (1050 °C), in the pressure range 10–200 MPa using pure water as fluid phase. All experiments were equilibrated at 200 MPa and then decompressed to lower pressures with rates varying from 0.0028 to 4.8 MPa/s. Isobaric saturation experiments were performed at the same temperature and at 900–950 °C to determine the equilibrium water solubility in the pressure range 30–250 MPa. The glasses obtained from decompression experiments were analyzed for their dissolved water content, vesicularity and bubble size distribution. All decompressed samples presented a first event of bubble nucleation at the capsule–melt interface. Homogeneous bubble nucleation in the melt only occurred in fast-decompressed experiments (4.8 and 1.7 MPa/s), for ΔP ≅ 100 MPa. For these decompression rates high water over-saturations were maintained until a rapid exsolution was triggered at ΔP > 150 MPa. For slower rates (0.0028, 0.024, 0.17 MPa/s) the degassing of the melt took place by diffusive growth of the bubbles nucleating at the capsule–melt interface. This process sensibly reduced water over-saturation in the melt, preventing homogeneous nucleation to occur. For decompression rates of 0.024 and 0.17 MPa/s low water over-saturations were attained in the melt, gradually declining toward equilibrium concentrations at low pressures. A near-equilibrium degassing path was observed for a decompression rate of 0.0028 MPa/s. Experimental data combined with natural pumice textures suggest that both homogeneous and heterogeneous bubble nucleations occurred in the phonolitic magma during the AD 79 Vesuvius plinian event. Homogeneous bubble nucleation probably occurred at a depth of ∼ 3 km, in response to a fast decompression of the magma during the ascent. 相似文献
86.
87.
依据渤海海冰物理和力学特征值和国内水池实验室能力,以1:10~1:30比尺要求,发展了DUT-1合成模型冰.文中简介该模型冰的理想参数、成分和制备过程.就其弯曲强度和弹性模量进行系统的实验分析.通过500多次弯曲实验,获得该模型冰在不同加载速度下的破坏方式,各向同性证据和弯曲强度为35~65kPa和弹性模量平均53MPa的结果.并且得到弯曲强度和弹性模量在实测湿密度范围内呈递增关系,浸水模型冰性能稳定时间超过4h,弹性模量与弯曲强度之比82%超过2000. 相似文献
88.
本文采用液压阻尼系统(HDS)控制立式圆柱钢制储罐的地震反应,建立了安装HDS储罐的力学分析模型,并进行了数值计算,从频域对安装HDS后储罐的地震响应进行了分析,研究了HDS的减震效果和HDS和HDS参数对储罐地震反应的影响。 相似文献
89.
二级结构地震反应的实验研究 总被引:2,自引:0,他引:2
林均岐 《地震工程与工程振动》2001,21(3):75-78
本文针对结构顶部的附属结构在正弦激励和地震动作用下的反应,设计了多层结构模型并研究了附属结构的多种情况。实验结果表明,附属结构在地震作用下可对主体结构产生不同的影响,根据附属结构的参数的不同可能导致主体结构的反应增大或减小,因此得出结论:在结构设计时对主体结构和附属结构进行整体考虑,能使结构的地震反应控制在最佳的水平。 相似文献
90.