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151.
石灰改良膨胀土力学性质的研究   总被引:3,自引:0,他引:3  
膨胀(?)主要是由强亲水性粘土矿物蒙脱石和伊利石组成的,是具有膨胀性、多裂隙性和超固结性的高塑性粘性土。在铁路施工中,膨胀土不能直接作为路基填土,必需进行改良。通过室内试验的方法来讨论石灰改良膨胀土的力学性质在各种影响因素下的变化规律。  相似文献   
152.
金龙山——丘岭金矿区含金矿源为层上泥盆统南羊山组和下石炭统袁家沟组。组成含金矿源层岩石为高频互层的细碎屑岩-碳酸盐岩,其中细砂岩、粉砂岩、碳酸盐岩含成矿流体物性较好.页岩、板岩含成矿流体物性较差,构成屏蔽层。金鸡岭Ⅰ级复式向斜控制着金、砷、锑等异常范围;松枣Ⅱ级复式背斜控制着金的矿化带;金龙山-丘岭金矿Ⅲ级背斜控制着金的矿(化)体;镇安——板岩镇断裂的次级断裂是金矿化体的容矿有利位置。在成矿过程中,构造变形与成矿流体的形成、运移及储集密切相关。其规律是:①原生构造导致成矿流体的初次聚集。②第一期构造变形导致成矿流体的聚集。③第二期构造变形导致成矿流体运移及金矿床形成。此期变形是金的主要成矿期。④第三期构造变形使成矿流体进一步聚集和金矿体的富集。⑤第四期构造变形是石英方解石脉的形成时期。总结出矿床形成模式。据此提出了在4种不同的构造部位找金的方向。  相似文献   
153.
北黄海盆地是发育于隆起背景之上的中、新生代沉积盆地。新一轮资源调查研究表明,北黄海中、新生代沉积盆地的基底由古生界沉积岩层和前寒武纪变质岩系等组成,盆地不同程度地发育下构造层(J3-K1)、中构造层(E2-E3)和上构造层(N);从油气资源和中、新生代地层发育情况出发,将北黄海海域划分为辽东-海洋岛隆起区、北黄海盆地和胶北.刘公岛隆起区等3个一级构造单元,其中北黄海盆地包括6个二级构造单元和24个三级构造单元;盆地褶皱、断裂构造十分发育,褶皱构造可划分为区域挤压型、局部伴生型和披盖型等三类,断裂构造主要可见近EW—NE向、NW向和NNE向三组,其中近EW—NE向和NNE向断裂比较发育,控制着盆地隆、坳分布格局和沉积特征。  相似文献   
154.
文章从国内外滑坡灾害、滑坡灾害的危害及现有滑坡监测方法等方面,论述了滑坡灾害带来的危害性,从而验证了滑坡监测的重要性。但目前现行的滑坡监测手段各有不足之处。针对这种情况,提出了新的测量方法改进其不足之处。位相测量剖面术的测量原理是将LCD投影仪安装于滑坡体上,在滑坡体外稳定地带放置监测系统,CCD光束中心垂直于滑坡体位移方向,监测系统由望远镜头和CCD组成,CCD输出的视频信号进入计算机。通过软件对图像进行处理,绘制出滑坡整体的三维面貌,并计算出滑动的距离,从而有效的观测滑坡体的运动过程。  相似文献   
155.
Nongla, a typical karst dynamic system (KDS) monitoring site, is located at Nongla Village, Mashan County, Guangxi, China. The data from a Greenspan CTDP300 multichannel data logger indicates that the KDS is highly sensitive to environmental changes. Multi-day and diurnal physico-chemical composition of epikarst spring water is quite different under different climatic conditions. During a day with no rainfall, water temperature and air temperature have similar variations. Electrical conductivity (EC) has good positive correlation with pH value and water temperature. During rainstorms, the physico-chemical composition of the spring water is initially strongly effected by dilution, pH and EC drop rapidly. However, half to one hour later, EC returns to normal and the CO2 effects will be the dominant physical effect. This is due to the high fissure rates and high permeability in the epikarst zone. Dilution effects were observed during the entire rainstorm event,whereas, it only acts during the earliest period of light rain. Therefore, it is necessary to examine the water–rock–CO2 combination as a whole system to explain the hydrochemical behavior of epikarst processes.  相似文献   
156.
不同浓度的Na2SO4水溶液的拉曼光谱显示了SO42-的四个拉曼活性带:980 cm-1处的SO42-的对称伸缩振动模式v1带,1 106 cm-1处的反对称伸缩振动模式v3带,448 cm-1处的变形振动模式v2带和617 cm-1处的变形振动模式v4带。482 cm-1处的肩膀峰是由于NaSO4-离子对的形成对448 cm-1的v2带的影响而形成的SO42-的一个新的振动峰。浓Na2SO4水溶液中,水共享离子对[Na+.H2O.SO42-]-是主要的离子对物种。随着Na2SO4水溶液浓度的增加,Na+和SO42-的相互作用增强,NaSO4-离子对所占的摩尔分数增加。  相似文献   
157.
We present a drought reconstruction for southeastern China based on a tree‐ring width chronology of Cryptomeria fortunei developed from two sampling sites in central Fujian. A reconstruction of July–February drought variability, spanning AD 1855–2011, was developed by calibrating total tree‐ring width data with the self‐calibrating Palmer drought severity index (scPDSI). The reconstruction was verified against an independent data set, and accounts for 36% of the actual scPDSI variance during the period 1955–2011. Relatively dry intervals were reconstructed between AD 1859–1880, 1899–1911, 1927–1933, 1946–1959, 1964–1970 and 1987–1997. Relatively wet conditions prevailed during 1855–1858, 1881–1898, 1912–1926, 1934–1945, 1960–1963, 1971–1986 and 1998–2011. Comparisons between our scPDSI reconstruction and a moisture‐sensitive tree‐ring width record from Vietnam revealed consistencies between the two data sets, suggesting similar drought regimes. Spectral peaks of 2.2–6.4 years may be indicative of El Niño‐Southern Oscillation (ENSO) activity, as also suggested by the significant correlations with sea surface temperatures (SSTs) in the eastern equatorial and southeastern Pacific Ocean and an extreme event analysis. The analysis of links between our scPDSI reconstruction and the large‐scale regional climatic variation shows that there is a relationship between regional drought variation and East Asian summer monsoon (EASM) intensity.  相似文献   
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160.
Accepting the concept of standardization introduced by the standardized precipitation index, similar methodologies have been developed to construct some other standardized drought indices such as the standardized precipitation evapotranspiration index (SPEI). In this study, the authors provided deep insight into the SPEI and recognized potential deficiencies/limitations in relating to the climatic water balance it used. By coupling another well‐known Palmer drought severity index (PDSI), we proposed a new standardized Palmer drought index (SPDI) through a moisture departure probabilistic approach, which allows multi‐scalar calculation for accurate temporal and spatial comparison of the hydro‐meteorological conditions of different locations. Using datasets of monthly precipitation, temperature and soil available water capacity, the moisture deficit/surplus was calculated at multiple temporal scales, and a couple of techniques were adopted to adjust corresponding time series to a generalized extreme value distribution out of several candidates. Results of the historical records (1900–2012) for diverse climates by multiple indices showed that the SPDI was highly consistent and correlated with the SPEI and self‐calibrated PDSI at most analysed time scales. Furthermore, a simple experiment of hypothetical temperature and/or precipitation change scenarios also verified the effectiveness of this newly derived SPDI in response to climate change impacts. Being more robust and preferable in spatial consistency and comparability as well as combining the simplicity of calculation with sufficient accounting of the physical nature of water supply and demand relating to droughts, the SPDI is promising to serve as a competent reference and an alternative for drought assessment and monitoring. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   
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