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1.
Using the database of automatic hydrometeorological stations, installed in the Don RIver delta and Taganrog Bay seashore, the sources of the anomalois scale water negative surge and salinization of the Azov Sea under conditions of low river flow in 2015–2016 are studied. The new schemes of stratification and advection of salty sea waters in the Don River mouth under different weather conditions, water discharge and levels are given.  相似文献   

2.
含水层渗透性空间分布的指示克立格估值   总被引:3,自引:0,他引:3  
宋刚  万力  胡伏生  高茂生  张琦伟 《地学前缘》2005,12(Z1):146-151
详细介绍了指示克立格估值计算的理论和方法。以指示变异函数为基本工具分析了华北某地区第四系含水层渗透性空间分布的结构特征,结果表明该地区含水层渗透性存在明显的各向异性特征。水平方向上,X轴方向的相关性较Y轴方向的好,Z轴的相关性最差。用指示克立格法对未采样点处进行估值,估值结果显示含水层渗透性由山前向滨海逐渐变低,在垂直方向上,渗透性变化不明显,浅部比深部略好;同时给出了估计精度,并认为对估计精度不高的区域可通过增加适当的工程加以控制。最后用交叉验证法对估值结果进行了检验,证明建立的指示变异函数模型合理且估值效果较好。这一实际应用表明指示克立格法可以很好地描述第四系含水层渗透性的空间分布规律。  相似文献   

3.
This work presents the results of a study of the biogeographical distribution of Late Albian-Maastrichtian ammonites, found in sequences of the Pacific coast of Russia. The taxa typical of the Pacific Realm were identified, and their distribution traced beyond the borders of this region. In addition, species-migrants, distributed within the studied area were established. As a results of our works, a high level of endemism of ammonite fauna of the East of Russia was noted (75–88% of endemic species, on average). The bipolarity, previously established in the distribution of ammonoids within the Pacific Paleobiogeographical Realm, as well as their high regional provincialism, was confirmed. The following division of the studied area into faunal ammonite provinces in the Late Cretaceous was proposed: Arctic Province; Boreal-Pacific Province, including northeastern Russia (Chukotka Peninsula, the Koryak Upland, Penzhyna Gulf) and the boreal coast of North America (Alaska Peninsula, Arctic Canada and British Columbia); Northwest Pacific Province, including the Primorye Territory, Sakhalin and Shikotan Islands, the Japanese Islands; Northeast Province of the Pacific (the western coast of the United States and Mexico); Southwest Pacific (Australia, New Zealand, Oceania) and Southeast (the western coast of South America and Antarctica, Seymour and James Ross Islands) Provinces. This division is confirmed by data on inoceramid species. In addition, levels of global transgressions and general sea level rise, associated with the appearances of most of widespread marine taxa in the Pacific shelf seas, are established. These include Late Albian, Cenomanian-Turonian boundary, Late Coniacian, Late Campanian, Early-Late Maastrichtian boundary. Moreover, migration of ammonites occurred due to the Tethys Ocean extension and followed the northern sea straits in the Arctic Ocean and within the Pacific Realm, depending on warm currents. Both the counter and one-way migrations were established.  相似文献   

4.
A review of theories of mechanisms of induced seismicity   总被引:1,自引:0,他引:1  
Theories of the physical processes leading to the stimulation of seismic activity by underground explosions, fluid injection, and reservoir impoundment are summarized. In all cases, the materials must be pre-stressed to a substantial fraction of their breaking strength in order for seismicity to be induced. Stress concentrations due to the presence of old faults or to inhomogeneities in the material properties play an important role in localizing induced seismicity.

For the few cases for which data are available, the stimulation of earthquakes by fluid injection in bore holes is adequately explained by a Coulomb-Mohr failure criterion and the concept of effective pressure in a water-filled porous mechanism. Reservoir-related earthquakes are most likely due to the same mechanism, but, in view of the low injection pressures, additional physical or chemical effects of the water on the materials may play an important role. There may be a weakening of the materials in old fault zones by the introduction of water or static fatigue in silicate rocks due to stress corrosion.  相似文献   


5.
考虑核电厂地基-基础的动力相互作用,应用显式动力有限差分法分析了地震作用下极软岩、较软岩、坚硬岩上核电厂建筑结构基础的地震响应特征,比较了岩石坚硬程度对基础加速度反应谱的影响。研究表明:随着岩石坚硬程度的提高,核电厂建筑物结构基础的地震响应有增加的趋势;在周期轴上,基础处的加速度反应谱曲线会随着岩石坚硬程度的提高逐渐向短周期(高频段)方向移动。在高频段,建造于较坚硬岩石上基础结构的加速度反应谱值偏大;在中等频段,建造于较软岩石上基础结构的加速度反应谱值偏大;在低频段,岩石坚硬程度对加速度反应谱的影响不显著。  相似文献   

6.
张玉成  杨光华  姜燕  姚捷  史永胜 《岩土力学》2010,31(Z1):349-356
结合爆破数值模拟中爆破荷载的特点,分析了各种荷载施加方法的特点及爆破震动场模拟的要求,基于圣维南荷载等效原理,提出了爆破荷载的等效施加方法,即将作用在炮孔壁上的爆破荷载等效后,施加在同排炮孔中心线或者面上来模拟爆破荷载的作用。结果表明,等效施加方法在近区存在一定差异,但在中远区吻合得较好。利用该等效荷载施加方法,采用三维实体模型计算分析了某沉管隧道基槽爆破施工对既有堤岸稳定性影响,计算了周围不同位置、不同深度位置处的振动响应,并在此基础上,分析研究了减小爆破振动对既有结构物影响的减振措施,可为类似工程提供借鉴。  相似文献   

7.
过去,人们对岩(矿)石磁参数测定工作不够重视,多数磁测工作是按照相应的工作规范只是测一测岩(矿)石磁参数.甚至有不少磁测工作不对工区内的岩(矿)石标本做磁参数测定工作,或只做少量的测定工作.而这些为数不多的磁参数测定工作也只是作磁化率和剩余磁化强度的平均数(众数)统计,没有对标本磁参数离散程度进行深入的统计研究.尽管利用变异系数表征磁参数的相对离散程度是很早就被人们认识到的.但是,目前就是在极少数关注磁参数离散程度的研究者中,也多引用标准离差,而不是变异系数.笔者对岩(矿)石标本磁参数的变异系数作了浅显的研究,并认为研究岩石磁性强度的自身不均匀性和相互之间的不均匀性对比,变异系数应当是一个不错的参数.  相似文献   

8.
高凡金矿床是次火山热液型中低温金(银)矿床,对矿石中主要矿石矿物自然金、石英,黄铁矿,银矿物,闪锌矿,方铅矿和方解石等矿物标型性研究,得出了高凡金(银)矿床的矿物标型特征及空间分布规律,利用这些规律可指导该矿床深部的找矿工作及区域上同类型矿床的寻找。  相似文献   

9.
铜精矿成分分析是判定其品质的重要手段,尤其是主元素铜的分析。目前,测定铜精矿中铜含量的主要分析方法有碘量法、电感耦合等离子体发射光谱法(ICP-OES)、火焰原子吸收光谱法(FAAS)、X射线荧光光谱法(XRF)、电解重量法等。为确保检测标准量值统一、准确、可靠,本文组织开展了铜精矿中铜镁铅锌的测定实验室间比对活动。通过对参加实验室的检测结果进行统计分析,评价参加实验室对铜精矿中铜镁铅锌测定的技术水平和能力。结果表明:大部分实验室的检测结果为满意,铜精矿中铜的满意率为92.9%,满意率较高;铜镁铅锌的满意率平均值为89.0%。少数实验室出现离群值主要在于样品前处理、检测人员对检测方法未能充分理解并熟练掌握、仪器状态等其他相关因素。碱浸法因样品分解不完全,不能作为铜精矿前处理方法;碱熔法因工序繁琐,易产生基体干扰,不适合作为铜精矿前处理方法。本文建议优先采用酸溶-滴定法测定铜精矿中的铜,而采用酸溶ICP-OES法测定铜精矿中的铜镁铅锌,该方法高效快捷,但其稳定性需要进一步的实验考察。  相似文献   

10.
结合工程勘察实践及现场载荷试验成果,提出将珊瑚砂分为海洋类珊瑚砂和濒海类珊瑚砂两大类,并在此基础上对珊瑚砂进行了规范定名,通过现场载荷试验对各类珊瑚砂的岩土力学特性进行了研究分析,阐明了各类珊瑚砂的岩土力学特性,对今后进一步研究珊瑚砂的岩土力学特性及工程实践具有一定指导意义.  相似文献   

11.
《International Geology Review》2012,54(12):1428-1439
The author suggests a hypothesis of multistage evolution of the mobile crust zones of the Earth, taking into consideration the type of crustal columnar section (oceanic, intermediate, continental, and orogenic), the history of tectonic and magmatic epochs (Caledonian, Hercynian, Kimmeridgian, and Alpine), and the factor of lineament type mobile zones existing during long periods of geological history and contributing to the activation of magmaticprocesses. --E.A. Alexandrov.  相似文献   

12.
含瓦斯煤孔隙率和有效应力影响因素试验研究   总被引:1,自引:0,他引:1  
陶云奇  许江  彭守建  袁梅 《岩土力学》2010,31(11):3417-3422
以孔隙率基本定义和力学平衡原理为出发点,充分考虑由煤层瓦斯的吸附膨胀和解吸收缩、温度效应的热胀冷缩和煤体骨架受孔隙瓦斯压力的压缩共同引起的本体变形,建立了在压缩条件下(扩容前)的含瓦斯煤孔隙率动态演化模型和以吸附热力学参数及瓦斯压力表达的有效应力方程,并分别根据现场实测孔隙率数据和含瓦斯煤三轴应力试验数据,对所建立的理论模型进行了验证。结果表明,理论计算值与实测资料和试验结论一致性较好,理论模型拟合精度较好,误差不大,所得结论对煤层气开采和矿井瓦斯灾害防治具有一定的指导意义。  相似文献   

13.
江志安 《岩土工程技术》2009,23(5):268-270,F0003
针对胶济客运专线某段路基沉降加大的状况,提出以潜孔钻机开孔、以高压旋喷注浆加固地基的方案。在施工过程中,对高压旋喷注浆的工序进行合理打破常规的优化,既保证了既有铁路的运营安全,也保证了处理线路的质量,有效解决了本工程的难题。优化后的方案经过实践的检验,有进一步研究分析和推广的价值。  相似文献   

14.
闫澍旺  郭林坪  曹永华 《岩土力学》2014,35(8):2286-2292
将可靠度理论应用于岩土工程稳定性分析过程中,即使是已证明安全的工程所得到的边坡或地基的失效概率通常较大,导致这一现象的原因是估算的方差偏大。计算土性指标的试验数据仅表征了该试验点的特征,而不是空间平均特征。在随机场理论应用于岩土工程可靠度分析的过程中,方差折减函数是将点特性过渡为空间平均特性的必要参数。首次对闫澍旺等提出的完全不相关距离理论中完全不相关距离的确定方法进行改进,不但理论上有所突破,而且计算方法更为简洁。对折减函数值的确定过程进行了分析,得到了用完全不相关距离方法确定折减函数的一般规律。  相似文献   

15.
多年冻土融沉性分类研究   总被引:2,自引:2,他引:0  
在冻土工程中,冻土的融沉性评价是工程地质勘察的主要内容之一,融沉性分类是冻土地基基础设计施工的重要依据.根据345个冻土原状样品融沉压缩试验数据,提出了细砾、砂土、粉土、黏性土、泥炭化黏性土和泥炭质土等6类土的融沉系数一含水量或融沉系数一超塑含水量线性回归方程式,得到与各融沉性分级相应的界限含水量或界限超塑含水量.最后...  相似文献   

16.
To fill in the large existing data gap, this study presents results of a comprehensive data set from Kuwait Bay (KB), showing the horizontal and vertical distribution of its prominent hydrodynamic variables (i.e., water temperature, seawater salinity, seawater density) and water quality variables (i.e., chlorophyll-a concentration, turbidity, dissolved oxygen (DO) concentration, DO saturation, apparent oxygen utilization, photosynthetic active radiation). Field measurements were carried out between 11 September 2014 and 17 August 2015 covering number of monitoring stations in the entire bay. The results revealed significant seasonal variations and apparent three-dimensional features of the measured variables exemplifying the necessity of not considering the bay as a well-mixed water body in the future oceanographic studies anytime of the year. However, well-mixed conditions (with the Brunt-Vaisala frequency of about 0.0002 s?1) were existent only in the winter. Bay’s water column began stratifying in late spring, and these were significantly intensified (with the Brunt-Vaisala frequency of about 0.0008 s?1) during the summer and early autumn. The stratification, together with the increase oxygen demand for decomposition processes and decrease in DO solubility in summer, led to the formation of a lower DO water mass (daytime DO concentration <4.2 mg l?1) at the lower layers. Results also suggested that the water of the KB is more transparent (indicated by lower turbidity) compared to the adjacent sea water. Measurement of light intensity along the water column indicated that the light extincts rapidly (i.e., the light reduced to approximately 10 % of the surface values at water depth of 2–6 m) in KB and many times absent at the water near the seabed. This study also suggested that the KB can be classified at a year-round negative, hypersaline, inverse, and hyperpycnal estuary.  相似文献   

17.
《International Geology Review》2012,54(10):1218-1225
Copper deposits of Cuba belong to the Jurassic lead-zinc-copper, Cretaceous copper and Paleogene copper complexes, which differ substantially in their formation conditions. The island is differentiated into a number of metallogenic zones formed at the initial and early stages of the Cuba folded province. Pinar del Rio, Pinos, Trinidad and Oriente zones, of an intrageanticlinal nature, are prospective with respect to copper vein deposits of the lead-Zinc-copper complex. The Sasa and Cauto zones - intrageosynclinal - are prospective with regard to copper-pyrite and copper vein deposits of the Cretaceous complex. A metallogenic study of the island is indicated in planning the exploration of its copper prospects. -- AGI Staff.  相似文献   

18.
试论粉喷桩地基承载力计算   总被引:8,自引:1,他引:7  
本文就粉喷桩在地其中的作用进行了分析,求得复合地基与群桩效应间的关系和一些有益的结论,并对粉喷桩的最佳尺度及负摩擦等问题提出了建议。  相似文献   

19.
Reaction of zoning of garnet   总被引:1,自引:0,他引:1  
Compositional zoning of garnet in metamorphic or igneous rocks preserves evidence of the equilibration history of the sample and can be interpreted in terms of a growth-fractionation, diffusion-exchange, or diffusion-reaction model. Diffusion zoning is usually assumed to result from exchange reactions between garnet and other phases as the partitioning coefficient varies in response to changing environmental conditions, primarily temperature. However, in many natural environments where garnet grew originally in divariant equilibrium with other phases, changing conditions can promote continuous or “divariant” reactions and consequent compositional shifts of phases that can be much greater in some systems showing these reactions than those related to the small changes of partitioning. Diffusional zoning related to overstepping of these continuous reactions must be related to incongruent reaction and necessitates formulation of a kinetic diffusion-reaction model involving moving phase boundaries as well as solid-state diffusion. Three samples containing zoned garnets from the metamorphic aureole around the Ronda ultramafic intrusion in southern Spain are used to illustrate two possible models of diffusion-reaction processes. The examples are particularly informative because the reactions are demonstrably irreversible and evidence of the reaction system is preserved. Partitioning data indicates that compositions of product phases are not in equilibrium with the original garnet and do not vary with extent of reaction; therefore, exchange reactions with garnet were not possible and garnet changed composition only by incongruent reaction. After a small amount of reaction, Mg/Fe of the rim composition approaches a value apparently in equilibrium with product phases, but the garnets are zoned inward to the original garnet composition preserved in the interior. Grossularite content is approximately constant and spessartite content variable but small, thus, the rim composition of pyrope or almandine is assumed to be fixed by the external reaction process and is taken as a boundary condition in the following models. The zoning profile of pyrope or almandine component between the fixed rim and core compositions (assumed to extend to ∞) is described in semiinfinite, half-space models appropriate for large garnets with narrow rims. The first model corresponds to a reaction system in which all garnet compositions are metastable (case 1) and zoning depends on the independent variables of the diffusion constant, velocity of the interface between garnet and matrix, and time. The second model, corresponding to systems in which the initial garnet composition is metastable but an equilibrium composition is stable (case 2), depends on the independent variables diffusion constant, time, and a function of reaction compositions. In case 1 the consumption velocity is assumed constant and a steady state zoning profile is reached at large time, whereas, in case 2, the velocity decreases with the concentration gradient and steady state is not possible. The models were tested using a reaction time estimated from cooling models of the aureole, mass of garnet consumed, determined petrographically, and phase compositions. The two cases are somewhat independent in that different parameters are independent variables. The estimate of the diffusion constant of 10?18±2 cm2/sec (assumed to be a mutual or binary coefficient for almandine and pyrope) is considered reasonable for the temperature range of reaction (probably 600–900° C), and the two models are consistent considering the probable error and possible real temperature differences. It is obvious that details of the metamorphic reaction system must be known to successfully apply diffusion models. Kinetic models, involving consumption or growth of the phase as well as diffusion are probably necessary when dealing with natural rocks. Several possible and interesting complications, such as cross coupling between components, can be investigated if more data were available. Experimental determination of diffusion constants allow natural reaction rates to be estimated by this method. Diffusion zoning is an important consideration that could increase the efficiency of experimentation with chemically recalcitrant phases.  相似文献   

20.
近年来中等复杂程度地球系统模式的研究进展   总被引:1,自引:3,他引:1  
近十几年来,地球系统模式领域活跃着一类新兴的模式——中等复杂程度的地球系统模式(EMICs),EMICs以其对计算能力的较低要求和对地球系统的较为完备的描述,使其应用几乎覆盖了简单模式和大气环流模式(CGCMs)的所有研究领域,特别在长期气候变化的模拟方面展现了得天独厚的优势,从而使得在长期气候变化的背景下研究近代气候变化更具现实意义。EMICs已经成为模拟地球系统的有力工具,为目前的CGCMs模拟提供了必要的补充,在简单模式与CGCMs之间架起了一座桥梁。首先回顾了中等复杂程度地球系统模式(EMICs)的发展现状,结合近年来国内外发表的文献探讨了EMICs的基本组成、应用领域,并对EMICs未来的发展趋势进行了预测。  相似文献   

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