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41.
42.
回顾了沉积混杂碉的研究历史,指出了沉积混杂岩的分布位置和形成机制,重新给出了沉积混杂岩的定义,依据沉积混杂作用的不同方式划分为四种类型,重力垮塌和重力汉混杂作用,冰筏混杂作用,古喀斯特混杂作用和损落混杂作用,最后探讨了海底混杂岩块的来源和搬运方式。 相似文献
43.
B. Borzi G. M. Calvi A. S. Elnashai E. Faccioli J. J. Bommer 《Soil Dynamics and Earthquake Engineering》2001,21(1):103
In recognition of the emergence of displacement-based seismic design as a potentially more rational approach than force-based techniques, this paper addresses derivation of inelastic displacement spectra and associated topics. A well-constrained earthquake strong-motion dataset is used to derive inelastic displacement spectra, displacement reduction factors and ductility–damping relationships. These are in a format amenable for use in design and assessment of structures with a wide range of response characteristics. 相似文献
44.
以钠基膨润土为原料制备了镍钛无机交联、有机交联系列改性膨润土,比较了二者对废水中化学需氧量(COD)、Cr(Ⅵ)、色度、浊度的去除效果,探讨了改性膨润土用量、pH值、搅拌时间等因素对实验的影响。结果表明:镍钛有机交联膨润土对COD和Cr(Ⅵ)的处理效果明显优于镍钛无机交联膨润土;二者对浊度和色度处理效果相当。其吸附行为符合Langmuir方程。 相似文献
45.
46.
The creative reconstruction of the Internet: Google and the privatization of cyberspace and DigiPlace 总被引:2,自引:0,他引:2
The Internet has often been portrayed as the ultimate leveler of information where existing hierarchies of power and privilege are undermined by meritocracy. Some websites and functions are, however, more equal than others. In particular, search engines such as Google have been a key means to construct meaning out of disorder. This ordering (or enclosing of the Internet commons), however, comes at a cost as a location within the top 10 Google search results, marks the boundary (albeit a fluid one) between the core and the periphery of the Internet. The recent incorporation of spatial elements into the Google indexing raises fresh and geographically relevant concerns. This article focuses on the construction, access and use of Google derived rankings to deploy geo-referenced information in the physical environment and the way this melding of code and place affects how people interact with place. Using the theoretical concept of DigiPlace this article analyzes how Google Maps and Google Earth are structured and shape what appears (and what does not) in cyberspace and DigiPlace. Of particular concern are the implications of a private corporation controlling this new space. 相似文献
47.
Geostatistically based history-matching methods make it possible to devise history-matching strategies that will honor geologic
knowledge about the reservoir. However, the performance of these methods is known to be impeded by slow convergence rates
resulting from the stochastic nature of the algorithm. It is the purpose of this paper to introduce a method that integrates
qualitative gradient information into the probability perturbation method to improve convergence. The potential of the proposed
method is demonstrated on a synthetic history-matching example. The results indicate that inclusion of qualitative gradient
information improves the performance of the probability perturbation method. 相似文献
48.
ABSTRACTThis paper presents the effectiveness of xanthan gum (XG) biopolymer in stabilising the expansive soil. The XG biopolymer is mixed with expansive soil in different proportions such as 0%, 0.2%, 0.5%, 0.8% and 1.0% by weight of the dry soil mass. The plasticity, compaction, swelling, compressibility, hydraulic conductivity, strength and durability characteristics of the treated and un-treated expansive soil are examined. Results show that the plasticity index of the treated soil mass initially increases but beyond 0.5% biopolymer addition it decreases sharply. The optimum moisture content and maximum dry density of treated soil, found out from light and heavy compaction tests, do not follow any definite trend. It is also found that increasing XG content increases compressibility slightly but, it reduces swelling pressure, differential free swelling value and hydraulic conductivity remarkably. On the other hand, time-dependent compressive strength and resistance to mass loss increases with increasing XG content. Microscopic examination confirms the formation of gel-like linkage, which brings about the modifications in the treated expansive soil. 相似文献
49.
WANG Weiwu 《山地科学学报》2007,4(3):237-247
In China, many scenic and tourism areas are suffering from the urbanization that results from physical development of tourism projects, leading to the removal of the vegetative cover, the creation of areas impermeable to water, in-stream modifications, and other problems. In this paper, the risk of soil erosion and its ecological risks in the West Lake Scenic Spots (WLSS) area were quantitatively evaluated by integrating the revised universal soil loss equation (RUSLE) with a digital elevation model (DEM) and geographical information system (GIS) software. The standard RUSLE factors were modified to account for local climatic and topographic characteristics reflected in the DEM maps, and for the soil types and vegetation cover types. An interface was created between the Areinfo software and RUSLE so that the level of soil erosion and its ecological risk in the WLSS area could be mapped immediately once the model factors were defined for the area. The results from an analysis using the Areinfo-RUSLE interface showed that the risk value in 93 % of the expanding western part of the WLSS area was moderate or more severe and the soil erosion risk in this area was thus large compared with that in the rest of the area. This paper mainly aimed to increase the awareness of the soil erosion risk in urbanizing areas and suggest that the local governments should consider the probable ecological risk resulting from soil erosion when enlarging and developing tourism areas. 相似文献
50.