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381.
382.
吴文璐 《成都信息工程学院学报》2011,26(3):277-282
余代数为各种各样的模态逻辑提供一致的语义框架.Lutz Schr?der证明了任意自函子的余代数类都有一个rank-1的公理化.反过来,每一个rank-1的模态逻辑都有一个可靠的、强完备的余代数语义.另一方面,Clemens Kupke等提出模态逻辑可以描述成布尔代数上的自函子,并基于对偶理论研究余代数逻辑的可靠完备性.通过对偶理论重新证明了rank-1的模态逻辑都是余代数的,并且证明通过对偶理论构造出来的函子和Schr?der所构造的函子是等价的. 相似文献
383.
透明矿物绝大多数属于造岩矿物.本方法是从透明矿物中选取色泽纯正、易采集、便于加工的矿物作原材应用于玉板画工艺中,将其加工后与粘合胶液混合调配出能适应石板填充作画的填料,随之进行画面刻绘、填充、打磨、抛光等工序.工艺中采用雕刻深浅变化使画面显现出似透非透的,与石板背景色形成交相辉映、约隐约现如出天然之韵味的效果.这种透明... 相似文献
384.
《Geomechanics and Geoengineering》2013,8(3):185-194
In this paper, a model for the analysis of footings having finite flexural rigidity resting on a granular bed on top of stone columns improved saturated soft (clayey) soil has been proposed. Soft soil has been modeled as a Kelvin–Voigt body to represent its time dependent behavior. Pasternak shear layer has been used to represent the granular layer and the stone columns have been idealized by means of nonlinear Winkler springs. Nonlinear behavior of granular fill, soft soil and stone columns has been invoked by means of hyperbolic constitutive relationships. Governing differential equations for the soil–foundation system have been obtained and finite difference method has been adopted for solving these, using the Gauss-elimination iterative scheme. Detailed parametric study for a combined footing has been carried out to study the influence of parameters, like magnitude of applied load, flexural rigidity of footing, diameter of stone column, spacing of stone column, ultimate bearing capacity of granular fill, poor foundation soil and stone column, relative stiffness of stone columns and degree of consolidation, on flexural response of the footing. 相似文献
385.
推导了等应变条件下桩阻作用时的碎石桩复合地基固结方程,并与现场沉降观测数据换算出碎石桩复合地基在路堤施工过程中的固结度对比,二者吻合较好,证明了公式的正确性。沉降观测数据还表明:使用碎石桩处理软土地基能加快地基的固结速率。 相似文献
386.
387.
《The Professional geographer》2013,65(4):487-488
Book Reviewed in this article: Geographical Aspects of Health and Disease in India. Rais Akhtarand A.T.A. Learmonth, eds. Antarctic Treaty System: An Assessment. Proceedings of a Workshop at Beardmore South Field Camp, Antarctica. American Electoral Mosaics. J. Clark Archerand Fred M. Shelley. Kompas op Suidwes-Afrika/Namibie. W.S. Barnard, ed. Jerusalem in the 19th Century: The Old City. Yehoshua Ben-Arieh. The World as a Total System. Kenneth E. Boulding. A Social History of Housing 1815–1985, Second Ed. John Burnett. Human Migration. W.A.V. Clark. Regional Population Projection Models. Andrei Rogers. The State of Population Theory: Forward from Malthus. David Colemanand Roger Schofield, eds. Imagining Tomorrow: History, Technology and the American Future. Joseph C. Corn, ed. Swidden Agriculture in Indonesia: The Subsistence Strategies of the Kalimantan Kantú. Michael R. Dove. Glacial Geologic Processes. David Drewry. Physics of Desertification. Farouk El-Bazand M.H.A. Hassan, eds. Housing the Homeless. Jon Ericksonand Charles Wilhelm, eds. Settlement Patterns in Missouri: A Study of Population Origins, with a Wall Map. Russel L. Gerlach. Desert Development: Man and Technology in Sparselands. Yehuda Gradus, ed. Nuclear Winter. The Evidence and Risks. Owen Greene, Ian Percivaland Irene Ridge. The Take-off of Suburbia and the Crisis of the Central City. Günter Heinritzand Elisabeth Lichtenberger, eds. Regional Input-Output Analysis. Geoffrey J. D. Hewings. Spatial Transportation Modeling. Christian Werner. The Atlas of Georgia. Thomas W. Hodlerand Howard A. Schretter, eds. Latin America. 5th ed. Preston E. Jamesand C.W. Minkel. Applied Remote Sensing. C.P. Lo. Localities, Class, and Gender. The Lancaster Regionalism Group. Urban Social Movements: The City after Castells. Stuart Lowe. Politics and Method. Doreen Masseyand Richard Meegan, eds. Land Use. A. S. Mather. The Kingdom of Coal. Donald L. Millerand Richard E. Sharpless. The Presidio and Militia on the Northern Frontier of New Spain, A Documentary History, Vol. 1: 1570–1700. Thomas H. Naylorand Charles W. Polzer, S.J., comps. andeds. Nuclear Power: Siting and Safety. Stan Openshaw. The Central African Republic: The Continent's Hidden Heart. Thomas O'Toole. Environmental and Dynamic Geomorphology. Márton Pécsi, ed. Remote Sensing Principles and Interpretation. Floyd F. Sabins, Jr. Acid Rain and Friendly Neighbors: The Policy Dispute between Canada and the United States. Jurgen Schmandtand Hilliard Roderick, eds. Earth's Changing Surface: An Introduction to Geomorphology. M.J. Selby. International Migration: The Female Experience. Rita J. Simonand Caroline B. Brettell, eds. On Geography and Its History. D.R. Stoddart. Transportation Networks: A Quantitative Approach. D. Teodorovic. Processes in Physical Geography. R.D. Thompson, A.M. Mannion, C.W. Mitchell, M. Parry, J.R.G. Townshend. Imaging Radar for Resources Surveys. J.W. Trevett. Dominance and Affection: The Making of Pets. Yi-Fu Tuan. Capturing the Horizon. The Historical Geography of Transportation since the Transportation Revolution of the Sixteenth Century. James E. Vance, Jr. Nations at Risk: The Impact of the Computer Revolution. Edward Yourdon. 相似文献
388.
THE INFLUENCE OF SEA-LEVEL CHANGE AND GEOLOGIC STRUCTURE ON CAVE DEVELOPMENT IN WEST-CENTRAL FLORIDA
The formation of caves in a portion of Citrus County, Florida is controlled structurally by northwest-southeast-trending joints that formed in the Suwannee Limestone during the uplift of Ocala Arch in the Miocene Epoch. The caves developed in a zone where saline water from the Gulf of Mexico and fresh water from the Ocala Uplift mixed. Further uplift elevated the caves above the mixing zone. Following subsequent lowering of regional baselevel, erosion caused sections of cave passages to collapse and/or be filled with sediment. The caves are fossil segments of a formerly larger, interconnected cave system. 相似文献
389.
《自然地理学》2013,34(4):351-373
Stone retaining walls in urban Hong Kong provided vertical habitats for spontaneous colonization by a diversified humid-tropical flora with large trees. A citywide survey assessed wall and tree characteristics to understand wall-tree relationships and identify conservation candidates. Nonparametric correlations were computed between 28 wall attributes versus tree count, tree biomass, and species-vegetation factors. Most of the 245 walls, with 1275 trees, were in residential areas. Moraceae dominated the 30 tree species, predominantly genus Ficus, and especially F. microcarpa. Natives formed the overwhelming majority, largely with pioneer and ruderal traits. The positive effect of adjacent built-up land use and negative effect of wall exposure indicated sheltering from wind could facilitate tree growth. Wall height was a key determinant as taller walls furnished more surfaces free from human disturbance and conducive to seed deposition by frugivorous birds and bats. Stone width offered more horizontal microsites for seeds to lodge. Stone roughness operated at the microscale to encourage nonarboreal vegetation. Joint attributes exerted strong influence on tree growth and less so on nontree affiliates. The walls-cum-vegetation, many older than 100 years, presented a precious natural-cum-cultural heritage, deserving protection as an urban ecological asset. 相似文献
390.