共查询到20条相似文献，搜索用时 562 毫秒
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Please refer to the attachment(s) for more details. 相似文献
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Some commonly used interpolation algorithms are analyzed briefly in this paper. Among all of the methods, biharmonic spline
interpolation, which is based on Green’s function and proposed by Sandwell, has become the mainstream method for its high
precision, simplicity and flexibility. However, the minimum curvature method has two flaws. First, it suffers from undesirable
oscillations between data points, which is solved by interpolation with splines in tension. Second, the computation time is
approximately proportional to the cube of the number of data constraints, making the method slow for situations with dense
data coverage. Focusing on the second problem, this paper introduces the moving surface spline interpolation method based
on Green’s function, and the interpolation error equations are deduced. Because the proposed method only chooses the nearest
data points by using the merge sort algorithm for interpolating, the computation time is greatly decreased. The optimal number
of the nearest points can be determined by using the interpolation error estimation equation. No matter how many data points
there are, this method can be implemented without difficulty. Examples show that the proposed method can obtain high interpolation
precision and high computation speed at the same time. 相似文献
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Influence of Marble’s Texture on its Mechanical Behavior 总被引：1，自引：1，他引：0
This research work studied the influence of texture on the mechanical properties of crystalline rocks at the scale of the laboratory sample. The experiments were performed on a marble varying in texture, so that the study was conducted on homogeneous (entirely xenoblastic or totally granoblastic) and heterogeneous (mix of the two textures) specimens. The mechanical behavior of the homogeneous and heterogeneous samples was investigated with static and dynamic, destructive and nondestructive tests, in natural conditions, at the laboratory temperature, and at higher temperatures. The specimens were heated to 100, 200, and 300 °C, in order to examine the effect of heating temperature on the elastic modulus and P-waves velocity. As a result, the pure granoblastic marble exhibits values of the elastic modulus, P-waves velocity, and strengths, both in natural conditions and on heated specimens, lower than xenoblastic samples. Such different behavior can be explained by a higher grain boundaries porosity of the granoblastic marble. On heterogeneous samples, only the Rock Impact Hardness Number (RIHN) appears able to highlight the dependence of the mechanical properties on the rock texture. In particular, the impact strength improves with increasing the percentage of xenoblastic texture inside the specimen. 相似文献
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This work concerns linearization methods for efficiently solving the Richards equation, a degenerate elliptic-parabolic equation which models flow in saturated/unsaturated porous media. The discretization of Richards’ equation is based on backward Euler in time and Galerkin finite elements in space. The most valuable linearization schemes for Richards’ equation, i.e. the Newton method, the Picard method, the Picard/Newton method and the L-scheme are presented and their performance is comparatively studied. The convergence, the computational time and the condition numbers for the underlying linear systems are recorded. The convergence of the L-scheme is theoretically proved and the convergence of the other methods is discussed. A new scheme is proposed, the L-scheme/Newton method which is more robust and quadratically convergent. The linearization methods are tested on illustrative numerical examples. 相似文献
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A note on India’s water budget and evapotranspiration 总被引：1，自引：0，他引：1
T. N. Narasimhan 《Journal of Earth System Science》2008,117(3):237-240
Some recent analyses of India’s water budget are based on information attributed to the Ministry of Water Resources. An examination
of the budget components indicates that they imply an evapotranspiration estimate that is significantly lower than what one
may expect based on information from other sources. If such is the case, India’s water resources situation may be more dire
than is otherwise perceived. For, higher evapotranspiration implies correspondingly reduced availability of water for human
use. It should be worthwhile to investigate and reconcile the apparent discrepancy between water budget and evapotranspiration,
considering the importance of water in the national context. 相似文献
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Doklady Earth Sciences - The role played by the Earth’s rotation is very important in problems of physics of the atmosphere and ocean. The importance of inertia forces is traditionally... 相似文献
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《Geoforum》2013
This paper forms part of an endeavour to elicit the cultural-geo-politics of rapprochement tourism between China and Taiwan from a grounded approach. It seeks to examine cross-strait tourists’ travel experiences on ‘the other side’ through the lens of ‘border’, ‘materiality’ and ‘identity’ in an attempt to move beyond the often state-centric analyses of cross-strait ties. Discussion shows that travel documents that are close to the personal or those that are part and parcel of a touring experience are far from inert; they participate in the social and political lives of their owners, feature in bordering practices between the Chinese and the Taiwanese, and are often platforms through which identities are performed. Importantly too, as the various travel narratives reveal, the ubiquitous border certainly does not exist only in its physical form; imagined and perceived social borders are equally potent in (re)shaping cross-strait relations. A study that captures the often neglected field of comparative tourists’ travel experiences is timely in the advent of a warming relationship between China and Taiwan and the unprecedented increase in tourism exchanges that ensues. 相似文献
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Acid rain has been a great threat to socioeconomic sustainable development of China; therefore, we develop an indicator system based on the sensitivity and adaptive capacity perspectives and employ the TOPSIS (Technique for Order Preference by Similarity to Ideal Solution) approach to investigate the impact of acid rain on socioeconomic vulnerability of China. Some empirical findings are obtained. First, there is significant provincial difference of socioeconomic vulnerability caused by acid rain in China. Specifically, Tibet, Qinghai, and Shanghai are the top three provinces with the largest vulnerability but Inner Mongolia, Xinjiang, and Jilin are bottom of the rankings. Second, adaptive capacity indicators overall appear more important than sensitivity indicators to measure the vulnerability of acid rain, and the most important indicators are population density and output value of agriculture, forestry, animal husbandry, and fishery while GDP per capita ranks the last. Third, upgrading energy structure and reducing outdated capacity in China prove to be effective means to mitigate vulnerability of acid rain, which has been validated in Guizhou and Hunan provinces. Finally, great attention should be attached to the population increase so as to curb the acid rain vulnerability, especially in Beijing and Tianjin. These results present a basis for future acid rain prevention planning and economic development in China. 相似文献
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Please?refer?to?the?attachment(s)?for?more?details. 相似文献
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Hsien-Tang Tsai Cheng-Jui Tseng Shian-Yang Tzeng Tung-Ju Wu Jen-der Day 《Natural Hazards》2012,62(1):83-91
Typhoon Morakot hit Taiwan in 2009, severely damaging the Alishan National Forest Recreation Area, a famous tourist resort
in Taiwan. The only highway to this area was under repair for 10 months after the typhoon. Consequently, Alishan’s tourism
industry suffered losses estimated at NT$1 billion. This work investigates the impacts of natural hazards on Taiwan’s tourism
industry. First, government, university, and industry experts were invited to a focus-group interview to update criteria for
tourism development in Taiwan. Next, the Analytic Hierarchy Process (AHP) was applied to rank the proposed criteria. Last,
two tourist attractions, one urban and one rural, are discussed in detail. This work proposes three novel dimensions for Taiwan’s
tourism development—destination attraction, destination arrangement, and contingency planning for natural hazards—which comprise
nine criteria. Analytical results will provide Taiwan’s tourism industry with references for future policy-making and sustainable
development. 相似文献
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E. V. Bibikova 《Petrology》2010,18(5):482-488
Analysis of isotope-geochemical data obtained for the early crustal complexes of the Earth provided constraints on the formation
time, scales of development, and geochemical features of protocrust. Most informative were isotope-geochemical and geochemical
data on the oldest zircons with ages up to 4.4 Ga, short-lived 146Sm/142Nd isotope system, and lead isotope composition of the oldest rocks of Greenland. The presence of positive 142Nd anomaly in the rocks of West Greenland and negative anomaly in the amphibolites of the oldest Nuvvuagittuq greenstone belt
of the Superior province (O’Neil et al., 2008) indicates the early differentiation of the Earth material into depleted mantle
and enriched (basaltic) crust (Caro et al., 2006; Benett et al., 2007a, b; O’Neil et al., 2008). Pb-Pb isotopic systematics
of the oldest crustal rocks from West Greenland and Labrador testifies that high μ enriched crust (238U/204Pb = 10.9) of basaltic composition already existed 3.9 Ga ago (Kamber et al., 2003). Based on isotope-geochemical and geochemical
features of the oldest zircons in the Late Archean greenstone belts of the Yilgarn block (Western Australia), the crust of
intermediate-felsic composition and water on the Earth’s surface already existed 4.4 Ga ago (Wilde et al., 2001). 相似文献
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B. J. Smith S. McCabe D. McAllister C. Adamson H. A. Viles J. M. Curran 《Environmental Earth Sciences》2011,63(7-8):1691-1700
Environmental controls on stone decay processes are rapidly changing as a result of changing climate. UKCP09 projections for the 2020s (2010–2039) indicate that over much of the UK seasonality of precipitation will increase. Summer dryness and winter wetness are both set to increase, the latter linked to projected precipitation increases in autumn and spring months. If so, this could increase the time that stone structures remain wet and possibly the depth of moisture penetration, and it appears that building stone in Northern Ireland has already responded through an increased incidence of algal ‘greening’. This paper highlights the need for understanding the effects of climate change through a series of studies of largely sandstone structures. Current and projected climatic trends are therefore considered to have aesthetic, physical and chemical implications that are not currently built into our models of sandstone decay, especially with respect to the role played by deep-seated wetness on sandstone deterioration and decay progression and the feedbacks associated with, for example surface algal growth. In particular, it is proposed that algal biofilms will aid moisture retention and further facilitate moisture and dissolved salt penetration to depth. Thus, whilst the outer surface of stone may continue to experience frequent wetting and drying associated with individual precipitation events, the latter is less likely to be complete, and the interiors of building blocks may only experience wetting/drying in response to seasonal cycling. A possible consequence of deeper salt penetration could be a delay in the onset of surface deterioration, but more rapid and effective retreat once it commences as decay mechanisms ‘tap into a reservoir of deep salt’. 相似文献
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Doklady Earth Sciences - 相似文献
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Tungsten isotope is a powerful tracer for the Earth’s accreting materials because of the distinct W isotope compositions of the non-carbonaceous meteorites and carbonaceous meteorites. To better understand the evolution of the early Earth, here we calculated the expected μ183W of the bulk silicate Earth for different assumed compositions of the proto-Earth’s mantle, the Moon-forming giant impactor, and the late veneer using a Monte Carlo approach. The result shows that the proto-Earth likely has a non-carbonaceous composition, while the carbonaceous chondrite-like materials were delivered to the Earth at the late stages of accretion. The predicted difference in μ183W values between the bulk silicate Earth and the non-carbonaceous meteorites of the scenarios assuming a pure carbonaceous composition for the giant impactor is slightly bigger than that of the scenarios assuming either a pure non-carbonaceous or a mixed carbonaceous-non-carbonaceous composition for the giant impactor (~5 ppm versus ~2 ppm). The ancient mantle reservoir that partially lacks the late veneer with carbonaceous composition should have a negative μ183W value (from ?3 to 0). Uncertainties introduced by the cosmogenic effects and mass-independent fractionation should be concerned during the high precision measurement of μ183W for meteorites and ancient terrestrial samples in further work. 相似文献
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Yu. M. Pushcharovsky 《Geotectonics》2006,40(4):325-326
Chronicle
Sergei Vasil’evich Ruzhentsev (on his 70th birthday) 相似文献20.
Hotspots are regions where the number of spatial objects is obviously high within the time intervals. As the behaviours of urban residents are considered as a typical kind of spatio-temporal pattern, the detection of hotspots of urban residents’ behaviours appears necessary, since important information might be discovered in hotspots. In this paper, we propose an approach to detect the spatio-temporal hotspots of urban residents’ behaviours. This approach is validated based on the GPS data of floating cars of a city in southern China. The approach consists of four main steps: first, the effective spatio-temporal trajectories and the important characteristic points contained in each trajectory are extracted from the GPS data; second, the spatio-temporal clusters are generated by clustering the characteristic points based on a kernel density estimation algorithm; third, the spatio-temporal hotspots are detected by filtering the spatio-temporal clusters with high densities; last, the detected hotspots are analysed and interpreted. The results show that the proposed approach is effective and useful in detecting hotspots of urban residents’ behaviours. 相似文献