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1.
空间数据的内插,误差估计,动态多边形构成和编辑是GIS中比较复杂的问题,其中大部分与空间邻接这一拓扑性质有关,现有的栅格结构与矢量结构采取取完全不同的处理方式,为了达成观察两种基础数据结构统一的认训。加拿大测绘学者们发展了空间数据结构的Voronoi方法。 相似文献
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本文提出了翁布里诺(Hombreiro)侵入体新的构造和岩石组构资料。翁布里诺侵入体是位于西班牙华力西构造带北部的一个同构造便位的花岗岩体。该岩体表现有两期塑性交形特征:早期变形与蒙多涅多(Mondonedo)推覆体的运动有关,此推覆体具有上盘向东的剪切指向;晚期变形则与比韦罗(Vivero)断层有关,此断层为一上盘向西运动的张性剪切带。这两期变形都始于高温近花岗岩固相线条件下,石英中保留有[c]-滑移组构可作证明。这一事实表明,在蒙多涅多推覆体上冲过程中,翁布里诺花岗岩发生侵位,在其定位过程中,张性断层不久即开始活动。本文提出,比韦罗断层的位置受地壳不稳定性所控制,而这种地壳不稳定性则由位于该断层下盘的许多侵入体的侵入作用所引起。 相似文献
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McKay CP Grunthaner FJ Lane AL Herring M Bartman RK Ksendzov A Manning CM Lamb JL Williams RM Ricco AJ Butler MA Murray BC Quinn RC Zent AP Klein HP Levin GV 《Planetary and Space Science》1998,46(6-7):769-777
The MOx instrument was developed to characterize the reactive nature of the martian soil. The objectives of MOx were: (1) to measure the rate of degradation of organics in the martian environment; (2) to determine if the reactions seen by the Viking biology experiments were caused by a soil oxidant and measure the reactivity of the soil and atmosphere: (3) to monitor the degradation, when exposed to the martian environment, of materials of potential use in future missions; and, finally, (4) to develop technologies and approaches that can be part of future soil analysis instrumentation. The basic approach taken in the MOx instrument was to place a variety of materials composed as thin films in contact with the soil and monitor the physical and chemical changes that result. The optical reflectance of the thin films was the primary sensing-mode. Thin films of organic materials, metals, and semiconductors were prepared. Laboratory simulations demonstrated the response of thin films to active oxidants. 相似文献
4.
Peterson JB Griffin GS Newcomb MG Alvarez DL Cantalupo CM Morgan D Miller KW Ganga K Pernic D Thoma M 《The Astrophysical journal》2000,535(2):L83-L86
Using all available major samples of Seyfert galaxies and their corresponding closely matched control samples of nonactive galaxies, we find that the bar ellipticities (or axial ratios) in Seyfert galaxies are systematically different from those in nonactive galaxies. Overall, there is a deficiency of bars with large ellipticities (i.e., "thin" or "strong" bars) in Seyfert galaxies compared to nonactive galaxies. Accompanied with a large dispersion due to small number statistics, this effect is strictly speaking at the 2 sigma level. To obtain this result, the active galaxy samples of near-infrared surface photometry were matched to those of normal galaxies in type, host galaxy ellipticity, absolute magnitude, and, to some extent, redshift. We discuss possible theoretical explanations of this phenomenon within the framework of galactic evolution, and, in particular, of radial gas redistribution in barred galaxies. Our conclusions provide further evidence that Seyfert hosts differ systematically from their nonactive counterparts on scales of a few kiloparsecs. 相似文献
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The coral reef at Kahekili, Maui is located ~300 m south of the Lahaina Wastewater Reclamation Facility which uses four Class V injection wells to dispose of 3-5 million gallons of wastewater effluent daily. Prior research documented that the wastewater effluent percolates into the nearshore region of Kahekili. To determine if the wastewater effluent was detectable in the surface waters offshore, we used algal bioassays from the nearshore region to 100 m offshore and throughout the water column from the surface to the benthos. These algal bioassays documented that significantly more wastewater effluent was detected in the surface rather than the benthic waters and allowed us to generate a three-dimensional model of the wastewater plume in the Kahekili coastal region. Samples located over freshwater seeps had the highest δ(15)N values (~30-35‰) and the effluent was detected in surface samples 500 m south and 100 m offshore of the freshwater seeps (~8-11‰). 相似文献
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迄今全世界已发现金19.3万吨,其中62%产于四个主要产金国,68%产于四种主要金矿床类型银已发现174万吨,55%产于四个主要产银国,45%产于四种主要银矿床类型铜已发现15.2亿吨,56%产于四个主要产铜国,88%产于四种主要铜矿床类型。 相似文献
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河南鲁山早前寒武纪太华群中分布着两类斜长角闪岩:一类为正常斜长角闪岩,主要产于晚太古代下太华群荡泽河组;另一类为富钠斜长角闪岩,产于古元古代上太华群雪花沟组,两类岩石外表特征和矿物成分相近似,但化学成分明显不同,正常斜长角闪岩具较低的Na2O(1.96%-2.86%),K2O(0.24%-0.64%),Ti,Y,Zr,Hf和∑REE含量,而富钠的斜长角闪岩以较高的Na2O(3.31%-5.50%) 相似文献
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