不同 Delaunay 三角网构建方法对土石方量计算差异研究     

王万平  邹永玲 《东北测绘》2014,(2):53-55

为了分析不同Delaunay三角网构建方法对土石方量计算的影响,叙述了目前三类Delaunay三角网构建方法---逐点插入法、三角网生长法和分而治之法的特点,建立了三角网土石方量计算公式。采用C＋＋语言进行了程序实现,分别计算了某建筑场地土石方量,三种方法生成三角形数目相同,土方量存在一定差异,但均在规范对土方计算要求的允许范围之内。三种三角网构建方法不同导致生成三角网局部的不同是土方量计算不一致的主要原因。这一研究成果具有重要的现实作用及意义。  相似文献   

AutoCAD地形建模及其在土方计算中的应用   总被引：2，自引：0，他引：2  

周乐韬  范东明  张献州  赵旭 《四川测绘》2003,26(3):121-123

提出一种利用地形碎部点在AutoCAD中建立实体地形模型并快速测量填挖方量的方法，同时绘出直观的填方边界和挖方边界。  相似文献   

激光扫描技术在土方量计算中的应用及精度分析   总被引：1，自引：0，他引：1  

孟志义 《北京测绘》2012,(4):64-66,102

土方量计算的方法有方格网法、断面法、等高线法、数字高程模型(DEM)方法等,本文提出一种利用激光扫描获取海量数据生成不规则三角网(TIN)来计算土方量的方法,介绍其作业方法、地形数据提取、土方量计算等。在实际工程中,用不同方法计算出来的土方量会存在差别,哪种计算方法的精度更高,通过精度分析得出相应结论。  相似文献   

断面法土石方测量与计算的自动化   总被引：2，自引：0，他引：2  

吴立军 《地理空间信息》2005,3(5):58-59,62

介绍了以AutoCAD和Excel为平台,在VisualBasic6.0编程环境中,编写断面一体化程序,实现断面法测量土石方自动化的方法。使土石方测量计算工作变得快捷、简单、方便。  相似文献   

Quantum-mechanical ab initio simulation of the Raman and IR spectra of Mn<Subscript>3</Subscript>Al<Subscript>2</Subscript>Si<Subscript>3</Subscript>O<Subscript>12</Subscript> spessartine     

Loredana Valenzano  Alessio Meyer  Raffaella Demichelis  Bartolomeo Civalleri  Roberto Dovesi 《Physics and Chemistry of Minerals》2009,36(7):415-420

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A theoretical investigation of the relative stabilities of Fe-free clinozoisite and orthozoisite     

B. Winkler  V. Milman  R. H. Nobes 《Physics and Chemistry of Minerals》2001,28(7):471-474

 The relative stabilities of orthozoisite, Ca₂Al₃[O|OH|Si₂O₇|SiO₄], space group Pnma, and the monoclinic polymorph, clinozoisite, space group P2₁/m, have been investigated using calculations based on density functional theory. It is found that orthozoisite is more stable than clinozoisite by about 1 kJ mol⁻¹ at zero pressure in the athermal limit. The bulk moduli of the two polymorphs have been calculated to be B_ortho=117.5(1.7) GPa and B_clino=136(4) GPa. Received: 20 March 2000 / Accepted: 26 February 2001  相似文献   

The crystal chemistry and Fe<Superscript>II</Superscript>–site properties of aluminosilicate garnet solid solutions as revealed by Mössbauer spectroscopy and electronic structure calculations     

C. A. Geiger  M. Grodzicki  G. Amthauer 《Physics and Chemistry of Minerals》2003,30(5):280-292

The three binary garnet solid solutions Fe^II₃Al₂Si₃O₁₂–X^II₃Al₂Si₃O₁₂ (X^II= Mg^II, Mn^II, Ca^II) have been investigated by ⁵⁷Fe Mössbauer spectroscopy at 298 and 77 K and by electronic structure calculations in the local spin density approximation. The spectra yield isomer shifts and quadrupole splittings that are typical for Fe^II in the dodecahedral X-site of 222 point symmetry and are similar for each of the three binaries recorded. Conversely, electronic structure calculations based on the experimental crystal structure of the different end-member garnets exhibit pronounced variations in some of the electronic properties of Fe^II that are not reflected in the spectroscopic data. These results are interpreted as indicating that the different X–O bonds in garnet solid solutions retain to a large degree the intrinsic lengths that they possess in their respective end members, and that the Fe–O bond does not change greatly as a function of composition. This is evidence for the state of alternating bonds and not for the virtual crystal approximation in describing the X–O bond types or lengths in aluminosilicate garnet solid solutions. The observed degree and behavior of the Fe^II doublet asymmetry in the Mössbauer spectra for the three solid solution series do not indicate major variations in the anisotropic recoil-free fraction of Fe^II. Variations in doublet asymmetry are more likely a result of complex next-nearest X-site neighbor interactions and/or some degree of short-range cation ordering, though doublets representing different local X-site cation configurations cannot be resolved or fitted to the experimental spectra.  相似文献   

AutoCAD Land Development Desktop在测绘工程中的应用   总被引：3，自引：1，他引：3  

羊远新  吴东 《北京测绘》2003,(3):35-39

鉴于AutoCADLandDevelopmentDesktop与现今很多的土木工程设计软件相兼容,本文结合实际测绘工作经验,对该软件的主要功能模块进行较为详细的说明,针对具体工程测量中遇到的数据采集、组织、检查以及土方量计算等方面的问题提出了解决方法,同时指出了在使用该软件过程应该注意的问题。  相似文献   

Multipole-refined charge density study of diopside at ambient conditions     

R. Bianchi  A. Forni  R. Oberti 《Physics and Chemistry of Minerals》2005,32(8-9):638-645

The experimental multipole electron density, ρ(r), of diopside was derived from high-resolution single-crystal diffraction at room temperature. Its topological analysis revealed predominantly ionic Si–O bonding, as found in electron density studies of other silicates. In particular, the non-bridging Si–O bonds are slightly less ionic in character than the bridging Si–O bonds. The Ca–O and Mg–O bonds are classified as pure closed-shell ionic interactions. An analysis of –∇²ρ(r) showed the presence of maxima around the oxygen atoms, associated to lone pairs domains that are involved in bonds with the surrounding ions. Calculation of atomic basins gave net charges of –1.56(12), 3.11(17), 1.79(13) and 1.88(18) e for O (averaged), Si, Ca and Mg atoms, respectively. O···O interactions between the O atoms at the vertices of the SiO₄ tetrahedron were also detected from the topological analysis of ρ(r), and indicate a cooperative interaction among the lone pairs of neighbouring oxygen atoms. All these results were also confirmed by periodic restricted Hartree–Fock (RHF) calculations. Electronic Supplementary Material Supplementary material is available for this article at and is accessible for authorized users.  相似文献   

The assemblage diaspore+quartz in metamorphic rocks: a petrological, experimental and thermodynamic study   总被引：1，自引：0，他引：1  

T. THEYE  C. CHOPIN  K.-D. GREVEL  & E. OCKENGA 《Journal of Metamorphic Geology》1997,15(1):17-28

The upper pressure limit of pyrophyllite is given by the equilibria (i) pyrophyllite=diaspore+quartz and (ii) pyrophyllite=diaspore+coesite. High- P experimental investigations carried out to locate equilibrium (i) yield brackets between 497 °C/24.8  kbar and 535 °C/25.1  kbar, and between 500 °C/23  kbar and 540 °C/23  kbar. Equilibrium (ii) was bracketed at 550 °C between 26.0 and 28.3  kbar. In the experimental P–T  range, equilibria (i) and (ii) are metastable with respect to kyanite. A stable P–T  grid is calculated using thermodynamic data derived under consideration of the present experimental results. According to these data, the lower pressure limit of the assemblage diaspore+quartz according to equilibrium (i) range from about 12  kbar/300 °C to 20  kbar/430 °C (in the presence of pure water). The upper stability of diaspore+quartz is limited by the reaction diaspore+quartz=kyanite+H₂O at about 450 °C (nearly independent of pressure) and, to higher pressure, by the quartz=coesite transition. Equilibrium (ii) is metastable over the whole P–T  range.
Natural occurrences600.S of the diaspore–quartz assemblage in metamorphic rocks in Sulawesi, New Caledonia, Amorgos and the Vanoise are characterized by minerals indicative of high- P such as ferro-magnesiocarpholite, glaucophane, sodic pyroxene and lawsonite. The metamorphic P–T  conditions of these rocks are estimated to be in the range 300–400 °C, >8  kbar. These data are compatible with the derived P–T  stability field of the diaspore+quartz assemblage. We conclude that, in metamorphic rocks, diaspore+quartz is, as ferrocarpholite, an indicator for unusual low- T  /very high- P settings.  相似文献