Framework agreement on climate change: a scientific and policy history     

Alan D. Hecht  Dennis Tirpak 《Climatic change》1995,29(4):371-402

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Chalcides and pnictides of group VIII transition metals: Far-infrared spectroscopic studies on compounds MX 2, MXY,and MY 2 with pyrite,marcasite, and arsenopyrite structure     

H. D. Lutz  G. Schneider  G. Kliche 《Physics and Chemistry of Minerals》1983,9(3-4):109-114

The far-infrared (FIR) spectra of pyrites, marcasites and loellingites, and arsenopyrites of the type MX ₂, MY ₂, and MXY with M=Fe, Co, Ru, Rh, Os, Ir X=S, Se, Te, and Y=P, As, and Sb have been studied, including group theoretical treatment of the phonon modes. The internal Y - Y and X - Y stretching modes, infrared (IR) allowed only in the case of the arsenopyrites, have been found to be in the range 440–490, 470–510, 450–490, 430–450 and 400–420 cm^?1 for MP ₂, MPS, MPSe, MAsS, and MSbS type compounds, respectively. From the obtained spectra intensity weighted mean phonon frequencies, i.e. central frequencies as defined by Plendl (1961), and mass weighted ones have been calculated and interpreted in terms of the strength of the MX and MY bonds, especially comparing 3d, 4d, and 5d transition metal compounds. Method of preparation and X-ray data of the chalcides and pnictides studied are also given.  相似文献   

Looking for a needle in a haystack: Probability density based classification and reconstruction of dormers from 3D point clouds     

Youness Dehbi  Sonja Koppers  Lutz Plümer 《Transactions in GIS》2021,25(1):44-70

Accurate reconstruction of roofs with dormers is challenging. Without careful separation of the dormer points from the points on the roof surface, the estimation of the roof areas is distorted. The characteristic distortion of the density distribution in comparison to the expected normal distribution is the starting point of our method. We propose a hierarchical method which improves roof reconstruction from LiDAR point clouds in a model‐based manner, separating dormer points from roof points using classification methods. The key idea is to exploit probability density functions to reveal roof properties and to skilfully design the features for a supervised learning method using support vector machines. The approach is tested based on real data as well as simulated point clouds.  相似文献   

Shock-induced formation of kyanite (Al<Subscript>2</Subscript>SiO<Subscript>5</Subscript>) from sillimanite within a dense metamorphic rock from the Ries crater (Germany)     

Volker?St?hleEmail author  Rainer?Altherr  Mario?Koch  Lutz?Nasdala 《Contributions to Mineralogy and Petrology》2004,148(2):150-159

A dense (~3.34 g cm^–3) garnet–sillimanite-rich metamorphic rock from the suevite breccia of the Ries impact crater was studied by scanning-electron microscopy and Raman microprobe spectroscopy. In the strongly shocked rock clast kyanite was formed from sillimanite under momentary high pressures of natural shock waves. Kyanite aggregates were found as thin (~0.3–2.0 m) seams along grain boundaries between, and fractures within, sillimanite grains. Within these seams kyanite c-axes are oriented perpendicular to original grain boundaries and fractures. In addition, larger (up to 10 m) isolated kyanite grains were rarely found within host sillimanite. Filamentary kyanite aggregates and isolated crystals typically show shrinkage cracks due to volume decrease (~10%). Locally, broad interstices between sillimanite crystals are filled with aluminosilicate glass containing a high volume fraction of sub-micrometer-sized euhedral crystals. The silica-rich glass suggests incongruent melting of sillimanite at local post-shock temperatures significantly higher than 1,300°C. The edges of adjacent sillimanite grains are thermally and chemically altered. The local generation of temperature spikes is attributed to strong shock wave interactions due to very high shock impedance contrasts.  相似文献   

Coalification history of the Stephanian Ciñera-Matallana pull-apart basin,NW Spain: Combining anisotropy of vitrinite reflectance and thermal modelling     

Kai?FringsEmail author  Rüdiger?Lutz  Helga?de?Wall  Laurence?N.?Warr 《International Journal of Earth Sciences》2004,93(1):92-106

The Stephanian Ciñera-Matallana Basin of NW Spain comprises 1,500 m of alluvial to lacustrine coal-bearing sediments, which were deposited in a late Variscan transtensional/transpressional pull-apart setting. The relationship between coalification pattern and rock deformation was evaluated by measurements of the anisotropy of vitrinite reflectance (AVR). The AVR ellipsoids reveal both pre-tectonic elements related to the bedding fabric and syn-tectonic elements related to folding, producing biaxial ellipsoid shapes with the maximum reflectance parallel to fold axes. The mean coalification gradient for the Stephanian succession is about 0.62 %Rr/km. Calculations of the mean palaeo-geothermal gradient are presented on the basis of three different empirical equations. A palaeo-geothermal gradient of 85 °C/km is considered the most realistic, with an overburden of about 1,000 m. 1-D numerical modelling of the burial history results in two possible scenarios, the most preferable involving a palaeo-heat flow of 150 mW/m² and an overburden of ca. 1,050 m. These results indicate that maximum coalification was related to a localised but high palaeo-heat flow/-geothermal gradient. The anisotropy of vitrinite reflectance highlights the interactive and transitional nature of sedimentary compaction and rock deformation on the maturation of organic material within strike-slip fault zones.  相似文献   

A Note on Short Period Temperature Fluctuations in the North Sea     

Hecht  A.; Hughes  P. 《ICES Journal of Marine Science》1971,34(1):6-17

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URBAN GEOGRAPHY WITHOUT A REGIONAL SYSTEM     

Lutz Holzner 《The Professional geographer》1966,18(3):129-131

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Identification and Modelling of Translational and Axial Symmetries and their Hierarchical Structures in Building Footprints by Formal Grammars          下载免费PDF全文

Youness Dehbi  Gerhard Gröger  Lutz Plümer 《Transactions in GIS》2016,20(5):645-663

Buildings and other man‐made objects, for many reasons such as economical or aesthetic, are often characterized by their symmetry. The latter predominates in the design of building footprints and building parts such as façades. Thus the identification and modeling of this valuable information facilitates the reconstruction of these buildings and their parts. This article presents a novel approach for the automatic identification and modelling of symmetries and their hierarchical structures in building footprints, providing an important prior for façade and roof reconstruction. The uncertainty of symmetries is explicitly addressed using supervised machine learning methods, in particular Support Vector Machines (SVMs). Unlike classical statistical methods, for SVMs assumptions on the a priori distribution of the data are not required. Both axial and translational symmetries are detected. The quality of the identified major and minor symmetry axes is assessed by a least squares based adjustment. Context‐free formal grammar rules are used to model the hierarchical and repetitive structure of the underlying footprints. We present an algorithm which derives grammar rules based on the previously acquired symmetry information and using lexical analysis describing regular patterns and palindrome‐like structures. This offers insights into the latent structures of building footprints and therefore describes the associated façade in a relational and compact way.  相似文献   

Semiempirical band structure calculations on skutterudite-type compounds     

M. Partik  H. D. Lutz 《Physics and Chemistry of Minerals》1999,27(1):41-46

Semiempirical band structure calculations were performed on several skutterudite-type compounds by using the extended Hückel method. Starting with the molecular orbital calculations on isolated P₄ and As₄ rings, the reason for the band dispersions of the skutterudites was found to be the interactions between the nonmetal atoms. Both the intermolecular and the intramolecular interactions between the phosphorus atoms are stronger than those between the arsenic atoms. Hence, the dispersion of the bands in CoP₃ is larger than that in CoAs₃. The COOP (crystal orbital overlap population) integrals of the intramolecular P-P bonds reveal the relation between the valence electron count and the observed bond lengths. The P-P bonds in the skutterudite-type compounds like TP₃ (T = Co, Rh, Ir) become stronger by reduction as in NiP₃ and weaker by oxidation as in RT₄X₁₂ (X = P, As, Sb; R = alkaline earth or rare earth metals) because the bands near the Fermi level are bonding. The electronic reason for the geometric distortion of the Ge₂Y₂ (Y = S, Se) units of mixed skutterudites TGe_1.5Y_1.5 is caused by an electron pair gap on germanium, which corresponds to low electron density perpendicular to the ring plane on the germanium atoms. Received: 6 October 1998 / Revised, accepted: 18 June 1999  相似文献   

Climate change impacts on runoff in the Ferghana Valley (Central Asia)     

Iuliia Radchenko  Yvonne Dernedde  Birgit Mannig  Hans-Georg Frede  Lutz Breuer 《Water Resources》2017,44(5):707-730

The main freshwater source of arid/semi-arid Central Asia is stored in its high mountain glaciers. Water for the downstream countries is mainly supplied through the Syrdarya River that originates at the confluence of the Naryn and Karadarya rivers in the Ferghana Valley. Runoff generation from glaciers plays a crucial role, although a considerable number of small tributaries supply the river with additional runoff from snowmelt and rain in the mountains surrounding the Ferghana Valley. Observations of rising air temperature and accelerated glacier shrinkage make it most likely that the relative contributions of the smaller tributaries will increase. Hitherto, assessments of climate change effects on the water resource availability have largely neglected the growing importance of the runoff from smaller tributaries. We used a dynamically downscaled A1B SRES scenario for climate change effects for the period 2071–2100 in relation to the reference period of 1971–2000 and a version of the conceptual hydrological Hydrologiska Byråns Vattenavdelning model (HBV-light) to estimate runoff contributions with particular respect to the small tributaries. The simulations showed a 12–42% decrease in summer runoff; and a 44–107% increase in winter-spring runoff. This indicates the hydrological regime is shifting towards a runoff from snowmelt earlier in the year. The study suggests that actions for climate change adaptation should be complemented by land management configured to secure optimal runoff supplement from the smaller catchments.  相似文献