Reassignment of the absorption spectra of purple yoderite     

K. Langer  G. Smith  U. Hålenius 《Physics and Chemistry of Minerals》1982,8(3):143-145

Polarized spectra E∥X, E∥Y, and E∥Z of purple yoderite, taken at 295 and 100 K, result in a revised interpretation for the mineral. Major bands at around 16,900 (X>Y?Z), 18,600 (X?Y), and 20,600 cm^?1 (X≈Z>Y) may be attributed to spin-allowed transitions of Mn³⁺ in trigonal bipyramids (A2 or A3). Minor features may be assigned to single ion Fe³⁺. However, charge transfer possibilities for bands at 18,600 and 25,500 cm^?1 in yoderite cannot be ruled out and are discussed. The extremely high intensity of Mn³⁺ spin-allowed bands (?, 216 to 1,900 [1·g-atom^?1·cm^?1]) is attributed to fivefold coordination of the A2 and A3 position and to the covalency of the Mn³⁺-O bonds.  相似文献   

Aromatic components of coal: relation of distribution pattern to rank     

Matthias Radke  Helmut Willsch  Detlev Leythaeuser  Marlies Teichmüller 《Geochimica et cosmochimica acta》1982,46(10):1831-1848

Aromatic distribution patterns have been evaluated for a series of twenty-four German high volatile bituminous B to low volatile bituminous coals of Upper Carboniferous Westphalian C-, B- and A-ages using high performance liquid chromatography and glass capillary gas chromatography. The study concentrates on dicyclic and tricyclic aromatic hydrocarbons most of which have been identified by combined gas chromatography-mass spectrometry. The distribution patterns of the methylhomologs of naphthalene and phenanthrene are strongly controlled by rank. A sudden increase of individual isomer ratios at 0.9% Rm coincides with an abrupt shift of the sporinite fluorescence colour from yellow towards red. A recently developed aromatics-derived maturity parameter, the Methylphenanthrene Index (MPI), correlated well with the vitrinite reflectance data over the whole rank range. Deviations have been attributed to variations of maceral composition or migration phenomena. The influence of artificial thermal alteration (350 and 400dgC) on the aromatic distribution pattern of coal is described.  相似文献   

Evaluation of an urban land surface scheme over a tropical suburban neighborhood     

Suraj?HarshanEmail author  Matthias?Roth  Erik?Velasco  Matthias?Demuzere 《Theoretical and Applied Climatology》2018,132(3-4):867-883

A two-step statistical downscaling method has been reviewed and adapted to simulate twenty-first-century climate projections for the Gulf of Fonseca (Central America, Pacific Coast) using Coupled Model Intercomparison Project (CMIP5) climate models. The downscaling methodology is adjusted after looking for good predictor fields for this area (where the geostrophic approximation fails and the real wind fields are the most applicable). The method’s performance for daily precipitation and maximum and minimum temperature is analysed and revealed suitable results for all variables. For instance, the method is able to simulate the characteristic cycle of the wet season for this area, which includes a mid-summer drought between two peaks. Future projections show a gradual temperature increase throughout the twenty-first century and a change in the features of the wet season (the first peak and mid-summer rainfall being reduced relative to the second peak, earlier onset of the wet season and a broader second peak).  相似文献   

Extension of the Averaging Time in Eddy-Covariance Measurements and Its Effect on the Energy Balance Closure   总被引：1，自引：0，他引：1  

Doojdao Charuchittipan  Wolfgang Babel  Matthias Mauder  Jens-Peter Leps  Thomas Foken 《Boundary-Layer Meteorology》2014,152(3):303-327

The modified ogive analysis and the block ensemble average were employed to investigate the impact of the averaging time extension on the energy balance closure over six land-use types. The modified ogive analysis, which requires a steady-state condition, can extend the averaging time up to a few hours and suggests that an averaging time of 30 min is still overall sufficient for eddy-covariance measurements over low vegetation. The block ensemble average, which does not require a steady-state condition, can extend the averaging time to several days. However, it can improve the energy balance closure for some sites during specific periods, when secondary circulations exist in the vicinity of the sensor. These near-surface secondary circulations mainly transport sensible heat, and when near-ground warm air is transported upward, the sensible heat flux observed by the block ensemble average will increase at longer averaging times. These findings suggest an alternative energy balance correction for a ground-based eddy-covariance measurement, in which the attribution of the residual depends on the ratio of sensible heat flux to the buoyancy flux. The fraction of the residual attributed to the sensible heat flux by this energy balance correction is larger than in the energy balance correction that preserves the Bowen ratio.  相似文献   

Analysis of change in relative uncertainty in GHG emissions from stationary sources for the EU 15     

Myroslava Lesiv  Andriy Bun  Matthias Jonas 《Climatic change》2014,124(3):505-518

Total uncertainty in greenhouse gas (GHG) emissions changes over time due to “learning” and structural changes in GHG emissions. Understanding the uncertainty in GHG emissions over time is very important to better communicate uncertainty and to improve the setting of emission targets in the future. This is a diagnostic study divided into two parts. The first part analyses the historical change in the total uncertainty of CO₂ emissions from stationary sources that the member states estimate annually in their national inventory reports. The second part presents examples of changes in total uncertainty due to structural changes in GHG emissions considering the GAINS (Greenhouse Gas and Air Pollution Interactions and Synergies) emissions scenarios that are consistent with the EU’s “20-20-20” targets. The estimates of total uncertainty for the year 2020 are made under assumptions that relative uncertainties of GHG emissions by sector do not change in time, and with possible future uncertainty reductions for non-CO₂ emissions, which are characterized by high relative uncertainty. This diagnostic exercise shows that a driving factor of change in total uncertainty is increased knowledge of inventory processes in the past and prospective future. However, for individual countries and longer periods, structural changes in emissions could significantly influence the total uncertainty in relative terms.  相似文献   

Uncertainty in an emissions-constrained world     

Matthias Jonas  Gregg Marland  Volker Krey  Fabian Wagner  Zbigniew Nahorski 《Climatic change》2014,124(3):459-476

Our study focuses on uncertainty in greenhouse gas (GHG) emissions from anthropogenic sources, including land use and land-use change activities. We aim to understand the relevance of diagnostic (retrospective) and prognostic (prospective) uncertainty in an emissions-temperature setting that seeks to constrain global warming and to link uncertainty consistently across temporal scales. We discuss diagnostic and prognostic uncertainty in a systems setting that allows any country to understand its national and near-term mitigation and adaptation efforts in a globally consistent and long-term context. Cumulative emissions are not only constrained and globally binding but exhibit quantitative uncertainty; and whether or not compliance with an agreed temperature target will be achieved is also uncertain. To facilitate discussions, we focus on two countries, the USA and China. While our study addresses whether or not future increase in global temperature can be kept below 2, 3, or 4 °C targets, its primary aim is to use those targets to demonstrate the relevance of both diagnostic and prognostic uncertainty. We show how to combine diagnostic and prognostic uncertainty to take more educated (precautionary) decisions for reducing emissions toward an agreed temperature target; and how to perceive combined diagnostic and prognostic uncertainty-related risk. Diagnostic uncertainty is the uncertainty contained in inventoried emission estimates and relates to the risk that true GHG emissions are greater than inventoried emission estimates reported in a specified year; prognostic uncertainty refers to cumulative emissions between a start year and a future target year, and relates to the risk that an agreed temperature target is exceeded.  相似文献   

Near-Surface Motion in the Nocturnal,Stable Boundary Layer Observed with Fibre-Optic Distributed Temperature Sensing   总被引：1，自引：1，他引：0  

Matthias J. Zeeman  John S. Selker  Christoph K. Thomas 《Boundary-Layer Meteorology》2015,154(2):189-205

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Scenarios for vulnerability: opportunities and constraints in the context of climate change and disaster risk     

Joern Birkmann  Susan L. Cutter  Dale S. Rothman  Torsten Welle  Matthias Garschagen  Bas van Ruijven  Brian O’Neill  Benjamin L. Preston  Stefan Kienberger  Omar D. Cardona  Tiodora Siagian  Deny Hidayati  Neysa Setiadi  Claudia R. Binder  Barry Hughes  Roger Pulwarty 《Climatic change》2015,133(1):53-68

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A new velocity field from the analysis of the Egyptian Permanent GPS Network (EPGN)   总被引：1，自引：0，他引：1  

Mohamed Saleh  Matthias Becker 《Arabian Journal of Geosciences》2014,7(11):4665-4682

For studying recent crustal movements and their relation to earthquake occurrence in large scales, the National Research Institute of Astronomy and Geophysics (NRIAG), Helwan, Cairo, Egypt started in 2006 the establishment of the Egyptian Permanent GPS Network (EPGN). Beginning with 4 stations in 2007, 15 stations were operational at the end of 2011. In addition, a station in Alexandria of the French “Centre d'Études Alexandrines” (CEALX) was added as station to the EPGN. Nowadays, 16 stations are operational and an extension to 20 in the near future is expected. The collected EPGN data of the last 6 years are used in this work to throw light upon the present state of recent crustal movement of the whole of Egypt. Bernese software V. 5.0 was used for processing the collected data according to the IGS standards. In addition, selected IGS, AFREF, and EPN sites are processed for reference frame definition. In this first comprehensive analysis of the permanent network, a complete and consistent evaluation resulted in the first estimates of present day horizontal velocities and coordinate time series.  相似文献   

Overview on the middle to upper Jurassic sedimentary succession of Gangta Bet in the Kachchh basin,western India,with special emphasis on its lithostratigraphy,biostratigraphy, and palaeoenvironment   总被引：1，自引：0，他引：1  

Matthias Alberti  Franz T. Fürsich  Dhirendra K. Pandey  Debahuti Mukherjee 《Journal of the Geological Society of India》2017,89(3):259-270

The Jurassic succession of Gangta Bet in the Kachchh basin of western India comprises around 130 m of mostly siliciclastic rocks. The strata belong to the Gangta Member of the Gadhada Formation and are herein sub-divided into four units: the Gangta sandstone beds, the lower silty sandstone beds, the upper silty sandstone beds, and the Gangta ammonite beds. These units can be separated by three marker horizons: the Brachiopod bed, the Gangta Conglomerate Bed, and the Gervillella Bed. Ammonites indicate an Oxfordian age for the upper half of the succession, but the scarcity of identifiable fossils in its basal part so far prevented precise biostratigraphic assignments. The shallow-water sediments can be interpreted as parasequences as a result of minor sea-level changes. Deposition took place close to the palaeo-coastline at water depths around the fair-weather wave-base.  相似文献