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  • 1
    Publikationsdatum: 2023-07-19
    Beschreibung: Raman spectroscopy has been widely used in mineralogy and petrology for identifying mineral phases. Some recent applications of Raman spectroscopy involve measuring the residual pressure of mineral inclusions, such as quartz inclusions in garnet host, to recover the entrapment pressure condition during metamorphism. The crystallographic orientations of entrapped inclusions and host are important to know for the modelling of their elastic interaction. However, the analysis of tiny entrapped mineral inclusions using EBSD technique requires time consuming polishing. The crystallographic orientations can be measured using polarized Raman spectroscopy, as the intensities of Raman bands depend on the mutual orientation between the polarization direction of the laser and the crystallographic orientation of the crystal. In this study, the Raman polarizability tensor of quartz is first obtained and is used to fit arbitrary orientations of quartz grains. We have implemented two rotation methods: (1) sample rotation method, where the sample is rotated on a rotation stage, and (2) polarizer rotation method, where the polarization directions of the incident laser and the scattered Raman signal are parallel and can be rotated using a circular polarizer. The precision of the measured crystallographic orientation is systematically studied and is shown to be ca. 0.25 degrees using quartz wafers and quartz plates that are cut along known orientations. It is shown that the orientation of tiny mineral inclusions (ca. 2–5 μm) can be precisely determined and yield consistent results with EBSD.
    Beschreibung: Alexander von Humboldt-Stiftung http://dx.doi.org/10.13039/100005156
    Beschreibung: Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/501100001659
    Beschreibung: Freie Universität Berlin (1008)
    Schlagwort(e): ddc:548 ; Raman spectroscopy ; Elastic thermobarometry ; Crystallographic orientation ; Quartz ; Inclusion
    Sprache: Englisch
    Materialart: doc-type:article
    Standort Signatur Erwartet Verfügbarkeit
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  • 2
    Publikationsdatum: 2022-06-24
    Beschreibung: We investigate the chemical budget of subduction zones at sub‐solidus conditions using a thermodynamic‐numerical simulation in which all major rock components are treated as soluble and potentially mobile in aqueous fluids. This new strategy significantly improves the accuracy of predicted fluid‐rock equilibrium compositions in open petrological systems. We show that all slabs release volatiles and nonvolatiles to the mantle wedge, contributing to its refertilization. But some mobile constituents, such as alkali and alumina, may be trapped along layer boundaries or traverse without interaction depending on chemical contrasts between adjacent lithologies. The accumulation of igneous alumina and silica in the limestones of the central‐eastern Pacific slabs drives their decarbonation and is marked by metasomatic garnet growth. Those slabs are also predicted to lose much of their alkalis before sub‐arc depth. Even when they are produced in the altered mafic and ultramafic layers, fluids reach the slab/mantle wedge interface with distinct compositional signatures that are typical of the sedimentary cover. We distinguished supply and transport limited regimes of element subduction by testing the sensitivity of our mass balance to changes in slab hydration state (HS). Transport limited slabs sensitive to HS include notably a hotspot of carbon release to the mantle wedge (e.g., Costa Rica). Finally, we show that the quantitative budgets do depend on the geometry of fluid flows, and on assuming that slabs are mechanically continuous structures, which is questionable. Taken together, these insights will help better constrain the long‐term chemical evolution of the shallow planetary interior, and the thermomechanical behavior of the subduction interface.
    Beschreibung: Plain Language Summary: Subduction zones return chemical elements from the surface to the deep Earth. But quantifying this transfer has been challenging. Here, we present a model where all major elements are partly mobile in the fluid phase, enabling us to compile a chemical budget for subduction zones in which only fluids mediate mass transport. We identify transport and supply regimes of element subduction as a function of lithospheric hydration state, rock compositions, and slab temperature. We show that the transport of many rock‐forming elements such as SiO2, CaO, and Al2O3, within and out of the slab, modifies rock composition and contributes to the efficiency of slab decarbonation. Our model of subduction fluid and rock compositions has important implications to understand the role of slab‐derived metasomatic fluid in modifying the composition of the mantle wedge over time, the mechanical properties of deeply subducted rocks, and it will inform future investigations for the high‐pressure petrology of rocky planets in general.
    Beschreibung: Key Points. Inter dependence of element transfers in subduction zones. Thermodynamics of intra‐slab metasomatism of major elements. Transport‐ and supply limited regimes of carbonate subduction.
    Beschreibung: Alexander von Humboldt‐Stiftung (Humboldt‐Stiftung) http://dx.doi.org/10.13039/100005156
    Beschreibung: Branco Weiss Fellowship—Society in Science
    Beschreibung: Swiss National Science Foundation
    Beschreibung: https://osf.io/y84d2/
    Schlagwort(e): ddc:551
    Sprache: Englisch
    Materialart: doc-type:article
    Standort Signatur Erwartet Verfügbarkeit
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  • 3
    Digitale Medien
    Digitale Medien
    s.l. ; Stafa-Zurich, Switzerland
    Advances in science and technology Vol. 55 (Sept. 2008), p. 84-90 
    ISSN: 1662-0356
    Quelle: Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
    Thema: Allgemeine Naturwissenschaft , Technik allgemein
    Notizen: A highly sensitive method for detecting oligonucleotide targets has been developed usingquantum dot (QD) functionalized nanotubes (NTs) that contain a cascade energy band-gaparchitecture. Their assembly with different types of QDs by the layer-by-layer (LBL) allowed forthe formation of fluorescence resonance energy transfer (FRET) structures in the NTs resulting inan enhanced fluorescence emission from dye labeled oligonucleotide targets captured by probeDNA through hybridization. This approach results in a significant enhancement of detection of dyelabeled oligonucleotide targets. The promising increase in detection sensitivity allows for lowdetection limits by tuning the QD emission, adding other types of QDs, or adjusting the distancebetween all photoactive compounds in the NTs. Hence, the strategy used here to produce newhybrid materials may pave a way for broadening application of NTs in the field of biochemicalmaterials, e.g. sensitive biosensors
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 4
    Digitale Medien
    Digitale Medien
    Springer
    Acta mechanica solida Sinica 3 (1990), S. 263-276 
    ISSN: 0894-9166
    Schlagwort(e): elastic-plastic fracture ; three dimensional stress field ; transition layer ; crack tip opening displacement CTOD
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Maschinenbau , Physik
    Notizen: Abstract In this paper, the stress and strain structures of Mode I 3-D crack in power hardening material are studied by analyzing the fundamental equations of elastic-plastic mechanics. It is shown that three regions, Z1,Z2 and Z3 can be divided in the thickness direction according to the stress characteristic. In region Z1, the stress components in the plane Perpendicular to z axis (thickness direction) can be solved first using the fundamental equations of plane strain state; in region Z3, they can be solved first by the equations of plane stress state. The region Z2 is defined as a transition layer. It is shown that the transition layer is the characteristic of Mode I 3-D crack in elastic-plastic state, and it is significant to the research on 3-D fracture. The crack tip opening displacement CTOD is chosen to describe the amplitude coefficient of the local stress field, and the distribution of CTOD in 3-D state is investigated.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 5
    ISSN: 1476-4687
    Quelle: Nature Archives 1869 - 2009
    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Notizen: [Auszug] Reversed critical wide angle reflection profiles of the crust–mantle boundary south of the Yarlung Zangbo suture in Tibet reveal a deep (70 km) Moho extending north from the High Himalayas, whilst to the south the Moho is 15 km higher. Even further south, reflections from 35 km depth may ...
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 6
    ISSN: 1573-1561
    Schlagwort(e): Insect sex pheromone ; mulberry clearwing moth ; Lepidoptera ; Sesiidae ; Paradoxecia pieli L. (E,Z)-3,13-octadecadien-yl acetate ; (E,Z)-3,13-octadecadien-1-ol ; single cell recording ; EAG
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract (E,Z)-3,13-OctadecadienyI acetate (1a) and (E,Z)-3,13-octadecadien-1-ol(2a) were identified from the sex pheromone gland of the virgin female mulberry clearwing mothParadoxecia pieli L., by GC analysis, EAG, SCR survey, and field bioassay. One female equivalent contained 250 ng of1a and 30 ng of2a. In the field tests, 100μg of synthetic1a was attractive to male moths of the species.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 7
    Digitale Medien
    Digitale Medien
    Springer
    Applied mathematics and mechanics 14 (1993), S. 677-683 
    ISSN: 1573-2754
    Schlagwort(e): moving boundary ; elastic wave problem ; excitation of wave ; exploding wave
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Maschinenbau , Mathematik , Physik
    Notizen: Abstract In this paper we have given an analytic excitation solution of exploding wave in infinite elastic body with growing spherical inner boundary, and the convergence region of series in this solution determined. Some characters of the displacement wave have also been discussed.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 8
    Digitale Medien
    Digitale Medien
    Springer
    Applied mathematics and mechanics 9 (1988), S. 603-610 
    ISSN: 1573-2754
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Maschinenbau , Mathematik , Physik
    Notizen: Abstract The stresses and strains are calculated for CT specimen of power hardening material in 3-D deformation state using ADINA finite element program, and the stress distribution at the vicinity of crack tip for Mode I fracture is analysed according to the results of calculation. It is found that the expression of stress can be written as the form of separation of variables of r and θ, then the function of r can be expanded in Laurant series. It is still found that the three normal stresses have the same order of magnitude. The conclusions offer two suppositions to obtain the theoretical expression of stress at the vinicity of crack tip for Mode I fracture with good ground, and the procedure of solution will be greatly simplified.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 9
    ISSN: 1040-0397
    Schlagwort(e): Reductive potentiometric stripping analysis ; Lead ; Potassium ferrocyanide ; Glassy carbon electrode ; Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Reductive potentiometric stripping analysis (RPSA), with potassium ferrocyanide as the reducing agent on a glassy carbon electrode, is applied for the determination of lead over the range 2 × 10-8-5 × 10-6 M. The relative standard deviation of 2 × 10-6 M lead for ten consecutive measurements is 2.5%. This technique has been used to determine the minute amount of lead in a human hair sample solution.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 10
    Publikationsdatum: 1983
    Schlagwort(e): Refraction seismics ; China ; CRUST ; earth mantle
    Standort Signatur Erwartet Verfügbarkeit
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