Search results for "inho"
showing 10 items of 132 documents
QUANTITATIVE CONVERGENCE RATES FOR SUBGEOMETRIC MARKOV CHAINS
2015
We provide explicit expressions for the constants involved in the characterisation of ergodicity of subgeometric Markov chains. The constants are determined in terms of those appearing in the assumed drift and one-step minorisation conditions. The results are fundamental for the study of some algorithms where uniform bounds for these constants are needed for a family of Markov kernels. Our results accommodate also some classes of inhomogeneous chains.
Dracocephalum ruyschiana L. (Svētezers, Livlande)
2020
Nordischer Drachenkopf. Karl Reinhold Kupffer Anmerkung: Von Herr Raudsep erhalten als bei Heiligensee in Livland gesamellt. Ende des 19., Anfang des 20. Jahrhunderts. /// Ruiša pūķgalve. Uzraksts: no Raudsepa kunga saņemts kā pie Svētezera Livlandē ievākts. 19.gadsimta beigas, 20. gadsimta sākums. /// Northern Dragon-head. Annotation: received from Mr. Raudsepp as collected at Svētezers in Livland.Late 19th century, early 20th century. [Attēls no LU Muzeja kolekcijas Herbarium Balticum (RIG I); (BOT2791_5).]
On new ways of group methods for reduction of evolution-type equations
2005
AbstractNew exact solutions of the evolution-type equations are constructed by means of a non-point (contact) symmetries. Also we analyzed the discrete symmetries of Maxwell equations in vacuum and decoupled ones to the four independent equations that can be solved independently.
Effect of RF Field Inhomogeneity and Sample Restriction on Spectral Resolution of CP/MAS-13C NMR Spectra of Natural Organic Matter
2010
It is well known that the induced B1 magnetic field in an NMR coil is inhomogeneously distributed. However, this issue has so far received little attention in the field of environmental NMR. As this research field often aims at quanti- tative results as well as relaxation phenomena, the repercussions of such inhomogeneity on peak integrals and relaxation times need to be taken into account. The objective of the present study was to test standard recording conditions on different sample positions in an NMR coil in order to determine the effect of the RF field inhomogeneity on the spectrum of a molecularly complex humic material and on some standard molecules of known structure and conformati…
Optical sectioning by two-pinhole confocal fluorescence microscopy.
2003
A two-pinhole axially superresolving confocal fluorescence imaging system is presented. Based on the concept of subtractive incoherent imaging, the system described here is equipped with a zero-focus complex-transmittance pupil filter in one of the collector paths. The optical sectioning capacity of the system is 25% superior to that of a free-pupil one-pinhole instrument.
Pinhole Zone Plate Lens for Ultrasound Focusing
2017
[EN] The focusing capabilities of a pinhole zone plate lens are presented and compared with those of a conventional Fresnel zone plate lens. The focusing properties are examined both experimentally and numerically. The results confirm that a pinhole zone plate lens can be an alternative to a Fresnel lens. A smooth filtering effect is created in pinhole zone plate lenses, giving rise to a reduction of the side lobes around the principal focus associated with the conventional Fresnel zone plate lens. The manufacturing technique of the pinhole zone plate lens allows the designing and constructing of lenses for different focal lengths quickly and economically and without the need to drill new p…
Brief an Garlieb H. Merkel
1798
Ms. 930a, Nr. 10, Bl. 26r-28v Schmidt-Phiseldeck, Konrad von. Brief an Garlieb H. Merkel, Kopenhagen, am 6. März 1798 Autora rokraksts / Autograph, vācu un latīņu val. / Deutsch und Latein [6] lpp. / S. Attēlu numuri / Bildnummern: 930a-010-1 – 930a-010-6 Der Verfasser äußert zum Beginn seines Briefes erneut sein Bedauern über die räumliche Trennung und wünscht sich, nach Italien zu reisen. Weimar, wo Merkel zum gegebenen Zeitpunkt wahrscheinlich weilte, glorifiziert Schmidt-Phiseldeck mit der Bezeichnung als „Weimar-Athen“. Gleichzeitig drückt der Verfasser seine Enttäuschung über die Politik Frankreichs bezüglich der Schweiz aus, erkennt aber in der Neutralität seiner neuen Heimat Dänemar…
Spatio-temporal cluster detection of chickenpox in Valencia, Spain in the period 2008-2012.
2015
Chickenpox is a highly contagious airborne disease caused by <em>Varicella zoster</em>, which affects nearly all non-immune children worldwide with an annual incidence estimated at 80-90 million cases. To analyze the spatiotemporal pattern of the chickenpox incidence in the city of Valencia, Spain two complementary statistical approaches were used. First, we evaluated the existence of clusters and spatio-temporal interaction; secondly, we used this information to find the locations of the spatio-temporal clusters via the space-time permutation model. The first method used detects any aggregation in our data but does not provide the spatial and temporal information. The second me…
Cosmological Constant and Local Gravity
2010
We discuss the linearization of Einstein equations in the presence of a cosmological constant, by expanding the solution for the metric around a flat Minkowski space-time. We demonstrate that one can find consistent solutions to the linearized set of equations for the metric perturbations, in the Lorentz gauge, which are not spherically symmetric, but they rather exhibit a cylindrical symmetry. We find that the components of the gravitational field satisfying the appropriate Poisson equations have the property of ensuring that a scalar potential can be constructed, in which both contributions, from ordinary matter and Lambda > 0, are attractive. In addition, there is a novel tensor potentia…
Vibrational Signature of Water Molecules in Asymmetric Hydrogen Bonding Environments
2013
The O–H stretching vibrational modes of water molecules are sensitive to their local environments. Here, we applied effective normal-mode analysis to isolate contributions of each of the two hydrogen atoms to the vibrational modes ν1 and ν3 of water molecules in the liquid phase. We demonstrate that the decoupling of the two contributions fd and the frequency splitting of the vibrational modes Δω13 are inextricably related to the symmetry of the hydrogen bonding environment. We show that ambient liquid water modeled at the density functional level of theory exhibits the characteristics of an asymmetric environment with an average decoupling of 0.82 and a splitting of 137 inverse centimeters…