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991.
992.
Ca2+ signaling in the dyadic cleft in ventricular myocytes is fundamentally discrete and stochastic. In this paper we study the stochastic binding of single Ca2+ ions to receptors in the cleft using two different models of diffusion; a stochastic and discrete Random walk (RW) model, and a deterministic continuous model. We investigate if the latter model, together with a stochastic receptor model, can reproduce binding events registered in fully stochastic RW simulations. By evaluating the continuous model goodness-of-fit, we present evidences that it can. The large fluctuations in binding rate observed at the time level of single time steps are integrated and smoothed at the larger time scale of binding events, explaining the continuous model goodness-of-fit. With this we demonstrate that the stochasticity and discreteness of the Ca2+ signaling in the dyadic cleft, determined by single binding events, can be described with a deterministic model of Ca2+ diffusion together with a stochastic model of the binding events. Time consuming RW simulations can thus be avoided. We also present a new analytical model of bi-molecular binding probabilities that is used in the RW simulations, and in the statistical analysis. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
993.
Rüdiger Schultz 《Annals of Operations Research》2000,100(1-4):55-84
Some developments in structure and stability of stochastic programs during the last decade together with interrelations to optimization theory and stochastics are reviewed. With weak convergence of probability measures as a backbone we discuss qualitative and quantitative stability of recourse models that possibly involve integer variables. We sketch stability in chance constrained stochastic programming and provide some applications in statistical estimation. Finally, an outlook is devoted to issues that were not discussed in detail and to some open problems. 相似文献
994.
Dr. Sambhu Radhakrishnan Dr. Karl Lauwers Dr. C. Vinod Chandran Dr. Julien Trébosc Dr. Sreeprasanth Pulinthanathu Sree Prof. Johan A. Martens Prof. Francis Taulelle Prof. Christine E. A. Kirschhock Dr. Eric Breynaert 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(64):15944-15953
Layered double hydroxides (LDHs) serve a score of applications in catalysis, drug delivery, and environmental remediation. Smarter crystallography, combining X-ray diffraction and NMR spectroscopy revealed how interplay between carbonate and pH determines the LDH structure and Al ordering in ZnAl LDH. Carbonate intercalated ZnAl LDHs were synthesized at different pH (pH 8.5, pH 10.0, pH 12.5) with a Zn/Al ratio of 2, without subsequent hydrothermal treatment to avoid extensive recrystallisation. In ideal configuration, all Al cations should be part of the LDH and be coordinated with 6 Zn atoms, but NMR revealed two different Al local environments were present in all samples in a ratio dependent on synthesis pH. NMR-crystallography, integrating NMR spectroscopy and X-ray diffraction, succeeded to identify them as Al residing in the highly ordered crystalline phase, next to Al in disordered material. With increasing synthesis pH, crystallinity increased, and the side phase fraction decreased. Using 1H−13C, 13C−27Al HETCOR NMR in combination with 27Al MQMAS, 27Al-DQ-SQ measurements and Rietveld refinement on high-resolution PXRD data, the extreme anion exchange selectivity of these LDHs for CO32− over HCO3− was linked to strict Al and CO32−ordering in the crystalline LDH. Even upon equilibration of the LDH in pure NaHCO3 solutions, only CO32− was adsorbed by the LDH. This reveals the structure directing role of bivalent cations such as CO32− during crystallization of [M2+4M3+2(OH)2]2+[A2−]1⋅yH2O LDH phases. 相似文献
995.
Wendel Johan Manchili Swathi K. Hryha Eduard Nyborg Lars 《Journal of Thermal Analysis and Calorimetry》2020,140(1):309-319
Journal of Thermal Analysis and Calorimetry - The purpose of the present work is to investigate humidification–dehumidification desalination system and to explore the effect of pertinent... 相似文献
996.
997.
R. M. Spearrin C. S. Goldenstein I. A. Schultz J. B. Jeffries R. K. Hanson 《Applied physics. B, Lasers and optics》2014,117(2):689-698
A mid-infrared laser absorption sensor was developed for gas temperature and carbon oxide (CO, CO2) concentrations in high-enthalpy, hydrocarbon combustion flows. This diagnostic enables non-intrusive, in situ measurements in harsh environments produced by hypersonic propulsion ground test facilities. The sensing system utilizes tunable quantum cascade lasers capable of probing the fundamental mid-infrared absorption bands of CO and CO2 in the 4–5 µm wavelength domain. A scanned-wavelength direct absorption technique was employed with two lasers, one dedicated to each species, free-space fiber-coupled using a bifurcated hollow-core fiber for remote light delivery on a single line of sight. Scanned-wavelength modulation spectroscopy with second-harmonic detection was utilized to extend the dynamic range of the CO measurement. The diagnostic was field-tested on a direct-connect scramjet combustor for ethylene–air combustion. Simultaneous, laser-based measurements of carbon monoxide and carbon dioxide provide a basis for evaluating combustion completion or efficiency with temporal and spatial resolution in practical hydrocarbon-fueled engines. 相似文献
998.
Tayfun Hüyük Antonio Di Nitto Grzegorz Jaworski Andrés Gadea José Javier Valiente-Dobón Johan Nyberg Marcin Palacz Pär-Anders Söderström Ramon Jose Aliaga-Varea Giacomo de Angelis Ayşe Ataç Javier Collado Cesar Domingo-Pardo Francisco Javier Egea Nizamettin Erduran Sefa Ertürk Gilles de France Rafael Gadea Vicente González Vicente Herrero-Bosch Ayşe Kaşkaş Victor Modamio Marek Moszynski Enrique Sanchis Andrea Triossi Robert Wadsworth 《The European Physical Journal A - Hadrons and Nuclei》2016,52(3):55
999.
Journal of Solution Chemistry - 相似文献