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991.
992.
Dasha Medvedeva Alexey Bobrovsky Natalia Boiko Valery Shibaev Igor Zavarzin Marina Kalik Mikhail Krayushkin 《Macromolecular rapid communications》2005,26(3):177-182
Summary: The phase behavior and optical properties of a cholesteric ternary copolymer, containing nematogenic phenylbenzoate, cholesteric, and photochromic diarylethene side groups, and its mixture with 2 wt.‐% fluorescent dopant were studied. The investigation of the kinetics of a photochemical opening‐cycle process of the photochromic groups in the cholesteric mixture proved the energy transfer from the fluorescent dopant to the photochromic diarylethene groups. It was shown that the fluorescence intensity of the fluorescent dopant could be controlled by the portion of the “closed” form of the diarylethene groups. During the photocyclization of the photochromic groups a “degeneration” of the selective light reflection of the cholesteric matrix is observed.
993.
Ming Song Th. U. Probst Natalia G. Berryman 《Analytical and bioanalytical chemistry》2001,370(6):744-751
An electrothermal vaporization-inductively coupled plasma-mass spectrometric (ETV-ICP-MS) method based on selective volatilization of cesium with KSCN as modifier has been developed for determination of radiocesium, i.e. 135Cs and 137Cs, in the presence of isobaric barium. A 10000 times excess of barium, which was volatilized at a temperature of 1100?°C, resulted only in a 1% signal increase in the signal of mass 135 amu. The recommended concentration of KSCN is 0.3 mM, and pretreatment and volatilization temperatures are 400?°C and 1100?°C, respectively. A ramp time of 1 s is recommeded for the volatilization step. The achieved limit of detection for 135Cs is 0.2 pg/mL (10 μBq/mL) and 4 fg (0.2 μBq) absolute for a sample volume of 20 μL. This means a limit of detection for 137Cs of 0.2 pg/mL (0.6 Bq/mL) and of 4 fg (0.01 Bq) absolute. Signal variations of 135Cs and 137Cs, respectively, in spiked samples with various matrices were investigated. 相似文献
994.
The 266nm photolysis products of 4,4′-bipyridine in cyclohexane, acetonitrile, methanol, hexafluoro-propanol and H2O/HCl solutions have been investigated by time-resolved Raman spectroscopy in the nanosecond time scale. The identification of some photochemical transients and the characterization of their structure and electronic configuration are discussed. 相似文献
995.
Prof. Dr. Natalia L. Klyachko Dr. Marina Sokolsky‐Papkov Nikorn Pothayee Maria V. Efremova Dr. Dmitry A. Gulin Nipon Pothayee Artem A. Kuznetsov Dr. Alexander G. Majouga Prof. Judy S. Riffle Prof. Dr. Yuri I. Golovin Prof. Dr. Alexander V. Kabanov 《Angewandte Chemie (International ed. in English)》2012,51(48):12016-12019
996.
997.
Natalia Shevchenko Stefan Boden Sven Eckert Dmitry Borin Michael Heinze Stefan Odenbach 《The European physical journal. Special topics》2013,220(1):63-77
X-ray attenuation techniques are an important diagnostic tool for investigating liquid metal two-phase flows or solidification studies in metallic alloys. X-ray visualization enables a general, intuitive understanding of flow phenomena or pattern formation in opaque liquid metal systems. Real-time and in-situ observations of the density distribution within thin solidifying samples achieve a spatial resolution of a few microns and contribute significantly to an improved understanding of dendritic growth processes. Moreover, X-ray radioscopy is a useful tool for a non-invasive, in-situ visualization and characterization of gas bubbles in nontransparent melts or for observations of the formation of metal foams. In this paper we consider three different fields of application which are under intensive investigation at HZDR and TUD: the bottom-up solidification of Ga-In alloys under the influence of buoyancy-driven and electromagnetically driven convection, the injection of Ar gas into liquid GaInSn, the study of Al foams with respect to foam formation and the characterization of their internal structure. 相似文献
998.
Processing of X-ray and optical streak-camera images after brightness amplification 5 proves unambiguously the existence of a preheating
of the foil in two-layer targets (polymer aerogel plus Al foil). We observed this effect earlier at the accuracy limit of
the experiment. Preheating may be explained by the initial transmission of laser radiation by an inhomogeneous plasma and
aerogel remnants. The fraction of laser energy that passed through a microheterogeneous plasma to the foil or shell is small
in comparison with the total energy in the pulse, but it comes to the target (foil or shell) at the initial period of the
laser pulse and can be significantly affected by the dynamics of plasma and the efficiency of spherical cryogenic thermonuclear
targets. 相似文献
999.
Geometriae Dedicata - In the paper we compute the virtual dimension (defined by the Hilbert polynomial) of a space of hypersurfaces of given degree containing s codimension 2 general linear... 相似文献
1000.