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101.
It is shown that Boltzmann's equation written in terms of microscopic density (namely the unaveraged Boltzmann function) has a wider range of validity as well as finer resolvability for fluctuations than the conventional Boltzmann equation governing Boltzmann's function. In fact the new Boltzmann equation for ideal gases has implications as a microscopically exact continuity equation like Klimontovich's equation for plasmas, and can be derived without invoking any statistical concepts, e.g., distribution functions, or molecular chaos. The Boltzmann equation in the older formalism is obtained by averaging this equation only under a restricted condition of the molecular chaos. The new Boltzmann equation is seen to contain information comparable with Liouville's equation, and serves as a master kinetic equation. A new hierarchy system is formulated in a certain parallelism to the BBGKY hierarchy. They are shown to yield an identical one-particle equation. The difference between the two hierarchy systems first appears in the two-particle equation. The difference is twofold. First, the present formalism includes thermal fluctuations that are missing in the BBGKY formalism. Second, the former allows us to formulate multi-time correlations as well, whereas the latter is restricted to simultaneous correlation. These two features are favorably utilized in deriving the Landau-Lifshitz fluctuation law in a most straightforward manner. Also, equations describing the nonequilibrium interaction between thermal and fluid-dynamical fluctuations are derived. 相似文献
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The reactivity of neurotransmitters toward hydrogen abstraction by an active oxygen species (the cumylperoxyl radical) is comparable to that of a strong antioxidant such as catechin due to the strong intramolecular hydrogen bonding, which has been successfully detected by ESR. 相似文献
106.
Photoinduced electron transfer of DNA as well as DNA bases with 9-mesityl-10-methylacridinium ion results in formation of all types of DNA base radical cations, which have been detected as the transient absorption spectra measurements, leading to efficient DNA cleavage in the absence of O2. 相似文献
107.
The anionic organic dye, zincon, was found to be a colorimetric probe for spermine and spermidine at pH 4.0 in pure aqueous solution through its aggregation by electrostatic interactions with them. The addition of spermine and spermidine led to bathochromic shifts with color changes from yellow to purple and dark brown, respectively, while other amines and basic amino acids induced no or minimal spectral and color changes. From Job’s plot and titration experiments, zincon interacted with spermine (+4 charges) and spermidine (+3 charges) in 4:1 and 3:1 stoichiometric ratios, respectively, indicating that each positive charge was bound to one zincon molecule. The detection limits were determined to be 25.1 for spermine and 30.7 nM for spermidine, which were sufficient below the critical concentration for cancer diagnosis. The results indicated that zincon can be a good candidate for simple, convenient colorimetric detection of spermine and spermidine in aqueous solution. 相似文献
108.
Dark-spot formation by vector beams 总被引:1,自引:0,他引:1
Dark-spot formation is demonstrated by calculating electric-field distribution near the focus produced by focusing higher-order transverse-mode vector beams with radial and azimuthal polarizations in addition to Laguerre-Gaussian beams with linear and circular polarizations. The size of the dark spot in the radial direction varies from one beam to another, but the size in the axial direction is almost the same. The radially polarized TM02-mode beam is predicted to form a dark spot solely by an axial electric field. 相似文献
109.
Asymmetric Total Synthesis of (−)‐Englerin A through Catalytic Diastereo‐ and Enantioselective Carbonyl Ylide Cycloaddition
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Dr. Taiki Hanari Dr. Naoyuki Shimada Dr. Yasunobu Kurosaki Dr. Neetipalli Thrimurtulu Dr. Hisanori Nambu Dr. Masahiro Anada Prof. Dr. Shunichi Hashimoto 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(33):11671-11676
An asymmetric total synthesis of the guaiane sesquiterpene (?)‐englerin A, a potent and selective inhibitor of the growth of renal cancer cell lines, was accomplished. The basis of the approach is a highly diastereo‐ and enantioselective carbonyl ylide cycloaddition with an ethyl vinyl ether dipolarophile under catalysis by dirhodium(II) tetrakis[N‐tetrachlorophthaloyl‐(S)‐tert‐leucinate], [Rh2(S‐TCPTTL)4], to construct the oxabicyclo[3.2.1]octane framework with concomitant introduction of the oxygen substituent at C9 on the exo‐face. Another notable feature of the synthesis is ruthenium tetraoxide‐catalyzed chemoselective oxidative conversion of C9 ethyl ether to C9 acetate. 相似文献
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