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121.
2,3-Di(pyrrole-2-yl)quinoxaline anion sensors with extended chromophores display dramatic enhancement in fluorescence intensity (sensing output), increased affinity for inorganic anions as well as strong selectivity for pyrophosphate over phosphate anion. 相似文献
122.
Khoroshun DV Inagaki A Suzuki H Vyboishchikov SF Musaev DG Morokuma K 《Journal of the American Chemical Society》2003,125(33):9910-9911
The reaction of a trinuclear polyhydride complex Ru3H5(C5H5)3 with cyclopentadiene, C5H6, has been studied computationally. A mechanism for the experimentally observed selective C-C bond activation is proposed. All three Ru centers participate in various steps of the mechanism. The catalytic involvement of two cluster hydrides in the transformation of the C5Hn fragment is emphasized. 相似文献
123.
Electrospray ionization mass spectrometry (ESI‐MS) was successfully applied to the structural analysis of lignin. The structure of oligomers fractionated from Eucalyptus globulus dioxane lignin was elucidated using tandem mass spectrometry, and the information on fragmentation patterns was provided by experiments on dimeric model compounds. Data obtained revealed a significant abundance in the lignin macromolecules of linear fragments that were composed of 8‐O‐4′‐linked syringyl/guaiacyl units and syringaresinol.
124.
Peter?EbenfeltEmail author Bernhard?Lamel Dmitry?Zaitsev 《Geometric And Functional Analysis》2003,13(3):546-573
We show that germs of local real-analytic CR automorphisms of a
real-analytic hypersurface M in
$\mathbb{C}$2 at a point
p M
are uniquelydetermined by their jets of some finite order at
p if and only if M is
not Levi-flat near p. This seems to be the first necessary and sufficient
result on finite jet determination and the first result of this kind in
the infinite type case.If M is of finite type at p,
we prove a stronger assertion: the local real-analytic
CR automorphisms of M fixing p
are analytically parametrized (and hence uniquely determined)
by their 2-jets at p.
This result is optimal since the automorphisms of the unit sphere are
not determined by their 1-jets at a point of the sphere. The finite
type condition is necessary since otherwise the needed jet order can
be arbitrarily high [Kow1,2], [Z2]. Moreover, we show, by an example,
that determination by 2-jets fails for finite type hypersurfaces already
in $\mathbb{C)$3.We also give an application to the dynamics of germs of local
biholomorphisms of $\mathbb{C)$2. 相似文献
125.
Nevinsky GA Kanyshkova TG Semenov DV Vlassov AV Gal'vita AV Buneva VN 《Applied biochemistry and biotechnology》2000,83(1-3):115-130
The human milk secretory immune system is known to be the first line of protection for the newborn infant against various
pathogens. Secretory IgA (sIgA), the typical immunoglobulin found in secretions, can fight infections through many mechanisms.
Using different methods, we have shown that sIgA from the milk of healthy women possesses DNAse and RNAse activities. The
catalytic center is localized in the light chain of catalytic sIgA, while the DNA-binding center is predominantly formed by
its heavy chain. The enzymic properties and substrate specificity of catalytic sIgA distinguish it from other known DNases
and RNases. It is reasonable to assume, that the milk DNA- and RNA-hydrolyzing antibodies are capable not only of neutralizing
viral and bacterial nucleic acids by binding these antigens as well as by hydrolyzing them. The DNA-hydrolyzing activity of
Abs raises the possibility that these catalytic Abs may provide protective functions for the newborn through the hydrolysis
of viral and bacterial nucleic acids. 相似文献
126.
We define the Krichever-Novikov-type Lie algebras of differential operators and pseudodifferential symbols on Riemann surfaces,
along with their outer derivations and central extensions. We show that the corresponding algebras of meromorphic operators
and symbols have many invariant traces and central extensions, given by the logarithms of meromorphic vector fields. Very
few of these extensions survive after passing to the algebras of operators and symbols holomorphic away from several fixed
points. We also describe the associated Manin triples and KdV-type hierarchies, emphasizing the similarities and differences
with the case of smooth symbols on the circle. 相似文献
127.
Dmitry Sergeevich Shtarev Artem Igorevich Blokh Egor Olegovich Nashchochin Anna Vladimirovna Shtareva 《Optical and Quantum Electronics》2018,50(5):228
We present a comparative analysis of the conduction band edge of the alkali earth metal bismuthates containing Mg, Ca, Sr, and Ba. The conduction band edges were computed using the method suggested by Butler and Ginley. The calculations reveal that they depend on the bismuthate’s composition and vary over a wide range. We demonstrate that the energy of the conduction band increases in the series Ca?→?Sr?→?Ba. It also increases with an increase of the alkali earth metal content. The performed calculations help to determine the potential alkali earth metal bismuthate photocatalysts. The most promising compositions found in this study include strontium and barium bismuthates in which the number of the alkali earth metal atoms in the cationic sublattice exceeds the number of the bismuth atoms. 相似文献
128.
Andrei V. Afonin Igor A. Ushakov Dmitry V. Pavlov Andrei V. Ivanov Al'bina I. Mikhaleva 《Magnetic resonance in chemistry : MRC》2010,48(9):685-692
The 1H, 13C and 15N NMR studies have shown that the E and Z isomers of pyrrole‐2‐carbaldehyde oxime adopt preferable conformation with the syn orientation of the oxime group with respect to the pyrrole ring. The syn conformation of E and Z isomers of pyrrole‐2‐carbaldehyde oxime is stabilized by the N? H···N and N? H···O intramolecular hydrogen bonds, respectively. The N? H···N hydrogen bond in the E isomer causes the high‐frequency shift of the bridge proton signal by about 1 ppm and increase the 1J(N, H) coupling by ~3 Hz. The bridge proton shows further deshielding and higher increase of the 1J(N, H) coupling constant due to the strengthening of the N? H···O hydrogen bond in the Z isomer. The MP2 calculations indicate that the syn conformation of E and Z isomers is by ~3.5 kcal/mol energetically less favorable than the anti conformation. The calculations of 1H shielding and 1J(N, H) coupling in the syn and anti conformations allow the contribution to these constants from the N? H···N and N? H···O hydrogen bondings to be estimated. The NBO analysis suggests that the N? H···N hydrogen bond in the E isomer is a pure electrostatic interaction while the charge transfer from the oxygen lone pair to the antibonding orbital of the N? H bond through the N? H···O hydrogen bond occurs in the Z isomer. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
129.
Henrik Hovde Sønsteby Dmitry Chernyshov Michael Getz Ola Nilsen Helmer Fjellvåg 《Journal of synchrotron radiation》2013,20(4):644-647
A multipurpose six‐axis κ‐diffractometer, together with the brilliance of the ESRF light source and a CCD area detector, has been explored for studying epitaxial relations and crystallinity in thin film systems. The geometrical flexibility of the six‐axis goniometer allows measurement of a large volume in reciprocal space, providing an in‐depth understanding of sample crystal relationships. By a set of examples of LaAlO3 thin films deposited by the atomic layer deposition technique, the possibilities of the set‐up are presented. A fast panoramic scan provides determination of the crystal orientation matrices, prior to more thorough inspection of single Bragg nodes. Such information, in addition to a broadening analysis of families of single reflections, is shown to correlate well with the crystallinity, crystallite size, strain and epitaxial relationships in the thin films. The proposed set‐up offers fast and easy sample mounting and alignment, along with crucial information on key features of the thin film structures. 相似文献
130.