氚核磁共振波谱在氚标记甾族化合物制备中的应用

本文介绍了十一种氚化甾族化合物的氚核磁共振谱。我们依照英国放化中心和英国萨里大学报道数据,(甾体骨架上的CH及CH_2各位置的谱线归属,应用了定位标记化合物作为对照)归属了其氚在化合物中标记的位置,根据其积分曲线定出了各位氚的相对百分含量。同时图谱中又提供了立体构型的信息,为氚化甾族化合物制备过程中,催化剂的选择,实验条件的控制及反应机理等研究提供了理论依据。     

Combined absorption of light in the process of photoactivation of biosystems

The light-oxygen effect consists in a direct excitation of molecular oxygen dissolved in aqueous media of biosystems by the light; it provides the possibility to use lasers for therapeutic purposes. The wavelength of the used light should strictly correspond to the oxygen absorption bands. However, laser therapy also makes use of lasers emitting at 0.89 μm (outside the known oxygen bands), which suggests the action of a new photoreceptor. Here we argue that this mechanism of photoreception is a modification of the light-oxygen effect involving the absorption of photon simultaneously by the oxygen molecule and O-H stretch of the H₂0 molecule of liquid water.     

Estimation of the proton energy spectrum in knee region by analog read-out of ARGO-YBJ experiment

Based on the six months data set of ARGO-YBJ experiment with analog read-out and its Monte Carlo simulation,we study the difference between different primaries induced showers by using the space-time information of the charged particles in Extensive Air Showers.With five parameters which can efficiently pick out primary proton induced showers as inputs of an artificial neural network,the proton spectrum from 100 TeV to 10 PeV can be obtained.     

Interpretation of IR spectra of the N-acethyl-4-dimethylaminopyridinium salts

In a harmonic approximation we calculate the frequencies of normal vibrations and their modes for a salt cation of N-acethyl-4-dimethylaminopyridinium hexachlorstibiate and of its three deuteroderivatives obtained on deuteration over a CH₃-group, over a ring, and over a ring and a CH₃-group. From the results of calculation, an interpretation of the IR spectra of the salts considered is carried out. To whom correspondences should be addressed. L. M. Litvinenko Institute of Physical and Organic Chemistry and the Chemistry of Coal, National Academy of Sciences of Ukraine, 70, R. Luxemburg Str., Donetsk, 340114, Ukraine. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 66, No. 2, pp. 158–162, March–April, 1999.     

Structural characterization of silver dialkylphosphite salts using solid‐state 109Ag and 31P NMR spectroscopy,IR spectroscopy and DFT calculations

High‐resolution solid‐state ¹⁰⁹Ag and ³¹P NMR spectroscopy was used to investigate a series of silver dialkylphosphite salts, Ag(O)P(OR)₂ (R = CH₃, C₂H₅, C₄H₉ and C₈H₁₇), and determine whether they adopt keto, enol or dimer structures in the solid state. The silver chemical shift, CS, tensors and |J(¹⁰⁹Ag, ³¹P)| values for these salts were determined using ¹⁰⁹Ag (Ξ = 4.652%) NMR spectroscopy. The magnitudes of J(¹⁰⁹Ag, ³¹P) range from 1250 ± 10 to 1318 ± 10 Hz and are the largest reported so far. These values indicate that phosphorus is directly bonded to silver for all these salts and thus exclude the enol structure. All ³¹P NMR spectra exhibit splittings due to indirect spin–spin coupling to ¹⁰⁷Ag (I = 1/2, NA = 51.8%) and ¹⁰⁹Ag (I = 1/2, NA = 48.2%). The ¹J(¹⁰⁹Ag, ³¹P) values measured by both ¹⁰⁹Ag and ³¹P NMR spectroscopy agree within experimental error. Analysis of ³¹P NMR spectra of stationary samples for these salts allowed the determination of the phosphorus CS tensors. The absence of characteristic P?O stretching absorption bands near 1250 cm^?1 in the IR spectra for these salts exclude the simple keto tautomer. Thus, the combination of solid‐state NMR and IR results indicate that these silver dialkylphosphite salts probably have a dimer structure. Values of silver and phosphorus CS tensors as well as ¹J(¹⁰⁹Ag, ³¹P) values for a dimer model calculated using the density functional theory (DFT) method are in agreement with the experimental observations. Copyright © 2010 John Wiley & Sons, Ltd.     

Synthesis of Iron Oxides by Co2 Laser vs. Thermally Induced Decomposition of Inorganic Salts

This paper reports on the synthesis of various iron oxides by the IR laser processing of different iron salts. X-ray diffraction techniques were used to characterize the reaction products. Some differences in terms of crystallite size and isotropy between these oxides and those obtained from the same salt by thermal means are described and explained. This revised version was published online in July 2006 with corrections to the Cover Date.     

餐盒用新型非发泡聚丙烯光降解性能红外光谱法检测

用红外光谱法测试研究了餐盒用新型非发泡聚丙烯光降解行为。结果表明，降解母粒含量不同，其红外吸收光谱图存在明显的差异；在光降解过程中，羰基指数存在明显的动态变化。     

A Uniform Exponential Spectrum for Linear Flows on Vector Bundles

For linear flows on vector bundles we define a uniform exponential spectrum. For a compact invariant set for the projected flow we obtain this spectrum by taking all accumulation points for the time tending to infinity of the union over the finite time exponential growth rates for all initial values in this set. Using direct arguments we show that for a connected compact invariant set this spectrum is a closed interval whose boundary points are Lyapunov exponents. For a compact invariant set on which the flow is chain transitive we show that this spectrum coincides with the Morse spectrum. In particular, this approach admits a straightforward analytic proof for the regularity and continuity properties of the Morse spectrum without using cohomology or ergodicity results.     

Formation and Evolution of Carbonate Species in Na-Doped Al2O3 and V2O5-Al2O3

A study is carried out by FT-IR spectroscopy of the carbonate species formed upon interaction of CO₂ with alumina and vanadia-alumina catalysts doped with sodium. It is found that the presence of sodium enhances the ability of the catalyst surface to adsorb CO₂, yielding to carbonate formation. The species formed changes in the presence of vanadium, shifting the ν_COO stretching bands towards higher wavenumbers than those recorded in Na-Al₂O₃ systems.