Semiempirical hyperfine structure and ab initio isotope shift predictions in Zr II

The fine structure of the even‐parity low configurations has been reanalyzed by simultaneous parameterization of the one‐ and two‐body interactions for the model space (4d + 5s)³. Using the calculated eigenfunctions, the magnetic‐dipole A hyperfine constants for the whole 37 existing levels of the model space were predicted and compared partially to those obtained using relativistic configuration‐interaction approach. Moreover, volume shifts (VS) and specific mass shifts (SMS) of numerous configurations of singly ionised zirconium are deduced by means of ab initio estimates combined with a few experimental isotope shift data available in literature: VS(4d¹5s²) = 840 MHz, VS(4d³) = ?649 MHz, VS(4d¹5p²) = ?387 MHz, VS(5s²5p¹) = 1250 MHz, and SMS(4d¹5s²) = ?634 MHz, SMS(4d³) = 484 MHz, SMS(5s²5p¹) = ?1459 MHz, referred to 4d²5s for the pair Zr⁹⁰–Zr⁹². © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011     

Complementary Site-Selective Halogenation of Nitrogen-Containing (Hetero)Aromatics with Superacids

Site-selective functionalization of arenes that is complementary to classical aromatic substitution reactions remains a long-standing quest in organic synthesis. Exploiting the generation of halenium ion through oxidative process and the protonation of the nitrogen containing function in HF/SbF₅, the chlorination and iodination of classically inert Csp²−H bonds of aromatic amines occurs. Furthermore, the superacid-promoted (poly)protonation of the molecules acts as a protection, favoring the late-stage selective halogenation of natural alkaloids and active pharmaceutical ingredients     

Quantum Number Dependence of Lineshift Coefficients Induced by Collisions with Noble Gas Perturbers in the nu(3) Band of NO(2)

To complete our study concerning lineshift in the rovibrational spectrum of (14)N(16)O(2), a pulse-driven three-channel lead salt diode laser spectrometer was applied to record high-resolution spectra at room temperature in the 6.2-μm region corresponding to the nu(3) band at low NO(2) concentrations. The shift was studied for collisions with the noble gases He, Ne, Ar, Kr, and Xe. This paper extends our recently published data in order to analyze the quantum number dependence of the shift effect more precisely. Therefore, in this paper, additionally eight unresolved NO(2) doublets covering an enlarged quantum number range (10 相似文献   

A new analytical formula to compute the step length of Padé approximants in the ANM: Application to buckling structures

In this paper, we propose a new analytical formula to define the next branch in the Asymptotic Numerical Method (ANM) using the Padé approximants. The proposed formula is based on the computation of the relative error of two consecutive Padé approximants. This formula is obtained by developing the relative error with respect to the path parameter. An appropriate matrix formulation is adopted for the computation of this relative error. A comparison between the analytical formula proposed in this paper and the classical continuation Padé approximants using the step length computed numerically using dichotomy method is presented for examples of buckling structures.     

Design and Simulation of a Broadband Bandpass Filter Based on Complementary Split Ring Resonator Circular “CSRRs”

Wireless Personal Communications - The aim of this article was to design CSRRs (complementary split ring resonator) miniaturized metamaterial cells. These cells should then be associated with...     

Highly stereoselective coordination polymerization of β‐myrcene from a lanthanide‐based catalyst: Access to bio‐sourced elastomers

Polymerization of β‐myrcene with neodymium borohydride‐based coordination catalysts is very efficient, affording poly‐β‐myrcene (polymyrcene, PMy) with high selectivity. With stoichiometric amounts of n‐butylethyl magnesium (BEM) as co‐catalyst, good control over macromolecular data along with cis‐stereoselectivity up to 98.5%, are obtained. In the presence of excess BEM, high level of transfer reactions efficiency between neodymium and magnesium is clearly evidenced whereas the selectivity switches to 3,4‐rich. Combining the neodymium pre‐catalyst with triisobutyl aluminum in the presence of a boron activator affords PMy in good yield, but the polymer material displays low solubility, likely due to the occurrence of crosslinking. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012     

Partial turbo detection with reduced complexity

In this article, we propose a novel method for reducing the complexity of the turbo detector MAP (maximum a posteriori). The basic idea consists in turbo detecting a part of intersymbol interference (ISI) after decomposing the channel in two parts. We show that we can reduce the trellis complexity in the turbo process at a certain cost, i.e. performance loss.     

Cations Insertion in Molybdenum Cluster Compounds: Electronic Structure and Electrochemical Study Using Cavity Microelectrode

Owing to the high lability of cations in the three-dimensional framework of K_1+x Mo₁₂S₁₄ (0 ≤ x ≤ 1.6), first-principles calculations and electrochemical methods have been carried out to study the insertion of cations in the empty channels of this compound. The cavity microelectrode that is a suitable electrode for powder material analysis has been used in voltammetric experiments. Results obtained for Li⁺, Na⁺, Rb⁺, K⁺, Cs⁺ and NH₄ ⁺ cations are presented and discussed.     

Hyperfine structure studies in the mixed configurations (4p 2 4d+4s 4p 4) of arsenic

The magnetic hyperfine structures of some levels of the 4p ² 4d configuration which mixes strongly with the 4s 4p ⁴ configuration, have been measured for the first time, using the Fabry-Perot technique in the far UV range. A good agreement is observed between experimental results and theoretical evaluations.     

Convenient one-pot formation of highly functionalized 5-bromo-2-aminothiazoles,potential endocannabinoid hydrolase MAGL inhibitors

Highly functionalized 5-bromo-2-amino-1,3-thiazoles bearing various substituents could be easily prepared by a rapid and efficient one-pot method, using simple starting materials and mild conditions while avoiding the use of metal catalysts or inconvenient reagents such as elemental halogens. These useful products can serve as starting materials for other reactions or as pharmacologically interesting compounds. In our work we have shown that the resulting 5-bromothiazole compounds could lead to monoacylglycerol lipase (MAGL) inhibition in the μM range.