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51.
Teresa Ksel Gran Schulz Gerald Drger Andreas Kirschning 《Angewandte Chemie (International ed. in English)》2020,59(30):12376-12380
This report discloses the photochemical homolytic cleavage of iodine azide after its formation following release from polymer‐bound bisazido iodate(I) anions. A series of radical reactions are reported including the 1,2‐functionlization of alkenes and the unprecedented chemoselective oxidation of secondary alcohols in the presence of primary alcohols. 相似文献
52.
At temperatures above the brittle-to-ductile transition (490 °C) in Te-doped GaAs three types of predominant defect configurations have been observed after uniaxial compression along a [001] direction: (i) twins and stacking faults (500 … 520 °C), (ii) slip zones of dislocations (≈550 °C) and (iii) dislocation cells (580 … 590 °C). In Part II quantitative details of the appearance of slip and cell formation are given. Leading segments of gliding half loops are mainly of 60° type. Cell walls were formed by multiple slip of perfect dislocations. 相似文献
53.
In the first part of this paper an experimental setup using Fourier-transform infrared spectroscopy (FTIR) in combination with a photoelastic modulator (PEM) for linear dichroism measurements is described. The second part shows the influence of PEM-amplitude and scan-velocity on the sensitivity of the instrument. The third part deals with the fringe-problem in the baselines of absorbance spectra and its influence on the determination of the linear dichroic ratio. 相似文献
54.
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56.
Gerald D Fong Robert L Kuczkowski Arthur J Ashe 《Journal of Molecular Spectroscopy》1978,70(2):197-208
The microwave spectrum of 121-SbC5H5, 123-SbC5H5, β-dideutero 121-SbC5H3D2 and 123-SbC5H3D2 has been assigned in the region 26.5–40.0 GHz. The respective rotational constants and uncertainties are: A = 4512.69 ± 0.42, B = 1738.00 ± 0.01, C = 1254.51 ± 0.01; A = 4512.84 ± 0.30, B = 1729.80 ± 0.01, C = 1250.22 ± 0.01; A = 4176.18 ± 0.33, B = 1660.94 ± 0.01, C = 1188.15 ± 0.01; A = 4176.60 ± 0.61, B = 1652.94 ± 0.03, C = 1184.03 ± 0.03 (in MHz units). The structure is found to be planar, C2v in symmetry. The and ∠CSbC = 92.9° ± 1.0°. The nuclear quadrupole coupling constants for the 121 and 123 antimony isotopes are χaa = 456.4 ± 4.1 MHz, η = 0.396 ± 0.008, and χaa = 583.00 ± 5.3 MHz, η = 0.399 ± 0.008, respectively. Several alternate techniques using the coupling constants as data support a σ-donating property for antimony. 相似文献
57.
Richard A. Stern Richard W. Babbitt John Borowick Gerald Mikucki William Bayha 《International Journal of Infrared and Millimeter Waves》1985,6(10):999-1016
This paper describes the theoretical and experimental results of a novel leaky-wave antenna incorporating a homogeneous dielectric transmission line and radiating aperture into a single structure. The primary objective of this investigation is to demonstrate the ability to control aperture radiation by simply cutting slots into a metal-free dielectric transmission line. Experimental line source antennas with identical periodic slots were designed to operate in the 35 GHz frequency region. The successful performance of these antennas resulted in the design of a dielectric line source antenna with a symmetrical amplitude taper which provided a lower sidelobe level. The design represents a significant breakthrough in achieving affordable, low-loss, lightweight antennas in the millimeter wave region. The most significant applications for this type of antenna include radar surveillance and tactical missile-seeker terminal guidance. 相似文献
58.
Dr. Xiaoming Jie Dr. Qiu Sun Dr. Constantin G. Daniliuc Robert Knitsch Prof. Dr. Michael Ryan Hansen Prof. Dr. Hellmut Eckert Dr. Gerald Kehr Prof. Dr. Gerhard Erker 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(6):1269-1273
The active six-membered cyclo-FLP 6 undergoes a rapid P/B addition reaction to carbon dioxide. At elevated temperature, the resulting heterobicyclo[2.2.2]octane derived product 7 undergoes ring opening and equilibrates with the cyclotetramer (7)4 . In the large macrocyclic structure, four monomeric six-membered cyclo-FLP units are connected by four CO2 molecules to form the supramolecular ring system. The P/B cyclo-FLP 6 undergoes a variety of additional cycloaddition reactions. 相似文献
59.
Ilse Fischer Gerald Gruber Franz Rendl Renata Sotirov 《Mathematical Programming》2006,105(2-3):451-469
We propose a dynamic version of the bundle method to get approximate solutions to semidefinite programs with a nearly arbitrary
number of linear inequalities. Our approach is based on Lagrangian duality, where the inequalities are dualized, and only
a basic set of constraints is maintained explicitly. This leads to function evaluations requiring to solve a relatively simple
semidefinite program. Our approach provides accurate solutions to semidefinite relaxations of the Max-Cut and the Equipartition
problem, which are not achievable by direct approaches based only on interior-point methods.
Received: April, 2004
The last author gratefully acknowledges the support from the Austrian Science Foundation FWF Project P12660-MAT. 相似文献
60.
Gerald Senarclens de Grancy Marc Reimann 《Central European Journal of Operations Research》2016,24(1):29-48
This paper systematically compares an ant colony optimization (ACO) and a greedy randomized adaptive search procedure (GRASP) metaheuristic. Both are used to solve the vehicle routing problem with time windows and multiple service workers. In order to keep the results comparable, the same route construction heuristic and local search procedures are used. It is shown that ACO clearly outperforms GRASP in the problem under study. Additionally, new globally best results for the used benchmark problems are presented. 相似文献