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141.
Volkerts M Bacelar JC van Goethem MJ Harakeh MN Hoefman M Huisman H Kalantar-Nayestanaki N Löhner H Messchendorp JG Ostendorf RW Schadmand S Scholten O Wilschut HW Simon RS Wagner V 《Physical review letters》2003,90(6):062301
For the first time a high-precision proton-deuteron bremsstrahlung experiment has been performed in which all the different exit channels have been distinguished separately. High-precision cross sections and analyzing powers in one of the outgoing channels, namely, the coherent bremsstrahlung with a proton and a deuteron in the final state, are presented at 190 MeV incoming proton beam energy and are compared to calculations based on the low-energy theorem. The results of the calculations vary considerably calling for a fully microscopic calculation. However, using a recipe including the initial- and final-state interactions, the predictions come close to the data. 相似文献
142.
Let X/Fp be an Artin–Schreier curve defined by the affine equation y
p
–y=f(x) where f(x)Fp[x] is monic of degree d. In this paper we develop a method for estimating the first slope of the Newton polygon of X. Denote this first slope by NP1(X/Fp). We use our method to prove that if p>d2 then NP1(X/Fp)(p–1)/d/(p–1). If p>2d4, we give a sufficient condition for the equality to hold. 相似文献
143.
An on-line photochemical reaction detector is described for the identification of ergot alkaloids by high-performance liquid chromatography. The fluorescence signal of alkaloids decreases within about 20 sec of irradiation and disappears selectively from complex chromatograms. The application of this principle to urine samples is described. 相似文献
144.
We study the transition from the vibrational, SU(5), to the rotational, SU(3), limit of the interacting boson model. We show how this model can be used to calculate energies, electromagnetic transitions, multipole moments, nuclear radii, and two-nucleon transfer intensities in transitional nuclei. 相似文献
145.
Tim Mller Fabian Scholten Trung Ngo Thanh Ilya Sinev Janis Timoshenko Xingli Wang Zarko Jovanov Manuel Gliech Beatriz Roldan Cuenya Ana Sofia Varela Peter Strasser 《Angewandte Chemie (International ed. in English)》2020,59(41):17974-17983
The direct electrochemical conversion of carbon dioxide (CO2) into multi‐carbon (C2+) products still faces fundamental and technological challenges. While facet‐controlled and oxide‐derived Cu materials have been touted as promising catalysts, their stability has remained problematic and poorly understood. Herein we uncover changes in the chemical and morphological state of supported and unsupported Cu2O nanocubes during operation in low‐current H‐Cells and in high‐current gas diffusion electrodes (GDEs) using neutral pH buffer conditions. While unsupported nanocubes achieved a sustained C2+ Faradaic efficiency of around 60 % for 40 h, the dispersion on a carbon support sharply shifted the selectivity pattern towards C1 products. Operando XAS and time‐resolved electron microscopy revealed the degradation of the cubic shape and, in the presence of a carbon support, the formation of small Cu‐seeds during the surprisingly slow reduction of bulk Cu2O. The initially (100)‐rich facet structure has presumably no controlling role on the catalytic selectivity, whereas the oxide‐derived generation of under‐coordinated lattice defects, can support the high C2+ product yields. 相似文献
146.
Scholten E Dhamankar H Bromberg L Rutledge GC Hatton TA 《Langmuir : the ACS journal of surfaces and colloids》2011,27(11):6683-6688
Carbamazepine (CBZ) microparticles of different sizes and shapes, including spheres, q-tips, elongated spheres, and tear-shaped particles, were formed by electrospraying solutions of different CBZ concentrations. The particle characteristics were determined by the interplay between jet formation, droplet breakup, solvent evaporation, and eventual particle solidification. The average particle size increased with increasing CBZ concentration, with particles of different shapes being observed for different CBZ concentrations. The cascade of sizes and shapes observed was interpreted in terms of Rayleigh instability theory as applied to charged jets and droplets, with the final sizes depending upon the time needed to evaporate the solvent sufficiently for CBZ to solidify; the lower the initial concentration of CBZ, the smaller the final droplets/particles that are formed. 相似文献
147.
148.
Lijuan J. Wang Margaret L. Grapperhaus Barnett S. Pitzele Timothy J. Hagen Kam F. Fok Jeffrey A. Scholten Dale P. Spangler Mihaly V. Toth Gina M. Jerome William M. Moore Pamela T. Manning James A. Sikorski 《Heteroatom Chemistry》2002,13(1):77-83
The efficient syntheses of two new types of conformationally constrained S‐[2‐[(1‐iminoethyl)amino]ethyl]homocysteine derivatives, 1‐amino‐3‐[2[(1‐iminoethyl)amino]ethylthio]cyclobutane carboxylic Acid ( 5 ) and (4S)‐4‐[[2‐[(1‐Iminoethyl)amino]ethyl]thio]‐L‐proline ( 6 ), are reported. These molecules represent the first attempts to probe conformational constraint near the α‐amino acid moiety of known homocysteine‐based inhibitors of nitric oxide synthase. Targets 5 and 6 were evaluated as potential inhibitors of the three human isoforms of nitric oxide synthase. © 2002 John Wiley & Sons, Inc. Heteroatom Chem 13:77–83, 2002; DOI 10.1002/hc.1109 相似文献