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101.
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P. Funk N. Hofreiter K. Mayrhofer K. Prachar W. Nöbauer L. Schmetterer J. Laub J. Cigler H. Reiter W. Gröbner 《Monatshefte für Mathematik》1962,66(2):179-192
Ohne Zusammenfassung 相似文献
104.
The total synthesis of the cytotoxin fasicularin is described. The key steps include the following: (1) an intermolecular Diels-Alder cycloaddition of a 2-(triflamido)acrolein with the dioxolane ketal of trideca-1,3-dien-7-one to establish the trans-perhydroisoquinoline stereochemistry, (2) a stereoelectronically controlled hydride addition to a N(1)-C(2) iminium ion to introduce the equatorial hexyl substituent, and (3) elaboration of the pyrido ring by an internal aldol reaction. 相似文献
105.
Mekhman S. Yusubov Tatyana V. Funk Roza Y. Yusubova Galina Zholobova Joo Yeon Park 《合成通讯》2013,43(21):3772-3784
m-Iodosylbenzoic acid–mediated reactions of various carbonyl compounds provided α-organosulfonyloxy carbonyl compounds in good yields. The final products could be easily isolated without any chromatographic purification by simple treatment of the crude mixture with an anionic exchange resin. 相似文献
106.
Ackermann M Ajello M Albert A Atwood WB Baldini L Ballet J Barbiellini G Bastieri D Bechtol K Bellazzini R Berenji B Blandford RD Bloom ED Bonamente E Borgland AW Bregeon J Brigida M Bruel P Buehler R Burnett TH Buson S Caliandro GA Cameron RA Cañadas B Caraveo PA Casandjian JM Cecchi C Charles E Chekhtman A Chiang J Ciprini S Claus R Cohen-Tanugi J Conrad J Cutini S de Angelis A de Palma F Dermer CD Digel SW do Couto e Silva E Drell PS Drlica-Wagner A Falletti L Favuzzi C Fegan SJ Ferrara EC 《Physical review letters》2011,107(24):241302
Satellite galaxies of the Milky Way are among the most promising targets for dark matter searches in gamma rays. We present a search for dark matter consisting of weakly interacting massive particles, applying a joint likelihood analysis to 10 satellite galaxies with 24 months of data of the Fermi Large Area Telescope. No dark matter signal is detected. Including the uncertainty in the dark matter distribution, robust upper limits are placed on dark matter annihilation cross sections. The 95% confidence level upper limits range from about 10(-26) cm3 s(-1) at 5 GeV to about 5×10(-23) cm3 s(-1) at 1 TeV, depending on the dark matter annihilation final state. For the first time, using gamma rays, we are able to rule out models with the most generic cross section (~3×10(-26) cm3 s(-1) for a purely s-wave cross section), without assuming additional boost factors. 相似文献
107.
A concise, diastereoselective total synthesis of (±)-cortistatin J has been completed in 20 steps from furan. Key steps include an intramolecular [4 + 3] cyclization of a disubstituted furan with a (Z)-2-(trialkylsilyloxy)-2-enal to construct the tetracyclic core and a (Z)-vinylsilane/iminium ion cyclization to form the A ring. 相似文献
108.
109.
Asymmetric first‐order transition and interlocked particle state in magnetocaloric La(Fe,Si)13 下载免费PDF全文
Anja Waske Lars Giebeler Bruno Weise Alexander Funk Manuel Hinterstein Markus Herklotz Konstantin Skokov Sebastian Fähler Oliver Gutfleisch Jürgen Eckert 《固体物理学:研究快报》2015,9(2):136-140
In‐situ synchrotron XRD measurements of the magnetocaloric material LaFe11.8Si1.2 are used to understand virgin effects and asymmetry of the underlying first order magnetovolume transition. A remarkable change of the transition kinetics occurs after the first cycle, which we attribute to the formation of cracks originating from the volume change. Tomographic imaging revealed that the bulk material disintegrates via an interlocked state where fragments are loosely connected. Though cracks have opened between the fragments, the transition is sharp, which we attribute to magnetostatic interactions. In the cycled sample we find a strong asymmetry between the transition interval upon heating and cooling, which we explain by isostatic pressure acting on parts of the sample during the cooling transition. (© 2015 WILEY‐VCH Verlag GmbH &Co. KGaA, Weinheim) 相似文献
110.
Molecular beam scattering measurements have been conducted to examine the adsorption dynamics of CO2 on Cu(1 1 0). The initial adsorption probability, S0, decreases exponentially from 0.43 ± 0.03 to a value close to the detection limit (∼0.03) within the impact energy range of Ei = (0.12-1.30) eV. S0 is independent of the adsorption temperature, Ts, and the impact angle, αi, i.e., the adsorption is non-activated and total energy scaling is obeyed. The coverage, Θ, dependent adsorption probability, S(Θ), agrees with precursor-assisted adsorption dynamics (Kisliuk type) above Ts ∼ 91 K. However, below that temperature adsorbate-assisted adsorption (S increases with Θ) has been observed. That effect is most distinct at large Ei and low Ts. The S(Θ) data have been modeled by Monte Carlo simulations. No indications of CO2 dissociation were obtained from Auger Electron Spectroscopy or the molecular beam scattering data. 相似文献