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排序方式: 共有75条查询结果,搜索用时 31 毫秒
1.
V. V. Shchepin P. S. Silaichev Yu. G. Stepanyan M. M. Kalyuzhnyi N. Yu. Russkikh M. I. Kodess 《Russian Journal of Organic Chemistry》2006,42(7):973-980
Zinc enolates derived from 1-aryl-2,2-dibromoalkanones react with N-substituted 3-aryl-2-cyanoprop-2-enamides and 5,5-dimethyl-2-oxo-2,5-dihydrofuran-3-carboxylic and 2-oxochromene-3-carboxylic acid derivatives to give, respectively, N-substituted 2-alkyl-3-aryl-2-aroyl-1-cyanocyclopropane-1-carboxamides, 6-(4-bromobenzoyl)-4,4,6-trimethyl-2-oxo-3-oxabicyclo[3.1.0]hexane-1-carboxylic acid ethyl ester and morpholide, and 1-alkyl-1-aroyl-2-oxo-1a,7b-dihydrocyclopropla[c]chromene-1a-carboxylic acids as a single geometric isomer. Treatment of 1-alkyl-1-aroyl-2-oxo-1a,7b-dihydrocyclopropa[c]chromene-1a-carboxylic acids with carboxylic acid anhydrides leads to the formation of the corresponding 9c-alkyl-1-aryl-3,4-dioxo-9b,9c-dihydro-2,5-dioxacyclopenta[2,3]cyclopropa[1,2-a]naphthalen-1-yl carboxylates. 相似文献
2.
E. V. Babaev Y. I. Koval V. B. Rybakov E. G. Paronikyan G. M. Stepanyan R. G. Paronikyan Sh. Sh. Dashyan S. A. Rzhevskii I. A. Shadrin 《Russian Chemical Bulletin》2018,67(2):313-320
The alkylation (allylation and propargylation) of 3-cyano-6-dialkylamino-2-pyridones containing a d-annulated ring occurs at the oxygen atom. The structures of the starting compounds and their alkylation products were determined by X-ray diffraction. The neurotropic and antimicrobial activity of alkylation products was examined. 相似文献
3.
Tvaskis V Christy ME Arrington J Asaturyan R Baker OK Blok HP Bosted P Boswell M Bruell A Cochran A Cole L Crowder J Dunne J Ent R Fenker HC Filippone BW Garrow K Gasparian A Gomez J Jackson HE Keppel CE Kinney E Lapikás L Liang Y Lorenzon W Lung A Mack DJ Martin JW McIlhany K Meekins D Milner RG Mitchell JH Mkrtchyan H Moreland B Nazaryan V Niculescu I Opper A Piercey RB Potterveld DH Rose B Sato Y Seo W Smith G Spurlock K van der Steenhoven G Stepanyan S Tadevosian V Uzzle A Vulcan WF Wood SA 《Physical review letters》2007,98(14):142301
We report on a study of the longitudinal to transverse cross section ratio, R=sigmaL/sigmaT, at low values of x and Q2, as determined from inclusive inelastic electron-hydrogen and electron-deuterium scattering data from Jefferson Laboratory Hall C spanning the four-momentum transfer range 0.06相似文献
4.
G. L. Arutyunyan K. A. Gevorkyan A. D. Arutyunyan R. V. Paronikyan G. M. Stepanyan G. A. Panosyan 《Russian Journal of Organic Chemistry》2014,50(10):1480-1484
A number of new 1,3-diazaadamantane derivatives containing quinoline fragments on C2 have been synthesized by condensation of 1,5-dialkyl-3,7-diazabicyclo[3.3.1]nonan-9-one, 1,5-dimethyl-3,7-diazabicyclo-[3.3.1]nonan-9-ol, and 1,5-dimethyl-3,7-diazabicyclo[3.3.1]nonane with 2-oxo-1,2-dihydroquinoline-3-carbaldehyde, 2-chloro- and 2-iodoquinoline-3-carbaldehyde, and quinoline-2-carbaldehyde. 相似文献
5.
Joo K Smith LC Burkert VD Minehart R Aznauryan IG Elouadrhiri L Stepanyan S Adams GS Amaryan MJ Anciant E Anghinolfi M Armstrong DS Asavapibhop B Audit G Auger T Avakian H Barrow S Bagdasaryan H Battaglieri M Beard K Bektasoglu M Bertozzi W Bianchi N Biselli AS Boiarinov S Bonner BE Brooks WK Calarco JR Capitani GP Carman DS Carnahan B Cole PL Coleman A Cords D Corvisiero P Crabb D Crannell H Cummings J De Sanctis E De Vita R Degtyarenko PV Demirchyan RA Denizli H Dennis LC Deppman A 《Physical review letters》2002,88(12):122001
Models of baryon structure predict a small quadrupole deformation of the nucleon due to residual tensor forces between quarks or distortions from the pion cloud. Sensitivity to quark versus pion degrees of freedom occurs through the Q2 dependence of the magnetic (M1+), electric (E1+), and scalar (S1+) multipoles in the gamma*p-->Delta(+)-->p pi(0) transition. We report new experimental values for the ratios E(1+)/M(1+) and S(1+)/M(1+) over the range Q2 = 0.4-1.8 GeV2, extracted from precision p(e,e(')p)pi(0) data using a truncated multipole expansion. Results are best described by recent unitary models in which the pion cloud plays a dominant role. 相似文献
6.
Arpi A. Stepanyan 《Journal of Contemporary Mathematical Analysis (Armenian Academy of Sciences)》2007,42(3):151-160
The paper proves that every almost everywhere finite measurable function is representable by an absolute convergent series in the Franklin systems generated by quasi-dyadic, weakly regular partitions. 相似文献
7.
E. S. Losev N. V. Netrebko S. A. Regirer A. S. Stepanyan N. N. Firsov 《Fluid Dynamics》1990,25(5):685-691
The start up behavior of a concentrated suspension of nonaggregating settling particles in a rotational viscometer is examined. The results of one of the experiments are presented.Translated from Izvestiya Akademii Nauk SSSR, Mekhanika Zhidkosti i Gaza, No. 5, pp. 44–51, September–October, 1990. 相似文献
8.
McKinnon B Hicks K Baltzell NA Carman DS Mestayer MD Mibe T Mirazita M Niccolai S Rossi P Stepanyan S Tedeschi DJ Ambrozewicz P Anghinolfi M Asryan G Avakian H Bagdasaryan H Baillie N Ball JP Batourine V Battaglieri M Bedlinskiy I Bellis M Benmouna N Berman BL Biselli AS Bouchigny S Boiarinov S Bradford R Branford D Briscoe WJ Brooks WK Bültmann S Burkert VD Butuceanu C Calarco JR Careccia SL Chen S Cole PL Collins P Coltharp P Crabb D Crede V Dale D De Masi R DeVita R De Sanctis E 《Physical review letters》2006,96(21):212001
A search for the Theta+ in the reaction gammad --> pK-K+n was completed using the CLAS detector at Jefferson Lab. A study of the same reaction, published earlier, reported the observation of a narrow Theta+ resonance. The present experiment, with more than 30 times the integrated luminosity of our earlier measurement, does not show any evidence for a narrow pentaquark resonance. The angle-integrated upper limit on Theta+ production in the mass range of 1.52-1.56 GeV/c2 for the gammad --> pK-Theta+ reaction is 0.3 nb (95% C.L.). This upper limit depends on assumptions made for the mass and angular distribution of Theta+ production. Using Lambda(1520) production as an empirical measure of rescattering in the deuteron, the cross section upper limit for the elementary gamman --> K-Theta+ reaction is estimated to be a factor of 10 higher, i.e., approximately 3 nb (95% C.L.). 相似文献
9.
10.
Olivier Colin Martin Ritter Corine Lacour Karine Truffin Sophie Mouriaux Sergey Stepanyan Bertrand Lecordier Pierre Vervisch 《Proceedings of the Combustion Institute》2019,37(4):4875-4883
The cycle to cycle combustion variability which is observed in spark-ignition engines is often caused by fluctuations of the early flame development. LES can be exploited for a better understanding and mastering of their origins. For that purpose appropriate models taking into account energy deposition, mixture ignition and transition to propagation are necessary requirements. This paper presents first DNS and LES of spark ignition with a real automotive coil and simplified pin-pin electrodes. The electrical circuit characteristics are provided by ISSIM while the energy deposition is modelled by Lagrangian particles. The ignition model is first evaluated in terms of initial spark radius on a pin-pin ignition experiment in pure air performed at CORIA and EM2C laboratories, showing that it pilots the radius of the torus formed by the initial shock wave. DNS of a quiescent lean propane/air mixture are then performed with this ignition system and a two-step mechanism. The impact of the modelled transferred energy during glow phase as well as the initial arc radius on the minimum ignition energy (MIE) are examined and compared to experimental values. Replacing the two-step chemistry by an analytically reduced mechanism leads to similar MIE but shows a different ignition kernel shape. Finally, LES of turbulent ignition using a Lagrangian arc model show a realistic prediction of the arc shape and its important role on the energy transfer location and thus on the flame kernel shape. 相似文献