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排序方式: 共有291条查询结果,搜索用时 31 毫秒
281.
Uehara S Abe K Abe K Adachi I Aihara H Arinstein K Asano Y Aulchenko V Aushev T Bakich AM Balagura V Barberio E Bedny I Belous K Bitenc U Bizjak I Blyth S Bondar A Bozek A Bracko M Browder TE Chang MC Chen A Chen WT Cheon BG Chistov R Choi SK Choi Y Choi YK Chuvikov A Dalseno J Danilov M Dash M Dragic J Eidelman S Epifanov D Fratina S Gabyshev N Garmash A Gershon T Gokhroo G Gorisek A Ha HC Hayasaka K Hayashii H Hazumi M Hinz L Hoshi Y Hou S Iijima T Inami K Ishikawa A Itoh R Iwasaki M 《Physical review letters》2006,96(8):082003
We report on a search for new resonant states in the process gamma gamma --> DD. A candidate C-even charmonium state is observed in the vicinity of 3.93 GeV/c2. The production rate and the angular distribution in the gamma gamma center-of-mass frame suggest that this state is the previously unobserved chi(c2)', the 2(3)P2 charmonium state. 相似文献
282.
283.
Michail N. Elinson Anatolii N. Vereshchagin Nikita O. Stepanov Pavel A. Belyakov Gennady I. Nikishin 《Tetrahedron letters》2010,51(50):6598-6601
Cascade assembly of N,N′-dialkylbarbituric acids and aldehydes in the presence of bromine leads to the selective and efficient formation of substituted 1,5-dihydro-2H,2′H-spiro(furo[2,3-d]pyrimidine-6,5′-pyrimidine)-2,2′,4,4′,6′-(1′H,3H,3′H)-pentones in 70-88% yields via a complex cascade process. Spirobarbiturates containing the furo[2,3-d]pyrimidine framework are a class of compounds with interesting pharmacological and physiological activity. 相似文献
284.
Fortal’nova E. A. Gavrilenkov O. N. Belous A. G. Politova E. D. 《Russian Journal of General Chemistry》2009,79(9):1987-1997
The properties of perovskite type ABO3 lithium-ion conducting oxides based on lanthanum lithium titanate (La,Li)TiO3, lanthanum lithium niobate and tantalate, and Li5La3M2O12 (M = Nb, Ta) garnets were considered. Approaches to modification of the properties of these oxides, as well as the charge-compensation
mechanisms associated with nonisovalent doping were discussed. Special consideration was given to phase formation and crystal
structure in relation to the composition and preparation conditions of the oxides. 相似文献
285.
Anatolii D. Pomogailo Kamila A. Kydralieva Anar A. Zaripova Vladimir S. Muratov Gulzhian I. Dzhardimalieva Svetlana I. Pomogailo Nina D. Golubeva Sharipa J. Jorobekova 《Macromolecular Symposia》2011,304(1):18-23
Summary: We have elaborated several approaches for the preparation of magneto-active nano-hybrid composites, including i) ex situ method, which consists of the precipitation of magnetic particles from Fe(II) and Fe(III) salts followed by their incorporation into the humic acids matrix and ii) a chemical precipitation method in situ where the magnetic particles are grown within the humic acids matrix. It was proven that adsorption of humic acids on the magnetic particle surface leads to an enhanced electrostatic and steric stabilization of particles, due to the absorbed layer of highly charged macromolecular compounds. The sorbents under study were found to reveal a high sorption capacity towards uranyl ions. Using the adsorption isotherm, in the linear form of the Langmuir equation, the adsorption parameters were estimated. The results obtained show that the adsorption of uranyl ions by the magneto-active nanocomposite is enhanced in comparison with the free HA. 相似文献
286.
Aaij R Abellan Beteta C Adeva B Adinolfi M Adrover C Affolder A Ajaltouni Z Albrecht J Alessio F Alexander M Alkhazov G Alvarez Cartelle P Alves AA Amato S Amhis Y Anderson J Appleby RB Aquines Gutierrez O Archilli F Arrabito L Artamonov A Artuso M Aslanides E Auriemma G Bachmann S Back JJ Bailey DS Balagura V Baldini W Barlow RJ Barschel C Barsuk S Barter W Bates A Bauer C Bauer T Bay A Bediaga I Belogurov S Belous K Belyaev I Ben-Haim E Benayoun M Bencivenni G Benson S Benton J Bernet R 《Physical review letters》2012,108(11):111602
A search for time-integrated CP violation in D(0)→h(-)h(+) (h=K, π) decays is presented using 0.62 fb(-1) of data collected by LHCb in 2011. The flavor of the charm meson is determined by the charge of the slow pion in the D(*+)→D(0)π(+) and D(*-)→D[over ˉ](0)π(-) decay chains. The difference in CP asymmetry between D(0)→K(-)K(+) and D(0)→π(-)π(+), ΔA(CP)≡A(CP)(K(-)K(+))-A(CP)(π(-)π(+)), is measured to be [-0.82±0.21(stat)±0.11(syst)]%. This differs from the hypothesis of CP conservation by 3.5 standard deviations. 相似文献
287.
The radical polymerization and copolymerization of salts of unsaturated carboxylic acids were used for the production of metal-containing polymers. The kinetic peculiarities and copolymerization parameters were estimated. The synthesis and structure of transition metal acrylates, maleates, fumarates, and itaconates are discussed. The influence of the metal atom on salt reactivities and reaction rates is observed. 相似文献
288.
Martin K. Leonowicz Marta Lawecka A. Ślawska-Waniewska Gulzhian I. Dzhardimalieva Aleksander S. Rozenberg Anatolii D. Pomogailo 《Macromolecular Symposia》2003,204(1):257-266
Metallopolymer nanocomposites on the bases of cobalt and iron acrylates as well as their cocrystallites have been obtained and characterized. Microstructure of the materials consists of both agglomerated and individual nanocrystallites which are homogeneously distributed in the polymer matrix. Mean crystallite size is 7-14 nm. All the composite materials exhibit soft magnetic properties at room temperature. The magnetic parameters are controlled by the intrinsic magnetic properties of the constituents and agglomeration of the particles. 相似文献
289.
We obtained order estimates for the entropy numbers of the Nikol'skii–Besov classes of functions with mixed smoothness in the metric of the space of quasi-continuous functions . We also showed that for , , , , the estimate of the corresponding asymptotic characteristic is exact in order. 相似文献
290.
Transition metal μ3-oxo-carboxylates on the base of acrylic, maleic, itaconic, and acetylenedicarboxylic acids are first obtained and characterized using the elemental analysis, IR spectroscopy, EXAFS, magnetochemistry, and mass-spectrometry. The metal atoms form a trinuclear cluster core with oxygen atom in the center and bridge carboxylate ligands. For maleate Fe(III), the lengths of Fe - Fe, Fe - Obridge, Fe - Oligand bonds are equal to 3.29, 1.94, and 2.03 Å, respectively. For polymer metal oxo-acrylates molecular-weight characteristics and topology structure are analyzed. They are network amorphous or amorphous-crystal metal-containing polymers. 相似文献