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991.
Yaxian Mao Gustavo Conesa Balbastre Masato Sano Yves Schutz Daicui Zhou 《The European Physical Journal C - Particles and Fields》2008,57(3):613-619
The possibility to study the fragmentation function of jets with energies below 50 GeV, which cannot be reconstructed in the
heavy-ion environment, is explored. We propose to measure the imbalance distribution between prompt photon and charged hadrons
with the ALICE experiment at LHC. In the present article, the case of proton–proton collisions at
TeV is examined with Monte-Carlo simulations. Performances for prompt photon identification and rejection of the π
0 decay photons are presented. We find that the measurement in proton–proton is meaningful with respect to statistical and
systematic errors for photon energies larger than 20 GeV. 相似文献
992.
Hisaya Sato Kenji Ogino Susumu Maruo Masato Sasaki 《Journal of Polymer Science.Polymer Physics》1991,29(9):1073-1080
The separation of styrene-methacrylate copolymers by chemical composition was studied using high-performance liquid chromatography (HPLC). With the combination of acrylonitrile (polar) gel and nonpolar eluent or of styrene (nonpolar) gel and polar eluent, poly(styrene-co-methylmethacrylate) was separated by the adsorption mechanism. The former is designated as normal and the latter as reversed phase. With other combinations, the copolymer was separated mainly by fractional dissolution mechanism. The sample eluted slightly earlier as molecular weight decreased. The molecular weight effect on the reversed-phase HPLC was smaller than that on the normal phase. A gel with an exclusion limit of 3 × 103 exhibited greater molecular weight dependence and worse resolution than a gel with an exclusion limit of 50 × 104. Poly(styrene-co-n-butyl methacrylate) also was separated on the basis of chemical composition by normal and reverse-phase HPLC. However, poly(styrene-co-t-butyl methacrylate) was separated only by reverse-phase HPLC. When octadecyl methacrylate gel was used instead of styrene gel in reverse-phase HPLC, a good separation was not obtained. This indicates a specific interaction between the phenyl group of the styrene gel and the sample. 相似文献
993.
994.
995.
Sakaiya T Azechi H Matsuoka M Izumi N Nakai M Shigemori K Shiraga H Sunahara A Takabe H Yamanaka T 《Physical review letters》2002,88(14):145003
One of the most important quantities to be measured for better understanding of the ablative Rayleigh-Taylor (RT) instability is the growth rate in the short wavelength region at which the RT instability is significantly reduced. The short wavelength ( 4.7-12 microm) RT growth rates for direct-drive targets were measured for the first time by utilizing the innovated moiré interferometry [M. Matsuoka et al., Rev. Sci. Instrum. 70, 637 (1999)]. These growth rates were reasonably well reproduced by the simulation that solves the Fokker-Planck equation for nonlocal heat transport. 相似文献
996.
Matsugi M Shimada R Ohata S Nojima M Fukuda N Minamikawa J Kita Y 《Chemical & pharmaceutical bulletin》2002,50(11):1511-1513
An improved synthetic route of OPC-29030, the platelet adhesion inhibitor, was established via the diastereoselective oxidation of a chiral non-racemic sulfide (R)-5 to (S(S))-6 by the catalytic oxidation using VO(acac)(2) and cumene hydroperoxide (CHP) in the presence of MS4A. Under the current condition, the diastereoselectivity was not influenced by the presence of moisture, and moderate to high selectivity (72% de) was obtained at -30 degrees C. The obtained sulfoxide, which diastereomeric excess was easily raised by the recrystallization, could successfully lead to OPC-29030. 相似文献
997.
Han LB Zhao CQ Onozawa Sy SY Goto M Tanaka M 《Journal of the American Chemical Society》2002,124(15):3842-3843
The oxidative addition of pure (R(P))-menthyl phenylphosphinate 1 to a platinum (0) complex proceeds readily with retention of configuration at the chiral phosphorus center which was unambiguously confirmed by an X-ray analysis. In the presence of a catalytic amount of palladium, the hydrophosphinylation of a variety of alkynes with 1 also takes place stereospecifically, with retention of configuration, affording high yields of the corresponding vinylphosphinates bearing a single chirality at phosphorus. 相似文献
998.
Kurihara M Hirooka A Kume S Sugimoto M Nishihara H 《Journal of the American Chemical Society》2002,124(30):8800-8801
A new reversible isomerization cycle for meta-ferrocenylazobenzene accomplished by combination of a single green light (546 nm) and redox change between Fe(II) and Fe(III) was discovered. In the Fe(II) state, trans-to-cis isomerization proceeded upon the green light irradiation exciting the metal-to-ligand charge transfer (MLCT) in a high quantum yield (Phit-->c = 0.51) which exceeds that of azobenzene (Phit-->c = 0.12 (313 nm excitation)). The cis molar ratio reached 35% in the photostationary state. The oxidation to the Fe(III) state followed by irradiation with the same green light led to the cis-to-trans back-reaction to recover almost all of the trans-form. The "on-off switching" of the MLCT character played an important role in the redox-dependent response to the green light for the isomerization. The photoisomerization behavior of ferrocenylazobenzenes was strongly dependent on the substitution position of the ferrocenyl moiety on the benzene ring. The MLCT excitation was not effective for the trans-to-cis conversion in para-ferrocenylazobenzene. Time-dependent density functional theory (TD-DFT) calculations for meta- and para-ferrcenylazobenzene showed that the origin of the visible band (MLCT band) is different. The initial orbital for the MLCT in meta-ferrocenylazobenzene is delocalized over Fe and the Cp ring, while that in para-ferrocenylazobenzene is localized on the iron. 相似文献
999.
Three chiral guests in a cylindrical capsule led to six diastereomeric complexes. 相似文献
1000.
Du YZ Tomohiro T Zhang G Nakamura K Kodaka M 《Chemical communications (Cambridge, England)》2004,(5):616-617
Biotinylated and pyruvate kinase immobilized nano-bio element have been prepared using hetero-bifunctional latex beads, where the enzyme activity is roughly half of the free enzyme. 相似文献