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排序方式: 共有202条查询结果,搜索用时 15 毫秒
1.
2.
A. Breakstone G. Claesson H. B. Crawley G. M. Dallavalle K. Doroba D. Drijard F. Fabbri A. Firestone M. A. Faessler H. G. Fischer S. Y. Fung S. Garpman W. Geist G. Giacomelli R. Gokieli M. Gorbics C. R. Gruhn P. Hanke M. Heiden W. Herr T. J. Ketel E. E. Kluge J. W. Lamsa T. Lohse I. Lund R. Mankel W. T. Meyer G. Mornacchi T. Nakada I. Otterlund M. Panter H. Pugh A. Putzer K. Rauschnabel B. Rensch F. Rimondi M. Schmelling G. P. Siroli R. Sosnowski E. Stenlund M. Szczekowski R. Szwed O. Ullaland R. Walczak D. Wegener M. Wunsch 《Zeitschrift fur Physik C Particles and Fields》1986,30(4):507-512
The relative yields of kaons and protons compared with the yield of pions at highp T and polar angles θ away from 90° (in the range from 10° to 45°) are presented forpp, dd, and αα interactions at a centre-of-mass energy \(\sqrt {s_{NN} } = 31\) GeV per nucleon-nucleon collision. The measured particle ratios depend on the atomic mass numberA of the beam particles and on θ. TheA dependence of the ratios becomes stronger for largerp T and is more pronounced at smaller polar angles. 相似文献
3.
W. Bell K. Braune G. Claesson D. Drijard M. A. Faessler H. G. Fischer H. Frehse R. W. Frey S. Garpman W. Geist C. Gruhn P. Hanke M. Heiden W. Herr P. G. Innocenti T. J. Ketel E. E. Kluge I. Lund G. Mornacchi T. Nakada I. Otterlund M. Panter B. Povh A. Putzer E. Stenlund T. J. M. Symons R. Szwed O. Ullaland 《Zeitschrift fur Physik C Particles and Fields》1986,30(4):513-520
Properties of secondaries associated with a high-p T charged trigger particle (3<p T <5 GeV/c) were studied for αp and αα interactions at c.m. energies \(\sqrt s = 88\) GeV and 125 GeV, respectively. Thep T distributions of secondaries in the away-jet and trigger-jet regions were compared with those for high-p T pp interactions. No statistically significant differences were seen, except at lowp T . Momentum and angular distributions of spectator and leading protons were studied as a function of charge and rapidity of the trigger hadron. The observed correlations between trigger charge and number of spectator protons provide evidence of valence quark contributions to the trigger jet. 相似文献
4.
The synthesis of 3-pyridyl biaryl systems can be readily achieved by means of palladium-catalyzed Suzuki cross-coupling reactions between aryl halides and 3-pyridylboroxin. A series of cross-couplings were conducted in order to investigate the scope and limitations of this protocol. 相似文献
5.
Copper was determined non-destructively by neutron-activation analysis in the high purity metals Be, Bi, Pb, Se, Sn, Tl and
in iron meteorite specimens down to concentrations of 40 ppb, while the minimum detectable mass for 1 g-samples as defined
recently byCurrie
25 was about 0.1 ppb Cu. γ,γ-coincidence counting of the annihilation radiation of64Cu essentially improved suppression of interferences by other γ-cascade emitters. The latter was achieved by increasing the
detector distances and by counting in centric and eccentric positions with respect to the detectors. Using the 180°-angle
correlation of the annihilation γ-quants of64Cu etc. an increase in selectivity—in relation to conventional coincidence methods—was achieved by a factor of about 103. A goniometer arrangement proved to be very advantageous.
相似文献
6.
Summary Optically pure (+)-beta-eudesmol is a possible starting material for the synthesis of several termite defense compounds. A
two step procedure for the isolation of gram quantities of (+)-beta-eudesmol from commercially availableAmyris balsamifera oil (syn. West Indian sandalwood oil), containing 8% beta-eudesmol, was developed. Step one consisted of an efficient vacuum
distillation of the total oil. Step two was a medium pressure LC separation with an AgNO3 impregnated silica gel stationary phase. Several other separation procedures failed due to the presence of many closely related
sesquiterpene alcohols (75% of the oil). 相似文献
7.
A new route has been developed for the micro-determination of227Ac in geological materials by neutron activation. The method is based on intense neutron irradiation of the analysed samples followed by separation and α-spectrometric determination of228Th, the β-decay product of the 6.1 hrs228Ac isotope formed. Two alternatives are considered for analysis related to the origin of the analysed matrix. The high sensitivity of the method is documented by the determination of 10?17 g227Ac/g sample. The method is successfully applied for age determination of five uranium containing materials and old uranium glass from Bohemia, CSSR. 相似文献
8.
Functionalized keto-enamines 6 were obtained by nucleophilic addition of enol ethers to the imine moiety of 2-azadienes derived from dehydroaspartic esters 4. Reactions of 2-azadiene 4c containing three electron-withdrawing substituents (CO(2)R) with enol ethers 5 in the presence of lithium perchlorate led to the formation of tetrahydropyridine derivatives 7 in a regio- and stereoselective fashion. 2H-[1,3]-oxazines 10 and pyridine derivatives 12 and 13 were obtained by heterocycloaddition reactions of electron-poor azadienes 4d-g containing two electron-withdrawing substituents (4-O(2)N-C(6)H(4), CO(2)R) in positions 1 and 4 with carbonyl derivatives (ethyl glyoxalate 9a and diethyl ketomalonate 9b) and the electron-deficient olefin tetracyanoethylene 11. 相似文献
9.
Breakstone A Crawley HB Dallavalle GM Doroba K Drijard D Fabbri F Firestone A Fischer HG Frehse F Geist W Giacomelli G Gokieli R Gorbics M Hanke P Heiden M Herr W Kluge EE Lamsa JW Lohse T Meyer WT Mornacchi G Nakada T Panter M Putzer A Rauschnabel K Rimondi F Siroli GP Sosnowski R Szczekowski M Ullaland O Wegener D 《Physical review letters》1985,55(20):2180-2183
10.
Estimation of diuretic drugs in biological fluids by HPLC 总被引:1,自引:0,他引:1
Summary This critical review of different methods proposed for the determination and screening of diuretics is directed mainly, because of its potential application, towards highperformance liquid chromatography. 相似文献