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31.
32.
M. Derrick K. K. Gan P. Kooijman J. S. Loos B. Musgrave L. E. Price J. Repond K. Sugano M. Valdata-Nappi D. Blockus B. Brabson J. -M. Brom C. Jung H. Ogren D. R. Rust C. Akerlof J. Chapman D. Errede M. T. Ken D. I. Meyer D. Nitz R. Thun R. Tschirhart S. Abachi P. Baringer B. G. Bylsma R. DeBonte D. Koltick F. J. Loeffler E. H. Low R. L. McIlwain D. H. Miller C. R. Ng L. K. Rangan E. I. Shibata B. Cork 《Zeitschrift fur Physik C Particles and Fields》1987,35(3):323-328
The charged particle multiplicity distributions for two-jet events ine + e ? annihilation at 29 GeV have been measured using the High Resolution Spectrometer at PEP. A Poisson distribution describes the data for both the complete event and for the single jets. In addition, no correlation is observed between the multiplicities in the two jets of an event. For fixed values of the prong number of the complete event, the multiplicity sharing between the two jets is in good agreement with a binomial distribution. The rapidity gap distribution is exponential with a slope equal to the mean rapidity density. These observations, which are consistent with a picture of independent emission of single particles, are contrasted to the results from soft hadronic collisions and conclusions are drawn about the nature of clusters. 相似文献
33.
Huub Kooijman Anthony L. Spek Henk Kleijn Hendrik L. van Maanen Johann T. B. H. Jastrzebski Gerard van Koten 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(4):481-483
The configuration of the chiral ring atoms of the title compound, C26H26N2O, obtained in an enantioselective synthesis, has been established relative to the known R configuration of the α‐methylbenzyl moieties. The crystal packing involves a two‐dimensional network of C—H?π interactions between the aromatic rings. 相似文献
34.
Alberico E Baumann W de Vries JG Drexler HJ Gladiali S Heller D Henderickx HJ Lefort L 《Chemistry (Weinheim an der Bergstrasse, Germany)》2011,17(45):12683-12695
The mechanism of the asymmetric hydrogenation of methyl (Z)-2-acetamidocinnamate (mac) catalysed by [Rh(MonoPhos)(2)(nbd)]SbF(6) (MonoPhos: 3,5-dioxa-4-phosphacyclohepta[2,1-a:3,4-a']dinaphthalen-4-yl)dimethylamine) was elucidated by using (1)H, (31)P and (103)Rh NMR spectroscopy and ESI-MS. The use of nbd allows one to obtain in pure form the rhodium complex that contains two units of the ligand. In contrast to the analogous complexes that contain cis,cis-1,5-cyclooctadiene (cod), this complex shows well-resolved NMR spectroscopic signals. Hydrogenation of these catalyst precursors at 1 bar total pressure gave rise to the formation of a bimetallic complex of general formula [Rh(MonoPhos)(2)](2)(SbF(6))(2); no solvate complexes were detected. In the dimeric complex both rhodium atoms are ligated to two MonoPhos ligands but, in addition, each rhodium atom also binds to one of the binaphthyl rings of a ligand that is bound to the other rhodium metal. Upon addition of mac, a mixture of diastereomeric complexes [Rh(MonoPhos)(2)(mac)]SbF(6) is formed in which the substrate is bound in a chelate fashion to the metal. Upon hydrogenation, these adducts are converted into a new complex [Rh(MonoPhos)(2){mac(H)(2)}]SbF(6) in which the methyl phenylalaninate mac(H)(2) is bound through its aromatic ring to rhodium. Addition of mac to this complex leads to displacement of the product by the substrate. No hydride intermediates could be detected and no evidence was found for the involvement at any stage of the process of complexes with only one coordinated MonoPhos. The collected data suggest that the asymmetric hydrogenation follows a Halpern-like mechanism in which the less abundant substrate-catalyst adduct is preferentially hydrogenated to phenylalanine methyl ester. 相似文献
35.
Abachi S Derrick M Kooijman P Musgrave B Price LE Repond J Sugano K Blockus D Brabson B Brom J Jung C Ogren H Rust DR Akerlof C Chapman J Errede D Ken MT Meyer DI Neal H Nitz D Thun R Tschirhart R Baringer P Bylsma BG DeBonte R Koltick D Low EH McIlwain RL Miller DH Ng CR Shibata EI 《Physical review D: Particles and fields》1989,40(3):902-905
36.
Abachi S Akerlof C Baringer P Blockus D Brabson B Brom J Bylsma BG Chapman J Cork B DeBonte R Derrick M Errede D Gan KK Jung C Ken MT Koltick D Kooijman P Loeffler FJ Loos JS Low EH McIlwain RL Meyer DI Miller DH Musgrave B Neal H Ng CR Nitz D Ogren H Paik HW Price LE Rangan LK Repond J Rust DR Shibata EI Sugano K Thun R Tschirhart R 《Physical review letters》1987,59(22):2519-2522
37.
M. Derrick P. Kooijman J.S. Loos B. Musgrave L.E. Price J. Schlereth K. Sugano J.M. Weiss D.E. Wood P. Baringer D. Blockus B. Brabson S.W. Gray C. Jung H. Neal H. Ogren D.R. Rust M. Valdata-Nappi B. Cork 《Physics letters. [Part B]》1985,158(6):519-524
The production of neutral K1(890) and ρ0 mesons was studied in e+e? annihilation at using the High Resolution Spectrometer at PEP. Differential cross sections are presented as a function of the scaled energy variable z and compared to π0 and K0 production. The measured multiplicities are 0.84±0.08 ?0 mesons and mesons per event for a meson momentum greater than 725 MeV/c. The ratios of vector meson to pseudoscalar meson production for (u,d), s and c quark are compared to predictions of the Lund model. 相似文献
38.
Koevoets RA Versteegen RM Kooijman H Spek AL Sijbesma RP Meijer EW 《Journal of the American Chemical Society》2005,127(9):2999-3003
Selective incorporation of bisurea guests in thermoplastic elastomers with poly(tetrahydrofuran) soft blocks and bisurea containing hard blocks is observed when the distances between the urea groups of host and guest match. The incorporation leads to significant modulation of mechanical properties. With bisurea-functionalized dyes as guests, a strong difference in extractability by detergent solution was shown between dyes differing by just one methylene unit between urea groups. Upon elongation of elastomer films, strong differences in alignability of matching and nonmatching dyes were observed. 相似文献
39.
Summary Nine different CuII(sulf)2 and three mixed CuII(sulf)2X2–3 (X=NH3 or pyridine) derivatives were prepared from CuII and sulfanilamides (sulfH=sulfadiazine, sulfadimethoxine, sulfadimidine, sulfamerazine, sulfamethoxydiazine, sulfamethoxypyridazine, sulfapyridine, sulfathiazole and sulfisomidine) in alkaline solution and their e.s.r., i.r. and ligandfield spectroscopic properties were evaluated. Two types of Cu(sulf)2 complexes were formed: dimeric and monomeric/ polymeric species. 相似文献
40.
Martijn J.J. Mulder Huub Kooijman Anthony L. Spek Jaap. G. Haasnoot Jan Reedijk 《Journal of chemical crystallography》2002,32(9):347-351
The crystal structure of the title compound, tetrabutylammonium bis(2-thioxo-1,3-dithiole-4,5-dithiolato)nickelate(III), [N(C4H9)4][Ni(C3S5)2], is the fourth known phase of this polymorphous compound. It is monoclinic space group P21/c, with a = 20.040(2) Å, b = 13.1151(17) Å, c = 12.1093(15) Å, = 105.456(15)°, and V = 3067.5(6) Å3 with Z = 4, for D
calc = 1.503 g cm–3. The [Ni(dmit)2] anion packing arrangement consists of arrays of side-on touching anions and these arrays are connected via head-to-tail close S S contacts. 相似文献