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41.
The CN(B2Σ+ - X2Σ+) tail band emission system for μ′ = 11–20 resulting from the energy transfer reaction Ar(3P0,2) + BrCN in a flowing afterglow apparatus was measured. The vibrational and rotational distributions were determined as a function of argon pressure. Numerous perturbed rotational lines were observed; analysis of the dependences of these lines on argon pressure, with the aid of experimental information already published, led to the following assignments as to the origins of the perturbations: For μ′ = 11, N′ = 20 and μ′ = 13, N′ = 9, the perturbing state is a 4Σ+; for μ′ = 12, N′ = 10 and 14, μ′ = 14, N′ = 7 and 10, and μ′ = 17, N′ ≈ 17–19 the perturbing state is A 2Πi. The perturbed rotational line, μ′ = 11, N′ = 20, is found to be the primary source of intensity in the μ′ =11 vibrational band, but in all other cases the perturbed rotational lines do not significantly aid in the populating of the vibrational state. The anomalously high vibrational populations found in the tail band emission system (μ′ = 12, 14, 17 and 18), as well as the significantly high rotational excitations observed in the μ′ = 12–20 vibrational bands, apparently arise directly from the reaction intermediate. 相似文献
42.
Munetaka Nakata Tsutomu Fukuyama Kozo Kuchitsu Harutoshi Takeo Chi Matsumura 《Journal of Molecular Spectroscopy》1980,83(1):118-129
The microwave spectra of eight isotopic species of COCl2 have been observed, and the following rotational constants have been obtained: An analysis of the rotational constants has resulted in the rs and rm structures. The equilibrium structure, re, has been estimated by combining the rm parameters derived according to Watson's method and the re bond distances estimated in our recent electron-diffraction and spectroscopic studies to be , , ∠eClCCl = 111.79 ± 0.24°. 相似文献
43.
Itaka K Kanayama N Nishiyama N Jang WD Yamasaki Y Nakamura K Kawaguchi H Kataoka K 《Journal of the American Chemical Society》2004,126(42):13612-13613
An siRNA nanocarrier formed through self-assembly of PEG-based block catiomer possessing two distinct amino groups with different pKa values in a side chain was developed. This design provided the carrier with a sufficient siRNA complexation and an assumed buffering capacity in the endosomes, allowing it to exhibit remarkable gene knockdown abilities as well as sufficient serum tolerability. 相似文献
44.
Morita Y Nishida S Kobayashi T Fukui K Sato K Shiomi D Takui T Nakasuji K 《Organic letters》2004,6(9):1397-1400
[structure: see text] A bowl-shaped neutral radical with a corannulene system has been designed and synthesized for the first time as a stable solid in air. An unequivocal characterization of the electronic properties of the radical shows that an appreciable amount of spin delocalization extends onto the corannulene unit's curved surface. 相似文献
45.
Gajare AS Toyota K Yoshifuji M Ozawa F 《Chemical communications (Cambridge, England)》2004,(17):1994-1995
1,2-Diphenyl-3,4-bis[(2,4,6-tri-tert-butylphenyl)phosphinidene]cyclobutene was used as an additive ligand in copper-catalysed amination reactions of halobenzenes with amines in the presence of base to afford the corresponding secondary or tertiary amines in good to excellent yields. 相似文献
46.
The electrophilic cyclization of propargylic aziridines is described. 3-Iodopyrroles having a variety of substituents were conveniently synthesized by the reaction of propargylic aziridines with iodine. The resulting substituted 3-iodopyrrole was further functionalized to the tri-substituted pyrroles with high efficiency. 相似文献
47.
N-Heterocyclic carbene-catalyzed transformation of 4-formylbenzoates and α,β-unsaturated aldehydes to cyclic hemiacetals is described. The reaction proceeded smoothly when the sulfopropyl-substituted imidazolium salt was used as the catalyst. Various substrates were converted to the corresponding cyclic hemiacetals in a stereoselective manner. 相似文献
48.
Toshifumi Yui Kiego Miyawaki Yoshinobu Kawano Kozo Ogawa 《Journal of carbohydrate chemistry》2013,32(8):905-914
ABSTRACT Miniature crystal models of six small carbohydrates were examined using the PM3 semiempirical quantum mechanics method. The minicrystal structures, consisting of 27 sugar residues, were optimized by the combined procedure of partial optimization and reconstruction of the model, while maintaining the original crystal symmetries. All of the minicrystals were successfully optimized without exhibiting a great increase in an energy at any reconstruction step. Some minicrystals showed a prolonged behavior of optimization cycles. A major source of structure change appeared to arise from hydroxyl group rotations wherein the largest movements mostly occurred in an early optimization stage. No significant deformations in geometry of either residues or hydrogen bonds were observed in the final minicrystal structures. The thermodynamic values calculated for the optimized minicrystals were in reasonably good agreement with the literature data. The present study indicated that the PM3 semiempirical method successfully predicted the basic features of intermolecular hydrogen bonding involved in a condensed system. 相似文献
49.
50.
T. Kondow A. Matsushita K. Kuchitsu K. Nishiyama Y. Morozumi K. Nagamine 《Hyperfine Interactions》1986,32(1-4):807-812
Surface muons produced in UT-MSL were introduced into argon gas of 4.0±0.2 atm with NO2 (0–30 ppm), and muonium signals were detected in the presence of a transverse (1.7–3.4 G) and a longitudinal magnetic field
(0–3.5 kG) at 295±1 K. The cross section for the transverse relaxation was (11.0±1.0)×10−16 cm2. The relaxation rates in different longitudinal magnetic fields show that the rate does not follow the conventional equation
which assumes that the relaxation occurs mainly by spin-exchange interaction. Similar measurements were performed for the
Mu+O2 system. These findings indicate that chemical reactions contribute to these relaxation rates. 相似文献