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1.
Mao‐Chuan Yuan Ping‐I Shih Chen‐Han Chien Ching‐Fong Shu 《Journal of polymer science. Part A, Polymer chemistry》2007,45(14):2925-2937
We have synthesized a blue‐light‐emitting polyfluorene (PF) derivative ( PF‐CBZ‐OXD ) that presents bulky hole‐transporting carbazole and electron‐transporting oxadiazole pendent groups functionalized at the C‐9 positions of alternating fluorene units. The results from photoluminescence and electrochemical measurements indicate that both the side chains and the PF main chain retain their own electronic characteristics in the copolymer. An electroluminescent device incorporating this polymer as the emitting layer was turned on at 4.5 V; it exhibited a stable blue emission with a maximum external quantum efficiency of 1.1%. Moreover, we doped PF‐CBZ‐OXD and its analogue PF‐TPA‐OXD with a red‐light‐emitting iridium phosphor for use as components of phosphorescent red‐light emitters to investigate the effect of the host's HOMO energy level on the degree of charge trapping and on the electrophosphorescent efficiency. We found that spectral overlap and individual energy level matching between the host and guest were both crucial features affecting the performance of the electroluminescence devices. Atomic force microscopy measurements indicated that the dipolar nature of PF‐CBZ‐OXD , in contrast to the general nonpolarity of polydialkylfluorenes, provided a stabilizing environment that allowed homogeneous dispersion of the polar iridium triplet dopant. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 2925–2937, 2007 相似文献
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W. Haerdi et Ed. Mérat 《Fresenius' Journal of Analytical Chemistry》1973,264(5):376-377
A method for the rapid separation of copper(II) traces on metallic mercury is proposed. The separation is rendered possible by the reduction of Cu(II) to Cu(I) on mercury in the presence of iodide ions followed by the adsorption of the uncharged complex, Cu(I), on Hg0. After a minute of agitation, this adsorption is quantitative (90–100%) for initial concentrations of Cu(II) between 10–4 to 10–6 M and iodide cone, of 10–2 to 10–3 M at pH 3. The volumes of the aqueous solutions are of the order of 3–10 ml and those of the drops of mercury between 0.5–1 ml. The tests were made using the isotope 64Cu (T
1/2 = 12.8 h).
Trennung von Metallspuren am Quecksilbertropfen; Anwendung auf die Anreicherung von Cu(II) und Cu(I)
Zusammenfassung Die Arbeit beschreibt eine Methode zur Schnelltrennung von Kupfer(II)-Spuren auf metallischem Quecksilber. Diese Vorkonzentration ist durch die Reduktion des Cu(II) zu Cu(I) durch Hg0 in Jodidmedium und anschließende Adsorption des ungeladenen Kupferjodidkomplexes, CuJ, an diesem Metall möglich. Die Adsorption ist nach 1 min Rühren quantitativ (90–100%) für Ausgangswerte von Cu(II) zwischen 10–6 und 10–4M, im Jodidmedium von 10–3 bis 10–2 M bei pH 3. Die Volumina der wäßrigen Lösung liegen in der Größenordnung von 3–10 ml, die der Hg-Tropfen von 0,5–1 ml. Die Versuche wurden mit Hilfe von 64Cu (T 1/2 = 12,8 h) durchgeführt.
Exposé présenté à la conférence Euroanalysis I, août 28 à septembre 1, 1972, à Heidelberg, Allemagne. 相似文献
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Hydroxylamine derivatives of (S)-prolinol have been generated using a Cope elimination. These undergo reverse-Cope elimination onto a pendant double bond to give morpholine N-oxides containing three contiguous chiral centres. 相似文献
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The result stated in the title is proved.Research of the second author partially supported by the National Science Foundation. He would also like to thank the Banach Institute, Polish Academy of Sciences and Universität Kaiserslautern for their hospitality. 相似文献
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Xue Hua Hui-Jie Hong Dai-Yan Zhang Qiao Liu Fong Leong Qi Yang Yuan-Jia Hu Xiao-Jia Chen 《Molecules (Basel, Switzerland)》2022,27(4)
In this study, a high-performance thin layer chromatography (HPTLC) method by two step gradient elution with two mobile phases was developed for the simultaneous analysis of seven constituents in Ophiopogonis Radix. The chromatography was performed on silica gel 60 F254 plate with dichloromethane-methanol-ethyl acetate-water (70:25:12:3, v/v/v/v) and dichloromethane-methanol (300:1, v/v) as the mobile phase for two step gradient elution. Then, the HPTLC profiles were observed after derivatization with 10% sulfuric acid in ethanol solution. The obtained HPTLC images were further analyzed by chemometric approaches and the samples could be clustered based on regions and/or growth years, which were two important factors affecting the constituents in Ophiopogonis Radix. Furthermore, five compounds including ophiopogonin D, ophiopojaponin C, ophiopogonin D’, ophiopogonin C’ and methylophiopogonanone B were screened as potential lipase inhibitors from Ophiopogonis Radix by the HPTLC-bioautographic method. The binding modes and interactions between the five compounds and lipase were further explored by molecular docking analysis. The developed HPTLC method could be used for quality control of Ophiopogonis Radix and screening of the potential lipase inhibitors. 相似文献
9.
Gerald D Fong Robert L Kuczkowski Arthur J Ashe 《Journal of Molecular Spectroscopy》1978,70(2):197-208
The microwave spectrum of 121-SbC5H5, 123-SbC5H5, β-dideutero 121-SbC5H3D2 and 123-SbC5H3D2 has been assigned in the region 26.5–40.0 GHz. The respective rotational constants and uncertainties are: A = 4512.69 ± 0.42, B = 1738.00 ± 0.01, C = 1254.51 ± 0.01; A = 4512.84 ± 0.30, B = 1729.80 ± 0.01, C = 1250.22 ± 0.01; A = 4176.18 ± 0.33, B = 1660.94 ± 0.01, C = 1188.15 ± 0.01; A = 4176.60 ± 0.61, B = 1652.94 ± 0.03, C = 1184.03 ± 0.03 (in MHz units). The structure is found to be planar, C2v in symmetry. The and ∠CSbC = 92.9° ± 1.0°. The nuclear quadrupole coupling constants for the 121 and 123 antimony isotopes are χaa = 456.4 ± 4.1 MHz, η = 0.396 ± 0.008, and χaa = 583.00 ± 5.3 MHz, η = 0.399 ± 0.008, respectively. Several alternate techniques using the coupling constants as data support a σ-donating property for antimony. 相似文献
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