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81.
Self-organization of cationic polymer particles through hydrophobic interaction on polymer films in aqueous system and characteristic
properties of the resulting particle monolayers were investigated. Cationic polymer particles bearing quaternary ammonium
groups on their surfaces effectively self-organized on polymer films. With an increase of the particle surface charge density,
the surface coverage and average aggregate size (N
a) decreased. The surface coverage control was accomplished by tuning the ionic strength of the media. The wettability of polymer
films for water was imparted by the formation of particle monolayers on them. Annealing of the particle monolayers resulted
in the increase of the adhesive strength, while the wettability for water was lost. Further improvements of both wettability
and adhesive strength of particle monolayers were achieved by the immobilization of silica colloids on the particle monolayers.
This method would be effective for the hydrophilization of polymer films. 相似文献
82.
Kazuo Mukai Kanae Nagai Aya Ouchi Tomomi Suzuki Katsuhiro Izumisawa Shin-Ichi Nagaoka 《国际化学动力学杂志》2019,51(9):643-656
Measurements of aroxyl radical (ArO•)-scavenging rate constants () of antioxidants (AOHs) (α-tocopherol (α-TocH) and three catechins (CatHs) (ie, epicatechin (EC), epigallocatechin (EGC), and epigallocatechin gallate (EGCG)) were performed in ethanol solution, using stopped-flow spectrophotometry. values were measured not only for each AOH, but also for the mixtures of two AOHs (α-TocH and CatH). A notable synergistic effect that the value of α-TocH increases 1.29, 1.84, and 1.65 times under the coexistence of constant concentrations of EC, EGC, and EGCG, respectively, was observed for the solutions including α-TocH and CatH. Similarly, values of CatHs (EC, EGC, and EGCG) increased 1.72, 2.25, and 2.34 times under the coexistence of constant concentrations of α-TocH, respectively. UV-Vis absorption of α-tocopheroxyl radical (α-Toc•) (λmax = 428 nm), which had been produced by reaction of α-TocH with ArO•, decreased remarkably under the coexistence of α-TocH and CatHs due to the fast α-TocH-regeneration reaction by CatHs. The result suggests that the prooxidant reaction due to α-Toc• is suppressed by the coexistence of CatHs. By analyzing the formation and decay curves of α-Toc•, it has been ascertained that one molecule of EGCG having three OH groups at B-ring may rapidly regenerate three molecules of α-Toc• to α-TocH. 相似文献
83.
Y. Inomata M. Aoyama T. Tsubono D. Tsumune Y. Kumamoto H. Nagai T. Yamagata M. Kajino Y. T. Tanaka T. T. Sekiyama E. Oka M. Yamada 《Journal of Radioanalytical and Nuclear Chemistry》2018,318(3):1587-1596
Distributions of radiocaesium (134Cs and 137Cs) derived from the Tokyo Electric Power Company (TEPCO) Fukushima Dai-ichi Nuclear Power Plant (FNPP1) accident in the North Pacific Ocean in the summer of 2012 were investigated. We have estimated the radiocaesium inventory in the surface layer using the optimal interpolation analysis and the subducted amount into the central mode water (CMW) by using vertical profiles of FNPP1-134Cs and mass balance analysis as the first approach. The inventory of the 134Cs in the surface layer in the North Pacific Ocean in August–December 2012 was estimated at 5.1?±?0.9 PBq on 1 October 2012, which corresponds to 8.6?±?1.5 PBq when it was decay corrected to the date of the FNPP1 accident, 11 March 2011. It was revealed that 56?±?10% of the released 134Cs into the North Pacific Ocean, which was estimated at 15.3?±?2.6 PBq, transported eastward in the surface layer in 2012. The amount of 134Cs subducted in the CMW was estimated to be 2.5?±?0.9 PBq based on the mass balance among the three domains of the surface layer, subtropical mode water, and CMW. 相似文献
84.
D. Okai R. Nagai G. Motoyama T. Fukami T. Yamasaki Y. Yokoyama H.M. Kimura A. Inoue 《Physica C: Superconductivity and its Applications》2010,470(20):1048-1051
The superconducting property of Zr(1−x)Cox (x = 10–50 at.%) alloys and a Zr55Co30Al15 bulk metallic glass fabricated using techniques of rapid solidification was investigated. The Zr55Co30Al15 alloy crystallized by heat treatment in a vacuum atmosphere exhibited superconductivity of Tc,on = 2.4 K. This was attributable to the superconducting property of a crystalline Zr–Co alloy precipitated in the Zr55Co30Al15 alloy. The Tc,on of the crystalline Zr(1−x)Cox alloy was sensitive to the Co content. The increase of Co content for the Zr(1−x)Cox alloy led to the decrease of Tc,on. The Zr(1−x)Cox alloy exhibited superconductivity of a maximum Tc,on = 3.9 K for the Zr80Co20 alloy with superconducting nanocrystal particles embedded in the amorphous matrix. 相似文献
85.
J Szeman H Ueda J Szejtli E Fenyvesi Y Machida T Nagai 《Chemical & pharmaceutical bulletin》1987,35(1):282-288
86.
Akon Higuchi Tadashi Nakajima Atsushi Morisato Michiaki Ando Kazukiyo Nagai Tsutomu Nakagawa 《Journal of Polymer Science.Polymer Physics》1996,34(13):2153-2160
Infrared spectra of CO2 sorbed in rubbery and glassy polymeric membranes were measured to examine the relationships between the spectroscopic data and the physical properties of the membranes. The two peaks observed in the spectra of CO2 were attributed to the R branch and P branch of CO2 sorbed in the membranes based on the consideration that both peaks were observed at a temperature above the glass transition temperature of the membranes. Apparent diffusion coefficients of CO2 in the membranes were measured from the desorption kinetics of CO2 detected by FTIR spectroscopy. The solubility coefficients of CO2 were also estimated from absorbance spectra of CO2 sorbed in the membranes using Lambert-Beer's rule. The permeability, solubility, and diffusion coefficients estimated by the FTIR method were found to correlate well with the coefficients obtained by conventional methods such as vacuum-pressure or sorption isotherm methods. © 1996 John Wiley & Sons, Inc. 相似文献
87.
Vibronic Structures in Absorption and Fluorescence Spectra of Firefly Oxyluciferin in Aqueous Solutions 下载免费PDF全文
Miyabi Hiyama Yoshifumi Noguchi Hidefumi Akiyama Kenta Yamada Nobuaki Koga 《Photochemistry and photobiology》2015,91(4):819-827
To elucidate the factors determining the spectral shapes and widths of the absorption and fluorescence spectra for keto and enol oxyluciferin and their conjugate bases in aqueous solutions, the intensities of vibronic transitions between their ground and first electronic excited states were calculated for the first time via estimation of the vibrational Franck–Condon factors. The major normal modes, overtones and combination tones in absorption and fluorescence spectra are similar for all species. The theoretical full widths at half maximum of absorption spectra are 0.4–0.7 eV and those for the fluorescence spectra are 0.4–0.5 eV, except for phenolate‐keto that exhibits exceptionally sharp peak widths due to the dominance of the 0–0′ or 0′–0 band. These spectral shapes and widths explain many relevant features of the experimentally observed spectra. 相似文献
88.
Abe T Miyakushi S Nagai K Norimatsu T 《Physical chemistry chemical physics : PCCP》2008,10(11):1562-1568
Some types of phthalocyanines (MPc (M = H(2), Cu, or Zn), a p-type semiconductor) were used in combination with 3,4,9,10-perylenetetracarboxyl-bisbenzimidazole (PTCBI, an n-type semiconductor), with which those photoelectrode characteristics in the water phase were investigated in terms of kinetics. Each film of the PTCBI/MPc bilayer functioned as a photoanode, where the photoinduced oxidation of thiol occurs at the MPc/water interface along with the hole conduction through the MPc layer. The holes originate on account of the photophysical events in the p/n interior, involving the charge separation of excitons at the p/n interface. The typical photoelectrochemical characteristic in the PTCBI/MPc photoanodes involved a transient photocurrent occurring in the initial stage under illumination (under potentiostatic conditions): thereafter, it attained a steady state. Moreover, both the initial spiky photocurrents and the steady-state photocurrents exhibited saturation at higher concentrations. An analysis with photoelectrode kinetics was performed by assuming an adsorption step prior to a rate-limiting charge transfer step, where equations were applied to photocurrents based on the Langmuir adsorption equilibrium. The kinetic analyses evidently showed that the photoanodic reactions are kinetically dominated by the charge transfer between MPc and thiol, where the overall kinetics for thiol oxidation decreases in the following order: H(2)Pc > ZnPc > CuPc; that is, it appeared that H(2)Pc acts as the more efficient photofunctional interface capable of oxidation in the water phase when PTCBI was concurrently employed as an electron conductor. Considering that the photocurrent generated is proportional to the surface concentration of thiol (Gamma) at the MPc as well as the intrinsic oxidation rate (cf., ZnPc > H(2)Pc approximately CuPc), the higher efficiency in the output at the H(2)Pc surface was attributed to an exceptionally high Gamma (i.e., from the kinetic analyses, the Gamma value at the H(2)Pc surface was also inferred to be 2-3 times higher than that at the other MPcs). Through the present kinetic analysis, it also revealed that the activity for thiol oxidation taking place at Pc ring is comparable to that at the conventional active catalysts (i.e., polycarboxyphthalocyaninato Co(ii) and Fe(iii)) where a central metal is an active site. 相似文献
89.
Taisei Ueda Tsuneyasu Adachi Shin-Ichi Nagai Jinsaku Sakakibara Mitsuo Murata 《Journal of heterocyclic chemistry》1988,25(3):791-794
[1,2,4]Triazino[3,2-f]purines 3a-e and [1,2,4]triazepino[3,2-f]purine 5 were synthesized by the reaction of 7,8-diamino-1,3-dimethylxanthine 1 with diketones such as glyoxal, diacetyl, dibenzoyl, pyruvic aldehyde dimethyl acetal, phenylglyoxal or acetylacetone in acetic acid in the presence of boric acid or polyphosphoric acid. 相似文献
90.