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981.
982.
Tadatomi Nishikubo Hiroto Kudo Mayu Yoshihara Ken Maruyama 《Journal of polymer science. Part A, Polymer chemistry》2005,43(10):2028-2037
The thermal curing reaction of polyfunctional oxetanes (oxetane resins) such as tris[4‐(3‐ethyloxetane‐3‐yl)methoxyphenyl]methane (TEOMP) and 1,3,5‐tris(3‐ethyl‐3‐oxetanylmethoxy)benzene with certain polyfunctional phenols was performed in bulk with quaternary onium salts as catalysts. The reaction proceeded smoothly at 180–220 °C and produced insoluble gel products, and the rate of gel production increased with the reaction temperature. The rate of the addition reaction of TEOMP with 3,3′,5,5′‐tetrachlorobisphenol A was also measured by IR spectroscopy, and the rate of reaction was proportional to the product of the oxetane concentration and the catalyst concentration in the film state. Furthermore, the glass‐transition temperatures and 5 and 10 wt % weight‐loss temperatures of the resulting gel products were confirmed with differential scanning calorimetry and thermogravimetric analysis, and the glass‐transition temperatures and 5 wt % weight‐loss temperatures were 127–162 °C and 323–351 °C, respectively. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 2028–2037, 2005 相似文献
983.
A. S. Levchenko A. N. Khotjantsev A. P. Ivashkin M. Abe M. A. Aliev V. V. Anisimovsky M. Aoki I. Arai Y. Asano T. Baker M. Blecher P. Depommier M. Hasinoff K. Horie H. C. Huang Y. Igarashi T. Ikeda J. Imazato M. M. Khabibullin Yu. G. Kudenko Y. Kuno L. S. Lee G. Y. Lim J. A. Macdonald D. R. Marlow C. R. Mindas O. V. Mineev C. Rangacharyulu S. Shimizu Y. -M. Shin A. Suzuki A. Watanabe N. V. Yershov T. Yokoi 《Physics of Atomic Nuclei》2002,65(12):2232-2237
The form factors of the decay K + → π 0 e + ν e (K e3) have been determined from the comparison of the experimental and Monte Carlo Dalitz distributions containing about 105 K e3 events. The following values of the parameters were obtained: λ +=0.0278±0.0017 (stat.)±0.0015 (syst.), |f S/f +(0)|=0.0040±0.0160 (stat.)±0.0067 (syst.), and |f T/f +(0)|=0.019±0.080 (stat.)±0.038 (syst.). Both scalar f S and tensor f T form factors are consistent with the Standard Model predictions of zero values. 相似文献
984.
Toshihiro Arai Yoichi Tominaga Shigeo Asai Masao Sumita 《Journal of Polymer Science.Polymer Physics》2005,43(18):2568-2577
Highly loaded graphite–polymer composites for a bipolar plate of polymer electrolyte fuel cell are studied. One of the composites contains of polypropylene (PP), and graphite powder and the other contains of poly(vinylidene fluoride) (PVDF) and the graphite, respectively. The electrical and physical properties for the composites are determined. Inverse gas chromatography (IGC) measurements are carried out to characterize the surface of the graphite and the interface between the graphite and each polymer, following the Fowkes scheme. The IGC measurements show that the surface of graphite is nucleophilic and strongly attracts electrophiles by acid–base interaction. It is considered to be reasonable that the main chain carbon atoms to which electronegative fluorine atoms bond in PVDF are nucleophilic and has strong acid–base interaction with graphite. Such strong interaction causes high electric resistivity, high flexural properties, and high melt viscosity of the composite. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 2568–2577, 2005 相似文献
985.
We introduce a one-dimensional model involving the nucleation and the drift of many particles. The model originates from interacting kink systems and simulates time evolution in modulated systems. In this model the nucleation rate of a particle depends nonlocally on the density of preexisting particles and the drift of particles is due to a weak and repulsive interaction among them. We first study the statistics of this model in the case that the drift of particles is negligible, and then consider the effects of the drift of particles. 相似文献
986.
Masahiro Hasegawa Kunio Arai Shozaburo Saito 《Journal of polymer science. Part A, Polymer chemistry》1987,25(11):3117-3125
The encapsulation of inorganic powder of submicron sizes was attempted with soapless emulsion polymerization of methyl methacrylate in water in the presence of the powder. The powders used were barium sulfate and calcium carbonate. The polymerizations were initiated by potassium persulfate and by sodium bisulfite-oxygen redox reaction. The encapsulation state of the powder with the polymer formed varied considerably with the initiators used. With potassium persulfate initiator the powder surface was partially or totally covered by polymer particles, while with redox initiator under air atmosphere the powder surface was well encapsulated with a film-like polymer layer. From the differences in the encapsulation states, an encapsulation mechanism is suggested for each initiator system. Based upon this mechanism, a new encapsulation process capable of covering uniformly fine powders with a film polymer is proposed. An important factor in the new process is the addition of an extremely small quantity of a surfactant into the reaction system prior to the polymerization. 相似文献
987.
The unexplored terahertz (THz) region involves important phenomena of both fundamental and applied natures. Examples include phonon interactions, rotational transitions, and intermolecular dynamics. Frequency tunable high-power THz wave generation has been successfully achieved utilizing lattice resonance of LiNbO3 and GaP crystals, respectively. Semiconductor devices utilizing the electron tunneling effect have also been developed. 相似文献
988.
Microcarpalide is a strong microfilament disrupting agent. The convergent and stereoselective synthesis of microcarpalide was succeeded via Julia olefination and macrolactonization. 相似文献
989.
990.