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831.
832.
Hisanao Hazama Hirofumi Nagao Ren Suzuki Michisato Toyoda Katsuyoshi Masuda Yasuhide Naito Kunio Awazu 《Rapid communications in mass spectrometry : RCM》2008,22(10):1461-1466
The mass spectra of peptides obtained with different matrices were compared using a matrix-assisted laser desorption/ionization (MALDI) ion source and a multi-turn time-of-flight (TOF) mass spectrometer, MULTUM-IMG, which has been developed at Osaka University. Two types of solid matrices, alpha-cyano-4-hydroxycinnamic acid (CHCA) and 2,5-dihydroxybenzoic acid (DHB), and a liquid matrix made from a mixture of 3-aminoquinoline and CHCA were used. When measuring the peak signal intensity of human angiotensin II [M+H]+ from a fixed sample position, the liquid matrix produced a stable signal over 1000 laser shots, while the signal obtained with CHCA and DHB decayed after about 300 and 100 shots, respectively. Significant differences in the mass resolving power were not observed between the spectra obtained with the three matrices. Signal peak areas were measured as a function of the cycle number in a multi-turn ion trajectory, i.e., the total flight time over a millisecond time scale. For both [M+H]+ of human angiotensin II and bovine insulin, the decay of the signal peak area was the most significant with CHCA, while that measured with DHB was the smallest. The results of the mean initial ion velocity measurements suggested that the extent of metastable decomposition of the analyte ions increased in order of DHB, the liquid matrix, and CHCA, which is consistent with the difference in the decay of the signal peak area as the total flight time increased. 相似文献
833.
Kosaku Tamura Masashi Shiotsuki Norihisa Kobayashi Toshio Masuda Fumio Sanda 《Journal of polymer science. Part A, Polymer chemistry》2009,47(14):3506-3517
Novel conjugated polymers containing 3,9‐ or 2,9‐linked carbazole units in the main chain were synthesized by the polycondensation of ethynyl‐ and iodo‐substituted 9‐arylenecarbazolylene monomers, and their optical and electrical properties were studied. Polymers with weight‐average molecular weights of 3400–12,000 were obtained in 76–99% yields by the Sonogashira coupling polycondensation in piperidine or tetrahydrofuran (THF)/piperidine at 30 °C for 48 h. All the 3,9‐linked polymers absorbed light around 300 nm. The para‐phenylene‐linked polymer also absorbed light around 350 nm, while meta‐phenylene‐linked one did not. The 3,9‐linked polymers absorbed light at a wavelength longer than the 2,9‐linked one. The polymers emitted blue fluorescence with high quantum yields (0.21–0.78) upon excitation at the absorption maxima. The polymers were oxidized around 0.6 V, and reduced around 0.5 V. Poly( 1 ) showed the dark conductivity of 3.7 × 10?11 S/cm (103 V/cm). © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3506–3517, 2009 相似文献
834.
We show the uniqueness of minimal actions of a compact Kac algebra with amenable dual on the AFD factor of type II1. This particularly implies the uniqueness of minimal actions of a compact group. Our main tools are a Rohlin type theorem,
the 2-cohomology vanishing theorem, and the Evans-Kishimoto type intertwining argument. 相似文献
835.
Makina Saito Ryo Mashita Hiroyuki Kishimoto Ryo Masuda Yoshitaka Yoda Makoto Seto 《Hyperfine Interactions》2017,238(1):99
Tyre rubber has been continuously developed to improve its performance, but the microscopic mechanisms behind these improvements, e.g. by adding nanoparticles to the rubber, are still not fully understood. We study the microscopic polymer dynamics of a rubber nanocomposite system consisting of polymer polybutadiene with 20 volume% of silica nanoparticles with diameters of 100 nm via quasi-elastic scattering experiments using gamma-ray time-domain interferometry. The result shows that the presence of silica nanoparticles caused the inter-chain α-relaxation dynamics to slow down in a shallowly supercooled state suggesting that the presence of the nanoparticles that came in contact with the polymer controlled the timescale of the polymer’s α-relaxation dynamics. Conversely, the presence of nanoparticles less affects the dynamics in a lower temperature region near T g. It is consistent with the result of the differential scanning calorimetry study showing negligible T g difference among the pure polymer and the nanocomposite system. It also shows that the quasi-elastic scattering experiment can be used to reveal the polymer dynamics in nanocomposites and is appropriate for characterising their microscopic dynamics for the purpose of improving tyre performance. 相似文献
836.
Ko Mibu Kazuaki Mikami Masaaki Tanaka Ryo Masuda Yoshitaka Yoda Makoto Seto 《Hyperfine Interactions》2017,238(1):92
The Morin transition of very thin Ir-doped α-Fe2O3 films, which is not detectable with conventional magnetization measurements, was studied by conversion electron Mössbauer spectroscopy using a 57Co source and nuclear resonant scattering using a synchrotron light source. It was found that (i) the Morin transition temperature increases as the Ir ratio increases, (ii) it decreases when the film thickness decreases, and (iii) the transition becomes irreversible when Ir ratio is small and the thickness is thin. These tendencies were found reproducible and systematic, although the mechanisms are to be clarified by further studies. 相似文献
837.
Naoto Shirahata Tetsu Yonezawa Yoshihiro Matsushita Yoshitake Masuda Kunihito Koumoto 《Macromolecular Symposia》2008,270(1):82-87
Fusion and growth behavior of gold nanoparticles in a relatively low temperature range were studied using a transmission electron microscopy (TEM). Using allylmercaptane (AM: 2-propene-1-thiol, HS CH2 CHCH2) as a particle stabilizer, a colloidal suspension of AM-terminated gold nanoparticles was prepared with a two-phase system. TEM observation revealed that the adjacent nanoparticles formed a particulate neck to give fused nanoproducts even at lower than 65 °C. Such fusion behavior allowed a non-spherical growth of the adjacent nanoparticles. Interestingly, the nanoparticle fused to form a nanowire-type structure when the thermal radical reaction occurred between the terminal double carbon bond of the stabilizer and the hydrogen terminated surface of silicon wafer. 相似文献
838.
839.
Herein reported is a unique synthetic route of Tofisopam, an anxiolytic drug containing a 2,3‐benzodiazepine core structure. 3,4‐Dimethoxypropylbenzene and 3,4‐dimethoxybenzoic acid, which are both of plant origin, and CO2 constitute its carbon skeleton. These three renewable substances are united by two C?C bond forming reactions, i.e., a Friedel–Crafts acylation reaction and a photoinduced carboxylation reaction to construct the major carbon framework. Finally, a methyl group is introduced by a Kumada‐type cross‐coupling reaction to furnish Tofisopam. Various analogs of Tofisopam are readily synthesized by introducing other substituents than a methyl group at the last C?C bond forming step. 相似文献
840.
Dongmei Yue Toru Fujii Kayo Terada Junichi Tabei Masashi Shiotsuki Fumio Sanda Toshio Masuda 《Macromolecular rapid communications》2006,27(17):1460-1464
Summary: A diastereomeric pair of novel N‐propargylphosphonamidates, HCCCH2NHP(O)(CH3)O‐L ‐menthyl was synthesized by the successive condensations of methylphosphonic dichloride with L ‐menthol and propargylamine. The (R)‐P‐isomer ( 1a ) was isolated, and the absolute configuration was determined by XRD. Polymerization of 1a , and a mixture of 1a and (S)‐P‐isomer ( 1b ) was carried out with a zwitterionic Rh complex as a catalyst. cis‐Stereoregular polymers with number‐average molecular weights of 5 600–9 800 were obtained in good yields. Poly( 1a ) and poly( 1a 29‐co‐ 1b 71) exhibited large specific rotations (+408 and −146°), and intense Cotton effects ([θ] = +2.25 and −0.9 × 104 deg · cm2 · dmol−1) based on the conjugated polyacetylene backbone around 325 nm in CHCl3, indicating that these polymers have helical structures, whose predominant helical senses are opposite.