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121.
Michel Pierre Takashi Suzuki Haruki Umakoshi 《Journal of Applied Analysis & Computation》2018,8(3):836-858
We consider the asymptotic behavior for large time of solutions to reaction-diffusion systems modeling reversible chemical reactions. We focus on the case where multiple equilibria exist. In this case, due to the existence of so-called "boundary equilibria", the analysis of the asymptotic behavior is not obvious. The solution is understood in a weak sense as a limit of adequate approximate solutions. We prove that this solution converges in L^1 toward an equilibrium as time goes to infinity and that the convergence is exponential if the limit is strictly positive. 相似文献
122.
J. S. Garitaonandia K. Suzuki J. D. Cashion E. Goikolea M. Insausti F. Plazaola R. Pizarro P. Gorria P. Minguez 《Hyperfine Interactions》2005,165(1-4):161-165
The crystallization of the Fe75Zr25 as-milled amorphous alloy has been studied by Mössbauer spectroscopy. The process begins at around 880 K with the complete and fast crystallization of the amorphous phase into the crystalline α-Fe and Fe2Zr ones but, from around 915 K, there is a sudden phase transformation into the Fe23Zr6 phase, which remains stable after cooling. A fitting for the Mössbauer contribution of the Fe23Zr6 phase, consistent with its crystalline structural features, has been obtained. 相似文献
123.
Mariame A. Hassan Loreto B. Feril Kosho Suzuki Nobuki Kudo Katsuro Tachibana Takashi Kondo 《Ultrasonics sonochemistry》2009,16(3):372-378
Three novel lipid-shell-type microbubbles (MBs), AS-0100, BG6356A and BG6356B, have been evaluated for their impact on ultrasound (US)-induced cell death and free radicals production. Previously studied and well-characterized US exposure conditions were employed in which human myelomonocytic lymphoma U937 cells were exposed to 1 MHz pulsed US beam (0.3 W/cm2, 10% duty factor) for 1 min with or without MBs. Three different concentrations of each MB were used. Apoptosis and cell lysis were assessed by examining phosphatidylserine externalization and by counting viable cells, respectively, 6 h post-exposure. Free radicals production and scavenging activities were evaluated using electron paramagnetic resonance (EPR)-spin trapping. The results showed that only AS-0100 and BG6356A were able to enhance the US-induced apoptosis, mainly by increasing the secondary necrosis. Apoptosis and cell lysis seemed to depend more on mechanical forces exerted by oscillating MBs while free radicals played a trivial role. BG series MBs exhibited pronounced scavenging activities. Generally, despite the need for further optimization, AS-0100 and BG6356A appear to be promising as adjuncts in cases where US-induced cell death is required. 相似文献
124.
Yoh Imai Satoshi Yamauchi Hirohisa Yokota Takehito Suzuki Kansuke Tsuji 《Optics Communications》2009,282(20):4141-4145
We numerically investigated the dependence of the decryption characteristics in a message modulation type chaos secure communication system using optical fiber ring resonators (OFRRs) on the coherence condition of carrier light. Since the output dynamics of OFRRs were formed on the basis of interference phenomenon among the circulated components in OFRRs, the coherence condition of input light affected inherently the OFRR output dynamics, resulting in the decryption characteristics. It was found that the decryption characteristics degraded as coherence length increased, i.e., as the spectral width of the input light decreased. The decryption characteristics also grew worse as the parameter differences between the transmitter and the receiver became larger. 相似文献
125.
Keigo Suzuki Masashi Inoguchi Keisuke Kageyama Hiroshi Takagi Yukio Sakabe 《Journal of nanoparticle research》2009,11(6):1349-1360
In this study, pulsed laser ablation, online annealing, and following size classification using a differential mobility analyzer
(DMA) were employed to fabricate quantum dots (QDs) of zinc oxide (ZnO). The irregularly shaped ZnO particles were obtained
at annealing temperature less than 873 K, which gradually transformed into spherical QDs with increasing the annealing temperature.
Finally, ZnO QDs with narrow size distribution having spherical shapes were successfully obtained at temperatures above 1173 K
under the DMA classification at a nominal size of 10 nm. TEM observation demonstrated that the ZnO QDs obtained by this process
were well-crystallized single crystallites with a wurtzite structure. Further, ZnO QDs with average sizes in the range of
4.8–8.1 nm were successfully fabricated by reducing the specified sizes of DMA. These features of the fabricated ZnO QDs are
favorable for investigation of intrinsic quantum size effect in ZnO. 相似文献
126.
T. Kubo T. Terai A. Suzuki N. Chikumoto 《Physica C: Superconductivity and its Applications》2009,469(15-20):1143-1145
Effects of fast neutron irradiation and post-annealing on magnetic properties of Rb3C60 were studied through the dc magnetization measurement. Rb3C60 powder samples were prepared in an evacuated quartz glass tube, and the temperature and the magnetic field dependences of dc magnetization were measured before and after irradiation and after post-annealing. The neutron fluences were 1.0, 1.8 and 3.3 × 1016 n/cm2, and the post-annealing was made at a temperature of 473 K for 3 h. Magnetic hysteresis of the samples irradiated at the fluence of 1.8 and 3.3 × 1016 n/cm2 disappeared, and the hysteresis curves hardly changed at the fluence of 1.0 × 1016 n/cm2. As for the post-annealing effect, the hysteresis curves of the sample irradiated at the fluence of 1.8 × 1016 n/cm2 were completely recovered after annealing, while those of the other samples, which had a magnetic background before irradiation, were not recovered. In this study, it was found that the loss of superconductivity in Rb3C60 powder is observed when the neutron irradiation fluence exceeds 1.0 × 1016 n/cm2, and the lost superconductivity is completely recovered by the post-annealing at 473 K for 3 h. 相似文献
127.
Kazuyuki Minami Toshiyuki Ishida Yasuki Asada Seiji Shirakawa Masanao Kobayashi Shoichi Suzuki Tomimasa Konishi Hidenori Mimura 《X射线光谱测定》2019,48(6):691-695
We investigate a miniaturized X-ray source using an ultraviolet (UV) laser and a pyroelectric crystal and discuss potential applications in medicine. The UV laser is the fourth harmonic of a Nd:YAG laser with a wavelength of 266 nm, repetition rate of 10 Hz, and pulse energy of 40 mJ. The pyroelectric crystal is a LiNbO3 cylinder of diameter 10 mm and length 6 mm. The prototype X-ray source we fabricated is an aluminum parallelepiped of dimensions 3 × 3 × 5 cm. The X-ray count rate of the X-ray source is maximized at approximately 1,400 cps for UV laser irradiation of approximately 5 min. After 30 min of irradiation by the UV laser, the temperature of the pyroelectric crystal rose from 295 K to 312 K. The principles of X-ray generation ensure that X-ray sources using UV lasers and pyroelectric crystals offer ample opportunity for miniaturization. We believe the X-ray source developed in this work is suitable for medical applications, although further study is needed to address points such as increasing the X-ray count rate and adjusting the temperature of the pyroelectric crystal. 相似文献
128.
Makoto Suzuki Tetsuya Tateishi Masahiko Matsuzawa Masakatsu Saito 《Macromolecular Symposia》1996,109(1):55-66
Amphoteric PVA hydrogels were made from mixed aqueous solutions of poly(acrylic acid), poly(allylamine) hydrochloride and poly(vinyl alcohol) by repetitive freezing and thawing. The hydrogen bond induced gelation produced an elastic and tough microporous hydrogel which generated tension as high as 0.3MPa corresponding to the solvent exchange from water to acetone. In this paper we show the microscopic structure of hydrogels determined by means of cryo-SEM technique and X-ray analysis. 相似文献
129.
We propose the novel preparation method, Self-seeding Process, based on the following concept for low temperature crystallization of oxide films. Introduction of desirable inhomogeneity should give lowering of a crystallization temperature through heterogeneous nucleation accompanied with reduced activation energy. We carried out inspection of the above concept through use of PZT films. PZT gel films with the desirable inhomogeneity of microstructure were prepared, and their crystallization behaviors was examined. The PZT film was successfully crystallized at 500°C by the self-seeding process. The single phase (001) oriented PZT film with 0.55 m in thickness was obtained at 550°C for 5 min. The self-seeding process by microstructure control is efficient for the low temperature process of the oxide thin film. 相似文献
130.
HAuCl(4) in aqueous solution was extracted to toluene or chloroform using a hydrophobically modified poly(amidoamine) dendrimer. Then, by reduction of Au(3+) ions with dimethylamineborane, gold nanoparticles in the size range of 2-4 nm were obtained in toluene or chloroform. It is suggested that gold nanoparticles are encapsulated by the dendrimer. Copyright 2000 Academic Press. 相似文献