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761.
The crystal structures of a series of three palladium(II) ternary complexes of 5-halogeno-2-aminobenzoic acid (5-X-AB, where X=Cl, Br and I) with 1,10-phenanthroline [Pd(5-Cl-AB)(phen)] (1), [Pd(5-Br-AB)(phen)] (2) and [Pd(5-I-AB)(phen)] (3) have been determined, and their coordination geometries and the crystal architecture characterized. All of the complexes are an isostructure in which each Pd(II) atom has basically similar square planar coordination geometry. The substitute halogen group at 5-position of AB plays an important role in producing the coordination bonds of the carboxylate and amino groups in which the carboxylate O atom and the amino N atom act as the negative monodentate ligand atoms. The coordination bond distances of O-Pd increase in the order 1<2<3, while those of N-Pd decrease in the same order. The binding of the complexes to the calf thymus DNA has also been studied by the fluorescence method. Each of the complexes shows high binding propensity to DNA which can be reflected as the relative order 1<2<3. 相似文献
762.
Kensuke Kuwamura Tohru Ikegami Sadahiro Masuo Shinjiro Machida Nobuo Tanaka Akira Itaya 《Journal of photochemistry and photobiology. A, Chemistry》2008,200(2-3):232-238
The direct photolysis of 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonate) (ABTS) in aqueous solution was investigated under monochromatic ultraviolet (UV) irradiation at 254 nm. ABTS was found to be directly photolyzed by UV irradiation to yield the one-electron oxidized radical, ABTS+, which is a blue-green colored persistent radical species that has strong visible absorption bands. The photochemical production of ABTS+ was strongly dependent on the solution pH and the presence of dissolved oxygen. The presence of dissolved oxygen increased the quantum yields at pH 3, whereas it inhibited the production of ABTS+ at pH 6.5. Spectrophotometric and spectrofluorometric data indicated that ABTS photolysis may occur as a result of the transfer of one-electron between the singlet excited state and the ground state of ABTS. Observations made during UV/H2O2 experiments with ABTS suggested that the dependence of the photoloysis of ABTS on the solution pH and the presence of dissolved oxygen is related to the role of the hydroperoxyl/superoxide radical (HO2/O2−), which appears to be formed via a secondary reaction of the reduced intermediate of ABTS with dissolved oxygen. The proposed photolytic reactions were supported by the observed stoichiometry between the amount of ABTS+ radicals produced and the amount of ABTS molecules decomposed. 相似文献
763.
Hideyuki Kaneko Junji Saito Nobuo Kawahara Shingo Matsuo Tomoaki Matsugi Norio Kashiwa 《Journal of polymer science. Part A, Polymer chemistry》2009,47(3):812-823
A new method to prepare the polypropylene (PP) macroinitiator for controlled radical polymerization was described. Bromination of terminally-unsaturated PP was carried out by using N-bromosuccinimide and 2,2′-azobis(isobutyronitrile) to give a brominated PP (PP-Br), that has allylic bromide moieties at or near the chain ends. Thus, the obtained PP-Br was successfully used as a macroinitiator for radical polymerization of styrene, methyl methacrylate, and n-butyl acrylate using a copper catalyst system. From 1H NMR analysis, it was confirmed that the chain extension polymerization was certainly initiated from allylic bromide moieties with high efficiency, leading to the PP-based block copolymers linking the polar segment. From differential scanning calorimetry, it was observed that peak melting temperature of block copolymers was higher than that of PP-Br and the obtained PP-PS block copolymers with different compositions of each segment demonstrated the unique morphological features due to the microphase separation between both segments. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 812–823, 2009 相似文献
764.
765.
Stefan T. Norberg Nobuo Ishizawa 《Acta Crystallographica. Section C, Structural Chemistry》2005,61(10):i99-i102
The room‐temperature structure of potassium titanyl phosphate (KTiOPO4, KTP) with Pna21 symmetry has been studied by means of synchrotron radiation. Each of the two crystallographically unique K1 and K2 cations is split over two sites that are shifted along the c direction by 0.287 (13) and 0.255 (13) Å for the K1a/b and K2a/b pairs, respectively. The refined populations of the minor K1b and K2b sites are 0.102 (12) and 0.132 (17), respectively. It is shown that accurate high‐resolution synchrotron data (Rmerged = 0.015 for 25 010 reflections, 9456 unique, sinθ/λ limit > 1.0) are required for the determination of a reliable structure model. 相似文献
766.
Katsuji Kasahara Hiroaki Sasaki Nobuo Donkai Tohru Yoshihara Tohru Takagishi 《Cellulose (London, England)》2001,8(1):23-28
Partial dissolution of cellulose by ferric sodium tartrate complex (FeTNa) solution was examined as refining treatment of the organic-solvent spun cellulose fiber (Tencel). The treatment conditions were discussed in terms of solvent strength, temperature, duration of the treatment, and free NaOH concentration by measuring the weight loss, crystallinity, and tenacity of the resultant yarns. For improving fibrillation resistance, the optimized solution of the FeTNa complex was composed of 1–1.5M FeCl3 with 20% excess sodium tartrate and 1 N free NaOH, and the duration of the treatment was 60 min at 20°C. The loss in weight and tenacity could be maintained as low as 5% and 30–40%, respectively, by the optimized conditions. The resulting yarn showed significantly improved fibrillation resistance. 相似文献
767.
Jafariah Jaafar Kanami Konishi Shigeru Terabe Tohru Ikegami Nobuo Tanaka 《Chromatographia》2009,69(11-12):1437-1441
A capillary electrophoresis method using indirect UV detection has been applied to the determination of arsenate [As(V)], arsenite [As(III)], monomethylarsonic acid and dimethylarsinic acid. The arsenic species were successfully separated in a successive multiple ionic polymer layer coated capillary. On-line sample preconcentration of arsenic compounds were performed by employing field enhanced sample injection. A baseline separation was achieved in a basic background solution of 10 mM 2,6-pyridinedicarboxylic acid at pH 10.3. The precision of migration time was 1.2–2.4% RSD and peak height was 8.1–12.9% RSD. The limits of detection at a S/N ratio of 3 for the four arsenic compounds were found to be 20–70 ppb, which are comparable to other on-line preconcentration techniques. The enhancement factor was improved by 230–1,500-fold. 相似文献
768.
Structure of an anthocyanin-anthocyanin dimer molecule in anthocyanin-producing cells of a carrot suspension culture 总被引:1,自引:0,他引:1
A novel anthocyanin, an anthocyanin-anthocyanin dimer, was isolated from the cells of an anthocyanin-producing carrot cell-line culture, and its structure was elucidated using spectroscopic methods. It consists of two molecules of the anthocyanin, cyanidin 3-[xylosyl-(sinapoyl-glucosyl)-galactoside], with a CH-CH3 linkage at the 8-8 position. This is the first report of the identification and isolation of an anthocyanin-anthocyanin dimer with a CH-CH3 linkage from intact plant cells. 相似文献
769.
We experimentally investigate the spatial and temporal properties of a nonlinear optical system composed of an optically addressed spatial light modulator and a two-dimensional optical feedback. The system property is examined using fringes with only one spatial wave vector. The fringes are spontaneously generated using a spatial frequency filter in the optical feedback. We also experimentally investigate the properties of the spatial light modulator in the system using ordinary interference fringes in order to compare with the system property. We demonstrate that the spatial frequency response of the nonlinear optical system is identical to that of the spatial light modulator. We also demonstrate the distinctive temporal behavior of diffraction lights from the fringes generated in the system. 相似文献
770.
Tomoaki Sawabe Koshi Okamura Tomoki Sueyoshi Takashi Miyamoto Kazuhiro Kudo Nobuo Ueno Masakazu Nakamura 《Applied Physics A: Materials Science & Processing》2009,95(1):225-232
Vertical electrical conduction in Au/(polycrystal-line pentacene)/Al diode structures and the influence of the kinetic energy
of incident Au atoms on the conduction property have been comprehensively studied using current–voltage–temperature (I–V–T) measurements, ultraviolet photoelectron spectroscopy (UPS), atomic-force-microscope (AFM) current imaging, etc. In the I–V characteristics, a symmetrical ohmic current component appeared when a low voltage was applied, and a super-linear one appeared
when a high positive voltage was applied to Au. The component in the high-forward-voltage region was concluded to be a thermionic
emission of holes from Au with a 0.23-eV injection barrier, which is the normal hole conduction through the highest occupied
molecular orbital of pentacene. On the other hand, the ohmic component was concluded to be a metal-like electron transport
through high-density gap states at grain boundaries which were induced by the Au penetration into pentacene. UPS and I–V–T measurements clearly indicated the generation of the gap states and the enhancement of their density by the reduction of
Au kinetic energy. For vertical-type devices with polycrystalline organic films, the ohmic conduction through the grain boundary
will increase the leakage current. On the contrary, it possibly enhances the carrier injection in lateral-type transistors
in the case of top-contact configuration. 相似文献