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861.
Matsuishi S Hayashi K Hirano M Hosono H 《Journal of the American Chemical Society》2005,127(36):12454-12455
Atomic hydrogen (H0) and trapped electrons generated by UV illumination (lambda approximately 330 nm) at 4 K were observed using electron paramagnetic resonance (EPR) in a 12CaO.7Al2O3 (C12A7) crystal heated in a hydrogen atmosphere. The concentration ratio of generated H0 to the electrons encaged in the subnanometer-sized cages of C12A7 (F+ centers) is almost 1:1, providing direct evidence that a hydride ion, H-, accommodated in the cage by the heat treatment was dissociated to a pair of an H0 and an electron by a UV photon: H- --> H0 + e- (F+). After annealing at 300 K, H0 was completely annihilated, while approximately 60% of the trapped electrons survived. The remaining electrons can hop between neighboring cages and give electrical conductivity to C12A7. The hyperfine splitting of the EPR spectrum of H0 in C12A7 (48.6 mT) is 4% smaller than that of the neutral hydrogen atom (50.6 mT), implying that H0 is trapped at the interstitial sites among the cages. 相似文献
862.
Sohei Fukui Yoshiharu ShimamuraYumiko Sunamoto Tasuku AbeToshiyuki Hirano Takao OiHirotaka Nagao 《Polyhedron》2007
cis-[Ru(NO)(CH3CN)(pyca)2] and trans-[Ru(NO)(OH)(pyca)2] (pyca = 2-pyridinecarboxylato) were synthesized and characterized by X-ray crystallography. Electrochemical behaviors of cis-[Ru(NO)(CH3CN)(pyca)2] and cis-[Ru(NO)(CH3O)(pyca)2] in acetonitrile were studied. These complexes showed two reduction processes in CH3CN. The controlled potential electrolyses of cis-[Ru(NO)(CH3O)(pyca)2] in a methanol–acetonitrile mixed solution were performed at the potential of the first reduction process. trans-[Ru(NO)(CH3O)(pyca)2] was isolated from the electrolyzed solution and characterized by IR and CV. The cis–trans geometrical change reaction occurred in the electrochemical one-electron reduction of cis-[Ru(NO)(CH3O)(pyca)2]. 相似文献
863.
Three pairs of N-substituted normorphine derivatives and the sulfate conjugates at the 6-position were tested for the analgesic and antagonistic activities and the development of physical dependence in mice. The compounds examined were nalorphine, nalorphine-6-sulfate (N-6-S), N-cyclopropylmethylnormorphine (CPN), N-cyclopropylmethylnormorphine-6-sulfate (C-6-S), N-dimethylallylnormorphine (DMN) and N-dimethylallylnormorphine-6-sulfate (D-6-S). The latter two pairs were newly synthesized. The analgesic activity of C-6-S and D-6-S was equipotent to that of CPN and DMN by the acetic acid writhing test on the s.c. injection, and the activity of N-6-S was about 2 times more potent than that of nalorphine. The antagonistic activity of N-6-S, C-6-S and D-6-S to morphine analgesia was higher than that of the parent compounds by the tail pinch test on i.c.v. injection. A withdrawal sign was seen in mice treated chronically with CPN, C-6-S and N-6-S by challenge with naloxone, whereas the mice treated with DMN, D-6-S and nalorphine showed no such sign. The effect of sulfation at the 6-position on the development of physical dependence was not well associated with the effect on agonistic and antagonistic activities. 相似文献
864.
865.
Copper‐Mediated C6‐Selective Dehydrogenative Heteroarylation of 2‐Pyridones with 1,3‐Azoles 下载免费PDF全文
Riko Odani Dr. Koji Hirano Prof. Dr. Tetsuya Satoh Prof. Dr. Masahiro Miura 《Angewandte Chemie (International ed. in English)》2014,53(40):10784-10788
A copper‐mediated C6‐selective dehydrogenative heteroarylation of 2‐pyridones with 1,3‐azoles has been developed. The reaction proceeded smoothly by twofold C? H cleavage even in the absence of noble‐metal catalysts. The observed site selectivity was directed by a pyridyl substituent on the nitrogen atom of the pyridone ring. This directing group was readily removed after the coupling event, thus leading to 2‐pyridone derivatives with a free N? H group. Moreover, in some cases, catalytic turnover of the Cu salt was also possible with the ideal terminal oxidant: molecular oxygen in air. 相似文献
866.
T. Matsushita E. Arakawa Y. Niwa Y. Inada T. Hatano T. Harada Y. Higashi K. Hirano K. Sakurai M. Ishii M. Nomura 《The European physical journal. Special topics》2009,167(1):113-119
Aiming for the realization of time-resolved specular X-ray reflectivity measurements on the sub-second to millisecond timescales, a conceptually new method of measuring specular X-ray reflectivity curves is developed. Using this method the entire profile of the reflectivity curve of interest is measured in place. A horizontally convergent X-ray beam which has a one-to-one correlation between its direction and energy is realized using a curved crystal or laterally graded multilayers on an elliptic substrate. The X-ray beam is then incident on the surface of the specimen placed at the focus such that the glancing angle in the vertical direction is the same for all X-ray components, which are reflected in the vertical direction by the surface and diverge in the horizontal plane. The perpendicular momentum transfer continuously changes as a function of the horizontal ray direction even with fixed glancing angle since the wavelength (energy) changes. The X-ray intensity distribution across the beam direction measured downstream of the specimen using a one- or two-dimensional detector represents the X-ray reflectivity curve. Specular X-ray reflectivity curves are measured with exposure times ranging from 2?ms to 1?s for a gold film of thickness 14.3?nm on a silicon substrate. The potential of this method for time-resolved measurements is demonstrated by recording reflectivity curves with a time resolution of 20?ms from a rotating specimen. 相似文献
867.
Okubo–Zweig–Iizuka-allowed partial decay widths, masses, and total decay width of charmonium states are studied in a nonrelativistic
coupled-channel framework based on microscopic effective quark interactions. With the help of the complex scale transformation,
the coupled channel equation is easily solved under the proper boundary condition for resonances. The obtained result as a
whole is very successful and encouraging for the traditional charmonium states including ψ(4040) whose features of mass and partial decay widths have been argued historically. The coupling mechanisms of these states
are investigated by reducing artificially the channel coupling strengths little by little and finally turning the coupling
off. The situations turn out to be quite different from what we would have naively supposed. Other solutions than the traditional
charmonium states were obatined at the same time. Some of them are discussed in relation with new particles observed recently. 相似文献
868.
Takayoshi Katase Hidenori Hiramatsu Hiroshi Yanagi Toshio Kamiya Masahiro Hirano Hideo Hosono 《Solid State Communications》2009,149(47-48):2121-2124
The epitaxial growth of Fe-based superconductors such as Co-doped SrFe2As2 (SrFe2As2:Co) was reported recently, but has still insufficient properties for a device application because they have rough surfaces and are decomposed by reactions with water vapor in an ambient atmosphere. This paper reports that epitaxial films of Co-doped BaFe2As2 grown at 700 °C show the onset superconducting transition temperature of ~20 K. The transition is sharper than those observed on the SrFe2As2:Co films, which would originate from their improved crystallinity. These films also have atomically-flat surfaces with step-and-terrace structures and exhibit chemical stability against exposure to water vapor. 相似文献
869.
We examined the electric field-assisted thermionic emission of atomic oxygen radical anion (O?) in a vacuum from fluorine-substituted derivatives of 12CaO·7Al2O3 (C12A7) with a composition of (12 ? x)CaO·7Al2O3·xCaF2 (0 ≤ x ≤ 0.8). Unsubstituted C12A7 easily decomposed into 5CaO?3Al2O3 (C5A3) and 3CaO?Al2O3 (C3A) above 830 °C during the emission experiment in a vacuum. The decomposition temperature range became narrower as the amount of F? ion substitution increased, e.g. the sample with x = 0.4 kept a single phase after the emission experiment at 900 °C. The emitted anionic species from the x = 0.4 sample were dominated by O? ions (~ 92%) together with a small amount of O2? ions (~ 4%) and F? ions (~ 4%). The absence of an O2 gas supply to the opposite side of the emission surface led to a nearly steady co-emission of O? ions and electrons with a ratio of < 1/1. The O2 gas supply markedly enhanced the O? ion emission, and suppressed the electron emission. A sustainable and high-purity O? ion emission with a current density of 11 nA cm? 2 was achieved at 830 °C with the supply of 40 Pa O2 gas. The similarity in these emission features to the unsubstituted C12A7, together with the improved thermal stability demonstrates that the F? ion-substituted C12A7 is a promising material for higher intensity O? ion emission at higher temperatures. 相似文献
870.
Shinji Yae Tatsuya Hirano Takashi Matsuda Naoki Fukumuro Hitoshi Matsuda 《Applied Surface Science》2009,255(8):4670-4672
Metal filled Si nanopores, that is, metal nanorods in an Si matrix, are produced by an electroless process that consists of three steps: (1) electroless displacement deposition of metal nanoparticles from a metal salt solution containing HF; (2) Si nanopore formation by metal-particle-enhanced HF etching; and (3) metal filling in nanopores by autocatalytic electroless deposition. Ag nanoparticles produce Si nanopores whose sizes are a few tens of nm in diameter and ca. 50 nm deep. Au nanoparticles produce finer and straighter nanopores on Si than the Ag case. These nanopores are filled with a Co or a Co-Ni alloy by autocatalytic deposition using dimethylamine-borane as a reducing agent. Phosphinate can be used as a reducing agent for the Au-deposited-and-pore-formed Si. The important feature of this process is that the metal nanoparticles, that is, the initiation points of the autocatalytic metal deposition, are present on the bottoms of the Si nanopores. 相似文献