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361.
362.
H. Momose N. Mori C. Hamaguchi T. Ikaida H. Arimoto N. Miura 《Physica E: Low-dimensional Systems and Nanostructures》1999,4(4):286
We present a review on recent study of the type I to type II transition in short-period superlattices (SLs) of GaAs/AlAs by means of cyclotron resonance (CR) in pulsed high magnetic fields. The behavior of CR varies depending on the thickness of the GaAs and AlAs layers. In CR of (GaAs)n/(AlAs)n, the resonance peak at the X minima was observed in the type II regime for n smaller than 14, whereas the resonance at the Γ point was observed for n>15. We estimated electron masses on X and Γ point in the SLs by using the empirical sp3 tight-binding method including second-nearest-neighbor interaction. These calculations have shown good agreement with the experimental results. Moreover, it was found that the angular dependence of the CR peak position does not obey the simple cosine dependence due to the subband mixing in high magnetic fields. From the angular dependence in the SLs, the longitudinal and transverses electron masses of AlAs at the X point were deduced to be mt=0.21m0 and ml=1.04m0, respectively. 相似文献
363.
Toshio Kawanami Kentaro Ishizuka Hiroshi Furuno Yoshihito Shiota Kazunari Yoshizawa Junji Inanaga 《Tetrahedron: Asymmetry》2017,28(11):1587-1590
A chiral BINOL dimer, (R,R)-3′,3″-BiBINOL, which possesses both rigid (atropos) and dynamic (tropos) axial chiralities, was found to work as an effective NMR chiral solvating reagent for the determination of the enantiomeric purities of various chiral sulfoxides. The unique chiral discrimination mechanism was also revealed by using DFT calculations and X-ray crystallographic analysis. 相似文献
364.
Chan Woo Lee Kazunari Masutani Tomokazu Kato Yoshiharu Kimura 《Journal of polymer science. Part A, Polymer chemistry》2012,50(7):1290-1297
A dilactone, 13,26‐dihexyl‐1,14‐dioxacyclohexacosane‐2,15‐dione (12‐HSAD), was synthesized by lipase‐catalyzed reaction of 12‐hydroxystearic acid (12‐HSA) in high yield. It was subjected to the ring‐opening polymerization with various catalysts to obtain poly(12‐hydroxystearate) (PHS). The polymerization system of 12‐HSAD showed an interesting polymerization behavior because of its large ring system. The polymers produced by this polymerization were directly reacted with L ‐lactide to obtain a diblock copolymer of poly(L ‐lactide)‐block‐poly‐(12‐hydroxystearate) (PLLA‐b‐PHS). Characterization of the resultant copolymers was also performed. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011 相似文献
365.
Dr. Angel T. Garcia-Esparza Dr. Tatsuya Shinagawa Dr. Samy Ould-Chikh Muhammad Qureshi Dr. Xuyuan Peng Dr. Nini Wei Dr. Dalaver H. Anjum Dr. Alain Clo Dr. Tsu-Chien Weng Dr. Dennis Nordlund Dr. Dimosthenis Sokaras Prof. Jun Kubota Prof. Kazunari Domen Prof. Kazuhiro Takanabe 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(21):5874-5878
For overall water-splitting systems, it is essential to establish O2-insensitive cathodes that allow cogeneration of H2 and O2. An acid-tolerant electrocatalyst is described, which employs a Mo-coating on a metal surface to achieve selective H2 evolution in the presence of O2. In operando X-ray absorption spectroscopy identified reduced Pt covered with an amorphous molybdenum oxyhydroxide hydrate with a local structural order composed of polyanionic trimeric units of molybdenum(IV). The Mo layer likely hinders O2 gas permeation, impeding contact with active Pt. Photocatalytic overall water splitting proceeded using MoOx/Pt/SrTiO3 with inhibited water formation from H2 and O2, which is the prevailing back reaction on the bare Pt/SrTiO3 photocatalyst. The Mo coating was stable in acidic media for multiple hours of overall water splitting by membraneless electrolysis and photocatalysis. 相似文献
366.
Kazunari Takaya Takahiro Kaneko Hajime Tanuma Tatsuhiro Nishide Hiroaki Sugiyama Nobuo Nakano Hisayuki Nagashima Yasuo Seto 《International Journal for Ion Mobility Spectrometry》2016,19(4):227-232
We determined new potential parameters for a calculation of ion mobility in air using the MOBCAL program. In our model, we regard air as a virtual uni-atomic molecular gas. And the Lennard-Jones parameters for various kinds of atoms in molecular ions were determined with simple and systematic methods. Using these parameters, we have calculated the mobilities of product ions from chemical warfare agents, normal saturated hydrocarbons, and illicit drugs. Most of the calculation results showed good agreement with the experimental values. Therefore this calculation method will be useful for understanding of the ion mobility spectrometry in air. 相似文献
367.
368.
Frontispiece: Heterometallic FeIII/K Coordination Polymer with a Wide Thermal Hysteretic Spin Transition at Room Temperature
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369.
Frontispiece: Formation and High Reactivity of the anti‐Dioxo Form of High‐Spin μ‐Oxodioxodiiron(IV) as the Active Species That Cleaves Strong C−H Bonds
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370.
Formation and High Reactivity of the anti‐Dioxo Form of High‐Spin μ‐Oxodioxodiiron(IV) as the Active Species That Cleaves Strong C−H Bonds
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Prof. Dr. Masahito Kodera Shin Ishiga Tomokazu Tsuji Katsutoshi Sakurai Prof. Dr. Yutaka Hitomi Dr. Yoshihito Shiota Dr. P. K. Sajith Prof. Dr. Kazunari Yoshizawa Dr. Kaoru Mieda Prof. Dr. Takashi Ogura 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(17):5924-5936
Recently, it was shown that μ‐oxo‐μ‐peroxodiiron(III) is converted to high‐spin μ‐oxodioxodiiron(IV) through O?O bond scission. Herein, the formation and high reactivity of the anti‐dioxo form of high‐spin μ‐oxodioxodiiron(IV) as the active oxidant are demonstrated on the basis of resonance Raman and electronic‐absorption spectral changes, detailed kinetic studies, DFT calculations, activation parameters, kinetic isotope effects (KIE), and catalytic oxidation of alkanes. Decay of μ‐oxodioxodiiron(IV) was greatly accelerated on addition of substrate. The reactivity order of substrates is toluene<ethylbenzene≈cumene<trans‐β‐methylstyrene. The rate constants increased proportionally to the substrate concentration at low substrate concentration. At high substrate concentration, however, the rate constants converge to the same value regardless of the kind of substrate. This is explained by a two‐step mechanism in which anti‐μ‐oxodioxodiiron(IV) is formed by syn‐to‐anti transformation of the syn‐dioxo form and reacts with substrates as the oxidant. The anti‐dioxo form is 620 times more reactive in the C?H bond cleavage of ethylbenzene than the most reactive diiron system reported so far. The KIE for the reaction with toluene/[D8]toluene is 95 at ?30 °C, which the largest in diiron systems reported so far. The present diiron complex efficiently catalyzes the oxidation of various alkanes with H2O2. 相似文献