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71.
Yttria-stabilized cubic zirconia bicrystals with [110] symmetric tilt grain boundaries are systematically fabricated by the diffusion bonding method. It is revealed that the grain-boundary atomistic structures, excess energies and solute segregation behaviours are strongly dependent on the macroscopic geometries of the boundaries. High-resolution transmission electron microscopy combined with lattice statics calculations suggests that the grain-boundary structures are characterized by the accumulation of coordination-deficient cation sites at their cores, whose densities have a clear correlation with excess energies and amounts of solute segregation. The orientation dependence of grain-boundary properties in cubic zirconia can thus be linked and understood via local grain-boundary atomistic structures with the characteristic miscoordinated cation sites. 相似文献
72.
T Yano K Ohmori H Takahashi T Kusumi K Suzuki 《Organic & biomolecular chemistry》2012,10(38):7685-7688
A catechin hetero-trimer isolated from Ziziphus jujuba has been synthesized. Among three constituent monomers, (-)-epiafzelechin and (-)-epigallocatechin were prepared by de novo synthesis. Trimer formation relied on the unified approach to oligomers based on the bromo-capping and the orthogonal activation, reaching the reported structure of the natural product. 相似文献
73.
Takenori Yamamoto Tsuyoshi Uda Takahiro Yamasaki Takahisa Ohno 《Physics letters. A》2009,373(43):3989-3993
We present first-principles simulations of As-doped Si carried out using several cubic supercells of up to 10 648 atoms. The 1s As donor level in each supercell splits into three states, which have A1, T2, and E symmetries, respectively. The 1s(A1) wavefunction is well converged in the largest cell, and its spread is close to those of the effective-mass theories. However, the calculated binding energies are smaller than experimental values. This discrepancy would be due to the self-interaction error within the approximated exchange-correlation density functional used in this calculation. Therefore, we also show perturbative calculations based on an impurity potential without the self-interaction error to estimate the binding energies of the 1s(A1) donor state. The estimated binding energy in the largest supercell agrees well with the experimental value. 相似文献
74.
75.
Shota Ooi Takayuki Tanaka Takahisa Ikeue Kazuhisa Yamasumi Kento Ueta Daiki Shimizu Masatoshi Ishida Hiroyuki Furuta Atsuhiro Osuka 《化学:亚洲杂志》2019,14(10):1771-1776
Copper complexes of corroles have recently been a subject of keen interest due to their ligand non‐innocent character and unique redox properties. Here we investigated bis‐copper complex of a triply‐linked corrole dimer that serves as a pair of divalent metal ligands but can be reduced to a pair of trivalent metal ligands. Reaction of triply‐linked corrole dimer 2 with Cu(acac)2 (acac=acetylacetonate) gave bis‐copper(II) complex 2Cu as a highly planar molecule with a mean‐plane deviation value of 0.020 Å, where the two copper ions were revealed to be divalent by ESR, SQUID, and XPS methods. Oxidation of 2Cu with two equivalents of AgBF4 gave complex 3Cu , which was characterized as a bis‐copper(II) complex of a dicationic triply‐linked corrole dimer not as the corresponding bis‐copper(III) complex. In accord with this assignment, the structural parameters around the copper ions were revealed to be quite similar for 2Cu and 3Cu . Importantly, the magnetic spin–spin interaction differs depending on the redox‐state of the ligand, being weak ferromagnetic in 2Cu and antiferromagnetic in 3Cu . 相似文献
76.
The formation of deeply-bound antikaonic nuclear states in nuclear (K−,N) reactions is investigated theoretically within a distorted-wave impulse approximation (DWIA), considering the isospin properties of the Fermi-averaged elementary amplitudes. We calculate the formation cross sections of the deeply-bound states by the (K−,N) reactions on the nuclear targets, 12C and 28Si, at incident K− lab momentum pK−=1.0 GeV/c and θlab=0°, introducing a complex effective nucleon number Neff for unstable bound states in the DWIA. The results show that the deeply-bound states can be populated dominantly by the (K−,n) reaction via the total isoscalar ΔT=0 transition owing to the isospin nature of the amplitudes, and that the cross sections described by ReNeff and ArgNeff enable to deduce the structure of the nuclear states; the calculated inclusive nucleon spectra for a deep -nucleus potential do not show distinct peak structure in the bound region. The few-body and states formed in (K−,N) reactions on s-shell nuclear targets, 3He, 3H and 4He, are also discussed. 相似文献
77.
Dan Phuong Nguyen Se-Young O Chan-Woo Park Keesam Shin Chan-Gyu Lee Toshitada Shimozaki Takahisa Okino 《Journal of magnetism and magnetic materials》2008,320(14):e264-e267
[Fe(0.5 nm)/Pt(0.5 nm)]40, [Fe(1 nm)/Pt(1.5 nm)]20 and [Fe(3 nm)/Pt(3 nm)]10 multilayer were prepared by DC magnetron sputtering. By conventional furnace annealing (CA) at 270–600 °C for various time, all of the films still remained the disordered structure with the soft magnetic phase. By rapid thermal annealing (RTA) at 500 °C for various time, we obtained the [Fe(1 nm)/Pt(1.5 nm)]20 and [Fe(3 nm)/Pt(3 nm)]10 films with L12 ordered FePt3 phase which was almost ferromagnetic at room temperature. However, the [Fe(0.5 nm)/Pt(0.5 nm)]40 films was still disordered state even under RTA. Compared with CA, RTA exposed an outstanding effect on accelerating the phase transition when the film thickness is over [Fe(0.5 nm)/Pt(0.5 nm)]40. 相似文献
78.
Stefan Machill Takahisa Shodai Yoji Sakurai Jun-ichi Yamaki 《Journal of Solid State Electrochemistry》1999,3(2):97-103
Tin-based composite oxide materials have received considerable attention as potential anode materials for rechargeable lithium
batteries. In this contribution we present the results of our investigations of the SnOB2O3P2O5 system. We have investigated its electrochemical properties and especially its cycling performance. A focus of our interest
was to explain the structural changes which occur during lithium cycling and their strong dependence on the preparation method.
A part of the SnO component was converted into a very stable metallic phase. In addition, a decrease was observed in capacity
owing to the formation of isolated and inactive tin grains. We also report on structural changes in the B2O3P2O5 matrix.
Received: 2 October 1997 / Accepted: 3 July 1998 相似文献
79.
80.
Takahisa Iida Toshio Sugizaki Toshifumi Kageyama Osamu Moriya 《Journal of polymer science. Part A, Polymer chemistry》1998,36(4):655-663
Tributylstannylated silicic acid (TBSA), which was regarded as a protected polymeric silanol against self-condensation to give silica gel, was newly prepared from the reaction of water glass (WG) and bis(tributyltin) oxide (TBO). The ratios of Si/Sn contained in TBSA were determined by gravimetric analysis to be in the range of 2–3. The gelation of TBSA in usual organic solvents such as hexane, benzene, and dichloromethane was not observed over 3 weeks. In addition, TBSA was shown to be a convenient precursor for the preparations of silica gel modified with organofunctional groups. From the reaction of TBSA with trimethoxysilanes and aromatic alcohols, the silica gels havingorganofunctional groups were obtained with the elimination of a tributyltin group. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 655–663, 1998 相似文献