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991.
Motoki Murai Takuya Kaji Takefumi Kuranaga Hiroshi Hamamoto Kazuhisa Sekimizu Masayuki Inoue 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2015,127(5):1576-1580
Lysocin E, a macrocyclic peptide, exhibits potent antibacterial activity against methicillin‐resistant Staphylococcus aureus (MRSA) through a novel mechanism. The first total synthesis of lysocin E was achieved by applying a full solid‐phase strategy. The developed approach also provides rapid access to the enantiomeric, epimeric, and N‐demethylated analogues of lysocin E. Significantly, the antibacterial activity of the unnatural enantiomer was comparable to that of the natural isomer, suggesting the absence of chiral recognition in its mode of action. 相似文献
992.
Gizem Dübek Franziska Hanusch Dr. Dominik Munz Prof. Shigeyoshi Inoue 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(14):5872-5878
Air- and moisture-stable heterobimetallic tetrahedral clusters [Cp(CO)2MSiR]2 (M=Mo or W; R=SitBu3) were isolated from the reaction of N-heterocyclic carbene (NHC) stabilized silyl(silylidene) metal complexes Cp(CO)2M=Si(SitBu3)NHC with a mild Lewis acid (BPh3). Alternatively, treatment of the NHC-stabilized silylidene complex Cp(CO)2W=Si(SitBu3)NHC with stronger Lewis acids such as AlCl3 or B(C6F5)3 resulted in the reversible coordination of the Lewis acid to one of the carbonyl ligands. Computational investigations revealed that the dimerization of the intermediate metal silylidyne (M≡Si) complex to a tetrahedral cluster instead of a planar four-membered ring is due to steric bulk. 相似文献
993.
994.
Abstract The annealing of bare thermal oxide on silicon at 400–500°C in a hydrogen bearing gas results in a reduced density of states Nss at the substrate silicon/oxide interface. Treatments of this type have played a role in MOS processing schedules for several years. However, a similar approach applied to large areas (cm2) of poly-silicon coated oxide appears to be less effective in reducing Nss. This may be due to the polysilicon acting as a partially impermeable barrier which tends to starve the substrate/oxide interface of hydrogen. In the present work hydrogenation of 2-inch diameter, polysilicon coated wafers has been accomplished by hydrogen ion implantation. H2+ ions of 135 kV energy were implanted (to a dose of 1015 cm?2) through a 7000 Å polysilicon coating into an underlying 1400 Å SiO2 layer. The polysilicon was removed after 30-min anneals carried out in pure N2 at 300, 400 or 500°C. Aluminium dots, 1 mm in diameter were then deposited on to the oxide and high frequency (1 MHz) and quasistatic C-V curves recorded for determinations of Nss. Control anneals on unimplanted material were carried out in pure N2 and N2-H2 ambients. Control samples annealed in pure N2 with their polysilicon coating intact had mid-gap Nss values of not less than 4 × 1010 cm?2 eV?1. The corresponding value after N2-H2 anneals on polysilicon-free wafers was 3 × 1010. H2 + implanted samples annealed in pure N2 with their polysilicon intact had mid-gap Nss values of 1 × 1010 cm?2 eV?1. The effectiveness of ion beam hydrogenation may depend upon confinement of the associated displacement damage to the polysilicon. This allows the implanted hydrogen to be activated within the SiO2 at temperatures similar to those employed for normal hydrogeneous gas annealing of the substrate silicon/oxide interface. 相似文献
995.
In the present article, we investigate the properties of bivariate Fibonacci polynomials of order k in terms of the generating functions. For k and ℓ (1 ≤ ℓ ≤ k − 1), the relationship between the bivariate Fibonacci polynomials of order k and the bivariate Fibonacci polynomials of order ℓ is elucidated. Lucas polynomials of order k are considered. We also reveal the relationship between Lucas polynomials of order k and Lucas polynomials of order ℓ. The present work extends several properties of Fibonacci and Lucas polynomials of order k, which will lead us a new type of geneses of these polynomials. We point out that Fibonacci and Lucas polynomials of order
k are closely related to distributions of order k and show that the distributions possess properties analogous to the bivariate Fibonacci and Lucas polynomials of order k. 相似文献
996.
Nakajima H Okuma Y Morioka K Miyake M Hemmi A Tobita T Yahiro M Yokoyama D Adachi C Soh N Nakano K Xue S Zeng H Uchiyama K Imato T 《Journal of separation science》2011,34(20):2906-2912
A fluorescence detection system for a microfluidic device using an organic light-emitting diode (OLED) as the excitation light source and a charge-coupled device (CCD) as the photo detector was developed. The OLED was fabricated on a glass plate by photolithography and a vacuum deposition technique. The OLED produced a green luminescence with a peak emission at 512 nm and a half bandwidth of 55 nm. The maximum external quantum efficiency of the OLED was 7.2%. The emission intensity of the OLED at 10 mA/cm(2) was 13 μW (1.7 mW/cm(2)). The fluorescence detection system consisted of the OLED device, two band-pass filters, a five microchannel poly(dimethylsiloxane) (PDMS) microfluidic device and a linear CCD. The fluorescence detection system was successfully used in a flow-based enzyme-linked immunosorbent assay on a PDMS microfluidic device for the rapid determination of immunoglobulin A (IgA), a marker for human stress. The detection limit (S/N=3) for IgA was 16.5 ng/mL, and the sensitivity was sufficient for evaluating stress. Compared with the conventional 96-well microtiter plate assay, the analysis time and the amounts of reagent and sample solutions could all be reduced. 相似文献
997.
Aoki S Ishii N Doi T Hatsuda T Ikeda Y Inoue T Murano K Nemura H Sasaki K;HAL QCD Collaboration 《Proceedings of the Japan Academy. Series B, Physical and biological sciences》2011,87(8):509-517
We propose a new method to extract hadron interactions above inelastic threshold from the Nambu-Bethe-Salpeter amplitude in lattice QCD. We consider the scattering such as A + B → C + D, where A, B, C, D are names of different 1-particle states. An extension to cases where particle productions occur during scatterings is also discussed. 相似文献
998.
D. Okai R. Nagai G. Motoyama H.M. Kimura A. Inoue 《Physica C: Superconductivity and its Applications》2011,471(21-22):725-729
The superconducting property of Zr55Co(30?x)Al15Nbx (x = 0–20 at.%) metallic glasses fabricated by rapid solidification was investigated. The Zr55Co(30–x)Al15Nbx (x = 5–20 at.%) metallic glasses with a mixture structure of amorphous and nanocrystal phases exhibited superconductivity of Tc,on = 1.8–2.6 K. The maximum Tc,on = 2.6 K was obtained for the Zr55Co10Al15Nb20 metallic glass. This was attributable to the superconducting property of nanocrystalline particles contained in the Zr55Co10Al15Nb20 alloy. The increase of Nb element in the Zr55Co(30–x)Al15Nbx alloy led to the increase of Tc,on and the decrease of glass transition temperature. The glass transition temperature was between 704 and 749 K for the Zr55Co(30–x)Al15Nbx (x = 0–20 at.%) alloys. The temperature interval of supercooled liquid state was between 51 and 68 K for the Zr55Co(30–x)Al15Nbx (x = 0–20 at.%) alloys. 相似文献
999.
Complexation of three kinds of tris(imidazolyl)calix[6]arenes containing alternate p-substituents (Calix-tBu, R(1) = R(2) = tert-butyl; Calix-NH(2), R(1) = tert-butyl, R(2) = NH(2); Calix-NO(2), R(1) = tert-butyl, R(2) = NO(2)) with Zn(ClO(4))(2)(H(2)O)(6) in acetonitrile, methanol, and THF was investigated via isothermal titration calorimetry (ITC). For the coordination of these calixarene ligands to Zn(II) in acetonitrile, typical one-phase exothermic titration curves were obtained, indicating the formation of 1:1 ligand-Zn(II) complexes accompanied by large conformational changes of the ligands. In contrast, the complexation in methanol was endothermic and dominated by favorable entropy changes. The entropy gains were achieved by extensive desolvation from both Zn(II) and the ligands. ITC measurements suggest a 2:1 ligand-Zn(II) complex formation in THF in the presence of excess ligands (Calix-NH(2) and Calix-NO(2)). The 2:1 complexes were converted to 1:1 complexes upon further addition of Zn(ClO(4))(2)(H(2)O)(6). The results indicate the important role of a coordinating solvent (acetonitrile) for direct formation of the 1:1 complexes under the conditions of excess ligand. Complexation of a ditopic ligand (Calix-Tri) with three triazole moieties on the wider rim was also studied via ITC. The first coordination of the imidazole moieties to Zn(II) was an exothermic process. This was followed by the entropically favorable coordination of the triazole moieties to the divalent cation. We have also investigated exchange of the fourth ligand (H(2)O) of the Zn(II) complex of Calix-NH(2) with butylamine, heptylamine, acetonitrile, and acetamide in a noncompetitive solvent, THF. The ΔH(0) tended to decrease upon increasing the electron-pair-donating ability of the guest ligand, whereas it was also affected by an entropic term due to restricted rotation of the guest ligand inside the calixarene cavity. 相似文献
1000.
Micellization behavior was investigated for polyoxyethylene-type nonionic surfactants with varying chain length (C(n)E(m)) in a room temperature ionic liquid, 1-butyl-3-methylimidazolium tetrafluoroborate (bmimBF(4)). Critical micelle concentration (cmc) was determined from the variation of (1)H NMR chemical shift with the surfactant concentration. The logarithmic value of cmc decreased linearly with the number of carbon atoms in the surfactant hydrocarbon chain, similarly to the case observed in aqueous surfactant solutions. However, the slope of the straight line is much smaller in bmimBF(4) than in aqueous solution. Thermodynamic parameters for micelle formation estimated from the temperature dependence of cmc showed that the micellization in bmimBF(4) is an entropy-driven process around room temperature. This behavior is also similar to the case in aqueous solution. However, the magnitude of the entropic contribution to the overall micellization free energy in bmimBF(4) is much smaller compared with that in aqueous solution. These results suggest that the micellization in bmimBF(4) proceeds through a mechanism similar to the hydrophobic interaction in aqueous surfactant solutions, although the solvophobic effect in bmimBF(4) is much weaker than the hydrophobic effect. 相似文献