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251.
The leading terms of an effective Hamiltonian for a linear molecule in a given vibrational state are presented up to κ10Tv order of magnitude, whereby higher-order l-dependent terms such as , , and have been neglected because in spectroscopic application they are of minor importance. This Hamiltonian therefore includes all those l-type interactions which could contribute to the fitting procedure, within a vibrational state where one or more bending vibrations are excited. 相似文献
252.
Yoshiharu Matsubara Toshikazu Uchida Takashi Ohnishi Koichi Kanehira Yoshiji Fujita Tsuneaki Hirashima Ikuzo Nishiguchi 《Tetrahedron letters》1985,26(37):4513-4516
Anodic oxidation in acetic acid of polycyclic cyclopropanes, namely tricyclene, cyclofenchene, and longicyclene, followed by hydrolysis brought about stereo- and regioselective formation of the corresponding homoallylic alcohols as the main product in good yields. 相似文献
253.
In order to determine the copper content x of copper Chevrel compound CuxMo6S8?y(0?y?0.4) as a function of copper activity aCu and sulfur deficit y, a solid state electrochemical cell, Cu/Rb4Cu16I7Cl13/CuxMo6S8?y/Pt, was constructed and coulometric titration studies were made at 400 K. For the evaluation of the coulometric titration data, measurements were made on the electronic conductivity of copper-ion conductor Rb4Cu16I7Cl13. Also, a brief investigation was made on the condition of formation of single phase Chevrel CuxMo6S8?y with varying x and y at 1000°C. The structural change of CuxMo6S8?y with a change in x and y was studied by the X-ray diffraction method. It was found that x for constant aCu decreases with increasing y. The maximum value xmax of x in CuxMo6S8?y in equilibrium with metallic copper was found to be expressed by . In the region of y<0.3, xmax exceeded 4, contrary to a presupposition that xmax is less than 4. X-ray analysis revealed that most of the copper Chevrel compounds denoted by CuxMo6S8 so far were sulfur deficient ones with y?0.4. The importance of sulfur deficit on the properties of the copper Chevrel compound was emphasized. 相似文献
254.
255.
Koichi Yamada Brenda P. Winnewisser Manfred Winnewisser 《Journal of Molecular Spectroscopy》1975,56(3):449-470
The recent assignment of the vibrational spectrum of the quasilinear molecule HCNO revealed several near coincidences between vibrational energy levels involving the two bending modes, ν4 (skeletal bending mode) and ν5 (HCN-bending mode), and the lowest-lying stretching mode, ν3 (NO stretching mode). By considering the correlation between the energy levels of a linear and a bent molecular model of HCNO, it is seen that resonance interactions which would be of third or higher order in a linear molecule Hamiltonian would be of first or second order in the Hamiltonian of a bent molecule, and thus might be significant in the quasilinear molecule HCNO. In this way we were able to identify the type of observed interaction occurring between three pairs of nearly coincident levels, (00010, 00002), (00020, 00012), and (00100, 00004). Anomalous centrifugal distortion effects had been observed and reported earlier for the pure rotational transitions arising from molecules in the 00010, 00020, and 00002 levels. Rotational transitions arising from molecules in the 00004 and 00100 vibrational states of HCNO and the 00100 state of DCNO are reported here for the first time. For two pairs of levels, (00010, 00002) and (00100, 00004), we could determine the magnitude of the coefficients of the interaction matrix elements from an analysis of the centrifugal distortion effects. 相似文献
256.
Tadatomi Nishikubo Takashi Iizawa Minoru Yamada Koichi Tsuchiya 《Journal of polymer science. Part A, Polymer chemistry》1983,21(7):2025-2045
Novel photosensitive polymers with pendant photosensitive group, such as cinnamic ester, and photosensitizer groups, such as N-carbamoyl-p-nitroaniline and N-carbamoly-4-nitro-1-naphthylamine, were synthesized from radical copolymerizations of (2-cinnamoyloxy)ethylmethacrylate with photosensitizer monomers, such as p-nitrophenylmethacrylamide and 4-nitro-1-na-phthylmethacrylamide, by using asobisisobutyronitrile (AIBN) in benzene and from the copolymerizations of (2-hydroxy)ethylmethacrylate or (2-hydroxy)ethylacrylate with photosensitizer monomers by using AIBN in DMF. This procedure was followed by condensation reactions of the copolymers with cinnamoyl chloride with pyridine as HCL acceptor in the same reaction flask. The photoreactivities of the polymers obtained were influenced by the concentration of photosensitive group and photosensitizer groups and their ratio in the polymer matrix. In addition, the photosensitivity of cinnamic ester groups attached to a soft polymer segment was higher than that of cinnamic ester group attached to a hard polymer segment when these polymers had the same pendant N-carbamoyl-p-nitroaniline group as photosensitizer. Furthermore, the spacer length between the polymer chain and photosensitizer group was important for increasing the photoreactivity of the photosensitive group in the polymers with pendant cinnamic ester and N-carbamoyl-p-nitroaniline groups. 相似文献
257.
258.
259.
Specimens of poly(vinylidene fluoride), crystal form II, annealed at different temperatures between 130 and 180°C were characterized by specific volume measurements, differential scanning calorimetry (DSC), and electron micróscopy. The degree of crystallinity calculated from the specific volume changed only by 15% i.e., from 50% to 65%. On the other hand, the melting behavior changed with annealing conditions. When a specimen was annealed above 170°C, two endothermic peaks appeared on either side of the annealing temperature. Results from DSC measurements made at different heating rates and electron microscopy showed that the two endotherms were caused by a bimodal distribution of lamellar thicknesses. The equilibrium melting point was found to be 210°C from the linear relation of the melting point and the annealing temperature. The equilibrium enthalpy and entropy of fusion were found to be 1.6 keal/mole and 3.3 eu/mole of repeat units by measurement on polymer–diluent mixtures. The surface free energy was found to be 5.1 kcal/mole of lamellar sequences from the plot of melting point versus reciprocal lamellar thickness obtained by electron microscopy. From a plot of enthalpy of fusion versus reciprocal lamellar thickness the surface enthalpy was found to be 20 keal/mole of lamellar sequences. These data lead to the estimate that a chain fold consists of about 30 repeat units. 相似文献
260.
A method has been developed to sequentially add indole-3-mercurials to dichlorinated quinones using palladium catalysis. These reactions can be used in the modular assembly of bis(indol-3-yl)benzoquinones, a significant natural product family. 相似文献