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31.
Durá J Grün A Bates PK Teichmann SM Ergler T Senftleben A Pflüger T Schröter CD Moshammer R Ullrich J Jaroń-Becker A Becker A Biegert J 《The journal of physical chemistry. A》2012,116(11):2662-2668
We study ionization of molecules by an intense laser field over a broad wavelength regime, ranging from 0.8 to 1.5 μm experimentally and from 0.6 to 10 μm theoretically. A reaction microscope is combined with an optical parametric amplifier to achieve ionization yields in the near-infrared wavelength regime. Calculations are done using the strong-field S-matrix theory and agreement is found between experiment and theory, showing that ionization of many molecules is suppressed compared to the ionization of atoms with identical ionization potentials at near-infrared wavelengths at around 0.8 μm, but not at longest wavelengths (10 μm). This is due to interference effects in the electron emission that are effective at low photoelectron energies but tend to average out at higher energies. We observe the transition between suppression and nonsuppression of molecular ionization in the near-infrared wavelength regime (1-5 μm). 相似文献
32.
When N-[2-(alkylsulfinyl)phenyl]-1H-indole-2-carboxamides with varying degrees of indolic and amidic N-alkylation are heated in an inert solvent or treated with trifluoroacetic anhydride; only compounds in which the amidic nitrogen is methylated cyclize to indolo[3,2-b]-1,5-benzothiazepinones (9, 10). Successful cyclization is attributed to the ability of N-Me amides to readily adopt a conformation conducive to cyclization, which other derivatives are unable to achieve. The analogous 3-indoleanilide, N,N-dimethyl N-[2-(ethylsulfinyl)phenyl]-1H-indole-3-carboxamide (17a), undergoes SES/rearrangement to produce 10 upon heating in p-xylene. An intermediate 3H-indolinium spirocyclic species is proposed to account for this result. 相似文献
33.
CY Tang N Phillips JI Bates AL Thompson MJ Gutmann S Aldridge 《Chemical communications (Cambridge, England)》2012,48(65):8096-8098
The reactions of Me(2)NH·BH(3) with cationic Rh(III) and Ir(III) complexes have been shown to generate the 18-electron aminoborane adduct [Ir(IMes)(2)(H)(2){κ(2)-H(2)BNMe(2))](+) and the remarkable 14-electron aminoboryl complex [Rh(IMes)(2)(H)-{B(H)NMe(2))](+). Neutron diffraction studies have been used for the first time to define H-atom locations in metal complexes of this type formed under catalytic conditions. 相似文献
34.
Choi SH Lee S Soto HE Lodge TP Bates FS 《Journal of the American Chemical Society》2011,133(6):1722-1725
Assessing the state of mixing on the molecular scale in soft solids is challenging. Concentrated solutions of micelles formed by self-assembly of polystyrene-block-poly(ethylene-alt-propylene) (PS-PEP) diblock copolymers in squalane (C(30)H(62)) adopt a body-centered cubic (bcc) lattice, with glassy PS cores. Utilizing small-angle neutron scattering (SANS) and isotopic labeling ((1)H and (2)H (D) polystyrene blocks) in a contrast-matching solvent (a mixture of squalane and perdeuterated squalane), we demonstrate quantitatively the remarkable fact that a commercial mixer can create completely random mixtures of micelles with either normal, PS(H), or deuterium-labeled, PS(D), cores on a well-defined bcc lattice. The resulting SANS intensity is quantitatively modeled by the form factor of a single spherical core. These results demonstrate both the possibility of achieving complete nanoscale mixing in a soft solid and the use of SANS to quantify the randomness. 相似文献
35.
Conductance measurements of 12 quaternary ammonium salts in propylene carbonate (PC) have been made at 25°C. The cations were either tetramethylammonium, tetraethylammonium, or tetra-n-butylammonium, and the concentrations of salt varied from about 2×10–4 to 5×10–3
M. The data were analyzed by the equation of Pitts. The results showed that the benzoate, nitrobenzoate, and pentachlorophenolate salts are completely dissociated. The nitrophenolate, chlorophenolate, methylsulfonate, and nitrate salts are only slightly associated (K
A
from 2.5 to 6.5), while the acetate, phenylacetate, and nitrophenolate salts display somewhat more extensive association, with ionpair association constants from 17 to 45. Limiting molar conductances for the anions were derived. The factors affecting ionic mobilities in this dipolar aprotic solvent are discussed.On leave 1973–1975 from the University of Gdask, Poland. 相似文献
36.
CO(2) capture by a task-specific ionic liquid 总被引:20,自引:0,他引:20
Reaction of 1-butyl imidazole with 3-bromopropylamine hydrobromide, followed by workup and anion exchange, yields a new room temperature ionic liquid incorporating a cation with an appended amine group. The new ionic liquid reacts reversibly with CO2, reversibly sequestering the gas as a carbamate salt. The new ionic liquid, which can be repeatedly recycled in this role, is comparable in efficiency for CO2 capture to commercial amine sequestering reagents, and yet is nonvolatile and does not require water to function. 相似文献
37.
D.R. Bates 《Chemical physics letters》1982,89(4):294-296
A plot of the measured electron—ion recombination coefficient against the number density of ambient ammonia shows an unexpectedly early fall which, it is suggested, may be due to the collisional coupling between the dissociative states and the other states being weakened by the growth in the clustering. 相似文献
38.
MoN and MoO molecules produced in a hollow cathode discharge have been trapped in Ne, Ar, and Kr matrices at 4.2 and 13 K and investigated by optical spectroscopy. Bands attributed to MoN were identified in the red and blue spectral regions and assigned by comparison with gas phase results to the A4π → X4Σ? (a) and B4Σ → X4Σ? (a) transitions, respectively. The ground state of Mo14N has been identified as 4Σ? with ωe = 1040 cm?1 in an Ar matrix. Absorptions assigned to MoO in the red spectral region form the (0-0) and (1-0) bands of at least one electronic transition, but could not definitely be correlated with the gas phase results. The ground state vibrational frequency for Mo16O in an Ar matrix is 893.5 cm?1. Additionally, Mo2 absorptions centered at 19 305 cm?1 were shown to be part of a vibrational progression with an average spacing of 181 cm?1. 相似文献
39.
R.H.T. Bates 《Physics Reports》1982,90(4):203-297
The many methods suggested and (some of them) tried out experimentally and/or observationally for imaging celestial objects through the Earth's atmosphere are reviewed. Their theoretical and physical bases are examined. Most attention is paid to Labeyrie's speckle interferometry and its several extensions devised during the past decade-astrophysical results obtained with the aid of these techniques are listed. Other forms of optical interferometry are discussed, as are related techniques in radio astronomy and ultrasonics. 相似文献
40.