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41.
42.
Microwave measurements of rotational transitions within vibrationally excited states of several isotopic species of HCN have given improved values for the pertinent Bv constants. These new data have been combined with infrared measurements given in the literature (ncluding Dv terms) to arrive at a set of rovibrational constants (α and γ constants) which is consistent with all available data. Bond distances resulting from several different Be approximations are intercompared to assess the variability of the re values and the importance of the γ terms. The latest r0 and rs bond distances are also given. 相似文献
43.
The microwave and millimeter wave spectra of HNCS in the three bending excited states, v4 = 1, v5 = 1, and v6 = 1, have been measured. The qR0, qR1, and qR2 branches for each of these three states and the qR3 branch for the lowest excited state have been assigned. Effective rotational and centrifugal distortion constants have been determined for each vibrational and Ka-rotational sub-state. Two local resonances, caused by the Coriolis induced asymmetry interaction and a b-type Coriolis resonance, allow unambiguous confirmation of the assignment of the state v6 = 1, the first excited state of the out-of-plane vibration. 相似文献
44.
The Doppler-limited rotational spectrum of the NH radical in its electronic (X) and vibrational ground state has been measured using the frequency stabilized Cologne side-band spectrometer in the frequency region near 2 THz. The nitrogen 14N nuclear hyperfine patterns have been observed accompanying the resolved fine (J′←J″) structure of the N=2←1 rotational transition. The observed peak frequencies were analyzed in detail together with the previously measured hyperfine frequencies of the N=1←0 rotational transition and with combination differences obtained from the high-resolution electronic spectra to derive precise rotational, centrifugal distortion, fine, and hyperfine parameters. In the numerical analysis the essential attention has been paid to partly resolved and unresolved hyperfine structures. The peak positions of the partly or fully overlapped lines were analyzed with the help of a profile simulation with estimated half-widths and calculated relative intensities and in this manner the least square fit of the unresolved and partly resolved lines was significantly improved. The NH radical is an extremely important species in nitrogen chemical reaction networks in the interstellar medium and atmospheric chemistry. 相似文献
45.
S.N. Mikhailenko VL.G. TyuterevV.I. Starikov K.K. AlbertB.P. Winnewisser M. Winnewisser G. MellauC. Camy-Peyret R. LanquetinJ.-M. Flaud J.W. Brault 《Journal of Molecular Spectroscopy》2002,213(2):91-121
Water vapor infrared spectra have been recorded at room temperature in the range 4200-6250 cm−1 at resolutions (FWHM) between 0.0053 and 0.0080 cm−1. The use of a White-type multireflection cell made large pressure × pathlength products possible up to 31.27 mbar×288.5 m. The high signal-to-noise ratio allowed us to observe lines with intensities as small as 10−26 cm−1/molecule cm−2 at T=296 K. Among about 5100 recorded water lines, about half of which are reported for the first time, 2351 lines have been assigned to the second triad of H216O (bands ν1+ν2, ν2+ν3, and 3ν2). This has allowed the determination of line positions and corresponding upper rovibrational states with considerably improved accuracy. The assignments of certain highly excited states have been confirmed by the analysis of flame spectra and hot emission spectra. New values of effective Hamiltonian parameters for the upper states {(110), (030), (011)} have been determined. The generating function model was used in the data reduction to account for the anomalously strong centrifugal distortion of the rovibrational levels and resonance interactions. The RMS standard deviation of the least-squares fit of the assigned H2O data was 5×10−3 cm−1 for line positions and 7×10−3 cm−1 for energy levels up to Jmax=20 and Ka(max)=13. Particular attention was paid to water lines in the transparency window 4200-5000 cm−1, in which existing databases are not sufficient. In this region, 1395 lines of four isotopic species of water have been recorded and over 900 accurate line positions of nine bands of H216O (ν1, ν3, 2ν2, ν1+ν2, ν2+ν3, 3ν2, 4ν2−ν2, 2ν2+ν3−ν2, ν1+2ν2−ν2) are reported in this range. A comparison of laboratory spectra with long path atmospheric spectra (20 km slant path in the mountains) in this region shows that many lines missing from available spectroscopic compilations (or considerably shifted compared to observations) are important for a proper interpretation of atmospheric observations. A comparison of the observed data with the best available predictions from the molecular electronic potential energy surface is discussed. 相似文献
46.
M. Winnewisser E.F. Pearson J. Galica B.P. Winnewisser 《Journal of Molecular Spectroscopy》1982,91(1):255-268
The pure rotational spectrum of CH3CNO was measured in the frequency range 75 to 230 GHz. For the ground state, transitions were measured for J between 9 and 28 and for K from 0 to 12. In the v10 = 1 state the measurements range from J = 0 to 19 and from K = 0 to 11. Numerous perturbations are observed, apparently due to accidental resonances with levels in other vibrational states. The contributions due to ΔK = 2, Δl = 2 matrix elements (l-type resonance and l-type doubling) are accounted for by matrix diagonalization, and the effects due to accidental resonances are presented graphically. 相似文献
47.
?. Urban D. Papou?ek S.P. Belov A.F. Krupnov M.Yu. Tretyakov Koichi Yamada G. Winnewisser 《Journal of Molecular Spectroscopy》1983,101(1):16-29
The submillimeterwave spectra of the pure inversion and inversion-rotation transitions in the ν2 excited state (79 transitons) and the diode laser spectra of the ν2 band (83 transitions) of 15NH3 have been measured. A simultaneous least squares analysis has been carried out of these data together with previously published wavenumbers of the pure inversion transitions and inversion-rotation transitions in the ground state measured by the microwave and Fourier spectroscopy, and the ν2 band transition frequencies obtained by the infrared-microwave two-photon technique. A theory of the Δk = ±3n interactions in the ground and ν2 excited states of ammonia (?. Urban, V. ?pirko, D. Papou?ek, J. Kauppinen, S. P. Belov, L. I. Gershtein, and A. F. Krupnov, J. Mol. Spectrosc.88, 274–282 (1981)) has been used in the analysis. The “smoothed” values of the ν2 band wavenumbers can be used for calibration purposes with better than 1 × 10?3 cm?1 precision. 相似文献
48.
Gisbert Winnewisser 《Nachrichten aus der Chemie》1978,26(7):413-419
49.
Alberto Gambi Marino Pedrali Manfred Winnewisser Guy Guelachvili 《Journal of Molecular Spectroscopy》1985,113(1):250-261
The Doppler-limited infrared spectrum of diazirine was recorded using a high-information Fourier transform spectrometer with a resolution of 0.0054 cm?1. The rovibrational structure of the ν9 fundamental (CH2 rocking) at 1124.9144 cm?1, which is a C-type band, was analyzed in detail with extensive use of spectrum simulation and correlation diagrams. The molecular constants for the upper energy level of this band were obtained from the overall rovibrational assignment of more than 2000 transitions, which cover the region from 1070 to 1220 cm?1. 相似文献
50.
The high resolution Fourier transform infrared spectra of thev
4-v
2 andv
7 band systems of tricarbon disulfide, SCCCS, were measured with a Bomem D A3.002 interferometer and an apodized resolution of 0.004 cm–1. The rotational structure of the bandsv
4-v
2, (v
4+v
7)–(v
2+v
7), (v
4+2v
7)–(v
2+2v
7) andv
7 could be resolved and assigned. The analysis confirmed that SCCCS displays the dynamics of a linear molecule. 相似文献