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251.
Jan E. Åman Stefan Åminneborg Ingemar Bengtsson Narit Pidokrajt 《General Relativity and Gravitation》2008,40(12):2557-2567
In 3+1 dimensions there are anti-de Sitter quotients which are black holes with toroidal event horizons. By analytic continuation
of the Schwarzschild-anti-de Sitter solution (and appropriate identifications) one finds two one parameter families of spacetimes
that contain these quotient black holes. One of these families consists of B-metrics (“bubbles of nothing”), the other of
black hole spacetimes. All of them have vanishing conserved charges.
I. Bengtsson was supported by VR. 相似文献
252.
“The laser-induced incandescence (LII) signal is proportional to soot volume fraction” is an often used statement in scientific
papers, and it has – within experimental uncertainties – been validated in comparisons with other diagnostic techniques in
several investigations. In 1984 it was shown theoretically in a paper by Melton that there is a deviation from this statement
in that the presence of larger particles leads to some overestimation of soot volume fractions. In the present paper we present
a detailed theoretical investigation of how the soot particle size influences the relationship between LII signal and soot
volume fraction for different experimental conditions. Several parameters have been varied; detection wavelength, time and
delay of detection gate, ambient gas temperature and pressure, laser fluence, level of aggregation and spatial profile. Based
on these results we are able, firstly, to understand how experimental conditions should be chosen in order to minimize the
errors introduced when assuming a linear dependence between the signal and volume fraction and secondly, to obtain knowledge
on how to use this information to obtain more accurate soot volume fraction data if the particle size is known.
PACS 42.62.-b; 44.40.+a; 61.46.Df; 78.70.-g; 65.80.+n 相似文献
253.
H. Bladh J. Johnsson J. Rissler H. Abdulhamid N.-E. Olofsson M. Sanati J. Pagels P.-E. Bengtsson 《Applied physics. B, Lasers and optics》2011,104(2):331-341
Laser-induced incandescence (LII) is a versatile technique for quantitative soot measurements in flames and exhausts. When
used for particle sizing, the time-resolved signals are analysed as these will show a decay rate dependent on the soot particle
size. Such an analysis has traditionally been based on the assumption of isolated primary particles. However, soot particles
in flames and exhausts are usually aggregated, which implies loss of surface area, less heat conduction and hence errors in
estimated particle sizes. In this work we present an experimental investigation aiming to quantify this effect. A soot generator,
based on a propane diffusion flame, was used to produce a stable soot stream and the soot was characterised by transmission
electron microscopy (TEM), a scanning mobility particle sizer (SMPS) and an aerosol particle mass analyzer coupled in series
after a differential mobility analyzer (DMA-APM). Despite nearly identical primary particle size distributions for three selected
operating conditions, LII measurements resulted in signal decays with significant differences in decay rate. However, the
three cases were found to have quite different levels of aggregation as shown both in TEM images and mobility size distributions,
and the results agree qualitatively with the expected effect of diminished heat conduction from aggregated particles resulting
in longer LII signal decays. In an attempt to explain the differences quantitatively, the LII signal dependence on aggregation
was modelled using a heat and mass transfer model for LII given the primary particle and aggregate size distribution data
as input. Quantitative agreement was not reached and reasons for this discrepancy are discussed. 相似文献
254.
Michael MecklenburgJuraj Svitel Fredrik WinquistJin Gang Katharina OrnsteinEstera Dey Xie BinEva Hedborg Ragnar NorrbyHans Arwin Ingemar LundströmBengt Danielsson 《Analytica chimica acta》2002,459(1):25-31
Bacterial infection and inflammation result in massive changes in serum glycoproteins. These changes were investigated by the interaction of the saccharide glycoprotein moiety with lectins. A panel of eight lectins (Canavalia ensiformis, Bandeiraea simplicifolia BS-I, Arachis hypogaea, Phytolacca americana, Phaseolus vulgaris, Artocarpus integrifolia, Triticum vulgaris and Pisum sativum) was used to differentiate human serum glycoproteins obtained from patients with various bacterial infections. Lectin functionalised sensing layers were created on gold-coated wafers and lectin-glycoprotein interactions were monitored by surface plasmon resonance. The interaction of the lectin panel with serum glycoproteins produces unique patterns. Principal component analysis (PCA) was used to analyse the patterns. The actual panel of eight lectins enabled discrimination between sera obtained from patients sick with bacterial infection and healthy patients. Extended lectin panels have the potential to distinguish between types of bacterial infection and identify specific disease state. 相似文献
255.
The 333.6-, 351.1-, and 363.8-nm lines of a cw argon ion laser are found to coincide with the BaS B1Σ+-X1Σ+ (12, 0) R(17), (6, 0) P(35), and (3, 0) R(125) transitions, respectively. Fluorescence transitions from the laser-prepared upper levels terminating in X1Σ+ V = 0–28, A1Σ+ V = 1–3, A′1Π V = 1–13, and a3Π1 V = 3–12 are assigned. These results are combined with a previous analysis of the extensively perturbed BaS A1Σ+-X1Σ+ system [R. F. Barrow, W. G. Burton, and P. A. Jones, Trans. Farad. Soc.67, 902–906 (1971)]. Every observed perturbation of the BaS A1Σ+ state is electronically and vibrationally assigned. The levels a3Π0 V = 10–13, a3Π1 V = 12–14, a3Π2 V = 15, and A′1Π V = 10–13 are sampled via their perturbations of A1Σ+ V = 0–2. Although the mutual interactions of the a3Π, A′1Π, and A1Σ+ states approach Hund's case (c) limit, a complete deperturbation is performed from a case (a) starting point. Of the five lowest energy electronic states of BaS, only b3Σ+ remains uncharacterized. Principal deperturbed molecular constants are (in cm−1, 1σ uncertainties in parentheses):
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256.
The particle-rotor model using strong coupling basis functions is briefly reviewed. Recent developments are discussed. For example, a formalism for odd-odd nuclei (and negative parity states in even nuclei) is presented. With a standard neutron-proton interaction, measured spins and moments of transitional and deformed Ho nuclei are used to extract their main configurations. Total energy calculations in the (ε, ψ)-plane based on the particle-rotor model are presented for185Au. 相似文献