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31.
Cleaver JE 《Photochemistry and photobiology》2011,87(6):1230-1239
The phosphorylation of H2Ax on its S139 site, γH2Ax, is important for the assembly of repair complexes at DNA double strand breaks (DSBs). The formation and functional role of γH2Ax after other kinds of DNA damage, especially UV light, where DSBs are rare, is less clear. Following UV light in the UVB and UVC ranges, complex distributions of γH2Ax can be identified, quite unlike the discrete enumerable foci seen after ionizing radiation. Several distinct distributions of γH2Ax occur: a low level nuclear-wide distribution of γH2Ax occurs during nucleotide excision repair; irregular focal distributions occur at arrested replication forks; high intensity nuclear-wide γH2Ax occurs in association with S-phase apoptosis. The intensity and distributions of γH2Ax vary according to the activity of excision repair, bypass polymerase and apoptotic caspases. The frequency of DSBs at arrested replication forks is low but highly variable in different cell types, and probably caused by enzymatic action. Despite the prominence of S139 phosphorylation following UV damage, mutation of this site has no influence on the UV damage response indicating that γH2Ax is a biomarker but not a participant in the UV-DNA damage response. 相似文献
32.
Two analytical procedures used to determine total, soluble, and insoluble solids in tomato paste were evaluated. The microwave oven (MO) method was compared to the vacuum oven (VO) method. The VO method is tedious and measured the three solids fractions in the paste directly, while the MO method measured the total solids directly but used an equation to calculate the water-soluble and -insoluble solids. The MO method was faster and less labor-intensive, and yielded small but statistically significant higher values for total and insoluble solids and lower statistically significant values for soluble solids. 相似文献
33.
34.
Doug Hensley 《Mathematische Nachrichten》1997,184(1):177-190
Given a finite field Fq of order q, a fixed polynomial g in –Fq[X] of positive degree, and two elements u and v in the ring of polynomials in R = Fq [X]/gFq[X], the question arises: How many pairs (a, 6) are there in R × R so that ab ? 1 mod g and so that a is close to u while b is close to v ? The answer is, about as many as one would expect. That is, there are no favored regions in R × R where inverse pairs cluster. The error term is quite sharp in most cases, being comparable to what would happen with random distribution of pairs. The proof uses Kloosterman sums and counting arguments. The exceptional cases involve fields of characteristic 2 and composite values of g. Even then the error term obtained is nontrivial. There is no computational evidence that inverses are in fact less evenly distributed in this case, however. 相似文献
35.
The electron affinity and first three ionization potentials of C3 are calculated using the multiconfigurational SCF and configuration interaction methods and by Möller-Plesset perturbation theory. Whereas Koopmans' theorem and SCF calculations indicate that the first cation state is 2Πu, upon inclusion of correlation effects both the 2Σu and 2Σg cation states are found to lie lower in energy. CI calculations indicate that the ground state (2Πg) anion is stable by 1.74 eV. Allowing for the error in the calculated electron affinity of the carbon atom, C3? is estimated to be stable by 2.0 eV, in excellent agreement with the 2.05 eV value determined from recent photodetachment measurements. No excited anion states are found to be bound at the equilibrium geometry of the neutral molecule. 相似文献
36.
John W. Cleaver 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》1969,20(2):213-229
Zusammenfassung Um eine analytische Lösung zu erhalten, welche Effekte der endlichen Entropie- und Wirbelstärkeerzeugung berücksichtigt, ist die linearisierte Theorie formell durch Einbeziehung von Grössen zweiter Ordnung erweitert worden. Anwendungen sind gegeben für den Fall einer ebenen Expansionsströmung eines harmonisch relaxierenden Gases, das sich nicht im Gleichgewicht befindet. Die Theorie zweiter Ordnung zeigt eine Verbesserung gegenüber der ersten Ordnung in der Voraussage der Zustandsgrössen entlang der Wand. Insbesondere wird eine Abschätzung der Abweichungen der asymptotischen Wandwerte des Druckes, der Temperatur usw. vom entsprechenden Gleichgewichtswert für unendliche Reaktionsgeschwindigkeiten ermöglicht. 相似文献
37.
Using the finite dimensional example of
, the universal covering of PSU(1,1), as a guide, we revisit the orbit method as it applies to
, the universal central extension of
. We clarify some aspects of the classification of coadjoint orbits, determine boundedness properties of the natural height function on these orbits, and calculate orbital integrals. 相似文献
38.
Doug Beder 《Nuclear Physics A》1978,305(2):411-417
The quadrupole moment of the ground state of the μ+e? atom is calculated to be (3memμ)?1; effects in a crystal are briefly discussed. 相似文献
39.
We show, by computer simulation, that tapered or pear-shaped particles, interacting through purely repulsive interactions, can freely self-assemble to form the three-dimensionally periodic, gyroid cubic phase. The Ia3d gyroid cubic phase is formed by these particles on both compression of an isotropic configuration and expansion of a smectic A bilayer arrangement. For the latter case, it is possible to identify the steps by which the topological transformation from nonintersecting planes to fully interpenetrating, periodic networks takes place. 相似文献
40.
Let E(1)p denote the rational elliptic surface with a single multiple fiber fp of multiplicity p. We construct an infinite family of homologous non-isotopic symplectic tori representing the primitive 2-dimensional homology
class [fp] in E(1)p when p>1. As a consequence, we get infinitely many non-isotopic symplectic tori in the fiber class of the rational elliptic surface
. We also show how these tori can be non-isotopically embedded as homologous symplectic submanifolds in other symplectic 4-manifolds. 相似文献