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**排序方式：**共有1203条查询结果，搜索用时 15 毫秒

1.

《Physica A》2006,372(2):203-209

The statistical theory of certain complex wave interference phenomena, like the statistical fluctuations of transmission and reflection of waves, is of considerable interest in many fields of physics. In this article, we shall be mainly interested in those situations where the complexity derives from the quenched randomness of scattering potentials, as in the case of disordered conductors, or, more in general, disordered waveguides.In studies performed in such systems one has found remarkable

*statistical regularities*, in the sense that the probability distribution for various macroscopic quantities involves a rather small number of relevant physical parameters, while the rest of the microscopic details serves as mere “scaffolding”. We shall review past work in which this feature was captured following a maximum-entropy approach, as well as later studies in which the existence of a limiting distribution, in the sense of a generalized central-limit theorem, has been actually demonstrated. We then describe a microscopic potential model that was developed recently, which gives rise to a further generalization of the central-limit theorem and thus to a limiting macroscopic statistics. 相似文献2.

Alexander Y. Nazarenko John D. Lamb 《Journal of inclusion phenomena and macrocyclic chemistry》1997,29(3-4):247-258

New polymer inclusion membranes (PIMs) containing 18-membered crownethers and dialkylnaphthalenesulfonic acid are proposed for Sr2+ and Pb2+removal from nitric acid solutions. The influence of source phasecomposition and stripping agents was characterized and permeabilitycoefficients were calculated. The PIMs are easy to prepare and may be usefulin separation and concentration procedures for these cations from complexmixtures such as nuclear waste. Long-term stability was obtained for atleast several weeks of constant use during which no significant change ofpermeability was observed. 相似文献

3.

《The Journal of chemical thermodynamics》2007,39(5):712-716

The heat capacity of water in the form of hexagonal ice was measured between

*T*= 0.5 K and*T*= 38 K using a semi-adiabatic calorimetric method. Since heat capacity data below*T*= 2 K have never been measured for water, this study presents the lowest measured values of the specific heat of water to date. Fits of the data were used to generate thermodynamic functions of water at smoothed temperatures between 0.5 K and 38 K. Both our experimental heat capacities and calculated enthalpy increments agree well with previously published values and thus supplement other studies well. 相似文献4.

Synthesis of lipid A derivatives and their interactions with polymyxin B and polymyxin B nonapeptide

**总被引：5，自引：0，他引：5** Yin N Marshall RL Matheson S Savage PB 《Journal of the American Chemical Society》2003,125(9):2426-2435

Lipid A is the causative agent of Gram-negative sepsis, a leading cause of mortality among hospitalized patients. Compounds that bind lipid A can limit its detrimental effects. Polymyxin B, a cationic peptide antibiotic, is one of the simplest molecules capable of selectively binding lipid A and may serve as a model for further development of lipid A binding agents. However, association of polymyxin B with lipid A is not fully understood, primarily due to the low solubility of lipid A in water and inhomogeneity of lipid A preparations. To better understand lipid A-polymyxin B interaction, pure lipid A derivatives were prepared with incrementally varied lipid chain lengths. These compounds proved to be more soluble in water than lipid A, with higher aggregation concentrations. Isothermal titration calorimetric studies of these lipid A derivatives with polymyxin B and polymyxin B nonapeptide indicate that binding stoichiometries (peptide to lipid A derivative) are less than 1 and that affinities of these binding partners correlate with the aggregation states of the lipid A derivatives. These studies also suggest that cooperative ionic interactions dominate association of polymyxin B and polymyxin B nonapeptide with lipid A. 相似文献

5.

《Nuclear Physics A》1986,458(4):652-668

The quark-meson RPA equations, which describe small oscillations of a bound quark-meson system about the stationary configuration, are derived through linearization of the classical time-dependent Euler-Lagrange problem. The method has an immediate application in phenomenological quark-meson models for baryons. It provides a test of the classical stability of these systems. A number of measurable quantities, such as the spectrum of excited states and the meson-soliton phase shifts can be calculated. We demonstrate the QMRPA on a simple, 3 + 1 dimensional model of the nucleon — the chiral quark-meson model. 相似文献

6.

《Topology and its Applications》1986,22(1):85-96

Let

*X*be a compact metric space with no isolated points. Then we may embed*X*as a subset of the Hilbert cube*Q*(*X*⊂*Q*) so that the only homeomorphism of*X*onto itself that extends to a homeomorphism of*Q*is the identity homeomorphism. Such an embedding is said to be rigid. In fact, there are uncountably many rigid embeddings*X*_{α}of*X*in*Q*so that for*α*≠*β*and any homeomorphism*h*of*Q*,*h*(*X*_{α})∩*X*_{β}is a*Z*-set in*Q*and a nowhere dense subset of each of*h*(*X*_{α}) and*X*_{β}. 相似文献7.

In an earlier paper, formulae for det

*A*as a ratio of products of principal minors of*A*were exhibited, for any given*symmetric*zero-pattern of*A*^{−1}. These formulae may be presented in terms of a spanning tree of the intersection graph of certain index sets associated with the zero pattern of*A*^{−1}. However, just as the determinant of a diagonal and of a triangular matrix are both the product of the diagonal entries, the symmetry of the zero pattern is not essential for these formulae. We describe here how analogous formulae for det*A*may be obtained in the asymmetric-zero-pattern case by introducing a directed spanning tree. We also examine the converse question of determining all possible zero patterns of*A*^{−1}which guarantee that a certain determinantal formula holds. 相似文献8.

9.

《Tetrahedron letters》1987,28(20):2259-2262

Diallyloxyphosphorylation of nucleoside hydroxyls followed by palladium(0)-catalyzed deallylation provides a new, general method for the preparation of the 3′- and 5′-monophosphates. 相似文献

10.