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931.
Single crystals of platinum trichloride were grown for the first time. The IR spectrum of single-crystal PtCl3 was recorded. The pressure of thermal dissociation of PtCl3 was measured by the static method with a quartz membrane-gauge zero-pressure manometer. An approximating equation for the dissociation pressure vs. temperature (540 K ≤ T ≤ 775 K) for the reaction 2 PtCl3(s) → 2 PtCl2(s) + Cl2(g) was found. The enthalpy (123.1±1.7 kJ mol−1) and entropy (183.6±2.8 J mol−1 K−1) for the dissociation of PtCl3(s) were calculated at 298.15 K.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2032–2034, October, 2004. 相似文献
932.
Tame JR 《Journal of computer-aided molecular design》2005,19(6):445-451
The use of simple linear mathematical models to estimate chemical properties is not a new idea. Albert Einstein used very
simple ‘gravity-like' forces to explain the capillarity of different liquids in 1900–1901. Today such models are used in more
complicated situations, and a great many have been developed to analyse interactions between proteins and their ligands. This
is not surprising, since proteins are too complicated to model accurately without lengthy numerical analysis, and simple models
often do at least as good a job in predicting binding constants as much more computationally expensive methods. One hundred
years after Einstein’s ‘miraculous year’ in which he transformed physics, it is instructive to recall some of his even earlier
work. As approximations, ‘scoring functions’ are excellent, but it is dangerous to read too much into them. A few cautionary
tales are presented for the beginner to the field of ligand affinity prediction by linear models. 相似文献
933.
934.
J. L. Oscarson S. E. Gillespie J. J. Christensen R. M. Izatt P. R. Brown 《Journal of solution chemistry》1988,17(9):865-885
The aqueous reactions, {ie865-1}were studied as a function of ionic strength at 275, 300, and 320°C using a flow calorimetric technique. Log K, H and S values were determined from the fits of the calculated and experimental heats while Cp values were calculated from the variation of H values with temperature. The log K and H values for the first two reactions agree well with literature values at these temperatures. No previous results have been reported for the third reaction. The use of equations containing identical numbers of positive and identical numbers of negative charges on both sides of the equal sign (isocoulombic reaction principle) was applied to the log K values determined in this study. The resulting plots of log K for the isocoulombic reactions vs. I/T were approximately linear, which demonstrates that the Cp values for these reactions are approximately zero.Deceased 5 September 1987 相似文献
935.
R. Balescu 《Journal of statistical physics》1987,48(5-6):1091-1107
The neoclassical theory of transport in magnetically confined plasmas is reviewed. The emphasis is laid on a set of relationships existing among the banana transport coefficients. The surface-averaged entropy production in such plasmas is evaluated. It is shown that neoclassical effects emerge from the entropy production due to parallel transport processes. The Pfirsch-Schlüter effect can be clearly interpreted as due to spatial fluctuations of parallel fluxes on a magnetic surface: the corresponding entropy production is the measure of these fluctuations. The banana fluxes can be formulated in a quasithermodynamic form in which the average entropy production is a bilinear form in the parallel fluxes and the conjugate generalized stresses. A formulation as a quadratic form in the thermodynamic forces is also possible, but leads to anomalies, which are discussed in some detail. 相似文献
936.
Thermal membrane potential across cation-exchange membranes was measured for various halide solutions. Linear relationships between thermal membrane potential () and temperature difference (T) were observed, and the temperature coefficient of thermal membrane potential (/T) decreases with increase in the molality of the external solution as predicted by a theory reported. When counterions of membranes are hydrogen ions, the sign of the coefficients turns into minus near 0.01 mol/kg of the external solution for all membranes, although the coefficients are always positive for all the other forms. The dependence of the coefficients on the molality of the external solutions sometimes deviated slightly from the theory. This deviation is attributed to some change in water content of the membranes. A reproducible method of measuring water content of membranes was applied to discuss the change in the state of the membranes. 相似文献
937.
938.
Keitaro Kiyosawa 《Journal of solution chemistry》2004,33(4):323-328
The freezing point of mixtures of H2
16O with H2
17O was measured as a function of the molal concentration. The freezing points rose linearly with increasing molal concentration above that of pure ordinary water, H2
16O, at 273.15 K. This confirms Kiyosawa's previous conclusion [K. Kiyosawa, J. Solution Chem.
20, 583 (1991).], drawn from findings on changes in the freezing point of mixtures of H2
16O with H2
18O or D2
16O that even a difference in the number of neutrons in the hydrogen or oxygen atoms of water molecules makes them behave as different entities with respect to the colligative properties of solutions. This has been confirmed to also occur in mixtures of H2
16O with H2
17O. 相似文献
939.
940.
Random walk on heterogeneous networks is a recently emerging approach to effective disease gene prioritization. Laplacian normalization is a technique capable of normalizing the weight of edges in a network. We use this technique to normalize the gene matrix and the phenotype matrix before the construction of the heterogeneous network, and also use this idea to define the transition matrices of the heterogeneous network. Our method has remarkably better performance than the existing methods for recovering known gene–phenotype relationships. The Shannon information entropy of the distribution of the transition probabilities in our networks is found to be smaller than the networks constructed by the existing methods, implying that a higher number of top-ranked genes can be verified as disease genes. In fact, the most probable gene–phenotype relationships ranked within top 3 or top 5 in our gene lists can be confirmed by the OMIM database for many cases. Our algorithms have shown remarkably superior performance over the state-of-the-art algorithms for recovering gene–phenotype relationships. All Matlab codes can be available upon email request. 相似文献