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101.
The hydrothermal reactions of MoO(3), an appropriate Cu(II) source, tetra-2-pyridylpyrazine (tpypyz), and phosphoric acid and/or an organophosphonate yielded a series of organic-inorganic hybrid materials of the copper-molybdophosphonate family. A common feature of the structures is the entrainment within the extended architectures of chemically robust [Mo(5)O(15)(O(3)PR)(2)](4)(-) clusters as molecular building blocks. The cluster is a characteristic feature of the one-dimensional materials [[Cu(2)(tpypyz)(H(2)O)(3)]Mo(5)O(15)(HPO(4))(O(3)PCH(2)CO(2)H)].H(2)O (1.H(2)O) and [[Cu(2)(tpypyz)(H(2)O)]Mo(5)O(15)(O(3)PC(6)H(5))(2)].2H(2)O (2.2H(2)O), the two-dimensional network [[Cu(2)(tpypyz)(H(2)O)(3)]Mo(5)O(15)(HPO(4))(2)].2H(2)O (5.2H(2)O) and the three-dimensional frameworks [[Cu(2)(tpypyz)(H(2)O)(2)]Mo(5)O(15)[O(3)P(CH(2))(n)()PO(3)]].xH(2)O [n = 3, x = 2.25 (6.2.25H(2)O); n = 4, x = 0.33 (7.0.33H(2)O)]. In the case of methylenediphosphonate as the phosphorus component, the unique chelating nature of the ligand precludes formation of the pentamolybdate core, resulting in the chain structures [[Cu(2)(tpypyz)(H(2)O)]Mo(3)O(8) (HO(3)PCH(2)PO(3))(2)].8H(2)O (3.8H(2)O) and [[Cu(2)(tpypyz)(H(2)O)](2)(Mo(3)O(8))(2)(O(3)PCH(2)PO(3))(3)].16.9H(2)O (4.16.9H(2)O). For structures 1-7, the secondary metal-ligand building block is the binuclear [Cu(2)(tpypyz)(H(2)O)(x)](4+) cluster. There is considerable structural versatility as a result of the variability in the number of attachment sites at the phosphomolybdate clusters, the coordination geometry of the Cu(II), which may be four-, five-, or six-coordinate, the extent of aqua ligation, and the participation of phosphate oxygen atoms as well as molybdate oxo groups in bonding to the copper sites. Crystal data: 1.H(2)O, C(26)H(28)N(6)Cu(2)Mo(5)O(28)P(2), monoclinic C2/c, a = 42.497(2) A, b = 10.7421(4) A, c = 20.5617(8) A, beta = 117.178(1) degrees, V = 8350.1(5) A(3), Z = 8; 2.2H(2)O, C(36)H(32)N(6)Cu(2)Mo(5)O(24)P(2), monoclinic P2(1)/c, a = 11.2478(7) A, b = 19.513(1) A, c = 21.063(1) A, beta = 93.608(1) degrees, V = 4613.7(5) A(3), Z = 4; 3.8H(2)O, C(26)H(40)N(6)Cu(2)Mo(3)O(29)P(4), monoclinic C2/c, a = 32.580(2) A, b = 17.8676(9) A, c = 15.9612(8) A, beta = 104.430(1) degrees, V = 8993.3(8) A(3), Z = 8; 4.16.9H(2)O, C(51)H(71.75)Cu(4)Mo(6)N(12)O(51)P(6), monoclinic P2(1)/c, a = 27.929(3) A, b = 12.892(2) A, c = 22.763(3) A, beta = 90.367(2) degrees, V = 8195.7(2) A(3), Z = 4;( )()5.2H(2)O, C(24)H(28)N(6)Cu(2)Mo(5)O(28)P(2), monoclinic P2(1)/n, a = 11.3222(4) A, b = 18.7673(7) A, c = 19.4124(7) A, beta = 98.819(1) degrees, V = 4076.1(3) A(3), Z = 4; 6.2.25H(2)O, C(27)H(28.5)N(6)Cu(2)Mo(5)O(24.25)P(2), monoclinic C2/c, a = 12.8366(5) A, b = 18.4221(8) A, c = 34.326(1) A, beta = 100.546(1) degrees, V = 7980.1(6) A(3), Z = 8; 7.(1)/(3)H(2)O, C(28)H(28.7)N(6)Cu(2)Mo(5)O(23.3)P(2), monoclinic C2/c, a = 12.577(1) A, b = 18.336(1) A, c = 36.476(3) A, beta = 91.929(2) degrees, V = 8407.3 A(3), Z = 8. 相似文献
102.
Adsorption isotherms of cationic surfactant, dodecylpyridinium chloride, on an Aerosil OX50 and isotherms of surface charge against the background of 0.001- and 0.1-M KCl solutions at pH 7 and 9 were measured and analyzed. Different forms of adsorption isotherms of surfactants at low and high electrolyte concentrations are explained from differences in the formation of the surface charge of Aerosil. Comparison of the isotherms of surfactant adsorption and surface charge allowed us to make conclusions about the surfactant orientation and structure of an adsorption layer, as well as to determine the fraction of surfactant molecules in the first and second adsorption layers. 相似文献
103.
The specific interaction of halide and alkali metal ions with carbon and graphite electrodes was investigated by monitoring the dimensional changes and the charging current during a linear potential scan. The potential of zero charge (pzc), as detected by a minimum in the length vs. potential curve, is shifted towards more negative values when a larger halide is the anion in a single electrolyte solution and as the solution concentration increases. This is interpreted in terms of increasing specific interactions. Alkali cations, on the other hand, do not exhibit any measurable effects of specific interaction,The differential capacity of both carbon and graphite increases due to specific interactions. However, the contribution to the capacity of the carbon is much larger than that for the graphite. This is interpreted on the basis of the much larger contribution of the edge planes in the carbon. 相似文献
104.
Yurkshtovich N. K. Golub N. V. Kaputskii F. N. Yurkshtovich T. L. Kosterova R. I. 《Russian Journal of Applied Chemistry》2004,77(3):471-475
Complexation of iron(III), aluminum(III), and chromium(III) cations with monocarboxy cellulose was studied by potentiometric titration and IR spectroscopy. The composition and stability constants of the complexes were determined. 相似文献
105.
The experimental investigation of the lateral interaction of the heads of pulsed jets and primary shock waves at various nozzle spacings and pressure ratio numbers is described. The various stages of formation of a composite pulsed jet issuing from a multinozzle block are classified and the flow development mechanisms are explored. It is shown for both a block and a single nozzle the shock wave travels with almost the same velocity, whereas the jet front formed at the exit from a single nozzle moves much more slowly than the jet front formed beyond a nozzle block. Long-lived lateral bursts of gas, whose dimensions are an order greater than those of the jet bursts, are detected. Their long period of existence considerably increases the stabilization time of the steady-state structure and parameters as compared with a single pulsed jet with the same flow rate.Translated from Izvestiya Akademii Nauk SSSR, Mekhanika Zhidkosti i Gaza, No. 6, pp. 153–159, November–December, 1987. 相似文献
106.
We measure the nonlinear refractive index of SF6 at three different CO2 laser lines. Higher terms than the cubic nonlinearity are found and the behavior of the refractive index as a function of the laser intensity depends strongly on the frequency used, reflecting the characteristic SF6 absorption dynamics. 相似文献
107.
The following tricyclic heterocyclic compounds are synthesized: 2-methylthiazolov (5, 4-e) benzo-1, 2, 3thiadiazole, 2-methylthiazolo (4, 5-e) benzo-1, 2, 3-thiadiazole, 2-methylthiazolo (4, 5-g) benzo-1, 2, 3-thiadiazole, and 2-methylthiazolo (5, 4-g) benzo-1, 2, 3-thiadiazole. The quaternary salts of these bases are used to prepare symmetrical and unsymmetrical trimethinecyanines and dimethinemercocyanines containing N-ethylrhodanine residues. The absorption maxima of these dyes are shifted toward the long-wave region as compared with the corresponding thiacyanines. 相似文献
108.
109.
V. I. Blynskii O. A. Bozhatkin E. S. Golub A. M. Lemeshevskaya S. V. Shvedov 《Journal of Applied Spectroscopy》2010,77(3):445-447
We examine the results of an effect of preliminary annealing on the spectral sensitivity of photodetectors in bipolar integrated
circuits, formed in silicon grown by the Czochralski method. We demonstrate the possibility of substantially improving the
sensitivity of photodetectors in the infrared region of the spectrum with twostep annealing. The observed effect is explained
by participation of oxidation in the gettering process, where oxidation precedes formation of a buried n+ layer in the substrate. 相似文献
110.
For the non-Hermitian and positive semidefinite systems of linear equations, we derive necessary and sufficient conditions for guaranteeing the unconditional convergence of the preconditioned Hermitian and skew-Hermitian splitting iteration methods. We then apply these results to block tridiagonal linear systems in order to obtain convergence conditions for the corresponding block variants of the preconditioned Hermitian and skew-Hermitian splitting iteration methods.