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221.
We consider a characterization of proteomics maps based on an alternative kind of neighborhood graphs for the protein spots on 2-D gel. The novel approach considers for every protein spot only the nearest neighborhood consisting of protein spots of higher abundance. The approach has the simplicity and advantages of the recently introduced characterization of proteome maps based on considering the nearest neighborhoods of protein spots, but it also has important additional desirable computational features. The characterization of the nearest neighborhood graphs of 2-D gel proteomics maps is sensitive to the number of spots considered and may lead to changes in the degree of similarity of different maps when the number of points has been changed, thus imposing restrictions on the protocol used for comparison of maps. The novel approach presented in this work is less sensitive to the number of points used in the analysis because graphs are constructed in a stepwise process in which the role of more distant neighbors has been diminished by linking a new spot to the nearest spot that has been already part of the neighborhood graph. In this way a graph with N + 1 spots is obtained from the graph on N spots by adding a single new link, while in the case of the nearest neighborhood graphs adding a new spot introduces novel neighborhoods and generally results in a graph that may differ significantly from the neighborhood graph on N points. 相似文献
222.
On 3-D graphical representation of proteomics maps and their numerical characterization 总被引:2,自引:0,他引:2
Randić M Zupan J Novic M 《Journal of chemical information and computer sciences》2001,41(5):1339-1344
We consider numerical characterization of proteomics maps by representing a map as a three-dimensional graphical object based on x, y coordinates of the spots and using their relative abundance as the z coordinate. In our representation the protein spots are first ordered based on their relative abundance and labeled accordingly. In the next step a 3-D path is constructed connecting spots having adjacent labels. Finally a matrix is constructed by assigning to each pairs of labels (i, j) matrix element, the numerical value of which is based on the quotients of the Euclidean distance and the distance along the 3-D zigzag between the two points. The approach has been illustrated on a fragment of a proteomics map and compared with 2-D graphical representation of proteomics maps. 相似文献
223.
224.
Zvjezdana Lazarević Jasna Vorkapić-Furač Jasenka Mühl 《Monatshefte für Chemie / Chemical Monthly》1992,123(12):1175-1179
Summary Stable enolic isomers of 2-aroyl-4-aracyl-1,3-cyclopentanediones such as3 and4 were prepared by condensation of aryl methyl ketones and diethyl maleate using an excess of sodium ethoxide (Aryl=C6H5, 4-C6H4CH3, 4-C6H4Br and 4-C6H4Cl).
-Tricarbonyl Verbindungen. I. 2,4-Disubstituierte 1,3-Cyclopentandione
Zusammenfassung Stabile Enol-Isomere von 2-Aroyl-4-aracyl-1,3-cyclopentandionen wie3 und4 wurden durch Kondensation von Arylmethylketonen und Diethylmaleat mit einem Überschuß von Natriumethoxid dargestellt (Aryl=C6H5, 4-C6H4CH3, 4-C6H4Br und 4-C6H4Cl).相似文献
225.
V. M. Adamović 《Mikrochimica acta》1968,56(3):534-537
Zusammenfassung Zur Bestimmung von Toxaphen wurde die Weiszsche Ringofentechnik angewandt, wobei zum Auswaschen der Ringe eine Diphenylamin-Petrolätherlösung benutzt wird und zur Entwicklung der Farbe der Ringe eine kurzfristige Bestrahlung mit UV-Licht Anwendung findet. Die Grenzwerte der Bestimmungen sind 0,5 bis 2,5g Toxaphen mit einer Genauigkeit von 100±2%.Auf die Möglichkeit der Anwendung anderer aromatischer Amine für eine Reihe anderer Organochlorpestizide wird hingewiesen.
Vorgetragen auf dem 1. jugoslawischen Kongreß für Ernährung, Belgrad, 5. bis 7. Dezember 1966. 相似文献
Summary The Weisz ring oven technique was used for determining Toxaphene, whereby a diphenylamine-petroleum ether solution was employed for washing out the rings and a brief irradiation with UV light for the development of the color of the rings. The limiting values of the determinations are 0.5 to 2.5g Toxaphene with an accuracy of 100±2%.The possibility of the application of other aromatic amines for a series of other organo chlorinated pesticides is pointed out.
Vorgetragen auf dem 1. jugoslawischen Kongreß für Ernährung, Belgrad, 5. bis 7. Dezember 1966. 相似文献
226.
Nesković OM Veljković MV Velicković SR Petkovska LT Perić-Grujić AA 《Rapid communications in mass spectrometry : RCM》2003,17(3):212-214
Ionization energies of hypervalent Li(2)F, Li(2)Cl and Na(2)Cl molecules detected by surface ionization electron impact neutralization mass spectrometry are reported. The ionization energies were 3.78 +/- 0.2 eV for Li(2)F, 4.93 +/- 0.2 eV for Li(2)Cl, and 4.21 +/- 0.2 eV for Na(2)Cl. The ionization energies (IE) agree with theoretical ionization energies calculated by ab initio methods, supporting the theoretical prediction that Li(2)F has a hyperlithiated configuration in which the odd electron delocalizes over the two lithiums and with photoionization measurement. The first ionization energy of Na(2)Cl was experimentally confirmed earlier and for Li(2)Cl as well.8 We have developed and used this new approach for the problem--in the present work ions were first formed by surface ionization, followed by electron attachment (neutralization). 相似文献
227.
Novak P Tepes P Cindrić M Ilijas M Dragojević S Mihaljević K 《Journal of chromatography. A》2004,1033(2):299-303
Directly coupled LC-MS and LC-NMR were applied to identify and structurally characterize an acarbose degradation product A in acidic media. A comparative analysis of the stop-flow LC-NMR (1H and TOCSY) and LC-MS data provided evidence that A is structurally related to acarbose, differing from the parent compound in a number of subunits present in the molecule. Spectral analysis revealed that A was the alpha-glucosidase inhibitor amylostatin XG. Complementary information obtained from the two methods led to the structural elucidation of A which was later corroborated by high-resolution NMR spectroscopy of the isolated molecule. 相似文献
228.
I. B. Plećaš A. D. Perić J. D. Drljača A. M. Kostadinović 《Journal of Radioanalytical and Nuclear Chemistry》1992,157(1):95-104
An optimization of mortar (as matrix), improved with bentonite clay, used for immobilization of radionuclides60Co,137Cs,85Sr and54Mn, is presented. A relatively simple mathematical model is given, which permits minimization of leach rate and permeability and maximization of compressive strength. An optimal solution, based on experimental data, is given. These results will be used for a future Yugoslav radioactive waste storing center. 相似文献
229.
Effect of the spacer length on the association and adsorption behavior of dissymmetric gemini surfactants 总被引:4,自引:0,他引:4
Sikirić M Primozic I Talmon Y Filipović-Vinceković N 《Journal of colloid and interface science》2005,281(2):473-481
A series of dissymmetric gemini surfactants with the general formula [C12H25(CH3)2N(CH2)sN(CH3)2C14H29]Br2 designed as 12-s-14, where s=2, 6, and 10, were synthesized and their physicochemical properties investigated. The effect of spacer length on Krafft temperature, adsorption at the air/solution interface, and association in aqueous solution was studied by tensiometry, conductometry, and cryo-transmission electron microscopy. The Krafft temperature was found to increase linearly with spacer length. In the submicellar concentration range the dissymmetric 12-s-14 surfactants display ion pairing and premicellar association. Adsorption at air/solution interfaces and micellization in aqueous solution are similar to the behavior of their symmetric counterparts and depend strongly on spacer length. 相似文献
230.
Summary The reaction of warm alcoholic solutions of acetates of CoII, MnII, ZnII and NiII with 2, 6-diacetylpyridine andS-methylisothiosemicarbazide hydrogen iodide yielded the complexes: [Co(H2L)I2]·H2O, [Mn(H2L)(MeOH)2]I2, [Zn(H2L)(MeOH)I]I and [Ni(HL)]I, (H2L=the pentadentate pentaaza-ligand 2, 6-diacetylpyridine bis(S-methylisothiosemicarbazone)). The reaction of methanolic solutions of [Ni(HL)]I and NH4NCS or LiOAc.2H2O, give [Ni(HL)]NCS and NiL, respectively. For the complexes of CoII, MnII and ZnII, a pentagonal bipyramidal configuration is proposed, with H2L in the equatorial plane and two unidentate ligands (I and/or MeOH) in the axial positions. The complexes [Ni(HL)]X (X=I or NCS) and NiL probably have monomeric five- and dimeric six-coordinate structures, respectively, in which only the chelate ligand is involved in coordination. 相似文献