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61.
Burlakov VV Arndt P Baumann W Spannenberg A Rosenthal U Parameswaran P Jemmis ED 《Chemical communications (Cambridge, England)》2004,(18):2074-2075
The 2,5-dititanabicyclo[2.2.0]hex-1(4)-ene (bis-titanocene-mu-(Z)-1,2,3-butatriene complex)3 is formed starting from [Cp2Ti(eta2-Me3SiC2SiMe3)] by in situ generated titanocene and 1,4-dichlorobut-2-yne via the 1-titanacyclobut-3-yne (2). 相似文献
62.
New experimental time-of-flight distributions are reported for Li+-N2 and Li2-CO at two center-of-mass energies of about 8 and 16 eV and large scattering angles θlab ? 120°. The Li+-N2 spectra show two widely spaced maxima, whereas the Li+-CO spectra show two and sometimes three maxima. The results are consistent with the model of rotational rainbows, and have also been analyzed in terms of an impulsive model involving collisions with the individual atoms of the molecules with energy-dependent masses. Classical trajectories for a simple model potential reveal only small contributions from vibrational excitation. 相似文献
63.
Vass S Grimm H Bányai I Meier G Gilányi T 《The journal of physical chemistry. B》2005,109(24):11870-11874
Slowly diffusing water molecules were found by quasi-elastic neutron scattering (QENS) in a sodium dodecyl sulfate (SDS) micellar solution, and both their diffusion coefficient (4.33 x 10(-6) cm2 x s(-1)) and mole fraction (0.057) were determined. After successfully checking the mean slowing down of solvent molecules by the gradient compensated stimulated spin-echo (GCSTE) pulse sequence NMR method, a similar effect was observed with this technique in the solvent phase of dodecyl trimethylammonium bromide (DTAB) and differing chain length (X = 12, 20, 30, and 40) ethoxylated nonyl phenol (9NX) micellar systems. Following the literature, the experimental results are qualitatively explained by assuming that, apart from ionic hydration, H-bonds may form between the solvent molecules and the O or N atoms present in the hydrophilic (head)groups of the micelle-forming monomers. 相似文献
64.
Uwe Klingebiel Dieter Bentmann Anton Meller 《Monatshefte für Chemie / Chemical Monthly》1978,109(5):1067-1073
Aminofluorosilanes react with lithiated amines undergoing LiF-elimination and substitution (1). The acyclic silicon-nitrogen-compound2 is isolated in the reaction with a difluorosilane after renewed lithiation.2 is cyclisated in the reaction with butyllithium by butane- and LiF-elimination (3). Aminofluorosilanes with bulky (4) or mesomeric stabilized (5) ligands form stable lithioaminofluorosilanes, which react with fluorosilanes giving substitution products (6, 7).6 and7 react with the lithium salt oftert-butylamin in a molar ratio of 12 to give8 and9 by intramolecular cyclisation.—The mass,1H and19F nmr spectra of the compounds are reported. 相似文献
65.
al-Ktaifani MM Bauer W Bergsträsser U Breit B Francis MD Heinemann FW Hitchcock PB Mack A Nixon JF Pritzkow H Regitz M Zeller M Zenneck U 《Chemistry (Weinheim an der Bergstrasse, Germany)》2002,8(11):2622-2633
Several independent synthetic routes are described leading to the formation of a novel unsaturated tetracyclic phosphorus carbon cage compound tBu4C4P6 (1), which undergoes a light-induced valence isomerization to produce the first hexaphosphapentaprismane cage tBu4C4P6 (2). A second unsaturated isomer tBu4C4P6 (9) of 1 and the bis-[W(CO)5] complex 13 of 1 are stable towards similar isomerization reactions. Another starting material for the synthesis of the hexaphosphapentaprismane cage tBu4C4P6 (2) is the trimeric mercury complex [(tBu4C4P6)Hg]3 (11), which undergoes elimination of mercury to afford the title compound 2. Single-crystal X-ray structural determinations have been carried out on compounds 1, 2, 9, 11, and 13. 相似文献
66.
R. H. Filby G. J. Van Berkel A. E. Bragg A. Joubert W. E. Robison C. A. Grimm 《Journal of Radioanalytical and Nuclear Chemistry》1985,91(2):361-368
National Bureau of Standards residual fuel oil Standard Reference Materials, SRM 1619, 1620a, 1634a, and former SRM 1634 were analyzed for 20 trace elements by instrumental neutron activation analysis to determine whether these materials are suitable trace element standards for elements other than the 6 elements certified in SRM 1634a. The SRM 1634a is a suitable standard for Ni, V, Se, Na, Zn, As, Cr, Fe, Ce, Sm and La but Co, Ba, Nd, Cs, Eu, Sc, and Sb appear to be heterogeneously distributed and are probably present in mineral particulates. The SRM 1619 is a convenient standard for V and for low Ni content oils, but SRM 1620a does not appear to be a suitable standard for any trace element investigated.To whom correspondence should be addressed. 相似文献
67.
Zusammenfassung Die Systeme Co
x
Mg
1-x
TiO3 (I) und Co
x
Cd
1-x
TiO3 (II) wurden röntgenographisch und spektralphotometrisch untersucht. I stellt eine lückenlose Mischkristallreihe dar. Mit wachsendemx nehmen bei I die Gitterkonstantena
0undc
0geringfügig zu und die drei Hauptabsorptionsbanden verschieben sich ein wenig in Richtung IR. In II liegt keine lückenlose Mischkristallreihe vor. Sowohl röntgenographisch als auch spektralphotometrisch wurde für die an CoTiO3 gesättigte CdTiO3-Phase die Zusammensetzung Co0,3Cd0,7TiO3 (II a) und für die an CdTiO3 gesättigte CoTiO3-Phase die Zusammensetzung Co0,8Cd0,2TiO3 (II b) gefunden.Beim Übergang III (x=0,1) wird eine beträchtliche IR-Verschiebung beobachtet. Die IR-Verschiebung ist die Folge der Gitteraufweitung bei der Substitution von Mg2+ durch Cd2+. Hierbei nimmt derRacah-Parameter geringfügig zu infolge Verminderung der covalenten Anteile der Bindung Co-O.
Mit 4 Abbildungen
11. Mitt.:D. Reinen, Mh. Chem.96, 730 (1965). 相似文献
The systems Co x Mg 1-x TiO3 (I) and Co x Cd 1-x TiO3 (II) had been investigated spectrophotometrically and by X-ray diffraction. I represents mixed crystals without any miscibility gap. An increase ofx causes a small enhancement of the lattice unitsa 0andc 0of I and the three main absorption bands will be shifted slightly towards IR. II are mixed crystals with a broad miscibility gap. Spectrophotometrically and by X-ray diffraction it could be found that the CdTiO3-phase saturated with CoTiO3 and the CoTiO3-phase saturated with CdTiO3 have the compositions Co0,3Cd0,7TiO3 (II a) and Co0,8Cd0,2TiO3 (II b), respectively. The transition III (x=0,1) produces a considerable shift of the main absorption bands towards IR as a consequence of the expansion of the lattice caused by the substitution of Cd2+ for Mg2+. This shift is accompanied by a small increase of theRacah-Parameter owing to a decrease of covalency of the bonding Co-O.
Mit 4 Abbildungen
11. Mitt.:D. Reinen, Mh. Chem.96, 730 (1965). 相似文献
68.
Indium(III) chloride forms in water with potassium 1,2‐dithiooxalate (dto) and potassium 1,2‐dithiosquarate (dtsq) stable coordination compounds. Due to the higher bridging ability of the 1,2‐dithiooxalate ligand in all cases only thiooxalate bridged binuclear complexes were found. From 1,2‐dithioquadratate with an identical donor atom set mononuclear trischelates could be isolated. Five crystalline complexes, (BzlMe3N)4[(dto)2In(dto)In(dto)2] ( 1 ), (BzlPh3P)4[(dto)2In(dto)In(dto)2] ( 2 ), (BzlMe3N)3[In(dtsq)3] ( 3 ), (Bu4N)3[In(dtsq)3] ( 4 ) and (Ph4P)[In(dtsq)2(DMF)2] ( 5 ), have been isolated and characterized by X‐ray analyses. Due to the type of the complex and the cations involved these compounds crystallize in different space groups with the following parameters: 1 , monoclinic in P21/c with a = 14.4035(5) Å, b = 10.8141(5) Å, c = 23.3698(9) Å, β = 124.664(2)°, and Z = 2; 2 , triclinic in P with a = 11.3872(7) Å, b = 13.6669(9) Å, c = 17.4296(10) Å, α = 88.883(5)°, β = 96.763(1)°, γ = 74.587(5)°, and Z = 1; 3 , hexagonal in R3 with a = 20.6501(16) Å, b = 20.6501(16) Å, c = 19.0706(13) Å and Z = 6; 4 , monoclinic in P21/c with a = 22.7650(15) Å, b = 20.4656(10) Å, c = 14.4770(9) Å, β = 101.095(5)°, and Z = 4; 5 , triclinic in P with a = 9.2227(6) Å, b = 15.3876(9) Å, c = 15.5298(9) Å, α = 110.526(1)°, β = 100.138(1)°, γ = 101.003(1)°, and Z = 2. 相似文献
69.
In this work a novel graphical method is applied to the presentation of intercomparison results. This is demonstrated with
the results of a recent intercomparison in measuring the 137Cs, 40K, and 90Sr activity concentration in milk powder. The “PomPlot”, an intuitive graphical method, is used for producing a summary overview
of the participants’ results of a common measurand. The “PomPlot” displays (relative) deviations of individual results from
the reference value on the horizontal axis and (relative) uncertainties on the vertical axis. 相似文献
70.