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11.
Kimel AV Astakhov GV Schott GM Kirilyuk A Yakovlev DR Karczewski G Ossau W Schmidt G Molenkamp LW Rasing T 《Physical review letters》2004,92(23):237203
Static and time-resolved magneto-optical spectra of the ferromagnetic semiconductor (Ga,Mn)As show that a pulsed photoexcitation with a fluence of 10 microJ/cm(2) is equivalent to the application of an external magnetic field of about 1 mT, which relaxes with a decay time of 30 ps. This relaxation is attributed to the spin relaxation of electrons in the conduction band and is found to be not affected by interactions with Mn ions. 相似文献
12.
Gould C Rüster C Jungwirth T Girgis E Schott GM Giraud R Brunner K Schmidt G Molenkamp LW 《Physical review letters》2004,93(11):117203
We introduce a new class of spintronic devices in which a spin-valve-like effect results from strong spin-orbit coupling in a single ferromagnetic layer rather than from injection and detection of a spin-polarized current by two coupled ferromagnets. The effect is observed in a normal-metal-insulator-ferromagnetic-semiconductor tunneling device. This behavior is caused by the interplay of the anisotropic density of states in (Ga,Mn)As with respect to the magnetization direction and the two-step magnetization reversal process in this material. 相似文献
13.
B. Gartner P. Ackerbauer M. Augsburger W.H. Breunlich M. Cargnelli D. Chatellard J.-P. Egger T. von Egidy F.J. Hartmann R. Jacot-Guillarmod E. Jeannet P. Kammel R.C. King A. Kosak B. Lauss J. Marton M. Mühlbauer F. Mulhauser C. Petitjean C. Piller W. Prymas L.A. Schaller L. Schellenberg H. Schneuwly W. Schott Y.A. Thalmann S. Tresch A. Werthmüller J. Zmeskal 《Hyperfine Interactions》1999,119(1-4):103-108
The energy and time distributions of the decay X-rays of excited, metastable, molecular (dμHe)*-resonances were measured. The comparison of the observed energy spectra with calculated ones suggests that decay from
the rotational state J = 1 dominates at the investigated conditions. The muon transfer rates from ground state deuterium to the helium isotopes
3He and 4He at low temperatures were determined from the time distributions of these spectra. Additionally, the temperature dependence
of the muon transfer rate was clearly established in deuterium / 4He mixtures.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
14.
F. Renz V. Martinez M. Klein M. Schott T. Hoffmann M. Blumers I. Fleischer G. Klingelhöfer R. Boča M. Menzel 《Hyperfine Interactions》2008,184(1-3):259-265
The precursors [Fe(III)(N???R???L)Cl] (N???R???LH2=N,N′-bis(2′-hydroxy- 5′-methyl-benzyliden)-1,7-diamino-4-R-4-azaheptane, R ?=? H, methyl(Me)) are high-spin (S?=?5/2) complexes. The Lewis-acidic precursors are combined with Lewis- Base-bridging-units [M(CN) x ] y??? (M = Fe(II), Ru(II), Co(III)) to form heptanuclear star-shaped [M{CN-Fe(III)(N???R???L)} x ]Cl y molecular switches. The star-shaped compounds are high-spin systems at room temperature. On cooling to 20 K some of the compounds exhibit multistability, i.e. several iron(III) centers within a molecule switch to the low-spin state as shown by Mössbauer spectroscopy. 相似文献
15.
The excitations connected with quantum condensation of a fermion gas are calculated quantitatively along the lines of a previous paper. We find exact agreement with earlier results: excitations of the phonon type in the absence of Coulomb interaction, strong indications for their nonexistence in the presence of this interaction. 相似文献
16.
G. Gattow und D. Schott 《Fresenius' Journal of Analytical Chemistry》1962,188(2):81-87
Zusammenfassung Bei der komplexometrischen Titration von Bi3+ mit ÄDTA gegen den Indicator Brenzcatechinviolett wurden Abweichungen vom theoretischen Wert festgestellt, wenn der pH-Wert der Probelösung mit 1 n Natronlauge Pyridin oder verd. Ammoniak eingestellt worden war. Die resultierenden negativen Abweichungen lassen sich durch die Bildung von Polykationen erklären.Die Größe des Titrationsfehlers wächst mit steigender Basizität und größerem Verteilungsgrad der zugesetzten Reagentien; sie verringert sich bei steigender Acidität der Probelösung. — Einmal gebildete Polykationen lassen sich durch Zugabe von Säure nicht sofort wieder auflösen.pH-Einstellungen mit 1 m NaHCO3- und 1 m NaCH3COO-Lösungen lieferten dagegen keine Fehltitrationen.Alle untersuchten Indicatoren ergaben unter konstanten Bedingungen gleiche Titrationsfehler.Herrn Prof. Dr. O. Glemser danken wir für sein förderndes Interesse. Der Deutschen Forschungsgemeinschaft gilt unser Dank für die uns zur Verfügung gestellten Hilfsmittel. 相似文献
17.
18.
Raman spectroscopic measurements were performed on aqueous acid to neutral silica-bearing solutions (0.005 ≤ m Si ≤ 0.02, 0 ≤ pH ≤ 8) and Al–silica solutions at temperature from 20 to 150°C. At 20°C, the spectrum of silica-bearing solutions exhibits only the bands of water and a completely polarized band at 785 cm?1. This band is attributed to the ν1 band of the tetrahedral Si(OH)4 molecule. In ${\text{Si(OH)}}_{\text{4}} {\kern 1pt} {\kern 1pt} - {\kern 1pt} {\text{AlCl}}_3 {\kern 1pt} - {\kern 1pt} {\text{HCl}}$ solutions, the intensity of this band decreases with increasing Al concentration, temperature, and pH. This decrease can be explained by the formation of an inner sphere complex between Al3+ and Si(OH)4 according to the reaction: ${\text{Al}}^{{\text{3 + }}} {\text{ + H}}_{\text{4}} {\text{SiO}}_{\text{4}}^{\text{0}} ({\text{aq}}){\text{ }} \Leftrightarrow {\text{ AlH}}_{\text{3}} {\text{SiO}}_{\text{4}}^{{\text{2 + }}} {\text{ + H}}^{\text{ + }} $ The fraction of complexed silica deduced from raman spectroscopic measurements is in good agreement with that calculated for the similar solution compositions and temperatures using the complexation constant generated by Pokrovski et al. (23) from potentiometric measurements. At ambient temperature, the formation of aluminum silicate complex is weak and does not account for more than ca. 5 % of the total Al in most natural waters. As temperature increases, this complex becomes more significant and can dominate Al speciation in acid (pH ≤ 2) hydrothermal solutions. 相似文献
19.
Alexander Carreño Eduardo Schott Ximena Zarate Juan Manuel Manriquez Juan C. Vega Miguel Mardones Alan H. Cowley Ivonne Chavez Juan P. Hinestroza Ramiro Arratia-Perez 《Chemical Papers》2017,71(6):1019-1030
Research in functionalized inorganic supports faces special challenges regarding the inmobilization of organic chains and efficient computational methods for the quantum chemical modeling of coordination compounds. The silylant 3-cloropropyltriethoxysilyl (R1) was anchored over silica gel in anhydrous conditions, in order to react with diethyl Iminodiacetate (DIDA) to obtain modified silica gel (R2), which was hydrolized in basic conditions previously synthesized and characterized by S BET, TGA and FTIR spectroscopy to obtain iminodiacetic acid groups IDA to prepare an modified inorganic support (R3) that is able to get hands on metals from the first transition series such as copper and nickel. The obtained experimental values showed that the functionalized grade of R3 corresponds to 0.1598 mmol of the nitrogen indicated that the adsorbed Cu(II) or Ni(II) have the stoichiometry for both cation of 1:1. Based on this relation, the three different structures were proposed to carry out the computational studies using density functional theory (DFT) in its LDA and PW91 with the TZP slater type basis set. The primary coordination sphere of copper(II) or nickel (II) ion in R3 are optimized, structural parameters are calculated, vibrational bands are assigned and energy gaps of frontier orbital (HOMO–LUMO) have been calculated. The calculated results reproduced the experimental data with good agreement. An energy decomposition analysis (EDA) of the different models proposed here was performed and suggest a 1:1 coordination form. 相似文献
20.