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101.
H. Meier E. Zimmerhackl W. Albrecht D. ßösche W. Hecker P. Menge A. Ruckdeschel E. Unger G. Zeitler 《Mikrochimica acta》1970,58(4):733-743
Zusammenfassung Die hochspannungselektrophoretische Wanderung der Halogenokomplexe der Platinmetalle und weiterer anorganischer Ionen wird bei Anwendung von Polycarbonsäuren (Oxalsäure, Bernsteinsäure, Apfelsäure, Weinsäure und Zitronensäure) als Elektrolyt untersucht und der Einfluß des pH-Werts und der Konzentration der Substanzen auf die Wanderung geprüft. Es wird festgestellt, daß die auf die abgestufte Komplexbildungstendenz der Polycarbonsäuren (Zitronensäure > Weinsäure Apfelsäure > Bernsteinsäure) rückführbaren Unterschiede der Wanderungsgeschwindigkeiten für die Trennung anorganischer Gemische gut einzusetzen sind. Für die Chlorokomplexe der Platinmetalle wird eine Abstufung der Beweglichkeiten in der Reihe Ir Pt Os > Rh > > Pd > Ru (> Rh) gefunden.
The high voltage electrophoretic separation of inorganic ions with special consideration of the platinum metals
Summary The high voltage eleetrophoretic migration of the halogen complexes of the platinum metals and other inorganic ions was studied with the employment of the polycarboxylic acids (oxalic, succinic, malic, tartaric, citric) as electrolyte, and the influence of the pH-value and the concentration of the substances on the migration investigated. It was found that the differences in the migration velocities, which may be traced back to the graded complex-forming tendency of the polycarboxylic acids (citric > tartaric malic > > succininic) can be used to good advantage in the separation of inorganic mixtures. With respect to the chlorocomplexes of the platinum metals, a decrease in the mobilities was discovered in the series Ir > Pt > Os > > Rh > Pd > Ru (>Rd).相似文献
102.
H. Meier E. Zimmerhackl W. Albrecht D. Bösche W. Hecker P. Menge A. Ruckdeschel E. Unger G. Zeitler 《Mikrochimica acta》1970,58(3):553-563
Zusammenfassung Die hochspannungselektrophoretische Wanderung der Halogenokomplexe der Platinmetalle und einer Reihe weiterer anorganischer Ionen wird mit Nitrilotriessigsäure und Äthylendiamintetraessigsäure als Elektrolyt in Abhängigkeit von verschiedenen Versuchsparametern (Elektrolytkonzentration,ph-Wert und Substanzmenge) untersucht. Die Wanderungsgeschwindigkeiten der verschiedenen Metallionen bzw.-komplexe zeigen charakteristische Abstufungen, die sich mit den für die hochspannungselektrophoretische Wanderung gültigen Gesetzmäßigkeiten erklären lassen. Beispielsweise beobachtet man eine Abnahme der Beweglichkeit bei Ersatz von Chlorid- durch Bromidionen (Masseneinfluß), Auswirkungen der vomph bzw. der Elektrolytkonzentration abhängigen unterschiedlichen Komplexierungen zwei- und dreiwertiger Ionen, Einflüsse der auf Hydrolyse zurückgehenden Änderungen der Ligandenzusammensetzung sowie Unterschiede der Wanderungsgeschwindigkeiten als Folge der Komplexierung mit NTE oder AeDTE.Durch die unter bestimmten Bedingungen erreichbare Abstufung der Beweglichkeiten können verschiedene Gemische, unter anderem auch die Chlorokomplexe der meisten Platinmetalle in der Reihenfolge Ir > Os Pt > Rh Pd > Ru (> Rh), getrennt werden. NTE ist dabei für Trennungen besser als AeDTE geeignet.
The high tension electrophoretic separation of inorganic ions with special reference to the platinum metals. I
Summary The high tension electrophoretic migration of the halogeno complexes of the platinum metals and several other inorganic ions was investigated with nitrilotriacetic acid and ethylenediaminetetraacetic acid as electrolytes in relation to the various experimental parameters (electrolyte concentration,ph-value, and amount of substance). The migration velocities of the various metal ions or complexes exhibit characteristic gradations that may be explained on the basis of the regularities that are valid for the high tension electrophoretic migration. Instances are: a decrease was observed in the mobility when chloride was replaced by bromide ions (mass effect), influence of different complexing of di- and trivalent ions that are related to changes in theph or electrolyte concentration, or influences of the changes due to hydrolysis in the composition of the ligands or alterations in the migration rates resulting from complexing with nitrolotriacetic acid or EDTA.The gradation of the mobility obtained under certain conditions are employed as the basis of a procedure for separating various mixtures, including also the chloro complexes of most of the platinum metals in the succession Ir > Os Pt > Rh Pd > Ru (> Rh). It has been found that NTE is better for separations than EDTA.相似文献
103.
J. Hladký S. NĚmeček M. Novák A. Prokeš J. Votruba K. -F. Albrecht A. Meyer M. Sachwitz B. N. Guskov V. G. Krivokhizhin M. F. Likhachev I. A. Savin G. Vesztergombi 《Czechoslovak Journal of Physics》1977,27(11):1210-1218
Results of the first elastic K
S
o
regeneration experiment on carbon, using magnetic spark chamber spectrometer, are presented in the beam momentum interval 10p50 GeV/c. The d ifferentia cross section d/dt is reconstructed in the range 0·0025–t0·02 (GeV/c)2 and its slopeB is found to be momentum independent with an average valueB=(65±11) (GeV/c)–2. The results are in agreement with the calculations using the coherent production model. 相似文献
104.
The coordination around the thorium(IV) ion in aqueous perchlorate, chloride and nitrate solutions has been determined from large angle X-ray scattering measurements. In perchlorate solutions, where inner-sphere complexes are not formed, the first coordination sphere contains 8.0±0.5 water molecules with Th-H2O bond lengths of 2.485 Å. In chloride solutions inner-sphere complexes are formed, which lead to an increase in the coordination number. In nitrate solutions the nitrate ions are bonded as bidentate ligands to the thorium ion. The bond lengths are similar to those found in crystalline hydrates of thorium nitrate. The coordination numbers found for thorium(IV) in solution are compared with previously reported values for lower charged ions of similar size.On leave from Department of Inorganic Chemistry Royal Institute of Technology S-10044 Stockholm Sweden 相似文献
105.
Wolfgang A. Herrmann Jo o D. G. Correia Georg R. J. Artus Richard W. Fischer Carlos C. Rom o 《Journal of organometallic chemistry》1996,520(1-2):139-142
Methyl(oxo)bis(η2-peroxo)rhenium(VII)1, the active species of the system CH3ReO3/H2O2 in the catalytic oxidation of different organic and organometallic compounds, is stabilized by a water molecule attached to the rhenium center. This water molecule can be removed and substituted by hexamethylphosphoramide (HMPA) to yield (hexamethylphosphoramide)methyl(oxo)bis(η2-peroxo rhenium(VII) (3). The synthesis, crystal structure (X-ray difraction study), and catalytic properties of which compound are reported. Crystal data are as follows: monoclinic, space group P21/n, A = 900.76(7) pm, B = 1229.80(11) pm, C = 1318.57(11) pm, β = 90.251(7)°, Rw = 0.034 for 1878 reflections. The catalytic properties of compound 3 in the oxidation of olefins with H2O2 are similar to those of 1. 相似文献
106.
Hisanobu Wakita Georg Johansson Magnus Sandström Peter L. Goggin Hitoshi Ohtaki 《Journal of solution chemistry》1991,20(7):643-668
Structures of the complexes formed in aqueous solutions between zinc(II) and iodide ions have been determined from large-angle X-ray scattering, Raman and far-IR measurements. The coordination in the hydrated Zn2+ hexaaqua ion and the first iodide complex, [ZnI]+, is octahedral, but is changed into tetrahedral in the higher complexes, [ZnI2(H2O)2], [ZnI3(H2O)]– and [ZnI4]2–. The Zn-I bond length is 2.635(4)Å in the [ZnI4]2– ion and slightly shorter, 2.592(6)Å, in the two lower tetrahedral complexes. In the octahedral [ZnI(H2O)5]+ complex the Zn-I bond length is 2.90(1)Å. The Zn-O bonding distances in the complexes are approximately the same as that in the hydrated Zn2+ ion, 2.10(1)Å. 相似文献
107.
A modified commercial mass spectrometer was used to perform quantitative measurements on negative ions of selected organic compounds at about 10?4 Torr source pressure. The pressure dependency of the molecular ion intensity on pure compounds and binary mixtures shows up two different sources of slow secondary electrons. At low total source pressures a log-log plot of the ion intensity against the sample amount is linear and slow electrons are produced predominantly by wall effects, whereas at high pressures plasma effects arise with a non-linear pressure dependency. 相似文献
108.
Albrecht M 《Chemistry (Weinheim an der Bergstrasse, Germany)》2000,6(19):3485-3489
Dinuclear triple-stranded helicates or meso-helicates are formed by self-assembly of linear ligand strands with appropriate metal ions. Very often this self-assembly proceeds with high diastereoselectivity leading either to the helicate or the meso-helicate. The stereoselectivity of the self-assembly process can be influenced by different factors such as the rigidity of the ligand (-->helicate), the number of methylene units in the alkyl spacers (even number of CH2 units --> helicate; odd number --> meso-helicate), template effects, or chiral substituents. 相似文献
109.
Georg Süss-Fink Bruno Therrien Mathieu Tschan Thomas R Ward Gabor Laurenczy 《Journal of organometallic chemistry》2004,689(8):1362-1369
By checking the chemistry underlying the concept of “supramolecular cluster catalysis” we identified two major errors in our publications related to this topic, which are essentially due to contamination problems. (1) The conversion of the “closed” cluster cation [H3Ru3(C6H6)(C6Me6)2(O)]+ (1) into the “open” cluster cation [H2Ru3(C6H6)(C6Me6)2(O)(OH)]+ (2), which we had ascribed to a reaction with water in the presence of ethylbenzene is simply an oxidation reaction which occurs in the presence of air. (2) The higher catalytic activity observed with ethylbenzene, which we had erroneously attributed to the “open” cluster cation [H2Ru3(C6H6)(C6Me6)2(O)(OH)]+ (2), was due to the formation of RuO2 · nH2O, caused by a hydroperoxide contamination present in ethylbenzene. 相似文献
110.
S. Francis Amevor Hans-Ulrich Hund Albrecht Salzer 《Journal of organometallic chemistry》1996,520(1-2):79-84
A series of heterodimetallic complexes of general formula (C5R5)M(μ-CO)3RuC5Me5 (M = Cr, Mo, W; R = Me, Et) has been prepared in good yields by the reaction of [C5R5M(CO)3]− with [C5Me5Ru(CH3CN)3]+. (C5Me4Et)W(μ-CO)3Ru(C5Me5) was characterized by a crystal structure determination. The W---Ru bond length of 2.41 Å is consistent with the formulation of a metal-metal triple bond, while the unsymmetrical bonding mode of the three bridging carbonyl groups reflects the inherent non-equivalence of the two different C5R5M-units. Using [CpRu(CH3CN)3]+ or [CpRu(CO)2(CH3CN)]+ as the cationic precursor leads to the formation of dimetallic species (C5R5)M(CO)5RuC5H5 with both bridging and terminal carbonyl groups. 相似文献