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1.
Robin F. Weitkamp Beate Neumann Hans‐Georg Stammler Berthold Hoge 《Angewandte Chemie (International ed. in English)》2020,59(14):5494-5499
We report on the first examples of isolated silanol–silanolate anions, obtained by utilizing weakly coordinating phosphazenium counterions. The silanolate anions were synthesized from the recently published phosphazenium hydroxide hydrate salt with siloxanes. The silanol–silanolate anions are postulated intermediates in the hydroxide‐mediated polymerization of aryl and alkyl siloxanes. The silanolate anions are strong nucleophiles because of the weakly coordinating character of the phosphazenium cation, which is perceptible in their activity in polysiloxane depolymerization. 相似文献
2.
3.
4.
Peter Jutzi Andreas Klipp Andreas Mix Beate Neumann Hans-Georg Stammler 《Silicon Chemistry》2007,3(3-4):151-156
Reaction of pentamethylcyclopentadienyl(pentachloro)disilane (2), prepared from hexachlorodisilane and potassium pentamethylcyclopentadienide
(Cp*K), with a further equivalent of Cp*K leads selectively to the title compound Cp*
2
Si
2
Cl
4 (3) which was characterized by NMR and X-ray structural data. Dehalogenation of 3 with four equivalents of sodium naphthalenide
offers an alternative route for the synthesis of decamethylsilicocene (1).
Dedicated to Professor Mitsuo Kira on the occasion of being honoured with the Wacker Silicon Award 2005. 相似文献
5.
A. Müller E. Krickemeyer F. El-Katri D. Rehder A. Stammler H. Bgge F. Hellweg 《无机化学与普通化学杂志》1995,621(7):1160-1170
Simple Trithio- and Perthiocarbonato Complexes with Interesting Bond Properties: [E(CS3)2]2? (E = Sn, Zn, Cd), [E(CS3)3]3? (E = As, Sb, Bi, Co), {Cu(CS3)?}∞ and [Zn(CS4)2]2? By reactions of potassium trithiocarbonate ( 1 ) with solutions of zinc(II)- acetylacetonate, cadmium(II)-chloride, tin(II)-chloride, arsenic(III)-sulfide (suspension), antimony(III)-chloride, bismuth(III)-chloride and copper(II)-chloride in dimethyl sulfoxide, as well as of trisodium hexanitrito cobaltate(III) in water, and the precipitation of the complexes with an aqueous solution of tetraphenylphosphonium chloride the compounds (PPh4)2[Zn(CS3)2] ( 2 ), (PPh4)2[Cd(CS3)2] ( 3 ), (PPh4)2[Sn(CS3)2] ( 4 ), (PPh4)3[As(CS3)3] ( 5 ), (PPh4)3[Sb(CS3)3] ( 6 ), (PPh4)3[Bi(CS3)3] ( 7 ), (PPh4)3[Co(CS3)3] ( 8 ) and (PPh4)Cu(CS3) ( 9 ) have been isolated. (PPh4)2[Zn(CS4)2] · CH3NO2 ( 10 ) has been prepared by heating a solution of 2 in nitromethane to 60--70°C in presence of air. The reaction of 1 in dimethyl sulfoxide with an aqueous tetraphenylphosphonium chloride solution in presence of oxygen leads to (PPh4)2[C2S6] ( 11 ). The compounds have been characterized by spectroscopical studies (IR, Raman, UV/Vis, 113Cd/59Co-NMR), magnetic susceptibility measurements, powder diffractometry, elemental analyses and single crystal X-ray structure analysis ( 4 – 7 , 10 and 11 ). The difficult growing of single crystals has been reported in detail. For crystal data see Inhaltsübersicht. 相似文献
6.
B. Bastian T. P. Knepper P. Hoffmann H. M. Ortner 《Fresenius' Journal of Analytical Chemistry》1994,348(10):674-679
A method for the identification and quantification of aromatic sulfonic acids in industrial waste water has been developed. The preparation of the samples comprises a clean-up step and an enrichment step, utilizing i) reversed-phase extraction and ii) ion-pair solid phase extraction. The aromatic sulfonic acids are separated by ion-pair chromatography with diode-array detection. An advantage of the developed ion-pair chromatographic method is the separation of linear alkylbenzenesulfonic acids (LAS), lignosulfonic acids and aromatic sulfonic acids in one chromatographic run. Also described is an optimized clean-up procedure for collected fractions of a preparative chromatographic run to identify monosulfonic acids with GC/MS after methylation. The detection limits for aromatic sulfonic acids in industrial waste waters are at the g/l level. 相似文献
7.
A. Kratzer K. Mutzbauer S. Henneberger G. M. Kalvius O. Hartmann R. Wäppling H. -H. Klauß M. A. C. De Melo F. J. Litterst Th. Stammler 《Hyperfine Interactions》1994,87(1):1055-1061
The high pressureSR spectrometer [1] formerly located at CERN has been transferred to theE1-beamline at PSI and put back into operation with only minor modifications. The essential features of the high pressure apparatus are described below. The instrument covers a pressure range up to 0.7 GPa which can be extended to 1.4 GPa depending on the design of the high pressure cell. First measurements at PSI were successfully carried out with a single crystalline sample of Gd metal. New developments in high pressure cell design are presented. They are expected to further improve the signal/background ratio and to extend the pressure range to 1 GPa. One type of cell will allow temperatures above 380 K.This work was supported by the German Federal Minister for Research and Technology (Bundesminister für Forschung und Technologie [BMFT]) under Contract Nr. 03KA2-TUM-4 and 03SE3STU. 相似文献
8.
Meier H Gerold J Kolshorn H Mühling B 《Chemistry (Weinheim an der Bergstrasse, Germany)》2004,10(2):360-370
Four OPV series 1-4 (a-d) with a terminal dialkylamino group as electron donor were prepared by Wittig-Horner reactions. To study the influence of the push-pull effect on the long-wavelength absorption, three of the four series contained terminal acceptor groups (CN, CHO, NO(2)). The length of the chromophores strongly affects the intramolecular charge transfer (ICT)-an effect which superimposes upon the extension of the conjugation. Increasing numbers n of repeat units cause an overall bathochromic shift for the purely donor-substituted series 1 a-4 a and the series 1 b-4 b with CN as weak acceptor. The two effects annihilate each other in the series 1 c-4 c with terminal CHO groups, so that the absorption maxima are almost independent of the length of the chromophore. A hypsochromic shift is observed for the series 1 d-4 d, which contains the strong acceptor group NO(2). This anomaly disappears on protonation of the dialkylamino group because the push-pull effect disappears in the ammonium salts. The results can be explained by semiempirical quantum mechanics (AM1, INDO/S). The HOMO-LUMO transition, which is mainly responsible for the ICT, becomes less important in the electron transitions S(0)-->S(1) when the distance between donor and acceptor is increased. The commonly used VB model, which contains an electroneutral and a zwitterionic resonance structure, is contrasted with a MO model with dipole segments at both ends of the OPV chains. The latter model turned out to be more appropriate-at least for donor-acceptor-substituted OPVs with n >/= 2. 相似文献
9.
New Copper Complexes Containing Phosphaalkene Ligands. Molecular Structure of [Cu{P(Mes*)C(NMe2)2}2]BF4 (Mes* = 2,4,6‐tBu3C6H2) Reaction of equimolar amounts of the inversely polarized phosphaalkene tBuP=C(NMe2)2 ( 1a ) and copper(I) bromide or copper(I) iodide, respectively, affords complexes [Cu3X3{μ‐P(tBu)C(NMe2)2}3] ( 2 ) (X =Br) and ( 3 ) (X = I) as the formal result of the cyclotrimerization of a 1:1‐adduct. Treatment of 1a with [Cu(L)Cl] (L = PiPr3; SbiPr3) leads to the formation of compounds [CuCl(L){P(tBu)C(NMe2)2}] ( 4a ) (L = PiPr3) and ( 4b ) (L = SbiPr3), respectively. Reaction of [(MeCN)4Cu]BF4 with two equivalents of PhP=C(NMe2)2 ( 1b ) yields complex [Cu{P(Ph)C(NMe2)2}2]BF4 ( 5b ). Similarly, compounds [Cu{P(Aryl)C(NMe2)2}2]BF4 ( 5c (Aryl = Mes and 5d (Aryl = Mes*)) are obtained from ArylP=C(NMe2)2 ( 1c : Aryl = Mes; 1d : Mes*) and [(MeCN)4Cu]BF4 in the presence of SbiPr3. Complexes 2 , 3 , 4a , 4b , and 5b‐5d are characterized by means of elemental analyses and spectroscopy (1H‐, 13C{1H}‐, 31P{1H}‐NMR). The molecular structure of 5d is determined by X‐ray diffraction analysis. 相似文献
10.
Transition Metal Substituted Acylphosphanes and Phosphaalkenes. 17. Synthesis and Structure of the μ-Isophosphaalkyne Complexes [(η5-C5H5)2(CO)2Fe2(μ-CO)(μ-C?PC6H2R3)] (R = Me, iPr, tBu) . Condensation of (η5-C5H5)2(CO)2Fe2(μ-CO)(μ-CSMe)}+SO3CF3? ( 6 ) with 2,4,6-R3C6H2PH(SiMe3) ( 7 ) ( a : R = Me, b : R = iPr, c : R = tBu) affords the complexes (η5-C5H5)2(CO)2Fe2(μ-CO)(η-C?PC6H2R3-2,4,6) ( 9 a–c ) with edge-bridging isophosphaalkyne ligands as confirmed by the x-ray structure analysis of 9 a . 相似文献