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991.
Acid alkali hexafluoroaluminates of K and Rb were prepared by precipitation of alkali fluoride containing H3AlF6 solutions with ethanol. Compounds were characterized by X-ray diffraction, IR spectroscopy,1H-NMR and chemical analysis. The constitution is MI(H3O)2AlF6. Lattice parameters were determined.Dehydration and thermal decomposition were investigated by thermal analysis (TG, DTG, DTA) on a derivatograph-Q and by high temperature X-ray diffraction. Thermal decomposition is accompanied by liberation of H2O and HF and a condensation of [AlF6]3– octahedra forming layer structures. Stable intermediate products are MIAlF4·0.5H2O and MIAlF4. At higher temperatures hydrolysis occurs.
Presented at the Microsymposium on Halogen Chemistry held in Budapest, 1987. 相似文献
Zusammenfassung Es wurden saure Kalium- und Rubidiumhexafluoroaluminate durch Fällung aus Alkalifluorid enthaltenden H3AlF6-Lösungen mit Ethanol dargestellt. Die erhaltenen Verbindungen wurden chemisch, röntgenographisch, IR- sowie1H-NMR-spektroskopisch charakterisiert. Die Konstitution der Verbindungen ist MI(H3O)2AlF6. Die Gitterkonstanten wurden aus Röntgendiffraktionsdaten bestimmt. Entwässerung und thermische Zersetzung wurden mittels Heizguiniertechnik und Thermoanalyse (TG, DTG, DTA) an einem Derivatograph-Q untersucht. Bei der thermischen Zersetzung erfolgt eine HF- und H2O-Abgabe sowie eine Kondensation von AlF 6 3– -Oktaedern unter Ausbildung von Schichtstrukturen. Als stabile Zwischenprodukte wurden MIAlF4·0.5H2O und MIAlF4 nachgewiesen. Bei höheren Temperaturen werden Hydrolysereaktionen beobachtet.
, H3AlF6, . M1(H3O)2AlF6 , - - . . (, , ) Q- , . [AlF6]3– . M1AlF4·0.5H2O M1AlF4. .
Presented at the Microsymposium on Halogen Chemistry held in Budapest, 1987. 相似文献
992.
U. I. Zhorszky 《Journal of mass spectrometry : JMS》1986,21(6):357-365
Bifunctional methoxonium ions \documentclass{article}\pagestyle{empty}\begin{document}$ {\rm R} -\mathop {\rm C}\limits^ + ({\rm OCH}_3 ) - ({\rm CH}_2 )_{\rm n} - {\rm OH}({\rm b}) $\end{document} and \documentclass{article}\pagestyle{empty}\begin{document}$ {\rm R} - \mathop {\rm C}\limits^ + ({\rm OCH}_3 ) - ({\rm CH}_2 )_{\rm n} - {\rm OCH}_3 ({\rm c}) $\end{document} (c) show as the main reactions those caused by functional group interaction, as has already been found for the analogous hydroxonium ions (g). Although there are similarities in the fragmentation behaviour of the isomeric ions b and g, their fragmentation pathways are different, proving b and g as distinct species. The dominant primary fragmentation for b and c is loss of CH3OH. The hydrogen migrations prior to this reaction have been established by deuterium labelling. The findings on the fragmentation behaviour of the bifunctional methoxonium ions have been extended to the general behaviour of hydroxy and alkoxy substituted alkoxonium ions. 相似文献
993.
The most stable structure of CB2H3
–, as established computationally, is the aromatic diboracyclopropenyl (diboriranyl) anion (5), while open-chainC
2v, isomer H2BCBH (7) is only 3 kcal/mol higher in energy at the QCISD(T)/6-311 +G**//MP2/6-31+G*+ZPE (HF/6-31 +G*). The 47-kcal/mol barrier between cyclic,5, and open-chain,7, structures suggests that both of them may be observed. The aromatic stabilization energy of the diboriranyl anion (18 kcal/mol) is half the value in the isoelectronic cyclopropenium ion, C3H3
+. The computed, by IGLO method (5a), and experimental (6a) chemical shifts,(13C) and(11B), agree within 4 ppm range. The theoretical vibrational frequencies of the most stable isomers,5 and7, are presented for experimental verification of these species. 相似文献
994.
Summary 2-Aminopyridine reacts with acetylacetone in the presence of VOII, MnII, FeII, CoII, NiII, and CuII metal salts to give complexes of the type [VO(Ap2ac)2X]X and [M(Ap2ac)2X2] where (Ap2ac) is the ligand formedin situ. The complexes are characterised as distorted octahedral by analyses, conductance, molecular weight, magnetic, electronic and i.r. spectral studies. The i.r. studies reveal that two molecules of aminopyridine are joined by a molecule of acetylacetone through a three carbon atom bridge and that the ligand coordinates through the azomethine and imino nitrogen atoms, whereas pyridine does not take part in coordination. The electronic spectra have been interpreted and tentative assignments are made. In the far i.r. spectra, various metal ligand vibrations are observed and discussed. Attempts to carry out electrophilic substitutions in the complexes failed. 相似文献
995.
On LaCo2P2 and Other New Compounds with ThCr2Si2- and CaBe2Ge2-Type Structure The compounds MCo2P2 (M = La, Ce, Pr, Nd, Sm, Th, U), MFe2P2 (M = La, Ce, U), and ThCo2As2 were prepared for the first time. Structure determinations from single crystal X-ray data of LaCo2P2 (R = 0.011; 325 F-values), CeCo2P2 (R = 0.023; 160 F), PrCo2P2 (R = 0.044; 441 F), LaFe2P2 (R = 0.024; 511 F), and CeFe2P2 (R = 0.016; 183 F) with 11 variable parameters each resulted in atomic positions within the range of the ThCr2Si2-type. The powder patterns of ThCo2P2, and ThCo2As2 show superstructure reflections indicating a CaBe2Ge2-type structure. The other compounds can be assigned to the ThCr2Si2-type. Chemical bonding of these can be rationalized by a simple band structure model where bonding transition metal – transition metal interactions are important. 相似文献
996.
The incongruent vaporization reactions of Ta2S and Ta6S have been investigated by mass-loss effusion in the temperature range 1576 to 1902 K. By extrapolation of PS(obs) to equilibrium the enthalpies of the reactions and Ta6S = 6 Ta(s) + S(g) were found to be and , respectively. Comparison between the above values, determined by a 2nd law treatment, and 3rd law values was used to derive fef (“free energy function”) values for Ta and S in the compounds. These postulated fef's, which apply only to the elements as present in the compounds measured, are compared to tabulated quantities for the pure solid elements to provide a criterion for 2nd and 3rd law evaluation. 相似文献
997.
H. J. Walther H. Eyer U. P. Schlunegger C. J. Porter E. A. Larka J. H. Beynon 《Journal of mass spectrometry : JMS》1982,17(2):81-85
Phenol and five acyclic isomeric compounds have been investigated using electron impact and field ionization techniques, mass analysed ion kinetic energy spectrometry and collision induced dissociation mass analysed ion kinetic energy spectrometry. The kinetic energy release data corresponding to the elimination of carbon monoxide from the molecular ions show that at least two structures of the reactant ion are involved. The electron impact and field ionization collision induced dissociation mass analysed ion kinetic energy spectra indicate that under electron impact conditions, the phenol ion partially isomerizes to another ion structure. An isomerization of about 40% to the structure of cis-2-hexen-4-yn-1-al is in good accordance with the spectral data. 相似文献
998.
A. Yu. Shaulov V. K. Skachkova O. B. Salamatina S. N. Rudnev A. N. Shchegolikhin S. M. Lomakin U. Eichhoff S. Steuernagel A. A. Samoilenko A. A. Berlin 《Polymer Science Series A》2006,48(3):228-233
The possibility of modifying boron polyoxide with an oligomeric amide upon thermal dehydration of orthoboric acid and oligomerization of caprolactam in a common melt is shown. The products obtained after thermal pretreatment of the initial blend containing 30 wt % caprolactam are investigated. It is shown that the main processes at T < 200°C are dehydration of orthoboric acid and hydrolysis of caprolactam with the formation of ε-aminocaproic acid. At temperatures of 225–260°C, the predominant process is the formation of boron polyoxide and a caprolactam-based oligomeric product. The data of 11B NMR spectroscopy show that the chemical transformations of caprolactam occur against the background of the N:B donor-acceptor interaction. The two-dimensional [11B-1H] heteronuclear correlation spectrum indicates that the systems obtained upon thermal treatment are solid solutions. 相似文献
999.
The nucleophile [ArTe−] generated in situ borohydride solution of Ar2Te2, reacts with 2-(chloromethyl) tetrahydrofuran and 2-(2-bromoethyl)-1,3-dioxolane resulting in L1 and L2, respectively. The complexes of palladium(II) and platinum(II) with L1/L2 having stoichiometries [MCl2·L2], [ML2](ClO4)2, [(DPPE)ML2](ClO)4)2, [(PPh3)2ML2](ClO4)2 and [(phen)ML2](ClO4)2 (where L = L1/L2 DPPE = Ph2PC H2CH2PPh2, PHEN = 1,10-phenanthroline and M = Pd/Pt) have been synthesized. IR, 1H, 125Te{1H} and 31P{1H} NMR and UV-vis spectral data of these species in conjunction with their molar conductance and molecular weight data have been used to authenticate the new species. In all complexes (1–20) the ligands L1 and L2 are coordinated through tellurium and in the complexes of formula [ML2](ClO4)2 (M = Pd, Pt) the ligand is bidentate with the oxygen atom used in complexation. In solution, complexes PtCl2L2 exist as a mixture of cis and trans isomers whereas only the trans isomer was observed for the palladium analogues. The [(phen)PdL2](ClO4)2(Q) quenches 1O2 readily. The plot of log [Q] vs time is linear. Mechanism compatible with the experimental observations is proposed. 相似文献
1000.
Tetra-coordinated boron derivatives, (EtO)B(DTZ) and (DTZH)B(DTZ), (where DTZ−− and DTZ− represent the anions of the Schiff base DTZH2) have been synthesized by 1:1 and 1:2 molar reactions of triethoxyborane with bibasic tridentate Schiff bases, derived by
the equimolar condensation of S-methyl or S-benzyldithiocarbazate with acetyl acetone or benzoyl acetone. Further 1:1 derivatives
have been shown to undergo replacement reactions witht-butyl alcohol, showing thereby the labile nature of the ethoxy group. Based on infrared and proton magnetic resonance spectral
studies and monomeric nature, suitable structures have been assigned to these derivatives. 相似文献