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31.
Simultaneous determination of ondansetron and tropisetron in human plasma using HPLC with UV detection 总被引:4,自引:0,他引:4
Bauer S Störmer E Kaiser R Tremblay PB Brockmöller J Roots I 《Biomedical chromatography : BMC》2002,16(3):187-190
A rapid and sensitive HPLC method for the simultaneous quantitation of ondansetron and tropisetron, two serotonin (5-HT) receptor antagonists frequently used in treatment and prevention of nausea and emesis, is described. The procedure involves liquid-liquid extraction of human plasma with dichloromethane coupled with reversed-phase HPLC and UV detection. The lower limits of quantification (LOQ) were 0.62 ng/mL for ondansetron and 1.25 ng/mL or tropisetron. Intra- and inter-assay coefficients of variation ranged from 1.5 to 7.5% and 5.3 to 13.7%, respectively. The sensitivity and precision were sufficient for determination of plasma concentrations after therapeutic administration of both drugs and the method can be used for the estimation of pharmacokinetic parameters. 相似文献
32.
The molecular structures of blue dichloro‐tetrakis(acrylamide) cobalt(II), [Co{O‐OC(NH2)CH=CH2}4Cl2] ( 1 ) and pink hexakis(acrylamide)cobalt(II) tetrachlorocobaltate(II), [Co{O‐OC‐(NH2)CH=CH2}6][CoCl4] ( 2 ), characterized by single X‐ray diffraction, IR spectroscopy and elemental analyses, are described. The coordination of CoII in 1 involves a tetragonally distorted octahedral structure with four O‐donor atoms of acrylamide in the equatorial positions and two chloride ions in the apical positions. The second complex 2 in ionic form contains CoII cations surrounded by an octahedral array of O‐coordinated acrylamide ligands, accompanied by a [CoCl4]2? anion. 相似文献
33.
HoClTe2O5: A Telluriumdioxide‐rich Holmium(III) Chloride Oxotellurate(IV) While attempting to synthesize anionically derivatized holmium oxotellurates by reacting holmium chloride (HoCl3) with tellurium oxide (TeO3; molar ratio 1 : 3, 800°C 10 d) in evacuated silica ampoules, transparent, greenish yellow and coarse single crystals of holmium(III) chloride oxotellurate(IV) HoClTe2O5 (triclinic, P1; a = 762.07(6), b = 796.79(6), c = 1010.36(8) pm, α = 100.987(4), ß = 99.358(4), γ = 91.719(4)°; Z = 4) were obtained. The crystal structure contains eightfold coordinated (Ho1)3+ (only surrounded by oxygen atoms) and sevenfold coordinated (Ho2)3+ cations (surrounded by one chloride and six oxide anions). Each sort of holmium polyhedra convenes independently to chains along [100] by edge‐sharing which again combine alternately via O6 and O9 to form 2{[Ho2O10(Cl1)]15—} layers parallel (001). Each of the four crystallographically different Te4+ cations are surrounded by three close oxygen atoms (d(Te—O) = 188 — 195 pm) and always one more situated further away. The stereochemical activity of the non‐bonding electron pairs (“lone pairs”) leads to ψ1‐trigonal bipyramidal coordination figures. The ψ1‐tetrahedral [TeO3]2— basic units form discrete [Te2O5]2— doubles with ecliptic conformation which are arranged in a fish‐bone pattern parallel to (001) on both sides of the 2{[Ho2O10Cl]15—} layers. The coherence of the 2{[Ho2(Cl1)Te4O10]+} layers is exclusively maintained via Cl2—Te1 contacts with an extraordinary long distance of 335 pm. As (Cl1)— belongs to the coordination sphere of (Ho2)3+ and (Cl2)— is only surrounded by Te4+, the compound should be correctly named holmium(III) chloride oxochlorotellurate(IV) Ho2Cl[Te4O10Cl] (Z = 2). 相似文献
34.
Braun T Steffen A Schorlemer V Neumann B Stammler HG 《Dalton transactions (Cambridge, England : 2003)》2005,(20):3331-3336
Treatment of a toluene solution of [PdMe(2)(Cy(2)PCH(2)PCy(2))](1) with pentafluoropyridine in the presence of traces of water affords the generation of the A-frame complexes [(PdMe)(2){mu-kappa(2)(P,P)Cy(2)PCH(2)PCy(2)}(2)(mu-F)][SiMeF(4)]() and [(PdMe)(2){mu-kappa(2)(P,P)Cy(2)PCH(2)PCy(2)}(2)(mu-F)][OC(5)NF(4)](2b). If the reaction is performed in an NMR tube equipped with a PFA inliner, complex 2b is produced, only. Treatment of 1 with pentafluoropyridine in the presence of an excess water yields the pyridyloxy complex [PdMe(OC(5)NF(4))(Cy(2)PCH(2)PCy(2))](3). Compound [(PdMe)(2){mu-kappa(2)(P,P)Cy(2)PCH(2)PCy(2)}(2)(mu-F)][FHF](2c) bearing a bifluoride anion instead of SiMeF(4)(-) or OC(5)NF(4)(-) can be generated by reaction of 1 with substoichiometric amounts of Et(3)N.3HF. The analogous complex [(PdMe)(2){mu-kappa(2)(P,P)Ph(2)PCH(2)PPh(2)}(2)(mu-F)][FHF] (5c) has been synthesized by addition of Ph(2)PCH(2)PPh(2) to a solution of [PdMe(2)(Me(2)NCH(2)CH(2)NMe(2))](4) in THF and subsequent treatment of the reaction mixture with Et(3)N.3HF. The structure of the A-frame complex 5c has been determined by X-ray crystallography. 相似文献
35.
36.
Kristian Syberg Maria Bille Nielsen Lauge Peter Westergaard Clausen Geert van Calster Annemarie van Wezel Chelsea Rochman Albert A. Koelmans Richard Cronin Sabine Pahl Steffen Foss Hansen 《Current Opinion in Green and Sustainable Chemistry》2021
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37.
Acrylamide complexes of metal nitrates: [M(O‐OC(NH2)CHCH2)n(H2O)m][NO3]2 (M = Co( 1 ), Ni( 2 ) (n = 6 and m = 0) and Zn( 3 ) (n = 4 and m = 2)) have been determined by using single crystal X‐ray diffraction analysis. All complexes crystallize in the triclinic space group . The structures of 1 and 2 represent octahedral species [M(AAm)6]2+ (AAm = O‐OC(NH2)CHCH2 and M = Co or Ni) and uncoordinated nitrate ions. The structure of 3 involves the octahedral cation [Zn(AAm)4(H2O)2]2+ in which the Zn2+ environment includes oxygen atoms of four acrylamide and two water molecules that are stabilized using ionic nitrate ions. The observations of the solid‐state IR spectroscopic vibrational frequencies of these acrylamide complexes are in agreement with the crystal structures. 相似文献
38.
Crystal Structures of Acid Hydrates and Oxonium Salts. XX. Oxonium Tetrafluoroborates H3OBF4, [H5O2]BF4, and [H(CH3OH)2]BF4 The crystal structures of three oxonium tetrafluoroborates were determined. H3OBF4, oxonium tetrafluoroborate proper, is triclinic with space group P1 , Z = 2 and the unit cell dimensions a = 4.758, b = 6.047, c = 6.352 Å and α = 80.40, β = 79.48, γ = 88.25° at ?26°C. Cations H3O+ and anions BF4? are linked by hydrogen bonds O? H…?F into ribbons of condensed rings. In [H5O2]BF4 (diaquohydrogen tetrafluoroborate, monoclinic, P21/c, Z = 4, a = 6.584, b = 9.725, c = 7.084 Å, β = 95.15° at ?100°C) the hydrogen bond in the cation H5O2+ is 2.412 Å short, asymmetric and approximately centered and the linking of cations and anions three-dimensional. In [H(CH3OH)2]BF4 (Bis(methanol)hydrogen tetrafluoroborate, monoclinic, P21/c, Z = 4, a = 5.197, b = 14.458, c = 9.318 Å, β = 94.61° at ?50°C) the cation [H(CH3OH)2]+ is characterized for the first time in a crystal structure with an again very short (2.394 Å), asymmetric and effectively centered hydrogen bond. By further hydrogen bonds cations and anions form only dimers of the formula unit of centrosymmetric cyclic structure. 相似文献
39.
Peter Bellotti Maximilian Koy Christian Gutheil Steffen Heuvel Frank Glorius 《Chemical science》2021,12(5):1810
A highly modular radical cascade strategy based upon radical cyclisation/allylic substitution sequence between alkyl/aryl bromides, 1,3-dienes and nucleophiles ranging from sulfinates to amines, phenols and 1,3-dicarbonyls is described (>80 examples). Palladium phosphine complexes – which merge properties of photo- and cross coupling-catalysts – allow to forge three bonds with complete 1,4-selectivity and stereocontrol, delivering highly value added carbocyclic and heterocyclic motifs that can feature – inter alia – vicinal quaternary centers, free protic groups, gem-difluoro motifs and strained rings. Furthermore, a flow chemistry approach was for the first time applied in palladium–photocatalysed endeavors involving radicals.Highly modular three-bond three-component cascade featuring palladium as dual photoredox/cross coupling catalyst. 相似文献
40.
Dr. Qingquan Lu Steffen Greßies Felix J. R. Klauck Prof. Dr. Frank Glorius 《Angewandte Chemie (International ed. in English)》2017,56(23):6660-6664
A MnI-catalyzed regioselective C−H allenylation is reported that allows a broad range of 2-allenylindoles to be synthesized regioselectively on a gram scale under simple conditions. Notably, a highly efficient chirality transfer was observed (up to 93 % ee) in this transformation. This procedure was further found to allow, for the first time, the direct preparation of ketones by MnI-catalyzed C−H activation. Mechanistic investigations revealed that the precoordination of the oxygen atom to the manganese center as well as the congested tertiary carbon atom in the propargylic carbonates play a crucial role. 相似文献