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31.
New ruthenium(II) complexes, [Ru(CO)(B)(LL)(PPh3)] (where, LL = tridentate Schiff bases; B = PPh3, pyridine, piperidine or morpholine) have been prepared by reacting [RuHCl(CO)(PPh3)3] or [RuHCl(CO)(PPh3)2(B)] with Schiff bases containing donor groups (O, N, X) viz., salicylaldehyde thiosemicarbazone (X = S), salicylaldehyde semicarbazone (X = O), o-hydroxyacetophenone thiosemicarbazone (X = S) and o-hydroxyacetophenone semicarbazone (X = O). The new complexes were characterised by elemental analysis, spectral (i.r., 1H- and 31P-n.m.r.), data. 相似文献
32.
Raman Natarajan Kulandaisamy Antonysamy Thangaraja Chinnathangavel Jeyasubramanian Kadarkaraithangam 《Transition Metal Chemistry》2003,28(1):29-36
Neutral tetradentate chelate complexes of CuII, NiII, CoII, MnII, ZnII and VOII have been prepared in EtOH using Schiff bases derived from acetoacetanilido-4-aminoantipyrine and 2-aminophenol/2-aminothiophenol. Microanalytical data, magnetic susceptibility, i.r., u.v.–vis., 1H-n.m.r. and e.s.r. spectral techniques were used to confirm the structures of the chelates. Electronic absorption and i.r. spectra of the complexes suggest a square-planar geometry around the central metal ion, except for VOII and MnII complexes which have square-pyramidal and octahedral geometry respectively. The cyclic voltammetric data for the CuII complexes in MeCN show two waves for copper(II) copper(III) and copper(II) copper(I) couples, whereas the VOII complexes in MeCN show two waves for vanadium(IV) vanadium(V) and vanadium(IV) vanadium(III) couples. The e.s.r. spectra of the CuII, VOII and MnII complexes were recorded in DMSO solution and their salient features reported. The in vitro antimicrobial activity of the investigated compounds was tested against the microorganisms such as Salmonella typhi, Staphylococcus aureus, Klebsiella pneumoniae, Bacillus subtilis, Shigella flexneri, Pseudomonas aeruginosa, Aspergillus niger and Rhizoctonia bataicola. Most of the metal chelates have higher antimicrobial activity than the free ligands. 相似文献
33.
K. Anitha S. Athimoolam S. Natarajan 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(9):o567-o570
In the structure of l ‐prolinium picrate, C5H10NO2+·C6H2N3O7−, the Cγ atom of the pyrrolidine ring has conformational disorder. Both the major and minor conformers of the pyrrolidine ring adopt conformations intermediate between a half‐chair and an envelope. Both the cation and anion are packed through chelated three‐centred N—H⋯O hydrogen bonds. The prolinium cation connects two different picrate anions, leading to an infinite chain running along the b axis. In 2‐methylpyridinium picrate, C6H8N+·C6H2N3O7−, the cations and anions are packed separately along the a axis and are interconnected by N—H⋯O hydrogen bonds. Intramolecular contacts between phenolate O atoms and adjacent nitro groups are identified in both structures. A graph‐set motif of R12(6) is observed in both structures. 相似文献
34.
The crystal structure of [C10N2H10]2[P2Mo5O21(OH)2] · 2H2O, contains the heteropolyanion, [P2Mo5O21(OH)2]4—, together with diprotonated 4, 4′‐bipyridine. The heteropolyanion is built up from five MoO6 octahedra sharing four common edges and one common corner, capped by two PO3(OH) tetrahedra. The structure is stabilized by hydrogen bonds involving the hydrogen atoms of the 4, 4′‐bipyridine, water molecules and the oxygen atoms of the pentamolybdatobisphosphate. This is the first example that this kind of cluster could be isolated in the presence of a poly‐functional aromatic molecule ion. Crystal data: triclinic, P1¯ (No. 2), a = 9.983(2)Å, b = 11.269(2)Å, c = 17.604(4)Å, α = 73.50(3)°, β = 84.07(3)°, γ = 67.96(3)°; V = 1760.0(6)Å3; Z = 2; R1 = 0.037 and wR2 = 0.081, for 9138 reflections [I > 2σ(I)]. 相似文献
35.
Vanadate garnet systems namely Ca2NaMg2V3O12, individually doped with Dy and Sm and also co-doped with both the RE ions were synthesized via the solid-state reaction route and their photoluminescence (PL) properties were investigated. The method of synthesis was verified by the formation of single phase compound through X-ray diffraction (XRD) studies. Existence of energy transfer in between the host and the dopant ions was established by PL investigation. Color coordinates of all the compounds were calculated and plotted on the CIE diagram. It was seen that the co-doped system has a near white light emission. It was concluded that this single phosphor is capable of converting the ultraviolet emission of a UV-LED into white light. 相似文献
36.
Synthesis,characterization and biological screening studies of mixed ligand complexes using flavonoids as precursors
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Flavonoids are a group of plant phenolics that provide various health benefits through cell signalling pathways and antioxidant effects. In the present study, a new series of mixed ligand complexes of Co(II), Ni(II), Cu(II) and Zn(II) were synthesized by incorporating curcumin and quercetin flavonoid precursors. The structural features of the synthesized complexes were explored using elemental analysis, thermogravimetric analysis, UV–visible, infrared, NMR, mass and electron paramagnetic resonance spectral analyses and conductivity measurements. These data support an octahedral geometry of the synthesized complexes. In silico biological activity score for the ligand was predicted using PASS online software. ADMET properties were studied using VLS3D online software. Anti‐inflammatory and antioxidant activities were experimentally validated which prove that theoretical predictions are in agreement with the experimental results. Interestingly the synthesized complexes interact with calf thymus DNA through groove binding mode. Moreover, they have good potential to cleave pUC19 DNA. Minimum inhibitory concentration values of the synthesized complexes reveal that they have better antimicrobial efficacy than the ligands. 相似文献
37.
Manimaran Kumar Murugesan Subban Ragavendran Chinnasamy Balasubramani Govindasamy Natarajan Devarajan Ganesan Abirami Seedevi Palaniappan 《Journal of Cluster Science》2021,32(5):1229-1240
Journal of Cluster Science - The titanium dioxide nanoparticles (TiO2NPs) were synthesized by the aqueous extract from P. djamor. The UV–Vis spectrum of TiO2NPs showed maximum absorption at... 相似文献
38.
Thangavelu Saravanan Rajendran Selvakumar Mukesh Doble Anju Chadha 《Tetrahedron: Asymmetry》2012,23(18-19):1360-1368
The stereochemical preference of the biocatalyst, Candida parapsilosis ATCC 7330, was investigated with respect to the E/Z configuration in the deracemization and the asymmetric reduction of aryl secondary alcohols and prochiral ketones, respectively. The biocatalyst preferred the E-isomers over Z-isomers as substrates as evidenced from the experimental results of >99% ee and up to 86% isolated yield for E-secondary alcohols. The synthesis of enantiomerically pure E-4-phenylbut-3-ene-1,2-diol (ee >99%, isolated yield 86%) by whole cell mediated deracemization is reported here for the first time. The geometric preference of the enzymes was confirmed by using the cell free extract of this biocatalyst. Mechanistic insights using in silico studies showed that the E-isomers when located in the active site are favourably placed with respect to the catalytic triad (Ser-Tyr-Lys) for hydride transfer from NADPH. 相似文献
39.
The chemoselective reaction of hydrazine on the ketone rather than the ester in a gem diester system with a γ‐keto group by hydrazinium sulfate and a tandem deesterification of one of the esters in this system by N,N‐dimethylformamide are reported. 相似文献
40.
Chokalingam Saravanan Marimuthu Senthilkumaran Bosco Christin Maria Arputham Ashwin Palaniswamy Suresh Paulpandian Muthu Mareeswaran 《Journal of inclusion phenomena and macrocyclic chemistry》2017,87(3-4):239-250
The ligand salt, Me6[14]diene·2HClO4 (L·2HClO4) was prepared by condensation of acetone and ethylene diamine in the presence of perchloric acid. On reduction of this diene ligand salt, L·2HClO4 with sodium borohydride, the two isomeric ligands, ‘tet-a’ and ‘tet-b’ were produced. The ligands, on reaction with ZnX2 (X=Cl, ClO4, NO3 or CH3COO) and ZnSO4 produced the corresponding complexes. These complexes have been characterized on the basis of elemental analyses; IR, UV–Vis and 1H-NMR spectroscopies; magnetic and conductance data. Based on these data, all of the complexes of the diene ligand L, as well as the perchlorate complexes of all of the ligands attained a square-pyramidal arrangement, whereas the complexes of ‘tet-a’ and ‘tet-b’, with X=NO3, Cl or CH3COO and with ZnSO4 salt, were octahedral. Moreover, all complexes were monometallic except the nitrato complex, [(ZnL)2(µ-NO3)](ClO4)3 which is bimetallic. The structure of [(ZnL)2(µ-NO3)](ClO4)3 has been confirmed by X-ray crystallography. In this complex the zinc centres lie within a N4O donor set, with the four nitrogen donors from L and one of the oxygen atom stemming from the bridging NO3. The complexes show different electrolytic behavior in different solvents. The antibacterial activities of the ligands and complexes towards different phytopathogenic bacteria have been investigated. 相似文献