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941.
《Journal of Coordination Chemistry》2012,65(4):651-662
Mixed ligand complexes of the type MLL′Cl2 (where M?=?Co(II), Ni(II), Cu(II), Zn(II), Cd(II), and Hg(II), L?=?ligand derived from the reaction between benzofuran-2-carbohydrazide and 3,4,5-trimethoxybenzaldehyde (TMeOBFC), and L′?=?ortho-phenylenediamine (opd)/2,6-diaminopyridine (2,6-dap)) have been synthesized. The complexes have been characterized by analytical data, IR, UV-Vis, 1H NMR, DART-MS and ESR spectral data, and magnetic studies. Molar conductance values indicate that the complexes are non-electrolytic in DMF. Antibacterial and antifungal activities of the ligands and complexes have been screened against bacteria Escherichia coli and Staphylococcus aureus and against fungi Aspergillus niger and Aspergillus flavus. 相似文献
942.
《Journal of Coordination Chemistry》2012,65(16):1505-1512
The reactions of the tetradentate amine-phenol type Schiff bases H2sal2en (1,2-ethylenebis(salicylideneimine) and H2sal2mp (1,2-benzylenebis(salicylideneimine)) with trans-[ReOCl3(PPh3)2] or (n-Bu4N)[ReOCl4] in air gave the products (µ-O)[ReO(sal2en)]2 (1) and [ReOCl(sal2mp)] (2), respectively. X-ray and spectroscopic studies have shown that 1 contains the linear O=Re–O–Re=O grouping, with the four donor atoms of sal2en2? coordinating in the square plane cis to the oxo ions. In 2, a cis oxo-chloro arrangement is observed with a phenolic oxygen being coordinated trans to the oxo group. The terminal Re=O bond lengths in 1 and 2 are 1.709(4) and 1.683(3)?Å, respectively. 相似文献
943.
《Journal of Coordination Chemistry》2012,65(21):3516-3524
Three asymmetric Schiff-base tetradentate diimines H2L1, H2L2, and H2L3 [(2-OH)C6H4N=CHC6H42-N=CHC6H3(2-OH)(5-X), X?=?H, CH3, Cl respectively] have been synthesized by a two step process. The reaction of 2-hydroxy aniline with 2-nitro-benzaldehyde in EtOH gave the starting Schiff base, 2-hydroxy-N-(2-nitrobenzylidene)aniline (SB-NO2), which was reduced into the amino derivative (SB-NH2) in solution. Reacting SB-NH2 with 2-hydroxybenzaldehyde, 2-hydroxy-5-methylbenzaldehyde and 2-hydroxy-5-chlorobenzaldehyde gave the three new ligands H2L1, H2L2, and H2L3 respectively. Their dimeric, binuclear metal complexes with Ni(II) and Fe(III) have also been synthesized. The ligands and their complexes were characterized by elemental analyses, LC–MS, IR, electronic, 1H and 13C-NMR spectra, TGA, conductivity and magnetic measurements. All of the spectroscopic, analytical and other data indicate octahedral geometry M2L2(H2O)X2 (M: Ni,Co;X: Cl or H2O), except for NiL2 which is monomeric. Antimicrobial activities of the ligands and the complexes were evaluated against five bacteria. While the ligands and the Ni complexes are inactive towards Pseudomonas aeruginosa and Staphylococcus aureus, Fe complexes are active; only Fe complexes are inactive against Escherichia coli. All of the compounds have antimicrobial activities against Bacillus subtilis, and Yersinia enterecolitica. 相似文献
944.
《Journal of Coordination Chemistry》2012,65(23):2621-2627
Schiff-base complexes of cobalt(II), nickel(II), copper(II) and, zinc(II) with 3-ethoxysalicyliden-p-aminoacetophenoneoxime (HL) were prepared and characterized on the basis of elemental analyses, IR, 1H- and 13C-NMR, electronic spectra, magnetic susceptibility measurements, molar conductivity and thermogravimetric analyses (TGA). A tetrahedral geometry has been assigned to the complexes. 相似文献
945.
《Journal of Coordination Chemistry》2012,65(18):3273-3289
A series of bis[4-(n-alkoxy)-N-(4′-R-phenyl)salicylideneiminato]oxovanadium(IV) complexes (n?=?6,?10,?14,?16,?18 and R?=?C3H7) were prepared and their mesogenic properties were investigated. The mesomorphic behaviors of the compounds were studied by polarized optical microscopy and differential scanning calorimetry. Ligands display SmA/SmC and unexpected nematic mesophases. The complexes bearing longer alkoxy carbon chain (n?=?10,?14,?16, and 18) showed both monotropic or enantiotropic transitions with smectic A and high ordered smectic E phases. However, the complex with shorter carbon chain length (n?=?6) showed monotropic transition with an unprecedented nematic (N) phase. A density functional theory study was carried out using DMol3 at BLYP/DNP level to obtain a stable optimized structure. A square-pyramidal geometry for the vanadyl complexes has been suggested. A νV=O stretching value of ~970?cm?1 corroborated absence of any V?=?O?···?V?=?O interactions. Cyclic voltammetry revealed a quasireversible one-electron response at 0.61?V for the VO(IV)–VO(V) redox couple. Variable temperature magnetic susceptibility measurements of the vanadyl complexes suggested absence of any exchange interactions among the vanadyl spin centers. 相似文献
946.
《Journal of Coordination Chemistry》2012,65(22):3969-3980
Tridentate Schiff bases (H2L1 or H2L2) were derived from condensation of acetylacetone and 2-aminophenol or 2-aminobenzoic acid. Binuclear square pyramidal complexes of the type [M2(L1)2]?·?nH2O (M?=?Fe–Cl, n?=?0; M?=?VO, n?=?1) were accessed from interaction of H2L1 with anhydrous FeCl3 and VOSO4?·?5H2O, respectively. A similar reaction with H2L2, however, produced mononuclear complexes [ML2(H2O) x ]?·?nH2O (M=Fe–Cl, x?=?0, n?=?0; M=VO, x?=?1, n?=?1). The compounds were characterized using elemental analysis, FT-IR, UV-Vis, and NMR (for ligand only), and mass spectroscopies and solution electrical conductivity studies. Magnetic susceptibility measurements suggest antiferromagnetic exchange in binuclear Fe(III) and VO(IV) complexes. Thermo gravimetric analysis (TGA) provided unambiguous evidence for the presence of coordinated as well as lattice water in [VOL2(H2O)]?·?H2O. Cyclic voltammetric studies showed well-defined redox processes corresponding to Fe(III)/Fe(II) and VO(V)/VO(IV). In vitro antimicrobial activities of the compounds were investigated against Klebsiella pneumoniae, Staphylococcus aureus, Pseudomonas aeroginosa, Escherichia coli, Bacillus subtilis, and Proteus vulgaris. H2L1 and its binuclear complexes exhibited pronounced activity against all the microorganisms tested. 相似文献
947.
《Journal of Coordination Chemistry》2012,65(4):329-337
Abstract A new, thiazole derivative ligand, 4-(1-phenyl-1-methylcyclobutane-3-yl)-2-(2-hydroxy-5-bromo benzylidenehydrazino) thiazole (LH), has been synthesized by the reaction of 2-hydroxy-5-bromobenzaldehyde, thiosemicarbazide and subsequently 1-phenyl-1-methyl-3-(2-chloro-1-oxoethyl) cyclobutane. Mononuclear complexes with a metal-ligand ratio of 1 : 2 have been prepared with Cd(II), Co(II), Cu(II), Ni(II) and Zn(II). The authenticity of the ligand and its complexes was established by elemental analyses, IR, 13C and 1H NMR spectra, magnetic susceptibility measurements and thermogravimetric analyses (TGA) and differential scanning calorimetry (DSC). 相似文献
948.
Mainak Ganguly Dr. Anjali Pal Dr. Yuichi Negishi Prof. Tarasankar Pal 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(49):15845-15855
The condensation products of salicylaldehyde and different diamines constitute an important class of diiminic Schiff bases (DSBs). This class of compounds has been rediscovered as reducing as well as capping agents under UV irradiation. UV irradiation of alkaline DSB solutions in the presence of water‐soluble copper salts has been employed to produce copper nanoparticles (CuNPs). Intriguing CuNP‐stimulated fluorescence behavior of the solution has been observed. Depending upon the nature of the spacer in between two iminic bonds, fluorescence enhancement or quenching is observed. Such surprising fluorescence contrast has been ascribed to far‐field radiation and lossy surface waves. 相似文献
949.
Dr. Martha V. Escárcega‐Bobadilla Giovanni Salassa Dr. Marta Martínez Belmonte Eduardo C. Escudero‐Adán Prof. Dr. Arjan W. Kleij 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(22):6805-6810
Supramolecular chirality effects have been achieved both for ditopic and monotopic substrates by using a programmable bis‐salphen scaffold that incorporates either two or three Zn nuclei. The dinuclear host shows preferential chirogenesis in the presence of ditopic systems, whereas effective chirality transfer to the trinuclear complex is realized through monotopic binding. The mode of binding in the trinuclear host has been investigated through X‐ray crystallography, CD measurements, UV/Vis spectroscopy, and DFT analysis. The bis‐salphen scaffold holds promise for the development of substrate‐specific host systems useful for determination of the absolute configuration of various types of organic molecules. 相似文献
950.