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Parinayok P Yamashita M Yonezu K Ohashi H Watanabe K Okaue Y Yokoyama T 《Journal of colloid and interface science》2011,364(1):272-275
In order to develop a chemical technique for the recovery of gold (Au) and platinum (Pt) in the metallic state from spent catalysts, e.g., catalysts for environmental protection and automobile and petroleum catalysts, the coprecipitation behaviors of Au(III) and Pt(IV) complex ions with Fe(OH)(2) as a scavenging and reducing agent were investigated. The Au(III) complex ions were found to be stoichiometrically and rapidly reduced to metallic Au due to electron transfer in acidic aqueous solution prior to coprecipitation with Fe(OH)(2). Conversely, Pt(IV) complex ions were reduced only after coprecipitation with Fe(OH)(2) due to electron transfer through a Pt(IV)-O-Fe(II) bond on the solid Fe(OH)(2). Using this chemical technique, Au and Pt can be selectively and effectively recovered in the metallic state. 相似文献
74.
Takayuki Miyaji Norihisa Fukaya Yukio Takagi Hiroyuki Yasuda 《Journal of organometallic chemistry》2011,696(8):1565-1569
The immobilization of diphenyl phosphine onto ordered mesoporous silicas using a tripodal linker unit possessing one bromopropyl group and three anchoring silicon atoms was investigated. Solid-state 31P, 29Si, and 13C cross-polarization/magic angle spinning (CP/MAS) NMR spectroscopic studies as well as isothermal nitrogen adsorption/desorption measurements revealed that grafting the tripodal linker unit and a subsequent reaction with potassium diphenylphosphide (the “bottom-up” method) successfully realized diphenylphosphino functionalization of silica while maintaining the mesoporous structure. In contrast, directly grafting tripodal diphenylphosphino ligands pre-synthesized from the tripodal linker unit onto silica (the “top-down” method) was unsuccessful. 相似文献
75.
Hidekazu Miyaji Yoshiaki Kobuke Jiro Kondo 《Molecular Crystals and Liquid Crystals》2013,570(1-2):283-290
Abstract Tetraethyltetramethylporphyrin substituted at two facing meso positions by N-methylimidazolyl groupings and its metal complexes were prepared. The absorption spectra of Zn and Mg complexes showed a characteristic splitting of Soret band and red-shifts of Q-bands indicating the exciton interaction of porphyrins in a slipped cofacial arrangement, where each imidazolyl group in one metal porphyrin is coordinated to metals in the other porphyrin skeleton. Typical upfield shifts in the 1H NMR spectra arising from such the stacking structure elucidated Zn and Mg complexes as a dimer and an oligomeric mixture, respectively. Bis(imidazolyl)substituted tetraethyltetramethyl-porphyrin was also prepared. It suggested the hydrogen bonded oligomer formation through imidazolyl-imidazolyl interactions in a columnar orientation. Electric conductivities of films prepared from these compounds werecharacterized. In a same line with behaviors in solution, samples capable of π-stacking interaction with adjacent porphyrins via ligand-to-metal coordination or hydrogen bonding exhibited higher conductivities as well as lower activation energies for the thermal conduction. These behaviors are understood as due to the overlap of π-systems of one porphyrin with neighboring porphyrins. 相似文献
76.
Nobuo Okabe Yasunori Muranishi Mamiko Odoko 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(7):m345-m347
The crystal structures of the title complexes, namely trans‐bis(isoquinoline‐3‐carboxylato‐κ2N,O)bis(methanol‐κO)cobalt(II), [Co(C10H6NO2)2(CH3OH)2], and the corresponding nickel(II) and copper(II) complexes, [Ni(C10H6NO2)2(CH3OH)2] and [Cu(C10H6NO2)2(CH3OH)2], are isomorphous and contain metal ions at centres of inversion. The three compounds have the same distorted octahedral coordination geometry, and each metal ion is bonded by two quinoline N atoms, two carboxylate O atoms and two methanol O atoms. Two isoquinoline‐3‐carboxylate ligands lie in trans positions, forming the equatorial plane, and the two methanol ligands occupy the axial positions. The complex molecules are linked together by O—H⋯O hydrogen bonds between the methanol ligands and neighbouring carboxylate groups. 相似文献
77.
78.
Nonintegral indices are found for the extra meridional reflections in the x-ray diffraction of drawn polyoxymethylene. The index of one of the extra reflections is estimated at 00l: l = 2.830 ± 0.003. A new model for the molecular conformation which accounts for the nonintegral indices is proposed. The new model is a helix with defects at constant intervals along the helix axis. The defect is an unwinding of the helix by 20° around the helix axis. This defect is believed to be characteristic of crystals of helical polymers. The interval between the defects is estimated as 18 monomers. The crystal structure with these defects is consistent with precise measurements of the layer line positions. 相似文献
79.
Synthesis of a new class of furan-fused tetracyclic compounds using o-quinodimethane chemistry and investigation of their antiviral Activity 总被引:1,自引:0,他引:1
Matsuya Y Sasaki K Nagaoka M Kakuda H Toyooka N Imanishi N Ochiai H Nemoto H 《The Journal of organic chemistry》2004,69(23):7989-7993
The synthesis and evaluation of antiviral activity of new furan-fused tetracyclic compounds are described. The syntheses were satisfactorily achieved on the basis of o-quinodimethane chemistry, using furan-containing benzocyclobutene derivatives as a substrate, in high generality and stereoselectivity. The various derivatives thus synthesized were examined on their inhibitory activity on virus growth using a hemagglutinin (HA) method, leading to a discovery of promising candidates for new antiviral drugs having high activity and good therapeutic index. 相似文献
80.
Miyaji H Dudic M Gasser G Green SJ Moran N Prokes I Labat G Stoeckli-Evans H Strawbridge SM Tucker JH 《Dalton transactions (Cambridge, England : 2003)》2004,(18):2831-2832
A heterodifunctionalised ferrocene, containing a carboxylic acid and an amidopyridine unit, self-assembles in organic solvents through complementary hydrogen bonds. 相似文献