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951.
Bharat T. Thaker Jayshree Lekhadia Ashwin Patel Purnima Thaker 《Transition Metal Chemistry》1994,19(6):623-631
Summary Binuclear complexes of OVIV have been prepared by reacting aromatic diamines with mixed-ligand (mononuclear) complexes of the type [(diamine), VO(PmAcp or PmbzP)], where (diamine) = 2,2-bipyridine or 1,10-phenanthroline, and PmAcp or PmbzP heterocyclic -diketone ligands = 1-phenyl-3-methyl-4-acetyl or 4-benzoyl-2-pyrazolin-5-one. 2,6-Diaminopyridine orm-phenylenediamine condenses with the MeCO or PhCO groups of PmAcp and PmbzP on two complex molecules, thus bridging the two VOII centres. The complexes have been characterized by electronic, i.r. and e.s.r. spectra, magnetic measurements, thermogravimetry, conductometry and microanalysis. The magnetic moments and the order of antiferromagnetism are explained on the basis of delocalized -orbitals, orientation of the metal orbitals and the bridging Schiff base. The metal-ligand bond is covalent. 相似文献
952.
Specific heat capacities, apparent molar heat capacities, densities, and apparent molar volumes have been determined for cytosine, uracil, thymine, adenine, cytidine, 2-deoxycytidine, uridine, thymidine and adenosine at temperatures from 25°C to 55°C. The results of these measurements have been used to calculate for the first time, the thermodynamic quantities:C
p,2
o
, (C
p,2
o
/T)p, (2
C
p,2
o
T
2)p,V
2
o
, (V
2
o
/T)p, and (2
V
2
o
/T
2)p. The-CH2-group contribution has been calculated at different temperatures. It has also been observed from the data for the nucleic acid bases and nucleosides that the additivity ruleC
p,2
o
(nucleoside)-C
p,2
o
(base) +C
p,2
o
(water)=C
p,2
o
(ribose) does not hold in these cases. 相似文献
953.
Meena V Patel Jeffrey J RohdeVijaya Gracias Teodozyj Kolasa 《Tetrahedron letters》2003,44(35):6665-6667
This communication describes an efficient one-pot procedure for the synthesis of 2-arylbenzo[b]thiophene derivatives via reaction of o-halo or nitro aryl carbonyl compounds with benzyl mercaptans in the presence of an excess of anhydrous K2CO3 at elevated temperature. 相似文献
954.
Anica Markovac Ambalal R. Patel Maurice P. MontagneLa Arthur B. Ash 《Journal of heterocyclic chemistry》1977,14(1):147-148
The preparation of 4-(3-nitrophenyl)-2-pieoline (3) was accomplished in one step by the Zecher-Krohnke ring-closure reaction. Compound 3 is the starling material for 2-lormyl-4-(3-arninophenyl)pyridine thiosemicarbazone (4-APPT), a promising antineoplastie agent. 相似文献
955.
956.
957.
R. A. A. Kubiak G. Patel W. Y. Leong R. Houghton E. H. C. Parker 《Applied Physics A: Materials Science & Processing》1986,41(3):233-235
Phosphorus-doped Si epilayers with bulk-like mobilities were grown by molecular beam epitaxy (Si-MBE) by coevaporation of phosphorus from a tin phosphide source. The behaviour of P doping as a function of growth parameters and of potential enhanced doping indicates a non-unity, almost growth-temperature independent incorporation efficiency with negligible surface segregation -a unique combination among coevaporated dopants in Si-MBE. 相似文献
958.
Srivatsan V Dasgupta AK Kale P Datla RR Soni D Patel M Patel R Mavadhiya C 《Journal of chromatography. A》2004,1031(1-2):307-313
The development and validation of a high-performance liquid chromatography (HPLC) method for the simultaneous determination of itraconazole and its metabolite, hydroxyitraconazole, in human plasma is described. The method involved liquid-phase extraction of itraconazole and hydroxyitraconazole using a hexane-dichloromethane (70:30) mixture, after addition of loratidine as an internal standard (IS). Separation was achieved with a reversed-phase C18 column (250 mm x 4.6 mm) employing fluorescence detection (excitation: 264 nm, emission: 380 nm). The mobile phase consisted of [0.01% triethylamine solution adjusted to pH 2.8 with orthophosphoric acid-acetonitrile (46:54)]-isopropanol (90:10, v/v) at a flow rate of 1.0 ml/min. For both the drug and metabolite, the standard curve was linear from 5.0 to 500 ng/ml with goodness of fit (r2) greater than 0.98 observed with four precision and accuracy batches during validation. An observed recovery was more than 70% for drug, metabolite and internal standard. The applicability of this method to pharmacokinetic studies was established after successful application during 35 subjects bioavailibity study. The method was found to be precise, accurate and specific during the study. 相似文献
959.
Vinay S. Sharma B. B. Jain H. N. Chauhan R. B. Patel 《Molecular Crystals and Liquid Crystals》2016,630(1):79-86
Two ester homologous series of carboxy (-COO-) and ethylene-carboxy (-CH=CH-COO-) mesogens, viz. α-4-[4’-n-alkoxybenzoyloxy] phenyl β-4’’-methoxy benzoyl ethylenes (1) and α-4-[4’-n-alkoxy cinnamoyloxy phenyl β-4’’-methoxy benzoyl ethylenes (2)] are discussed. Series (1) and (2) differ at their central linking group. Mesophase are observed at four and five number members in both homologue series. Enantiotropic nematogenic property is observed in both series (1) and (2), while some smectic property is exhibited in series (2). Thermal stability of nematic-isotropic in series (1) is relatively low as compared to (2), smectogenic property is totally absent in series (2). In phase diagram, solid-nematic, solid-isotropic, and nematic-isotropic curve follow zigzag path rising and falling. Transition temperatures are observed through hot stage polarizing microscope. Analytical data supports the structure of molecules. Threaded, Schlieren-type textures of homologues are observed through microscope. 相似文献
960.
A novel bis-chalcone, (2E,2′E)-3,3′-(1,4-phenylene)bis(1-(2-aminophenyl)prop-2-en-1-one) is synthesized through a base catalyzed Claisen-Schmidt condensation reaction of terephthalaldehyde with 2-aminoacetophenone. Its structure (sp. gr. P\(\bar 1\), Z = 2) is determined from single crystal X-ray diffraction data. There are two independent centrosymmetric molecules with no significant differences in bond lengths and angles between them. The NMR, IR, HRMS, and UV spectral data of the prepared bis-chalcone are presented. 相似文献