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471.
Kartar S. Arora C. G. Overberger 《Journal of polymer science. Part A, Polymer chemistry》1984,22(7):1587-1602
The syntheses of two new pyrene-containing monomers—2-(1-pyrenyl)methyl-2-oxazoline ( 6 ) and methyl 2-(1-pyrenyl)acetamidopropenoate ( 12 )—and their polymerization are described. Cationic isomerization polymerization of 6 with ethylene glycol ditosylate initiator gave poly[N-(1-pyrenyl)acetyl ethylenimine] ( 7 ) and free-radical polymerization of 12 with AIBN initiator gave poly[methyl 2-(1-pyrenyl)acetamidopropenoate] ( 15 ). The monomer model compounds of the two polymers, namely, N,N-diethyl(1-pyrenyl)acetamide ( 9 ) and methyl 2-methyl-2-(1-pyrenyl)acetamidopropanoate ( 14 ), were also synthesized. The polymers were characterized by elemental analysis, IR spectroscopy, and a comparison of their 1H-NMR spectra with those of the respective monomer model compounds. 相似文献
472.
Kapildev K. Arora 《Tetrahedron》2005,61(45):10793-10800
Synthesis and characterization of molecular assemblies of pyridine adducts, 1a, 2a and 3a, of 3,5-dinitrobenzoic acid, 1, 3,5-dinitrobenzamide, 2 and 3,5-dinitrobenzonitrile, 3, respectively, have been reported. All these adducts were obtained by crystallization of 1, 2 and 3 from pyridine. However, crystallization of 1 from pyridine in the presence of benzene resulted in the formation of a pyridinium adduct, 1b, along with a water molecule. All the adducts crystallize in a 1:1 molecular ratio except 1a, which forms a 1:2 adduct, as characterized by single crystal X-ray diffraction method. The adducts crystallize in different space groups—1a, orthorhombic, Pna21; 1b, monoclinic, P21; 2a, monoclinc, C2/c; 3a, triclinic, . In two-dimensional arrangement, 1a, 1b and 3a form sheet structures. In 1a, within the two-dimensional sheets, large cavities are formed, which are occupied by pyridine molecules. In 1b, the sheets are catenated to form a chicken-wire network. However, 2a formed a crossed ribbon packing pattern with empty channels in the three-dimensional structure. 相似文献
473.
The interaction of quinolone drugs Norfloxacin (NR) and Ciprofloxacin (CP) with magnesium, calcium and barium perchlorates was investigated. Solid complexes, obtained as products of this interaction, were isolated and characterized by elemental and thermal analysis, FT-IR spectral and electrical conductivity measurements. The spectral studies of the isolated complexes suggest that NR and CP act as bidentate ligands that bind through one carboxylic oxygen atom and the exocyclic carbonyl oxygen atom. The obtained results indicate the formation of the complexes of the following formulas: [M(CP)2](ClO4)2·xH2O and [M(NR)2](ClO4)2·xH2O, where M = Mg(II), Ca(II), and Ba(II). 相似文献
474.
475.
Raman spectra of CdS nanocrystals in Nafion: longitudinal optical and confined acoustic phonon modes
P. Nandakumar C. Vijayan M. Rajalakshmi Akhilesh K. Arora Y. V. G. S. Murti 《Physica E: Low-dimensional Systems and Nanostructures》2001,11(4)
Quantum confinement effects on the longitudinal optical and acoustic phonons in CdS nanocrystals in the strongly confined regime in the polymer matrix Nafion are studied using Raman spectroscopy. The LO-phonon modes show size-dependent asymmetric broadening though the broadening and asymmetry are less than those predicted by the phonon confinement models. Two types of confined acoustic modes corresponding to n=1, l=0 and n=1, l=2 spheroidal vibrations are observed. Softening of the spheroidal modes is observed in the strongly confined regime. 相似文献
476.
Manju Arora Vandna Luthra Ramadhar Singh S. K. Gupta 《Applied biochemistry and biotechnology》2001,96(1-3):173-181
Vibrational spectra of insulator emeraldine base (EB) form of polyaniline and electrical conductive sulfuric acid-and phosphoric
acid-doped emeraldine salts (ES) were studied in the region of 4000-400 cm−1 at ambient temperature by Fourier transform infrared spectroscopy. Infrared transmittance spectra of EB and ES were investigated
to understand the bonding behavior of different organic and inorganic groups present in the polymeric chains and their structural
variations on protonation by sulfate or phosphate ion inclusion in the polymer salt network. These studies revealed the para-coupling
of deformed disubstituted benzenoid (B) and quinoid (Q) rings with ends capped predominantly by (B4Q1) units. The deformation
of B and Q rings was confirmed by the appearance of many weak bands, very weak bands, and satellite structures in strong transmittance
peaks of polymeric chain-constituting groups. Protonation takes place at the nitrogen sites of Q rings and forms semiquinone
radical ions in ES. The vibrational bands pertaining to B rings, Q rings, B4Q1 units, semiquinone segment, sulfate ions, and
phosphate ions were observed and assigned from these measurements. The shift in peak position of some bands with gain or loss
in intensity and appearance of some new bands were observed in sulfuric acid-and phosphoric acid-doped ES spectra. These variations
are attributed to the formation of new structural groups in ES on protonation and a change in crystalline field by sulfate
and phosphate ion doping for crosslinking the polymeric chains. 相似文献
477.
Singh Mayur Pratap Arora Kanwer Singh Shajan Nikhil Pandu Sangeetha Ranga Shome Mahadev Kumar Rajneesh Shukla Dinesh 《Journal of Thermal Analysis and Calorimetry》2019,137(4):1155-1167
Journal of Thermal Analysis and Calorimetry - Continuous cooling transformation diagrams were obtained for a simulated coarse-grain heat-affected zone of API X-80 and X-65 steels using Gleeble-3800... 相似文献
478.
479.
Single crystals of calcium tungstate and strontium tungstate have been grown by double decomposition flux reaction technique using lithium chloride as flux. Growth conditions are optimized to synthesize well faceted crystals. Effect of primary and secondary flux density in the growth charge has been studied. Thermogravimetric study reveals that the grown crystals are highly stable in the temperature range 25 – 1000°C. Analysis of optical absorption normal to the ab‐plane in the spectral range of 200 – 800 nm reveals the true absorption edge, the nature of transition being the allowed indirect one at 4.60 eV and 4.56 eV respectively for CaWO4 and SrWO4. The crystals have been characterized by determining useful pertinent optical and dielectric parameters. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
480.