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501.
A new chemoentrapment strategy for recycling osmium in the catalytic olefin cleavage reaction is reported. The new strategy utilizes KOH/i-PrOH to generate water-soluble Os(VI) species as a recyclable metal catalyst after the oxidative cleavage reaction. For the recycling of the catalyst, NaIO4-NaClO2 was found to be the best combination of secondary oxidants and acetonitrile-water was chosen as an optimal solvent for the best recycling results. The new method allows for an efficient recycling of osmium in the reactions involving mono- and di-substituted olefins with 1 mol % of OsO4 without any significant side reactions and loss of yield. 相似文献
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Falko Wachholz Heiko Duwensee Ralf Schmidt Michael Zwanzig Jan Gimsa Stefan Fiedler Gerd‐Uwe Flechsig 《Electroanalysis》2009,21(19):2153-2159
Gold nanostructuring of smooth gold disk‐electrodes has been performed by electrodeposition. FE‐SEM images indicate a strongly enlarged electrochemically active surface of the modified electrodes. This could be approved by the gold oxide reduction peak in cyclic voltammetry. The electrodes were also applied for sequence‐specific DNA detection. For this, complementary single stranded capture probes were immobilized on the electrodes and consecutively hybridized with complementary and noncomplementary [OsO4(bipy)]‐labeled DNA targets. We found that intermediate dehybridization steps did not decrease the sensitivity for the specific target. Moreover, the surface modification increased the voltammetric signal by an approx. factor of 9. Further, an enhanced linear calibration range was observed. The presented simple nanostructuring process holds great promise for many electrochemical sensor applications. 相似文献
504.
Shigeru Yamago Prof. Dr. Takeshi Yamada Dr. Manabu Togai Yuu Ukai Eiichi Kayahara Na Pan Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(4):1018-1029
Several organostibine chain‐transfer agents possessing polar functional groups have been prepared by the reactions of azo initiators and tetramethyldistibine ( 1 ). Carbon‐centered radicals thermally generated from the azo initiators were trapped by 1 to yield the corresponding organostibine chain‐transfer agents. The high yields observed in the synthesis of the chain‐transfer agents strongly suggest that distibines have excellent radicophilic reactivity. As the reactions proceeded under neutral conditions, functional groups that are incompatible with ionic conditions were incorporated into the chain‐transfer agents. The chain‐transfer agents were used in living radical polymerization to synthesize the corresponding α‐functionalized polymers. As the functional groups in the chain‐transfer agents did not interfere with the polymerization reaction, well‐controlled polymers possessing number‐average molecular weights (Mns) predetermined by the monomer/transfer agent ratios were synthesized with low polydispersity indices (PDIs). The organostibanyl ω‐polymer ends were transformed into a number of different functional groups by radical‐coupling, radical‐addition, and oxidation reactions. Therefore, it was possible to synthesize well‐controlled telechelic polymers with the same and also with different functional groups at their α‐ and ω‐polymer ends. Distibine 1 was also found to increase PDI control in the living radical polymerization of styrene and methyl methacrylate (MMA) using a purified organostibine chain‐transfer agent. Well‐controlled poly(methyl methacrylate)s with Mn values ranging from 10 000 to 120 000 with low PDIs (1.05–1.15) were synthesized by the addition of a catalytic amount of 1 . The results have been attributed to the high reactivity of distibine 1 towards polymer‐end radicals, which are spontaneously deactivated to yield organostibine dormant species. 相似文献
505.
Synthesis and characterization of antimony trichloride and bismuth trichloride complexes with valine
J. G. Shao Y. X. Yang B. W. Li L. P. Zhang Y. R. Chen X. L. Liu 《Journal of Thermal Analysis and Calorimetry》2009,96(1):277-285
Two compounds of antimony trichloride and bismuth trichloride with valine are synthesized by solid phase synthesis at room
temperature. Their compositions, determined by element analysis, are Sb(C5H10O2N)3·2H2O and Bi(C5H10O2N)2Cl·0.5H2O. The crystal structure of antimony complex with valine belongs to triclinic system and its lattice parameters are: a=0.9599 nm, b=1.5068 nm, c=1.9851 nm, α=92.270, β=95.050, γ=104.270. The crystal structure of bismuth complex with valine belongs to monoclinic system
and its lattice parameters are: a=1.6012 nm, b=1.8941 nm, c=1.839 nm, β=99.73°. The far-infrared spectra and infrared spectra show that the amino group and carboxyl of valine may be
coordinated to antimony and bismuth, respectively, in two compounds. The TG-DSC results also reveal that the complexes were
formed. 相似文献
506.
Turn on the lantern! The stibine donor ligand of a cationic palladium complex acts as a Lewis acid and reacts with a fluoride anion to afford the corresponding fluorostiboranyl-palladium species (see scheme). Bindung of the fluoride anion to the antimony center induces a change in denticity of the triphosphine unit and leads to a bright-orange trigonal-bipyramidal d(8)?lantern complex. 相似文献
507.
Sandrine Rup 《Tetrahedron letters》2010,51(23):3123-3126
All the works reported about oxidative cleavage of olefins by the RuCl3/NaIO4 catalytic system have been performed in biphasic water/organic solvent(s). The first organic solvent-free oxidation of CC double bond by 2% RuCl3/4.1 equiv NaIO4/H2O is described here using both the emulsifier Aliquat® 336 and 20 kHz ultrasonic irradiation. 相似文献
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