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Solvent bar microextraction combined with high‐performance liquid chromatography for preconcentration and determination of pramipexole in biological samples
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Ensieh Ghasemi Salim Kheradmand Orkideh Ghorban Dadrass 《Biomedical chromatography : BMC》2014,28(4):486-491
A simple, rapid and sensitive analytical method for preconcentration and determination of pramipexole in different biological samples has been developed using solvent bar microextraction (SBME) combined with HPLC‐UV. The target drugs were extracted from 10 mL of basic aqueous sample solution into an organic extracting solvent located inside the pores of a polypropylene hollow fiber, then back‐extracted into an acidified aqueous solution in the lumen of the hollow fiber. In order to obtain high extraction efficiency, the effect of different variables on the extraction efficiency was studied simultaneously using an experimental design. The experimental parameters of SBME were optimized using a Box–Behnken design after a Plackett–Burman screening design. Under the optimized conditions, an enrichment factor up to 96 was achieved and the relative standard deviation of the method was 4.64% (n = 5). The linear range was 0.05–2000 µg/L with a correlation coefficient (r) of 0.987. Finally, the applicability of the proposed method was evaluated by extraction and determination of pramipexole in plasma and urine samples. The results indicated that SBME method has excellent clean‐up and high preconcentration factor and can serve as a simple and sensitive method for analysis of pramipexole in biological samples. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
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Alexandre Requet Olivier Colin Flavien Bourdreux Salim M. Salim Sylvain Marque Christine Thomassigny Christine Greck Jonathan Farjon Damien Prim 《Magnetic resonance in chemistry : MRC》2014,52(6):273-278
Pyridylmethylamines or pma are versatile platforms for different catalytic transformations. Five pma‐ligands and their respective Pd complexes have been studied by liquid state NMR. By comparing 1H, 13C and 15N chemical shifts for each pma/pma–Pd couple, a general trend for the metallacycle atoms concerns variations of the electronic distribution at the pendant arm, especially at the nitrogen atom of the ligand. Moreover, the increase of the chemical shift of the pendant arm nitrogen atom from primary to tertiary amine is also related to the increase of crowding within the complex. This statement is in good agreement with X‐ray data collected for several complexes. Catalytic results for the Suzuki–Miyaura reaction involving the pma–Pd complexes showed within this series that a sterically crowded and electron‐rich ligand in the metallacycle was essential to reach the coupling product with a good selectivity. In this context, NMR study of chemical shifts of all active nuclei especially in the metallacycle could give a trend of reactivity in the studied family of pma–Pd complexes. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
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Laurent Piccolo Salim NassreddineGuy Toussaint Christophe Geantet 《Journal of chromatography. A》2010,1217(37):5872-5873
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Cubic liquid crystalline nanoparticles (cubosomes) of bicontinuous nature with internal networks of water channels have received great interests in nanomedicine applications, particularly as potential vehicle for loading and release of therapeutic agents. These nanoparticles have been most commonly produced using monoolein and phytantriol. In this study, we explore the use of a Guerbet branched chain glycolipid, namely 2-hexyl-decyl-β-D glucopyranoside (β-Glc?OC10C6), as a new and alternative material for cubosomes production. The fully hydrated glycolipid assumes a reverse bicontinuous cubic liquid crystal phase of an Ia3d space group with lattice parameter of ca. 74 Å, as confirmed using a small-angle X-ray scattering. Dynamic light scattering and a conventional transmission electron microscopy were used to investigate the average size and morphology of the cubosomes. The effectiveness of Poloxamer 407 (stabiliser typically used in other cubosome systems against aggregations and particle coalescence) in providing steric stabilisation of the glycolipid cubosomes was assessed through visual assessment. 相似文献
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Salim F. Haddad Roger D. Willett Brendan Twamley 《Journal of chemical crystallography》2010,40(11):902-908
Abstract
An analysis is made of the supramolecular interactions in the two polymorphic structures of 3,5-dibromo-2,6-diaminopyridinium bromide, with particular emphasis on the roles of hydrogen and halogen bonding. Because of the extensive hydrogen bonding capabilities, hydrogen bonding interactions dominate in both phases. This causes a competition between C–Br···Br–C and C–Br···Br− halogen bonding interactions, with the former dominating in the orthorhombic Pbca phase and the latter in the monoclinic P21/c phase. For Pbca phase a = 5.5197(11) ?, b = 15.040(3) ?, c = 23.2555(5) ?, and for P21/c phase a = 8.1143(19) ?, b = 14.226(3) ?, c = 8.9005(18) ?, β = 113.18(2)°. 相似文献90.
Mousa Al-Noaimi Mohammad El-khateeb Salim F. Haddad Haytham Saadeh 《Transition Metal Chemistry》2010,35(7):877-883