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121.
Pirilä M Martikainen M Ainassaari K Kuokkanen T Keiski RL 《Journal of colloid and interface science》2011,353(1):257-262
Dissolved arsenic in drinking water is a global concern as it causes serious health problems. The purpose of this research was to study the applicability of an industrial intermediate product, a mixture of titanium hydroxide and titanium dioxide for removing aqueous arsenic. The material is common, inexpensive, and non-toxic, making it an attractive choice for drinking water purification. The kinetics and equilibrium of removing both primary inorganic arsenic forms, As(III) and As(V), were studied by separate batch experiments. The tested material functioned well in removing both of these arsenic forms. The apparent values for Langmuir monolayer sorption capacities were 31.8 mg/g for As(III) and 33.4 mg/g for As(V) at pH 4. The studied TiO(2) performed the best in acidic conditions, but also reasonably well in other pH conditions. 相似文献
122.
Markus Lindqvist Dr. Kirill Axenov Dr. Martin Nieger Dr. Minna Räisänen Prof. Markku Leskelä Prof. Timo Repo 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(31):10412-10418
Dimethylamino‐(+)‐camphorenamine reacted with an equimolar amount of Piers’ borane, HB(C6F5)2, to give the corresponding iminium–hydroborate zwitterionic salt. Being in equilibrium with the parent enamine–HB(C6F5)2 N–B pair, this salt was able to split hydrogen heterolytically, hydrogenating the iminium group in the molecule. Detailed studies revealed that the hydrogen splitting in this reaction proceeded through an intermolecular pathway leading to a bornylamine–HB(C6F5)2 adduct. When the starting enamine is present in excess over HB(C6F5)2, the produced bornylamine–HB(C6F5)2 adduct breaks up, eliminating free bornylamine and forming the initial camphorenamine– HB(C6F5)2 pair. This results in hydrogenation of the camphorenamine framework in a catalytic fashion. 相似文献
123.
Kallio M Jussila M Raimi P Hyötyläinen T 《Analytical and bioanalytical chemistry》2008,391(6):2357-2363
A previously constructed semi-rotating cryogenic modulator was modified for comprehensive two-dimensional gas chromatography
(GC×GC). The retention time repeatability was improved by replacing the modulator control program unit with a new system.
Peak widths obtained with the modified modulator were comparable with those obtained with the previous modulator and other
modulator types. The modulator was easy to construct and it can be installed in any commercial GC system. The constructed
GC×GC–FID system and data obtained by gas chromatography–mass spectrometry (GC–MS) were used for identification of unknowns
in forest aerosol samples.
Figure A semi-rotating cryogenic modulator in which modulation is based on two-step cryogenic trapping with continuously flowing
carbon dioxide has been developed for comprehensive two-dimensional gas chromatography 相似文献
124.
Aminlashgari N Hakkarainen M 《Journal of the American Society for Mass Spectrometry》2012,23(6):1071-1076
Novel surface assisted laser desorption ionization-mass spectrometry (SALDI-MS) method was developed for rapid analysis of
low molecular mass polyesters and their degradation products by laser desorption ionization-mass spectrometry. Three polycaprolactone
materials were analyzed by the developed method before and after hydrolytic degradation. The signal-to-noise values obtained
by SALDI-MS were 20–100 times higher compared with the ones obtained by using traditional MALDI-MS matrices. A clean background
at low mass range and higher resolution was obtained by SALDI-MS. Different nanoparticle, cationizing agent, and solvent combinations
were evaluated. Halloysite nanoclay and magnesium hydroxide showed the best potential as SALDI surfaces. The SALDI-MS spectrum
of the polyester hydrolysis products was verified by ESI-MS. The developed SALDI-MS method possesses several advantages over
existing methods for similar analyses. 相似文献
125.
Single-drop microextraction (SDME), an emerging miniaturised extraction technique, was for the first time combined with multiple headspace extraction (MHE) to enable the quantitative determination of volatiles in solid matrixes by SDME technique. The concept of multiple headspace single-drop microextraction (MHS-SDME) was then applied for quantitative determination of styrene in polystyrene (PS) samples. Good linearity for the multiple headspace extraction was obtained when the migration of styrene was facilitated by grinding the samples and incubating them for 1 h at 150 degrees C prior the first extraction. Two microlitres of butyl acetate was used as the single-drop microextraction solvent and the extraction time was 5 min per cycle. The relative standard deviation (RSD) for single-drop microextraction of styrene standard at n=6 was 7.6%. Linearity was shown for styrene concentrations between 0.005 and 0.75 microg/ml (R2=0.999). This corresponds to total amount of styrene between 0.1 and 15 microg. The limit of quantitation for styrene standard at S/N 10 was 0.005 microg/ml. The developed method was validated against and showed good agreement with an earlier reported dissolution-precipitation method. 相似文献
126.