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101.
102.
Inter- and intra-individual variability of the loratadine (LOR) metabolism in Caucasian subjects was assessed during a bioequivalence study for two pharmaceutical formulations (solid oral dosage forms) containing 10 mg of the active substance. The analytical data were obtained by applying a reliable, low-cost and sensitive ion pair liquid chromatography/fluorescence (IPLC/FLD) method for determination of both loratadine and descarboethoxyloratadine (DCL) in human plasma samples. The sample preparation procedure is based on liquid-liquid extraction of the target analytes from alkalinized plasma using diethyl-ether. The separation of the analytes and 8-chloroazatadine as internal standard (IS) was achieved through an isocratic ion pair (IP) elution on a Purospher((R)) STAR RP-18 column. The mobile phase containing sodium dodecyl sulfate (SDS) as ion pairing agent was pumped at a flow rate of 1 mL/min. Fluorescence detection (FLD) was achieved at 280 nm (excitation) and 440 nm (emission) wavelengths. The increased sensitivity of the method is also based on a large sample injected volume (250 microL). Linear response was found over the 0.5-20 ng/mL concentration interval for both target compounds. Low limits of quantification (LLOQ) around 0.3 ng/mL were found for LOR and DCL. Method validation is presented. 相似文献
103.
Adsorption of heavy metals (Pb, Zn, and Cu) on a new bioadsorbent based on starch reinforced with modified cellulose with toluene‐diisocyanate has been studied using batch‐adsorption technology. The study was carried out in order to find if this bio material, designed for seedling pots manufacture, is able to act like a barrier between soil pollutants and plants. The influence of contact time, pH, adsorbent dose, and salt concentrations was also evaluated. The obtained data were examined using the Langmuir and Freundlich adsorption models. Optimal results were obtained at pH 5.0, temperature of 25°C, contact time of 120 minutes, and an adsorbent dose of 4 mg/mL. Experimental data along with computed Langmuir parameters show that the adsorption process is favorable, and the maximum adsorption capacity of the adsorbent for lead, zinc, and copper was 66.66, 58.82, and 47.61 mg/g, respectively. 相似文献
104.
Margareta Socaciu Carmina Plosceanu Iuliana Cuculescu I. Muşcutariu 《Phase Transitions》2013,86(4):249-257
The use is described of absorption spectroscopy for determining phase transitions in the mesogenic compound cholesteryl myristate (CM) and in binary mixtures of terephthalbis-butyl-aniline (TBBA) and cholesteryl myristate. The temperature dependence of the optical densities in the visible region at phase transitions is reported. The transition temperatures obtained with this method are in good agreement with the results obtained with other methods. 相似文献
105.
A synergistic catalytic system for the first asymmetric addition of aldehydes to in situ generated prochiral oxocarbenium ions has been developed. The dual catalytic protocol allows the simultaneous activation of both electrophile and nucleophile and provides access to a variety of valuable chiral 2H-chromenes with excellent enantioselectivities. 相似文献
106.
A series of new thiourea catalysts prepared from natural amino acids have been applied in organocatalytic asymmetric Michael additions of α-nitrocyclohexanone to nitroalkenes. The resulting addition products are formed with excellent enantioselectivities (up to an er of 98:2) in good yields (up to 90%). 相似文献
107.
PA 6 and PA6,6 sheets irradiated with electron beam were investigated in relation to their thermal stability in various environments (air, distilled water and NaCl 5% solution) at 70 °C. The preexposure doses were 100, 200, 400 and 600 kGy at a dose rate of 22.4 kGy/s. The FTIR spectra allowed the evaluation of the progress of sample oxidation by elucidating the contributions of each environment to the ageing of polyamides. The increases in the absorbance at 1652 cm?1 placed the surrounding aggressive attack in the following sequence: air<water<NaCl solution. A scheme of degradation mechanism is proposed for the explanation on the involvement of amidic units. 相似文献
108.
Mirela‐Fernanda Zaltariov Maria Cazacu Sergiu Shova Angelica Vlad Iuliana Stoica Elena Hamciuc 《Journal of polymer science. Part A, Polymer chemistry》2012,50(18):3775-3787
Bis[N‐(4‐carboxyphenyl)phtalimidyl]dimethylsilane prepared by the reaction between bis(3,4‐dicarboxyphenyl)dimethylsilane anhydride and p‐aminobenzoic acid has been used to built three novel hydrogen‐bonded supramolecular polymers as a result of cocrystallization with pyridine derivatives: 4,4′‐bipyridyl ( SP1 ), 1,2‐bis(4‐pyridyl)ethylene ( SP2 ), and 4,4′‐azopyridine ( SP3 ). The structures of the dianhydride, diacid, and derived supramolecular polymers were investigated by Fourier transform infrared (FTIR) and proton magnetic resonance (1H NMR) spectroscopy. Self‐assembling was proved by the presence of the IR absorption bands around 1900 and 2400 cm?1 specific for hydrogen bond. The association constant values were estimated by using FTIR spectroscopy in solid state. According to X‐ray diffraction study, the bis(3,4‐dicarboxyphenyl)dimethylsilane anhydride ( 1 ) has an isolated molecular structure. Bis[N‐(4‐carboxyphenyl)phtalimidyl]dimethylsilane ( 2 ) molecules are associated in the crystal structure via dimeric O? H … O hydrogen bonds resulting in the wavy 1D supramolecular chain. The main packing motif for SP1 and SP3 is represented by wavy chain formed by alternating sequences of 4,4′‐bipyridyl or 4,4′‐azopyridine and bis[N(4‐carboxyphenyl)phtalimidyl]dimethylsilane molecules linked by O? H … N hydrogen bonds. Thermal behavior was studied by differential scanning calorimetry and thermogravimetric analysis. The ability for the structuration in film was emphasized by atomic force microscopy. The molecular transport ability of the reversible associations was estimated by dynamic water vapor sorption (DVS) analysis. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012 相似文献
109.
110.
M. Ulmeanu F. Jipa C. Luculescu A. Moldovan M. Zamfirescu 《Applied Physics A: Materials Science & Processing》2011,104(3):839-843
Single pulse near field study on a Co(3 nm)/Cu(6 nm)/Co(20 nm) multilayer structure was experimentally investigated with a
laser pulse width of 200 fs at a wavelength of 775 nm. For the near field experiments, we have used polystyrene colloidal
particles of 700 nm diameter deposited by spin coating on top of the multilayer structure, as well on top of Co (50 nm) and
Cu (50 nm) thin films. The diameter and the morphologies of the holes were investigated by scanning electron microscopy (SEM)
and atomic force microscopy (AFM). We have estimated the fluence thresholds values for the near field and discuss their values
in respect with the enhancement factor of the intensity of the electromagnetic field due to the use of the colloidal particles.
We compare the depths and the widths of the holes obtained at the same peak laser fluence for the Co thin film (50 nm), Cu
thin film (50 nm) and Co(3 nm)/Cu(6 nm)/Co(20 nm) multilayer structure. Depending on the laser fluence, the ablation depth
can reach the first, the second, or the third layer. Theoretical estimations of the intensity enhancement were done using
the finite-difference time-domain (FDTD) by using the RSoft software. This type of a selective distribution of the ablation
depth, in the near field regime, of a planar metal/dielectric interface can open new perspective in the excitation of propagating
surface plasmons. 相似文献