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71.
Sevgi Tatar Ulu 《中国化学》2012,30(3):634-638
A simple, rapid and sensitive high performance liquid chromatography (HPLC) method was developed for the determination of metoclopramide in pharmaceutical preparation. The method is based on the derivatization of metoclopramide with fluorescamine. The separation was achieved on a C18 column using methanol‐water (70:30, V/V) mobile phase. Fluorescence detector was used at the excitation and emission of 403 and 485 nm, respectively. The method was validated for linearity, limit of detection, limit of quantification, precision, accuracy, recovery, robustness and system suitability. The assay was linear over the concentration range of 100–2000 ng/mL. The mean recovery was 100.37%. The proposed method was successfully applied to the assay of metoclopramide in tablet preparation. The preparation was also analyzed with an official method and statistical comparison by t‐ and F‐tests revealed that there was no significant difference between the results of the two methods with respect to mean values and standard deviations at the 95% confidence level. 相似文献
72.
A novel precolumn derivatization reversed-phase high-performance liquid chromatography method with fluorescence detection is described for the determination of ranitidine in human plasma. The method was based on the reaction of ranitidine with 4-fluoro-7-nitrobenzo-2-oxa-1,3-diazole forming yellow colored fluorescent product. The separation was achieved on a C(18) column using methanol-water (60:40, v/v) mobile phase. Fluorescence detection was used at the excitation and emission of 458 and 521 nm, respectively. Lisinopril was utilized as an internal standard. The flow rate was 1.2 mL/min. Ranitidine and lisinopril appeared at 3.24 and 2.25 min, respectively. The method was validated for system suitability, precision, accuracy, linearity, limit of detection, limit of quantification, recovery and robustness. Intra- and inter-day precisions of the assays were in the range of 0.01-0.44%. The assay was linear over the concentration range of 50-2000 ng/mL. The mean recovery was determined to be 96.40 ± 0.02%. This method was successfully applied to a pharmacokinetic study after oral administration of a dose (150 mg) of ranitidine. 相似文献
73.
Nasser-eddine Tatar 《Applicable analysis》2013,92(1):27-43
A viscoelastic Timoshenko beam is investigated. We prove an exponential decay of solutions for a large class of kernels with weaker conditions than the existing ones in the literature. This will allow the use of other types of viscoelastic material for Timoshenko type beams than the usually used ones. 相似文献
74.
75.
Nasser–eddine Tatar 《Mediterranean Journal of Mathematics》2012,9(1):199-210
We consider an abstract second order semilinear integrodifferential equation involving fractional time derivatives of order
between 1 and 2. Well–posedness is established under appropriate conditions on the initial data and the nonlinearity which
is itself a fractional integral. These conditions will determine the exact underlying space where to look for solutions. 相似文献
76.
Demet Gülen 《Journal of luminescence》2012,132(3):795-800
Significance of the Lorentzian dispersion relationship in controlling the optical response of the nanospheres surrounded by a homogeneous non-absorbing dielectric medium is examined. Nanospheres with size much smaller than the wavelength of the incident light are considered as prototype systems that can cover the generic optical response of Lorentzian nanoparticles. Absorption cross-section of the Lorentzian nanospheres is treated in the quasistatic approximation of classical electrodynamics and the resulting optical resonance is evaluated in terms of its dependencies on the parameters of the system. It has been illustrated that the underlying dispersion governs both the amount and the direction of the shift experienced by the optical resonance of nanospheres. Contrary to Drude nanospheres (well-known red shifters), Lorentzian nanospheres are shown to be blue shifters of the optical resonance. The amount of blue shift is dominated by the increase in the oscillator strength of the nanosphere material. Embedding media with higher dielectric constant and/or materials with larger high frequency dielectric constant lead to a suppression of the amount of blue shift induced by the oscillator strength. Further quantification of the blue shift characteristics against the red shift characteristics of Drude nanospheres is provided. The results can be instrumental for manipulating the optical response of plexcitonic nanophotonic devices. 相似文献
77.
This paper is devoted to some class of inverse coefficient problems. By using a well-known transformation, the inverse problem is transformed to a new problem without the unknown time dependent coefficient. Therefore, the new inverse problem can be solved easily. To show the efficiency of the present method, some examples are presented. 相似文献
78.
A novel, selective, sensitive and simple spectrophotometric method was developed and validated for the determination of the
antidepressant duloxetine hydrochloride in pharmaceutical preparation. The method was based on the reaction of duloxetine
hydrochloride with 1,2-naphthoquinone-4-sulphonate (NQS) in alkaline media to yield orange colored product. The formation
of this complex was also confirmed by UV-visible, FTIR, 1H NMR, Mass spectra techniques and thermal analysis. This method was validated for various parameters according to ICH guidelines.
Beer’s law is obeyed in a range of 5.0–60 μg/mL at the maximum absorption wavelength of 480 nm. The detection limit is 0.99
μg/mL and the recovery rate is in a range of 98.10–99.57%. The proposed methods was validated and applied to the determination
of duloxetine hydrochloride in pharmaceutical preparation. The results were statistically analyzed and compared to those of
a reference UV spectrophotometric method. 相似文献
79.
Demet Goen Colak Eckhard Birckner Ioan Cianga Ulrich S. Schubert Yusuf Yagci 《European Polymer Journal》2009,45(3):940-945
This contribution reports on detailed photophysical investigations of poly(p-phenylene) PPP and poly(p-phenylene-vinylene) (PPV) derivatives laterally decorated with polystyrene (PPV-PSt) or poly(ε-caprolactone) (PPP-PCL, PPP-altPCL, PPV-PCL and PPV-PCL-Br). The polymers emit blue and exhibit very high relative and absolute photoluminescence quantum yield, Φf, in dilute solution, thin film (spin-coated and inkjet-printed) and bulk state. This is ascribed to the presence of the lateral macromolecules, which suppress the strong π-π interactions and consequently excimers formation. Lower Φf value was obtained for the bromine containing polymer and its corresponding model compound dibromodistyrylbenzene Br2-DSB, which was ascribed to heavy atom effect enabling intersystem crossing from S1 to T1. However, studies at 77 K did not reveal phosphorescence, in contrast an enhancement of the fluorescence intensity with respect to room temperature measurement was observed. 相似文献
80.
Alper Tolga Çolak Demet Akduman Okan Zafer Yeşilel Orhan Büyükgüngör 《Transition Metal Chemistry》2009,34(8):861-868
Two pyridine-2,5-dicarboxylic acid (pydcH2) complexes of nickel(II) with 2,2′-bipyridine and 1,10-phenanthroline were synthesized and characterized by elemental, spectroscopic,
thermal analysis, magnetic measurements and single crystal X-ray diffraction techniques. Both [Ni(pydc)(bipy)2]·7H2O and [Ni(pydc)(phen)2]·6.5H2O crystallize in the monoclinic system and P21/c space group. The Ni(II) ions are coordinated by two bidentate bipy or phen ligands and one pydc dianion in a distorted
octahedral geometry. The pydc ligand is coordinated through the pyridine nitrogen atom and oxygen atom of carboxyl group as
a bidentate ligand. Both carboxylate groups of pydc are deprotonated but only the 2-carboxylate is coordinated to the metal.
Thermal decompositions of the complexes have been studied over the range 30–600 °C on heating in a static air atmosphere. 相似文献