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A novel and simple chemiluminescence (CL) method has been developed and validated for determination of metformin. This method
is based on hydroxyl radical chemiluminescence—the hydroxyl radical generated by reaction of Cu(II) and hydrogen peroxide
oxidizes rhodamine B (RhB) to produce weak CL which can be enhanced by metformin. At the same time, metformin molecularly
imprinted polymer (MIP) was synthesized. After enrichment based on the selectivity of metformin-MIP, the CL method was successfully
applied to the determination of metformin in human serum. The linear range was from 1.0×10−8 to 1.0×10−6 g mL−1 and the detection limit was 4×10−9 g mL−1. The relative standard deviation at 2.0×10−7 g mL−1 by use of MIP was 3.67% (n=7). 相似文献
75.
采用十八烷基硅烷键合硅胶(200mm×4.6mm,5μm)为固定相,以0.01mol/L磷酸二氢钾-甲醇-三乙胺(95∶5∶0.5)为流动相(用磷酸调节pH值至3.0),在210nm波长测定金贝痰咳清颗粒中盐酸麻黄碱含量;以乙腈-0.4%磷酸溶液(13∶87)为流动相,在327nm波长测定金贝痰咳清颗粒中绿原酸含量。盐酸麻黄碱在0.204—1.02μg范围内线性关系良好(r=0.9998),回收率为99.31%(RSD为0.70%)。绿原酸在0.09—0.45μg范围内线性关系良好(r=0.9996),回收率为99.05%(RSD为0.65%)。该方法简便准确,重复性好,处方中其他成分对测定无干扰,可作为本产品的质量控制方法。 相似文献
76.
A rapid and simple near infra red reflectance spectroscopic method was described for determination of anti-diabetic tablets. Partial least squares method was applied to the Savitsky-Golay smoothed first derivative spectral data revealed over wavelength range 1000-2500 nm from 11 different pulverized tablet batches in 2-mm quartz cell. The results were agreed well with those obtained by the official British Pharmacopoiea 1998 UV assay of metformin. 相似文献
77.
A molecularly imprinted solid phase extraction (MISPE) method has been developed for the rapid screening of metformin. Newly synthesized molecularly imprinted polymer (MIP) particles were slurry-packed into a micro-column for selective solid phase extraction (SPE) of metformin. With CH3CN flowing at 0.5 ml/min, a total binding capacity of 1600 ng metformin was determined for the 20 mg of MIP particles. A broad range of MISPE conditions was evaluated with respect to sample solvent, pH, and buffer compositions. A 95±2% binding could be achieved from one 20-μl injection of sample solution in acetonitrile plus phosphate buffer, up to 1200 ng of metformin. However, the micro-column interacted indiscriminately with phenformin, a structural analogue, to attain 49±2% binding. Separation of phenformin from metformin was ultimately achieved, using differential pulsed elution (DPE) with 1 M trifluoromethacrylic acid in acetonitrile. Final pulsed elution (FPE) using 3% trifluoroacetic acid in methanol was good for the quantitative elution of metformin. The MISPE–DPE–FPE method, with UV detection at 240 nm, afforded a detection limit of 0.8 μg/ml (or 16 ng) for metformin. Each MISPE–DPE–FPE analysis required less than 5 min to complete. 相似文献
78.
A multi-pumping flow system for the chemiluminometric determination of the hypoglycaemic drug metformin was implemented. The developed methodology was based on the metformin-induced inhibition (metformin acts as a Cu(II) scavenger) of the catalytic effect of Cu(II) ions on the chemiluminescent reaction between luminol and hydrogen peroxide. The flow manifold configuration was based on the utilisation of multiple solenoid-actuated micro-pumps that were simultaneously accountable for sample/reagent introduction and reaction zone formation/propulsion, thus resulting in a fully automated, simple and highly selective multi-pumping flow system. A versatile sample manipulation allowed the establishment of distinct sampling strategies with low reagent consumption. The characteristic pulsed flow ensured an effective sample/reagent mixing leading to a better and faster reaction zone homogenisation and thus improved analytical signals. Linear calibration plots were obtained for metformin hydrochloride concentrations ranging from 5 to 15 mg L–1 with a relative standard deviation lower than 2.0% (n=5). Detection limit was 0.94 mg L–1, and the sampling rate was about 95 determinations per hour. The developed methodology was applied to the analysis of pharmaceutical formulations and the obtained results were in agreement with those furnished by the reference method with relative percentage deviations of lower than 1.5%. 相似文献
79.
Simultaneous determination of two antidiabetic drugs, metformin and glyburide, in pharmaceutical tablet formulations were investigated. Normal phase thin layer chromatography plate (silica gel 60 F254) was used as stationary phase and water/methanol/ammonium sulfate (2/1/0.5 w/v) as mobile phase to determine two pharmaceutically active ingredients, in three different formulations of Glucovance®. This system gave a good resolution for metformin (R f value of 0.43 ± 0.01) and glyburide (R f value of 0.64 ± 0.02). Determination was by densitometry in the absorbance mode at 237 nm. The linear regression data for the calibration plot showed a good relationship with r = 0.99581 and 0.99982 for metformin and glyburide, respectively. The method was validated for precision and recovery. The limits of detection and quantification were 25.24 and 84.12 ng spot?1 for metformin and 12.26 and 40.86 ng spot?1 for glyburide, respectively. Stability study has been carried out for samples and standard solutions. 相似文献
80.
Jin-long Dong Bin Wen Zhen Song Jie Chai Bin Liu Wen-juan Tian Gang Liang Bin-sheng Yang 《Arabian Journal of Chemistry》2021,14(7):103236
The chromium(III) complex, Cr(C7H3NO4)2·C4H12N5 (1), was synthesised by chelating chromium with dipicolinic (H2dipic) in methanol, and its structure was characterised using elemental analysis (EA), spectroscopy (infrared, UV–visible, and fluorescence) and single-crystal X-ray method. The density functional theoretical (DFT) computation was performed using the Gaussian 09 package. The stability of solution at different temperatures and pH values, the electrochemical, morphological and thermal properties of complex 1 were discussed. The preliminary bioactivities of complex 1 in streptozotocin (STZ)-induced type 2 diabetes mellitus (T2DM) mice were investigated using daily oral gavage for 12 weeks. The cytotoxicity was assessed using the methyl thiazolyl tetrazolium (MTT) assays, and the acute toxicity experiment test was carried out on healthy C57BL/6 mice with this complex. The complex 1 crystallised in the monoclinic system with the space group P2(1)/n, R1 = 0.0642. The DFT-optimised structure of complex 1 was in excellent agreement with the X-ray crystal structure. The complex 1 exhibited good physical and chemical properties and beneficial function on blood glucose and lipid metabolism for T2DM. The antidiabetic activity of chromium(III) might be associated with chromium(VI). Furthermore, the cytotoxicity and the acute toxicity experiments showed that the complex 1 was hypotonic and secure to organism. The study of complex 1 showed that the prepared complex on the basis of H2dipic and Met could inhibit hyperglycaemia and hyperlipidaemia in vivo and did not have potential toxicity. These results demonstrated that the complex 1 might provide an important reference for the development of functional hypoglycaemic foods or pharmaceuticals of T2DM. 相似文献