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排序方式: 共有150条查询结果,搜索用时 18 毫秒
1.
Javid T Safarov 《The Journal of chemical thermodynamics》2003,35(12):1929-1937
The (p,ρ,T) and (ps,ρs,Ts) properties of {(1−x)CH3OH + xLiBr} over a wide range of state parameters are reported for the first time. The experiments were carried out in a constant volume piezometer over a temperature range from 298.15 K to 398.15 K, at 0.08421, 0.13617, 0.19692, 0.23133 and 0.26891 mole fractions and from atmospheric pressure up to 60 MPa. The experimental uncertainties are ΔT=±3 mK for temperature, Δp=±5·10−2 MPa for high pressure and Δp=±5·10−4 MPa for atmospheric pressure, Δρ=±3·10−2 kg · m−3 for density. An equation of state was derived for correlation of the experimental data of the solutions. 相似文献
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Azlan Mohd Zain Habibollah HaronSultan Noman Qasem Safian Sharif 《Applied Mathematical Modelling》2012,36(4):1477-1492
Surface roughness is one of the most common performance measurements in machining process and an effective parameter in representing the quality of machined surface. The minimization of the machining performance measurement such as surface roughness (Ra) must be formulated in the standard mathematical model. To predict the minimum Ra value, the process of modeling is taken in this study. The developed model deals with real experimental data of the Ra in the end milling machining process. Two modeling approaches, regression and Artificial Neural Network (ANN), are applied to predict the minimum Ra value. The results show that regression and ANN models have reduced the minimum Ra value of real experimental data by about 1.57% and 1.05%, respectively. 相似文献
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Mansoori Arsalan Zahednezhad Fahimeh Bavili Tabrizi Ahad Shahbazi Mojarrad Javid 《Journal of the Iranian Chemical Society》2020,17(1):89-101
Journal of the Iranian Chemical Society - In the present study, we aimed to optimize the synthesis stages of S-pregabalin ((S)-3-(aminomethyl)-5-methylhexanoic acid), a well-known anticonvulsant... 相似文献
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D. V. Abramov K. S. Khor’kov S. V. Kutrovskaya M. A. A. Noman V. G. Prokoshev 《Bulletin of the Russian Academy of Sciences: Physics》2012,76(6):618-621
The structure of a heterostructures-based semiconductor laser is experimentally investigated by complex means involving systems of scanning electron microscopy, scanning probe microscopy, and Raman spectroscopy. The possibilities of high-resolution microscopy for diagnostics of layered microelectronic systems are demonstrated. 相似文献
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A stability indicating capillary electrophoretic method for separation and determination of cetirizine dihydrochloride and its major impurities in bulk and a tablet dosage form was developed. The electrophoretic separation was performed in an uncoated fused-silica capillary (75 cm × 50 μm i.d.) using 75 mM sodium phosphate (pH 2.8) as background electrolyte, with an applied voltage of +25 kV at 25°C and UV detection at 230 nm. Fexofenadine was used as internal standard. The proposed method was found selective for determination of the main drug and its major impurities. The regression data obtained from the calibration plots indicated linear relationship (r 2 = 0.998) over the concentration range of 40–240 μg/mL of cetirizine. Repeatability and reproducibility of the method, assessed as intra-day and inter-day variation and expressed as RSD (%), were 1.3 and 2.6, respectively. Stress tests on cetirizine under acidic, basic, oxidative and heat incubating at 80°C conditions revealed that no major compound was formed under the applied conditions and the proposed CE method is applicable for stability studies on cetirizine. Then, the method was successfully applied to the determination of cetirizine in bulk and a tablet dosage form. 相似文献
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Mostafa El Khomsi Hamada Imtara Mohammed Kara Anouar Hmamou Amine Assouguem Brahim Bourkhiss Mahmoud Tarayrah Mashail N. AlZain Nurah M. Alzamel Omar Noman Driss Hmouni 《Molecules (Basel, Switzerland)》2022,27(2)
Anchusa italica Retz has been used for a long time in phytotherapy. The aim of the present study was to determine the antioxidant and antibacterial activities of extracts from the leaves and roots of Anchusa italica Retz. We first determined the content of phenolic compounds and flavonoids using Folin–Ciocalteu reagents and aluminum chloride (AlCl3). The antioxidant activity was determined using three methods: reducing power (FRAP), 2.2-diphenyl-1-picrylhydrazyl (DPPH), total antioxidant capacity (TAC). The antimicrobial activity was investigated against four strains of Escherichia coli, two strains of Klebsiella pneumoniae and coagulase-negative Staphylococcus, and one fungal strain of Candida albicans. The results showed that the root extract was rich in polyphenols (43.29 mg GAE/g extract), while the leave extract was rich in flavonoids (28.88 mg QE/g extract). The FRAP assay showed a strong iron reduction capacity for the root extract (IC50 of 0.11 µg/mL) in comparison to ascorbic acid (IC50 of 0.121 µg/mL). The DPPH test determined an IC50 of 0.11 µg/mL for the root extract and an IC50 of 0.14 µg/mL for the leaf extract. These values are low compared to those for ascorbic acid (IC50 of 0.16 µg/mL) and BHT (IC50 0.20 µg/mL). The TAC values of the leaf and root extracts were 0.51 and 0.98 mg AAE/g extract, respectively. In vitro, the extract showed inhibitory activity against all strains studied, with diameters of zones of inhibition in the range of 11.00–16.00 mm for the root extract and 11.67–14.33 mm for the leaf extract. The minimum inhibitory concentration was recorded for the leaf extract against E. coli (ATB:57), corresponding to 5 mg/mL. Overall, this research indicates that the extracts of Anchusa italica Retz roots and leaves exert significant antioxidant and antibacterial activities, probably because of the high content of flavonoids and polyphenols. 相似文献
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In this paper, we extend the notion of common property (E.A) to pairs of hybrid mappings defined on an arbitrary set with values in a semi-metric space and use it to prove some coincidence and common fixed point theorems in semi-metric (potent semi-metric) spaces under strict contractions. Our results generalize several previously known fixed point theorems of the existing literature. 相似文献