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《Arabian Journal of Chemistry》2022,15(5):103758
This work suggests a green method for synthesizing Au nanoparticles (AuNPs) using the aqueous extract of Salix aegyptiaca extract. The mechanism of green synthesized AuNPs was examined by molecular electrostatic potential (MEP) calculations. AuNPs were characterized with different techniques such as Ultraviolet–visible spectroscopy (UV–vis), Fourier-transform infrared spectroscopy (FT-IR) spectroscopy, X-ray diffraction (XRD), and Transmission electron microscopy (TEM). Electrochemical investigation of modified glassy carbon electrode using AuNPs (AuNPs/GCE) shows that the electronic transmission rate between the modified electrode and [Fe (CN)6]3?/4? increased. Process of oxidation, energy gap, and chemical reactivity indexes of the (+)-epicatechin (2S,3S) were investigated using electrochemical techniques (cyclic voltammetry (CV) and differential pulse voltammetry (DPV) as well as UV–Visible spectroscopy and compared with quantum mechanical calculations. DPV and CV were used to obtain HOMO energies of the (+)-epicatechin (2S,3S), an optical energy gap was obtained from the UV–Vis spectroscopy. Frontier molecular orbitals analysis (FMO) and reactivity indexes such as chemical hardness (?), electrophilicity (?), electronic chemical potential (μ), electron acceptor power (?+), electron donor power (??) were determined with functional theory (DFT) calculations. In summary, the HOMO energy obtained from the experimental analyses (EHOMO (from DPV) = -5.24 eV, and EHOMO (from CV) = -5.28 eV) has a relative agreement with the HOMO energy calculated by B3LYP/6–31 g (d, p) including the solvent effect (water) (EHOMO (from B3LYP) = -5.75 eV). Also, UV–Vis spectroscopy gives the bandgap energy equal to 4.31 eV, while the 4.13 eV is calculated by TD-DFT-b3lyp/6–31 + g(d). 相似文献
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Two new acyclic diterpene-(-lactones named hanliuine III (1) and hanliuine IV (2) were isolated from leaves of Salix matsudana (Chinese name "hanliu"). Their structures were deduced from spectral data. 相似文献
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Two new acyclic diterpene-γ-lactones named hanliuine(Ⅲ) (1) and hanliunine IV(2) were isolated from leaves of Salix matsudana (Chinese name “hanliu”). Their structures were deduced from spectral data. 相似文献
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柠条、沙柳根与土及土与土界面摩擦特性 总被引:6,自引:2,他引:6
通过直剪试验研究了垂直荷载、土体干密度、土体含水率对柠条根-土界面、沙柳根-土界面以及土-土界面摩擦特性的影响.结果表明:柠条根-土界面、沙柳根-土界面与土-土界面的剪切特性相似,均服从莫尔-库仑理论;柠条根-土界面、沙柳根-土界面的摩擦系数随着土体干密度的增大而增大;土壤含水率对柠条根-土界面、沙柳根-土界面摩擦系数和黏聚力的影响与素土相同,三者的摩擦系数随含水率增加逐渐减小,而黏聚力随着含水率增大呈先增大后减少的变化.在自然生境下主要根系分布层,柠条、沙柳的根-土界面摩擦系数大于土-土界面,尽管根-土界面黏聚力小于土-土界面黏聚力,但是根-土界面的摩擦系数的增大仍使根-土界面抗剪强度大于土-土界面,说明根-土结合面抵抗位移的能力大于土-土界面;2种植物相比,柠条根系抵抗根-土分离的能力优于沙柳. 相似文献
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G. G. Zapesochnaya V. A. Kurkin V. B. Braslavskii N. V. Filatova 《Chemistry of Natural Compounds》2002,38(4):314-318
Column chromatography over silica gel and polyamide was used to isolate 14 phenolic substances from bark of sharp-leaved willow (Salix acutifolia Willd.). These included naringenin, prunin, (-)-salipurposide, (+)-catechin, isosalipurposide, 6-coumarylisosalipurposide, isosalipurpol (flavonoids), triandrin, syringin (phenylpropanoids), and salicyl alcohol (saligenin) and its derivatives acylsaligenin, salicin, salicortin, and tremulacin. Nine of these were isolated for the first time from this species. They were identified using UV, IR, NMR, and mass spectra, chemical transformations, and comparison with authentic samples. 相似文献
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Xiao Liu Yibei Wan Penglei Liu Lei Zhao 《Journal of Dispersion Science and Technology》2019,40(4):507-518
A study on the adsorption of sulfamethazine sodium (SMS) from aqueous solution onto the activated carbon (AC)-based Salix psammophila (SP) by phosphoric acid activation was conducted. The central composite design under response surface methodology was employed for the removal of SMS and the process parameters were optimized. Influence of adsorbent dose, initial concentration of SMS, contact time and solution pH on the adsorption capacity of AC was investigated. The optimum adsorption conditions were obtained using adsorbent dosage of 0.54?g/L, initial concentration of 322?mg/L, contact time of 8?hours, pH value of 4.04. Kinetic studies showed the adsorption followed a pseudo-second-order model and Elovich model. The experimental equilibrium data were fitted Koble-Corrigan model and Freundlich model well and the maximum monolayer adsorption capacity of AC calculated by Langmuir model was 338.58?mg/g at 25?°C. In addition, AC was characterized by the SEM–EDS, BET, FITR and point of zero charge (pHpzc). The mechanisms of SMS sorption onto AC were explored. Desorption and regeneration tests were carried out to evaluate the feasibility of reusing the AC. This study indicated the AC prepared from SP was an excellent adsorbent with the low cost and high performance. 相似文献
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Two new phytane‐type diterpene‐γ‐lactones named Hanliuin III ( 3 ) and Hanliuin IV ( 4 ), together with two previously reported diterpenes, six known flavonoids and five other known compounds were isolated from Salix matsudana. The structures of two new compounds were deduced from spectroscopic methods and 2D NMR techniques. 相似文献