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181.
利用聚乙二醇(PEG 1500)引发乙交酯和D,L-丙交酯开环共聚合制备聚丙交酯乙交酯(PLGA)三嵌段共聚物(PLGA-PEG-PLGA)温敏水凝胶材料,并通过核磁共振氢谱(1H NMR)确定产物的结构及组成.应用倒置小瓶法测量得到不同浓度下PLGA-PEG-PLGA水凝胶的溶胶-凝胶相变温度为27~32℃.此外,体外降解实验及细胞毒性实验结果表明,质量分数为25%的水凝胶有满意的降解速度及良好的生物相容性.同时,利用紫外-可见光谱分析了载万古霉素水凝胶的体外药物释放行为,结果表明,万古霉素可以持续释放12 d.抗菌实验结果表明,载万古霉素水凝胶具有良好的抗菌效果.表明PLGA-PEG-PLGA三嵌段温敏水凝胶是一种较理想的万古霉素缓释载体,具有良好的临床应用前景. 相似文献
182.
汽油馏分的硫化物形态分布研究 总被引:7,自引:0,他引:7
采用气相色谱和硫化学发光检测(GC-SCD)技术,经过对色谱条件的优化,建立了汽油馏分中硫化物形态分布的测定方法。用标准物质的保留时间辅以化学法脱除硫醇、硫醚的方法对107个硫化物进行了定性;标准硫化物保留时间重复测定结果的相对标准偏差(RSD)≤0.25%。用内标法对主要的硫化物和总硫含量进行了定量,方法的加标回收率为96%~115%;同一样品重复测定5次,含硫大于7 mg/kg的硫化物组分重复测定结果的RSD≤8.9%。所建立的方法可用于不同装置的汽油馏分的硫化物形态分布规律的研究。 相似文献
183.
Wang Sufang Zheng Jiwen Liu Guoxing Chen Keliang Bat Xingping Zheng Pingzi Zhang Huanqiao Xu Jincheng Liu Zuhua Ruan Ming LV Jun Xu Kan 《中国物理C(英文版)》1994,18(1):6-12
The complete fusion excitation function for the 16O+natS reaction has been measured in the range of 50-75 MeV with a step of 1.0MeV by using 1a position sensitive △E-E telescope system. The model parameters have been extracted from data analysis.The striking gross structure of the excitation function has been observed. The energies of peaks are at ECM=38,43 and 48 MeV respectively. 相似文献
184.
Wu Jinyi Sun Dongke Wang Jincheng Zhu Mingfang 《The European physical journal. E, Soft matter》2020,43(5):1-12
The European Physical Journal E - Fluctuating viscoelasticity for conformation-tensor-based models is studied at equilibrium, in simple-shear deformation, and in uniaxial extension. The models... 相似文献
185.
Two decades ago, standard quantum mechanics entered into a new territory called space-fractional quantum mechanics, in which wave dynamics and effects are described by the fractional Schrödinger equation. Such territory is now a key and hot topic in diverse branches of physics, particularly in optics driven by the recent theoretical proposal for emulating the fractional Schrödinger equation. However, the light-wave propagation in saturable nonlinear media with space fractional derivatives is yet to be clearly disclosed. Here, such nonlinear optics phenomenon is theoretically investigated based on the nonlinear fractional Schrödinger equation with nonlinear lattices—periodic distributions of either focusing cubic (Kerr) or quintic saturable nonlinearities—and the existence and evolution of localized wave structures allowed by the model are addressed. The model upholds two kinds of one-dimensional soliton families, including fundamental solitons (single peak) and higher-order solitonic structures consisting of two-hump solitons (in-phase) and dipole ones (anti-phase). Notably, the dipole solitons can be robust stable physical objects localized merely within a single well of the nonlinear lattices—previously thought impossible. Linear-stability analysis and direct simulations are executed for both soliton families, and their stability regions are acquired. The predicted solutions can be readily observed in optical experiments and beyond. 相似文献
186.
187.
ß‐Ga2O3 Nanorod Synthesis with a One‐step Microwave Irradiation Hydrothermal Method and its Efficient Photocatalytic Degradation for Perfluorooctanoic Acid 下载免费PDF全文
Baoxiu Zhao Xiang Li Long Yang Fen Wang Jincheng Li Wenxiang Xia Weijiang Li Li Zhou Colin Zhao 《Photochemistry and photobiology》2015,91(1):42-47
ß‐Ga2O3 nanorod was first directly prepared by the microwave irradiation hydrothermal way without any subsequent heat treatments, and its characterizations were analyzed by X‐ray diffraction (XRD), scanning electron microscope (SEM), high‐resolution transmission electron microscope (HRTEM), UV–Vis diffuse reflection spectroscopy techniques, and also its photocatalytic degradation for perfluorooctanoic acid (PFOA) was investigated. XRD patterns revealed that ß‐Ga2O3 crystallization increased with the enhancement of microwave power and the adding of active carbon (AC). PFOA, as an environmental and persistent pollutant, is hard decomposed by hydroxyl radicals (HO·); however, it is facilely destroyed by ß‐Ga2O3 photocatalytic reaction in an anaerobic atmosphere. The important factors such as pH, ß‐Ga2O3 dosage and bubbling atmosphere were researched, and the degradation and defluorination was 98.8% and 56.2%, respectively. Reductive atmosphere reveals that photoinduced electron may be the major reactant for PFOA. Furthermore, the degradation kinetics for PFOA was simulated and constant and half‐life was calculated, respectively. 相似文献
188.
189.
OsO4⋅Streptavidin: A Tunable Hybrid Catalyst for the Enantioselective cis‐Dihydroxylation of Olefins
190.
An efficient catalytic system has been developed for the synthesis of unsymmetrical substituted alkynes via the thiosemicarbazone salicylaldiminato palladium(II)-catalyzed alkynylation couplings between arylboronic acids and alkynes or alkynyl carboxylic acids under mild conditions. 相似文献