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关键词： 贝壳   净水剂   平衡吸附量   综合实验  

摘要： 设计了一个包含贝壳净水剂的制备、平衡吸附量的计算和不同贝壳净水效果评价的物理化学综合实验。通过开展本实验,学生不仅可以了解重金属污染问题,更可以掌握净水剂的一般制备方法以及通过吸附实验对材料净水效果进行评价的基本手段。本实验可以将课堂学习的理论知识与生活中问题相结合,利用所学的知识解决实际问题,并培养严谨的科学思维和对物理化学学习的兴趣。

关键词： Food systems   affordability   nutrient composition   protein   complementary food  

摘要： Weak market linkages, unavailability of cold-storage, and the significant loss of eggs due to breakage and low shelf-life contribute to the unaffordability and the low consumption of eggs in low-income countries like Ethiopia. The effect of spray- and oven-drying of eggs from local (Ethiopian) and exotic (imported) chicken breeds on physical, techno-functional, and nutritional composition of egg-powders were evaluated. Exotic (n = 150) and local (n = 140) eggs were spray/oven dried. The yield, bulk-density, flowability, and the foaming-, emulsification-, and water/oil absorption-capacity of the egg powders were assessed. The concentrations in energy, protein, fat, ash, and minerals were determined. The egg-powders' contribution to nutrient requirements for a child and their potential use as an alternative protein source in ready to use therapeutic foods (RUTF) were estimated. The low moisture (<5%) and water activity (a(w)similar to 0.4-0.5) of the egg-powders implied unfavorable conditions for microbial growth. Local eggs had higher energy and fat content, whereas protein was higher in the exotic eggs (P <.05). About 12.5 g of egg powder (one egg) can fulfill >75%, 30%, and 40% of fat, energy, and calcium requirements for children 6-23 months of age, respectively. Only 6 g and 4 g of egg-powder are needed to fulfill protein and choline requirements, respectively. Considering the quality/quantity of proteins, egg powders can be alternative protein sources in RUTFs. The drying of local and exotic eggs with oven- and spray-drying yielded egg powders with acceptable techno-functional properties, but future studies should elucidate differences observed by egg type and drying;and investigate the shelf-life. Drying eggs can be a viable food systems' intervention that can improve the safety and quality of diets in low-income countries like Ethiopia.

关键词： Camellia oil   Camellia hainanica   Camellia sinensis   unsaturated fatty acids   vitamin E  

摘要： Woody plants are important source of edible oil, and Camellia hainanica and Camellia sinensis are two new option. The physicochemical properties and fatty acid composition were determined in both species. The oil content of C. hainanica was 37.60-41.60%, and that of C. sinensis was 31.04-33.20%. There were no significant differences in saponification value, refractive index or relative density (P > 0.05). The types of fatty acids were the same in both species, but the composition was significantly different (P < 0.01). Among the nine fatty acids measured, only the concentration of oleic acid was higher in C. hainanica oil than that C. sinensis oil. The contents of vitamin E and total phenols in C. hainanica oil were significantly higher than those in C. sinensis oil (P < 0.01). The higher unsaturated fatty acids, vitamin E, and total phenols, in C. hainanica give it a greater advantage.

关键词： Density   ultrasonic speed   viscosity   gentamicin sulphate   alpha-amino acids   solute-solvent interaction  

摘要： The amino acid-drug interactions have been examined by using measurements of physical properties, such as densities, rho, ultrasonic speeds, u and viscosities, eta of glycine, l-alanine, l-valine and l-isoleucine in aqueous-gentamicin sulphate solvents at the temperatures from 293.15 to 318.15 K with intervals of 5 . K. The rho data are used to calculate the apparent molar properties, V-phi, V-phi degrees, and the transfer volumes, V-phi,V-tr degrees. From the u data, the apparent molar isentropic compressibilities, K-s,K-phi, K-s,K-phi degrees and the transfer cornpressibilities, K-s,K-phi,K-tr degrees have been evaluated. The eta data were used to evaluate Falkenhagen coefficient, A, Jones-Dole coefficient, B. The enthalpies, Delta H degrees(#) and entropies, Delta S degrees(#) and activation parameters, Delta mu(1)degrees(#) and Delta mu(2)degrees(#) of viscous flow were also calculated. The effect of concentration, temperature and solute structure were discussed in terms of solute-solvent and solute-solute interactions prevailing in these systems. The structure making/breaking ability of amino acids has also been examined using temperature derivative of B-coefficient, dB/dT. In addition, the values of V-phi degrees, K-s,K-phi degrees, B and Delta mu(2)degrees(#) have also been split into groups' contributions of the amino acids. (C) 2020 Elsevier B.V. All rights reserved.

关键词： 物理化学   实验室管理   实验技术人员  

摘要： 文章从“物理化学实验室的定位”“实验室制度和安全管理建设”“实验室安全管理建设”“实验室虚拟仿真建设”“实验室管理队伍建设”“实验室管理的可行性措施”6个方面,探讨了物理化学实验室的管理工作现状,提出可行性方案,进一步优化物理化学实验室的科学管理,为教学、科研提供更加优质的平台。

关键词： Biomass combustion   Particulate matter   Soot   Ashes   TEM   XRD   TGA  

摘要： Physical characteristics and quantitative elemental composition of PM and residual ash produced from sugarcane leaves(SCL)combustion were investigated using TEM-EDS compared with forest leaves(FRL).SEM-EDS was used to analyze the microstructure and chemical composition of biomass raw leaves and *** analysis was also performed to investigate the characterization of the crystalline nanostructure,structure of PM,and residual ash compared to the TEM image processing *** oxidation kinetics of biomass raw materials,PM,and residual ash were investigated by *** morphology of fine and ultrafine agglomerate structure of SCL soot and residual ash are not significantly different from the FRL soot and residual *** average diameter sizes of single primary nanoparticles of SCL and FRL soot are approximately 37 nm and 35 nm,while the sizes of residual ash are about 18 nm and 22 nm,*** single primary nanoparticles of soot are mainly composed of curve line crystallites of carbon fringes,while residual ash is composed of straightline lattice *** average fringe lengths of SCL and FRL soot are about 1.25 nm and 1.04 nm from the outer shell and 0.89 nm and 0.74 nm from the inner *** interlayer spacing of curve line carbon fringes of SCL and FRL soot is approximately 0.359 nm and 0.362 nm by the TEM image analysis and it was matched with XRD *** biomass PMs are mainly composed of soot,Si,Ca,and K compounds:SiO_(2),CaCO3,and KCl.

关键词： Dielectric   Physicochemical   Porous composite  

摘要： This paper provides a comprehensive analysis of the dielectric and physicochemical properties of the porous hydroxyapatite/comstarch (HAp/Cs) composites in a new perspective. The porous composites have been characterized via SEM, FTIR, XRD and dielectric spectroscopy. The dielectric permittivity spectra were obtained in Ku-band ( 12.4-18.0 GHz) and it was correlated with the physicochemical properties of the porous HAp/Cs. Porous HAp/Cs composites exhibits low epsilon' and negative epsilon '', which influenced by the microstructural morphology, interaction between Hap and Cs, as well as crystalline features due to the various proportion of the HAp/Cs. The physicochemical effect of the composites results in the dielectric polarization and energy loss. This phenomenon indicates the presence of the three obvious relaxation responses in the epsilon' spectrum (13.2-14.0, 15.2-16.0, and 16.6-17.4 GHz) and the negative behaviours in the epsilon '' spectrum. The relationships between physicochemical and dielectric properties of the porous composite facilitate the development of the non-destructive microwave evaluation test for the porous composite. (C) 2020 Elsevier B.V. All rights reserved.

关键词： 项目式教学   翻转学习   物理化学   表界面现象  

摘要： 根据物理化学教学现状及教学活动中存在问题,展开了全面分析,并提出了项目驱动式翻转学习的教学模式,对课程项目进行了优化设计,有效展开创新型教学活动,结合表界面现象一章的教学内容,用具体教学案例说明这种新型教学模式的具体实施策略。该模式有助于培养学生思维的独立性和学习的自主性,激发学生的学习积极性,使课堂教学的质量和效果得到明显提高。

关键词： Jackfruit seed   Artocarpus heterophyllus   starch   gel   rice   potato   gelatinization   retrogradation  

摘要： The physicochemical properties of jackfruit seed starch (JSS) were investigated and compared with rice (RS) and potato (PS) starch. The amylose content of JSS (25%) was similar to PS (27%) but higher than RS (17%). The small granules of JSS (7.9 mu m) was comparable to RS (9.7 mu m), and both starches had A-type crystallinity. In contrast, PS had larger granules (43.4 mu m) and displayed B-type crystallinity. The DSC results showed that peak gelatinization temperature of JSS (85.0 degrees C) was significantly higher than RS (66.9 degrees C) and PS (63.7 degrees C), corresponding to higher pasting temperatures and lower swelling power at lower temperatures. There was no significant difference in stability between the starch gels after four freeze-thaw cycles. Formation of JSS gels with significantly higher hardness, chewiness and elastic modulus (G '), but lower fracturability demonstrated JSS ability to form strong gels. This would be beneficial for food applications requiring gelation with firm and elastic textural attributes.