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关键词： 物理化学实验   LBL教学模式   TBL教学模式   两级组长制  

摘要： 在物理化学实验课程中实施LBL和TBL混合模式教学全覆盖,在教学过程中教师更加注重教学设计,实现老实验新做、基础实验综合化,使教学实施更加有效,教学质量持续提升。通过"两级组长制"设置充分发挥学生的主体作用。以蔗糖水解反应的速率常数测定实验为例具体展示了LBL及TBL组合教学模式在物理化学实验中的实施效果。实践表明,LBL和TBL组合教学模式下,学生既夯实了专业技能,同时其主观能动性、团队责任意识、沟通协调能力等综合技能均得到显著提升。

关键词： Drying   Pectin   Rheology   Emulsifying properties   Antioxidant activity  

摘要： This work investigates the effect of drying okra pods by different techniques [freeze-drying (FD), sun-drying (SD), oven-drying (OD) and microwave-drying (MD)] on the molecular structure, physicochemical and antioxidant properties of the subsequently extracted OP. Remarkably, although the degree of methyl esterification (similar to 41.1 %) remained similar among samples, the content of galacturonic acid (62.67-68.77 %), average number molecular weight (MnI: 758.8-808.5 kDa, MnII: 20.9-24.2 kDa), and to a greater extent the apparent viscosity of an aqueous solution of pectin molecules, water holding capacity (0.21-10.71 g/g) and emulsifying activity (42.3-72.7 %) and stability (38.6-53.5 %), decreased with the drying temperature in the order of FD-OP > SD-OP > OD-OP > MD-OP. On the other hand, only FD-OP presented a higher proportion of galactan and/or arabinan side chains [(Ara+ Gal) / Rha = 12.37%] compared to the rest of the samples, with values ranging from 7.79 to 9.17%. FD-OP and SD-OP resulted in lower DPPH and ABTS radical scavenging activities.

关键词： 超星学习通   物理化学   混合式教学  

摘要： 以发挥学生的积极主动性,提高学生的学习效率为目标,利用物理化学在超星平台的教学探索为例,旨在调动学生的主观能动性,提高学生的学习效率及物理化学的教学质量和效果。

关键词： 物化化学实验   网络教学   虚拟实验  

摘要： 物理化学的网络实验教学具有特有的时空灵活性和高效性,有利于提高实验教学质量和学生的学习兴趣,但其弊端在于虚拟实验其无法代替真实的实验环境与真实操作,不利于学生动手能力与实验能力的提高.因此,物理化学实验教学改革的方向应是网络教学与真实实验操作的结合,二者的相互补充将大大促进物理化学实验教学的改进与提高.

关键词： 物理化学   纳米金属粉   HMX   催化分解   纳米钛粉   纳米锆粉  

摘要： 为了获得纳米级金属粉对HMX热分解的催化作用及分解动力学的影响规律,采用差示扫描量热法(DSC)、热重法(TG)研究了普通级和纳米级金属钛粉、锆粉与HMX混合体系的热分解,采用等温热重法研究了上述混合体系的分解动力学。结果表明,纳米级金属粉使HMX在固相的热分解提前,HMX/金属粉质量比为2∶1时,纳米钛粉和纳米锆粉分别使HMX固相起始分解温度降低了3.9℃和3.0℃,使HMX固相分解比例由0.5%分别增至18.3%和4.6%;HMX在固相的分解深度随纳米金属粉含量增加而增加;HMX/金属粉混合体系固相初期分解反应机理函数均为成核和生长(n=1)的Avrami-Erofeyev方程,钛粉显著降低了HMX固相分解的表观活化能和指前因子,提高了以反应速率常数之比表示的催化分解系数,缩短了分解时间;HMX/纳米钛粉质量比5∶1混合体系的等温分解表观活化能Ea为138.9kJ/mol,指前因子ln(A/s^-1)为25.47;此外,还发现金属粉/HMX混合体系、金属氧化物/HMX混合体系、各种相态单质HMX的动力学参数有同一“动力学补偿效应”关系。

关键词： Chromium(III) complex   5-Aminopyridine-2-carboxylic acid   Oligomerization   2-Chloro-2-propen-1-ol   Crystal structure  

摘要： This publication presents a new chromium(III) complex with 5-aminopyridine-2-carboxylate anions. The title compound was characterized by single-crystal X-ray diffraction analysis, potentiometric and con-ductometric titrations. The oligomerization reaction of the 2-chloro-2-propen-1-ol alcohol was carried out using the title complex as a catalyst for the reaction. The resulting product was examined by MALDI-TOF MS and infrared spectroscopy. The catalytic activity of the complex in the oligomerization reaction of 2-chloro-2-propen-1-ol was determined. (C) 2020 Elsevier Ltd. All rights reserved.

关键词： Insulin  

摘要： Lanthanide nanoparticles and nanorods especially their biocompatible oxide forms like cerium oxide nanopartides (CNPs) with therapeutic applications are used to cure neurological oxidative stresses. Thus it tempts to study their biocompatible aspects by interactions with several biologically significant molecules. In-Vitro interactions of 15-240 mu M CNPs with water, Phosphate buffered saline (PBS), DMEM media, Insulin (Ins) hemoglobin (Hb) and ds-DNA at 37 degrees C were studied. Their physicochemical properties study by Borosil Mansingh Survismeter (BMS) showed the first order interaction with the protein-protein structure breaking behaviour of CNPs with Hb, Ins, and DNA. Zeta potential measurements of CNPs in different biological medium show a net increase in negative charge magnitude with good colloidal stability. K-b = 4 x 106 mM(-1) of CNPs DNA infer noncovalent interactions. Circular dichroism and FTIR revealed a loss of secondary conformation with increasing CNPs concentration. In-silico molecular docking depicts CNP interaction via conventional hydrogen bonding, carbon hydrogen bonding and electrostatic interactions at the minor groove of DNA. The study reports in-dept unfolding functional mechanism investigated by physicochemical, spectroscopic. and In-Silico approaches of protein on interactions with CNPs for safer-by-design use in medicine and pharmaceutics. Fundamentally the CeO2 in similar to 62% and Ce2O3 in similar to 38% with Ce4+ and Ce3+ oxidation potentials develop a unique case of electronic configurations with 4f(0)5d(0)6s(0) and 4f(1)5d(0)6s(0) electrons respectively which these studies a novel one. (C) 2020 Published by Elsevier B.V.

关键词： 物理化学   相分离   剪切力   食用油  

摘要： 食用油滴在水中,由于油的强疏水性,两者会完全分离成两个独立的液态相:油相和水相,即使强烈震荡,两相依然互不相溶,只会使油在剪切力的作用下打散成为无数近乎完美球形的小油滴悬浮于水中,这是已经研究了上百年的物理化学领域中的“相分离”现象。

关键词： Starch lecithin complexes   Physicochemical properties   Digestibility  

摘要： The objective of this study was to investigate the physicochemical properties and in vitro digestibility of lotus seed starch-ledthin indusion complexes (ICs), prepared by dynamic high pressure homogenization. Raman spectrometry indicated that the IC formed between starch and lecithin, compared with the control mixture. could modify the helix rearrangement between different amylose conformations, to promote the formation of an ordered and stable V-type conformation. The content of amylose single helix appeared to be an important factor in the formation of starch-lipid complexes. Dispersion stability and solubility determinations indicated that the effect of mixing lecithin with starch mainly focused on the dispersion stability and not the solubility of starch emulsions. ICs with a V-type conformation, formed by homogenization of lecithin and amylose. achieved the same, or better emulsion stability as mixed lecithin, and the formation of ICs reduced the affinity of starch chains for water molecules, lowering their solubility. Digestion analysis suggested that the higher proportion of micro-crystalline region in V-6I complexes, resulted in a lower digestion rate and a higher resistant starch (RS) content. (C) 2020 Elsevier B.V. All rights reserved.

关键词： 科学研究   物理化学   教学质量  

摘要： 分析物理化学教学现状,探讨将科学研究与物理化学教学有机融合的教学模式,初步培养学生创新意识和科研素养,激发学生学习兴趣,有效提升物理化学教学质量。