教学课程资源库 更多>>

关键词： 物理化学   课程思政   立德树人   道德素质  

摘要： 在教学过程中,传统思想政治课教学对大学生思想品行形成的影响力,课程思政是将思想政治教育融入专业课及专业基础课知识教学过程,是一种全新育人模式。在课程思政的背景下,根据物理化学课程特点,挖掘每一个章节的思政教育元素,将爱国主义、团队协作精神和人与自然和谐相处的生态文明等内容于教于课程知识教学过程中,润物细无声,帮助学生树立科学的价值观和人生观。

关键词： 物理化学实验   基本操作   细节  

摘要： 讨论了几个常见的基本操作细节对实验结果的影响,说明了在物理化学实验教学中注意操作细节的重要性。

关键词： 物理化学   学习方法   学习效果  

摘要： 针对物理化学课程逻辑性、理论性、概念性、系统性都很强的特点,提出了预习、听课和记笔记、做实验、复习、重视习题等五个环节的学习方法体系。掌握科学的物理化学学习方法,可以激发学生学习的主观能动性,培养其逻辑思维能力、安静治学和团队合作的精神,学会用物理化学知识解决具体问题。教学经历证明,上述学习方法可以取得良好的学习效果。

关键词： Algae   Cell disruption   Biofuel   Formic acid assisted extraction   Hydrothermal hydrolysis  

摘要： A one-step process that integrates cell disruption with lipid extraction from wet microalgae was proposed by using n-hexane/formic acid. The scanning electron microscopy showed that raw microalgae cells were completely disrupted. The derivative thermogravimetric analysis indicated that formic acid could lead to a fast-thermal decomposition of microalgae residues at the temperatures ranged from 175 to 280 degrees C. The Fourier transform infrared spectroscopy revealed that the intensities of C=O vibrations increased with an increase of the carbonyl compounds. When microalgae were treated with this mixed solvent at an n-hexane/formic acid ratio of 9:2 (v/v) and an addition dosage of 80 mL/g wet microalgae at 80 degrees C for 2 h, the optimal crude lipid yield was 256.3 mg/g dry weight. A high fatty acid methyl ester (FAME) content of 83.6% was achieved, dominated by palmitic acid, palmitoleic acid, oleic acid, and linoleic acid. Compared with the conventional methods including n-hexane, ethanol, n-hexane/methanol, and chloroform/methanol without pre-treatment, the crude lipid yields increased by 15%-402%. Compared with the chloroform/methanol extraction supplemented by ultrasound, microwave, hydro thermal, and dilute nitric acid pre-treatments, the achieved FAME contents increased by 79%-99%. Additionally, the energy yield from n-hexane/formic acid extraction reached up to 8.55 kJ/g volatile solid. (C) 2020 Published by Elsevier Ltd.

关键词： Physiology   Soils   Oxidation   Functional groups   Minerals  

摘要： Biochar has triggered a black gold rush in environmental studies as a carbon-rich material with well-developed porous structure and tunable functionality. While much attention has been placed on its apparent ability to store carbon in the ground, immobilize soil pollutants, and improve soil fertility, its temporally evolving in situ performance in these roles must not be overlooked. After field application, various environmental factors, such as temperature variations, precipitation events and microbial activities, can lead to its fragmentation, dissolution, and oxidation, thus causing drastic changes to the physicochemical properties. Direct monitoring of biochar-amended soils can provide good evidence of its temporal evolution, but this requires long-term field trials. Various artificial aging methods, such as chemical oxidation, wet-dry cycling and mineral modification, have therefore been designed to mimic natural aging mechanisms. Here we evaluate the science of biochar aging, critically summarize aging-induced changes to biochar properties, and offer a state-of-the-art for artificial aging simulation approaches. In addition, the implications of biochar aging are also considered regarding its potential development and deployment as a soil amendment. We suggest that for improved simulation and prediction, artificial aging methods must shift from qualitative to quantitative approaches. Furthermore, artificial preaging may serve to synthesize engineered biochars for green and sustainable environmental applications.

关键词： 电化学过程   化学计量   物理效应   物理原理   物理化学   化学变化  

摘要： 一、物理化学特性量(physicochemical property quantities)的标准物质,它们的基准,约定基准(标准)化学与物理之间的紧密联系是不言而喻的,因此要完全脱离开物理原理来说明化学运动的规律性是很困难的。例如,电化学过程中,在化学变化的同时伴随有电的物理效应,因此所有电化学的过程也必须服从有关电的一切物理规律性。

关键词： 新工科   逻辑思维能力   物理化学   教学改革  

摘要： 逻辑思维能力培养是新工科背景下教学改革的重要方向。文章探讨了物理化学教学中培养学生逻辑思维能力的基本方法有:巧妙运用形式逻辑和高数思维,灵活运用逻辑结构图,适时穿插逻辑思维方式。教学实践表明,该尝试不仅促进了学生对物理化学知识的理解和掌握,而且强化了学生的逻辑思维能力训练和培养。

关键词： HIV-1 Tat protein   Spectroscopic methods   Conformational changes   Structural stability   Aggregation  

摘要： HIV-1 transactivator of transcription protein is one of the most promising AIDS vaccine candidates and plays central roles in the virus life cycle and pathogenesis. Understanding structural properties of vaccine candidate antigens leads to rational design of vaccines which improves their presentation to immune system and facilitates their manufacturing and storage. This study aims to investigate structural properties and stability of one variant of HIV-1 Tat recombinant protein using different spectroscopic, electrophoretic, and microscopic methods. Therefore, after the gene transformation, protein expression was optimized in E. coli cells and the C-terminal His(6)-tagged protein was purified using Ni-NTA resin. The structural stability of the pure protein was then investigated under different conditions including pH, Zn2+ ions, thermal and chemical stress. Acidic and alkaline pHs affects spectroscopic properties of the vaccine in different ways. The structure unfolding experiment shows relatively poor stability of the zinc-free protein sample compared to the ion-containing one. According to the quenching experiment and also thermal stability study results, the protein has attained more structural compactness in the presence of Zn2+. Secondary structure of the protein is mainly disordered and didn't significantly affect under various conditions. Finally, different degrees of oligomerization and aggregation were found under physiological conditions. (C) 2020 Elsevier B.V. All rights reserved.

关键词： Phthalyl sulfacetamide   Cyclodextrin   Inclusion complex formation   H-1 NMR   Computational modeling  

摘要： Phthalyl sulfacetamide (PSA) is an antibiotic sulfonamide. In this study, inclusion complexes (ICs) of alpha- (alpha CD) and beta-cyclodextrin (beta CD) were prepared in aqueous solution and in solid state with PSA using the ultrasonication (US) process. The structural and thermal characteristics of the US-assisted ICs were investigated by UV-Vis absorption, fluorescence, Fourier transform infrared (FT-IR) spectroscopy, proton nuclear magnetic resonance (H-1 NMR) spectroscopy, differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD) and computational modeling techniques. The improved dissolution of PSA in the presence of CD was confirmed by UV-Vis absorption. The experimental and computational modeling studies proved that the stoichiometry of the Its was 1:1 for PSA/CD-ICs. It was also observed that the IC formation between beta CD and PSA was the strongest when compared to alpha CD host. The enhanced thermal stability of PSA was achieved for PSA/CD-ICs when compared to pure form of PSA. FT-IR, H-1 NMR and computational modeling studies indicated that biologically active sulfonamide group (ring-A) of PSA was encapsulated in the hydrophobic CD cavity. The stability of ICs in terms of energetic, thermodynamic and electronic properties was verified and the PSA/beta CD-IC revealed higher stability compared to that of PSA/alpha CD-IC, as determined by PM3 method. (C) 2020 Elsevier B.V. All rights reserved.