教学课程资源库 更多>>

关键词： 材料类专业   物理化学   教学改革  

摘要： 结合材料物理化学学科特点以及其在人才培养中的重要的地位与作用,本文立足于应用型本科人才培养要求,结合教学实践,对材料专业的物理化学课程的教学改革进行了初步探索,以期达到契合专业需求、激发学生学习兴趣、改善教学效果的目的。

关键词： Physicochemical model   Equivalent circuit model   Lead-acid battery  

摘要： Lead-acid batteries with the largest markets among all kinds of batteries have advantages of mature technology, low price, good high/low temperature stability, high reliability, high safety and convenient maintenance. Improving their performance such as energy density and cyclability is still active research topic. In this paper, a new modeling method for lead-acid batteries through combining the physico-chemical model with the equivalent circuit model has been developed, which can broaden the appli-cation of the two models. The physicochemical model is used to replace the parameter identification experiment of the equivalent circuit model, which reduces the experimental cost. The physicochemical model is used to replace the calculation module of the electromotive force and the state of charge of the circuit model, which simplifies the equivalent circuit model and reduces its calculation time. A new empirical formula of equivalent circuit parameter is proposed based on the physicochemical model, the average relative error of the simulation results is reduced significantly. The results suggest that this paper's approach can be used for performance prediction and optimization of lead-acid batteries. (C) 2020 Elsevier Ltd. All rights reserved.

关键词： environmental gradients   Lake Victoria   nutrients   Nyanza Gulf   water quality  

摘要： Many large lake ecosystems are experiencing increasing eutrophication and persistent cyanobacteria-dominated algal blooms affecting their water quality and ecosystem productivity because of widespread non-point and point nutrient sources. Accordingly, the present study utilized data of July 2003 and January–February 2004, as well as previous measurements of nutrients and physico-chemical variables (electrical conductivity, dissolved oxygen, temperature, pH, turbidity and chlorophyll-a), to characterize the spatial and temporal trends, as a means of better understanding the factors influencing lake environmental conditions, as support tools for long-term ecosystem management and for better understanding the long-term trends and effects. Inshore gulf areas were found to represent zones of maximum nutrient concentrations, compared to the deep main lake zones, with significant inter-parameter correlations. Phosphorus, silicon and chlorophyll-a concentrations were significantly correlated. Water electrical conductivity was also significantly and positively correlated with soluble reactive silicon (SRSi), alkalinity hardness DO, while exhibiting a negative association with water transparency. Water turbidity and transparency, electrical conductivity, and SRSi concentrations clearly describe a gradient from the gulf into the main lake. For such a shallow gulf, these findings suggest primary productivity is influenced mainly by the availability of nutrients, light transparency and the extent of availability of resuspended nutrients. The increasing eutrophic state of Lake Victoria is a serious concern since it contributes to an increased potential of more frequent occurrences of cyanobacterial blooms, a potential public health risk to both humans and wildlife. Improved understanding of influences from previous fish species introductions and concomitant changes in indigenous fish species, increased lake basin population and anthropogenic activities, water hyacinth resurgences

关键词： 物理化学   教学模式   翻转课堂   对分课堂  

摘要： 在当今高等教育创新人才培养要求下,结合国内外教育先进技术方法,通过物理化学教学实践,探索了讲授课堂、翻转课堂、对分课堂等3种教学模式,教学实效性结果表明,开放式的教学更利于提高教学质量,对分课堂教学模式更适合于我校学生学习物理化学。

关键词： Multi-walled carbon nanotubes   cytotoxicity   macrophages   gene expression profiles   nanomaterials  

摘要： Multi-walled carbon nanotubes (MWCNTs) have industrial applications in the nanotechnology field. The physico-chemical properties of MWCNTs vary greatly depending on MWCNT manufacture and application. It has been pointed out that their needle shape and high durability are important factors that determine the biopersistence of fibers and can lead to inhalation toxicity or cytotoxicity. In this study, we prepared six suspensions of MWCNTs differing in diameter and length, and performedin vitrocell-based assays for 24 h using NR8383 rat alveolar macrophages. Rigid, needle-shaped MWCNTs with a large diameter (>50 mu m) penetrated the cytoplasm and decreased cell survival without generating intracellular reactive oxygen species (ROS), significantly up-regulated many genes involved in inflammatory responses, response to oxidative stress and apoptosis, and extracellular matrix degradation. Bent MWCNTs with a small diameter (<20 mu m) were phagocytosed in vacuole-like cellular compartments and decreased cell survival along with intracellular ROS generation. Straight, thin MWCNTs with a small diameter (<20 mu m) caused a slight intracellular ROS generation but no decrease in cell viability. Some straight, long, and thin MWCNTs were found in the mitochondria and near the nuclei;however, no mutagenesis was observed. Thein vitrocell-based assays showed high cytotoxicity of MWCNTs with a large diameter (>50 mu m), moderate and low cytotoxicity of MWCNTs with a small diameter (<20 mu m). These results suggested that the diameter of MWCNTs considerably contributes to their cytotoxicity.

关键词： Aminated graphitic green adsorbent   Agro-waste/biomass material   Adsorption   Box-Behnken design (BBD)   Wastewater treatment   Tetracycline  

摘要： There is an urgent demand to abate contamination of the water resources and wastewaters from antibiotics, released predominately from the municipal and healthcare effluents. Herein, we modified an eco-friendly and renewable agro-waste/biomass material in order to obtain an efficient adsorbent against the antibiotic tetracycline hydrochloride (TC). Corn stover biomass was thermally converted to porous reduced graphite oxide (RGO) and then was post functionalized to an aminated graphitic carbonaceous material (ACS-RGO). The materials were characterized by nitrogen adsorption/desorption, scanning electron microscopy (SEM), transmission electron microscope (TEM), as well as Raman and FTIR spectroscopy. The sorption process was statistically modeled, by systematically varying crucial factors, based on Box-Behnken design (BBD). The model analysis illustrated the effect of independent variables and their correlations in order to determine the optimum parameters/conditions. The highest TC removal (100%) was found to occur for initial TC concentration of 48.74 mg/L, 0.98 gL dosage of adsorbent, 51.6 min contact time and at pH 7.4. The maximum monolayer adsorption capacity estimated to be 132.9 mg of TC per gram of ACS-RGO. (C) 2020 Elsevier B.V. All rights reserved.

关键词： 翻转学习   案例教学   物理化学   创新应用能力  

摘要： 结合我校应用型人才培养方案和培养目标,通过改革物理化学课堂教学提高学生知识掌握能力和应用能力。在传统课堂的基础上,将案例教学结合在翻转学习的教学过程中,充分提高学生的学习积极性与主动性。以稀溶液的依数性为教学案例,阐述翻转学习与案例教学的实施过程。学生深度参与课堂、融入课堂并互动,师生之间在教学中达到共鸣,实现教学相长,从而提高物理化学教学质量。

关键词： 物理化学   慕课   特色   反思  

摘要： “物理化学”是化学专业的重要基础课程,知识体系繁杂。“物理化学(1)”慕课立足上册教材内容,自2019年9月在安徽省网络课程中心平台上线,已经开课两个周期。本文对学生的MOOC学习效果进行了评价,从三个方面总结了建设特色,厘清了后期建设思路,为相关学科课程建设提供一定的借鉴。

关键词： 物理化学实验   线上线下一体化   一流课程  

摘要： 为满足物理化学一流课程建设的需求,培养创新型和应用型人才,将现代信息技术与物理化学实验教学相融合,建立线上线下一体化的实验课程势在必行。充分利用线上资源,做好线上线下课程的有机衔接,能够发挥学生的主体作用,激发学生的学习兴趣和探索求知的热情,提升高校实验教学水平和人才培养质量。

关键词： 物理化学   线上教学   以学生为中心  

摘要： 物理化学课程是化学工程与工艺、能源化学工程等专业的基础课程。本文以东莞理工学院“物理化学”课程为例,结合线上教学的特点,就如何上好物理化学课程进行了简要的探讨,获得的经验对于物理化学教学有一定的借鉴意义。