无机化学课程中6s2惰性电子对效应教学实践与体会

在无机化学6s~2惰性电子对效应教学过程中,提出"理论性、直观性和规律性"教学三原则,使学生在较为轻松的氛围中理解和掌握该概念,成功化解了教学过程中知识点分散、学习难度大与学生理解力间存在的差距。同时,培养了学生综合归纳和发现问题、解决问题的能力,使大一新生感受到大学化学知识的系统性,对解决问题方法的学习及能力培养的重要性。     

立体化学教学中不对称催化科研成果的融入

在基础有机化学教学中引入不对称催化的概念和科研成果,可将立体化学融入贯穿到有机化学课程的章节教学中,丰富立体化学的教学内容。通过对知识点的串联解析使学生了解不对称催化反应,从而逐步加深对立体化学的理解。组织相关研究方向的学术专题报告和科研实践,不仅有助于巩固相关理论知识,还可以让学生在知识熏陶和实验实践中培养自身的学术素养和科研能力,提高学习热情和积极性。     

核心素养视域下化学学科知识的教学困境及消解策略

目前教育正在迈入核心素养的时代。核心素养为本的知识教学引发了很多教师的不适。需要对课堂教学与知识教学、核心素养和知识教学等关系进行梳理和理解。结合“金属钠及其化合物”内容,阐述了化学教学中存在的知识教学困境主要包括:知识点选择困境、包含知识的情境选择困境和训练反馈练习选择困境。提出教学困境的消解策略有:选择具有培养学生关键能力和必备品格的核心知识;创造出有利于知识学习的教学情境;充分发挥知识学习过程的引领作用和构建以促进学生意义启迪旨趣的知识教学。     

学科能力视域下的初中化学命题评价研究——以阶段性学业水平测试为例

化学学科能力是核心素养的重要组成部分,包括学习理解能力、应用实践能力和迁移创新能力.依据初中化学学科核心素养和关键能力的评价模型,对区域初中化学阶段性学业水平测试进行命题评价研究,分析统计了学科能力的占比、得分率以及与5大主题知识点的匹配情况,并从学科认识方式考查的角度对例题进行分析阐述.针对学生部分层级能力表现欠佳等...     

探究性学习中生成性资源的应用

以课堂演示实验中产生的一次纰漏为契机,展开探究性学习,探究实验室制乙烯中的主要副产物,从而使学生既掌握了相关知识点,又培养了学生的逻辑思维能力和实验分析能力。     

以核心素养为导向的聚合反应工程教学探讨——以“理想混合反应器的热稳定性”为例

在核心素养理念下,以聚合反应工程教材中的"理想混合反应器的热稳定性"小节教学设计为例,挖掘工程学科教学过程中蕴含的教育价值。通过对热稳定性原理的解析、探讨,以及对工业中热稳定性实例的分析,引导学生以工程科学思维去认识原理性概念;以探讨问题为驱动,进行探究式学习,培养学生工程问题意识和实践应用能力;在课程教学过程中落实大学生核心素养的培养和发展。     

科学问题驱动核心知识点的串联理解及综合应用——结构化学专业课

通过设计有效的科学问题,学生运用计算化学的技术获得相应的数据资料,并利用结构化学学到的理论知识对数据进行分析、归纳和总结,进而阐明科学问题,实现科学问题驱动结构化学核心知识点的串联理解。通过这种方式,学生能够进行深度和追求理解的学习,极大地提高学生分析及论证能力和他们的学科素养。     

高职基础化学实训实施“项目化教学”的实践与探索

在高职基础化学实训教学改革中对项目化教学模式的应用进行了探索与实践,通过对基础化学实训内容的创新与重构,采用"理一实一体"的教学方式,构建了新型的教学评价模式,学生的综合职业能力得到显著提升,取得满意的教学效果。教改实践表明:项目化教学模式能够有效地激发学生的学习兴趣和自觉性,培养学生良好的职业素养和学习行为习惯,充分体现了"以能力为本位"的现代职业教育理念。对项目化教学模式的探索将是一个很有价值的创新型实践过程。     

基于结构性思维的生物化学实验教学探索

为了多维度地培养学生的实践创新能力、终身学习能力及信息获取能力等核心素养,以具体实验为例,探讨结构性思维在生物化学实验教学中的综合应用。教学实践表明：结构性思维可使知识更有序、梯度更明确、更易表达,实验操作变得程序化,学生学习倾向主动,是一种多维度地培养学生核心素养的教学模式。     

Materials Studio和Matlab等软件在化学动力学教学中的应用

在化学动力学讲授中应用Materials Studio和Matlab等软件对过渡态理论及稳态近似法等相关知识点进行辅助教学,使抽象的化学理论变得形象、简单。这有利于培养学生的形象思维能力,提高了课堂教学效果,激发了学生对物理化学课程的学习兴趣。     

妙用思维导图 学好大学化学

This paper introduces the production methods, production ideas and production steps of the "College Chemistry" mind mapping. We discuss the specific presentation of how the mind mapping is used in the various chapters of "College Chemistry" and how to use the mind mapping to learn about "College Chemistry". With the mind mapping in "College Chemistry", students' mastery of knowledge has been significantly improved, the learning initiative has been enhanced, and the learning efficiency, in particular, students' ability to summarize has been improved.     

Hen egg white fractionation by ion-exchange chromatography

Major hen egg white proteins have been widely studied for their functional properties but these studies still are unable to explain, alone, all of the biological properties of hen egg white. Hence, it is still interesting to produce pure and non-altered proteins to improve our knowledge on the biological properties of hen egg white. Presently, identification and characterization of both bioactive peptides and minor proteins from hen egg white is essential work for progressing in the understanding of hen egg white biological properties. With this objective in mind, a new process for a complete "mucin free" hen egg white fractionation based on ion exchange chromatography is proposed. "Mucin free" egg white is fractionated into six different fractions. Four of them are high-recovery yield purified fractions of lysozyme, ovotransferrin, ovalbumin and flavoprotein. The two other fractions are enriched in recently detected minor proteins in hen egg white.     

可调移动重叠分离图法用于高效液相色谱多台阶梯度分离条件优化的研究

计算机辅助高效液相色谱（HPLC）分离条件优化可以低成本、快速地得到优化的分离条,因而已较为广泛地用于复杂样品的分离分析。基于移动重叠分离图方法,又发展了一种新型的多台阶梯度分离条件的优化方法可调移动重叠分离图法。该方法通过预测不同流动相条件下各组分的保留时间、峰宽和分离度,绘制出对于样品中各组分的重叠分离区域图。在对当前台阶流动相组成进行优化的同时,考虑其对后面一到两个台阶上流出组分保留的影响,实时地重新绘制对于后面台阶上流出组分的重叠分离区域图。通过观察当前台阶流动相条件对当前台阶和后面台阶上流出组分分离的影响,综合考虑样品中所有组分的分离情况,找到更接近全局最优的分离条件。通过扫描的方法对优化得到的分离条件进行微调,能够进一步提高分离效果。采用文献数据对可调移动重叠分离图法的应用加以说明,在二元流动相体系下,证明了该方法在HPLC方法建立方面的优越性。     

Chaoticity of some chemical attractors: a computer assisted proof

In this paper we study dynamics of two chemical attractors. By means of computer assisted proof, we show that these chemical attractors are chaotic in terms of positive entropy. We prove that the fourth power of the Poincaré map derived from one chemical attractor and the second power of the Poincaré map derived from the other chemical attractor are semi-conjugate to the 2-shift map, therefore the entropies of the two Poincaré maps are not less than log 2 and log 2, respectively. The positivity of entropies of these two maps shows that the corresponding attractors are chaotic.AMS subject classification: 34D15, 34D35, 37C10     

On graphical and numerical characterization of proteomics maps

We outlined a mathematical approach suitable for characterization of experimental data given by 2-D densitograms. In particular we consider numerical characterization of proteomics maps. The basis of our approach is to order "spots" of a 2-D map and assign them unique labels (that in general will depend on the criteria used for ordering). In this way a map is "translated" into a sequence. In the next step one associates with the generated sequence a geometrical path and views such a path as a mathematical object that needs characterization. We have ordered spots representing proteins in 2-D gel plates according to their relative intensities which results in a zigzag path that produces a complicated "fingerprint" pattern. Mathematical characterization of zigzag pattern follows similar mathematical characterizations of embedded patterns based on matrices, the elements of which are given as quotients of Euclidean distance between spots and the distance along the zigzag path. The leading eigenvalue of constructed matrices is taken to represent characterization of the original 2-D map. Comparison of different 2-D maps (simulated by using random generator) allows one to construct partial order, which although qualitative in nature gives some insight into perturbation induced by foreign agents to the proteome of the control cell.     

增强无机化学教学的趣味性策略的案例研究

针对无机化学的理论知识学习的"枯燥",提出无机化学教学趣味性的三大增强策略,一是设定情境,让"枯燥"的知识生动起来;二是善用比喻,让"困难"的知识有趣起来;三是自创"小诗",让"复杂"的知识幽默起来。通过实践,三大增强策略的效果很好,值得广泛推广。     

Relative hydrophobicity/hydrophilicity of fructose, glucose, sucrose, and trehalose as probed by 1-propanol: a differential approach in solution thermodynamics

Earlier, we developed the 1-propanol probing methodology that could separately evaluate the relative hydrophobicity and hydrophilicity scale of a given sample. We applied it here to fructose, glucose, sucrose, and trehalose and evaluated the same for these saccharides. We then construct a two-dimensional map with the hydrophobicity and the hydrophilicity axes and plot the above saccharides together with other nonelectrolytes subjected earlier to the same analysis. We point out that these saccharides together with other so-called "osmolytes" that accumulate in vivo under H2O stress occupy a small specific region near H2O in this map.     

pH-dependence of 31P-NMR spectroscopic parameters of monofluorophosphate, phosphate, hypophosphate, phosphonate, phosphinate and their dimers and trimers

³¹P-NMR chemical shifts and coupling constants of nine inorganic phosphorus compounds composed of different structural units or oxidation numbers P^V, P^IV, P^III, and P^I were measured in the pH-range 3 11. A concise map of NMR data providing the pH-dependence of the chemical shift (-pH map) was set up to be used for identifying phosphorus compounds under varying pH-conditions. Chemical shifts of monofluorophosphate, as well as most phosphorus compounds of oxidation numbers 5 and 4, were greatly dependent on pH, in contrast to the less or negligible pH-dependence of phosphorus compounds of oxidation numbers 1 and 3. Monofluorophosphate gave the parameters: =+1.3±0.2 ppm and ¹J_PF=870±0.2 Hz, that remained unchanged at pH>6, but varied at pH<6. The practical use of the -pH map was shown with a few kinetic experiments in which monofluorophosphate was enzymatically hydrolyzed by alkaline phosphatase (EC3.1.3.1) at pH 7.2 and non-enzymatically at pH 3.     

Formulation–composition map of a lecithin-based emulsion

Formulation–composition map is an interesting tool to predict the nature of an emulsion, stability, viscosity and nevertheless to decide the mixing protocol of its ingredients. Information based on optimum formulation (environmental conditions at which the affinity of an emulsifier for oil and for aqueous phase is same), which is depicted through hydrophilic–lipophilic deviation (HLD) concept, is necessary to make a formulation–composition map of an emulsion. In order to apply this concept in food emulsions, it is necessary to determine characteristic constants of each component of the system, i.e. the aqueous phase, the oil phase and the emulsifier at equilibrium. In this work formulation–composition map of a sunflower oil–water–lecithin system, based on the knowledge of phase behavior of lecithin at equilibrium and emulsification, was made. The shape of inversion line on formulation–composition map was not the classical stair type rather an almost vertical inversion line at water-fraction (f_w) near 0.20 was observed. It was supposed to be linked to the viscosity of oil phase which was 50 times the viscosity of aqueous phase. Additionally, emulsions were of oil-in-water (O/W) type for f_w higher than 0.20, but their viscosity and the drop size behavior with respect to salt concentration as formulation variable did not show the existence of transitional inversion line on formulation–composition map. Such map in advance can certainly facilitate the guidelines for dynamic emulsification.