后疫情时代微信融入无机化学实验教学的初探

针对后疫情时代的教学需要和地方高校的信息化教学资源的不足,通过创建微信公众号和微信群,初步探索了微信融入无机化学实验教学的新模式。课前通过公众号的推文引导学生进行有目标的预习,养成自主学习和独立思考的习惯。课堂中,先通过微信群进行预习测试,并基于测试反馈调整需要重点讨论的实验要点,再通过微信群共享师生在实验过程中对实验操作、实验现象和实验结果拍摄的照片或视频,充分激发学生兴趣,提升学生的能力。课后结合拍摄的错误操作的照片撰写公众号推文,进行实验反馈,帮助学生形成反思的习惯。     

优化中学化学实验教学环境实做举措

从实验环境入手,主要解决当前困扰中学化学实验教学的难题,着眼于优化中学化学实验教学环境,着重解决了5个方面的问题：（1）明确指出了中学化学实验的现实环境;（2）做好高一学生的“起始”工作;（3）改学生分组实验中的验证性实验为探究性实验,开放实验室并重新设计活页的《化学实验报告》;（4）利用数码摄像机拍摄课堂上难以完成的实验,提高实验教学的质量和容量;（5）引导学生做实验题时将虚拟环境转化为现实环境。     

通过化学实验报告改革提升大学生科技写作水平

目前我国高校本科生的毕业论文存在较多问题,集中表现在数据处理不当、论文逻辑不清、书写格式混乱、写作不规范等方面,而这些方面的改进都需要长期的训练和积累。以“无机及分析化学实验”课程的实验报告书写改革为例,通过对实验报告进行分层次的3种不同模式的改革方式,使学生加深了对于实验课程的认识,提高了科技论文写作的水平。此项改革的进一步推广有助于学生在大学4年的学习中逐步提升科技写作能力,从而能够书写出清晰、规范、科学、严谨的优秀毕业论文,同时也为他们未来的深造和工作奠定坚实的写作基础。     

物理化学实验教学的创新研究

选择物理化学实验教学中经典的热力学、电化学和表面化学实验进行教学创新研究.通过将实验对象生活化、实验操作视频化、实验教学案例化、实验过程自主化、实验报告论文化,对学生进行全面的科学训练,以提高学生的综合素质和创新能力.     

学生实验课教学改革初探

当前学生实验课教学中普遍存在以下两个弊端:一忽视实验的思维过程。目前大多数的情况是,课前预习"实验报告"课上看着"报告"做实验、记录实验现象填写"报告",课后（或课上）完成"报告"。在学生看、做、记、写的过程中"想"得不够,往往只满足照看报告,"这么做",而缺乏认真思索,离开实验报告就会束手无策,有的甚至照课本抄,把实验原理、现象抄上报告,就算应付了事。     

新课程背景下化学实验报告的优化设计

新课程背景下化学实验报告的设计重在探究,贵在引导,必须优化实验目的,完善实验教学的“三维”目标;优化实验器材,还学生自主选用的权利;优化实验过程,变验证性实验为探究性实验;优化问题和讨论,加强实验后的归纳和反思。     

化学实验报告中“实验反思”的2种评价方法

运用开放试题的质性评价方法PTA量表和SOLO分类理论优化中学生实验报告中的“实验反思”的评价,构建化学实验反思评价的PTA量表与SOLO分类水平,为教师改进批改实验报告和评价学生实验操作提供参考。     

有机化学实验多媒体课件的制作

有机化学是化学专业的一门重要的基础课程 ,同时也是一门原理性、概念性、结构性、实验性较强的学科。实验教学是有机化学教学中不可缺少的一部分 ,传统实验教学要求学生预习、实验、写实验报告 ,最后由教师批改实验报告并给出实验成绩。学生实验前预习的程度、学生的实验成绩大部分由预习报告和实验报告决定 ,而这些报告往往不能完全反映学生的真实情况。计算机可以将多媒体信息 ,如声音、图像、动画、模拟等集于一体 ,将实验过程设计成形象、直观的操作软件 ,让学生在计算机上模拟实验操作 ,最后给学生一个预习成绩单 ,以此作为考察学生预…     

贯穿论文式实验报告的综合能力培养教学实践

加强实验教学是培养学生科学素养和综合创新能力的重要途径。基于"两性一度"的课程教学要求,针对目前实验教学中撰写实验报告存在的问题,以物理化学实验课程为例,进行了教学改革与实践。采取贯穿科研论文式实验报告撰写各环节的科学素养和能力培养模式,该论文式实验报告有利于学生整体把握,提出问题、分析问题和总结,实验报告的各个部分与实际教学环节相统一,取得了满意的效果。充分发挥了教师主导和学生主体的协同优势,激发了学生学习的积极性和主观能动性,有利于培养德智体美劳全面发展的高素质人才。     

基于化学专业本科生视角的大学化学实验教学的优化

以化学专业本科学生的视角,针对化学实验教学中存在的问题与不足,提出了大学化学实验教学的优化方案,包括全过程的网络平台化、实验过程中对操作的规范与严格、预习报告和实验报告的表格化以及实验前对相关知识与背景的拓展和实验后的再强化等建议。     

Investigation of the sorption of water vapor on cation-substituted vermiculite. 2. Thermodynamic description of sorption equilibria

The changes in the thermodynamic functions of the sorbents were calculated for the first time from measurements of the deformations of vermiculite during the sorption of water vapor and adsorption-calorimetric data.Institute of Physical Chemistry, Russian Academy of Sciences, 117915 Moscow. Institute of Colloid Chemistry and the Chemistry of Water, Academy of Sciences of the Ukraine, 252180 Kiev. Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 6, pp. 1270–1275, June, 1992.     

Thermodynamics of ionization of water over wide ranges of temperature and pressure

We have summarized results of many experimental investigations of the thermodynamics of ionization of H₂O(liq.) from 0–300°C and from 1.0 atm to nearly 8000 atm. Results of these investigations (equilibrium constants, enthalpies of ionization, heat capacities, partial molal volumes, and compressibilities) have been used for a number of thermodynamic calculations. It is particularly noteworthy that it is possible to use thermal data from 0–145°C with an equilibrium constant for 25°C in calculating reasonably accurate equilibrium constants for temperatures as high as 300°C. Similarly, it is possible to use volumetric data that refer to 1.0 atm in calculating useful equilibrium constants that apply for pressures as high as 2000 atm.Much of the work reported here was done while the author was on leave at the University of Lethbridge.     

Thermochemical study of aliphatic and phenyl-substituted geminal diacetates

The standard enthalpies of combustion _c H ^o of aliphatic diacetates1 and aromatic diacetates2 were measured calorimetrically. The enthalpies of vaporization _vap H ^o or sublimation _sub H ^o of1 and2 were obtained from the temperature function of the vapor pressure measured in a flow system. From _f H ^o(g) of1 and2 new values of group increments for the estimation of standard enthalpies of formation of these classes of compounds were derived. The geminal interaction energy between the geminal acyloxy groups shows no anomeric stabilization.Geminal Substituent Effects, Part 12, for part 11 see Ref. 7.     

Thermodynamics of lonization of aqueous lodic acid,an “almost-strong” electrolyte

We have made calorimetric measurements of enthalpies of dilution of aqueous iodic acid and have used these results for evaluation of the standard enthalpy of ionization of HIO₃(aq.). We have also made calorimetric measurements of enthalpies of addition of perchloric acid solution to aqueous solutions of KIO₃, KNO₃, NaIO₃, and NaNO₃ and have used these results to obtain further values for the standard enthalpy of ionization of HIO₃(aq.). On the basis of all these results, we have selected H^o=–660±125 cal-mole^–1 as the best available standard enthalpy of ionization of HIO₃(aq.) at 298.15°K, compared to the previously accepted –2400 cal-mole^–1. Using the best available K=0.157 for ionization, we also obtain G^o=1097 cal-mole^–1 and S^o=–5.9 cal-^oK^–1-mole^–1 for ionization of HIO₃(aq) at 298.15°K.On study leave from Department of Inorganic and Analytical Chemistry, LaTrobe University, Bundoora, Victoria, 3083, Australia, to University of Lethbridge.On study leave from Department of Chemistry, University of Wollongong, Wollongong, N.S.W. 2500, Australia, to University of Lethbridge.     

Relation between characteristic adsorption energy and internal pressure in the theory of volume filling of micropores

An equation for the internal pressure acting on an adsorbate in micropores was obtained on the basis of the assumption that the chemical potential of an adsorbate in micropores is equal to that in an equilibrium gas phase and using the Dubinin-Radushkevich equation. The empirical relation between the characteristic adsorption energy and the half width of pores was expressed in terms of internal pressure and diameter of adsorbate molecules. The two-dimensional pressure was calculated for micropores with plane-parallel walls, where the width of a micropore coincides with the diameter of an adsorbate molecule. The results obtained were compared with the two-dimensional pressure of a monolayer on a free planar surface for an adsorbate and adsorbent of the same nature.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1928–1930, October, 1995.     

Thermochemistry of aqueous solutions of alkylated nucleic acid bases. VIII. Enthalpies of hydration of 6-alkyluracils

Enthalpies of solution in water H _sol ^o and enthalpies of sublimation H _sub ^o were determined for a number of crystalline derivatives of uracil: 1,6-dimethyluracil (m ₂ ^1,6 Ura), 1,3,6-trimethyluracil (m ₃ ^1,3,6 Ura), 6-ethyl-1,3-dimethyluracil (e⁶m ₂ ^1,3 Ura), 6-propyl-1,3-dimethyluracil (pr⁶m ₂ ^1,3 Ura) and 6-butyl-1,3-dimethyluracil (but⁶m ₂ ^1,3 Ura). Standard enthalpies of hydration H _hydr ^o and standard enthalpies of interaction H _int ^o of the solutes with their hydration shells were calculated. The data obtained show that dependence of H _int ^o on the number of-CH₂- groups of n-alkyl chain added upon substitution of diketopyrimidine ring is nonlinear. This finding is discussed in connection with results of X-ray diffraction structure determinations for the crystalline compounds.     

STUDIES ON THE REACTIVITY PATTERNS OF HETEROCYCLICS IN AQUEOUS DMSO‐INTERACTION BETWEEN POSITIVE END OF SULFOXIDE DIPOLE AND LONE PAIR ON RING NITROGEN IN PYRIDINE DERIVATIVES

Abstract

The signals for the α, β, and γ protons of pyridine exhibit a downfield shift in DMSO-d₆, compared to CCl₄ as solvent, the order being γ > β > α. This is attributed to an interaction between the positive end of the DMSO dipole and the lone pair of electrons on the ring nitrogen. This effect is also reflected in the faster rate of alkaline hydrolysis of ethyl isonicotinate over ethyl nicotinate and ethyl picolinate in aqueous DMSO relative to aqueous ethanol. Similar solvent effects are also observed in the pmr spectrum of pyrazine.     

Protonation of leucoemeraldine in the solid state and in solution

The protonation of leucoemeraldine in power form and in N-methylpyrrolidinone (NMP) solution by HCIO₄ and HBF₄ has been studied by x-ray photoelectron spectroscopy (XPS), infrared (IR), and ultraviolet (UV)-visible absorption spectroscopy. In powder form, less than 25% of the amine nitrogens can be protonated in the absence of oxygen. The effects of oxygen on the degree of protonation and the distribution of amine and imine units upon deprotonation of the salt are investigated. The degree of protonation in leuccemeraldine can be increased to about 50% with 3 M HCIO₄, similar to that achievable with emeraldine base in powder form. In NMP solution, leucoemeraldine is easily oxidized by dissolved oxygen. Protonation of both leucoemeraldine and emeraldine base in NMP solutions results in metastable species which gradually undergo deprotonation. The resulting products are affected by the O₂ content of the solutions. © 1993 John Wiley & Sons, Inc.     

碳量子点上转换材料的制备及其应用研究进展

碳量子点(CQD)具有化学惰性,生物相容性和低毒性等优势,可能在能源、生物医药等领域得到广泛的应用. CQD可通过表面被聚合物(例如PEG)钝化而表现出很强的光致发光特性.在生物成像,疾病检测和药物输送中使用表面钝化后的功能化生物分子更为有效.并且碳材料由于其优异的电化学性能还展现出在催化、电子器件等许多领域广泛的应用前景.我们将对近年来碳量子点发光材料的研究进行总结,并讨论碳量子点在能源、环境和其他一些领域的应用.     

钾明矾溶液水解度计算公式

根据盐类水解关系式和水的离子积计算公式,建立了计算盐类水解度和水解产物离解常数的完全方程式。计算值同实验值比较,钾明矾溶液水解度平均偏差为0.6％,离解常数pK_b=11.6±0.1,水的离子积pK_w平均偏差小于0.06,从而改进了苏联的计算公式。