“双师网课”推动精准教学辅导与讨论——以钉钉网课为例

新型冠状病毒肺炎疫情爆发以来,全国各级各类学校延期开学,但停课不停教、停课不停学。各学校教师都在学习利用各种网络资源,开展在线教学,也为深入挖掘“互联网+教育”教学新模式带来了契机。本文以钉钉平台为例,谈谈如何应用钉钉软件实现“双师网课”推动精准教学辅导与讨论,增加学生的学习主动性,提升教学效果。

科教融合建设一流本科专业——厦门大学创建国家级一流化学专业的探索与实践

厦门大学化学专业在九十余年的发展中积累了丰富的办学经验,并拥有雄厚的教学与科学研究实力。本文从人才培养模式、课程体系、实践教学平台、师资队伍建设、质量保障体系等方面,介绍了该专业综合改革的主要举措及成效,并提出了下一步专业建设和改革的主要规划。

Observation of high ionic conductivity of polyelectrolyte microgels in salt-free solutions

Here, we report an observation that illustrate the potential of polyelectrolyte microgels in salt-free solutions to display a high ionic conductivity. Laser light scattering and ionic conductivity tests on very dilute aqueous dispersions of the microgels indicate that both small size and swollen state of gel particles play vital roles, which should favor the counterions to freely penetrate and leave gel particles, and thus can contribute to the ion-conducting property. Upon discovering this on microgels that are composed of imidazolium-based poly(ionic liquid), we also illustrate the generality of the finding to single lithium-ion polyelectrolyte microgels that are of more technically relevant features for applications, for instance, as injectable liquid “microgel-in-solution” electrolytes of high conductivity(ca. 8.2 × 10^(-2)S/m at 25.0 ℃ for1.0 × 10^(-2)g/m L of microgels in a LiNO_(3)-free 1:1 v/v mixture of 1,2-dioxolane and dimethoxymethane) and high lithium-ion transference number(0.87) for use in the rechargeable lithium-sulfur battery.

Tungsten oxide nanowires and polyaniline hybrid film-based electrochromic device with multicolor display and enhanced capacitance

Electrochromic devices(ECDs)have exhibited promising applications in the fields of energy-saving intelligent buildings and next-generation displays because of their simple structure,low power consumption,and multicolor displays.W_(18)O_(49)/polyaniline(PANI)hybrid films are prepared and assembled to ECDs.Compared with pure PANI and W_(18)O_(49) films,the hybrid film exhibits superior electrochemical and electrochromic performance,including high optical modulation(70.2%),large areal capacity(79.6 mF/cm^(2)),and good capacitance retention.The excellent electrochemical and electrochromic performance is ascribed to the formation of the donor(PANI)-acceptor(W_(18)O_(49))pair,the porous structure in the nanowires,and the large surface area,which enhance electron delocalization of the W_(18)O_(49)/PANI,improve the ion diffusion rate,and increase the charge storage sites.Furthermore,benefitting from the outstanding optical,electrical,and multifunctional properties,the W_(18)O_(49)/PANI hybrid film-based ECD platform is expected to play an important role in electrochromism and energy storage.

Light-mediated CO_(2)-responsiveness of metallopolymer microgels

Here, we report a finding on light-mediated CO_(2)^(-)responsiveness. It is found on the microgels that are made of side-chain type metallopolymers containing metalla-aromatics. Turbidity and laser light scattering studies on dilute aqueous dispersion of these microgels in dark indicate high CO_(2)^(-)responsivity, but poor reversibility upon N2 purge, which can be improved by exposing to light. This light-mediated CO_(2)^(-)responsiveness can be elucidated by the loss of aromaticity from initial photoexcitation and concurrent formation of a less reactive, antiaromatic excited state of relatively low CO_(2) binding affinity, and by subsequent relief of antiaromaticity that can enhance the CO_(2) removal. The finding is also checked by CO_(2) uptake-release experiments on the microgels, which enables both CO_(2) capture of high capacity and CO_(2) removal of good reversibility under a mild condition, allowing effective and reversible response to dilute CO_(2).

Engineering of responsive polymer based nano-reactors for facile mass transport and enhanced catalytic degradation of 4-nitrophenol

Silver nanoparticles with average diameter of 10 ± 3 nm were synthesized within the sieves of poly（N-isopropylacrylamide-2-hydroxyethylmethacrylate-acrylic acid）（p（NIPAAm-HEMA-AAc））polymer microgels. Free radial emulsion polymerization was employed for synthesis of p（NIPAAm-HEMA-AAc） polymer microgels. Silver nanoparticles were introduced within the microgels sphere by in situ reduction method. Microgels and hybrid microgels were characterized by Fourier transform infrared spectroscopy, ultra violet-visible spectroscopy,transmission electron microscopy and dynamic light scattering measurements. Catalytic activity of Ag-p（NIPAAm-HEMA-AAc） hybrid microgels was studied using catalytic reduction of 4-nitrophenol（4-NP） as a model reaction in aqueous media. The influence of sodium borohydride（Na BH4） concentration, catalyst dose and 4-NP concentration on catalytic reduction of 4-NP was investigated. A linear relationship was found between catalyst dose and apparent rate constant（kapp）. The mechanism of catalysis by hybrid microgels was explored for further development in this area. The deep analysis of catalytic process reveals that the unique combination of NIPAAm, HEMA and AAc does not only stabilize silver nanoparticles in polymer network but it also enhances the mass transport of hydrophilic substrate like 4-NP from outside to inside the polymer network.