目的评价“对分课堂”与案例教学联合模式在提升专业型公共卫生硕士(Master of Public Health,MPH)研究生健康干预计划设计能力中的应用效果。方法于2022—2023学年和2023—2024学年春季学期,采用全面调查方法选取北京大学选修健康教育...目的评价“对分课堂”与案例教学联合模式在提升专业型公共卫生硕士(Master of Public Health,MPH)研究生健康干预计划设计能力中的应用效果。方法于2022—2023学年和2023—2024学年春季学期,采用全面调查方法选取北京大学选修健康教育与健康促进课程的所有MPH研究生为研究对象。采用“对分课堂”与案例教学对课程进行改革,采用历史对照单盲试验设计、描述性分析等方法比较MPH研究生健康干预计划设计能力提升效果。结果基于课程分析,本研究提出了加强对健康行为和传播理论价值的思考、健康教育干预计划实践训练以及逻辑实践训练3项改革重点。MPH研究生健康干预计划设计能力提升结果显示,试验组学生的健康干预项目计划书总分为(89.35±3.59)分,高于对照组;评价方案、背景与需求评估、干预策略、行为理论或传播理论维度得分分别为(26.95±0.64)分、(26.90±1.37)分、(26.30±1.60)分、(9.20±0.92)分,均高于对照组。结论“对分课堂”与案例教学联合模式在提升MPH学生健康干预项目设计的整体质量,尤其是评价方案设计方面具有积极作用。因此,可认为该教学模式对于提升MPH研究生健康干预计划设计能力具有一定的积极作用。展开更多
Arsenic-contaminated groundwater is widely used in agriculture.To meet the increasing demand for safe water in agriculture,an efficient and cost-effective method for As removal from groundwater is urgently needed.We h...Arsenic-contaminated groundwater is widely used in agriculture.To meet the increasing demand for safe water in agriculture,an efficient and cost-effective method for As removal from groundwater is urgently needed.We hypothesized that Fe(oxyhydr)oxide(FeOOH)minerals precipitated in situ from indigenous Fe in groundwater may immobilize As,providing a solution for safely using As-contaminated groundwater in irrigation.To confirm this hypothesis and identify the controlling mechanisms,we comprehensively evaluated the transport,speciation changes,and immobilization of As and Fe in agricultural canals irrigated using As-contaminated groundwater.The efficiently removed As and Fe in the canals accumulated in shallow sediment rather than subsurface sediment.Linear combination fitting(LCF)analysis of X-ray absorption near edge spectroscopy(XANES)indicated that As(Ⅴ)was the dominant As species,followed by As(Ⅲ),and therewas no FeAsO_(4) precipitate.Sequential extraction revealed higher contents of amorphous FeOOH and associated As in shallower sediment than in the subsurface layer.Stoichiometric molar ratio calculations,SEM-EDS,FTIR,and fluorescence spectroscopy collectively demonstrated that the microbial reductive dissolution of amorphous FeOOH proceeded via reactive dissolved organic matter(DOM)consumption in subsurface anoxic porewater environment facilitating high labile As,whereas in surface sediment,the in situ-generated amorphous FeOOH was stable and strongly inhibited As release via adsorption.In summary,groundwater Fe^(2+)can efficiently precipitate in benthic surface sediment as abundant amorphous FeOOH,which immobilizes most of the dissolved As,protecting agricultural soil from contamination.This field research supports the critical roles of the phase and reactivity of in situ-generated FeOOH in As immobilization and provides new insight into the sustainable use of contaminated water.展开更多
Blue-light emitting materials with high purity and good luminous efficiency have attracted considerable attention from both academic and commercial researchers for their great potential use in OLEDs.In order to improv...Blue-light emitting materials with high purity and good luminous efficiency have attracted considerable attention from both academic and commercial researchers for their great potential use in OLEDs.In order to improve thermal stability and lower the possibility to generate fluorescence quenching of organic blue-light emitting materials formed by carbazole,a linear organic molecule containing carbazole and triarylamine group,named N4,N4’-bis(9-ethyl-9H-carbazol-3-yl)-N4,N4’-diphenyl-[1,1’-biphenyl]-4,4’-diamine(DPECB),was synthesized via the Buchwald-Hartwig reaction.The structure of DPECB was characterized by nuclear magnetic resonance(NMR)and infrared spectroscopy.The UV-Vis absorption spectrum shows that DPECB exhibits two strong absorption peaks in the near ultraviolet region(around 305 and 355 nm).The fluorescence emission spectrum indicates that DPECB displays blue light emission both in solution(428-445 nm)and solid-state(466 nm).Additionally,DPECB shows clearly aggregation-induced emission enhancement(AIEE)effect in the mixed solvent of DMF/H2O.As the thermogravimetric analysis shows,DPECB demonstrates excellent thermostability with a 5%decomposition temperature of 457℃owing to the introduction of triarylamine group.The electrochemical property of DPECB was studied through cyclic voltammetry,and its HOMO and LUMO energy levels are-5.27 and-2.25 eV,respectively.These results indicate that DPECB is a promising blue-light emitting material with potential commercial applications.展开更多
文摘目的评价“对分课堂”与案例教学联合模式在提升专业型公共卫生硕士(Master of Public Health,MPH)研究生健康干预计划设计能力中的应用效果。方法于2022—2023学年和2023—2024学年春季学期,采用全面调查方法选取北京大学选修健康教育与健康促进课程的所有MPH研究生为研究对象。采用“对分课堂”与案例教学对课程进行改革,采用历史对照单盲试验设计、描述性分析等方法比较MPH研究生健康干预计划设计能力提升效果。结果基于课程分析,本研究提出了加强对健康行为和传播理论价值的思考、健康教育干预计划实践训练以及逻辑实践训练3项改革重点。MPH研究生健康干预计划设计能力提升结果显示,试验组学生的健康干预项目计划书总分为(89.35±3.59)分,高于对照组;评价方案、背景与需求评估、干预策略、行为理论或传播理论维度得分分别为(26.95±0.64)分、(26.90±1.37)分、(26.30±1.60)分、(9.20±0.92)分,均高于对照组。结论“对分课堂”与案例教学联合模式在提升MPH学生健康干预项目设计的整体质量,尤其是评价方案设计方面具有积极作用。因此,可认为该教学模式对于提升MPH研究生健康干预计划设计能力具有一定的积极作用。
基金supported by the National Natural Science Foundation of China(Nos.41830753,42277201,42377242,and 41977286)the Scientific Research Foundation of Guangzhou University(No.YJ2023027)the College Student Innovation and Entrepreneurship Training Program(No.S202311078057).
文摘Arsenic-contaminated groundwater is widely used in agriculture.To meet the increasing demand for safe water in agriculture,an efficient and cost-effective method for As removal from groundwater is urgently needed.We hypothesized that Fe(oxyhydr)oxide(FeOOH)minerals precipitated in situ from indigenous Fe in groundwater may immobilize As,providing a solution for safely using As-contaminated groundwater in irrigation.To confirm this hypothesis and identify the controlling mechanisms,we comprehensively evaluated the transport,speciation changes,and immobilization of As and Fe in agricultural canals irrigated using As-contaminated groundwater.The efficiently removed As and Fe in the canals accumulated in shallow sediment rather than subsurface sediment.Linear combination fitting(LCF)analysis of X-ray absorption near edge spectroscopy(XANES)indicated that As(Ⅴ)was the dominant As species,followed by As(Ⅲ),and therewas no FeAsO_(4) precipitate.Sequential extraction revealed higher contents of amorphous FeOOH and associated As in shallower sediment than in the subsurface layer.Stoichiometric molar ratio calculations,SEM-EDS,FTIR,and fluorescence spectroscopy collectively demonstrated that the microbial reductive dissolution of amorphous FeOOH proceeded via reactive dissolved organic matter(DOM)consumption in subsurface anoxic porewater environment facilitating high labile As,whereas in surface sediment,the in situ-generated amorphous FeOOH was stable and strongly inhibited As release via adsorption.In summary,groundwater Fe^(2+)can efficiently precipitate in benthic surface sediment as abundant amorphous FeOOH,which immobilizes most of the dissolved As,protecting agricultural soil from contamination.This field research supports the critical roles of the phase and reactivity of in situ-generated FeOOH in As immobilization and provides new insight into the sustainable use of contaminated water.
基金Fundamental Research Program of Shanxi Province(20210302124637,202203021211102,J20230701)。
文摘Blue-light emitting materials with high purity and good luminous efficiency have attracted considerable attention from both academic and commercial researchers for their great potential use in OLEDs.In order to improve thermal stability and lower the possibility to generate fluorescence quenching of organic blue-light emitting materials formed by carbazole,a linear organic molecule containing carbazole and triarylamine group,named N4,N4’-bis(9-ethyl-9H-carbazol-3-yl)-N4,N4’-diphenyl-[1,1’-biphenyl]-4,4’-diamine(DPECB),was synthesized via the Buchwald-Hartwig reaction.The structure of DPECB was characterized by nuclear magnetic resonance(NMR)and infrared spectroscopy.The UV-Vis absorption spectrum shows that DPECB exhibits two strong absorption peaks in the near ultraviolet region(around 305 and 355 nm).The fluorescence emission spectrum indicates that DPECB displays blue light emission both in solution(428-445 nm)and solid-state(466 nm).Additionally,DPECB shows clearly aggregation-induced emission enhancement(AIEE)effect in the mixed solvent of DMF/H2O.As the thermogravimetric analysis shows,DPECB demonstrates excellent thermostability with a 5%decomposition temperature of 457℃owing to the introduction of triarylamine group.The electrochemical property of DPECB was studied through cyclic voltammetry,and its HOMO and LUMO energy levels are-5.27 and-2.25 eV,respectively.These results indicate that DPECB is a promising blue-light emitting material with potential commercial applications.
