The problem of water and sulfur poisoning in flue gas atmosphere remains a significant obstacle for low-temperature deNO_(x) catalysts.This study investigated the sulfation mechanism of the CoMn_(2)O_(4)/CeTiO_(x)(CMC...The problem of water and sulfur poisoning in flue gas atmosphere remains a significant obstacle for low-temperature deNO_(x) catalysts.This study investigated the sulfation mechanism of the CoMn_(2)O_(4)/CeTiO_(x)(CMCT)catalyst during the selective catalytic reduction of NO_(x) with NH3 under conditions containing H2O and SO_(2) at 150℃.Employing a comprehensive suite of time-resolved analysis and characterization techniques,the evolution of sulfate species was systematically categorized into three stages:initial rapid surface sulfate accumulation,the transformation of surface sulfates to bulk metal sulfates,and partial sulfates decomposition after the removal of H2O and SO_(2).These findings indicate that bulk metal sulfates irreversibly deactivate the catalyst by distorting active component lattices and consuming oxygen vacancies,whereas surface sulfates(including ammonium sulfates and surface-coordinated metal sulfates)cause reversible performance loss through decomposition.Furthermore,the competitive adsorption of H2O and SO_(2) significantly influences the catalytic efficiency,with H2O suppressing SO_(2) adsorption while simultaneously enhancing the formation of Brönsted acid sites.This research underscores the critical role of sulfate dynamics on catalyst performance,revealing the enhanced SO_(2) resistance of the Eley-Rideal mechanism facilitated by the Ce-Ti support relative to the Langmuir-Hinshelwood pathway.Collectively,the study unravels the complex interplay of sulfate dynamics influencing catalyst performance and provides potential approaches to mitigate deactivation in demanding atmospheric conditions.展开更多
Electrosynthesis of hydrogen peroxide(H2O2)is an on-site method that enables independent distribution applications in many fields due to its small-scale and sustainable features.The crucial point remains developing hi...Electrosynthesis of hydrogen peroxide(H2O2)is an on-site method that enables independent distribution applications in many fields due to its small-scale and sustainable features.The crucial point remains developing highly active,selective and cost-effective electrocatalysts.The electrosynthesis of H2O2 in acidic media is more practical owing to its stability and no need for further purification.We herein report a phosphorus and selenium tuning Co-based non-precious catalyst(CoPSe)toward two-electron oxygen reduction reaction(2e–ORR)to produce H2O2 in acidic media.The starting point of using both P and Se is finding a balance between strong ORR activity of CoSe and weak activity of CoP.The results demonstrated that the CoPSe catalyst exhibited the optimized 2e–ORR activity compared with CoP and CoSe.It disclosed an onset potential of 0.68 V and the H2O2 selectivity 76%-85%in a wide potential range(0–0.5 V).Notably,the CoPSe catalyst overcomes a significant challenge of a narrow-range selectivity for transitionmetal based 2e–ORR catalysts.Finally,combining with electro-Fenton reaction,an on-site system was constructed for efficient degradation of organic pollutants.This work provides a promising non-precious Co-based electrocatalyst for the electrosynthesis of H2O2 in acidic media.展开更多
Ara h 2是花生主要过敏原之一,为开发食物中Ara h 2过敏原成分的快速检测方法,减少因误食导致花生过敏事件的发生,该研究采用鼠源单克隆抗体作为捕获抗体、兔源多克隆抗体作为检测抗体,通过棋盘法优化抗体工作浓度,建立了一种检测花生...Ara h 2是花生主要过敏原之一,为开发食物中Ara h 2过敏原成分的快速检测方法,减少因误食导致花生过敏事件的发生,该研究采用鼠源单克隆抗体作为捕获抗体、兔源多克隆抗体作为检测抗体,通过棋盘法优化抗体工作浓度,建立了一种检测花生过敏原Ara h 2的间接双抗夹心化学发光酶免疫分析法,并对该方法的灵敏度、准确度、精密度和特异性进行评价。该方法的检出限为1.085 ng/mL,线性范围为3.12~200 ng/mL,添加回收率为78.30%~94.39%,批内和批间变异系数均小于10%,且特异性良好,与其他常见食物过敏原无交叉反应。该方法与相同抗体所建立的间接双抗夹心酶联免疫吸附测定(enzyme-linked immunosorbent assay, ELISA)方法相比,在灵敏度上表现出一定优势。该研究开发的化学发光酶免疫分析法可对花生食品生产过程中和消费前的Ara h 2过敏原成分检测提供可靠的技术支持。展开更多
针对西北绿洲灌区长期施用化学氮肥造成农田氮损失、土壤肥力下降等问题,研究不同绿肥还田和施氮水平对作物产量和土壤N_(2)O排放的影响及机制具有重要意义。本研究基于甘肃河西走廊石羊河流域布设的田间试验于2019—2021年在春小麦收...针对西北绿洲灌区长期施用化学氮肥造成农田氮损失、土壤肥力下降等问题,研究不同绿肥还田和施氮水平对作物产量和土壤N_(2)O排放的影响及机制具有重要意义。本研究基于甘肃河西走廊石羊河流域布设的田间试验于2019—2021年在春小麦收获后复种毛叶苕子,毛叶苕子开花期设置7500 kg hm^(-2)(G_(1))、15,000 kg hm^(-2)(G_(2))、22,500 kg hm^(-2)(G_(3))和30,000 kg hm^(-2)(G_(4))4个还田量。翌年春小麦播前设置2个施氮水平,分别为减氮15%(N153)和减氮30%(N126),以无绿肥传统施氮(G0N180)作为对照。结果表明,与G0N180相比,绿肥还田结合减量施氮显著提高了小麦籽粒产量,降低了麦田N_(2)O排放量和排放强度,其中以G_(4)N153处理产量最高,达9135.33~9250.42 kg hm^(-2)。同一还田量下,减氮30%较减氮15%处理显著降低了N_(2)O排放量;同一施氮水平下,G_(3)、G_(4)较G_(1)、G_(2)显著降低N_(2)O排放量。研究还发现,N_(2)O排放的消减主要发生在小麦拔节期以前,这主要归因于绿肥还田结合减量施氮处理显著降低了小麦播种期及苗期的土壤硝态氮、铵态氮含量和硝酸还原酶、亚硝酸还原酶活性。回归分析表明,小麦播种期及苗期的土壤速效氮含量和酶活性与N_(2)O排放量呈显著正相关(P<0.01)。在减氮15%水平下,G_(4)较G_(1)、G_(2)、G_(3)提高了小麦开花期和成熟期土壤速效氮含量,保障了小麦生育后期氮素吸收。综上所述,在河西绿洲灌区,绿肥还田结合减量施氮可显著提高小麦产量、降低土壤N_(2)O排放量和排放强度,其中绿肥还田量30,000 kg hm^(-2)结合减量施氮15%效果最佳。展开更多
为建立花生致敏蛋白Ara h 2双抗夹心酶联免疫吸附试验(ELISA)检测方法,本研究基于所制备的抗体,采用双抗体夹心检测模式,以Ara h 2鼠源单克隆抗体作为捕获抗体、兔源多克隆抗体作为检测抗体,并通过棋盘法优化抗体工作浓度,对该方法的灵...为建立花生致敏蛋白Ara h 2双抗夹心酶联免疫吸附试验(ELISA)检测方法,本研究基于所制备的抗体,采用双抗体夹心检测模式,以Ara h 2鼠源单克隆抗体作为捕获抗体、兔源多克隆抗体作为检测抗体,并通过棋盘法优化抗体工作浓度,对该方法的灵敏度、准确度、精密度和特异性进行鉴定。结果表明,建立的双抗夹心ELISA检测方法对Ara h 2的检出限为5.04 ng·mL^(-1),线性范围为15.63~1 000 ng·mL^(-1),添加回收率为80.12%~96.03%,批内和批间变异系数均小于10%,且特异性良好、与其他常见食物过敏原无交叉反应。本研究可为致敏蛋白Ara h 2检测提供一种快速高效的方法。展开更多
文摘The problem of water and sulfur poisoning in flue gas atmosphere remains a significant obstacle for low-temperature deNO_(x) catalysts.This study investigated the sulfation mechanism of the CoMn_(2)O_(4)/CeTiO_(x)(CMCT)catalyst during the selective catalytic reduction of NO_(x) with NH3 under conditions containing H2O and SO_(2) at 150℃.Employing a comprehensive suite of time-resolved analysis and characterization techniques,the evolution of sulfate species was systematically categorized into three stages:initial rapid surface sulfate accumulation,the transformation of surface sulfates to bulk metal sulfates,and partial sulfates decomposition after the removal of H2O and SO_(2).These findings indicate that bulk metal sulfates irreversibly deactivate the catalyst by distorting active component lattices and consuming oxygen vacancies,whereas surface sulfates(including ammonium sulfates and surface-coordinated metal sulfates)cause reversible performance loss through decomposition.Furthermore,the competitive adsorption of H2O and SO_(2) significantly influences the catalytic efficiency,with H2O suppressing SO_(2) adsorption while simultaneously enhancing the formation of Brönsted acid sites.This research underscores the critical role of sulfate dynamics on catalyst performance,revealing the enhanced SO_(2) resistance of the Eley-Rideal mechanism facilitated by the Ce-Ti support relative to the Langmuir-Hinshelwood pathway.Collectively,the study unravels the complex interplay of sulfate dynamics influencing catalyst performance and provides potential approaches to mitigate deactivation in demanding atmospheric conditions.
基金the National Natural Science Foundation of China(Nos.21805052,21974031,2278092)Science and Technology Research Project of Guangzhou(Nos.202102020787 and 202201000002)+2 种基金Department of Science&Technology of Guangdong Province(No.2022A156)Key Discipline of Materials Science and Engineering,Bureau of Education of Guangzhou(No.20225546)the Innovation&Entrepreneurship for the College Students of Guangzhou University(No.XJ202111078175).
文摘Electrosynthesis of hydrogen peroxide(H2O2)is an on-site method that enables independent distribution applications in many fields due to its small-scale and sustainable features.The crucial point remains developing highly active,selective and cost-effective electrocatalysts.The electrosynthesis of H2O2 in acidic media is more practical owing to its stability and no need for further purification.We herein report a phosphorus and selenium tuning Co-based non-precious catalyst(CoPSe)toward two-electron oxygen reduction reaction(2e–ORR)to produce H2O2 in acidic media.The starting point of using both P and Se is finding a balance between strong ORR activity of CoSe and weak activity of CoP.The results demonstrated that the CoPSe catalyst exhibited the optimized 2e–ORR activity compared with CoP and CoSe.It disclosed an onset potential of 0.68 V and the H2O2 selectivity 76%-85%in a wide potential range(0–0.5 V).Notably,the CoPSe catalyst overcomes a significant challenge of a narrow-range selectivity for transitionmetal based 2e–ORR catalysts.Finally,combining with electro-Fenton reaction,an on-site system was constructed for efficient degradation of organic pollutants.This work provides a promising non-precious Co-based electrocatalyst for the electrosynthesis of H2O2 in acidic media.
文摘Ara h 2是花生主要过敏原之一,为开发食物中Ara h 2过敏原成分的快速检测方法,减少因误食导致花生过敏事件的发生,该研究采用鼠源单克隆抗体作为捕获抗体、兔源多克隆抗体作为检测抗体,通过棋盘法优化抗体工作浓度,建立了一种检测花生过敏原Ara h 2的间接双抗夹心化学发光酶免疫分析法,并对该方法的灵敏度、准确度、精密度和特异性进行评价。该方法的检出限为1.085 ng/mL,线性范围为3.12~200 ng/mL,添加回收率为78.30%~94.39%,批内和批间变异系数均小于10%,且特异性良好,与其他常见食物过敏原无交叉反应。该方法与相同抗体所建立的间接双抗夹心酶联免疫吸附测定(enzyme-linked immunosorbent assay, ELISA)方法相比,在灵敏度上表现出一定优势。该研究开发的化学发光酶免疫分析法可对花生食品生产过程中和消费前的Ara h 2过敏原成分检测提供可靠的技术支持。
文摘针对西北绿洲灌区长期施用化学氮肥造成农田氮损失、土壤肥力下降等问题,研究不同绿肥还田和施氮水平对作物产量和土壤N_(2)O排放的影响及机制具有重要意义。本研究基于甘肃河西走廊石羊河流域布设的田间试验于2019—2021年在春小麦收获后复种毛叶苕子,毛叶苕子开花期设置7500 kg hm^(-2)(G_(1))、15,000 kg hm^(-2)(G_(2))、22,500 kg hm^(-2)(G_(3))和30,000 kg hm^(-2)(G_(4))4个还田量。翌年春小麦播前设置2个施氮水平,分别为减氮15%(N153)和减氮30%(N126),以无绿肥传统施氮(G0N180)作为对照。结果表明,与G0N180相比,绿肥还田结合减量施氮显著提高了小麦籽粒产量,降低了麦田N_(2)O排放量和排放强度,其中以G_(4)N153处理产量最高,达9135.33~9250.42 kg hm^(-2)。同一还田量下,减氮30%较减氮15%处理显著降低了N_(2)O排放量;同一施氮水平下,G_(3)、G_(4)较G_(1)、G_(2)显著降低N_(2)O排放量。研究还发现,N_(2)O排放的消减主要发生在小麦拔节期以前,这主要归因于绿肥还田结合减量施氮处理显著降低了小麦播种期及苗期的土壤硝态氮、铵态氮含量和硝酸还原酶、亚硝酸还原酶活性。回归分析表明,小麦播种期及苗期的土壤速效氮含量和酶活性与N_(2)O排放量呈显著正相关(P<0.01)。在减氮15%水平下,G_(4)较G_(1)、G_(2)、G_(3)提高了小麦开花期和成熟期土壤速效氮含量,保障了小麦生育后期氮素吸收。综上所述,在河西绿洲灌区,绿肥还田结合减量施氮可显著提高小麦产量、降低土壤N_(2)O排放量和排放强度,其中绿肥还田量30,000 kg hm^(-2)结合减量施氮15%效果最佳。
文摘为建立花生致敏蛋白Ara h 2双抗夹心酶联免疫吸附试验(ELISA)检测方法,本研究基于所制备的抗体,采用双抗体夹心检测模式,以Ara h 2鼠源单克隆抗体作为捕获抗体、兔源多克隆抗体作为检测抗体,并通过棋盘法优化抗体工作浓度,对该方法的灵敏度、准确度、精密度和特异性进行鉴定。结果表明,建立的双抗夹心ELISA检测方法对Ara h 2的检出限为5.04 ng·mL^(-1),线性范围为15.63~1 000 ng·mL^(-1),添加回收率为80.12%~96.03%,批内和批间变异系数均小于10%,且特异性良好、与其他常见食物过敏原无交叉反应。本研究可为致敏蛋白Ara h 2检测提供一种快速高效的方法。
