为探讨酸雨胁迫下毛竹(Phyllostachys pubescens)色素含量变化及其对光合速率和叶绿素荧光动力学参数的影响,试验模拟酸雨(SO42-∶NO3-=4∶1摩尔比),设定p H 2.5、4.0、5.6和6.9(CK),对毛竹3年生盆栽实苗进行处理,测定了叶片色素含量、...为探讨酸雨胁迫下毛竹(Phyllostachys pubescens)色素含量变化及其对光合速率和叶绿素荧光动力学参数的影响,试验模拟酸雨(SO42-∶NO3-=4∶1摩尔比),设定p H 2.5、4.0、5.6和6.9(CK),对毛竹3年生盆栽实苗进行处理,测定了叶片色素含量、净光合速率(Pn)、叶绿素荧光动力学参数并进行分析。结果表明:p H 5.6酸雨处理增加了毛竹叶片中叶绿素a(Chl a)和类胡萝卜素(Car)含量,使得光合速率(Pn)升高;p H 4.0和p H 2.5处理使Chl a、Car、Chl a+b、Chl a/b降低,Pn下降;随着处理时间延长影响效果越明显,75 d时Pn与对照(CK)相比差异极显著。p H 4.0和p H 2.5处理使荧光诱导动力学曲线的IPJ点荧光强度出现不同程度降低,处理75 d时初始荧光(F0)降低11.73%和17.59%,峰值P点荧光(Fp)降低25.46%和31.41%,反应中心密度(RC/CSo)降低22.94%和26.22%,实际量子产额(Yield)下降20.41%和35.31%、光化学淬灭系数(q P)下降15.48%和19.42%,表观光合电子传递速率(ETR)下降22.02%和25.14%,非光化学淬灭系数(q N)上升23.16%和33.46%。p H 5.6处理使荧光强度升高,F0和Fp分别比CK增加30%和18.57%,q P和ETR上升8.38%和13.53%,q N下降17.65%。酸雨胁迫使毛竹叶片天线色素吸收能量(ABS/RC)、捕获能量(TRo/RC)和热耗散能量(DIo/RC)升高;以吸收光能为基础的性能指数(PIABS)、最大光化学效率(φPo)、电子传递量子产额(φEo)、电子传递效率(ψo)和电子传递能量(ETo/RC)降低。轻度酸雨处理促进毛竹叶片光合色素合成并提高Pn,重度酸雨胁迫下光合色素含量降低,Pn下降。荧光诱导动力学曲线OJIP曲线及JIP-test分析可作为快速检测毛竹在酸雨胁迫条件下生理响应机制的方法。展开更多
The use of H2SO4‐,HCl‐,H3PO4‐,and CH3COOH‐activated montmorillonite(Mt)and WOx/H3PO4‐activated Mt as catalysts for the gas‐phase dehydration of glycerol was investigated.The WOx/H3PO4‐activated Mt catalysts wer...The use of H2SO4‐,HCl‐,H3PO4‐,and CH3COOH‐activated montmorillonite(Mt)and WOx/H3PO4‐activated Mt as catalysts for the gas‐phase dehydration of glycerol was investigated.The WOx/H3PO4‐activated Mt catalysts were prepared by an impregnation method using H3PO4‐activated Mt(Mt‐P)as the support.The catalysts were characterized using powder X‐ray diffraction,Fourier‐transform infrared spectroscopy,N2adsorption‐desorption,diffuse reflectance ultraviolet‐visible spectroscopy,temperature‐programmed desorption of NH3,and thermogravimetric analysis.The acid activation of Mt and WOx loaded on Mt‐P affected the strength and number of acid sites arising from H+exchange,the leaching of octahedral Al3+cations from Mt octahedral sheets,and the types of WOx(2.7≤x≤3)species(i.e.,isolated WO4/WO6‐containing clusters,two‐dimensional[WO6]polytungstates,or three‐dimensional WO3crystals).The strong acid sites were weakened,and the weak and medium acid sites were strengthened when the W loading on Mt‐P was12wt%(12%W/Mt‐P).The12%W/Mt‐P catalyst showed the highest catalytic activity.It gave a glycerol conversion of89.6%and an acrolein selectivity of81.8%at320°C.Coke deposition on the surface of the catalyst led to deactivation.展开更多
文摘为探讨酸雨胁迫下毛竹(Phyllostachys pubescens)色素含量变化及其对光合速率和叶绿素荧光动力学参数的影响,试验模拟酸雨(SO42-∶NO3-=4∶1摩尔比),设定p H 2.5、4.0、5.6和6.9(CK),对毛竹3年生盆栽实苗进行处理,测定了叶片色素含量、净光合速率(Pn)、叶绿素荧光动力学参数并进行分析。结果表明:p H 5.6酸雨处理增加了毛竹叶片中叶绿素a(Chl a)和类胡萝卜素(Car)含量,使得光合速率(Pn)升高;p H 4.0和p H 2.5处理使Chl a、Car、Chl a+b、Chl a/b降低,Pn下降;随着处理时间延长影响效果越明显,75 d时Pn与对照(CK)相比差异极显著。p H 4.0和p H 2.5处理使荧光诱导动力学曲线的IPJ点荧光强度出现不同程度降低,处理75 d时初始荧光(F0)降低11.73%和17.59%,峰值P点荧光(Fp)降低25.46%和31.41%,反应中心密度(RC/CSo)降低22.94%和26.22%,实际量子产额(Yield)下降20.41%和35.31%、光化学淬灭系数(q P)下降15.48%和19.42%,表观光合电子传递速率(ETR)下降22.02%和25.14%,非光化学淬灭系数(q N)上升23.16%和33.46%。p H 5.6处理使荧光强度升高,F0和Fp分别比CK增加30%和18.57%,q P和ETR上升8.38%和13.53%,q N下降17.65%。酸雨胁迫使毛竹叶片天线色素吸收能量(ABS/RC)、捕获能量(TRo/RC)和热耗散能量(DIo/RC)升高;以吸收光能为基础的性能指数(PIABS)、最大光化学效率(φPo)、电子传递量子产额(φEo)、电子传递效率(ψo)和电子传递能量(ETo/RC)降低。轻度酸雨处理促进毛竹叶片光合色素合成并提高Pn,重度酸雨胁迫下光合色素含量降低,Pn下降。荧光诱导动力学曲线OJIP曲线及JIP-test分析可作为快速检测毛竹在酸雨胁迫条件下生理响应机制的方法。
基金supported by the National Natural Science Foundation of China(21373185,41672033,21506188,21404090)the Open Project Programs of Engineering Research Center of Non-metallic Minerals of Zhejiang Province(ZD2015k07)+2 种基金of State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology(GCTKF2014006)of Key Laboratory of High Efficient Processing of Bamboo of Zhejiang Province(2016)of State Key Laboratory of Chemical Resource Engineering,Beijing University of Chemical Technology(CRE-2016-C-303)~~
文摘The use of H2SO4‐,HCl‐,H3PO4‐,and CH3COOH‐activated montmorillonite(Mt)and WOx/H3PO4‐activated Mt as catalysts for the gas‐phase dehydration of glycerol was investigated.The WOx/H3PO4‐activated Mt catalysts were prepared by an impregnation method using H3PO4‐activated Mt(Mt‐P)as the support.The catalysts were characterized using powder X‐ray diffraction,Fourier‐transform infrared spectroscopy,N2adsorption‐desorption,diffuse reflectance ultraviolet‐visible spectroscopy,temperature‐programmed desorption of NH3,and thermogravimetric analysis.The acid activation of Mt and WOx loaded on Mt‐P affected the strength and number of acid sites arising from H+exchange,the leaching of octahedral Al3+cations from Mt octahedral sheets,and the types of WOx(2.7≤x≤3)species(i.e.,isolated WO4/WO6‐containing clusters,two‐dimensional[WO6]polytungstates,or three‐dimensional WO3crystals).The strong acid sites were weakened,and the weak and medium acid sites were strengthened when the W loading on Mt‐P was12wt%(12%W/Mt‐P).The12%W/Mt‐P catalyst showed the highest catalytic activity.It gave a glycerol conversion of89.6%and an acrolein selectivity of81.8%at320°C.Coke deposition on the surface of the catalyst led to deactivation.
