Atomic force microscope was employed to study the surface structure of purple membrane (PM) using contact mode in liquid. The surface structures of native PM and PM partly dissolved by detergent CHAPS were com- pared....Atomic force microscope was employed to study the surface structure of purple membrane (PM) using contact mode in liquid. The surface structures of native PM and PM partly dissolved by detergent CHAPS were com- pared. Results show that 6 mmol/L CHAPS could induce some cracks and holes in PM. While Bateriorhodopsin (BR) was still presented as trimers in the two-dimensional hex- agonal structure. We assume that it was caused by the inter- action between CHAPS micellar and PM. Both absorption spectra and flash photolysis kinetic spectra indicated that BR抯 biochemical functions have been changed.展开更多
随着城市化和工业化的迅速发展,加之特殊的地形和天气气候条件,新疆地区面临严峻的大气污染问题。再分析数据时空连续性好、分辨率高,可有效弥补新疆地区地面观测站点稀疏不足的问题。文中聚焦新疆地区细颗粒物污染物(PM_(2.5)),采用中...随着城市化和工业化的迅速发展,加之特殊的地形和天气气候条件,新疆地区面临严峻的大气污染问题。再分析数据时空连续性好、分辨率高,可有效弥补新疆地区地面观测站点稀疏不足的问题。文中聚焦新疆地区细颗粒物污染物(PM_(2.5)),采用中国高分辨率高质量近地表空气污染物数据集(China High Air Pollutants,CHAP)和新疆35个国控站点观测数据,首先综合评估了CHAP PM_(2.5)质量浓度在新疆的适用性,进而深入分析了该地区2000-2022年PM_(2.5)质量浓度的时空分布和变化特征。结果表明,CHAP PM_(2.5)在新疆的适用性整体较高,在27个站点CHAP与站点实测值的相关系数均超过0.9,且北疆站点高于南疆;从平均绝对百分误差、均方根误差、标准偏差比等统计量来看,CHAP PM_(2.5)在相对洁净地区数值偏高约6.9%,在污染高值区偏低约4.8%。分析表明,2000-2022年新疆地区年均PM_(2.5)质量浓度整体呈下降趋势,由50μg/m^(3)降至37μg/m^(3),下降幅度约为26%,尤其在2016年后下降速度加快。从空间分布来看,PM_(2.5)质量浓度高值区分布在北疆的乌鲁木齐-昌吉-石河子城市群和南疆的塔里木盆地。南、北疆地区PM_(2.5)质量浓度的季节变化差异明显,南疆地区在春季浓度较高,最大均值(94μg/m^(3))出现在4月份;北疆地区在冬季浓度较高,最大均值(62μg/m^(3))出现在1月份。文中研究可为新疆大气污染重点区域的机理研究和防治措施的制定实施提供科学参考。展开更多
利用废弃蛋壳制备碳羟基磷灰石,并利用其吸附废水中的Cd2+.考察了Cd2+初始浓度、pH值、吸附时间、吸附剂用量以及温度等因素对吸附效果的影响,结果表明:当废水中Cd2+初始浓度为30 mg/L、pH=7、吸附时间35 m in、温度35℃时,碳羟基磷灰石...利用废弃蛋壳制备碳羟基磷灰石,并利用其吸附废水中的Cd2+.考察了Cd2+初始浓度、pH值、吸附时间、吸附剂用量以及温度等因素对吸附效果的影响,结果表明:当废水中Cd2+初始浓度为30 mg/L、pH=7、吸附时间35 m in、温度35℃时,碳羟基磷灰石对Cd2+去除率高达99.9%.吸附实验还表明该吸附符合Freundlich方程.展开更多
基金supported by the State Key Basic Research and Development Plan Project(Grant No.199801012).
文摘Atomic force microscope was employed to study the surface structure of purple membrane (PM) using contact mode in liquid. The surface structures of native PM and PM partly dissolved by detergent CHAPS were com- pared. Results show that 6 mmol/L CHAPS could induce some cracks and holes in PM. While Bateriorhodopsin (BR) was still presented as trimers in the two-dimensional hex- agonal structure. We assume that it was caused by the inter- action between CHAPS micellar and PM. Both absorption spectra and flash photolysis kinetic spectra indicated that BR抯 biochemical functions have been changed.
文摘随着城市化和工业化的迅速发展,加之特殊的地形和天气气候条件,新疆地区面临严峻的大气污染问题。再分析数据时空连续性好、分辨率高,可有效弥补新疆地区地面观测站点稀疏不足的问题。文中聚焦新疆地区细颗粒物污染物(PM_(2.5)),采用中国高分辨率高质量近地表空气污染物数据集(China High Air Pollutants,CHAP)和新疆35个国控站点观测数据,首先综合评估了CHAP PM_(2.5)质量浓度在新疆的适用性,进而深入分析了该地区2000-2022年PM_(2.5)质量浓度的时空分布和变化特征。结果表明,CHAP PM_(2.5)在新疆的适用性整体较高,在27个站点CHAP与站点实测值的相关系数均超过0.9,且北疆站点高于南疆;从平均绝对百分误差、均方根误差、标准偏差比等统计量来看,CHAP PM_(2.5)在相对洁净地区数值偏高约6.9%,在污染高值区偏低约4.8%。分析表明,2000-2022年新疆地区年均PM_(2.5)质量浓度整体呈下降趋势,由50μg/m^(3)降至37μg/m^(3),下降幅度约为26%,尤其在2016年后下降速度加快。从空间分布来看,PM_(2.5)质量浓度高值区分布在北疆的乌鲁木齐-昌吉-石河子城市群和南疆的塔里木盆地。南、北疆地区PM_(2.5)质量浓度的季节变化差异明显,南疆地区在春季浓度较高,最大均值(94μg/m^(3))出现在4月份;北疆地区在冬季浓度较高,最大均值(62μg/m^(3))出现在1月份。文中研究可为新疆大气污染重点区域的机理研究和防治措施的制定实施提供科学参考。
文摘利用废弃蛋壳制备碳羟基磷灰石,并利用其吸附废水中的Cd2+.考察了Cd2+初始浓度、pH值、吸附时间、吸附剂用量以及温度等因素对吸附效果的影响,结果表明:当废水中Cd2+初始浓度为30 mg/L、pH=7、吸附时间35 m in、温度35℃时,碳羟基磷灰石对Cd2+去除率高达99.9%.吸附实验还表明该吸附符合Freundlich方程.
