在前期FeN/C催化剂研究的基础上,以不同的含硫化合物为硫源,在Ar气氛下高温热处理获得一系列FeNS/C催化剂。使用线性扫描伏安法测试催化剂的氧还原活性,通过热重分析、比表面积和孔径分布测试对催化剂前驱体的热性质及催化剂的结构等进...在前期FeN/C催化剂研究的基础上,以不同的含硫化合物为硫源,在Ar气氛下高温热处理获得一系列FeNS/C催化剂。使用线性扫描伏安法测试催化剂的氧还原活性,通过热重分析、比表面积和孔径分布测试对催化剂前驱体的热性质及催化剂的结构等进行表征。结果表明,分别以硫脲为硫源,1,10-菲啰啉为氮源,FeCl_3为铁源,Black Pearl 2000为载体,催化剂前驱体中硫含量为1wt.%时,所得催化剂比表面积为559. 39 m^2/g,且催化剂表现出较好的氧还原催化活性。硫源的种类、热性质对催化剂的氧还原活性有着明显影响。展开更多
Subaerial fallout from the Holocene eruption of Mount Mazama in the Oregon Cascade Range was deposited upon relatively low permeability volcanic and volcaniclastic bedrock and regolith. In the Walker Rim study area, e...Subaerial fallout from the Holocene eruption of Mount Mazama in the Oregon Cascade Range was deposited upon relatively low permeability volcanic and volcaniclastic bedrock and regolith. In the Walker Rim study area, erosion by ephemeral streams shortly after the eruption disrupted the lateral continuity of the 270 to 300 cm-thick pumice deposit. Co-evolution of the surface- and ground-water systems in a low-relief, low-slope landscape allowed diffuse groundwater discharge from the banks of the evolving stream system. Accumulation of organic material from groundwater dependent ecosystems at these sites of discharge allowed peat deposits to form on gently sloping erosion surfaces cut into the pumice deposit. Following early stream incision, fine-grained, silt-rich deposits accumulated in valleys and contributed permeability barriers to the lateral migration of water in the pumice aquifer. Fens discharge from the pumice aquifer through gently sloping surfaces patterned after the slope of the erosion surface cut into the pumice deposit and overlain by approximately 1 m of peat on the sloping surface and alluvium or iron-cemented pumice overlain by alluvium at the toe of the slope. The predominant source of groundwater is snowmelt which infiltrates the pumice deposit during the freshet. However, shallow groundwater flow also takes place along permeable pathways in bedrock units. Locally, low volume discharge takes place along faults. The snowmelt-dependent hydrologic system that supports the fens of the Walker Rim study area occurs at elevations primarily above 1585 m.展开更多
The novel Fe-N co-doped ordered mesoporous carbon with high catalytic activity in m-cresol removal was prepared by urea-assisted impregnation and simple pyrolysis method.During the preparation of the Fe-NC catalyst,th...The novel Fe-N co-doped ordered mesoporous carbon with high catalytic activity in m-cresol removal was prepared by urea-assisted impregnation and simple pyrolysis method.During the preparation of the Fe-NC catalyst,the complexation of N elements in urea could anchor Fe,and the formation of C3N4during urea pyrolysis could also prevent migration and aggregation of Fe species,which jointly improve the dispersion and stability of Fe.The FeN4sites and highly dispersed Fe nanoparticles synergistically trigger the dual-site peroxymonosulfate (PMS) activation for highly efficient m-cresol degradation,while the ordered mesoporous structure of the catalyst could improve the mass transfer rate of the catalytic process,which together promote catalytic degradation of m-cresol by PMS activation.Reactive oxygen species (ROS) analytic experiments demonstrate that the system degrades m-cresol by free radical pathway mainly based on SO_(4)^(-)·and·OH,and partially based on·OH as the active components,and a possible PMS activation mechanism by 5Fe-50 for m-cresol degradation was proposed.This study can provide theoretical guidance for the preparation of efficient and stable catalysts for the degradation of organic pollutants by activated PMS.展开更多
Activity 1.Think about the following questions and write down your answers before reading the text.1.Have you ever tried Liuzhou Luosifen?If so,what did you think of it?2.What makes Liuzhou Luosifen unique compared to...Activity 1.Think about the following questions and write down your answers before reading the text.1.Have you ever tried Liuzhou Luosifen?If so,what did you think of it?2.What makes Liuzhou Luosifen unique compared to other types of noodles?展开更多
目的探讨姜黄素(curcumin)对乳腺癌细胞中顺铂(Cisplatin,CDDP)治疗敏感性的影响及其可能机制。方法 CCK-8检测、Hoechst染色观察CDDP、姜黄素单独及联合用药48 h对MCF7细胞增殖抑制和细胞凋亡的影响;Western blot分析MCF7细胞在CDDP(0...目的探讨姜黄素(curcumin)对乳腺癌细胞中顺铂(Cisplatin,CDDP)治疗敏感性的影响及其可能机制。方法 CCK-8检测、Hoechst染色观察CDDP、姜黄素单独及联合用药48 h对MCF7细胞增殖抑制和细胞凋亡的影响;Western blot分析MCF7细胞在CDDP(0、1.25、2.5、5、10、20μg/m L)、姜黄素(0、1、5、20、30、50、100μmol/L)单独及联合处理后FEN1(flap endonuclease 1)表达水平的变化;CCK-8检测沉默FEN1对MCF7细胞中CDDP敏感性的影响。结果 CDDP、姜黄素均可以剂量依赖方式抑制MCF7细胞增殖,其IC50分别为5、30μmol/L;与单独2μg/m L CDDP处理组比较,2μg/m L CDDP联合20μmol/L姜黄素、30μmol/L姜黄素处理组对细胞增殖的抑制效应明显增强[分别为(84.1±0.8)%、(51.1±0.5)%、(29.4±0.3)%,P<0.05];与单独20μmol/L姜黄素处理组比较,20μmol/L姜黄素联合2μg/m L CDDP、5μg/m L CDDP处理组对细胞增殖的抑制效应也明显增强[分别为(76.9±0.7)%、(42.4±0.3)%、(31.6±0.4)%,P<0.05];2μg/m L CDDP联合20μmol/L姜黄素组的细胞凋亡明显增强(P<0.05);与Control siRNA组比较,FEN1 siRNA+CDDP组可显著增强CDDP抑制MCF7细胞增殖的敏感性[(25.4±0.3)%vs(18.7±0.2)%,P<0.05];CDDP增殖抑制无效浓度或低浓度时,FEN1蛋白的表达随CDDP的处理剂量依赖性上调,而姜黄素可剂量依赖性下调FEN1蛋白表达;与单独CDDP和姜黄素处理组比较,2μg/m L CDDP联合20μmol/L姜黄素组可显著降低FEN1蛋白表达(P<0.05)。结论姜黄素可增强CDDP对乳腺癌细胞的敏感性,其机制与降低细胞FEN1的表达有关。展开更多
因其速率快、稳定性高,非金属N与金属共掺杂的碳材料作为新型高效ORR催化剂而引起了人们的广泛关注.采用包含色散力校正的密度泛函理论方法系统地研究了氧分子在FeN_4掺杂的碳纳米管上的吸附、氢化特性.结果表明:(1)O_2倾向于以end-on...因其速率快、稳定性高,非金属N与金属共掺杂的碳材料作为新型高效ORR催化剂而引起了人们的广泛关注.采用包含色散力校正的密度泛函理论方法系统地研究了氧分子在FeN_4掺杂的碳纳米管上的吸附、氢化特性.结果表明:(1)O_2倾向于以end-on模式吸附在Fe顶位,O-O键与衬底表面成一定角度,并指向五元环,对应的吸附能为1.62 e V.(2)O_2在FeN_4-CNTs上更倾向于直接氢化为OOH,然后解离为O+OH,整个路径的限速步为OOH的解离,对应的势垒为1.19 eV.展开更多
因其较好的稳定性和催化活性,非金属N与金属共掺杂的富勒烯(C60)作为新型氧化还原反应(ORR)催化剂受到了人们的广泛关注.采用基于密度泛函理论的第一性原理方法系统地研究了Fe N4掺杂对C60催化特性的调制规律,揭示了O_2在Fe N4掺杂的C6...因其较好的稳定性和催化活性,非金属N与金属共掺杂的富勒烯(C60)作为新型氧化还原反应(ORR)催化剂受到了人们的广泛关注.采用基于密度泛函理论的第一性原理方法系统地研究了Fe N4掺杂对C60催化特性的调制规律,揭示了O_2在Fe N4掺杂的C60上的吸附和氢化特性.结果表明:(1)O_2倾向于以side-on模式吸附在Fe的顶位上,O-O键平行于C60的球切面,与Fe形成O-Fe-O三元环结构,对应的吸附能为1.48 e V.(2)O_2的氢化反应路径可以分为两条:(i)O_2先解离为O+O,然后氢化为O+OH.O_2的解离为反应的速控步,势垒为2.82 e V.(ii)O_2先氢化形成OOH结构,然后解离.氢化为反应的速控步,势垒为2.83 e V.展开更多
文摘在前期FeN/C催化剂研究的基础上,以不同的含硫化合物为硫源,在Ar气氛下高温热处理获得一系列FeNS/C催化剂。使用线性扫描伏安法测试催化剂的氧还原活性,通过热重分析、比表面积和孔径分布测试对催化剂前驱体的热性质及催化剂的结构等进行表征。结果表明,分别以硫脲为硫源,1,10-菲啰啉为氮源,FeCl_3为铁源,Black Pearl 2000为载体,催化剂前驱体中硫含量为1wt.%时,所得催化剂比表面积为559. 39 m^2/g,且催化剂表现出较好的氧还原催化活性。硫源的种类、热性质对催化剂的氧还原活性有着明显影响。
文摘Subaerial fallout from the Holocene eruption of Mount Mazama in the Oregon Cascade Range was deposited upon relatively low permeability volcanic and volcaniclastic bedrock and regolith. In the Walker Rim study area, erosion by ephemeral streams shortly after the eruption disrupted the lateral continuity of the 270 to 300 cm-thick pumice deposit. Co-evolution of the surface- and ground-water systems in a low-relief, low-slope landscape allowed diffuse groundwater discharge from the banks of the evolving stream system. Accumulation of organic material from groundwater dependent ecosystems at these sites of discharge allowed peat deposits to form on gently sloping erosion surfaces cut into the pumice deposit. Following early stream incision, fine-grained, silt-rich deposits accumulated in valleys and contributed permeability barriers to the lateral migration of water in the pumice aquifer. Fens discharge from the pumice aquifer through gently sloping surfaces patterned after the slope of the erosion surface cut into the pumice deposit and overlain by approximately 1 m of peat on the sloping surface and alluvium or iron-cemented pumice overlain by alluvium at the toe of the slope. The predominant source of groundwater is snowmelt which infiltrates the pumice deposit during the freshet. However, shallow groundwater flow also takes place along permeable pathways in bedrock units. Locally, low volume discharge takes place along faults. The snowmelt-dependent hydrologic system that supports the fens of the Walker Rim study area occurs at elevations primarily above 1585 m.
基金gratefully acknowledge the financial support of the National Natural Science Foundation of China(22108145 and 21978143)the Shandong Province Natural Science Foundation(ZR2020QB189)+1 种基金State Key Laboratory of Heavy Oil Processing(SKLHOP202203008)the Talent Foundation funded by Province and Ministry Co-construction Collaborative Innovation Center of Eco-chemical Engineering(STHGYX2201).
文摘The novel Fe-N co-doped ordered mesoporous carbon with high catalytic activity in m-cresol removal was prepared by urea-assisted impregnation and simple pyrolysis method.During the preparation of the Fe-NC catalyst,the complexation of N elements in urea could anchor Fe,and the formation of C3N4during urea pyrolysis could also prevent migration and aggregation of Fe species,which jointly improve the dispersion and stability of Fe.The FeN4sites and highly dispersed Fe nanoparticles synergistically trigger the dual-site peroxymonosulfate (PMS) activation for highly efficient m-cresol degradation,while the ordered mesoporous structure of the catalyst could improve the mass transfer rate of the catalytic process,which together promote catalytic degradation of m-cresol by PMS activation.Reactive oxygen species (ROS) analytic experiments demonstrate that the system degrades m-cresol by free radical pathway mainly based on SO_(4)^(-)·and·OH,and partially based on·OH as the active components,and a possible PMS activation mechanism by 5Fe-50 for m-cresol degradation was proposed.This study can provide theoretical guidance for the preparation of efficient and stable catalysts for the degradation of organic pollutants by activated PMS.
文摘Activity 1.Think about the following questions and write down your answers before reading the text.1.Have you ever tried Liuzhou Luosifen?If so,what did you think of it?2.What makes Liuzhou Luosifen unique compared to other types of noodles?
文摘目的探讨姜黄素(curcumin)对乳腺癌细胞中顺铂(Cisplatin,CDDP)治疗敏感性的影响及其可能机制。方法 CCK-8检测、Hoechst染色观察CDDP、姜黄素单独及联合用药48 h对MCF7细胞增殖抑制和细胞凋亡的影响;Western blot分析MCF7细胞在CDDP(0、1.25、2.5、5、10、20μg/m L)、姜黄素(0、1、5、20、30、50、100μmol/L)单独及联合处理后FEN1(flap endonuclease 1)表达水平的变化;CCK-8检测沉默FEN1对MCF7细胞中CDDP敏感性的影响。结果 CDDP、姜黄素均可以剂量依赖方式抑制MCF7细胞增殖,其IC50分别为5、30μmol/L;与单独2μg/m L CDDP处理组比较,2μg/m L CDDP联合20μmol/L姜黄素、30μmol/L姜黄素处理组对细胞增殖的抑制效应明显增强[分别为(84.1±0.8)%、(51.1±0.5)%、(29.4±0.3)%,P<0.05];与单独20μmol/L姜黄素处理组比较,20μmol/L姜黄素联合2μg/m L CDDP、5μg/m L CDDP处理组对细胞增殖的抑制效应也明显增强[分别为(76.9±0.7)%、(42.4±0.3)%、(31.6±0.4)%,P<0.05];2μg/m L CDDP联合20μmol/L姜黄素组的细胞凋亡明显增强(P<0.05);与Control siRNA组比较,FEN1 siRNA+CDDP组可显著增强CDDP抑制MCF7细胞增殖的敏感性[(25.4±0.3)%vs(18.7±0.2)%,P<0.05];CDDP增殖抑制无效浓度或低浓度时,FEN1蛋白的表达随CDDP的处理剂量依赖性上调,而姜黄素可剂量依赖性下调FEN1蛋白表达;与单独CDDP和姜黄素处理组比较,2μg/m L CDDP联合20μmol/L姜黄素组可显著降低FEN1蛋白表达(P<0.05)。结论姜黄素可增强CDDP对乳腺癌细胞的敏感性,其机制与降低细胞FEN1的表达有关。
文摘因其速率快、稳定性高,非金属N与金属共掺杂的碳材料作为新型高效ORR催化剂而引起了人们的广泛关注.采用包含色散力校正的密度泛函理论方法系统地研究了氧分子在FeN_4掺杂的碳纳米管上的吸附、氢化特性.结果表明:(1)O_2倾向于以end-on模式吸附在Fe顶位,O-O键与衬底表面成一定角度,并指向五元环,对应的吸附能为1.62 e V.(2)O_2在FeN_4-CNTs上更倾向于直接氢化为OOH,然后解离为O+OH,整个路径的限速步为OOH的解离,对应的势垒为1.19 eV.
文摘因其较好的稳定性和催化活性,非金属N与金属共掺杂的富勒烯(C60)作为新型氧化还原反应(ORR)催化剂受到了人们的广泛关注.采用基于密度泛函理论的第一性原理方法系统地研究了Fe N4掺杂对C60催化特性的调制规律,揭示了O_2在Fe N4掺杂的C60上的吸附和氢化特性.结果表明:(1)O_2倾向于以side-on模式吸附在Fe的顶位上,O-O键平行于C60的球切面,与Fe形成O-Fe-O三元环结构,对应的吸附能为1.48 e V.(2)O_2的氢化反应路径可以分为两条:(i)O_2先解离为O+O,然后氢化为O+OH.O_2的解离为反应的速控步,势垒为2.82 e V.(ii)O_2先氢化形成OOH结构,然后解离.氢化为反应的速控步,势垒为2.83 e V.
