Doping effects of manganese (Mn) on catalytic performance and structure evolution of NiMgO catalysts for synthesis of multi-walled carbon nanotubes (MWCNTs) from methane were investigated for the first time. Addit...Doping effects of manganese (Mn) on catalytic performance and structure evolution of NiMgO catalysts for synthesis of multi-walled carbon nanotubes (MWCNTs) from methane were investigated for the first time. Addition of Mn in NiMgO catalyst can greatly improve the MWCNTs yield. Mno.2NiMgO catalyst among the tested ones gives the highest MWCNTs yield as 2244%, which is two times higher than that of the catalyst without Mn. The structure evolution, reduction behaviors and surface chemical properties of MnNiMgO catalysts with various Mn contents were studied in detail. It was found that the stable solid solution of NiMgO2 formed in NiMgO catalyst was disturbed by the addition of Mn. Instead, another solid solution of MnMg608 is formed. More amount of Ni can be reduced and dispersed on the catalyst surface to be acted as active sites. Importantly, the changes of Ni content on the surface are correlated with the Ni particle size and the outer diameter of MWCNTs, suggesting the controllable synthesis of MWCNTs over MnNiMgO catalysts.展开更多
[Objective] The study aimed to discuss the impact of rainfall change on agricultural non-point source pollution in Uangping County. E Method ] Based on daily precipitation data of Liangping from 1955 to 2011, changes ...[Objective] The study aimed to discuss the impact of rainfall change on agricultural non-point source pollution in Uangping County. E Method ] Based on daily precipitation data of Liangping from 1955 to 2011, changes of precipitation and frequency of heavy rain in Uangping during a year were analyzed firstly, and then the risk of surface runoff caused by rainfall to agricultural non-point source pollution was studied, finally chan- ging trends of annual average precipitation and frequency during 1955 -2011 were discussed using Mann-Kendal method. [ Result] Total precipitati- on of heavy rain in Liangping mainly concentrated from late May to early September, especially in eady and middle July as well as early September. Meanwhile, fertilizer and pesticide were applied to main crops in Liangping in the periods above, so agricultural non-point source pollution became more serious. In recent 57 years, annual average precipitation and frequency of heavy rain in Liangping showed an increasing trend respectively, and surface runoff rose with the increase of the precipitation, thereby probably enlarging agricultural pollution area. [ Conclusion] The research could provide a theoretical basis and technical support for the control of agricultural non-point source pollution.展开更多
The importance of CF3-containing molecules in pharmaceuticals, agrochemicals and materials intrigues the intense interest in synthetic methodology of these compounds. With a purpose to enrich trifluoromethylation meth...The importance of CF3-containing molecules in pharmaceuticals, agrochemicals and materials intrigues the intense interest in synthetic methodology of these compounds. With a purpose to enrich trifluoromethylation methodology, we carefully examined the substrate scope of hydroxytrifluoromethylation of alkenes using iodotrifluoromethane, and the reaction provided β-trifluoromethyl alcohols in good yields under extremely mild conditions without catalysts. We found that our reaction can be applied to not only styrenes but also various aliphatic alkenes with excellent selectivity;no ketone was detected in most of our cases. Another feature of our discovery is “simple”. The reaction was carried out in air, irradiated by visible light, at room temperature and most importantly no catalyst was needed. A solution of CF3I in DMSO was used as the facile trifluoromethylating reagent, which simplified the utilization of gaseous CF3I. Based on 19F NMR spectroscopy, we observed a halogen bond between CF3I and tertiary amine in this reaction. The interaction may promote single electron transfer by the visible light irradiation.展开更多
The combination of field surveys with analysis of microstructure of tectonite and Electron Backscatter Diffraction(EBSD) on quartz fabric indicated that three periods of ductile shear events developed in the Paishanlo...The combination of field surveys with analysis of microstructure of tectonite and Electron Backscatter Diffraction(EBSD) on quartz fabric indicated that three periods of ductile shear events developed in the Paishanlou gold deposits and the E-W and NE-striking ductile shear zones were formed during each event.The E-W-striking ductile shear zone,accompanied by compressional and dextral shear slip,was shear-cut by the NE-striking shear zones,accompanied by compressional-sinistral shear slip and sinistral-normal shear slip,successively.An E-W-striking ductile shear zone developed at a deeper tectonic level and at middle- to high-temperatures,accompanied by abundant microstructures,including microlayering between a polycrystal quartz belt and mica,and quartz deformation was depended on cylinder(10-10) or <c> glide.The development of an E-W-striking shear zone can be seen as a tectonic pattern in the region of the Paishanlou gold deposits of the collision between the Mongolian tectonic belt and the North Archean Craton from Suolun to the Linxi suture zone during the Indosinian.The NE-striking ductile shear zone developed approximately 160 Ma during the early Yianshanian at middle to shallow tectonic levels and at middle- to low-temperatures,accompanied by typical microstructures,including polycrystal quartz aggregation and quartz subgrain rotation recrystallization,etc.,and quartz deformation was depended on prismatic(1011) glide.The last ductile shear event around the NE-striking shear zone developed at low temperatures and shallow tectonic levels,yielding to a pre-existing NE-striking shear zone,accompanied by abundant microstructures,including low-temperature quartz grain boundary migration and bulging recrystallization.The last ductile shear movement may be related to lithosphere thinning and the destruction of the North China Craton from approximately 130-120 Ma,and this shear event resulted directly in the mineralization in the Paishanlou region.展开更多
In this study, liquid crystal(LC) was used to study the interactions of alkyl polyglycosides(APG) with gelatin and bovine serum albumin(BSA) at the LC-aqueous interface. The LC easily undergo an orientational tr...In this study, liquid crystal(LC) was used to study the interactions of alkyl polyglycosides(APG) with gelatin and bovine serum albumin(BSA) at the LC-aqueous interface. The LC easily undergo an orientational transition from a homeotropic to a planar state after proteins were in contact to the LCaqueous interface decorated with APG, thus inducing an optical change from dark to bright. The optical image analysis reveals that the rearrangement rate of APG monolayer is tightly dependent on the concentration and chemical structure of the protein of interest. For example, the rearrangement rate of APG monolayer increases with an increasing gelatin concentration. We also find that the chemical structure of the proteins has a significant impact on the difference in the growth behavior of bright domains in LC.展开更多
The decoration of CNTs surface by magnetic nanoparticles was achieved by an ultrasonication-assisted hydrothermal method(UAHM).The effect of ultrasonication time on the crystal structure,magnetic performance,and che...The decoration of CNTs surface by magnetic nanoparticles was achieved by an ultrasonication-assisted hydrothermal method(UAHM).The effect of ultrasonication time on the crystal structure,magnetic performance,and chemical composition of the magnetic CNT composite material was determined.X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FTIR),transmission electron microscopy(TEM),and vibrating sample magnetometry were used to characterize the physical,chemical,and magnetic properties of the composites.The composites synthesized via the UAHM exhibited superparamagnetic properties.The ultrasonication time was a critical factor that affected the structure and magnetic performance of the composites.By simply controlling the ultrasonication time,the crystal phase structure of Fe oxide could be selectively modulated and the magnetic performance of the MCs could be effectively tuned.展开更多
Combined with field studies, microscopic observations, and EBSD fabric analysis, we defined a possible Early Cretaceous metamorphic core complex (MCC) in the Wulian area along the Sulu orogenic belt in eastern China...Combined with field studies, microscopic observations, and EBSD fabric analysis, we defined a possible Early Cretaceous metamorphic core complex (MCC) in the Wulian area along the Sulu orogenic belt in eastern China. The MCC is of typical Cordilleran type with five elements: (1) a master detachment fault and sheared rocks beneath it, a lower plate of crystalline rockswith (2) middle crust metamorphic rocks, (3) syn-kinematic plutons, (4) an upper plate of weakly deformed Proterozoic metamorphic rocks, and (5) Cretaceous volcanic-sedimentary rocks in the supradetachment basin. Some postkinematic incursions cut across the master detachment fault zone and two plates. In the upper plate, Zhucheng (诸城) Basin basement consists of the Proterozoic Fenzishan (粉子山) Group, Jinning period granite (762–834 Ma). The s u pr a de tac hme nt ba sin a bo ve the Proterozoic rocks is filled with the Early Cretaceous Laiyang (莱阳) (~135–125 Ma) and Qingshan (青山) groups (120–105 Ma), as wellas the Late Cretaceous Wangshi (王氏) Group (85–65 Ma). The detachment fault zone is developed at the base and margin of the superposed basin. Pseudotachylite and micro breccia layers located at the top of the detachment fault. Stretching lineation and foliation are well developed in the ductile shear belt in the detachment faults. The stretching lineation indicates a transport direction of nearly east to west on the whole, while the foliations trend WNW, WSW, and SE. Protomylonite, mylonite, and ultramylonite are universally developed in the faults, transitioning to mylonitic gneiss, and finally to gneiss downward. Microstructure and quartz preferred orientation show that the mylonites formed at high greenschist facies to low greenschist facies as a whole. The footwall metamorphic rock series of the Wulian MCC are chiefly UHP (ultrahigh pressure) metamorphic rocks. Syntectonic rocks developed simultaneously with the Wulian MCC detachment and extension. Geological research has demonstrated that the MCC is associated with small-scale intrusive rocks developing in the vicinity of the detachment faults, for instance, dike. Geochronology results indicate that the denudation of the Wulian MCC occurred at about 135–122 Ma. Its development and exhumation was irrelevant to the Sulu UHP metamorphism zone rapid exhumation during Triassic Period but resulted from the crustal extension of North China Craton and adjacent area.展开更多
基金supported by the National Natural Science Foundation of China(20776089)the Fundamental Research Funds for the Central Universities(2014NZYQN20)
文摘Doping effects of manganese (Mn) on catalytic performance and structure evolution of NiMgO catalysts for synthesis of multi-walled carbon nanotubes (MWCNTs) from methane were investigated for the first time. Addition of Mn in NiMgO catalyst can greatly improve the MWCNTs yield. Mno.2NiMgO catalyst among the tested ones gives the highest MWCNTs yield as 2244%, which is two times higher than that of the catalyst without Mn. The structure evolution, reduction behaviors and surface chemical properties of MnNiMgO catalysts with various Mn contents were studied in detail. It was found that the stable solid solution of NiMgO2 formed in NiMgO catalyst was disturbed by the addition of Mn. Instead, another solid solution of MnMg608 is formed. More amount of Ni can be reduced and dispersed on the catalyst surface to be acted as active sites. Importantly, the changes of Ni content on the surface are correlated with the Ni particle size and the outer diameter of MWCNTs, suggesting the controllable synthesis of MWCNTs over MnNiMgO catalysts.
基金the Innovative and Entrepreneurship Training Program for Undergraduates in China in 2013(201310643003)Innovative and Entrepreneurship Training Program for Undergraduates in Chongqing in 2012(201210643009)+1 种基金Scientific and Technological Research Project of Education of Chongqing(KJ091106)Project for Young Scholars of Chongqing Three Gorges University(11QN-22)
文摘[Objective] The study aimed to discuss the impact of rainfall change on agricultural non-point source pollution in Uangping County. E Method ] Based on daily precipitation data of Liangping from 1955 to 2011, changes of precipitation and frequency of heavy rain in Uangping during a year were analyzed firstly, and then the risk of surface runoff caused by rainfall to agricultural non-point source pollution was studied, finally chan- ging trends of annual average precipitation and frequency during 1955 -2011 were discussed using Mann-Kendal method. [ Result] Total precipitati- on of heavy rain in Liangping mainly concentrated from late May to early September, especially in eady and middle July as well as early September. Meanwhile, fertilizer and pesticide were applied to main crops in Liangping in the periods above, so agricultural non-point source pollution became more serious. In recent 57 years, annual average precipitation and frequency of heavy rain in Liangping showed an increasing trend respectively, and surface runoff rose with the increase of the precipitation, thereby probably enlarging agricultural pollution area. [ Conclusion] The research could provide a theoretical basis and technical support for the control of agricultural non-point source pollution.
基金the National Natural Science Foundation of China (Nos.21672239,21737004 and 21421002)Key Laboratory of Photochemical Conversion and Optoelectr onic Materials,TIPC,CAS,the Sanming Institute of Fluorochemical Industry (Nos.FCIT201704GR,FCIT201705GR,FCIT201701BR)STS Program of Chinese Academy of Science (KF-STS-QYZX-068).
文摘The importance of CF3-containing molecules in pharmaceuticals, agrochemicals and materials intrigues the intense interest in synthetic methodology of these compounds. With a purpose to enrich trifluoromethylation methodology, we carefully examined the substrate scope of hydroxytrifluoromethylation of alkenes using iodotrifluoromethane, and the reaction provided β-trifluoromethyl alcohols in good yields under extremely mild conditions without catalysts. We found that our reaction can be applied to not only styrenes but also various aliphatic alkenes with excellent selectivity;no ketone was detected in most of our cases. Another feature of our discovery is “simple”. The reaction was carried out in air, irradiated by visible light, at room temperature and most importantly no catalyst was needed. A solution of CF3I in DMSO was used as the facile trifluoromethylating reagent, which simplified the utilization of gaseous CF3I. Based on 19F NMR spectroscopy, we observed a halogen bond between CF3I and tertiary amine in this reaction. The interaction may promote single electron transfer by the visible light irradiation.
基金supported by National Crisis Mine Program(Grant No.20089931)National Natural Science Foundation of China(Grant Nos.90814006,91214301,41172089)Foundation of Shandong Provincial Key Laboratory of Depositional Mineralization&Sedimentary Minerals(Grant No.DMSM201005)
文摘The combination of field surveys with analysis of microstructure of tectonite and Electron Backscatter Diffraction(EBSD) on quartz fabric indicated that three periods of ductile shear events developed in the Paishanlou gold deposits and the E-W and NE-striking ductile shear zones were formed during each event.The E-W-striking ductile shear zone,accompanied by compressional and dextral shear slip,was shear-cut by the NE-striking shear zones,accompanied by compressional-sinistral shear slip and sinistral-normal shear slip,successively.An E-W-striking ductile shear zone developed at a deeper tectonic level and at middle- to high-temperatures,accompanied by abundant microstructures,including microlayering between a polycrystal quartz belt and mica,and quartz deformation was depended on cylinder(10-10) or <c> glide.The development of an E-W-striking shear zone can be seen as a tectonic pattern in the region of the Paishanlou gold deposits of the collision between the Mongolian tectonic belt and the North Archean Craton from Suolun to the Linxi suture zone during the Indosinian.The NE-striking ductile shear zone developed approximately 160 Ma during the early Yianshanian at middle to shallow tectonic levels and at middle- to low-temperatures,accompanied by typical microstructures,including polycrystal quartz aggregation and quartz subgrain rotation recrystallization,etc.,and quartz deformation was depended on prismatic(1011) glide.The last ductile shear event around the NE-striking shear zone developed at low temperatures and shallow tectonic levels,yielding to a pre-existing NE-striking shear zone,accompanied by abundant microstructures,including low-temperature quartz grain boundary migration and bulging recrystallization.The last ductile shear movement may be related to lithosphere thinning and the destruction of the North China Craton from approximately 130-120 Ma,and this shear event resulted directly in the mineralization in the Paishanlou region.
基金supported by the National Natural Science Foundation of China (Nos. 51273220, 50903011)the Project of Postgraduate Degree Construction, Southwest University for Nationalities (No. 2015XWD-S0703)
文摘In this study, liquid crystal(LC) was used to study the interactions of alkyl polyglycosides(APG) with gelatin and bovine serum albumin(BSA) at the LC-aqueous interface. The LC easily undergo an orientational transition from a homeotropic to a planar state after proteins were in contact to the LCaqueous interface decorated with APG, thus inducing an optical change from dark to bright. The optical image analysis reveals that the rearrangement rate of APG monolayer is tightly dependent on the concentration and chemical structure of the protein of interest. For example, the rearrangement rate of APG monolayer increases with an increasing gelatin concentration. We also find that the chemical structure of the proteins has a significant impact on the difference in the growth behavior of bright domains in LC.
基金supported by The National Natural Science Foundation of China (Nos. 21406039, 21506174)the Project of Postgraduate Degree Construction, Southwest University for Nationalities (No. 2015XWD-S0703)
文摘The decoration of CNTs surface by magnetic nanoparticles was achieved by an ultrasonication-assisted hydrothermal method(UAHM).The effect of ultrasonication time on the crystal structure,magnetic performance,and chemical composition of the magnetic CNT composite material was determined.X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FTIR),transmission electron microscopy(TEM),and vibrating sample magnetometry were used to characterize the physical,chemical,and magnetic properties of the composites.The composites synthesized via the UAHM exhibited superparamagnetic properties.The ultrasonication time was a critical factor that affected the structure and magnetic performance of the composites.By simply controlling the ultrasonication time,the crystal phase structure of Fe oxide could be selectively modulated and the magnetic performance of the MCs could be effectively tuned.
基金supported by the National Natural Science Foundation of China(Nos.90814006,91214301)the Natural Science Foundation of Shandong Province(No.ZR2009EQ002)+1 种基金the Foundation of the Shandong Provincial Key Laboratory of Depositional Mineralization & Sedimentary Minerals(No.DMSM201005)the National Key Basic Research Development Program (973Program) of China(No.2012CB723104)
文摘Combined with field studies, microscopic observations, and EBSD fabric analysis, we defined a possible Early Cretaceous metamorphic core complex (MCC) in the Wulian area along the Sulu orogenic belt in eastern China. The MCC is of typical Cordilleran type with five elements: (1) a master detachment fault and sheared rocks beneath it, a lower plate of crystalline rockswith (2) middle crust metamorphic rocks, (3) syn-kinematic plutons, (4) an upper plate of weakly deformed Proterozoic metamorphic rocks, and (5) Cretaceous volcanic-sedimentary rocks in the supradetachment basin. Some postkinematic incursions cut across the master detachment fault zone and two plates. In the upper plate, Zhucheng (诸城) Basin basement consists of the Proterozoic Fenzishan (粉子山) Group, Jinning period granite (762–834 Ma). The s u pr a de tac hme nt ba sin a bo ve the Proterozoic rocks is filled with the Early Cretaceous Laiyang (莱阳) (~135–125 Ma) and Qingshan (青山) groups (120–105 Ma), as wellas the Late Cretaceous Wangshi (王氏) Group (85–65 Ma). The detachment fault zone is developed at the base and margin of the superposed basin. Pseudotachylite and micro breccia layers located at the top of the detachment fault. Stretching lineation and foliation are well developed in the ductile shear belt in the detachment faults. The stretching lineation indicates a transport direction of nearly east to west on the whole, while the foliations trend WNW, WSW, and SE. Protomylonite, mylonite, and ultramylonite are universally developed in the faults, transitioning to mylonitic gneiss, and finally to gneiss downward. Microstructure and quartz preferred orientation show that the mylonites formed at high greenschist facies to low greenschist facies as a whole. The footwall metamorphic rock series of the Wulian MCC are chiefly UHP (ultrahigh pressure) metamorphic rocks. Syntectonic rocks developed simultaneously with the Wulian MCC detachment and extension. Geological research has demonstrated that the MCC is associated with small-scale intrusive rocks developing in the vicinity of the detachment faults, for instance, dike. Geochronology results indicate that the denudation of the Wulian MCC occurred at about 135–122 Ma. Its development and exhumation was irrelevant to the Sulu UHP metamorphism zone rapid exhumation during Triassic Period but resulted from the crustal extension of North China Craton and adjacent area.