Formation of a p–n heterojunction rather than p-type or n-type semiconductors can enhance the separation of photogenerated electrons and holes and increase the quantum efficiency of photocatalytic reactions owing to ...Formation of a p–n heterojunction rather than p-type or n-type semiconductors can enhance the separation of photogenerated electrons and holes and increase the quantum efficiency of photocatalytic reactions owing to the difference of the electric potential in the inner electric field near the junction,pointing from n toward p. n-Ag3PO4/p-Ag2CO3 p–n heterojunction composites are prepared through a facile coprecipitation process. The obtained Ag3PO4/Ag2CO3 p–n heterojunctions exhibit excellent photocatalytic performance in the removal of rhodamine B（RhB） compared with Ag3PO4 and Ag2CO3. The 40%-Ag3PO4/Ag2CO3 composite photocatalyst（40 mol% Ag3PO4 and 60 mol% Ag2CO3） exhibits the best photocatalytic activity under visible light,demonstrating the ability to completely degrade RhB within 15 min. Transient photovoltage characterization and an active species trapping experiment further indicate that the formation of a p–n heterojunction structure can greatly enhance the separation efficiency of photogenerated carriers and produce more free h＋active species,which is the predominant contributor for RhB removal.展开更多
A study was carried out on contribution of iron pbosphate to phosphorus nutrition of rice plant nnderwaterlogged and moist conditions, respectively, by use of synthetic Fe￣(32) PO_4 . nH_2O, tagging directly the iron...A study was carried out on contribution of iron pbosphate to phosphorus nutrition of rice plant nnderwaterlogged and moist conditions, respectively, by use of synthetic Fe￣(32) PO_4 . nH_2O, tagging directly the ironphophate in calcareous paddy soils.Results showed that under waterlogged condition, similar to iron phosphate in acidic paddy soils, that incalcareous paddy soils was an important source of phosphorus to rice plant, and the amount of phosphorusoriginated from it generally constituted 30-65% of the total phosphorus absorbed by rice plant.展开更多
Si/SiGe P-channel Metal-Oxide-Semiconductor Field Effect Transistor (PMOSFET) using P+ (phosphor ion) implantation technology is successfully fabricated. P+ implantation into SiGe virtual substrate induces a narrow de...Si/SiGe P-channel Metal-Oxide-Semiconductor Field Effect Transistor (PMOSFET) using P+ (phosphor ion) implantation technology is successfully fabricated. P+ implantation into SiGe virtual substrate induces a narrow defect region slightly below the SiGe/Si interface,which gives rise to strongly enhanced strain relaxation of SiGe virtual substrate. X-Ray Diffraction (XRD) tests show that the degree of relaxation of SiGe layer is 96% while 85% before implantation. After annealed,the sample appeared free of Threading Dislocation densities (TDs) within the SiGe layer to the limit of Trans-mission Electron Microscopy (TEM) analysis. Atomic Force Microscope (AFM) test of strained Si channel surface shows that Root Mean Square (RMS) is 1.1nm. The Direct Current (DC) characters measured by HP 4155B indicate that the maximum saturated transconductance is twice bigger than that of bulk Si PMOSFET.展开更多
Chemical forms of the phosphate adsorbed on goethite surfaces and characteristics of the coordinategroups which exchange with P on goethite surfaces in solutions with different pll values were investigated.Results sho...Chemical forms of the phosphate adsorbed on goethite surfaces and characteristics of the coordinategroups which exchange with P on goethite surfaces in solutions with different pll values were investigated.Results showed that the chemical forms of P on goethite surfaces changed from the dominance of monodentatecorrdination to that of bidentate one with increasing pH of the solution. By influencing types of phosphateions in solutions, pH affected the chemical forms of P on goethite surfaces. The amount of OH￣- displacedby phosphate on goethite surfaces was the most at pH 7.0, the second at pH 9.0, and the least at pH 4.5.展开更多
A mild,green,convenient and scalable N-bromosuccinimide(NBS)promoted direct phosphorylation strategy of secondary phosphine oxides and alcohols for the synthesis of various phosphinate esters was developed.A variety o...A mild,green,convenient and scalable N-bromosuccinimide(NBS)promoted direct phosphorylation strategy of secondary phosphine oxides and alcohols for the synthesis of various phosphinate esters was developed.A variety of substrates are well-tolerated and the desirable compounds were afforded in moderate to excellent yields(up to 92%).This reaction is conducted at room temperature without the addition of any oxidant and metal catalyst,which provides a new strategy for the synthesis of phosphinate esters.展开更多
Determining how agricultural management practices affect soil phosphorus(P) over the winter may further our understanding of the soil P cycle under specific environmental conditions in eastern Canada. This study asses...Determining how agricultural management practices affect soil phosphorus(P) over the winter may further our understanding of the soil P cycle under specific environmental conditions in eastern Canada. This study assessed changes over winter for soil P fractions and other selected chemical properties as affected by tillage and P fertilization. In 1992, a long-term corn(Zea mays L.) and soybean(Glycine max L.) rotational experiment was established in the province of Quebec, Canada. Soil samples(0–15 cm) were collected in fall 2001 and 2007 after a soybean harvest, and in the following spring 2002 and 2008 before corn seeding, in main plots under moldboard plow and no-till managements and selected subplots fertilized with 0, 17.5, or 35 kg P ha-1and 160 kg N ha-1. Soil samples were analyzed for P fractions and other chemical properties to assess changes over winter for 2001–2002 and 2007–2008. Changes over winter of all soil P fractions were significant for the two periods, indicating the occurrence of soil P transformation and movement over winter. The Mehlich-3-extractable Fe, Al, Ca, and Mg decreased during the two studied periods. Tillage had no significant effect on all soil P fractions. The resin-extractable P in 2001–2002 and Na HCO3-extractable inorganic P and Na OH-extractable organic P during the two winters were significantly increased under P fertilization. This study demonstrated that P in cultivated soils changed during winter as a result of changes in labile P fractions possibly due to the solubilization of residual fertilizer P combined with environmental factors.展开更多
基金supported by the National Natural Science Foundation of China(2100705351302241)+1 种基金the Education Department of Henan Province(2012GGJS-174)Xuchang University Science Research Foundation(2015011)~~
文摘Formation of a p–n heterojunction rather than p-type or n-type semiconductors can enhance the separation of photogenerated electrons and holes and increase the quantum efficiency of photocatalytic reactions owing to the difference of the electric potential in the inner electric field near the junction,pointing from n toward p. n-Ag3PO4/p-Ag2CO3 p–n heterojunction composites are prepared through a facile coprecipitation process. The obtained Ag3PO4/Ag2CO3 p–n heterojunctions exhibit excellent photocatalytic performance in the removal of rhodamine B（RhB） compared with Ag3PO4 and Ag2CO3. The 40%-Ag3PO4/Ag2CO3 composite photocatalyst（40 mol% Ag3PO4 and 60 mol% Ag2CO3） exhibits the best photocatalytic activity under visible light,demonstrating the ability to completely degrade RhB within 15 min. Transient photovoltage characterization and an active species trapping experiment further indicate that the formation of a p–n heterojunction structure can greatly enhance the separation efficiency of photogenerated carriers and produce more free h＋active species,which is the predominant contributor for RhB removal.
文摘A study was carried out on contribution of iron pbosphate to phosphorus nutrition of rice plant nnderwaterlogged and moist conditions, respectively, by use of synthetic Fe￣(32) PO_4 . nH_2O, tagging directly the ironphophate in calcareous paddy soils.Results showed that under waterlogged condition, similar to iron phosphate in acidic paddy soils, that incalcareous paddy soils was an important source of phosphorus to rice plant, and the amount of phosphorusoriginated from it generally constituted 30-65% of the total phosphorus absorbed by rice plant.
基金Supported by the Funds of National Key Laboratory of Analog IC (2000JS09.3.1.DZ02).
文摘Si/SiGe P-channel Metal-Oxide-Semiconductor Field Effect Transistor (PMOSFET) using P+ (phosphor ion) implantation technology is successfully fabricated. P+ implantation into SiGe virtual substrate induces a narrow defect region slightly below the SiGe/Si interface,which gives rise to strongly enhanced strain relaxation of SiGe virtual substrate. X-Ray Diffraction (XRD) tests show that the degree of relaxation of SiGe layer is 96% while 85% before implantation. After annealed,the sample appeared free of Threading Dislocation densities (TDs) within the SiGe layer to the limit of Trans-mission Electron Microscopy (TEM) analysis. Atomic Force Microscope (AFM) test of strained Si channel surface shows that Root Mean Square (RMS) is 1.1nm. The Direct Current (DC) characters measured by HP 4155B indicate that the maximum saturated transconductance is twice bigger than that of bulk Si PMOSFET.
文摘Chemical forms of the phosphate adsorbed on goethite surfaces and characteristics of the coordinategroups which exchange with P on goethite surfaces in solutions with different pll values were investigated.Results showed that the chemical forms of P on goethite surfaces changed from the dominance of monodentatecorrdination to that of bidentate one with increasing pH of the solution. By influencing types of phosphateions in solutions, pH affected the chemical forms of P on goethite surfaces. The amount of OH￣- displacedby phosphate on goethite surfaces was the most at pH 7.0, the second at pH 9.0, and the least at pH 4.5.
文摘A mild,green,convenient and scalable N-bromosuccinimide(NBS)promoted direct phosphorylation strategy of secondary phosphine oxides and alcohols for the synthesis of various phosphinate esters was developed.A variety of substrates are well-tolerated and the desirable compounds were afforded in moderate to excellent yields(up to 92%).This reaction is conducted at room temperature without the addition of any oxidant and metal catalyst,which provides a new strategy for the synthesis of phosphinate esters.
基金supported by Agriculture and Agri-Food Canada(AAFC)the MOE(Ministry of Education of China)-AAFC Ph.D.Research Program
文摘Determining how agricultural management practices affect soil phosphorus(P) over the winter may further our understanding of the soil P cycle under specific environmental conditions in eastern Canada. This study assessed changes over winter for soil P fractions and other selected chemical properties as affected by tillage and P fertilization. In 1992, a long-term corn(Zea mays L.) and soybean(Glycine max L.) rotational experiment was established in the province of Quebec, Canada. Soil samples(0–15 cm) were collected in fall 2001 and 2007 after a soybean harvest, and in the following spring 2002 and 2008 before corn seeding, in main plots under moldboard plow and no-till managements and selected subplots fertilized with 0, 17.5, or 35 kg P ha-1and 160 kg N ha-1. Soil samples were analyzed for P fractions and other chemical properties to assess changes over winter for 2001–2002 and 2007–2008. Changes over winter of all soil P fractions were significant for the two periods, indicating the occurrence of soil P transformation and movement over winter. The Mehlich-3-extractable Fe, Al, Ca, and Mg decreased during the two studied periods. Tillage had no significant effect on all soil P fractions. The resin-extractable P in 2001–2002 and Na HCO3-extractable inorganic P and Na OH-extractable organic P during the two winters were significantly increased under P fertilization. This study demonstrated that P in cultivated soils changed during winter as a result of changes in labile P fractions possibly due to the solubilization of residual fertilizer P combined with environmental factors.
