Molecular catalysts for H2-evolution are of interest for their integration into light-harvesting complexes for photocatalytic water splitting.Here,we report the meso-tetra(4-carboxyphenyl)porphine[(TCPP)Pt^(Ⅱ)]comple...Molecular catalysts for H2-evolution are of interest for their integration into light-harvesting complexes for photocatalytic water splitting.Here,we report the meso-tetra(4-carboxyphenyl)porphine[(TCPP)Pt^(Ⅱ)]complex as a molecular H2-evolving photocatalyst using chloranilic acid(CA)as a sacrificial electron donor,the choice of which is critical to the stability of the photocatalyst.When triethanolamine was used,[(TCPP)Pt^(Ⅱ)]decomposed to form Pt nanoparticles.Density functional theory calculations together with evidence from electrochemical and spectroscopic analyses suggested that the catalysis was possibly initiated by a proton-coupled electron transfer(PCET)to form[(TCPP)Pt^(Ⅰ)]-N-H,followed by another electron injection and protonation to form a[(TCPP)Pt^(Ⅱ)-hydride]-N-H intermediate that can release H2.As the whole catalytic cycle involves the injection of multiple electrons,a light-harvesting network should be helpful by providing multiple photo-induced electrons.Thus,we integrated this molecular catalyst into a light-harvesting metal-organic framework to boost its activity by~830 times.This work presents a mechanistic study of the photocatalytic H2 evolution and energy transfer and highlights the importance of a light-harvesting network for multiple electron injections.展开更多
Most extant nonhuman primates occasionally prey on fast-moving, warm-blooded animals; however, Indriidae, Lepilemuridae, and Colobinae either scavenged for meat or did not eat meat at all. Here we report six cases of ...Most extant nonhuman primates occasionally prey on fast-moving, warm-blooded animals; however, Indriidae, Lepilemuridae, and Colobinae either scavenged for meat or did not eat meat at all. Here we report six cases of animal consumption by the snub-nosed monkey Rhinopithecus bieti in a wild, habituated group between 2004 and 2009 in Yunnan, China. At present, only males in an all-male unit within the study group were involved in active hunting. Such a male-biased activity may be related to the group structure and spatial spread of R. bieti. Two females were observed eating freshly killed birds. The findings confirmed that R. bieti engaged in scavenging and, when hunting, employed a cranio-cervical bite to kill their prey. Meat eating is likely a nutrient maximization feeding strategy in R. bieti, especially in males. A begging behavior occurred after successful prey capture. Although begging was observed, no sharing of the meat was seen. The present findings illuminate the dietary diversity of R. bieti and their ability to expand their dietary spectrum.展开更多
This research seeks to evaluate the economic benefits to be gained by installing a small-scale wind turbine for a customer with a three-phase electrical supply requirement. The evidence for the claims made in this pap...This research seeks to evaluate the economic benefits to be gained by installing a small-scale wind turbine for a customer with a three-phase electrical supply requirement. The evidence for the claims made in this paper is obtained by using actual data obtained from the installed equipment over a three year period. The objective is to accurately appraise the financial investment using real data. There appears to be limited studies conducted into this type of research, possibly because the renewable energy sector is in the infancy stage in the host country, Ireland. There are some wind energy installations with financial appraisal techniques based on modeled data, which may, or may not, be accurate. The study concludes by claiming that the financial benefits of the wind energy turbine installation had disappointing results when compared to predicted benefits based on modeled data.展开更多
Sorghum bicolor is among main staple crops of Chad but it is commonly attacked by Striga hermonthica. Assessment of sorghum varieties for resistance to this weed was carried out during three cropping seasons （2005-2...Sorghum bicolor is among main staple crops of Chad but it is commonly attacked by Striga hermonthica. Assessment of sorghum varieties for resistance to this weed was carried out during three cropping seasons （2005-2008）, in controlled conditions; promising entries （those which fulfilled at least 75% of selection criteria） were evaluated in farmer field in 2008-2009 seasons. There were five sites （Bebedjia, Deli, Bekao, Koudoti and Ndaba）. The objective was to evaluate some sorghum entries for S. hermonthica resistance in farmer field. Sorghum test was composed of four entries in Fisher blocks as experimental designs, with five replications. Among different observed variables, there were striga plant count and weight of sorghum grains. One promising entry was selected at Bebedjia and Ndaba （53）, two at Deli and Koudoti （50 and 53）. No entry was selected at Bekao. Promising entries for the whole Southern zone of Chad were composed of 50 and 53. The best entry was 53 because it was promising in all sites except Bekao.展开更多
We investigate the structure,trapping,and diffusion behaviors of helium(He) at vacancy in a Fe single crystal using first-principles simulations.Vacancy with more space can provide the lower electron density region fo...We investigate the structure,trapping,and diffusion behaviors of helium(He) at vacancy in a Fe single crystal using first-principles simulations.Vacancy with more space can provide the lower electron density region for He binding in comparison with intrinsic Fe,causing He to diffuse into the vacancy inner easily.We provide the quantitative microscopic studies related to the atomic-level thermo-kinetic trapping processes.Moreover,such physical viewpoint can be applied to other vacancy-like defects such as vacancy clusters,void and grain boundaries which can open a space with reduced electron density region to increase He binding in metals and metal alloys.展开更多
The pollution of soils by heavy metals has dramatically increased in recent decades. Phytoextraction is a technology that extracts elements from polluted soils using hyperaccumulator plants. The selection of appropria...The pollution of soils by heavy metals has dramatically increased in recent decades. Phytoextraction is a technology that extracts elements from polluted soils using hyperaccumulator plants. The selection of appropriate plant materials is an important factor for successful phytoextraction in field. A field study was conducted to compare the efficiency of six high-biomass forage species in their phytoextraction of heavy metals(Cd, Pb, and Zn) from contaminated soil under two harvesting strategies(double harvesting or single harvesting). Among the tested plants, amaranth accumulated the greatest amounts of Cd and Zn, whereas Rumex K^(-1) had the highest amount of Pb in the shoot under both double and single harvesting. Furthermore, double harvesting significantly increased the shoot biomass of amaranth, sweet sorghum and sudangrass and resulted in higher heavy metal contents in the shoot. Under double harvesting, the total amounts of extracted Cd, Pb and Zn(i.e., in the first plus second crops) for amaranth were 945, 2 650 and 12 400 g ha^(-1), respectively, the highest recorded among the six plant species. The present results indicate that amaranth has great potential for the phytoextraction of Cd from contaminated soils. In addition, the double harvesting method is likely to increase phytoextraction efficiency in practice.展开更多
Radiation forces and trapping stability of metallic （i.e. gold） Rayleigh particle by combined beam are analyzed, and the combined beam is formed by superimposing two partially coherent off-axis fiat-topped beams. Th...Radiation forces and trapping stability of metallic （i.e. gold） Rayleigh particle by combined beam are analyzed, and the combined beam is formed by superimposing two partially coherent off-axis fiat-topped beams. The dependences of radiation forces on off-axis distance parameter, correlation length and particle radius are illustrated by numerical examples. The results show that there exist critical values d0,c and or σ0,c for the combined beam. For 0〈d ≤ d0,c or 0〈σ0 ≤ σ0,c the Gaussianlike intensity profile takes place at the geometrical focal plane, so that the transverse gradient force can act as restoring force. As the off-axis distance parameter increases or the correlation length decreases, the maximal intensity, the radiation force and trapping stiffness become smaller, while the transverse and longitudinal trapping ranges become larger. In comparison with a single beam, the combined beam is more favourable for trapping metallic Rayleigh particle owing to the stronger trapping stiffness and the larger trapping range.展开更多
文摘Molecular catalysts for H2-evolution are of interest for their integration into light-harvesting complexes for photocatalytic water splitting.Here,we report the meso-tetra(4-carboxyphenyl)porphine[(TCPP)Pt^(Ⅱ)]complex as a molecular H2-evolving photocatalyst using chloranilic acid(CA)as a sacrificial electron donor,the choice of which is critical to the stability of the photocatalyst.When triethanolamine was used,[(TCPP)Pt^(Ⅱ)]decomposed to form Pt nanoparticles.Density functional theory calculations together with evidence from electrochemical and spectroscopic analyses suggested that the catalysis was possibly initiated by a proton-coupled electron transfer(PCET)to form[(TCPP)Pt^(Ⅰ)]-N-H,followed by another electron injection and protonation to form a[(TCPP)Pt^(Ⅱ)-hydride]-N-H intermediate that can release H2.As the whole catalytic cycle involves the injection of multiple electrons,a light-harvesting network should be helpful by providing multiple photo-induced electrons.Thus,we integrated this molecular catalyst into a light-harvesting metal-organic framework to boost its activity by~830 times.This work presents a mechanistic study of the photocatalytic H2 evolution and energy transfer and highlights the importance of a light-harvesting network for multiple electron injections.
基金granted by the key project of NSFC (No.30630016)the 973 Program (2007CB411600)+1 种基金the project of NSFC (No.30970442) China Program of TNC
文摘Most extant nonhuman primates occasionally prey on fast-moving, warm-blooded animals; however, Indriidae, Lepilemuridae, and Colobinae either scavenged for meat or did not eat meat at all. Here we report six cases of animal consumption by the snub-nosed monkey Rhinopithecus bieti in a wild, habituated group between 2004 and 2009 in Yunnan, China. At present, only males in an all-male unit within the study group were involved in active hunting. Such a male-biased activity may be related to the group structure and spatial spread of R. bieti. Two females were observed eating freshly killed birds. The findings confirmed that R. bieti engaged in scavenging and, when hunting, employed a cranio-cervical bite to kill their prey. Meat eating is likely a nutrient maximization feeding strategy in R. bieti, especially in males. A begging behavior occurred after successful prey capture. Although begging was observed, no sharing of the meat was seen. The present findings illuminate the dietary diversity of R. bieti and their ability to expand their dietary spectrum.
文摘This research seeks to evaluate the economic benefits to be gained by installing a small-scale wind turbine for a customer with a three-phase electrical supply requirement. The evidence for the claims made in this paper is obtained by using actual data obtained from the installed equipment over a three year period. The objective is to accurately appraise the financial investment using real data. There appears to be limited studies conducted into this type of research, possibly because the renewable energy sector is in the infancy stage in the host country, Ireland. There are some wind energy installations with financial appraisal techniques based on modeled data, which may, or may not, be accurate. The study concludes by claiming that the financial benefits of the wind energy turbine installation had disappointing results when compared to predicted benefits based on modeled data.
文摘Sorghum bicolor is among main staple crops of Chad but it is commonly attacked by Striga hermonthica. Assessment of sorghum varieties for resistance to this weed was carried out during three cropping seasons （2005-2008）, in controlled conditions; promising entries （those which fulfilled at least 75% of selection criteria） were evaluated in farmer field in 2008-2009 seasons. There were five sites （Bebedjia, Deli, Bekao, Koudoti and Ndaba）. The objective was to evaluate some sorghum entries for S. hermonthica resistance in farmer field. Sorghum test was composed of four entries in Fisher blocks as experimental designs, with five replications. Among different observed variables, there were striga plant count and weight of sorghum grains. One promising entry was selected at Bebedjia and Ndaba （53）, two at Deli and Koudoti （50 and 53）. No entry was selected at Bekao. Promising entries for the whole Southern zone of Chad were composed of 50 and 53. The best entry was 53 because it was promising in all sites except Bekao.
基金supported by the National Natural Science Foundation of China (Grant No. 51101135)the Natural Science Foundation of Shandong (Grant No. ZR2010AM002)
文摘We investigate the structure,trapping,and diffusion behaviors of helium(He) at vacancy in a Fe single crystal using first-principles simulations.Vacancy with more space can provide the lower electron density region for He binding in comparison with intrinsic Fe,causing He to diffuse into the vacancy inner easily.We provide the quantitative microscopic studies related to the atomic-level thermo-kinetic trapping processes.Moreover,such physical viewpoint can be applied to other vacancy-like defects such as vacancy clusters,void and grain boundaries which can open a space with reduced electron density region to increase He binding in metals and metal alloys.
基金supported by the National Natural Science Foundation of China (No. 41501340)the Zhejiang Provincial Natural Science Foundation of China (No. LQ14D010002)
文摘The pollution of soils by heavy metals has dramatically increased in recent decades. Phytoextraction is a technology that extracts elements from polluted soils using hyperaccumulator plants. The selection of appropriate plant materials is an important factor for successful phytoextraction in field. A field study was conducted to compare the efficiency of six high-biomass forage species in their phytoextraction of heavy metals(Cd, Pb, and Zn) from contaminated soil under two harvesting strategies(double harvesting or single harvesting). Among the tested plants, amaranth accumulated the greatest amounts of Cd and Zn, whereas Rumex K^(-1) had the highest amount of Pb in the shoot under both double and single harvesting. Furthermore, double harvesting significantly increased the shoot biomass of amaranth, sweet sorghum and sudangrass and resulted in higher heavy metal contents in the shoot. Under double harvesting, the total amounts of extracted Cd, Pb and Zn(i.e., in the first plus second crops) for amaranth were 945, 2 650 and 12 400 g ha^(-1), respectively, the highest recorded among the six plant species. The present results indicate that amaranth has great potential for the phytoextraction of Cd from contaminated soils. In addition, the double harvesting method is likely to increase phytoextraction efficiency in practice.
基金supported by the Key Project of Chinese Ministry of Education(No.210186)the Scientific Foundation of Chengdu University of Information Technology(No.KYTZ201023)
文摘Radiation forces and trapping stability of metallic （i.e. gold） Rayleigh particle by combined beam are analyzed, and the combined beam is formed by superimposing two partially coherent off-axis fiat-topped beams. The dependences of radiation forces on off-axis distance parameter, correlation length and particle radius are illustrated by numerical examples. The results show that there exist critical values d0,c and or σ0,c for the combined beam. For 0〈d ≤ d0,c or 0〈σ0 ≤ σ0,c the Gaussianlike intensity profile takes place at the geometrical focal plane, so that the transverse gradient force can act as restoring force. As the off-axis distance parameter increases or the correlation length decreases, the maximal intensity, the radiation force and trapping stiffness become smaller, while the transverse and longitudinal trapping ranges become larger. In comparison with a single beam, the combined beam is more favourable for trapping metallic Rayleigh particle owing to the stronger trapping stiffness and the larger trapping range.
