Aims Light-use efficiency(LUE)is an important tool for scaling up local CO_(2)flux(F_(CO_(2)))tower observations to regional and global carbon dynamics.Using a data set including F_(CO_(2))and environmental factors ob...Aims Light-use efficiency(LUE)is an important tool for scaling up local CO_(2)flux(F_(CO_(2)))tower observations to regional and global carbon dynamics.Using a data set including F_(CO_(2))and environmental factors obtained from an alpine meadow on the Tibetan Plateau,we examined both diurnal and seasonal changes in LUE and the environmental factors controlling these changes.Our objectives were to(i)characterize the diurnal and daily variability of LUE in an alpine meadow,(ii)clarify the causes of this variability,and(iii)explore the possibility of applying the LUE approach to this alpine meadow by examining the relationship between daily LUE and hourly LUE at satellite visiting times.Methods First,we obtained the LUE—the ratio of the gross primary production(GPP)to the absorbed photosynthetically active radiation(APAR)—from the flux tower and meteorological observations.We then characterized the patterns of diurnal and seasonal changes in LUE,explored the environmental controls on LUE using univariate regression analyses and evaluated the effects of diffuse radiation on LUE by assigning weights through a linear programming method to beam photosynthetically active radiation(PAR)and diffuse PAR,which were separated from meteorological observations using an existing method.Finally,we examined the relationships between noontime hourly LUE and daily LUE and those between adjusted noontime hourly and daily LUE because satellites visit the site only once or twice a day,near noon.Important Findings The results showed that(i)the LUE of the alpine meadow generally followed the diurnal and seasonal patterns of solar radiation but fluctuated with changes in cloud cover.(ii)The fraction of diffuse light played a dominant role in LUE variation.Daily minimum temperature and vapor pressure deficit also affected LUE variation.(iii)The adjusted APAR,defined as the weighted linear sum of diffuse APAR and beam APAR,was linearly correlated with GPP on different temporal scales.(iv)Midday adjusted LUE was closely related to daily展开更多
As an alternative to Li-ion batteries,aqueous Zn batteries have gained attention due to the abundance of Zn metal,low reduction potential(-0.76 V vs.standard hydrogen electrode),and high theoretical capacity(820 mAh g...As an alternative to Li-ion batteries,aqueous Zn batteries have gained attention due to the abundance of Zn metal,low reduction potential(-0.76 V vs.standard hydrogen electrode),and high theoretical capacity(820 mAh g^(-1))of multivalent Zn2+ion.However,the growth of Zn dendrites and the formation of irreversible surface reaction byproducts pose challenges for ensuring a long battery lifespan and commercialization.Herein,the Cu foil coated with a single-walled carbon nanotube(SWCNT)layer using a facile doctor blade casting method is utilized.The SWCNT-coated Cu foil demonstrates a significantly longer battery lifespan compared to the bare Cu in the half-cell tests.Through operando optical microscopy imaging,we are able to provide intuitive evidence that Zn deposition occurs between the carbon nanotube(CNT)coating and Cu substrate,in agreement with the computational results.Also,with various imaging techniques,the flat morphology and homogeneous distribution of Zn beneath the SWCNT layer are demonstrated.In addition,the full-cell using CNT-coated Cu exhibits a long cycle life compared to the control group,thereby demonstrating improved electrochemical performance with limited Zn for the cycling process.展开更多
Moisture removal and water recovery from the air are vital for regulating indoor humidity and mitigating water scarcity.Most atmospheric water harvesters(AWH)focus primarily on increasing the moisture capture rate,but...Moisture removal and water recovery from the air are vital for regulating indoor humidity and mitigating water scarcity.Most atmospheric water harvesters(AWH)focus primarily on increasing the moisture capture rate,but for it to be economical and sustainable,it is essential to consider the energy required to recover and harvest the captured water.Here,a mechanically flexible,biphilic sorption-based AWH made of green,environmentally friendly material is presented.It consists of a hygroscopic chitosan polymer embedded within a flexible,hydrophobic silica xerogel that can harvest 86.3 g water/g chitosan at 97%relative humidity and 25℃reaching saturation after 30 days(i.e.2.88 g water/g chitosan/day).Roughly 88%of the sorbed moisture was recovered by mechanical squeezing(ca.0.020 MPa)within 150 s.Repeated water harvesting experiments and uniaxial compression tests demonstrate that chitosan-silica xerogel is durable for longterm operations,providing a fast,reliable,and sustainable moisture removal and water harvesting tool.展开更多
The industrial adoption of microbial electrosynthesis(MES)is hindered by high overpotentials deriving from low electrolyte conductivity and inefficient cell designs.In this study,a mixed microbial consortium originati...The industrial adoption of microbial electrosynthesis(MES)is hindered by high overpotentials deriving from low electrolyte conductivity and inefficient cell designs.In this study,a mixed microbial consortium originating from an anaerobic digester operated under saline conditions(∼13 g L^(−1)NaCl)was adapted for acetate production from bicarbonate in galvanostatic(0.25 mA cm^(−2))H-type cells at 5,10,15,or 20 g L^(−1)NaCl concentration.The acetogenic communities were successfully enriched only at 5 and 10 g L^(−1)NaCl,revealing an inhibitory threshold of about 6 g L^(−1)Na^(+).The enriched planktonic communities were then used as inoculum for 3D printed,three-chamber cells equipped with a gas diffusion biocathode.The cells were fed with CO_(2)gas and operated galvanostatically(0.25 or 1.00 mA cm^(−2)).The highest production rate of 55.4 g m^(−2) d^(−1)(0.89 g L^(−1)d^(−1)),with 82.4%Coulombic efficiency,was obtained at 5 g L^(−1)NaCl concentration and 1 mA cm^(−2)applied current,achieving an average acetate production of 44.7 kg MWh−1.Scanning electron microscopy and 16S rRNA sequencing analysis confirmed the formation of a cathodic biofilm dominated by Acetobacterium sp.Finally,three 3D printed cells were hydraulically connected in series to simulate an MES stack,achieving three-fold production rates than with the single cell at 0.25 mA cm^(−2).This confirms that three-chamber MES cells are an efficient and scalable technology for CO_(2)bio-electro recycling to acetate and that moderate saline conditions(5 g L^(−1)NaCl)can help reduce their power demand while preserving the activity of acetogens.展开更多
Prof.Zhifang Chai,born in October 1942,is a radioanalytical chemist working at the Institute of High Energy Physics,Chinese Academy of Sciences and Soochow University.He graduated from Fudan University in 1964.As an A...Prof.Zhifang Chai,born in October 1942,is a radioanalytical chemist working at the Institute of High Energy Physics,Chinese Academy of Sciences and Soochow University.He graduated from Fudan University in 1964.As an Alexander von Humboldt Foundation fellow,he worked at Cologne University,Germany from1980 to 1982.展开更多
A new putative transposon was identified in the tobacco budworm, Helio- this virescens. This transposon was characterized as a full length CORE-SINE （65 bp of ＂CORE＂ core specific nucleotide short interspersed elem...A new putative transposon was identified in the tobacco budworm, Helio- this virescens. This transposon was characterized as a full length CORE-SINE （65 bp of ＂CORE＂ core specific nucleotide short interspersed elements） that resembled sequences from three other lepidopterans and humans. In particular, the A-box and B-box regions of this sequence most closely conformed to the signature of CORE-SINEs from widely divergent species. This CORE-SINE was present as a polymorphism in a hypervariable region of the gene hscp, which is the target of pyrethroid insecticides and other xenobiotics in the nerve axon. We described this new putative transposon as Noct-1 due to its presence in a noctuid moth. This is the first description of a full-length CORE-SINE with the A-box, B-box, target site duplication, and candidate core domain from an insect.展开更多
Recursion by herbivores is the repeated use of the same site or plants. Recursion by wild animals is rarely investigated but may be ubiquitous. Optimal foraging theory predicts site recursion as a function of the qual...Recursion by herbivores is the repeated use of the same site or plants. Recursion by wild animals is rarely investigated but may be ubiquitous. Optimal foraging theory predicts site recursion as a function of the quality of the site, extent of its last use, and time since its last use because these influence site resource status and recovery. We used GPS collars, behaviour and site sampling to investigate recursion to foraging sites for two elephant Elephas maximus borneensis herds in the Lower Kinabatangan Wildlife Sanctuary, Borneo, over a 12 month period. Recursion occurred to 48 out of 87 foraging sites and was most common within 48 hours or between 151-250 days, indicating two different types ofrecursion. Recursion was more likely to occur if the site had previously been occupied for longer. Moreover, the time spent at a site at recursion was the same as the time spent at the site on the first occasion. The number of days that had passed between the first visit and recursion was also positively correlated with how much time was spent at the site at recursion. Habitat type also influenced the intensity of site-use, with more time spent at recursion within riverine/open grass areas along forest margins compared to other habitat types. Recursion is a common behaviour used by the elephants and its pattern suggests it may be a foraging strategy for revisiting areas of greater value. The qualities of recursion sites might usefully be incorporated into landscape management strategies for elephant conservation in the area [Current Zoology 60 （4）： 551-559, 2014].展开更多
基金Supported by the projects‘Integrated Study for Terrestrial Carbon Management of Asia in the 21st Century Based on Scientific Advancements’and‘Early Detection and Prediction of Climate Warming Based on the Long-Term Monitoring of Alpine Ecosystems on the Tibetan Plateau’funded by the Ministry of the Environment,Japanresearch fund from the Program for New Century Excellent Talents in University,from Ministry of Education,China,to J.C.
文摘Aims Light-use efficiency(LUE)is an important tool for scaling up local CO_(2)flux(F_(CO_(2)))tower observations to regional and global carbon dynamics.Using a data set including F_(CO_(2))and environmental factors obtained from an alpine meadow on the Tibetan Plateau,we examined both diurnal and seasonal changes in LUE and the environmental factors controlling these changes.Our objectives were to(i)characterize the diurnal and daily variability of LUE in an alpine meadow,(ii)clarify the causes of this variability,and(iii)explore the possibility of applying the LUE approach to this alpine meadow by examining the relationship between daily LUE and hourly LUE at satellite visiting times.Methods First,we obtained the LUE—the ratio of the gross primary production(GPP)to the absorbed photosynthetically active radiation(APAR)—from the flux tower and meteorological observations.We then characterized the patterns of diurnal and seasonal changes in LUE,explored the environmental controls on LUE using univariate regression analyses and evaluated the effects of diffuse radiation on LUE by assigning weights through a linear programming method to beam photosynthetically active radiation(PAR)and diffuse PAR,which were separated from meteorological observations using an existing method.Finally,we examined the relationships between noontime hourly LUE and daily LUE and those between adjusted noontime hourly and daily LUE because satellites visit the site only once or twice a day,near noon.Important Findings The results showed that(i)the LUE of the alpine meadow generally followed the diurnal and seasonal patterns of solar radiation but fluctuated with changes in cloud cover.(ii)The fraction of diffuse light played a dominant role in LUE variation.Daily minimum temperature and vapor pressure deficit also affected LUE variation.(iii)The adjusted APAR,defined as the weighted linear sum of diffuse APAR and beam APAR,was linearly correlated with GPP on different temporal scales.(iv)Midday adjusted LUE was closely related to daily
基金Ministry of Science and ICT,South Korea,Grant/Award Number:C310200National Research Foundation of Korea(NRF),Grant/Award Number:2020R1C1C1012308。
文摘As an alternative to Li-ion batteries,aqueous Zn batteries have gained attention due to the abundance of Zn metal,low reduction potential(-0.76 V vs.standard hydrogen electrode),and high theoretical capacity(820 mAh g^(-1))of multivalent Zn2+ion.However,the growth of Zn dendrites and the formation of irreversible surface reaction byproducts pose challenges for ensuring a long battery lifespan and commercialization.Herein,the Cu foil coated with a single-walled carbon nanotube(SWCNT)layer using a facile doctor blade casting method is utilized.The SWCNT-coated Cu foil demonstrates a significantly longer battery lifespan compared to the bare Cu in the half-cell tests.Through operando optical microscopy imaging,we are able to provide intuitive evidence that Zn deposition occurs between the carbon nanotube(CNT)coating and Cu substrate,in agreement with the computational results.Also,with various imaging techniques,the flat morphology and homogeneous distribution of Zn beneath the SWCNT layer are demonstrated.In addition,the full-cell using CNT-coated Cu exhibits a long cycle life compared to the control group,thereby demonstrating improved electrochemical performance with limited Zn for the cycling process.
基金Innovation and Technology Commission,Grant/Award Number:ITS/022/15Research Grants Council,University Grants Committee,Grant/Award Number:E-HKUST601/17+2 种基金The European Union-Hong Kong Research and Innovation Cooperation Co-funding Mechanism,Grant/Award Number:E-HKUST601/17The European Union's Horizon 2020,Grant/Award Number:BIORIMAthe Project of Hetao Shenzhen-Hong Kong Science and Technology Innovation Cooperation Zone,Grant/Award Number:HZQB-KCZYB-2020083。
文摘Moisture removal and water recovery from the air are vital for regulating indoor humidity and mitigating water scarcity.Most atmospheric water harvesters(AWH)focus primarily on increasing the moisture capture rate,but for it to be economical and sustainable,it is essential to consider the energy required to recover and harvest the captured water.Here,a mechanically flexible,biphilic sorption-based AWH made of green,environmentally friendly material is presented.It consists of a hygroscopic chitosan polymer embedded within a flexible,hydrophobic silica xerogel that can harvest 86.3 g water/g chitosan at 97%relative humidity and 25℃reaching saturation after 30 days(i.e.2.88 g water/g chitosan/day).Roughly 88%of the sorbed moisture was recovered by mechanical squeezing(ca.0.020 MPa)within 150 s.Repeated water harvesting experiments and uniaxial compression tests demonstrate that chitosan-silica xerogel is durable for longterm operations,providing a fast,reliable,and sustainable moisture removal and water harvesting tool.
基金This work was performed on the framework of the Science Foundation Ireland(SFI)Pathfinder Award on“Hybrid Bio-Solar Reactors for wastewater treatment and CO_(2)recycling”(award nr.19/FIP/ZE/7572 PF)PD is supported by the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement,project ATMESPHERE,No 101029266.SP is a Serra Hunter Fellow(UdG-AG-575)+4 种基金acknowledges the funding from the ICREA Academia award.LEQUIA has been recognised as a consolidated research group by the Catalan Government(2021-SGR-01352)UZI is supported by EPSRC(EP/P029329/1 and EP/V030515/1)VOF is supported by the Enterprise Ireland Technology Centres Programme(TC/2014/0016)Science Foundation Ireland(14/IA/2371,19/FFP/6746 and 16/RC/3889)DP acknowledges the support of the VIVALDI project that has received funding from the European Union's Horizon 2020 research and innovation program under grant agreement 101000441.
文摘The industrial adoption of microbial electrosynthesis(MES)is hindered by high overpotentials deriving from low electrolyte conductivity and inefficient cell designs.In this study,a mixed microbial consortium originating from an anaerobic digester operated under saline conditions(∼13 g L^(−1)NaCl)was adapted for acetate production from bicarbonate in galvanostatic(0.25 mA cm^(−2))H-type cells at 5,10,15,or 20 g L^(−1)NaCl concentration.The acetogenic communities were successfully enriched only at 5 and 10 g L^(−1)NaCl,revealing an inhibitory threshold of about 6 g L^(−1)Na^(+).The enriched planktonic communities were then used as inoculum for 3D printed,three-chamber cells equipped with a gas diffusion biocathode.The cells were fed with CO_(2)gas and operated galvanostatically(0.25 or 1.00 mA cm^(−2)).The highest production rate of 55.4 g m^(−2) d^(−1)(0.89 g L^(−1)d^(−1)),with 82.4%Coulombic efficiency,was obtained at 5 g L^(−1)NaCl concentration and 1 mA cm^(−2)applied current,achieving an average acetate production of 44.7 kg MWh−1.Scanning electron microscopy and 16S rRNA sequencing analysis confirmed the formation of a cathodic biofilm dominated by Acetobacterium sp.Finally,three 3D printed cells were hydraulically connected in series to simulate an MES stack,achieving three-fold production rates than with the single cell at 0.25 mA cm^(−2).This confirms that three-chamber MES cells are an efficient and scalable technology for CO_(2)bio-electro recycling to acetate and that moderate saline conditions(5 g L^(−1)NaCl)can help reduce their power demand while preserving the activity of acetogens.
文摘Prof.Zhifang Chai,born in October 1942,is a radioanalytical chemist working at the Institute of High Energy Physics,Chinese Academy of Sciences and Soochow University.He graduated from Fudan University in 1964.As an Alexander von Humboldt Foundation fellow,he worked at Cologne University,Germany from1980 to 1982.
文摘A new putative transposon was identified in the tobacco budworm, Helio- this virescens. This transposon was characterized as a full length CORE-SINE （65 bp of ＂CORE＂ core specific nucleotide short interspersed elements） that resembled sequences from three other lepidopterans and humans. In particular, the A-box and B-box regions of this sequence most closely conformed to the signature of CORE-SINEs from widely divergent species. This CORE-SINE was present as a polymorphism in a hypervariable region of the gene hscp, which is the target of pyrethroid insecticides and other xenobiotics in the nerve axon. We described this new putative transposon as Noct-1 due to its presence in a noctuid moth. This is the first description of a full-length CORE-SINE with the A-box, B-box, target site duplication, and candidate core domain from an insect.
文摘Recursion by herbivores is the repeated use of the same site or plants. Recursion by wild animals is rarely investigated but may be ubiquitous. Optimal foraging theory predicts site recursion as a function of the quality of the site, extent of its last use, and time since its last use because these influence site resource status and recovery. We used GPS collars, behaviour and site sampling to investigate recursion to foraging sites for two elephant Elephas maximus borneensis herds in the Lower Kinabatangan Wildlife Sanctuary, Borneo, over a 12 month period. Recursion occurred to 48 out of 87 foraging sites and was most common within 48 hours or between 151-250 days, indicating two different types ofrecursion. Recursion was more likely to occur if the site had previously been occupied for longer. Moreover, the time spent at a site at recursion was the same as the time spent at the site on the first occasion. The number of days that had passed between the first visit and recursion was also positively correlated with how much time was spent at the site at recursion. Habitat type also influenced the intensity of site-use, with more time spent at recursion within riverine/open grass areas along forest margins compared to other habitat types. Recursion is a common behaviour used by the elephants and its pattern suggests it may be a foraging strategy for revisiting areas of greater value. The qualities of recursion sites might usefully be incorporated into landscape management strategies for elephant conservation in the area [Current Zoology 60 （4）： 551-559, 2014].
