Landscape pathology is a research approach that can provide validation of the effectiveness of regional controls of forest disease at a landscape scale. In this paper, we analyzed the effects of stand features, manage...Landscape pathology is a research approach that can provide validation of the effectiveness of regional controls of forest disease at a landscape scale. In this paper, we analyzed the effects of stand features, management approaches, and geographical locations on poplar canker disease incidence (DI) and disease severity index (DSI) of individual trees at a 10 km x 10 km mesoscale landscape in Qingfeng County, China. DI varied significantly with stand age, tree densities, and the degree of canopy closure. DI in stands younger than 4 years old was significantly lower than that in the stands over 6 years old and reached the highest value at a stand age of 8-10 years. Overall, DI was positively correlated with stand age, stand density, andthe degree of canopy closure. DI was significantly lower in agro-forest stand patches than in other three patch types, i.e. isolated patch, pure stand patch, and mixed stand patch. Poplar plantations distributed around and near to villages exhibited significantly higher DI mainly due to human activities and herbivores. Fragmentation or connectivity in this mesoscale landscape seemed not impact disease occurrence. DSI was not significantly correlated with stand density, but varied significantly with tree varieties and trees ages. DSI was highest in stands of 10-12 year trees for all poplar varieties we studied here. Plantation density and plantation age were thus critical factors in determining DI and DSI. A logistic predictive model of disease occurrence was developed for the study area, considering varieties, age, height, density, canopy cover, stand types, patch types, management status, and stand geographical locations. Our study here shows that adjustment of stand density by thinning at different plantation ages is an effective approach controlling the occurrence canker disease in short-rotation poplar plantations at the landscape scale.展开更多
Real-time monitoring and wireless transmission of farmland soil moisture have been paid with more and more attention in the research of agricultural drought monitoring, early warning and prevention and control technol...Real-time monitoring and wireless transmission of farmland soil moisture have been paid with more and more attention in the research of agricultural drought monitoring, early warning and prevention and control technology. The hardware design and software design of soil moisture monitoring in farmland were carried out, and a monitoring system based on the principles of ZigBee and GPRS technologies was developed and applied to the actual monitoring of soil moisture in farmland. This study provides a good idea to promote real-time monitoring, wireless transmission and intelligent management of soil moisture in farmland.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
Twelve new grayanoids(1-12)along with five known compounds were isolated from flowers of Rhododendron molle.Their structures were fully characterized using a combination of spectroscopic analyses,computational calcula...Twelve new grayanoids(1-12)along with five known compounds were isolated from flowers of Rhododendron molle.Their structures were fully characterized using a combination of spectroscopic analyses,computational calculations,and single crystal X-ray diffraction.Rhomollone A(1)possesses an unprecedented 5/6/6/5 tetra-cyclic ring system(B-nor grayanane)incorporating a cyclopentene-1,3-dione scaffold.Rhodomollein XLIII(2)is a dimeric grayanoid,containing a novel 14-membered heterocyclic ring with a C2 symmetry axis.The antinociceptive activities of compounds 3,4,6,7,and 12-17 were evaluated by an acetic acid-induced writhing test.Among them,compounds 3,7,12,15 and 16 displayed significant antinociceptive activities at a dose of 20 mg/kg with inhibition rates ranging from41.9%to 91.6%.Compounds 6 and 13 inhibited 46.0%and 39.4%of the acetic acid-induced writhes at a dose of 2 mg/kg,while compound 17 inhibited 34.3%of the writhes at a dose of 0.4 mg/kg.展开更多
Nanofilms that can fast permeate solvents and accurately sieve molecules are of significant importance for separation.A promising strategy is to align the inner cavities of macrocycles into the channels within nanofil...Nanofilms that can fast permeate solvents and accurately sieve molecules are of significant importance for separation.A promising strategy is to align the inner cavities of macrocycles into the channels within nanofilms,and control the channel size by selecting the macrocycles.However,the channels outside the macrocycles are ignored.Here,we prepare nanofilms with hydrophobic channels(cyclodextrin inner cavity)and hydrophilic channels(cyclodextrin outer space)through interfacial polymerization of azobenzene-4,4’-dicarbonyl dichloride and amino-functionalizedβ-cyclodextrin.By utilizing the significant geometric changes caused by the photoisomerization of azobenzene,nanofilms with adjustable hydrophilic channel sizes were obtained.Our nanofilms have high permeability to polar and non-polar solvents,and can distinguish molecules with almost the same molecular weight but different shapes.This work expands the development of next-generation nanofilms generated through interfacial polymerization by incorporating rational molecular design.展开更多
Polycyclic aromatic hydrocarbons(PAHs)present significant risks to human health owing to their carcinogenic,teratogenic,and mutagenic properties.The contamination of surface water with PAHs via runoff has become a pro...Polycyclic aromatic hydrocarbons(PAHs)present significant risks to human health owing to their carcinogenic,teratogenic,and mutagenic properties.The contamination of surface water with PAHs via runoff has become a prominent source of water pollution.While the capacity of bioretention systems to remove PAHs from runoff is recognized,the dynamics of PAH migration and degradation in these systems are not well-understood.This study aims to explain the migration and fate of PAHs in bioretention systems through a series of experiments and model simulations.This study constructed bioretention systems with three different media types and found that these systems achieved PAH load reductions exceeding 92%.Notably,naphthalene(NAP),fluoranthene(FLT),and pyrene(PYR)tended to accumulate in the media’s upper layer,at depths of 10 to 40 cm.To further analyze the migration and fate of PAHs during multi-site rainfall events and across prolonged operation,we applied the HYDRUS-1D model under three distinct scenarios.The findings of this study indicated that NAP degraded in 40 d,whereas FLT and PYR showed incomplete degradation after 120 d.During continuous rainfall events,there was no clear pattern of PAH accumulation;however,FLT and PYR persisted in the bioretention systems.The combination of experimental and simulation findings highlights the inevitable accumulation of PAHs during extended use of bioretention systems.This research provides a theoretical basis for improving operational efficiency,advancing PAH degradation in bioretention systems,and reducing their toxicity.展开更多
基金supported by the twelfth five-year science and technology support program of China(2012BAD19B0801)
文摘Landscape pathology is a research approach that can provide validation of the effectiveness of regional controls of forest disease at a landscape scale. In this paper, we analyzed the effects of stand features, management approaches, and geographical locations on poplar canker disease incidence (DI) and disease severity index (DSI) of individual trees at a 10 km x 10 km mesoscale landscape in Qingfeng County, China. DI varied significantly with stand age, tree densities, and the degree of canopy closure. DI in stands younger than 4 years old was significantly lower than that in the stands over 6 years old and reached the highest value at a stand age of 8-10 years. Overall, DI was positively correlated with stand age, stand density, andthe degree of canopy closure. DI was significantly lower in agro-forest stand patches than in other three patch types, i.e. isolated patch, pure stand patch, and mixed stand patch. Poplar plantations distributed around and near to villages exhibited significantly higher DI mainly due to human activities and herbivores. Fragmentation or connectivity in this mesoscale landscape seemed not impact disease occurrence. DSI was not significantly correlated with stand density, but varied significantly with tree varieties and trees ages. DSI was highest in stands of 10-12 year trees for all poplar varieties we studied here. Plantation density and plantation age were thus critical factors in determining DI and DSI. A logistic predictive model of disease occurrence was developed for the study area, considering varieties, age, height, density, canopy cover, stand types, patch types, management status, and stand geographical locations. Our study here shows that adjustment of stand density by thinning at different plantation ages is an effective approach controlling the occurrence canker disease in short-rotation poplar plantations at the landscape scale.
基金Supported by Special Scientific Research Fund of Meteorology in the Public Welfare Profession of China(GYHY201306046-05)
文摘Real-time monitoring and wireless transmission of farmland soil moisture have been paid with more and more attention in the research of agricultural drought monitoring, early warning and prevention and control technology. The hardware design and software design of soil moisture monitoring in farmland were carried out, and a monitoring system based on the principles of ZigBee and GPRS technologies was developed and applied to the actual monitoring of soil moisture in farmland. This study provides a good idea to promote real-time monitoring, wireless transmission and intelligent management of soil moisture in farmland.
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supported by grants from the National Natural Science Foundation of China(Nos.21572274 and 21732008)the CAMS Innovation Fund for Medical Sciences(No.2016-I2M1-010,China)
文摘Twelve new grayanoids(1-12)along with five known compounds were isolated from flowers of Rhododendron molle.Their structures were fully characterized using a combination of spectroscopic analyses,computational calculations,and single crystal X-ray diffraction.Rhomollone A(1)possesses an unprecedented 5/6/6/5 tetra-cyclic ring system(B-nor grayanane)incorporating a cyclopentene-1,3-dione scaffold.Rhodomollein XLIII(2)is a dimeric grayanoid,containing a novel 14-membered heterocyclic ring with a C2 symmetry axis.The antinociceptive activities of compounds 3,4,6,7,and 12-17 were evaluated by an acetic acid-induced writhing test.Among them,compounds 3,7,12,15 and 16 displayed significant antinociceptive activities at a dose of 20 mg/kg with inhibition rates ranging from41.9%to 91.6%.Compounds 6 and 13 inhibited 46.0%and 39.4%of the acetic acid-induced writhes at a dose of 2 mg/kg,while compound 17 inhibited 34.3%of the writhes at a dose of 0.4 mg/kg.
基金supported by the National Natural Science Foundation of China(No.22090050)National Key Research and Development Program of China(No.2021YFA1200403)+3 种基金Joint NSFC-ISF Research Grant Program(No.22161142020)Natural Science Foundation of Hubei Province(No.2020CFA037)Zhejiang Provincial Natural Science Foundation of China(No.LD21B050001)Key Research and Development and Promotion Projects in Henan Province(Nos.212102310081 and 232102320125).
文摘Nanofilms that can fast permeate solvents and accurately sieve molecules are of significant importance for separation.A promising strategy is to align the inner cavities of macrocycles into the channels within nanofilms,and control the channel size by selecting the macrocycles.However,the channels outside the macrocycles are ignored.Here,we prepare nanofilms with hydrophobic channels(cyclodextrin inner cavity)and hydrophilic channels(cyclodextrin outer space)through interfacial polymerization of azobenzene-4,4’-dicarbonyl dichloride and amino-functionalizedβ-cyclodextrin.By utilizing the significant geometric changes caused by the photoisomerization of azobenzene,nanofilms with adjustable hydrophilic channel sizes were obtained.Our nanofilms have high permeability to polar and non-polar solvents,and can distinguish molecules with almost the same molecular weight but different shapes.This work expands the development of next-generation nanofilms generated through interfacial polymerization by incorporating rational molecular design.
基金the National Natural Science Foundation of China(Nos.52070157 and 52000150)the Scientific Research Item of Shaanxi Provincial Land Engineering Construction Group(China)(DJNY2022-30 and DJNY-2023-YB-31).
文摘Polycyclic aromatic hydrocarbons(PAHs)present significant risks to human health owing to their carcinogenic,teratogenic,and mutagenic properties.The contamination of surface water with PAHs via runoff has become a prominent source of water pollution.While the capacity of bioretention systems to remove PAHs from runoff is recognized,the dynamics of PAH migration and degradation in these systems are not well-understood.This study aims to explain the migration and fate of PAHs in bioretention systems through a series of experiments and model simulations.This study constructed bioretention systems with three different media types and found that these systems achieved PAH load reductions exceeding 92%.Notably,naphthalene(NAP),fluoranthene(FLT),and pyrene(PYR)tended to accumulate in the media’s upper layer,at depths of 10 to 40 cm.To further analyze the migration and fate of PAHs during multi-site rainfall events and across prolonged operation,we applied the HYDRUS-1D model under three distinct scenarios.The findings of this study indicated that NAP degraded in 40 d,whereas FLT and PYR showed incomplete degradation after 120 d.During continuous rainfall events,there was no clear pattern of PAH accumulation;however,FLT and PYR persisted in the bioretention systems.The combination of experimental and simulation findings highlights the inevitable accumulation of PAHs during extended use of bioretention systems.This research provides a theoretical basis for improving operational efficiency,advancing PAH degradation in bioretention systems,and reducing their toxicity.