Environmental science is an interdisciplinary science developed in the process of understanding and solving ecolog-ical and environmental problems.In order to tackle these problems,environmental science research is ex...Environmental science is an interdisciplinary science developed in the process of understanding and solving ecolog-ical and environmental problems.In order to tackle these problems,environmental science research is expected to reveal the source,behavior,fate,exposure,and risks of pollutants in the environment and develop potential solutions to control pollution.It provides the scientific basis for decision-makers to establish environmental and economic poli-cies,and promote concerted efforts for the sustainable development of society.Here,we articulate the development patterns,challenges,and future research needs of environmental science in China based on literature review and expert panel discussion.Environmental science research has evolved significantly in the past decade with an increas-ing diversity of environmental pollutants and health impacts,new technologies and methods,deepening fusion of multiple disciplines,and emerging solutions for pollution control.Its future development relies on the advances in our knowledge on the fate and transport of pollutants,regional environmental processes,ecotoxicological effects,environmental exposure and health effects,environmental analysis and monitoring,source control and reduction,environmental remediation,as well as environmental risk management.For each of these fields,we summarize the significant challenges and highlight the research demands for China.Based on the status quo of China’s environmen-tal science research and future needs,we provide recommendations to promote its future development,including encouraging innovation and interdisciplinary research,providing decision support for national needs,encouraging international collaboration,and improving collaboration mechanisms.展开更多
Enhanced mass concentrations of aromatic-derived secondary organic aerosol(SOA)are frequently observed during humid-haze events.However,the influencing mechanism of relative humidity(RH)in aromatic-derived SOA formati...Enhanced mass concentrations of aromatic-derived secondary organic aerosol(SOA)are frequently observed during humid-haze events.However,the influencing mechanism of relative humidity(RH)in aromatic-derived SOA formation remains incompletely understood.Here,the RH dependence of SOA formation in the presence of NOx was explored by a series of chamber experiments for toluene(TOL)and 1,3,5-trimethylbenzene(TMB)photooxidation.The yield of TOL SOA and TMB SOA increased by 221%and 52%with increasing RH from~8%to~70%,respectively.Analytical results from a high-resolution mass spectrometer showed that SOA constituents with high oxygen content(O/C>0.6)were more abundant in SOA formed in the~70%RH experiment.The elevated yields and O/C of SOA could be attributed to the promoted formation and particle-phase diffusivity of highly oxidized molecules.In addition,in comparison with TMB,TOL could produce more unsaturated aldehydes,which are oxidized into carboxylic acids with high O/C,leading to a more sensitive response of TOL SOA formation to the change in RH.Our work provides mechanistic insights into RH roles in aromatic SOA formation and is helpful for a better understanding of humid-haze events.展开更多
The increasing population and continuous urbanization make food security a key consideration in sustainable development.Efficient farming strategies with low environmental footprints are thus increasingly required to ...The increasing population and continuous urbanization make food security a key consideration in sustainable development.Efficient farming strategies with low environmental footprints are thus increasingly required to meet food demands.This study presents a design for environmentally friendly,economical,and modular vertical farming systems,in which vegetables are cultivated in a carbon dioxide(CO_(2))-enriched atmosphere enabled by direct air capture(DAC)and subjected to artificial light exposure.We established a vertical farming setup and conducted experiments to identify productive cultivation strategies by regulating lighting,CO_(2)concentration,biochar application,and plant species.Additionally,a self-developed DAC rotary adsorber was utilized to achieve stable and efficient CO_(2)enrichment.Compared with the control group,the fresh weight of the vegetables in the experimental groups increased by up to 57.5%.Furthermore,we performed a comprehensive evaluation of the design and demonstrated that integrating photovoltaic-thermal(PVT)and DAC units increased the system’s net present value(NPV)by 157%compared with a conventional design without these units.Importantly,we found it possible to maintain the low carbon footprint of the system(0.468 kg-CO_(2)equivalent·kg−1(CO_(2)eq·kg−1)-vegetable)in the production process.Parametric studies and an application analysis on a global scale reveal the wide adaptability of this strategy to diverse conditions.These findings,together with the modular characteristics of vertical farming systems,highlight the promising potential of this design to increase food security and foster sustainable agriculture.展开更多
Rare earth elements are highly applicable in photocatalysis due to their partially filled 4f orbitals,existing in electronic structures that facilitate the transfer of electrons during the reaction process.Among these...Rare earth elements are highly applicable in photocatalysis due to their partially filled 4f orbitals,existing in electronic structures that facilitate the transfer of electrons during the reaction process.Among these materials,CeO_(2)has a distinctive external electronic structure(4f^(1)5d^(1)6s^(2)),abundant oxygen vacancies,and strong conversion ability of Ce^(4+)/Ce^(3+),which makes it an attractive candidate in the field of photocatalysis.To broaden its practical applications in the visible region,the drawbacks of a wide band gap and a slow Ce^(4+)/Ce^(3+)cycle have been addressed through the modification of CeO_(2),thereby accelerating light absorption and self-circulation,and enhancing photocatalytic activity.This paper presents a review of the preparation of modified CeO_(2)catalysts and their application in the conversion of cerium valence state in the photocatalytic degradation of pollutants in water.Furthermore,this paper presents a summary of the most recent development and current challenges,as well as prospect for the application of modified CeO_(2)-based materials.展开更多
The coexistence of emerging containments,such as antibiotic resistant bacteria(ARB),antibiotic-resistant genes(ARGs)and antibiotics,potentially influence elimination efficiencies in UV light-emitting diode(UV-LED)alon...The coexistence of emerging containments,such as antibiotic resistant bacteria(ARB),antibiotic-resistant genes(ARGs)and antibiotics,potentially influence elimination efficiencies in UV light-emitting diode(UV-LED)alone and UV-LED/H_(2)O_(2) system as their complex interactions.Tetracycline(TC)degradation efficiency(kF)correlated closely with its UV molar absorbance(R^(2)=0.831)in UV-LED alone system and with·OH yield(R^(2)=0.999)in UV-LED/H_(2)O_(2) system across studied wavelengths(265,280 and 310 nm).The kF values for intracellular DNA(i-ARGs)also exhibited a high correlation with UV-LED wavelengths in both systems(R^(2)=0.997-0.999).The coexistence of TC and ARB/ARGs resulted in a mutual inhibition of their degradation efficiencies due to competition for photons and·OH,along with the consequent reduction in intracellular ROS within ARB,with their degradation efficiencies exhibiting marked dependence on wavelength in both systems.Notably,the UV-LED/H_(2)O_(2) system at 265 nm effectively achieved the simultaneous removal of TC,ARB and ARGs with minimal energy consumption,and successfully fragmented ARGs.The degradation pathway of TC was analyzed,and the biotoxicity of its degradation intermediates demonstrated the environmental friendliness and safety of UV-LED/H_(2)O_(2) technology.This study elucidated the competitive interactions between antibiotics and ARB/ARGs within UV-LED/H_(2)O_(2) system,providing a promising approach for their simultaneous removal while ensuring energy efficiency.展开更多
Green manuring is essential for improving soil quality and nutrient uptake.With the gradual depletion of phosphorus(P)resources,more attention is being paid to the role of green manures in cultivation systems,such as ...Green manuring is essential for improving soil quality and nutrient uptake.With the gradual depletion of phosphorus(P)resources,more attention is being paid to the role of green manures in cultivation systems,such as maize-green manure intercropping,to find possible pathways for enhancing soil P utilization.A maize-green manure intercropping experiment was started in 2009 to investigate the effects and mechanisms for enhancing P uptake and yield in maize.Three species of green manures(hairy vetch(HV),needle leaf pea(NP),sweet pea(SP))and a sole maize treatment(CK)were used,resulting in four treatments(CK,HVT,NPT,and SPT)in the experiment.During 2020-2023,the intercropping treatments enhanced maize yields in 2020 and 2021,particularly in HVT with increases of 13.7%(1.96 t ha^(-1))and 13.0%(2.13 t ha^(-1))compared with CK,respectively.Grain P accumulation of maize was significantly higher in the intercropping treatments than CK in 2020,2021,and 2023,and with an average increase of 10.6%over the four years(5.2% for NPT,10.8% for SPT and 15.9% for HVT)compared with CK.Intercropping promoted maize growth with a greater root length density and a higher organic acid release rate.HVT changed the soil properties more dramatically than the other treatments,with increases in the acid phosphatase and alkaline phosphatase activities of 29.8 and 38.5%,respectively,in the topsoil(0-15 cm),while the soil p H was reduced by 0.37 units compared to CK(p H=8.44).Intercropping treatments facilitated the conversion of non-labile P to mod-labile P and stimulated the growth of soil bacteria in the topsoil.Compared with CK,the relative abundance of Gemmatimonadota,known for accumulating polyphosphate,and Actinobacteriota,a prominent source of bioactive compounds,increased significantly in the intercropping treatments,especially in HVT and SPT.A PLS-PM analysis showed that intercropping promoted soil P mobilization and the enrichment of beneficial bacteria by regulating maize root morphology and physiology.Our results highlight that maize-green manure intercropping optimizes root traits,soil properties and bacterial composition,which contribute to greater maize P uptake and yield,providing an effective strategy for sustainable crop production.展开更多
Amorphous materials represent a promising platform for advancing CO_(2)electrochemical reduction due to their inherently diverse coordination environments.In this study,we demonstrate computationally the superior perf...Amorphous materials represent a promising platform for advancing CO_(2)electrochemical reduction due to their inherently diverse coordination environments.In this study,we demonstrate computationally the superior performance of amorphous CuNi alloys for CO_(2)electrochemical reduction.By integrating machine learning forcefields for efficient structure generation and density functional theory for subsequent structural refinement and property calculations,we reveal the potential of these disordered systems to outperform their crystalline counterparts.Machine learning forcefields can generate a bulk structure containing a mixture of Cu and Ni atoms,resulting in enhanced catalytic performance.Effective screening of the amorphous surfaces is used to identify undercoordinated Cu and Ni sites in the amorphous structure to synergistically promote selective CO production and favor ethanol formation over ethylene via the stabilization of the*COCHO intermediate,resulting in significantly lower Gibbs free energy changes compared to the crystalline counterpart.The varying atomic coordination environments on amorphous surfaces promote both C–C bond formation and subsequent proton-electron transfer,leading to ethanol formation.These findings demonstrate the superior catalytic performance of amorphous CuNi,highlighting its potential for efficient and selective electroreduction of CO_(2).展开更多
Based on monthly runoff and climate datasets spanning 2000–2024,this study employed the Theil–Sen’s slope estimation,Mann–Kendall(M–K)trend test,as well as Pearson correlation and Spearman rank correlation analys...Based on monthly runoff and climate datasets spanning 2000–2024,this study employed the Theil–Sen’s slope estimation,Mann–Kendall(M–K)trend test,as well as Pearson correlation and Spearman rank correlation analyses to systematically examine the spatiotemporal patterns of runoff and its climatic driving mechanisms across Tajikistan,providing a scientific basis for sustainable water resource utilization and management in the study area.Results indicated that during 2000–2024,the annual runoff in Tajikistan exhibited statistically non-significant long-term trend(P=0.76),while displaying pronounced seasonal variability and strong spatial heterogeneity.Spring and summer average runoff primarily exhibited slight declining tendencies,while winter average runoff exhibited pronounced reduction in localized regions,such as the Syr Darya Basin,the Vakhsh River Basin,and the lower reaches of the Zeravshan River Basin.Precipitation emerged as the dominant positive driver of runoff,exhibiting moderate to strong positive correlations across over 78.00%of the country,whereas potential evapotranspiration consistently functioned as a negative driver.Rising temperatures exerted a dual competitive effect on runoff:in high-elevation,glacier-covered regions,rising temperatures temporarily increased runoff by accelerating glacier melt;however,at the national scale,the negative impact of rising temperature on runoff has played a slightly dominant role to a certain extent by enhancing evapotranspiration.Collectively,these results indicated that the present stability of runoff in Tajikistan is strongly dependent on the short-term compensatory effects of glacier melt and the risk of future runoff decline is likely to intensify as glacier reserves continue to diminish.This study provides a critical scientific evidence to inform sustainable water resource management in Tajikistan and underscores the need for glacier conservation and integrated water resource management strategies.展开更多
Observation-based method for O_(3)formation sensitivity research is an important tool to analyze the causes of ground-level O_(3)pollution,which has broad application potentials in determining the O_(3)pollution forma...Observation-based method for O_(3)formation sensitivity research is an important tool to analyze the causes of ground-level O_(3)pollution,which has broad application potentials in determining the O_(3)pollution formation mechanism and developing prevention and control strategies.This paper outlined the development history of research on O_(3)formation sensitivity based on observational methods,described the principle and applicability of the methodology,summarized the relative application results in China and provided recommendations on the prevention and control of O_(3)pollution in China based on relevant study results,and finally pointed out the shortcomings and future development prospects in this field in China.The overview study showed that the O_(3)formation sensitivity in some urban areas in China in recent years presented a gradual shifting tendency from the VOC-limited regime to the transition regime or the NO_(x)-limited regime due to the implementation of the O_(3)precursors emission reduction policies;O_(3)pollution control strategies and precursor control countermeasures should be formulated based on local conditions and the dynamic control capability of O_(3)pollution control measures should be improved.There are still some current deficiencies in the study field in China.Therefore,it is recommended that a stereoscopic monitoring network for atmospheric photochemical components should be further constructed and improved;the atmospheric chemical mechanisms should be vigorously developed,and standardized methods for determining the O_(3)formation sensitivity should be established in China in the near future.展开更多
This work describes the development,optimisation and validation of an analytical method for the rapid determination of 17 priority pharmaceutical compounds and endocrine disrupting chemicals(EDCs).Rather than studying...This work describes the development,optimisation and validation of an analytical method for the rapid determination of 17 priority pharmaceutical compounds and endocrine disrupting chemicals(EDCs).Rather than studying compounds from the same therapeutic class,the analyses aimed to determine target compounds with the highest risk potential(with particular regard to Scotland),providing a tool for further monitoring in different water matrices.Prioritisation was based on a systematic environmental risk assessment approach,using consumption data;wastewater treatment removal efficiency;environmental occurrence;toxicological effects;and pre-existing regulatory indicators.This process highlighted 17 compounds across various therapeutic classes,which were then quantified,at environmentally relevant concentrations,by a single analytical methodology.Analytical determination was achieved using a single-step solid phase extraction(SPE)procedure followed by high-performance liquid chromatography with tandem mass spectrometry(HPLC-MS/MS).The fully optimised method performed well for the majority of target compounds,with recoveries>71%for 15 of 17 analytes.The limits of quantification for most target analytes(14 of 17)ranged from 0.07 ng/L to 1.88 ng/L in river waters.The utility of this method was then demonstrated using real water samples associated with a rural hospital/setting.Eight compounds were targeted and detected,with the highest levels found for the analgesic,paracetamol(at up to 105,910 ng/L in the hospital discharge).This method offers a robust tool to monitor high priority pharmaceutical and EDC levels in various aqueous sample matrices.展开更多
The planning environmental impact assessment （EIA） of transmission and transformation power grid at levels of 500 and 220 kV had been finished completely in the 13 municipalities of Jiangsu Province by the end of 20...The planning environmental impact assessment （EIA） of transmission and transformation power grid at levels of 500 and 220 kV had been finished completely in the 13 municipalities of Jiangsu Province by the end of 2012, which played important roles in guiding and planning the following transmission and transformation projects in environmental protection. In this paper, through the detail analysis on the objective and significance of the planning EIA of transmission and transformation power grid, legal basis and planning EIA practices, some suggestions and thinking about the planning EIA of transmission and transformation power grid were put forward.展开更多
The potential environmental implications of a Pb(Lead)-Zn(Zinc)sulfide tailing impoundment were found to be dependent on its geochemical characteristics.One typical lead-zinc sulfide tailing impoundment was studied.Te...The potential environmental implications of a Pb(Lead)-Zn(Zinc)sulfide tailing impoundment were found to be dependent on its geochemical characteristics.One typical lead-zinc sulfide tailing impoundment was studied.Ten boreholes were set with the grid method and 36 tailings were sampled and tested.According to the results of metal content analysis,the tailing samples contained considerably high contents of heavy metals,ranging from 6.99 to 89.0 mg/kg for Cd,75.3 to 602 mg/kg for Cu,0.53%to 2.63%for Pb and 0.30%to 2.54%for Zn.Most of the heavy metals in the sample matrix showed a uniform concentration distribution,except Cd.Cd,Pb,Zn,and Mn were associated with each other,and were considered to be the dominant contributors based on hierarchical cluster analysis.XRD,SEM and XPS were employed for evaluation of the tailing weathering characteristics,confirming that the tailings had undergone intensive weathering.The maximum potential acidity of the tailings reached 244 kg H2SO4/ton;furthermore,the bioavailability of heavy metals like Pb,Cd,Cr,Cu,and Zn was 37.8%,12.9%,12.2%,5.95%,and 5.46%respectively.These metals would be potentially released into drainage by the weathering process.Analysis of a gastrointestinal model showed that Pb,Cr,Ni and Cu contained in the tailings were high-risk metals.Thus,control of the heavy metals’migration and their environmental risks should be planned from the perspective of geochemistry.展开更多
Polycyclic aromatic hydrocarbons (PAHs) are potentially carcinogenic and mutagenic compounds that have raised considerable environmental concern. The highest concentrations of PAHs in the coastal sediment samples in C...Polycyclic aromatic hydrocarbons (PAHs) are potentially carcinogenic and mutagenic compounds that have raised considerable environmental concern. The highest concentrations of PAHs in the coastal sediment samples in China was 5.8-11.0μg/g (dry weight) in the core from the Huangpu River, Shanghai. The second highest concentration of PAHs was 4.42μg/g (dry weight) in surface sediment of Victoria Harbour in Hong Kong, and 5.73μg/g (dry weight) in sediment of Jiaozhou Bay, Qingdao City. The low concentrations of PAHs were always in the sediments far away from industrial zones and cities, and ranged from 0.10 to 0.30μg/g (dry weight). Several environmental parameters are considered for the identification of sources of PAHs in marine environment. High proportion of naphthalene, low molecular weight PAHs and alkylated PAHs, plus high ratio of phenanthrene to anthracene (>15) and low ratio of fluoranthene to pyrene (<1) suggested a petrogenic source. According to these parameters, the Changjiang (Yangtze) River estuary of Shanghai, Jiaozhou Bay of Qingdao City, Zhujiang (Pearl) River mouth, Jiulong River mouth and most of Hong Kong coastal waters were heavily contaminated by PAHs from petrogenic sources. However, PAHs in rural coastal areas were dominated by pyrolytic origin PAHs. This review clearly showed that oil pollution and incomplete combustion of oil, coal and biomass are the main reason for PAHs anormalies in the study areas.展开更多
As an anticonvulsant,oxcarbazepine(OXC)has attracted considerable attention for its potential threat to aquatic organisms.Density functional theory has been used to study the mechanisms and kinetics of OXC degradation...As an anticonvulsant,oxcarbazepine(OXC)has attracted considerable attention for its potential threat to aquatic organisms.Density functional theory has been used to study the mechanisms and kinetics of OXC degradation initiated by OH radicals in aqueous environment.A total of fourteen OH-addition pathways were investigated,and the addition to the C8 position of the right benzene ringwas themost vulnerable pathway,resulting in the intermediate IM8.The H-abstraction reactions initiated by OH radicalswere also explored,where the extraction site of the methylene group(C14)on the seven-member carbon heterocyclic ring was found to be the optimal path.The calculations show that the total rate constant of OXC with OH radicals is 9.47×10^(9)(mol/L)^(−1)sec^(−1),and the half-life time is 7.32 s at 298 K with the[·OH]of 10^(−11) mol/L.Moreover,the branch ratio values revealed that OH-addition(89.58%)shows more advantageous than H-abstraction(10.42%).To further understand the potential eco-toxicity of OXC and its transformation products to aquatic organisms,acute toxicity and chronic toxicity were evaluated using ECOSAR software.The toxicity assessment revealed that most degradation products such as OXC-2OH,OXC-4OH,OXC-1O-1OOH,and OXC-1OH’are innoxious to fish and daphnia.Conversely,green algae are more sensitive to these compounds.This study can provide an extensive investigation into the degradation of OXC by OH radicals and enrich the understanding of the aquatic oxidation processes of pharmaceuticals and personal care products(PPCPs).展开更多
As a kind of biological fertilizer sources, green manure can improve soil fertility and the quality of agricultural products. This paper introduced the germplasm resource of green manures in the major provinces in Chi...As a kind of biological fertilizer sources, green manure can improve soil fertility and the quality of agricultural products. This paper introduced the germplasm resource of green manures in the major provinces in China, mainly summarized the characteristics of decomposition and nutrients release of returning green manures to soils, as well as the influence on soil fertility and succeeding crops, with the aim to provide references for rational utilization of green manures and the scientific management of farmland nutrients.展开更多
Forest plays a vital role in the global biogeochemical cycles through a high rate of carbon sequestration and harboring biodiversity.However,local species diversity is declining while also becoming increasingly homoge...Forest plays a vital role in the global biogeochemical cycles through a high rate of carbon sequestration and harboring biodiversity.However,local species diversity is declining while also becoming increasingly homogenized across communities.Although eff ects of local biotic processes(e.g.,speciesα-diversity and stand structural heterogeneity)and environmental factors on aboveground biomass(AGB)have been widely tested,there is a huge knowledge gap for the eff ect of regional biotic processes(i.e.,taxonomic and functionalβ-diversity)in forests.Here,we hypothesized that regional and local environmental factors along with biotic processes jointly regulate AGB through species shifts in tropical forests.Using piecewise structural equation modeling(pSEM),we linked climatic water availability,soil fertility,stand structural heterogeneity(either tree DBH inequality,height inequality,or stand density),speciesα-diversity,taxonomic or functionalβ-diversity(and its two components;β-turnover andβ-richness),and AGB across 189 inventory plots in tropical forests of Sri Lanka.Soil fertility and climatic water availability shaped local and regional biotic processes.Stand structural heterogeneity promoted speciesα-diversity but declinedβ-diversity(but increasedβ-taxonomic turnover).Speciesα-diversity and stand structural heterogeneity promoted AGB whereas taxonomic and functionalβ-diversity declined(butβ-taxonomic turnover increased)AGB.The relationships of AGB with speciesα-diversity andβ-diversity varied from signifi cant to nonsignifi cant positive depending on the specifi c combinations of stand structural heterogeneity metrics used.This study shows that local biotic processes could increase AGB due to the local and regional niche complementarity eff ect whereas the regional biotic processes could restrict AGB due to the regional selection or functional redundancy eff ect under favorable environmental conditions.We argue that biotic homogenization,as well as drought conditions,may have strong divergent impacts on forest functions and that the impacts of tree diversity loss may greatly reduce carbon sequestration.展开更多
Rape is a crop that can be widely used as a green manure.After returning to the field,it has the ability to fertilize and improve the quality of agricultural products.This paper summarized the application model of rap...Rape is a crop that can be widely used as a green manure.After returning to the field,it has the ability to fertilize and improve the quality of agricultural products.This paper summarized the application model of rape as a green manure and the decomposing characteristics of rape after being returned to the field,and clarified the ecological effects of returning rape to the field,with an attempt to provide scientific basis for the reasonable use of rape and nutrient management in farmland.展开更多
Land surface evapotranspiration (ET) is an important part of the hydrologic cycle and energy balances.With the development of remote sensing technology,research on monitoring and estimating of evapotranspiration has m...Land surface evapotranspiration (ET) is an important part of the hydrologic cycle and energy balances.With the development of remote sensing technology,research on monitoring and estimating of evapotranspiration has made important progress.This paper summarizes advances in measuring and estimating regional evapotranspiration at home and abroad based on traditional methods and remote sensing.This summary includes such methods as Bowen,Gradient,Penman-Monteith,Water Balance,Eddy Correlation,SPAC,Energy Balance and Remote Sensing.Also,the evapotranspiration achievements in the Heihe River Basin are also discussed.Finally,the existing problems in regional evapotranspiration research and future development prospects are also discussed at the conclusion of this paper.展开更多
The cavitation in axial piston pumps threatens the reliability and safety of the overall hydraulic system.Vibration signal can reflect the cavitation conditions in axial piston pumps and it has been combined with mach...The cavitation in axial piston pumps threatens the reliability and safety of the overall hydraulic system.Vibration signal can reflect the cavitation conditions in axial piston pumps and it has been combined with machine learning to detect the pump cavitation.However,the vibration signal usually contains noise in real working conditions,which raises concerns about accurate recognition of cavitation in noisy environment.This paper presents an intelligent method to recognise the cavitation in axial piston pumps in noisy environment.First,we train a convolutional neural network(CNN)using the spectrogram images transformed from raw vibration data under different cavitation conditions.Second,we employ the technique of gradient-weighted class activation mapping(Grad-CAM)to visualise class-discriminative regions in the spectrogram image.Finally,we propose a novel image processing method based on Grad-CAM heatmap to automatically remove entrained noise and enhance class features in the spectrogram image.The experimental results show that the proposed method greatly improves the diagnostic performance of the CNN model in noisy environments.The classification accuracy of cavitation conditions increases from 0.50 to 0.89 and from 0.80 to 0.92 at signal-to-noise ratios of 4 and 6 dB,respectively.展开更多
[ Objective] The aim was to study the natural environment of Karst mountain areas in northern Guangdong. [ Method] Through the col- lection of topography, climate, soil and vegetation data in the Karst mountain areas ...[ Objective] The aim was to study the natural environment of Karst mountain areas in northern Guangdong. [ Method] Through the col- lection of topography, climate, soil and vegetation data in the Karst mountain areas of Northern Guangdong, combined with field investigation, the natural environment of Karst mountain areas in northern Guangdong was analyzed. [ Result] The Karst topography of the area is widely distributed. Most places were in subtropical climate zone, with high temperature and rainfall in the same period, and abundant precipitation. There was a large area of contiguous distribution of limestone with dissolution area. Vegetations included typical limestone evergreen and deciduous broadleaved mixed forest, limestone shrub and grassy slopes in mountain and hill. Limestone vegetation had typical limestone mixed evergreen broadleaf forest, limestone shrub, limestone hilly mountain grass slope. [ Conclusion] The study provided theoretical basis for the protection of natural environment of Karst mountain areas in northern Guangdong.展开更多
基金This work was supported by the National Natural Science Foundation of China(Grant No.L1924041)Research Project on the Discipline Development Strategy of Academic Divisions of the Chinese Academy of Sciences(Grant No.XK2019DXC006).
文摘Environmental science is an interdisciplinary science developed in the process of understanding and solving ecolog-ical and environmental problems.In order to tackle these problems,environmental science research is expected to reveal the source,behavior,fate,exposure,and risks of pollutants in the environment and develop potential solutions to control pollution.It provides the scientific basis for decision-makers to establish environmental and economic poli-cies,and promote concerted efforts for the sustainable development of society.Here,we articulate the development patterns,challenges,and future research needs of environmental science in China based on literature review and expert panel discussion.Environmental science research has evolved significantly in the past decade with an increas-ing diversity of environmental pollutants and health impacts,new technologies and methods,deepening fusion of multiple disciplines,and emerging solutions for pollution control.Its future development relies on the advances in our knowledge on the fate and transport of pollutants,regional environmental processes,ecotoxicological effects,environmental exposure and health effects,environmental analysis and monitoring,source control and reduction,environmental remediation,as well as environmental risk management.For each of these fields,we summarize the significant challenges and highlight the research demands for China.Based on the status quo of China’s environmen-tal science research and future needs,we provide recommendations to promote its future development,including encouraging innovation and interdisciplinary research,providing decision support for national needs,encouraging international collaboration,and improving collaboration mechanisms.
基金supported by the National Key Research and Development Program of China (Grant No. 2023YFC3706203)the National Natural Science Foundation of China (Grant Nos. 91644214, 22361162668, and 22406109)+1 种基金the China Postdoctoral Science Foundation (Grant No. 2024M751797)Shandong Postdoctoral Science Foundation (SDCX-ZG-202400178)
文摘Enhanced mass concentrations of aromatic-derived secondary organic aerosol(SOA)are frequently observed during humid-haze events.However,the influencing mechanism of relative humidity(RH)in aromatic-derived SOA formation remains incompletely understood.Here,the RH dependence of SOA formation in the presence of NOx was explored by a series of chamber experiments for toluene(TOL)and 1,3,5-trimethylbenzene(TMB)photooxidation.The yield of TOL SOA and TMB SOA increased by 221%and 52%with increasing RH from~8%to~70%,respectively.Analytical results from a high-resolution mass spectrometer showed that SOA constituents with high oxygen content(O/C>0.6)were more abundant in SOA formed in the~70%RH experiment.The elevated yields and O/C of SOA could be attributed to the promoted formation and particle-phase diffusivity of highly oxidized molecules.In addition,in comparison with TMB,TOL could produce more unsaturated aldehydes,which are oxidized into carboxylic acids with high O/C,leading to a more sensitive response of TOL SOA formation to the change in RH.Our work provides mechanistic insights into RH roles in aromatic SOA formation and is helpful for a better understanding of humid-haze events.
基金the National Research Foundation(NRF),Prime Minister’s Office,Singapore,under its Campus for Research Excellence and Technological Enterprise(CREATE)program(A-0001032-01-00)the National Natural Science Foundation of China(52376011).
文摘The increasing population and continuous urbanization make food security a key consideration in sustainable development.Efficient farming strategies with low environmental footprints are thus increasingly required to meet food demands.This study presents a design for environmentally friendly,economical,and modular vertical farming systems,in which vegetables are cultivated in a carbon dioxide(CO_(2))-enriched atmosphere enabled by direct air capture(DAC)and subjected to artificial light exposure.We established a vertical farming setup and conducted experiments to identify productive cultivation strategies by regulating lighting,CO_(2)concentration,biochar application,and plant species.Additionally,a self-developed DAC rotary adsorber was utilized to achieve stable and efficient CO_(2)enrichment.Compared with the control group,the fresh weight of the vegetables in the experimental groups increased by up to 57.5%.Furthermore,we performed a comprehensive evaluation of the design and demonstrated that integrating photovoltaic-thermal(PVT)and DAC units increased the system’s net present value(NPV)by 157%compared with a conventional design without these units.Importantly,we found it possible to maintain the low carbon footprint of the system(0.468 kg-CO_(2)equivalent·kg−1(CO_(2)eq·kg−1)-vegetable)in the production process.Parametric studies and an application analysis on a global scale reveal the wide adaptability of this strategy to diverse conditions.These findings,together with the modular characteristics of vertical farming systems,highlight the promising potential of this design to increase food security and foster sustainable agriculture.
基金Project supported by National Key Research and Development Program of China(2022YFB3504100,2021YFB3500600)National Natural Science Foundation of China(22208170)+4 种基金Basic Scientific Research Expenses Program of Universities directly under Inner Mongolia Autonomous Region(JY20220286)Cooperation Foundation for the Chunhui Plan Program of Ministry of Education of China(202200554)Open Project Program of Key Laboratory of Opticelectric Sensing and Analytical Chemistry for Life Science,MOE(M2024-7)Open Project Program of Anhui Province Key Laboratory of Pollutant Sensitive Materials and Environmental RemediatiSon(PSMER2023008)the Open Foundation of State Environmental Protection Key Laboratory of Soil Environmental Management and Pollution Control(SEMPC2023004)。
文摘Rare earth elements are highly applicable in photocatalysis due to their partially filled 4f orbitals,existing in electronic structures that facilitate the transfer of electrons during the reaction process.Among these materials,CeO_(2)has a distinctive external electronic structure(4f^(1)5d^(1)6s^(2)),abundant oxygen vacancies,and strong conversion ability of Ce^(4+)/Ce^(3+),which makes it an attractive candidate in the field of photocatalysis.To broaden its practical applications in the visible region,the drawbacks of a wide band gap and a slow Ce^(4+)/Ce^(3+)cycle have been addressed through the modification of CeO_(2),thereby accelerating light absorption and self-circulation,and enhancing photocatalytic activity.This paper presents a review of the preparation of modified CeO_(2)catalysts and their application in the conversion of cerium valence state in the photocatalytic degradation of pollutants in water.Furthermore,this paper presents a summary of the most recent development and current challenges,as well as prospect for the application of modified CeO_(2)-based materials.
基金supported by Major Scientific and Technological Innovation Project of Shandong Province(No.2020CXGC011204)Qingdao Natural Science Foundation(No.23-2-1-234-zyyd-jch).
文摘The coexistence of emerging containments,such as antibiotic resistant bacteria(ARB),antibiotic-resistant genes(ARGs)and antibiotics,potentially influence elimination efficiencies in UV light-emitting diode(UV-LED)alone and UV-LED/H_(2)O_(2) system as their complex interactions.Tetracycline(TC)degradation efficiency(kF)correlated closely with its UV molar absorbance(R^(2)=0.831)in UV-LED alone system and with·OH yield(R^(2)=0.999)in UV-LED/H_(2)O_(2) system across studied wavelengths(265,280 and 310 nm).The kF values for intracellular DNA(i-ARGs)also exhibited a high correlation with UV-LED wavelengths in both systems(R^(2)=0.997-0.999).The coexistence of TC and ARB/ARGs resulted in a mutual inhibition of their degradation efficiencies due to competition for photons and·OH,along with the consequent reduction in intracellular ROS within ARB,with their degradation efficiencies exhibiting marked dependence on wavelength in both systems.Notably,the UV-LED/H_(2)O_(2) system at 265 nm effectively achieved the simultaneous removal of TC,ARB and ARGs with minimal energy consumption,and successfully fragmented ARGs.The degradation pathway of TC was analyzed,and the biotoxicity of its degradation intermediates demonstrated the environmental friendliness and safety of UV-LED/H_(2)O_(2) technology.This study elucidated the competitive interactions between antibiotics and ARB/ARGs within UV-LED/H_(2)O_(2) system,providing a promising approach for their simultaneous removal while ensuring energy efficiency.
基金supported financially by the National Key Research&Development Program of China(2021YFD1700200)the National Natural Science Foundation of China(32402686)+3 种基金the Earmarked Fund for China Agriculture Research System(CARS-22)the Fundamental Research Funds for Central Non-profit Scientific Institution,China(1610132022013)the Science and Technology Innovation Project of Chinese Academy of Agricultural Sciencesthe China National Crop Germplasm Resources Platform for Green Manure(NICGR-2024-19)。
文摘Green manuring is essential for improving soil quality and nutrient uptake.With the gradual depletion of phosphorus(P)resources,more attention is being paid to the role of green manures in cultivation systems,such as maize-green manure intercropping,to find possible pathways for enhancing soil P utilization.A maize-green manure intercropping experiment was started in 2009 to investigate the effects and mechanisms for enhancing P uptake and yield in maize.Three species of green manures(hairy vetch(HV),needle leaf pea(NP),sweet pea(SP))and a sole maize treatment(CK)were used,resulting in four treatments(CK,HVT,NPT,and SPT)in the experiment.During 2020-2023,the intercropping treatments enhanced maize yields in 2020 and 2021,particularly in HVT with increases of 13.7%(1.96 t ha^(-1))and 13.0%(2.13 t ha^(-1))compared with CK,respectively.Grain P accumulation of maize was significantly higher in the intercropping treatments than CK in 2020,2021,and 2023,and with an average increase of 10.6%over the four years(5.2% for NPT,10.8% for SPT and 15.9% for HVT)compared with CK.Intercropping promoted maize growth with a greater root length density and a higher organic acid release rate.HVT changed the soil properties more dramatically than the other treatments,with increases in the acid phosphatase and alkaline phosphatase activities of 29.8 and 38.5%,respectively,in the topsoil(0-15 cm),while the soil p H was reduced by 0.37 units compared to CK(p H=8.44).Intercropping treatments facilitated the conversion of non-labile P to mod-labile P and stimulated the growth of soil bacteria in the topsoil.Compared with CK,the relative abundance of Gemmatimonadota,known for accumulating polyphosphate,and Actinobacteriota,a prominent source of bioactive compounds,increased significantly in the intercropping treatments,especially in HVT and SPT.A PLS-PM analysis showed that intercropping promoted soil P mobilization and the enrichment of beneficial bacteria by regulating maize root morphology and physiology.Our results highlight that maize-green manure intercropping optimizes root traits,soil properties and bacterial composition,which contribute to greater maize P uptake and yield,providing an effective strategy for sustainable crop production.
基金partially funded by EPSRC (EP/T022213/1, EP/W032260/1 and EP/P020194/1) via our membership of the UK’s HEC Materials Chemistry Consortium, which is funded by EPSRC (EP/L000202)part of the “Advancing Solid Interface and Lubricants by First Principles Material Design (SLIDE)” project that has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (Grant agreement No. 865633)
文摘Amorphous materials represent a promising platform for advancing CO_(2)electrochemical reduction due to their inherently diverse coordination environments.In this study,we demonstrate computationally the superior performance of amorphous CuNi alloys for CO_(2)electrochemical reduction.By integrating machine learning forcefields for efficient structure generation and density functional theory for subsequent structural refinement and property calculations,we reveal the potential of these disordered systems to outperform their crystalline counterparts.Machine learning forcefields can generate a bulk structure containing a mixture of Cu and Ni atoms,resulting in enhanced catalytic performance.Effective screening of the amorphous surfaces is used to identify undercoordinated Cu and Ni sites in the amorphous structure to synergistically promote selective CO production and favor ethanol formation over ethylene via the stabilization of the*COCHO intermediate,resulting in significantly lower Gibbs free energy changes compared to the crystalline counterpart.The varying atomic coordination environments on amorphous surfaces promote both C–C bond formation and subsequent proton-electron transfer,leading to ethanol formation.These findings demonstrate the superior catalytic performance of amorphous CuNi,highlighting its potential for efficient and selective electroreduction of CO_(2).
基金funded by the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB0720203)the National Key Research and Development Program of China(2023YFF0805603).
文摘Based on monthly runoff and climate datasets spanning 2000–2024,this study employed the Theil–Sen’s slope estimation,Mann–Kendall(M–K)trend test,as well as Pearson correlation and Spearman rank correlation analyses to systematically examine the spatiotemporal patterns of runoff and its climatic driving mechanisms across Tajikistan,providing a scientific basis for sustainable water resource utilization and management in the study area.Results indicated that during 2000–2024,the annual runoff in Tajikistan exhibited statistically non-significant long-term trend(P=0.76),while displaying pronounced seasonal variability and strong spatial heterogeneity.Spring and summer average runoff primarily exhibited slight declining tendencies,while winter average runoff exhibited pronounced reduction in localized regions,such as the Syr Darya Basin,the Vakhsh River Basin,and the lower reaches of the Zeravshan River Basin.Precipitation emerged as the dominant positive driver of runoff,exhibiting moderate to strong positive correlations across over 78.00%of the country,whereas potential evapotranspiration consistently functioned as a negative driver.Rising temperatures exerted a dual competitive effect on runoff:in high-elevation,glacier-covered regions,rising temperatures temporarily increased runoff by accelerating glacier melt;however,at the national scale,the negative impact of rising temperature on runoff has played a slightly dominant role to a certain extent by enhancing evapotranspiration.Collectively,these results indicated that the present stability of runoff in Tajikistan is strongly dependent on the short-term compensatory effects of glacier melt and the risk of future runoff decline is likely to intensify as glacier reserves continue to diminish.This study provides a critical scientific evidence to inform sustainable water resource management in Tajikistan and underscores the need for glacier conservation and integrated water resource management strategies.
基金supported by the National Research Program for Key Issues in Air Pollution Control(No.DQGG202121)the Beijing Municipal Science&Technology Commission(No.Z181100005418015)+1 种基金National Natural Science Foundation of China(No.42075094)the National Research Program for Key Issue in Air Pollution Control(No.DQGG2021101)。
文摘Observation-based method for O_(3)formation sensitivity research is an important tool to analyze the causes of ground-level O_(3)pollution,which has broad application potentials in determining the O_(3)pollution formation mechanism and developing prevention and control strategies.This paper outlined the development history of research on O_(3)formation sensitivity based on observational methods,described the principle and applicability of the methodology,summarized the relative application results in China and provided recommendations on the prevention and control of O_(3)pollution in China based on relevant study results,and finally pointed out the shortcomings and future development prospects in this field in China.The overview study showed that the O_(3)formation sensitivity in some urban areas in China in recent years presented a gradual shifting tendency from the VOC-limited regime to the transition regime or the NO_(x)-limited regime due to the implementation of the O_(3)precursors emission reduction policies;O_(3)pollution control strategies and precursor control countermeasures should be formulated based on local conditions and the dynamic control capability of O_(3)pollution control measures should be improved.There are still some current deficiencies in the study field in China.Therefore,it is recommended that a stereoscopic monitoring network for atmospheric photochemical components should be further constructed and improved;the atmospheric chemical mechanisms should be vigorously developed,and standardized methods for determining the O_(3)formation sensitivity should be established in China in the near future.
文摘This work describes the development,optimisation and validation of an analytical method for the rapid determination of 17 priority pharmaceutical compounds and endocrine disrupting chemicals(EDCs).Rather than studying compounds from the same therapeutic class,the analyses aimed to determine target compounds with the highest risk potential(with particular regard to Scotland),providing a tool for further monitoring in different water matrices.Prioritisation was based on a systematic environmental risk assessment approach,using consumption data;wastewater treatment removal efficiency;environmental occurrence;toxicological effects;and pre-existing regulatory indicators.This process highlighted 17 compounds across various therapeutic classes,which were then quantified,at environmentally relevant concentrations,by a single analytical methodology.Analytical determination was achieved using a single-step solid phase extraction(SPE)procedure followed by high-performance liquid chromatography with tandem mass spectrometry(HPLC-MS/MS).The fully optimised method performed well for the majority of target compounds,with recoveries>71%for 15 of 17 analytes.The limits of quantification for most target analytes(14 of 17)ranged from 0.07 ng/L to 1.88 ng/L in river waters.The utility of this method was then demonstrated using real water samples associated with a rural hospital/setting.Eight compounds were targeted and detected,with the highest levels found for the analgesic,paracetamol(at up to 105,910 ng/L in the hospital discharge).This method offers a robust tool to monitor high priority pharmaceutical and EDC levels in various aqueous sample matrices.
基金Supported by the National Key Technology R&D Program(2012BAC20B1003)the Key National Social Science Fund Project(12&ZD214)the Special Fund Project for the Scientific Research of the Environmental Protection Welfare Industry(201209001)
文摘The planning environmental impact assessment （EIA） of transmission and transformation power grid at levels of 500 and 220 kV had been finished completely in the 13 municipalities of Jiangsu Province by the end of 2012, which played important roles in guiding and planning the following transmission and transformation projects in environmental protection. In this paper, through the detail analysis on the objective and significance of the planning EIA of transmission and transformation power grid, legal basis and planning EIA practices, some suggestions and thinking about the planning EIA of transmission and transformation power grid were put forward.
基金supported by the National Key Research and Development Plan(No.2018YFC1802803)Guangdong Provincial Science and Technology Program(No.2015B020237003)the 2017 Central Special Fund for Soil,Preliminary Study on Harmless Treatment and Comprehensive Utilization of Tailings in Dabao Mountain(18HK0108)。
文摘The potential environmental implications of a Pb(Lead)-Zn(Zinc)sulfide tailing impoundment were found to be dependent on its geochemical characteristics.One typical lead-zinc sulfide tailing impoundment was studied.Ten boreholes were set with the grid method and 36 tailings were sampled and tested.According to the results of metal content analysis,the tailing samples contained considerably high contents of heavy metals,ranging from 6.99 to 89.0 mg/kg for Cd,75.3 to 602 mg/kg for Cu,0.53%to 2.63%for Pb and 0.30%to 2.54%for Zn.Most of the heavy metals in the sample matrix showed a uniform concentration distribution,except Cd.Cd,Pb,Zn,and Mn were associated with each other,and were considered to be the dominant contributors based on hierarchical cluster analysis.XRD,SEM and XPS were employed for evaluation of the tailing weathering characteristics,confirming that the tailings had undergone intensive weathering.The maximum potential acidity of the tailings reached 244 kg H2SO4/ton;furthermore,the bioavailability of heavy metals like Pb,Cd,Cr,Cu,and Zn was 37.8%,12.9%,12.2%,5.95%,and 5.46%respectively.These metals would be potentially released into drainage by the weathering process.Analysis of a gastrointestinal model showed that Pb,Cr,Ni and Cu contained in the tailings were high-risk metals.Thus,control of the heavy metals’migration and their environmental risks should be planned from the perspective of geochemistry.
文摘Polycyclic aromatic hydrocarbons (PAHs) are potentially carcinogenic and mutagenic compounds that have raised considerable environmental concern. The highest concentrations of PAHs in the coastal sediment samples in China was 5.8-11.0μg/g (dry weight) in the core from the Huangpu River, Shanghai. The second highest concentration of PAHs was 4.42μg/g (dry weight) in surface sediment of Victoria Harbour in Hong Kong, and 5.73μg/g (dry weight) in sediment of Jiaozhou Bay, Qingdao City. The low concentrations of PAHs were always in the sediments far away from industrial zones and cities, and ranged from 0.10 to 0.30μg/g (dry weight). Several environmental parameters are considered for the identification of sources of PAHs in marine environment. High proportion of naphthalene, low molecular weight PAHs and alkylated PAHs, plus high ratio of phenanthrene to anthracene (>15) and low ratio of fluoranthene to pyrene (<1) suggested a petrogenic source. According to these parameters, the Changjiang (Yangtze) River estuary of Shanghai, Jiaozhou Bay of Qingdao City, Zhujiang (Pearl) River mouth, Jiulong River mouth and most of Hong Kong coastal waters were heavily contaminated by PAHs from petrogenic sources. However, PAHs in rural coastal areas were dominated by pyrolytic origin PAHs. This review clearly showed that oil pollution and incomplete combustion of oil, coal and biomass are the main reason for PAHs anormalies in the study areas.
基金This work was supported by the Shandong Provincial Natural Science Foundation of China(No.ZR2021MB039)the National Natural Science Foundation of China(No.21607089)the Shandong Provincial Key Research and Development Program(Major Scientific and Technological Innovation Project)(No.2020CXGC011402).
文摘As an anticonvulsant,oxcarbazepine(OXC)has attracted considerable attention for its potential threat to aquatic organisms.Density functional theory has been used to study the mechanisms and kinetics of OXC degradation initiated by OH radicals in aqueous environment.A total of fourteen OH-addition pathways were investigated,and the addition to the C8 position of the right benzene ringwas themost vulnerable pathway,resulting in the intermediate IM8.The H-abstraction reactions initiated by OH radicalswere also explored,where the extraction site of the methylene group(C14)on the seven-member carbon heterocyclic ring was found to be the optimal path.The calculations show that the total rate constant of OXC with OH radicals is 9.47×10^(9)(mol/L)^(−1)sec^(−1),and the half-life time is 7.32 s at 298 K with the[·OH]of 10^(−11) mol/L.Moreover,the branch ratio values revealed that OH-addition(89.58%)shows more advantageous than H-abstraction(10.42%).To further understand the potential eco-toxicity of OXC and its transformation products to aquatic organisms,acute toxicity and chronic toxicity were evaluated using ECOSAR software.The toxicity assessment revealed that most degradation products such as OXC-2OH,OXC-4OH,OXC-1O-1OOH,and OXC-1OH’are innoxious to fish and daphnia.Conversely,green algae are more sensitive to these compounds.This study can provide an extensive investigation into the degradation of OXC by OH radicals and enrich the understanding of the aquatic oxidation processes of pharmaceuticals and personal care products(PPCPs).
基金Supported by the Natural Science Foundation of Guangxi(2017GXNSFBA198204)the Key Science and Technology Project of Guangxi(Guike AA17204059-9&AA172040459-10)+1 种基金the Planning Project for Scientific Research and Technological Development of Xixiangtang District,Nanning City(2017-2-10309)the Special Fund for the Fundamental Research of Guangxi Academy of Agricultural Sciences(Guinongke 2018YT07&2018YM28)
文摘As a kind of biological fertilizer sources, green manure can improve soil fertility and the quality of agricultural products. This paper introduced the germplasm resource of green manures in the major provinces in China, mainly summarized the characteristics of decomposition and nutrients release of returning green manures to soils, as well as the influence on soil fertility and succeeding crops, with the aim to provide references for rational utilization of green manures and the scientific management of farmland nutrients.
基金funded by the Swedish Energy Agency(Project No 35586-1)for supporting the fieldworkSpecial Project(No.521100221033)of Hebei University for the interpretation of results
文摘Forest plays a vital role in the global biogeochemical cycles through a high rate of carbon sequestration and harboring biodiversity.However,local species diversity is declining while also becoming increasingly homogenized across communities.Although eff ects of local biotic processes(e.g.,speciesα-diversity and stand structural heterogeneity)and environmental factors on aboveground biomass(AGB)have been widely tested,there is a huge knowledge gap for the eff ect of regional biotic processes(i.e.,taxonomic and functionalβ-diversity)in forests.Here,we hypothesized that regional and local environmental factors along with biotic processes jointly regulate AGB through species shifts in tropical forests.Using piecewise structural equation modeling(pSEM),we linked climatic water availability,soil fertility,stand structural heterogeneity(either tree DBH inequality,height inequality,or stand density),speciesα-diversity,taxonomic or functionalβ-diversity(and its two components;β-turnover andβ-richness),and AGB across 189 inventory plots in tropical forests of Sri Lanka.Soil fertility and climatic water availability shaped local and regional biotic processes.Stand structural heterogeneity promoted speciesα-diversity but declinedβ-diversity(but increasedβ-taxonomic turnover).Speciesα-diversity and stand structural heterogeneity promoted AGB whereas taxonomic and functionalβ-diversity declined(butβ-taxonomic turnover increased)AGB.The relationships of AGB with speciesα-diversity andβ-diversity varied from signifi cant to nonsignifi cant positive depending on the specifi c combinations of stand structural heterogeneity metrics used.This study shows that local biotic processes could increase AGB due to the local and regional niche complementarity eff ect whereas the regional biotic processes could restrict AGB due to the regional selection or functional redundancy eff ect under favorable environmental conditions.We argue that biotic homogenization,as well as drought conditions,may have strong divergent impacts on forest functions and that the impacts of tree diversity loss may greatly reduce carbon sequestration.
基金Supported by Guangxi Innovation-driven Development Project(GK AA17204045,GK AA17204097)Science and Technology Development Fund of Guangxi Academy of Agricultural Sciences(GKN 2018YT07,GKN 2020YM112)+2 种基金Guangxi Characteristic Crop Experiment Station Project(G TS201417)Guangxi Science and Technology Vanguard Project(GKN JZ202014)Science and Technology Planning Project of Xixiangtang District,Nanning City(201810211)。
文摘Rape is a crop that can be widely used as a green manure.After returning to the field,it has the ability to fertilize and improve the quality of agricultural products.This paper summarized the application model of rape as a green manure and the decomposing characteristics of rape after being returned to the field,and clarified the ecological effects of returning rape to the field,with an attempt to provide scientific basis for the reasonable use of rape and nutrient management in farmland.
基金supported by The National Natural Science Foundation of China (40771006)the Knowledge Innovation Program of the Chinese Academy of Sciences (KZCX2-XB2-04)
文摘Land surface evapotranspiration (ET) is an important part of the hydrologic cycle and energy balances.With the development of remote sensing technology,research on monitoring and estimating of evapotranspiration has made important progress.This paper summarizes advances in measuring and estimating regional evapotranspiration at home and abroad based on traditional methods and remote sensing.This summary includes such methods as Bowen,Gradient,Penman-Monteith,Water Balance,Eddy Correlation,SPAC,Energy Balance and Remote Sensing.Also,the evapotranspiration achievements in the Heihe River Basin are also discussed.Finally,the existing problems in regional evapotranspiration research and future development prospects are also discussed at the conclusion of this paper.
基金National Key R&D Program of China,Grant/Award Number:2018YFB1702503Open Foundation of the State Key Laboratory of Fluid Power and Mechatronic Systems,Grant/Award Number:GZKF-202108+2 种基金Open Foundation of the Guangdong Provincial Key Laboratory of Electronic Information Products Reliability TechnologyChina National Postdoctoral Program for Innovative Talents,Grant/Award Number:BX20200210China Postdoctoral Science Foundation,Grant/Award Number:2019M660086。
文摘The cavitation in axial piston pumps threatens the reliability and safety of the overall hydraulic system.Vibration signal can reflect the cavitation conditions in axial piston pumps and it has been combined with machine learning to detect the pump cavitation.However,the vibration signal usually contains noise in real working conditions,which raises concerns about accurate recognition of cavitation in noisy environment.This paper presents an intelligent method to recognise the cavitation in axial piston pumps in noisy environment.First,we train a convolutional neural network(CNN)using the spectrogram images transformed from raw vibration data under different cavitation conditions.Second,we employ the technique of gradient-weighted class activation mapping(Grad-CAM)to visualise class-discriminative regions in the spectrogram image.Finally,we propose a novel image processing method based on Grad-CAM heatmap to automatically remove entrained noise and enhance class features in the spectrogram image.The experimental results show that the proposed method greatly improves the diagnostic performance of the CNN model in noisy environments.The classification accuracy of cavitation conditions increases from 0.50 to 0.89 and from 0.80 to 0.92 at signal-to-noise ratios of 4 and 6 dB,respectively.
基金Supported by Guangdong Excellent Innovational Youth Training Program(LYM11126)National Natural Science Fund(30870469,31170486)
文摘[ Objective] The aim was to study the natural environment of Karst mountain areas in northern Guangdong. [ Method] Through the col- lection of topography, climate, soil and vegetation data in the Karst mountain areas of Northern Guangdong, combined with field investigation, the natural environment of Karst mountain areas in northern Guangdong was analyzed. [ Result] The Karst topography of the area is widely distributed. Most places were in subtropical climate zone, with high temperature and rainfall in the same period, and abundant precipitation. There was a large area of contiguous distribution of limestone with dissolution area. Vegetations included typical limestone evergreen and deciduous broadleaved mixed forest, limestone shrub and grassy slopes in mountain and hill. Limestone vegetation had typical limestone mixed evergreen broadleaf forest, limestone shrub, limestone hilly mountain grass slope. [ Conclusion] The study provided theoretical basis for the protection of natural environment of Karst mountain areas in northern Guangdong.
