Hard carbons are promising anode materials for sodium-ion batteries(SIBs),but they face challenges in balancing rate capability,specific capacity,and initial Coulombic efficiency(ICE).Direct pyrolysis of the precursor...Hard carbons are promising anode materials for sodium-ion batteries(SIBs),but they face challenges in balancing rate capability,specific capacity,and initial Coulombic efficiency(ICE).Direct pyrolysis of the precursor often fails to create a suitable structure for sodium-ion storage.Molecular-level control of graphitization with open channels for Na^(+)ions is crucial for high-performance hard carbon,whereas closed pores play a key role in improving the low-voltage(<0.1 V)plateau capacity of hard carbon anodes for SIBs.However,creation of these closed pores presents significant challenges.This work proposes a zinc gluconate-assisted catalytic carbonization strategy to regulate graphitization and create numerous nanopores simultaneously.As the temperature increases,trace amounts of zinc remain as single atoms in the hard carbon,featuring a uniform coordination structure.This mitigates the risk of electrochemically irreversible sites and enhances sodium-ion transport rates.The resulting hard carbon shows an excellent reversible capacity of 348.5 mAh g^(-1) at 30 mA g^(-1) and a high ICE of 92.84%.Furthermore,a sodium storage mechanism involving“adsorption-intercalation-pore filling”is elucidated,providing insights into the pore structure and dynamic pore-filling process.展开更多
Tin(IV)oxide(Sn_(3)O_(4))is layered tin and exhibits mixed valence states.It has emerged as a highly promising visible-light pho-tocatalyst,attracting considerable attention.This comprehensive review is aimed at provi...Tin(IV)oxide(Sn_(3)O_(4))is layered tin and exhibits mixed valence states.It has emerged as a highly promising visible-light pho-tocatalyst,attracting considerable attention.This comprehensive review is aimed at providing a detailed overview of the latest advance-ments in research,applications,advantages,and challenges associated with Sn_(3)O_(4)photocatalytic nanomaterials.The fundamental con-cepts and principles of Sn_(3)O_(4)are introduced.Sn_(3)O_(4)possesses a unique crystal structure and optoelectronic properties that allow it to ab-sorb visible light efficiently and generate photoexcited charge carriers that drive photocatalytic reactions.Subsequently,strategies for the control and improved performance of Sn_(3)O_(4)photocatalytic nanomaterials are discussed.Morphology control,ion doping,and hetero-structure construction are widely employed in the optimization of the photocatalytic performance of Sn_(3)O_(4)materials.The effective imple-mentation of these strategies improves the photocatalytic activity and stability of Sn_(3)O_(4)nanomaterials.Furthermore,the review explores the diverse applications of Sn_(3)O_(4)photocatalytic nanomaterials in various fields,such as photocatalytic degradation,photocatalytic hydro-gen production,photocatalytic reduction of carbon dioxide,solar cells,photocatalytic sterilization,and optoelectronic sensors.The discus-sion focuses on the potential of Sn_(3)O_(4)-based nanomaterials in these applications,highlighting their unique attributes and functionalities.Finally,the review provides an outlook on the future development directions in the field and offers guidance for the exploration and de-velopment of novel and efficient Sn_(3)O_(4)-based nanomaterials.Through the identification of emerging research areas and potential avenues for improvement,this review aims to stimulate further advancements in Sn_(3)O_(4)-based photocatalysis and facilitate the translation of this promising technology into practical applications.展开更多
The hydrological process in the dry–warm valley of the mountainous area of southwest China has unique characteristics and has attracted scientific attention worldwide.Given that this is an area with fragile ecosystem...The hydrological process in the dry–warm valley of the mountainous area of southwest China has unique characteristics and has attracted scientific attention worldwide.Given that this is an area with fragile ecosystems and intensive water resource conflicts in the upper reaches of the Yangtze River,a systematic identification of its hydrological responses to climate and land use variations needs to be performed.In this study,MIKE SHE was employed and calibrated for the Anning River Basin in the dry–warm valley.Subsequently,a deep learning neural network model of the long short-term memory(LSTM)and a traditional multi-model ensemble mean(MMEM)method were used for an ensemble of 31 global climate models(GCMs)for climate projection.The cellular automata–Markov model was implemented to project the spatial pattern of land use considering climatic,social,and economic conditions.Four sets of climate projections and three sets of land use projections were generated and fed into the MIKE SHE to project hydrologic responses from 2021 to 2050.For the calibration and first validation periods of the daily simulation,the coefficients of determination(R)were 0.85 and 0.87 and the Nash–Sutcliffe efficiency values were 0.72 and 0.73,respectively.The advanced LSTM performed better than the traditional MMEM method for daily temperature and monthly precipitation.The average monthly temperature projection under representative concentration pathway 8.5(RCP8.5)was expected to be slightly higher than that under RCP4.5;this is contrary to the average monthly precipitation from June to October.The variations in streamflow and actual evapotranspiration(ET)were both more sensitive to climate change than to land use change.There was no significant relationship between the variations in streamflow and the ET in the study area.This work could provide general variation conditions and a range of hydrologic responses to complex and changing environments,thereby assisting with stochastic uncertainty and optimizing water resource management in critical regions.展开更多
Excessive amounts of nitrogen(N)fertilizers are applied during wolfberry production,resulting in some soil problems as well as potential environmental risks in the Qinghai-Tibet Plateau.In this study,organic fertilize...Excessive amounts of nitrogen(N)fertilizers are applied during wolfberry production,resulting in some soil problems as well as potential environmental risks in the Qinghai-Tibet Plateau.In this study,organic fertilizers were used to replace part of the N fertilizer in wolfberry fields with different fertility levels.N fertilizer rates had 0,50,100,150,200,and 250 g N/plant.Organic fertilizer rates had 0,2,4,6,8,and 10 kg organic fertilizer/plant.The experimental treatments included 6 combinations of N0M10,N50M8,N100M6,N150M4,N200M2,and control was N250M0.The results showed that in the high-fertility soils,combinations of N150M4,N100M6 and N50M8 treatments were increased in yields,fruit shape index,flavonoid content,total phenol content,mineral nutrient content,and antioxidant activity of wolfberry fruits.Also they were improved in soil fertility and decreased in residual nitrate through the soil depth of 0-300 cm.In the soil with less fertility,fruit yield,amino acid contents,flavonoids,total phenols,mineral nutrients and antioxidant activity of fruits were increased by the N200M2,N150M4 and N100M6 treatments and soil fertility was improved as well.Also more residual nitrate was found in the depth of 0-100 cm of soil with both chemical and organic fertilizer compared with the control.Therefore,in the Qinghai-Tibet Plateau,combining decreased N fertilizer with organic fertilizer rather than chemical fertilizer alone could help farmers achieve satisfactory yields and quality of wolfberry fruits and reduce the risk of nitrate leaching.In conclusion,50-150 g/plant of N fertilizer combined with 4-8 kg/plant of organic fertilizer in high-fertility gardens and 100-200 g/plant of N fertilizer combined with 2-6 kg/plant of organic fertilizer in low-fertility gardens are recommended for wolfberry cultivation.展开更多
Peel color is an important appearance quality of melons that significantly affects consumer preferences.In this study,a near-isogenic line NIL-G(dark green peel)was generated from B8(grey-green peel)and B15(white peel...Peel color is an important appearance quality of melons that significantly affects consumer preferences.In this study,a near-isogenic line NIL-G(dark green peel)was generated from B8(grey-green peel)and B15(white peel).The F_2 population constructed by crossing NIL-G and B15 was used to study the inheritance pattern of peel color,and bulked-segregant analysis sequencing(BSA-seq)was employed to identify the interval in which the target gene was located.Genetic analysis showed that a dominant gene controls the dark green peel trait at maturity.BSAseq and molecular markers were used to localize the candidate gene in a 263.7 kb interval of chromosome 4,which contained the CmAPRR2 gene with known functions.Moreover,allelic sequence analysis revealed four SNP variations of the CmAPRR2 gene in B15,of which SNP.G614331A was located at the junction of the 6th exon and 6th intron.The G-to-A mutation caused alternative splicing of the transcript of CmAPRR2 in B15,generating two transcripts(CmAPRR2-A and CmAPRR2-B)with premature termination codons.Furthermore,the Kompetitive Allele Specific PCR(KASP)marker,APRR2-G/A,was developed based on this SNP and shown to co-segregate with the peel color phenotype in the F_(2) population.Compared to white-peel B15,the expression level of CmAPRR2 in dark green peel NIL-G was higher at each growth stage.Therefore,CmAPRR2 may be the key gene controlling the fruit color of melons.This study identified a novel allelic variant of CmAPRR2 that leads to white peel formation in mature melons.We also provides a theoretical basis for further research on the gene regulatory mechanism of melon peel colors,which promotes using molecular marker-assisted selection to modify melon peel colors in the future.展开更多
Fencing for grazing exclusion is regarded as a traditional and effective method for the natural restoration of degraded alpine steppe,and it effectively promotes plant growth and enhances soil carbon stocks.Arbuscular...Fencing for grazing exclusion is regarded as a traditional and effective method for the natural restoration of degraded alpine steppe,and it effectively promotes plant growth and enhances soil carbon stocks.Arbuscular mycorrhizal fungi(AMF)are essential microorganisms in grassland that play a major role in plant-derived C translocation into the soil.However,the effects of fencing on AMF communities and their contributions to soil carbon sequestration are still unclear.In this study,alpine steppe areas with three different fencing durations(free grazing,medium-term fencing for 5-6 years and long-term fencing for more than 10 years)in the northern Tibetan Plateau were selected to explore the effects of grazing exclusion on AMF communities and their roles in soil carbon sequestration.The results showed that medium-and long-term fencing significantly increased both plant aboveground biomass and soil organic carbon(SOC)content.The AMF community composition varied significantly during different fencing durations,with a dramatic increase in the relative abundance of Glomus but a significant reduction in the relative abundance of Diversispora with longer fencing time.Medium-term fencing significantly increased AMF richness and the ShannonWiener index.Meanwhile,fencing significantly increased hyphal length density(HLD),glomalin-related soil protein(GRSP)and the proportion of macroaggregates(250-2,000μm),all of which contribute positively to SOC.Structural equation modeling revealed that fencing time positively influenced HLD and the AMF community composition,subsequently affecting T-GRSP,which was tightly correlated with SOC.Our findings suggest the potentially important contribution of AMF to SOC sequestration,so more attention should be paid to AMF during alpine steppe fencing,particularly for enhancing the efficiency of degraded grassland restoration efforts.展开更多
Increasing yield is one of the most important goals in crop breeding. Soybean （Glycine max L. Merr.）, one of the most economically important leguminous seed crops, provides the majority of plant proteins, and more t...Increasing yield is one of the most important goals in crop breeding. Soybean （Glycine max L. Merr.）, one of the most economically important leguminous seed crops, provides the majority of plant proteins, and more than a quarter of the world＇s food and animal feed （Graham and Vance, 2003）. The yield of soybean is finally determined by the number of seeds per unit area, which affected by many characters, such as height, branching number, photosynthesis, seed size, seed number. The number of seeds per pod is taken for one of the critical components that related to yield （You et al., 1995）.展开更多
Dissolved organic nitrogen(DON) has attracted much attention in drinking water treatment due to its potential to produce nitrogenous disinfection by-products(N-DBPs). This work was designed to explore the transformati...Dissolved organic nitrogen(DON) has attracted much attention in drinking water treatment due to its potential to produce nitrogenous disinfection by-products(N-DBPs). This work was designed to explore the transformation and fate of DON and dissolved inorganic nitrogen(DIN) in drinking water treatment. The changes of DON and formation of N-DBPs were evaluated along the water treatment route(i.e., pre-ozonation and biologicalcontact oxidation, delivery pipes’ transportation, coagulation-sedimentation, sand filtration, post-ozonation, biological activated carbon, ultrafiltration and disinfection) of drinking water treatment plant(DWTP). The transformation mechanism of DON was comprehensively investigated by molecular weight fractionation, three-dimensional fluorescence, LCOCD(Liquid Chromatography-Organic Carbon Detection), total free amino acids. A detailed comparison was made between concentrations and variations of DON and DIN affected by seasons in the drinking water treatment. Regardless of seasonal variation in raw water concentration, the DON removal trends between different treatment processes remain constant in the present study. Compared to other treatment processes, pre-ozonation and coagulation-sedimentation exhibited the dominant DON removal in different seasons, i.e.,11.13%-14.45% and 14.98%-22.49%, respectively. Contrary, biological-contact oxidation and biological activated carbon negatively impacted the DON removal, in which DON increased by 1.76%-6.49% in biological activated carbon. This may be due to the release of soluble microbial products(SMPs) from bacterial metabolism, which was further validated by the rise of biopolymers in LC-OCD.展开更多
The radial basis functions(RBFs)play an important role in the numerical simulation processes of partial differential equations.Since the radial basis functions are meshless algorithms,its approximation is easy to impl...The radial basis functions(RBFs)play an important role in the numerical simulation processes of partial differential equations.Since the radial basis functions are meshless algorithms,its approximation is easy to implement and mathematically simple.In this paper,the commonly⁃used multiquadric RBF,conical RBF,and Gaussian RBF were applied to solve boundary value problems which are governed by partial differential equations with variable coefficients.Numerical results were provided to show the good performance of the three RBFs as numerical tools for a wide range of problems.It is shown that the conical RBF numerical results were more stable than the other two radial basis functions.From the comparison of three commonly⁃used RBFs,one may obtain the best numerical solutions for boundary value problems.展开更多
The effective disposal of daily city infrastructure cases is an important issue for urban management. To more effectively utilize a large amount of historical cases data collected and accumulated in the urban grid man...The effective disposal of daily city infrastructure cases is an important issue for urban management. To more effectively utilize a large amount of historical cases data collected and accumulated in the urban grid management system, and to analyze their spatial distribution pattern information for city managers, this study used the comparative kernel density analysis method in two types of cases (i.e. power facilities and traffic guardrail) in Xicheng District, Beijing for the year 2016 and 2017. This research analyzes them at different scales (300 m, 600 m, 1,200 m), and the experiment results show that the method of comparative kernel density analysis is able to provide an intuitively spatial visualization distribution analysis of city infrastructure related cases. The quantitative information of spatial agglomeration degree is helpful for city managers making decision.展开更多
Cation effect has emerged as a promising strategy for modulating the product distribution during the electrocatalytic CO_(2)reduction reaction(CO_(2)RR).However,the strategy of solely increasing bulk cation concentrat...Cation effect has emerged as a promising strategy for modulating the product distribution during the electrocatalytic CO_(2)reduction reaction(CO_(2)RR).However,the strategy of solely increasing bulk cation concentration in the electrolyte to intensify cation effect at the electrode interface exacerbates carbonate formation issue.Therefore,it is crucial to achieve local cation enrichment at the electrolyte interface without increasing bulk cation concentration.Herein,we propose a"surface charge density modulation"strategy to strengthen interfacial electric field,intensifying the local cation effect at the electrode interface in a low-concentration electrolyte.We implement this strategy using leaf-like CuO nanosheets,introducing a high-curvature morphology into the catalysts.As a result,the CuO nanosheets display 3.4-fold enhancement in Faradic efficiency(FE)of multi-carbon products(C_(2+))compared to CuO nanospheres with low-curvature.In-situ Raman spectroscopy and control experiment varying concentration of K^(+)reveal the mechanism on how the cation effect and interfacial electric field influence CO_(2)RR performance.展开更多
As the world strives to reduce the impact of population growth, urbanization, agricultural expansion, and climate change on food security, energy and water shortage, resource over-exploration, biodiversity loss, envir...As the world strives to reduce the impact of population growth, urbanization, agricultural expansion, and climate change on food security, energy and water shortage, resource over-exploration, biodiversity loss, environmental pollution, and ultimately human health, timely and higher resolution land cover information is urgently needed to achieve the sustainable development goals of the United Nations.展开更多
This paper presents a multi-HVDC emergency coordinated modulating strategy to enhance the transient stability of hybrid AC/DC power systems.First,the main factors that affect the unbalanced energy distribution during ...This paper presents a multi-HVDC emergency coordinated modulating strategy to enhance the transient stability of hybrid AC/DC power systems.First,the main factors that affect the unbalanced energy distribution during a fault are analyzed,and the dominant generators are determined online.Next,considering the influence on both generators in the sending and receiving ends,the assessment index that evaluates the effects of DC power support is established.On the basis of this,a dynamic DC power support strategy is put forward,and the DC support sequence table is promptly updated by the changing dominant generators.The AC/DC hybrid power system with multi-DC lines is built and used as a test system.The simulation results of different scenarios demonstrate that the proposed method could follow the dominant generator dynamically and adjust the DC participating in modulation to enhance the transient stability effectively and quickly.展开更多
Dear Editor,Alzheimer’s disease(AD)is the most common neurodegenerative disorder and the No.1 cause of dementia in elderly with no effective treatments.1 The application of stem cell-derived extracellular vesicles(EV...Dear Editor,Alzheimer’s disease(AD)is the most common neurodegenerative disorder and the No.1 cause of dementia in elderly with no effective treatments.1 The application of stem cell-derived extracellular vesicles(EVs)has emerged as a promising therapeutic strategy for AD.2 EVs are small bilipid layer-enclosed vesicles that display blood-brain barrier(BBB)penetrating ability and similar potency to their parental cells.展开更多
The effects of temperature and step-down relative humidity controlled hot-air drying(THC-HAD)on the drying kinetics,energy efficiency and quality,i.e.,rehydration ratio(RR),color parameters(L*,a*,b*),total color diffe...The effects of temperature and step-down relative humidity controlled hot-air drying(THC-HAD)on the drying kinetics,energy efficiency and quality,i.e.,rehydration ratio(RR),color parameters(L*,a*,b*),total color difference(ΔE*),Panax notoginseng saponins(PNS)content,and ginsenosides content(R1,Rg1,Re,Rd,Rb1)of Panax notoginseng roots were evaluated.The drying time was significantly affected by the drying temperature followed by the relative humidity(RH)of the drying air.Special combination of drying conditions,i.e.,drying temperature of 50°C,relative humidity of 40%for 3 h and then continuous dehumidification from 40%to 8%allowed to shorten the drying time by 25%compared to drying at the same temperature and continuous dehumidification.The longer was the drying time under constant high RH of drying air,the lower was the RR of dried samples.The step-down RH strategy contributed to the formation of a porous structure,enhancement of drying efficiency and quality improvement.Generally,the ginsenosides content increased with the increase in temperature,while no obvious trend was recorded for ginsenoside R1.The contents of the ginsenoside R1,Rg1,Rb1 and PNS decreased with the increase in the drying time under constant high RH.Taking into account the drying time,energy consumption and quality attributes,drying at the temperature of 50°C,constant RH of 40%for 3 h and then step-down RH from 40%to 8%was proposed as the most favorable combination of drying conditions for dehydration of whole Panax notoginseng roots.展开更多
In order to further understand the mechanism of material volume change in the drying process,numerical simulations(considering or neglecting shrinkage)of heat and mass transfer during convective drying of carrot slice...In order to further understand the mechanism of material volume change in the drying process,numerical simulations(considering or neglecting shrinkage)of heat and mass transfer during convective drying of carrot slices under constant and controlled temperature and relative humidity were carried out.Simulated results were validated with experimental data.The results of the simulation show that the Quadratic model fitted well to the moisture ratio and the material temperature data trend with average relative errors of 5.9%and 8.1%,respectively.Additionally,the results of the simulation considering shrinkage show that the moisture and temperature distributions during drying are closer to the experimental data than the results of the simulation disregarding shrinkage.The material moisture content was significantly related to the shrinkage of dried tissue.Temperature and relative humidity significantly affected the volume shrinkage of carrot slices.The volume shrinkage increased with the rising of the constant temperature and the decline of relative humidity.This model can be used to provide more information on the dynamics of heat and mass transfer during drying and can also be adapted to other products and dryers devices.展开更多
This research explored the application of pulsed vacuum technology on the drying(PVD)of pineapple slices.Influences of drying temperature and pulsed vacuum ratio(PVR)on drying characteristics and pineapple quality(col...This research explored the application of pulsed vacuum technology on the drying(PVD)of pineapple slices.Influences of drying temperature and pulsed vacuum ratio(PVR)on drying characteristics and pineapple quality(color,rehydration characteristics,microstructure,and texture)were analyzed.As expected,increasing the drying temperature resulted in a higher drying rate and effective moisture diffusivity.The optimal PVR of 5:5 was beneficial in accelerating the drying rate of pineapple slices and the corresponding effective moisture diffusion coefficient(8.9601×10^(-10))was higher than other PVR conditions based on material center temperature.The material temperature increased during the normal pressure period and decreased rapidly when the pressure dropped to the vacuum condition,which indirectly reflected the moisture transfer that occurred during the vacuum holding period,while moisture diffusion happened during the atmospheric pressure holding period.The optimal pulsed vacuum drying process(PVR of 5:5)could expand air and water vapor and create a looser structure so as to obtain better rehydration performance(rehydration ratio(RR)was 5.43).High drying temperature led to the decrease of L^(*)value,the increase ofΔE value,and even the formation of surface scorch at 80℃.At the same drying temperature,the color quality depended on the drying time,and the color difference increased with the extension of the drying time.The chewiness and hardness of pineapple slices dried by PVD were significantly higher than those of fresh samples,which was conducive to the chewing taste.展开更多
The creation of Cu^(0)/Cu^(+)interface over Cubased catalysts is known to facilitate the production of multicarbon(C_(2+))products during CO_(2)reduction reaction(CO_(2)RR).However,the Cu^(+)moieties exhibit high susc...The creation of Cu^(0)/Cu^(+)interface over Cubased catalysts is known to facilitate the production of multicarbon(C_(2+))products during CO_(2)reduction reaction(CO_(2)RR).However,the Cu^(+)moieties exhibit high susceptibility towards reduction into Cu^(0)at a high current density.Thus,a comprehensive understanding and rational shaping strategy for the construction and stabilization of Cu^(0)/Cu^(+)interface in Cu-based catalysts is imperative.Herein,we proposed a controllable“nanoparticle assembly”strategy to obtain hollow spherical assemblies(HSA)composed of numerous Cu_(2)O nanoparticles(HSA-Cu_(2)O).The HSA-Cu_(2)O catalysts significantly enhance the selectivity of C_(2+)products,resulting in an impressive overall Faraday efficiency(FE)of 79.2%±0.7%at a partial current density of 317.1 mA cm−2.The HSA-Cu_(2)O catalysts undergo in-situ electrochemically reconstruction during CO_(2)RR,achieving Cu^(0)/Cu^(+)interfacial sites with a high density.The Auger electron spectra,in-situ Raman,and morphological evolution studies have confirmed that the combination of the Cu^(0)/Cu^(+)interface and hollow sphere architecture facilitated the concentration of*CO intermediates,thereby promoting C–C dimerization to boost C_(2+)selectivity in CO_(2)RR.展开更多
基金supported by the National Natural Science Foundation of China(22209103)Science and Technology Commission of Shanghai Municipality(22010500400)Australian Research Council(FT180100705)。
文摘Hard carbons are promising anode materials for sodium-ion batteries(SIBs),but they face challenges in balancing rate capability,specific capacity,and initial Coulombic efficiency(ICE).Direct pyrolysis of the precursor often fails to create a suitable structure for sodium-ion storage.Molecular-level control of graphitization with open channels for Na^(+)ions is crucial for high-performance hard carbon,whereas closed pores play a key role in improving the low-voltage(<0.1 V)plateau capacity of hard carbon anodes for SIBs.However,creation of these closed pores presents significant challenges.This work proposes a zinc gluconate-assisted catalytic carbonization strategy to regulate graphitization and create numerous nanopores simultaneously.As the temperature increases,trace amounts of zinc remain as single atoms in the hard carbon,featuring a uniform coordination structure.This mitigates the risk of electrochemically irreversible sites and enhances sodium-ion transport rates.The resulting hard carbon shows an excellent reversible capacity of 348.5 mAh g^(-1) at 30 mA g^(-1) and a high ICE of 92.84%.Furthermore,a sodium storage mechanism involving“adsorption-intercalation-pore filling”is elucidated,providing insights into the pore structure and dynamic pore-filling process.
基金the National Natural Science Foundation of China(No.52272212)the Natural Science Foundation of Shandong Province(Nos.ZR2022JQ20 and ZR2023MB126)+2 种基金the Taishan Scholar Project of Shandong Province(No.tsqn202211168)the Key Laboratory of Optic-electric Sensing and Analytical Chemistry for Life Science,MOE(No.M2022-7)the STIEI scientific research funding project(No.GCC2023036).
文摘Tin(IV)oxide(Sn_(3)O_(4))is layered tin and exhibits mixed valence states.It has emerged as a highly promising visible-light pho-tocatalyst,attracting considerable attention.This comprehensive review is aimed at providing a detailed overview of the latest advance-ments in research,applications,advantages,and challenges associated with Sn_(3)O_(4)photocatalytic nanomaterials.The fundamental con-cepts and principles of Sn_(3)O_(4)are introduced.Sn_(3)O_(4)possesses a unique crystal structure and optoelectronic properties that allow it to ab-sorb visible light efficiently and generate photoexcited charge carriers that drive photocatalytic reactions.Subsequently,strategies for the control and improved performance of Sn_(3)O_(4)photocatalytic nanomaterials are discussed.Morphology control,ion doping,and hetero-structure construction are widely employed in the optimization of the photocatalytic performance of Sn_(3)O_(4)materials.The effective imple-mentation of these strategies improves the photocatalytic activity and stability of Sn_(3)O_(4)nanomaterials.Furthermore,the review explores the diverse applications of Sn_(3)O_(4)photocatalytic nanomaterials in various fields,such as photocatalytic degradation,photocatalytic hydro-gen production,photocatalytic reduction of carbon dioxide,solar cells,photocatalytic sterilization,and optoelectronic sensors.The discus-sion focuses on the potential of Sn_(3)O_(4)-based nanomaterials in these applications,highlighting their unique attributes and functionalities.Finally,the review provides an outlook on the future development directions in the field and offers guidance for the exploration and de-velopment of novel and efficient Sn_(3)O_(4)-based nanomaterials.Through the identification of emerging research areas and potential avenues for improvement,this review aims to stimulate further advancements in Sn_(3)O_(4)-based photocatalysis and facilitate the translation of this promising technology into practical applications.
基金This study was supported by the National Key Research Program of China(2016YFC0502209)Beijing Municipal Natural Science Foundation(JQ18028)the National Natural Science Foundation of China(51879007 and U20A20117).
文摘The hydrological process in the dry–warm valley of the mountainous area of southwest China has unique characteristics and has attracted scientific attention worldwide.Given that this is an area with fragile ecosystems and intensive water resource conflicts in the upper reaches of the Yangtze River,a systematic identification of its hydrological responses to climate and land use variations needs to be performed.In this study,MIKE SHE was employed and calibrated for the Anning River Basin in the dry–warm valley.Subsequently,a deep learning neural network model of the long short-term memory(LSTM)and a traditional multi-model ensemble mean(MMEM)method were used for an ensemble of 31 global climate models(GCMs)for climate projection.The cellular automata–Markov model was implemented to project the spatial pattern of land use considering climatic,social,and economic conditions.Four sets of climate projections and three sets of land use projections were generated and fed into the MIKE SHE to project hydrologic responses from 2021 to 2050.For the calibration and first validation periods of the daily simulation,the coefficients of determination(R)were 0.85 and 0.87 and the Nash–Sutcliffe efficiency values were 0.72 and 0.73,respectively.The advanced LSTM performed better than the traditional MMEM method for daily temperature and monthly precipitation.The average monthly temperature projection under representative concentration pathway 8.5(RCP8.5)was expected to be slightly higher than that under RCP4.5;this is contrary to the average monthly precipitation from June to October.The variations in streamflow and actual evapotranspiration(ET)were both more sensitive to climate change than to land use change.There was no significant relationship between the variations in streamflow and the ET in the study area.This work could provide general variation conditions and a range of hydrologic responses to complex and changing environments,thereby assisting with stochastic uncertainty and optimizing water resource management in critical regions.
基金supported by The Open Project of State Key Laboratory of Plateau Ecology and Agriculture,Qinghai University(2020-KF-001)the Grand S&T Project of Qinghai Province(2019-NK-A11)the Key R&D Project of Qinghai Province(2018-NK-128).
文摘Excessive amounts of nitrogen(N)fertilizers are applied during wolfberry production,resulting in some soil problems as well as potential environmental risks in the Qinghai-Tibet Plateau.In this study,organic fertilizers were used to replace part of the N fertilizer in wolfberry fields with different fertility levels.N fertilizer rates had 0,50,100,150,200,and 250 g N/plant.Organic fertilizer rates had 0,2,4,6,8,and 10 kg organic fertilizer/plant.The experimental treatments included 6 combinations of N0M10,N50M8,N100M6,N150M4,N200M2,and control was N250M0.The results showed that in the high-fertility soils,combinations of N150M4,N100M6 and N50M8 treatments were increased in yields,fruit shape index,flavonoid content,total phenol content,mineral nutrient content,and antioxidant activity of wolfberry fruits.Also they were improved in soil fertility and decreased in residual nitrate through the soil depth of 0-300 cm.In the soil with less fertility,fruit yield,amino acid contents,flavonoids,total phenols,mineral nutrients and antioxidant activity of fruits were increased by the N200M2,N150M4 and N100M6 treatments and soil fertility was improved as well.Also more residual nitrate was found in the depth of 0-100 cm of soil with both chemical and organic fertilizer compared with the control.Therefore,in the Qinghai-Tibet Plateau,combining decreased N fertilizer with organic fertilizer rather than chemical fertilizer alone could help farmers achieve satisfactory yields and quality of wolfberry fruits and reduce the risk of nitrate leaching.In conclusion,50-150 g/plant of N fertilizer combined with 4-8 kg/plant of organic fertilizer in high-fertility gardens and 100-200 g/plant of N fertilizer combined with 2-6 kg/plant of organic fertilizer in low-fertility gardens are recommended for wolfberry cultivation.
基金supported by the Innovation and Development Program of Beijing Vegetable Research Center,China(KYCX202301)the Construction of Cucurbits Collaboration and Innovation Center,China(XTCX202301)+3 种基金the Youth Research Fund of Beijing Academy of Agriculture and Forestry Sciences,China(QNJJ202426)the National Natural Science Foundation of China(U21A20229 and 32102397)the Scientific Research Foundation of the Higher Education Institutions for Distinguished Young Scholars in Anhui Province,China(2022AH020037)and the Key Research and Development Projects of Anhui Province,China(2023z04020019)。
文摘Peel color is an important appearance quality of melons that significantly affects consumer preferences.In this study,a near-isogenic line NIL-G(dark green peel)was generated from B8(grey-green peel)and B15(white peel).The F_2 population constructed by crossing NIL-G and B15 was used to study the inheritance pattern of peel color,and bulked-segregant analysis sequencing(BSA-seq)was employed to identify the interval in which the target gene was located.Genetic analysis showed that a dominant gene controls the dark green peel trait at maturity.BSAseq and molecular markers were used to localize the candidate gene in a 263.7 kb interval of chromosome 4,which contained the CmAPRR2 gene with known functions.Moreover,allelic sequence analysis revealed four SNP variations of the CmAPRR2 gene in B15,of which SNP.G614331A was located at the junction of the 6th exon and 6th intron.The G-to-A mutation caused alternative splicing of the transcript of CmAPRR2 in B15,generating two transcripts(CmAPRR2-A and CmAPRR2-B)with premature termination codons.Furthermore,the Kompetitive Allele Specific PCR(KASP)marker,APRR2-G/A,was developed based on this SNP and shown to co-segregate with the peel color phenotype in the F_(2) population.Compared to white-peel B15,the expression level of CmAPRR2 in dark green peel NIL-G was higher at each growth stage.Therefore,CmAPRR2 may be the key gene controlling the fruit color of melons.This study identified a novel allelic variant of CmAPRR2 that leads to white peel formation in mature melons.We also provides a theoretical basis for further research on the gene regulatory mechanism of melon peel colors,which promotes using molecular marker-assisted selection to modify melon peel colors in the future.
基金supported by the Second Tibetan Plateau Scientific Expedition and Research Program,China(2019QZKK0304)the National Natural Science Foundation of China(31800380 and 31761123001-1)。
文摘Fencing for grazing exclusion is regarded as a traditional and effective method for the natural restoration of degraded alpine steppe,and it effectively promotes plant growth and enhances soil carbon stocks.Arbuscular mycorrhizal fungi(AMF)are essential microorganisms in grassland that play a major role in plant-derived C translocation into the soil.However,the effects of fencing on AMF communities and their contributions to soil carbon sequestration are still unclear.In this study,alpine steppe areas with three different fencing durations(free grazing,medium-term fencing for 5-6 years and long-term fencing for more than 10 years)in the northern Tibetan Plateau were selected to explore the effects of grazing exclusion on AMF communities and their roles in soil carbon sequestration.The results showed that medium-and long-term fencing significantly increased both plant aboveground biomass and soil organic carbon(SOC)content.The AMF community composition varied significantly during different fencing durations,with a dramatic increase in the relative abundance of Glomus but a significant reduction in the relative abundance of Diversispora with longer fencing time.Medium-term fencing significantly increased AMF richness and the ShannonWiener index.Meanwhile,fencing significantly increased hyphal length density(HLD),glomalin-related soil protein(GRSP)and the proportion of macroaggregates(250-2,000μm),all of which contribute positively to SOC.Structural equation modeling revealed that fencing time positively influenced HLD and the AMF community composition,subsequently affecting T-GRSP,which was tightly correlated with SOC.Our findings suggest the potentially important contribution of AMF to SOC sequestration,so more attention should be paid to AMF during alpine steppe fencing,particularly for enhancing the efficiency of degraded grassland restoration efforts.
基金supported by the National Natural Science Foundation of China(Grant Nos.31271297 and 31222042) "One-hundred talents" Startup Funds from Chinese Academy of SciencesNational Key Basic Research Program(No. 2009CB 118402)
文摘Increasing yield is one of the most important goals in crop breeding. Soybean （Glycine max L. Merr.）, one of the most economically important leguminous seed crops, provides the majority of plant proteins, and more than a quarter of the world＇s food and animal feed （Graham and Vance, 2003）. The yield of soybean is finally determined by the number of seeds per unit area, which affected by many characters, such as height, branching number, photosynthesis, seed size, seed number. The number of seeds per pod is taken for one of the critical components that related to yield （You et al., 1995）.
文摘Dissolved organic nitrogen(DON) has attracted much attention in drinking water treatment due to its potential to produce nitrogenous disinfection by-products(N-DBPs). This work was designed to explore the transformation and fate of DON and dissolved inorganic nitrogen(DIN) in drinking water treatment. The changes of DON and formation of N-DBPs were evaluated along the water treatment route(i.e., pre-ozonation and biologicalcontact oxidation, delivery pipes’ transportation, coagulation-sedimentation, sand filtration, post-ozonation, biological activated carbon, ultrafiltration and disinfection) of drinking water treatment plant(DWTP). The transformation mechanism of DON was comprehensively investigated by molecular weight fractionation, three-dimensional fluorescence, LCOCD(Liquid Chromatography-Organic Carbon Detection), total free amino acids. A detailed comparison was made between concentrations and variations of DON and DIN affected by seasons in the drinking water treatment. Regardless of seasonal variation in raw water concentration, the DON removal trends between different treatment processes remain constant in the present study. Compared to other treatment processes, pre-ozonation and coagulation-sedimentation exhibited the dominant DON removal in different seasons, i.e.,11.13%-14.45% and 14.98%-22.49%, respectively. Contrary, biological-contact oxidation and biological activated carbon negatively impacted the DON removal, in which DON increased by 1.76%-6.49% in biological activated carbon. This may be due to the release of soluble microbial products(SMPs) from bacterial metabolism, which was further validated by the rise of biopolymers in LC-OCD.
基金the Natural Science Foundation of Anhui Province(Grant No.1908085QA09)the University Natural Science Research Project of Anhui Province(KJ2019A0591).
文摘The radial basis functions(RBFs)play an important role in the numerical simulation processes of partial differential equations.Since the radial basis functions are meshless algorithms,its approximation is easy to implement and mathematically simple.In this paper,the commonly⁃used multiquadric RBF,conical RBF,and Gaussian RBF were applied to solve boundary value problems which are governed by partial differential equations with variable coefficients.Numerical results were provided to show the good performance of the three RBFs as numerical tools for a wide range of problems.It is shown that the conical RBF numerical results were more stable than the other two radial basis functions.From the comparison of three commonly⁃used RBFs,one may obtain the best numerical solutions for boundary value problems.
文摘The effective disposal of daily city infrastructure cases is an important issue for urban management. To more effectively utilize a large amount of historical cases data collected and accumulated in the urban grid management system, and to analyze their spatial distribution pattern information for city managers, this study used the comparative kernel density analysis method in two types of cases (i.e. power facilities and traffic guardrail) in Xicheng District, Beijing for the year 2016 and 2017. This research analyzes them at different scales (300 m, 600 m, 1,200 m), and the experiment results show that the method of comparative kernel density analysis is able to provide an intuitively spatial visualization distribution analysis of city infrastructure related cases. The quantitative information of spatial agglomeration degree is helpful for city managers making decision.
基金supported by the National Natural Science Foundation of China(Nos.U22B20143 and 22478121)Shanghai Municipal Science and Technology Major Project,the Science and Technology Commission of Shanghai Municipality(No.22dz1205900)+1 种基金the Fundamental Research Funds for the Central Universities(No.JKD01241702)F.W.L.acknowledges the financial support from the ARC Centre of Excellence for Green Electrochemical Transformation of Carbon Dioxide(No.CE230100017).
文摘Cation effect has emerged as a promising strategy for modulating the product distribution during the electrocatalytic CO_(2)reduction reaction(CO_(2)RR).However,the strategy of solely increasing bulk cation concentration in the electrolyte to intensify cation effect at the electrode interface exacerbates carbonate formation issue.Therefore,it is crucial to achieve local cation enrichment at the electrolyte interface without increasing bulk cation concentration.Herein,we propose a"surface charge density modulation"strategy to strengthen interfacial electric field,intensifying the local cation effect at the electrode interface in a low-concentration electrolyte.We implement this strategy using leaf-like CuO nanosheets,introducing a high-curvature morphology into the catalysts.As a result,the CuO nanosheets display 3.4-fold enhancement in Faradic efficiency(FE)of multi-carbon products(C_(2+))compared to CuO nanospheres with low-curvature.In-situ Raman spectroscopy and control experiment varying concentration of K^(+)reveal the mechanism on how the cation effect and interfacial electric field influence CO_(2)RR performance.
基金partially supported by the National Key Research and Development Program of China(2016YFA0600103)Delos Living LLCthe Cyrus Tang Foundation
文摘As the world strives to reduce the impact of population growth, urbanization, agricultural expansion, and climate change on food security, energy and water shortage, resource over-exploration, biodiversity loss, environmental pollution, and ultimately human health, timely and higher resolution land cover information is urgently needed to achieve the sustainable development goals of the United Nations.
基金This work was supported in part by the National Natural Science Foundation of China(51637005)the Science and Technology Project of SGCC(SGBJDK00KJJS1900088).
文摘This paper presents a multi-HVDC emergency coordinated modulating strategy to enhance the transient stability of hybrid AC/DC power systems.First,the main factors that affect the unbalanced energy distribution during a fault are analyzed,and the dominant generators are determined online.Next,considering the influence on both generators in the sending and receiving ends,the assessment index that evaluates the effects of DC power support is established.On the basis of this,a dynamic DC power support strategy is put forward,and the DC support sequence table is promptly updated by the changing dominant generators.The AC/DC hybrid power system with multi-DC lines is built and used as a test system.The simulation results of different scenarios demonstrate that the proposed method could follow the dominant generator dynamically and adjust the DC participating in modulation to enhance the transient stability effectively and quickly.
基金We thank Dr.Xinrui Qi,Jie Zhu,Yanyan Zhang,Huiran Wu,Meng Shi,and Jiazhen Qian for technical assistances and proofreading the manuscript.This work was supported in part by research grants from the National Natural Science Foundation of China(No.91949204 and No.81830037 to J.C.Z.,No.81971145 and No.82271477 to X.X.,No.82001116 to G.G.)Shanghai Health and Wellness Committee,Basic Scientific Research Project,(No.20204Y0031 to Y.W.).
文摘Dear Editor,Alzheimer’s disease(AD)is the most common neurodegenerative disorder and the No.1 cause of dementia in elderly with no effective treatments.1 The application of stem cell-derived extracellular vesicles(EVs)has emerged as a promising therapeutic strategy for AD.2 EVs are small bilipid layer-enclosed vesicles that display blood-brain barrier(BBB)penetrating ability and similar potency to their parental cells.
基金supported in part by the Hebei Province Key Research and Development Project(Grant No.203777119D,19227210D)in part by the Scientific Research Projects of Universities in Hebei Province(Grant No.ZD2021056)in part by the Hebei Province College and Middle School Students Science and Technology Innovation Ability Cultivation Project(Grant No.2021H060505)and part by China Agriculture Research System of MOF and MARA(CARS-21).
文摘The effects of temperature and step-down relative humidity controlled hot-air drying(THC-HAD)on the drying kinetics,energy efficiency and quality,i.e.,rehydration ratio(RR),color parameters(L*,a*,b*),total color difference(ΔE*),Panax notoginseng saponins(PNS)content,and ginsenosides content(R1,Rg1,Re,Rd,Rb1)of Panax notoginseng roots were evaluated.The drying time was significantly affected by the drying temperature followed by the relative humidity(RH)of the drying air.Special combination of drying conditions,i.e.,drying temperature of 50°C,relative humidity of 40%for 3 h and then continuous dehumidification from 40%to 8%allowed to shorten the drying time by 25%compared to drying at the same temperature and continuous dehumidification.The longer was the drying time under constant high RH of drying air,the lower was the RR of dried samples.The step-down RH strategy contributed to the formation of a porous structure,enhancement of drying efficiency and quality improvement.Generally,the ginsenosides content increased with the increase in temperature,while no obvious trend was recorded for ginsenoside R1.The contents of the ginsenoside R1,Rg1,Rb1 and PNS decreased with the increase in the drying time under constant high RH.Taking into account the drying time,energy consumption and quality attributes,drying at the temperature of 50°C,constant RH of 40%for 3 h and then step-down RH from 40%to 8%was proposed as the most favorable combination of drying conditions for dehydration of whole Panax notoginseng roots.
基金supported by Earmarked Fund for China Agriculture Research System(CARS-21).
文摘In order to further understand the mechanism of material volume change in the drying process,numerical simulations(considering or neglecting shrinkage)of heat and mass transfer during convective drying of carrot slices under constant and controlled temperature and relative humidity were carried out.Simulated results were validated with experimental data.The results of the simulation show that the Quadratic model fitted well to the moisture ratio and the material temperature data trend with average relative errors of 5.9%and 8.1%,respectively.Additionally,the results of the simulation considering shrinkage show that the moisture and temperature distributions during drying are closer to the experimental data than the results of the simulation disregarding shrinkage.The material moisture content was significantly related to the shrinkage of dried tissue.Temperature and relative humidity significantly affected the volume shrinkage of carrot slices.The volume shrinkage increased with the rising of the constant temperature and the decline of relative humidity.This model can be used to provide more information on the dynamics of heat and mass transfer during drying and can also be adapted to other products and dryers devices.
基金supported in part by the Science and Technology Program of Hebei(Grant No.203777119D,19227210D)in part by the Scientific Research Projects of Universities in Hebei Province(Grant No.ZD2021056).
文摘This research explored the application of pulsed vacuum technology on the drying(PVD)of pineapple slices.Influences of drying temperature and pulsed vacuum ratio(PVR)on drying characteristics and pineapple quality(color,rehydration characteristics,microstructure,and texture)were analyzed.As expected,increasing the drying temperature resulted in a higher drying rate and effective moisture diffusivity.The optimal PVR of 5:5 was beneficial in accelerating the drying rate of pineapple slices and the corresponding effective moisture diffusion coefficient(8.9601×10^(-10))was higher than other PVR conditions based on material center temperature.The material temperature increased during the normal pressure period and decreased rapidly when the pressure dropped to the vacuum condition,which indirectly reflected the moisture transfer that occurred during the vacuum holding period,while moisture diffusion happened during the atmospheric pressure holding period.The optimal pulsed vacuum drying process(PVR of 5:5)could expand air and water vapor and create a looser structure so as to obtain better rehydration performance(rehydration ratio(RR)was 5.43).High drying temperature led to the decrease of L^(*)value,the increase ofΔE value,and even the formation of surface scorch at 80℃.At the same drying temperature,the color quality depended on the drying time,and the color difference increased with the extension of the drying time.The chewiness and hardness of pineapple slices dried by PVD were significantly higher than those of fresh samples,which was conducive to the chewing taste.
基金supported by the National Natural Science Foundation of China(21838003,21771170,22008069)the Shanghai Municipal Science and Technology Major Project+1 种基金the Fundamental Research Funds for the Central Universities(JKD01241702)the Shanghai Rising-Star Program(20QA1402700)。
文摘The creation of Cu^(0)/Cu^(+)interface over Cubased catalysts is known to facilitate the production of multicarbon(C_(2+))products during CO_(2)reduction reaction(CO_(2)RR).However,the Cu^(+)moieties exhibit high susceptibility towards reduction into Cu^(0)at a high current density.Thus,a comprehensive understanding and rational shaping strategy for the construction and stabilization of Cu^(0)/Cu^(+)interface in Cu-based catalysts is imperative.Herein,we proposed a controllable“nanoparticle assembly”strategy to obtain hollow spherical assemblies(HSA)composed of numerous Cu_(2)O nanoparticles(HSA-Cu_(2)O).The HSA-Cu_(2)O catalysts significantly enhance the selectivity of C_(2+)products,resulting in an impressive overall Faraday efficiency(FE)of 79.2%±0.7%at a partial current density of 317.1 mA cm−2.The HSA-Cu_(2)O catalysts undergo in-situ electrochemically reconstruction during CO_(2)RR,achieving Cu^(0)/Cu^(+)interfacial sites with a high density.The Auger electron spectra,in-situ Raman,and morphological evolution studies have confirmed that the combination of the Cu^(0)/Cu^(+)interface and hollow sphere architecture facilitated the concentration of*CO intermediates,thereby promoting C–C dimerization to boost C_(2+)selectivity in CO_(2)RR.
