Beta-diversity reflects the spatial changes in community species composition which helps to understand how communities are assembled and biodiversity is formed and maintained. Larch(Larix) forests, which are coniferou...Beta-diversity reflects the spatial changes in community species composition which helps to understand how communities are assembled and biodiversity is formed and maintained. Larch(Larix) forests, which are coniferous forests widely distributed in the mountainous and plateau areas in North and Southwest China, are critical for maintaining the environmental conditions and species diversity. Few studies of larch forests have examined the beta-diversity and its constituent components(species turnover and nestedness-resultant components). Here, we used 483 larch forest plots to determine the total betadiversity and its components in different life forms(i.e., tree, shrub, and herb) of larch forests in China and to evaluate the main drivers that underlie this beta-diversity. We found that total betadiversity of larch forests was mainly dependent on the species turnover component. In all life forms,total beta-diversity and the species turnover component increased with increasing geographic, elevational, current climatic, and paleoclimatic distances. In contrast, the nestedness-resultant component decreased across these same distances. Geographic and environmental factors explained 20%-25% of total beta-diversity, 18%-27% of species turnover component, and 4%-16% of nestedness-resultant component. Larch forest types significantly affected total beta-diversity and species turnover component. Taken together, our results indicate that life forms affect beta-diversity patterns of larch forests in China, and that beta-diversity is driven by both niche differentiation and dispersal limitation. Our findings help to greatly understand the mechanisms of community assemblies of larch forests in China.展开更多
As the need for high-energy–density batteries continues to grow, lithium-sulfur(Li–S) batteries have become a highly promising next-generation energy solution due to their low cost and exceptional energy density com...As the need for high-energy–density batteries continues to grow, lithium-sulfur(Li–S) batteries have become a highly promising next-generation energy solution due to their low cost and exceptional energy density compared to commercially available Li-ion batteries. Research into carbon-based sulfur hosts for Li–S batteries has been ongoing for over two decades, leading to a significant number of publications and patents.However, the commercialization of Li–S batteries has yet to be realized. This can be attributed, in part, to the instability of the Li metal anode. However, even when considering just the cathode side, there is still no consensus on whether carbon-based hosts will prove to be the best sulfur hosts for the industrialization of Li–S batteries. Recently, there has been controversy surrounding the use of carbon-based materials as the ideal sulfur hosts for practical applications of Li–S batteries under high sulfur loading and lean electrolyte conditions. To address this question, it is important to review the results of research into carbon-based hosts, assess their strengths and weaknesses, and provide a clear perspective. This review systematically evaluates the merits and mechanisms of various strategies for developing carbon-based host materials for high sulfur loading and lean electrolyte conditions. The review covers structural design and functional optimization strategies in detail, providing a comprehensive understanding of the development of sulfur hosts. The review also describes the use of efficient machine learning methods for investigating Li–S batteries. Finally, the outlook section lists and discusses current trends, challenges, and uncertainties surrounding carbon-based hosts, and concludes by presenting our standpoint and perspective on the subject.展开更多
By the virtue of their olfactory,physicochemical,and biological characteristics,essential oils(EOs)have drawn wide attention as additives in daily chemicals like perfume or personal care products.Nevertheless,they are...By the virtue of their olfactory,physicochemical,and biological characteristics,essential oils(EOs)have drawn wide attention as additives in daily chemicals like perfume or personal care products.Nevertheless,they are physicochemically unstable and susceptible to degradation or loss.Microencapsulation offers a feasible strategy to stabilize and prolong release of EO.This review summarizes the recognized benefits and functional properties of various preparation and characterization methods,wherein innovative fabrication strategies and their formation mechanisms are especially emphasized.Progress in combining detecting/measuring technologies with kinetic modelling are discussed,to give an integral approach of controlling the dynamic release of encapsulated EOs.Moreover,new development trends of EOs capsules are also highlighted.展开更多
Background:Larch(Larix Mill.)forests are widely distributed in the upper parts of mountainous areas in China,playing vital roles in constructing mountain landscapes and maintaining mountain environments.Despite their ...Background:Larch(Larix Mill.)forests are widely distributed in the upper parts of mountainous areas in China,playing vital roles in constructing mountain landscapes and maintaining mountain environments.Despite their importance,our knowledges on the large-scale patterns of structure characteristics and the relationships between different structure variables are unclear.In this paper,we investigated 155 plots from 11 natural larch forest types across the country to explore the biogeographic patterns of the structure characteristics and the allometric relationships between different structure variables for Chinese larch forests.Results:The structure characteristics were significantly different among larch forest types.For different larch forest types,the power function fits the relationships between tree height and diameter at breast height(DBH),average DBH and stem density,and taper and stem density well,but with different exponents among larch forest types.The power exponents of the allometric relationships between tree height and DBH for different larch forest types varied from 0.61 to 0.93(mean=0.86)by standard major axis regression(SMA),and from 0.51 to 0.78(mean=0.56)by ordinary least square regression(OLS).The 50%,75%and 95%quantile regression(QR)and OLS indicated that the average DBH and taper of the L.gmelinii forests,L.gmelinii var.principis-rupprechtii forests,and L.sibirica forests were significantly correlated with stem density.Conclusions:The relationship between tree height and DBH showed a power function relationship for all larch forest types in China,but with different exponents.Overall,stem density was negatively correlated with average DBH and taper.The Sect.Larix forests exhibited stand density effect.Our findings provide an important basis for recognizing the biogeographic patterns of structure factors and for the management of larch forests in China.展开更多
Larch forests are important for species diversity,as well as soil and water conservation in mountain regions.In this study,we determined large-scale patterns of species richness in larch forests and identified the fac...Larch forests are important for species diversity,as well as soil and water conservation in mountain regions.In this study,we determined large-scale patterns of species richness in larch forests and identified the factors that drive these patterns.We found that larch forest species richness was high in southern China and low in northern China,and that patterns of species richness along an elevational gradient depend on larch forest type.In addition,we found that patterns of species richness in larch forests are best explained by contemporary climatic factors.Specifically,mean annual temperature and annual potential evapotranspiration were the most important factors for species richness of tree and shrub layers,while mean temperature of the coldest quarter and anomaly of annual precipitation from the Last Glacial Maximum to the present were the most important for that of herb layer and the whole community.Community structural factors,especially stand density,are also associated with the species richness of larch forests.Our findings that species richness in China's larch forests is mainly affected by energy availability and cold conditions support the ambient energy hypothesis and the freezing tolerance hypothesis.展开更多
The ever-increasing demands for modern energy storage applications drive the search for novel anode materials of lithium(Li)-ion batteries(LIBs) with high storage capacity and long cycle life, to outperform the conven...The ever-increasing demands for modern energy storage applications drive the search for novel anode materials of lithium(Li)-ion batteries(LIBs) with high storage capacity and long cycle life, to outperform the conventional LIBs anode materials. Hence, we report amorphous ternary phosphorus chalcogenide(aP_(4)SSe_(2)) as an anode material with high performance for LIBs. Synthesized via the mechanochemistry method, the a-P_(4)SSe_(2) compound is endowed with amorphous feature and offers excellent cycling stability(over 1500 mA h g^(-1) capacity after 425 cycles at 0.3 A g^(-1)), owing to the advantages of isotropic nature and synergistic effect of multielement forming Li-ion conductors during battery operation. Furthermore,as confirmed by ex situ X-ray diffraction(XRD) and transmission electron microscope(TEM), the a-P_(4)SSe_(2)anode material has a reversible and multistage Li-storage mechanism, which is extremely beneficial to long cycle life for batteries. Moreover, the autogenous intermediate electrochemical products with fast ionic conductivity can facilitate Li-ion diffusion effectively. Thus, the a-P_(4)SSe_(2)electrode delivers excellent rate capability(730 mA h g^(-1)capacity at 3 A g^(-1)). Through in situ electrochemical impedance spectra(EIS) measurements, it can be revealed that the resistances of charge transfer(R_(SEI)) and solid electrolyte interphase(R_(Ct)) decrease along with the formation of Li-ion conductors whilst the ohmic resistance(R_(Ω)) remains unchanged during the whole electrochemical process, thus resulting in rapid reaction kinetics and stable electrode to obtain excellent rate performance and cycling ability for LIBs. Moreover, the formation mechanism and electrochemical superiority of the a-P_(4)SSe_(2)phase, and its expansion to P_(4)S_(3-x)Se_(x)(x = 0, 1, 2, 3) family can prove its significance for LIBs.展开更多
There are many papers related to stability, some on suppression or on stabilization are one type of them. Functional differential systems are common and important in practice. They are special situations of neutral di...There are many papers related to stability, some on suppression or on stabilization are one type of them. Functional differential systems are common and important in practice. They are special situations of neutral differential systems and generalization of ordinary differential systems. We discussed conditions on suppression on functional system with Markovian switching in our previous work: “Suppression of Functional System with Markovian Switching”. Based on it, by slightly modifying and adding some conditions, we get this paper. In this paper, we will study a functional system whose coefficient satisfies the local Lipschitz condition and the one-sided polynomial growth condition under Markovian switching. By introducing two appropriate intensity Brownian noise, we find the potential explosion system stabilized.展开更多
Solid-state lithium batteries(SSLBs)have been broadly accepted as a promising candidate for the next generation lithium-ion batteries(LIBs)with high energy density,long duration,and high safety.The intrinsic non-flamm...Solid-state lithium batteries(SSLBs)have been broadly accepted as a promising candidate for the next generation lithium-ion batteries(LIBs)with high energy density,long duration,and high safety.The intrinsic non-flammable nature and electrochemical/thermal/mechanical stability of solid electrolytes are expected to fundamentally solve the safety problems of conventional LIBs.However,thermal degradation and thermal runaway could also happen in SSLBs.For example,the large interfacial resistance between solid electrolytes and electrodes could aggravate the joule heat generation;the anisotropic thermal diffusion could trigger the uneven temperature distribution and formation of hotspots further leading to lithium dendrite growth.Considerable research efforts have been devoted to exploring solid electrolytes with outstanding performance and harmonizing interfacial incompatibility in the past decades.There have been fewer comprehensive reports investigating the thermal reaction process,thermal degradation,and thermal runaway of SSLBs.This review seeks to highlight advanced thermal-related analysis techniques for SSLBs,by focusing particularly on multiscale and multidimensional thermal-related characterization,thermal monitoring techniques such as sensors,thermal experimental techniques imitating the abuse operating condition,and thermalrelated advanced simulations.Insightful perspectives are proposed to bridge fundamental studies to technological relevance for better understanding and performance optimization of SSLBs.展开更多
The constant increase in global energy demand and stricter environmental standards are calling for advanced energy storage technologies that can store electricity from intermittent renewable sources such as wind,solar...The constant increase in global energy demand and stricter environmental standards are calling for advanced energy storage technologies that can store electricity from intermittent renewable sources such as wind,solar,and tidal power,to allow the broader implementation of the renewables.The gridoriented sodium-ion batteries,potassium ion batteries and multivalent ion batteries are cheaper and more sustainable alternatives to Li-ion,although they are still in the early stages of development.Additional optimisation of these battery systems is required,to improve the energy and power density,and to solve the safety issues caused by dendrites growth in anodes.Electrolyte,one of the most critical components in these batteries,could significantly influence the electrochemical performances and operations of batteries.In this review,the definitions and influences of three critical components(salts,solvents,and additives)in electrolytes are discussed.The significant advantages,challenges,recent progress and future optimisation directions of various electrolytes for monovalent and multivalent ions batteries(i.e.organic,ionic liquid and aqueous liquid electrolytes,polymer and inorganic solid electrolytes)are summarised to guide the practical application for grid-oriented batteries.展开更多
Background:Mesencephalic astrocyte-derived neurotrophic factor(MANF)is a new candidate growth factor for dopaminergic neurons against endoplasmic reticulum stress(ER stress).HSP70 family,a chaperon like heat shock pro...Background:Mesencephalic astrocyte-derived neurotrophic factor(MANF)is a new candidate growth factor for dopaminergic neurons against endoplasmic reticulum stress(ER stress).HSP70 family,a chaperon like heat shock protein family,was proved to be involved in the MANF induced survival pathway in 6-OHDA treated SHSY-5Y cells.However,the ER stress relative transcriptome,in MANF signaling cascades is still investigated.The involvement of HSP70,a 70kd member of HSP70 family,need further to be verified.Methods:The cell apoptosis was assayed by MTT,TUNEL staining and western blot of cleaved Caspase-3.The differentially expressed genes in SHSY-5Y cells under different conditions(control,6-OHDA,6-OHDA+MANF)were investigated by RNA-seq.Expression of HSP70 was further confirmed by real-time PCR.RNAi knockdown for HSP70 was performed to investigate the role of HSP70 in the MANF signaling pathway.Results:MANF inhibits 6-OHDA-induced apoptosis in SHSY-5Y cells.Six ER stress relative genes(HSP70,GRP78,xbp-1,ATF-4,ATF-6,MAPK)were found enriched in 6-OHDA+MANF treatment group.HSP70 was the most significantly up-regulated gene under 6-OHDA+MANF treatment in SHSY-5Y cells.RNAi knockdown for HSP70 inhibits the protective effects of MANF against 6-OHDA toxicity in SHSY-5Y cells.Conclusion:MANF exerts a protective role against 6-OHDA induced apoptosis in SHSY-5Y cells via up-regulating some ER stress genes,including HSP70 family members.The HSP70 expression level plays a key role in MANFmediated survival pathway.展开更多
Metal sulfides such as Bismuth sulfide(Bi2 S3) hold immense potential to be promoted as anode materials for lithium-ion batteries(LIBs),owing to their high theoretical gravimetric and volumetric capacities.However,the...Metal sulfides such as Bismuth sulfide(Bi2 S3) hold immense potential to be promoted as anode materials for lithium-ion batteries(LIBs),owing to their high theoretical gravimetric and volumetric capacities.However,the poor electrical conductivity and volume expansion during cycling hinder the practical applications of Bi2 S3.In this work,we used pyrrole and glucose as carbon source to design the surface carbon coating on the surface of Bi2 S3 particles,to improve the structural stability of Bi2 S3.Two composite materials were synthesized-Bi2 S3 coated with nitrogen doped carbon(Bi2 S3@NC),and Bi2 S3 coated with carbon(Bi2 S3@C).When used as anode active materials,both Bi2 S3@NC and Bi2 S3@C showed improved performance compared to Bi2 S3,which confirms surface carbon coating as an effective and scalable way for the modification of Bi2 S3 material.The electrode based on Bi2 S3@NC materials demonstrated higher performance than that of Bi2 S3@C,with an initial discha rge capacity of 1126.5 mA h/g,good cycling stability(500 mA h/g after 200 cycles at 200 mA/g) and excellent rate capability.Finally,Li storage and migration mechanisms in Bi2 S3 are revealed using first principle density functional theory calculations.展开更多
Aims Soil respiration is one of the most important components in the car-bon(c)cycle in terrestrial ecosystems.to investigate the contribution of each component of c cycle to the total soil c efflux,we quantified the ...Aims Soil respiration is one of the most important components in the car-bon(c)cycle in terrestrial ecosystems.to investigate the contribution of each component of c cycle to the total soil c efflux,we quantified the rates of litter,root,and other mineral soil respiration from 2012 to 2014 in the primary and secondary tropical mountain rain forests in Hainan Island,china.Methods the seasonal dynamics of soil(Rs),non-litter(RNL)and non-root(RNR)respiration rates were measured using an automatic chamber system(Li-8100).Litter removal and root removal treatments were used to assess the contribution of litter and roots to belowground c production.We estimated the annual c efflux of each compo-nent of soil respiration in primary and secondary forests using a temperature-based exponential model and analyzed the impact of each component in each forest type.Important Findingsthe annual total soil c efflux was significantly higher in the primary rain forest(1567±205 g c m^(−2)yr^(−1))than that in the secondary forest(1300±70 g c m^(−2)yr^(−1),P<0.05).the litter,root,and mineral soils contributed 22%(349±185 g c m^(−2)yr^(−1)),38%(589±100 g c m^(−2)yr^(−1)),and 40%(628±128 g c m^(−2)yr^(−1))to the total soil c efflux in primary rain forest,respectively.In secondary forest,these three components contributed 11%(148±35 g c m^(−2)yr^(−1)),45%(572±259 g c m^(−2)yr^(−1)),and 44%(580±226 g c m^(−2)yr^(−1)),respectively.the temperature sensitivity(Q10)of Rs(2.70±0.14)in the primary forest was significantly higher than that in the secondary forest(2.34±0.12),with the Q10 values for respiration decreasing in the order of RNR>Rs>RNL.these results show that the difference in litter respiration between primary and secondary forest caused the major difference in annual soil respiration efflux between these two forest types.In addition,the litter respiration is more sensitive to the soil temperature than the other soil respiration components.展开更多
Using inorganic fibrous membranes as protective layers has yielded success in suppressing dendrite growth.However,conventional fibrous membranes usually have large voids and low affinity for Li,promoting inhomogeneous...Using inorganic fibrous membranes as protective layers has yielded success in suppressing dendrite growth.However,conventional fibrous membranes usually have large voids and low affinity for Li,promoting inhomogeneous charge distribution and allowing some dendrites to grow.Herein,we introduce a highly aligned TiO_(2)/SiO_(2)(A-TS)electrospun nanofiber membrane as a protective layer for the Li metal anode.The A-TS membrane is fabricated by a custom-made electrospinning system with an automatic fiber alignment collector that allows control of the fibers’orientation.At the scale of the individual fibers,their high binding energies with Li can attract more“dead”Li by reacting with the SiO_(2) component of the composite,avoiding uncontrollable deposition on the metal anode.At the membrane scale,these highly ordered structures achieve homogeneous contact and charge distribution on the Li metal surface,leaving no vulnerable areas to nucleate dendrite formation.Additionally,the excellent mechanical and thermal stability properties of the A-TS membrane prevent any potential puncturing by dendrites or thermal runaway in a battery.Hence,an A-TS@Li anode exhibits stable cycling performance when used in both Li-S and Li-NCM811 batteries,highlighting significant reference values for the future design and development of high-energy-density metal-based battery systems.展开更多
基金supported by the Major Program for Basic Research Project of Yunnan Province (No. 202101BC070002)the National Natural Science Foundation of China (No. 32201426, No. 31988102)the National Science and Technology Basic Project of China (No. 2015FY210200)
文摘Beta-diversity reflects the spatial changes in community species composition which helps to understand how communities are assembled and biodiversity is formed and maintained. Larch(Larix) forests, which are coniferous forests widely distributed in the mountainous and plateau areas in North and Southwest China, are critical for maintaining the environmental conditions and species diversity. Few studies of larch forests have examined the beta-diversity and its constituent components(species turnover and nestedness-resultant components). Here, we used 483 larch forest plots to determine the total betadiversity and its components in different life forms(i.e., tree, shrub, and herb) of larch forests in China and to evaluate the main drivers that underlie this beta-diversity. We found that total betadiversity of larch forests was mainly dependent on the species turnover component. In all life forms,total beta-diversity and the species turnover component increased with increasing geographic, elevational, current climatic, and paleoclimatic distances. In contrast, the nestedness-resultant component decreased across these same distances. Geographic and environmental factors explained 20%-25% of total beta-diversity, 18%-27% of species turnover component, and 4%-16% of nestedness-resultant component. Larch forest types significantly affected total beta-diversity and species turnover component. Taken together, our results indicate that life forms affect beta-diversity patterns of larch forests in China, and that beta-diversity is driven by both niche differentiation and dispersal limitation. Our findings help to greatly understand the mechanisms of community assemblies of larch forests in China.
基金support from EPSRC-New Investigator Award 2020 (EP/V002260/1)The Faraday Institute-Battery Study and Seed Research Project (FIRG052)+2 种基金The Royal Society-International Exchanges 2021 Cost Share (NSFC)(IECNSFC211074)the China Scholarship Council (CSC, No. 201806130168)the International Postdoctoral Exchange Fellowship Program (Grant No. PC2022020)
文摘As the need for high-energy–density batteries continues to grow, lithium-sulfur(Li–S) batteries have become a highly promising next-generation energy solution due to their low cost and exceptional energy density compared to commercially available Li-ion batteries. Research into carbon-based sulfur hosts for Li–S batteries has been ongoing for over two decades, leading to a significant number of publications and patents.However, the commercialization of Li–S batteries has yet to be realized. This can be attributed, in part, to the instability of the Li metal anode. However, even when considering just the cathode side, there is still no consensus on whether carbon-based hosts will prove to be the best sulfur hosts for the industrialization of Li–S batteries. Recently, there has been controversy surrounding the use of carbon-based materials as the ideal sulfur hosts for practical applications of Li–S batteries under high sulfur loading and lean electrolyte conditions. To address this question, it is important to review the results of research into carbon-based hosts, assess their strengths and weaknesses, and provide a clear perspective. This review systematically evaluates the merits and mechanisms of various strategies for developing carbon-based host materials for high sulfur loading and lean electrolyte conditions. The review covers structural design and functional optimization strategies in detail, providing a comprehensive understanding of the development of sulfur hosts. The review also describes the use of efficient machine learning methods for investigating Li–S batteries. Finally, the outlook section lists and discusses current trends, challenges, and uncertainties surrounding carbon-based hosts, and concludes by presenting our standpoint and perspective on the subject.
基金This work is supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDA16020405)National Natural Science Foundation of China(Nos.21821005,81772417,and 21902160)。
文摘By the virtue of their olfactory,physicochemical,and biological characteristics,essential oils(EOs)have drawn wide attention as additives in daily chemicals like perfume or personal care products.Nevertheless,they are physicochemically unstable and susceptible to degradation or loss.Microencapsulation offers a feasible strategy to stabilize and prolong release of EO.This review summarizes the recognized benefits and functional properties of various preparation and characterization methods,wherein innovative fabrication strategies and their formation mechanisms are especially emphasized.Progress in combining detecting/measuring technologies with kinetic modelling are discussed,to give an integral approach of controlling the dynamic release of encapsulated EOs.Moreover,new development trends of EOs capsules are also highlighted.
基金the National Science and Technology Basic Project of China(No.2015FY210200)National Natural Science Foundation(No.31988102).
文摘Background:Larch(Larix Mill.)forests are widely distributed in the upper parts of mountainous areas in China,playing vital roles in constructing mountain landscapes and maintaining mountain environments.Despite their importance,our knowledges on the large-scale patterns of structure characteristics and the relationships between different structure variables are unclear.In this paper,we investigated 155 plots from 11 natural larch forest types across the country to explore the biogeographic patterns of the structure characteristics and the allometric relationships between different structure variables for Chinese larch forests.Results:The structure characteristics were significantly different among larch forest types.For different larch forest types,the power function fits the relationships between tree height and diameter at breast height(DBH),average DBH and stem density,and taper and stem density well,but with different exponents among larch forest types.The power exponents of the allometric relationships between tree height and DBH for different larch forest types varied from 0.61 to 0.93(mean=0.86)by standard major axis regression(SMA),and from 0.51 to 0.78(mean=0.56)by ordinary least square regression(OLS).The 50%,75%and 95%quantile regression(QR)and OLS indicated that the average DBH and taper of the L.gmelinii forests,L.gmelinii var.principis-rupprechtii forests,and L.sibirica forests were significantly correlated with stem density.Conclusions:The relationship between tree height and DBH showed a power function relationship for all larch forest types in China,but with different exponents.Overall,stem density was negatively correlated with average DBH and taper.The Sect.Larix forests exhibited stand density effect.Our findings provide an important basis for recognizing the biogeographic patterns of structure factors and for the management of larch forests in China.
基金supported by the National Natural Science Foundation of China(No.31988102)the National Science and Technology Basic Project of China(No.2015FY210200).
文摘Larch forests are important for species diversity,as well as soil and water conservation in mountain regions.In this study,we determined large-scale patterns of species richness in larch forests and identified the factors that drive these patterns.We found that larch forest species richness was high in southern China and low in northern China,and that patterns of species richness along an elevational gradient depend on larch forest type.In addition,we found that patterns of species richness in larch forests are best explained by contemporary climatic factors.Specifically,mean annual temperature and annual potential evapotranspiration were the most important factors for species richness of tree and shrub layers,while mean temperature of the coldest quarter and anomaly of annual precipitation from the Last Glacial Maximum to the present were the most important for that of herb layer and the whole community.Community structural factors,especially stand density,are also associated with the species richness of larch forests.Our findings that species richness in China's larch forests is mainly affected by energy availability and cold conditions support the ambient energy hypothesis and the freezing tolerance hypothesis.
基金supported by the Regional Innovation and Development Joint Fundthe National Natural Science Foundation of China (Grant No. U20A20249)+1 种基金the Science and Technology Program of Guangdong Province of China (Grant No.2019A050510012, 2020A050515007, 2020A0505090001)the Guangzhou emerging industry development fund project of Guangzhou development and reform commission。
文摘The ever-increasing demands for modern energy storage applications drive the search for novel anode materials of lithium(Li)-ion batteries(LIBs) with high storage capacity and long cycle life, to outperform the conventional LIBs anode materials. Hence, we report amorphous ternary phosphorus chalcogenide(aP_(4)SSe_(2)) as an anode material with high performance for LIBs. Synthesized via the mechanochemistry method, the a-P_(4)SSe_(2) compound is endowed with amorphous feature and offers excellent cycling stability(over 1500 mA h g^(-1) capacity after 425 cycles at 0.3 A g^(-1)), owing to the advantages of isotropic nature and synergistic effect of multielement forming Li-ion conductors during battery operation. Furthermore,as confirmed by ex situ X-ray diffraction(XRD) and transmission electron microscope(TEM), the a-P_(4)SSe_(2)anode material has a reversible and multistage Li-storage mechanism, which is extremely beneficial to long cycle life for batteries. Moreover, the autogenous intermediate electrochemical products with fast ionic conductivity can facilitate Li-ion diffusion effectively. Thus, the a-P_(4)SSe_(2)electrode delivers excellent rate capability(730 mA h g^(-1)capacity at 3 A g^(-1)). Through in situ electrochemical impedance spectra(EIS) measurements, it can be revealed that the resistances of charge transfer(R_(SEI)) and solid electrolyte interphase(R_(Ct)) decrease along with the formation of Li-ion conductors whilst the ohmic resistance(R_(Ω)) remains unchanged during the whole electrochemical process, thus resulting in rapid reaction kinetics and stable electrode to obtain excellent rate performance and cycling ability for LIBs. Moreover, the formation mechanism and electrochemical superiority of the a-P_(4)SSe_(2)phase, and its expansion to P_(4)S_(3-x)Se_(x)(x = 0, 1, 2, 3) family can prove its significance for LIBs.
文摘There are many papers related to stability, some on suppression or on stabilization are one type of them. Functional differential systems are common and important in practice. They are special situations of neutral differential systems and generalization of ordinary differential systems. We discussed conditions on suppression on functional system with Markovian switching in our previous work: “Suppression of Functional System with Markovian Switching”. Based on it, by slightly modifying and adding some conditions, we get this paper. In this paper, we will study a functional system whose coefficient satisfies the local Lipschitz condition and the one-sided polynomial growth condition under Markovian switching. By introducing two appropriate intensity Brownian noise, we find the potential explosion system stabilized.
基金the National Natural Science Foundation of China(52172097)National Key R&D Program of China(2021YFB2400200)+7 种基金Key Research and Development Program of Shaanxi Province(2022GY-301)Zhejiang Provincial Natural Science Foundation of China(LGF21E020001)the Fundamental Research Foundation for the Central Universities of China(xjh012020031)China Scholarship Council foundation(201906285020)International Exchanges 2021 Cost Share(NSFC)scheme(IEC\NSFC\211074)EPSRC Project(EP/V002260/1)Faraday Institute Seed Project(FIRG052)Faraday Institution LiSTAR Programme(EP/S003053/1,Grant FIRG014).
文摘Solid-state lithium batteries(SSLBs)have been broadly accepted as a promising candidate for the next generation lithium-ion batteries(LIBs)with high energy density,long duration,and high safety.The intrinsic non-flammable nature and electrochemical/thermal/mechanical stability of solid electrolytes are expected to fundamentally solve the safety problems of conventional LIBs.However,thermal degradation and thermal runaway could also happen in SSLBs.For example,the large interfacial resistance between solid electrolytes and electrodes could aggravate the joule heat generation;the anisotropic thermal diffusion could trigger the uneven temperature distribution and formation of hotspots further leading to lithium dendrite growth.Considerable research efforts have been devoted to exploring solid electrolytes with outstanding performance and harmonizing interfacial incompatibility in the past decades.There have been fewer comprehensive reports investigating the thermal reaction process,thermal degradation,and thermal runaway of SSLBs.This review seeks to highlight advanced thermal-related analysis techniques for SSLBs,by focusing particularly on multiscale and multidimensional thermal-related characterization,thermal monitoring techniques such as sensors,thermal experimental techniques imitating the abuse operating condition,and thermalrelated advanced simulations.Insightful perspectives are proposed to bridge fundamental studies to technological relevance for better understanding and performance optimization of SSLBs.
文摘The constant increase in global energy demand and stricter environmental standards are calling for advanced energy storage technologies that can store electricity from intermittent renewable sources such as wind,solar,and tidal power,to allow the broader implementation of the renewables.The gridoriented sodium-ion batteries,potassium ion batteries and multivalent ion batteries are cheaper and more sustainable alternatives to Li-ion,although they are still in the early stages of development.Additional optimisation of these battery systems is required,to improve the energy and power density,and to solve the safety issues caused by dendrites growth in anodes.Electrolyte,one of the most critical components in these batteries,could significantly influence the electrochemical performances and operations of batteries.In this review,the definitions and influences of three critical components(salts,solvents,and additives)in electrolytes are discussed.The significant advantages,challenges,recent progress and future optimisation directions of various electrolytes for monovalent and multivalent ions batteries(i.e.organic,ionic liquid and aqueous liquid electrolytes,polymer and inorganic solid electrolytes)are summarised to guide the practical application for grid-oriented batteries.
基金This study is supported by the National Major Scientific and Technological Special Project for Significant New Drugs Development(2014ZX09102043-003)National Natural Science Foundation of China(81371403)+1 种基金Shanghai Science and Technology Commission(13JC1401102)Natural Science Foundation of Jiangsu Province of China(BK20140275).
文摘Background:Mesencephalic astrocyte-derived neurotrophic factor(MANF)is a new candidate growth factor for dopaminergic neurons against endoplasmic reticulum stress(ER stress).HSP70 family,a chaperon like heat shock protein family,was proved to be involved in the MANF induced survival pathway in 6-OHDA treated SHSY-5Y cells.However,the ER stress relative transcriptome,in MANF signaling cascades is still investigated.The involvement of HSP70,a 70kd member of HSP70 family,need further to be verified.Methods:The cell apoptosis was assayed by MTT,TUNEL staining and western blot of cleaved Caspase-3.The differentially expressed genes in SHSY-5Y cells under different conditions(control,6-OHDA,6-OHDA+MANF)were investigated by RNA-seq.Expression of HSP70 was further confirmed by real-time PCR.RNAi knockdown for HSP70 was performed to investigate the role of HSP70 in the MANF signaling pathway.Results:MANF inhibits 6-OHDA-induced apoptosis in SHSY-5Y cells.Six ER stress relative genes(HSP70,GRP78,xbp-1,ATF-4,ATF-6,MAPK)were found enriched in 6-OHDA+MANF treatment group.HSP70 was the most significantly up-regulated gene under 6-OHDA+MANF treatment in SHSY-5Y cells.RNAi knockdown for HSP70 inhibits the protective effects of MANF against 6-OHDA toxicity in SHSY-5Y cells.Conclusion:MANF exerts a protective role against 6-OHDA induced apoptosis in SHSY-5Y cells via up-regulating some ER stress genes,including HSP70 family members.The HSP70 expression level plays a key role in MANFmediated survival pathway.
基金the financial support from the Engineering and Physical Sciences Research Council (EPSRC) in the UK (grant number EP/M027066/1,EP/R021554/1)Athena at HPC Midlands+, which was funded by EPSRC (grant number EP/P020232/1) of the UK+1 种基金Eureka HPC cluster at the University of SurreyUK Materials and Molecular Modelling Hub for computational resources, which are partially funded by EPSRC (EP/P020194/1)。
文摘Metal sulfides such as Bismuth sulfide(Bi2 S3) hold immense potential to be promoted as anode materials for lithium-ion batteries(LIBs),owing to their high theoretical gravimetric and volumetric capacities.However,the poor electrical conductivity and volume expansion during cycling hinder the practical applications of Bi2 S3.In this work,we used pyrrole and glucose as carbon source to design the surface carbon coating on the surface of Bi2 S3 particles,to improve the structural stability of Bi2 S3.Two composite materials were synthesized-Bi2 S3 coated with nitrogen doped carbon(Bi2 S3@NC),and Bi2 S3 coated with carbon(Bi2 S3@C).When used as anode active materials,both Bi2 S3@NC and Bi2 S3@C showed improved performance compared to Bi2 S3,which confirms surface carbon coating as an effective and scalable way for the modification of Bi2 S3 material.The electrode based on Bi2 S3@NC materials demonstrated higher performance than that of Bi2 S3@C,with an initial discha rge capacity of 1126.5 mA h/g,good cycling stability(500 mA h/g after 200 cycles at 200 mA/g) and excellent rate capability.Finally,Li storage and migration mechanisms in Bi2 S3 are revealed using first principle density functional theory calculations.
基金National Natural Science Foundation of China(31321061,31330012)National Basic Research Program of China on Global Change(2014CB954001).
文摘Aims Soil respiration is one of the most important components in the car-bon(c)cycle in terrestrial ecosystems.to investigate the contribution of each component of c cycle to the total soil c efflux,we quantified the rates of litter,root,and other mineral soil respiration from 2012 to 2014 in the primary and secondary tropical mountain rain forests in Hainan Island,china.Methods the seasonal dynamics of soil(Rs),non-litter(RNL)and non-root(RNR)respiration rates were measured using an automatic chamber system(Li-8100).Litter removal and root removal treatments were used to assess the contribution of litter and roots to belowground c production.We estimated the annual c efflux of each compo-nent of soil respiration in primary and secondary forests using a temperature-based exponential model and analyzed the impact of each component in each forest type.Important Findingsthe annual total soil c efflux was significantly higher in the primary rain forest(1567±205 g c m^(−2)yr^(−1))than that in the secondary forest(1300±70 g c m^(−2)yr^(−1),P<0.05).the litter,root,and mineral soils contributed 22%(349±185 g c m^(−2)yr^(−1)),38%(589±100 g c m^(−2)yr^(−1)),and 40%(628±128 g c m^(−2)yr^(−1))to the total soil c efflux in primary rain forest,respectively.In secondary forest,these three components contributed 11%(148±35 g c m^(−2)yr^(−1)),45%(572±259 g c m^(−2)yr^(−1)),and 44%(580±226 g c m^(−2)yr^(−1)),respectively.the temperature sensitivity(Q10)of Rs(2.70±0.14)in the primary forest was significantly higher than that in the secondary forest(2.34±0.12),with the Q10 values for respiration decreasing in the order of RNR>Rs>RNL.these results show that the difference in litter respiration between primary and secondary forest caused the major difference in annual soil respiration efflux between these two forest types.In addition,the litter respiration is more sensitive to the soil temperature than the other soil respiration components.
基金supported by the National Key Research and Development Program of China(grant no.2017YFC0503903)National Natural Science Foundation of China(grant no.31621091).
基金National Natural Science Foundation of China(52172097)Key Research and Development Program of Shaanxi Province(2022GY-301)+3 种基金Zhejiang Provincial Natural Science Foundation of China(LGF21E020001)Fundamental Research Foundation for the Central Universities of China(xjh012020031)China Scholarship Council foundation(201906285020)Qiong Cai would like to acknowledge the funding support from Faraday Institution LiSTAR Programme(EP/S003053/1,Grant FIRG014).
文摘Using inorganic fibrous membranes as protective layers has yielded success in suppressing dendrite growth.However,conventional fibrous membranes usually have large voids and low affinity for Li,promoting inhomogeneous charge distribution and allowing some dendrites to grow.Herein,we introduce a highly aligned TiO_(2)/SiO_(2)(A-TS)electrospun nanofiber membrane as a protective layer for the Li metal anode.The A-TS membrane is fabricated by a custom-made electrospinning system with an automatic fiber alignment collector that allows control of the fibers’orientation.At the scale of the individual fibers,their high binding energies with Li can attract more“dead”Li by reacting with the SiO_(2) component of the composite,avoiding uncontrollable deposition on the metal anode.At the membrane scale,these highly ordered structures achieve homogeneous contact and charge distribution on the Li metal surface,leaving no vulnerable areas to nucleate dendrite formation.Additionally,the excellent mechanical and thermal stability properties of the A-TS membrane prevent any potential puncturing by dendrites or thermal runaway in a battery.Hence,an A-TS@Li anode exhibits stable cycling performance when used in both Li-S and Li-NCM811 batteries,highlighting significant reference values for the future design and development of high-energy-density metal-based battery systems.
基金supported by the National Key Research and Development Program of China(grant no.2017YFA0605101)Ministry of Science and Technology of China(grant no.2015FY210200)National Natural Science Foundation of China(grant nos.31700374,31621091).
文摘森林生态系统碳库通常包括植被、土壤、凋落物与木质残体等几个组分。本研究旨在探讨中国一种重要的森林生态系统—水青冈林(Fagus L.)中这些碳库的沿海拔梯度格局变化及其驱动因子。在中国贵州省梵净山,沿海拔梯度(1095–1930 m)调查了9个水青冈林各碳库的碳储量。采用方差分解探讨了林龄、气候及其他因子对碳储量的影响,同时对梵净山与贵州和全球其他地区水青冈林的碳储量进行了比较。梵净山水青冈林生态系统碳储量在190.5–504.3 Mg C ha^(–1)之间,其主要组分包括植被碳库(33.7–73.9%)和土壤碳库(23.9–65.5%),而木质残体(0.05–3.1%)和凋落物(0.2–0.7%)对该生态系统碳储量的贡献不超过4%。随海拔升高,生态系统碳储量呈增加趋势,其中植被与木质残体碳库增加,而凋落物与土壤碳库无明显的变化趋势。对梵净山水青冈林,气候与林龄是其各组分碳储量海拔格局形成的主要原因;而对于全球水青冈林,林龄是其碳储量变化的主导因子。相比全球其他地区的水青冈林,贵州水青冈林具有较高的植被碳储量积累速率,这可能与贵州较高的降水量有关。本研究结果有助于理解中国水青冈林碳收支及其在区域碳循环中的可能作用,同时强调了林龄与气候对碳积累的重要性。
基金supported by the National Natural Science Foundation of China(no.31988102)the National Key Research and Development Program of China(no.2017YFC0503906)Key Research Program of Frontier Sciences,Chinese Academy of Sciences(QYZDY-SSW-SMC011).
