The division of arid areas is important in water and land resources management, planning and for a long-term agricultural, economic and social planning. Northwest China （NW） dominates the main arid areas in China. T...The division of arid areas is important in water and land resources management, planning and for a long-term agricultural, economic and social planning. Northwest China （NW） dominates the main arid areas in China. There is thus a need to adopt adequate concepts relative to the scope of arid areas of NW China and identify its climate types and characteristics. In this study, we analyzed climatic data over the last 30 years （1981-2010） from 191 stations in three provinces and three autonomous regions of NW China. The factor-cluster analysis technique （FC）, an objective and automated method was employed to classify the dry/wet climate zones. The traditional methods with predefined thresholds were adopted for providing a comparison with FC. The results showed that the wet/dry climate zones by FC were mainly distributed along mountains, rivers and desert borders. Climate-division boundaries relied heavily on the major terrain features surrounding the grouped stations. It also showed that the climate was dry in the plain sandy areas but relatively wet in the high mountain areas. FC method can reflect the climate characteristics more fully in NW China with varied and complicated topography, and outperform the tradi- tional climate classifications. Arid areas of NW China were defined as four climate types, including five resultant classes in FC classifications. The Qinling and Da Hinggan Mountains were two important boundaries, besides main administrative boundaries. The results also indicated that there are some differences between two traditional clas- sifications. The precipitation moved and fluctuated to an extent, which confirmed that climate change played an important role in the dry/wet climate zoning, and the boundaries of dry/wet climate zones might change and migrate with time. This paper is expected to provide a more in-depth understanding on the climate characteristics in arid areas of NW China, and then contribute to formulate reasonable water and land management planning and agri- cultural production programs.展开更多
Background:The accurate estimation of carbon-water flux is critical for understanding the carbon and water cycles of terrestrial ecosystems and further mitigating climate change.Model simulations and observations have...Background:The accurate estimation of carbon-water flux is critical for understanding the carbon and water cycles of terrestrial ecosystems and further mitigating climate change.Model simulations and observations have been widely used to research water and carbon cycles of terrestrial ecosystems.Given the advantages and limitations of each method,combining simulations and observations through a data assimilation technique has been proven to be highly promising for improving carbon-water flux simulation.However,to the best of our knowledge,few studies have accomplished both parameter optimization and the updating of model state variables through data assimilation for carbon-water flux simulation in multiple vegetation types.And little is known about the variation of the performance of data assimilation for carbon-water flux simulation in different vegetation types.Methods:In this study,we assimilated leaf area index(LAI)time-series observations into a biogeochemical model(Biome-BGC)using different assimilation algorithms(ensemble Kalman filter algorithm(EnKF)and unscented Kalman filter(UKF))in different vegetation types(deciduous broad-leaved forest(DBF),evergreen broad-leaved forest(EBF)and grassland(GL))to simulate carbon-water flux.Results:The validation of the results against the eddy covariance measurements indicated that,overall,compared with the original simulation,assimilating the LAI into the Biome-BGC model improved the carbon-water flux simulations(R^(2)increased by 35%,root mean square error decreased by 10%;the sum of the absolute error decreased by 8%)but more significantly,improved the water flux simulations(R^(2)increased by 31%,root mean square error decreased by 18%;the sum of the absolute error decreased by 16%).Among the different forest types,the data assimilation techniques(both EnKF and UKF)achieved the best performance towards carbon-water flux in EBF(R^(2)increased by 44%,root mean square error decreased by 24%;the sum of the absolute error decreased by 28%),and the performances of EnKF and UKF showed slightly different when simulating carbon fluxes.Conclusion:We suggest that to reduce the uncertainty in global carbon-water flux quantification,forthcoming data assimilation treatment should consider the vegetation types where the data assimilation experiments are carried out,the simulated objectives and the assimilation algorithms.展开更多
The unique structural features represented by micro-nanoneedle tip structure reflect wonderful physical and chemical properties.The tip effect includes the concentration of energy such as electrons,photons and magneti...The unique structural features represented by micro-nanoneedle tip structure reflect wonderful physical and chemical properties.The tip effect includes the concentration of energy such as electrons,photons and magnetism in the tip region,which has promising applications in the fields of energy conversion,water capture,environmental restoration and so on.In this review,a comprehensive and systematic summary of the latest advances in the application of the tip effect in different fields is provided.Utilizing advanced Finite Difference Time Domain simulation,we further propose our understanding of the fundamental mechanism of the tip effect induced by micro-nanostructure.However,we need to forge the present study to further reveal the essential law of the tip effect from the perspective of theoretical calculations.This review would provide a solid foundation for further development and application of the tip effect.展开更多
Taxifolin loaded zein-caseinate nanoparticles(TZP)were fabricated by the anti-solvent method and were used as an oral delivery vehicle to improve their bioavailability in the rat.The formulations of TZP were optimized...Taxifolin loaded zein-caseinate nanoparticles(TZP)were fabricated by the anti-solvent method and were used as an oral delivery vehicle to improve their bioavailability in the rat.The formulations of TZP were optimized.With mass ratio of 1:1:2 between taxifolin,zein and sodium caseinate,the particle size andζpotential of TZP were(168.74±0.35)nm and−(57.67±0.25)mV,while the encapsulation and loading efficiency of taxifolin were(85.83±0.89)%and(17.11±0.88)%,respectively.After freeze-drying,TZP exhibited excellent redispersibility in water without aggregation.Physicochemical characterization showed that taxifolin existed in amorphous form in TZP and its interaction with the protein was observed.After encapsulating in TZP,the excellent dispersion of taxifolin in water signifi cantly improve its diffusion velocity through a semipermeable membrane.After oral administration,taxifolin and its 5 metabolites were identifi ed in rat plasma by ultra high performance liquid chromatography(UPLC)with quadrupole time-of-flight mass spectrometry(UPLC-QTOF-MS).The dynamic variation of taxifolin and its metabolites in plasma were then quantifi ed by UPLC with a triple-quadrupole typemass spectroscopy(UPLC-QqQ-MS/MS).A pharmacokinetic study showed that the bioavailability of taxifolin increased from 0.35%to 0.52%through TZP fabrication.The plasma concentration of taxifolin glucuronide and methylated taxifolin glucuronide was much higher than taxifolin.Glucuronidation was the dominating metabolism pathway of taxifolin in vivo.展开更多
Streptomyces agglomeratus 5-1-8 with strong anti methicillin-resistant Staphylococcus aureus(MRSA)ability,isolated from the frozen soil of Tibet in China,has a strong ability to kill the multi-drugs-resistant MRSA.To ...Streptomyces agglomeratus 5-1-8 with strong anti methicillin-resistant Staphylococcus aureus(MRSA)ability,isolated from the frozen soil of Tibet in China,has a strong ability to kill the multi-drugs-resistant MRSA.To identify the second-ary metabolism ability of this strain,we describe here the phenotypic characteristics of this strain,along with its high-quality draft genome sequence,its annotation,and analysis.The 7.1M draft genome encodes 6,284 putative open reading frames(ORFs),of which 4,416 ORFs were assigned with clusters of orthologous genes(COG)categories.Also,65 t RNA genes and 24 r RNA operons were identified.The genome contains 12 gene clusters involved in antibiotics production and 1 gene cluster involved in anticancer-compounds production;4 gene clusters belong to polyketides and nonribosomal peptides,1gene cluster belong to the butyrolactone,4 gene clusters belong to the bacteriocin or lantipeptide,and 3 gene clusters belong to the others.This genome-sequence data will facilitate efforts to probe the potential of new antibiotics to kill multidrugs-resistant MRSA.展开更多
Slope gradient is one of the critically important factors which drive the erosional response of microtopographic surfaces. This study investigates the effect of slope gradient on the evolution of erosion under accumul...Slope gradient is one of the critically important factors which drive the erosional response of microtopographic surfaces. This study investigates the effect of slope gradient on the evolution of erosion under accumulative rainfall in laboratory experiments and calculates critical slope values that help evaluate land suitability for farming and similar purposes. Dynamics of accumulative runoff, accumulated sediment and their rates in each erosion stage are studied when the slope gradient varies. The critical slope value for the microtopographic surface was calculated according to the relationship between the sediment yield and slope gradient. The amount of eroded soil downhill in each erosion stage was calculated using DEM data of point cloud. Results show that 1) a steeper slope would increase cumulative runoff;2) cumulative sediment increases rapidly initially and then stabilizes with the increase of slope;3) the critical slope value for the whole erosion is determined as 10°. The findings of the dynamics of interrill erosion and sediment characteristics are useful information for future research of erosion prediction and conservation of soil and water in the Chinese Loess Plateau.展开更多
With the continuous development and advancement of science and technology,WEB-based online insurance system has become an inevitable choice to adapt to the development trend of the times.On the basis of establishing a...With the continuous development and advancement of science and technology,WEB-based online insurance system has become an inevitable choice to adapt to the development trend of the times.On the basis of establishing a system,it is necessary to manage the safe operation structure,thus effectively establishing complete supervision and maintenance.The system ensures that the management level of insured information security technology can be optimized.This paper briefly analyzes the framework of the WEB-based online insurance system and discusses the security mode and system implementation.展开更多
Soil erosion models are effective tools for assessing soil erosion indicators and simulating erosion processes.China has some of the most severe soil erosion in the world.To better apply soil erosion models to address...Soil erosion models are effective tools for assessing soil erosion indicators and simulating erosion processes.China has some of the most severe soil erosion in the world.To better apply soil erosion models to address soil erosion issues,it is necessary to understand the development process and current status of soil erosion modeling research in China.In this study,a combination of bibliometric analysis and statistical methods was used to review and organize Chinese soil erosion models(1982-2022)from various perspectives,including keywords,model operations,model classification,model spatiotemporal scales,and model geographical applications.This findings of this analysis indicate that the study of soil erosion models in China mainly focuses on large scales(regional and large river basins)using empirical models including USLE,RUSLE,and CSLE.The research areas are primarily concentrated in southeastern and central China.The research content has gradually shifted from studying soil erosion characteristics to analyzing influencing factors,spatiotemporal evolution of erosion,and erosion process and morphology stages.However,there are several issues in current Chinese soil erosion modeling research.These include a lack of validation of model application results with field measurements,limited application areas for the models,and relatively weak research on erosion process mechanisms.On this basis,it is recommended that future research should increase the observation of soil erosion processes and establish methods for data or mathematical formula conversion based on different geographical environments.Also,there is a need to strengthen research on erosion process mechanisms.The findings of this study should provide a valuable resource for researchers to future understand the development process and current issues of Chinese soil erosion models,providing insights for future research directions.展开更多
Plasmonic nanostructures have been widely employed to enhance the chiral light-matter interactions for chirality sensing owing to their intriguing optical properties.However,a quantitative understanding of the correla...Plasmonic nanostructures have been widely employed to enhance the chiral light-matter interactions for chirality sensing owing to their intriguing optical properties.However,a quantitative understanding of the correlation between enhanced molecular chirality and plasmonic properties in plasmonic nanoparticle-molecule complexes remains a challenge yet to be addressed.Here we demonstrate the complex interactions between Ag nanoparticles and biomolecules that generate distinct plasmonic circular dichroism signals ranging from UV to visible wavelengths.By deliberately changing the surface coverage of chiral molecules,the geometry of Ag nanoparticles,and the aggregation states of the complexes,three distinct underlying mechanisms were found to be intertwined and hybridized for enhancing circular dichroism signals.We further employed the chiral plasmonic nanoparticle-molecule complexes to quantify the enantiomeric purity of cysteine and explore their possible applications in other chiral molecules.The insights gained from this work shed light on the underlying mechanisms dictating the enhanced circular dichroism signals of chiral plasmonic nanoparticle-molecule complexes.展开更多
Plasmonic nanocrystals with intrinsic chirality are becoming a hot research focus and offer a wide range of applications in optics,biomedicine,asymmetric catalysis,and enantioselective sensing.Making use of the enanti...Plasmonic nanocrystals with intrinsic chirality are becoming a hot research focus and offer a wide range of applications in optics,biomedicine,asymmetric catalysis,and enantioselective sensing.Making use of the enantioselective interaction of chiral biomolecules and plasmonic nanocrystals,the biomolecules-directed synthesis endows chiral plasmonic nanocrystals with tunable optical properties and excellent biocompatibility.Recent advances in the biomolecule-directed geometric control of intrinsically chiral plasmonic nanomaterials have further provided great opportunities for their widespread applications in many emerging technological areas.The review summarizes the recent progress of biomolecule-directed synthesis and potential applications of chiral plasmonic nanocrystals and discusses their development prospects.展开更多
Anisotropic Au nanorods with intrinsically chiral geometry have drawn significant attention in the applications of nanophotonics,biosensing,and catalysis due to their strong chirality-dependent activities.However,tuni...Anisotropic Au nanorods with intrinsically chiral geometry have drawn significant attention in the applications of nanophotonics,biosensing,and catalysis due to their strong chirality-dependent activities.However,tuning the geometry and optical chirality of chiral Au nanorods remains a significant challenge.Here we report the integration of foreign ions with the seed-mediated chiral growth method for achieving chiral Au nanorods with the desired geometry and optical chirality.By deliberately controlling the addition of foreign ions,chiral Au nanorods with two different intrinsically chiral geometries(faceted and dendritic nanorods)can be obtained.Moreover,the chiral Au nanorods exhibit appealing morphologically dependent electrocatalytic activities toward the oxidation of tryptophan enantiomers.We further employed an epitaxial growth strategy to construct chiral Au@Pt and Au@Pd core–shell nanorods,which also exhibit remarkable enantioselectivities and catalytic activities.This work holds promise for the rational design of chiral nanomaterials with tunable geometry and chirality-dependent activities toward asymmetric photocatalysis and electrocatalysis.展开更多
The urgent need for renewable energy has driven rapid advancements in hydrogen production technologies.Among these,water electrolysis for green hydrogen,recognized for its significant environmental benefits,has garner...The urgent need for renewable energy has driven rapid advancements in hydrogen production technologies.Among these,water electrolysis for green hydrogen,recognized for its significant environmental benefits,has garnered increasing attention and emerged as a critical technology for achieving carbon neutrality and peak carbon emissions targets.Currently,the mainstream electrolyzers include alkaline water electrolyzers(AWE),proton exchange membrane electrolyzers(PEM),and anion exchange membrane electrolyzers(AEM).However,these technologies face significant challenges in large-scale industrial applications,including high costs,limited hydrogen production efficiency,and insufficient durability.Consequently,the development of innovative electrolyzers that combine high efficiency,low cost,and long lifespan has become imperative.In this review,the innovative design of bipolar membrane electrolyzers is first introduced.Subsequently,several types of advanced electrolyzers are summarized,including semi-vapor electrolyzers,electrolyzers employing flow-engineered three-dimensional electrodes,quasi-gas-phase electrolyzers,and bioinspired structural electrolyzers,and their specific advantages and potential applications are discussed in detail.Following this,this review delves into two key strategies for achieving membrane-free electrolyzers,analyzing their design principles and practical applicability.Last but not least,the challenges faced by the further development of electrolyzers were analyzed,and potential solutions were proposed,aiming to promote breakthrough advancements in hydrogen production through water electrolysis.展开更多
Criminals exploit the robust anonymity afforded by Tor for illicit purposes,prompting heightened interest among researchers in de-anonymization attacks on the Tor network.The execution of experiments on de-anonymizati...Criminals exploit the robust anonymity afforded by Tor for illicit purposes,prompting heightened interest among researchers in de-anonymization attacks on the Tor network.The execution of experiments on de-anonymization attacks within a real Tor network presents considerable challenges,hence the necessity for a simulation environment.However,existing methods for simulating the Tor network are inadequate regarding realism,flexibility,and scalability,with some being prohibitively expensive.In this paper,we develop a lightweight and scalable Tor network simulation environment based on Kubernetes(K8s),employing Docker containers to simulate Tor relays.The results demonstrate that a network of up to a thousand Tor relays can be simulated using just four standard hosts.Furthermore,two de-anonymization attack experiments were conducted within this simulated environment,which exhibited high levels of realism and flexibility.Finally,a hybrid networking approach combining multi-granularity relays was explored to enhance further the balance between realism and cost in Tor network simulations.展开更多
Rational design and construction of chiral-achiral hybrid structures are of great importance to realize the multifunctional complex chiral structures toward emerging technological applications. However, significant ch...Rational design and construction of chiral-achiral hybrid structures are of great importance to realize the multifunctional complex chiral structures toward emerging technological applications. However, significant challenges remain due to the lack of fine control over the heterostructure. Here, we have developed a general bottom-up synthetic strategy for the site-selective growth of Cu nanodomains on intrinsically chiral Au nanocrystals. Chiral AuCu heterostructures with three distinct architectures were achieved by controlling the overgrowth of Cu nanodomains in a site-specific manner. The geometry-dependent plasmonic chirality of the heterostructures was demonstrated experimentally by circular dichroism spectroscopy and theoretically through finite-difference time-domain simulations. The site-specific geometric control of chiral AuCu heterostructures was also extended to employ anisotropic chiral Au nanoplates and nanorods as the building blocks. By virtue of the galvanic replacement reactions between metal ions and Cu atoms, chiral heterostructures with increasing architectural complexity and compositional diversity can be further achieved. The current work not only opens up a promising strategy to synthesize complex chiral hybrid nanostructures but also provides an important knowledge framework that guides the rational design of multifunctional chiral hybrid nanostructures toward chiroptical applications.展开更多
Mammals have evolved mechanisms to sense hypoxia and induce hypoxic responses.Recently,high-throughput techniques have greatly promoted global studies of protein expression changes during hypoxia and the identificatio...Mammals have evolved mechanisms to sense hypoxia and induce hypoxic responses.Recently,high-throughput techniques have greatly promoted global studies of protein expression changes during hypoxia and the identification of candidate genes associated with hypoxiaadaptive evolution,which have contributed to the understanding of the complex regulatory networks of hypoxia.In this study,we developed an integrated resource for the expression dynamics of proteins in response to hypoxia(iHypoxia),and this database contains 2589 expression events of 1944 proteins identified by low-throughput experiments(LTEs)and 422,553 quantitative expression events of 33,559 proteins identified by high-throughput experiments from five mammals that exhibit a response to hypoxia.Various experimental details,such as the hypoxic experimental conditions,expression patterns,and sample types,were carefully collected and integrated.Furthermore,8788 candidate genes from diverse species inhabiting low-oxygen environments were also integrated.In addition,we conducted an orthologous search and computationally identified 394,141 proteins that may respond to hypoxia among 48 animals.An enrichment analysis of human proteins identified from LTEs shows that these proteins are enriched in certain drug targets and cancer genes.Annotation of known posttranslational modification(PTM)sites in the proteins identified by LTEs reveals that these proteins undergo extensive PTMs,particularly phosphorylation,ubiquitination,and acetylation.iHypoxia provides a convenient and user-friendly method for users to obtain hypoxia-related information of interest.展开更多
Comprehensive Summary,Sensing the chirality of molecules is of great importance to fields such as enantioselective synthesis,pharmaceutical industry,and biomedicine.Plasmonic nanoparticles are ideal candidates for mol...Comprehensive Summary,Sensing the chirality of molecules is of great importance to fields such as enantioselective synthesis,pharmaceutical industry,and biomedicine.Plasmonic nanoparticles are ideal candidates for molecular sensing due to their inherent plasmonic properties that significantly enhance their sensitivity to surrounding molecules.Developing plasmonic nanoparticle-molecule complexes for chirality sensing has drawn enormous attention in recent years due to their intriguing properties and potential applications.Thus,in this review,we believe it is timely to circumnavigate the rational design of plasmonic nanoparticle-molecule complexes and widen the scope of their emerging applications in chirality sensing.First,we present different fundamental mechanisms for plasmon-based chirality that are built on the system of plasmonic nanoparticle-molecule complexes.Second,we review the typical applications of plasmonic nanoparticle-molecule complexes in chirality sensing.Third,we discuss the emerging biomedical applications that the plasmon-based chirality has attracted enormous interest.Finally,we provide an outlook on the challenges and opportunities in the field of plasmonic approaches for chirality sensing.展开更多
基金supported by the Special Foundation of National Science & Technology Supporting Plan (2011BAD29B09)the National Natural Science Foundation of China (31172039)+2 种基金the ‘111’ Project from the Ministry of Edu- cation and the State Administration of Foreign Experts Affairs (B12007)the Supporting Project of Young Technology Nova of Shaanxi Province (2010KJXX-04)the Supporting Plan of Young Elites and basic operational cost of research from Northwest A&F University
文摘The division of arid areas is important in water and land resources management, planning and for a long-term agricultural, economic and social planning. Northwest China （NW） dominates the main arid areas in China. There is thus a need to adopt adequate concepts relative to the scope of arid areas of NW China and identify its climate types and characteristics. In this study, we analyzed climatic data over the last 30 years （1981-2010） from 191 stations in three provinces and three autonomous regions of NW China. The factor-cluster analysis technique （FC）, an objective and automated method was employed to classify the dry/wet climate zones. The traditional methods with predefined thresholds were adopted for providing a comparison with FC. The results showed that the wet/dry climate zones by FC were mainly distributed along mountains, rivers and desert borders. Climate-division boundaries relied heavily on the major terrain features surrounding the grouped stations. It also showed that the climate was dry in the plain sandy areas but relatively wet in the high mountain areas. FC method can reflect the climate characteristics more fully in NW China with varied and complicated topography, and outperform the tradi- tional climate classifications. Arid areas of NW China were defined as four climate types, including five resultant classes in FC classifications. The Qinling and Da Hinggan Mountains were two important boundaries, besides main administrative boundaries. The results also indicated that there are some differences between two traditional clas- sifications. The precipitation moved and fluctuated to an extent, which confirmed that climate change played an important role in the dry/wet climate zoning, and the boundaries of dry/wet climate zones might change and migrate with time. This paper is expected to provide a more in-depth understanding on the climate characteristics in arid areas of NW China, and then contribute to formulate reasonable water and land management planning and agri- cultural production programs.
基金supported by the National Natural Science Foundation of China(No.41301451).
文摘Background:The accurate estimation of carbon-water flux is critical for understanding the carbon and water cycles of terrestrial ecosystems and further mitigating climate change.Model simulations and observations have been widely used to research water and carbon cycles of terrestrial ecosystems.Given the advantages and limitations of each method,combining simulations and observations through a data assimilation technique has been proven to be highly promising for improving carbon-water flux simulation.However,to the best of our knowledge,few studies have accomplished both parameter optimization and the updating of model state variables through data assimilation for carbon-water flux simulation in multiple vegetation types.And little is known about the variation of the performance of data assimilation for carbon-water flux simulation in different vegetation types.Methods:In this study,we assimilated leaf area index(LAI)time-series observations into a biogeochemical model(Biome-BGC)using different assimilation algorithms(ensemble Kalman filter algorithm(EnKF)and unscented Kalman filter(UKF))in different vegetation types(deciduous broad-leaved forest(DBF),evergreen broad-leaved forest(EBF)and grassland(GL))to simulate carbon-water flux.Results:The validation of the results against the eddy covariance measurements indicated that,overall,compared with the original simulation,assimilating the LAI into the Biome-BGC model improved the carbon-water flux simulations(R^(2)increased by 35%,root mean square error decreased by 10%;the sum of the absolute error decreased by 8%)but more significantly,improved the water flux simulations(R^(2)increased by 31%,root mean square error decreased by 18%;the sum of the absolute error decreased by 16%).Among the different forest types,the data assimilation techniques(both EnKF and UKF)achieved the best performance towards carbon-water flux in EBF(R^(2)increased by 44%,root mean square error decreased by 24%;the sum of the absolute error decreased by 28%),and the performances of EnKF and UKF showed slightly different when simulating carbon fluxes.Conclusion:We suggest that to reduce the uncertainty in global carbon-water flux quantification,forthcoming data assimilation treatment should consider the vegetation types where the data assimilation experiments are carried out,the simulated objectives and the assimilation algorithms.
基金This work was supported by the National Natural Science Foundation of China(Grant No.51863005,51462006,51102230,51671062,51871065,and 51971068)the Guangxi Natural Science Foundation(No.2018GXNSFDA281051,2014GXNSFAA118401,and 2020GXNSFGA297004)+2 种基金the Science Research and Technology Development Program of Guangxi(AD17195073,AA19182014 and AA17202030-1)the Guangxi Bagui Scholar Foundation,the Guangxi Collabora-tive Innovation Centre of Structure and Property for New Energy and Materials,the Guangxi Advanced Functional Materials Foundation and Application Talents Small Highlands,Chinesisch-Deutsche Kooperationsgruppe(GZ1528)the Innovation Project of GUET Graduate Education(2019YCXS114 and 2018YJCX88).
文摘We deviseda functional form stable compositephase-change materials(PCMs)toachieve a three-dimensional(3D)interconnectedporous carbon aerogel structure for encapsulating polyethyleneglycol(PEG).Anovelhomogeneity reinforced carbonaerogel witha well-interconnected porous structure was constructed bycombining a flexible carbonresource from biomass guar gum with hard-brittle carbonfrom polyimide,to overcome severeshrinkage andpoor mechanical performance of traditionalcarbon aerogel.Thesupportingcarbon aerogel-encapsulated PEG produced thenovel composite PCMswithgood structure stability andcomprehensive energy storage performance.Theresults showed thatthecomposite PCMsdisplayed awell-defined 3Dinterconnected structure,and theirenergy storage capacities were 171.5 and169.5 J/g,which changed onlyslightlyafter 100 thermalcycles,andthe compositescould maintainthe equilibrium temperature at50.0−58.1℃ for about 760.3 s.The thermal conductivityofthe compositescould reach0.62 W m^(−1) K^(−1),which effectively enhanced the thermalresponse rate.And thecomposite PCMs exhibited good leakage-proof performance andexcellent light–thermal conversion.The compressive strengthof thecomposite PCMscan improveupto 1.602 MPa.Results indicatethatthisstrategy canbe efficiently usedtodevelop novel composite PCMswithimproved comprehensive thermalperformance and high light–thermal conversion.
基金financially supported by the Natural Science Foundation of China(No.51902101)Natural Science Foundation of Jiangsu Province(No.BK20201381)+1 种基金Science Foundation of Nanjing University of Posts and Telecommunications(No.NY219144)the National College Student Innovation and Entrepreneurship Training Program(No.202210293017Z).
文摘The unique structural features represented by micro-nanoneedle tip structure reflect wonderful physical and chemical properties.The tip effect includes the concentration of energy such as electrons,photons and magnetism in the tip region,which has promising applications in the fields of energy conversion,water capture,environmental restoration and so on.In this review,a comprehensive and systematic summary of the latest advances in the application of the tip effect in different fields is provided.Utilizing advanced Finite Difference Time Domain simulation,we further propose our understanding of the fundamental mechanism of the tip effect induced by micro-nanostructure.However,we need to forge the present study to further reveal the essential law of the tip effect from the perspective of theoretical calculations.This review would provide a solid foundation for further development and application of the tip effect.
基金supported by the National Natural Science Foundation of China(32060541).
文摘Taxifolin loaded zein-caseinate nanoparticles(TZP)were fabricated by the anti-solvent method and were used as an oral delivery vehicle to improve their bioavailability in the rat.The formulations of TZP were optimized.With mass ratio of 1:1:2 between taxifolin,zein and sodium caseinate,the particle size andζpotential of TZP were(168.74±0.35)nm and−(57.67±0.25)mV,while the encapsulation and loading efficiency of taxifolin were(85.83±0.89)%and(17.11±0.88)%,respectively.After freeze-drying,TZP exhibited excellent redispersibility in water without aggregation.Physicochemical characterization showed that taxifolin existed in amorphous form in TZP and its interaction with the protein was observed.After encapsulating in TZP,the excellent dispersion of taxifolin in water signifi cantly improve its diffusion velocity through a semipermeable membrane.After oral administration,taxifolin and its 5 metabolites were identifi ed in rat plasma by ultra high performance liquid chromatography(UPLC)with quadrupole time-of-flight mass spectrometry(UPLC-QTOF-MS).The dynamic variation of taxifolin and its metabolites in plasma were then quantifi ed by UPLC with a triple-quadrupole typemass spectroscopy(UPLC-QqQ-MS/MS).A pharmacokinetic study showed that the bioavailability of taxifolin increased from 0.35%to 0.52%through TZP fabrication.The plasma concentration of taxifolin glucuronide and methylated taxifolin glucuronide was much higher than taxifolin.Glucuronidation was the dominating metabolism pathway of taxifolin in vivo.
基金supported by the National Natural Science Foundation of China (Grant No. 31400437)the international cooperation program of Gansu (1504WKCA097)+1 种基金the application transformationfoundation of CAS (HHS-CGZH-16-02)UK BBSRC China Partnering Grant (BB/J020419/1)
文摘Streptomyces agglomeratus 5-1-8 with strong anti methicillin-resistant Staphylococcus aureus(MRSA)ability,isolated from the frozen soil of Tibet in China,has a strong ability to kill the multi-drugs-resistant MRSA.To identify the second-ary metabolism ability of this strain,we describe here the phenotypic characteristics of this strain,along with its high-quality draft genome sequence,its annotation,and analysis.The 7.1M draft genome encodes 6,284 putative open reading frames(ORFs),of which 4,416 ORFs were assigned with clusters of orthologous genes(COG)categories.Also,65 t RNA genes and 24 r RNA operons were identified.The genome contains 12 gene clusters involved in antibiotics production and 1 gene cluster involved in anticancer-compounds production;4 gene clusters belong to polyketides and nonribosomal peptides,1gene cluster belong to the butyrolactone,4 gene clusters belong to the bacteriocin or lantipeptide,and 3 gene clusters belong to the others.This genome-sequence data will facilitate efforts to probe the potential of new antibiotics to kill multidrugs-resistant MRSA.
文摘Slope gradient is one of the critically important factors which drive the erosional response of microtopographic surfaces. This study investigates the effect of slope gradient on the evolution of erosion under accumulative rainfall in laboratory experiments and calculates critical slope values that help evaluate land suitability for farming and similar purposes. Dynamics of accumulative runoff, accumulated sediment and their rates in each erosion stage are studied when the slope gradient varies. The critical slope value for the microtopographic surface was calculated according to the relationship between the sediment yield and slope gradient. The amount of eroded soil downhill in each erosion stage was calculated using DEM data of point cloud. Results show that 1) a steeper slope would increase cumulative runoff;2) cumulative sediment increases rapidly initially and then stabilizes with the increase of slope;3) the critical slope value for the whole erosion is determined as 10°. The findings of the dynamics of interrill erosion and sediment characteristics are useful information for future research of erosion prediction and conservation of soil and water in the Chinese Loess Plateau.
文摘With the continuous development and advancement of science and technology,WEB-based online insurance system has become an inevitable choice to adapt to the development trend of the times.On the basis of establishing a system,it is necessary to manage the safe operation structure,thus effectively establishing complete supervision and maintenance.The system ensures that the management level of insured information security technology can be optimized.This paper briefly analyzes the framework of the WEB-based online insurance system and discusses the security mode and system implementation.
基金jointly supported by the Natural Science Basic Research Program of Shaanxi Province,China(2021JZ-17)Agricultural Key-scientific and Core-technological Project of Shaanxi Province,China(2024NYGG011)the Shaanxi Agricultural Collaborative Innovation and Extension Alliance,China(LMR202204)。
文摘Soil erosion models are effective tools for assessing soil erosion indicators and simulating erosion processes.China has some of the most severe soil erosion in the world.To better apply soil erosion models to address soil erosion issues,it is necessary to understand the development process and current status of soil erosion modeling research in China.In this study,a combination of bibliometric analysis and statistical methods was used to review and organize Chinese soil erosion models(1982-2022)from various perspectives,including keywords,model operations,model classification,model spatiotemporal scales,and model geographical applications.This findings of this analysis indicate that the study of soil erosion models in China mainly focuses on large scales(regional and large river basins)using empirical models including USLE,RUSLE,and CSLE.The research areas are primarily concentrated in southeastern and central China.The research content has gradually shifted from studying soil erosion characteristics to analyzing influencing factors,spatiotemporal evolution of erosion,and erosion process and morphology stages.However,there are several issues in current Chinese soil erosion modeling research.These include a lack of validation of model application results with field measurements,limited application areas for the models,and relatively weak research on erosion process mechanisms.On this basis,it is recommended that future research should increase the observation of soil erosion processes and establish methods for data or mathematical formula conversion based on different geographical environments.Also,there is a need to strengthen research on erosion process mechanisms.The findings of this study should provide a valuable resource for researchers to future understand the development process and current issues of Chinese soil erosion models,providing insights for future research directions.
基金supported by the National Natural Science Foundation of China(22174104 to Q.Z.)support of the Natural Science Foundation of Jiangsu Province(BK20240448)。
文摘Plasmonic nanostructures have been widely employed to enhance the chiral light-matter interactions for chirality sensing owing to their intriguing optical properties.However,a quantitative understanding of the correlation between enhanced molecular chirality and plasmonic properties in plasmonic nanoparticle-molecule complexes remains a challenge yet to be addressed.Here we demonstrate the complex interactions between Ag nanoparticles and biomolecules that generate distinct plasmonic circular dichroism signals ranging from UV to visible wavelengths.By deliberately changing the surface coverage of chiral molecules,the geometry of Ag nanoparticles,and the aggregation states of the complexes,three distinct underlying mechanisms were found to be intertwined and hybridized for enhancing circular dichroism signals.We further employed the chiral plasmonic nanoparticle-molecule complexes to quantify the enantiomeric purity of cysteine and explore their possible applications in other chiral molecules.The insights gained from this work shed light on the underlying mechanisms dictating the enhanced circular dichroism signals of chiral plasmonic nanoparticle-molecule complexes.
基金supported by the National Natural Science Foundation of China(Nos.22174104,22472119,22405195)support of the Natural Science Foundation of Jiangsu Province(No.BK20240448)support of the Largescale Instrument and Equipment Sharing Foundation of Wuhan University and the Core Facility of Wuhan University.
文摘Plasmonic nanocrystals with intrinsic chirality are becoming a hot research focus and offer a wide range of applications in optics,biomedicine,asymmetric catalysis,and enantioselective sensing.Making use of the enantioselective interaction of chiral biomolecules and plasmonic nanocrystals,the biomolecules-directed synthesis endows chiral plasmonic nanocrystals with tunable optical properties and excellent biocompatibility.Recent advances in the biomolecule-directed geometric control of intrinsically chiral plasmonic nanomaterials have further provided great opportunities for their widespread applications in many emerging technological areas.The review summarizes the recent progress of biomolecule-directed synthesis and potential applications of chiral plasmonic nanocrystals and discusses their development prospects.
基金supported by the National Natural Science Foundation of China(Nos.22174104,22472119,and 22405195)funded by the Basic Research Program of Jiangsu(No.BK20240448 to L.C.S.)。
文摘Anisotropic Au nanorods with intrinsically chiral geometry have drawn significant attention in the applications of nanophotonics,biosensing,and catalysis due to their strong chirality-dependent activities.However,tuning the geometry and optical chirality of chiral Au nanorods remains a significant challenge.Here we report the integration of foreign ions with the seed-mediated chiral growth method for achieving chiral Au nanorods with the desired geometry and optical chirality.By deliberately controlling the addition of foreign ions,chiral Au nanorods with two different intrinsically chiral geometries(faceted and dendritic nanorods)can be obtained.Moreover,the chiral Au nanorods exhibit appealing morphologically dependent electrocatalytic activities toward the oxidation of tryptophan enantiomers.We further employed an epitaxial growth strategy to construct chiral Au@Pt and Au@Pd core–shell nanorods,which also exhibit remarkable enantioselectivities and catalytic activities.This work holds promise for the rational design of chiral nanomaterials with tunable geometry and chirality-dependent activities toward asymmetric photocatalysis and electrocatalysis.
基金supported by the National Natural Science Foundation of China(22479079)the Natural Science Foundation of Jiangsu Province(BK20201381)the Science Foundation of Nanjing University of Posts and Telecommunications(NY219144,NY221046).
文摘The urgent need for renewable energy has driven rapid advancements in hydrogen production technologies.Among these,water electrolysis for green hydrogen,recognized for its significant environmental benefits,has garnered increasing attention and emerged as a critical technology for achieving carbon neutrality and peak carbon emissions targets.Currently,the mainstream electrolyzers include alkaline water electrolyzers(AWE),proton exchange membrane electrolyzers(PEM),and anion exchange membrane electrolyzers(AEM).However,these technologies face significant challenges in large-scale industrial applications,including high costs,limited hydrogen production efficiency,and insufficient durability.Consequently,the development of innovative electrolyzers that combine high efficiency,low cost,and long lifespan has become imperative.In this review,the innovative design of bipolar membrane electrolyzers is first introduced.Subsequently,several types of advanced electrolyzers are summarized,including semi-vapor electrolyzers,electrolyzers employing flow-engineered three-dimensional electrodes,quasi-gas-phase electrolyzers,and bioinspired structural electrolyzers,and their specific advantages and potential applications are discussed in detail.Following this,this review delves into two key strategies for achieving membrane-free electrolyzers,analyzing their design principles and practical applicability.Last but not least,the challenges faced by the further development of electrolyzers were analyzed,and potential solutions were proposed,aiming to promote breakthrough advancements in hydrogen production through water electrolysis.
基金supported by National Key Research and Development Program of China(No.2023YFB3106600)National Natural Science Foundation of China(62372056)
文摘Criminals exploit the robust anonymity afforded by Tor for illicit purposes,prompting heightened interest among researchers in de-anonymization attacks on the Tor network.The execution of experiments on de-anonymization attacks within a real Tor network presents considerable challenges,hence the necessity for a simulation environment.However,existing methods for simulating the Tor network are inadequate regarding realism,flexibility,and scalability,with some being prohibitively expensive.In this paper,we develop a lightweight and scalable Tor network simulation environment based on Kubernetes(K8s),employing Docker containers to simulate Tor relays.The results demonstrate that a network of up to a thousand Tor relays can be simulated using just four standard hosts.Furthermore,two de-anonymization attack experiments were conducted within this simulated environment,which exhibited high levels of realism and flexibility.Finally,a hybrid networking approach combining multi-granularity relays was explored to enhance further the balance between realism and cost in Tor network simulations.
基金supported by the National Natural Science Foundation of China (22174104 to Q.Z.)the support of the Hubei Provincial Natural Science Foundation of China (2022CFB627)the Fundamental Research Funds for the Central Universities (20422022kf1039)。
文摘Rational design and construction of chiral-achiral hybrid structures are of great importance to realize the multifunctional complex chiral structures toward emerging technological applications. However, significant challenges remain due to the lack of fine control over the heterostructure. Here, we have developed a general bottom-up synthetic strategy for the site-selective growth of Cu nanodomains on intrinsically chiral Au nanocrystals. Chiral AuCu heterostructures with three distinct architectures were achieved by controlling the overgrowth of Cu nanodomains in a site-specific manner. The geometry-dependent plasmonic chirality of the heterostructures was demonstrated experimentally by circular dichroism spectroscopy and theoretically through finite-difference time-domain simulations. The site-specific geometric control of chiral AuCu heterostructures was also extended to employ anisotropic chiral Au nanoplates and nanorods as the building blocks. By virtue of the galvanic replacement reactions between metal ions and Cu atoms, chiral heterostructures with increasing architectural complexity and compositional diversity can be further achieved. The current work not only opens up a promising strategy to synthesize complex chiral hybrid nanostructures but also provides an important knowledge framework that guides the rational design of multifunctional chiral hybrid nanostructures toward chiroptical applications.
基金supported by grants from the National Key R&D Program of China(Grant No.2021YFA1302100 to Ze-Xian Liu)the National Natural Science Foundation of China(Grant No.U2004152 to Zhenlong Wang,Grant Nos.81972239 and 91953123 to Ze-Xian Liu)+2 种基金the Fostering Fund of Fundamental Research for Young Teachers of Zhengzhou University,China(Grant No.JC21343016 to Han Cheng)the Program for Guangdong Introducing Innovative and Entrepreneurial Teams,China(Grant No.2017ZT07S096 to Ze-Xian Liu)the Tip-Top Scientific and Technical Innovative Youth Talents of Guangdong Special Support Program,China(Grant No.2019TQ05Y351 to Ze-Xian Liu).
文摘Mammals have evolved mechanisms to sense hypoxia and induce hypoxic responses.Recently,high-throughput techniques have greatly promoted global studies of protein expression changes during hypoxia and the identification of candidate genes associated with hypoxiaadaptive evolution,which have contributed to the understanding of the complex regulatory networks of hypoxia.In this study,we developed an integrated resource for the expression dynamics of proteins in response to hypoxia(iHypoxia),and this database contains 2589 expression events of 1944 proteins identified by low-throughput experiments(LTEs)and 422,553 quantitative expression events of 33,559 proteins identified by high-throughput experiments from five mammals that exhibit a response to hypoxia.Various experimental details,such as the hypoxic experimental conditions,expression patterns,and sample types,were carefully collected and integrated.Furthermore,8788 candidate genes from diverse species inhabiting low-oxygen environments were also integrated.In addition,we conducted an orthologous search and computationally identified 394,141 proteins that may respond to hypoxia among 48 animals.An enrichment analysis of human proteins identified from LTEs shows that these proteins are enriched in certain drug targets and cancer genes.Annotation of known posttranslational modification(PTM)sites in the proteins identified by LTEs reveals that these proteins undergo extensive PTMs,particularly phosphorylation,ubiquitination,and acetylation.iHypoxia provides a convenient and user-friendly method for users to obtain hypoxia-related information of interest.
基金supported by the National Natural Science Foundation of China(Grant No.22174104 to Q.Z.).L.S.acknowledges the support of the Hubei Provincial Natural Science Foundation of China(Grant No.2022CFB627)the Fundamental Research Funds for the Central Universities(Grant No.20422022kf1039).
文摘Comprehensive Summary,Sensing the chirality of molecules is of great importance to fields such as enantioselective synthesis,pharmaceutical industry,and biomedicine.Plasmonic nanoparticles are ideal candidates for molecular sensing due to their inherent plasmonic properties that significantly enhance their sensitivity to surrounding molecules.Developing plasmonic nanoparticle-molecule complexes for chirality sensing has drawn enormous attention in recent years due to their intriguing properties and potential applications.Thus,in this review,we believe it is timely to circumnavigate the rational design of plasmonic nanoparticle-molecule complexes and widen the scope of their emerging applications in chirality sensing.First,we present different fundamental mechanisms for plasmon-based chirality that are built on the system of plasmonic nanoparticle-molecule complexes.Second,we review the typical applications of plasmonic nanoparticle-molecule complexes in chirality sensing.Third,we discuss the emerging biomedical applications that the plasmon-based chirality has attracted enormous interest.Finally,we provide an outlook on the challenges and opportunities in the field of plasmonic approaches for chirality sensing.
