Li metal is widely recognized as the desired anode for next-generation energy storage,Li metal batteries,due to its highest theoretical capacity and lowest potential.Nonetheless,it suffers from unstable electrochemica...Li metal is widely recognized as the desired anode for next-generation energy storage,Li metal batteries,due to its highest theoretical capacity and lowest potential.Nonetheless,it suffers from unstable electrochemical behaviors like dendrite growth and side reactions in practical application.Herein,we report a highly stable anode with collector,Li_(5)Mg@Cu,realized by the melting-rolling process.The Li_(5)Mg@Cu anode delivers ultrahigh cycle stability for 2000 and 1000 h at the current densities of 1 and 2 mA cm^(-2),respectively in symmetric cells.Meanwhile,the Li_(5)Mg@Cu|LFP cell exhibits a high-capacity retention of 91.8% for 1000 cycles and 78.8% for 2000 cycles at 1 C.Moreover,we investigate the suppression effects of Mg on the dendrite growth by studying the performance of Li_(x)Mg@Cu electrodes with different Mg contents(2.0-16.7 at%).The exchange current density,surface energy,Li^(+)diffusion coefficient,and chemical stability of Li_(x)Mg@Cu concretely reveal this improving suppression effect when Mg content becomes higher.In addition,a Mg-rich phase with“hollow brick”morphology forming in the high Mg content Li_(x)Mg@Cu guides the uniform deposition of Li.This study reveals the suppression effects of Mg on Li dendrites growth and offers a perspective for finding the optimal component of Li-Mg alloys.展开更多
High-performance catalyst is significant for the sustainable hydrogen(H_(2))production by electrocatalytic water splitting.Optimizing porous structure and active groups of substrate can promote the interaction of subs...High-performance catalyst is significant for the sustainable hydrogen(H_(2))production by electrocatalytic water splitting.Optimizing porous structure and active groups of substrate can promote the interaction of substrate and active metal particles,enabling excellent catalytic properties and stability.Herein,the optimization strategy of delignification and 2,2,6,6-tetramethylpyperidine-1-oxyl(TEMPO)oxidization was developed to modify the porous structure and active groups of wood substrate,and Ru doped Co/CO_(2)P(Ru-Co/CO_(2)P)nanoparticles were encapsulated into the optimized wood carbon substrate(Ru-Co/CO_(2)P@TDCW)for the efficient pH-universal hydrogen evolution reaction(HER).The nanopore and carboxyl groups were produced by delignification and TEMPO oxidation,which accelerated the dispersion and deposition of Ru-Co/CO_(2)P nanoparticles.The RuCo alloy and RuCoP nanoparticles were produced with the doping of Ru,and more Ru-Co/CO_(2)P nanoparticles were anchored by the delignified and TEMPO oxidized wood carbon(TDCW).As anticipated,the Ru-Co/CO_(2)P@TDCW catalyst exhibited excellent pH-universal HER activity,and only 16.6,93,and 43 mV of overpotentials were required to deliver the current density of 50 mA cm^(-2)in alkaline,neutral,and acidic electrolytes,outperforming the noble Pt/C/TDCW catalyst significantly.In addition,Ru-Co/CO_(2)P@TDCW catalyst presented excellent stability for more than 600 h working at 100 mA cm^(-2)in alkaline solution(1.0 M KOH).Density function theory(DFT)results revealed that energy barriers for the dissociation of H_(2)O and the formation of H_(2)were decreased by the doping of Ru,and the conductivity and efficiency of electron migration were also enhanced.This work demonstrated a strategy to optimize the structure and properties of wood carbon substrate,providing a promising strategy to synthesize high-efficiency catalyst for H_(2)production.展开更多
Objective:The varying environmental exposure to iodine has long been a topic of interest,particularly given the noticeable increase in the incidence of papillary thyroid carcinoma(PTC)compared to other histopathologic...Objective:The varying environmental exposure to iodine has long been a topic of interest,particularly given the noticeable increase in the incidence of papillary thyroid carcinoma(PTC)compared to other histopathological subtypes globally.This rise in thyroid cancer incidence has been attributed to several factors,including improved detection of early tumors,a higher prevalence of modifiable individual risk factors,and differing exposure to environmental risk factors such as iodine levels.This study aims to explore the epigenetic mechanisms that promote thyroid cancer progression under excess iodine exposure.Materials and methods:This study outlines the following strategy:(i)risk factors were identified through statistical analysis of questionnaire responses in a retrospective iatrogenic study;(ii)following the identification of risk factors,RNA sequencing was performed using tissues from iodine-adequate(IA)and iodine-excess(IE)regions;(iii)candidate hub genes were selected via bioinformatics analysis;(iv)molecular biological techniques were employed to verify the functionality of the key gene.Results:Through careful selection,we focused on SPSB4,a ubiquitin ligase previously unreported in relation to both iodine and thyroid cancer.By optimizing the dosage of PTC cell line activities,we determined how varying iodine levels can either enhance or impair the vitality of thyroid cancer cells.As anticipated,migration and invasion assays revealed significant changes when SPSB4 function was disrupted at the critical dose of KIO3.Conclusion:In terms of epigenetic alterations,SPSB4 emerges as a promising candidate for further investigation,particularly in understanding thyroid cancer progression and potential carcinogenesis.Moreover,E3 ubiquitin ligases,including SPSB4,play a role in orchestrating adipose thermogenesis to maintain body temperature during cold stimuli.This study could also shed light on the influence of iodine on thermogenesis mediated by SPSB4 under cold conditions,while suggesting future exploration of SPSB4's effects on thyroid cancer in colder regions.展开更多
Benefiting from the widespread potential applications in the era of the Internet of Thing and metaverse,triboelectric and piezoelectric nanogenerators(TENG&PENG)have attracted considerably increasing attention.The...Benefiting from the widespread potential applications in the era of the Internet of Thing and metaverse,triboelectric and piezoelectric nanogenerators(TENG&PENG)have attracted considerably increasing attention.Their outstanding characteristics,such as self-powered ability,high output performance,integration compatibility,cost-effectiveness,simple configurations,and versatile operation modes,could effectively expand the lifetime of vastly distributed wearable,implantable,and environmental devices,eventually achieving self-sustainable,maintenance-free,and reliable systems.However,current triboelectric/piezoelectric based active(i.e.self-powered)sensors still encounter serious bottlenecks in continuous monitoring and multimodal applications due to their intrinsic limitations of monomodal kinetic response and discontinuous transient output.This work systematically summarizes and evaluates the recent research endeavors to address the above challenges,with detailed discussions on the challenge origins,designing strategies,device performance,and corresponding diverse applications.Finally,conclusions and outlook regarding the research gap in self-powered continuous multimodal monitoring systems are provided,proposing the necessity of future research development in this field.展开更多
Rhododendron micranthum Turcz.is a shrub esteemed for its ornamental and medicinal attributes within the Changbai Mountain range of China.We selected 3-year saplings and subjected them to four distinct light condi-tio...Rhododendron micranthum Turcz.is a shrub esteemed for its ornamental and medicinal attributes within the Changbai Mountain range of China.We selected 3-year saplings and subjected them to four distinct light condi-tions:full light(CK),70%light(L1),50%light(L2),and 30%light(L3)to investigate variations in morphology,photosynthetic responses,stomatal ultrastructure as well as the mechanisms through which these saplings adapt to differing lighting environments.The results indicate that L2 leaves exhibit significantly greater length,width,and petiole development compared to other treatments across varying intensities.Over time,chlorophyll content and PSII levels in L2-treated saplings surpass those observed in other treatments;Proline(PRO),malondialdehyde(MDA),and soluble protein(SP)contents are markedly lower under L2 treatment.Catalase(CAT)and superoxide dismutase(SOD)demonstrate significant correlations across various light con-ditions but respond differently among treatments,indicat-ing distinct species sensitivities to light intensity while both contribute to environmental stress resistance mechanisms.Findings reveal that R.micranthum saplings at 50%light intensity benefit from enhanced protection via antioxidant enzymes,and shading reduces osmotic adjustment sub-stances yet increases chlorophyll content.Stomatal length/width along with conductance rates and net photosynthesis rates for L2 exceed those of CK,suggesting an improved photosynthetic structure conducive to efficient photosynthe-sis under this condition.Thus,moderate shading represents optimal growth at 50%illumination,a critical factor promot-ing sapling development.This research elucidates the ideal environment for R.micranthum adaptation to varying light conditions supporting future conservation initiatives.展开更多
Selenium is an essential trace element for humans and animals.As the active center of selenoproteins,the addition of selenium is beneficial to enhance the antioxidant ability.However,the high cost limits the applicati...Selenium is an essential trace element for humans and animals.As the active center of selenoproteins,the addition of selenium is beneficial to enhance the antioxidant ability.However,the high cost limits the application of organic Se in agriculture animal production.Selenized glucose(SeGlu)is a newly invented organoselenium material with good stability,low toxicity and low cost.This assay found that SeGlu was able to increase selenium deposition in liver of newborn broilers,and enhance the antioxidant capacity of liver by elevating the activities of antioxidant enzymes such as total superoxide dismutase and glutathione peroxidase.This paper as the first example clarifying the mechanism of SeGlu to enhance the antioxidant ability of chicks,shows that SeGlu can be used as an organic selenium enrichment additive for early nutrition of poultry.As a cross-discipline study involving chemistry,biology and agriculture animal science,the work may be beneficial for studies in related fields and prompt the development of the selenium science.展开更多
We studied changes in the concentrations of aggregate-cementing agents after different reclamation times and with different fertilization regimes,as well as the formation mechanism of aggregates in reclaimed soil,to p...We studied changes in the concentrations of aggregate-cementing agents after different reclamation times and with different fertilization regimes,as well as the formation mechanism of aggregates in reclaimed soil,to provide a theoretical basis for rapid reclamation of soil fertility in the subsidence area of coal mines in Shanxi Province,China.In this study,soil samples of 0–20 cm depth were collected from four fertilization treatments of a longterm experiment started in 2008:no fertilizer (CK),inorganic fertilizer (NPK),chicken manure compost (M),and50%inorganic fertilizer plus 50%chicken manure compost (MNPK).The concentrations of cementing agents and changes in soil aggregate size distribution and stability were analysed.The results showed that the formation of>2 mm aggregates,the aggregate mean weight diameter (MWD),and the proportion of>0.25 mm water-stable aggregates (WR_(0.25)) increased significantly after 6 and 11 years of reclamation.The concentration of organic cementing agents tended to increase with reclamation time,whereas free iron oxide (Fed) and free aluminium oxide(Ald) concentrations initially increased but then decreased.In general,the MNPK treatment signi?cantly increased the concentrations of organic cementing agents and CaCO_(3),and CaCO_(3) increased by 60.4%at 11 years after reclamation.Additionally,CaCO_(3) had the greatest effect on the stability of aggregates,promoting the formation of>0.25 mm aggregates and accounting for 54.4%of the variance in the proportion and stability of the aggregates.It was concluded that long-term reclamation is bene?cial for improving soil structure.The MNPK treatment was the most effective measure for increasing maize grain yield and concentration of organic cementing agents and CaCO_(3).展开更多
Aluminum(Al)-ion batteries have emerged as a potential alternative to conventional ion batteries that rely on less abundant and costly materials like lithium.Nonetheless,given the nascent stage of advancement in Al-io...Aluminum(Al)-ion batteries have emerged as a potential alternative to conventional ion batteries that rely on less abundant and costly materials like lithium.Nonetheless,given the nascent stage of advancement in Al-ion batteries(AIBs),attaining electrode materials that can leverage both intercalation capacity and structural stability remains challenging.Herein,we demonstrate a C3N4-derived layered N,S heteroatom-doped carbon,obtained at different pyrolysis temperatures,as a cathode material for AIBs,encompassing the diffusion-controlled intercalation and surface-induced capacity with ultrahigh reversibility.The developed layered N,S-doped corbon(N,S-C)cathode,synthesized at 900℃,delivers a specific capacity of 330 mAhg^(-1)with a relatively high coulombic efficiency of~85%after 500 cycles under a current density of 0.5 A g^(-1).Owing to its reinforced adsorption capability and enlarged interlayer spacing by doping N and S heteroatoms,the N,S-C900 cathode demonstrates outstanding energy storage capacity with excellent rate performance(61 mAhg^(-1)at 20 A g^(-1))and ultrahigh reversibility(90 mAhg^(-1)at 5Ag^(-1)after 10000cycles).展开更多
A phased array feed(PAF)is a type of receiving array that places phased array antennas on the focal plane of a radio telescope to expand its field of view and improve observation efficiency.Owing to the mutual couplin...A phased array feed(PAF)is a type of receiving array that places phased array antennas on the focal plane of a radio telescope to expand its field of view and improve observation efficiency.Owing to the mutual coupling effect between elements caused by a tightly arranged feed array,which changes the performance of a PAF,this paper presents a 7×7 rectangular feed array model for a 25 m reflector telescope.By adjusting the element spacings,the performance of a PAF with different spacings is comprehensively analyzed with respect to the mutual coupling effect via performance statistics and comparison.This research aims to provide a reference for the preliminary design of a related PAF.展开更多
The mechanisms of enhancing spin-orbit torque(SOT) have attracted significant attention, particularly regarding the influence of extrinsic scattering mechanisms on SOT efficiency, as they complement intrinsic contribu...The mechanisms of enhancing spin-orbit torque(SOT) have attracted significant attention, particularly regarding the influence of extrinsic scattering mechanisms on SOT efficiency, as they complement intrinsic contributions. In multilayer systems, extrinsic interfacial scattering, along with scattering from defects or impurities inside the materials, plays a crucial role in affecting the SOT efficiency. In this study, we successfully fabricated high-quality epitaxially grown [Ir/Pt]N superlattices with an increasing number of interfaces using a magnetron sputtering system to investigate the contribution of extrinsic interfacial scattering to SOT efficiency. We measured SOT efficiency through spin-torque ferromagnetic resonance methods and determined the spin Hall angle using the spin pumping technique. Additionally, we calculated spin transparency based on the SOT efficiency and spin Hall angle. Our findings indicate that the values of SOT efficiency, spin Hall angle, and spin transparency are enhanced in the superlattice structure compared to Pt, which we attribute to the increase in interfacial scattering.This research offers an effective strategy for designing and fabricating advanced spintronic devices.展开更多
Exploring optimal operational schemes for synergistic development is crucial for sustainable management in river basins.This study introduces a multi-objective synergistic optimization framework aimed at analyzing the...Exploring optimal operational schemes for synergistic development is crucial for sustainable management in river basins.This study introduces a multi-objective synergistic optimization framework aimed at analyzing the interplay among flood control,ecological integrity,and desilting objectives under varying watersediment conditions.The framework encompasses multi-objective reservoir optimal operation,scheme decision,and trade-off analysis among competing objectives.To address the optimization model,an elite mutation-based multiobjective particle swarm optimization(MOPSO)algorithm that integrates genetic algorithms(GA)is developed.The coupling coordination degree is employed for optimal scheme decision-making,allowing for the adjustment of weight ratios to investigate the trade-offs between objectives.This research focuses on the Sanmenxia and Xiaolangdi cascade reservoirs in the Yellow River,utilizing three representative hydrological years:1967,1969,and 2002.The findings reveal that:(1)the proposed model effectively generates Pareto fronts for multi-objective operations,facilitating the recommendation of optimal schemes based on coupling coordination degrees;(2)as water-sediment conditions shift from flooding to drought,competition intensifies between the flood control and desilting objectives.While flood control and ecological objectives compete during flood and dry years,they demonstrate synergies in normal years(r=0.22);conversely,ecological and desilting objectives are consistently competitive across all three typical years,with the strongest competition observed in the normal year(r=-0.95);(3)the advantages conferred to ecological objectives increase as water-sediment conditions shift from flooding to drought.However,the promotion of the desilting objective requires more complex trade-offs.This study provides a model and methodological approach for the multi-objective optimization of flood control,sediment management,and ecological considerations in reservoir clusters.Moreover,the methodologies presented herein can be extended to other water resource systems for multi-objective optimization and decision-making.展开更多
Selenium nanoparticles(SeNPs)are increasingly recognized for their exceptional antibacterial properties.This study aimed to develop a green,safe,and efficient method for the biosynthesis of SeNPs using the fungus Euro...Selenium nanoparticles(SeNPs)are increasingly recognized for their exceptional antibacterial properties.This study aimed to develop a green,safe,and efficient method for the biosynthesis of SeNPs using the fungus Eurotium cristatum,a novel approach in SeNP synthesis.The process yielded(36.40±4.22)mg of SeNPs per liter of 1.2 mmol/L sodium selenite supplementation.These SeNPs exhibited an average diameter of 231.7 nm and a negative charge,and they remained stable when stored at 4℃.Ultraviolet and visible spectrophotometry revealed a maximum absorption peak at 212 nm,suggesting effective nanoparticle formation.Fourier transform infrared spectrometry indicated that proteins and carbohydrates in the mycelium contributed to the SeNP synthesis.Concentrations of SeNPs below 50μg Se/mL did not exhibit cytotoxic effects on the growth and proliferation of human hepatocyte L-02 cells.The minimum inhibitory concentration of SeNPs was found to be 2 mg/mL against both methicillin-resistant Staphylococcus aureus(Gram-positive)and Escherichia coli(Gram-negative).The SeNPs compromised the cellular integrity of test strains,causing leakage of intracellular contents and disruption of the oxidative stress system,leading to irreversible damage.Our results demonstrate the potential of SeNPs biosynthesized by E.cristatum to act as effective antibacterial agents,signifying a novel and promising approach to developing natural antimicrobial solutions.展开更多
Avian wings are central to their remarkable flight ability and diverse life history strategies,including behaviors such as fighting and mating.These multifaceted functions are intricately tied to wing shape,which vari...Avian wings are central to their remarkable flight ability and diverse life history strategies,including behaviors such as fighting and mating.These multifaceted functions are intricately tied to wing shape,which varies significantly across species because of the complex interplay of evolutionary and ecological pressures.Many indices have been developed to quantify wing characteristics to facilitate the study and comparison of avian wing morphology across species.This study provides a comprehensive overview of existing quantitative methods for analyzing avian wing shapes.We then constructed a new quantification framework through the beta distribution,which can generate indices reflecting the shape of avian wings(center,dispersion,skewness,and kurtosis).Next,we used the flight feathers of 613 bird species to perform different quantitative analyses and explore the relationships between various wing shape quantification methods and life history traits,which serve as proxies for the selective forces shaping wing morphology.We find that the wing shape indices are more strongly associated with ecological variables than with morphological variables,especially for migration,habitat and territoriality.This research guides the selection of appropriate methods for wing shape analysis,contributing to a deeper understanding of avian morphology and its evolutionary drivers.展开更多
The emergent metagrating,with its unique and flexible beam shaping capabilities,offers new paths to efficient modulation of acoustic waves.In this work,an acoustic metagrating is demonstrated for high-efficiency and w...The emergent metagrating,with its unique and flexible beam shaping capabilities,offers new paths to efficient modulation of acoustic waves.In this work,an acoustic metagrating is demonstrated for high-efficiency and wide-angle anomalous refraction.It is shown that the normal reflection and transmission can be totally suppressed by properly modulating the amplitude and phase characteristics of the metagrating supercells for high-efficiency anomalous refraction.The anomalous refraction behavior is achieved in the wide range of incident angles from 28°to 78°,and the efficiency of-1st order diffraction is higher than 90%by finely designing the metagrating structure.The anomalous refraction behaviors are verified experimentally at incidence angle of 28°,45°,and 78°,respectively.The demonstrated metagrating is anticipated to possess efficient wide-angle composite wavefront engineering applications in such fields as communications.展开更多
Dear Editor,The true frogs classified under the genus Rana, with widespread distribution in Eurasia and North America,constitute a varied and intricate group (Yuan et al., 2016;Chen et al., 2022). In total, 52 species...Dear Editor,The true frogs classified under the genus Rana, with widespread distribution in Eurasia and North America,constitute a varied and intricate group (Yuan et al., 2016;Chen et al., 2022). In total, 52 species within this genus have been documented (IUCN, 2024), with 28 of those species found in China (Amphibia China, 2024).展开更多
Changbaishan,an intraplate volcano,is characterized by an approximately 6 km wide summit caldera and last erupted in 1903.Changbaishan experienced a period of unrest between 2002 and 2006.The activity developed in thr...Changbaishan,an intraplate volcano,is characterized by an approximately 6 km wide summit caldera and last erupted in 1903.Changbaishan experienced a period of unrest between 2002 and 2006.The activity developed in three main stages,including shield volcano(basalts),cone-construction(trachyandesites to trachytes with minor basalts),and caldera-forming stages(trachytes to comendites).This last stage is associated with one of the more energetic eruptions of the last millennium on Earth,the 946 CE,VEI 7 Millennium Eruption(ME),which emitted over 100 km^(3) of pyroclastics.Compared to other active calderas,the plumbing system of Changbaishan and its evolution mechanisms remain poorly constrained.Here,we merge new whole-rock,glass,mineral,isotopic,and geobarometry data with geophysical data and present a model of the plumbing system.The results show that the volcano is characterized by at least three main magma reservoirs at different depths:a basaltic reservoir at the Moho/lower crust depth,an intermediate reservoir at 10-15 km depth,and a shallower reservoir at 0.5-3 km depth.The shallower reservoir was involved in the ME eruption,which was triggered by a fresh trachytic melt entering a shallower reservoir where a comenditic magma was stored.The trachytes and comendites originate from fractional crystallization processes and minor assimilation of upper crust material,while the less evolved melts assimilate lower crust material.Syn-eruptive magma mingling occurred during the ME eruption phase.The magma reservoirs of the caldera-forming stage partly reactivate those of the cone-construction stage.The depth of the magma storage zones is controlled by the layering of the crust.The plumbing system of Changbaishan is vertically extensive,with crystal mush reservoirs renewed by the replenishment of new trachytic to trachyandesitic magma from depth.Unlike other volcanoes,evidence of a basaltic recharge is lacking.The interpretation of the signals preceding possible future eruptions should consider the multi-level nature of the Changbaishan plumbing system.A new arrival of magma may destabilize a part of or the entire system,thus triggering eruptions of different sizes and styles.The reference model proposed here for Changbaishan represents a prerequisite to properly understand periods of unrest to potentially anticipate future volcanic eruptions and to identify the mechanisms controlling the evolution of the crust below volcanoes.展开更多
Background:Magnolia bark(Magnolia Officinalis REHD.&WILS.and Magnolia officinalis REHD.&WILS.VAR.biloba REHD.&WILS,Hou Po in Chinese),is widely applied in clinical prescriptions and Chinese patent medicine...Background:Magnolia bark(Magnolia Officinalis REHD.&WILS.and Magnolia officinalis REHD.&WILS.VAR.biloba REHD.&WILS,Hou Po in Chinese),is widely applied in clinical prescriptions and Chinese patent medicines.Origin place is a crucial factor affecting the quality of Hou Po,and chemical composition is an important index for evaluating its quality,which is closely related to its clinical efficacy.This study aims to develop a novel method for rapidly,accurately and comprehensively identifying the origin places of Hou Po and predicting the contents of its important chemical components.Methods:High performance liquid chromatography was used to analyze the contents of magnolol and honokiol and ultra-performance liquid chromatography the contents of magnocurarine and magnoflorine.The cold soak method was used to determine the contents of water-soluble extracts.The E-nose and colorimeter were used to determine the odor and color characteristics,respectively,of the collected Hou Po samples.Results:Using several statistical algorithms,different discriminant models based on the E-nose and colorimeter data were established to distinguish the origin place of Hou-Po and predict the chemical components of honokiol,magnolol,magnocurarine,magnoflorine and water-soluble extracts.The results showed that the Random Forest classifier combined with the ten-fold cross-validation method provided the highest classification accuracy for origin place,accounting for 99.53%among these models.The correlation coefficients between predicted and experimental values of the five chemical components were all higher than 0.96.Conclusion:This study has indicated that the electronic nose and colorimeter are promising methods for evaluating the quality of Chinese herbal medicines both qualitatively and quantitatively.展开更多
Monolayer molybdenum disulfide(MoS2) is a novel two-dimensional material that exhibits potential application in lubrication technology. In this work, molecular dynamics was used to investigate the lubrication behaviou...Monolayer molybdenum disulfide(MoS2) is a novel two-dimensional material that exhibits potential application in lubrication technology. In this work, molecular dynamics was used to investigate the lubrication behaviour of different polar fluid molecules(i.e., water, methanol and decane) confined in monolayer Mo S2 nanoslits. The pore width effect(i.e., 1.2, 1.6 and 2.0 nm) was also evaluated. Results revealed that decane molecules exhibited good lubricating performance compared to the other two kinds of molecules. The friction coefficient followed the order of decane b methanol b water, and decreased evidently as the slit width increased, except for decane. Analysis of the spatial distribution and mobility of different confined fluid molecules showed that a solid-like layer was formed near the slit wall. This phenomenon led to the extra low friction coefficient of confined decane molecules.展开更多
In this paper,the abnormal experimental phenomenon on barrel erosion under extreme working conditions in the ultra-long life experiment(>10000 h)of ion thruster ion optics is studied by the Immersed-Finite-Element ...In this paper,the abnormal experimental phenomenon on barrel erosion under extreme working conditions in the ultra-long life experiment(>10000 h)of ion thruster ion optics is studied by the Immersed-Finite-Element Particle-In-Cell Monte-Carlo-Collision(IFE-PIC-MCC)method and the grid erosion evaluation model.The transport process of beam ions and Charge Exchange(CEX)ions in the grid system,and the characteristics and mechanisms of the aperture barrel erosion under extreme erosion conditions(i.e.the cylindrical erosion and chamfer erosion)were systematically studied.Thanks to the advantage of the IFE method for dealing with complex boundaries in structured mesh,the aperture barrel erosion morphology of the accelerator grid is reconstructed accurately based on the experimental results.The results show that,with the evolution of working conditions,the mechanism of the aperture barrel erosion changes significantly,which relies heavily on the accelerator grid morphology.The change of the accelerator grid aperture barrel morphology has a significant effect on the behavior of CEX ions,and only affects the local electric field distribution,but has no effect on the upstream plasma sheath.As the erosion progresses,the erosion position moves downstream along the grid aperture axis direction,and the erosion range becomes narrower.Regardless of the erosion phase,the erosion rate of the CEX ions located downstream of the decelerator grid is the largest.The erosion rate is related to the mean incident energy and angle,and their variation is closely related to the position and trajectory of CEXions.展开更多
基金supported by the Qingdao Jiuhuanxinyue New Energy Technology Co.,Ltd.the Guangdong Basic and Applied Basic Research Foundation(Grant No.2021B1515120071)+2 种基金the 21C Innovation Laboratory,Contemporary Amperex Technology Ltd.(Grant No.21C-OP-202112)the financial support from the Guangdong Basic and Applied Basic Research Foundation(Grant No.2024A1515011873)the Shenzhen Science and Technology Program(Grant No.JCYJ20220531095212027).
文摘Li metal is widely recognized as the desired anode for next-generation energy storage,Li metal batteries,due to its highest theoretical capacity and lowest potential.Nonetheless,it suffers from unstable electrochemical behaviors like dendrite growth and side reactions in practical application.Herein,we report a highly stable anode with collector,Li_(5)Mg@Cu,realized by the melting-rolling process.The Li_(5)Mg@Cu anode delivers ultrahigh cycle stability for 2000 and 1000 h at the current densities of 1 and 2 mA cm^(-2),respectively in symmetric cells.Meanwhile,the Li_(5)Mg@Cu|LFP cell exhibits a high-capacity retention of 91.8% for 1000 cycles and 78.8% for 2000 cycles at 1 C.Moreover,we investigate the suppression effects of Mg on the dendrite growth by studying the performance of Li_(x)Mg@Cu electrodes with different Mg contents(2.0-16.7 at%).The exchange current density,surface energy,Li^(+)diffusion coefficient,and chemical stability of Li_(x)Mg@Cu concretely reveal this improving suppression effect when Mg content becomes higher.In addition,a Mg-rich phase with“hollow brick”morphology forming in the high Mg content Li_(x)Mg@Cu guides the uniform deposition of Li.This study reveals the suppression effects of Mg on Li dendrites growth and offers a perspective for finding the optimal component of Li-Mg alloys.
基金financially supported by the National Natural Science Foundation of China(32101452)the Research Foundation of Education Bureau of Hunan Province(22B0283)+2 种基金the Hunan Provincial Natural Science Foundation(2022JJ40865)the Talents Research Funding of Central South University of Forestry and Technology(2021YJ007)the Scientific Innovation Fund for Graduate of Central South University of Forestry and Technology(2024CX02005)。
文摘High-performance catalyst is significant for the sustainable hydrogen(H_(2))production by electrocatalytic water splitting.Optimizing porous structure and active groups of substrate can promote the interaction of substrate and active metal particles,enabling excellent catalytic properties and stability.Herein,the optimization strategy of delignification and 2,2,6,6-tetramethylpyperidine-1-oxyl(TEMPO)oxidization was developed to modify the porous structure and active groups of wood substrate,and Ru doped Co/CO_(2)P(Ru-Co/CO_(2)P)nanoparticles were encapsulated into the optimized wood carbon substrate(Ru-Co/CO_(2)P@TDCW)for the efficient pH-universal hydrogen evolution reaction(HER).The nanopore and carboxyl groups were produced by delignification and TEMPO oxidation,which accelerated the dispersion and deposition of Ru-Co/CO_(2)P nanoparticles.The RuCo alloy and RuCoP nanoparticles were produced with the doping of Ru,and more Ru-Co/CO_(2)P nanoparticles were anchored by the delignified and TEMPO oxidized wood carbon(TDCW).As anticipated,the Ru-Co/CO_(2)P@TDCW catalyst exhibited excellent pH-universal HER activity,and only 16.6,93,and 43 mV of overpotentials were required to deliver the current density of 50 mA cm^(-2)in alkaline,neutral,and acidic electrolytes,outperforming the noble Pt/C/TDCW catalyst significantly.In addition,Ru-Co/CO_(2)P@TDCW catalyst presented excellent stability for more than 600 h working at 100 mA cm^(-2)in alkaline solution(1.0 M KOH).Density function theory(DFT)results revealed that energy barriers for the dissociation of H_(2)O and the formation of H_(2)were decreased by the doping of Ru,and the conductivity and efficiency of electron migration were also enhanced.This work demonstrated a strategy to optimize the structure and properties of wood carbon substrate,providing a promising strategy to synthesize high-efficiency catalyst for H_(2)production.
基金supported by National Natural Science Foundation of China(8183000355)。
文摘Objective:The varying environmental exposure to iodine has long been a topic of interest,particularly given the noticeable increase in the incidence of papillary thyroid carcinoma(PTC)compared to other histopathological subtypes globally.This rise in thyroid cancer incidence has been attributed to several factors,including improved detection of early tumors,a higher prevalence of modifiable individual risk factors,and differing exposure to environmental risk factors such as iodine levels.This study aims to explore the epigenetic mechanisms that promote thyroid cancer progression under excess iodine exposure.Materials and methods:This study outlines the following strategy:(i)risk factors were identified through statistical analysis of questionnaire responses in a retrospective iatrogenic study;(ii)following the identification of risk factors,RNA sequencing was performed using tissues from iodine-adequate(IA)and iodine-excess(IE)regions;(iii)candidate hub genes were selected via bioinformatics analysis;(iv)molecular biological techniques were employed to verify the functionality of the key gene.Results:Through careful selection,we focused on SPSB4,a ubiquitin ligase previously unreported in relation to both iodine and thyroid cancer.By optimizing the dosage of PTC cell line activities,we determined how varying iodine levels can either enhance or impair the vitality of thyroid cancer cells.As anticipated,migration and invasion assays revealed significant changes when SPSB4 function was disrupted at the critical dose of KIO3.Conclusion:In terms of epigenetic alterations,SPSB4 emerges as a promising candidate for further investigation,particularly in understanding thyroid cancer progression and potential carcinogenesis.Moreover,E3 ubiquitin ligases,including SPSB4,play a role in orchestrating adipose thermogenesis to maintain body temperature during cold stimuli.This study could also shed light on the influence of iodine on thermogenesis mediated by SPSB4 under cold conditions,while suggesting future exploration of SPSB4's effects on thyroid cancer in colder regions.
基金supported by the National Key R&D Program of China(Grant Nos.2022YFB3603403,2021YFB3600502)the National Natural Science Foundation of China(Grant Nos.62075040,62301150)+3 种基金the Southeast University Interdisciplinary Research Program for Young Scholars(2024FGC1007)the Start-up Research Fund of Southeast University(RF1028623164)the Nanjing Science and Technology Innovation Project for Returned Overseas Talent(4206002302)the Fundamental Research Funds for the Central Universities(2242024K40015).
文摘Benefiting from the widespread potential applications in the era of the Internet of Thing and metaverse,triboelectric and piezoelectric nanogenerators(TENG&PENG)have attracted considerably increasing attention.Their outstanding characteristics,such as self-powered ability,high output performance,integration compatibility,cost-effectiveness,simple configurations,and versatile operation modes,could effectively expand the lifetime of vastly distributed wearable,implantable,and environmental devices,eventually achieving self-sustainable,maintenance-free,and reliable systems.However,current triboelectric/piezoelectric based active(i.e.self-powered)sensors still encounter serious bottlenecks in continuous monitoring and multimodal applications due to their intrinsic limitations of monomodal kinetic response and discontinuous transient output.This work systematically summarizes and evaluates the recent research endeavors to address the above challenges,with detailed discussions on the challenge origins,designing strategies,device performance,and corresponding diverse applications.Finally,conclusions and outlook regarding the research gap in self-powered continuous multimodal monitoring systems are provided,proposing the necessity of future research development in this field.
基金funded by the National Natural Science Foundation of China(No.32171770)Natural Science Foundation Program of Jilin Provincial Department of Education(No.JJKH20230074KJ).
文摘Rhododendron micranthum Turcz.is a shrub esteemed for its ornamental and medicinal attributes within the Changbai Mountain range of China.We selected 3-year saplings and subjected them to four distinct light condi-tions:full light(CK),70%light(L1),50%light(L2),and 30%light(L3)to investigate variations in morphology,photosynthetic responses,stomatal ultrastructure as well as the mechanisms through which these saplings adapt to differing lighting environments.The results indicate that L2 leaves exhibit significantly greater length,width,and petiole development compared to other treatments across varying intensities.Over time,chlorophyll content and PSII levels in L2-treated saplings surpass those observed in other treatments;Proline(PRO),malondialdehyde(MDA),and soluble protein(SP)contents are markedly lower under L2 treatment.Catalase(CAT)and superoxide dismutase(SOD)demonstrate significant correlations across various light con-ditions but respond differently among treatments,indicat-ing distinct species sensitivities to light intensity while both contribute to environmental stress resistance mechanisms.Findings reveal that R.micranthum saplings at 50%light intensity benefit from enhanced protection via antioxidant enzymes,and shading reduces osmotic adjustment sub-stances yet increases chlorophyll content.Stomatal length/width along with conductance rates and net photosynthesis rates for L2 exceed those of CK,suggesting an improved photosynthetic structure conducive to efficient photosynthe-sis under this condition.Thus,moderate shading represents optimal growth at 50%illumination,a critical factor promot-ing sapling development.This research elucidates the ideal environment for R.micranthum adaptation to varying light conditions supporting future conservation initiatives.
基金supported by the Open Project of Jiangsu Key Laboratory of Animal genetic Breeding and Molecular Design(No.AGBMD202202)the Jiangsu Agricultural Science and Technology Innovation Fund(Nos.[CX(21)3131]and[CX(20)3010])+2 种基金the“JBGS”Project of Seed Industry Revitalization in Jiangsu Province(Nos.[JBGS[2021]027 and JBGS[2021]105])the Science and Education Integration Project of Yangzhou University(No.[KJRH202115])Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)。
文摘Selenium is an essential trace element for humans and animals.As the active center of selenoproteins,the addition of selenium is beneficial to enhance the antioxidant ability.However,the high cost limits the application of organic Se in agriculture animal production.Selenized glucose(SeGlu)is a newly invented organoselenium material with good stability,low toxicity and low cost.This assay found that SeGlu was able to increase selenium deposition in liver of newborn broilers,and enhance the antioxidant capacity of liver by elevating the activities of antioxidant enzymes such as total superoxide dismutase and glutathione peroxidase.This paper as the first example clarifying the mechanism of SeGlu to enhance the antioxidant ability of chicks,shows that SeGlu can be used as an organic selenium enrichment additive for early nutrition of poultry.As a cross-discipline study involving chemistry,biology and agriculture animal science,the work may be beneficial for studies in related fields and prompt the development of the selenium science.
基金supported financially by the National Natural Science Foundation of China(41807102,U1710255-3 and 41907215)the Special Fund for Science and Technology Innovation Teams of Shanxi Province,China(202304051001042)the Distinguished and Excellent Young Scholar Cultivation Project of Shanxi Agricultural University,China(2022YQPYGC05)。
文摘We studied changes in the concentrations of aggregate-cementing agents after different reclamation times and with different fertilization regimes,as well as the formation mechanism of aggregates in reclaimed soil,to provide a theoretical basis for rapid reclamation of soil fertility in the subsidence area of coal mines in Shanxi Province,China.In this study,soil samples of 0–20 cm depth were collected from four fertilization treatments of a longterm experiment started in 2008:no fertilizer (CK),inorganic fertilizer (NPK),chicken manure compost (M),and50%inorganic fertilizer plus 50%chicken manure compost (MNPK).The concentrations of cementing agents and changes in soil aggregate size distribution and stability were analysed.The results showed that the formation of>2 mm aggregates,the aggregate mean weight diameter (MWD),and the proportion of>0.25 mm water-stable aggregates (WR_(0.25)) increased significantly after 6 and 11 years of reclamation.The concentration of organic cementing agents tended to increase with reclamation time,whereas free iron oxide (Fed) and free aluminium oxide(Ald) concentrations initially increased but then decreased.In general,the MNPK treatment signi?cantly increased the concentrations of organic cementing agents and CaCO_(3),and CaCO_(3) increased by 60.4%at 11 years after reclamation.Additionally,CaCO_(3) had the greatest effect on the stability of aggregates,promoting the formation of>0.25 mm aggregates and accounting for 54.4%of the variance in the proportion and stability of the aggregates.It was concluded that long-term reclamation is bene?cial for improving soil structure.The MNPK treatment was the most effective measure for increasing maize grain yield and concentration of organic cementing agents and CaCO_(3).
基金the financial support from the National Natural Science Foundation of China(Grand No.52203092)an SSF Synergy Program(EM16-0004)the National Academic Infrastructure for Supercomputing in Sweden(NAISS)funded by the Swedish Research Council through grant agreement no.202206725
文摘Aluminum(Al)-ion batteries have emerged as a potential alternative to conventional ion batteries that rely on less abundant and costly materials like lithium.Nonetheless,given the nascent stage of advancement in Al-ion batteries(AIBs),attaining electrode materials that can leverage both intercalation capacity and structural stability remains challenging.Herein,we demonstrate a C3N4-derived layered N,S heteroatom-doped carbon,obtained at different pyrolysis temperatures,as a cathode material for AIBs,encompassing the diffusion-controlled intercalation and surface-induced capacity with ultrahigh reversibility.The developed layered N,S-doped corbon(N,S-C)cathode,synthesized at 900℃,delivers a specific capacity of 330 mAhg^(-1)with a relatively high coulombic efficiency of~85%after 500 cycles under a current density of 0.5 A g^(-1).Owing to its reinforced adsorption capability and enlarged interlayer spacing by doping N and S heteroatoms,the N,S-C900 cathode demonstrates outstanding energy storage capacity with excellent rate performance(61 mAhg^(-1)at 20 A g^(-1))and ultrahigh reversibility(90 mAhg^(-1)at 5Ag^(-1)after 10000cycles).
基金This work was supported by the Chinese Academy of Sciences"Light of West China"Program(2020-XBQNXZ-018)the National Natural Science Foundation of China(11973078)the Natural Science Foundation of Xinjiang Uygur Autonomous Region(2022D01A358)。
文摘A phased array feed(PAF)is a type of receiving array that places phased array antennas on the focal plane of a radio telescope to expand its field of view and improve observation efficiency.Owing to the mutual coupling effect between elements caused by a tightly arranged feed array,which changes the performance of a PAF,this paper presents a 7×7 rectangular feed array model for a 25 m reflector telescope.By adjusting the element spacings,the performance of a PAF with different spacings is comprehensively analyzed with respect to the mutual coupling effect via performance statistics and comparison.This research aims to provide a reference for the preliminary design of a related PAF.
基金financially supported by the Science Center of the National Science Foundation of China (Grant No. 52088101)the National Natural Science Foundation of China (Grant Nos. 52161160334, 12274437, 12174426, and 52271237)+1 种基金the Chinese Academy of Sciences (CAS) Project for Young Scientists in Basic Research No. YSBR-084the CAS Youth Interdisciplinary Team。
文摘The mechanisms of enhancing spin-orbit torque(SOT) have attracted significant attention, particularly regarding the influence of extrinsic scattering mechanisms on SOT efficiency, as they complement intrinsic contributions. In multilayer systems, extrinsic interfacial scattering, along with scattering from defects or impurities inside the materials, plays a crucial role in affecting the SOT efficiency. In this study, we successfully fabricated high-quality epitaxially grown [Ir/Pt]N superlattices with an increasing number of interfaces using a magnetron sputtering system to investigate the contribution of extrinsic interfacial scattering to SOT efficiency. We measured SOT efficiency through spin-torque ferromagnetic resonance methods and determined the spin Hall angle using the spin pumping technique. Additionally, we calculated spin transparency based on the SOT efficiency and spin Hall angle. Our findings indicate that the values of SOT efficiency, spin Hall angle, and spin transparency are enhanced in the superlattice structure compared to Pt, which we attribute to the increase in interfacial scattering.This research offers an effective strategy for designing and fabricating advanced spintronic devices.
基金National Natural Science Foundation of China,Grant/Award Number:U2243228The Belt and Road Special Foundation of the National Key Laboratory of Water Disaster Prevention,Grant/Award Number:2022nkms04+1 种基金MOE(Ministry of Education in China)Liberal Arts and Social Sciences Foundation,Grant/Award Number:23YJCZH332Natural Science Foundation of Anhui Province,Grant/Award Numbers:2208085US03,2308085US13。
文摘Exploring optimal operational schemes for synergistic development is crucial for sustainable management in river basins.This study introduces a multi-objective synergistic optimization framework aimed at analyzing the interplay among flood control,ecological integrity,and desilting objectives under varying watersediment conditions.The framework encompasses multi-objective reservoir optimal operation,scheme decision,and trade-off analysis among competing objectives.To address the optimization model,an elite mutation-based multiobjective particle swarm optimization(MOPSO)algorithm that integrates genetic algorithms(GA)is developed.The coupling coordination degree is employed for optimal scheme decision-making,allowing for the adjustment of weight ratios to investigate the trade-offs between objectives.This research focuses on the Sanmenxia and Xiaolangdi cascade reservoirs in the Yellow River,utilizing three representative hydrological years:1967,1969,and 2002.The findings reveal that:(1)the proposed model effectively generates Pareto fronts for multi-objective operations,facilitating the recommendation of optimal schemes based on coupling coordination degrees;(2)as water-sediment conditions shift from flooding to drought,competition intensifies between the flood control and desilting objectives.While flood control and ecological objectives compete during flood and dry years,they demonstrate synergies in normal years(r=0.22);conversely,ecological and desilting objectives are consistently competitive across all three typical years,with the strongest competition observed in the normal year(r=-0.95);(3)the advantages conferred to ecological objectives increase as water-sediment conditions shift from flooding to drought.However,the promotion of the desilting objective requires more complex trade-offs.This study provides a model and methodological approach for the multi-objective optimization of flood control,sediment management,and ecological considerations in reservoir clusters.Moreover,the methodologies presented herein can be extended to other water resource systems for multi-objective optimization and decision-making.
基金supported by Key Research and Development Program of Shaanxi(2024NC-GJHX-12)the National Natural Science Foundation of China(32172301).
文摘Selenium nanoparticles(SeNPs)are increasingly recognized for their exceptional antibacterial properties.This study aimed to develop a green,safe,and efficient method for the biosynthesis of SeNPs using the fungus Eurotium cristatum,a novel approach in SeNP synthesis.The process yielded(36.40±4.22)mg of SeNPs per liter of 1.2 mmol/L sodium selenite supplementation.These SeNPs exhibited an average diameter of 231.7 nm and a negative charge,and they remained stable when stored at 4℃.Ultraviolet and visible spectrophotometry revealed a maximum absorption peak at 212 nm,suggesting effective nanoparticle formation.Fourier transform infrared spectrometry indicated that proteins and carbohydrates in the mycelium contributed to the SeNP synthesis.Concentrations of SeNPs below 50μg Se/mL did not exhibit cytotoxic effects on the growth and proliferation of human hepatocyte L-02 cells.The minimum inhibitory concentration of SeNPs was found to be 2 mg/mL against both methicillin-resistant Staphylococcus aureus(Gram-positive)and Escherichia coli(Gram-negative).The SeNPs compromised the cellular integrity of test strains,causing leakage of intracellular contents and disruption of the oxidative stress system,leading to irreversible damage.Our results demonstrate the potential of SeNPs biosynthesized by E.cristatum to act as effective antibacterial agents,signifying a novel and promising approach to developing natural antimicrobial solutions.
基金supported by the National Natural Science Foundation of China(No.32170491)the Scientific Research Team Project of the College of Life Sciences,Beijing Normal University in 2024。
文摘Avian wings are central to their remarkable flight ability and diverse life history strategies,including behaviors such as fighting and mating.These multifaceted functions are intricately tied to wing shape,which varies significantly across species because of the complex interplay of evolutionary and ecological pressures.Many indices have been developed to quantify wing characteristics to facilitate the study and comparison of avian wing morphology across species.This study provides a comprehensive overview of existing quantitative methods for analyzing avian wing shapes.We then constructed a new quantification framework through the beta distribution,which can generate indices reflecting the shape of avian wings(center,dispersion,skewness,and kurtosis).Next,we used the flight feathers of 613 bird species to perform different quantitative analyses and explore the relationships between various wing shape quantification methods and life history traits,which serve as proxies for the selective forces shaping wing morphology.We find that the wing shape indices are more strongly associated with ecological variables than with morphological variables,especially for migration,habitat and territoriality.This research guides the selection of appropriate methods for wing shape analysis,contributing to a deeper understanding of avian morphology and its evolutionary drivers.
基金Project supported by the National Key Research and Development Program of China(Grant Nos.2023YFB3811400 and 2022YFB3806000)the National Natural Science Foundation of China(Grant No.12074314)+1 种基金the Science and Technology New Star Program of Shaanxi Province,China(Grant No.2023KJXX-148)the Fundamental Research Funds for the Central Universities。
文摘The emergent metagrating,with its unique and flexible beam shaping capabilities,offers new paths to efficient modulation of acoustic waves.In this work,an acoustic metagrating is demonstrated for high-efficiency and wide-angle anomalous refraction.It is shown that the normal reflection and transmission can be totally suppressed by properly modulating the amplitude and phase characteristics of the metagrating supercells for high-efficiency anomalous refraction.The anomalous refraction behavior is achieved in the wide range of incident angles from 28°to 78°,and the efficiency of-1st order diffraction is higher than 90%by finely designing the metagrating structure.The anomalous refraction behaviors are verified experimentally at incidence angle of 28°,45°,and 78°,respectively.The demonstrated metagrating is anticipated to possess efficient wide-angle composite wavefront engineering applications in such fields as communications.
基金supported by the National Natural Science Foundation of China (No.31970499 to Liuwang NIE)。
文摘Dear Editor,The true frogs classified under the genus Rana, with widespread distribution in Eurasia and North America,constitute a varied and intricate group (Yuan et al., 2016;Chen et al., 2022). In total, 52 species within this genus have been documented (IUCN, 2024), with 28 of those species found in China (Amphibia China, 2024).
基金funded by the National Natural Science Foundation of China under Grant Nos.41972313 and 41790453by the Engineering Research Center of Geothermal Resources Development Technology and Equipment,Ministry of Education,Jilin University,China.
文摘Changbaishan,an intraplate volcano,is characterized by an approximately 6 km wide summit caldera and last erupted in 1903.Changbaishan experienced a period of unrest between 2002 and 2006.The activity developed in three main stages,including shield volcano(basalts),cone-construction(trachyandesites to trachytes with minor basalts),and caldera-forming stages(trachytes to comendites).This last stage is associated with one of the more energetic eruptions of the last millennium on Earth,the 946 CE,VEI 7 Millennium Eruption(ME),which emitted over 100 km^(3) of pyroclastics.Compared to other active calderas,the plumbing system of Changbaishan and its evolution mechanisms remain poorly constrained.Here,we merge new whole-rock,glass,mineral,isotopic,and geobarometry data with geophysical data and present a model of the plumbing system.The results show that the volcano is characterized by at least three main magma reservoirs at different depths:a basaltic reservoir at the Moho/lower crust depth,an intermediate reservoir at 10-15 km depth,and a shallower reservoir at 0.5-3 km depth.The shallower reservoir was involved in the ME eruption,which was triggered by a fresh trachytic melt entering a shallower reservoir where a comenditic magma was stored.The trachytes and comendites originate from fractional crystallization processes and minor assimilation of upper crust material,while the less evolved melts assimilate lower crust material.Syn-eruptive magma mingling occurred during the ME eruption phase.The magma reservoirs of the caldera-forming stage partly reactivate those of the cone-construction stage.The depth of the magma storage zones is controlled by the layering of the crust.The plumbing system of Changbaishan is vertically extensive,with crystal mush reservoirs renewed by the replenishment of new trachytic to trachyandesitic magma from depth.Unlike other volcanoes,evidence of a basaltic recharge is lacking.The interpretation of the signals preceding possible future eruptions should consider the multi-level nature of the Changbaishan plumbing system.A new arrival of magma may destabilize a part of or the entire system,thus triggering eruptions of different sizes and styles.The reference model proposed here for Changbaishan represents a prerequisite to properly understand periods of unrest to potentially anticipate future volcanic eruptions and to identify the mechanisms controlling the evolution of the crust below volcanoes.
基金supported by the National Natural Science Foundation of China(81573542&81403054)Beijing University of Chinese Medicine(2019-JYB-JS-006).
文摘Background:Magnolia bark(Magnolia Officinalis REHD.&WILS.and Magnolia officinalis REHD.&WILS.VAR.biloba REHD.&WILS,Hou Po in Chinese),is widely applied in clinical prescriptions and Chinese patent medicines.Origin place is a crucial factor affecting the quality of Hou Po,and chemical composition is an important index for evaluating its quality,which is closely related to its clinical efficacy.This study aims to develop a novel method for rapidly,accurately and comprehensively identifying the origin places of Hou Po and predicting the contents of its important chemical components.Methods:High performance liquid chromatography was used to analyze the contents of magnolol and honokiol and ultra-performance liquid chromatography the contents of magnocurarine and magnoflorine.The cold soak method was used to determine the contents of water-soluble extracts.The E-nose and colorimeter were used to determine the odor and color characteristics,respectively,of the collected Hou Po samples.Results:Using several statistical algorithms,different discriminant models based on the E-nose and colorimeter data were established to distinguish the origin place of Hou-Po and predict the chemical components of honokiol,magnolol,magnocurarine,magnoflorine and water-soluble extracts.The results showed that the Random Forest classifier combined with the ten-fold cross-validation method provided the highest classification accuracy for origin place,accounting for 99.53%among these models.The correlation coefficients between predicted and experimental values of the five chemical components were all higher than 0.96.Conclusion:This study has indicated that the electronic nose and colorimeter are promising methods for evaluating the quality of Chinese herbal medicines both qualitatively and quantitatively.
基金Supported by the National NaturalScience Foundation of China(21576130,21490584)Project of Jiangsu Natural Science Foundation of China(BK20171464)+1 种基金Qing Lan ProjectJiangsu Overseas Visiting Scholar Program for University Prominent Young&Middleaged Teachers and Presidents
文摘Monolayer molybdenum disulfide(MoS2) is a novel two-dimensional material that exhibits potential application in lubrication technology. In this work, molecular dynamics was used to investigate the lubrication behaviour of different polar fluid molecules(i.e., water, methanol and decane) confined in monolayer Mo S2 nanoslits. The pore width effect(i.e., 1.2, 1.6 and 2.0 nm) was also evaluated. Results revealed that decane molecules exhibited good lubricating performance compared to the other two kinds of molecules. The friction coefficient followed the order of decane b methanol b water, and decreased evidently as the slit width increased, except for decane. Analysis of the spatial distribution and mobility of different confined fluid molecules showed that a solid-like layer was formed near the slit wall. This phenomenon led to the extra low friction coefficient of confined decane molecules.
基金supported by the National Key R & D Program of China (No. 2020YFC2201100)the National Key R & D Program for Intergovernmental International Scientific and Technological Innovation Cooperation, China (No. 2021YFE0116000)+5 种基金the National Natural Science Foundation of China (Nos. 12175032, 12102082, 12275044, 12211530449)the Fundamental Research Funds for the Central Universities of China (Nos. DUT21GJ206 and DUT22QN232)the S & T Program of Hebei, China (Nos. YCYZ202201, 216Z1901G and 206Z1902G)the S & T Innovation Program of Hebei, China (Nos. SJMYF2022X18 and SJMYF2022X06)the Advanced Space Propulsion Laboratory of BICE and Beijing Engineering Research Center of Efficient and Green Aerospace Propulsion Technology, China (No. Lab ASP-2020-06)the Funded by Science and Technology Project of Hebei Education Department, China (No. ZC2023144)
文摘In this paper,the abnormal experimental phenomenon on barrel erosion under extreme working conditions in the ultra-long life experiment(>10000 h)of ion thruster ion optics is studied by the Immersed-Finite-Element Particle-In-Cell Monte-Carlo-Collision(IFE-PIC-MCC)method and the grid erosion evaluation model.The transport process of beam ions and Charge Exchange(CEX)ions in the grid system,and the characteristics and mechanisms of the aperture barrel erosion under extreme erosion conditions(i.e.the cylindrical erosion and chamfer erosion)were systematically studied.Thanks to the advantage of the IFE method for dealing with complex boundaries in structured mesh,the aperture barrel erosion morphology of the accelerator grid is reconstructed accurately based on the experimental results.The results show that,with the evolution of working conditions,the mechanism of the aperture barrel erosion changes significantly,which relies heavily on the accelerator grid morphology.The change of the accelerator grid aperture barrel morphology has a significant effect on the behavior of CEX ions,and only affects the local electric field distribution,but has no effect on the upstream plasma sheath.As the erosion progresses,the erosion position moves downstream along the grid aperture axis direction,and the erosion range becomes narrower.Regardless of the erosion phase,the erosion rate of the CEX ions located downstream of the decelerator grid is the largest.The erosion rate is related to the mean incident energy and angle,and their variation is closely related to the position and trajectory of CEXions.
