Climate change is expected to alter the popu-lation dynamics of pioneer tree species and their planned use in sustainable forest management,but we have a lim-ited understanding of how their demographic rates change in...Climate change is expected to alter the popu-lation dynamics of pioneer tree species and their planned use in sustainable forest management,but we have a lim-ited understanding of how their demographic rates change in response to climate changes during ecological restora-tion.Based on 12 years of demographic data for a pioneer tree species(Pinus massoniana)censused in three plots that correspond to three stages of ecological restoration in south-eastern China.We built integral projection models(IPMs)to assess vital rates(survival,growth,reproduction)and population growth in each plot,then evaluated demographic changes to simulated changes in seasonal mean temperature and precipitation in the current and previous census period.The plot representing the medium restoration stage had the highest population growth rate(λ=0.983).Mean population survival probability increased with ecological restoration,and reproduction probability was significantly suppressed at the high restoration stage.Survival is always the most important vital rate forλ,and climate affectsλprimarily via survival at each restoration stage.The current spring tem-perature was the most critical climate variable forλin the low and medium restoration stages,and previous summer temperature was most critical in the high restoration stage.Simulated warming leads to a decrease in the stochastic population growth rate(λ_(s))of P.massoniana in every stage.These findings suggest that during ecological restoration,P.massoniana responds to habitat change via modified demo-graphic performance,thus altering its response to climate change.Despite diverse responses to climate change,the persistence of P.massoniana populations is facing a wide-spread threat of warming states at each restoration stages.展开更多
Alpha-voltaic cell is a type of micro nuclear battery that provides several decades of reliable power in the nano watt to microwatt range,supplying for special applications where traditional chemical batteries or sola...Alpha-voltaic cell is a type of micro nuclear battery that provides several decades of reliable power in the nano watt to microwatt range,supplying for special applications where traditional chemical batteries or solar cells are difficult to operate.However,the power conversion efficiency of the alpha-voltaic cells reported are still far behind the theoretical limit,making the development of alpha-voltaic cell challenging.Developing advanced semiconductor transducers with higher efficiency in converting the energy of alpha particles into electric energy is proving to be necessary for realizing high-power conversion efficiency.Herein,we propose an alpha-voltaic cell based on SiC PIN transducer that includes a sensitive region with an area of 1 cm^(2),a width of 51.2μm,and a charge collection efficiency of 95.6%at 0 V bias.We find that optimizing the unintentional doping concentration and crystal quality of the SiC epitaxial layer can significantly increase the absorption and utilization of the energy of alpha particles,resulting in a 2.4-fold enhancement in power conversion efficiency compared with that of the previous study.Electrical properties of the SiC alpha-voltaic cell are measured using an He-ion accelerator as the equivalentα-radioisotopes,with the best power conversion efficiency of 2.10%and maximum output power density of 406.66 nW cm-2 is obtained.Our research makes a big leap in SiC alpha-voltaic cell,bridging the gap between micro nuclear batteries and practical applications in micro-electromechanical systems,micro aerial vehicles,and tiny satellites.展开更多
The performance of cesium lead halide per-ovskite devices is seriously affected by grain boundaries and other charge traps in the poly-crystalline perovskite thin films.LiBr doping could effectively passivate defects ...The performance of cesium lead halide per-ovskite devices is seriously affected by grain boundaries and other charge traps in the poly-crystalline perovskite thin films.LiBr doping could effectively passivate defects in CsPbBr_(3) perovskite thin films,but it is still unclear that whether the passivation can help the carriers to diffuse across the grain boundaries.Here we have studied the carrier recombina-tion and diffusion dynamics in LiBr passivat-ed CsPbBr_(3) perovskite film with poly(9-vinyl-carbazole)(PVK)film underneath by using ultrafast transient absorption spectroscopy and transient absorption microscopy.The photoluminescence imaging and transient absorption morphological imaging show that LiBr passivating has made the grain size larger and reduced grain boundaries in CsPbBr_(3) film.The transient absorption spectroscopy and time-re-solved photoluminescence data indicate that LiBr passivating has slowed down the bimolecu-lar recombination rate and extended the carrier lifetime.The photoexcited hot holes in the perovskite layer would transfer to the PVK layer in the initial 2 ps.And the transient absorp-tion microscopy measurements reveal that the LiBr passivation can help the carriers to diffuse across the grain boundaries to the surrounding grains in the CsPbBr_(3) perovskite films.The carrier diffusion time is around 100 ps when the distance between two grains is~0.9μm.展开更多
The gold nano-plates(Au NPLs)have been extensively studied for their high quality factor as mechanical resonators.But it remains still unclear how the thickness and morphology of Au NPLs affect the hot electron diffus...The gold nano-plates(Au NPLs)have been extensively studied for their high quality factor as mechanical resonators.But it remains still unclear how the thickness and morphology of Au NPLs affect the hot electron diffusion.Here we have employed transient absorption microscopy to gain spatiotemporal imaging of the hot electron diffusion in Au NPLs.Au NPLs of varying thickness over 200 nm were synthesized.It was found that the hot electron diffusion of Au NPL excited at the boundary is obviously faster than that excited at the internal surface.And thinner Au NPLs exhibit a faster hot electron diffusion rate compared to thicker Au NPLs.Because the time constant of hot electron cooling(electron-phonon coupling)is independent of the excited position and thickness of Au NPLs,the effect of electron-phonon coupling on hot electron diffusion should be ruled out.So the hot electron diffusion rate is highly dimensionality-dependent.The quasi-one-dimensional diffusion along the boundary of nanoplate has the fastest rate of 50 cm^(2)/s,and the three-dimensional diffusion has the slowest rate of 22 cm^(2)/s.The fundamental investigation on the hot electrons transport property of Au NPLs offers a new insight for designing metal-based optoelectronic devices.展开更多
Objective:This study aimed to figure out whether the combination of the prostate health index(PHI)and prostate-specific membrane antigen(PSMA)-PET/MR could improve the diagnostic accuracy for prostate cancer(PCa)than ...Objective:This study aimed to figure out whether the combination of the prostate health index(PHI)and prostate-specific membrane antigen(PSMA)-PET/MR could improve the diagnostic accuracy for prostate cancer(PCa)than that of each individual method used alone.Methods:In this prospective,observational study,41 patients who underwent the systematic prostate biopsy between June 2019 and September 2022 were enrolled.Both the PHI test and ^(18)F-PSMA-1007-PET/MR were performed prior to biopsies.The diagnostic accuracy of different models was compared by logistic regression,areas under the curve(AUCs)of the receiver operating characteristic,and net reclassification index(NRI).Results:Among the 41 patients,14(34.1%)were pathologically diagnosed with PCa.The PHI in the PCa group was significantly higher than that in the benign group(44.4 vs.35.0,p=0.048).Similarly,all the patients in the PCa group received positive results of ^(18)F-PSMA-1007-PET/MR,of which the positive rate was significantly higher than that in benign group(100%vs.62.96%,p=0.025).The ^(18)F-PSMA-1007-PET/MR provided additional diagnostic values to the PHI(AUC:0.802 vs.0.692,p=0.025).However,there was no significant difference between the combination model and the ^(18)F-PSMA-1007-PET/MR alone(AUC 0.802 vs.0.685,p=0.071).The optimal PHI cutoff of the combination model is 32,with which the model could significantly reduce unnecessary biopsies(NRI:22.22%,95%confidence interval:6.54%–37.90%,p=0.005).However,among patients with the PHI of≥43.5,there was no significant difference between the combination model and the PHI alone(NRI:11.11%,95%confidence interval:−0.74%–22.97%,p=0.066).Conclusion:The combination of the PHI and ^(18)F-PSMA-1007-PET/MR outperforms the PHI alone for predicting PCa,especially in avoiding unnecessary biopsies.However,for patients with the PHI of≥43.5,the addition of ^(18)F-PSMA-1007-PET/MR to the PHI does not yield additional benefits.展开更多
The bimetallic nanostructures that mix a plasmonic metal with a transition metal in the form of the core-shell nanoparticles are promising to promote catalytic performance.But it is still unclear how the heat(hot elec...The bimetallic nanostructures that mix a plasmonic metal with a transition metal in the form of the core-shell nanoparticles are promising to promote catalytic performance.But it is still unclear how the heat(hot electrons and phonons)transfers on the interface between two metals.We have designed and synthesized Au@Cu bimetallic nanoparticles with Au as core and Cu as shell.By using transient absorption spectroscopy,we find that there are two plasmon induced heat funneling processes from Au core to Cu shell.One is the electron temperature equilibrium(electron heat transfer)with equilibration time of~560 fs.The other is the lattice temperature equilibrium(lattice heat transfer)with equilibration time of~13 ps.This plasmon induced heat funneling may be universal in similar bimetallic nanostructures,so our finding could contribute to further understanding the catalytic mechanism of bimetallic plasmonic photothermal catalysis.展开更多
Theranostic carbon dots(CDs)have attracted widespread attention recently due to their tunable optical properties and diverse bioactivities.Beyond fluorescent imaging application,the photothermal property endows CDs wi...Theranostic carbon dots(CDs)have attracted widespread attention recently due to their tunable optical properties and diverse bioactivities.Beyond fluorescent imaging application,the photothermal property endows CDs with the potential for microbial inactivation.However,realization of the effective conversion between fluorescence and heat in one CD system has rarely been reported.Herein,we provide a simple strategy for targeted microbial theranostics based on 4-carboxyphenylboronic acid-derived CDs(PCBA-CDs)which possess concentration-dependent photoluminescence/photothermal features.At lower concentrations,PCBA-CDs show bright and stable fluorescent signals ranging from blue to green.The fluorescence intensity gradually decreases with increasing concentration,while on the contrary,the photothermal effect of PCBA-CDs ascends progressively due to the rearrangement of electronic transitions in aggregated CDs.PCBA-CDs also demonstrate high affinity to the polysaccharide structures on the surface of microbe which allows rapid microbial fluorescence imaging as well as specific photothermal ablation of pathogens in skin wounds using PCBA-CDs at lower and higher concentrations,respectively.This study supplies a facile nanotheranostic strategy for just-in-time microbial management using bioactive CDs.展开更多
Due to the serious harm of diabetes to human health,development of sensitive assays for glucose level is of high significance for early prevention and treatment of diabetes.Currently,most conventional enzyme-based glu...Due to the serious harm of diabetes to human health,development of sensitive assays for glucose level is of high significance for early prevention and treatment of diabetes.Currently,most conventional enzyme-based glucose sensors suffer from high cost and low stability due to the inherent defects of natural enzymes.Herein,we develop a pure nanozyme-based glucose detection method using Ag@Au core/shell triangular nanoplates(TNPs),which combines glucose oxidase(GOD)-and horseradish peroxidase(HRP)-like activities of the Au shell and inherent plasmonic properties of Ag TNPs.The sensing mechanism is based on the fact that the Au shell possessed GOD-like activity,enabling the oxidation of glucose to produce H2O2,which can further etch the silver core,leading to the decrease of absorbance at 800 nm and the color change from blue to colorless.Compared with the previous nanozymes-based glucose sensors,our method avoids the use of enzymes and organic chromogenic agent.Moreover,the stability of the Ag@Au core/shell TNPs is much better than that of Ag TNPs due to the protection by the coating of the Au shell.This method was successfully applied to the detection of urine samples from patients with diabetes,indicating its practical applicability for real sample analysis.展开更多
An appropriate flow mode of electrolyte has a positive effect on process efficiency, surface roughness, and machining accuracy in the electrochemical machining（ECM） process. In this study, a new dynamic lateral flow...An appropriate flow mode of electrolyte has a positive effect on process efficiency, surface roughness, and machining accuracy in the electrochemical machining（ECM） process. In this study, a new dynamic lateral flow mode, in which the electrolyte flows from the leading edge to the trailing edge, was proposed in trepanning ECM of a diffuser. Then a numerical model of the channel was set up and simulated by using computational fluid dynamics software. The result showed that the distribution of the flow field was comparatively uniform in the inter-electrode gap. Furthermore, a fixture was designed to realize this new flow mode and then corresponding experiments were carried out. The experimental results illustrated that the feeding rate of the cathode reached 2 mm/min, the best taper angle was about 0.4°, and the best surface roughness was up to Ra= 0.115 lm. It reflects that this flow mode is suitable and effective, and can also be applied to machining other complex structures in trepanning ECM.展开更多
Autophagy plays a vital role in maintaining the balance of normal physiological state of living cells.In this paper,a polarity-specific two-phot on fluorescent probe Lyso-NA based on naphthalimide was synthesized for ...Autophagy plays a vital role in maintaining the balance of normal physiological state of living cells.In this paper,a polarity-specific two-phot on fluorescent probe Lyso-NA based on naphthalimide was synthesized for the purpose of monitoring autophagy during biological research.The results of photophysical properties and theoretical calculation con firmed that different polarities of solvents mainly effected fluorescent intensities of probe.Fluoresce nt intensity,quantum yield and fluorescence lifetime of probe kept a good linear relationship with polarity respectively.In addition,due to its low toxicity and selective accumulation in lysosomes,Lyso-NA is suitable for detecting changes in lysosomal polarity of living cells.Compare with the imaging results of plasmid transfection,a better performed realtime long-term fluoresce nt visualization of autophagy in living cells was achieved.Probe Lyso-NA can work as an efficient and cost effective imaging tool for visualizing autophagy in living cells.展开更多
Enhancing ion conductance and controlling transport pathway in organic electrolyte could be used to modulate ionic kinetics to handle signals. In a Pt/Poly(3-hexylthiophene-2,5-diyl)/Polyethylene?Li CF3SO3/Pt hetero-j...Enhancing ion conductance and controlling transport pathway in organic electrolyte could be used to modulate ionic kinetics to handle signals. In a Pt/Poly(3-hexylthiophene-2,5-diyl)/Polyethylene?Li CF3SO3/Pt hetero-junction, the electrolyte layer handled at high temperature showed nano-fiber microstructures accompanied with greatly improved salt solubility. Ions with high mobility were confined in the nano-fibrous channels leading to the semiconducting polymer layer,which is favorable for modulating dynamic doping at the semiconducting polymer/electrolyte interface by pulse frequency.Such a device realized synaptic-like frequency selectivity, i.e., depression at low frequency stimulation but potentiation at high-frequency stimulation.展开更多
Creating refractory high-entropy alloys(RHEAs)effectively without impurities is a momentous challenge.Conventional methods for the preparation of RHEAs have exacting requirements for raw material purity and energy con...Creating refractory high-entropy alloys(RHEAs)effectively without impurities is a momentous challenge.Conventional methods for the preparation of RHEAs have exacting requirements for raw material purity and energy consumption.Molten salt electrolytic oxides are applied to the preparation of HEAs by virtue of their low cost and high efficiency.However,the use of graphite anodes in electrolysis will result in the carbon contamination of the products due to the deposition of CO_(3)^(2−)at the cathode.Increasing the reaction temperature accelerates the deoxidation of the oxide,thus reducing the amount of carbide but not eliminating it.Switching HfH_(2)instead of HfO_(2)and using Nb_(2)O_(5)to shield the precursor can effectively remove carbon contamination.However,this leads to a complicated preparation process and energy waste.Herein,we use the solid oxygen ion-conducting membrane(SOM)containing graphite and Sn(named as SOM@C/Sn)anode to separate the carbon from the molten salt and prevent the circulation of CO_(3)^(2−).The pure single-phase TiZrHfNbTa RHEA can be produced in only one-step with the SOM@C/Sn anode,which completely solves the problem of carbon contamination in the molten salt electrolysis preparation of HEAs.This work provides a feasible solution for the preparation of novel complex alloys such as carbon-free RHEAs in a low-cost short process.展开更多
Although many plasmonic nanosenosrs have been established for the detection of mercury(Ⅱ)(Hg^(2+)),few of them is feasible for analyzing natural samples with very complex matrices because of insufficient method selec...Although many plasmonic nanosenosrs have been established for the detection of mercury(Ⅱ)(Hg^(2+)),few of them is feasible for analyzing natural samples with very complex matrices because of insufficient method selectivity.To address this challenge,we propose an epitaxial and lattice-mismatch approach to the synthesis of a unique Au/Ag_(2)S dimeric nanostructure,which consists of an Au segment with excellent plasmonic characteristics,and a highly stable Ag_(2)S portion with minimum solubility product (K_(sp)(Ag_(2)S)=6.3×10^(-50)).The detection relies on the chemical conversion of Ag_(2)S to HgS when reacting with Hg^(2+),resulting in a red shift in the absorption band of the connecting Au NPs.The concurrent color changes of the solution from gray purple to dark green and finally to navy correlate well with Hg^(2+)concentration,thus enables UV-vis quantitation and a naked-eye readout of the Hg^(2+)concentration.This method exhibits superior selectivity towards Hg^(2+) over other interfering ions tested because Hg^(2+) is the only ion that can react with Ag_(2)S to form HgS with even smaller solubility product (K_(sp)(HgS)=4×10^(-53)).The detection limit of this method is 1.21μmol/L,calculated by the signal-to-noise of 3.The practicability of the method was verified by analyzing the Hg^(2+)in sewage water samples without sample pretreatment with satisfactory recoveries (93.1%-102.8%) and relative standard deviations (1.38%-2.89%).We believe this method holds great potential for on-the-spot detection of Hg^(2+) in environmental water samples with complex matrices.展开更多
Under weak grid conditions,grid impedance is coupled with a control system for voltage source converter based high-voltage direct current(VSC-HVDC)systems,resulting in decreased synchronization stability.Unfortunately...Under weak grid conditions,grid impedance is coupled with a control system for voltage source converter based high-voltage direct current(VSC-HVDC)systems,resulting in decreased synchronization stability.Unfortunately,most studies are based on the assumption that impedance ratio(R/X)is sufficiently small to ignore the effects of grid impedance.In this study,we establish a dynamic coupling model that includes grid impedance and control loops,revealing the influence mechanism of R/X on synchronization stability from a physical perspective.We also quantify the stability range of R/X in the static analysis model and introduce a sensitivity factor to measure its effect on voltage stability.Additionally,we utilize a dynamic analysis model to evaluate power angle convergence,proposing a corresponding stability criterion.We then present a method of synchronous voltage reconstruction aimed at enhancing the grid strength.Theoretical analysis shows that this method can effectively mitigate the effects of coupling between grid impedance and the controller under weak grid conditions,ensuring stable operation even under extremely weak grid conditions.Experiments validate the accuracy and effectiveness of the analysis and method.展开更多
The progress of aqueous zinc‐ion batteries faces several challenges in zinc electrode technologies.Nevertheless,MXenes exhibit versatile functionalities,such as tunable terminal groups,excellent conductivity,and dive...The progress of aqueous zinc‐ion batteries faces several challenges in zinc electrode technologies.Nevertheless,MXenes exhibit versatile functionalities,such as tunable terminal groups,excellent conductivity,and diverse chemical composition,making them highly suitable for integration into aqueous zinc‐ion batteries.This review highlights recent breakthroughs in employing MXenes to enhance the stability of zinc anodes,encompassing strategies such as protective coatings,incorpo-ration of MXenes into zinc frameworks,and electrolyte enhancements.By employing these novel methods,researchers seek to tackle crucial issues concerning the stability and efficiency of zinc electrodes,thus promoting the commercial viability of aqueous zinc‐ion batteries.展开更多
Exploring high‐energy density rechargeable lithium(Li)batteries is urgently needed to meet the demand of the large‐scale electric vehicle market.Conversion‐type metal fluorides(MFx)have been considered as desirable...Exploring high‐energy density rechargeable lithium(Li)batteries is urgently needed to meet the demand of the large‐scale electric vehicle market.Conversion‐type metal fluorides(MFx)have been considered as desirable cathode materials for next‐generation rechargeable batteries because of their high operational voltages,environmental non‐toxicity,low cost,and high thermal stability.In this review,we present the most promising and feasible MFx applied in rechargeable Li batteries in terms of capacity,discharge po-tential,volume change,fabricated methods,crystal structure,and cost/abun-dance.The electrochemical performance is briefly illustrated,and the recent advances in mechanisms focused on MFx cathodes upon cyclic processes are noted and discussed in detail.Finally,prospects for the current challenges and possible research directions,with the aim to provide some inspiration for the development of MFx‐based cathodes are presented.展开更多
Macrocycles are key tools for molecular recognition and self-assembly.However,traditionally prevalent macrocyclic compounds exhibit specific cavities with diameters usually less than 1 nm,limiting their range of appli...Macrocycles are key tools for molecular recognition and self-assembly.However,traditionally prevalent macrocyclic compounds exhibit specific cavities with diameters usually less than 1 nm,limiting their range of applications in supramolecular chemistry.The efficient synthesis of giant macrocycles remains a significant challenge because an increase in the monomer number results in cyclizationentropy loss.In this study,we developed a low-entropy-penalty synthesis strategy for producing giant macrocycles in high yields.In this process,long and rigid monomers possessing two reaction modules were condensed with paraformaldehyde via Friedel–Crafts reaction.A series of giant macrocycles with cavities of sizes ranging from 2.0 to 4.7 nm were successfully synthesized with cyclization yields of up to 72%.Experimental results and theoretical calculations revealed that extending the monomer length rather than increasing the monomer numbers could notably reduce the cyclization-entropy penalty and avoid configuration twists,thereby favoring the formation of giant macrocycles with large cavities.Significantly,the excellent self-assembly capacity of these giant macrocycles promoted their assembly into organogels.The xerogels exhibited enhanced photoluminescence quantum efficiencies of up to 83.1%.Mechanism investigation revealed the excellent assembly capacity originated from the abundantπ–πinteractions sites of the giant macrocycles.The outstanding emission enhancement resulted from the restricted nonradiative decay processes of rotation/vibration and improved radiative decay process of fluorescence.This study provides an effective and general method for achieving giant macrocycles,thereby expanding the supramolecular toolbox for host–vip chemistry and assembly applications.Moreover,the intriguing assembly and photophysical properties demonstrate the feasibility of developing novel and unique properties by expanding the macrocycle size.展开更多
Camellia oil(CO)extracted from mature camellia seeds has gained considerable attention for nutritional and medicinal applications because of its excellent biological activities.The main bioactive components present in...Camellia oil(CO)extracted from mature camellia seeds has gained considerable attention for nutritional and medicinal applications because of its excellent biological activities.The main bioactive components present in CO are fatty acids,vitamin E,squalene,phytosterol,flavonoids,and polyphenols.Numerous studies have demonstrated the potential health benefits of CO,including regulation of lipid and blood pressure levels,inhibiting tumor growth,protecting against Alzheimer’s disease,and having anti-asthmatic,anti-diabetic,anti-inflammatory,antioxidant,and antibacterial properties.However,the molecular mechanisms of the bioactive substances present in CO are still unclear,limited,and no adequate data has been gathered regarding their health effects.Due to the rapid growth of biological applications of CO,it is necessary to provide an updated review of the current research progress in this area.In this review,the advancements in the compositions and structures of CO are discussed in detail.Additionally,recent research related to CO’s therapeutic potential is discussed.In conclusion,a perspective on the prospects and challenges of CO in biomedicine is also provided.A mechanistic understanding of the chemical compositions and multifunctional properties of CO can provide the basis for the further exploitation of CO in medicine and functional foods.展开更多
Comprehensive Summary The configuration of the anomeric glycosidic linkages is crucial for maintaining the biological functions and activities of carbohydrate molecules.However,their stereochemistry control in glycosy...Comprehensive Summary The configuration of the anomeric glycosidic linkages is crucial for maintaining the biological functions and activities of carbohydrate molecules.However,their stereochemistry control in glycosylation represents one of the most challenging tasks in carbohydrate chemistry.展开更多
基金supported by the National Natural Science Foundation of China(grant no.31971638)the Public Welfare Project of Fujian Science and Technology Department(grant no.2024R1002001).
文摘Climate change is expected to alter the popu-lation dynamics of pioneer tree species and their planned use in sustainable forest management,but we have a lim-ited understanding of how their demographic rates change in response to climate changes during ecological restora-tion.Based on 12 years of demographic data for a pioneer tree species(Pinus massoniana)censused in three plots that correspond to three stages of ecological restoration in south-eastern China.We built integral projection models(IPMs)to assess vital rates(survival,growth,reproduction)and population growth in each plot,then evaluated demographic changes to simulated changes in seasonal mean temperature and precipitation in the current and previous census period.The plot representing the medium restoration stage had the highest population growth rate(λ=0.983).Mean population survival probability increased with ecological restoration,and reproduction probability was significantly suppressed at the high restoration stage.Survival is always the most important vital rate forλ,and climate affectsλprimarily via survival at each restoration stage.The current spring tem-perature was the most critical climate variable forλin the low and medium restoration stages,and previous summer temperature was most critical in the high restoration stage.Simulated warming leads to a decrease in the stochastic population growth rate(λ_(s))of P.massoniana in every stage.These findings suggest that during ecological restoration,P.massoniana responds to habitat change via modified demo-graphic performance,thus altering its response to climate change.Despite diverse responses to climate change,the persistence of P.massoniana populations is facing a wide-spread threat of warming states at each restoration stages.
基金financially supported by the National Natural Science Foundation of China(Nos.12050005,11922507,and 12205016)supported by Major State Basic Research Development Program of China(No.2021YFB3201000)。
文摘Alpha-voltaic cell is a type of micro nuclear battery that provides several decades of reliable power in the nano watt to microwatt range,supplying for special applications where traditional chemical batteries or solar cells are difficult to operate.However,the power conversion efficiency of the alpha-voltaic cells reported are still far behind the theoretical limit,making the development of alpha-voltaic cell challenging.Developing advanced semiconductor transducers with higher efficiency in converting the energy of alpha particles into electric energy is proving to be necessary for realizing high-power conversion efficiency.Herein,we propose an alpha-voltaic cell based on SiC PIN transducer that includes a sensitive region with an area of 1 cm^(2),a width of 51.2μm,and a charge collection efficiency of 95.6%at 0 V bias.We find that optimizing the unintentional doping concentration and crystal quality of the SiC epitaxial layer can significantly increase the absorption and utilization of the energy of alpha particles,resulting in a 2.4-fold enhancement in power conversion efficiency compared with that of the previous study.Electrical properties of the SiC alpha-voltaic cell are measured using an He-ion accelerator as the equivalentα-radioisotopes,with the best power conversion efficiency of 2.10%and maximum output power density of 406.66 nW cm-2 is obtained.Our research makes a big leap in SiC alpha-voltaic cell,bridging the gap between micro nuclear batteries and practical applications in micro-electromechanical systems,micro aerial vehicles,and tiny satellites.
基金supported by the National Natural Science Foundation of China(No.22273006)。
文摘The performance of cesium lead halide per-ovskite devices is seriously affected by grain boundaries and other charge traps in the poly-crystalline perovskite thin films.LiBr doping could effectively passivate defects in CsPbBr_(3) perovskite thin films,but it is still unclear that whether the passivation can help the carriers to diffuse across the grain boundaries.Here we have studied the carrier recombina-tion and diffusion dynamics in LiBr passivat-ed CsPbBr_(3) perovskite film with poly(9-vinyl-carbazole)(PVK)film underneath by using ultrafast transient absorption spectroscopy and transient absorption microscopy.The photoluminescence imaging and transient absorption morphological imaging show that LiBr passivating has made the grain size larger and reduced grain boundaries in CsPbBr_(3) film.The transient absorption spectroscopy and time-re-solved photoluminescence data indicate that LiBr passivating has slowed down the bimolecu-lar recombination rate and extended the carrier lifetime.The photoexcited hot holes in the perovskite layer would transfer to the PVK layer in the initial 2 ps.And the transient absorp-tion microscopy measurements reveal that the LiBr passivation can help the carriers to diffuse across the grain boundaries to the surrounding grains in the CsPbBr_(3) perovskite films.The carrier diffusion time is around 100 ps when the distance between two grains is~0.9μm.
基金supported by the National Natural Science Foundation of China(No.22273006).
文摘The gold nano-plates(Au NPLs)have been extensively studied for their high quality factor as mechanical resonators.But it remains still unclear how the thickness and morphology of Au NPLs affect the hot electron diffusion.Here we have employed transient absorption microscopy to gain spatiotemporal imaging of the hot electron diffusion in Au NPLs.Au NPLs of varying thickness over 200 nm were synthesized.It was found that the hot electron diffusion of Au NPL excited at the boundary is obviously faster than that excited at the internal surface.And thinner Au NPLs exhibit a faster hot electron diffusion rate compared to thicker Au NPLs.Because the time constant of hot electron cooling(electron-phonon coupling)is independent of the excited position and thickness of Au NPLs,the effect of electron-phonon coupling on hot electron diffusion should be ruled out.So the hot electron diffusion rate is highly dimensionality-dependent.The quasi-one-dimensional diffusion along the boundary of nanoplate has the fastest rate of 50 cm^(2)/s,and the three-dimensional diffusion has the slowest rate of 22 cm^(2)/s.The fundamental investigation on the hot electrons transport property of Au NPLs offers a new insight for designing metal-based optoelectronic devices.
基金supported by the National Key Research and Development Program of China(2021YFC2009300 and 2021YFC2009305 to Xu D)Science and Technology Commission of Shanghai Municipality(20Y11904700 to Xu D)+3 种基金National Nature Science Foundation of China(82173045 and 81972405 to Xu D,82072844 and 82272878 to Chen L,82003136 and 82272854 to Huang H)Nature Science Foundation of Shanghai(20ZR1433600,to Chen L)the Shanghai Sailing Program(22YF1440500 to Huang D)the Science and Technology Innovation Action Plan of Shanghai(1Y11904500 to Huang H).
文摘Objective:This study aimed to figure out whether the combination of the prostate health index(PHI)and prostate-specific membrane antigen(PSMA)-PET/MR could improve the diagnostic accuracy for prostate cancer(PCa)than that of each individual method used alone.Methods:In this prospective,observational study,41 patients who underwent the systematic prostate biopsy between June 2019 and September 2022 were enrolled.Both the PHI test and ^(18)F-PSMA-1007-PET/MR were performed prior to biopsies.The diagnostic accuracy of different models was compared by logistic regression,areas under the curve(AUCs)of the receiver operating characteristic,and net reclassification index(NRI).Results:Among the 41 patients,14(34.1%)were pathologically diagnosed with PCa.The PHI in the PCa group was significantly higher than that in the benign group(44.4 vs.35.0,p=0.048).Similarly,all the patients in the PCa group received positive results of ^(18)F-PSMA-1007-PET/MR,of which the positive rate was significantly higher than that in benign group(100%vs.62.96%,p=0.025).The ^(18)F-PSMA-1007-PET/MR provided additional diagnostic values to the PHI(AUC:0.802 vs.0.692,p=0.025).However,there was no significant difference between the combination model and the ^(18)F-PSMA-1007-PET/MR alone(AUC 0.802 vs.0.685,p=0.071).The optimal PHI cutoff of the combination model is 32,with which the model could significantly reduce unnecessary biopsies(NRI:22.22%,95%confidence interval:6.54%–37.90%,p=0.005).However,among patients with the PHI of≥43.5,there was no significant difference between the combination model and the PHI alone(NRI:11.11%,95%confidence interval:−0.74%–22.97%,p=0.066).Conclusion:The combination of the PHI and ^(18)F-PSMA-1007-PET/MR outperforms the PHI alone for predicting PCa,especially in avoiding unnecessary biopsies.However,for patients with the PHI of≥43.5,the addition of ^(18)F-PSMA-1007-PET/MR to the PHI does not yield additional benefits.
基金supported by the National Naural Science Foudation of China(No.21873013 and No.22273006).
文摘The bimetallic nanostructures that mix a plasmonic metal with a transition metal in the form of the core-shell nanoparticles are promising to promote catalytic performance.But it is still unclear how the heat(hot electrons and phonons)transfers on the interface between two metals.We have designed and synthesized Au@Cu bimetallic nanoparticles with Au as core and Cu as shell.By using transient absorption spectroscopy,we find that there are two plasmon induced heat funneling processes from Au core to Cu shell.One is the electron temperature equilibrium(electron heat transfer)with equilibration time of~560 fs.The other is the lattice temperature equilibrium(lattice heat transfer)with equilibration time of~13 ps.This plasmon induced heat funneling may be universal in similar bimetallic nanostructures,so our finding could contribute to further understanding the catalytic mechanism of bimetallic plasmonic photothermal catalysis.
基金supported by the National Natural Science Foundation of China(Nos.32071399 and 62175071)the Guangdong Basic and Applied Basic Research Foundation(Nos.2021A1515011988 and 2021A1515110265)+2 种基金the Science and Technology Program of Guangzhou(No.2019050001)the Project on the Education Department of Guangdong(Nos.2021KTSCX238 and 2022ZDZX2077)the Natural Science Research Project of Guangdong Food and Drug Vocational College(Nos.2020ZR01 and 2022ZR02).
文摘Theranostic carbon dots(CDs)have attracted widespread attention recently due to their tunable optical properties and diverse bioactivities.Beyond fluorescent imaging application,the photothermal property endows CDs with the potential for microbial inactivation.However,realization of the effective conversion between fluorescence and heat in one CD system has rarely been reported.Herein,we provide a simple strategy for targeted microbial theranostics based on 4-carboxyphenylboronic acid-derived CDs(PCBA-CDs)which possess concentration-dependent photoluminescence/photothermal features.At lower concentrations,PCBA-CDs show bright and stable fluorescent signals ranging from blue to green.The fluorescence intensity gradually decreases with increasing concentration,while on the contrary,the photothermal effect of PCBA-CDs ascends progressively due to the rearrangement of electronic transitions in aggregated CDs.PCBA-CDs also demonstrate high affinity to the polysaccharide structures on the surface of microbe which allows rapid microbial fluorescence imaging as well as specific photothermal ablation of pathogens in skin wounds using PCBA-CDs at lower and higher concentrations,respectively.This study supplies a facile nanotheranostic strategy for just-in-time microbial management using bioactive CDs.
基金supported by the National Natural Science Foundation of China(No.21876206)the Fundamental Research Funds for the Central Universities(No.18CX02037A)。
文摘Due to the serious harm of diabetes to human health,development of sensitive assays for glucose level is of high significance for early prevention and treatment of diabetes.Currently,most conventional enzyme-based glucose sensors suffer from high cost and low stability due to the inherent defects of natural enzymes.Herein,we develop a pure nanozyme-based glucose detection method using Ag@Au core/shell triangular nanoplates(TNPs),which combines glucose oxidase(GOD)-and horseradish peroxidase(HRP)-like activities of the Au shell and inherent plasmonic properties of Ag TNPs.The sensing mechanism is based on the fact that the Au shell possessed GOD-like activity,enabling the oxidation of glucose to produce H2O2,which can further etch the silver core,leading to the decrease of absorbance at 800 nm and the color change from blue to colorless.Compared with the previous nanozymes-based glucose sensors,our method avoids the use of enzymes and organic chromogenic agent.Moreover,the stability of the Ag@Au core/shell TNPs is much better than that of Ag TNPs due to the protection by the coating of the Au shell.This method was successfully applied to the detection of urine samples from patients with diabetes,indicating its practical applicability for real sample analysis.
基金co-supported by the National Natural Science Foundation of China (51675271)–ChinaKey Project of Jiangsu Provincial Research and Development (BE2015160)–ChinaFundamental Research Funds for the Central Universities (NE 2017003)–China
文摘An appropriate flow mode of electrolyte has a positive effect on process efficiency, surface roughness, and machining accuracy in the electrochemical machining（ECM） process. In this study, a new dynamic lateral flow mode, in which the electrolyte flows from the leading edge to the trailing edge, was proposed in trepanning ECM of a diffuser. Then a numerical model of the channel was set up and simulated by using computational fluid dynamics software. The result showed that the distribution of the flow field was comparatively uniform in the inter-electrode gap. Furthermore, a fixture was designed to realize this new flow mode and then corresponding experiments were carried out. The experimental results illustrated that the feeding rate of the cathode reached 2 mm/min, the best taper angle was about 0.4°, and the best surface roughness was up to Ra= 0.115 lm. It reflects that this flow mode is suitable and effective, and can also be applied to machining other complex structures in trepanning ECM.
基金This work was supported by the National Natural Science Foundation of China(Nos.22077001,21778001 and 21672001)the Natural Science Foundation of Anhui Province(No.2008085J08)+2 种基金the Natural Science Foundation of Education Department of Anhui Province(No.KJ2019A0010)Joint Open Fund of Jiangsu Collaborative Innovation Center for Ecological Building Material and Environmental Protection Equipments,Key Laboratory for Advanced Technology in Environmental Protection of Jiangsu Province(No.JH201803)the Open fund for Discipline Construction in Institute of Physical Science and In formation Technology of Anhui University.
文摘Autophagy plays a vital role in maintaining the balance of normal physiological state of living cells.In this paper,a polarity-specific two-phot on fluorescent probe Lyso-NA based on naphthalimide was synthesized for the purpose of monitoring autophagy during biological research.The results of photophysical properties and theoretical calculation con firmed that different polarities of solvents mainly effected fluorescent intensities of probe.Fluoresce nt intensity,quantum yield and fluorescence lifetime of probe kept a good linear relationship with polarity respectively.In addition,due to its low toxicity and selective accumulation in lysosomes,Lyso-NA is suitable for detecting changes in lysosomal polarity of living cells.Compare with the imaging results of plasmid transfection,a better performed realtime long-term fluoresce nt visualization of autophagy in living cells was achieved.Probe Lyso-NA can work as an efficient and cost effective imaging tool for visualizing autophagy in living cells.
基金supported by National Natural Science foundation of China (Grant Nos. 51371103 and 51231004)National Basic Research Program of China (Grant No. 2010CB832905)+1 种基金National Hi-tech (R&D) Project of China (Grant Nos. 2012AA03A706, 2013AA030801)the Research Project of Chinese Ministry of Education (No. 113007A)
文摘Enhancing ion conductance and controlling transport pathway in organic electrolyte could be used to modulate ionic kinetics to handle signals. In a Pt/Poly(3-hexylthiophene-2,5-diyl)/Polyethylene?Li CF3SO3/Pt hetero-junction, the electrolyte layer handled at high temperature showed nano-fiber microstructures accompanied with greatly improved salt solubility. Ions with high mobility were confined in the nano-fibrous channels leading to the semiconducting polymer layer,which is favorable for modulating dynamic doping at the semiconducting polymer/electrolyte interface by pulse frequency.Such a device realized synaptic-like frequency selectivity, i.e., depression at low frequency stimulation but potentiation at high-frequency stimulation.
基金the National Natural Science Foundation of China(Nos.52031008,12102307,and 11872284).
文摘Creating refractory high-entropy alloys(RHEAs)effectively without impurities is a momentous challenge.Conventional methods for the preparation of RHEAs have exacting requirements for raw material purity and energy consumption.Molten salt electrolytic oxides are applied to the preparation of HEAs by virtue of their low cost and high efficiency.However,the use of graphite anodes in electrolysis will result in the carbon contamination of the products due to the deposition of CO_(3)^(2−)at the cathode.Increasing the reaction temperature accelerates the deoxidation of the oxide,thus reducing the amount of carbide but not eliminating it.Switching HfH_(2)instead of HfO_(2)and using Nb_(2)O_(5)to shield the precursor can effectively remove carbon contamination.However,this leads to a complicated preparation process and energy waste.Herein,we use the solid oxygen ion-conducting membrane(SOM)containing graphite and Sn(named as SOM@C/Sn)anode to separate the carbon from the molten salt and prevent the circulation of CO_(3)^(2−).The pure single-phase TiZrHfNbTa RHEA can be produced in only one-step with the SOM@C/Sn anode,which completely solves the problem of carbon contamination in the molten salt electrolysis preparation of HEAs.This work provides a feasible solution for the preparation of novel complex alloys such as carbon-free RHEAs in a low-cost short process.
基金supported by the National Natural Science Foundation of China(No.21876206)the Key Fundamental Project of Shandong Natural Science Foundation(No.ZR2020ZD13)+1 种基金the Science and Technology Projects of Qingdao(No.21–1–4-sf-7-nsh)the Youth Innovation and Technology project of Universities in Shandong Province(No.2020KJC007)。
文摘Although many plasmonic nanosenosrs have been established for the detection of mercury(Ⅱ)(Hg^(2+)),few of them is feasible for analyzing natural samples with very complex matrices because of insufficient method selectivity.To address this challenge,we propose an epitaxial and lattice-mismatch approach to the synthesis of a unique Au/Ag_(2)S dimeric nanostructure,which consists of an Au segment with excellent plasmonic characteristics,and a highly stable Ag_(2)S portion with minimum solubility product (K_(sp)(Ag_(2)S)=6.3×10^(-50)).The detection relies on the chemical conversion of Ag_(2)S to HgS when reacting with Hg^(2+),resulting in a red shift in the absorption band of the connecting Au NPs.The concurrent color changes of the solution from gray purple to dark green and finally to navy correlate well with Hg^(2+)concentration,thus enables UV-vis quantitation and a naked-eye readout of the Hg^(2+)concentration.This method exhibits superior selectivity towards Hg^(2+) over other interfering ions tested because Hg^(2+) is the only ion that can react with Ag_(2)S to form HgS with even smaller solubility product (K_(sp)(HgS)=4×10^(-53)).The detection limit of this method is 1.21μmol/L,calculated by the signal-to-noise of 3.The practicability of the method was verified by analyzing the Hg^(2+)in sewage water samples without sample pretreatment with satisfactory recoveries (93.1%-102.8%) and relative standard deviations (1.38%-2.89%).We believe this method holds great potential for on-the-spot detection of Hg^(2+) in environmental water samples with complex matrices.
基金supported in part by the National Natural Science Foundation of China(No.52077037)in part by the Science and Technology Projects of Jiangsu Province(No.BE2022016).
文摘Under weak grid conditions,grid impedance is coupled with a control system for voltage source converter based high-voltage direct current(VSC-HVDC)systems,resulting in decreased synchronization stability.Unfortunately,most studies are based on the assumption that impedance ratio(R/X)is sufficiently small to ignore the effects of grid impedance.In this study,we establish a dynamic coupling model that includes grid impedance and control loops,revealing the influence mechanism of R/X on synchronization stability from a physical perspective.We also quantify the stability range of R/X in the static analysis model and introduce a sensitivity factor to measure its effect on voltage stability.Additionally,we utilize a dynamic analysis model to evaluate power angle convergence,proposing a corresponding stability criterion.We then present a method of synchronous voltage reconstruction aimed at enhancing the grid strength.Theoretical analysis shows that this method can effectively mitigate the effects of coupling between grid impedance and the controller under weak grid conditions,ensuring stable operation even under extremely weak grid conditions.Experiments validate the accuracy and effectiveness of the analysis and method.
基金Talent Recruitment Project of Guangdong Province,Grant/Award Number:2019QN01C883Shenzhen Science and Technology Innovation Project,Grant/Award Number:JCYJ20220818102402004+1 种基金Shenzhen Sauvage Nobel Laureate Laboratory for Smart MaterialsHIT‐CityU Joint Laboratory on Zinc‐based Batteries。
文摘The progress of aqueous zinc‐ion batteries faces several challenges in zinc electrode technologies.Nevertheless,MXenes exhibit versatile functionalities,such as tunable terminal groups,excellent conductivity,and diverse chemical composition,making them highly suitable for integration into aqueous zinc‐ion batteries.This review highlights recent breakthroughs in employing MXenes to enhance the stability of zinc anodes,encompassing strategies such as protective coatings,incorpo-ration of MXenes into zinc frameworks,and electrolyte enhancements.By employing these novel methods,researchers seek to tackle crucial issues concerning the stability and efficiency of zinc electrodes,thus promoting the commercial viability of aqueous zinc‐ion batteries.
基金National Key Research and Development Program of China,Grant/Award Number:2022YFB2502000National Natural Science Foundation of China,Grant/Award Numbers:22109137,51972285,52225208,U21A20174Leading nonnative and Entrepreneur Team introduction Program of Zhejiang,Grant/Award Number:2020R01002。
文摘Exploring high‐energy density rechargeable lithium(Li)batteries is urgently needed to meet the demand of the large‐scale electric vehicle market.Conversion‐type metal fluorides(MFx)have been considered as desirable cathode materials for next‐generation rechargeable batteries because of their high operational voltages,environmental non‐toxicity,low cost,and high thermal stability.In this review,we present the most promising and feasible MFx applied in rechargeable Li batteries in terms of capacity,discharge po-tential,volume change,fabricated methods,crystal structure,and cost/abun-dance.The electrochemical performance is briefly illustrated,and the recent advances in mechanisms focused on MFx cathodes upon cyclic processes are noted and discussed in detail.Finally,prospects for the current challenges and possible research directions,with the aim to provide some inspiration for the development of MFx‐based cathodes are presented.
基金National Natural Science Foundation of China,Grant/Award Numbers:21971192,22201211Open Research Fund of School of Chemistry and Chemical Engineering,Henan Normal UniversityNatural Science Foundation of Tianjin Municipality,Grant/Award Numbers:22JCQNJC00190,23JCZDJC00660。
文摘Macrocycles are key tools for molecular recognition and self-assembly.However,traditionally prevalent macrocyclic compounds exhibit specific cavities with diameters usually less than 1 nm,limiting their range of applications in supramolecular chemistry.The efficient synthesis of giant macrocycles remains a significant challenge because an increase in the monomer number results in cyclizationentropy loss.In this study,we developed a low-entropy-penalty synthesis strategy for producing giant macrocycles in high yields.In this process,long and rigid monomers possessing two reaction modules were condensed with paraformaldehyde via Friedel–Crafts reaction.A series of giant macrocycles with cavities of sizes ranging from 2.0 to 4.7 nm were successfully synthesized with cyclization yields of up to 72%.Experimental results and theoretical calculations revealed that extending the monomer length rather than increasing the monomer numbers could notably reduce the cyclization-entropy penalty and avoid configuration twists,thereby favoring the formation of giant macrocycles with large cavities.Significantly,the excellent self-assembly capacity of these giant macrocycles promoted their assembly into organogels.The xerogels exhibited enhanced photoluminescence quantum efficiencies of up to 83.1%.Mechanism investigation revealed the excellent assembly capacity originated from the abundantπ–πinteractions sites of the giant macrocycles.The outstanding emission enhancement resulted from the restricted nonradiative decay processes of rotation/vibration and improved radiative decay process of fluorescence.This study provides an effective and general method for achieving giant macrocycles,thereby expanding the supramolecular toolbox for host–vip chemistry and assembly applications.Moreover,the intriguing assembly and photophysical properties demonstrate the feasibility of developing novel and unique properties by expanding the macrocycle size.
基金funded by the National Natural Science Foundation of China(82003953)Jiangxi Provincial Natural Science Foundation(20212BAB216009,20202BAB216039)+3 种基金Science and Technology Project of Education Department of Jiangxi Province(GJJ201252)Science and Technology Research Project of Jiangxi Administration of Traditional Chinese Medicine(2021A327)2020-2022 Young Talents Support Project of Chinese Society of Chinese Medicine(2020-QNRC2-07)Jiangxi University of Chinese Medicine Science and Technology Innovation Team Development Program(CXTD22007,CXTD22004).
文摘Camellia oil(CO)extracted from mature camellia seeds has gained considerable attention for nutritional and medicinal applications because of its excellent biological activities.The main bioactive components present in CO are fatty acids,vitamin E,squalene,phytosterol,flavonoids,and polyphenols.Numerous studies have demonstrated the potential health benefits of CO,including regulation of lipid and blood pressure levels,inhibiting tumor growth,protecting against Alzheimer’s disease,and having anti-asthmatic,anti-diabetic,anti-inflammatory,antioxidant,and antibacterial properties.However,the molecular mechanisms of the bioactive substances present in CO are still unclear,limited,and no adequate data has been gathered regarding their health effects.Due to the rapid growth of biological applications of CO,it is necessary to provide an updated review of the current research progress in this area.In this review,the advancements in the compositions and structures of CO are discussed in detail.Additionally,recent research related to CO’s therapeutic potential is discussed.In conclusion,a perspective on the prospects and challenges of CO in biomedicine is also provided.A mechanistic understanding of the chemical compositions and multifunctional properties of CO can provide the basis for the further exploitation of CO in medicine and functional foods.
基金supported by the National Natural Science Foundation of China(Nos.21977115 and 21672248).
文摘Comprehensive Summary The configuration of the anomeric glycosidic linkages is crucial for maintaining the biological functions and activities of carbohydrate molecules.However,their stereochemistry control in glycosylation represents one of the most challenging tasks in carbohydrate chemistry.
