Ongoing climate change has a considerable influence on the seasonality,timing,and intensity of rainfall worldwide,and is also predicted to decrease snow cover in cold ecosystems.Larch is a widely distributed tree spec...Ongoing climate change has a considerable influence on the seasonality,timing,and intensity of rainfall worldwide,and is also predicted to decrease snow cover in cold ecosystems.Larch is a widely distributed tree species in boreal Eurasia,calling for a comprehensive understanding of how larch adapts to changes in both rainfall and snowfall by adjusting carbon-water physiology.Here,we conducted a short-term rainfall(−60% ambient rainfall;three-year)and snowfall(−73% ambient snowfall;two-year)exclusions experiment in Larix gmelinii forest in northeastern China,and aimed to explore the responses of hydraulic(leaf pressure-volume traits,leaf and branch hydraulic conductivity and embolism resistance),stomatal(stomatal closure point and stomatal safety margin),and economic(photosynthetic rate,nutrient and non-structural carbohydrates contents)traits to rainfall and snowfall reductions.Despite the weak alternation of leaf and branch hydraulic traits,both rainfall and snowfall reductions significantly led to early stomatal closure and increased stomatal safety margins(the difference between stomatal closure point and xylem embolism threshold,describing drought resistance by merging both hydraulic and stomatal strategies).Reductions in rainfall and snowfall induced water or/and low-temperature stress,resulting in more conservative leaf economic traits,including a reduced photosynthetic rate,lower leaf nitrogen concentration,and higher leaf density.In addition,larch responded to reductions in rainfall and snowfall by up-regulating non-structural carbohydrates in the xylem,which helps repair embolism or lower the freezing point acting as osmolytes.Overall,our findings reveal that larch could adapt to the drought and snowpack reduction by strict stomatal regulation and investing non-structural carbohydrates in embolism repairing,at the cost of carbon assimilation.展开更多
Severe lithium dendrite growth and elevated thermal runaway risks pose significant hurdles for fast-charging lithium metal batteries(LMBs)This study reports a polydopamine-functionalized hydroxyapatite/aramid(PDA@HA)h...Severe lithium dendrite growth and elevated thermal runaway risks pose significant hurdles for fast-charging lithium metal batteries(LMBs)This study reports a polydopamine-functionalized hydroxyapatite/aramid(PDA@HA)hybrid nanofibers separator to synchronously improve th fast-charging LMB's stability and safety.(1)The separator's surface,enriched with lithiophilic carbonyl and hydroxyl groups,accelerates Li~+ion desolvation,while electrophilic imine groups impede anion movement.This dual mechanism optimizes the Li^(+)-ion flux distribution on th anode,mitigating dendrite formation.(2)The polar PDA modification layer fosters the development of a Li_(3)N/LiF-rich solid electrolyt interface,further enhancing Li anode stability.Consequently,Li//Li symmetric cells with PDA@HA separators exhibit extended cycle life in L plating/stripping tests:5000 h at 1 mA cm^(-2)and 700 h at 20 mA cm^(-2),respectively,outperforming PP separators(80 h and 8 h).In LiFePO_(4)(LFP,^(2.1)mg cm^(-2))//Li full cell evaluation,the PDA@HA separator enables stable operation for 11,000 cycles at 18.2C with 87%capacity retention,significantly outperforming existing fast-charging LMB counterparts in literature.At a high LFP loading of 15.5 mg cm^(-2),the cel maintains 137.6 mAh g^(-1)(2.13 mAh cm^(-2))over 250 cycles at 3C,achieving 98%capacity retention.Moreover,the PDA@HA separato increases threshold temperature for thermal runaway and reduces the exothermic rate,intensifying the battery's thermal safety.This research underscores the importance of functional separator design in improving Li metal anode reversibility,fast-charging performance,and therma safety of LMBs.展开更多
Poor Li plating reversibility and high thermal runaway risks are key challenges for fast charging lithiumion batteries with graphite anodes.Herein,a dielectric and fire-resistant separator based on hybrid nanofibers o...Poor Li plating reversibility and high thermal runaway risks are key challenges for fast charging lithiumion batteries with graphite anodes.Herein,a dielectric and fire-resistant separator based on hybrid nanofibers of barium sulfate(BS)and bacterial cellulose(BC)is developed to synchronously enhance the battery's fast charging and thermal-safety performances.The regulation mechanism of the dielectric BS/BC separator in enhancing the Li^(+)ion transport and Li plating reversibility is revealed.(1)The Max-Wagner polarization electric field of the dielectric BS/BC separator can accelerate the desolvation of solvated Li^(+)ions,enhancing their transport kinetics.(2)Moreover,due to the charge balancing effect,the dielectric BS/BC separator homogenizes the electric field/Li^(+)ion flux at the graphite anode-separator interface,facilitating uniform Li plating and suppressing Li dendrite growth.Consequently,the fast-charge graphite anode with the BS/BC separator shows higher Coulombic efficiency(99.0%vs.96.9%)and longer cycling lifespan(100 cycles vs.59 cycles)than that with the polypropylene(PP)separator in the constantlithiation cycling test at 2 mA cm^(-2).The high-loading LiFePO4(15.5 mg cm^(-2))//graphite(7.5 mg cm^(-2))full cell with the BS/BC separator exhibits excellent fast charging performance,retaining 70%of its capacity after 500 cycles at a high rate of 2C,which is significantly better than that of the cell with the PP separator(retaining only 27%of its capacity after 500 cycles).More importantly,the thermally stable BS/BC separator effectively elevates the critical temperature and reduces the heat release rate during thermal runaway,thereby significantly enhancing the battery's safety.展开更多
Titanium dioxide(TiO_(2))has been an important protective ingredient in mineral-based sunscreens since the 1990s.However,traditional TiO_(2)nanoparticle formulations have seen little improvement over the past decades ...Titanium dioxide(TiO_(2))has been an important protective ingredient in mineral-based sunscreens since the 1990s.However,traditional TiO_(2)nanoparticle formulations have seen little improvement over the past decades and continue to face persistent challenges related to light transmission,biosafety,and visual appearance.Here,we report the discovery of two-dimensional(2D)TiO_(2),characterized by a micro-sized lateral dimension(~1.6μm)and atomic-scale thickness,which fundamentally resolves these long-standing issues.The 2D structure enables exceptional light management,achieving 80%visible light transparency—rendering it nearly invisible on the skin—while maintaining UV-blocking performance comparable to unmodified rutile TiO_(2)nanoparticles.Its larger lateral size results in a two-orders-of-magnitude reduction in skin penetration(0.96 w/w%),significantly enhancing biosafety.Moreover,the unique layered architecture inherently suppresses the generation of reactive oxygen species(ROS)under sunlight exposure,reducing the ROS generation rate by 50-fold compared to traditional TiO_(2)nanoparticles.Through precise metal element modulation,we further developed the first customizable sunscreen material capable of tuning UV protection ranges and automatically matching diverse skin tones.The 2D TiO_(2)offers a potentially transformative approach to modern sunscreen formulation,combining superior UV protection,enhanced safety and a natural appearance.展开更多
With the exponential growth of the data traffic in wireless communication systems, terahertz(THz) frequency band is envisioned as a promising candidate to support ultra-broadband for future beyond fifth generation(5G)...With the exponential growth of the data traffic in wireless communication systems, terahertz(THz) frequency band is envisioned as a promising candidate to support ultra-broadband for future beyond fifth generation(5G), bridging the gap between millimeter wave(mmWave) and optical frequency ranges. The purpose of this paper is to provide a comprehensive literature review on the development towards THz communications and presents some key technologies faced in THz wireless communication systems. Firstly, despite the substantial hardware problems that have to be developed in terms of the THz solid state superheterodyne receiver, high speed THz modulators and THz antennas, the practical THz channel model and the efficient THz beamforming are also described to compensate for the severe path attenuation. Moreover, two different kinds of lab-level THz communication systems are introduced minutely, named a solid state THz communication system and a spatial direct modulation THz communication system, respectively. The solid state THz system converts intermediate frequency(IF) modulated signal to THz frequency while the direct modulation THz system allows the high power THz sources to input for approving the relatively long distance communications. Finally, we discuss several potential application scenarios as well as some vital technical challenges that will be encountered in the future THz communications.展开更多
Imaging polarimetry is one of the most widely used analytical technologies for object detection and analysis.To date,most metasurface-based polarimetry techniques are severely limited by narrow operating bandwidths an...Imaging polarimetry is one of the most widely used analytical technologies for object detection and analysis.To date,most metasurface-based polarimetry techniques are severely limited by narrow operating bandwidths and inevitable crosstalk,leading to detrimental effects on imaging quality and measurement accuracy.Here,we propose a crosstalkfree broadband achromatic full Stokes imaging polarimeter consisting of polarization-sensitive dielectric metalenses,implemented by the principle of polarization-dependent phase optimization.Compared with the single-polarization optimization method,the average crosstalk has been reduced over three times under incident light with arbitrary polarization ranging from 9μm to 12μm,which guarantees the measurement of the polarization state more precisely.The experimental results indicate that the designed polarization-sensitive metalenses can effectively eliminate the chromatic aberration with polarization selectivity and negligible crosstalk.The measured average relative errors are 7.08%,8.62%,7.15%,and 7.59%at 9.3,9.6,10.3,and 10.6μm,respectively.Simultaneously,the broadband full polarization imaging capability of the device is also verified.This work is expected to have potential applications in wavefront detection,remote sensing,light-field imaging,and so forth.展开更多
The adsorption of cationic-nonionic mixed surfactant onto bentonite and its effect on bentonite structure were investigated. The objective was to improve the understanding of surfactant behavior on clay mineral for it...The adsorption of cationic-nonionic mixed surfactant onto bentonite and its effect on bentonite structure were investigated. The objective was to improve the understanding of surfactant behavior on clay mineral for its possible use in remediation technologies of soil and groundwater contaminated by toxic organic compounds. The cationic surfactant used was hexadecylpyridinium bromide （HDPB）, and the nonionic surfactant was Triton X-100 （TXl00）. Adsorption of TXl00 was enhanced significantly by the addition of HDPB, but this enhancement decreased with an increase in the fraction of the cationic surfactant. Part of HDPB was replaced by TXl00 which decreased the adsorption of HDPB. However, the total adsorbed amount of the mixed surfactant was still increased substantially, indicating the synergistic effect between the cationic and nonionic surfactants. The surfaetant-modified bentonite was characterized by Brunauer-Emmett-Teller specific surface area measurement, Fourier transform infrared spectroscopy, and thermogravimetric-derivative thermogravimetric/differential thermal analyses. Surfactant intercalation was found to decrease the bentonite specific surface area, pore volume, and surface roughness and irregularities, as calculated by nitrogen adsorption-desorption isotherms. The co-adsorption of the cationic and nonionic surfactants increased the ordering conformation of the adsorbed surfactants on bentonite, but decreased the thermal stability of the organobentonite system.展开更多
Gas identification and concentration measurements are important for both understanding and monitoring a variety of phenomena from industrial processes to environmental change.Here a novel mid-IR plasmonic gas sensor w...Gas identification and concentration measurements are important for both understanding and monitoring a variety of phenomena from industrial processes to environmental change.Here a novel mid-IR plasmonic gas sensor with on-chip direct readout is proposed based on unity integration of narrowband spectral response,localized field enhancement and thermal detection.A systematic investigation consisting of both optical and thermal simulations for gas sensing is presented for the first time in three sensing modes including refractive index sensing,absorption sensing and spectroscopy,respectively.It is found that a detection limit less than 100 ppm for CO2 could be realized by a combination of surface plasmon resonance enhancement and metal-organic framework gas enrichment with an enhancement factor over 8000 in an ultracompact optical interaction length of only several microns.Moreover,on-chip spectroscopy is demonstrated with the compressive sensing algorithm via a narrowband plasmonic sensor array.An array of 80 such sensors with an average resonance linewidth of 10 nm reconstructs the CO2 molecular absorption spectrum with the estimated resolution of approximately 0.01 nm far beyond the state-of-the-art spectrometer.The novel device design and analytical method are expected to provide a promising technique for extensive applications of distributed or portable mid-IR gas sensor.展开更多
Aqueous zinc-iodine(Zn-I_(2))batteries are promising candidates for low-cost grid-scale energy storage systems.However,the long-term stability and energy density of the Zn-I_(2)batteries are largely hindered by the la...Aqueous zinc-iodine(Zn-I_(2))batteries are promising candidates for low-cost grid-scale energy storage systems.However,the long-term stability and energy density of the Zn-I_(2)batteries are largely hindered by the lack of feasible and scalable methods that coherently suppress polyiodide shuttling and Zn dendrites growth,especially at high current densities.Herein,a flexible,thin and lightweight poly(3,4-ethy lenedioxythiophene):polystyrene sulfonate(PEDOT:PSS)nanopaper is designed as an“anion-cation regulation”synergistic interlayer to tackle the above issues.The PEDOT:PSS interlayer exhibits a 3D nanofibrous network with uniformly distributed mesopores,abundant polar groups and intrinsic conductivity,which renders an even Zn^(2+)flux at Zn anode and facilitates homogeneous current distributions at I_(2)cathode.Meanwhile,such interlayer can act as physiochemical shield to enhance the utilization of I_(2)cathode via the coulombic repulsion and chemical adsorption effect against polyiodide shuttling.Thus,long-term dendrite-free Zn plating/stripping is achieved at simultaneous high current density and high areal capacity(550 h at 10 m A cm^(-2)/5 m Ah cm^(-2)).Zn-I_(2)batteries harvest a high capacity(230 m Ah g^(-1)at 0.1 A g^(-1))and an ultralong lifespan(>20000 cycles)even at 10 A g^(-1).This work demonstrates the potential use of the multifunctional interlayers for Zn-I_(2)battery configuration innovation by synergistic regulation of cations and anions at the electrodes/electrolyte interface.展开更多
Herpesviruses antagonize host antiviral responses through a myriad of molecular strategies culminating in the death of the host cells.Pseudorabies virus(PRV)is a significant veterinary pathogen in pigs,causing neurolo...Herpesviruses antagonize host antiviral responses through a myriad of molecular strategies culminating in the death of the host cells.Pseudorabies virus(PRV)is a significant veterinary pathogen in pigs,causing neurological sequalae that ultimately lead to the animal's demise.PRV is known to trigger apoptotic cell death during the late stages of infection.The virion host shutdown protein(VHS)encoded by UL41 plays a crucial role in the PRV infection process.In this study,we demonstrate that UL41 inhibits PRV-induced activation of inflammatory cytokine and negatively regulates the cGAS-STING-mediated antiviral activity by targeting IRF3,thereby inhibiting the translocation and phosphorylation of IRF3.Notably,mutating the conserved amino acid sites(E192,D194,and D195)in the RNase domain of UL41 or knocking down UL41 inhibits the immune evasion of PRV,suggesting that UL41 may play a crucial role in PRV's evasion of the host immune response during infection.These results enhance our understanding of how PRV structural proteins assist the virus in evading the host immune response.展开更多
As the basic protective element, steel plate had attracted world-wide attention because of frequent threats of explosive loads. This paper reports the relationships between microscopic defects of Q345 steel plate unde...As the basic protective element, steel plate had attracted world-wide attention because of frequent threats of explosive loads. This paper reports the relationships between microscopic defects of Q345 steel plate under the explosive load and its macroscopic dynamics simulation. Firstly, the defect characteristics of the steel plate were investigated by stereoscopic microscope(SM) and scanning electron microscope(SEM). At the macroscopic level, the defect was the formation of cave which was concentrated in the range of 0-3.0 cm from the explosion center, while at the microscopic level, the cavity and void formation were the typical damage characteristics. It also explains that the difference in defect morphology at different positions was the combining results of high temperature and high pressure. Secondly, the variation rules of mechanical properties of steel plate under explosive load were studied. The Arbitrary Lagrange-Euler(ALE) algorithm and multi-material fluid-structure coupling method were used to simulate the explosion process of steel plate. The accuracy of the method was verified by comparing the deformation of the simulation results with the experimental results, the pressure and stress at different positions on the surface of the steel plate were obtained. The simulation results indicated that the critical pressure causing the plate defects may be approximately 2.01 GPa. On this basis, it was found that the variation rules of surface pressure and microscopic defect area of the Q345 steel plate were strikingly similar, and the corresponding mathematical relationship between them was established. Compared with Monomolecular growth fitting models(MGFM) and Logistic fitting models(LFM), the relationship can be better expressed by cubic polynomial fitting model(CPFM). This paper illustrated that the explosive defect characteristics of metal plate at the microscopic level can be explored by analyzing its macroscopic dynamic mechanical response.展开更多
Heavy metal pollution is a major issue after tailing pond failure accident.It is important to predict pollution trends for limited data of pollution sources.A simple phase separation heavy metal model was built for ea...Heavy metal pollution is a major issue after tailing pond failure accident.It is important to predict pollution trends for limited data of pollution sources.A simple phase separation heavy metal model was built for early warning simulation of heavy metal pollution accidents.Based on this,a new simulation framework has been developed to predict the pollution trends of the downstream according to the measured data at upstream sections.By setting the upstream monitoring date as the inflow boundary condition,the changing processes of heavy metal manganese(Mn) with different phases in the downstream can be accurately simulated and forecasted.Results showed that the concentration of the suspended phase in the downstream was larger than that in the aqueous phase and sediment phase.With this,the early warning of pollution trends after accidents could be made a few days ahead.It indicates that the impact of sediment on heavy metal should not be ignored in the early warning of tailing pond failure accidents.展开更多
A series of graphene–TiO2photocatalysts was synthesized by doping TiO2 with graphene oxide via hydrothermal treatment. The photocatalytic capability of the catalysts under ultraviolet irradiation was evaluated in ter...A series of graphene–TiO2photocatalysts was synthesized by doping TiO2 with graphene oxide via hydrothermal treatment. The photocatalytic capability of the catalysts under ultraviolet irradiation was evaluated in terms of sodium pentachlorophenol（PCP-Na） decomposition and mineralization. The structural and physicochemical properties of these nanocomposites were characterized by X-ray diffraction, N2adsorption–desorption, transmission electron microscopy, scanning electron microscopy, Ultraviolet–visible diffuse reflectance spectroscopy, X-ray photoelectron spectroscopy, electron paramagnetic resonance spectra, and Fourier-transform infrared spectroscopy. The graphene–TiO2nanocomposites exhibited higher photocatalytic efficiency than commercial P25 for the degradation of PCP-Na, and 63.4% to 82.9% of the total organic carbon was fully mineralized. The improved photocatalytic activity may be attributed to the accelerated interfacial electron-transfer process and the significantly prolonged lifetime of electron-hole pairs imparted by graphene sheets in the nanocomposites. However,excessive graphene and the inhomogeneous aggregation of TiO2 nanoparticles may decrease photodegradation efficiency.展开更多
Soil-derived fungi represent an insufficiently tapped reservoir for discovering new and bioactive natural products(NPs),and despite an ever-increasing number of unknown NPs have been discovered over the past few decad...Soil-derived fungi represent an insufficiently tapped reservoir for discovering new and bioactive natural products(NPs),and despite an ever-increasing number of unknown NPs have been discovered over the past few decades,much of the hidden biosynthetic potential is still in an urgent need to be disclosed.In this research,a chemical inves-tigation was performed on a wetland soil-derived fungus Aspergillus calidoustus TJ403-EL05,leading to the isolation of a total of fourteen drimane sesquiterpenoids(1-14),incorporating three new ones,namely ustusols F-H(1-3).Their structures,comprising absolute configurations,were completely authenticated by widespread spectroscopic data,quantum chemical 13C NMR and ECD calculations,and X-ray crystallography experiments.Compound 14 exhibited moderate anti-inflammatory activity by inhibiting the LPS-induced NO release(IC_(50)=25.6μM).展开更多
Terahertz communication technology can provide abundant frequency resources,strong confidentiality,antijamming capability,communication tracking capability and the ability to achieve highspeed data transmissions and c...Terahertz communication technology can provide abundant frequency resources,strong confidentiality,antijamming capability,communication tracking capability and the ability to achieve highspeed data transmissions and can serve as an important technical method for high-speed communications in the future.Among these terahertz communication technologies,terahertz direct modulation technology is a key means to achieve low system complexity and power consumption.In this paper,a review and outlook of terahertz direct modulation technology are proposed from the aspects of high-electron-mobilitytransistor-based terahertz direct modulation,parallelswitch terahertz direct modulation,diode-based terahertz direct modulation,quantum cascade laser-based terahertz direct modulation and new-material-based terahertz direct modulation.We hope through this paper that more readers can gain knowledge about the development and challenges of terahertz direct modulation technology for high-speed communication systems,thus promoting the development of high-speed terahertz communication technology based on direct modulation.展开更多
Silver(9 wt.%)was loaded on Co_(3)O_(4)-nanofiber using reduction and impregnation methods,respectively.Due to the stronger electronegativity of silver,the ratios of surface Co^(3+)/Co^(2+) on Ag/Co_(3)O_(4) were high...Silver(9 wt.%)was loaded on Co_(3)O_(4)-nanofiber using reduction and impregnation methods,respectively.Due to the stronger electronegativity of silver,the ratios of surface Co^(3+)/Co^(2+) on Ag/Co_(3)O_(4) were higher than on Co_(3)O_(4),which further led to more adsorbed oxygen species as a result of the charge compensation.Moreover,the introducing of silver also obviously improved the reducibility of Co_(3)O_(4).Hence the Ag/Co_(3)O_(4) showed better catalytic performance than Co_(3)O_(4) in benzene oxidation.Compared with the Ag/Co_(3)O_(4) synthesized via impregnation method,the one prepared using reduction method(named as Ag Co-R)exhibited higher contents of surface Co^(3+) and adsorbed oxygen species,stronger reducibility,as well as more active surface lattice oxygen species.Consequently,Ag Co-R showed lowest T_(90) value of 183℃,admirable catalytic stability,largest normalized reaction rate of1.36×10^(-4)mol/(h·m^(2))(150℃),and lowest apparent activation energy(E_(a))of 63.2 kJ/mol.The analyzing of in-situ DRIFTS indicated benzene molecules were successively oxidized to phenol,o-benzoquinone,small molecular intermediates,and finally to CO_(2) and water on the surface of Ag Co-R.At last,potential reaction pathways including five detailed steps were proposed.展开更多
1.Introduction In the era of the new century,driven by the development of the intelligent society,the integration of the field of electronics and information with various technical fields and industries has accelerate...1.Introduction In the era of the new century,driven by the development of the intelligent society,the integration of the field of electronics and information with various technical fields and industries has accelerated and become the major driving force for a new round of technological revolution and industrial transformation.This has advanced the profound adjustment of global technology,industry,and division of labor as well as reshaping the innovation and competitiveness of countries around the world.Electronics information has received the most concentrated research and development investment worldwide and has been actively advancing and playing a leading role in dissemination.Naturally,it has become an important strategic area in which the world’s scientific and technological powers seek economic advances and competitive advantages.展开更多
[ Objective] The study aimed to forecast the first flowering date of Osmanthus fragrans. [ Method] Based on the data about flowering stage of O. fragrans in Guilin City from 1999 -2012, the correlation between meteoro...[ Objective] The study aimed to forecast the first flowering date of Osmanthus fragrans. [ Method] Based on the data about flowering stage of O. fragrans in Guilin City from 1999 -2012, the correlation between meteorological factors and the first flowering date of O. fragrans was analyzed, and a forecast model for the first flowering date of O. fragrans was established. EResult] Among meteorological factors, precipitation, humidity, temperature and sunshine hours could obviously affect the first flowering date of O. fragrans, especially humidity in August, temperature and sunshine hours in September. The forecast model could exactly forecast the first flowering date in the partial early or too late year, and the av- erage error of date was 6 days. The factors influencing the first flowering date of O. fragrans are complex, and there is an artificial error in record data of the flowering stage, so using a single model to forecast the first flowering date have some disadvantages. When forecasting the first flower- ing date, we should consider all influencing factors to get a good forecast result. [ Conclusion] The research could provide a new method to forecast the first flowednq date of O. fraclrans.展开更多
VOCs can exert great harm to both human and environment,and catalytic oxidation is believed to be an effective technique to eliminate these pollutants.In this paper,Ag-Mn bimetal catalysts with 10 wt.%of silver were s...VOCs can exert great harm to both human and environment,and catalytic oxidation is believed to be an effective technique to eliminate these pollutants.In this paper,Ag-Mn bimetal catalysts with 10 wt.%of silver were synthesized using doping,impregnation,and reduction methods respectively,and then they were applied to the catalytic oxidation of benzene.Through series of characterizations it showed that the loading of silver using reduction method significantly resulted in improved physico-chemical properties of manganese oxides,such as larger surface area and pore volume,higher proportion of surface Mn~(3+)and Mn~(4+),stronger reducibility and more active of surface oxygen species,which were all beneficial to its catalytic activity.As a result,the Ag-Mn catalysts synthesized by reduction method showed a lower T_(90)value(equals to the temperature at which 90%of initial benzene was removed)of 203℃.Besides,both the used and fresh Ag-Mn catalysts synthesized by reduction method showed preferable stability in this research.展开更多
基金supported by the National Key R&D Program of China(2022YFE0127900,2021YFD2200401)the National Natural Science Foundation of China(31901278).
文摘Ongoing climate change has a considerable influence on the seasonality,timing,and intensity of rainfall worldwide,and is also predicted to decrease snow cover in cold ecosystems.Larch is a widely distributed tree species in boreal Eurasia,calling for a comprehensive understanding of how larch adapts to changes in both rainfall and snowfall by adjusting carbon-water physiology.Here,we conducted a short-term rainfall(−60% ambient rainfall;three-year)and snowfall(−73% ambient snowfall;two-year)exclusions experiment in Larix gmelinii forest in northeastern China,and aimed to explore the responses of hydraulic(leaf pressure-volume traits,leaf and branch hydraulic conductivity and embolism resistance),stomatal(stomatal closure point and stomatal safety margin),and economic(photosynthetic rate,nutrient and non-structural carbohydrates contents)traits to rainfall and snowfall reductions.Despite the weak alternation of leaf and branch hydraulic traits,both rainfall and snowfall reductions significantly led to early stomatal closure and increased stomatal safety margins(the difference between stomatal closure point and xylem embolism threshold,describing drought resistance by merging both hydraulic and stomatal strategies).Reductions in rainfall and snowfall induced water or/and low-temperature stress,resulting in more conservative leaf economic traits,including a reduced photosynthetic rate,lower leaf nitrogen concentration,and higher leaf density.In addition,larch responded to reductions in rainfall and snowfall by up-regulating non-structural carbohydrates in the xylem,which helps repair embolism or lower the freezing point acting as osmolytes.Overall,our findings reveal that larch could adapt to the drought and snowpack reduction by strict stomatal regulation and investing non-structural carbohydrates in embolism repairing,at the cost of carbon assimilation.
基金supported by the National Natural Science Foundation of China(Grant No.52202328,52372099,52271222)the Shanghai Sailing Program(22YF1455500)。
文摘Severe lithium dendrite growth and elevated thermal runaway risks pose significant hurdles for fast-charging lithium metal batteries(LMBs)This study reports a polydopamine-functionalized hydroxyapatite/aramid(PDA@HA)hybrid nanofibers separator to synchronously improve th fast-charging LMB's stability and safety.(1)The separator's surface,enriched with lithiophilic carbonyl and hydroxyl groups,accelerates Li~+ion desolvation,while electrophilic imine groups impede anion movement.This dual mechanism optimizes the Li^(+)-ion flux distribution on th anode,mitigating dendrite formation.(2)The polar PDA modification layer fosters the development of a Li_(3)N/LiF-rich solid electrolyt interface,further enhancing Li anode stability.Consequently,Li//Li symmetric cells with PDA@HA separators exhibit extended cycle life in L plating/stripping tests:5000 h at 1 mA cm^(-2)and 700 h at 20 mA cm^(-2),respectively,outperforming PP separators(80 h and 8 h).In LiFePO_(4)(LFP,^(2.1)mg cm^(-2))//Li full cell evaluation,the PDA@HA separator enables stable operation for 11,000 cycles at 18.2C with 87%capacity retention,significantly outperforming existing fast-charging LMB counterparts in literature.At a high LFP loading of 15.5 mg cm^(-2),the cel maintains 137.6 mAh g^(-1)(2.13 mAh cm^(-2))over 250 cycles at 3C,achieving 98%capacity retention.Moreover,the PDA@HA separato increases threshold temperature for thermal runaway and reduces the exothermic rate,intensifying the battery's thermal safety.This research underscores the importance of functional separator design in improving Li metal anode reversibility,fast-charging performance,and therma safety of LMBs.
基金financially supported by the National Natural Science Foundation of China(Grant No.52202328,52372099)the Shanghai Sailing Program(22YF1455500).
文摘Poor Li plating reversibility and high thermal runaway risks are key challenges for fast charging lithiumion batteries with graphite anodes.Herein,a dielectric and fire-resistant separator based on hybrid nanofibers of barium sulfate(BS)and bacterial cellulose(BC)is developed to synchronously enhance the battery's fast charging and thermal-safety performances.The regulation mechanism of the dielectric BS/BC separator in enhancing the Li^(+)ion transport and Li plating reversibility is revealed.(1)The Max-Wagner polarization electric field of the dielectric BS/BC separator can accelerate the desolvation of solvated Li^(+)ions,enhancing their transport kinetics.(2)Moreover,due to the charge balancing effect,the dielectric BS/BC separator homogenizes the electric field/Li^(+)ion flux at the graphite anode-separator interface,facilitating uniform Li plating and suppressing Li dendrite growth.Consequently,the fast-charge graphite anode with the BS/BC separator shows higher Coulombic efficiency(99.0%vs.96.9%)and longer cycling lifespan(100 cycles vs.59 cycles)than that with the polypropylene(PP)separator in the constantlithiation cycling test at 2 mA cm^(-2).The high-loading LiFePO4(15.5 mg cm^(-2))//graphite(7.5 mg cm^(-2))full cell with the BS/BC separator exhibits excellent fast charging performance,retaining 70%of its capacity after 500 cycles at a high rate of 2C,which is significantly better than that of the cell with the PP separator(retaining only 27%of its capacity after 500 cycles).More importantly,the thermally stable BS/BC separator effectively elevates the critical temperature and reduces the heat release rate during thermal runaway,thereby significantly enhancing the battery's safety.
基金supported by the National Key Research and Development Project(No.2019YFA0705403)the National Natural Science Foundation of China(No.T2293693,52273311)+2 种基金the Guangdong Basic and Applied Basic Research Foundation(No.2020B0301030002)and the Shenzhen Basic Research Project(Nos.WDZC20200824091903001,JSGG20220831105402004,JCYJ20220818100806014)Shenzhen Major Science and Technology Projects(Nos.KCXFZ20240903094013018,KCXFZ20240903094203005)。
文摘Titanium dioxide(TiO_(2))has been an important protective ingredient in mineral-based sunscreens since the 1990s.However,traditional TiO_(2)nanoparticle formulations have seen little improvement over the past decades and continue to face persistent challenges related to light transmission,biosafety,and visual appearance.Here,we report the discovery of two-dimensional(2D)TiO_(2),characterized by a micro-sized lateral dimension(~1.6μm)and atomic-scale thickness,which fundamentally resolves these long-standing issues.The 2D structure enables exceptional light management,achieving 80%visible light transparency—rendering it nearly invisible on the skin—while maintaining UV-blocking performance comparable to unmodified rutile TiO_(2)nanoparticles.Its larger lateral size results in a two-orders-of-magnitude reduction in skin penetration(0.96 w/w%),significantly enhancing biosafety.Moreover,the unique layered architecture inherently suppresses the generation of reactive oxygen species(ROS)under sunlight exposure,reducing the ROS generation rate by 50-fold compared to traditional TiO_(2)nanoparticles.Through precise metal element modulation,we further developed the first customizable sunscreen material capable of tuning UV protection ranges and automatically matching diverse skin tones.The 2D TiO_(2)offers a potentially transformative approach to modern sunscreen formulation,combining superior UV protection,enhanced safety and a natural appearance.
基金supported by the National High Technology Research and Development Program of China (863 program) of China under Grant No.2011AA010200 supported by the National Natural Science Foundation of China (NSFC) under Grant No.61771116 and No.91738102
文摘With the exponential growth of the data traffic in wireless communication systems, terahertz(THz) frequency band is envisioned as a promising candidate to support ultra-broadband for future beyond fifth generation(5G), bridging the gap between millimeter wave(mmWave) and optical frequency ranges. The purpose of this paper is to provide a comprehensive literature review on the development towards THz communications and presents some key technologies faced in THz wireless communication systems. Firstly, despite the substantial hardware problems that have to be developed in terms of the THz solid state superheterodyne receiver, high speed THz modulators and THz antennas, the practical THz channel model and the efficient THz beamforming are also described to compensate for the severe path attenuation. Moreover, two different kinds of lab-level THz communication systems are introduced minutely, named a solid state THz communication system and a spatial direct modulation THz communication system, respectively. The solid state THz system converts intermediate frequency(IF) modulated signal to THz frequency while the direct modulation THz system allows the high power THz sources to input for approving the relatively long distance communications. Finally, we discuss several potential application scenarios as well as some vital technical challenges that will be encountered in the future THz communications.
基金Sichuan Science and Technology Program(2020YFJ0001)the National Natural Science Foundation of China(61975210,62222513)+1 种基金National Key Research and Development Program(SQ2021YFA1400121)China Postdoctoral Science Foundation(2021T140670)
文摘Imaging polarimetry is one of the most widely used analytical technologies for object detection and analysis.To date,most metasurface-based polarimetry techniques are severely limited by narrow operating bandwidths and inevitable crosstalk,leading to detrimental effects on imaging quality and measurement accuracy.Here,we propose a crosstalkfree broadband achromatic full Stokes imaging polarimeter consisting of polarization-sensitive dielectric metalenses,implemented by the principle of polarization-dependent phase optimization.Compared with the single-polarization optimization method,the average crosstalk has been reduced over three times under incident light with arbitrary polarization ranging from 9μm to 12μm,which guarantees the measurement of the polarization state more precisely.The experimental results indicate that the designed polarization-sensitive metalenses can effectively eliminate the chromatic aberration with polarization selectivity and negligible crosstalk.The measured average relative errors are 7.08%,8.62%,7.15%,and 7.59%at 9.3,9.6,10.3,and 10.6μm,respectively.Simultaneously,the broadband full polarization imaging capability of the device is also verified.This work is expected to have potential applications in wavefront detection,remote sensing,light-field imaging,and so forth.
基金supported by the National Natural Science Foundation of China (No. 40972151)the National HiTech Research and Development Program (863) of China(No. 2009AA064001)
文摘The adsorption of cationic-nonionic mixed surfactant onto bentonite and its effect on bentonite structure were investigated. The objective was to improve the understanding of surfactant behavior on clay mineral for its possible use in remediation technologies of soil and groundwater contaminated by toxic organic compounds. The cationic surfactant used was hexadecylpyridinium bromide （HDPB）, and the nonionic surfactant was Triton X-100 （TXl00）. Adsorption of TXl00 was enhanced significantly by the addition of HDPB, but this enhancement decreased with an increase in the fraction of the cationic surfactant. Part of HDPB was replaced by TXl00 which decreased the adsorption of HDPB. However, the total adsorbed amount of the mixed surfactant was still increased substantially, indicating the synergistic effect between the cationic and nonionic surfactants. The surfaetant-modified bentonite was characterized by Brunauer-Emmett-Teller specific surface area measurement, Fourier transform infrared spectroscopy, and thermogravimetric-derivative thermogravimetric/differential thermal analyses. Surfactant intercalation was found to decrease the bentonite specific surface area, pore volume, and surface roughness and irregularities, as calculated by nitrogen adsorption-desorption isotherms. The co-adsorption of the cationic and nonionic surfactants increased the ordering conformation of the adsorbed surfactants on bentonite, but decreased the thermal stability of the organobentonite system.
基金We are grateful for financial supports from National Key Research and Development Program of China(No.2019YFB2203402)National Natural Science Foundation of China(Nos.11774383,11774099,11874029)+3 种基金Guangdong Science and Technology Program International Cooperation Program(2018A050506039)Guangdong Natural Science Founds for Distinguished Young Scholars(No.2020B151502074),Pearl River Talent Plan Program of Guangdong(No.2019QN01X120)Fundamental Research Funds for the Central Universities,Royal Society Newton Advanced Fellowship(No.NA140301)Key Frontier Scientific Research Program of the Chinese Academy of Sciences(No.QYZDBSSW-JSC014).
文摘Gas identification and concentration measurements are important for both understanding and monitoring a variety of phenomena from industrial processes to environmental change.Here a novel mid-IR plasmonic gas sensor with on-chip direct readout is proposed based on unity integration of narrowband spectral response,localized field enhancement and thermal detection.A systematic investigation consisting of both optical and thermal simulations for gas sensing is presented for the first time in three sensing modes including refractive index sensing,absorption sensing and spectroscopy,respectively.It is found that a detection limit less than 100 ppm for CO2 could be realized by a combination of surface plasmon resonance enhancement and metal-organic framework gas enrichment with an enhancement factor over 8000 in an ultracompact optical interaction length of only several microns.Moreover,on-chip spectroscopy is demonstrated with the compressive sensing algorithm via a narrowband plasmonic sensor array.An array of 80 such sensors with an average resonance linewidth of 10 nm reconstructs the CO2 molecular absorption spectrum with the estimated resolution of approximately 0.01 nm far beyond the state-of-the-art spectrometer.The novel device design and analytical method are expected to provide a promising technique for extensive applications of distributed or portable mid-IR gas sensor.
基金supported by the Outstanding Youth Scientist Foundation of Hunan Province(Grant No.2021JJ10017)the National Natural Science Foundation of China(Grant No.52173229)。
文摘Aqueous zinc-iodine(Zn-I_(2))batteries are promising candidates for low-cost grid-scale energy storage systems.However,the long-term stability and energy density of the Zn-I_(2)batteries are largely hindered by the lack of feasible and scalable methods that coherently suppress polyiodide shuttling and Zn dendrites growth,especially at high current densities.Herein,a flexible,thin and lightweight poly(3,4-ethy lenedioxythiophene):polystyrene sulfonate(PEDOT:PSS)nanopaper is designed as an“anion-cation regulation”synergistic interlayer to tackle the above issues.The PEDOT:PSS interlayer exhibits a 3D nanofibrous network with uniformly distributed mesopores,abundant polar groups and intrinsic conductivity,which renders an even Zn^(2+)flux at Zn anode and facilitates homogeneous current distributions at I_(2)cathode.Meanwhile,such interlayer can act as physiochemical shield to enhance the utilization of I_(2)cathode via the coulombic repulsion and chemical adsorption effect against polyiodide shuttling.Thus,long-term dendrite-free Zn plating/stripping is achieved at simultaneous high current density and high areal capacity(550 h at 10 m A cm^(-2)/5 m Ah cm^(-2)).Zn-I_(2)batteries harvest a high capacity(230 m Ah g^(-1)at 0.1 A g^(-1))and an ultralong lifespan(>20000 cycles)even at 10 A g^(-1).This work demonstrates the potential use of the multifunctional interlayers for Zn-I_(2)battery configuration innovation by synergistic regulation of cations and anions at the electrodes/electrolyte interface.
基金supported by the Fundamental Research Funds for the Central Universities(31920230001)Gansu Youth Science and Technology Fund Project(22JR5RA193 and 21JR1RA212).
文摘Herpesviruses antagonize host antiviral responses through a myriad of molecular strategies culminating in the death of the host cells.Pseudorabies virus(PRV)is a significant veterinary pathogen in pigs,causing neurological sequalae that ultimately lead to the animal's demise.PRV is known to trigger apoptotic cell death during the late stages of infection.The virion host shutdown protein(VHS)encoded by UL41 plays a crucial role in the PRV infection process.In this study,we demonstrate that UL41 inhibits PRV-induced activation of inflammatory cytokine and negatively regulates the cGAS-STING-mediated antiviral activity by targeting IRF3,thereby inhibiting the translocation and phosphorylation of IRF3.Notably,mutating the conserved amino acid sites(E192,D194,and D195)in the RNase domain of UL41 or knocking down UL41 inhibits the immune evasion of PRV,suggesting that UL41 may play a crucial role in PRV's evasion of the host immune response during infection.These results enhance our understanding of how PRV structural proteins assist the virus in evading the host immune response.
基金Science and Technology Project of Fire Rescue Bureau of Ministry of Emergency Management(Grant No.2022XFZD05)S&T Program of Hebei(Grant No.22375419D)National Natural Science Foundation of China(Grant No.11802160).
文摘As the basic protective element, steel plate had attracted world-wide attention because of frequent threats of explosive loads. This paper reports the relationships between microscopic defects of Q345 steel plate under the explosive load and its macroscopic dynamics simulation. Firstly, the defect characteristics of the steel plate were investigated by stereoscopic microscope(SM) and scanning electron microscope(SEM). At the macroscopic level, the defect was the formation of cave which was concentrated in the range of 0-3.0 cm from the explosion center, while at the microscopic level, the cavity and void formation were the typical damage characteristics. It also explains that the difference in defect morphology at different positions was the combining results of high temperature and high pressure. Secondly, the variation rules of mechanical properties of steel plate under explosive load were studied. The Arbitrary Lagrange-Euler(ALE) algorithm and multi-material fluid-structure coupling method were used to simulate the explosion process of steel plate. The accuracy of the method was verified by comparing the deformation of the simulation results with the experimental results, the pressure and stress at different positions on the surface of the steel plate were obtained. The simulation results indicated that the critical pressure causing the plate defects may be approximately 2.01 GPa. On this basis, it was found that the variation rules of surface pressure and microscopic defect area of the Q345 steel plate were strikingly similar, and the corresponding mathematical relationship between them was established. Compared with Monomolecular growth fitting models(MGFM) and Logistic fitting models(LFM), the relationship can be better expressed by cubic polynomial fitting model(CPFM). This paper illustrated that the explosive defect characteristics of metal plate at the microscopic level can be explored by analyzing its macroscopic dynamic mechanical response.
基金supported by the National Nature Science Foundation of China (No.41807471)the Fundamental Research Funds for the Central Universities,China University of Geosciences (Wuhan)(Nos.G1323519399 and 162301182698)。
文摘Heavy metal pollution is a major issue after tailing pond failure accident.It is important to predict pollution trends for limited data of pollution sources.A simple phase separation heavy metal model was built for early warning simulation of heavy metal pollution accidents.Based on this,a new simulation framework has been developed to predict the pollution trends of the downstream according to the measured data at upstream sections.By setting the upstream monitoring date as the inflow boundary condition,the changing processes of heavy metal manganese(Mn) with different phases in the downstream can be accurately simulated and forecasted.Results showed that the concentration of the suspended phase in the downstream was larger than that in the aqueous phase and sediment phase.With this,the early warning of pollution trends after accidents could be made a few days ahead.It indicates that the impact of sediment on heavy metal should not be ignored in the early warning of tailing pond failure accidents.
基金supported by the National Natural Science Foundation of China (No. 41371472)
文摘A series of graphene–TiO2photocatalysts was synthesized by doping TiO2 with graphene oxide via hydrothermal treatment. The photocatalytic capability of the catalysts under ultraviolet irradiation was evaluated in terms of sodium pentachlorophenol（PCP-Na） decomposition and mineralization. The structural and physicochemical properties of these nanocomposites were characterized by X-ray diffraction, N2adsorption–desorption, transmission electron microscopy, scanning electron microscopy, Ultraviolet–visible diffuse reflectance spectroscopy, X-ray photoelectron spectroscopy, electron paramagnetic resonance spectra, and Fourier-transform infrared spectroscopy. The graphene–TiO2nanocomposites exhibited higher photocatalytic efficiency than commercial P25 for the degradation of PCP-Na, and 63.4% to 82.9% of the total organic carbon was fully mineralized. The improved photocatalytic activity may be attributed to the accelerated interfacial electron-transfer process and the significantly prolonged lifetime of electron-hole pairs imparted by graphene sheets in the nanocomposites. However,excessive graphene and the inhomogeneous aggregation of TiO2 nanoparticles may decrease photodegradation efficiency.
基金The National Natural Science Foundation for Distinguished Young Scholars,81725021,Yonghui Zhangthe National Natural Science Foundation of China,Nos.81573316,31870326+4 种基金the Innovative Research Groups of the National Natural Science Foundation of China,No.81721005,Yonghui Zhangthe Fundamental Research Funds for the Central Universities,No.2020kfyXJJS083,Zhengxi Huthe National Key R&D Program of China,No.2021YFA0910500,Yonghui Zhangthe Research and Development Program of Hubei Province,No.2020BCA058,Jianping Wangthe Chinese Medicine Research Foundation of Health Commission of Hubei Province,No.ZY2021Z019,Jianping Wang.
文摘Soil-derived fungi represent an insufficiently tapped reservoir for discovering new and bioactive natural products(NPs),and despite an ever-increasing number of unknown NPs have been discovered over the past few decades,much of the hidden biosynthetic potential is still in an urgent need to be disclosed.In this research,a chemical inves-tigation was performed on a wetland soil-derived fungus Aspergillus calidoustus TJ403-EL05,leading to the isolation of a total of fourteen drimane sesquiterpenoids(1-14),incorporating three new ones,namely ustusols F-H(1-3).Their structures,comprising absolute configurations,were completely authenticated by widespread spectroscopic data,quantum chemical 13C NMR and ECD calculations,and X-ray crystallography experiments.Compound 14 exhibited moderate anti-inflammatory activity by inhibiting the LPS-induced NO release(IC_(50)=25.6μM).
基金the The National Key Research and Development Program of China under Contract No.2018YFB1801503National Natural Science Foundation of China under Contract Nos.61931006,61921002,61771327,61927813,61775229,61991430 and 62022022.
文摘Terahertz communication technology can provide abundant frequency resources,strong confidentiality,antijamming capability,communication tracking capability and the ability to achieve highspeed data transmissions and can serve as an important technical method for high-speed communications in the future.Among these terahertz communication technologies,terahertz direct modulation technology is a key means to achieve low system complexity and power consumption.In this paper,a review and outlook of terahertz direct modulation technology are proposed from the aspects of high-electron-mobilitytransistor-based terahertz direct modulation,parallelswitch terahertz direct modulation,diode-based terahertz direct modulation,quantum cascade laser-based terahertz direct modulation and new-material-based terahertz direct modulation.We hope through this paper that more readers can gain knowledge about the development and challenges of terahertz direct modulation technology for high-speed communication systems,thus promoting the development of high-speed terahertz communication technology based on direct modulation.
基金supported by the National Natural Science Foundation of China(No.22176123)the Natural Science Foundation of Xinjiang(Nos.2020D01C021,2021D01C036)the National Natural Science Foundation of China-Xinjiang Joint Fund(No.U2003123)。
文摘Silver(9 wt.%)was loaded on Co_(3)O_(4)-nanofiber using reduction and impregnation methods,respectively.Due to the stronger electronegativity of silver,the ratios of surface Co^(3+)/Co^(2+) on Ag/Co_(3)O_(4) were higher than on Co_(3)O_(4),which further led to more adsorbed oxygen species as a result of the charge compensation.Moreover,the introducing of silver also obviously improved the reducibility of Co_(3)O_(4).Hence the Ag/Co_(3)O_(4) showed better catalytic performance than Co_(3)O_(4) in benzene oxidation.Compared with the Ag/Co_(3)O_(4) synthesized via impregnation method,the one prepared using reduction method(named as Ag Co-R)exhibited higher contents of surface Co^(3+) and adsorbed oxygen species,stronger reducibility,as well as more active surface lattice oxygen species.Consequently,Ag Co-R showed lowest T_(90) value of 183℃,admirable catalytic stability,largest normalized reaction rate of1.36×10^(-4)mol/(h·m^(2))(150℃),and lowest apparent activation energy(E_(a))of 63.2 kJ/mol.The analyzing of in-situ DRIFTS indicated benzene molecules were successively oxidized to phenol,o-benzoquinone,small molecular intermediates,and finally to CO_(2) and water on the surface of Ag Co-R.At last,potential reaction pathways including five detailed steps were proposed.
基金This work has been supported by the Strategic Research on Disruptive Technologies for Engineering Science and Technology(2019-ZD-27-04).
文摘1.Introduction In the era of the new century,driven by the development of the intelligent society,the integration of the field of electronics and information with various technical fields and industries has accelerated and become the major driving force for a new round of technological revolution and industrial transformation.This has advanced the profound adjustment of global technology,industry,and division of labor as well as reshaping the innovation and competitiveness of countries around the world.Electronics information has received the most concentrated research and development investment worldwide and has been actively advancing and playing a leading role in dissemination.Naturally,it has become an important strategic area in which the world’s scientific and technological powers seek economic advances and competitive advantages.
基金Supported by the Scientific Research and Technological Development Project of Guilin City ( 20100317)
文摘[ Objective] The study aimed to forecast the first flowering date of Osmanthus fragrans. [ Method] Based on the data about flowering stage of O. fragrans in Guilin City from 1999 -2012, the correlation between meteorological factors and the first flowering date of O. fragrans was analyzed, and a forecast model for the first flowering date of O. fragrans was established. EResult] Among meteorological factors, precipitation, humidity, temperature and sunshine hours could obviously affect the first flowering date of O. fragrans, especially humidity in August, temperature and sunshine hours in September. The forecast model could exactly forecast the first flowering date in the partial early or too late year, and the av- erage error of date was 6 days. The factors influencing the first flowering date of O. fragrans are complex, and there is an artificial error in record data of the flowering stage, so using a single model to forecast the first flowering date have some disadvantages. When forecasting the first flower- ing date, we should consider all influencing factors to get a good forecast result. [ Conclusion] The research could provide a new method to forecast the first flowednq date of O. fraclrans.
基金funded by the National Natural Science Foundation of China (No.22176123)the Natural Science Foundation of Xinjiang (No.2021D01C036)the National Undergraduate Innovation and Entre-preneurship of China (No.2021110755038)。
文摘VOCs can exert great harm to both human and environment,and catalytic oxidation is believed to be an effective technique to eliminate these pollutants.In this paper,Ag-Mn bimetal catalysts with 10 wt.%of silver were synthesized using doping,impregnation,and reduction methods respectively,and then they were applied to the catalytic oxidation of benzene.Through series of characterizations it showed that the loading of silver using reduction method significantly resulted in improved physico-chemical properties of manganese oxides,such as larger surface area and pore volume,higher proportion of surface Mn~(3+)and Mn~(4+),stronger reducibility and more active of surface oxygen species,which were all beneficial to its catalytic activity.As a result,the Ag-Mn catalysts synthesized by reduction method showed a lower T_(90)value(equals to the temperature at which 90%of initial benzene was removed)of 203℃.Besides,both the used and fresh Ag-Mn catalysts synthesized by reduction method showed preferable stability in this research.
