With the rapid development of electric vehicles,hybrid electric vehicles and smart grids,people's demand for large-scale energy storage devices is increasingly intense.As a new type of secondary battery,potassium ...With the rapid development of electric vehicles,hybrid electric vehicles and smart grids,people's demand for large-scale energy storage devices is increasingly intense.As a new type of secondary battery,potassium ion battery is promising to replace the lithium-ion battery in the field of large-scale energy storage by virtue of its low price and environmental friendliness.At present,the research on the anode materials of potassium ion batteries mainly focuses on carbon materials and the design of various nanostructured metal-based materials.Problems such as poor rate performance and inferior cycle life caused by electrode structure comminution during charge and discharge have not been solved.Quantum dots/nanodots materials are a new type of nanomaterials that can effectively improve the utilization of electrode materials and reduce production costs.In addition,quantum dots/nanodots materials can enhance the electrode reaction kinetics,reduce the stress generated in cycling,and effectively alleviate the agglomeration and crushing of electrode materials.In this review,we will systematically introduce the synthesis methods,K+storage properties and K+storage mechanisms of carbon quantum dots and carbon-based transition metal compound quantum dots composites.This review will have significant references for potassium ion battery researchers.展开更多
The efficiency of perovskite solar cells(PSCs)has progressed rapidly,exceeding 26%for single-junction devices and surpassing 34%in perovskite-silicon tandem configurations,establishing PSCs as a promising alternative ...The efficiency of perovskite solar cells(PSCs)has progressed rapidly,exceeding 26%for single-junction devices and surpassing 34%in perovskite-silicon tandem configurations,establishing PSCs as a promising alternative to traditional photovoltaic technologies.However,their commercialization is constrained by significant stability challenges in outdoor environments.This review critically examines key cell-level issues affecting the long-term performance and reliability of PSCs,focusing on instabilities arising from the intrinsic phases of the perovskite absorber and external stress factors.Mitigation strategies to enhance stability are discussed,alongside recent advancements in charge transport layers,electrodes,and interfaces aimed at reducing environmental degradation and improving energy level alignment for efficient charge extraction.The importance of accelerated aging tests and the establishment of standardized protocols is underscored for accurately predicting device lifetimes and identifying failure mechanisms,thereby ensuring stability under real-world conditions.Furthermore,a comprehensive techno-economic analysis evaluates how advancements in materials and strategic innovations influence efficiency,durability,and cost,which are critical for the commercial adoption of PSCs.This review delineates the essential steps required to transition PSC technology from laboratory-scale research to widespread commercialization within the global photovoltaic industry.展开更多
A sp^(2) carbon-conjugated covalent organic framework (BDATN) was modified through γ-ray radiation reduction and subsequent acidification with hydrochloric acid to yield a novel functional COF (named rBDATN-HCl) for ...A sp^(2) carbon-conjugated covalent organic framework (BDATN) was modified through γ-ray radiation reduction and subsequent acidification with hydrochloric acid to yield a novel functional COF (named rBDATN-HCl) for Cr(Ⅵ) removal.The morphology and structure of rBDATN-HCl were analyzed and identified by SEM,FTIR,XRD and solid-state13C NMR.It is found that the active functional groups,such as hydroxyl and amide,were introduced into BDATN after radiation reduction and acidification.The prepared rBDATN-HCl demonstrates a photocatalytic reduction removal rate of Cr(Ⅵ) above 99%after 60min of illumination with a solid-liquid ratio of 0.5 mg/mL,showing outstanding performance,which is attributed to the increase of dispersibility and adsorption sites of r BDATN-HCl.In comparison to the cBDATN-HCl synthesized with chemical reduction,rBDATN-HCl exhibits a better photoreduction performance for Cr(Ⅵ),demonstrating the advantages of radiation preparation of rBDATN-HCl.It is expected that more functionalized sp^(2) carbon-conjugated COFs could be obtained by this radiation-induced reduction strategy.展开更多
Metallic magnesium and its alloys,as new types of metallic structural materials,show great application potential in fields such as aerospace,electronics,and biomedicine.However,magnesium is chemically active and highl...Metallic magnesium and its alloys,as new types of metallic structural materials,show great application potential in fields such as aerospace,electronics,and biomedicine.However,magnesium is chemically active and highly susceptible to oxidation and corrosion in various environmental conditions,which can compromise its structural integrity and significantly reduce its service life.Therefore,it is of great significance to strengthen the development and application of corrosion protection technology for magnesium materials.At present,the nitridation of magnesium and its alloys is regarded as an effective surface treatment method to enhance corrosion resistance.To create durable nitrided layers on magnesium substrates with long-term stability,it is essential to thoroughly comprehend the influence of various techniques and processing conditions,as well as the resulting layer composition and microstructure.Additionally,a detailed understanding of how these fabricated layers behave in corrosive environments is crucial for optimizing their performance.This paper systematically reviews the research achievements and latest progress in the surface nitridation on magnesium alloys.The principles,advantages,drawbacks of different nitridation process,as well as their applications in enhancing the corrosion resistance of magnesium alloys are discussed.Furthermore,the paper summarizes the main technologies in the fabrication of magnesium nitride films,such as pulsed laser deposition,low-pressure chemical vapor deposition,reactive magnetron sputtering,thermal plasma synthesis,and molecular beam epitaxy,which offers a valuable reference for experimental research on magnesium nitride film.Finally,it also discusses the challenges and prospects of the research on the surface nitriding of magnesium and its alloys.展开更多
Energetic materials,characterized by their capacity to store and release substantial energy,hold pivotal significance in some fields,particularly in defense applications.Microfluidics,with its ability to manipulate fl...Energetic materials,characterized by their capacity to store and release substantial energy,hold pivotal significance in some fields,particularly in defense applications.Microfluidics,with its ability to manipulate fluids and facilitate droplet formation at the microscale,enables precise control of chemical reactions.Recent scholarly endeavors have increasingly harnessed microfluidic reactors in the realm of energetic materials,yielding morphologically controllable particles with enhanced uniformity and explosive efficacy.However,crucial insights into microfluidic-based methodologies are dispersed across various publications,necessitating a systematic compilation.Accordingly,this review addresses this gap by concentrating on the synthesis of energetic materials through microfluidics.Specifically,the methods based on micro-mixing and droplets in the previous papers are summarized and the strategies to control the critical parameters within chemical reactions are discussed in detail.Then,the comparison in terms of advantages and disadvantages is attempted.As demonstrated in the last section regarding perspectives,challenges such as clogging,dead zones,and suboptimal production yields are non-ignoble in the promising fields and they might be addressed by integrating sound,optics,or electrical energy to meet heightened requirements.This comprehensive overview aims to consolidate and analyze the diverse array of microfluidic approaches in energetic material synthesis,offering valuable insights for future research directions.展开更多
Today, agricultural production is threatened by crop pathogens, including plant-parasitic nematodes. Because of their harmful effects on the environment and human health, synthetic nematicides are gradually being bann...Today, agricultural production is threatened by crop pathogens, including plant-parasitic nematodes. Because of their harmful effects on the environment and human health, synthetic nematicides are gradually being banned in several countries. This study evaluates the nematicidal activity of Datura metel oil. Datura metel seed oil was obtained using the Soxhlet extractor in hexane. The resulting oil was characterized by determining physicochemical parameters and molecular composition using GC-MS. The nematicidal activity of the oil was assessed by determining the number of dead nematodes. Physicochemical characterization gave an acidity index of 0.3% and a peroxide index of 10 meq.O2/Kg, while GC-MS analysis identified 30 molecules made up mainly of fatty acid esters, four of which represented over 74% of the oil’s total weight. The nematicidal activity of the oil, expressed in terms of mortality rate as a function of concentration, showed mortality rates of 58;69 and 79% over 48 hours of incubation at concentrations of 25, 50 and 100 µg/mL respectively. The activity observed could be linked to the high presence of the four compounds most commonly identified in the oil. These results suggest that Datura metel oil could be a promising alternative to synthetic pesticides for the control of crop pests.展开更多
Enhancing the output capacity of semiconductor bridge(SCB) through the application of composite nano-energetic films is a subject of wide concern. Furthermore, improving the safety, reliability, and production efficie...Enhancing the output capacity of semiconductor bridge(SCB) through the application of composite nano-energetic films is a subject of wide concern. Furthermore, improving the safety, reliability, and production efficiency of energetic semiconductor bridge(ESCB) is the primary focus for large-scale engineering applications in the future. Here, the Al/CuO nano-film ESCB was efficiently fabricated using 3D direct writing. The electrostatic safety of the film is enhanced by precisely adjusting the particle size of Al, while ensuring that the SCB can initiate the film with small energy. The burst characteristics of SCB/ESCB were thoroughly investigated by employing a 100 μF tantalum capacitor to induce SCB and ESCB under an intense voltage gradient. The solid-state heating process of both SCB and ESCB was analyzed with multi physical simulation(MPS). The experimental results demonstrate that the critical burst time of both SCB and ESCB decreases with increasing voltage. Under the same voltage, the critical burst time of ESCB is longer than that of SCB, primarily due to differences in the melting to vaporization stage. The MPS results indicate that the highest temperature is observed at the V-shaped corner of SCB. Due to the thermal contact resistance between SCB and the film, heat conduction becomes more concentrated in the central region of the bridge, resulting in a faster solid-state heating process for ESCB compared to SCB.The results of the gap ignition experiments indicate that at a 19 mm gap, an ESCB with a film mass of 10 mg can ignite nickel hydrazine nitrate(NHN) and cyclotrimethylenetrinitramine(RDX). This suggests that thermite ESCB can serve as a novel, safe, and reliable energy exchange element and initiator in largescale engineering applications.展开更多
In floristic research,the grid mapping method is a crucial and highly effective tool for investigating the flora of specific regions.This methodology aids in the collection of comprehensive data,thereby promoting a th...In floristic research,the grid mapping method is a crucial and highly effective tool for investigating the flora of specific regions.This methodology aids in the collection of comprehensive data,thereby promoting a thorough understanding of regional plant diversity.This paper presents findings from a grid mapping study conducted in the Surkhan-Sherabad botanical-geographic region(SShBGR),acknowledged as one of the major floristic areas in southwestern Uzbekistan.Using an expansive dataset of 14,317 records comprised of herbarium specimens and field diary entries collected from 1897 to 2023,we evaluated the stages and seasonal dynamics of data accumulation,species richness(SR),and collection density(CD)within 5 km×5 km grid cells.We further examined the taxonomic and life form composition of the region's flora.Our analysis revealed that the grid mapping phase(2021–2023)produced a significantly greater volume of specimens and taxonomic diversity compared with other periods(1897–1940,1941–1993,and 1994–2020).Field research spanned 206 grid cells during 2021–2023,resulting in 11,883 samples,including 6469 herbarium specimens and 5414 field records.Overall,fieldwork covered 251 of the 253 grid cells within the SShBGR.Notably,the highest species diversity was documented in the B198 grid cell,recording 160 species.In terms of collection density,the E198 grid cell produced 475 samples.Overall,we identified 1053 species distributed across 439 genera and 78 families in the SShBGR.The flora of this region aligned significantly with the dominant families commonly found in the Holarctic,highlighting vital ecological connections.Among our findings,the Asteraceae family was the most polymorphic,with 147 species,followed by the continually stable and diverse Poaceae,Fabaceae,Brassicaceae,and Amaranthaceae.Besides,our analysis revealed a predominance of therophyte life forms,which constituted 52%(552 species)of the total flora.The findings underscore the necessity for continual data collection efforts to further enhance our understanding of the biodiversity in the SShBGR.The results of this study demonstrated that the application of grid-based mapping in floristic studies proves to be an effective tool for assessing biodiversity and identifying key taxonomic groups.展开更多
Stretchability is a crucial property of flexible all-in-one supercapacitors.This work reports a novel hydrogel electrolyte,polyacrylamidedivinylbenzene-Li2SO4(PAM-DVB-Li)synthesized by using a strategy of combining hy...Stretchability is a crucial property of flexible all-in-one supercapacitors.This work reports a novel hydrogel electrolyte,polyacrylamidedivinylbenzene-Li2SO4(PAM-DVB-Li)synthesized by using a strategy of combining hydrophobic nodes and hydrophilic networks as well as a method of dispersing hydrophobic DVB crosslinker to acrylamide monomer/Li2SO4 aqueous solution by micelles and followedγ-radiation induced polymerization and crosslinking.The resultant PAM-DVB-Li hydrogel electrolyte possesses excellent mechanical properties with 5627±241%stretchability and high ionic conductivity of 53±3 mS cm^(-1).By in situ polymerization of conducting polyaniline(PANI)on the PAM-DVB-Li hydrogel electrolyte,a novel all-in-one supercapacitor,PAM-DVB-Li/PANI,with highly integrated structure is prepared further.Benefiting from the excellent properties of hydrogel electrolyte and the all-in-one structure,the device exhibits a high specific capacitance of 469 mF cm^(-2) at 0.5 mA cm^(-2),good cyclic stability,safety,and deformation damage resistance.More importantly,the device demonstrates a superior tensile resistance(working normally under no more than 300%strain,capacitance stability in 1000 cycles of 1000%stretching and 10 cycles of 3000%stretching)far beyond that of other all-in-one supercapacitors.This work proposes a novel strategy to construct tensile-resistant all-in-one flexible supercapacitors that can be used as an energy storage device for stretchable electronic devices.展开更多
The advantageous magnetic,optical,and antibacterial properties of magnetic nanoparticles have recently drawn a lot of attention in the field of biomedicine.One of the most famous super paramagnetic materials,nanoferri...The advantageous magnetic,optical,and antibacterial properties of magnetic nanoparticles have recently drawn a lot of attention in the field of biomedicine.One of the most famous super paramagnetic materials,nanoferrite,is made up of two types of spinel structures:inverse and normal.Cobalt ferrite's inverse spinel structure offers several benefits,including excellent magnetostrictivity,good coupling efficiency,and inexpensive cost.This study's objective is to synthesize,characterize,and investigate the characteristics of the electrochemical properties of Co_(x)Fe_(1-x)Fe_(2)O_(4)/Fe_(2)O_(3)(x=0.30 and 0.77)nanoparticles using the chemical co-precipitation method.The physical properties of the produced nanoparticles were investigated using x-ray diffraction(XRD),transmission electron microscopy(TEM),and a vibrating sample magnetometer(VSM).The band gap properties of magneto-nano powders,including the direct and indirect band gap energies,and Urbach energy,are found.Scanning electron microscopy showed the presence of spherical nanoparticles ranging from 20.7 nm-23.7 nm.The analysis of Co_(x)Fe_(1-x)Fe_(2)O_(4)/Fe_(2)O_(3)(x=0.30 and 0.77)nanoparticles,for instance,reveals differences in their surface characteristics that are significant for their potential applications.Parameters like dnorm,de,and di,along with shape index and curvedness,contribute to a comprehensive understanding of the molecular surface,which is crucial for the design of new materials with desired physical and chemical properties.Molecular docking studies have revealed promising interactions between certain crystals and DNA gyrase,mirroring the binding mode of known inhibitors.This suggests potential for these crystals to serve as antimicrobial agents in future research.Such findings are crucial as they contribute to the development of new treatments against antibiotic-resistant bacteria,a growing global health concern.展开更多
Heterogeneous catalysts have attracted wide attention due to their remarkable oxygen evolution reaction(OER)capabilities.Herein,a one-step strategy involving the coupling of NixSeywith CeO_(2)is proposed to concurrent...Heterogeneous catalysts have attracted wide attention due to their remarkable oxygen evolution reaction(OER)capabilities.Herein,a one-step strategy involving the coupling of NixSeywith CeO_(2)is proposed to concurrently construct heterogeneous interfaces,adjust phase structure,and regulate electronic configuration,thereby enhancing OER performance.Thanks to the role of CeO_(2)coupling in reducing the activation-energy and accelerating the reaction kinetics,the heterogeneous NixSey/CeO_(2)catalyst exhibits a low overpotential of 218 mV at 10 mA/cm2and long-term stability(>400 h)in 1.0 mol/L KOH for OER.Moreover,the post-OER characterization reveals that the NixSeymatrix is reconstructed into NiOOH,while the incorporated CeO_(2)nanocrystals self-assemble into larger polycrystalline particles.Theoretical analysis further demonstrates that the optimized electronic states at NiOOH/CeO_(2)interfaces can modulate intermediate chemisorption toward favorable OER kinetics.This study offers fresh perspectives on the synthesis and structure-activity relationship of CeO_(2)-coupled electrocatalysts.展开更多
Chloroform and other volatile organic pollutants have garnered widespread attention from the public and researchers,because of their potential harm to the respiratory system,nervous system,skin,and eyes.However,resear...Chloroform and other volatile organic pollutants have garnered widespread attention from the public and researchers,because of their potential harm to the respiratory system,nervous system,skin,and eyes.However,research on chloroform vapor sensing is still in its early stages,primarily due to the lack of specific recognition motif.Here we report a mesoporous photonic crystal sensor incorporating carbon dots-based nanoreceptor(HMSS@CDs-PCs)for enhanced chloroform sensing.The colloidal PC packed with hollow mesoporous silica spheres provides an interconnected ordered macro-meso-hierarchical porous structure,ideal for rapid gas sensing utilizing the photonic bandgap shift as the readout signal.The as-synthesized CDs with pyridinic-N-oxide functional groups adsorbed in the hollow mesoporous silica spheres are found to not only serve as the chloroform adsorption sites,but also a molecular glue that prevents crack formation in the colloidal PC.The sensitivity of HMSS@CDs-PCs sensor is 0.79 nm ppm^(-1)and an impressively low limit of detection is 3.22 ppm,which are the best reported values in fast-response chloroform vapor sensor without multi-signal assistance.The positive response time is 7.5 s and the negative response time 9 s.Furthermore,relatively stable sensing can be maintained within a relative humidity of 20%-85%RH and temperature of 25-55℃.This study demonstrates that HMSS@CDs-PCs sensors have practical application potential in indoor and outdoor chloroform vapor detection.展开更多
The difficulty in fabricating a multifaceted composite heterojunction system based on Cd_(x) Zn_(1-x) S limits the enhancement of photocatalytic performance.In the present scrutiny,novel ZnO/Cd_(x) Zn_(1-x) S/CdS com-...The difficulty in fabricating a multifaceted composite heterojunction system based on Cd_(x) Zn_(1-x) S limits the enhancement of photocatalytic performance.In the present scrutiny,novel ZnO/Cd_(x) Zn_(1-x) S/CdS com-posite heterojunctions are successfully prepared by the alkaline dissolution etching method.The internal electric field at the interface of I-type and Z-scheme heterojunction improved the effective charge sepa-ration.The ZC 8 sample exhibits excellent photocatalytic performance and the H2 production efficiency is 15.67 mmol g^(−1) h^(−1) with good stability up to 82.9%in 24-hour cycles.The performance of CH_(4) and CO capacity in the CO_(2) RR process is 3.47μmol g^(−1) h^(−1) and 23.5μmol g^(−1) h^(−1),respectively.The photogener-ated accelerated charge transport is then examined in detail by in situ X-ray photoelectron spectroscopy(ISXPS)and density functional theory(DFT)calculations.This work presents a new idea for the synthe-sis of Cd_(x) Zn_(1-x) S solid-solution-based materials and provides a solid reference for the detailed mechanism regarding the electric field at the heterojunction interface.展开更多
Although supported solid amine adsorbents have attracted great attention for CO_(2) capture,critical chemical deactivation problems including oxidative degradation and urea formation have severely restricted their pra...Although supported solid amine adsorbents have attracted great attention for CO_(2) capture,critical chemical deactivation problems including oxidative degradation and urea formation have severely restricted their practical applications for flue gas CO_(2) capture.In this work,we reveal that the nature of surface hydroxyl groups(metal hydroxyl Al–OH and nonmetal hydroxyl Si–OH)plays a key role in the deactivation mechanisms.The polyethyleneimine(PEI)supported on Al–OH-containing substrates suffers from severe oxidative degradation during the CO_(2) capture step due to the breakage of amine-support hydrogen bonding networks,but exhibits an excellent anti-urea formation feature by preventing dehydration of carbamate products under a pure CO_(2) regeneration atmosphere.In contrast,PEI supported on Si–OHcontaining substrates exhibits excellent anti-oxidative stability under simulated flue gas conditions by forming a robust hydrogen bonding protective network with Si–OH,but suffers from obvious urea formation during the pure CO_(2) regeneration step.We also reveal that the urea formation problem for PEI-SBA-15 can be avoided by the incorporation of an OH-containing PEG additive.Based on the intrinsic understanding of degradation mechanisms,we successfully synthesized an adsorbent 40PEI-20PEG-SBA-15 that demonstrates outstanding stability and retention of a high CO_(2) capacity of 2.45 mmol g^(−1) over 1000 adsorption–desorption cycles,together with negligible capacity loss during aging in simulated flue gas(10%CO_(2)+5%O_(2)+3%H_(2)O)for one month at 60–70℃.We believe this work makes great contribution to the advancement in the field of ultra-stable solid amine-based CO_(2) capture materials.展开更多
Understanding the unique characteristics of continuous-flow photochemistry will lead to a paradigm shift in the way we enhance sustainability and wellbeing.In this mini-review,we first provide a succinct overview of w...Understanding the unique characteristics of continuous-flow photochemistry will lead to a paradigm shift in the way we enhance sustainability and wellbeing.In this mini-review,we first provide a succinct overview of working principles of this technique and discuss several recent synthetic protocols.Then,emphasis is given to those representative examples which address environmental issues such as indoor air pollutants and water contamination.Finally,recent progress made using this technique to deal with rising CO2 emission,solar energy utilization and biomedical equipment is described.It is believed that this mini-review could inspire more chemists to utilize this technique in their research,either in the academic or industrial field.展开更多
With the exploration of novel sustainable protocol for functional polyamides'(PAs)construction as the starting point,herein,the small molecular model compound(M 1-ssBIC)was prepared firstly by manual grinding of m...With the exploration of novel sustainable protocol for functional polyamides'(PAs)construction as the starting point,herein,the small molecular model compound(M 1-ssBIC)was prepared firstly by manual grinding of monofunctional benzoxazine(1a)and isocyanide(1 b)via solid-state benzoxazine-isocyanide chemistry(ssBIC)to evaluate the feasibility of ssBIC.Linear PAs(P1-series polymers)were subsequently synthesized from biunctional benzoxazine(2a)and isocyanide(2b),and the influence of the loading of catalyst(octylphosphonic acid)(OPA)on the polymerization was investigated.Afterwards,two kinds of cross-linked PAs were successfully constructed via ssBIC by using trifunctional benzoxazine(3a)and cross-linked polybenzoxazine(4a)as reaction substrates,respectively,thus verifying the adaptability of ssBIC.Structural characterization indicates that amide,phenolic hydroxyl and tertiary amine substructures,with metal-complexing capability,have been successfully integrated into the obtained PAs.A type of representative PA/silver composite(P3-AgNPs)was prepared subsequently via in situ reduction treatment,and its application as recyclable reduction catalyst for organic pollutant p-nitrophenol(4-NP)was preliminarily investigated here to provide the example for possible downstream application of ssBIC.We think that this current work could provide a new pathway for the construction of functional PAs through facile and sustainable ssBIC protocol.展开更多
Objective:To investigate the phytochemical properties and the anticonvulsant potential of the ethyl acetate soluble fraction of ethanol leaf extract of Globimetida braunii,a plant used in ethnomedicine for the treatme...Objective:To investigate the phytochemical properties and the anticonvulsant potential of the ethyl acetate soluble fraction of ethanol leaf extract of Globimetida braunii,a plant used in ethnomedicine for the treatment of epilepsy.Methods:The phytochemical screening was carried out using standard protocol while the anticonvulsant activity was studied using maximal electroshock test in chicks,pentylenetetrazole and 4-aminopyridine—induced seizures in mice.Results:The preliminary phytochemical screening carried out on the crude ethanol extract revealed the presence of saponins,carbohydrates,flavonoids,tannins,anthraquinones and steroids.Similarly,tannins,flavonoids and steroids/terpenes were found to be present in the ethyl acetate fraction,In the pharmacological screening,150 mg/kg of the fraction protected 83.33%of animals against pentylenetetrazole-induced seizure in mice whereas sodium valproate a standard anti-epileptic drug offered 100%protection.In the 4-aminopyridine-induced seizure model,the fraction produced a significant(P<0.05)increase in the mean onset of seizure in unprotected animals.The fraction did not exhibit a significant activity against maximal electroshock convulsion.The median lethal dose of the fraction was found to be 1261.91 mg/kg.Conclusions:These results suggest that the ethyl acetate fraction of Globimetula braunii leaves extract possesses psychoactive compound that may be useful in the management of petit mal epilepsy and lend credence to the ethnomedical use of the plant in the management of epilepsy.展开更多
Exploding foil initiator(EFI)is a kind of advanced device for initiating explosives,but its function is unstable when it comes to directly igniting pyrotechnics.To solve the problem,this research aims to reveal the ig...Exploding foil initiator(EFI)is a kind of advanced device for initiating explosives,but its function is unstable when it comes to directly igniting pyrotechnics.To solve the problem,this research aims to reveal the ignition mechanism of EFIs directly igniting pyrotechnics.An oscilloscope,a photon Doppler velocimetry,and a plasma spectrum measurement system were employed to obtain information of electric characteristics,impact pressure,and plasma temperature.The results of the electric characteristics and the impact pressure were inconsistent with ignition results.The only thing that the ignition success tests had in common was that their plasma all had a relatively long period of high-temperature duration(HTD).It eventually concludes that the ignition mechanism in this research is the microconvection heat transfer rather than the shock initiation,which differs from that of exploding foil initiators detonating explosives.Furthermore,the methods for evaluating the ignition success of semiconductor bridge initiators are not entirely applicable to the tests mentioned in this paper.The HTD is the critical parameter for judging the ignition success,and it is influenced by two factors:the late time discharge and the energy of the electric explosion.The longer time of the late time discharge and the more energy of the electric explosion,the easier it is to expand the HTD,which improves the probability of the ignition success.展开更多
The trade-off between efficiency and stability has limited the application of TiO_(2)as a catalyst due to its poor surface reactivity.Here,we present a modification of a TiO_(2)layer with highly stable Sub-5 nm Fe_(2)...The trade-off between efficiency and stability has limited the application of TiO_(2)as a catalyst due to its poor surface reactivity.Here,we present a modification of a TiO_(2)layer with highly stable Sub-5 nm Fe_(2)O_(3)nanoparticles(NP)by modulating its structure-surface reactivity relationship to attain efficiency-stability balance via a voltage-assisted oxidation approach.In situ simultaneous oxidation of the Ti substrate and Fe precursor using high-energy plasma driven by high voltage resulted in uniform distribution of Fe_(2)O_(3)NP embedded within porous TiO_(2)layer.Comprehensive surface characterizations with density functional theory demonstrated an improved electronic transition in TiO_(2)due to the presence of surface defects from reactive oxygen species and possible charge transfer from Ti to Fe;it also unexpectedly increased the active site in the TiO_(2)layer due to uncoordinated electrons in Sub-5 nm Fe_(2)O_(3)NP/TiO_(2)catalyst,thereby enhancing the adsorption of chemical functional groups on the catalyst.This unique embedded structure exhibited remarkable improvement in reducing 4-nitrophenol to 4-aminophenol,achieving approximately 99%efficiency in 20 min without stability decay after 20 consecutive cycles,outperforming previously reported TiO_(2)-based catalysts.This finding proposes a modified-electrochemical strategy enabling facile construction of TiO_(2)with nanoscale oxides extandable to other metal oxide systems.展开更多
Lithium-oxygen batteries are a promising technology because they can greatly surpass the energy density of lithium-ion batteries.However,this theoretical characteristic has not yet been converted into a real device wi...Lithium-oxygen batteries are a promising technology because they can greatly surpass the energy density of lithium-ion batteries.However,this theoretical characteristic has not yet been converted into a real device with high cyclability.Problems with air contamination,metallic lithium reactivity,and complex discharge and charge reactions are the main issues for this technology.A fast and reversible oxygen reduction reaction(ORR)is crucial for good performance of secondary batteries',but the partial knowledge of its mechanisms,especially when devices are concerned,hinders further development.From this perspective,the present work uses operando Raman experiments and electrochemical impedance spectroscopy(EIS)to assess the first stages of the discharge processes in porous carbon electrodes,following their changes cycle by cycle at initial operation.A growth kinetic formation of the discharge product signal(Li_(2)O_(2))was observed with operando Raman,indicating a first-order reaction and enabling an analysis by a microkinetic model.The solution mechanism in the evaluated system was ascribed for an equivalent circuit with three time constants.While the time constant for the anode interface reveals to remain relatively constant after the first discharge,its surface seemed to be more non-uniform.The model indicated that the reaction occurs at the Li_(2)O_(2) surface,decreasing the associated resistance during the initial discharge phase.Furthermore,the growth of Li_(2)O_(2) forms a hetero-phase between Li_(2)O_(2)/electrolyte,while creating a more compact and homogeneous on the Li_(2)O_(2)/cathode surface.The methodology here described thus offers a way of directly probing changes in surface chemistry evolution during cycling from a device through EIS analysis.展开更多
基金financial support from the Doctoral Foundation of Henan University of Engineering(No.D2022025)National Natural Science Foundation of China(No.U2004162)+1 种基金National Natural Science Foundation of China(No.52302138)Key Project for Science and Technology Development of Henan Province(No.232102320221)。
文摘With the rapid development of electric vehicles,hybrid electric vehicles and smart grids,people's demand for large-scale energy storage devices is increasingly intense.As a new type of secondary battery,potassium ion battery is promising to replace the lithium-ion battery in the field of large-scale energy storage by virtue of its low price and environmental friendliness.At present,the research on the anode materials of potassium ion batteries mainly focuses on carbon materials and the design of various nanostructured metal-based materials.Problems such as poor rate performance and inferior cycle life caused by electrode structure comminution during charge and discharge have not been solved.Quantum dots/nanodots materials are a new type of nanomaterials that can effectively improve the utilization of electrode materials and reduce production costs.In addition,quantum dots/nanodots materials can enhance the electrode reaction kinetics,reduce the stress generated in cycling,and effectively alleviate the agglomeration and crushing of electrode materials.In this review,we will systematically introduce the synthesis methods,K+storage properties and K+storage mechanisms of carbon quantum dots and carbon-based transition metal compound quantum dots composites.This review will have significant references for potassium ion battery researchers.
基金supported by a National Research Foundation of Korea(NRF)grant(No.2016R1A3B 1908249),funded by the Korean government.
文摘The efficiency of perovskite solar cells(PSCs)has progressed rapidly,exceeding 26%for single-junction devices and surpassing 34%in perovskite-silicon tandem configurations,establishing PSCs as a promising alternative to traditional photovoltaic technologies.However,their commercialization is constrained by significant stability challenges in outdoor environments.This review critically examines key cell-level issues affecting the long-term performance and reliability of PSCs,focusing on instabilities arising from the intrinsic phases of the perovskite absorber and external stress factors.Mitigation strategies to enhance stability are discussed,alongside recent advancements in charge transport layers,electrodes,and interfaces aimed at reducing environmental degradation and improving energy level alignment for efficient charge extraction.The importance of accelerated aging tests and the establishment of standardized protocols is underscored for accurately predicting device lifetimes and identifying failure mechanisms,thereby ensuring stability under real-world conditions.Furthermore,a comprehensive techno-economic analysis evaluates how advancements in materials and strategic innovations influence efficiency,durability,and cost,which are critical for the commercial adoption of PSCs.This review delineates the essential steps required to transition PSC technology from laboratory-scale research to widespread commercialization within the global photovoltaic industry.
基金supported by the National Natural Science Foundation of China(No.U2067212)the National Science Fund for Distinguished Young Scholars(No.21925603).
文摘A sp^(2) carbon-conjugated covalent organic framework (BDATN) was modified through γ-ray radiation reduction and subsequent acidification with hydrochloric acid to yield a novel functional COF (named rBDATN-HCl) for Cr(Ⅵ) removal.The morphology and structure of rBDATN-HCl were analyzed and identified by SEM,FTIR,XRD and solid-state13C NMR.It is found that the active functional groups,such as hydroxyl and amide,were introduced into BDATN after radiation reduction and acidification.The prepared rBDATN-HCl demonstrates a photocatalytic reduction removal rate of Cr(Ⅵ) above 99%after 60min of illumination with a solid-liquid ratio of 0.5 mg/mL,showing outstanding performance,which is attributed to the increase of dispersibility and adsorption sites of r BDATN-HCl.In comparison to the cBDATN-HCl synthesized with chemical reduction,rBDATN-HCl exhibits a better photoreduction performance for Cr(Ⅵ),demonstrating the advantages of radiation preparation of rBDATN-HCl.It is expected that more functionalized sp^(2) carbon-conjugated COFs could be obtained by this radiation-induced reduction strategy.
基金supported by the National Natural Science Foundation of China(No.22172148).
文摘Metallic magnesium and its alloys,as new types of metallic structural materials,show great application potential in fields such as aerospace,electronics,and biomedicine.However,magnesium is chemically active and highly susceptible to oxidation and corrosion in various environmental conditions,which can compromise its structural integrity and significantly reduce its service life.Therefore,it is of great significance to strengthen the development and application of corrosion protection technology for magnesium materials.At present,the nitridation of magnesium and its alloys is regarded as an effective surface treatment method to enhance corrosion resistance.To create durable nitrided layers on magnesium substrates with long-term stability,it is essential to thoroughly comprehend the influence of various techniques and processing conditions,as well as the resulting layer composition and microstructure.Additionally,a detailed understanding of how these fabricated layers behave in corrosive environments is crucial for optimizing their performance.This paper systematically reviews the research achievements and latest progress in the surface nitridation on magnesium alloys.The principles,advantages,drawbacks of different nitridation process,as well as their applications in enhancing the corrosion resistance of magnesium alloys are discussed.Furthermore,the paper summarizes the main technologies in the fabrication of magnesium nitride films,such as pulsed laser deposition,low-pressure chemical vapor deposition,reactive magnetron sputtering,thermal plasma synthesis,and molecular beam epitaxy,which offers a valuable reference for experimental research on magnesium nitride film.Finally,it also discusses the challenges and prospects of the research on the surface nitriding of magnesium and its alloys.
基金financially supported by Science and Technology on Applied Physical Chemistry Laboratory,China(Grant No.61426022220303)supported by the Young Scientists Fund of the National Natural Science Foundation of China(Grant No.52305617)。
文摘Energetic materials,characterized by their capacity to store and release substantial energy,hold pivotal significance in some fields,particularly in defense applications.Microfluidics,with its ability to manipulate fluids and facilitate droplet formation at the microscale,enables precise control of chemical reactions.Recent scholarly endeavors have increasingly harnessed microfluidic reactors in the realm of energetic materials,yielding morphologically controllable particles with enhanced uniformity and explosive efficacy.However,crucial insights into microfluidic-based methodologies are dispersed across various publications,necessitating a systematic compilation.Accordingly,this review addresses this gap by concentrating on the synthesis of energetic materials through microfluidics.Specifically,the methods based on micro-mixing and droplets in the previous papers are summarized and the strategies to control the critical parameters within chemical reactions are discussed in detail.Then,the comparison in terms of advantages and disadvantages is attempted.As demonstrated in the last section regarding perspectives,challenges such as clogging,dead zones,and suboptimal production yields are non-ignoble in the promising fields and they might be addressed by integrating sound,optics,or electrical energy to meet heightened requirements.This comprehensive overview aims to consolidate and analyze the diverse array of microfluidic approaches in energetic material synthesis,offering valuable insights for future research directions.
文摘Today, agricultural production is threatened by crop pathogens, including plant-parasitic nematodes. Because of their harmful effects on the environment and human health, synthetic nematicides are gradually being banned in several countries. This study evaluates the nematicidal activity of Datura metel oil. Datura metel seed oil was obtained using the Soxhlet extractor in hexane. The resulting oil was characterized by determining physicochemical parameters and molecular composition using GC-MS. The nematicidal activity of the oil was assessed by determining the number of dead nematodes. Physicochemical characterization gave an acidity index of 0.3% and a peroxide index of 10 meq.O2/Kg, while GC-MS analysis identified 30 molecules made up mainly of fatty acid esters, four of which represented over 74% of the oil’s total weight. The nematicidal activity of the oil, expressed in terms of mortality rate as a function of concentration, showed mortality rates of 58;69 and 79% over 48 hours of incubation at concentrations of 25, 50 and 100 µg/mL respectively. The activity observed could be linked to the high presence of the four compounds most commonly identified in the oil. These results suggest that Datura metel oil could be a promising alternative to synthetic pesticides for the control of crop pests.
基金supported by the National Natural Science Foundation of China(Grant Nos.22275092 and 52372084)the Postgraduate Research&Practice Innovation Program of Jiangsu Province(Grant No.KYCX24_0709)+1 种基金the Fundamental Research Funds for the Central Universities(Grant No.30923010920)the State Key Laboratory of Transient Chemical Effects and Control,China,(Grant No.6142602230201).
文摘Enhancing the output capacity of semiconductor bridge(SCB) through the application of composite nano-energetic films is a subject of wide concern. Furthermore, improving the safety, reliability, and production efficiency of energetic semiconductor bridge(ESCB) is the primary focus for large-scale engineering applications in the future. Here, the Al/CuO nano-film ESCB was efficiently fabricated using 3D direct writing. The electrostatic safety of the film is enhanced by precisely adjusting the particle size of Al, while ensuring that the SCB can initiate the film with small energy. The burst characteristics of SCB/ESCB were thoroughly investigated by employing a 100 μF tantalum capacitor to induce SCB and ESCB under an intense voltage gradient. The solid-state heating process of both SCB and ESCB was analyzed with multi physical simulation(MPS). The experimental results demonstrate that the critical burst time of both SCB and ESCB decreases with increasing voltage. Under the same voltage, the critical burst time of ESCB is longer than that of SCB, primarily due to differences in the melting to vaporization stage. The MPS results indicate that the highest temperature is observed at the V-shaped corner of SCB. Due to the thermal contact resistance between SCB and the film, heat conduction becomes more concentrated in the central region of the bridge, resulting in a faster solid-state heating process for ESCB compared to SCB.The results of the gap ignition experiments indicate that at a 19 mm gap, an ESCB with a film mass of 10 mg can ignite nickel hydrazine nitrate(NHN) and cyclotrimethylenetrinitramine(RDX). This suggests that thermite ESCB can serve as a novel, safe, and reliable energy exchange element and initiator in largescale engineering applications.
基金supported by the grant from the State Programs"Grid Mapping of the Flora of Uzbekistan'during 2020–2024"the grant from the State Programs"Creation of the Digital Platform of the Plant World of Central Uzbekistan"during 2025–2029the State Research Project"Taxonomic Revision of Polymorphic Plant Families of the Flora of Uzbekistan"from the Institute of Botany,Academy of Sciences of the Republic of Uzbekistan (A-FA-2021-427)
文摘In floristic research,the grid mapping method is a crucial and highly effective tool for investigating the flora of specific regions.This methodology aids in the collection of comprehensive data,thereby promoting a thorough understanding of regional plant diversity.This paper presents findings from a grid mapping study conducted in the Surkhan-Sherabad botanical-geographic region(SShBGR),acknowledged as one of the major floristic areas in southwestern Uzbekistan.Using an expansive dataset of 14,317 records comprised of herbarium specimens and field diary entries collected from 1897 to 2023,we evaluated the stages and seasonal dynamics of data accumulation,species richness(SR),and collection density(CD)within 5 km×5 km grid cells.We further examined the taxonomic and life form composition of the region's flora.Our analysis revealed that the grid mapping phase(2021–2023)produced a significantly greater volume of specimens and taxonomic diversity compared with other periods(1897–1940,1941–1993,and 1994–2020).Field research spanned 206 grid cells during 2021–2023,resulting in 11,883 samples,including 6469 herbarium specimens and 5414 field records.Overall,fieldwork covered 251 of the 253 grid cells within the SShBGR.Notably,the highest species diversity was documented in the B198 grid cell,recording 160 species.In terms of collection density,the E198 grid cell produced 475 samples.Overall,we identified 1053 species distributed across 439 genera and 78 families in the SShBGR.The flora of this region aligned significantly with the dominant families commonly found in the Holarctic,highlighting vital ecological connections.Among our findings,the Asteraceae family was the most polymorphic,with 147 species,followed by the continually stable and diverse Poaceae,Fabaceae,Brassicaceae,and Amaranthaceae.Besides,our analysis revealed a predominance of therophyte life forms,which constituted 52%(552 species)of the total flora.The findings underscore the necessity for continual data collection efforts to further enhance our understanding of the biodiversity in the SShBGR.The results of this study demonstrated that the application of grid-based mapping in floristic studies proves to be an effective tool for assessing biodiversity and identifying key taxonomic groups.
基金financial support from National Natural Science Foundation of China(No.12375336,11875078)。
文摘Stretchability is a crucial property of flexible all-in-one supercapacitors.This work reports a novel hydrogel electrolyte,polyacrylamidedivinylbenzene-Li2SO4(PAM-DVB-Li)synthesized by using a strategy of combining hydrophobic nodes and hydrophilic networks as well as a method of dispersing hydrophobic DVB crosslinker to acrylamide monomer/Li2SO4 aqueous solution by micelles and followedγ-radiation induced polymerization and crosslinking.The resultant PAM-DVB-Li hydrogel electrolyte possesses excellent mechanical properties with 5627±241%stretchability and high ionic conductivity of 53±3 mS cm^(-1).By in situ polymerization of conducting polyaniline(PANI)on the PAM-DVB-Li hydrogel electrolyte,a novel all-in-one supercapacitor,PAM-DVB-Li/PANI,with highly integrated structure is prepared further.Benefiting from the excellent properties of hydrogel electrolyte and the all-in-one structure,the device exhibits a high specific capacitance of 469 mF cm^(-2) at 0.5 mA cm^(-2),good cyclic stability,safety,and deformation damage resistance.More importantly,the device demonstrates a superior tensile resistance(working normally under no more than 300%strain,capacitance stability in 1000 cycles of 1000%stretching and 10 cycles of 3000%stretching)far beyond that of other all-in-one supercapacitors.This work proposes a novel strategy to construct tensile-resistant all-in-one flexible supercapacitors that can be used as an energy storage device for stretchable electronic devices.
文摘The advantageous magnetic,optical,and antibacterial properties of magnetic nanoparticles have recently drawn a lot of attention in the field of biomedicine.One of the most famous super paramagnetic materials,nanoferrite,is made up of two types of spinel structures:inverse and normal.Cobalt ferrite's inverse spinel structure offers several benefits,including excellent magnetostrictivity,good coupling efficiency,and inexpensive cost.This study's objective is to synthesize,characterize,and investigate the characteristics of the electrochemical properties of Co_(x)Fe_(1-x)Fe_(2)O_(4)/Fe_(2)O_(3)(x=0.30 and 0.77)nanoparticles using the chemical co-precipitation method.The physical properties of the produced nanoparticles were investigated using x-ray diffraction(XRD),transmission electron microscopy(TEM),and a vibrating sample magnetometer(VSM).The band gap properties of magneto-nano powders,including the direct and indirect band gap energies,and Urbach energy,are found.Scanning electron microscopy showed the presence of spherical nanoparticles ranging from 20.7 nm-23.7 nm.The analysis of Co_(x)Fe_(1-x)Fe_(2)O_(4)/Fe_(2)O_(3)(x=0.30 and 0.77)nanoparticles,for instance,reveals differences in their surface characteristics that are significant for their potential applications.Parameters like dnorm,de,and di,along with shape index and curvedness,contribute to a comprehensive understanding of the molecular surface,which is crucial for the design of new materials with desired physical and chemical properties.Molecular docking studies have revealed promising interactions between certain crystals and DNA gyrase,mirroring the binding mode of known inhibitors.This suggests potential for these crystals to serve as antimicrobial agents in future research.Such findings are crucial as they contribute to the development of new treatments against antibiotic-resistant bacteria,a growing global health concern.
基金supported by the grants from the National Natural Science Foundation of China(No.22202098)the Natural Science Foundation of Henan Province(No.242300420199)。
文摘Heterogeneous catalysts have attracted wide attention due to their remarkable oxygen evolution reaction(OER)capabilities.Herein,a one-step strategy involving the coupling of NixSeywith CeO_(2)is proposed to concurrently construct heterogeneous interfaces,adjust phase structure,and regulate electronic configuration,thereby enhancing OER performance.Thanks to the role of CeO_(2)coupling in reducing the activation-energy and accelerating the reaction kinetics,the heterogeneous NixSey/CeO_(2)catalyst exhibits a low overpotential of 218 mV at 10 mA/cm2and long-term stability(>400 h)in 1.0 mol/L KOH for OER.Moreover,the post-OER characterization reveals that the NixSeymatrix is reconstructed into NiOOH,while the incorporated CeO_(2)nanocrystals self-assemble into larger polycrystalline particles.Theoretical analysis further demonstrates that the optimized electronic states at NiOOH/CeO_(2)interfaces can modulate intermediate chemisorption toward favorable OER kinetics.This study offers fresh perspectives on the synthesis and structure-activity relationship of CeO_(2)-coupled electrocatalysts.
基金supported by the National Key Research and Development Program of China(No.2022YFB3205500)National Natural Science Foundation of China(Nos.U23A20360 and 62303192)QL wishes to thank Water Research Australia(WRA 1144/21)for funding support.
文摘Chloroform and other volatile organic pollutants have garnered widespread attention from the public and researchers,because of their potential harm to the respiratory system,nervous system,skin,and eyes.However,research on chloroform vapor sensing is still in its early stages,primarily due to the lack of specific recognition motif.Here we report a mesoporous photonic crystal sensor incorporating carbon dots-based nanoreceptor(HMSS@CDs-PCs)for enhanced chloroform sensing.The colloidal PC packed with hollow mesoporous silica spheres provides an interconnected ordered macro-meso-hierarchical porous structure,ideal for rapid gas sensing utilizing the photonic bandgap shift as the readout signal.The as-synthesized CDs with pyridinic-N-oxide functional groups adsorbed in the hollow mesoporous silica spheres are found to not only serve as the chloroform adsorption sites,but also a molecular glue that prevents crack formation in the colloidal PC.The sensitivity of HMSS@CDs-PCs sensor is 0.79 nm ppm^(-1)and an impressively low limit of detection is 3.22 ppm,which are the best reported values in fast-response chloroform vapor sensor without multi-signal assistance.The positive response time is 7.5 s and the negative response time 9 s.Furthermore,relatively stable sensing can be maintained within a relative humidity of 20%-85%RH and temperature of 25-55℃.This study demonstrates that HMSS@CDs-PCs sensors have practical application potential in indoor and outdoor chloroform vapor detection.
基金financially supported by the National Key Re-search and Development Program of China[No.2022YFF1202500,2022YFF1202502]the National Natural Science Foundation of China[62071459]+1 种基金the Subject arrangement Foundation of Shen-zhen[No.JCYJ20180507182057026]the International Science and Technology Cooperation Project of Bingtuan[No.2022BC008]。
文摘The difficulty in fabricating a multifaceted composite heterojunction system based on Cd_(x) Zn_(1-x) S limits the enhancement of photocatalytic performance.In the present scrutiny,novel ZnO/Cd_(x) Zn_(1-x) S/CdS com-posite heterojunctions are successfully prepared by the alkaline dissolution etching method.The internal electric field at the interface of I-type and Z-scheme heterojunction improved the effective charge sepa-ration.The ZC 8 sample exhibits excellent photocatalytic performance and the H2 production efficiency is 15.67 mmol g^(−1) h^(−1) with good stability up to 82.9%in 24-hour cycles.The performance of CH_(4) and CO capacity in the CO_(2) RR process is 3.47μmol g^(−1) h^(−1) and 23.5μmol g^(−1) h^(−1),respectively.The photogener-ated accelerated charge transport is then examined in detail by in situ X-ray photoelectron spectroscopy(ISXPS)and density functional theory(DFT)calculations.This work presents a new idea for the synthe-sis of Cd_(x) Zn_(1-x) S solid-solution-based materials and provides a solid reference for the detailed mechanism regarding the electric field at the heterojunction interface.
基金supported by the Fundamental Research Funds for the National Natural Science Foundation of China 52225003,22208021,22109004the National Key R&D Program of China 2022YFB4101702.
文摘Although supported solid amine adsorbents have attracted great attention for CO_(2) capture,critical chemical deactivation problems including oxidative degradation and urea formation have severely restricted their practical applications for flue gas CO_(2) capture.In this work,we reveal that the nature of surface hydroxyl groups(metal hydroxyl Al–OH and nonmetal hydroxyl Si–OH)plays a key role in the deactivation mechanisms.The polyethyleneimine(PEI)supported on Al–OH-containing substrates suffers from severe oxidative degradation during the CO_(2) capture step due to the breakage of amine-support hydrogen bonding networks,but exhibits an excellent anti-urea formation feature by preventing dehydration of carbamate products under a pure CO_(2) regeneration atmosphere.In contrast,PEI supported on Si–OHcontaining substrates exhibits excellent anti-oxidative stability under simulated flue gas conditions by forming a robust hydrogen bonding protective network with Si–OH,but suffers from obvious urea formation during the pure CO_(2) regeneration step.We also reveal that the urea formation problem for PEI-SBA-15 can be avoided by the incorporation of an OH-containing PEG additive.Based on the intrinsic understanding of degradation mechanisms,we successfully synthesized an adsorbent 40PEI-20PEG-SBA-15 that demonstrates outstanding stability and retention of a high CO_(2) capacity of 2.45 mmol g^(−1) over 1000 adsorption–desorption cycles,together with negligible capacity loss during aging in simulated flue gas(10%CO_(2)+5%O_(2)+3%H_(2)O)for one month at 60–70℃.We believe this work makes great contribution to the advancement in the field of ultra-stable solid amine-based CO_(2) capture materials.
基金Financial support from the National Natural Science Foundation of China(No.21771088)Zhejiang Provincial Natural Science Foundation of China(No.LY20B010005)the open research funds of JLU(2020-9)&FJIRSM,CAS(No.20170034)。
文摘Understanding the unique characteristics of continuous-flow photochemistry will lead to a paradigm shift in the way we enhance sustainability and wellbeing.In this mini-review,we first provide a succinct overview of working principles of this technique and discuss several recent synthetic protocols.Then,emphasis is given to those representative examples which address environmental issues such as indoor air pollutants and water contamination.Finally,recent progress made using this technique to deal with rising CO2 emission,solar energy utilization and biomedical equipment is described.It is believed that this mini-review could inspire more chemists to utilize this technique in their research,either in the academic or industrial field.
基金supported by the National Natural Science Foundation of China(No.21774103)the Youth Science and Technology Innovation Team of SWPU(Nos.2017CXTD05,2018CXTD05).
文摘With the exploration of novel sustainable protocol for functional polyamides'(PAs)construction as the starting point,herein,the small molecular model compound(M 1-ssBIC)was prepared firstly by manual grinding of monofunctional benzoxazine(1a)and isocyanide(1 b)via solid-state benzoxazine-isocyanide chemistry(ssBIC)to evaluate the feasibility of ssBIC.Linear PAs(P1-series polymers)were subsequently synthesized from biunctional benzoxazine(2a)and isocyanide(2b),and the influence of the loading of catalyst(octylphosphonic acid)(OPA)on the polymerization was investigated.Afterwards,two kinds of cross-linked PAs were successfully constructed via ssBIC by using trifunctional benzoxazine(3a)and cross-linked polybenzoxazine(4a)as reaction substrates,respectively,thus verifying the adaptability of ssBIC.Structural characterization indicates that amide,phenolic hydroxyl and tertiary amine substructures,with metal-complexing capability,have been successfully integrated into the obtained PAs.A type of representative PA/silver composite(P3-AgNPs)was prepared subsequently via in situ reduction treatment,and its application as recyclable reduction catalyst for organic pollutant p-nitrophenol(4-NP)was preliminarily investigated here to provide the example for possible downstream application of ssBIC.We think that this current work could provide a new pathway for the construction of functional PAs through facile and sustainable ssBIC protocol.
基金supported by Ahmadu Bello University Board of Research Grant(Grant No.:DAPM/BOD/05)
文摘Objective:To investigate the phytochemical properties and the anticonvulsant potential of the ethyl acetate soluble fraction of ethanol leaf extract of Globimetida braunii,a plant used in ethnomedicine for the treatment of epilepsy.Methods:The phytochemical screening was carried out using standard protocol while the anticonvulsant activity was studied using maximal electroshock test in chicks,pentylenetetrazole and 4-aminopyridine—induced seizures in mice.Results:The preliminary phytochemical screening carried out on the crude ethanol extract revealed the presence of saponins,carbohydrates,flavonoids,tannins,anthraquinones and steroids.Similarly,tannins,flavonoids and steroids/terpenes were found to be present in the ethyl acetate fraction,In the pharmacological screening,150 mg/kg of the fraction protected 83.33%of animals against pentylenetetrazole-induced seizure in mice whereas sodium valproate a standard anti-epileptic drug offered 100%protection.In the 4-aminopyridine-induced seizure model,the fraction produced a significant(P<0.05)increase in the mean onset of seizure in unprotected animals.The fraction did not exhibit a significant activity against maximal electroshock convulsion.The median lethal dose of the fraction was found to be 1261.91 mg/kg.Conclusions:These results suggest that the ethyl acetate fraction of Globimetula braunii leaves extract possesses psychoactive compound that may be useful in the management of petit mal epilepsy and lend credence to the ethnomedical use of the plant in the management of epilepsy.
文摘Exploding foil initiator(EFI)is a kind of advanced device for initiating explosives,but its function is unstable when it comes to directly igniting pyrotechnics.To solve the problem,this research aims to reveal the ignition mechanism of EFIs directly igniting pyrotechnics.An oscilloscope,a photon Doppler velocimetry,and a plasma spectrum measurement system were employed to obtain information of electric characteristics,impact pressure,and plasma temperature.The results of the electric characteristics and the impact pressure were inconsistent with ignition results.The only thing that the ignition success tests had in common was that their plasma all had a relatively long period of high-temperature duration(HTD).It eventually concludes that the ignition mechanism in this research is the microconvection heat transfer rather than the shock initiation,which differs from that of exploding foil initiators detonating explosives.Furthermore,the methods for evaluating the ignition success of semiconductor bridge initiators are not entirely applicable to the tests mentioned in this paper.The HTD is the critical parameter for judging the ignition success,and it is influenced by two factors:the late time discharge and the energy of the electric explosion.The longer time of the late time discharge and the more energy of the electric explosion,the easier it is to expand the HTD,which improves the probability of the ignition success.
基金supported by the National Projects of the National Research Foundation(NRF)funded by Republic of Korea(#2022R1F1A1072739 and#2022R1A2C1004392)Prof.Nashrah is also grateful for financial supports by the YU Infra-Project in conjunction with BK21 FOUR National Program(#222A251009)by the Nano-Fab-NRF grant funded by Republic of Korea(#2009-0082580).
文摘The trade-off between efficiency and stability has limited the application of TiO_(2)as a catalyst due to its poor surface reactivity.Here,we present a modification of a TiO_(2)layer with highly stable Sub-5 nm Fe_(2)O_(3)nanoparticles(NP)by modulating its structure-surface reactivity relationship to attain efficiency-stability balance via a voltage-assisted oxidation approach.In situ simultaneous oxidation of the Ti substrate and Fe precursor using high-energy plasma driven by high voltage resulted in uniform distribution of Fe_(2)O_(3)NP embedded within porous TiO_(2)layer.Comprehensive surface characterizations with density functional theory demonstrated an improved electronic transition in TiO_(2)due to the presence of surface defects from reactive oxygen species and possible charge transfer from Ti to Fe;it also unexpectedly increased the active site in the TiO_(2)layer due to uncoordinated electrons in Sub-5 nm Fe_(2)O_(3)NP/TiO_(2)catalyst,thereby enhancing the adsorption of chemical functional groups on the catalyst.This unique embedded structure exhibited remarkable improvement in reducing 4-nitrophenol to 4-aminophenol,achieving approximately 99%efficiency in 20 min without stability decay after 20 consecutive cycles,outperforming previously reported TiO_(2)-based catalysts.This finding proposes a modified-electrochemical strategy enabling facile construction of TiO_(2)with nanoscale oxides extandable to other metal oxide systems.
基金supported by the S?o Paulo Research Foundation (FAPESP) (2017/11958-1)the strategic importance of the support given by ANP (Brazil's National Oil,Natural Gas and Biofuels Agency)through the R&D levy regulation and the support from the Brazilian Coordination for the Improvement of Higher Education and Personnel (CAPES)CNPq (PQ-2 grant:Process 304442/2019-4 and UFMT STI-Server for access to their computing resources)。
文摘Lithium-oxygen batteries are a promising technology because they can greatly surpass the energy density of lithium-ion batteries.However,this theoretical characteristic has not yet been converted into a real device with high cyclability.Problems with air contamination,metallic lithium reactivity,and complex discharge and charge reactions are the main issues for this technology.A fast and reversible oxygen reduction reaction(ORR)is crucial for good performance of secondary batteries',but the partial knowledge of its mechanisms,especially when devices are concerned,hinders further development.From this perspective,the present work uses operando Raman experiments and electrochemical impedance spectroscopy(EIS)to assess the first stages of the discharge processes in porous carbon electrodes,following their changes cycle by cycle at initial operation.A growth kinetic formation of the discharge product signal(Li_(2)O_(2))was observed with operando Raman,indicating a first-order reaction and enabling an analysis by a microkinetic model.The solution mechanism in the evaluated system was ascribed for an equivalent circuit with three time constants.While the time constant for the anode interface reveals to remain relatively constant after the first discharge,its surface seemed to be more non-uniform.The model indicated that the reaction occurs at the Li_(2)O_(2) surface,decreasing the associated resistance during the initial discharge phase.Furthermore,the growth of Li_(2)O_(2) forms a hetero-phase between Li_(2)O_(2)/electrolyte,while creating a more compact and homogeneous on the Li_(2)O_(2)/cathode surface.The methodology here described thus offers a way of directly probing changes in surface chemistry evolution during cycling from a device through EIS analysis.
