In order to obtain a fundamental understanding of the corrosion behavior oftin in atmosphere, in situ IR-RAS (infrared reflection absorption spectroscopy) measurements wereperformed on tin in humid air containing SO_2...In order to obtain a fundamental understanding of the corrosion behavior oftin in atmosphere, in situ IR-RAS (infrared reflection absorption spectroscopy) measurements wereperformed on tin in humid air containing SO_2 and NO_2 at room temperature. Time-resolved in situ IRspectra in air of 90 percent RH (relative humidity) containing 1 X 10^(-5)-2.2 X 10^(-5) SO_2suggested that the tin oxide layers worked as a protective film and no significant corrosionoccurred. The corrosion products in air of 80 percent-90 percent RH containing 1 X 10^(-5)-2.2 X10^(-5) NO_2 were SnO_2, SnO, nitrate and hyponitrite. The synergistic effect of SO_2 and NO_2 oncorrosion of tin was not observed in air of 90 percent RH containing 0.84 X 10^(-6) SO_2 and 1.8 X10^(-6) NO_2.展开更多
Situs inversus totalis(SIT)is a rare congenital anomaly in which the major organs are reversed from their normal positions.In patients with SIT,the right-lobe graft must be placed in the left upper quadrant(LUQ).Howev...Situs inversus totalis(SIT)is a rare congenital anomaly in which the major organs are reversed from their normal positions.In patients with SIT,the right-lobe graft must be placed in the left upper quadrant(LUQ).However,hepatic outflow obstruction is a critical issue,often requiring radiologic intervention because of compression or kinking following graft regeneration of the vessels[1–3].Therefore,preoperative planning is essential to address the challenges of graft placement and vein reconstruction.Despite these complexities,we previously reported techniques using a reversed modified right-lobe(mRL)graft from a donor in a conventional recipient with SIT[2].Here,we successfully applied a similar concept.展开更多
Optimizing the microchannel design of the next generation of chips requires an understanding of the in situ property evolution of the chip-based materials under fast cooling.This work overcomes the conventional relian...Optimizing the microchannel design of the next generation of chips requires an understanding of the in situ property evolution of the chip-based materials under fast cooling.This work overcomes the conventional reliance on reheating data of melt-quenched glasses by demonstrating direct observations of glass transition on cooling curves utilizing the most advanced fast differential scanning calorimetry.By leveraging an MEMS chip sensor that allows for rapid heat extraction from microgram-sized samples to a purged gas coolant,the device is able to reach ultra-fast cooling rates of up to 40,000 K·s^(−1).Four thermal regions are identified by examining the cooling behaviors of two metallic glasses.This is because the actual rate of the specimen can differ from the programmed rate,especially at high set rate when the actual rate decreases before the glass transition is completed.We define the operational window for reliable cooling curve analysis,build models with empirical and theoretical analyses to determine the maximum feasible cooling rate,and demonstrate how optimizing sample mass and environment temperature broaden this window.The method avoids deceptive structural relaxation effects verified by fictivetemperature analysis and permits the capture of full glass transition during cooling.展开更多
By means the in situ halogenation of the vinyl C-H bond in o-hydroxyphenyl enaminones,the step efficient synthesis of 3-diphenylphosphinyl chromones has been realized through the challenging construction of C-P(Ⅲ) bo...By means the in situ halogenation of the vinyl C-H bond in o-hydroxyphenyl enaminones,the step efficient synthesis of 3-diphenylphosphinyl chromones has been realized through the challenging construction of C-P(Ⅲ) bond by using diphenyl phosphine as reaction partner.In addition,the tunable synthesis of 2-phosphoryl chromanones has been achieved via hydrophosphorylation by simply modifying reaction conditions without using metal reagent.展开更多
Deep mining of natural resources,like coal,is increasingly utilizing directional blasting technology with slit charge for rock blasting at greater depths.This study,based on numerical simulation methods,analyzes the d...Deep mining of natural resources,like coal,is increasingly utilizing directional blasting technology with slit charge for rock blasting at greater depths.This study,based on numerical simulation methods,analyzes the dynamic behavior of slit charge blasting in three aspects:slit tube dynamic response,hoop stress evolution,and crack propagation.According to research findings,the failure mode of the slit tube mainly manifests as a tensile fracture of the inner wall and a shear fracture at the end connection,where the end connection of the slit tube is the weak point of the overall structure.The dynamic response of the slit tube mainly exhibits radial response in the vertical direction of the slit and hoop response in the slit direction.The hoop tensile stress plays a crucial role in determining the spread of cracks caused by explosions.As the in situ stress increases,the peak hoop tensile stress reduces,and the peak hoop compressive stress increases.This hinders the propagation of cracks.In addition,the directional impact is most pronounced in the middle of the borehole,with the longest primary directional crack observed.Conversely,the directional impact is least favorable near the bottom of the borehole.When the in situ stress reaches 60MPa,the purpose of directional fracture has not been achieved,suggesting combining presplit blasting for in situ stress relief to improve rock breaking efficiency.展开更多
Escalating global energy demands and climate urgency necessitate advanced electrochemical energy conversion and storage technologies(EECSTs)like electrocatalysis and rechargeable batteries.Improving their performance ...Escalating global energy demands and climate urgency necessitate advanced electrochemical energy conversion and storage technologies(EECSTs)like electrocatalysis and rechargeable batteries.Improving their performance relies on elucidating reaction mechanisms and structure-performance relationships via in situ studies.This review summarizes recent in situ studies of EECSTs through a variety of advanced characterization techniques aiming at mapping reaction pathways for the rational design of overall high-performance reaction systems.We outline the principles,capabilities,advantages,and limitations of various in situ techniques.Their applications in in situ studies of fuel cells,water/CO_(2)electrolysis,and lithium batteries are highlighted with representative examples.These studies enable dynamic tracking of chemical and structural evolution of overall reaction systems,including materials,intermediates,products,and surroundings during operation,providing insights critical to rational system design.Future advancements will involve integrating multimodal in situ/operando approaches with artificial intelligence to enable real-time monitoring at practical scales.Such integration promises precise mechanistic insights and robust structure-performance correlations,ultimately accelerating the development of high-performance EECSTs aligned with sustainability and market requirements.展开更多
The formation of copper deposits is closely related to hydrothermal processes.Understanding the migration of copper in hydrothermal fluids aids in reconstructing mineralization processes and deciphering deposit genesi...The formation of copper deposits is closely related to hydrothermal processes.Understanding the migration of copper in hydrothermal fluids aids in reconstructing mineralization processes and deciphering deposit genesis.Copper primarily exists as Cu^(+)and Cu^(2+)in hydrothermal solutions,with redox conditions governing their interconversion.In chloride-rich geological fluids,Cu-Cl complexes are considered critical for copper transport.However,the specific types and valence transitions of Cu-Cl complexes under varying hydrothermal conditions remain poorly understood.This study employed in situ Raman spectroscopy to systematically analyze Cu+HCl and CuCl_(2)+K_(2)S_(2)O_(3)/H_(2) systems under saturated vapor pressure at 25-300℃,elucidating the effects of temperature,Cl^(-)concentration,and redox conditions on copper speciation.In the Cu^(+)HCl system,copper dissolved as monovalent Cu-Cl complexes.At high temperatures(>200℃),[CuCl_(2)]^(-)is the dominated species,whereas[CuCl_(3)]^(2-)becomes prevalent at lower temperatures and higher HCl concentrations.For the Cu^(2+)-Cl system,the dominant species transitioned from[Cu(H_(2)O)n]^(2+)(<50℃)to[CuCl_(4)]^(2-)(100℃)and further to[CuCl]^(+)and[CuCl_(2)]^(0) at 300℃.The introduction of reducing agents(K_(2)S_(2)O_(3)/H_(2))facilitated Cu^(2+)→Cu^(+)reduction,thereby stabilizing Cu^(+)-Cl complexes and inducing partial copper precipitation.The behavior of copper in chloriderich hydrothermal fluids observed in this study indicates that high-temperature oxidizing fluids facilitate Cu mobilization,while cooling and redox changes promote deposition and ore minerals formation.展开更多
In situ tumor vaccines,which leverage the antigenic profile of individual tumors,have demonstrated significant potential in tumor immunotherapy.However,their efficacy is often limited by the immunosuppressive tumor mi...In situ tumor vaccines,which leverage the antigenic profile of individual tumors,have demonstrated significant potential in tumor immunotherapy.However,their efficacy is often limited by the immunosuppressive tumor microenvironment(TME)and insufficient tumor targeting.To address these challenges,we engineered in situ nanovaccines through the self-assembly of the photosensitizer indocyanine green,immune adjuvant aluminum(Al^(3+)),and hydrophilic drug zoledronic acid(ZOL).Intravenous injection of these nanovaccines led to efficient tumor accumulation,enhancing drug bioavailability and enabling the release of tumor-associated antigens via photothermal therapy.Additionally,the built-in ZOL induces polarization of tumor-associated macrophages,reversing the immunosuppressive TME.The potent antitumor immune response triggered by these nanovaccines effectively suppresses tumor growth.This study,which integrates a straightforward assembly method,substantial drug loading capacity,and promising therapeutic outcomes,introduces a novel and effective paradigm for carrier-free in situ nanovaccines in cancer treatment.展开更多
The increasing power density of chips poses a significant challenge in the form of material aging for aluminumfilled polydimethylsiloxane(Al/PDMS)composites,which are widely used in thermal interface materials.Despite...The increasing power density of chips poses a significant challenge in the form of material aging for aluminumfilled polydimethylsiloxane(Al/PDMS)composites,which are widely used in thermal interface materials.Despite the growing importance of this issue,the specific mechanisms behind the interfacial aging process remain elusive,hindering a comprehensive grasp of the aging dynamics in these composites.In our research,we have developed an in-situ Raman aging monitoring system that leverages the non-contact and high-resolution capabilities of Raman spectroscopy to study the interface aging process.Our findings indicate a notable decrease in the intensity of the Raman peak as further cross-linking of the molecules during aging,with the most pronounced decline occurring at the interface between aluminum and PDMS.This insight could potentially elucidate why the interface in composite materials is frequently the site of failure during aging.Our study offers a versatile methodology for investigating the interfacial aging of polymer composites,contributing to a broader understanding of the interface behavior in composite materials at the molecular level.展开更多
Anode-free sodium metal batteries hold significant promise for high-energy-density storage but face critical challenges related to sodium deposition dynamics and interfacial instability.Traditional approaches,such as ...Anode-free sodium metal batteries hold significant promise for high-energy-density storage but face critical challenges related to sodium deposition dynamics and interfacial instability.Traditional approaches,such as alloy-based current collectors or fluorinated interfaces,often suffer from irreversible volume expansion or corrosive fabrication processes.This study introduces a solvent co-intercalation-mediated in situ sodiophilic interface engineering strategy to overcome these limitations.A graphitized carbon-modified aluminum current collector dynamically regulates interfacial evolution through solvated sodium-ion co-intercalation during initial cycling,prompting the formation of a C-NaF interface with ultralow Na^(+)adsorption energy.This sodiophilic interface not only facilitates uniform sodium nucleation by providing abundant sodium-philic sites but also encourages the preferential decomposition of anions in the electrolyte,leading to the creation of a robust and NaF-rich solid electrolyte interphase.Consequently,the asymmetric half-cell delivers an ultralow nucleation overpotential(9.7 mV at 0.5 mA cm^(-2))and maintains an average coulombic efficiency of 99.8%over 400 cycles at 1 mA cm^(-2).When combined with a Na_(3)V_(2)(PO_(4))_(2)O_(2)F(NVPOF)cathode,the full cell achieves an energy density of 363 Wh kg^(-1) with 80%capacity retention after 250 cycles at 0.5 C.This work integrates molecular-level dynamic interfacial engineering with macroscopic electrochemical stability,providing a scalable industrial solution for next-generation battery systems.展开更多
Understanding gas generation in lithium-ion batteries during thermal runaway is critical to designing safer electric vehicles.We developed an in situ gas analysis system capable of measuring gases as they are generate...Understanding gas generation in lithium-ion batteries during thermal runaway is critical to designing safer electric vehicles.We developed an in situ gas analysis system capable of measuring gases as they are generated inside a lab-scale battery cell during thermal abuse.Two phases of gas-generating reactions were observed in charged Lithium Nickel Cobalt Manganese Aluminum Oxide(NCMA)-graphite cells.By adding a lithium iron phosphate(LFP)-based reference electrode inside the cell,we find that reactions occurring between the anode and electrolyte generate H_(2) and CO_(2) in the 80–130℃ temperature range.These reactions are correlated with the self-heating onset observed in accelerated rate calorimetry(ARC)and involve both solid electrolyte interphase(SEI)and intercalated lithium.Above 160℃,reactions occurring due to cathode decomposition accelerate thermal runaway and generate large amounts of carbon dioxide,and to a lesser extent,hydrogen and ethylene.The methods presented herein can be used to evaluate cell thermal stability for the design of safer batteries.展开更多
A versatile spectroelectrochemical measurement method of surface-enhanced Raman scattering spectroscopy is developed,and its capability is assessed in an actual electrochemical system.The spectroelectrochemical cell c...A versatile spectroelectrochemical measurement method of surface-enhanced Raman scattering spectroscopy is developed,and its capability is assessed in an actual electrochemical system.The spectroelectrochemical cell consists of a plasmonic sensor with metal nanoparticles and a wire-type working electrode.The advantages of this method over conventional surface-enhanced Raman scattering methods are as follows:1)surface-enhanced Raman scattering for electrode materials that show little plasmon resonance;and 2)measurement without undesirable influences on the physical and chemical states of the electrode surface and transport phenomena of reaction species.During the measurement,the sensor contacts the working electrode wire at a single point,allowing the surface-enhanced Raman scattering signal to be obtained from the interfacial area of the working electrode surface without significantly disturbing the mass transfer of the reaction species.As plasmon-active metal nanoparticles are modified on the sensor surface in advance,destructive and complicated pretreatment processes on the working electrode are not required.The method is applied to the in situ analysis of electrolyte decomposition reactions in a Li metal battery to reveal the potential of each decomposition product of an organic solvent containing Li.The obtained surface-enhanced Raman scattering spectrum corresponding to the voltammogram reveals the pathway for obtaining decomposition products,such as Li_(2)CO_(3).In particular,Li_(2)O_(2)was clearly detected with our setup.It is also revealed from the setup that the Ni electrode surface,in contrast to the Cu,does not hold a stable Li-containing composite layer.Such in situ chemical information will contribute to the effective interfacial design of high-performance batteries.展开更多
Although manganese Prussian blue analogues(Mn-PBAs)offer advantages as cost-effective,high-energy-density cathode materials for sodium-ion batteries,their practical application is severely constrained by substantial c...Although manganese Prussian blue analogues(Mn-PBAs)offer advantages as cost-effective,high-energy-density cathode materials for sodium-ion batteries,their practical application is severely constrained by substantial capacity degradation during long-term cycling.This performance deterioration is closely associated with the structural instability of the material during the cycling process,which is mainly attributed to the gradual dissolution of the active material into the electrolyte and severe lattice distortion during Na+intercalation/deintercalation.Fortunately,the aforementioned challenges can be effectively addressed by fabricating an in situ engineered nickel cage(ISE-NC)on Mn-PBAs(denoted as Mn-PBAs-NC).Experimental characterization combined with theoretical calculations reveals that this spontaneously formed nickel cage not only suppresses the diffusion of Mn-PBAs into the electrolyte but also acts as a structural stabilizer,significantly alleviating lattice distortion during cycling.This dual stabilization mechanism ensures remarkable cycling stability,with Mn-PBAs-NC delivering a retained capacity of 96.4 mA h g^(−1)(80%capacity retention)over 2,300 cycles at 2 C,elevating the cycle life of Mn-PBAs to unprecedented levels.展开更多
Successful ex situ conservation of plant populations requires a high degree of genetic representativeness.However,spatially biased sampling in ex situ conservation efforts may fail to capture all wild genetic clusters...Successful ex situ conservation of plant populations requires a high degree of genetic representativeness.However,spatially biased sampling in ex situ conservation efforts may fail to capture all wild genetic clusters for species with range-wide genetic structure.To investigate the extent of spatially biased sampling in living collections and the coverage of wild genetic clusters in plant populations under ex situ conservation worldwide,we combined a global synthesis of ex situ conservation efforts with a case study of an endangered riparian plant species,Myricaria laxiflora.Our analysis of ex situ conservation worldwide revealed that the majority(82.6%)of ex situ populations fail to cover all wild genetic clusters,largely due to spatially biased sampling with low geographic coverage.Our case study of M.laxiflora showed that genetic diversity differed between the ex situ and upstream populations,while it was comparable between ex situ populations and other wild populations.However,current ex situ populations did not cover all wild genetic clusters,as the upstream genetic cluster was previously uncollected.Our study suggests that the failure to cover all wild genetic clusters in ex situ populations is a widespread issue,and ex situ populations with high genetic diversity can also fail to cover all wild genetic clusters.In future ex situ conservation programs,both the importance of high genetic diversity and the high coverage of wild genetic clusters should be prioritized.展开更多
The strength-ductility synergy in heterogeneous materials offers significant advantages,though their scalable and controlled fabrication remains challenging.This study introduces an in situ fabrication strategy for he...The strength-ductility synergy in heterogeneous materials offers significant advantages,though their scalable and controlled fabrication remains challenging.This study introduces an in situ fabrication strategy for heterogeneous lamellar titanium(HLT)alloy via laser powder bed fusion of a powder mixture consisting of Ti6Al4V(TC4)and 3 wt%Fe.By periodically varying the scanning velocity between layers,a heterogeneous lamellar microstructure is achieved due to the unique Fe distribution originating from the various volumetric energy densities(VEDs).Consequently,the HLT achieves high yield strength(1036 MPa)and ultimate tensile strength(1419 MPa)without compromising uniform elongation(UE),surpassing most TC4 alloys.The high strength may be attributed to precipitation strengthening originating from the nano-sizedαandωprecipitates,while the high UE and work hardening arise from the strain-induced martensite(SIM)and strong hetero-deformation induced(HDI)stress.The denser dual-phase interfaces and smaller grains in the low VED layers contribute to the higher sensitivity to the SIM.A strain gradient between soft and hard layers evolves during loading,and it further enhances the HDI strengthening and SIM behavior.Through this work,the in situ fabrication method and the deformation mechanism of lamellar heterostructure could offer valuable reference for the optimization and application of heterogeneous materials.展开更多
Lithium metal batteries(LMBs)represent a promising solution for next-generation energy storage due to their high energy density,but the growth of lithium dendrites presents significant challenges to their performance ...Lithium metal batteries(LMBs)represent a promising solution for next-generation energy storage due to their high energy density,but the growth of lithium dendrites presents significant challenges to their performance and safety.This review provides a comprehensive overview of the mechanisms behind lithium dendrite formation and the role of in situ/operando observation and phase field simulation in understanding and mitigating this issue,The key driving factors of dendrite growth,such as lithium-ion flux heterogeneity,surface defects,and localized stress,are explored through advanced experimental techniques,which enable real-time visualization of dendrite nucleation and growth dynamics.Complementarily,phase field simulations provide insights into subsurface and temporal evolution of dendrites by modeling thermodynamic and kinetic processes,while machine learning techniques optimize simulation accuracy through data-driven parameter refinement.The integration of experimental observations with simulation models holds great potential in improving understanding and predictive capabilities.Despite ongoing progress,challenges remain in resolving technical limitations in observation techniques,improving computational efficiency,and fostering interdisciplinary collaboration.This review highlights the synergy between experimental and computational strategies in advancing the development of LMBs and calls for continued research to overcome existing hurdles and unlock the full potential of lithium metal anodes.展开更多
Programmable/reprogrammable magneto-responsive composites(MRCs)are highly desirable for applications in soft robotics,morphable actuators,and biomedical devices due to their capabilities of undergoing reversible,compl...Programmable/reprogrammable magneto-responsive composites(MRCs)are highly desirable for applications in soft robotics,morphable actuators,and biomedical devices due to their capabilities of undergoing reversible,complex,untethered,and rapid deformations.However,current MRC-based devices primarily rely on soft matrices,which revert to their original shapes and cease functioning when external magnetic fields are removed.Moreover,their magnetization programming,deformations,and functioning need to alternate between encoding and actuation platforms,limiting the adaptability and efficiency.Here,we present a reprogrammable magnetic shape-memory composite(RM-SMC)integrating a shape-memory polymer(SMP)skeleton with phase-transition magnetic microcapsules.High-intensity laser melts microcapsules for magnetic realignment under programmed fields,while low-intensity laser softens SMP for structural reconfiguration without compromising integrity.This dual-laser strategy facilitates in situ magnetization programming,shape morphing,and function execution within a single material system.Our innovative approach enables unique applications,including omnidirectional multi-degree-of-freedom actuators that can activate light switches,solar trackers that optimize energy capture,and adaptive impellers that modulate fluid pumping.By eliminating platform alternation and enabling shape/function retention post-actuation,the RM-SMC platform overcomes critical limitations in conventional MRCs,establishing a paradigm for multifunctional devices requiring persistent configuration control and field-independent operation.展开更多
Radiation-induced brain injury remains one of the most severe complications of radiotherapy for head and neck tumors,with limited options for prevention and treatment.In situ neural regeneration technology has demonst...Radiation-induced brain injury remains one of the most severe complications of radiotherapy for head and neck tumors,with limited options for prevention and treatment.In situ neural regeneration technology has demonstrated promising therapeutic effects in various neurodegenerative and neurotrauma conditions.In this study,we overexpressed the neural transcription factor NeuroD1 using in situ neural regeneration technology in a radiation-induced brain injury mouse model.This approach converted reactive astrocytes into neurons,increased neuronal density,protected endogenous neurons,decreased microglial activation,reduced peripheral CD8+T cell infiltration,and diminished angiogenesis in the injured area,leading to a significant reduction in lesion volume.Additionally,we explored the potential mechanisms of NeuroD1 in situ neural regeneration technology through bulk RNA sequencing,which showed an upregulation of neurogenesis-related genes and a downregulation of immune response-related and angiogenesis-related genes.Furthermore,our findings suggested that NeuroD1 in situ neural regeneration technology converted reactive astrocytes into neurons and reduced microglial activation in a thalamic hemorrhagic stroke mouse model.In summary,this study supports NeuroD1 in situ neural regeneration technology as a potential therapeutic approach for treating radiation-induced brain injury and hemorrhagic stroke,and offers new insights into the therapeutic role of NeuroD1 in delayed brain injury.展开更多
Economical,stable,and corrosion-resistant catalytic electrodes are still urgently needed for the oxygen evolution reaction(OER)in water and seawater.Herein,a mild electroless plating strategy is used to achieve large-...Economical,stable,and corrosion-resistant catalytic electrodes are still urgently needed for the oxygen evolution reaction(OER)in water and seawater.Herein,a mild electroless plating strategy is used to achieve large-scale preparation of the“integrated”phosphorus-based precatalyst(FeP-NiP)on nickel foam(NF),which is in situ reconstructed into a highly active and corrosion-resistant(Fe)NiOOH phase for OER.The interaction between phosphate anions(PO_(x)^(y-))and iron ions(Fe^(3+))tunes the electronic structure of the catalytic phase to further enhance OER kinetics.The integrated FeP-NiP@NF electrode exhibits low overpotentials for OER in alkaline water/seawater,requiring only 275/289,320/336,and 349/358 mV to reach 0.1,0.5,and 1.0 A cm^(−2),respectively.The in situ reconstructed PO_(x)^(y-)anion electrostatically repels Cl−in seawater electrolytes,allowing stable operation for over 7 days at 1.0 A cm^(−2) in extreme electrolytes(1.0 M KOH+seawater and 6.0 M KOH+seawater),demonstrating industrial-level stability.This study overcomes the complex synthesis limitations of P-based materials through innovative material design,opening new avenues for electrochemical energy conversion.展开更多
Advanced oxidation processes(AOPs)that utilize the highly potent hydroxyl radical(·OH)are a cornerstone of modern environmental remediation.Among these,the Fenton reaction is renowned for its effectiveness[1].How...Advanced oxidation processes(AOPs)that utilize the highly potent hydroxyl radical(·OH)are a cornerstone of modern environmental remediation.Among these,the Fenton reaction is renowned for its effectiveness[1].However,its practical application has been persistently hampered by two fundamental constraints:a strict reliance on acidic conditions(typically pH 2-4)and the need to be continuously supplied,costly externally generated hydrogen peroxide(H_(2)O_(2))[2-4].展开更多
文摘In order to obtain a fundamental understanding of the corrosion behavior oftin in atmosphere, in situ IR-RAS (infrared reflection absorption spectroscopy) measurements wereperformed on tin in humid air containing SO_2 and NO_2 at room temperature. Time-resolved in situ IRspectra in air of 90 percent RH (relative humidity) containing 1 X 10^(-5)-2.2 X 10^(-5) SO_2suggested that the tin oxide layers worked as a protective film and no significant corrosionoccurred. The corrosion products in air of 80 percent-90 percent RH containing 1 X 10^(-5)-2.2 X10^(-5) NO_2 were SnO_2, SnO, nitrate and hyponitrite. The synergistic effect of SO_2 and NO_2 oncorrosion of tin was not observed in air of 90 percent RH containing 0.84 X 10^(-6) SO_2 and 1.8 X10^(-6) NO_2.
文摘Situs inversus totalis(SIT)is a rare congenital anomaly in which the major organs are reversed from their normal positions.In patients with SIT,the right-lobe graft must be placed in the left upper quadrant(LUQ).However,hepatic outflow obstruction is a critical issue,often requiring radiologic intervention because of compression or kinking following graft regeneration of the vessels[1–3].Therefore,preoperative planning is essential to address the challenges of graft placement and vein reconstruction.Despite these complexities,we previously reported techniques using a reversed modified right-lobe(mRL)graft from a donor in a conventional recipient with SIT[2].Here,we successfully applied a similar concept.
基金supported by the National Natural Science Foundation of China (Grant Nos.92580120 and 52471188)。
文摘Optimizing the microchannel design of the next generation of chips requires an understanding of the in situ property evolution of the chip-based materials under fast cooling.This work overcomes the conventional reliance on reheating data of melt-quenched glasses by demonstrating direct observations of glass transition on cooling curves utilizing the most advanced fast differential scanning calorimetry.By leveraging an MEMS chip sensor that allows for rapid heat extraction from microgram-sized samples to a purged gas coolant,the device is able to reach ultra-fast cooling rates of up to 40,000 K·s^(−1).Four thermal regions are identified by examining the cooling behaviors of two metallic glasses.This is because the actual rate of the specimen can differ from the programmed rate,especially at high set rate when the actual rate decreases before the glass transition is completed.We define the operational window for reliable cooling curve analysis,build models with empirical and theoretical analyses to determine the maximum feasible cooling rate,and demonstrate how optimizing sample mass and environment temperature broaden this window.The method avoids deceptive structural relaxation effects verified by fictivetemperature analysis and permits the capture of full glass transition during cooling.
基金financially supported by the National Natural Science Foundation of China (No.22261026)。
文摘By means the in situ halogenation of the vinyl C-H bond in o-hydroxyphenyl enaminones,the step efficient synthesis of 3-diphenylphosphinyl chromones has been realized through the challenging construction of C-P(Ⅲ) bond by using diphenyl phosphine as reaction partner.In addition,the tunable synthesis of 2-phosphoryl chromanones has been achieved via hydrophosphorylation by simply modifying reaction conditions without using metal reagent.
基金National Natural Science Foundation of China,Grant/Award Numbers:52204085,52227805。
文摘Deep mining of natural resources,like coal,is increasingly utilizing directional blasting technology with slit charge for rock blasting at greater depths.This study,based on numerical simulation methods,analyzes the dynamic behavior of slit charge blasting in three aspects:slit tube dynamic response,hoop stress evolution,and crack propagation.According to research findings,the failure mode of the slit tube mainly manifests as a tensile fracture of the inner wall and a shear fracture at the end connection,where the end connection of the slit tube is the weak point of the overall structure.The dynamic response of the slit tube mainly exhibits radial response in the vertical direction of the slit and hoop response in the slit direction.The hoop tensile stress plays a crucial role in determining the spread of cracks caused by explosions.As the in situ stress increases,the peak hoop tensile stress reduces,and the peak hoop compressive stress increases.This hinders the propagation of cracks.In addition,the directional impact is most pronounced in the middle of the borehole,with the longest primary directional crack observed.Conversely,the directional impact is least favorable near the bottom of the borehole.When the in situ stress reaches 60MPa,the purpose of directional fracture has not been achieved,suggesting combining presplit blasting for in situ stress relief to improve rock breaking efficiency.
基金supported by the National Key Research and Development Program of China(2023YFA1508004)the National Natural Science Foundation of China(T2293692,22502164,92472203,22222903,52271229,22472074,22272069,22361132532,and 22021001)+6 种基金the Industry-University-Research Joint Innovation Project of Fujian Province(2023H6029)the Beijing National Laboratory for Molecular Sciences(BNLMS202305)the Scientific and Technological Project of Yunnan Precious Metals Laboratory(YPML-20240502063)the Liaoning Binhai Laboratory(Grant No.2024-05)the State Key Laboratory of Fine Chemicals,Dalian University of Technology(KF 2401)the Postdoctoral Fellowship Program of CPSF under Grant Number GZC20240897the China Postdoctoral Science Foundation(No.2025M770016).
文摘Escalating global energy demands and climate urgency necessitate advanced electrochemical energy conversion and storage technologies(EECSTs)like electrocatalysis and rechargeable batteries.Improving their performance relies on elucidating reaction mechanisms and structure-performance relationships via in situ studies.This review summarizes recent in situ studies of EECSTs through a variety of advanced characterization techniques aiming at mapping reaction pathways for the rational design of overall high-performance reaction systems.We outline the principles,capabilities,advantages,and limitations of various in situ techniques.Their applications in in situ studies of fuel cells,water/CO_(2)electrolysis,and lithium batteries are highlighted with representative examples.These studies enable dynamic tracking of chemical and structural evolution of overall reaction systems,including materials,intermediates,products,and surroundings during operation,providing insights critical to rational system design.Future advancements will involve integrating multimodal in situ/operando approaches with artificial intelligence to enable real-time monitoring at practical scales.Such integration promises precise mechanistic insights and robust structure-performance correlations,ultimately accelerating the development of high-performance EECSTs aligned with sustainability and market requirements.
基金jointly funded by the Strategic Priority Research Program of the Chinese Academy of Sciences(grant No.XDA0430301)the National Natural Science Foundation of China(grant Nos.42130109,41973059)。
文摘The formation of copper deposits is closely related to hydrothermal processes.Understanding the migration of copper in hydrothermal fluids aids in reconstructing mineralization processes and deciphering deposit genesis.Copper primarily exists as Cu^(+)and Cu^(2+)in hydrothermal solutions,with redox conditions governing their interconversion.In chloride-rich geological fluids,Cu-Cl complexes are considered critical for copper transport.However,the specific types and valence transitions of Cu-Cl complexes under varying hydrothermal conditions remain poorly understood.This study employed in situ Raman spectroscopy to systematically analyze Cu+HCl and CuCl_(2)+K_(2)S_(2)O_(3)/H_(2) systems under saturated vapor pressure at 25-300℃,elucidating the effects of temperature,Cl^(-)concentration,and redox conditions on copper speciation.In the Cu^(+)HCl system,copper dissolved as monovalent Cu-Cl complexes.At high temperatures(>200℃),[CuCl_(2)]^(-)is the dominated species,whereas[CuCl_(3)]^(2-)becomes prevalent at lower temperatures and higher HCl concentrations.For the Cu^(2+)-Cl system,the dominant species transitioned from[Cu(H_(2)O)n]^(2+)(<50℃)to[CuCl_(4)]^(2-)(100℃)and further to[CuCl]^(+)and[CuCl_(2)]^(0) at 300℃.The introduction of reducing agents(K_(2)S_(2)O_(3)/H_(2))facilitated Cu^(2+)→Cu^(+)reduction,thereby stabilizing Cu^(+)-Cl complexes and inducing partial copper precipitation.The behavior of copper in chloriderich hydrothermal fluids observed in this study indicates that high-temperature oxidizing fluids facilitate Cu mobilization,while cooling and redox changes promote deposition and ore minerals formation.
基金supported by Natural Science Foundation of Shandong Province(Nos.ZR2023MB081,ZR2024QB346)Shandong Traditional Chinese Medicine Technology Project(No.Q-2023127).
文摘In situ tumor vaccines,which leverage the antigenic profile of individual tumors,have demonstrated significant potential in tumor immunotherapy.However,their efficacy is often limited by the immunosuppressive tumor microenvironment(TME)and insufficient tumor targeting.To address these challenges,we engineered in situ nanovaccines through the self-assembly of the photosensitizer indocyanine green,immune adjuvant aluminum(Al^(3+)),and hydrophilic drug zoledronic acid(ZOL).Intravenous injection of these nanovaccines led to efficient tumor accumulation,enhancing drug bioavailability and enabling the release of tumor-associated antigens via photothermal therapy.Additionally,the built-in ZOL induces polarization of tumor-associated macrophages,reversing the immunosuppressive TME.The potent antitumor immune response triggered by these nanovaccines effectively suppresses tumor growth.This study,which integrates a straightforward assembly method,substantial drug loading capacity,and promising therapeutic outcomes,introduces a novel and effective paradigm for carrier-free in situ nanovaccines in cancer treatment.
基金supported by the National Natural Science Foundation of China(No.52303092)Talent Recruitment Project of Guangdong Province(No.2023QN10X078)+2 种基金Open Project of Yunnan Precious Metals Laboratory Co.,Ltd(No.YPML-2023050278)National Key R&D Project from Ministry of Science and Technology of China(No.2022YFA1203100)Shenzhen Science and Technology Research Funding(No.JCYJ20200109114401708)。
文摘The increasing power density of chips poses a significant challenge in the form of material aging for aluminumfilled polydimethylsiloxane(Al/PDMS)composites,which are widely used in thermal interface materials.Despite the growing importance of this issue,the specific mechanisms behind the interfacial aging process remain elusive,hindering a comprehensive grasp of the aging dynamics in these composites.In our research,we have developed an in-situ Raman aging monitoring system that leverages the non-contact and high-resolution capabilities of Raman spectroscopy to study the interface aging process.Our findings indicate a notable decrease in the intensity of the Raman peak as further cross-linking of the molecules during aging,with the most pronounced decline occurring at the interface between aluminum and PDMS.This insight could potentially elucidate why the interface in composite materials is frequently the site of failure during aging.Our study offers a versatile methodology for investigating the interfacial aging of polymer composites,contributing to a broader understanding of the interface behavior in composite materials at the molecular level.
基金supported by the Natural Science Foundation Project of CQ(cstb2023nscq-msX0046).
文摘Anode-free sodium metal batteries hold significant promise for high-energy-density storage but face critical challenges related to sodium deposition dynamics and interfacial instability.Traditional approaches,such as alloy-based current collectors or fluorinated interfaces,often suffer from irreversible volume expansion or corrosive fabrication processes.This study introduces a solvent co-intercalation-mediated in situ sodiophilic interface engineering strategy to overcome these limitations.A graphitized carbon-modified aluminum current collector dynamically regulates interfacial evolution through solvated sodium-ion co-intercalation during initial cycling,prompting the formation of a C-NaF interface with ultralow Na^(+)adsorption energy.This sodiophilic interface not only facilitates uniform sodium nucleation by providing abundant sodium-philic sites but also encourages the preferential decomposition of anions in the electrolyte,leading to the creation of a robust and NaF-rich solid electrolyte interphase.Consequently,the asymmetric half-cell delivers an ultralow nucleation overpotential(9.7 mV at 0.5 mA cm^(-2))and maintains an average coulombic efficiency of 99.8%over 400 cycles at 1 mA cm^(-2).When combined with a Na_(3)V_(2)(PO_(4))_(2)O_(2)F(NVPOF)cathode,the full cell achieves an energy density of 363 Wh kg^(-1) with 80%capacity retention after 250 cycles at 0.5 C.This work integrates molecular-level dynamic interfacial engineering with macroscopic electrochemical stability,providing a scalable industrial solution for next-generation battery systems.
基金supported by General Motors Research and Development。
文摘Understanding gas generation in lithium-ion batteries during thermal runaway is critical to designing safer electric vehicles.We developed an in situ gas analysis system capable of measuring gases as they are generated inside a lab-scale battery cell during thermal abuse.Two phases of gas-generating reactions were observed in charged Lithium Nickel Cobalt Manganese Aluminum Oxide(NCMA)-graphite cells.By adding a lithium iron phosphate(LFP)-based reference electrode inside the cell,we find that reactions occurring between the anode and electrolyte generate H_(2) and CO_(2) in the 80–130℃ temperature range.These reactions are correlated with the self-heating onset observed in accelerated rate calorimetry(ARC)and involve both solid electrolyte interphase(SEI)and intercalated lithium.Above 160℃,reactions occurring due to cathode decomposition accelerate thermal runaway and generate large amounts of carbon dioxide,and to a lesser extent,hydrogen and ethylene.The methods presented herein can be used to evaluate cell thermal stability for the design of safer batteries.
基金is partly based on the results obtained from the“Research and Development Initiative for Scientific Innovation of New Generation Batteries 2 and 3(RISING2 and RISING3)”projects commissioned by the New EnergyIndustrial Technology Development Organization(NEDO),Japan(Project codes:JPNP16001 and JPNP21006).
文摘A versatile spectroelectrochemical measurement method of surface-enhanced Raman scattering spectroscopy is developed,and its capability is assessed in an actual electrochemical system.The spectroelectrochemical cell consists of a plasmonic sensor with metal nanoparticles and a wire-type working electrode.The advantages of this method over conventional surface-enhanced Raman scattering methods are as follows:1)surface-enhanced Raman scattering for electrode materials that show little plasmon resonance;and 2)measurement without undesirable influences on the physical and chemical states of the electrode surface and transport phenomena of reaction species.During the measurement,the sensor contacts the working electrode wire at a single point,allowing the surface-enhanced Raman scattering signal to be obtained from the interfacial area of the working electrode surface without significantly disturbing the mass transfer of the reaction species.As plasmon-active metal nanoparticles are modified on the sensor surface in advance,destructive and complicated pretreatment processes on the working electrode are not required.The method is applied to the in situ analysis of electrolyte decomposition reactions in a Li metal battery to reveal the potential of each decomposition product of an organic solvent containing Li.The obtained surface-enhanced Raman scattering spectrum corresponding to the voltammogram reveals the pathway for obtaining decomposition products,such as Li_(2)CO_(3).In particular,Li_(2)O_(2)was clearly detected with our setup.It is also revealed from the setup that the Ni electrode surface,in contrast to the Cu,does not hold a stable Li-containing composite layer.Such in situ chemical information will contribute to the effective interfacial design of high-performance batteries.
基金financially supported by the Ten-thousand Talents Programthe K. C. Wong Pioneer Talent Program+3 种基金China Three Gorges Corporation (WWKY-2021–0027)Inner Mongolia Science and Technology Plan (2021ZD0033)the National Natural Science Foundation of China (52202121)funded by China Petroleum&Chemical Corporation (123091)
文摘Although manganese Prussian blue analogues(Mn-PBAs)offer advantages as cost-effective,high-energy-density cathode materials for sodium-ion batteries,their practical application is severely constrained by substantial capacity degradation during long-term cycling.This performance deterioration is closely associated with the structural instability of the material during the cycling process,which is mainly attributed to the gradual dissolution of the active material into the electrolyte and severe lattice distortion during Na+intercalation/deintercalation.Fortunately,the aforementioned challenges can be effectively addressed by fabricating an in situ engineered nickel cage(ISE-NC)on Mn-PBAs(denoted as Mn-PBAs-NC).Experimental characterization combined with theoretical calculations reveals that this spontaneously formed nickel cage not only suppresses the diffusion of Mn-PBAs into the electrolyte but also acts as a structural stabilizer,significantly alleviating lattice distortion during cycling.This dual stabilization mechanism ensures remarkable cycling stability,with Mn-PBAs-NC delivering a retained capacity of 96.4 mA h g^(−1)(80%capacity retention)over 2,300 cycles at 2 C,elevating the cycle life of Mn-PBAs to unprecedented levels.
基金supported by National Key Research and Development Program of China(2024YFF1307400)Hubei Provincial Natural Science Foundation and Three Gorges Innovation Development Joint Fund(Grant No.2023AFD195)China Three Gorges Corporation(NBZZ202300130).
文摘Successful ex situ conservation of plant populations requires a high degree of genetic representativeness.However,spatially biased sampling in ex situ conservation efforts may fail to capture all wild genetic clusters for species with range-wide genetic structure.To investigate the extent of spatially biased sampling in living collections and the coverage of wild genetic clusters in plant populations under ex situ conservation worldwide,we combined a global synthesis of ex situ conservation efforts with a case study of an endangered riparian plant species,Myricaria laxiflora.Our analysis of ex situ conservation worldwide revealed that the majority(82.6%)of ex situ populations fail to cover all wild genetic clusters,largely due to spatially biased sampling with low geographic coverage.Our case study of M.laxiflora showed that genetic diversity differed between the ex situ and upstream populations,while it was comparable between ex situ populations and other wild populations.However,current ex situ populations did not cover all wild genetic clusters,as the upstream genetic cluster was previously uncollected.Our study suggests that the failure to cover all wild genetic clusters in ex situ populations is a widespread issue,and ex situ populations with high genetic diversity can also fail to cover all wild genetic clusters.In future ex situ conservation programs,both the importance of high genetic diversity and the high coverage of wild genetic clusters should be prioritized.
基金financially supported by the National Natural Science Foundation of China(No.52375347)Shanghai Pujiang Programme(No.8003PJD023)Natural Science Foundation of Ningbo(Grant No.2023J008)。
文摘The strength-ductility synergy in heterogeneous materials offers significant advantages,though their scalable and controlled fabrication remains challenging.This study introduces an in situ fabrication strategy for heterogeneous lamellar titanium(HLT)alloy via laser powder bed fusion of a powder mixture consisting of Ti6Al4V(TC4)and 3 wt%Fe.By periodically varying the scanning velocity between layers,a heterogeneous lamellar microstructure is achieved due to the unique Fe distribution originating from the various volumetric energy densities(VEDs).Consequently,the HLT achieves high yield strength(1036 MPa)and ultimate tensile strength(1419 MPa)without compromising uniform elongation(UE),surpassing most TC4 alloys.The high strength may be attributed to precipitation strengthening originating from the nano-sizedαandωprecipitates,while the high UE and work hardening arise from the strain-induced martensite(SIM)and strong hetero-deformation induced(HDI)stress.The denser dual-phase interfaces and smaller grains in the low VED layers contribute to the higher sensitivity to the SIM.A strain gradient between soft and hard layers evolves during loading,and it further enhances the HDI strengthening and SIM behavior.Through this work,the in situ fabrication method and the deformation mechanism of lamellar heterostructure could offer valuable reference for the optimization and application of heterogeneous materials.
基金the financial support of the National Natural Science Foundation of China(Nos.12172206 and 11972218)。
文摘Lithium metal batteries(LMBs)represent a promising solution for next-generation energy storage due to their high energy density,but the growth of lithium dendrites presents significant challenges to their performance and safety.This review provides a comprehensive overview of the mechanisms behind lithium dendrite formation and the role of in situ/operando observation and phase field simulation in understanding and mitigating this issue,The key driving factors of dendrite growth,such as lithium-ion flux heterogeneity,surface defects,and localized stress,are explored through advanced experimental techniques,which enable real-time visualization of dendrite nucleation and growth dynamics.Complementarily,phase field simulations provide insights into subsurface and temporal evolution of dendrites by modeling thermodynamic and kinetic processes,while machine learning techniques optimize simulation accuracy through data-driven parameter refinement.The integration of experimental observations with simulation models holds great potential in improving understanding and predictive capabilities.Despite ongoing progress,challenges remain in resolving technical limitations in observation techniques,improving computational efficiency,and fostering interdisciplinary collaboration.This review highlights the synergy between experimental and computational strategies in advancing the development of LMBs and calls for continued research to overcome existing hurdles and unlock the full potential of lithium metal anodes.
基金supported by the National Natural Science Foundation of China(Nos.52075516,61927814,62325507,and 52122511)the National Key Research and Development Program of China(No.2021YFF0502700)+2 种基金the Major Scientific and Technological Projects in Anhui Province(202103a05020005,202203a05020014)the Students’Innovation and Entrepreneurship Foundation of USTC(CY2022G09)the Hefei Municipal Natural Science Foundation(No.HZR2450)。
文摘Programmable/reprogrammable magneto-responsive composites(MRCs)are highly desirable for applications in soft robotics,morphable actuators,and biomedical devices due to their capabilities of undergoing reversible,complex,untethered,and rapid deformations.However,current MRC-based devices primarily rely on soft matrices,which revert to their original shapes and cease functioning when external magnetic fields are removed.Moreover,their magnetization programming,deformations,and functioning need to alternate between encoding and actuation platforms,limiting the adaptability and efficiency.Here,we present a reprogrammable magnetic shape-memory composite(RM-SMC)integrating a shape-memory polymer(SMP)skeleton with phase-transition magnetic microcapsules.High-intensity laser melts microcapsules for magnetic realignment under programmed fields,while low-intensity laser softens SMP for structural reconfiguration without compromising integrity.This dual-laser strategy facilitates in situ magnetization programming,shape morphing,and function execution within a single material system.Our innovative approach enables unique applications,including omnidirectional multi-degree-of-freedom actuators that can activate light switches,solar trackers that optimize energy capture,and adaptive impellers that modulate fluid pumping.By eliminating platform alternation and enabling shape/function retention post-actuation,the RM-SMC platform overcomes critical limitations in conventional MRCs,establishing a paradigm for multifunctional devices requiring persistent configuration control and field-independent operation.
基金the National Natural Science Foundation of China,Nos.81925031(to YT)82330099(to YT)+7 种基金82404189(to KZ)the Key-Area Research and Development Program of Guangdong Province,No.2023B0303040003(to YT)STI 2030-Major Projects,No.2022ZD0211603(to YT)Guangzhou Key Projects of Brain Science and Brain-Like Intelligence Technology,No.202206060002(to GC and YS)Science and Technology Project of Guangdong Province,No.2018B030332001(to GC)Guangdong Provincial Pearl River Project,No.2021ZT09Y552(to GC)the Guangdong Basic and Applied Basic Research Foundation,No.2022A1515110189(to KZ)Sun Yat-sen Pilot Scientific Research Fund,No.YXQH202427(to KZ).
文摘Radiation-induced brain injury remains one of the most severe complications of radiotherapy for head and neck tumors,with limited options for prevention and treatment.In situ neural regeneration technology has demonstrated promising therapeutic effects in various neurodegenerative and neurotrauma conditions.In this study,we overexpressed the neural transcription factor NeuroD1 using in situ neural regeneration technology in a radiation-induced brain injury mouse model.This approach converted reactive astrocytes into neurons,increased neuronal density,protected endogenous neurons,decreased microglial activation,reduced peripheral CD8+T cell infiltration,and diminished angiogenesis in the injured area,leading to a significant reduction in lesion volume.Additionally,we explored the potential mechanisms of NeuroD1 in situ neural regeneration technology through bulk RNA sequencing,which showed an upregulation of neurogenesis-related genes and a downregulation of immune response-related and angiogenesis-related genes.Furthermore,our findings suggested that NeuroD1 in situ neural regeneration technology converted reactive astrocytes into neurons and reduced microglial activation in a thalamic hemorrhagic stroke mouse model.In summary,this study supports NeuroD1 in situ neural regeneration technology as a potential therapeutic approach for treating radiation-induced brain injury and hemorrhagic stroke,and offers new insights into the therapeutic role of NeuroD1 in delayed brain injury.
基金funding support from Natural Science Foundation of Shanghai(Grant No.23ZR1443900)the National Natural Science Foundation of China(Grant Nos.22178309,22476131 and 22176127)。
文摘Economical,stable,and corrosion-resistant catalytic electrodes are still urgently needed for the oxygen evolution reaction(OER)in water and seawater.Herein,a mild electroless plating strategy is used to achieve large-scale preparation of the“integrated”phosphorus-based precatalyst(FeP-NiP)on nickel foam(NF),which is in situ reconstructed into a highly active and corrosion-resistant(Fe)NiOOH phase for OER.The interaction between phosphate anions(PO_(x)^(y-))and iron ions(Fe^(3+))tunes the electronic structure of the catalytic phase to further enhance OER kinetics.The integrated FeP-NiP@NF electrode exhibits low overpotentials for OER in alkaline water/seawater,requiring only 275/289,320/336,and 349/358 mV to reach 0.1,0.5,and 1.0 A cm^(−2),respectively.The in situ reconstructed PO_(x)^(y-)anion electrostatically repels Cl−in seawater electrolytes,allowing stable operation for over 7 days at 1.0 A cm^(−2) in extreme electrolytes(1.0 M KOH+seawater and 6.0 M KOH+seawater),demonstrating industrial-level stability.This study overcomes the complex synthesis limitations of P-based materials through innovative material design,opening new avenues for electrochemical energy conversion.
基金Cardiff University and the Max Planck Centre for Fundamental Heterogeneous Catalysis(FUNCAT)for financial supportthe Marie Skłodowska-Curie Actions Fellowship(101107009-AtomCat4Fuel)UKRI(EP/Y029305/1)。
文摘Advanced oxidation processes(AOPs)that utilize the highly potent hydroxyl radical(·OH)are a cornerstone of modern environmental remediation.Among these,the Fenton reaction is renowned for its effectiveness[1].However,its practical application has been persistently hampered by two fundamental constraints:a strict reliance on acidic conditions(typically pH 2-4)and the need to be continuously supplied,costly externally generated hydrogen peroxide(H_(2)O_(2))[2-4].
