MXenes,the most recent addition to the 2D material family,have attracted significant attention owing to their distinctive characteristics,including high surface area,conductivity,surface characteristics,mechanical str...MXenes,the most recent addition to the 2D material family,have attracted significant attention owing to their distinctive characteristics,including high surface area,conductivity,surface characteristics,mechanical strength,etc.This review begins by presenting MXenes,providing insights into their structural characteristics,synthesis methods,and surface functional groups.The review covers a thorough analysis of MXene surface properties,including surface chemistry and termination group impacts.The properties of MXenes are influenced by their synthesis,which can be fluorine-based or fluorinedependent.Fluorine-based synthesis techniques involve etching with fluorine-based reagents,mainly including HF or LiF/HCl,while fluorine-free methods include electrochemical etching,chemical vapor deposition(CVD),alkaline etching,Lewis acid-based etching,etc.These techniques result in the emergence of functional groups such as-F,-O,-OH,-Cl,etc.on the MXenes surface,depending on the synthesis method used.Properties of MXenes,such as electrical conductivity,electronic properties,catalytic activity,magnetic properties,mechanical strength,and chemical and thermal stability,are examined,and the role of functional groups in determining these properties is explored.The review delves into the diverse applications of MXenes,encompassing supercapacitors,battery materials,hydrogen storage,fuel cells,electromagnetic interference(EMI) shielding,pollutant removal,water purification,flexible electronics,sensors,additive manufacturing,catalysis,biomedical and healthcare fields,etc.Finally,this article outlines the challenges and opportunities in the current and future development of MXenes research,addressing various aspects such as synthesis scalability,etching challenges,and multifunctionality,and exploring novel applications.The review concludes with future prospects and conclusions envisioning the impact of MXenes on future technologies and innovation.展开更多
Nowadays,the rapid development of the social economy inevitably leads to global energy and environmental crisis.For this reason,more and more scholars focus on the development of photocatalysis and/or electrocatalysis...Nowadays,the rapid development of the social economy inevitably leads to global energy and environmental crisis.For this reason,more and more scholars focus on the development of photocatalysis and/or electrocatalysis technology for the advantage in the sustainable production of high-value-added products,and the high efficiency in pollutants remediation.Although there is plenty of outstanding research has been put forward continuously,most of them focuses on catalysis performance and reaction mechanisms in laboratory conditions.Realizing industrial application of photo/electrocatalytic processes is still a challenge that needs to be overcome by social demand.In this regard,this review comprehensively summarized several explorations in thefield of photo/electrocatalytic reduction towards potential industrial applications in recent years.Special attention is paid to the successful attempts and the current status of photo/electrocatalytic water splitting,carbon dioxide conversion,resource utilization from waste,etc.,by using advanced reactors.The key problems and challenges of photo/electrocatalysis in future industrial practice are also discussed,and the possible development directions are also pointed out from the industry view.展开更多
Flexible sensors based on MXene-polymer composites are highly prospective for next-generation wearable electronics used in human-machine interfaces.One of the motivating factors behind the progress of flexible sensors...Flexible sensors based on MXene-polymer composites are highly prospective for next-generation wearable electronics used in human-machine interfaces.One of the motivating factors behind the progress of flexible sensors is the steady arrival of new conductive materials.MXenes,a new family of 2D nanomaterials,have been draw-ing attention since the last decade due to their high electronic conduc-tivity,processability,mechanical robustness and chemical tunability.In this review,we encompass the fabrication of MXene-based polymeric nanocomposites,their structure-property relationship,and applications in the flexible sensor domain.Moreover,our discussion is not only lim-ited to sensor design,their mechanism,and various modes of sensing platform,but also their future perspective and market throughout the world.With our article,we intend to fortify the bond between flexible matrices and MXenes thus promoting the swift advancement of flexible MXene-sensors for wearable technologies.展开更多
Applying iodine fertilizers to cultivate iodine-rich crops for daily intake is an effective approach for iodine supplementation,especially for aromatic rice.Field experiments were conducted during the early growing se...Applying iodine fertilizers to cultivate iodine-rich crops for daily intake is an effective approach for iodine supplementation,especially for aromatic rice.Field experiments were conducted during the early growing seasons of 2021 and 2022 to evaluate the impacts of foliar application of iodine fertilizer on aromatic rice and to explore the optimal iodine fertilizer concentration.At the full heading stage,six different concentrations of sodium iodide solutions of 0%(CK),0.010%(T1),0.025%(T2),0.050%(T3),0.075%(T4),and 0.100%(T5)were applied to indica aromatic rice cultivars Meixiangzhan 2 and Xiangyaxiangzhan.The results showed that sodium iodide treatments significantly increased the iodine and sodium contents in both leaves and grains.Compared with the CK,the T1 and T2 treatments increased the 2-acetyl-1-pyrroline(2-AP)content in mature grains by 8.41%-101.66%and 13.58%-74.60%,respectively.Improvements in the contents of 1-pyrroline-5-carboxylic acid,proline,1-pyrroline,and methylglyoxal,as well as the activity of proline dehydrogenase were also detected.Additionally,sodium iodide treatments remarkably decreased the chalky grain rate,chalkiness area,and chalkiness degree of aromatic rice,with the T2 treatment exhibiting a 17.79%-47.42%decrease in chalkiness degree compared with the CK.Meanwhile,T1 and T2 treatments showed beneficial impacts on chlorophyll content,photosynthetic characteristics,and yield components,while T3,T4,and T5 treatments exhibited adverse effects on leaf and grain yields.The linear discriminant analysis revealed significant differences between treatments.The correlation analysis and piecewise structural equation modeling showed that the iodine and sodium influenced the photosynthetic characteristics and chlorophyll content of the leaves,thereby regulating the 2-AP biosynthesis and yield components,ultimately affecting the 2-AP content and yield.Overall,this study suggests that foliar application of 0.025%sodium iodide is an effective method to enrich the iodine content in rice grains,improve the grain aroma and appearance quality of aromatic rice,without detrimental effects on grain yield.展开更多
This study aims to further enhance the oil recovery of reservoirs in the Zhong-2 Block of the Gudao Oilfield by identifying the most effective microbial-flooding activator systems and applying them in the field.We beg...This study aims to further enhance the oil recovery of reservoirs in the Zhong-2 Block of the Gudao Oilfield by identifying the most effective microbial-flooding activator systems and applying them in the field.We began by analyzing the structure of the reservoirs'endogenous microbial communities to understand the potential impact of microbial flooding.This was followed by determining commonly used activator systems based on their abilities to stimulate oil-displacement functional bacteria.Through laboratory experiments on oil displacement efficiency and sweep characteristics,we determined the optimal activator injection method(injection ratio)and the requisite bacterial concentration for maximal microbial-flooding efficacy.Finally,we selected the optimal activator systems and applied them to field tests.Our findings suggest the target block is highly receptive to microbial-flooding.In terms of performance,the activator systems ranked as No.3>No.4>No.1>No.2.Interestingly,a deep activator system,when compared to the top-performing No.3 system,exhibited a higher bacterial concentration peak and longer peaking duration.Optimal oil displacement effects were observed at a 1:4 vol ratio between the No.3 activator and deep activator systems,with bacterial concentrations of up to 106 cells/mL or above.Field tests with the selected activator systems,following a specific injection protocol,demonstrated a notable increase in oil production and a reduction in water cut.展开更多
As a promising ultra-wide bandgap semiconductor material,gallium oxide(Ga_(2)O_(3))is attracting extensive attention of researchers due to its feasible growth process,appropriate bandgap of 4.4 e V-5.3 e V allowing fo...As a promising ultra-wide bandgap semiconductor material,gallium oxide(Ga_(2)O_(3))is attracting extensive attention of researchers due to its feasible growth process,appropriate bandgap of 4.4 e V-5.3 e V allowing for deep-ultraviolet(deepUV)detection,good physical and chemical stability,high breakdown field strength and electron mobility,etc.Different from the strict processes for controllable crystalline Ga_(2)O_(3)(usually refer to as stable monoclinicβ-Ga_(2)O_(3)),amorphous Ga_(2)O_(3)(a-Ga_(2)O_(3))film can be prepared uniformly at low temperature on a large-area deposition substrate,suggesting great advantages such as low manufacturing cost and excellent flexibility,dispensing with high-temperature and high vacuum techniques.Thus,a-Ga_(2)O_(3)extremely facilitates important applications in various applied fields.Therefore,in this concise review,we summarize several major deposition methods for a-Ga_(2)O_(3)films,of which the characteristics are discussed.Additionally,potential methods to optimize the film properties are proposed by right of the inspiration from some recent studies.Subsequently,the applications of a-Ga_(2)O_(3)thin films,e.g.,in photodetectors,resistive random access memories(RRAMs)and gas sensors,are represented with a fruitful discussion of their structures and operating mechanisms.展开更多
The purpose of this study was to investigate the clinical application of severe acute respiratory distress syndrome coronavirus-2(SARS-CoV-2)specific antibody detection and anti-SARS-CoV-2 specific monoclonal antibodi...The purpose of this study was to investigate the clinical application of severe acute respiratory distress syndrome coronavirus-2(SARS-CoV-2)specific antibody detection and anti-SARS-CoV-2 specific monoclonal antibodies(mAbs)in the treatment of coronavirus infectious disease 2019(COVID-19).The dynamic changes of SARS-CoV-2 specific antibodies during COVID-19 were studied.Immunoglobulin M(IgM)appeared earlier and lasted for a short time,while immunoglobulin G(IgG)appeared later and lasted longer.IgM tests can be used for early diagnosis of COVID-19,and IgG tests can be used for late diagnosis of COVID-19 and identification of asymptomatic infected persons.The combination of antibody testing and nucleic acid testing,which complement each other,can improve the diagnosis rate of COVID-19.Monoclonal anti-SARS-CoV-2 specific antibodies can be used to treat hospitalized severe and critically ill patients and non-hospitalized mild to moderate COVID-19 patients.COVID-19 convalescent plasma,highly concentrated immunoglobulin,and anti-SARS-CoV-2 specific mAbs are examples of anti-SARS-CoV-2 antibody products.Due to the continuous emergence of mutated strains of the novel coronavirus,especially omicron,its immune escape ability and infectivity are enhanced,making the effects of authorized products reduced or invalid.Therefore,the optimal application of anti-SARS-CoV-2 antibody products(especially anti-SARS-CoV-2 specific mAbs)is more effective in the treatment of COVID-19 and more conducive to patient recovery.展开更多
Magneto-dielectric properties of Co_(2)Z ferrite materials are tuned via Gd doping for applications in high-frequency antennas and filters in the present work.Ba_(3)Co_(2)Fe_(24-x)Gd_(x)O_(41)(x=0.00,0.05,0.10,0.15,an...Magneto-dielectric properties of Co_(2)Z ferrite materials are tuned via Gd doping for applications in high-frequency antennas and filters in the present work.Ba_(3)Co_(2)Fe_(24-x)Gd_(x)O_(41)(x=0.00,0.05,0.10,0.15,and 0.20)materials are successfully prepared by using solid-state method at 925℃for 4 h with 2.5-wt%Bi_(2)O_(3)sintering aids.The content of Gd^(3+)ion can affect micromorphology,grain size,bulk density,and magneto-dielectric properties of the ferrite.With Gd^(3+)ion content increasing,saturation magnetization(Ms)first increases and then decreases.The maximum value of Ms is 44.86 emu/g at x=0.15.Additionally,sites occupied by Gd^(3+)ions can change magnetic anisotropy constant of the ferrite.Magnetocrystalline anisotropy constant(K_1)is derived from initial magnetization curve,and found to be related to spin-orbit coupling and intersublattice interactions between metal ions.The real part of magnetic permeability(μ′)and real part of dielectric permittivity(ε′)are measured in a frequency range of 10 MHz-1 GHz.When x=0.15,material has excellent magneto-dielectric properties(μ′≈12.2 andε′≈17.61),low magnetic loss(tanδμ≈0.03 at 500 MHz),and dielectric loss(tanδε≈0.04 at 500 MHz).The results show that Gd-doped Co_(2)Z ferrite has broad application prospects in multilayer filters and high-frequency antennas.展开更多
Two-dimensional(2D)/quasi-2D organic-inorganic halide perovskites are regarded as naturally formed multiple quantum wells with inorganic layers isolated by long organic chains,which exhibit layered structure,large exc...Two-dimensional(2D)/quasi-2D organic-inorganic halide perovskites are regarded as naturally formed multiple quantum wells with inorganic layers isolated by long organic chains,which exhibit layered structure,large exciton binding energy,strong nonlinear optical effect,tunable bandgap via changing the layer number or chemical composition,improved environmental stability,and excellent optoelectronic properties.The extensive choice of long organic chains endows 2D/quasi-2D perovskites with tunable electron-phonon coupling strength,chirality,or ferroelectricity properties.In particular,the layered nature of 2D/quasi-2D perovskites allows us to exfoliate them to thin plates to integrate with other materials to form heterostructures,the fundamental structural units for optoelectronic devices,which would greatly extend the functionalities in view of the diversity of 2D/quasi-2D perovskites.In this paper,the recent achievements of 2D/quasi-2D perovskite-based heterostructures are reviewed.First,the structure and physical properties of 2D/quasi-2D perovskites are introduced.We then discuss the construction and characterizations of 2D/quasi-2D perovskite-based heterostructures and highlight the prominent optical properties of the constructed heterostructures.Further,the potential applications of 2D/quasi-2D perovskite-based heterostructures in photovoltaic devices,light emitting devices,photodetectors/phototransistors,and valleytronic devices are demonstrated.Finally,we summarize the current challenges and propose further research directions in the field of 2D/quasi-2D perovskite-based heterostructures.展开更多
优化氮肥施用和秸秆还田技术为途径的农业管理措施被认为是提升农业可持续性的有效手段,然而当前关于氮肥和秸秆还田对小麦产量和N_(2)O排放影响的研究仍十分有限。为此,本研究基于2000—2022年发表的关于长江中下游流域氮肥和秸秆投入...优化氮肥施用和秸秆还田技术为途径的农业管理措施被认为是提升农业可持续性的有效手段,然而当前关于氮肥和秸秆还田对小麦产量和N_(2)O排放影响的研究仍十分有限。为此,本研究基于2000—2022年发表的关于长江中下游流域氮肥和秸秆投入下小麦产量和N_(2)O排放变化的文献,运用随机森林建模,定量分析氮肥和秸秆还田对小麦产量和N_(2)O排放的影响,并结合情景设置进行了特定地点的小麦产量和N_(2)O排放模拟,同时评估了碳排放强度(CEE)和净生态系统经济效益(NEEB)。结果表明,建立的区域尺度小麦产量与N_(2)O排放对氮秸互作响应的随机森林模型,验证结果R^(2)分别为0.66和0.65,RMSE分别为0.70和1.11。结果表明施氮量和土壤有机质是影响小麦产量和N_(2)O排放的重要因素。综合来看,达到最大产量所需的氮肥量为208~212 kg hm^(-2),达到最小CEE所需的氮肥量为113~130 kg hm^(-2),达到最高的NEEB所需的氮肥量为202~205 kg hm^(-2),其中在6.75 t hm^(-2)的秸秆投入下施用202 kg hm^(-2)的氮肥可以获得最高的生态收益1.37万元。优化氮肥和秸秆投入具备减少作物碳排放强度并获得最大净生态环境效益的潜力。展开更多
The research analyzed characters of soil stabilizer and detailed the solidification mechanism.Furthermore,new type soil stabilizer Q2 was used in a base of Beijing Vocational College of Agriculture and a solidified ro...The research analyzed characters of soil stabilizer and detailed the solidification mechanism.Furthermore,new type soil stabilizer Q2 was used in a base of Beijing Vocational College of Agriculture and a solidified road with length of 250 m,width of 4 m and thickness of 0.25 m were constructed.The road was tested with an agricultural truck and subgrade tolerance to freezing was tested also.It is suggested that new type soil stabilizer would reduce construction cost of road,protect environment,and reduce construction period,with high value of application.展开更多
Monolithic catalysts of Pt/La-Al2O3 and Pt/Ce0.67Zr0.3302 were prepared to investigate methane selective catalytic reduction (SCR) of NO. The results indicate that Pt/Ce0.67Zr0.33O2 shows high activity and both NO a...Monolithic catalysts of Pt/La-Al2O3 and Pt/Ce0.67Zr0.3302 were prepared to investigate methane selective catalytic reduction (SCR) of NO. The results indicate that Pt/Ce0.67Zr0.33O2 shows high activity and both NO and CH4 can be converted completely at 450℃. Meanwhile, NO and CH4 can be converted completely when there exists excess oxygen. The Pt/Ce0.67Zr0.33O2 catalyst were further investigated by using methane as reducing agent to SCR NO in a novel equipment which combined the CH4 selective catalytic reduction of NO with methane combustion. The result shows that the catalyst is high active and the novel equipment is very effective. The conversion of NO is above 92% under the conditions used in this work. The prepared burner and catalysts have great potential for application.展开更多
A kind of active composite antibacterial material was prepared with CaHPO4 as the container, Ag^+ and Zn^2+ were adsorbed through ion-exchange, then it was doped with small scale of rare earth and photocatalyst, and...A kind of active composite antibacterial material was prepared with CaHPO4 as the container, Ag^+ and Zn^2+ were adsorbed through ion-exchange, then it was doped with small scale of rare earth and photocatalyst, and was finally calcined at a certain temperature. The properties and application of the composite material antibacterial were investigated. Some tests show that the as-prepared antibacterial powders modified by opaque agents such os SnO2 and ZrO2, possess beautiful white and excellent climate resistance at normal temperatures and are promising candidate materials for antibacterial plastics and dope. The result of the application in glaze indicates that Ag^+ can still exist stably, with no color change for the glaze, even being sintered at 1200℃ . SEM , EDS , antibacterial activity analyses and contrast tests reveal that the as-prepared antibacterial powders and the antibacterial glaze both have excellent antibacterial activities, without color change, in the case of dark or brightness.展开更多
The finding of the robust ferroelectricity in HfO_(2)-based thin films is fantastic from the view point of both the fundamentals and the applications.In this review article,the current research status of the future pr...The finding of the robust ferroelectricity in HfO_(2)-based thin films is fantastic from the view point of both the fundamentals and the applications.In this review article,the current research status of the future prospects for the ferroelectric HfO_(2)-based thin films and devices are presented from fundamentals to applications.The related issues are discussed,which include:1)The ferroelectric characteristics observed in HfO_(2)-based films and devices associated with the factors of dopant,strain,interface,thickness,defect,fabrication condition,and more;2)physical understanding on the observed ferroelectric behaviors by the density functional theory(DFT)-based theory calculations;3)the characterizations of microscopic and macroscopic features by transmission electron microscopes-based and electrical properties-based techniques;4)modeling and simulations,5)the performance optimizations,and 6)the applications of some ferroelectric-based devices such as ferroelectric random access memory,ferroelectric-based field effect transistors,and the ferroelectric tunnel junction for the novel information processing systems.展开更多
A split-plot experiment in a rice-winter wheat rotation system was performed to study the effects of water regime and wheat straw application in rice-growing season on N2O emission from following wheat growing season....A split-plot experiment in a rice-winter wheat rotation system was performed to study the effects of water regime and wheat straw application in rice-growing season on N2O emission from following wheat growing season. Water regime in the rice-growing season was designed as the conventional irrigation (flooding/drainage cycle) and the permanent flooding. Wheat straw was incorporated with three rates of 0, 225 and 450 g m-2 into the paddy soil for each water regime just before rice was transplanted. N2O emission was measured by static chamber-gas chromatograph method. Results from the variance analysis indicated that the permanent flooding in rice-growing season markedly enhanced N2O emission in following wheat growing season (P=0. 003), and that the effect of straw application on N2O emission was distinguished between two water regimes. Under the conventional irrigation, incoporation of wheat straw reduced N2O emission in the following wheat growing season, while there were no significant differences in the emission for the straw application rates of 225 and 450 g m-2. No significant differences in N2O emissions were observed among the three rates of straw application for the permanent flooding regime. In addition, the seasonal variation of N2O emission was regulated by soil temperature and moisture. The daily N2O flux (Y, mg m-2 d-1) can be quantitatively described by soil temperature (T, ℃) and moisture (W, WFPS %) asY=A0+A1T+A2W+A3W2(n=23, R2 ≥0. 4159** )or y=C0+C1W+C2W2(n=23,R2≥0. 4074** ). Compared with the effect of soil temperature on N2O emission, soil moisture was an important factor regulating the seasonal pattern of N2O emission.展开更多
One-dimensional(1D)SiO_(2) nanofibers(SNFs),one of the most popular inorganic nanomaterials,have aroused widespread attention because of their excellent chemical stability,as well as unique optical and thermal charact...One-dimensional(1D)SiO_(2) nanofibers(SNFs),one of the most popular inorganic nanomaterials,have aroused widespread attention because of their excellent chemical stability,as well as unique optical and thermal characteristics.Electrospinning is a straightforward and versatile method to prepare 1D SNFs with programmable structures,manageable dimensions,and modifiable properties,which hold great potential in many cutting-edge applications including aerospace,nanodevice,and energy.In this review,substantial advances in the structural design,controllable synthesis,and multifunctional applications of electrospun SNFs are highlighted.We begin with a brief introduction to the fundamental principles,available raw materials,and typical apparatus of electrospun SNFs.We then discuss the strategies for preparing SNFs with diverse structures in detail,especially stressing the newly emerging three-dimensional SiO_(2) nanofibrous aerogels.We continue with focus on major breakthroughs about brittleness-to-flexibility transition of SNFs and the means to achieve their mechanical reinforcement.In addition,we showcase recent applications enabled by electrospun SNFs,with particular emphasis on physical protection,health care and water treatment.In the end,we summarize this review and provide some perspectives on the future development direction of electrospun SNFs.展开更多
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korean government(MSIT)(NRF-2020R1A6A1A03043435 and 2020R1A2C1099862)supported by the Korea Institute for Advancement of Technology(KIAT)grant funded by the Korean Government(MOTIE)(P0012451,The Competency Development Program for Industry Specialist)。
文摘MXenes,the most recent addition to the 2D material family,have attracted significant attention owing to their distinctive characteristics,including high surface area,conductivity,surface characteristics,mechanical strength,etc.This review begins by presenting MXenes,providing insights into their structural characteristics,synthesis methods,and surface functional groups.The review covers a thorough analysis of MXene surface properties,including surface chemistry and termination group impacts.The properties of MXenes are influenced by their synthesis,which can be fluorine-based or fluorinedependent.Fluorine-based synthesis techniques involve etching with fluorine-based reagents,mainly including HF or LiF/HCl,while fluorine-free methods include electrochemical etching,chemical vapor deposition(CVD),alkaline etching,Lewis acid-based etching,etc.These techniques result in the emergence of functional groups such as-F,-O,-OH,-Cl,etc.on the MXenes surface,depending on the synthesis method used.Properties of MXenes,such as electrical conductivity,electronic properties,catalytic activity,magnetic properties,mechanical strength,and chemical and thermal stability,are examined,and the role of functional groups in determining these properties is explored.The review delves into the diverse applications of MXenes,encompassing supercapacitors,battery materials,hydrogen storage,fuel cells,electromagnetic interference(EMI) shielding,pollutant removal,water purification,flexible electronics,sensors,additive manufacturing,catalysis,biomedical and healthcare fields,etc.Finally,this article outlines the challenges and opportunities in the current and future development of MXenes research,addressing various aspects such as synthesis scalability,etching challenges,and multifunctionality,and exploring novel applications.The review concludes with future prospects and conclusions envisioning the impact of MXenes on future technologies and innovation.
基金supported by the National Natural Science Foundation of China(22278030,22090032,22090030,22288102,22242019)the Fundamental Research Funds for the Central Universities(buctrc202119,2312018RC07)+1 种基金Major Program of Qingyuan Innovation Laboratory(Grant No.001220005)the Experiments for Space Exploration Program and the Qian Xuesen Laboratory,China Academy of Space Technology。
文摘Nowadays,the rapid development of the social economy inevitably leads to global energy and environmental crisis.For this reason,more and more scholars focus on the development of photocatalysis and/or electrocatalysis technology for the advantage in the sustainable production of high-value-added products,and the high efficiency in pollutants remediation.Although there is plenty of outstanding research has been put forward continuously,most of them focuses on catalysis performance and reaction mechanisms in laboratory conditions.Realizing industrial application of photo/electrocatalytic processes is still a challenge that needs to be overcome by social demand.In this regard,this review comprehensively summarized several explorations in thefield of photo/electrocatalytic reduction towards potential industrial applications in recent years.Special attention is paid to the successful attempts and the current status of photo/electrocatalytic water splitting,carbon dioxide conversion,resource utilization from waste,etc.,by using advanced reactors.The key problems and challenges of photo/electrocatalysis in future industrial practice are also discussed,and the possible development directions are also pointed out from the industry view.
基金The authors would like to acknowledge the support from the Natural Sciences and Engineering Research Council of Canada in the form of Discovery Grants to ARR and SS(RGPIN-2019-07246 and RGPIN-2022-04988).A.Rosenkranz greatly acknowledges the financial support given by ANID-Chile within the project Fondecyt Regular 1220331 and Fondequip EQM190057.B.Wang gratefully acknowledges the financial support given by the Alexander von Humboldt Foundation.
文摘Flexible sensors based on MXene-polymer composites are highly prospective for next-generation wearable electronics used in human-machine interfaces.One of the motivating factors behind the progress of flexible sensors is the steady arrival of new conductive materials.MXenes,a new family of 2D nanomaterials,have been draw-ing attention since the last decade due to their high electronic conduc-tivity,processability,mechanical robustness and chemical tunability.In this review,we encompass the fabrication of MXene-based polymeric nanocomposites,their structure-property relationship,and applications in the flexible sensor domain.Moreover,our discussion is not only lim-ited to sensor design,their mechanism,and various modes of sensing platform,but also their future perspective and market throughout the world.With our article,we intend to fortify the bond between flexible matrices and MXenes thus promoting the swift advancement of flexible MXene-sensors for wearable technologies.
基金supported by the National Natural Science Foundation of China(Grant No.31971843)the Technology System of Modern Agricultural Industry in Guangdong Province,China(Grant No.2020KJ105)+1 种基金the Guangzhou Science and Technology Project,Guangdong Province,China(Grant No.202103000075)the Special Rural Revitalization Funds of Guangdong Province,China(Grant No.2021KJ382)。
文摘Applying iodine fertilizers to cultivate iodine-rich crops for daily intake is an effective approach for iodine supplementation,especially for aromatic rice.Field experiments were conducted during the early growing seasons of 2021 and 2022 to evaluate the impacts of foliar application of iodine fertilizer on aromatic rice and to explore the optimal iodine fertilizer concentration.At the full heading stage,six different concentrations of sodium iodide solutions of 0%(CK),0.010%(T1),0.025%(T2),0.050%(T3),0.075%(T4),and 0.100%(T5)were applied to indica aromatic rice cultivars Meixiangzhan 2 and Xiangyaxiangzhan.The results showed that sodium iodide treatments significantly increased the iodine and sodium contents in both leaves and grains.Compared with the CK,the T1 and T2 treatments increased the 2-acetyl-1-pyrroline(2-AP)content in mature grains by 8.41%-101.66%and 13.58%-74.60%,respectively.Improvements in the contents of 1-pyrroline-5-carboxylic acid,proline,1-pyrroline,and methylglyoxal,as well as the activity of proline dehydrogenase were also detected.Additionally,sodium iodide treatments remarkably decreased the chalky grain rate,chalkiness area,and chalkiness degree of aromatic rice,with the T2 treatment exhibiting a 17.79%-47.42%decrease in chalkiness degree compared with the CK.Meanwhile,T1 and T2 treatments showed beneficial impacts on chlorophyll content,photosynthetic characteristics,and yield components,while T3,T4,and T5 treatments exhibited adverse effects on leaf and grain yields.The linear discriminant analysis revealed significant differences between treatments.The correlation analysis and piecewise structural equation modeling showed that the iodine and sodium influenced the photosynthetic characteristics and chlorophyll content of the leaves,thereby regulating the 2-AP biosynthesis and yield components,ultimately affecting the 2-AP content and yield.Overall,this study suggests that foliar application of 0.025%sodium iodide is an effective method to enrich the iodine content in rice grains,improve the grain aroma and appearance quality of aromatic rice,without detrimental effects on grain yield.
基金funded by the National Natural Science Foun-dation of China(No.51974343)the China Postdoctoral Science Foundation(No.2021M703588)the Open Fund of Hubei Key Laboratory of Drilling and Production Engineering for Oil and Gas(Yangtze University)(No.YQZC202307).
文摘This study aims to further enhance the oil recovery of reservoirs in the Zhong-2 Block of the Gudao Oilfield by identifying the most effective microbial-flooding activator systems and applying them in the field.We began by analyzing the structure of the reservoirs'endogenous microbial communities to understand the potential impact of microbial flooding.This was followed by determining commonly used activator systems based on their abilities to stimulate oil-displacement functional bacteria.Through laboratory experiments on oil displacement efficiency and sweep characteristics,we determined the optimal activator injection method(injection ratio)and the requisite bacterial concentration for maximal microbial-flooding efficacy.Finally,we selected the optimal activator systems and applied them to field tests.Our findings suggest the target block is highly receptive to microbial-flooding.In terms of performance,the activator systems ranked as No.3>No.4>No.1>No.2.Interestingly,a deep activator system,when compared to the top-performing No.3 system,exhibited a higher bacterial concentration peak and longer peaking duration.Optimal oil displacement effects were observed at a 1:4 vol ratio between the No.3 activator and deep activator systems,with bacterial concentrations of up to 106 cells/mL or above.Field tests with the selected activator systems,following a specific injection protocol,demonstrated a notable increase in oil production and a reduction in water cut.
基金Project supported by the National Key Research and Development Program of China(Grant No.2022YFB3605404)the National Natural Science Foundation of China(Grant Nos.62204126 and 62204125)+1 种基金the Natural Science Research Start-up Foundation of Recruiting Talents of Nanjing University of Posts and Telecommunications(Grant Nos.XK1060921119,XK1060921002,and XK1060921115)the Open Fund of the Key Laboratory of Aerospace Information Materials and Physics(NUAA)MIIT。
文摘As a promising ultra-wide bandgap semiconductor material,gallium oxide(Ga_(2)O_(3))is attracting extensive attention of researchers due to its feasible growth process,appropriate bandgap of 4.4 e V-5.3 e V allowing for deep-ultraviolet(deepUV)detection,good physical and chemical stability,high breakdown field strength and electron mobility,etc.Different from the strict processes for controllable crystalline Ga_(2)O_(3)(usually refer to as stable monoclinicβ-Ga_(2)O_(3)),amorphous Ga_(2)O_(3)(a-Ga_(2)O_(3))film can be prepared uniformly at low temperature on a large-area deposition substrate,suggesting great advantages such as low manufacturing cost and excellent flexibility,dispensing with high-temperature and high vacuum techniques.Thus,a-Ga_(2)O_(3)extremely facilitates important applications in various applied fields.Therefore,in this concise review,we summarize several major deposition methods for a-Ga_(2)O_(3)films,of which the characteristics are discussed.Additionally,potential methods to optimize the film properties are proposed by right of the inspiration from some recent studies.Subsequently,the applications of a-Ga_(2)O_(3)thin films,e.g.,in photodetectors,resistive random access memories(RRAMs)and gas sensors,are represented with a fruitful discussion of their structures and operating mechanisms.
文摘The purpose of this study was to investigate the clinical application of severe acute respiratory distress syndrome coronavirus-2(SARS-CoV-2)specific antibody detection and anti-SARS-CoV-2 specific monoclonal antibodies(mAbs)in the treatment of coronavirus infectious disease 2019(COVID-19).The dynamic changes of SARS-CoV-2 specific antibodies during COVID-19 were studied.Immunoglobulin M(IgM)appeared earlier and lasted for a short time,while immunoglobulin G(IgG)appeared later and lasted longer.IgM tests can be used for early diagnosis of COVID-19,and IgG tests can be used for late diagnosis of COVID-19 and identification of asymptomatic infected persons.The combination of antibody testing and nucleic acid testing,which complement each other,can improve the diagnosis rate of COVID-19.Monoclonal anti-SARS-CoV-2 specific antibodies can be used to treat hospitalized severe and critically ill patients and non-hospitalized mild to moderate COVID-19 patients.COVID-19 convalescent plasma,highly concentrated immunoglobulin,and anti-SARS-CoV-2 specific mAbs are examples of anti-SARS-CoV-2 antibody products.Due to the continuous emergence of mutated strains of the novel coronavirus,especially omicron,its immune escape ability and infectivity are enhanced,making the effects of authorized products reduced or invalid.Therefore,the optimal application of anti-SARS-CoV-2 antibody products(especially anti-SARS-CoV-2 specific mAbs)is more effective in the treatment of COVID-19 and more conducive to patient recovery.
基金the National Key Research and Development Program of China(Grant No.2022YFB3504800)the National Natural Science Foundation of China(Grant Nos.61901142,52003256,and 51902037)the Natural Science Foundation of Shanxi Province,China(Grant No.201901D211259)。
文摘Magneto-dielectric properties of Co_(2)Z ferrite materials are tuned via Gd doping for applications in high-frequency antennas and filters in the present work.Ba_(3)Co_(2)Fe_(24-x)Gd_(x)O_(41)(x=0.00,0.05,0.10,0.15,and 0.20)materials are successfully prepared by using solid-state method at 925℃for 4 h with 2.5-wt%Bi_(2)O_(3)sintering aids.The content of Gd^(3+)ion can affect micromorphology,grain size,bulk density,and magneto-dielectric properties of the ferrite.With Gd^(3+)ion content increasing,saturation magnetization(Ms)first increases and then decreases.The maximum value of Ms is 44.86 emu/g at x=0.15.Additionally,sites occupied by Gd^(3+)ions can change magnetic anisotropy constant of the ferrite.Magnetocrystalline anisotropy constant(K_1)is derived from initial magnetization curve,and found to be related to spin-orbit coupling and intersublattice interactions between metal ions.The real part of magnetic permeability(μ′)and real part of dielectric permittivity(ε′)are measured in a frequency range of 10 MHz-1 GHz.When x=0.15,material has excellent magneto-dielectric properties(μ′≈12.2 andε′≈17.61),low magnetic loss(tanδμ≈0.03 at 500 MHz),and dielectric loss(tanδε≈0.04 at 500 MHz).The results show that Gd-doped Co_(2)Z ferrite has broad application prospects in multilayer filters and high-frequency antennas.
基金support from National Key Research and Development Program of China (2018YFA0704403)NSFC (62074064)Innovation Fund of WNLO
文摘Two-dimensional(2D)/quasi-2D organic-inorganic halide perovskites are regarded as naturally formed multiple quantum wells with inorganic layers isolated by long organic chains,which exhibit layered structure,large exciton binding energy,strong nonlinear optical effect,tunable bandgap via changing the layer number or chemical composition,improved environmental stability,and excellent optoelectronic properties.The extensive choice of long organic chains endows 2D/quasi-2D perovskites with tunable electron-phonon coupling strength,chirality,or ferroelectricity properties.In particular,the layered nature of 2D/quasi-2D perovskites allows us to exfoliate them to thin plates to integrate with other materials to form heterostructures,the fundamental structural units for optoelectronic devices,which would greatly extend the functionalities in view of the diversity of 2D/quasi-2D perovskites.In this paper,the recent achievements of 2D/quasi-2D perovskite-based heterostructures are reviewed.First,the structure and physical properties of 2D/quasi-2D perovskites are introduced.We then discuss the construction and characterizations of 2D/quasi-2D perovskite-based heterostructures and highlight the prominent optical properties of the constructed heterostructures.Further,the potential applications of 2D/quasi-2D perovskite-based heterostructures in photovoltaic devices,light emitting devices,photodetectors/phototransistors,and valleytronic devices are demonstrated.Finally,we summarize the current challenges and propose further research directions in the field of 2D/quasi-2D perovskite-based heterostructures.
文摘优化氮肥施用和秸秆还田技术为途径的农业管理措施被认为是提升农业可持续性的有效手段,然而当前关于氮肥和秸秆还田对小麦产量和N_(2)O排放影响的研究仍十分有限。为此,本研究基于2000—2022年发表的关于长江中下游流域氮肥和秸秆投入下小麦产量和N_(2)O排放变化的文献,运用随机森林建模,定量分析氮肥和秸秆还田对小麦产量和N_(2)O排放的影响,并结合情景设置进行了特定地点的小麦产量和N_(2)O排放模拟,同时评估了碳排放强度(CEE)和净生态系统经济效益(NEEB)。结果表明,建立的区域尺度小麦产量与N_(2)O排放对氮秸互作响应的随机森林模型,验证结果R^(2)分别为0.66和0.65,RMSE分别为0.70和1.11。结果表明施氮量和土壤有机质是影响小麦产量和N_(2)O排放的重要因素。综合来看,达到最大产量所需的氮肥量为208~212 kg hm^(-2),达到最小CEE所需的氮肥量为113~130 kg hm^(-2),达到最高的NEEB所需的氮肥量为202~205 kg hm^(-2),其中在6.75 t hm^(-2)的秸秆投入下施用202 kg hm^(-2)的氮肥可以获得最高的生态收益1.37万元。优化氮肥和秸秆投入具备减少作物碳排放强度并获得最大净生态环境效益的潜力。
基金Beijing Agricultural Science and Technology Project(2013011202)~~
文摘The research analyzed characters of soil stabilizer and detailed the solidification mechanism.Furthermore,new type soil stabilizer Q2 was used in a base of Beijing Vocational College of Agriculture and a solidified road with length of 250 m,width of 4 m and thickness of 0.25 m were constructed.The road was tested with an agricultural truck and subgrade tolerance to freezing was tested also.It is suggested that new type soil stabilizer would reduce construction cost of road,protect environment,and reduce construction period,with high value of application.
基金Supported by the National High Technology Research and Development Program of China (863 Program, 2006AA06Z347)the NationalNatural Science Foundation of China (20773090).
文摘Monolithic catalysts of Pt/La-Al2O3 and Pt/Ce0.67Zr0.3302 were prepared to investigate methane selective catalytic reduction (SCR) of NO. The results indicate that Pt/Ce0.67Zr0.33O2 shows high activity and both NO and CH4 can be converted completely at 450℃. Meanwhile, NO and CH4 can be converted completely when there exists excess oxygen. The Pt/Ce0.67Zr0.33O2 catalyst were further investigated by using methane as reducing agent to SCR NO in a novel equipment which combined the CH4 selective catalytic reduction of NO with methane combustion. The result shows that the catalyst is high active and the novel equipment is very effective. The conversion of NO is above 92% under the conditions used in this work. The prepared burner and catalysts have great potential for application.
文摘A kind of active composite antibacterial material was prepared with CaHPO4 as the container, Ag^+ and Zn^2+ were adsorbed through ion-exchange, then it was doped with small scale of rare earth and photocatalyst, and was finally calcined at a certain temperature. The properties and application of the composite material antibacterial were investigated. Some tests show that the as-prepared antibacterial powders modified by opaque agents such os SnO2 and ZrO2, possess beautiful white and excellent climate resistance at normal temperatures and are promising candidate materials for antibacterial plastics and dope. The result of the application in glaze indicates that Ag^+ can still exist stably, with no color change for the glaze, even being sintered at 1200℃ . SEM , EDS , antibacterial activity analyses and contrast tests reveal that the as-prepared antibacterial powders and the antibacterial glaze both have excellent antibacterial activities, without color change, in the case of dark or brightness.
基金supported by National Key Research and Development Program(grant 2019YFB2205100)National Science Foundation of China(grant 92064001)。
文摘The finding of the robust ferroelectricity in HfO_(2)-based thin films is fantastic from the view point of both the fundamentals and the applications.In this review article,the current research status of the future prospects for the ferroelectric HfO_(2)-based thin films and devices are presented from fundamentals to applications.The related issues are discussed,which include:1)The ferroelectric characteristics observed in HfO_(2)-based films and devices associated with the factors of dopant,strain,interface,thickness,defect,fabrication condition,and more;2)physical understanding on the observed ferroelectric behaviors by the density functional theory(DFT)-based theory calculations;3)the characterizations of microscopic and macroscopic features by transmission electron microscopes-based and electrical properties-based techniques;4)modeling and simulations,5)the performance optimizations,and 6)the applications of some ferroelectric-based devices such as ferroelectric random access memory,ferroelectric-based field effect transistors,and the ferroelectric tunnel junction for the novel information processing systems.
基金This work was supported by the Hundred Talents Program launched by the Chinese Academy of Sciencesthe National Key Basic Research Development Foundation of China(G1999011805).
文摘A split-plot experiment in a rice-winter wheat rotation system was performed to study the effects of water regime and wheat straw application in rice-growing season on N2O emission from following wheat growing season. Water regime in the rice-growing season was designed as the conventional irrigation (flooding/drainage cycle) and the permanent flooding. Wheat straw was incorporated with three rates of 0, 225 and 450 g m-2 into the paddy soil for each water regime just before rice was transplanted. N2O emission was measured by static chamber-gas chromatograph method. Results from the variance analysis indicated that the permanent flooding in rice-growing season markedly enhanced N2O emission in following wheat growing season (P=0. 003), and that the effect of straw application on N2O emission was distinguished between two water regimes. Under the conventional irrigation, incoporation of wheat straw reduced N2O emission in the following wheat growing season, while there were no significant differences in the emission for the straw application rates of 225 and 450 g m-2. No significant differences in N2O emissions were observed among the three rates of straw application for the permanent flooding regime. In addition, the seasonal variation of N2O emission was regulated by soil temperature and moisture. The daily N2O flux (Y, mg m-2 d-1) can be quantitatively described by soil temperature (T, ℃) and moisture (W, WFPS %) asY=A0+A1T+A2W+A3W2(n=23, R2 ≥0. 4159** )or y=C0+C1W+C2W2(n=23,R2≥0. 4074** ). Compared with the effect of soil temperature on N2O emission, soil moisture was an important factor regulating the seasonal pattern of N2O emission.
基金This work was supported by the National Natural Science Foundation of China(Nos.21961132024,51925302,and 52173055)the Ministry of Science and Technology of China(No.2021YFE0105100)the Fundamental Research Funds for the Central Universities and the DHU Distinguished Young Professor Program(No.LZA2020001).
文摘One-dimensional(1D)SiO_(2) nanofibers(SNFs),one of the most popular inorganic nanomaterials,have aroused widespread attention because of their excellent chemical stability,as well as unique optical and thermal characteristics.Electrospinning is a straightforward and versatile method to prepare 1D SNFs with programmable structures,manageable dimensions,and modifiable properties,which hold great potential in many cutting-edge applications including aerospace,nanodevice,and energy.In this review,substantial advances in the structural design,controllable synthesis,and multifunctional applications of electrospun SNFs are highlighted.We begin with a brief introduction to the fundamental principles,available raw materials,and typical apparatus of electrospun SNFs.We then discuss the strategies for preparing SNFs with diverse structures in detail,especially stressing the newly emerging three-dimensional SiO_(2) nanofibrous aerogels.We continue with focus on major breakthroughs about brittleness-to-flexibility transition of SNFs and the means to achieve their mechanical reinforcement.In addition,we showcase recent applications enabled by electrospun SNFs,with particular emphasis on physical protection,health care and water treatment.In the end,we summarize this review and provide some perspectives on the future development direction of electrospun SNFs.