This study proposes a lightweight rice disease detection model optimized for edge computing environments.The goal is to enhance the You Only Look Once(YOLO)v5 architecture to achieve a balance between real-time diagno...This study proposes a lightweight rice disease detection model optimized for edge computing environments.The goal is to enhance the You Only Look Once(YOLO)v5 architecture to achieve a balance between real-time diagnostic performance and computational efficiency.To this end,a total of 3234 high-resolution images(2400×1080)were collected from three major rice diseases Rice Blast,Bacterial Blight,and Brown Spot—frequently found in actual rice cultivation fields.These images served as the training dataset.The proposed YOLOv5-V2 model removes the Focus layer from the original YOLOv5s and integrates ShuffleNet V2 into the backbone,thereby resulting in both model compression and improved inference speed.Additionally,YOLOv5-P,based on PP-PicoDet,was configured as a comparative model to quantitatively evaluate performance.Experimental results demonstrated that YOLOv5-V2 achieved excellent detection performance,with an mAP 0.5 of 89.6%,mAP 0.5–0.95 of 66.7%,precision of 91.3%,and recall of 85.6%,while maintaining a lightweight model size of 6.45 MB.In contrast,YOLOv5-P exhibited a smaller model size of 4.03 MB,but showed lower performance with an mAP 0.5 of 70.3%,mAP 0.5–0.95 of 35.2%,precision of 62.3%,and recall of 74.1%.This study lays a technical foundation for the implementation of smart agriculture and real-time disease diagnosis systems by proposing a model that satisfies both accuracy and lightweight requirements.展开更多
A 12-metal Zn(Ⅱ)-Nd(Ⅲ) cluster 1(sizes:1.8 nm×2.0 nm×2.0 nm) was synthesized from a long-chain type Schiff base ligand.It displays ratiometric fluorescence response to neopterin(Neo) with high selectivity ...A 12-metal Zn(Ⅱ)-Nd(Ⅲ) cluster 1(sizes:1.8 nm×2.0 nm×2.0 nm) was synthesized from a long-chain type Schiff base ligand.It displays ratiometric fluorescence response to neopterin(Neo) with high selectivity and sensitivity,which can be expressed by the equation I_(545)_(nm)/I_(1060)_(nm)=A·[Neo]^(2)+B·[Neo]+C.1 is used to quantitatively test Neo concentrations in fetal calf serum(FCS) and urine,and the recovery ranges are 98.57%-103.82% and 99.25%-103.50%,respectively,while the relative standard deviations(RSDs) are 7.89%-9.46% and 1.85%-4.16%,respectively.The limits of detection of 1 to Neo in FCS and urine are 0.034 and 0.021 μmol/L,respectively.展开更多
A high-performance ammonia(NH3)sensor is prepared based on CeO_(2)/NiO composite,using a hydrothermal method.Experimental findings confirm that the CeO_(2)/NiO composite significantly enhances the performance of the N...A high-performance ammonia(NH3)sensor is prepared based on CeO_(2)/NiO composite,using a hydrothermal method.Experimental findings confirm that the CeO_(2)/NiO composite significantly enhances the performance of the NiO-based NH3 sensor.This improvement is primarily due to the increase in oxygen vacancies(Ov),chemically adsorbed oxygen(Oc),and the proportion of Ni3+on the surface of the CeO_(2)/NiO.The CeO_(2)/NiO sensor shows a high response to NH3,exhibiting response/recovery times of 1.8 s/0.9 s at the NH3 concentration of 5×10^(−6)mL/m^(3),with the theoretical lowest detection limit of 98.651×10^(−9)mL/m^(3).Additionally,the CeO_(2)/NiO sensor has been successfully applied in the simulated detection of Helicobacter pylori infection,highlighting its significant research value and potential application prospects in biomedical diagnostics.展开更多
Palladium diselenide(PdSe_(2)),a novel two-dimensional(2D)material with a unique pentagonal crystal structure including anisotropic properties,has emerged as a highly promising candidate for developing the next genera...Palladium diselenide(PdSe_(2)),a novel two-dimensional(2D)material with a unique pentagonal crystal structure including anisotropic properties,has emerged as a highly promising candidate for developing the next generation photoelectronic devices.In this review,firstly,we have shed light on key figures of merit for polarization detection.After that,this review mainly highlights the structural and electronic properties of PdSe_(2)focusing on its strong polarization sensitivity,tunable bandgap,and excellent environmental stability,making it ideal for developing the photoelectronic devices such as broadband photodetectors and their further applications in polarization detection-based imaging systems.We also discuss challenges in scalable synthesis,material stability,and integration with other low-dimensional materials,offering future research directions to optimize PdSe_(2)for commercial applications.Owing to the outstanding optoelectronic properties of PdSe_(2),it stands at the forefront of optoelectronic materials,poised to enable new innovations in polarization photodetection.展开更多
Nickel oxide(NiO)based gas sensors have at-tracted intense attention due to its high re-sponse to hydrogen sulfide(H_(2)S)gas.It has been demonstrated that the NiO sensors with exposed(111)facet exhibit excellent perf...Nickel oxide(NiO)based gas sensors have at-tracted intense attention due to its high re-sponse to hydrogen sulfide(H_(2)S)gas.It has been demonstrated that the NiO sensors with exposed(111)facet exhibit excellent perfor-mance,but the single-orientation NiO sensors with exposed(111)facet have rarely been studied.In this work,high quality(111)-ori-ented NiO epitaxial films were fabricated by pulsed laser deposition.Detailed crystalline structural information was revealed by using synchrotron based X-ray diffraction(XRD)technology.These NiO thin films show good se-lectivity for H_(2)S gas detection.Without further modification,the highest response to 100 ppm H_(2)S was measured to be 13.07 at 300℃,and limit of detection(LOD)could be as low as 186 ppb.Fitting of the electrical response curves during adsorption and desorption of H_(2)S gas indicates the two-site Langmuir kinetic processes.Combining with XPS and XAS measure-ments,the mechanism was discussed.Density functional theory(DFT)calculations show that NiO with exposed(111)facets has the most negative adsorption energy,indicating more sen-sitive to H_(2)S.These results could inspire more studies of metal oxide semiconductor-based gas sensors with specific surface.展开更多
Rapid and accurate detection of infectious virus particles, not just viral nucleic acid, is essential to avoid unnecessary quarantine and effectively control the spread of viral diseases such as coronavirus disease 20...Rapid and accurate detection of infectious virus particles, not just viral nucleic acid, is essential to avoid unnecessary quarantine and effectively control the spread of viral diseases such as coronavirus disease 2019 (COVID-19), severe acute respiratory syndrome (SARS), and Middle East respiratory syndrome (MERS). Real-time quantitative polymerase chain reaction (RT-qPCR) was the most widely used detection technique during the COVID-19 outbreak. However, it cannot discriminate between intact infectious viruses and surface-distorted, non-infectious virus particles or naked viral RNA. In this study, we present a strategy for the specific detection of infectious coronaviruses by combining viral receptor capture and reverse transcription loop-mediated isothermal amplification (RT-LAMP). We successfully applied this strategy to detect infectious virus particles of the SARS-CoV-2 surrogate virus and the human coronavirus NL63 (HCoV-NL63). Virus particles were first captured on ELISA plates coated with the recombinant human angiotensin-converting enzyme 2 (hACE2) receptor. Viral RNA was then extracted from the particles and detected by RT-LAMP using virus-specific primers. In our experimental setting, the proposed method had a minimum detection limit (LOD) of 90 PFU/mL, sensitivity of 96.2%, and specificity of 100%. Our study provides a proof-of-concept that viral receptor capture combined with RT-LAMP can differentiate infectious coronaviruses from non-infectious virions or naked viral RNA. This paves the way for this virus detection strategy to become a mainstream tool for the management, prevention and control of epidemic coronavirus diseases.展开更多
In this work,a novel bifunctional zirconium dioxide@zeolitic imidazolate framework-90(ZrO_(2)@ZIF-90)nanozyme was successfully developed for the catalytic degradation and electrochemical detection of methyl parathion(...In this work,a novel bifunctional zirconium dioxide@zeolitic imidazolate framework-90(ZrO_(2)@ZIF-90)nanozyme was successfully developed for the catalytic degradation and electrochemical detection of methyl parathion(MP).The ZrO_(2)@ZIF-90 nanozyme with phosphatase hydrolysis activity can convert MP into p-nitrophenol(p-NP).The addition of ZrO_(2)riched in Lewis acid Zr(IV)sites significantly enhanced the phosphatase hydrolysis activity of ZIF-90.ZrO_(2)@ZIF-90 also displayed satisfactory electrocatalytic performance on account of the high surface area,high porosity and powerful enrichment ability of the ZIF-90 and the excellent ion transfer capacity of ZrO_(2).A ZrO_(2)@ZIF-90 nanozyme modified glassy carbon electrode(ZrO_(2)@ZIF-90/GCE)was then fabricated to analyze p-NP formed through MP degradation.Under the optimized conditions,the developed sensor displayed satisfactory analytical performance with a low limit of detection of 0.53μmol/L and two wide linear ranges(3-10 and 10-200μmol/L).ZrO_(2)@ZIF-90 nanozyme accomplished to the degradation and electrochemical detection of MP in river water and spiked fruits.This study identifies a promising new strategy for the design of bifunctional nanozymes for the detection of environmental hazards.展开更多
As a highly energy-efficient and sensitive radiation source,narrowband thermal emitters provide an ideal solution for non-contact gas detection,enabling the widespread application of mid-infrared“molecular fingerprin...As a highly energy-efficient and sensitive radiation source,narrowband thermal emitters provide an ideal solution for non-contact gas detection,enabling the widespread application of mid-infrared“molecular fingerprint”technology.However,most narrowband thermal emitters lack reconfigurability,limiting their adaptability in practical applications.In this study,we propose a novel dual-band switchable narrowband thermal emitter in the mid-infrared region.The emitter consists of an aperiodic Ge/SiO_(2)/Ge/SiO_(2)(GSGS)structure and a phase change material In_(3)SbTe_(2)(IST).When IST is in the crystalline state,the emitter achieves narrowband emission peaks at wavelengths of 3.79μm and 6.12μm,corresponding to the“on”state.However,when IST transitions to the amorphous state,the dual-band high emission disappears and it features angle-and polarization-independent behavior,representing the“off”state.Furthermore,we verify the physical mechanism behind the high emission through phase and amplitude calculations as well as electric field distribution analysis.Notably,the introduction of the IST provides an additional degree of freedom for tunability.Furthermore,by adjusting the thickness of the spacer layer,the emitter can be precisely tuned to match the characteristic absorption peaks of various mid-infrared gases,such as CH_(4),CO_(2),CO,and NO,enabling multi-gas detection in mixed gas environments.The proposed thermal emitter serves as an effective and low-cost alternative for dual-band narrowband mid-infrared light sources,contributing to the advancement of multi-gas detection strategies.展开更多
Conventional gas sensing materials(e.g.,metal oxides)suffer from deficient sensitivity and serve cross-sensitivity issues due to the lack of efficient adsorption sites.Herein,the heteroatom atomically doping strategy ...Conventional gas sensing materials(e.g.,metal oxides)suffer from deficient sensitivity and serve cross-sensitivity issues due to the lack of efficient adsorption sites.Herein,the heteroatom atomically doping strategy is demonstrated to significantly enhance the sensing performance of metal oxides-based gas sensing materials.Specifically,the Sn atoms were incorporated into porous Fe_(2)O_(3)in the form of atomically dispersed sites.As revealed by X-ray absorption spectroscopy and atomic-resolution scanning transmission electron microscopy,these Sn atoms successfully occupy the Fe sites in the Fe_(2)O_(3)lattice,forming the unique Sn-O-Fe sites.Compared to Fe-O-Fe sites(from bare Fe_(2)O_(3))and Sn-O-Sn sites(from SnO_(2)/Fe_(2)O_(3)with high Sn loading),the Sn-O-Fe sites on porous Fe_(2)O_(3)exhibit a superior sensitivity(Rg/Ra=2646.6)to 1 ppm NO_(2),along with dramatically increased selectivity and ultra-low limits of detection(10 ppb).Further theoretical calculations suggest that the strong adsorption of NO_(2)on Sn-O-Fe sites(N atom on Sn site,O atom on Fe site)contributes a more efficient gas response,compared to NO_(2)on Fe-O-Fe sites and other gases on Sn-O-Fe sites.Moreover,the incorporated Sn atoms reduce the bandgap of Fe_(2)O_(3),not only facilitating the electron release but also increasing the NO_(2)adsorption at a low working temperature(150°C).This work introduces an effective strategy to construct effective adsorption sites that show a unique response to specific gas molecules,potentially promoting the rational design of atomically modified gas sensing materials with high sensitivity and high selectivity.展开更多
Drone swarm systems,equipped with photoelectric imaging and intelligent target perception,are essential for reconnaissance and strike missions in complex and high-risk environments.They excel in information sharing,an...Drone swarm systems,equipped with photoelectric imaging and intelligent target perception,are essential for reconnaissance and strike missions in complex and high-risk environments.They excel in information sharing,anti-jamming capabilities,and combat performance,making them critical for future warfare.However,varied perspectives in collaborative combat scenarios pose challenges to object detection,hindering traditional detection algorithms and reducing accuracy.Limited angle-prior data and sparse samples further complicate detection.This paper presents the Multi-View Collaborative Detection System,which tackles the challenges of multi-view object detection in collaborative combat scenarios.The system is designed to enhance multi-view image generation and detection algorithms,thereby improving the accuracy and efficiency of object detection across varying perspectives.First,an observation model for three-dimensional targets through line-of-sight angle transformation is constructed,and a multi-view image generation algorithm based on the Pix2Pix network is designed.For object detection,YOLOX is utilized,and a deep feature extraction network,BA-RepCSPDarknet,is developed to address challenges related to small target scale and feature extraction challenges.Additionally,a feature fusion network NS-PAFPN is developed to mitigate the issue of deep feature map information loss in UAV images.A visual attention module(BAM)is employed to manage appearance differences under varying angles,while a feature mapping module(DFM)prevents fine-grained feature loss.These advancements lead to the development of BA-YOLOX,a multi-view object detection network model suitable for drone platforms,enhancing accuracy and effectively targeting small objects.展开更多
Traditional Pt/C electrode materials are prone to corrosion and detachment during H_(2)S detection,leading to a decrease in fuel cell-type sensor performance.Here,a high-performance H_(2)S sensor based on Pt loaded Ti...Traditional Pt/C electrode materials are prone to corrosion and detachment during H_(2)S detection,leading to a decrease in fuel cell-type sensor performance.Here,a high-performance H_(2)S sensor based on Pt loaded Ti_(3)C_(2)electrode material with-O/-OH terminal groups was designed and prepared.Experimental tests showed that the Pt/Ti_(3)C_(2)sensor has good sensitivity(0.162μA/ppm)and a very low detection limit to H_(2)S(10 ppb).After 90 days of stability testing,the response of the Pt/Ti_(3)C_(2)sensor shows a smaller decrease of 2%compared to that of the Pt/C sensor(22.9%).Meanwhile,the sensor also has high selectivity and repeatability.The density functional theory(DFT)calculation combined with the experiment results revealed that the improved H_(2)S sensing mechanism is attributed to the fact that the strong interaction between Pt and Ti_(3)C_(2)via the Pt-O-Ti bonding can reduce the formation energy of Pt and Ti_(3)C_(2),ultimately prolonging the sensor’s service life.Furthermore,the catalytic property of Pt can decrease the adsorption energy and dissociation barrier of H_(2)S on Pt/Ti_(3)C_(2)surface,greatly enhance the ability to generate protons and effectively transfer charges,realizing good sensitivity and high selectivity of the sensor.The sensor works at room temperature,making it very promising in the field of H_(2)S detection in future.展开更多
Novel ZnSe/NiO heterostructure nanocomposites were successfully prepared by one-step hydrothermal method.The ZnSe/NiO-based sensor exhibits a response of~96.47% to 8×10^(-6) NO_(2) at 140℃,which is significantly...Novel ZnSe/NiO heterostructure nanocomposites were successfully prepared by one-step hydrothermal method.The ZnSe/NiO-based sensor exhibits a response of~96.47% to 8×10^(-6) NO_(2) at 140℃,which is significantly higher than those of intrinsic ZnSe-based(no response)and NiO-based(~19.65%)sensors.The theoretical detection limit(LOD)of the sensor is calculated to be 8.91×10^(-9),indicating that the sensor can be applied to detect the ultralow concentrations of NO_(2).The effect of NiO content on the gas-sensing performance of the nanocomposites was investigated in detail.The optimal NiO content in the nanocomposite is determined to be15.16%to achieve the highest response.The as-fabricated sensor also presents an excellent selectivity to several possible interferents such as methanol,ethanol,acetone,benzene,ammonia and formaldehyde.The enhanced sensing performance can be attributed to the formation of p-p heterostructures between ZnSe and NiO,which induces the charge transfer across the interfaces and yields more active sites.展开更多
Even in small concentrations,toxic metals like lead,cadmium,and mercury are dangerous to the environment and human health.Environmental monitoring depends on precisely identifying these heavy metals,particularly cadmi...Even in small concentrations,toxic metals like lead,cadmium,and mercury are dangerous to the environment and human health.Environmental monitoring depends on precisely identifying these heavy metals,particularly cadmium ions(Cd(Ⅱ)).In this study,we present a novel screen-printed carbon electrode(SPCE)modified with single crystallineα-Fe_(2)O_(3)nano-hexagons that functions as a sensor for detecting Cd(Ⅱ).The performance of the fabricated sensor was thoroughly assessed and compared with unmodified SPCE using the voltammetric method.The crystalline structure of the synthesizedα-Fe_(2)O_(3)nano-hexagons was confirmed through XRD,and surface analysis revealed an average diameter and thickness of 86 nm and 9 nm,respectively.Theα-Fe_(2)O_(3)modified SPCE yields a 7-fold enhanced response(at pH 5.0 vs.Ag/AgCl)to Cd(Ⅱ)than bare SPCE.The modified electrode effectively detects Cd(Ⅱ)with a linear response range of up to 333.0μmol/L and a detection limit of 0.65 nmol/L under ideal circumstances.This newly fabricated sensor offers significant potential for environmental monitoring applications by providing outstanding practicality,anti-interference ability,and repeatability for detecting Cd(Ⅱ)in water samples.展开更多
With the development of environmental monitoring,it is urgent to establish NO_(2)sensor with good sensing performance.Compared with the traditional NO_(2)sensors made of metal oxides,NO_(2)sensors made of n-p heterost...With the development of environmental monitoring,it is urgent to establish NO_(2)sensor with good sensing performance.Compared with the traditional NO_(2)sensors made of metal oxides,NO_(2)sensors made of n-p heterostructure nanocomposites have good sensing performance in detection limit and operating temperature.ZnO nanoflake arrays with polyaniline film grown on the surface were prepared on ceramic tubes by hydrothermal and vapor diffusion method.The gas-phase diffusion method can control the heterostructure by adjusting the diffusion time.At room temperature(25℃),the construction of rich n-p heterogeneous interface enables the sensor prepared by the nanocomposite to respond to NO_(2),showing the sensing performance with the response value of 28.00 to10.00×10^(-6)NO_(2);the detection limit improved to0.01×10^(-6)and the recovery time of 18 s.In this work,the sensing mechanism of NO_(2)at heterogeneous interface is analyzed,which provides a promising material for the detection of low concentration NO_(2)at room temperature.展开更多
In this paper,the host-vip interaction of cucurbit[7]uril(Q[7]) and chromone(CMO) has been developed as a fluorescent probe for the highly selective detection of Zn2+ and Cd^(2+) in water based on a chelation-enhanc...In this paper,the host-vip interaction of cucurbit[7]uril(Q[7]) and chromone(CMO) has been developed as a fluorescent probe for the highly selective detection of Zn2+ and Cd^(2+) in water based on a chelation-enhanced fluorescence(CHEF) mechanism.There was a good linear relationship between the fluorescence intensity of the CMO@Q[7] probe and the concentration of Zn^(2+ )or Cd^(2+) in the range of 0-3.0×10^(-5) mol/L and the detection limit for Zn^(2+) and Cd2+ was found to be 2.03×10^(-6) mol/L and 1.89×10^(-6)mol/L,respectively.The X-ray crystal structure indicated that different coordination fashions were triggered by Zn^(2+) and Cd^(2+ )in the CMO@Q[7] complexes,respectively.However,both metal ions coordinated with the carbonyl oxygen of CMO,which was encapsulated in the cavity of Q[7],thus leading to the enhancement of recognition fluorescence emission of CMO.展开更多
文摘This study proposes a lightweight rice disease detection model optimized for edge computing environments.The goal is to enhance the You Only Look Once(YOLO)v5 architecture to achieve a balance between real-time diagnostic performance and computational efficiency.To this end,a total of 3234 high-resolution images(2400×1080)were collected from three major rice diseases Rice Blast,Bacterial Blight,and Brown Spot—frequently found in actual rice cultivation fields.These images served as the training dataset.The proposed YOLOv5-V2 model removes the Focus layer from the original YOLOv5s and integrates ShuffleNet V2 into the backbone,thereby resulting in both model compression and improved inference speed.Additionally,YOLOv5-P,based on PP-PicoDet,was configured as a comparative model to quantitatively evaluate performance.Experimental results demonstrated that YOLOv5-V2 achieved excellent detection performance,with an mAP 0.5 of 89.6%,mAP 0.5–0.95 of 66.7%,precision of 91.3%,and recall of 85.6%,while maintaining a lightweight model size of 6.45 MB.In contrast,YOLOv5-P exhibited a smaller model size of 4.03 MB,but showed lower performance with an mAP 0.5 of 70.3%,mAP 0.5–0.95 of 35.2%,precision of 62.3%,and recall of 74.1%.This study lays a technical foundation for the implementation of smart agriculture and real-time disease diagnosis systems by proposing a model that satisfies both accuracy and lightweight requirements.
基金Project supported by the National Natural Science Foundation of China (21771141)。
文摘A 12-metal Zn(Ⅱ)-Nd(Ⅲ) cluster 1(sizes:1.8 nm×2.0 nm×2.0 nm) was synthesized from a long-chain type Schiff base ligand.It displays ratiometric fluorescence response to neopterin(Neo) with high selectivity and sensitivity,which can be expressed by the equation I_(545)_(nm)/I_(1060)_(nm)=A·[Neo]^(2)+B·[Neo]+C.1 is used to quantitatively test Neo concentrations in fetal calf serum(FCS) and urine,and the recovery ranges are 98.57%-103.82% and 99.25%-103.50%,respectively,while the relative standard deviations(RSDs) are 7.89%-9.46% and 1.85%-4.16%,respectively.The limits of detection of 1 to Neo in FCS and urine are 0.034 and 0.021 μmol/L,respectively.
基金supported by the Natural Science Foundation of Xinjiang Uygur Autonomous Region of China“Preparation and application of self-powered carbon nitride/metal oxide humidity sensors”(2023D01C05).
文摘A high-performance ammonia(NH3)sensor is prepared based on CeO_(2)/NiO composite,using a hydrothermal method.Experimental findings confirm that the CeO_(2)/NiO composite significantly enhances the performance of the NiO-based NH3 sensor.This improvement is primarily due to the increase in oxygen vacancies(Ov),chemically adsorbed oxygen(Oc),and the proportion of Ni3+on the surface of the CeO_(2)/NiO.The CeO_(2)/NiO sensor shows a high response to NH3,exhibiting response/recovery times of 1.8 s/0.9 s at the NH3 concentration of 5×10^(−6)mL/m^(3),with the theoretical lowest detection limit of 98.651×10^(−9)mL/m^(3).Additionally,the CeO_(2)/NiO sensor has been successfully applied in the simulated detection of Helicobacter pylori infection,highlighting its significant research value and potential application prospects in biomedical diagnostics.
基金supported by the National Key Research and Development Program of China under Grant No.2019YFB 2203400the“111 project”under Grant No.B20030.
文摘Palladium diselenide(PdSe_(2)),a novel two-dimensional(2D)material with a unique pentagonal crystal structure including anisotropic properties,has emerged as a highly promising candidate for developing the next generation photoelectronic devices.In this review,firstly,we have shed light on key figures of merit for polarization detection.After that,this review mainly highlights the structural and electronic properties of PdSe_(2)focusing on its strong polarization sensitivity,tunable bandgap,and excellent environmental stability,making it ideal for developing the photoelectronic devices such as broadband photodetectors and their further applications in polarization detection-based imaging systems.We also discuss challenges in scalable synthesis,material stability,and integration with other low-dimensional materials,offering future research directions to optimize PdSe_(2)for commercial applications.Owing to the outstanding optoelectronic properties of PdSe_(2),it stands at the forefront of optoelectronic materials,poised to enable new innovations in polarization photodetection.
基金supported by the National Key Research and Development Program of China(No.2022YFA1603902)the National Natural Science Foundation of China(No.12175235,No.62271462,and No.12004407)。
文摘Nickel oxide(NiO)based gas sensors have at-tracted intense attention due to its high re-sponse to hydrogen sulfide(H_(2)S)gas.It has been demonstrated that the NiO sensors with exposed(111)facet exhibit excellent perfor-mance,but the single-orientation NiO sensors with exposed(111)facet have rarely been studied.In this work,high quality(111)-ori-ented NiO epitaxial films were fabricated by pulsed laser deposition.Detailed crystalline structural information was revealed by using synchrotron based X-ray diffraction(XRD)technology.These NiO thin films show good se-lectivity for H_(2)S gas detection.Without further modification,the highest response to 100 ppm H_(2)S was measured to be 13.07 at 300℃,and limit of detection(LOD)could be as low as 186 ppb.Fitting of the electrical response curves during adsorption and desorption of H_(2)S gas indicates the two-site Langmuir kinetic processes.Combining with XPS and XAS measure-ments,the mechanism was discussed.Density functional theory(DFT)calculations show that NiO with exposed(111)facets has the most negative adsorption energy,indicating more sen-sitive to H_(2)S.These results could inspire more studies of metal oxide semiconductor-based gas sensors with specific surface.
基金supported by the National Natural Science Foundation of China(32470160)the National Key Research and Development Program of China(2021YFC2300100,GZNL2023A01008)+2 种基金the Shenzhen Science and Technology Program(#JSGG20200225150431472,JSGG20210901145403012,and JSGG20220301090005007)the“Pearl River Talent Plan”Innovation and Entrepreneurship Team Project of Guangdong Province(2016LJ06Y540 and 2019ZT08Y464)the Science and Technology Program of Guangdong Province,China(2021B1212040017).
文摘Rapid and accurate detection of infectious virus particles, not just viral nucleic acid, is essential to avoid unnecessary quarantine and effectively control the spread of viral diseases such as coronavirus disease 2019 (COVID-19), severe acute respiratory syndrome (SARS), and Middle East respiratory syndrome (MERS). Real-time quantitative polymerase chain reaction (RT-qPCR) was the most widely used detection technique during the COVID-19 outbreak. However, it cannot discriminate between intact infectious viruses and surface-distorted, non-infectious virus particles or naked viral RNA. In this study, we present a strategy for the specific detection of infectious coronaviruses by combining viral receptor capture and reverse transcription loop-mediated isothermal amplification (RT-LAMP). We successfully applied this strategy to detect infectious virus particles of the SARS-CoV-2 surrogate virus and the human coronavirus NL63 (HCoV-NL63). Virus particles were first captured on ELISA plates coated with the recombinant human angiotensin-converting enzyme 2 (hACE2) receptor. Viral RNA was then extracted from the particles and detected by RT-LAMP using virus-specific primers. In our experimental setting, the proposed method had a minimum detection limit (LOD) of 90 PFU/mL, sensitivity of 96.2%, and specificity of 100%. Our study provides a proof-of-concept that viral receptor capture combined with RT-LAMP can differentiate infectious coronaviruses from non-infectious virions or naked viral RNA. This paves the way for this virus detection strategy to become a mainstream tool for the management, prevention and control of epidemic coronavirus diseases.
基金financially supported by the National Natural Science Foundation of China(No.31972149)Innovation Capability Improvement Project of Scientific and Technological Small and Medium-sized Enterprises in Shandong Province(No.2022TSGC2409)the Mac Diarmid Institute for Advanced Materials and Nanotechnology and the Dodd-Walls Centre for Photonic and Quantum Technologies。
文摘In this work,a novel bifunctional zirconium dioxide@zeolitic imidazolate framework-90(ZrO_(2)@ZIF-90)nanozyme was successfully developed for the catalytic degradation and electrochemical detection of methyl parathion(MP).The ZrO_(2)@ZIF-90 nanozyme with phosphatase hydrolysis activity can convert MP into p-nitrophenol(p-NP).The addition of ZrO_(2)riched in Lewis acid Zr(IV)sites significantly enhanced the phosphatase hydrolysis activity of ZIF-90.ZrO_(2)@ZIF-90 also displayed satisfactory electrocatalytic performance on account of the high surface area,high porosity and powerful enrichment ability of the ZIF-90 and the excellent ion transfer capacity of ZrO_(2).A ZrO_(2)@ZIF-90 nanozyme modified glassy carbon electrode(ZrO_(2)@ZIF-90/GCE)was then fabricated to analyze p-NP formed through MP degradation.Under the optimized conditions,the developed sensor displayed satisfactory analytical performance with a low limit of detection of 0.53μmol/L and two wide linear ranges(3-10 and 10-200μmol/L).ZrO_(2)@ZIF-90 nanozyme accomplished to the degradation and electrochemical detection of MP in river water and spiked fruits.This study identifies a promising new strategy for the design of bifunctional nanozymes for the detection of environmental hazards.
基金supported by the National Natural Science Foundation of China(Grant No.52106099)the Natural Science Foundation of Shandong Province(Grant No.ZR2022YQ57)the Taishan Scholars Program。
文摘As a highly energy-efficient and sensitive radiation source,narrowband thermal emitters provide an ideal solution for non-contact gas detection,enabling the widespread application of mid-infrared“molecular fingerprint”technology.However,most narrowband thermal emitters lack reconfigurability,limiting their adaptability in practical applications.In this study,we propose a novel dual-band switchable narrowband thermal emitter in the mid-infrared region.The emitter consists of an aperiodic Ge/SiO_(2)/Ge/SiO_(2)(GSGS)structure and a phase change material In_(3)SbTe_(2)(IST).When IST is in the crystalline state,the emitter achieves narrowband emission peaks at wavelengths of 3.79μm and 6.12μm,corresponding to the“on”state.However,when IST transitions to the amorphous state,the dual-band high emission disappears and it features angle-and polarization-independent behavior,representing the“off”state.Furthermore,we verify the physical mechanism behind the high emission through phase and amplitude calculations as well as electric field distribution analysis.Notably,the introduction of the IST provides an additional degree of freedom for tunability.Furthermore,by adjusting the thickness of the spacer layer,the emitter can be precisely tuned to match the characteristic absorption peaks of various mid-infrared gases,such as CH_(4),CO_(2),CO,and NO,enabling multi-gas detection in mixed gas environments.The proposed thermal emitter serves as an effective and low-cost alternative for dual-band narrowband mid-infrared light sources,contributing to the advancement of multi-gas detection strategies.
基金supported by the National Key Research and Development Project of China(Grant No.2022YFB3205500)the National Natural Science Foundation of China(Grant No.12275190,12105201)+2 种基金Jiangsu Funding Program for Excellent Postdoctoral Talent(Grant No.2024ZB723)the Shenzhen Research Funding Program(JCYJ20230807154402004)supported by the Collaborative Innovation Center of Suzhou Nano Science&Technology,the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD),the 111 Project,the Joint International Research Laboratory of Carbon-Based Functional Materials and Devices,and the Suzhou Key Laboratory of Functional Nano&Soft Materials and Soochow University-Western University Centre for Synchrotron Radiation Research.
文摘Conventional gas sensing materials(e.g.,metal oxides)suffer from deficient sensitivity and serve cross-sensitivity issues due to the lack of efficient adsorption sites.Herein,the heteroatom atomically doping strategy is demonstrated to significantly enhance the sensing performance of metal oxides-based gas sensing materials.Specifically,the Sn atoms were incorporated into porous Fe_(2)O_(3)in the form of atomically dispersed sites.As revealed by X-ray absorption spectroscopy and atomic-resolution scanning transmission electron microscopy,these Sn atoms successfully occupy the Fe sites in the Fe_(2)O_(3)lattice,forming the unique Sn-O-Fe sites.Compared to Fe-O-Fe sites(from bare Fe_(2)O_(3))and Sn-O-Sn sites(from SnO_(2)/Fe_(2)O_(3)with high Sn loading),the Sn-O-Fe sites on porous Fe_(2)O_(3)exhibit a superior sensitivity(Rg/Ra=2646.6)to 1 ppm NO_(2),along with dramatically increased selectivity and ultra-low limits of detection(10 ppb).Further theoretical calculations suggest that the strong adsorption of NO_(2)on Sn-O-Fe sites(N atom on Sn site,O atom on Fe site)contributes a more efficient gas response,compared to NO_(2)on Fe-O-Fe sites and other gases on Sn-O-Fe sites.Moreover,the incorporated Sn atoms reduce the bandgap of Fe_(2)O_(3),not only facilitating the electron release but also increasing the NO_(2)adsorption at a low working temperature(150°C).This work introduces an effective strategy to construct effective adsorption sites that show a unique response to specific gas molecules,potentially promoting the rational design of atomically modified gas sensing materials with high sensitivity and high selectivity.
基金supported by the Natural Science Foundation of China,Grant No.62103052.
文摘Drone swarm systems,equipped with photoelectric imaging and intelligent target perception,are essential for reconnaissance and strike missions in complex and high-risk environments.They excel in information sharing,anti-jamming capabilities,and combat performance,making them critical for future warfare.However,varied perspectives in collaborative combat scenarios pose challenges to object detection,hindering traditional detection algorithms and reducing accuracy.Limited angle-prior data and sparse samples further complicate detection.This paper presents the Multi-View Collaborative Detection System,which tackles the challenges of multi-view object detection in collaborative combat scenarios.The system is designed to enhance multi-view image generation and detection algorithms,thereby improving the accuracy and efficiency of object detection across varying perspectives.First,an observation model for three-dimensional targets through line-of-sight angle transformation is constructed,and a multi-view image generation algorithm based on the Pix2Pix network is designed.For object detection,YOLOX is utilized,and a deep feature extraction network,BA-RepCSPDarknet,is developed to address challenges related to small target scale and feature extraction challenges.Additionally,a feature fusion network NS-PAFPN is developed to mitigate the issue of deep feature map information loss in UAV images.A visual attention module(BAM)is employed to manage appearance differences under varying angles,while a feature mapping module(DFM)prevents fine-grained feature loss.These advancements lead to the development of BA-YOLOX,a multi-view object detection network model suitable for drone platforms,enhancing accuracy and effectively targeting small objects.
基金the National Key R&D Program of China(No.2023YFB3210102).
文摘Traditional Pt/C electrode materials are prone to corrosion and detachment during H_(2)S detection,leading to a decrease in fuel cell-type sensor performance.Here,a high-performance H_(2)S sensor based on Pt loaded Ti_(3)C_(2)electrode material with-O/-OH terminal groups was designed and prepared.Experimental tests showed that the Pt/Ti_(3)C_(2)sensor has good sensitivity(0.162μA/ppm)and a very low detection limit to H_(2)S(10 ppb).After 90 days of stability testing,the response of the Pt/Ti_(3)C_(2)sensor shows a smaller decrease of 2%compared to that of the Pt/C sensor(22.9%).Meanwhile,the sensor also has high selectivity and repeatability.The density functional theory(DFT)calculation combined with the experiment results revealed that the improved H_(2)S sensing mechanism is attributed to the fact that the strong interaction between Pt and Ti_(3)C_(2)via the Pt-O-Ti bonding can reduce the formation energy of Pt and Ti_(3)C_(2),ultimately prolonging the sensor’s service life.Furthermore,the catalytic property of Pt can decrease the adsorption energy and dissociation barrier of H_(2)S on Pt/Ti_(3)C_(2)surface,greatly enhance the ability to generate protons and effectively transfer charges,realizing good sensitivity and high selectivity of the sensor.The sensor works at room temperature,making it very promising in the field of H_(2)S detection in future.
基金financially supported by the National Natural Science Foundation of China(No.61971085)Dalian Science and Technology Innovation Fund Project(No.2019J12GX048)。
文摘Novel ZnSe/NiO heterostructure nanocomposites were successfully prepared by one-step hydrothermal method.The ZnSe/NiO-based sensor exhibits a response of~96.47% to 8×10^(-6) NO_(2) at 140℃,which is significantly higher than those of intrinsic ZnSe-based(no response)and NiO-based(~19.65%)sensors.The theoretical detection limit(LOD)of the sensor is calculated to be 8.91×10^(-9),indicating that the sensor can be applied to detect the ultralow concentrations of NO_(2).The effect of NiO content on the gas-sensing performance of the nanocomposites was investigated in detail.The optimal NiO content in the nanocomposite is determined to be15.16%to achieve the highest response.The as-fabricated sensor also presents an excellent selectivity to several possible interferents such as methanol,ethanol,acetone,benzene,ammonia and formaldehyde.The enhanced sensing performance can be attributed to the formation of p-p heterostructures between ZnSe and NiO,which induces the charge transfer across the interfaces and yields more active sites.
文摘Even in small concentrations,toxic metals like lead,cadmium,and mercury are dangerous to the environment and human health.Environmental monitoring depends on precisely identifying these heavy metals,particularly cadmium ions(Cd(Ⅱ)).In this study,we present a novel screen-printed carbon electrode(SPCE)modified with single crystallineα-Fe_(2)O_(3)nano-hexagons that functions as a sensor for detecting Cd(Ⅱ).The performance of the fabricated sensor was thoroughly assessed and compared with unmodified SPCE using the voltammetric method.The crystalline structure of the synthesizedα-Fe_(2)O_(3)nano-hexagons was confirmed through XRD,and surface analysis revealed an average diameter and thickness of 86 nm and 9 nm,respectively.Theα-Fe_(2)O_(3)modified SPCE yields a 7-fold enhanced response(at pH 5.0 vs.Ag/AgCl)to Cd(Ⅱ)than bare SPCE.The modified electrode effectively detects Cd(Ⅱ)with a linear response range of up to 333.0μmol/L and a detection limit of 0.65 nmol/L under ideal circumstances.This newly fabricated sensor offers significant potential for environmental monitoring applications by providing outstanding practicality,anti-interference ability,and repeatability for detecting Cd(Ⅱ)in water samples.
基金financially supported by the National Natural Science Foundation of China(Nos.21771060,61271126)the International Science&Technology Cooperation Program of China(No.2016YFE0115100)+1 种基金the Program for Science and Technology Project of Heilongjiang province(No.JQ2021B002)the Reform and Development Fund Project of Local University supported by the Central Government,Heilongjiang Touyan Innovation Team Program。
文摘With the development of environmental monitoring,it is urgent to establish NO_(2)sensor with good sensing performance.Compared with the traditional NO_(2)sensors made of metal oxides,NO_(2)sensors made of n-p heterostructure nanocomposites have good sensing performance in detection limit and operating temperature.ZnO nanoflake arrays with polyaniline film grown on the surface were prepared on ceramic tubes by hydrothermal and vapor diffusion method.The gas-phase diffusion method can control the heterostructure by adjusting the diffusion time.At room temperature(25℃),the construction of rich n-p heterogeneous interface enables the sensor prepared by the nanocomposite to respond to NO_(2),showing the sensing performance with the response value of 28.00 to10.00×10^(-6)NO_(2);the detection limit improved to0.01×10^(-6)and the recovery time of 18 s.In this work,the sensing mechanism of NO_(2)at heterogeneous interface is analyzed,which provides a promising material for the detection of low concentration NO_(2)at room temperature.
基金support from the Science and Technology Support Plan of Guizhou Province [Guizhou Science and Technology Cooperation Support (2020) 4Y218]。
文摘In this paper,the host-vip interaction of cucurbit[7]uril(Q[7]) and chromone(CMO) has been developed as a fluorescent probe for the highly selective detection of Zn2+ and Cd^(2+) in water based on a chelation-enhanced fluorescence(CHEF) mechanism.There was a good linear relationship between the fluorescence intensity of the CMO@Q[7] probe and the concentration of Zn^(2+ )or Cd^(2+) in the range of 0-3.0×10^(-5) mol/L and the detection limit for Zn^(2+) and Cd2+ was found to be 2.03×10^(-6) mol/L and 1.89×10^(-6)mol/L,respectively.The X-ray crystal structure indicated that different coordination fashions were triggered by Zn^(2+) and Cd^(2+ )in the CMO@Q[7] complexes,respectively.However,both metal ions coordinated with the carbonyl oxygen of CMO,which was encapsulated in the cavity of Q[7],thus leading to the enhancement of recognition fluorescence emission of CMO.
