The implementation of multiple pathogen testing is essential for a rapid response to future outbreaks and for reducing disease transmission.This study introduces a 96-channel microfluidic chip,fabricated through a mol...The implementation of multiple pathogen testing is essential for a rapid response to future outbreaks and for reducing disease transmission.This study introduces a 96-channel microfluidic chip,fabricated through a molding process,which enables the batch detection of pathogens.It explores the rapid lysis and elution processes of pathogens within the microfluidic chips to ensure that nucleic acid extraction,elution,and amplification are completed entirely within the chip.This chip can extract nucleic acids from samples in just 10 min,achieving an extraction efficiency comparable to that of traditional in-tube methods.An oil phase is pre-loaded into the chip to effectively prevent aerosol contamination.This approach allows for the simultaneous detection of 21 common respiratory pathogens,with a detection limit of 10 copies per reaction.Furthermore,applications involving clinical samples demonstrate significant practicality.Compared to many traditional in-tube pathogen detection methods and molecular biology technologies that utilize microfluidic chips,this detection chip not only enables simultaneous detection of multiple pathogens but also demonstrates high sensitivity.展开更多
Purpose–For the commonly used concrete mix for railway tunnel linings,concrete model specimens were made,and springback and core drilling tests were conducted at different ages.The springback strength was measured to...Purpose–For the commonly used concrete mix for railway tunnel linings,concrete model specimens were made,and springback and core drilling tests were conducted at different ages.The springback strength was measured to the compressive strength of the core sample with a diameter of 100mm and a height-to-diameter ratio of 1:1.By comparing the measured strength values,the relationship between the measured values under different strength measurement methods was analyzed.Design/methodology/approach–A comparative test of the core drilling method and the rebound method was conducted on the side walls of tunnel linings in some under-construction railways to study the feasibility of the rebound method in engineering quality supervision and inspection.Findings–Tests showed that the rebound strength was positively correlated with the core drill strength.The core drill test strength was significantly higher than the rebound test strength,and the strength still increased after 56 days of age.The rebound method is suitable for the general survey of concrete strength during the construction process and is not suitable for direct supervision and inspection.Originality/value–By studying the correlation of test strength of tunnel lining concrete using two methods,the differences in test results of different methods are proposed to provide a reference for the test and evaluation of tunnel lining strength in railway engineering.展开更多
The current study examines damage detection in fluid-conveying pipes supported on a Pasternak foundation.This study proposes a novel method that uses the matching pursuit(MP)algorithm for damage detection.The governin...The current study examines damage detection in fluid-conveying pipes supported on a Pasternak foundation.This study proposes a novel method that uses the matching pursuit(MP)algorithm for damage detection.The governing equations of motion for the pipe are derived using Hamilton’s principle.The finite element method,combined with the Galerkin approach,is employed to obtain the mass,damping,and stiffness matrices.To identify damage locations through pipe mode-shape decomposition,an index called the“matching pursuit residual”is introduced as a novel contribution of this study.The proposed method facilitates damage detection at various levels and locations under different boundary conditions.The findings demonstrate that the MP residual damage index can accurately localize damage in the pipes.Furthermore,the results of the numerical and experimental tests showcase the efficiency of the proposed method,highlighting that the MP signal approximation algorithm effectively detects damage in structures.展开更多
The lightning accidents still occurred frequently in facilities protected by the protective angle method.After years of research,the expert team of the China Lightning Science(Jindun)Industry-University-Research Insti...The lightning accidents still occurred frequently in facilities protected by the protective angle method.After years of research,the expert team of the China Lightning Science(Jindun)Industry-University-Research Institute Collaboration Base has redefined the working principle of lightning rods,developed a new type of lightning rod(lightning interceptor),proposed a new theory of regional lightning protection,and established an engineering technology method for regional lightning protection(semi-circular method).Significant results have been achieved in multiple professional fields.In this paper,the research and application effects of lightning rods and protection angle method,regional lightning protection theory,and semi-circular method are introduced,which can be used as a reference for relevant technical personnel.展开更多
Due to their high water content,stimulus responsiveness,and biocompatibility,hydrogels,which are functional materials with a three-dimensional network structure,are widely applied in fields such as biomedicine,environ...Due to their high water content,stimulus responsiveness,and biocompatibility,hydrogels,which are functional materials with a three-dimensional network structure,are widely applied in fields such as biomedicine,environmental monitoring,and flexible electronics.This paper provides a systematic review of hydrogel charac-terization methods and their applications,focusing on primary evaluation techniques for physical properties(e.g.,mechanical strength,swelling behavior,and pore structure),chemical properties(e.g.,composition,crosslink density,and degradation behavior),biocompatibility,and functional properties(e.g.,drug release,environmental stimulus response,and conductivity).It analyzes the challenges currently faced by characterization methods,such as a lack of standardization,difficulties in dynamic monitoring,an insufficient micro-macro correlation,and poor adaptability to complex environments.It proposes solutions,such as a hierarchical standardization system,in situ imaging technology,cross-scale characterization,and biomimetic testing platforms.Looking ahead,hydrogel characterization techniques will evolve toward intelligent,real-time,multimodal coupling and standardized approaches.These techniques will provide superior technical support for precision medicine,environmental restoration,and flexible electronics.They will also offer systematic methodological guidance for the performance optimization and practical application of hydrogel materials.展开更多
This article presents four techniques for assessing verticality:the plumb line approach,the total station distance technique,the three-point centering method,and the centroid method.Given the significant error associa...This article presents four techniques for assessing verticality:the plumb line approach,the total station distance technique,the three-point centering method,and the centroid method.Given the significant error associated with the total station horizontal distance technique when measuring circular piers,this paper proposes the centroid method.This method calculates verticality by determining the coordinates of the center points at both ends of the pier.Experimental findings indicate that the centroid method achieves accuracy in measuring the verticality of circular piers comparable to the three-point centering method,while offering a faster inspection process.Furthermore,the paper explores the concept of composite verticality and validates the effectiveness of the centroid method in measuring composite verticality and its practical applications through comparative experiments.展开更多
In the aerospace field, residual stress directly affects the strength, fatigue life and dimensional stability of thin-walled structural components, and is a key factor to ensure flight safety and reliability. At prese...In the aerospace field, residual stress directly affects the strength, fatigue life and dimensional stability of thin-walled structural components, and is a key factor to ensure flight safety and reliability. At present, research on residual stress at home and abroad mainly focuses on the optimization of traditional detection technology, stress control of manufacturing process and service performance evaluation, among which research on residual stress detection methods mainly focuses on the improvement of the accuracy, sensitivity, reliability and other performance of existing detection methods, but it still faces many challenges such as extremely small detection range, low efficiency, large error and limited application range.展开更多
Software systems are vulnerable to security breaches as they expand in complexity and functionality.The confidentiality,integrity,and availability of data are gravely threatened by flaws in a system’s design,implemen...Software systems are vulnerable to security breaches as they expand in complexity and functionality.The confidentiality,integrity,and availability of data are gravely threatened by flaws in a system’s design,implementation,or configuration.To guarantee the durability&robustness of the software,vulnerability identification and fixation have become crucial areas of focus for developers,cybersecurity experts and industries.This paper presents a thorough multi-phase mathematical model for efficient patch management and vulnerability detection.To uniquely model these processes,the model incorporated the notion of the learning phenomenon in describing vulnerability fixation using a logistic learning function.Furthermore,the authors have used numerical methods to approximate the solution of the proposed framework where an analytical solution is difficult to attain.The suggested systematic architecture has been demonstrated through statistical analysis using patch datasets,which offers a solid basis for the research conclusions.According to computational research,learning dynamics improves security response and results in more effective vulnerability management.The suggested model offers a systematic approach to proactive vulnerability mitigation and has important uses in risk assessment,software maintenance,and cybersecurity.This study helps create more robust software systems by increasing patch management effectiveness,which benefits developers,cybersecurity experts,and sectors looking to reduce security threats in a growing digital world.展开更多
Legume foods are not only trendy but also rich in nutrients and offer unique health benefits.Nevertheless,allergies to soy and other legumes have emerged as critical issues in food safety,presenting significant challe...Legume foods are not only trendy but also rich in nutrients and offer unique health benefits.Nevertheless,allergies to soy and other legumes have emerged as critical issues in food safety,presenting significant challenges to the food processing industry and impacting consumer health.The complexity of legume allergens,coupled with inadequate allergen identification methods and the absence of robust detection and evaluation systems,complicates the management of these allergens.Here,we provide a comprehensive and critical review,mentioning various aspects related to legume allergies,including the types of legume allergens,the mechanisms behind these allergies,and the immunoglobulin E(Ig E)-binding epitopes involved,summarizing and discussing the detection techniques and the impact of different processing techniques on sensitization to legume proteins.Furthermore,this paper provides an overview of research advances in diagnostic and therapeutic strategies for legume allergens and discusses current challenges and prospects for studying legume allergens.展开更多
Accurate prediction of coal and gas outburst(CGO)hazards is paramount in gas disaster prevention and control.This paper endeavors to overcome the constraints posed by traditional prediction indexes when dealing with C...Accurate prediction of coal and gas outburst(CGO)hazards is paramount in gas disaster prevention and control.This paper endeavors to overcome the constraints posed by traditional prediction indexes when dealing with CGO incidents under low gas pressure conditions.In pursuit of this objective,we have studied and established a mechanical model of the working face under abnormal stress and the excitation energy conditions of CGO,and proposed a method for predicting the risk of CGO under abnormal stress.On site application verification shows that when a strong outburst hazard level prediction is issued,there is a high possibility of outburst disasters occurring.In one of the three locations where we predicted strong outburst hazards,a small outburst occurred,and the accuracy of the prediction was higher than the traditional drilling cuttings index S and drilling cuttings gas desorption index q.Finally,we discuss the mechanism of CGO under the action of stress anomalies.Based on the analysis of stress distribution changes and energy accumulation characteristics of coal under abnormal stress,this article believes that the increase in outburst risk caused by high stress abnormal gradient is mainly due to two reasons:(1)The high stress abnormal gradient leads to an increase in the plastic zone of the coal seam.After the working face advances,it indirectly leads to an increase in the gas expansion energy that can be released from the coal seam before reaching a new stress equilibrium.(2)Abnormal stress leads to increased peak stress of coal body in front of working face.When coal body in elastic area transforms to plastic area,its failure speed is accelerated,which induces accelerated gas desorption and aggravates the risk of outburst.展开更多
Near-Earth Asteroids posed a threat to human civilization,making their monitoring crucial.As the demand for asteroid detection technology increased,precise detection of these celestial bodies became an urgent task to ...Near-Earth Asteroids posed a threat to human civilization,making their monitoring crucial.As the demand for asteroid detection technology increased,precise detection of these celestial bodies became an urgent task to understand their characteristics and assess potential impact risks.To improve asteroid detection accuracy and efficiency,we proposed an advanced image processing method and a deep learning network for automatic asteroid detection.Specifically,we aligned star clusters and overlaid images to exploit asteroid motion rates,transforming them into object-like trajectories and improving the signal-to-noise ratio.This approach created the Asteroid Trajectory Image Data set under various conditions.We modified CenterNet2 network to develop AstroCenterNet by integrating Multi-channel Histogram Truncation for feature enhancement,using the SimAM attention mechanism to expand contextual information and suppress noise,and refining Feature Pyramid Network to improve low-level feature detection.Our results demonstrated a detection accuracy of 98.4%,a recall of 97.6%,a mean Average Precision of 94.01%,a false alarm rate of 1.6%,and a processing speed of approximately 17.86 frames per second,indicating that our method achieves high precision and efficiency.展开更多
The drilling gas production situation indicates a certain correlation between the shale gas reservoir in the Sichuan Basin and the high and low changes in formation resistivity.These variations are observed in the fir...The drilling gas production situation indicates a certain correlation between the shale gas reservoir in the Sichuan Basin and the high and low changes in formation resistivity.These variations are observed in the first member of the Longmaxi Formation to the Wufeng Formation at the bottom of the Longmaxi Formation.Given this correlation and based on the logging electrical data,this study employs the wide-field electromagnetic method(WFEM)to experimentally detect the electrical characteristics of the deep shale gas target layer in the Yibin area of southern Sichuan.The study also tests the regularity and effectiveness of the electrical parameters for evaluating favorable areas of shale gas reservoirs.In terms of specific operation,the structural pattern of the study area is implemented based on the wide-field electromagnetic results and geological data for comprehensive analysis,which identifies the main hidden faults and their influence range on low resistance.The detailed spatial distribution of the upper Ordovician Wufeng Formation and the lower Silurian Longmaxi Formation in the target layer with a buried depth of 2000-5000m is described.This layer exhibits the characteristics of a continuous and stable distribution of organic shale.After verifying the subsequent electrical logging data,the electrical logging curve is found to be essentially consistent with the shape and trend of the wide-field resistivity curve.This consistency demonstrates the effectiveness of WFEM in detecting shale gas layers.展开更多
BACKGROUND Helicobacter pylori(H.pylori),a globally prevalent pathogen,is exhibiting increasing rates of antimicrobial resistance.However,clinical implementation of pre-treatment susceptibility testing remains limited...BACKGROUND Helicobacter pylori(H.pylori),a globally prevalent pathogen,is exhibiting increasing rates of antimicrobial resistance.However,clinical implementation of pre-treatment susceptibility testing remains limited due to the organism’s fastidious growth requirements and prolonged culture time.AIM To propose a novel detection method utilizing antibiotic-supplemented media to inhibit susceptible strains,while resistant isolates were identified through urease-mediated hydrolysis of urea,inducing a phenol red color change for visual confirmation.METHODS Colombia agar was supplemented with urea,phenol red,and nickel chloride,and the final pH was adjusted to 7.35.Antibiotic-selective media were prepared by incorporating amoxicillin(0.5μg/mL),clarithromycin(2μg/mL),metronidazole(8μg/mL),or levofloxacin(2μg/mL)into separate batches.Gastric antral biopsies were homogenized and inoculated at 1.0×105 CFU onto the media,and then incubated under microaerobic conditions at 37°C for 28-36 hours.Resistance was determined based on a color change from yellow to pink,and the results were validated via broth microdilution according to Clinical and Laboratory Standards Institute guidelines.RESULTS After 28-36 hours of incubation,the drug-resistant H.pylori isolates induced a light red color change in the medium.Conversely,susceptible strains(H.pylori 26695 and G27)produced no visible color change.Compared with the conventional 11-day protocol,the novel method significantly reduced detection time.Among 201 clinical isolates,182 were successfully evaluated using the new method,resulting in a 90.5%detection rate.This was consistent with the 95.5%agreement rate observed when compared with microdilution-based susceptibility testing.The success rate of the novel approach was significantly higher than that of the comparative method(P<0.01).The accuracy of the new method was comparable to that of the dilution method.CONCLUSION The novel detection method can rapidly detect H.pylori drug resistance within 28-36 hours.With its operational simplicity and high diagnostic performance,it holds strong potential for clinical application in the management of H.pylori antimicrobial resistance.展开更多
Current damage detection methods based on model updating and sensitivity Jacobian matrixes show a low convergence ratio and computational efficiency for online calculations.The aim of this paper is to construct a real...Current damage detection methods based on model updating and sensitivity Jacobian matrixes show a low convergence ratio and computational efficiency for online calculations.The aim of this paper is to construct a real-time automated damage detection method by developing a theory-assisted adaptive mutiagent twin delayed deep deterministic(TA2-MATD3)policy gradient algorithm.First,the theoretical framework of reinforcement-learning-driven damage detection is established.To address the disadvantages of traditional mutiagent twin delayed deep deterministic(MATD3)method,the theory-assisted mechanism and the adaptive experience playback mechanism are introduced.Moreover,a historical residential house built in 1889 was taken as an example,using its 12-month structural health monitoring data.TA2-MATD3 was compared with existing damage detection methods in terms of the convergence ratio,online computing efficiency,and damage detection accuracy.The results show that the computational efficiency of TA2-MATD3 is approximately 117–160 times that of the traditional methods.The convergence ratio of damage detection on the training set is approximately 97%,and that on the test set is in the range of 86.2%–91.9%.In addition,the main apparent damages found in the field survey were identified by TA2-MATD3.The results indicate that the proposed method can significantly improve the online computing efficiency and damage detection accuracy.This research can provide novel perspectives for the use of reinforcement learning methods to conduct damage detection in online structural health monitoring.展开更多
Reservoirs with a group of vertical fractures in a vertical transversely isotropic(VTI)background are considered as orthorhombic(ORT)medium.However,fracture detection in ORT medium using seismic inversion methods rema...Reservoirs with a group of vertical fractures in a vertical transversely isotropic(VTI)background are considered as orthorhombic(ORT)medium.However,fracture detection in ORT medium using seismic inversion methods remains challenging,as it requires the estimation of more than eight parameters.Assuming the reservoir to be a weakly anisotropic ORT medium with small contrasts in the background elastic parameters,a new azimuthal elastic impedance equation was first derived using parameter combinations and mathematical approximations.This equation exhibited almost the same accuracy as the original equation and contained only six model parameters:the compression modulus,anisotropic shear modulus,anisotropic compression modulus,density,normal fracture weakness,and tangential fracture weakness.Subsequently,a stepwise inversion method using second-order derivatives of the elastic impedance was developed to estimate these parameters.Moreover,the Thomsen anisotropy parameter,epsilon,was estimated from the inversion results using the ratio of the anisotropic compression modulus to the compression modulus.Synthetic examples with moderate noise and field data examples confirm the feasibility and effectiveness of the inversion method.The proposed method exhibited accuracy similar to that of previous inversion strategies and could predict richer vertical fracture information.Ultimately,the method was applied to a three-dimensional work area,and the predictions were consistent with logging and geological a priori information,confirming the effectiveness of this method.Summarily,the proposed stepwise inversion method can alleviate the uncertainty of multi-parameter inversion in ORT medium,thereby improving the reliability of fracture detection.展开更多
The protection effectiveness of traditional Lightning Strike Protection(LSP)for composite rotor blade of helicopter can be diminished due to the explosion risk in overlapping attachment under lightning strike,so a new...The protection effectiveness of traditional Lightning Strike Protection(LSP)for composite rotor blade of helicopter can be diminished due to the explosion risk in overlapping attachment under lightning strike,so a new protection method based on Air Breakdown and insulating adhesive layer(AB-LSP method)was designed to avoid it.In this study,a numerical method was developed to simulate the electrical breakdown,and verified by experiment results.Based on this method,a Finite Element Model(FEM)was established to investigate the effect of two factors(breakdown strength and initial ablation temperature of adhesive layer)on the LSP effectiveness.The results show that the breakdown strength impacts more to the ablation damage in composite than that of high-temperature resistance.Then,another FEM was established to predict the ablation damage by lightning strike in the AB-LSP method protected composite rotor blade.The mechanisms and potential key parameters(magnitude of lightning current,discharge channel location,adhesive layer thickness,and air gap width)that could affect the protection effectiveness were analyzed.The introduction of air breakdown changes the current conduction path and reduces explosion risk.After rational design,this method can offer effective lightning protection for composite helicopter rotor blade and other composite structures.展开更多
Nonlinear Rossby waves are used to describe typical wave phenomena in large-scale atmosphere andocean.Owing to the nonlinearity of the involved problems,the weakly nonlinear method,ie the derivative ex-pansion method,...Nonlinear Rossby waves are used to describe typical wave phenomena in large-scale atmosphere andocean.Owing to the nonlinearity of the involved problems,the weakly nonlinear method,ie the derivative ex-pansion method,was mainly used to investigate Rossby waves under the combined effects of the generalizedβ-effect and the basic flow effect.The derivative expansion method has the advantage of capturing the multi-scalecharacteristics of wave processes simultaneously.In the case where the perturbation expansion is independentof secular terms,the nonlinear equations describing the amplitude evolution of nonlinear waves were derived,such as the Korteweg-de Vries equation,the Boussinesq equation and Zakharov-Kuznetsov equation.Both quali-tative and quantitative analyses indicate that the generalizedβ-effect is the key factor inducing the evolution ofRossby solitary waves.展开更多
SiC/Al-based composite foams were prepared by a two-step foaming method.The influence of the SiC content and its distribution uniformity on the foaming stability,cell structure,and mechanical properties of the aluminu...SiC/Al-based composite foams were prepared by a two-step foaming method.The influence of the SiC content and its distribution uniformity on the foaming stability,cell structure,and mechanical properties of the aluminum foams was investigated.The macro/micro-features of the aluminum foams were characterized and analyzed.Results demonstrate that an appropriate increase in SiC content and the uniform distribution of SiC can improve the foaming stability,optimize the cell diameter and cell wall thickness,ameliorate the cell distribution,and enhance the hardness and compressive strength of the aluminum foams.However,either insufficient or excessive SiC leads to uneven distribution of SiC particles,which is unfavorable to foaming stability and good cell structure formation.With 6wt%SiC,both the foaming stability and cell structure of the aluminum foam reach the optimal state,resulting in the highest compressive strength and optimal energy absorption capacity.展开更多
Norfloxacin is widely used owing to its strong bactericidal effect on Gram-negative bacteria.However,the residual norfloxacin in the environment can be biomagnified via food chain andmay damage the human liver and del...Norfloxacin is widely used owing to its strong bactericidal effect on Gram-negative bacteria.However,the residual norfloxacin in the environment can be biomagnified via food chain andmay damage the human liver and delay the bone development ofminors.Present work described a reliable and sensitive smartphone colorimetric sensing system based on cobaltdoped Fe_(3)O_(4) magnetic nanoparticles(Co-Fe_(3)O_(4) MNPs)for the visual detection of norfloxacin.Compared with Fe_(3)O_(4),Co-Fe_(3)O_(4) MNPs earned more remarkably peroxidase-like activity and TMB(colorless)was rapidly oxidized to oxTMB(blue)with the presence of H_(2)O_(2).Interestingly,the addition of low concentration of norfloxacin can accelerate the color reaction process of TMB,and blue deepening of the solution can be observed with the naked eye.However,after adding high concentration of norfloxacin,the activity of nanozymewas inhibited,resulting in the gradual fading of the solution.Based on this principle,a colorimetric sensor integrated with smartphone RGB mode was established.The visual sensor exhibited good linearity for norfloxacin monitoring in the range of 0.13-2.51μmol/L and 17.5-100μmol/L.The limit of visual detectionwas 0.08μmol/L.In the actualwater sample analysis,the spiked recoveries of norfloxacin were over the range of 95.7%-104.7%.These results demonstrated that the visual sensor was a convenient and fast method for the efficient and accurate detection of norfloxacin in water,which may have broad application prospect.展开更多
With the gradual penetration of the internet of things(IoT)into all areas of life,the scale of IoT devices shows an explosive growth trend.The era of internet of everything is coming,and the important position of IoT ...With the gradual penetration of the internet of things(IoT)into all areas of life,the scale of IoT devices shows an explosive growth trend.The era of internet of everything is coming,and the important position of IoT security is becoming increasingly prominent.Due to the large number types of IoT devices,there may be different security vulnerabilities,and unknown attack forms and virus samples are appear.In other words,large number of IoT devices,large data volumes,and various attack forms pose a big challenge of malicious traffic identification.To solve these problems,this paper proposes a concept drift detection and adaptation(CDDA)method for IoT security framework.The AI model performance is evaluated by verifying the effectiveness of IoT traffic for data drift detection,so as to select the best AI model.The experimental test are given to confirm that the feasibility of the framework and the adaptive method in practice,and the effect on the performance of IoT traffic identification is also verified.展开更多
基金supported by grants from the National Key Research and Development Program of China(Nos.2023YFA0915200,2023YFA0915204)the Equipment Research and Development Projects of the Chinese Academy of Sciences(No.PTYQ2024YZ0010)+3 种基金the Science and Technology Commission of Shanghai Municipality Project(No.XTCX-KJ-2024-038)the Natural Science Foundation of Hebei Province of China(No.H2024206249)the Postdoctoral Fellowship Program of CPSF(No.GZC20232838)Science and Technology Commission of Shanghai Municipality(No.22S31901700).
文摘The implementation of multiple pathogen testing is essential for a rapid response to future outbreaks and for reducing disease transmission.This study introduces a 96-channel microfluidic chip,fabricated through a molding process,which enables the batch detection of pathogens.It explores the rapid lysis and elution processes of pathogens within the microfluidic chips to ensure that nucleic acid extraction,elution,and amplification are completed entirely within the chip.This chip can extract nucleic acids from samples in just 10 min,achieving an extraction efficiency comparable to that of traditional in-tube methods.An oil phase is pre-loaded into the chip to effectively prevent aerosol contamination.This approach allows for the simultaneous detection of 21 common respiratory pathogens,with a detection limit of 10 copies per reaction.Furthermore,applications involving clinical samples demonstrate significant practicality.Compared to many traditional in-tube pathogen detection methods and molecular biology technologies that utilize microfluidic chips,this detection chip not only enables simultaneous detection of multiple pathogens but also demonstrates high sensitivity.
文摘Purpose–For the commonly used concrete mix for railway tunnel linings,concrete model specimens were made,and springback and core drilling tests were conducted at different ages.The springback strength was measured to the compressive strength of the core sample with a diameter of 100mm and a height-to-diameter ratio of 1:1.By comparing the measured strength values,the relationship between the measured values under different strength measurement methods was analyzed.Design/methodology/approach–A comparative test of the core drilling method and the rebound method was conducted on the side walls of tunnel linings in some under-construction railways to study the feasibility of the rebound method in engineering quality supervision and inspection.Findings–Tests showed that the rebound strength was positively correlated with the core drill strength.The core drill test strength was significantly higher than the rebound test strength,and the strength still increased after 56 days of age.The rebound method is suitable for the general survey of concrete strength during the construction process and is not suitable for direct supervision and inspection.Originality/value–By studying the correlation of test strength of tunnel lining concrete using two methods,the differences in test results of different methods are proposed to provide a reference for the test and evaluation of tunnel lining strength in railway engineering.
文摘The current study examines damage detection in fluid-conveying pipes supported on a Pasternak foundation.This study proposes a novel method that uses the matching pursuit(MP)algorithm for damage detection.The governing equations of motion for the pipe are derived using Hamilton’s principle.The finite element method,combined with the Galerkin approach,is employed to obtain the mass,damping,and stiffness matrices.To identify damage locations through pipe mode-shape decomposition,an index called the“matching pursuit residual”is introduced as a novel contribution of this study.The proposed method facilitates damage detection at various levels and locations under different boundary conditions.The findings demonstrate that the MP residual damage index can accurately localize damage in the pipes.Furthermore,the results of the numerical and experimental tests showcase the efficiency of the proposed method,highlighting that the MP signal approximation algorithm effectively detects damage in structures.
基金Supported by the Real-time Monitoring of Electromagnetic Pulse Protection(Lightning)Effect and Grounding Resistance for Guangdong Yuedian Zhuhai Biqing Bay Sea Wind Farmthe Research on Key Technologies of Lightning Intelligent Protection System for Guangdong Energy Hehe Sea Wind Farm(SFC/QZW-ZX-XF-24-020).
文摘The lightning accidents still occurred frequently in facilities protected by the protective angle method.After years of research,the expert team of the China Lightning Science(Jindun)Industry-University-Research Institute Collaboration Base has redefined the working principle of lightning rods,developed a new type of lightning rod(lightning interceptor),proposed a new theory of regional lightning protection,and established an engineering technology method for regional lightning protection(semi-circular method).Significant results have been achieved in multiple professional fields.In this paper,the research and application effects of lightning rods and protection angle method,regional lightning protection theory,and semi-circular method are introduced,which can be used as a reference for relevant technical personnel.
文摘Due to their high water content,stimulus responsiveness,and biocompatibility,hydrogels,which are functional materials with a three-dimensional network structure,are widely applied in fields such as biomedicine,environmental monitoring,and flexible electronics.This paper provides a systematic review of hydrogel charac-terization methods and their applications,focusing on primary evaluation techniques for physical properties(e.g.,mechanical strength,swelling behavior,and pore structure),chemical properties(e.g.,composition,crosslink density,and degradation behavior),biocompatibility,and functional properties(e.g.,drug release,environmental stimulus response,and conductivity).It analyzes the challenges currently faced by characterization methods,such as a lack of standardization,difficulties in dynamic monitoring,an insufficient micro-macro correlation,and poor adaptability to complex environments.It proposes solutions,such as a hierarchical standardization system,in situ imaging technology,cross-scale characterization,and biomimetic testing platforms.Looking ahead,hydrogel characterization techniques will evolve toward intelligent,real-time,multimodal coupling and standardized approaches.These techniques will provide superior technical support for precision medicine,environmental restoration,and flexible electronics.They will also offer systematic methodological guidance for the performance optimization and practical application of hydrogel materials.
文摘This article presents four techniques for assessing verticality:the plumb line approach,the total station distance technique,the three-point centering method,and the centroid method.Given the significant error associated with the total station horizontal distance technique when measuring circular piers,this paper proposes the centroid method.This method calculates verticality by determining the coordinates of the center points at both ends of the pier.Experimental findings indicate that the centroid method achieves accuracy in measuring the verticality of circular piers comparable to the three-point centering method,while offering a faster inspection process.Furthermore,the paper explores the concept of composite verticality and validates the effectiveness of the centroid method in measuring composite verticality and its practical applications through comparative experiments.
文摘In the aerospace field, residual stress directly affects the strength, fatigue life and dimensional stability of thin-walled structural components, and is a key factor to ensure flight safety and reliability. At present, research on residual stress at home and abroad mainly focuses on the optimization of traditional detection technology, stress control of manufacturing process and service performance evaluation, among which research on residual stress detection methods mainly focuses on the improvement of the accuracy, sensitivity, reliability and other performance of existing detection methods, but it still faces many challenges such as extremely small detection range, low efficiency, large error and limited application range.
基金supported by grants received by the first author and third author from the Institute of Eminence,Delhi University,Delhi,India,as part of the Faculty Research Program via Ref.No./IoE/2024-25/12/FRP.
文摘Software systems are vulnerable to security breaches as they expand in complexity and functionality.The confidentiality,integrity,and availability of data are gravely threatened by flaws in a system’s design,implementation,or configuration.To guarantee the durability&robustness of the software,vulnerability identification and fixation have become crucial areas of focus for developers,cybersecurity experts and industries.This paper presents a thorough multi-phase mathematical model for efficient patch management and vulnerability detection.To uniquely model these processes,the model incorporated the notion of the learning phenomenon in describing vulnerability fixation using a logistic learning function.Furthermore,the authors have used numerical methods to approximate the solution of the proposed framework where an analytical solution is difficult to attain.The suggested systematic architecture has been demonstrated through statistical analysis using patch datasets,which offers a solid basis for the research conclusions.According to computational research,learning dynamics improves security response and results in more effective vulnerability management.The suggested model offers a systematic approach to proactive vulnerability mitigation and has important uses in risk assessment,software maintenance,and cybersecurity.This study helps create more robust software systems by increasing patch management effectiveness,which benefits developers,cybersecurity experts,and sectors looking to reduce security threats in a growing digital world.
基金financially supported by National Natural Science Foundation of China(32460627 and 32272359)the Special Research Fund of Natural Science(Special Post)of Guizhou University(2022)54。
文摘Legume foods are not only trendy but also rich in nutrients and offer unique health benefits.Nevertheless,allergies to soy and other legumes have emerged as critical issues in food safety,presenting significant challenges to the food processing industry and impacting consumer health.The complexity of legume allergens,coupled with inadequate allergen identification methods and the absence of robust detection and evaluation systems,complicates the management of these allergens.Here,we provide a comprehensive and critical review,mentioning various aspects related to legume allergies,including the types of legume allergens,the mechanisms behind these allergies,and the immunoglobulin E(Ig E)-binding epitopes involved,summarizing and discussing the detection techniques and the impact of different processing techniques on sensitization to legume proteins.Furthermore,this paper provides an overview of research advances in diagnostic and therapeutic strategies for legume allergens and discusses current challenges and prospects for studying legume allergens.
基金supported by the National Natural Science Foundation of China(52174162)the Fundamental Research Funds for the Central Universities(FRF-TP-20-002A3).
文摘Accurate prediction of coal and gas outburst(CGO)hazards is paramount in gas disaster prevention and control.This paper endeavors to overcome the constraints posed by traditional prediction indexes when dealing with CGO incidents under low gas pressure conditions.In pursuit of this objective,we have studied and established a mechanical model of the working face under abnormal stress and the excitation energy conditions of CGO,and proposed a method for predicting the risk of CGO under abnormal stress.On site application verification shows that when a strong outburst hazard level prediction is issued,there is a high possibility of outburst disasters occurring.In one of the three locations where we predicted strong outburst hazards,a small outburst occurred,and the accuracy of the prediction was higher than the traditional drilling cuttings index S and drilling cuttings gas desorption index q.Finally,we discuss the mechanism of CGO under the action of stress anomalies.Based on the analysis of stress distribution changes and energy accumulation characteristics of coal under abnormal stress,this article believes that the increase in outburst risk caused by high stress abnormal gradient is mainly due to two reasons:(1)The high stress abnormal gradient leads to an increase in the plastic zone of the coal seam.After the working face advances,it indirectly leads to an increase in the gas expansion energy that can be released from the coal seam before reaching a new stress equilibrium.(2)Abnormal stress leads to increased peak stress of coal body in front of working face.When coal body in elastic area transforms to plastic area,its failure speed is accelerated,which induces accelerated gas desorption and aggravates the risk of outburst.
基金funded by the National Science and Technology Major Project(2022ZD0117401)the National Defense Science and Technology Innovation Special Zone Project Foundation of China(grant No.19-163-21-TS-001-067-01)support was provided by the Chinese Academy of Sciences(CAS)“Light of West China”Program(No.2020-XBQNXZ-016 and No.2022-XBQNXZ-016).
文摘Near-Earth Asteroids posed a threat to human civilization,making their monitoring crucial.As the demand for asteroid detection technology increased,precise detection of these celestial bodies became an urgent task to understand their characteristics and assess potential impact risks.To improve asteroid detection accuracy and efficiency,we proposed an advanced image processing method and a deep learning network for automatic asteroid detection.Specifically,we aligned star clusters and overlaid images to exploit asteroid motion rates,transforming them into object-like trajectories and improving the signal-to-noise ratio.This approach created the Asteroid Trajectory Image Data set under various conditions.We modified CenterNet2 network to develop AstroCenterNet by integrating Multi-channel Histogram Truncation for feature enhancement,using the SimAM attention mechanism to expand contextual information and suppress noise,and refining Feature Pyramid Network to improve low-level feature detection.Our results demonstrated a detection accuracy of 98.4%,a recall of 97.6%,a mean Average Precision of 94.01%,a false alarm rate of 1.6%,and a processing speed of approximately 17.86 frames per second,indicating that our method achieves high precision and efficiency.
基金Supported by the Sichuan Natural Resources Investment Group Technology Innovation Project"Application Research of Wide Area Electromagnetic Method in Shale Gas Electrical Detection in Southern Sichuan"。
文摘The drilling gas production situation indicates a certain correlation between the shale gas reservoir in the Sichuan Basin and the high and low changes in formation resistivity.These variations are observed in the first member of the Longmaxi Formation to the Wufeng Formation at the bottom of the Longmaxi Formation.Given this correlation and based on the logging electrical data,this study employs the wide-field electromagnetic method(WFEM)to experimentally detect the electrical characteristics of the deep shale gas target layer in the Yibin area of southern Sichuan.The study also tests the regularity and effectiveness of the electrical parameters for evaluating favorable areas of shale gas reservoirs.In terms of specific operation,the structural pattern of the study area is implemented based on the wide-field electromagnetic results and geological data for comprehensive analysis,which identifies the main hidden faults and their influence range on low resistance.The detailed spatial distribution of the upper Ordovician Wufeng Formation and the lower Silurian Longmaxi Formation in the target layer with a buried depth of 2000-5000m is described.This layer exhibits the characteristics of a continuous and stable distribution of organic shale.After verifying the subsequent electrical logging data,the electrical logging curve is found to be essentially consistent with the shape and trend of the wide-field resistivity curve.This consistency demonstrates the effectiveness of WFEM in detecting shale gas layers.
基金Supported by the Guangxi Science and Technology Major Projects,No.AA23073012the National Natural Science Foundation of China,No.32360035 and No.32060018。
文摘BACKGROUND Helicobacter pylori(H.pylori),a globally prevalent pathogen,is exhibiting increasing rates of antimicrobial resistance.However,clinical implementation of pre-treatment susceptibility testing remains limited due to the organism’s fastidious growth requirements and prolonged culture time.AIM To propose a novel detection method utilizing antibiotic-supplemented media to inhibit susceptible strains,while resistant isolates were identified through urease-mediated hydrolysis of urea,inducing a phenol red color change for visual confirmation.METHODS Colombia agar was supplemented with urea,phenol red,and nickel chloride,and the final pH was adjusted to 7.35.Antibiotic-selective media were prepared by incorporating amoxicillin(0.5μg/mL),clarithromycin(2μg/mL),metronidazole(8μg/mL),or levofloxacin(2μg/mL)into separate batches.Gastric antral biopsies were homogenized and inoculated at 1.0×105 CFU onto the media,and then incubated under microaerobic conditions at 37°C for 28-36 hours.Resistance was determined based on a color change from yellow to pink,and the results were validated via broth microdilution according to Clinical and Laboratory Standards Institute guidelines.RESULTS After 28-36 hours of incubation,the drug-resistant H.pylori isolates induced a light red color change in the medium.Conversely,susceptible strains(H.pylori 26695 and G27)produced no visible color change.Compared with the conventional 11-day protocol,the novel method significantly reduced detection time.Among 201 clinical isolates,182 were successfully evaluated using the new method,resulting in a 90.5%detection rate.This was consistent with the 95.5%agreement rate observed when compared with microdilution-based susceptibility testing.The success rate of the novel approach was significantly higher than that of the comparative method(P<0.01).The accuracy of the new method was comparable to that of the dilution method.CONCLUSION The novel detection method can rapidly detect H.pylori drug resistance within 28-36 hours.With its operational simplicity and high diagnostic performance,it holds strong potential for clinical application in the management of H.pylori antimicrobial resistance.
基金supported by National Key Research and Development Program of China(2023YFF0906100)National Natural Science Foundation of China(52408008)Key Research and Development Program of Jiangsu Province(BE2022833).
文摘Current damage detection methods based on model updating and sensitivity Jacobian matrixes show a low convergence ratio and computational efficiency for online calculations.The aim of this paper is to construct a real-time automated damage detection method by developing a theory-assisted adaptive mutiagent twin delayed deep deterministic(TA2-MATD3)policy gradient algorithm.First,the theoretical framework of reinforcement-learning-driven damage detection is established.To address the disadvantages of traditional mutiagent twin delayed deep deterministic(MATD3)method,the theory-assisted mechanism and the adaptive experience playback mechanism are introduced.Moreover,a historical residential house built in 1889 was taken as an example,using its 12-month structural health monitoring data.TA2-MATD3 was compared with existing damage detection methods in terms of the convergence ratio,online computing efficiency,and damage detection accuracy.The results show that the computational efficiency of TA2-MATD3 is approximately 117–160 times that of the traditional methods.The convergence ratio of damage detection on the training set is approximately 97%,and that on the test set is in the range of 86.2%–91.9%.In addition,the main apparent damages found in the field survey were identified by TA2-MATD3.The results indicate that the proposed method can significantly improve the online computing efficiency and damage detection accuracy.This research can provide novel perspectives for the use of reinforcement learning methods to conduct damage detection in online structural health monitoring.
基金sponsorship of the National Natural Science Foundation of China(42430809,42274157,42030103,42404132)the Fund of State Key Laboratory of Deep Oil and Gas,China University of Petroleum(East China)(SKLDOG2024-ZYTS-02)+5 种基金the Postdoctoral Fellowship Program of CPSF(GZB20240850)the Postdoctoral Project of Qingdao(QDBSH20240102082)the Fundamental Research Funds for the Central Universities(24CX07004A,24CX06036A)the CNPC Innovation Fund(2024DQ02-0505,2024DQ02-0136)the Innovation fund project for graduate student of China University of Petroleum(East China)the Fundamental Research Funds for the Central Universities(24CX04002A).
文摘Reservoirs with a group of vertical fractures in a vertical transversely isotropic(VTI)background are considered as orthorhombic(ORT)medium.However,fracture detection in ORT medium using seismic inversion methods remains challenging,as it requires the estimation of more than eight parameters.Assuming the reservoir to be a weakly anisotropic ORT medium with small contrasts in the background elastic parameters,a new azimuthal elastic impedance equation was first derived using parameter combinations and mathematical approximations.This equation exhibited almost the same accuracy as the original equation and contained only six model parameters:the compression modulus,anisotropic shear modulus,anisotropic compression modulus,density,normal fracture weakness,and tangential fracture weakness.Subsequently,a stepwise inversion method using second-order derivatives of the elastic impedance was developed to estimate these parameters.Moreover,the Thomsen anisotropy parameter,epsilon,was estimated from the inversion results using the ratio of the anisotropic compression modulus to the compression modulus.Synthetic examples with moderate noise and field data examples confirm the feasibility and effectiveness of the inversion method.The proposed method exhibited accuracy similar to that of previous inversion strategies and could predict richer vertical fracture information.Ultimately,the method was applied to a three-dimensional work area,and the predictions were consistent with logging and geological a priori information,confirming the effectiveness of this method.Summarily,the proposed stepwise inversion method can alleviate the uncertainty of multi-parameter inversion in ORT medium,thereby improving the reliability of fracture detection.
文摘The protection effectiveness of traditional Lightning Strike Protection(LSP)for composite rotor blade of helicopter can be diminished due to the explosion risk in overlapping attachment under lightning strike,so a new protection method based on Air Breakdown and insulating adhesive layer(AB-LSP method)was designed to avoid it.In this study,a numerical method was developed to simulate the electrical breakdown,and verified by experiment results.Based on this method,a Finite Element Model(FEM)was established to investigate the effect of two factors(breakdown strength and initial ablation temperature of adhesive layer)on the LSP effectiveness.The results show that the breakdown strength impacts more to the ablation damage in composite than that of high-temperature resistance.Then,another FEM was established to predict the ablation damage by lightning strike in the AB-LSP method protected composite rotor blade.The mechanisms and potential key parameters(magnitude of lightning current,discharge channel location,adhesive layer thickness,and air gap width)that could affect the protection effectiveness were analyzed.The introduction of air breakdown changes the current conduction path and reduces explosion risk.After rational design,this method can offer effective lightning protection for composite helicopter rotor blade and other composite structures.
文摘Nonlinear Rossby waves are used to describe typical wave phenomena in large-scale atmosphere andocean.Owing to the nonlinearity of the involved problems,the weakly nonlinear method,ie the derivative ex-pansion method,was mainly used to investigate Rossby waves under the combined effects of the generalizedβ-effect and the basic flow effect.The derivative expansion method has the advantage of capturing the multi-scalecharacteristics of wave processes simultaneously.In the case where the perturbation expansion is independentof secular terms,the nonlinear equations describing the amplitude evolution of nonlinear waves were derived,such as the Korteweg-de Vries equation,the Boussinesq equation and Zakharov-Kuznetsov equation.Both quali-tative and quantitative analyses indicate that the generalizedβ-effect is the key factor inducing the evolution ofRossby solitary waves.
基金Doctoral Startup Fund(20192066,20212028)Laijin Excellent Doctoral Fund(20202021)+1 种基金Scientific and Technological Innovation of Colleges and Universities in Shanxi Province(2020L0342)Fundamental Research Program of Shanxi Province(202303021222178)。
文摘SiC/Al-based composite foams were prepared by a two-step foaming method.The influence of the SiC content and its distribution uniformity on the foaming stability,cell structure,and mechanical properties of the aluminum foams was investigated.The macro/micro-features of the aluminum foams were characterized and analyzed.Results demonstrate that an appropriate increase in SiC content and the uniform distribution of SiC can improve the foaming stability,optimize the cell diameter and cell wall thickness,ameliorate the cell distribution,and enhance the hardness and compressive strength of the aluminum foams.However,either insufficient or excessive SiC leads to uneven distribution of SiC particles,which is unfavorable to foaming stability and good cell structure formation.With 6wt%SiC,both the foaming stability and cell structure of the aluminum foam reach the optimal state,resulting in the highest compressive strength and optimal energy absorption capacity.
基金supported by the National Natural Science Foundation of China (No.21976211).
文摘Norfloxacin is widely used owing to its strong bactericidal effect on Gram-negative bacteria.However,the residual norfloxacin in the environment can be biomagnified via food chain andmay damage the human liver and delay the bone development ofminors.Present work described a reliable and sensitive smartphone colorimetric sensing system based on cobaltdoped Fe_(3)O_(4) magnetic nanoparticles(Co-Fe_(3)O_(4) MNPs)for the visual detection of norfloxacin.Compared with Fe_(3)O_(4),Co-Fe_(3)O_(4) MNPs earned more remarkably peroxidase-like activity and TMB(colorless)was rapidly oxidized to oxTMB(blue)with the presence of H_(2)O_(2).Interestingly,the addition of low concentration of norfloxacin can accelerate the color reaction process of TMB,and blue deepening of the solution can be observed with the naked eye.However,after adding high concentration of norfloxacin,the activity of nanozymewas inhibited,resulting in the gradual fading of the solution.Based on this principle,a colorimetric sensor integrated with smartphone RGB mode was established.The visual sensor exhibited good linearity for norfloxacin monitoring in the range of 0.13-2.51μmol/L and 17.5-100μmol/L.The limit of visual detectionwas 0.08μmol/L.In the actualwater sample analysis,the spiked recoveries of norfloxacin were over the range of 95.7%-104.7%.These results demonstrated that the visual sensor was a convenient and fast method for the efficient and accurate detection of norfloxacin in water,which may have broad application prospect.
基金supported by 2023 Teaching Research Project of the Education Department of Anhui Province:Exploration of Optimizing Teaching Strategies for Embedded Courses in the Context of“New Engineering”(Project No.2023jyxm0460)2024 High-quality Course on Ideological and Political Education Integrated into Curriculum at Anhui University of Engineering:“Data Structures and Algorithms”(Project No.2024szyzk40)Industry-University-Research Cooperation Project of Anhui University of Engineering:“Online detection of surface quality defects in high-speed wire rod”(Project No.HX-2024-11-003).
文摘With the gradual penetration of the internet of things(IoT)into all areas of life,the scale of IoT devices shows an explosive growth trend.The era of internet of everything is coming,and the important position of IoT security is becoming increasingly prominent.Due to the large number types of IoT devices,there may be different security vulnerabilities,and unknown attack forms and virus samples are appear.In other words,large number of IoT devices,large data volumes,and various attack forms pose a big challenge of malicious traffic identification.To solve these problems,this paper proposes a concept drift detection and adaptation(CDDA)method for IoT security framework.The AI model performance is evaluated by verifying the effectiveness of IoT traffic for data drift detection,so as to select the best AI model.The experimental test are given to confirm that the feasibility of the framework and the adaptive method in practice,and the effect on the performance of IoT traffic identification is also verified.
