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Strain localization-controlled rock failure using digital volume correlation technology: In situ compression tests on 3D-printed rocklike samples with a single initial flaw
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作者 Yulong Shao Jingwei Yang +4 位作者 Jineon Kim Chen He Jae-Joon Song Hong Yin Junsu Leem 《Journal of Rock Mechanics and Geotechnical Engineering》 2025年第7期4329-4348,共20页
The study of rock failure mechanisms is fundamental to geotechnical engineering,as it enhances design quality and mitigates disaster risks.This research employed in situ compression tests on 3D-printed rocklike sample... The study of rock failure mechanisms is fundamental to geotechnical engineering,as it enhances design quality and mitigates disaster risks.This research employed in situ compression tests on 3D-printed rocklike samples with a single flaw,combining Micro-CT scans and a specialized loading device to analyze their behavior.Mechanical properties and failure modes of these printed samples were compared to those of natural flawed sandstones,demonstrating the capability of 3D printing to replicate natural rock characteristics.By reconstructing 3D crack evolution from 2D CT images and applying digital volume correlation(DVC),the study visualized internal strain fields and established a relationship between strain patterns and rock failure.The results reveal that crack initiation consistently occurs at the flaw,advancing into tensile and secondary shear or mixed cracks.For flaw angles(α)ranging from 0°to 45°,the 3D-printed samples exhibited a higher number of newly formed cracks and a faster increase in crack volume with strain.In contrast,for flaw angles of 45°≤α≤90°,the opposite trend was observed.The internal strain field exhibited significant strain localization,with this uneven distribution playing a critical role in sample failure.When the flaw angle was in the range of 0°≤α≤30°,failure was primarily driven by tensile cracks,forming distinct tensile bands.Conversely,for 30°<α≤90°,a combination of tensile and shear cracks dominated the failure,producing both shear and tensile bands in the sample.Additionally,the strain field component ε_(yy) showed a strong correlation with the evolution of internal damage,providing valuable insights into the underlying rock failure mechanisms. 展开更多
关键词 3D printing In situ compression test CT scanning Digital volume correlation(DVC) Damage evolution Strain localization Failure mechanism
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Performance test of digital volume correlation on tracking left atrium motion from cardiac CT
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作者 Zhengduo Zhu Jiaqiu Wang +8 位作者 Hao Wu Minglong Chen Zidun Wang Runxin Fang Xianjue Huang Hujin Xie Han Yu Yuchu Tian Zhiyong Li 《Acta Mechanica Sinica》 2025年第4期156-164,共9页
The accurate assessment of cardiac motion is crucial for diagnosing and monitoring cardiovascular diseases.In this context,digital volume correlation(DVC)has emerged as a promising technique for tracking cardiac motio... The accurate assessment of cardiac motion is crucial for diagnosing and monitoring cardiovascular diseases.In this context,digital volume correlation(DVC)has emerged as a promising technique for tracking cardiac motion from cardiac computed tomography angiographic(CTA)images.This paper presents a comprehensive performance evaluation of the DVC method,specifically focusing on tracking the motion of the left atrium using cardiac CTA data.The study employed a comparative experimental approach while simultaneously optimizing the existing DVC algorithm.Multiple sets of controlled experiments were designed to conduct quantitative analyses on the parameters“radius”and“step”.The results revealed that the optimized DVC algorithm enhanced tracking accuracy within a reasonable computational time.These findings contributed to the understanding of the efficacy and limitations of the DVC algorithm in analyzing heart deformation. 展开更多
关键词 Atrial fibrillation Digital volume correlation Left atrium Cardiac CT Motion tracking
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A Hybrid Approach to Software Testing Efficiency:Stacked Ensembles and Deep Q-Learning for Test Case Prioritization and Ranking
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作者 Anis Zarrad Thomas Armstrong Jaber Jemai 《Computers, Materials & Continua》 2026年第3期1726-1746,共21页
Test case prioritization and ranking play a crucial role in software testing by improving fault detection efficiency and ensuring software reliability.While prioritization selects the most relevant test cases for opti... Test case prioritization and ranking play a crucial role in software testing by improving fault detection efficiency and ensuring software reliability.While prioritization selects the most relevant test cases for optimal coverage,ranking further refines their execution order to detect critical faults earlier.This study investigates machine learning techniques to enhance both prioritization and ranking,contributing to more effective and efficient testing processes.We first employ advanced feature engineering alongside ensemble models,including Gradient Boosted,Support Vector Machines,Random Forests,and Naive Bayes classifiers to optimize test case prioritization,achieving an accuracy score of 0.98847 and significantly improving the Average Percentage of Fault Detection(APFD).Subsequently,we introduce a deep Q-learning framework combined with a Genetic Algorithm(GA)to refine test case ranking within priority levels.This approach achieves a rank accuracy of 0.9172,demonstrating robust performance despite the increasing computational demands of specialized variation operators.Our findings highlight the effectiveness of stacked ensemble learning and reinforcement learning in optimizing test case prioritization and ranking.This integrated approach improves testing efficiency,reduces late-stage defects,and improves overall software stability.The study provides valuable information for AI-driven testing frameworks,paving the way for more intelligent and adaptive software quality assurance methodologies. 展开更多
关键词 Software testing test case prioritization test case ranking machine learning reinforcement learning deep Q-learning
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Driving innovation in technical textiles,digitalisation and testing
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《China Textile》 2026年第1期38-39,共2页
Members of the British Textile Machinery Association(BTMA)can look back on 2025 as a year marked by notable technological advances and continued progress in global trade,despite an uncertain and volatile market.“Our ... Members of the British Textile Machinery Association(BTMA)can look back on 2025 as a year marked by notable technological advances and continued progress in global trade,despite an uncertain and volatile market.“Our members have been very active over the past 12 months and this has resulted in new technologies for the production of technical fibres and fabrics,the introduction of AI and machine learning into process control systems and significant advances in materials testing,”says BTMA CEO Jason Kent.“There’s real excitement about what can be achieved in 2026 as we look ahead to upcoming exhibitions such as JEC Composites in Paris in March and Techtextil in Frankfurt in April.” 展开更多
关键词 technical textiles digitalisation production technical fibres technological advances process control systems materials testing says machine learning testing
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Correlation between life satisfaction,pleasure level,and negative emotion in patients with chronic renal failure
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作者 Lin-Lin Zhang You-Li Zhang +3 位作者 Ting Liu Jian Wang Chen Chen Xiao-Yu Wang 《World Journal of Psychiatry》 2026年第1期291-298,共8页
BACKGROUND Anxiety,depression,and other negative emotions are common among patients with chronic renal failure(CRF).Analyzing the factors related to negative emotions is necessary to provide targeted nursing care.AIM ... BACKGROUND Anxiety,depression,and other negative emotions are common among patients with chronic renal failure(CRF).Analyzing the factors related to negative emotions is necessary to provide targeted nursing care.AIM To explore the correlations among life satisfaction,pleasure levels,and negative emotions in patients with CRF.METHODS One hundred patients with CRF who received therapy at the First Affiliated Hospital of Jinzhou Medical University between December 2022 and February 2025 were included.The Depression,Anxiety,and Stress Scale(DASS-21),Satisfaction with Life Scale(SWLS),and Temporal Experience of Pleasure Scale(TEPS)were used to evaluate negative emotions,life satisfaction,and pleasure level,respectively.Pearson’s correlation coefficient analyzed the correlation between life satisfaction,pleasure level,and negative emotions.Linear regression analysis identified the factors affecting negative emotions.RESULTS The average DASS-21 score among patients with CRF was 51.90±2.30,with subscale scores of 17.90±1.50 for depression,18.53±1.18 for anxiety,and 15.47±2.36 for stress,all significantly higher than the domestic norm(P<0.05).The average SWLS score was 22.17±4.90.Correlation analysis revealed a negative correlation between the SWLS and total DASS-21 scores(P<0.05),but not with the individual depression,anxiety,or stress dimensions.The average TEPS score was 67.80±8.34.TEPS scores were negatively correlated with the DASS-21 score and the stress dimension(P<0.05),but not with depression or anxiety.Linear regression analysis showed that TEPS scores significantly influenced DASS-21 scores(P<0.05).CONCLUSION Patients with CRF experience high levels of negative emotions,which are negatively correlated with life satisfaction and pleasure.Furthermore,pleasure level had an impact on negative emotions. 展开更多
关键词 Chronic renal failure HEMODIALYSIS Negative emotion Life satisfaction PLEASURE correlation
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Janus effect of inter-orbital hybridization on correlation strength of strongly correlated systems:A dynamical mean-field study
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作者 Jian Sun Yinchang Zhao Chao Lian 《Chinese Physics B》 2026年第2期529-537,共9页
In multi-orbital systems,the correlation strength is typically attributed to Coulomb interactions and Hund's couplings.However,this study demonstrates that on-site inter-orbital hybridization can also significant ... In multi-orbital systems,the correlation strength is typically attributed to Coulomb interactions and Hund's couplings.However,this study demonstrates that on-site inter-orbital hybridization can also significant influence the correlation strength of the system.We investigate the impact of on-site inter-orbital hybridization on the correlation strength of a two-orbital Hubbard model on a square lattice using the dynamical mean-field theory combined with Lanczos exact diagonalization.Our findings reveal a distinct Janus effect:on-site inter-orbital hybridization enhances correlation strength in the non-half-filled regime while suppresses it at half-filling.This dual role of on-site inter-orbital hybridization provides a fundamental mechanism for tuning the strength of correlations in multi-orbital systems. 展开更多
关键词 strongly correlated multi-orbital system inter-orbital hybridization dynamical mean-field theory
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A REST API Fuzz Testing Framework Based on GUI Interaction and Specification Completion
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作者 Zonglin Li Xu Zhao +2 位作者 Yan Cao Yazhe Li Yihong Zhang 《Computers, Materials & Continua》 2026年第3期2201-2222,共22页
With the rapid development of Internet technology,REST APIs(Representational State Transfer Application Programming Interfaces)have become the primary communication standard in modern microservice architectures,raisin... With the rapid development of Internet technology,REST APIs(Representational State Transfer Application Programming Interfaces)have become the primary communication standard in modern microservice architectures,raising increasing concerns about their security.Existing fuzz testing methods include random or dictionary-based input generation,which often fail to ensure both syntactic and semantic correctness,and OpenAPIbased approaches,which offer better accuracy but typically lack detailed descriptions of endpoints,parameters,or data formats.To address these issues,this paper proposes the APIDocX fuzz testing framework.It introduces a crawler tailored for dynamic web pages that automatically simulates user interactions to trigger APIs,capturing and extracting parameter information from communication packets.A multi-endpoint parameter adaptation method based on improved Jaccard similarity is then used to generalize these parameters to other potential API endpoints,filling in gaps in OpenAPI specifications.Experimental results demonstrate that the extracted parameters can be generalized with 79.61%accuracy.Fuzz testing using the enriched OpenAPI documents leads to improvements in test coverage,the number of valid test cases generated,and fault detection capabilities.This approach offers an effective enhancement to automated REST API security testing. 展开更多
关键词 REST APIs fuzz testing OpenAPI specifications
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IoT-Assisted Cloud Data Sharing with Revocation and Equality Test under Identity-Based Proxy Re-Encryption
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作者 Han-Yu Lin Tung-Tso Tsai Yi-Chuan Wang 《Computers, Materials & Continua》 2026年第3期431-447,共17页
Cloud services,favored by many enterprises due to their high flexibility and easy operation,are widely used for data storage and processing.However,the high latency,together with transmission overheads of the cloud ar... Cloud services,favored by many enterprises due to their high flexibility and easy operation,are widely used for data storage and processing.However,the high latency,together with transmission overheads of the cloud architecture,makes it difficult to quickly respond to the demands of IoT applications and local computation.To make up for these deficiencies in the cloud,fog computing has emerged as a critical role in the IoT applications.It decentralizes the computing power to various lower nodes close to data sources,so as to achieve the goal of low latency and distributed processing.With the data being frequently exchanged and shared between multiple nodes,it becomes a challenge to authorize data securely and efficiently while protecting user privacy.To address this challenge,proxy re-encryption(PRE)schemes provide a feasible way allowing an intermediary proxy node to re-encrypt ciphertext designated for different authorized data requesters without compromising any plaintext information.Since the proxy is viewed as a semi-trusted party,it should be taken to prevent malicious behaviors and reduce the risk of data leakage when implementing PRE schemes.This paper proposes a new fog-assisted identity-based PRE scheme supporting anonymous key generation,equality test,and user revocation to fulfill various IoT application requirements.Specifically,in a traditional identity-based public key architecture,the key escrow problem and the necessity of a secure channel are major security concerns.We utilize an anonymous key generation technique to solve these problems.The equality test functionality further enables a cloud server to inspect whether two candidate trapdoors contain an identical keyword.In particular,the proposed scheme realizes fine-grained user-level authorization while maintaining strong key confidentiality.To revoke an invalid user identity,we add a revocation list to the system flows to restrict access privileges without increasing additional computation cost.To ensure security,it is shown that our system meets the security notion of IND-PrID-CCA and OW-ID-CCA under the Decisional Bilinear Diffie-Hellman(DBDH)assumption. 展开更多
关键词 Equality test proxy re-encryption IDENTITY-BASED REVOCABLE fog computing
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The measurement of the energy correlations between two^(252)Cf prompt fission neutrons
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作者 Huai-Yong Bai Hang Li +8 位作者 Hong-Jun Zhang Cheng-Guo Pang Ming Su Zhong-Hua Xiong Ji Wen Fan Gao Chen-Guang Li Xiao-Dong Wang Li-Sheng Yang 《Nuclear Science and Techniques》 2026年第4期202-215,共14页
The energy correlations of prompt fission neutrons have not yet been considered in the related coincidence and multiplication measurement techniques.To measure and verify the energy correlations,an experiment was perf... The energy correlations of prompt fission neutrons have not yet been considered in the related coincidence and multiplication measurement techniques.To measure and verify the energy correlations,an experiment was performed with a total measurement duration of approximately 1200 h.In the experiment,eight CLYC detectors and sixteen EJ309 liquid scintillation detectors were utilized,and the fission moment was tagged with the measured fissionγ-rays.The relative ratios of the energy spectra of the neutrons correlated with different energy neutrons to the^(252)Cf fission neutron energy spectra were obtained.The present results may be helpful for studying fission physics and nuclear technology applications. 展开更多
关键词 Energy correlations Prompt fission neutrons Energy spectrum Fissionγ-rays
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Electronic correlations and topological states at the interface of twisted bilayer graphene and chromium oxychloride
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作者 Minsheng Li Zehao Jia +6 位作者 Xiangyu Cao Qiang Ma Chang Jiang Yuda Zhang Linfeng Ai Pengliang Leng Faxian Xiu 《Chinese Physics B》 2026年第2期185-192,共8页
When two layers of graphene are stacked with a twist angle of approximately 1.1°,strong interlayer coupling gives rise to a pair of flat bands in twisted bilayer graphene(TBG),resulting in pronounced electron–el... When two layers of graphene are stacked with a twist angle of approximately 1.1°,strong interlayer coupling gives rise to a pair of flat bands in twisted bilayer graphene(TBG),resulting in pronounced electron–electron interactions.At half filling of the flat bands,TBG exhibits correlated insulating states.Here,we investigate the electrical transport properties of heterostructures composed of TBG and the antiferromagnetic insulator chromium oxychloride(CrOCl),and propose a strategy to modulate the correlated insulating states in TBG.During the transition from a conventional phase to a strong interfacial coupling phase,kink-like features are observed in the charge neutrality point(CNP),correlated insulating state,and band insulating state.Under a perpendicular magnetic field,the system exhibits broadened quantum Hall plateaus in the strong interfacial coupling regime.Electrons localized in the CrOCl layer screen the bottom gate,rendering the carrier density in TBG less sensitive to variations in the bottom gate voltage.These phenomena are well captured by a charge-transfer model between TBG and CrOCl.Our results provide insights into the control of electronic correlations and topological states in graphene moirésystems via interfacial charge coupling. 展开更多
关键词 twisted bilayer graphene correlated insulating state CrOCl interfacial coupling charge transfer
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Dynamic characteristics analysis of rack railway track system under traction conditions by experimental test
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作者 Zhihui Chen Guojun Yang +3 位作者 Zaigang Chen Haitao Zhang Jizhong Yang Wanming Zhai 《Railway Engineering Science》 2026年第1期40-54,共15页
The dynamic characteristics of the track system can directly affect its service performance and failure process.To explore the load characteristics and dynamic response of the track system under the dynamic loads from... The dynamic characteristics of the track system can directly affect its service performance and failure process.To explore the load characteristics and dynamic response of the track system under the dynamic loads from the rack vehicle in traction conditions,a systematic test of the track subsystem was carried out on a large-slope test line.In the test,the bending stress of the rack teeth,the wheel-rail forces,and the acceleration of crucial components in the track system were measured.Subsequently,a detailed analysis was conducted on the tested signals of the rack railway track system in the time domain and the time-frequency domains.The test results indicate that the traction force significantly affects the rack tooth bending stress and the wheel-rail forces.The vibrations of the track system under the traction conditions are mainly caused by the impacts generated from the gear-rack engagement,which are then transferred to the sleepers,the rails,and the ballast beds.Furthermore,both the maximum stress on the racks and the wheel-rail forces measured on the rails remain below their allowable values.This experimental study evaluates the load characteristics and reveals the vibration characteristics of the rack railway track system under the vehicle’s ultimate load,which is very important for the load-strengthening design of the key components such as racks and the vibration and noise reduction of the track system. 展开更多
关键词 Rack railway Vehicle-track coupled dynamics Traction condition Experimental test Gear-rack engagement
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Octupole correlations of the K^(π)=5/2^(+)ground-state band in^(229)Th
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作者 Yuan-Yuan Wang Peng-Wei Zhao 《Chinese Physics B》 2026年第2期156-161,共6页
The octupole correlations of the K^(π)=5/2^(+)ground state and the rotational spectrum built on it in^(229)Th are studied using the microscopic relativistic density functional theory on a three-dimensional lattice sp... The octupole correlations of the K^(π)=5/2^(+)ground state and the rotational spectrum built on it in^(229)Th are studied using the microscopic relativistic density functional theory on a three-dimensional lattice space and the reflection-asymmetric triaxial particle rotor model.It is found that^(229)Th has a ground state with static axial octupole and quadrupole deformations.The occurrence of octupole correlations,driven by the octupole deformation,is analyzed through the evolution of single-particle levels around the Fermi surface.The experimental energy spectrum and the electromagnetic transition probabilities,including B(E2)and B(M1),are reasonably well reproduced. 展开更多
关键词 octupole correlation relativistic density functional theory reflection-asymmetric triaxial particle rotor model rotational spectrum
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Monotonic triaxial testing and hypoplastic modelling of calcareous sand:A focus on particle breakage and initial relative density
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作者 Jiarui Chen Yaolan Tang +4 位作者 Shun Wang Chunshun Zhang Wei Wei Jie Dong Congying Li 《Journal of Rock Mechanics and Geotechnical Engineering》 2026年第2期1504-1525,共22页
The stress-strain behavior of calcareous sand is significantly influencedby particle breakage(B)and initial relative density(Dri),but few constitutive models consider their combined effects.To bridge this gap,we condu... The stress-strain behavior of calcareous sand is significantly influencedby particle breakage(B)and initial relative density(Dri),but few constitutive models consider their combined effects.To bridge this gap,we conducted a series of triaxial tests on calcareous sand with varying Dri and stress paths,examining particle breakage and critical state behavior.Key findingsinclude:(1)At a constant stress ratio(η),B follows a hyperbolic relationship with mean effective stress(p'),and for a given p',B increases proportionally withη;(2)The critical state line(CSL)moves downward with increasing Dri,whereas the critical state friction angle(φcs)decreases with increasing B.Based on these findings,we propose a unifiedbreakage evolution model to quantify particle breakage in calcareous sand under various loading conditions.Integrating this model with the Normal Consolidation Line(NCL)and CSL equations,we successfully simulate the steepening of NCL and CSL slopes as B increases with the onset of particle breakage.Furthermore,we quantitatively evaluate the effect of B onφcs.Finally,within the framework of Critical State Soil Mechanics and Hypoplasticity theory,we develop a hypoplastic model incorporating B and Dri.The model is validated through strong agreement with experimental results across various initial relative densities,stress paths and drainage conditions. 展开更多
关键词 Calcareous sand Constitutive model HYPOPLASTICITY Particle breakage Initial relative density Triaxial test
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Aptamer&MOF-functionalized multichannel paper chip for point-of-care testing of small extracellular vesicle membrane protein profile
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作者 Shaoqiang Wen Lang Zhang +7 位作者 Zhan Huang Meng Chen Yuzhi Xu Xing Huang Zhou Zhang Xiaoyong Zou Zong Dai Si-Yang Liu 《Chinese Chemical Letters》 2026年第2期687-692,共6页
Small extracellular vesicles(sEVs)membrane protein profile(sEVpp)is a novel biomarker for cancer,and it can reveal the in-depth phenotype information.The point-of-care testing(POCT)of sEVpp holds great significance fo... Small extracellular vesicles(sEVs)membrane protein profile(sEVpp)is a novel biomarker for cancer,and it can reveal the in-depth phenotype information.The point-of-care testing(POCT)of sEVpp holds great significance for mass screening of cancer,so the cost-effective and simple detection methods of sEVpp are urgently demanded.Herein,we constructed a paper-based multichannel sEVpp POCT device(sEVpp-PAD)enabled by functional DNA probes and metal-organic framework(MOF).The core components are aptamer/MOF-modified paper chips.The modified aptamers can immunocapture the sEV expressing corresponding proteins,while the modified MOF can provide abundant sites for aptamer-modification,reduce the nonspecific protein absorption,and act as reference for ratiometric detection.Simply powered by two syringes,the sEVpp-PAD can efficiently capture sEVs expressing corresponding protein from cell culture media and sera.Furthermore,a detection probe(DP)consisted of CD63 aptamer and G-quadruplex was developed for the colorimetric detection of captured sEVs.Utilizing this device,the sEVpp in various hepatocellular carcinoma cell culture medium and,more importantly,in human sera can be accurately determined,only with$2 device,$0.2 detection reagents and 1.8 h procedure.This simple strategy for sEVpp detection can innovatively promote the POCT and subtyping of cancer based on sEV-related liquid biopsy. 展开更多
关键词 Small extracellular vesicles Protein profile Point-of-care testing Paper-based analytical device Metal-organic frameworks
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Design and optimization of a compact high-energy electron source applied to on-site non-destructive testing for electrical equipment
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作者 Hai-Meng Wang Yi-Feng Zeng +2 位作者 Hao Hu Jun-Yang Li Tong-Ning Hu 《Nuclear Science and Techniques》 2026年第4期28-40,共13页
X-rays are widely used in the non-destructive testing(NDT)of electrical equipment.Radio frequency(RF)electron linear accelerators can generate MeV high-energy X-rays with strong penetrating ability;however,the system ... X-rays are widely used in the non-destructive testing(NDT)of electrical equipment.Radio frequency(RF)electron linear accelerators can generate MeV high-energy X-rays with strong penetrating ability;however,the system generally has a large scale,which is not suitable for on-site testing.Compared with the S-band(S-linac)at the same stage of beam energy,the accelerator working in the X-band(X-linac)can compress the facility scale by over 2/3 in the longitudinal direction,which is convenient for the on-site NDT of electrical equipment.To address the beam quality and design complexity simultaneously,the non-dominated sorting genetic algorithmⅡ(NSGA-Ⅱ),which is a multi-objective genetic algorithm(MOGA),was developed to optimize the cavity chain design of the X-linac.Additionally,the designs of the focusing coils,electron gun,and RF couplers,which are other key components of the X-linac,were introduced in this context.In particular,the focusing coil distributions were optimized using a genetic algorithm.Furthermore,after designing such key components,PARMELA software was adopted to perform beam dynamics calculations with the optimized accelerating fields and magnetic fields.The results show that the beam performance was obtained with a capture ratio of more than 90%,an energy spread of less than 10%,and an average energy of approximately 3 MeV.The design and simulation results indicate that the proposed NSGAⅡ-based approach is feasible for X-linac accelerator design.Furthermore,it can be generalized as a universal technique for industrial electron linear accelerators provided that specific optimization objectives and constraints are set according to different application scenarios and requirements. 展开更多
关键词 Non-destructive testing X-band linac accelerator Focusing coils Electron gun Radio frequency couplers
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Thermodynamic performance calculation and test verification of gas-liquid two-phase water ramjet engine
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作者 Pingan LIU Dianlong SUN +4 位作者 Xile QIAN Shang LIU Tao WANG Jingtao CHENG Kejing XU 《Chinese Journal of Aeronautics》 2026年第1期1-17,共17页
Underwater gas-liquid two-phase propulsion technology is an emerging propulsion method that offers high efficiency and unrestricted navigation speed.The integration of this technology into water ramjet engines can sig... Underwater gas-liquid two-phase propulsion technology is an emerging propulsion method that offers high efficiency and unrestricted navigation speed.The integration of this technology into water ramjet engines can significantly enhance propulsion efficiency and holds substantial potential for broad applications.However,forming a gas-liquid two-phase flow within the nozzle requires introducing a large amount of rammed seawater.At this time,there is a complex phase transition problem of combustion products in the combustion chamber,which makes the thermodynamic calculation for gas-liquid two-phase water ramjet engines particularly challenging.This paper proposes a thermodynamic calculation method for gas-liquid two-phase water ramjet engines,based on the energy equation for gas-liquid two-phase flow and traditional thermodynamic principles,enabling thermodynamic calculations under conditions of ultra-high water-fuel ratios.Additionally,ground ignition tests of the gas-liquid two-phase engine were conducted,yielding critical engine test parameters.The results demonstrate that the gas-liquid two-phase water ramjet engine achieves a high specific impulse,with a theoretical maximum specific impulse of up to 7000(N s)/kg.The multiphase flow effects significantly impact engine performance,with specific impulse losses reaching up to 25.86%.The error between the thrust and specific impulse in the ground test and the theoretical values is within 10%,validating the proposed thermodynamic calculation method as a reliable reference for further research on gas-liquid two-phase water ramjet engines. 展开更多
关键词 Gas-liquid two-phase flow Ignition test Multiphase flow Thermal calculation Water ramjet engine
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Design of Virtual Driving Test Environment for Collecting and Validating Bad Weather SiLS Data Based on Multi-Source Images Using DCU with V2X-Car Edge Cloud
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作者 Sun Park JongWon Kim 《Computers, Materials & Continua》 2026年第3期448-467,共20页
In real-world autonomous driving tests,unexpected events such as pedestrians or wild animals suddenly entering the driving path can occur.Conducting actual test drives under various weather conditions may also lead to... In real-world autonomous driving tests,unexpected events such as pedestrians or wild animals suddenly entering the driving path can occur.Conducting actual test drives under various weather conditions may also lead to dangerous situations.Furthermore,autonomous vehicles may operate abnormally in bad weather due to limitations of their sensors and GPS.Driving simulators,which replicate driving conditions nearly identical to those in the real world,can drastically reduce the time and cost required for market entry validation;consequently,they have become widely used.In this paper,we design a virtual driving test environment capable of collecting and verifying SiLS data under adverse weather conditions using multi-source images.The proposed method generates a virtual testing environment that incorporates various events,including weather,time of day,and moving objects,that cannot be easily verified in real-world autonomous driving tests.By setting up scenario-based virtual environment events,multi-source image analysis and verification using real-world DCUs(Data Concentrator Units)with V2X-Car edge cloud can effectively address risk factors that may arise in real-world situations.We tested and validated the proposed method with scenarios employing V2X communication and multi-source image analysis. 展开更多
关键词 Virtual driving test DCU bad weather SiLS autonomous environment V2X-Car edge cloud
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Thermomechanical coupling analysis of granite fracture shear behavior:True triaxial test and numerical approaches
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作者 Zhufeng Yue Fanzhen Meng +4 位作者 Qijin Cai Dongliang Tian Yuantao Wen Wei Wang Dawei Hu 《Journal of Rock Mechanics and Geotechnical Engineering》 2026年第2期1337-1358,共22页
High geo-stress and high temperature in deep rock engineering increase the possibility of engineering and geological disasters in discontinuous rocks.However,the influence of thermomechanical coupling on the shear beh... High geo-stress and high temperature in deep rock engineering increase the possibility of engineering and geological disasters in discontinuous rocks.However,the influence of thermomechanical coupling on the shear behavior and damage evolution of prefractured granite remains immature.In this context,true triaxial laboratory tests and discrete element method simulations under different confining pressures(σ3=3 MPa,σ2=4 MPa,andσ3=80 MPa,σ2=100 MPa)and temperatures(25℃-500℃)were carried out on rough granite fractures with two different orientations.Results indicate that high temperature and high confining pressure increase the peak strength of the prefractured specimen,leading to more microcracks in the host rock and more gouges between the surfaces.Thermal strengthening at low temperatures(<300℃)and residual stick-slip only occur under a greater confining pressure for prefractured specimens.High confining pressure suppresses generation of the thermal microcracks in the heating stage.Cracks first initiate in the asperities on the fracture surfaces,and then propagate into the rock matrix during the mechanical loading stage.In addition,prefractured granite with a larger fracture angle is characterized by smaller peak and residual strength,faster residual slip,fewer new cracks on the specimen surface,and a more pronounced thermal strengthening effect on peak strength.The slip tendency analysis indicates that a higher maximum principal stress(s1)and a large fracture angle(45°-75°)generally result in a higher potential for fracture slip or activation.This study will contribute to a better understanding of the fracture shear mechanism under true triaxial thermomechanical coupling conditions and provides new insights into the stability evaluation of deep dynamic geological hazards. 展开更多
关键词 Thermomechanical coupling effect Real-time high temperature Prefractured granite Fracture angle True triaxial shear test
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Magnetic pulse welding of Al-5754 with Al-7075 and MARS 380:Weldability windows and ballistic testing
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作者 Benoit Lagain Thomas Heuzé +1 位作者 Guillaume Racineux Michel Arrigoni 《Defence Technology(防务技术)》 2026年第1期64-79,共16页
Joining dissimilar materials encounters significant engineering challenges due to the contrast in material properties that makes conventional welding not feasible.Magnetic Pulse Welding(MPW)offers a solidstate joining... Joining dissimilar materials encounters significant engineering challenges due to the contrast in material properties that makes conventional welding not feasible.Magnetic Pulse Welding(MPW)offers a solidstate joining technique that overcomes these issues by using impact to create strong bonds without melting the substrate materials.This study investigates the weldability of aluminum alloy Al-5754 with Al-7075 and MARS 380 steel,used in armouring solutions of defense systems,by the use of MPW.In this work,weldability windows are investigated by varying standoff distances between the coating material and its substrate(0.25-4.5 mm)and discharge energies(5-13 kJ)with both O-shape and U-shape inductors.Mechanical strength of the welded joints were assessed through single lap shear tests,identifying optimal welding parameters.Then,the velocity profiles of the flyer plates were measured using heterodyne velocimetry to understand the dynamics of the impact.Then,substructures assembled with the optimal welding conditions were subjected to ballistic testing using 7.62 mm×51 mm NATO and 9 mm×19 mm Parabellum munitions to evaluate the resilience of the welds under ballistic impact.The outcomes demonstrate that MPW effectively joins Al-5754 with both Al-7075 and MARS 380,producing robust welds capable of withstanding ballistic impacts under certain conditions.This research advances the application of MPW in lightweight ballistic protection of defense systems,contributing to the development of more resilient and lighter protective structures. 展开更多
关键词 Magnetic pulse welding(MPW) Dissimilar material joining Weldability windows Impact welding Ballistic testing
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Key role of Levitt’s carbon monoxide breath test in revealing coexistent Gilbert syndrome and erythropoietic protoporphyria:A case report
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作者 Ling-Ling Kang Hou-De Zhang 《World Journal of Clinical Cases》 2026年第1期28-33,共6页
It is challenging to diagnose isolated hyperbilirubinemia with rare and complex etiologies under the constraints of traditional testing conditions.Herein,we present a rare case of coexisting Gilbert syndrome(GS)and er... It is challenging to diagnose isolated hyperbilirubinemia with rare and complex etiologies under the constraints of traditional testing conditions.Herein,we present a rare case of coexisting Gilbert syndrome(GS)and erythropoietic protoporphyria(EPP),which has not been previously documented.CASE SUMMARY We present a rare case of coexisting GS and EPP in a 23-year-old Chinese male with a long history of jaundice and recently found splenomegaly.Serial nonspecific hemolysis screening tests yielded inconsistent results,and investigations for common hemolytic etiologies were negative.However,Levitt’s carbon monoxide breath test,which measures erythrocyte lifespan(the gold-standard marker of hemolysis),demonstrated significant hemolysis,revealing a markedly shortened erythrocyte lifespan of 11 days(normal average 120 days).Genetic testing subsequently confirmed EPP with a homozygous ferrochelatase gene mutation and GS with a heterozygous uridine diphosphate glucuronosyl trans-ferase 1A1 gene mutation.CONCLUSION The rapid,non-invasive Levitt’s carbon monoxide breath test resolved the diagnostic challenge posed by a rare and complex cause of hyperbilirubinemia. 展开更多
关键词 Isolated hyperbilirubinemia Erythropoietic protoporphyria Gilbert syndrome HEMOLYSIS Levitt’s carbon monoxide breath test Erythrocyte lifespan Case report
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