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A review of the standardized measurement of the characteristics of graphene-based materials
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作者 Zhang Donghui Li Wan +2 位作者 Ou Bingxian Wang Liangwang Ge Guanglu 《新型炭材料(中英文)》 北大核心 2026年第1期91-108,共18页
Standardization is necessary for the early industrialization of the new materials and technology.It is achieved by having agreed practices for the measurement of properties and other characteristics.The promising use ... Standardization is necessary for the early industrialization of the new materials and technology.It is achieved by having agreed practices for the measurement of properties and other characteristics.The promising use of graphene-based materials in fields like electronics,energy,and composites has resulted in standards for their nomenclature,the measurement of key characteristics,and their specification,etc.Among these,standards for measuring the key characteristics are crucial.The critical parameters are the number of layers,the type and concentration of defects and functional groups,elemental composition,sheet resistance,and carrier mobility.Standards for characterizing these have been analyzed by the International Organization for Standardization Technical Committee in ISO/TC229 and the International Electrotechnical Commission Technical Committee in IEC/TC113.These give details of applicable or preferred samples,the fundamental principles of the techniques,specific precautions,and points for attention in the relevant standards.The pivotal role of the ISO/TC229 and IEC/TC113 standards is considered and challenges and future trends are outlined. 展开更多
关键词 Nanotechnology Graphene-based materials measurement standards Critical characteristics Quality control
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Comparison of three different instruments for vault measurements after implantable collamer lens implantation
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作者 Bo-Liang Li Ming-Rui Cheng +6 位作者 Wei-Teng Chang Ya-Di Lei Guang-Han Xu Ming-Wei Li Zhi-Wei Mao Xun Chen Xiao-Ying Wang 《International Journal of Ophthalmology(English edition)》 2026年第3期475-482,共8页
AIM:To evaluate the differences and consistency of vault measurements obtained by Scheimpflug tomography(Pentacam),anterior segment optical coherence tomography(AS-OCT,CASIA II),and ultrasound biomicroscopy(UBM)follow... AIM:To evaluate the differences and consistency of vault measurements obtained by Scheimpflug tomography(Pentacam),anterior segment optical coherence tomography(AS-OCT,CASIA II),and ultrasound biomicroscopy(UBM)following implantable collamer lens(ICL)V4c implantation.METHODS:Vault measurements were acquired using three modalities:Pentacam,CASIA II AS-OCT,and UBM.Repeated-measures analysis of variance was used to compare the vault values obtained by the three devices.The correlation and consistency of measurements among the three instruments were assessed using the Pearson correlation coefficient,intraclass correlation coefficient(ICC),and Bland-Altman plots.RESULTS:This retrospective study enrolled 210 myopic eyes of 210 patients(158 women and 52 men)who underwent ICL implantation:108 eyes had a myopic ICL V4c implanted,and 102 eyes had a toric ICL V4c implanted.The mean vault values measured by Pentacam,CASIA II,and UBM were 452.64±204.20μm,538.57±203.54μm,and 560.95±227.54μm,respectively,with statistically significant differences among the three groups(P<0.05).Pearson correlation analysis showed strong positive correlations between vault values measured by different instruments(all P<0.001).ICC results indicated good consistency among the three measurement modalities(all P<0.001).Stratified analysis revealed that when the vault value was≤250μm,the correlation and consistency of measurements across the three instruments were lower than those in the medium and high vault subgroups.CONCLUSION:Vault values measured by Pentacam are lower than those obtained by CASIA II and UBM,with UBM yielding the highest mean vault values.Measurements from the three instruments are not interchangeable but can serve as mutual references due to their significant correlation and good overall consistency.Pentacam and CASIA II demonstrate the highest consistency in vault measurement.Notably,when the vault value is≤250μm,the consistency between Pentacam and the other two instruments decreases significantly. 展开更多
关键词 implantable collamer lens vault measurement scheimpflug tomography anterior segment optical coherence tomography ultrasound biomicroscopy measurement consistency
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Exploring recent breakthroughs in robotic biomechanical and electrophysiological measurement tools
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作者 Hui-Yao Shi Si Tang +3 位作者 Jia-Lin Shi Peng Yu Chan-Min Su Lian-Qing Liu 《Biomedical Engineering Communications》 2026年第1期35-47,共13页
Single-cell biomechanics and electrophysiology measuring tools have transformed biological research over the last few decades,which enabling a comprehensive and nuanced understanding of cellular behavior and function.... Single-cell biomechanics and electrophysiology measuring tools have transformed biological research over the last few decades,which enabling a comprehensive and nuanced understanding of cellular behavior and function.Despite their high-quality information content,these single-cell measuring techniques suffer from laborious manual processing by highly skilled workers and extremely low throughput(tens of cells per day).Recently,numerous researchers have automated the measurement of cell mechanical and electrical signals through robotic localization and control processes.While these efforts have demonstrated promising progress,critical challenges persist,including human dependency,learning complexity,in-situ measurement,and multidimensional signal acquisition.To identify key limitations and highlight emerging opportunities for innovation,in this review,we comprehensively summarize the key steps of robotic technologies in single-cell biomechanics and electrophysiology.We also discussed the prospects and challenges of robotics and automation in biological research.By bridging gaps between engineering,biology,and data science,this work aims to stimulate interdisciplinary research and accelerate the translation of robotic single-cell technologies into practical applications in the life sciences and medical fields. 展开更多
关键词 BIOMECHANICS ELECTROPHYSIOLOGY micro-nano manipulation automated cell measurement ROBOTICS
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Advances and Prospects in Body-Size Measurement of Sheep:From 2D Vision to 3D Reconstruction and 2D-3D Fusion
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作者 DAI Weijiao LIANG Yudongchen +5 位作者 ZHOU Yong YAO Chao ZHANG Cheng SONG Yongjian LI Guoliang TIAN Fang 《智慧农业(中英文)》 2026年第1期120-147,共28页
[Significance]In alignment with the national germplasm security strategy,current research efforts are accelerating the adoption of precision breeding in sheep.Within the whole-genome selection,accurate phenotyping of ... [Significance]In alignment with the national germplasm security strategy,current research efforts are accelerating the adoption of precision breeding in sheep.Within the whole-genome selection,accurate phenotyping of body morphometrics is critical for assessing growth performance and breeding value.Traditional manual measurements are inefficient,prone to human error,and may cause stress to sheep,limiting their suitability for precision sheep management.By summarizing the applications of sheep body size measurement technologies and analyzing their development directions,this paper provides theoretical references and practical guidance for the research and application of non contact sheep body size measurement.[Progress]This review synthesizes progress across three principal methodological paradigms:two-dimensional(2D)image-based techniques,three-dimensional(3D)point cloud-based approaches,and integrated 2D-3D fusion systems.2D methods,employing either handcrafted geometric features or deep learning-based keypoint detector algorithms,are cost-effective and operationally simple but sensitive to variation in imaging conditions and unable to capture critical circumference metrics.3D point-cloud approaches enable precise reconstruction of full animal morphology,supporting comprehensive body-size acquisition with higher accuracy,yet face challenges including high hardware costs,complex data workflows,and sensitivity to posture variability.Hybrid 2D-3D fusion systems combine semantic richness from RGB imagery with geometric completeness from point clouds.Having been effectively validated in other livestock specise,e.g.,cattle and pigs,these fusion systems have demonstrated excellent performance,providing important technical references and practical insights for sheep body size measurement.[Conclusions and Prospects]Firstly,future research should focus on constructing large-scale,high-quality datasets for sheep body size measurement that encompass diverse breeds,growth stages,and environmental conditions,thereby enhancing model robustness and generalization.Secondly,the development of lightweight artificial intelligence models is essential.Techniques such as model compression,quantization,and algorithmic optimization can substantially reduce computational complexity and storage requirements,facilitating deployment in resource-constrained environments.Thirdly,the 3D point cloud processing pipeline should be streamlined to improve the efficiency of data acquisition,filtering,registration,and segmentation,while promoting the integration of low-cost,high-resilience vision systems into practical farming scenarios.Fourthly,specific emphasis should be placed on improving the accuracy of curved-dimensional measurements,such as chest circumference,abdominal circumference,and shank circumference,through advances in pose standardization,refined 3D segmentation strategies,and multimodal data fusion.Finally,the cross-fertilization of sheep body size measurement technologies with analogous methods for other livestock species offers a promising pathway for mutual learning and collaborative innovation,accelerating the industrialization of automated sheep morphometric systems and supporting the development of intelligent,data-driven pasture management practices. 展开更多
关键词 smart breeding computer vision image recognition three-dimensional reconstruction 2D-3D body measurement
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Integrated N_(2)-Ar measurements of trace extraterrestrial samples
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作者 Fei Su XuHang Zhang +5 位作者 ChuanTong Zhang YouJuan Li ZiHeng Liu JianNan Li HeJiu Hui HuaiYu He 《Earth and Planetary Physics》 2026年第1期22-29,共8页
As one of the major volatile components in extraterrestrial materials,nitrogen(N_(2))isotopes serve not only as tracers for the formation and evolution of the solar system,but also play a critical role in assessing pl... As one of the major volatile components in extraterrestrial materials,nitrogen(N_(2))isotopes serve not only as tracers for the formation and evolution of the solar system,but also play a critical role in assessing planetary habitability and the search for extraterrestrial life.The integrated measurement of N_(2)and argon(Ar)isotopes by using noble gas mass spectrometry represents a state-of-the-art technique for such investigations.To support the growing demands of planetary science research in China,we have developed a high-efficiency,high-precision method for the integrated analysis of N_(2)and Ar isotopes.This was achieved by enhancing gas extraction and purification systems and integrating them with a static noble gas mass spectrometer.This method enables integrated N_(2)-Ar isotope measurements on submilligram samples,significantly improving sample utilization and reducing the impact of sample heterogeneity on volatile analysis.The system integrates CO_(2)laser heating,a modular two-stage Zr-Al getter pump,and a CuO furnace-based purification process,effectively reducing background levels(N_(2)blank as low as 0.35×10^(−6)cubic centimeters at standard temperature and pressure[ccSTP]).Analytical precision is ensured through calibration with atmospheric air and CO corrections.To validate the reliability of the method,we performed N_(2)-Ar isotope analyses on the Allende carbonaceous chondrite,one of the most extensively studied meteorites internationally.The measured N_(2)concentrations range from 19.2 to 29.8 ppm,withδ15N values between−44.8‰and−33.0‰.Concentrations of 40Ar,36Ar,and 38Ar are(12.5-21.1)×10^(−6)ccSTP/g,(90.9-150.3)×10^(−9)ccSTP/g,and(19.2-30.7)×10^(−9)ccSTP/g,respectively.These values correspond to cosmic-ray exposure ages of 4.5-5.7 Ma,consistent with previous reports.Step-heating experiments further reveal distinct release patterns of N and Ar isotopes,as well as their associations with specific mineral phases in the meteorite.In summary,the combined N_(2)-Ar isotopic system offers significant advantages for tracing volatile sources in extraterrestrial materials and will provide essential analytical support for upcoming Chinese planetary missions,such as Tianwen-2. 展开更多
关键词 integrated N_(2)-Ar measurement noble gas mass spectrometer extraterrestrial samples
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Suppression of Dry-Coupled Rubber Layer Interference in Ultrasonic Thickness Measurement:A Comparative Study of Empirical Mode Decomposition Variants
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作者 Weichen Wang Shaofeng Wang +4 位作者 Wenjing Liu Luncai Zhou Erqing Zhang Ting Gao Grigory Petrishin 《Structural Durability & Health Monitoring》 2026年第1期302-316,共15页
In dry-coupled ultrasonic thickness measurement,thick rubber layers introduce high-amplitude parasitic echoes that obscure defect signals and degrade thickness accuracy.Existing methods struggle to resolve overlap-pin... In dry-coupled ultrasonic thickness measurement,thick rubber layers introduce high-amplitude parasitic echoes that obscure defect signals and degrade thickness accuracy.Existing methods struggle to resolve overlap-ping echoes under variable coupling conditions and non-stationary noise.This study proposes a novel dual-criterion framework integrating energy contribution and statistical impulsivity metrics to isolate specimen re-flections from coupling-layer interference.By decomposing A-scan signals into Intrinsic Mode Functions(IMFs),the framework employs energy contribution thresholds(>85%)and kurtosis indices(>3)to autonomously select IMFs containing valid specimen echoes.Hybrid time-frequency thresholding further suppresses interference through amplitude filtering and spectral focusing.Experimental results demonstrate the framework’s robustness,achieving 92.3%thickness accuracy for 5 mm steel specimens with 5 mm rubber coupling,outperforming conventional methods by up to 18.7%.The dual-criterion approach reduces operator dependency by 37%and maintainsΔT<0.03 mm under surface roughness up to 6.3μm,offering a practical solution for industrial nondestructive testing with thick dry-coupled interfaces. 展开更多
关键词 Empirical mode decomposition complete ensemble EMD with adaptive noise(CEEMDAN) dry-coupled ultrasonic testing thickness measurement signal interference suppression
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HALIMA:a hybrid array for lifetime measurement of neutron-rich nuclei at IMP
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作者 Zi-Hao Jia Yong-De Fang +37 位作者 Si-Cheng Wang Wei Hua Hong-Yi Wu Guang-Xin Zhang Cen-Xi Yuan Zhi-Xuan Wang Jun-Hong Xu Jian-Hong Li Wen Liang Yu-Hong Tan Wen-Jun Pan Yu-Xuan Ren MKumar Raju Song Guo Guang-Shun Li Yun-Hua Qiang Min-Liang Liu Bing Ding Ming-Hui Huang Ning-Tao Zhang Bing-Shui Gao Peng Ma He-Run Yang Ruo-Fu Chen Hai-Xia Li Rong-Hua Li Xiu-Hua Wang Cui-Hong Chen Hai-Bo Yang Jian-Song Wang Xiao-Hui Sun Zhi-Huan Li Hui Hua Wei Wang Xin-Xing Xu Xiao-Hong Zhou Zai-Guo Gan Yu-Hu Zhang 《Nuclear Science and Techniques》 2026年第2期169-182,共14页
A new multi-detector array named HALIMA(Hybrid Array for LIfetime MeAsurement)has been developed at Lanzhou for nuclear structure studies in fission.The array comprises eight BGO-shielded High-Purity Germanium detecto... A new multi-detector array named HALIMA(Hybrid Array for LIfetime MeAsurement)has been developed at Lanzhou for nuclear structure studies in fission.The array comprises eight BGO-shielded High-Purity Germanium detectors and twenty fast Ce-doped Lanthanum Bromide[LaBr_(3)(Ce)]detectors shielded with CsI(Tl).HALIMA is further complemented by two ancillary detector systems:fission fragment(FF)detectors and β detectors.This configuration enables precise sub-nanosecond lifetime measurements using the fourfold FF/β-Ge-LaBr_(3)(Ce)-LaBr_(3)(Ce)coincidence technique.The performance and specifications of the detectors,associated electronics,and the data acquisition system are presented in detail.The advantage of FF selectivity is emphasized,which significantly enhances sensitivity to specific fission channels.Using this approach,the lifetimes of the nuclear excited states populated in the spontaneous fission of^(252)Cf were measured,showing good agreement with the established literature values. 展开更多
关键词 FFs/β-γrays coincidences SELECTIVITY Spontaneous fission LaBr_(3)(Ce) HPGE Solar cells Lifetime measurement
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Multi-objective ANN-driven genetic algorithm optimization of energy efficiency measures in an NZEB multi-family house building in Greece
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《建筑节能(中英文)》 2026年第2期62-62,共1页
The goal of the present work is to demonstrate the potential of Artificial Neural Network(ANN)-driven Genetic Algorithm(GA)methods for energy efficiency and economic performance optimization of energy efficiency measu... The goal of the present work is to demonstrate the potential of Artificial Neural Network(ANN)-driven Genetic Algorithm(GA)methods for energy efficiency and economic performance optimization of energy efficiency measures in a multi-family house building in Greece.The energy efficiency measures include different heating/cooling systems(such as low-temperature and high-temperature heat pumps,natural gas boilers,split units),building envelope components for floor,walls,roof and windows of variable heat transfer coefficients,the installation of solar thermal collectors and PVs.The calculations of the building loads and investment and operating and maintenance costs of the measures are based on the methodology defined in Directive 2010/31/EU,while economic assumptions are based on EN 15459-1 standard.Typically,multi-objective optimization of energy efficiency measures often requires the simulation of very large numbers of cases involving numerous possible combinations,resulting in intense computational load.The results of the study indicate that ANN-driven GA methods can be used as an alternative,valuable tool for reliably predicting the optimal measures which minimize primary energy consumption and life cycle cost of the building with greatly reduced computational requirements.Through GA methods,the computational time needed for obtaining the optimal solutions is reduced by 96.4%-96.8%. 展开更多
关键词 energy efficiency measures gas boilerssplit units building envelope components energy efficiency economic performance artificial neural network ann driven multi objective optimization economic performance optimization ANN driven GA methods
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Measurement of emissivity with a new grey body and novel IR thermal sensor dubbed TMOS 被引量:1
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作者 Moshe Avraham Shlomi Bouscher +2 位作者 Jonathan Nemirovsky Yael Nemirovsky 《红外与毫米波学报》 北大核心 2025年第1期17-24,共8页
The concept of emissivity has been with the scientific and engineering world since Planck formulated his blackbody radiation law more than a century ago.Nevertheless,emissivity is an elusive concept even for ex⁃perts.... The concept of emissivity has been with the scientific and engineering world since Planck formulated his blackbody radiation law more than a century ago.Nevertheless,emissivity is an elusive concept even for ex⁃perts.It is a vague and fuzzy concept for the wider community of engineers.The importance of remote sensing of temperature by measuring IR radiation has been recognized in a wide range of industrial,medical,and environ⁃mental uses.One of the major sources of errors in IR radiometry is the emissivity of the surface being measured.In real experiments,emissivity may be influenced by many factors:surface texture,spectral properties,oxida⁃tion,and aging of surfaces.While commercial blackbodies are prevalent,the much-needed grey bodies with a known emissivity,are unavailable.This study describes how to achieve a calibrated and stable emissivity with a blackbody,a perforated screen,and a reliable and linear novel IR thermal sensor,18 dubbed TMOS.The Digital TMOS is now a low-cost commercial product,it requires low power,and it has a small form factor.The method⁃ology is based on two-color measurements,with two different optical filters,with selected wavelengths conform⁃ing to the grey body definition of the use case under study.With a photochemically etched perforated screen,the effective emissivity of the screen is simply the hole density area of the surface area that emits according to the blackbody temperature radiation.The concept is illustrated with ray tracing simulations,which demonstrate the approach.Measured results are reported. 展开更多
关键词 BLACKBODY grey body graybody cavity blackbody extended area blackbody EMISSIVITY IR thermometry remote temperature measurement
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Voices that matter:The impact of patient-reported outcome measures on clinical decision-making 被引量:1
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作者 Naveen Jeyaraman Madhan Jeyaraman +2 位作者 Swaminathan Ramasubramanian Sangeetha Balaji Sathish Muthu 《World Journal of Methodology》 2025年第2期54-61,共8页
The critical role of patient-reported outcome measures(PROMs)in enhancing clinical decision-making and promoting patient-centered care has gained a profound significance in scientific research.PROMs encapsulate a pati... The critical role of patient-reported outcome measures(PROMs)in enhancing clinical decision-making and promoting patient-centered care has gained a profound significance in scientific research.PROMs encapsulate a patient's health status directly from their perspective,encompassing various domains such as symptom severity,functional status,and overall quality of life.By integrating PROMs into routine clinical practice and research,healthcare providers can achieve a more nuanced understanding of patient experiences and tailor treatments accordingly.The deployment of PROMs supports dynamic patient-provider interactions,fostering better patient engagement and adherence to tre-atment plans.Moreover,PROMs are pivotal in clinical settings for monitoring disease progression and treatment efficacy,particularly in chronic and mental health conditions.However,challenges in implementing PROMs include data collection and management,integration into existing health systems,and acceptance by patients and providers.Overcoming these barriers necessitates technological advancements,policy development,and continuous education to enhance the acceptability and effectiveness of PROMs.The paper concludes with recommendations for future research and policy-making aimed at optimizing the use and impact of PROMs across healthcare settings. 展开更多
关键词 Patient-reported outcome measures Clinical decision-making Patient-centered care Healthcare technology Data management Policy development
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Coal-rock gas accumulation mechanism and the whole petroleum system of coal measures 被引量:1
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作者 LI Guoxin JIA Chengzao +2 位作者 ZHAO Qun ZHOU Tianqi GAO Jinliang 《Petroleum Exploration and Development》 2025年第1期33-49,共17页
Coal measures are significant hydrocarbon source rocks and reservoirs in petroliferous basins.Many large gas fields and coalbed methane fields globally are originated from coal-measure source rocks or accumulated in c... Coal measures are significant hydrocarbon source rocks and reservoirs in petroliferous basins.Many large gas fields and coalbed methane fields globally are originated from coal-measure source rocks or accumulated in coal rocks.Inspired by the discovery of shale oil and gas,and guided by“the overall exploration concept of considering coal rock as reservoir”,breakthroughs in the exploration and development of coal-rock gas have been achieved in deep coal seams with favorable preservation conditions,thereby opening up a new development frontier for the unconventional gas in coal-rock reservoirs.Based on the data from exploration and development practices,a systematic study on the accumulation mechanism of coal-rock gas has been conducted.The mechanisms of“three fields”controlling coal-rock gas accumulation are revealed.It is confirmed that the coal-rock gas is different from CBM in accumulation process.The whole petroleum systems in the Carboniferous–Permian transitional facies coal measures of the eastern margin of the Ordos Basin and in the Jurassic continental facies coal measures of the Junggar Basin are characterized,and the key research directions for further developing the whole petroleum system theory of coal measures are proposed.Coal rocks,compared to shale,possess intense hydrocarbon generation potential,strong adsorption capacity,dual-medium reservoir properties,and partial or weak oil and gas self-sealing capacity.Additionally,unlike other unconventional gas such as shale gas and tight gas,coal-rock gas exhibits more complex accumulation characteristics,and its accumulation requires a certain coal-rock play form lithological and structural traps.Coal-rock gas also has the characteristics of conventional fractured gas reservoirs.Compared with the basic theory and model of the whole petroleum system established based on detrital rock formations,coal measures have distinct characteristics and differences in coal-rock reservoirs and source-reservoir coupling.The whole petroleum system of coal measures is composed of various types of coal-measure hydrocarbon plays with coal(and dark shale)in coal measures as source rock and reservoir,and with adjacent tight layers as reservoirs or cap or transport layers.Under the action of source-reservoir coupling,coal-rock gas is accumulated in coal-rock reservoirs with good preservation conditions,tight oil/gas is accumulated in tight layers,conventional oil/gas is accumulated in traps far away from sources,and coalbed methane is accumulated in coal-rock reservoirs damaged by later geological processes.The proposed whole petroleum system of coal measures represents a novel type of whole petroleum system. 展开更多
关键词 coal measure coal-rock gas coalbed methane tight gas coal-rock play accumulation mechanism whole petroleum system whole petroleum system of coal measures
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Variations in quantifying patient reported outcome measures to estimate treatment effect 被引量:1
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作者 Sathish Muthu Srujun Vadranapu 《World Journal of Methodology》 2025年第2期44-53,共10页
In the practice of healthcare,patient-reported outcomes(PROs)and PRO measures(PROMs)are used as an attempt to observe the changes in complex clinical situations.They guide us in making decisions based on the evidence ... In the practice of healthcare,patient-reported outcomes(PROs)and PRO measures(PROMs)are used as an attempt to observe the changes in complex clinical situations.They guide us in making decisions based on the evidence regarding patient care by recording the change in outcomes for a particular treatment to a given condition and finally to understand whether a patient will benefit from a particular treatment and to quantify the treatment effect.For any PROM to be usable in health care,we need it to be reliable,encapsulating the points of interest with the potential to detect any real change.Using structured outcome measures routinely in clinical practice helps the physician to understand the functional limitation of a patient that would otherwise not be clear in an office interview,and this allows the physician and patient to have a meaningful conver-sation as well as a customized plan for each patient.Having mentioned the rationale and the benefits of PROMs,understanding the quantification process is crucial before embarking on management decisions.A better interpretation of change needs to identify the treatment effect based on clinical relevance for a given condition.There are a multiple set of measurement indices to serve this effect and most of them are used interchangeably without clear demarcation on their differences.This article details the various quantification metrics used to evaluate the treatment effect using PROMs,their limitations and the scope of usage and implementation in clinical practice. 展开更多
关键词 Patient-reported outcome measures Treatment effect Minimal clinical important difference Patient-accepted symptom state Minimum detectable change ORTHOPEDICS
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Natural gas types and coal-rock gas classification in the whole petroleum system of coal measures 被引量:1
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作者 ZHANG Junfeng LI Guoxin +1 位作者 JIA Chengzao ZHAO Qun 《Petroleum Exploration and Development》 2025年第4期894-906,共13页
There are various types of natural gas resources in coal measures,making them major targets for natural gas exploration and development in China.In view of the particularity of the whole petroleum system of coal measu... There are various types of natural gas resources in coal measures,making them major targets for natural gas exploration and development in China.In view of the particularity of the whole petroleum system of coal measures and the reservoir-forming evolution of natural gas in coal,this study reveals the formation,enrichment characteristics and distribution laws of coal-rock gas by systematically reviewing the main types and geological characteristics of natural gas in the whole petroleum system of coal measures.First,natural gas in the whole petroleum system of coal measures is divided into two types,conventional gas and unconventional gas,according to its occurrence characteristics and accumulation mechanism,and into six types,distal detrital rock gas,special rock gas,distal/proximal tight sandstone gas,inner-source tight sandstone gas,shale gas,and coal-rock gas,according to its source and reservoir lithology.The natural gas present in coal-rock reservoirs is collectively referred to as coal-rock gas.Existing data indicate significant differences in the geological characteristics of coal-rock gas exploration and development between shallow and deep layers in the same area,with the transition depth boundary generally 1500-2000 m.Based on the current understanding of coal-rock gas and respecting the historical usage conventions of coalbed methane terminology,coal-rock gas can be divided into deep coal-rock gas and shallow coalbed methane according to burial depth.Second,according to the research concept of“full-process reservoir formation”in the theory of the whole petroleum system of coal measures,based on the formation and evolution of typical coal-rock gas reservoirs,coal-rock gas is further divided into four types:primary coal-rock gas,regenerated coal-rock gas,residual coal-rock gas,and bio coal-rock gas.The first two belong to deep coal-rock gas,while the latter two belong to shallow coal-rock gas.Third,research on the coal-rock gas reservoir formation and evolution shows that shallow coal-rock gas is mainly residual coal-rock gas or bio coal-rock gas formed after geological transformation of primary coal-rock gas,with the reservoir characteristics such as low reservoir pressure,low gas saturation,adsorbed gas in dominance,and gas production by drainage and depressurization,while deep coal-rock gas is mainly primary coal-rock gas and regenerated coal-rock gas,with the reservoir characteristics such as high reservoir pressure,high gas saturation,abundant free gas,and no or little water.In particular,the primary coal-rock gas is wide in distribution,large in resource quantity,and good in reservoir quality,making it the most favorable type of coal-rock gas for exploration and development. 展开更多
关键词 whole petroleum system of coal measures coal measure gas coalbed methane coal-rock gas coal-rock gas reservoir formation and evolution coal-rock gas classification
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Channel Measurement and Analysis of Human Body Radar Cross Section in26 GHz ISAC Systems 被引量:1
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作者 DUAN Hongyu WANG Mengyang +4 位作者 DUO Hao HE Danping MA Yihua LU Bin ZHONG Zhangdui 《ZTE Communications》 2025年第2期3-10,共8页
Radar cross section(RCS)plays a critical role in modeling target scattering characteristics and enhancing the precision of target detection and localization in integrated sensing and communication(ISAC)systems.This pa... Radar cross section(RCS)plays a critical role in modeling target scattering characteristics and enhancing the precision of target detection and localization in integrated sensing and communication(ISAC)systems.This paper investigates the human body RCS at 26 GHz via multiangle channel measurements under different clothing conditions.Based on calibrated electromagnetic(EM)parameters,the RCS characteristics of the human body in far-field conditions are analyzed using ray-tracing(RT)simulations.Some suggestions for the design of ISAC systems are also discussed.The results provide a solid theoretical foundation and practical reference for the modeling of target scattering characteristics for ISAC channels. 展开更多
关键词 channel measurement human body radar cross section integrated sensing and communication RAY-TRACING
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MODIFIED BRASCAMP-LIEB INEQUALITIES AND LOG-SOBOLEV INEQUALITIES FOR ONE-DIMENSIONAL LOG-CONCAVE MEASURE 被引量:1
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作者 Denghui WU Jiazu ZHOU 《Acta Mathematica Scientia》 2025年第1期104-117,共14页
In this paper,we develop Maurey’s and Bobkov-Ledoux’s methods to prove modified Brascamp-Lieb inequalities and log-Sobolev inequalities for one-dimensional log-concave measure.To prove these inequalities,the harmoni... In this paper,we develop Maurey’s and Bobkov-Ledoux’s methods to prove modified Brascamp-Lieb inequalities and log-Sobolev inequalities for one-dimensional log-concave measure.To prove these inequalities,the harmonic Prékopa-Leindler inequality is used.We prove that these new inequalities are more efficient in estimating the variance and entropy for some functions with exponential terms. 展开更多
关键词 Brunn-Minkowski inequality Prékopa-Leindler inequality Brascamp-Lieb inequality log-Sobolev inequality log-concave measure
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In-flight measurement method and application research of helicopter rotor blade motion parameters 被引量:1
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作者 Jiahong ZHENG Weizhen CHENG +2 位作者 Yan LI Shuaike JIAO Xide LI 《Chinese Journal of Aeronautics》 2025年第9期190-207,共18页
Accurate measurement of helicopter rotor motion parameters(flap,lead-lag,torsion,and azimuth angles)is essential for rotor blade design,helicopter dynamics modeling,and flight safety and health monitoring.However,the ... Accurate measurement of helicopter rotor motion parameters(flap,lead-lag,torsion,and azimuth angles)is essential for rotor blade design,helicopter dynamics modeling,and flight safety and health monitoring.However,the existing methods face challenges in testing equipment installation,calibration,and data transmission,resulting in limited reports on real-time in-flight measurements of blade motion parameters.This paper proposes a non-contact optoelectronic method based on two-dimensional position-sensitive detectors for in-flight measurement and a ground calibration system to obtain real-time rotor motion parameters during helicopter flight.The proposed method establishes the time evolution relationship of rotor motion parameters and verifies the performance of the in-flight measurement system regarding measurement resolution and accuracy through the construction of a blade motion posture experimental platform.The proposed method has been applied to the flight measurement of a medium-sized single-rotor helicopter,and the obtained results have been compared with theoretical analysis outcomes.Furthermore,this paper examines the characteristics of blade motion parameters during flight and discusses the challenges and potential solutions for measuring rotor motion parameters during helicopter flight using the proposed method. 展开更多
关键词 Blade motion parameters Flight test Helicopter rotors measureMENT Optical instruments Position sensitive detector
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Application of Fuzzy Inference System in Gas Turbine Engine Fault Diagnosis Against Measurement Uncertainties 被引量:1
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作者 Shuai Ma Yafeng Wu +1 位作者 Zheng Hua Linfeng Gou 《Chinese Journal of Mechanical Engineering》 2025年第1期62-83,共22页
Robustness against measurement uncertainties is crucial for gas turbine engine diagnosis.While current research focuses mainly on measurement noise,measurement bias remains challenging.This study proposes a novel perf... Robustness against measurement uncertainties is crucial for gas turbine engine diagnosis.While current research focuses mainly on measurement noise,measurement bias remains challenging.This study proposes a novel performance-based fault detection and identification(FDI)strategy for twin-shaft turbofan gas turbine engines and addresses these uncertainties through a first-order Takagi-Sugeno-Kang fuzzy inference system.To handle ambient condition changes,we use parameter correction to preprocess the raw measurement data,which reduces the FDI’s system complexity.Additionally,the power-level angle is set as a scheduling parameter to reduce the number of rules in the TSK-based FDI system.The data for designing,training,and testing the proposed FDI strategy are generated using a component-level turbofan engine model.The antecedent and consequent parameters of the TSK-based FDI system are optimized using the particle swarm optimization algorithm and ridge regression.A robust structure combining a specialized fuzzy inference system with the TSK-based FDI system is proposed to handle measurement biases.The performance of the first-order TSK-based FDI system and robust FDI structure are evaluated through comprehensive simulation studies.Comparative studies confirm the superior accuracy of the first-order TSK-based FDI system in fault detection,isolation,and identification.The robust structure demonstrates a 2%-8%improvement in the success rate index under relatively large measurement bias conditions,thereby indicating excellent robustness.Accuracy against significant bias values and computation time are also evaluated,suggesting that the proposed robust structure has desirable online performance.This study proposes a novel FDI strategy that effectively addresses measurement uncertainties. 展开更多
关键词 Performance-based fault diagnosis Gas turbine engine Fuzzy inference system measurement uncertainty Regression and classification
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A Synergistic Multi-Attribute Decision-Making Method for Educational Institutions Evaluation Using Similarity Measures of Possibility Pythagorean Fuzzy Hypersoft Sets
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作者 Khuram Ali Khan Saba Mubeen Ishfaq +1 位作者 Atiqe Ur Rahman Salwa El-Morsy 《Computer Modeling in Engineering & Sciences》 SCIE EI 2025年第1期501-530,共30页
Due to the numerous variables to take into account as well as the inherent ambiguity and uncertainty,evaluating educational institutions can be difficult.The concept of a possibility Pythagorean fuzzy hypersoft set(pP... Due to the numerous variables to take into account as well as the inherent ambiguity and uncertainty,evaluating educational institutions can be difficult.The concept of a possibility Pythagorean fuzzy hypersoft set(pPyFHSS)is more flexible in this regard than other theoretical fuzzy set-like models,even though some attempts have been made in the literature to address such uncertainties.This study investigates the elementary notions of pPyFHSS including its set-theoretic operations union,intersection,complement,OR-and AND-operations.Some results related to these operations are also modified for pPyFHSS.Additionally,the similarity measures between pPyFHSSs are formulated with the assistance of numerical examples and results.Lastly,an intelligent decision-assisted mechanism is developed with the proposal of a robust algorithm based on similarity measures for solving multi-attribute decision-making(MADM)problems.A case study that helps the decision-makers assess the best educational institution is discussed to validate the suggested system.The algorithmic results are compared with the most pertinent model to evaluate the adaptability of pPyFHSS,as it generalizes the classical possibility fuzzy set-like theoretical models.Similarly,while considering significant evaluating factors,the flexibility of pPyFHSS is observed through structural comparison. 展开更多
关键词 Hypersoft set Pythagorean fuzzy hypersoft set computational complexity multi-attribute decision-making optimization similarity measures uncertainty
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Correlation between the rock mass properties and maximum horizontal stress:A case study of overcoring stress measurements
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作者 Peng Li Meifeng Cai +2 位作者 Shengjun Miao Yuan Li Yu Wang 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS 2025年第1期39-48,共10页
Understanding the mechanical properties of the lithologies is crucial to accurately determine the horizontal stress magnitude.To investigate the correlation between the rock mass properties and maximum horizontal stre... Understanding the mechanical properties of the lithologies is crucial to accurately determine the horizontal stress magnitude.To investigate the correlation between the rock mass properties and maximum horizontal stress,the three-dimensional(3D)stress tensors at 89 measuring points determined using an improved overcoring technique in nine mines in China were adopted,a newly defined characteristic parameter C_(ERP)was proposed as an indicator for evaluating the structural properties of rock masses,and a fuzzy relation matrix was established using the information distribution method.The results indicate that both the vertical stress and horizontal stress exhibit a good linear growth relationship with depth.There is no remarkable correlation between the elastic modulus,Poisson's ratio and depth,and the distribution of data points is scattered and messy.Moreover,there is no obvious relationship between the rock quality designation(RQD)and depth.The maximum horizontal stress σ_(H) is a function of rock properties,showing a certain linear relationship with the C_(ERP)at the same depth.In addition,the overall change trend of σ_(H) determined by the established fuzzy identification method is to increase with the increase of C_(ERP).The fuzzy identification method also demonstrates a relatively detailed local relationship betweenσ_H and C_(ERP),and the predicted curve rises in a fluctuating way,which is in accord well with the measured stress data. 展开更多
关键词 overcoring stress measurements elastic modulus Poisson's ratio rock quality designation maximum horizontal stress fuzzy identification
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A centroid measurement method based on 3D scanning 被引量:1
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作者 HE Xin LI Zhen 《Journal of Measurement Science and Instrumentation》 2025年第2期186-194,共9页
The centroid coordinate serves as a critical control parameter in motion systems,including aircraft,missiles,rockets,and drones,directly influencing their motion dynamics and control performance.Traditional methods fo... The centroid coordinate serves as a critical control parameter in motion systems,including aircraft,missiles,rockets,and drones,directly influencing their motion dynamics and control performance.Traditional methods for centroid measurement often necessitate custom equipment and specialized positioning devices,leading to high costs and limited accuracy.Here,we present a centroid measurement method that integrates 3D scanning technology,enabling accurate measurement of centroid across various types of objects without the need for specialized positioning fixtures.A theoretical framework for centroid measurement was established,which combined the principle of the multi-point weighing method with 3D scanning technology.The measurement accuracy was evaluated using a designed standard component.Experimental results demonstrate that the discrepancies between the theoretical and the measured centroid of a standard component with various materials and complex shapes in the X,Y,and Z directions are 0.003 mm,0.009 mm,and 0.105 mm,respectively,yielding a spatial deviation of 0.106 mm.Qualitative verification was conducted through experimental validation of three distinct types.They confirmed the reliability of the proposed method,which allowed for accurate centroid measurements of various products without requiring positioning fixtures.This advancement significantly broadened the applicability and scope of centroid measurement devices,offering new theoretical insights and methodologies for the measurement of complex parts and systems. 展开更多
关键词 centroid measurement mass characteristic parameter 3D scanning 3D point cloud data no specialized positioning fixtures multi-point weighing method
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