Structural finger-jointed (FJ) lumber was used mainly in structural applications including glue-laminated beams and wooden I-joists and more recently in parallel chord wood trusses. The paper evaluated strength proper...Structural finger-jointed (FJ) lumber was used mainly in structural applications including glue-laminated beams and wooden I-joists and more recently in parallel chord wood trusses. The paper evaluated strength properties of structural FJ lumber by three nondestructive methods (edge-wise bending, longitudinal and transversal vibration) in order to find an alternative to traditional evaluation methods. Lumber was sawn from the logs following a pattern typically used in China to maximize the volume of recovered sawn timbers. After kiln-dried, these rough-sawed lumbers were planned to 4.5 cm thick, 9.0 cm wide and 100cm long. The lumber pieces were assigned to two groups (low-grade and high- grade groups) according to their dynamical modulus of elasticity. FJ lumber was produced by cutting a series of sloping fingers (finger length 20, 25 and 35 mm) on the end of the wood pieces to be joined and interlocking the two pieces. Each finger-jointed lumber with one same finger length had three types: L-L, L-H and H-H. The FJ lumber was nondestructively tested using edge-wise bending, longitudinal and transversal vibration methods. After three methods, tensile and bending strengths of FJ lumber were tested to build dynamical relationships between MOE and strengths. The results showed that dynamic MOEs were good indicators of the static MOE, but both dynamic MOE and static MOE had a bad correlation with tensile strength of finger jointed lumber.展开更多
Earthen sites are widely distributed throughout China, and most of them belong to archaeological sites with significant values, which not only directly witness the origin, formation and development of Chinese civiliza...Earthen sites are widely distributed throughout China, and most of them belong to archaeological sites with significant values, which not only directly witness the origin, formation and development of Chinese civilization, but also possess important values for conservation and exhibition. Many researches and practices on their conservation and consolidation have been carried out; however, the consolidation effect is mainly judged by visual observation and expert evaluation. Scientific assessment of conservation and consolidation effects is a challenging issue. Many instruments in other fields cannot be directly applied to the conservation of cultural relics due to their peculiarity. In order to assess the effects of field conservation experiments, this paper tries to understand the consolidation effects at Liangzhu site using nondestructive or micro-damage methods, including thermo-physical parameters testing, infrared thermal imaging, high-density microelectrode resistivity testing, portable microscope observation, and hydrophilic and hydrophobic testing, and thereby explores the practicable methods for evaluating the properties of consolidation materials for earthen sites treatment.展开更多
Nondestructive and noninvasive neutron assays are essential applications of neutron techniques.Neutron resonance transmission analysis(NRTA)is a powerful nondestructive method for investigating the elemental compositi...Nondestructive and noninvasive neutron assays are essential applications of neutron techniques.Neutron resonance transmission analysis(NRTA)is a powerful nondestructive method for investigating the elemental composition of an object.The back-streaming neutron line(Back-n)is a newly built time-of-flight facility at the China Spallation Neutron Source(CSNS)that provides neutrons in the eV to 300 MeV range.A feasibility study of the NRTA method for nuclide identification was conducted at the CSNS Back-n via two test experiments.The results demonstrate that it is feasible to identify different elements and isotopes in samples using the NRTA method at Back-n.This study reveals its potential future applications.展开更多
To obtain thermal contact resistance（TCR） between the vertical double-diffused metal-oxide-semiconductor（VDMOS） and the heat sink, we derived the relationship between the total thermal resistance and the contact f...To obtain thermal contact resistance（TCR） between the vertical double-diffused metal-oxide-semiconductor（VDMOS） and the heat sink, we derived the relationship between the total thermal resistance and the contact force imposed on the VDMOS. The total thermal resistance from the chip to the heat sink is measured under different contact forces, and the TCR can be extracted nondestructively from the derived relationship. Finally, the experimental results are compared with the simulation results.展开更多
We assessed growth traits and wood properties ofDH32-29, a clone of Eucalyptus urophylla x E. grandis, at age of two to six years in Guangdong in China. Analysis of variance of studied traits showed that there were si...We assessed growth traits and wood properties ofDH32-29, a clone of Eucalyptus urophylla x E. grandis, at age of two to six years in Guangdong in China. Analysis of variance of studied traits showed that there were significant differences （1% level） on all studied traits among ages except for wood basic density. Analysis of age trends of growth traits and wood properties revealed that rotation length of DH32-29 should be more than six years or longer. Phenotypic correlations among traits at individual ages indicated that correlations between growth traits were strongly positive. There was significant change in relationship between growth and wood basic density with increasing age, ranging from -0.03 to -0.54 at 2 and 5 year and 0.003 to 0.3 at 3, 4 and 6 year. Correlations between Pilodyn pin penetration and basic density measured on increment cores showed that Pilodyn could rank or group genotypes or sites into density classes, but failure to predict individual tree and individual clone.展开更多
The paper addresses the first eddy current benchmark problem proposed by the World Federation of Nondestructive Evaluation Centers (WFNDEC). The problem simulates the eddy current response to the presence of an axisym...The paper addresses the first eddy current benchmark problem proposed by the World Federation of Nondestructive Evaluation Centers (WFNDEC). The problem simulates the eddy current response to the presence of an axisymmetric circumferential defect in an Inconel-600 tube. All simulations employ the axisymmetric code of the electromagnetic field simulator Finite Element Method Magnetics. For three different frequencies of excitation, it is explained how the displacement of the detecting coil inside the tube leads to a variation in the impedance of the eddy current coil. Variations of the resistive and inductive components of the impedance with distance from the defect region are used to build the impedance trajectory for each frequency of analysis.展开更多
A finite element reconstruction algorithm for ultrasound tomography based on the Helmholtz equation in frequency domain is presented to monitor the grouting defects in reinforced concrete structures.In this algorithm,...A finite element reconstruction algorithm for ultrasound tomography based on the Helmholtz equation in frequency domain is presented to monitor the grouting defects in reinforced concrete structures.In this algorithm,a hybrid regularizations-based iterative Newton method is implemented to provide stable inverse solutions.Furthermore,a dual mesh scheme and an adjoint method are adopted to reduce the computation cost and improve the efficiency of reconstruction.Simultaneous reconstruction of both acoustic velocity and attenuation coefficient for a reinforced concrete model is achieved with multiple frequency data.The algorithm is evaluated with numerical simulation under various practical scenarios including varied transmission/receiving modes,different noise levels,different source/detector numbers,and different contrast levels between the heterogeneity and background region.Results obtained suggest that the algorithm is insensitive to noise,and the reconstructions are quantitatively accurate in terms of the location,size and acoustic properties of the target over a range of contrast levels.展开更多
The need for the rapid assessment of the photosynthetic pigment contents in plants has encouraged the development of studies to produce nondestructive quantification methods.This need is driven by the fact that data o...The need for the rapid assessment of the photosynthetic pigment contents in plants has encouraged the development of studies to produce nondestructive quantification methods.This need is driven by the fact that data on the photosynthetic pigment contents can provide a variety of important information that is related to plant conditions.Using deep chemometrics,we developed a novel one-dimensional convolutional neural network(CNN)model to predict the photosynthetic pigment contents in a nondestructive and real-time manner.Intact leaf reflectance spectra from spectroscopic measurements were used as the inputs.The prediction was simultaneously carried out for three main photosynthetic pigments,i.e.,chlorophyll,carotenoid and anthocyanin.The experimental results show that the prediction accuracy is very satisfying,with a mean absolute error(MAE)=0.0122±0.0004 for training and 0.0321±0.0022 for validation(data range of 0–1).展开更多
Rice panicle traits serve as critical indicators of both yield potential and germplasm resource quality.However,traditional manual measurements of these traits,which typically involve threshing,are not only laborious ...Rice panicle traits serve as critical indicators of both yield potential and germplasm resource quality.However,traditional manual measurements of these traits,which typically involve threshing,are not only laborious and time-consuming but also prone to introducing measurement errors.This study introduces a high-throughput and nondestructive method,termed extraction of panicle traits(EOPT),along with the software Panicle Analyzer,which is designed to assess unshaped intact rice panicle traits,including the panicle grain number,grain length,grain width,and panicle length.To address the challenge of grain occlusion within an intact panicle,we define a panicle morphology index to quantify the occlusion levels among the rice grains within the panicle.By calibrating the grain number obtained directly from rice panicle images based on the panicle morphology index,we substantially improve the grain number detection accuracy.For measuring grain length and width,the EOPT selects rice grains using an intersection over union threshold of 0.8 and a confidence threshold of 0.7 during the grain detection process.The mean values of these grains were calculated to represent all the panicle grain lengths and widths.In addition,EOPT extracted the main path of the skeleton of the rice panicle using the Astar algorithm to determine panicle lengths.Validation on a dataset of 1,554 panicle images demonstrated the effectiveness of the proposed method,achieving 93.57%accuracy in panicle grain counting with a mean absolute percentage error of 6.62%.High accuracy rates were also recorded for grain length(96.83%)and panicle length(9713%).Moreover,the utility of EOPT was confirmed across different years and scenes,both indoors and outdoors.A genome-wide association study was conducted,leveraging the phenotypic traits obtained via EOPT and genotypic data.This study identified single-nucleotide polymorphisms associated with grain length,width,number per panicle,and panicle length,further emphasizing the utility and potential of this method in advancing rice breeding.展开更多
基金supported in part by the Chinese Academy of Forestry under CAFINT2007K04the Minist of Scince and Technology of P.R.China under Grant No.200704013
文摘Structural finger-jointed (FJ) lumber was used mainly in structural applications including glue-laminated beams and wooden I-joists and more recently in parallel chord wood trusses. The paper evaluated strength properties of structural FJ lumber by three nondestructive methods (edge-wise bending, longitudinal and transversal vibration) in order to find an alternative to traditional evaluation methods. Lumber was sawn from the logs following a pattern typically used in China to maximize the volume of recovered sawn timbers. After kiln-dried, these rough-sawed lumbers were planned to 4.5 cm thick, 9.0 cm wide and 100cm long. The lumber pieces were assigned to two groups (low-grade and high- grade groups) according to their dynamical modulus of elasticity. FJ lumber was produced by cutting a series of sloping fingers (finger length 20, 25 and 35 mm) on the end of the wood pieces to be joined and interlocking the two pieces. Each finger-jointed lumber with one same finger length had three types: L-L, L-H and H-H. The FJ lumber was nondestructively tested using edge-wise bending, longitudinal and transversal vibration methods. After three methods, tensile and bending strengths of FJ lumber were tested to build dynamical relationships between MOE and strengths. The results showed that dynamic MOEs were good indicators of the static MOE, but both dynamic MOE and static MOE had a bad correlation with tensile strength of finger jointed lumber.
基金supported by the National"12th Five-Year"Plan for Science and Technology Support(Grant No.2014BAK16B02)the Key Project of the State Administration of Cultural Heritage(Grant No.20120207)the Project on Basic Research of Gansu Province's Innovation Group(Grant No.145RJIF336)
文摘Earthen sites are widely distributed throughout China, and most of them belong to archaeological sites with significant values, which not only directly witness the origin, formation and development of Chinese civilization, but also possess important values for conservation and exhibition. Many researches and practices on their conservation and consolidation have been carried out; however, the consolidation effect is mainly judged by visual observation and expert evaluation. Scientific assessment of conservation and consolidation effects is a challenging issue. Many instruments in other fields cannot be directly applied to the conservation of cultural relics due to their peculiarity. In order to assess the effects of field conservation experiments, this paper tries to understand the consolidation effects at Liangzhu site using nondestructive or micro-damage methods, including thermo-physical parameters testing, infrared thermal imaging, high-density microelectrode resistivity testing, portable microscope observation, and hydrophilic and hydrophobic testing, and thereby explores the practicable methods for evaluating the properties of consolidation materials for earthen sites treatment.
基金This work was supported by the National Natural Science Foundation of China(No.12035017)Youth Innovation Promotion Association CAS(No.2023014)Guangdong Basic and Applied Basic Research Foundation(Nos.2020A1515010360 and 2022B1515120032).
文摘Nondestructive and noninvasive neutron assays are essential applications of neutron techniques.Neutron resonance transmission analysis(NRTA)is a powerful nondestructive method for investigating the elemental composition of an object.The back-streaming neutron line(Back-n)is a newly built time-of-flight facility at the China Spallation Neutron Source(CSNS)that provides neutrons in the eV to 300 MeV range.A feasibility study of the NRTA method for nuclide identification was conducted at the CSNS Back-n via two test experiments.The results demonstrate that it is feasible to identify different elements and isotopes in samples using the NRTA method at Back-n.This study reveals its potential future applications.
基金Project supported by the National Natural Science Foundation of China(Grant No.61204081)
文摘To obtain thermal contact resistance（TCR） between the vertical double-diffused metal-oxide-semiconductor（VDMOS） and the heat sink, we derived the relationship between the total thermal resistance and the contact force imposed on the VDMOS. The total thermal resistance from the chip to the heat sink is measured under different contact forces, and the TCR can be extracted nondestructively from the derived relationship. Finally, the experimental results are compared with the simulation results.
基金This study was undertaken as a project for National Key Technology R&D Program for the 12th Five-year Plan(China) "Breeding and Selection of New Variety with High Yield and High Resistance of Eucalyptus"(2012BAD01B04-1)Special Fund for Forestry Industry Research in the Public Interest "Project of Veneer Variety Breeding and Cultivation Model Optimization for Eucalyptus"(201104003-07)
文摘We assessed growth traits and wood properties ofDH32-29, a clone of Eucalyptus urophylla x E. grandis, at age of two to six years in Guangdong in China. Analysis of variance of studied traits showed that there were significant differences （1% level） on all studied traits among ages except for wood basic density. Analysis of age trends of growth traits and wood properties revealed that rotation length of DH32-29 should be more than six years or longer. Phenotypic correlations among traits at individual ages indicated that correlations between growth traits were strongly positive. There was significant change in relationship between growth and wood basic density with increasing age, ranging from -0.03 to -0.54 at 2 and 5 year and 0.003 to 0.3 at 3, 4 and 6 year. Correlations between Pilodyn pin penetration and basic density measured on increment cores showed that Pilodyn could rank or group genotypes or sites into density classes, but failure to predict individual tree and individual clone.
文摘The paper addresses the first eddy current benchmark problem proposed by the World Federation of Nondestructive Evaluation Centers (WFNDEC). The problem simulates the eddy current response to the presence of an axisymmetric circumferential defect in an Inconel-600 tube. All simulations employ the axisymmetric code of the electromagnetic field simulator Finite Element Method Magnetics. For three different frequencies of excitation, it is explained how the displacement of the detecting coil inside the tube leads to a variation in the impedance of the eddy current coil. Variations of the resistive and inductive components of the impedance with distance from the defect region are used to build the impedance trajectory for each frequency of analysis.
基金Project(31200748)supported by the National Natural Science Foundation of China
文摘A finite element reconstruction algorithm for ultrasound tomography based on the Helmholtz equation in frequency domain is presented to monitor the grouting defects in reinforced concrete structures.In this algorithm,a hybrid regularizations-based iterative Newton method is implemented to provide stable inverse solutions.Furthermore,a dual mesh scheme and an adjoint method are adopted to reduce the computation cost and improve the efficiency of reconstruction.Simultaneous reconstruction of both acoustic velocity and attenuation coefficient for a reinforced concrete model is achieved with multiple frequency data.The algorithm is evaluated with numerical simulation under various practical scenarios including varied transmission/receiving modes,different noise levels,different source/detector numbers,and different contrast levels between the heterogeneity and background region.Results obtained suggest that the algorithm is insensitive to noise,and the reconstructions are quantitatively accurate in terms of the location,size and acoustic properties of the target over a range of contrast levels.
基金This work was funded by the Ministry of Research,Technology,and Higher Education of the Republic of Indonesia under Penelitian Dasar Unggulan Perguruan Tinggi(PDUPT)Scheme,(Grant No.058/SP2H/LT/MONO/L7/2019).
文摘The need for the rapid assessment of the photosynthetic pigment contents in plants has encouraged the development of studies to produce nondestructive quantification methods.This need is driven by the fact that data on the photosynthetic pigment contents can provide a variety of important information that is related to plant conditions.Using deep chemometrics,we developed a novel one-dimensional convolutional neural network(CNN)model to predict the photosynthetic pigment contents in a nondestructive and real-time manner.Intact leaf reflectance spectra from spectroscopic measurements were used as the inputs.The prediction was simultaneously carried out for three main photosynthetic pigments,i.e.,chlorophyll,carotenoid and anthocyanin.The experimental results show that the prediction accuracy is very satisfying,with a mean absolute error(MAE)=0.0122±0.0004 for training and 0.0321±0.0022 for validation(data range of 0–1).
基金supported by the National Key Research and Development Program of China(2021YFD1200504 and 2022YFD2002304)the Key Core Technology Project in Agri-culture of Hubei Province(HBNYHXGG2023-9)the Supporting Project for High-Quality Development of Seed Industry of Hubei Province(HBZY2023B001-06).
文摘Rice panicle traits serve as critical indicators of both yield potential and germplasm resource quality.However,traditional manual measurements of these traits,which typically involve threshing,are not only laborious and time-consuming but also prone to introducing measurement errors.This study introduces a high-throughput and nondestructive method,termed extraction of panicle traits(EOPT),along with the software Panicle Analyzer,which is designed to assess unshaped intact rice panicle traits,including the panicle grain number,grain length,grain width,and panicle length.To address the challenge of grain occlusion within an intact panicle,we define a panicle morphology index to quantify the occlusion levels among the rice grains within the panicle.By calibrating the grain number obtained directly from rice panicle images based on the panicle morphology index,we substantially improve the grain number detection accuracy.For measuring grain length and width,the EOPT selects rice grains using an intersection over union threshold of 0.8 and a confidence threshold of 0.7 during the grain detection process.The mean values of these grains were calculated to represent all the panicle grain lengths and widths.In addition,EOPT extracted the main path of the skeleton of the rice panicle using the Astar algorithm to determine panicle lengths.Validation on a dataset of 1,554 panicle images demonstrated the effectiveness of the proposed method,achieving 93.57%accuracy in panicle grain counting with a mean absolute percentage error of 6.62%.High accuracy rates were also recorded for grain length(96.83%)and panicle length(9713%).Moreover,the utility of EOPT was confirmed across different years and scenes,both indoors and outdoors.A genome-wide association study was conducted,leveraging the phenotypic traits obtained via EOPT and genotypic data.This study identified single-nucleotide polymorphisms associated with grain length,width,number per panicle,and panicle length,further emphasizing the utility and potential of this method in advancing rice breeding.
