The dense and accurate measurement of 3D texture is helpful in evaluating the pavement function.To form dense mandatory constraints and improve matching accuracy,the traditional binocular reconstruction technology was...The dense and accurate measurement of 3D texture is helpful in evaluating the pavement function.To form dense mandatory constraints and improve matching accuracy,the traditional binocular reconstruction technology was improved threefold.First,a single moving laser line was introduced to carry out global scanning constraints on the target,which would well overcome the difficulty of installing and recognizing excessive laser lines.Second,four kinds of improved algorithms,namely,disparity replacement,superposition synthesis,subregion segmentation,and subregion segmentation centroid enhancement,were established based on different constraint mechanism.Last,the improved binocular reconstruction test device was developed to realize the dual functions of 3D texture measurement and precision self-evaluation.Results show that compared with traditional algorithms,the introduction of a single laser line scanning constraint is helpful in improving the measurement’s accuracy.Among various improved algorithms,the improvement effect of the subregion segmentation centroid enhancement method is the best.It has a good effect on both overall measurement and single pointmeasurement,which can be considered to be used in pavement function evaluation.展开更多
The staggered distribution of joints and fissures in space constitutes the weak part of any rock mass.The identification of rock mass structural planes and the extraction of characteristic parameters are the basis of ...The staggered distribution of joints and fissures in space constitutes the weak part of any rock mass.The identification of rock mass structural planes and the extraction of characteristic parameters are the basis of rock-mass integrity evaluation,which is very important for analysis of slope stability.The laser scanning technique can be used to acquire the coordinate information pertaining to each point of the structural plane,but large amount of point cloud data,uneven density distribution,and noise point interference make the identification efficiency and accuracy of different types of structural planes limited by point cloud data analysis technology.A new point cloud identification and segmentation algorithm for rock mass structural surfaces is proposed.Based on the distribution states of the original point cloud in different neighborhoods in space,the point clouds are characterized by multi-dimensional eigenvalues and calculated by the robust randomized Hough transform(RRHT).The normal vector difference and the final eigenvalue are proposed for characteristic distinction,and the identification of rock mass structural surfaces is completed through regional growth,which strengthens the difference expression of point clouds.In addition,nearest Voxel downsampling is also introduced in the RRHT calculation,which further reduces the number of sources of neighborhood noises,thereby improving the accuracy and stability of the calculation.The advantages of the method have been verified by laboratory models.The results showed that the proposed method can better achieve the segmentation and statistics of structural planes with interfaces and sharp boundaries.The method works well in the identification of joints,fissures,and other structural planes on Mangshezhai slope in the Three Gorges Reservoir area,China.It can provide a stable and effective technique for the identification and segmentation of rock mass structural planes,which is beneficial in engineering practice.展开更多
Based on some analyses of existing chaotic image encryption frameworks and a new designed three-dimensional improved logistic chaotic map(3D-ILM),an asymmetric image encryption algorithm using public-key Rivest–Shami...Based on some analyses of existing chaotic image encryption frameworks and a new designed three-dimensional improved logistic chaotic map(3D-ILM),an asymmetric image encryption algorithm using public-key Rivest–Shamir–Adleman(RSA)is presented in this paper.In the first stage,a new 3D-ILM is proposed to enhance the chaotic behavior considering analysis of time sequence,Lyapunov exponent,and Shannon entropy.In the second stage,combined with the public key RSA algorithm,a new key acquisition mathematical model(MKA)is constructed to obtain the initial keys for the 3D-ILM.Consequently,the key stream can be produced depending on the plain image for a higher security.Moreover,a novel process model(NPM)for the input of the 3D-ILM is built,which is built to improve the distribution uniformity of the chaotic sequence.In the third stage,to encrypt the plain image,a pre-process by exclusive OR(XOR)operation with a random matrix is applied.Then,the pre-processed image is performed by a permutation for rows,a downward modulo function for adjacent pixels,a permutation for columns,a forward direction XOR addition-modulo diffusion,and a backward direction XOR addition-modulo diffusion to achieve the final cipher image.Moreover,experiments show that the the proposed algorithm has a better performance.Especially,the number of pixels change rate(NPCR)is close to ideal case 99.6094%,with the unified average changing intensity(UACI)close to 33.4634%,and the information entropy(IE)close to 8.展开更多
Epitaxial ferroelectric one direction over the thin fihns on single-crystal substrates generally show a preferred domain orientation in other in demonstration of a poor polarization retention. This behavior will affec...Epitaxial ferroelectric one direction over the thin fihns on single-crystal substrates generally show a preferred domain orientation in other in demonstration of a poor polarization retention. This behavior will affect their application in nonvolatile ferroelectric random access memories where bipolar polarization states are used to store the logic 0 and 1 data. Here the retention characteristics of BiFe03 thin films with Srftu03 bottom electrodes on both GdSc03 (110) and SrTiO3 (100) substrates are studied and compared, and the results of piezoresponse force microscopy provide a long time retention property of the films on two substrates. It is found that bismuth ferrite thin films grown on GdScO3 substrates show no preferred domain variants in comparison with the preferred downward polarization orientation toward bottom electrodes on SrTi03 substrates. Tile retention test from a positive-up domain to a negative-down domain using a signal generator and an oscilloscope coincidentally shows bistable polarization states on the GdSeOa substrate over a measuring time of 500s, unlike the preferred domain orientation on SrTi03, where more than 65~o of upward domains disappear after 1 s. In addition, different sizes of domains have been written and read by using the scanning tip of piezoresponse force microscopy, where the polarization can stabilize over one month. This study paves one route to improve the polarization retention property through the optimization of the lattice-mismatched stresses between films and substrates.展开更多
Edge detection plays an important role in geological interpretation of potential field data,which can indicate the subsurface faults,contact,and other tectonic features.A variety of methods have been proposed to detec...Edge detection plays an important role in geological interpretation of potential field data,which can indicate the subsurface faults,contact,and other tectonic features.A variety of methods have been proposed to detect and enhance the edges.3 D structure tensor can well delineate the edges of geological bodies,however,it is sensitive to noise and additional false edges need to be removed artificially.In order to overcome these disadvantages,this paper redefines the 3 D structure tensor with a Gaussian envelop and proposes a new normalized edge detector,which can remove the additional false edges and reduce the influence of noise effectively,and balance the edges of different amplitude anomalies completely.This method has been tested on the synthetic and measured gravity data,showing that the new improved method achievesbetter results and reveals more details.展开更多
Objective To study the effect of using improved 2D computer-assisted fluoroscopic navigation through simulating 3D vertebrae image to guide pedicle screw internal fixation.Methods Posterior pedicle screw internal fixa...Objective To study the effect of using improved 2D computer-assisted fluoroscopic navigation through simulating 3D vertebrae image to guide pedicle screw internal fixation.Methods Posterior pedicle screw internal fixation,distraction展开更多
A convective and stratiform cloud classification method for weather radar is proposed based on the density-based spatial clustering of applications with noise(DBSCAN)algorithm.To identify convective and stratiform clo...A convective and stratiform cloud classification method for weather radar is proposed based on the density-based spatial clustering of applications with noise(DBSCAN)algorithm.To identify convective and stratiform clouds in different developmental phases,two-dimensional(2D)and three-dimensional(3D)models are proposed by applying reflectivity factors at 0.5°and at 0.5°,1.5°,and 2.4°elevation angles,respectively.According to the thresholds of the algorithm,which include echo intensity,the echo top height of 35 dBZ(ET),density threshold,andεneighborhood,cloud clusters can be marked into four types:deep-convective cloud(DCC),shallow-convective cloud(SCC),hybrid convective-stratiform cloud(HCS),and stratiform cloud(SFC)types.Each cloud cluster type is further identified as a core area and boundary area,which can provide more abundant cloud structure information.The algorithm is verified using the volume scan data observed with new-generation S-band weather radars in Nanjing,Xuzhou,and Qingdao.The results show that cloud clusters can be intuitively identified as core and boundary points,which change in area continuously during the process of convective evolution,by the improved DBSCAN algorithm.Therefore,the occurrence and disappearance of convective weather can be estimated in advance by observing the changes of the classification.Because density thresholds are different and multiple elevations are utilized in the 3D model,the identified echo types and areas are dissimilar between the 2D and 3D models.The 3D model identifies larger convective and stratiform clouds than the 2D model.However,the developing convective clouds of small areas at lower heights cannot be identified with the 3D model because they are covered by thick stratiform clouds.In addition,the 3D model can avoid the influence of the melting layer and better suggest convective clouds in the developmental stage.展开更多
In recent years, El Nino Modoki (a type of pseudo-El Nino) has been distinguished as a unique large-scale ocean warming phenomenon happening in the central tropical Pacific that is quite different from the tradition...In recent years, El Nino Modoki (a type of pseudo-El Nino) has been distinguished as a unique large-scale ocean warming phenomenon happening in the central tropical Pacific that is quite different from the traditional El Nino. In this study, EOF analysis was used to successfully separate El Nino and El Nino Modoki. The abilities of the NINO3 index, NINO3.4 index, NINO1+2 index and NINO4 index in characterizing El Nino were explored in detail. The resulting suggestion was that, comparatively, NINO3 is the optimal index for monitoring El Nino among the four NINO indices, as the other NINO indices were found to be less good at distinguishing between El Nino and El Nino Modoki signals, or were easily disturbed by El Nino Modoki signals. Further, an improved El Nino Modoki index (IEMI) was introduced in the current paper to better represent the El Nino Modoki that is captured by the second leading EOF mode of monthly tropical Pacific sea surface temperature anomalies (SSTAs). The IEMI is an improvement of the El Nino Modoki index (EMI) through adjustments made to the inappropriate weight coefficients of the three boxes of EMI. The IEMI therefore overcomes the EMI’s inability to monitor the two historical El Nino Modoki events, as well as avoids the possible risk (present in the EMI) of excluding the interference of the El Nino signal. The realistic and potential advantages of the IEMI are clear.展开更多
An effective hybrid optimization method is proposed by integrating an adaptive Kriging(A-Kriging)into an improved partial swarm optimization algorithm(IPSO)to give a so-called A-Kriging-IPSO for maximizing the bucklin...An effective hybrid optimization method is proposed by integrating an adaptive Kriging(A-Kriging)into an improved partial swarm optimization algorithm(IPSO)to give a so-called A-Kriging-IPSO for maximizing the buckling load of laminated composite plates(LCPs)under uniaxial and biaxial compressions.In this method,a novel iterative adaptive Kriging model,which is structured using two training sample sets as active and adaptive points,is utilized to directly predict the buckling load of the LCPs and to improve the efficiency of the optimization process.The active points are selected from the initial data set while the adaptive points are generated using the radial random-based convex samples.The cell-based smoothed discrete shear gap method(CS-DSG3)is employed to analyze the buckling behavior of the LCPs to provide the response of adaptive and input data sets.The buckling load of the LCPs is maximized by utilizing the IPSO algorithm.To demonstrate the efficiency and accuracy of the proposed methodology,the LCPs with different layers(2,3,4,and 10 layers),boundary conditions,aspect ratios and load patterns(biaxial and uniaxial loads)are investigated.The results obtained by proposed method are in good agreement with the literature results,but with less computational burden.By applying adaptive radial Kriging model,the accurate optimal resultsebased predictions of the buckling load are obtained for the studied LCPs.展开更多
The widely used energy transfer theory is a foundation of luminescence, in which the rates of Stokes and anti-Stokes processes have the same calculation formula. An improvement on the anti-Stokes energy transfer to ex...The widely used energy transfer theory is a foundation of luminescence, in which the rates of Stokes and anti-Stokes processes have the same calculation formula. An improvement on the anti-Stokes energy transfer to explain the fluorescence intensity reversal between the red and green fluorescence of Er(0.5)Yb(9.5):FOV is reported in the present article. The range of the intensity reversal Z was measured to be 877. Dynamic processes for 16 levels were simulated. A coefficient, the improvement factor of the intensity ratio of Stokes to anti-Stokes processes in quantum Raman theory compared to classical Raman theory, is introduced to successfully describe the anti-Stokes energy transfer. A new method to calculate the distance between the rare earth ions, which is critical for the energy transfer calculation, is proposed. The validity of these important improvements is also proved by experiment.展开更多
Specific fluorophore was introduced into ionic liquid based on its tunability,thus a kind of novel fluorescent ionic liquid probe[P66614][HQS]was designed,synthesized and characterized.Compared with non-fluorescent HQ...Specific fluorophore was introduced into ionic liquid based on its tunability,thus a kind of novel fluorescent ionic liquid probe[P66614][HQS]was designed,synthesized and characterized.Compared with non-fluorescent HQS,ionic liquid[P66614][HQS]emitted a certain amount of fluorescence,which could be attributed to the well-delocalized frontier orbitals and its charge transfer character,as demonstrated by quantum chemical calculation.Considering the interaction of[P66614][HQS]with metal ions,the application for detecting specific substance as a chemical sensor,such as Al3+was investigated.Compared with the traditional probe HQS,significant improvements in Al^3+detecting was achieved by[P66614][HQS]with stronger binding ability,better sensitivity and selectivity.The better performance of[P66614][HQS]was contributed to the changed charge distribution,leading to the stronger binding interaction.We believe that this new fluorescent ionic liquid exhibited unique properties in detecting Al^3+in aqueous solution,which would broaden the application of ionic liquids.展开更多
We improve the performance of organic light-emitting diodes (OLEDs) with both a MoO3 hole injection layer (HIL) and a MoO3 doped hole transport layer (HTL), and present a systematical and comparative investigati...We improve the performance of organic light-emitting diodes (OLEDs) with both a MoO3 hole injection layer (HIL) and a MoO3 doped hole transport layer (HTL), and present a systematical and comparative investigation on these devices. Compared with OLEDs with only MoO3 HIL or MoO3 doped HTL, OLEDs with both MoO3 HIL and MoO3 doped HTL show superior performance in driving voltage, power efficiency, and stability. Based on the typical NPB/Alq3 heterojunction structure, OLEDs with both MoO3 HIL and MoO3 doped HTL show a driving voltage of 5.4 V and a power efficiency of 1.41 lm/W for 1000 cd/m2, and a lifetime of around 0. 88 h with an initial luminance of 5268 cd/m2 under a constant current of 190 mA/cm2 operation in air without encapsulation. While OLEDs with only MoO3 HIL or MoO3 doped HTL show higher driving voltages of 6.4 V or 5.8 V and lower power efficiencies of 1.201m/W or 1.341m/W for 1000cd/m2, and a shorter lifetime of 0.33 or 0.60h with an initial luminance of around 5122 or 5300cd/m2 under a constant current of 200 or 216mA/cm2 operation. Our results demonstrate clearly that using both MoO3 HIL and MoO3 doped HTL is a simple and effective approach to simultaneoasly improve both the hole injection and transport efficiency, resulting from the lowered energy barrier at the anode interface and the increased hole carrier density in MoO3 doped HTL.展开更多
With the advancement of image sensing technology, estimating 3Dhuman pose frommonocular video has becomea hot research topic in computer vision. 3D human pose estimation is an essential prerequisite for subsequentacti...With the advancement of image sensing technology, estimating 3Dhuman pose frommonocular video has becomea hot research topic in computer vision. 3D human pose estimation is an essential prerequisite for subsequentaction analysis and understanding. It empowers a wide spectrum of potential applications in various areas, suchas intelligent transportation, human-computer interaction, and medical rehabilitation. Currently, some methodsfor 3D human pose estimation in monocular video employ temporal convolutional network (TCN) to extractinter-frame feature relationships, but the majority of them suffer from insufficient inter-frame feature relationshipextractions. In this paper, we decompose the 3D joint location regression into the bone direction and length, wepropose the TCG, a temporal convolutional network incorporating Gaussian error linear units (GELU), to solvebone direction. It enablesmore inter-frame features to be captured andmakes the utmost of the feature relationshipsbetween data. Furthermore, we adopt kinematic structural information to solve bone length enhancing the use ofintra-frame joint features. Finally, we design a loss function for joint training of the bone direction estimationnetwork with the bone length estimation network. The proposed method has extensively experimented on thepublic benchmark dataset Human3.6M. Both quantitative and qualitative experimental results showed that theproposed method can achieve more accurate 3D human pose estimations.展开更多
基金supported by National Natural Science Foundation of China (52178422)Doctoral Research Foundation of Hubei University of Arts and Science (2059047)National College Students’Innovation and Entrepreneurship Training Program (202210519021).
文摘The dense and accurate measurement of 3D texture is helpful in evaluating the pavement function.To form dense mandatory constraints and improve matching accuracy,the traditional binocular reconstruction technology was improved threefold.First,a single moving laser line was introduced to carry out global scanning constraints on the target,which would well overcome the difficulty of installing and recognizing excessive laser lines.Second,four kinds of improved algorithms,namely,disparity replacement,superposition synthesis,subregion segmentation,and subregion segmentation centroid enhancement,were established based on different constraint mechanism.Last,the improved binocular reconstruction test device was developed to realize the dual functions of 3D texture measurement and precision self-evaluation.Results show that compared with traditional algorithms,the introduction of a single laser line scanning constraint is helpful in improving the measurement’s accuracy.Among various improved algorithms,the improvement effect of the subregion segmentation centroid enhancement method is the best.It has a good effect on both overall measurement and single pointmeasurement,which can be considered to be used in pavement function evaluation.
基金the National Natural Science Foundation of China(51909136)the Open Research Fund of Key Laboratory of Geological Hazards on Three Gorges Reservoir Area(China Three Gorges University),Ministry of Education,Grant No.2022KDZ21Fund of National Major Water Conservancy Project Construction(0001212022CC60001)。
文摘The staggered distribution of joints and fissures in space constitutes the weak part of any rock mass.The identification of rock mass structural planes and the extraction of characteristic parameters are the basis of rock-mass integrity evaluation,which is very important for analysis of slope stability.The laser scanning technique can be used to acquire the coordinate information pertaining to each point of the structural plane,but large amount of point cloud data,uneven density distribution,and noise point interference make the identification efficiency and accuracy of different types of structural planes limited by point cloud data analysis technology.A new point cloud identification and segmentation algorithm for rock mass structural surfaces is proposed.Based on the distribution states of the original point cloud in different neighborhoods in space,the point clouds are characterized by multi-dimensional eigenvalues and calculated by the robust randomized Hough transform(RRHT).The normal vector difference and the final eigenvalue are proposed for characteristic distinction,and the identification of rock mass structural surfaces is completed through regional growth,which strengthens the difference expression of point clouds.In addition,nearest Voxel downsampling is also introduced in the RRHT calculation,which further reduces the number of sources of neighborhood noises,thereby improving the accuracy and stability of the calculation.The advantages of the method have been verified by laboratory models.The results showed that the proposed method can better achieve the segmentation and statistics of structural planes with interfaces and sharp boundaries.The method works well in the identification of joints,fissures,and other structural planes on Mangshezhai slope in the Three Gorges Reservoir area,China.It can provide a stable and effective technique for the identification and segmentation of rock mass structural planes,which is beneficial in engineering practice.
基金the National Natural Science Foundation of China(Grant No.61972103)the Natural Science Foundation of Guangdong Province of China(Grant No.2023A1515011207)+3 种基金the Special Project in Key Area of General University in Guangdong Province of China(Grant No.2020ZDZX3064)the Characteristic Innovation Project of General University in Guangdong Province of China(Grant No.2022KTSCX051)the Postgraduate Education Innovation Project of Guangdong Ocean University of China(Grant No.202263)the Foundation of Guangdong Provincial Engineering and Technology Research Center of Far Sea Fisheries Management and Fishing of South China Sea.
文摘Based on some analyses of existing chaotic image encryption frameworks and a new designed three-dimensional improved logistic chaotic map(3D-ILM),an asymmetric image encryption algorithm using public-key Rivest–Shamir–Adleman(RSA)is presented in this paper.In the first stage,a new 3D-ILM is proposed to enhance the chaotic behavior considering analysis of time sequence,Lyapunov exponent,and Shannon entropy.In the second stage,combined with the public key RSA algorithm,a new key acquisition mathematical model(MKA)is constructed to obtain the initial keys for the 3D-ILM.Consequently,the key stream can be produced depending on the plain image for a higher security.Moreover,a novel process model(NPM)for the input of the 3D-ILM is built,which is built to improve the distribution uniformity of the chaotic sequence.In the third stage,to encrypt the plain image,a pre-process by exclusive OR(XOR)operation with a random matrix is applied.Then,the pre-processed image is performed by a permutation for rows,a downward modulo function for adjacent pixels,a permutation for columns,a forward direction XOR addition-modulo diffusion,and a backward direction XOR addition-modulo diffusion to achieve the final cipher image.Moreover,experiments show that the the proposed algorithm has a better performance.Especially,the number of pixels change rate(NPCR)is close to ideal case 99.6094%,with the unified average changing intensity(UACI)close to 33.4634%,and the information entropy(IE)close to 8.
基金Supported by the National Basic Research Program of China under Grant No 2014CB921004the National Natural Science Foundation of China under Grant No 61225020
文摘Epitaxial ferroelectric one direction over the thin fihns on single-crystal substrates generally show a preferred domain orientation in other in demonstration of a poor polarization retention. This behavior will affect their application in nonvolatile ferroelectric random access memories where bipolar polarization states are used to store the logic 0 and 1 data. Here the retention characteristics of BiFe03 thin films with Srftu03 bottom electrodes on both GdSc03 (110) and SrTiO3 (100) substrates are studied and compared, and the results of piezoresponse force microscopy provide a long time retention property of the films on two substrates. It is found that bismuth ferrite thin films grown on GdScO3 substrates show no preferred domain variants in comparison with the preferred downward polarization orientation toward bottom electrodes on SrTi03 substrates. Tile retention test from a positive-up domain to a negative-down domain using a signal generator and an oscilloscope coincidentally shows bistable polarization states on the GdSeOa substrate over a measuring time of 500s, unlike the preferred domain orientation on SrTi03, where more than 65~o of upward domains disappear after 1 s. In addition, different sizes of domains have been written and read by using the scanning tip of piezoresponse force microscopy, where the polarization can stabilize over one month. This study paves one route to improve the polarization retention property through the optimization of the lattice-mismatched stresses between films and substrates.
基金Supported by Project of National Major Science and Technology(No.2016ZX05026-007-01)
文摘Edge detection plays an important role in geological interpretation of potential field data,which can indicate the subsurface faults,contact,and other tectonic features.A variety of methods have been proposed to detect and enhance the edges.3 D structure tensor can well delineate the edges of geological bodies,however,it is sensitive to noise and additional false edges need to be removed artificially.In order to overcome these disadvantages,this paper redefines the 3 D structure tensor with a Gaussian envelop and proposes a new normalized edge detector,which can remove the additional false edges and reduce the influence of noise effectively,and balance the edges of different amplitude anomalies completely.This method has been tested on the synthetic and measured gravity data,showing that the new improved method achievesbetter results and reveals more details.
文摘Objective To study the effect of using improved 2D computer-assisted fluoroscopic navigation through simulating 3D vertebrae image to guide pedicle screw internal fixation.Methods Posterior pedicle screw internal fixation,distraction
基金funded by the Key-Area Research and Development Program of Guangdong Province(Grant No.2020B1111200001)the Key project of monitoring,early warning and prevention of major natural disasters of China(Grant No.2019YFC1510304)+1 种基金the S&T Program of Hebei(Grant No.19275408D)the Scientific Research Projects of Weather Modification in Northwest China(Grant No.RYSY201905).
文摘A convective and stratiform cloud classification method for weather radar is proposed based on the density-based spatial clustering of applications with noise(DBSCAN)algorithm.To identify convective and stratiform clouds in different developmental phases,two-dimensional(2D)and three-dimensional(3D)models are proposed by applying reflectivity factors at 0.5°and at 0.5°,1.5°,and 2.4°elevation angles,respectively.According to the thresholds of the algorithm,which include echo intensity,the echo top height of 35 dBZ(ET),density threshold,andεneighborhood,cloud clusters can be marked into four types:deep-convective cloud(DCC),shallow-convective cloud(SCC),hybrid convective-stratiform cloud(HCS),and stratiform cloud(SFC)types.Each cloud cluster type is further identified as a core area and boundary area,which can provide more abundant cloud structure information.The algorithm is verified using the volume scan data observed with new-generation S-band weather radars in Nanjing,Xuzhou,and Qingdao.The results show that cloud clusters can be intuitively identified as core and boundary points,which change in area continuously during the process of convective evolution,by the improved DBSCAN algorithm.Therefore,the occurrence and disappearance of convective weather can be estimated in advance by observing the changes of the classification.Because density thresholds are different and multiple elevations are utilized in the 3D model,the identified echo types and areas are dissimilar between the 2D and 3D models.The 3D model identifies larger convective and stratiform clouds than the 2D model.However,the developing convective clouds of small areas at lower heights cannot be identified with the 3D model because they are covered by thick stratiform clouds.In addition,the 3D model can avoid the influence of the melting layer and better suggest convective clouds in the developmental stage.
基金supported by the National Natural Science Foun-dation of China (Grant Nos. 40675028 and 40975029)the National Basic Research Program of China (Grant No.2006CB403600)the State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics (LASG)
文摘In recent years, El Nino Modoki (a type of pseudo-El Nino) has been distinguished as a unique large-scale ocean warming phenomenon happening in the central tropical Pacific that is quite different from the traditional El Nino. In this study, EOF analysis was used to successfully separate El Nino and El Nino Modoki. The abilities of the NINO3 index, NINO3.4 index, NINO1+2 index and NINO4 index in characterizing El Nino were explored in detail. The resulting suggestion was that, comparatively, NINO3 is the optimal index for monitoring El Nino among the four NINO indices, as the other NINO indices were found to be less good at distinguishing between El Nino and El Nino Modoki signals, or were easily disturbed by El Nino Modoki signals. Further, an improved El Nino Modoki index (IEMI) was introduced in the current paper to better represent the El Nino Modoki that is captured by the second leading EOF mode of monthly tropical Pacific sea surface temperature anomalies (SSTAs). The IEMI is an improvement of the El Nino Modoki index (EMI) through adjustments made to the inappropriate weight coefficients of the three boxes of EMI. The IEMI therefore overcomes the EMI’s inability to monitor the two historical El Nino Modoki events, as well as avoids the possible risk (present in the EMI) of excluding the interference of the El Nino signal. The realistic and potential advantages of the IEMI are clear.
基金Vietnam National Foundation for Science and Technology Development(NAFOSTED)under Grant number 107.02-2019.330.
文摘An effective hybrid optimization method is proposed by integrating an adaptive Kriging(A-Kriging)into an improved partial swarm optimization algorithm(IPSO)to give a so-called A-Kriging-IPSO for maximizing the buckling load of laminated composite plates(LCPs)under uniaxial and biaxial compressions.In this method,a novel iterative adaptive Kriging model,which is structured using two training sample sets as active and adaptive points,is utilized to directly predict the buckling load of the LCPs and to improve the efficiency of the optimization process.The active points are selected from the initial data set while the adaptive points are generated using the radial random-based convex samples.The cell-based smoothed discrete shear gap method(CS-DSG3)is employed to analyze the buckling behavior of the LCPs to provide the response of adaptive and input data sets.The buckling load of the LCPs is maximized by utilizing the IPSO algorithm.To demonstrate the efficiency and accuracy of the proposed methodology,the LCPs with different layers(2,3,4,and 10 layers),boundary conditions,aspect ratios and load patterns(biaxial and uniaxial loads)are investigated.The results obtained by proposed method are in good agreement with the literature results,but with less computational burden.By applying adaptive radial Kriging model,the accurate optimal resultsebased predictions of the buckling load are obtained for the studied LCPs.
基金Project supported by the National Natural Science Foundation of China (Grant No 10674019)
文摘The widely used energy transfer theory is a foundation of luminescence, in which the rates of Stokes and anti-Stokes processes have the same calculation formula. An improvement on the anti-Stokes energy transfer to explain the fluorescence intensity reversal between the red and green fluorescence of Er(0.5)Yb(9.5):FOV is reported in the present article. The range of the intensity reversal Z was measured to be 877. Dynamic processes for 16 levels were simulated. A coefficient, the improvement factor of the intensity ratio of Stokes to anti-Stokes processes in quantum Raman theory compared to classical Raman theory, is introduced to successfully describe the anti-Stokes energy transfer. A new method to calculate the distance between the rare earth ions, which is critical for the energy transfer calculation, is proposed. The validity of these important improvements is also proved by experiment.
基金We acknowledge the support of the National Key Basic Research Program of China(2015CB251401)the Natural Science Foundation of China(21776239)+1 种基金Zhejiang Provincial Natural Science Foundation of China(LZ17B060001)the Fundamental Research Funds of the Central Universities,the instrument support of professor Peng Xiaogang,professor Jin Yizheng and associate professor Qin Haiyan.
文摘Specific fluorophore was introduced into ionic liquid based on its tunability,thus a kind of novel fluorescent ionic liquid probe[P66614][HQS]was designed,synthesized and characterized.Compared with non-fluorescent HQS,ionic liquid[P66614][HQS]emitted a certain amount of fluorescence,which could be attributed to the well-delocalized frontier orbitals and its charge transfer character,as demonstrated by quantum chemical calculation.Considering the interaction of[P66614][HQS]with metal ions,the application for detecting specific substance as a chemical sensor,such as Al3+was investigated.Compared with the traditional probe HQS,significant improvements in Al^3+detecting was achieved by[P66614][HQS]with stronger binding ability,better sensitivity and selectivity.The better performance of[P66614][HQS]was contributed to the changed charge distribution,leading to the stronger binding interaction.We believe that this new fluorescent ionic liquid exhibited unique properties in detecting Al^3+in aqueous solution,which would broaden the application of ionic liquids.
基金Supported by the National Natural Science Foundation of China under Grant No 11274402the National Basic Research Program of China under Grant No 2012CB933704+1 种基金the Natural Science Foundation of Guangdong Province under Grant No S2012020011003the Program for Changjiang Scholars and Innovative Research Team in University under Grant No IRT13042
文摘We improve the performance of organic light-emitting diodes (OLEDs) with both a MoO3 hole injection layer (HIL) and a MoO3 doped hole transport layer (HTL), and present a systematical and comparative investigation on these devices. Compared with OLEDs with only MoO3 HIL or MoO3 doped HTL, OLEDs with both MoO3 HIL and MoO3 doped HTL show superior performance in driving voltage, power efficiency, and stability. Based on the typical NPB/Alq3 heterojunction structure, OLEDs with both MoO3 HIL and MoO3 doped HTL show a driving voltage of 5.4 V and a power efficiency of 1.41 lm/W for 1000 cd/m2, and a lifetime of around 0. 88 h with an initial luminance of 5268 cd/m2 under a constant current of 190 mA/cm2 operation in air without encapsulation. While OLEDs with only MoO3 HIL or MoO3 doped HTL show higher driving voltages of 6.4 V or 5.8 V and lower power efficiencies of 1.201m/W or 1.341m/W for 1000cd/m2, and a shorter lifetime of 0.33 or 0.60h with an initial luminance of around 5122 or 5300cd/m2 under a constant current of 200 or 216mA/cm2 operation. Our results demonstrate clearly that using both MoO3 HIL and MoO3 doped HTL is a simple and effective approach to simultaneoasly improve both the hole injection and transport efficiency, resulting from the lowered energy barrier at the anode interface and the increased hole carrier density in MoO3 doped HTL.
基金supported by the Key Project of NSFC(Grant No.U1908214)Special Project of Central Government Guiding Local Science and Technology Development(Grant No.2021JH6/10500140)+5 种基金the Program for Innovative Research Team in University of Liaoning Province(LT2020015)the Support Plan for Key Field Innovation Team of Dalian(2021RT06)the Support Plan for Leading Innovation Team of Dalian University(XLJ202010)the Science and Technology Innovation Fund of Dalian(Grant No.2020JJ25CY001)in part by the National Natural Science Foundation of China under Grant 61906032the FundamentalResearch Funds for the Central Universities under Grant DUT21TD107.
文摘With the advancement of image sensing technology, estimating 3Dhuman pose frommonocular video has becomea hot research topic in computer vision. 3D human pose estimation is an essential prerequisite for subsequentaction analysis and understanding. It empowers a wide spectrum of potential applications in various areas, suchas intelligent transportation, human-computer interaction, and medical rehabilitation. Currently, some methodsfor 3D human pose estimation in monocular video employ temporal convolutional network (TCN) to extractinter-frame feature relationships, but the majority of them suffer from insufficient inter-frame feature relationshipextractions. In this paper, we decompose the 3D joint location regression into the bone direction and length, wepropose the TCG, a temporal convolutional network incorporating Gaussian error linear units (GELU), to solvebone direction. It enablesmore inter-frame features to be captured andmakes the utmost of the feature relationshipsbetween data. Furthermore, we adopt kinematic structural information to solve bone length enhancing the use ofintra-frame joint features. Finally, we design a loss function for joint training of the bone direction estimationnetwork with the bone length estimation network. The proposed method has extensively experimented on thepublic benchmark dataset Human3.6M. Both quantitative and qualitative experimental results showed that theproposed method can achieve more accurate 3D human pose estimations.