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Dynamic patterns of gene expression during leaf initiation 被引量:1
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作者 Ting Yu Chunmei Guan +3 位作者 Jin Wang Muhammad Sajjad Lingjian Ma Yuling Jiao 《Journal of Genetics and Genomics》 SCIE CAS CSCD 2017年第12期599-601,共3页
The establishment of leaf dorsoventral(adaxial-abaxial)polarity conditions flattening of the leaf,an essential feature of land plants that optimizes light absorbance.Leaf primordia initiate from peripheral zone(PZ... The establishment of leaf dorsoventral(adaxial-abaxial)polarity conditions flattening of the leaf,an essential feature of land plants that optimizes light absorbance.Leaf primordia initiate from peripheral zone(PZ)at the flank of the shoot apical meristem(SAM),which maintains stem cells in the shoot apex. 展开更多
关键词 dynamic patterns gene expression
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Research on dynamics patterns and parameter characters of crustal deformation field before and after strong earthquake
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作者 周硕愚 施顺英 +3 位作者 吴云 杨国华 李正媛 王若柏 《Acta Seismologica Sinica(English Edition)》 EI CSCD 1998年第1期47-55,共9页
Based on the dynamic monitoring data of crustal deformation, the parameter evolution for the dynamics pattern and fractal dimension of crustal deformation field and the integral activity level of many faults etc. befo... Based on the dynamic monitoring data of crustal deformation, the parameter evolution for the dynamics pattern and fractal dimension of crustal deformation field and the integral activity level of many faults etc. before and after the Tangshan (1976) and Lijiang (1996) strong earthquakes and others are studied by using the method of pattern dynamics. It is exposed that two time space characters, the ordered dimension drop of the deformation field and the accelerated motion of multi fault before an earthquake, are probably caused by the deformation localization and fault softening after the seismogenic process enters the nonlinear stage. They could be an important seismic precursor if they occurred repeatedly before strong earthquakes. 展开更多
关键词 crustal deformation dynamic pattern process of dimension drop accelerative motion of fault seismic precursor
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Dynamic evolution patterns of the degree of ground resistivity anisotropy and the sets mogenic process 被引量:1
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作者 毛桐恩 胥广银 +2 位作者 范思源 赵明 孙景芳 《Acta Seismologica Sinica(English Edition)》 CSCD 1999年第2期200-205,共8页
Following a new train of thinking, this paper has explored first the potential information in the ground resistivitydata observed by the existing geoelectric observation system, investigated and proposed a new dimensi... Following a new train of thinking, this paper has explored first the potential information in the ground resistivitydata observed by the existing geoelectric observation system, investigated and proposed a new dimensionlessgeoelectric precursor factor, the degree of ground resistivity anisotropy, S, and studied the characteristics of dynamic evolution pattern of S during the seismogenic process. The results show that, during the seismogenic process, the degree of ground resistivity anisotropy (S) displays h process of 'normal' → 'abnormal strengthening(amplitude, range)' → 'abnormal weakening'→ 'earthquake occurrence'→ 'normal'. The earthquake wouldoccur at the time when the S value has entered the late stage of strengthening and turns to weaken and in the gradient belt on the margin ofS anomaly region. The dynamic evolution pattern ofS reflects the changes of the tectonicstress field during the seismogenic process. Therefore, it would be possible to trace the process of earthquake generation and occurrence from the dynamic evolution pattern ofS so as to service eaJ'thquake prediction. 展开更多
关键词 degree of ground resistivity anisotropy dynamic evolution pattern seismogenic process
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Internal Dynamics of the Generation of Atmospheric Teleconnection Patterns
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作者 李志锦 纪立人 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 1996年第1期19-32,共14页
A preferred growing perturbation concept has been introduced into the dynamical study on the generation ofatmospheric teleconnection patterns.It is shown that all the important teleconnection patterns observed in the ... A preferred growing perturbation concept has been introduced into the dynamical study on the generation ofatmospheric teleconnection patterns.It is shown that all the important teleconnection patterns observed in the realatmosphere may be established through internal barotropic dynamical processes. 展开更多
关键词 Preferred growing mode Teleconnection pattern Barotropic dynamical process
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Nanoindentation Models of Monolayer Graphene and Graphyne under Point Load Pattern Studied by Molecular Dynamics
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作者 向浪 吴建 +2 位作者 马双英 王芳 张凯旺 《Chinese Physics Letters》 SCIE CAS CSCD 2015年第9期108-111,共4页
Molecular dynamics simulations are performed to study the nanoindentation models of monolayer suspended graphene and graphyne. Fullerenes are selected as indenters. Our results show that Young's modulus of monolayer-... Molecular dynamics simulations are performed to study the nanoindentation models of monolayer suspended graphene and graphyne. Fullerenes are selected as indenters. Our results show that Young's modulus of monolayer-thick graphyne is almost half of that of graphene, which is estimated to be 0.50 TPa. The mechanical properties of graphene and graphyne are different in the presence of strain. A pre-tension has an important effect on the mechanical properties of a membrane. Both the pre-tension and Young's modulus plots demonstrate index behavior. The toughness of graphyne is stronger than that of graphene due to Young's modulus magnitude. Young's moduli of graphene and graphyne are almost independent of the size ratio of indenter to membrane. 展开更多
关键词 Nanoindentation Models of Monolayer Graphene and Graphyne under Point Load pattern Studied by Molecular dynamics
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Formation Dynamics and Quantitative Prediction of Hydrocarbons of the Superpressure System in the Dongying Sag 被引量:4
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作者 SUI Fenggui HAO Xuefeng LIU Qing ZHUO Qin'gong ZHANG Shouchun 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2008年第1期164-173,共10页
Based on the theory of formation dynamics of oil/gas pools, the Dongying sag can be divided into three dynamic systems regarding the accumulation of oil and gas: the superpressure closed system, the semi-closed syste... Based on the theory of formation dynamics of oil/gas pools, the Dongying sag can be divided into three dynamic systems regarding the accumulation of oil and gas: the superpressure closed system, the semi-closed system and the normal pressure open system. Based on the analysis of genesis of superpressure in the superpressure closed system and the rule of hydrocarbon expulsion, it is found that hydrocarbon generation is related to superpressure, which is the main driving factor of hydrocarbon migration. Micro fractures formed by superpressure are the main channels for hydrocarbon migration. There are three dynamic patterns for hydrocarbon expulsion: free water drainage, hydrocarbon accumulation and drainage through micro fissures. In the superpressure closed system, the oil-driving-water process and oil/gas accumulation were completed in lithologic traps by way of such two dynamic patterns as episodic evolution of superpressure systems and episodic pressure release of faults. The oil-bearing capacity of lithologic traps is intimately related to reservoir-forming dynamic force. Quantitative evaluation of dynamic conditions for pool formation can effectively predict the oil-bearing capability of traps. 展开更多
关键词 superpressure closed system hydrocarbon expulsion dynamics dynamic patterns for pool formation quantitative prediction Dongying sag
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Dynamical pattern recognition for univariate time series and its application to an axial compressor
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作者 Jingtao Hu Weiming Wu +1 位作者 Zejian Zhu Cong Wang 《Control Theory and Technology》 EI CSCD 2024年第1期39-55,共17页
In this paper, a learning and recognition approach is proposed for univariate time series composed of output measurements of general nonlinear dynamical systems. Firstly, a class of dynamical systems in the canonical ... In this paper, a learning and recognition approach is proposed for univariate time series composed of output measurements of general nonlinear dynamical systems. Firstly, a class of dynamical systems in the canonical form is derived to describe the univariate time series by introducing coordinate transformation. An observer-based deterministic learning technique is then adopted to achieve dynamical modeling of the associated transformed systems of the training univariate time series, and the modeling results in the form of radial basis function network (RBFN) models are stored in a pattern library. Subsequently, multiple observer-based dynamical estimators containing the RBFN models in the pattern library are constructed for a test univariate time series, and a recognition decision scheme is proposed by the derived recognition indicator. On this basis, more concise recognition conditions are provided, which is beneficial for verifying the recognition results. Finally, simulation studies on the Rossler system and aero-engine stall warning verify the effectiveness of the proposed approach. 展开更多
关键词 dynamical pattern recognition Deterministic learning Stall warning Radial basis function network Sampled-data observer
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Pattern dynamics and bifurcation in delayed SIR network with diffusion network
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作者 Wenjie Yang Qianqian Zheng Jianwei Shen 《International Journal of Biomathematics》 SCIE 2024年第2期87-111,共25页
The spread of infectious diseases often presents the emergent properties,which leads to more dificulties in prevention and treatment.In this paper,the SIR model with both delay and network is investigated to show the ... The spread of infectious diseases often presents the emergent properties,which leads to more dificulties in prevention and treatment.In this paper,the SIR model with both delay and network is investigated to show the emergent properties of the infectious diseases'spread.The stability of the SIR model with a delay and two delay is analyzed to illustrate the effect of delay on the periodic outbreak of the epidemic.Then the stability conditions of Hopf bifurcation are derived by using central manifold to obtain the direction of bifurcation,which is vital for the generation of emergent behavior.Also,numerical simulation shows that the connection probability can affect the types of the spatio-temporal patterns,further induces the emergent properties.Finally,the emergent properties of COVID-19 are explained by the above results. 展开更多
关键词 pattern dynamics SIR model random network connection probability Hopf bifurcation
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Can small-scale altitudinal gradients predict spatial and temporal patterns in tropical forests?
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作者 Mariana Caroline Moreira Morelli Cléber Rodrigo de Souza +4 位作者 Jean Daniel Morel Vinícius Andrade Maia Alisson Borges Miranda Santos Kaline Fernandes Miranda Rubens Manoel dos Santos 《Journal of Forestry Research》 SCIE CAS CSCD 2021年第5期1854-1865,共11页
In tropical montane forests,compositional and structural changes are commonly driven by broad-scale altitudinal variation.Here,given the lack of knowledge on small-scale vegetation changes and temporal dynamics,we add... In tropical montane forests,compositional and structural changes are commonly driven by broad-scale altitudinal variation.Here,given the lack of knowledge on small-scale vegetation changes and temporal dynamics,we address the effects of small-scale variations in soil and altitude on tree community structure,temporal dynamics and phylogenetic diversity in a semi-deciduous tropical forest of the Atlantic Forest Domain,southeastern Brazil.In 2010 and 2015 we sampled thirty plots of 400 m^(2),set up along an altitudinal gradient between 1000 and 1500 m a.s.I..In each plot,we collected soil samples for chemical and textural analyses.We fitted linear models to test the effects of altitude and soil on community dynamics and phylogenetic parameters.Altitude and soil explained the spatial variation in number of individuals and phylogenetic diversity metrics.From lower to higher altitudes,we found decreasing fertility,increasing tree density and decreasing phylogenetic diversity.Altitude significantly influenced the increases in total biomass(from 240.9 to 255.4 t ha^(-1))and individual biomass(from 0.15 to 0.17 t)recorded in the interval.And while community temporal dynamics had rates of 1.96%for mortality,1.02%for recruitment,1.61%for biomass loss and 2.81%for biomass gain,none of them were explained by altitude or soil.Temporal species substitution averaged0.1 in the interval.Altogether,these results suggest that the small-scale variations in altitude and soil likely determine the conditions and resources that drive community assembly and structure,which are expressed by spatial variations along the altitudinal gradient.At the same time,temporal patterns were not influenced by altitude-related environmental variation,resulting in a similar dynamic behaviour across the gradient,suggesting that broad-scale factors may play a more important role than local ones. 展开更多
关键词 Fine-scale Semideciduous forests Montane forests dynamic patterns
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Multiphase convolutional dense network for the classification of focal liver lesions on dynamic contrast-enhanced computed tomography 被引量:3
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作者 Su-E Cao Lin-Qi Zhang +10 位作者 Si-Chi Kuang Wen-Qi Shi Bing Hu Si-Dong Xie Yi-Nan Chen Hui Liu Si-Min Chen Ting Jiang Meng Ye Han-Xi Zhang Jin Wang 《World Journal of Gastroenterology》 SCIE CAS 2020年第25期3660-3672,共13页
BACKGROUND The accurate classification of focal liver lesions(FLLs)is essential to properly guide treatment options and predict prognosis.Dynamic contrast-enhanced computed tomography(DCE-CT)is still the cornerstone i... BACKGROUND The accurate classification of focal liver lesions(FLLs)is essential to properly guide treatment options and predict prognosis.Dynamic contrast-enhanced computed tomography(DCE-CT)is still the cornerstone in the exact classification of FLLs due to its noninvasive nature,high scanning speed,and high-density resolution.Since their recent development,convolutional neural network-based deep learning techniques has been recognized to have high potential for image recognition tasks.AIM To develop and evaluate an automated multiphase convolutional dense network(MP-CDN)to classify FLLs on multiphase CT.METHODS A total of 517 FLLs scanned on a 320-detector CT scanner using a four-phase DCECT imaging protocol(including precontrast phase,arterial phase,portal venous phase,and delayed phase)from 2012 to 2017 were retrospectively enrolled.FLLs were classified into four categories:Category A,hepatocellular carcinoma(HCC);category B,liver metastases;category C,benign non-inflammatory FLLs including hemangiomas,focal nodular hyperplasias and adenomas;and category D,hepatic abscesses.Each category was split into a training set and test set in an approximate 8:2 ratio.An MP-CDN classifier with a sequential input of the fourphase CT images was developed to automatically classify FLLs.The classification performance of the model was evaluated on the test set;the accuracy and specificity were calculated from the confusion matrix,and the area under the receiver operating characteristic curve(AUC)was calculated from the SoftMax probability outputted from the last layer of the MP-CDN.RESULTS A total of 410 FLLs were used for training and 107 FLLs were used for testing.The mean classification accuracy of the test set was 81.3%(87/107).The accuracy/specificity of distinguishing each category from the others were 0.916/0.964,0.925/0.905,0.860/0.918,and 0.925/0.963 for HCC,metastases,benign non-inflammatory FLLs,and abscesses on the test set,respectively.The AUC(95%confidence interval)for differentiating each category from the others was 0.92(0.837-0.992),0.99(0.967-1.00),0.88(0.795-0.955)and 0.96(0.914-0.996)for HCC,metastases,benign non-inflammatory FLLs,and abscesses on the test set,respectively.CONCLUSION MP-CDN accurately classified FLLs detected on four-phase CT as HCC,metastases,benign non-inflammatory FLLs and hepatic abscesses and may assist radiologists in identifying the different types of FLLs. 展开更多
关键词 Deep learning Convolutional neural networks Focal liver lesions CLASSIFICATION Multiphase computed tomography dynamic enhancement pattern
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AUTOMATIC ORDER-DETERMINATION OF TRANSIENT IN--PLANE DISPLACEMENT MOIRE PATTERNS 被引量:1
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作者 方竞 K.H.Laermann 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 1993年第1期86-92,共7页
This paper presents a fringe-carrier method that eliminates sign ambiguity of transient moire fringes which can be used to automatically determine the relative orders. A fringe carrier is preset in the static state of... This paper presents a fringe-carrier method that eliminates sign ambiguity of transient moire fringes which can be used to automatically determine the relative orders. A fringe carrier is preset in the static state of the specimen and the dynamic in-plane displacements are recorded as the modulation to the frequency of the carrier fringes when the specimen is loaded by impact. According to a modulating criterion developed from the modulation degree, the fringes of the transient moire patterns keep monotonical in orders so that they can be automatically encoded in grey levels by a digital image system. The moire orders purely caused by dynamic loadings are evaluated by subtracting the grey-value of the unmodulated carrier image from that of the modulated carrier images encoded by their orders. With the subtracted moire orders the strain components can be obtained, and, correspondingly, the histograms of dynamic displacement moire images are shown with order variation by image-difference. 展开更多
关键词 dynamic moire patterns transient strains digital impage processing
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Geometrically-Compatible Dislocation Pattern and Modeling of Crystal Plasticity in Body-Centered Cubic(BCC)Crystal at Micron Scale Dedicated to Professor Karl Stark Pister for his 95th birthday 被引量:1
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作者 Yuxi Xie Shaofan Li 《Computer Modeling in Engineering & Sciences》 SCIE EI 2021年第12期1419-1440,共22页
The microstructure of crystal defects,e.g.,dislocation patterns,are not arbitrary,and it is possible that some of them may be related to the microstructure of crystals itself,i.e.,the lattice structure.We call those d... The microstructure of crystal defects,e.g.,dislocation patterns,are not arbitrary,and it is possible that some of them may be related to the microstructure of crystals itself,i.e.,the lattice structure.We call those dislocation patterns or substructures that are related to the corresponding crystal microstructure as the Geometrically Compatible Dislocation Patterns(GCDP).Based on this notion,we have developed a Multiscale Crystal Defect Dynamics(MCDD)to model crystal plasticity without or with minimum empiricism.In this work,we employ the multiscale dislocation pattern dynamics,i.e.,MCDD,to simulate crystal plasticity in body-centered cubic(BCC)single crystals,mainlyα-phase Tantalum(α-Ta)single crystals.The main novelties of the work are:(1)We have successfully simulated crystal plasticity at micron scale without any empirical parameter inputs;(2)We have successfully employed MCDD to perform direct numerical simulation of inelastic hysteresis of the BCC crystal;(3)We have used MCDD crystal plasticity model to demonstrate the size-effect of crystal plasticity and(4)We have captured cross-slip which may lead to size-effect. 展开更多
关键词 α-phase tantalum BCC crystal crystal plasticity dislocation pattern dynamics multiscale simulation size effect
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Decomposition dynamic of higher plant pigments by HPLC analysis
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作者 LUOYi ZHANGTing-zhou +2 位作者 ZHOUQi-xing MAODa-qing WANDong-mei 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2004年第5期847-850,共4页
The fate of the litter of dominant vegetation(willows and reeds) is one of the aspects studied in the frame of the project “Onderzoek Milieu Effecten Sigmaplan”. One of the questions to be considered is how long the... The fate of the litter of dominant vegetation(willows and reeds) is one of the aspects studied in the frame of the project “Onderzoek Milieu Effecten Sigmaplan”. One of the questions to be considered is how long the litter stays within the estuary. In this paper, the time the leaf litter(Salix triandra and Phragmites australis) stayed in the Schelde estuary was studied by using plant pigment as biomarkers with HPLC application. After analyzing the original data from the incubation experiment described by Dubuison and Geers(1999), the decomposition dynamics patterns of pigments were analyzed and described, and these decomposition dynamics patterns were used as calibration patterns. By using Spearman Rank Order Correlation, the calibration patterns of the pigments which were significant(p<0.05) were grouped. In this way, several groups of the calibration patterns of pigment decomposition were achieved. The presence or absence of these groups of pigments (whether they can be detected or not from HPLC) was shown to be useful in determining the time the litter has stayed in the water. Combining data of DW and POC, more precise timing can be obtained. 展开更多
关键词 decomposition dynamics pattern Salix triandra Phragmites australis Spearman Rank Order Correlation Schelde Estuary HPLC
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Application Strategy of Dynamic Management Mode in Municipal Road Survey and Design Management
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作者 Liji Wang 《Journal of Architectural Research and Development》 2022年第4期36-41,共6页
With the continuous improvement of urbanization level,the construction of municipal roads has received more attention.The rational application of dynamic management mode to the survey and design management of municipa... With the continuous improvement of urbanization level,the construction of municipal roads has received more attention.The rational application of dynamic management mode to the survey and design management of municipal roads is conducive to improve the survey and design management level of municipal roads and further realizing the optimization of the construction effect of municipal roads.In this paper,the various factors which are affecting the management of municipal road survey and design as well the principles of municipal road design were discussed.Further,the recommendation of the application strategy of dynamic management mode in municipal road survey and design management was proposed in this paper. 展开更多
关键词 dynamic management pattern Municipal administration path Survey and design management
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Hollow hexagonal pattern with surface discharges in a?dielectric barrier discharge
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作者 冯建宇 董丽芳 +3 位作者 李彩霞 刘莹 杜天 郝芳 《Plasma Science and Technology》 SCIE EI CAS CSCD 2017年第5期37-42,共6页
The hollow hexagonal pattern involved in surface discharges is firstly investigated in a?dielectric barrier discharge system. The spatiotemporal structures of the pattern are studied using an intensified charge-coupl... The hollow hexagonal pattern involved in surface discharges is firstly investigated in a?dielectric barrier discharge system. The spatiotemporal structures of the pattern are studied using an intensified charge-coupled device and photomultiplier. Instantaneous images taken by an intensified charge-coupled device and optical correlation measurements show that the surface discharges are induced by volume discharges. The optical signals indicate that the discharge filaments constituting the hexagonal frame discharge randomly at the first current pulse or the second pulse, once?or twice. There is no?interleaving of several sub-lattices, which indicates that the ‘memory' effect is no longer in force due to surface discharges. By using the emission spectrum method, both the molecule vibration temperature?and electron density of the surface discharges are larger than that of the volume discharges. 展开更多
关键词 dielectric barrier discharge hollow hexagonal pattern volume discharges surface discharges spatiotemporal dynamics plasma parameters
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Self-erasable dynamic surface patterns via controllable elastic modulus boosting multi-encoded and tamper-proof information storage 被引量:2
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作者 Ziquan Fang Xiaofeng Lin +8 位作者 Yihui Lin Jiamin Gao Li Gong Ruijun Lin Guoyi Pan Jianyu Wu Wenjing Lin Xudong Chen Guobin Yi 《Nano Research》 SCIE EI CSCD 2023年第1期634-644,共11页
Dynamic surface patterns(DSPs)have attracted significant interest in anti-counterfeiting,enabling information to be stored,encrypted and decrypted in response to external stimuli.However,creating dynamic surface patte... Dynamic surface patterns(DSPs)have attracted significant interest in anti-counterfeiting,enabling information to be stored,encrypted and decrypted in response to external stimuli.However,creating dynamic surface patterns,capable of controlling wrinkling time and independently modulating different information in both wrinkled and fluorescent states,remains a tremendous challenge.These limit DSPs to further enhance tamper-proofing capacity and extend the information storage density.Here,a rationally designed patterning strategy based on controllable elastic modulus was demonstrated to fabricate self-erasable dynamic surface patterns(S-DSPs)that increase information storage density.These novel S-DSPs strategically integrated amino co-oligomers(ACOs)with the 9-anthracenemethanol(9-AM)as skin layers,designing a bilayer multi-encoding system which could carry several different types of information with wrinkled and fluorescent patterns.The ACOs with relatively low molecular weight can endow the elastic modulus of skin layers with a wide range of regulation.As a result,the difference between the compressive strain and the critical wrinkle strain in the bilayer system would be precisely modulated by photo-dimerization to form quick-response(minimum<1 min)and self-erasable(3 min–8 days)wrinkled patterns for S-DSPs.Meanwhile,the fluorescence pattern could be independently erased and reprogrammed without affecting the change in the wrinkle pattern under modulus-controlled conditions.Moreover,controllable self-erasure in S-DSPs significantly develops tamper-proof capabilities in a supply chain.This original strategy could provide a new approach to the tamper-proof,high-density,and multi-encoded information storage in the product security or inkless printing. 展开更多
关键词 dynamic surface patterns muti-encoding tamper-proofing information storage self-erasure inkless printing
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A New Elastoplastic 3D Sand Production Model for Fractured Gas Fields
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作者 Hongtao Liu Hongtao Jing +3 位作者 Zhixiong Tu Shiyong Qin Junhui Wei Xiaotong Yu 《Fluid Dynamics & Materials Processing》 EI 2023年第7期1851-1862,共12页
Reservoirs characterized by high temperature,high-pressure,medium high cementation strength,low porosity,and low permeability,in general,are not affected by sand production issues.Since 2009,however,it is known that c... Reservoirs characterized by high temperature,high-pressure,medium high cementation strength,low porosity,and low permeability,in general,are not affected by sand production issues.Since 2009,however,it is known that cases exists where sand is present and may represent a significant technical problem(e.g.,the the Dina II condensate gas field).In the present study,the main factors affecting sand production in this type of reservoir are considered(mechanical properties,stress fields,production system,completion method and gas flow pattern changes during the production process).On this basis,a new liquid-solid coupled porous elasto-plastic 3D sand production model is introduced and validated through comparison with effective sand production data.The related prediction errors are found to be within 15%,which represents the necessary prerequisite for the utilization of such a model for the elaboration of sand prevention measures. 展开更多
关键词 Medium-high strength sand production mechanism fluid-solid coupling sand production prediction dynamic sand production pattern
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POSITIVITY-PRESERVING LOCAL DISCONTINUOUS GALERKIN METHOD FOR PATTERN FORMATION DYNAMICAL MODEL IN POLYMERIZING ACTIN FLOCKS
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作者 Xiuhui Guo Lulu Tian +1 位作者 Yang Yang Hui Guo 《Journal of Computational Mathematics》 SCIE CSCD 2023年第4期623-642,共20页
In this paper,we apply local discontinuous Galerkin(LDG)methods for pattern formation dynamical model in polymerizing actin focks.There are two main dificulties in designing effective numerical solvers.First of all,th... In this paper,we apply local discontinuous Galerkin(LDG)methods for pattern formation dynamical model in polymerizing actin focks.There are two main dificulties in designing effective numerical solvers.First of all,the density function is non-negative,and zero is an unstable equilibrium solution.Therefore,negative density values may yield blow-up solutions.To obtain positive numerical approximations,we apply the positivitypreserving(PP)techniques.Secondly,the model may contain stif source.The most commonly used time integration for the PP technique is the strong-stability-preserving Runge-Kutta method.However,for problems with stiff source,such time discretizations may require strictly limited time step sizes,leading to large computational cost.Moreover,the stiff source any trigger spurious filament polarization,leading to wrong numerical approximations on coarse meshes.In this paper,we combine the PP LDG methods with the semi-implicit Runge-Kutta methods.Numerical experiments demonstrate that the proposed method can yield accurate numerical approximations with relatively large time steps. 展开更多
关键词 pattern formation dynamical model Local discontinuous Galerkin method Positive-preserving technique Semi-implicit Runge-Kutta method Stiff source
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On the physical model of earthquake precursor fields and the mechanism of precursors'timespace distribution(Ⅲ)──anomalies of seismicity and crustal deformation and their mechanisms when a strong earthquake is in prep 被引量:3
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作者 梅世蓉 《Acta Seismologica Sinica(English Edition)》 CSCD 1996年第2期223-234,共12页
By studying the seismicity pattern before 37 earthquakes with M≥6. 0 in North China and the pattern of crustal deformation in the Capital Area from 1954 to 1992, some abnormal characteristics of these patterns before... By studying the seismicity pattern before 37 earthquakes with M≥6. 0 in North China and the pattern of crustal deformation in the Capital Area from 1954 to 1992, some abnormal characteristics of these patterns before strong earthquakes have been extracted. A comparison has been made between the anomalies of these two kinds of Patterns. From the results we can know the following. ① Before a strong earthquake, the seismicity will strengthen and the crustal deformation rate will increase. ② Several years before a strong earthquake, there will be seismic gaps and deformation gaps around the epicenter of the quake. ③ The dynamic parameters of patterns all show a decrease in information dimension. This means that the crustal deformation has become more and more localized with time and it gives an important indication showing that a strong earthquake is in preparation. At the end of the paper, the physical mechanisms of the abnormal patterns of seismicity and crustal deformationhave been explained in a unified way in terms of the earthquake-generating model of a inhomogeneous strongbody in inhmogeneous media. 展开更多
关键词 seismicity pattern crustal deformation field localization of deformation pattern dynamics information dimension.
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Light-induced dynamic RGD pattern for sequential modulation of macrophage phenotypes 被引量:1
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作者 Yilun Luo Xiaowen Zheng +2 位作者 Peiqi Yuan Xingyao Ye Lie Ma 《Bioactive Materials》 SCIE 2021年第11期4065-4072,共8页
Due to the critical roles of macrophage in immune response and tissue repair,harnessing macrophage phenotypes dynamically to match the tissue healing process on demand attracted many attentions.Although there have dev... Due to the critical roles of macrophage in immune response and tissue repair,harnessing macrophage phenotypes dynamically to match the tissue healing process on demand attracted many attentions.Although there have developed many advanced platforms with dynamic features for cell manipulation,few studies have designed a dynamic chemical pattern to sequentially polarize macrophage phenotypes and meet the immune requirements at various tissue repair stages.Here,we propose a novel strategy for spatiotemporal manipulation of macrophage phenotypes by a UV-induced dynamic Arg-Gly-Asp(RGD)pattern.By employing a photo-patterning technique and the specific interaction between cyclodextrin(CD)and azobenzene-RGD(Azo-RGD),we prepared a polyethylene glycol-dithiol/polyethylene glycol-norbornene(PEG-SH/PEG-Nor)hydrogel with dynamic RGD-patterned surface.After irradiation with 365-nm UV light,the homogeneous RGD surface was transformed to the RGD-patterned surface which induced morphological transformation of macrophages from round to elongated and subsequent phenotypic transition from pro-inflammation to anti-inflammation.The mechanism of phenotypic polarization induced by RGD pattern was proved to be related to Rho-associated protein kinase 2(ROCK2).Sequential modulation of macrophage phenotypes by the dynamic RGD-patterned surface provides a remote and non-invasive strategy to manipulate immune reactions and achieve optimized healing outcomes. 展开更多
关键词 Light-responsive dynamic RGD pattern Macrophage phenotype Immune response Tissue repair
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