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Discovering the cellular-localized functional modules and modular interactions in response to liver cancer
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作者 朱晶 Guo Zheng +3 位作者 Yang Da Zhang Min Wang Jing Wang Chenguang 《High Technology Letters》 EI CAS 2008年第4期437-442,共6页
In this paper, we firstly identify the functional modules enriched with differentially expressed genes (DEGs) and characterized by biological processes in specific cellular locations, based on gene ontology (GO) a... In this paper, we firstly identify the functional modules enriched with differentially expressed genes (DEGs) and characterized by biological processes in specific cellular locations, based on gene ontology (GO) and microarray data. Then, we further define and filter disease relevant signature modules according to the ranking of the disease discriminating abilities of the pre-selected functional modules. At last, we analyze the potential way by which they cooperate towards human disease. Application of the proposed method to the analysis of a liver cancer dataset shows that, using the same false discovery rate ( FDR ) threshold, we can find more biologically meaningful and detailed processes by using the cellular localization information. Some biological evidences support the relevancy of our biological modules to the disease mechanism. 展开更多
关键词 MICROARRAY Gene Ontology functional module cellular location liver cancer
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Functional cartography of heterogeneous combat networks using operational chain-based label propagation algorithm
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作者 CHEN Kebin JIANG Xuping +2 位作者 ZENG Guangjun YANG Wenjing ZHENG Xue 《Journal of Systems Engineering and Electronics》 2025年第5期1202-1215,共14页
To extract and display the significant information of combat systems,this paper introduces the methodology of functional cartography into combat networks and proposes an integrated framework named“functional cartogra... To extract and display the significant information of combat systems,this paper introduces the methodology of functional cartography into combat networks and proposes an integrated framework named“functional cartography of heterogeneous combat networks based on the operational chain”(FCBOC).In this framework,a functional module detection algorithm named operational chain-based label propagation algorithm(OCLPA),which considers the cooperation and interactions among combat entities and can thus naturally tackle network heterogeneity,is proposed to identify the functional modules of the network.Then,the nodes and their modules are classified into different roles according to their properties.A case study shows that FCBOC can provide a simplified description of disorderly information of combat networks and enable us to identify their functional and structural network characteristics.The results provide useful information to help commanders make precise and accurate decisions regarding the protection,disintegration or optimization of combat networks.Three algorithms are also compared with OCLPA to show that FCBOC can most effectively find functional modules with practical meaning. 展开更多
关键词 functional cartography heterogeneous combat network functional module label propagation algorithm operational chain
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Identification of Risk Pathways and Functional Modules for Coronary Artery Disease Based on Genome-wide SNP Data 被引量:3
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作者 Xiang Zhao Yi-Zhao Luan +8 位作者 Xiaoyu Zuo Ye-Da Chen Jiheng Qin Lv Jin Yiqing Tan Meihua Lin Naizun Zhang Yan Liang Shao-Qi Rao 《Genomics, Proteomics & Bioinformatics》 SCIE CAS CSCD 2016年第6期349-356,共8页
Coronary artery disease (CAD) is a complex human disease, involving multiple genes and their nonlinear interactions, which often act in a modular fashion. Genome-wide single nucleotide polymorphism (SNP) profiling... Coronary artery disease (CAD) is a complex human disease, involving multiple genes and their nonlinear interactions, which often act in a modular fashion. Genome-wide single nucleotide polymorphism (SNP) profiling provides an effective technique to unravel these underlying genetic interplays or their functional involvements for CAD. This study aimed to identify the susceptible pathways and modules for CAD based on SNP omics. First, the Wellcome Trust Case Control Consortium (WTCCC) SNP datasets of CAD and control samples were used to assess the joint effect of multiple genetic variants at the pathway level, using logistic kernel machine regression model. Then, an expanded genetic network was constructed by integrating statistical gene-gene interactions involved in these susceptible pathways with their protein protein interaction (PPI) knowledge. Finally, risk functional modules were identified by decomposition of the network. Of 276 KEGG pathways analyzed, 6 pathways were found to have a significant effect on CAD. Other than glycerolipid metabolism, glycosaminoglycan biosynthesis, and cardiac muscle contraction pathways, three pathways related to other diseases were also revealed, including Alzheimer's disease, non-alcoholic fatty liver disease, and Huntington's disease. A genetic epistatic network of 95 genes was further constructed using the abovementioned integrative approach. Of 10 functional modules derived from the network, 6 have been annotated to phospholipase C activity and cell adhesion molecule binding, which also have known functional involvement in Alzheimer's disease. These findings indicate an overlap of the underlying molecular mechanisms between CAD and Alzheimer's disease, thus providing new insights into the molecular basis for CAD and its molecular relationships with other diseases. 展开更多
关键词 Coronary artery disease Genome-wide SNP profiling Risk pathway functional module Genetic network
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Functional modules with disease discrimination abilities for various cancers 被引量:3
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作者 YAO Chen ZHANG Min +4 位作者 ZOU JinFeng LI HongDong WANG Dong ZHU Jing GUO Zheng 《Science China(Life Sciences)》 SCIE CAS 2011年第2期189-193,共5页
Selecting differentially expressed genes(DEGs) is one of the most important tasks in microarray applications for studying multi-factor diseases including cancers.However,the small samples typically used in current mic... Selecting differentially expressed genes(DEGs) is one of the most important tasks in microarray applications for studying multi-factor diseases including cancers.However,the small samples typically used in current microarray studies may only partially reflect the widely altered gene expressions in complex diseases,which would introduce low reproducibility of gene lists selected by statistical methods.Here,by analyzing seven cancer datasets,we showed that,in each cancer,a wide range of functional modules have altered gene expressions and thus have high disease classification abilities.The results also showed that seven modules are shared across diverse cancers,suggesting hints about the common mechanisms of cancers.Therefore,instead of relying on a few individual genes whose selection is hardly reproducible in current microarray experiments,we may use functional modules as functional signatures to study core mechanisms of cancers and build robust diagnostic classifiers. 展开更多
关键词 differentially expressed gene functional module classification diverse cancers
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A Network Partition Algorithm for Mining Gene Functional Modules of Colon Cancer from DNA Microarray Data
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作者 Xiao-Gang Ruan Jin-Lian Wang Jian-Geng Li 《Genomics, Proteomics & Bioinformatics》 SCIE CAS CSCD 2006年第4期245-252,共8页
Computational analysis is essential for transforming the masses of microarray datainto a mechanistic understanding of cancer. Here we present a method for findinggene functional modules of cancer from microarray data ... Computational analysis is essential for transforming the masses of microarray datainto a mechanistic understanding of cancer. Here we present a method for findinggene functional modules of cancer from microarray data and have applied it tocolon cancer. First, a colon cancer gene network and a normal colon tissue genenetwork were constructed using correlations between the genes. Then the modulesthat tended to have a homogeneous functional composition were identified by split-ting up the network. Analysis of both networks revealed that they are scale-free.Comparison of the gene functional modules for colon cancer and normal tissuesshowed that the modules’ functions changed with their structures. 展开更多
关键词 DNA microarray data colon cancer gene functional module GN algorithm
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Converging assemblies:A putative building block for brain function and for interfacing with the brain
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作者 Eran Stark Lidor Spivak 《Neural Regeneration Research》 2026年第3期1124-1125,共2页
The organization of biological neuronal networks into functional modules has intrigued scientists and inspired engineers to develop artificial systems.These networks are characterized by two key properties.First,they ... The organization of biological neuronal networks into functional modules has intrigued scientists and inspired engineers to develop artificial systems.These networks are characterized by two key properties.First,they exhibit dense interconnectivity(Braitenburg and Schüz,1998;Campagnola et al.,2022).The strength and probability of connectivity depend on cell type,inter-neuronal distance,and species.Still,every cortical neuron receives input from thousands of other neurons while transmitting output to a similar number of neurons.Second,communication between neurons occurs primarily via chemical or electrical synapses. 展开更多
关键词 cortical neuron INTERCONNECTIVITY neuronal networks functional modules dense interconnectivity braitenburg artificial systemsthese converging assemblies biological neuronal networks
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Relationship between angle kappa,angle alpha and objective visual quality in patients with multifocal intraocular lens
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作者 Zhu Chaojie Long Tan +2 位作者 Ma Ting Yan Jie Wang Rui 《国际眼科杂志》 2025年第9期1399-1405,共7页
AIM:To investigate how angles kappa and alpha affect postoperative visual quality in patients with multifocal intraocular lens(mIOLs)implantation.METHODS:Retrospective cases series.A total of 46 patients(46 eyes)who u... AIM:To investigate how angles kappa and alpha affect postoperative visual quality in patients with multifocal intraocular lens(mIOLs)implantation.METHODS:Retrospective cases series.A total of 46 patients(46 eyes)who underwent phacoemulsification were subsumed.The correlation between Preoperative angles kappa and alpha,wave-front aberrations and objective visual quality of cornea,internal,and total eye after surgery were analyzed using iTrace.RESULTS:The magnitude of angle kappa was negatively correlated with internal and total modulation transfer function(MTF)at 3 mm;the magnitude of angle kappa was positively correlated with astigmatism,trefoil,higher-order aberrations(HOAs)of both internal and total eye at 3 mm.The magnitude of angle alpha was negatively correlated with total MTF and total Strehl ratio at 3 mm.The magnitude of angle alpha was positively correlated with corneal coma at 5 mm,internal astigmatism at both 3 mm and 5 mm,and total spherical aberration(SA)at 3 mm.Multivariate linear regression analysis showed that,among candidate independent variables(kappa,alpha,astigmatism,SA,coma,trefoil,and HOAs),astigmatism is the only independent factor for altering corneal MTF at 3 mm and 5 mm;astigmatism and HOAs emerged as independent factors for altering internal MTF at 3 mm and 5 mm,and total MTF at 3 mm;astigmatism,SA and HOAs emerged as independent factors for altering total MTF at 5 mm.CONCLUSION:With greater preoperative angle kappa or angle alpha,patients who accept mIOL implantation tend to have larger internal astigmatism and HOAs,which resulting in poor visual quality,especially those with small pupil size. 展开更多
关键词 angle kappa angle alpha modulation transfer function CATARACT Strehl ratio
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Design and implementation of an integrated and rapidly assembled infrared three-band optical system
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作者 Shuanglong Tan Yulin Wang +3 位作者 Guangwei Shi Shuaiwei Mu Xin Zhang Lin Ma 《Astronomical Techniques and Instruments》 2025年第2期88-99,共12页
Continuing advancement in astronomy,space exploration,and scientific detection,has increased demand for infrared multi-band detection systems.Traditional three-band optical systems,designed to simultaneously image at ... Continuing advancement in astronomy,space exploration,and scientific detection,has increased demand for infrared multi-band detection systems.Traditional three-band optical systems,designed to simultaneously image at infrared short-wave,mid-wave,and long-wave bands typically rely on dispersive elements,leading to bulky sizes,complex system architectures,low efficiency,and challenges in rapid assembly.To overcome these obstacles,in combination with the latest third-generation infrared detectors,we propose a design for a compact and lightweight three-band optical system,with infrared capabilities in all three required bands.The core of this approach is an integrated design philosophy that emphasizes the high steepness of mirror surfaces.This design achieves uniform correction and optimization of chromatic aberration and off-axis aberration across the spectral range.We introduce a novel integration of optical and mechanical elements to replace traditional assembly,reducing manufacturing and assembly errors,and degrees of freedom,associated with high-power optical elements.Confirming the effectiveness through a combination of simulations and experimental comparisons,the measured mid-wave full-field transfer function exceeds 0.405 at 17 lp/mm,satisfying the imaging requirements of the system.The optical system is lightweight and compact,with a total mass under 408 g and a compact volume of justΦ112 mm×117 mm.This serves as a valuable reference for the engineering application of high-performance,compact multi-band infrared composite detection systems for astronomy and space exploration. 展开更多
关键词 Three-band infrared INTEGRATED Rapid assembly Modulation Transfer Function(MTF)
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Unraveling the interplay of DNAzyme and interfacial factors for enhanced biosensing
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作者 Yiyang Shen Zhen Zhang +1 位作者 Ruyi Liang Tongbo Wu 《Chinese Chemical Letters》 SCIE CAS CSCD 2024年第12期249-253,共5页
Deoxyribozyme(DNAzyme)and its substrate hybridization are crucial for achieving desirable detection performance in the DNAzyme coupling nanomaterial biosensor system.However,interfacial factors such as electrostatic r... Deoxyribozyme(DNAzyme)and its substrate hybridization are crucial for achieving desirable detection performance in the DNAzyme coupling nanomaterial biosensor system.However,interfacial factors such as electrostatic repulsion,steric hindrance,and nonspecific adsorption from gold nanoparticles make this hybridization process complicated and challenging.Moreover,the DNAzyme structure changes with different application purposes,which might affect the DNAzyme and substrate's connection.Few studies have focused on the interplay of DNAzyme and interfacial factors in the biosensor field.In this work,three types of DNAzyme variants were designed,and their biosensor performance rules were studied and summarized with the synergistic effect of interfacial factors.Additionally,corresponding biosensor applications,such as multiple modulation functions and mi RNA detections,were constructed based on the distinct principles of DNAzyme variants. 展开更多
关键词 DNAZYME Gold nanoparticles Interfacial factor Multiple modulation functions miRNA detection
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Urban niche dynamics of Kaifeng city 被引量:2
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作者 Ding Shengyan1, Li Zhiheng1,2,3 1. College of Environment & Planning, Henan University, Kaifeng 475001, China 2. Xishuangbanna Tropical Botanic Garden, CAS, Kunming 650223, China 3. Graduate School of the Chinese Academy of Sciences, Beijing 100039, China 《Journal of Geographical Sciences》 SCIE CSCD 2007年第2期221-233,共13页
Niche theory is one of the most important ecological theories. It is widely applied to analyzing such phenomena as competition among, and evolution of, urban ecosystem functional modules. This paper describes a study ... Niche theory is one of the most important ecological theories. It is widely applied to analyzing such phenomena as competition among, and evolution of, urban ecosystem functional modules. This paper describes a study concerning'different functional modules of Kaifeng city urban ecosystem. Niche theory and techniques were used to analyze the changes of these functional modules in the period 1994-2003. The results showed that, in the period 1994-2003: (1) Niche value of the atmospheric environment and urban virescence modules increased, while niche value of the water environment and sound environment modules decreased; (2) niche value of the tertiary industry module increased, niche value of the secondary industry module decreased, while niche value of the primary industry module showed little change; and (3) niche value of the infrastructure, resource distribution, and production & social security modules increased, while niche value of the population module decreased. This study may contribute to macroscopic planning of urban functional modules, economic development, and environmental protection. 展开更多
关键词 NICHE PATTERN functional modules DYNAMIC Kaifeng city
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MDA-TOEPGA:A novel method to identify miRNA-disease association based on two-objective evolutionary programming genetic algorithm
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作者 BUWEN CAO JIAWEI LUO +1 位作者 SAINAN XIAO XIANGJUN ZHOU 《BIOCELL》 SCIE 2022年第8期1925-1933,共9页
The association between miRNA and disease has attracted more and more attention.Until now,existing methods for identifying miRNA related disease mainly rely on top-ranked association model,which may not provide a full... The association between miRNA and disease has attracted more and more attention.Until now,existing methods for identifying miRNA related disease mainly rely on top-ranked association model,which may not provide a full landscape of association between miRNA and disease.Hence there is strong need of new computational method to identify the associations from miRNA group view.In this paper,we proposed a framework,MDA-TOEPGA,to identify miRNAdisease association based on two-objective evolutionary programming genetic algorithm,which identifies latent miRNAdisease associations from the view of functional module.To understand the miRNA functional module in diseases,the case study is presented.We have been compared MDA-TOEPGA with several state-of-the-art functional module algorithm.Experimental results showed that our method cannot only outperform classical algorithms,such as K-means,IK-means,MCODE,HC-PIN,and ClusterONE,but can also achieve an ideal overall performance in terms of a composite score consisting of f1,Sensitivity,and Accuracy.Altogether,our study showed that MDA-TOEPGA is a promising method to investigate miRNA-disease association from the landscapes of functional module. 展开更多
关键词 MiRNA functional module MiRNA-disease association Two-objective Evolutionary programming genetic algorithm
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Animal Hospital Management System Design Based on C/S/S Structure
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作者 HUANG Jing ZHAO Jie WEI Xiaoli 《Journal of Northeast Agricultural University(English Edition)》 CAS 2008年第1期79-82,共4页
By analysis of the functions of animal hospital's departments, combining with management information development truth, the paper developed animal hospital management system. The system included six modules, like sys... By analysis of the functions of animal hospital's departments, combining with management information development truth, the paper developed animal hospital management system. The system included six modules, like system management module basic information management module, sections management module, and so on. The paper used Visual C++6.0 and SQL Server 2000, and ODBC database accessing technology, which can encapsulate any database table and operation into class. The system could make any window to share table's operation to realize hospital management quickly and efficiency. 展开更多
关键词 management system Visual C++6.0 functional modules interface design
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Two-way Video Synthesis Hardware System Based on DM642
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作者 云骞 胡德计 《电脑知识与技术》 2012年第2X期1400-1401,共2页
DM642 is a DSP chip specially used for video processing that offered by TI company,it adds a lot of peripheral devices and inter faces based on C6000 series of chips,with the high speed computing ability,it has a wide... DM642 is a DSP chip specially used for video processing that offered by TI company,it adds a lot of peripheral devices and inter faces based on C6000 series of chips,with the high speed computing ability,it has a wide range of applications in multimedia field.This pa per analyzes and describes the works and the main functional modules of two-way video synthesis hardware system based on DM642. 展开更多
关键词 DM642 video synthesis functional modules
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Identification of linear continuous-time system using wavelet modulating filters 被引量:4
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作者 贺尚红 钟掘 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2004年第3期270-277,共8页
An approach to identification of linear continuous-time system is studied with modulating functions. Based on wavelet analysis theory, the multi-resolution modulating functions are designed, and the corresponding filt... An approach to identification of linear continuous-time system is studied with modulating functions. Based on wavelet analysis theory, the multi-resolution modulating functions are designed, and the corresponding filters have been analyzed. Using linear modulating filters, we can obtain an identification model that is parameterized directly in continuous-time model parameters. By applying the results from discrete-time model identification to the obtained identification model, a continuous-time estimation method is developed. Considering the accuracy of parameter estimates, an instrumental variable (Ⅳ) method is proposed, and the design of modulating integral filter is discussed. The relationship between the accuracy of identification and the parameter of modulating filter is investigated, and some points about designing Gaussian wavelet modulating function are outlined. Finally, a simulation study is also included to verify the theoretical results. 展开更多
关键词 parameter estimation modulation function continuous-time system WAVELET Gaussian function.
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Analysis of the optical quality by determining the modulation transfer function for anterior corneal surface in myopes 被引量:6
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作者 Yan-Zhen Zheng, Yao-Yu Li 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2012年第2期196-201,共6页
AIM: To describe the characteristics of modulation transfer function (MTF) of anterior corneal surface, and obtain the the normal reference range of MTF at different spatial frequencies and optical zones of the anteri... AIM: To describe the characteristics of modulation transfer function (MTF) of anterior corneal surface, and obtain the the normal reference range of MTF at different spatial frequencies and optical zones of the anterior corneal surface in myopes. METHODS: Four hundred eyes from 200 patients were examined under SIRIUS corneal topography system. Phoenis analysis software was applied to simulate the MTF curves of anterior corneal surface at vertical and horizontal meridians at the 3, 4, 5, 6, 7mm optical zones of cornea. The MTF values at spatial frequencies of 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55 and 60 cycles/degree (c/d) were selected. RESULTS: The MTF curve of anterior corneal surface decreased rapidly from low to intermediate frequency (0-15cpd) at various optical zones of cornea, the value decreased to 0 slowly at higher frequency (>15cpd). With the increase of the optical zones of cornea, MTF curve decreased gradually. 3) In the range of 3 mm- 6 mm optical zones of the cornea, the MTF values measured at horizontal meridian were greater than the corresponding values at horizontal meridian of each spatial frequency, the difference was statistically significant (P<0.05). At 7 mm optical zones of cornea, the MTF values measured at horizontal meridian were less than the corresponding values at vertical meridian at 10-60 spatial frequencies (cpd), and the difference was statistically significant in 25, 30, 35, 40, 45, 50 cpd(P<0.05). CONCLUSION: MTF can be used to describe the imaging quality of optical systems at anterior corneal surface objectively in detail. 展开更多
关键词 modulation transfer function optical quality CORNEA point spread function optical transfer function phase transfer function
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Modulation transfer function characteristic of uniform-doping transmission-mode GaAs/GaAlAs photocathode 被引量:2
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作者 任玲 常本康 《Chinese Physics B》 SCIE EI CAS CSCD 2011年第8期398-402,共5页
The resolution characteristic can be obtained by the modulation transfer function (MTF) of a GaAs/GaA1As photocathode. After establishing the theoretical model of GaAs(100)-oriented atomic configuration and the fo... The resolution characteristic can be obtained by the modulation transfer function (MTF) of a GaAs/GaA1As photocathode. After establishing the theoretical model of GaAs(100)-oriented atomic configuration and the formula for the ionized impurity scattering of the non-equilibrium carriers, this paper calculates the trajectories of photoelectrons in a photocathode. Thus the distribution of photoelectron spots on the emit-face is obtained, which is namely the point spread function. The MTF is obtained by Fourier transfer of the line spread function obtained from the point spread function. The MTF obtained from these calculations is shown to depend heavily on the electron diffusion length, and enhanced considerably by decreasing the electron diffusion length and increasing the doping concentration. Furthermore, the resolution is enhanced considerably by increasing the active-layer thickness, especially at high spatial frequencies. The best spatial resolution is 860 lp/mm, for the GaAs photocathode of doping concentration 1 ×10^19 cm 3 electron diffusion length 3.6 μm and the active-layer thickness 2 μm, under the 633-nm light irradiated. This research will contribute to the future improvement of the cathode's resolution for preparing a high performance GaAs photocathode, and improve the resolution of a low light level image intensifier. 展开更多
关键词 GaAs/GaAlAs photocathode uniform-doping modulation transfer function spatial res-olution
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Temporal Characteristics of GaAs NEA and Alkali Metal Photocathodes 被引量:2
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作者 李相民 周立伟 《Journal of Beijing Institute of Technology》 EI CAS 2003年第4期381-384,共4页
The temporal characteristics of GaAs NEA and alkali metal photocathodes are studied using Monte Carlo simulation method. The electron transit time and its distribution functions in the photocathodes are calculated. Ba... The temporal characteristics of GaAs NEA and alkali metal photocathodes are studied using Monte Carlo simulation method. The electron transit time and its distribution functions in the photocathodes are calculated. Based on the results, the time modulation transfer functions and temporal resolutions of the photocathodes are obtained. The results show that the response time and temporal resolution of alkali metal photocathode is in femitosecond order and those of GaAs NEA photocathode are in picosecond order. 展开更多
关键词 GaAs photocathode alkali metal photocathode Monte Carlo simulation time modulation transfer function
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A new modulation transfer function for ocean wave spectra retrieval from X-band marine radar imagery 被引量:1
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作者 陈忠彪 张彪 +2 位作者 何宜军 丘仲锋 PERRIE William 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2015年第5期1132-1141,共10页
When imaging ocean surface waves by X-band marine radar, the radar backscatter from the sea surface is modulated by the long surface gravity waves. The modulation transfer function (MTF) comprises tilt, hydrodynamic... When imaging ocean surface waves by X-band marine radar, the radar backscatter from the sea surface is modulated by the long surface gravity waves. The modulation transfer function (MTF) comprises tilt, hydrodynamic, and shadowing modulations. A conventional linear MTF was derived using HH-polarized radar observations under conditions of deep water. In this study, we propose a new quadratic polynomial MTF based on W-polarized radar measurements taken from heterogeneous nearshore wave fields. This new MTF is obtained using a radar-observed image spectrum and in situ buoy-measured wave frequency spectrum. We validate the MTF by comparing peak and mean wave periods retrieved from X-band marine radar image sequences with those measured by the buoy. It is shown that the retrieval accuracies of peak and mean wave periods of the new MTF are better than the conventional MTF. The results also show that the bias and root mean square errors of the peak and mean wave periods of the new MTF are 0.05 and 0.88 s, and 0.32 and 0.53 s, respectively, while those of the conventional MTF are 0.61 and 0.98 s, and 1.39 and 1.48 s, respectively. Moreover, it is also shown that the retrieval results are insensitive to the coefficients in the proposed MTF. 展开更多
关键词 X-band marine radar modulation transfer function ocean wave spectra
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An Improved Coupling of Numerical and Physical Models for Simulating Wave Propagation 被引量:1
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作者 阳志文 柳淑学 李金宣 《China Ocean Engineering》 SCIE EI CSCD 2014年第1期1-16,共16页
An improved coupling of numerical and physical models for simulating 2D wave propagation is developed in this paper. In the proposed model, an unstructured finite element model (FEM) based Boussinesq equations is ap... An improved coupling of numerical and physical models for simulating 2D wave propagation is developed in this paper. In the proposed model, an unstructured finite element model (FEM) based Boussinesq equations is applied for the numerical wave simulation, and a 2D piston-type wavemaker is used for the physical wave generation. An innovative scheme combining fourth-order Lagrange interpolation and Runge-Kutta scheme is described for solving the coupling equation. A Transfer function modulation method is presented to minimize the errors induced from the hydrodynamic invalidity of the coupling model and/or the mechanical capability of the wavemaker in area where nonlinearities or dispersion predominate. The overall performance and applicability of the coupling model has been experimentally validated by accounting for both regular and irregular waves and varying bathymetry. Experimental results show that the proposed numerical scheme and transfer function modulation method are efficient for the data transfer from the numerical model to the physical model up to a deterministic level. 展开更多
关键词 coupling numerical model physical model wave propagation transfer function modulation
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Characterization of a Multimodal and Multispectral Led Imager: Application to Organic Polymer’s Microspheres with Diameter Φ = 10.2 μm 被引量:2
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作者 Marcel A. Agnero Jérémie T. Zoueu Kouakou Konan 《Optics and Photonics Journal》 2016年第7期171-183,共14页
Multispectral microscopy enables information enhancement in the study of specimens because of the large spectral band used in this technique. A low cost multimode multispectral microscope using a camera and a set of q... Multispectral microscopy enables information enhancement in the study of specimens because of the large spectral band used in this technique. A low cost multimode multispectral microscope using a camera and a set of quasi-monochromatic Light Emitting Diodes (LEDs) ranging from ultraviolet to near-infrared wavelengths as illumination sources was constructed. But the use of a large spectral band provided by non-monochromatic sources induces variation of focal plan of the imager due to chromatic aberration which rises up the diffraction effects and blurs the images causing shadow around them. It results in discrepancies between standard spectra and extracted spectra with microscope. So we need to calibrate that instrument to be a standard one. We proceed with two types of images comparison to choose the reference wavelength for image acquisition where diffraction effect is more reduced. At each wavelength chosen as a reference, one image is well contrasted. First, we compare the thirteen well contrasted images to identify that presenting more reduced shadow. In second time, we determine the mean of the shadow size over the images from each set. The correction of the discrepancies required measurements on filters using a standard spectrometer and the microscope in transmission mode and reflection mode. To evaluate the capacity of our device to transmit information in frequency domain, its modulation transfer function is evaluated. Multivariate analysis is used to test its capacity to recognize properties of well-known sample. The wavelength 700 nm was chosen to be the reference for the image acquisition, because at this wavelength the images are well contrasted. The measurement made on the filters suggested correction coefficients in transmission mode and reflection mode. The experimental instrument recognized the microsphere’s properties and led to the extraction of the standard transmittance and reflectance spectra. Therefore, this microscope is used as a conventional instrument. 展开更多
关键词 Multispectral Imaging Reference Wavelength Correction Coefficients Modulation Transfer Function
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