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基于CNN-BiLSTM及ResNet网络的板中损伤TFM定位与检测研究
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作者 颜劲夫 何其骏 +1 位作者 瞿业峰 李义丰 《南京大学学报(自然科学版)》 CAS CSCD 北大核心 2024年第4期566-576,共11页
针对全聚焦(Total Focusing Method,TFM)成像技术因其耗时长,在工业应用中受限的问题,提出一种基于CNN-BiLSTM(Convolutional Neural Network-Bi-directional Long Short-Term Memory)网络的快速TFM成像方法,首先利用卷积神经网络从全... 针对全聚焦(Total Focusing Method,TFM)成像技术因其耗时长,在工业应用中受限的问题,提出一种基于CNN-BiLSTM(Convolutional Neural Network-Bi-directional Long Short-Term Memory)网络的快速TFM成像方法,首先利用卷积神经网络从全矩阵数据中提取关键特征,接着结合双向长短期记忆网络来预测金属板上损伤的区域位置,再使用TFM技术在损伤区域进行精确成像.为了进一步提升损伤检测的准确性,引入基于ResNet网络的损伤尺寸检测方法以实现对损伤大小的精确检测.为了验证方法的有效性,利用有限元分析软件ABAQUS建立三维铝板仿真模型,并通过模型变换构建神经网络数据集.实验结果表明,与传统全聚焦成像方法相比,CNN-BiLSTM网络展现出较高的区域定位精度,定位准确率达到95.26%,并具有显著的效率优势,平均定位速度提升了46.4%;同时,损伤尺寸大小的检测结果验证了基于ResNet网络的方法在损伤尺寸评估方面的有效性和准确性,在测试集上达到了99.26%的准确率. 展开更多
关键词 LAMB波 tfm 损伤检测 CNN-BiLSTM ResNet
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基于深度学习的兰姆波SCF-TFM超分辨率成像
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作者 孙刘家 韩庆邦 +1 位作者 靳琪琳 葛考 《仪器仪表学报》 EI CAS CSCD 北大核心 2024年第6期101-110,共10页
腐蚀和裂纹是结构板常见的缺陷形式,兰姆波在非贯穿型损伤处发生模式转换是制约兰姆波成像质量的主要因素。此外,声波衍射遵循瑞利准则,超声成像存在分辨率极限。本文设计了一个全卷积神经网络对接收信号进行分割与重构,实现目标模态的... 腐蚀和裂纹是结构板常见的缺陷形式,兰姆波在非贯穿型损伤处发生模式转换是制约兰姆波成像质量的主要因素。此外,声波衍射遵循瑞利准则,超声成像存在分辨率极限。本文设计了一个全卷积神经网络对接收信号进行分割与重构,实现目标模态的自动拾取,抹除杂波和模式转换的干扰。提出符号相干因子全聚焦成像法(SCF-TFM),在全矩阵聚焦成像过程中施加符号相干因子,抑制非目标区域散射波对成像结果的干扰,同时考虑散射信号的幅值及相位信息,可以一定程度上突破瑞利准则的限制,实现超分辨率成像。实验结果表明:对于单个盲孔缺陷,该方法成像结果的横向分辨率比全聚焦提高62.41%,信噪比提升58.23%;而对于多个非对称盲孔缺陷,当缺陷间距大于瑞利准则分辨率极限时,该方法的信噪比提高了92.89%;缺陷间距小于瑞利准则分辨率极限时,该方法可以实现超分辨率成像。 展开更多
关键词 兰姆波 非对称盲孔缺陷 全卷积神经网络 SCF-tfm 超分辨率成像
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特高压换流阀TFM板卡降温研究与工程实践
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作者 李凤祁 张娟 +4 位作者 佘振球 娄彦涛 马元社 崔斌 陈二松 《高压电器》 CAS CSCD 北大核心 2024年第8期245-251,共7页
特高压换流阀用TFM板内置直流均压电阻,工作温度高,具有明显的安全应用隐患。文中在理论分析基础上,通过仿真和试验,提出了可兼容原板卡设计和接口的电阻降温改进方案。基于热应力、振动、局放以及板卡功能等试验,进一步验证了所提出方... 特高压换流阀用TFM板内置直流均压电阻,工作温度高,具有明显的安全应用隐患。文中在理论分析基础上,通过仿真和试验,提出了可兼容原板卡设计和接口的电阻降温改进方案。基于热应力、振动、局放以及板卡功能等试验,进一步验证了所提出方案的可行性和可靠性。改进方案的工程应用及其现场测温结果表明,所提出方案可在兼容原有TFM板卡设计和接口的同时,显著降低电阻工作温度。 展开更多
关键词 换流阀 tfm 直流均压电阻 降温
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Sparse Reconstructive Evidential Clustering for Multi-View Data
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作者 Chaoyu Gong Yang You 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2024年第2期459-473,共15页
Although many multi-view clustering(MVC) algorithms with acceptable performances have been presented, to the best of our knowledge, nearly all of them need to be fed with the correct number of clusters. In addition, t... Although many multi-view clustering(MVC) algorithms with acceptable performances have been presented, to the best of our knowledge, nearly all of them need to be fed with the correct number of clusters. In addition, these existing algorithms create only the hard and fuzzy partitions for multi-view objects,which are often located in highly-overlapping areas of multi-view feature space. The adoption of hard and fuzzy partition ignores the ambiguity and uncertainty in the assignment of objects, likely leading to performance degradation. To address these issues, we propose a novel sparse reconstructive multi-view evidential clustering algorithm(SRMVEC). Based on a sparse reconstructive procedure, SRMVEC learns a shared affinity matrix across views, and maps multi-view objects to a 2-dimensional humanreadable chart by calculating 2 newly defined mathematical metrics for each object. From this chart, users can detect the number of clusters and select several objects existing in the dataset as cluster centers. Then, SRMVEC derives a credal partition under the framework of evidence theory, improving the fault tolerance of clustering. Ablation studies show the benefits of adopting the sparse reconstructive procedure and evidence theory. Besides,SRMVEC delivers effectiveness on benchmark datasets by outperforming some state-of-the-art methods. 展开更多
关键词 Evidence theory multi-view clustering(MVC) optimization sparse reconstruction
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Contrastive Consistency and Attentive Complementarity for Deep Multi-View Subspace Clustering
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作者 Jiao Wang Bin Wu Hongying Zhang 《Computers, Materials & Continua》 SCIE EI 2024年第4期143-160,共18页
Deep multi-view subspace clustering (DMVSC) based on self-expression has attracted increasing attention dueto its outstanding performance and nonlinear application. However, most existing methods neglect that viewpriv... Deep multi-view subspace clustering (DMVSC) based on self-expression has attracted increasing attention dueto its outstanding performance and nonlinear application. However, most existing methods neglect that viewprivatemeaningless information or noise may interfere with the learning of self-expression, which may lead to thedegeneration of clustering performance. In this paper, we propose a novel framework of Contrastive Consistencyand Attentive Complementarity (CCAC) for DMVsSC. CCAC aligns all the self-expressions of multiple viewsand fuses them based on their discrimination, so that it can effectively explore consistent and complementaryinformation for achieving precise clustering. Specifically, the view-specific self-expression is learned by a selfexpressionlayer embedded into the auto-encoder network for each view. To guarantee consistency across views andreduce the effect of view-private information or noise, we align all the view-specific self-expressions by contrastivelearning. The aligned self-expressions are assigned adaptive weights by channel attention mechanism according totheir discrimination. Then they are fused by convolution kernel to obtain consensus self-expression withmaximumcomplementarity ofmultiple views. Extensive experimental results on four benchmark datasets and one large-scaledataset of the CCAC method outperformother state-of-the-artmethods, demonstrating its clustering effectiveness. 展开更多
关键词 Deep multi-view subspace clustering contrastive learning adaptive fusion self-expression learning
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Low-Rank Multi-View Subspace Clustering Based on Sparse Regularization
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作者 Yan Sun Fanlong Zhang 《Journal of Computer and Communications》 2024年第4期14-30,共17页
Multi-view Subspace Clustering (MVSC) emerges as an advanced clustering method, designed to integrate diverse views to uncover a common subspace, enhancing the accuracy and robustness of clustering results. The signif... Multi-view Subspace Clustering (MVSC) emerges as an advanced clustering method, designed to integrate diverse views to uncover a common subspace, enhancing the accuracy and robustness of clustering results. The significance of low-rank prior in MVSC is emphasized, highlighting its role in capturing the global data structure across views for improved performance. However, it faces challenges with outlier sensitivity due to its reliance on the Frobenius norm for error measurement. Addressing this, our paper proposes a Low-Rank Multi-view Subspace Clustering Based on Sparse Regularization (LMVSC- Sparse) approach. Sparse regularization helps in selecting the most relevant features or views for clustering while ignoring irrelevant or noisy ones. This leads to a more efficient and effective representation of the data, improving the clustering accuracy and robustness, especially in the presence of outliers or noisy data. By incorporating sparse regularization, LMVSC-Sparse can effectively handle outlier sensitivity, which is a common challenge in traditional MVSC methods relying solely on low-rank priors. Then Alternating Direction Method of Multipliers (ADMM) algorithm is employed to solve the proposed optimization problems. Our comprehensive experiments demonstrate the efficiency and effectiveness of LMVSC-Sparse, offering a robust alternative to traditional MVSC methods. 展开更多
关键词 CLUSTERING multi-view Subspace Clustering Low-Rank Prior Sparse Regularization
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Multi-View & Transfer Learning for Epilepsy Recognition Based on EEG Signals
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作者 Jiali Wang Bing Li +7 位作者 Chengyu Qiu Xinyun Zhang Yuting Cheng Peihua Wang Ta Zhou Hong Ge Yuanpeng Zhang Jing Cai 《Computers, Materials & Continua》 SCIE EI 2023年第6期4843-4866,共24页
Epilepsy is a central nervous system disorder in which brain activity becomes abnormal.Electroencephalogram(EEG)signals,as recordings of brain activity,have been widely used for epilepsy recognition.To study epilep-ti... Epilepsy is a central nervous system disorder in which brain activity becomes abnormal.Electroencephalogram(EEG)signals,as recordings of brain activity,have been widely used for epilepsy recognition.To study epilep-tic EEG signals and develop artificial intelligence(AI)-assist recognition,a multi-view transfer learning(MVTL-LSR)algorithm based on least squares regression is proposed in this study.Compared with most existing multi-view transfer learning algorithms,MVTL-LSR has two merits:(1)Since traditional transfer learning algorithms leverage knowledge from different sources,which poses a significant risk to data privacy.Therefore,we develop a knowledge transfer mechanism that can protect the security of source domain data while guaranteeing performance.(2)When utilizing multi-view data,we embed view weighting and manifold regularization into the transfer framework to measure the views’strengths and weaknesses and improve generalization ability.In the experimental studies,12 different simulated multi-view&transfer scenarios are constructed from epileptic EEG signals licensed and provided by the Uni-versity of Bonn,Germany.Extensive experimental results show that MVTL-LSR outperforms baselines.The source code will be available on https://github.com/didid5/MVTL-LSR. 展开更多
关键词 multi-view learning transfer learning least squares regression EPILEPSY EEG signals
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ER-Net:Efficient Recalibration Network for Multi-ViewMulti-Person 3D Pose Estimation
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作者 Mi Zhou Rui Liu +1 位作者 Pengfei Yi Dongsheng Zhou 《Computer Modeling in Engineering & Sciences》 SCIE EI 2023年第8期2093-2109,共17页
Multi-view multi-person 3D human pose estimation is a hot topic in the field of human pose estimation due to its wide range of application scenarios.With the introduction of end-to-end direct regression methods,the fi... Multi-view multi-person 3D human pose estimation is a hot topic in the field of human pose estimation due to its wide range of application scenarios.With the introduction of end-to-end direct regression methods,the field has entered a new stage of development.However,the regression results of joints that are more heavily influenced by external factors are not accurate enough even for the optimal method.In this paper,we propose an effective feature recalibration module based on the channel attention mechanism and a relative optimal calibration strategy,which is applied to themulti-viewmulti-person 3D human pose estimation task to achieve improved detection accuracy for joints that are more severely affected by external factors.Specifically,it achieves relative optimal weight adjustment of joint feature information through the recalibration module and strategy,which enables the model to learn the dependencies between joints and the dependencies between people and their corresponding joints.We call this method as the Efficient Recalibration Network(ER-Net).Finally,experiments were conducted on two benchmark datasets for this task,Campus and Shelf,in which the PCP reached 97.3% and 98.3%,respectively. 展开更多
关键词 multi-view multi-person pose estimation attention mechanism computer vision
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Relational graph location network for multi-view image localization
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作者 YANG Yukun LIU Xiangdong 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2023年第2期460-468,共9页
In multi-view image localization task,the features of the images captured from different views should be fused properly.This paper considers the classification-based image localization problem.We propose the relationa... In multi-view image localization task,the features of the images captured from different views should be fused properly.This paper considers the classification-based image localization problem.We propose the relational graph location network(RGLN)to perform this task.In this network,we propose a heterogeneous graph construction approach for graph classification tasks,which aims to describe the location in a more appropriate way,thereby improving the expression ability of the location representation module.Experiments show that the expression ability of the proposed graph construction approach outperforms the compared methods by a large margin.In addition,the proposed localization method outperforms the compared localization methods by around 1.7%in terms of meter-level accuracy. 展开更多
关键词 multi-view image localization graph construction heterogeneous graph graph neural network
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Diverse Deep Matrix Factorization With Hypergraph Regularization for Multi-View Data Representation
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作者 Haonan Huang Guoxu Zhou +2 位作者 Naiyao Liang Qibin Zhao Shengli Xie 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2023年第11期2154-2167,共14页
Deep matrix factorization(DMF)has been demonstrated to be a powerful tool to take in the complex hierarchical information of multi-view data(MDR).However,existing multiview DMF methods mainly explore the consistency o... Deep matrix factorization(DMF)has been demonstrated to be a powerful tool to take in the complex hierarchical information of multi-view data(MDR).However,existing multiview DMF methods mainly explore the consistency of multi-view data,while neglecting the diversity among different views as well as the high-order relationships of data,resulting in the loss of valuable complementary information.In this paper,we design a hypergraph regularized diverse deep matrix factorization(HDDMF)model for multi-view data representation,to jointly utilize multi-view diversity and a high-order manifold in a multilayer factorization framework.A novel diversity enhancement term is designed to exploit the structural complementarity between different views of data.Hypergraph regularization is utilized to preserve the high-order geometry structure of data in each view.An efficient iterative optimization algorithm is developed to solve the proposed model with theoretical convergence analysis.Experimental results on five real-world data sets demonstrate that the proposed method significantly outperforms stateof-the-art multi-view learning approaches. 展开更多
关键词 Deep matrix factorization(DMF) diversity hypergraph regularization multi-view data representation(MDR)
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特高压直流输电换流阀TFM板误触发原因分析及解决方案
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作者 张娟 崔斌 王潇 《电工技术》 2023年第7期207-209,共3页
TFM板是直流输电换流阀组件的核心元器件,用于触发晶闸管并实时监测晶闸管的状态,对晶闸管进行保护。近年来曾发生过手动紧急闭锁换流阀后,再次对其进行充电时晶闸管误触发导通的事故。对该事故进行分析研究,通过试验、仿真、故障复现... TFM板是直流输电换流阀组件的核心元器件,用于触发晶闸管并实时监测晶闸管的状态,对晶闸管进行保护。近年来曾发生过手动紧急闭锁换流阀后,再次对其进行充电时晶闸管误触发导通的事故。对该事故进行分析研究,通过试验、仿真、故障复现等方式找到误触发导通的原因,提出合理的优化解决方案并应用于进行工程,有效避免了类似事故的发生,提高了换流阀的可靠性。 展开更多
关键词 换流阀 tfm 误触发 直流过流保护
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管道超声相控阵全聚焦成像仿真及算法优化
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作者 张鑫宇 范惜梅 +2 位作者 李忠虎 李靖 王金明 《电子测量技术》 北大核心 2024年第6期151-156,共6页
针对厚壁管道内部缺陷识别困难、可视化差等问题,提出基于超声相控阵理论和全聚焦算法对厚壁管道内部缺陷进行图像重构。并针对全聚焦成像效率低的缺点,采用有限元法对外径为550 mm,壁厚为65 mm的厚壁管道超声相控阵全聚焦成像进行仿真... 针对厚壁管道内部缺陷识别困难、可视化差等问题,提出基于超声相控阵理论和全聚焦算法对厚壁管道内部缺陷进行图像重构。并针对全聚焦成像效率低的缺点,采用有限元法对外径为550 mm,壁厚为65 mm的厚壁管道超声相控阵全聚焦成像进行仿真,模拟缺陷检测过程和成像结果,并使用稀疏矩阵对算法进行优化。结果表明:在基本满足成像质量要求的情况下,采用激发中心频率为5 MHz,阵元宽度为0.5 mm,阵元间距为1 mm,阵元数量为32时,稀疏激发矩阵比全矩阵全聚焦成像效率提高了74.81%,有效提高了成像速度,满足全聚焦快速成像的需求。 展开更多
关键词 厚壁管道 超声相控阵 全聚焦方法 全矩阵 稀疏矩阵
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汽车4S店TFM客户细分模型及其方法研究 被引量:6
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作者 谢鹏寿 张宽 +2 位作者 范宏进 贵向泉 张恩展 《小型微型计算机系统》 CSCD 北大核心 2019年第10期2165-2169,共5页
针对汽车4S店客户消费模式不同于其他行业,而传统RFM模型难以适用于汽车4S店客户细分的问题,课题组对传统RFM模型的数据分析指标进行优化改进,形成可适用于汽车4S店的TFM客户细分模型.该模型可依据客户的行为属性通过K均值聚类算法进行... 针对汽车4S店客户消费模式不同于其他行业,而传统RFM模型难以适用于汽车4S店客户细分的问题,课题组对传统RFM模型的数据分析指标进行优化改进,形成可适用于汽车4S店的TFM客户细分模型.该模型可依据客户的行为属性通过K均值聚类算法进行客户细分,最后随机抽取某汽车4S店客户数据进行实验验证.实验结果表明,改进的TFM模型能够有效细分客户,为汽车4S店针对不同价值的客户制定相应的个性化服务以及营销策略提供了良好的参考依据. 展开更多
关键词 tfm模型 汽车4S店 客户细分 K均值算法 聚类分析
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时频调制的MIMO-CE-OFDM-LFM雷达通信一体化信号设计
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作者 马启成 卢建斌 +1 位作者 耿春波 史慧成 《无线电通信技术》 北大核心 2024年第4期720-729,共10页
实际环境中的信道多为参数随时间变化的随参信道。为了更好地适应随参信道环境,设计了4个频率和4个时隙的基于时频调制(Time Frequency Modulation, TFM)的线性调频(Linear Frequency Modulation, LFM)雷达通信一体化(Dual-Functional R... 实际环境中的信道多为参数随时间变化的随参信道。为了更好地适应随参信道环境,设计了4个频率和4个时隙的基于时频调制(Time Frequency Modulation, TFM)的线性调频(Linear Frequency Modulation, LFM)雷达通信一体化(Dual-Functional Radar and Communication, DFRC)脉冲信号。为了进一步增强其抗多径衰落的能力,在其基础上引入正交频分复用(Orthogonal Frequency Division Multiplexing, OFDM)技术来生成基于TFM的OFDM-LFM DFRC脉冲信号。为了实现恒模传输一体化脉冲信号,在其基础上引入恒包络(Constant Envelope, CE)技术来生成基于TFM的CE-OFDM-LFM DFRC脉冲信号。为了突破香农信道容量的上限和增大信号的发射能量,在其基础上引入多输入多输出(Multiple-Input Multiple-Output, MIMO)技术来生成基于TFM的MIMO-CE-OFDM-LFM DFRC脉冲信号。通信误比特率(Bit Error Rate, BER)仿真结果表明,设计的4个信号在通信传输时均具有优良的BER性能。雷达模糊度函数(Radar Ambiguity Function, RAF)仿真结果表明,设计的4个信号在雷达探测中均具备优良的距离和速度分辨率。 展开更多
关键词 误比特率 模糊函数 恒包络 多输入多输出 正交频分复用 时频调制
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半定量PCR比较正常小鼠和Tfm小鼠Leydig细胞17α-羟化酶mRNA的水平
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作者 沙家豪 周作民 +1 位作者 王黎熔 林敏 《生殖与避孕》 CAS CSCD 北大核心 1996年第4期300-304,共5页
本研究运用反转录合成cDNA和半定量PCR的方法,测定了正常小鼠和Tfm小鼠Leydig细胞中17α-羟化酶mRNA/β-肌动蛋白mRNA的比值,以比较二者睾丸Leydig细胞中17α-羟化酶mRNA的水平。结果显示... 本研究运用反转录合成cDNA和半定量PCR的方法,测定了正常小鼠和Tfm小鼠Leydig细胞中17α-羟化酶mRNA/β-肌动蛋白mRNA的比值,以比较二者睾丸Leydig细胞中17α-羟化酶mRNA的水平。结果显示:1.正常小鼠Leydig细胞的17α-羟化酶和β-肌动蛋白cDNA的PCR扩增指数期均在28个循环时完成,Tfm小鼠的β-肌动蛋白cD-NA的PCR扩增指数期在28个循环完成,而17α-羟化酶cDNA的PCR扩增指数期直至32个循环仍没完成;2.在指数期时,正常小鼠Legdig细胞中17α-羟化酶cDNA/β-肌动蛋白cDNA为4.28±0.88,Tfm小鼠为0.079±0.04;正常小鼠17α-羟化酶mRNA的水平高于Tfm小鼠54.18倍。结果进一步证实Tfm小鼠Leydig细胞17α-羟化酶mRNA水平低下是导致该酶活性降低的根本原因。 展开更多
关键词 tfm小鼠 LEYDIG细胞 羟化酶 MRNA 聚合酶链反应
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TFM调制的原理及DSP实现
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作者 刘凯 高勇 《现代电子技术》 2007年第23期64-66,共3页
TFM具有很高的频谱利用率,然而相关的文章却很少。针对这种情况,详细介绍了TFM调制的原理,指出其应用的部分响应类型,并给出了实用的表达式和流程图。由于TFM预滤波器的时域表达式很难从数学上推导出来,提出了一种在Matlab中对其频域响... TFM具有很高的频谱利用率,然而相关的文章却很少。针对这种情况,详细介绍了TFM调制的原理,指出其应用的部分响应类型,并给出了实用的表达式和流程图。由于TFM预滤波器的时域表达式很难从数学上推导出来,提出了一种在Matlab中对其频域响应进行IFFT变换的方法。在DSP中实现预滤波时,使用了查表法代替卷积法,降低了运算量。 展开更多
关键词 tfm 部分响应技术 预滤波器 DSP 查表法
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HMDSO和TFM混合气体等离子体聚合膜的结构与性能
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作者 林晓 陈捷 徐纪平 《辐射研究与辐射工艺学报》 CAS CSCD 北大核心 1990年第4期231-234,共4页
在钟罩式内极反应器中进行了六甲基二硅氧烷(HMDSO)和四氟化碳(TFM)混合气体等离子体聚合。用IR、XPS、X射线对聚合膜结构进行了表征。等离子体共聚合膜中含有Si和F,聚合膜中元素组成依赖于起始混合气体单体的比,Si/C元素比随着混合气体... 在钟罩式内极反应器中进行了六甲基二硅氧烷(HMDSO)和四氟化碳(TFM)混合气体等离子体聚合。用IR、XPS、X射线对聚合膜结构进行了表征。等离子体共聚合膜中含有Si和F,聚合膜中元素组成依赖于起始混合气体单体的比,Si/C元素比随着混合气体中TFM浓度增加而减小,而F/C比增大。测定了复合膜的气体透过性,等离子体共聚合方法是制备气体分离膜的可行方法。同时,还测定了等离子体聚合膜的接触角,并计算了表面能。 展开更多
关键词 HMDSO tfm 等离子体 聚合膜 XPS
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TFM——一种新的财务管理理念 被引量:1
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作者 吴尚宗 文金丽 《市场周刊(财经论坛)》 2004年第3期62-63,共2页
TFM意即“全面财务管理”。财务管理不只是财会人员的事,要“全员参与”、“全过程管理”,因为它是一项价值管理、综合管理,也是工人阶级当家作主的体现。TFM的主要内容:产品开发、材料采购、生产及销售过程、筹资与投资财务管理等。TF... TFM意即“全面财务管理”。财务管理不只是财会人员的事,要“全员参与”、“全过程管理”,因为它是一项价值管理、综合管理,也是工人阶级当家作主的体现。TFM的主要内容:产品开发、材料采购、生产及销售过程、筹资与投资财务管理等。TFM的主要方法:全面预算、责任中心管理、TFM小组等。 展开更多
关键词 tfm 全面财务管理 企业管理 资金成本 价值管理 经济效益 成本控制 管理理念
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基于TFM-PBM耦合模型的离心泵内微气泡破碎合并的模拟研究 被引量:4
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作者 高颂 徐燕燕 +2 位作者 李继香 叶爽 黄伟光 《化工学报》 EI CAS CSCD 北大核心 2021年第10期5082-5093,共12页
了解离心泵内微气泡的发生特性,对于优化现有基于旋转流场的微气泡发生装置的性能、提高工业废水废气的污染物去除率至关重要。在考虑气泡破碎合并的前提下,通过将双流体模型(TFM)与群体平衡模型(PBM)进行耦合,求解离心泵内气液两相旋... 了解离心泵内微气泡的发生特性,对于优化现有基于旋转流场的微气泡发生装置的性能、提高工业废水废气的污染物去除率至关重要。在考虑气泡破碎合并的前提下,通过将双流体模型(TFM)与群体平衡模型(PBM)进行耦合,求解离心泵内气液两相旋转流场,研究了入口体积气含率(IGVF)、入口气泡尺寸对泵内气泡沿程尺寸变化、出口气泡尺寸分布的影响,并结合Luo等的破碎合并模型分析成因。结果表明,随IGVF增加,叶轮内气体聚集引起局部气含率陡升,气泡由破碎主导转变为合并主导,而后在蜗壳内气含率恢复正常,气泡又变为破碎主导,总体上出口气泡尺寸逐渐增大。另外,入口气泡尺寸对出口气泡尺寸的影响对IGVF敏感,当IGVF较低时,随入口气泡尺寸增大,出口气泡尺寸先增大后减小;而当IGVF较高时,由于泵内气体聚集,入口气泡尺寸的影响并不明显。 展开更多
关键词 离心泵 微气泡 气液两相流 tfm-PBM耦合模型 气含率 粒度分布
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多晶硅流化床反应器内气固两相流场与气泡尺寸分布的TFM-KTGF模拟 被引量:3
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作者 陆时杰 陈彩霞 +1 位作者 夏梓洪 倪昊尹 《华东理工大学学报(自然科学版)》 CAS CSCD 北大核心 2015年第6期758-764,共7页
硅烷流化床法是生产太阳能级多晶硅的重要技术,流化床反应器床层内的气泡大小和分布特性是影响晶体硅纯度和致密度的关键因素。使用TFM-KTGF两相流模型,基于Ansys Fluent软件平台模拟计算了多晶硅流化床内气固两相流场。在200倍粒径的... 硅烷流化床法是生产太阳能级多晶硅的重要技术,流化床反应器床层内的气泡大小和分布特性是影响晶体硅纯度和致密度的关键因素。使用TFM-KTGF两相流模型,基于Ansys Fluent软件平台模拟计算了多晶硅流化床内气固两相流场。在200倍粒径的网格尺寸条件下,对直径0.5m的圆柱形流化床多晶硅反应器内等温流场进行了模拟,借助Matlab图像处理工具对气含率进行后处理,得到多晶硅流化床内气泡尺寸分布。比较了经典的Gidaspow曳力模型和文献报道的亚网格修正曳力模型(SGS)对气泡尺寸分布的影响。结果表明:由SGS模型得到的平均气泡尺寸沿床高变化规律与Mori-Wen经验公式较吻合,最大偏差是12.6%,小于Gidaspow模型的21.4%;使用不同的曳力模型对气泡分布特性有较大影响。这些结果为进一步开展多晶硅反应器的热态模拟研究提供了基础。 展开更多
关键词 流化床 tfm-KTGF 多晶硅 曳力模型 气泡尺寸分布
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