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A Graph with Adaptive AdjacencyMatrix for Relation Extraction
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作者 Run Yang YanpingChen +1 位作者 Jiaxin Yan Yongbin Qin 《Computers, Materials & Continua》 SCIE EI 2024年第9期4129-4147,共19页
The relation is a semantic expression relevant to two named entities in a sentence.Since a sentence usually contains several named entities,it is essential to learn a structured sentence representation that encodes de... The relation is a semantic expression relevant to two named entities in a sentence.Since a sentence usually contains several named entities,it is essential to learn a structured sentence representation that encodes dependency information specific to the two named entities.In related work,graph convolutional neural networks are widely adopted to learn semantic dependencies,where a dependency tree initializes the adjacency matrix.However,this approach has two main issues.First,parsing a sentence heavily relies on external toolkits,which can be errorprone.Second,the dependency tree only encodes the syntactical structure of a sentence,which may not align with the relational semantic expression.In this paper,we propose an automatic graph learningmethod to autonomously learn a sentence’s structural information.Instead of using a fixed adjacency matrix initialized by a dependency tree,we introduce an Adaptive Adjacency Matrix to encode the semantic dependency between tokens.The elements of thismatrix are dynamically learned during the training process and optimized by task-relevant learning objectives,enabling the construction of task-relevant semantic dependencies within a sentence.Our model demonstrates superior performance on the TACRED and SemEval 2010 datasets,surpassing previous works by 1.3%and 0.8%,respectively.These experimental results show that our model excels in the relation extraction task,outperforming prior models. 展开更多
关键词 relation extraction graph convolutional neural network adaptive adjacency matrix
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Relation Matrix of Water Exchange for Sea Bays and Its Application 被引量:21
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作者 孙健 陶建华 《China Ocean Engineering》 SCIE EI 2006年第4期529-544,共16页
Water exchange is an important hydrodynamic character of sea bays, and it is the basis for the study of the environmental capacity of sea bays. In this paper, a relation matrix is set up to describe the interaction am... Water exchange is an important hydrodynamic character of sea bays, and it is the basis for the study of the environmental capacity of sea bays. In this paper, a relation matrix is set up to describe the interaction among different areas of a sea bay, and to predict the water quality of those areas. The relation matrix is calculated based on the numerical results from a water quality model. This method is applied to the study of water exchange and the prediction of water quality of the Bohai Sea. The Bohai Sea is divided into five areas, and the effect of seasonal wind is taken into consideration. The results show a) the relation matrix can be used to study the water exchange among different areas and predict water quality of different areas at the respective characteristic time, b) the reduction of pollutant is dependent on both water exchange and initial distribution of the pollutant, and c) the half-life time of the pollutant is longer than the half-exchange time of the sea water. 展开更多
关键词 water exchange relation matrix water quality model half-exchange time half-life time Bohai Sea
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General calculation formulas and recurrence relations of radial matrix elements for relativistic n-dimensional hydrogen atom of spin S=0 被引量:1
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作者 CHENChang-yuan LUFa-lin SUNDong-sheng 《原子与分子物理学报》 CAS CSCD 北大核心 2004年第3期432-440,共9页
In this paper, the general calculation formulas of radial matrix elements for relativistic n-dimensional hydrogen atom of spin S=0 are obtained, and the recurrence relation of different power order radial matrix eleme... In this paper, the general calculation formulas of radial matrix elements for relativistic n-dimensional hydrogen atom of spin S=0 are obtained, and the recurrence relation of different power order radial matrix elements are also derived. 展开更多
关键词 n-dimensional hydrogen atom-type potential Klein-Cordon equation Radial matrix dements GENERAL calculation FORMULAS RECURRENCE relations
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Practical Method for Determining All the Minimum Solutions of Fuzzy Matrix Equation and Transitive Closure of Fuzzy Relation 被引量:2
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作者 阎家杰 赵万忠 《Chinese Quarterly Journal of Mathematics》 CSCD 1993年第4期99-103,共5页
In this paper,the new theory frame and practical methhod for determining all the minimum solutions of Fuzzy matrix equation and transitive closure of Fuzzy relation is described,and it has been carried out on the mier... In this paper,the new theory frame and practical methhod for determining all the minimum solutions of Fuzzy matrix equation and transitive closure of Fuzzy relation is described,and it has been carried out on the miero-computer quickly and accurately. 展开更多
关键词 fuzzy matrix equation minimum solution fuzzy relation transitive closure
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Inverse Transformation of Elliptical Relative State Transition Matrix 被引量:1
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作者 Jianfeng Yin Yinrui Rao Chao Han 《International Journal of Astronomy and Astrophysics》 2014年第3期419-428,共10页
A new set of relative orbit elements (ROEs) is used to derive a new elliptical formation flying model in previous work. In-plane and out-of-plane relative motions can be completely decoupled, which benefits elliptical... A new set of relative orbit elements (ROEs) is used to derive a new elliptical formation flying model in previous work. In-plane and out-of-plane relative motions can be completely decoupled, which benefits elliptical formation design. In order to study the elliptical control strategy and perturbation effects, it is necessary to derive the inverse transformation of the relative state transition matrix based on relative orbit elements. Poisson bracket theory is used to obtain the linear transformations between the two representations: the relative orbit elements and the geocentric orbital frame. In this paper, the details of these transformations are presented. 展开更多
关键词 relatIVE ORBIT Elements ELLIPTICAL Formation FLYING relatIVE State Transition matrix Inverse Transformation POISSON BRACKET
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Attribute Reduction in Decision Systems Based on Relation Matrix
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作者 ZHONG Cheng LI Jin-Hai 《浙江海洋学院学报(自然科学版)》 CAS 2010年第5期507-514,共8页
This paper proposes,from the viewpoint of relation matrix,a new algorithm of attribute reduction for decision systems.Two new and relative reasonable indices are first defined to measure significance of the attributes... This paper proposes,from the viewpoint of relation matrix,a new algorithm of attribute reduction for decision systems.Two new and relative reasonable indices are first defined to measure significance of the attributes in decision systems and then a heuristic algorithm of attribute reduction is formulated.Moreover,the time complexity of the algorithm is analyzed and it is proved to be complete.Some numerical experiments are also conducted to access the performance of the presented algorithm and the results demonstrate that it is not only effective but also efficient. 展开更多
关键词 Rough sets Decision systems Attribute reduction relation matrix MATLAB software
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Optimization of Tribological Performance of Al-6061T6-15% SiCp-15% Al<sub>2</sub>O<sub>3</sub>Hybrid Metal Matrix Composites Using Taguchi Method &Grey Relational Analysis
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作者 Ashok Kr. Mishra Vinod Kumar Rajesh Kr. Srivastava 《Journal of Minerals and Materials Characterization and Engineering》 2014年第4期351-361,共11页
In this investigation, optimization of tribological performance parameters of Al-6061T6 alloy reinforced with SiC (15% by weight) and Al2O3 (15% by weight) particulates having particle size of 37 μm each has been pre... In this investigation, optimization of tribological performance parameters of Al-6061T6 alloy reinforced with SiC (15% by weight) and Al2O3 (15% by weight) particulates having particle size of 37 μm each has been presented. The wear and frictional properties of the hybrid metal matrix composites have been studied by performing dry sliding wear test using pin-on-disc wear tester. A L27 orthogonal array is selected for the analysis of the data. From the test results it is observed that sliding distance has the significant contribution in controlling the friction and wear behaviour of hybrid composites. A confirmation test is also carried out to verify the accuracy of the results obtained through the optimization. In addition an optical micrograph test is also performed on the wear tracks to study the wear mechanism. 展开更多
关键词 Metal matrix Composites (MMCs) Friction Wear Taguchi Method Grey relatIONAL ANALYSIS ANALYSIS of Variance (ANOVA)
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Relative Ding Projective Modules over Formal Triangular Matrix Rings
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作者 Hongyan Fan Xi Tang 《Journal of Applied Mathematics and Physics》 2023年第6期1598-1614,共17页
Let U be a (B, A)-bimodule, A and B be rings, and be a formal triangular matrix ring. In this paper, we characterize the structure of relative Ding projective modules over T under some conditions. Furthermore, using t... Let U be a (B, A)-bimodule, A and B be rings, and be a formal triangular matrix ring. In this paper, we characterize the structure of relative Ding projective modules over T under some conditions. Furthermore, using the left global relative Ding projective dimensions of A and B, we estimate the relative Ding projective dimension of a left T-module. 展开更多
关键词 Formal Triangular matrix Ring relative Ding Projective Module relative Ding Projective Dimension
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RELATIVE ASYMPTOTICS FOR ORTHOGONAL MATRIX POLYNOMIALS WITH RESPECT TO A PERTURBED MATRIX MEASURE ON THE UNIT CIRCLE
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作者 Hossain O. Yakhlef Francisco Marcellán 《Approximation Theory and Its Applications》 2002年第4期1-19,共19页
Given a positive definite matrix measure Ω supported on the unit circle T, then main purpose of this paper is to study the asymptotic behavior of L n()L n(Ω) -1 and Φ n(z;)Φ n(z;Ω) -1 where(z)=Ω(z)+Mδ(z-w... Given a positive definite matrix measure Ω supported on the unit circle T, then main purpose of this paper is to study the asymptotic behavior of L n()L n(Ω) -1 and Φ n(z;)Φ n(z;Ω) -1 where(z)=Ω(z)+Mδ(z-w); |w|>1,M is a positive definite matrix and δ is the Dirac matrix measure. Here, L n(·) means the leading coefficient of the orthonormal matrix polynomials Φ n(z;·). Finally, we deduce the asymptotic behavior of Φ n(w;)Φ n(w;Ω)* in the case when M=I. 展开更多
关键词 relatIVE ASYMPTOTICS FOR ORTHOGONAL matrix POLYNOMIALS WITH RESPECT TO A PERTURBED matrix MEASURE ON THE UNIT CIRCLE
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Application of Matrix Method of Presenting Semantic Relations in Didactic Practice
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作者 Eva Lelakova Marta Lackova 《Psychology Research》 2015年第1期1-9,共9页
关键词 语义关系 应用程序 矩阵法 矩阵分析 语言学 可替代 组件化 词汇
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Matrix γ-carboxyglutamate protein and Fetuin-A, in wet type age-related macular degeneration
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作者 Alireza Javadzadeh Amir Ghorbanihaghjo +4 位作者 Ebadolah Heidari Nader Baharivand Karim Sadeghi Rana Sorkhabi Mohammad Hossein Ahoor 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2015年第3期556-559,共4页
AIM: To evaluate the high sensitivity C-reactive protein(hs CRP), Fetuin-A and matrix γ-carboxyglutamate protein(MGP) as the main factors for vascular calcification and inflammation in serum of patients with advanced... AIM: To evaluate the high sensitivity C-reactive protein(hs CRP), Fetuin-A and matrix γ-carboxyglutamate protein(MGP) as the main factors for vascular calcification and inflammation in serum of patients with advanced age-related macular degeneration(ARMD) in comparison to healthy controls. METHODS: The subjects were 40 patients with choroidal neovascularization(CNV) having a mean age of70.9 ±9.1y and a matched group of 49 apparently healthy control subjects. The ARMD was diagnosed using a slitlamp with superfield lens, fundus photography and fluorescein angiography. Measurement of hs CRP was done by nephelometry method. Levels of Fetuin-A and MGP were measured by enzyme-linked immunosorbent assay(ELISA) technique.RESULTS: hs CRP [0.45(0.07-2.63) mg/L vs 0.25(0.03-1.2) mg/L, P =0.02)] and Fetuin-A levels(50.27 ±5.04 vs44.99±10.28 ng/m L, P =0.009) were higher in the patients than in the control groups. We could not find significant difference in MGP level between two groups(P =0.08).There was not a significant correlation between MGP with Fetuin-A and hs CRP among the patients(P =0.7, P =0.9respectively). A significant negative correlation of hs CRP with Fetuin-A was observed in both case and control groups(P =0.004, r =-0.33 and P =0.001, r =-0.54,respectively).CONCLUSION: Although our study shows that serum hs CRP and Fetuin-A is increased in CNV patients as well as negatively correlated with both study groups, their direct role on pathogenesis of ARMD required future studies. 展开更多
关键词 high sensitivity C-reactive protein FETUIN-A matrix γ-carboxyglutamate protein age-related macular degeneration choroidal neovascularization
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基于微流控芯片评估富血小板血浆促进子宫内膜细胞的增殖
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作者 闻哲嘉 吕芳 《中国组织工程研究》 CAS 北大核心 2025年第10期2091-2096,共6页
背景:富血小板血浆可促进薄型子宫内膜细胞的增殖,但存在剂量难以控制、取样困难等问题。微流控芯片具有高通量、低消耗、操作简便等优点,为模拟子宫内膜细胞在体微环境提供了新途径。目的:利用三通道微流控芯片构建富血小板血浆促进子... 背景:富血小板血浆可促进薄型子宫内膜细胞的增殖,但存在剂量难以控制、取样困难等问题。微流控芯片具有高通量、低消耗、操作简便等优点,为模拟子宫内膜细胞在体微环境提供了新途径。目的:利用三通道微流控芯片构建富血小板血浆促进子宫内膜细胞增殖的研究模型。方法:从1名女性外周静脉血中提取富血小板血浆。采用含不同浓度[0%(对照),0.5%,1%,2%]富血小板血浆的无血清细胞培养基培养人子宫内膜间质细胞,采用划痕实验检测细胞迁移,CCK-8法检测细胞增殖。利用聚二甲基硅氧烷胶制备微流控芯片,该微流控芯片设计有3个通道,中间通道为细胞外基质水凝胶通道,左右两侧分别为人子宫内膜间质细胞及富血小板血浆通道,3个通道之间保存有可以相互沟通以及实现物质交换的面积,实验组两侧通道分别加入人子宫内膜间质细胞(绿色荧光蛋白GFP标记)和含0.5%富血小板血浆的无血清培养基,对照组两侧通道分别加入人子宫内膜间质细胞(绿色荧光蛋白GFP标记)和无血清细胞培养基,共培养48 h后,采用Ki67免疫荧光染色观察细胞增殖与迁移。结果与结论:(1)细胞划痕实验和CCK-8检测结果显示,与对照组相比,0.5%,1%,2%浓度的富血小板血浆可促进人子宫内膜间质细胞的迁移与增殖(P <0.05),并且0.5%浓度富血小板血浆的促进细胞迁移与增殖作用强于其他2个浓度(P <0.05);(2)Ki67免疫荧光染色结果显示,与对照组相比,实验组人子宫内膜间质细胞的增殖和迁移能力更强;(3)实验证实通过三通道微流控芯片可以模拟子宫内膜细胞的微环境,同时利用该系统验证了富血小板血浆可显著促进子宫内膜间质细胞的增殖与迁移。 展开更多
关键词 微流控芯片 富血小板血浆 子宫内膜间质细胞 子宫内膜增殖 迁移 细胞外基质 薄型子宫内膜 子宫内膜相关疾病
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Insulin-like growth factor binding protein related protein 1 knockdown attenuates hepatic ?brosis via the regulation of MMPs/TIMPs in mice 被引量:11
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作者 Jun-Jie Ren Ting-Juan Huang +5 位作者 Qian-Qian Zhang Hai-Yan Zhang Xiao-Hong Guo Hui-Qin Fan Ren-Ke Li Li-Xin Liu 《Hepatobiliary & Pancreatic Diseases International》 SCIE CAS CSCD 2019年第1期38-47,共10页
Background: Previous research suggested that insulin-like growth factor binding protein related protein 1(IGFBPrP1), as a novel mediator, contributes to hepatic fibrogenesis. Matrix metalloproteinases(MMP) and tissue ... Background: Previous research suggested that insulin-like growth factor binding protein related protein 1(IGFBPrP1), as a novel mediator, contributes to hepatic fibrogenesis. Matrix metalloproteinases(MMP) and tissue inhibitors of metalloproteinases(TIMP) play an essential role in hepatic fibrogenesis by regulating homeostasis and remodeling of the extracellular matrix(ECM). However, the interaction between IGFBPrP1 and MMP/TIMP is not clear. The present study was to knockdown IGFBPrP1 to investigate the correlation between IGFBPrP1 and MMP/TIMP in hepatic fibrosis. Methods: Hepatic fibrosis was induced by thioacetamide(TAA) in mice. Knockdown of IGFBPrP1 expression by ultrasound-targeted microbubble destruction-mediated CMB-shRNA-IGFBPrP1 delivery, or inhibition of the Hedgehog(Hh) pathway by cyclopamine treatment, was performed in TAA-induced liver fibrosis mice. Hepatic fibrosis was determined by hematoxylin and eosin and Sirius red staining. Hepatic expression of IGFBPrP1, α-smooth muscle actin( α-SMA), transforming growth factor β 1(TGF β1), collagen I, MMPs/TIMPs, Sonic Hedgehog(Shh), and glioblastoma family transcription factors(Gli1) were investigated by immunohistochemical staining and Western blotting analysis. Results: We found that hepatic expression of IGFBPrP1, TGF β1, α-SMA, and collagen I were increased longitudinally in mice with TAA-induced hepatic fibrosis, concomitant with MMP2/TIMP2 and MMP9/TIMP1 imbalance and Hh pathway activation. Knockdown of IGFBPrP1 expression, or inhibition of the Hh pathway, reduced the hepatic expression of IGFBPrP1, TGF β1, α-SMA, and collagen I and re-established MMP2/TIMP2 and MMP9/TIMP1 balance. Conclusions: Our findings suggest that IGFBPrP1 knockdown attenuates liver fibrosis by re-establishing MMP2/TIMP2 and MMP9/TIMP1 balance, concomitant with the inhibition of hepatic stellate cell activation, down-regulation of TGF β1 expression, and degradation of the ECM. Furthermore, the Hh pathway mediates IGFBPrP1 knockdown-induced attenuation of hepatic fibrosis through the regulation of MMPs/TIMPs balance. 展开更多
关键词 HEPATIC fibrosis INSULIN-LIKE growth factor binding PROTEIN relatED PROTEIN 1 matrix METALLOPROTEINASE Tissue inhibitor of METALLOPROTEINASE Ultrasound-targeted microbubble destruction Hedgehog signaling pathway
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Hierarchical Detailed Description for Spatial Direction Relations 被引量:5
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作者 WANG Jing JIANG Gangwu GUO Rui 《Geo-Spatial Information Science》 2008年第1期56-61,共6页
Direction relation is an important spatial relation. Descriptions and representations for direction relations have different levels of detail because of the varying dimensions of spatial objects and different scales o... Direction relation is an important spatial relation. Descriptions and representations for direction relations have different levels of detail because of the varying dimensions of spatial objects and different scales of the embedding spaces. Based on a direction- relation matrix, the hierarchical frame of spatial direction relations which partitions direction relations orderly and thoroughly is built. Interior direction relations are used to perfect the representation of direction relations and the binary-encoding idea is creatively applied to construct an interior detailed matrix describing multiple interior direction relations by a uniform matrix. The model integrates topological information into the description model for direction relations, which will lay the foundations of spatial compositive reasoning. 展开更多
关键词 spatial direction relations direction-relation matrix levels of detail spatial reasoning GIS
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EVOLUTION OF THE MICROCRACKS IN WHISKER TOUGHENING CERAMIC MATRIX COMPOSITES 被引量:2
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作者 Li Wenfang, South China University of Technology, Guangzhou 510641, R. R. ChinaDu Shanyi, Harbin Institute of Technology, Harbin 150001 《Acta Mechanica Solida Sinica》 SCIE EI 1995年第1期75-83,共9页
The modified equivalent inclusion theory by the authors and the internal variable theory are employed to investigate the evolution of the microcracks in whisker toughening ceramics and the influence of the microcracks... The modified equivalent inclusion theory by the authors and the internal variable theory are employed to investigate the evolution of the microcracks in whisker toughening ceramics and the influence of the microcracks on the mechanical properties of the material. The effect of residual thermostrain, whisker content and aspect ratio is considered. The modulus, initial nonlinear load, strength and nonlinear constitutive relation are calculated and some important conclusions are given. 展开更多
关键词 WHISKER MICROCRACK ceramic matrix composites material strength nonlinear constitutive relation
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Interaction between insulin-like growth factor binding protein-related protein 1 and transforming growth factor beta 1 in primary hepatic stellate cells 被引量:3
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作者 Xiu-Qing Li Qian-Qian Zhang +3 位作者 Hai-Yan Zhang Xiao-Hong Guo Hui-Qin Fan Li-Xin Liu 《Hepatobiliary & Pancreatic Diseases International》 SCIE CAS CSCD 2017年第4期395-404,共10页
BACKGROUND: We previously showed that insulin-like growth factor binding protein-related protein 1 (IGFBPrP1) is a novel mediator in liver fibrosis. Transforming growth factor beta 1 (TGF beta 1) is known as the stron... BACKGROUND: We previously showed that insulin-like growth factor binding protein-related protein 1 (IGFBPrP1) is a novel mediator in liver fibrosis. Transforming growth factor beta 1 (TGF beta 1) is known as the strongest effector of liver fibrosis. Therefore, we aimed to investigate the detailed interaction between IGFBPrP1 and TGF beta 1 in primary hepatic stellate cells (HSCs). METHODS: We overexpressed TGF beta 1 or IGFBPrP1 and inhibited TGF beta 1 expression in primary HSCs for 6, 12, 24, 48, 72, and 96 hours to investigate their interaction and observe the accompanying expressions of a-smooth muscle actin (alpha-SMA), collagen I, fibronectin, and phosphorylated-mothers against decapentaplegic homolog 2/3 (p-Smad2/3). RESULTS: We found that the adenovirus vector encoding the TGF beta 1 gene (AdTGF beta 1) induced IGFBPrP1 expression while that of alpha-SMA, collagen I, fibronectin, and TGF beta 1 increased gradually. Concomitantly, AdIGFBPrP1 upregulated TGF beta 1, alpha-SMA, collagen I, fibronectin, and p-Smad2/3 in a time-dependent manner while IGFBPrP1 expression was decreased at 96 hours. Inhibition of TGF beta 1 expression reduced the IGFBPrP1-stimulated expression of alpha-SMA, collagen I, fibronectin, and p-Smad2/3. CONCLUSIONS: These findings for the first time suggest the existence of a possible mutually regulation between IGFBPrP1 and TGF beta 1, which likely accelerates liver fibrosis progression. Furthermore, IGFBPrP1 likely participates in liver fibrosis in a TGF beta 1-depedent manner, and may act as an upstream regulatory factor of TGF beta 1 in the Smad pathway. 展开更多
关键词 insulin-like growth factor binding protein related protein 1 transforming growth factor in primary hepatic stellate cells alpha-smooth muscle actin extracellular matrix Smad pathway
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The construction and combined operation for fuzzy consistent matrixes 被引量:2
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作者 姚敏 沈斌 骆建华 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2005年第1期27-31,共5页
Fuzziness is one of the general characteristics of human thinking and objective things. Introducing fuzzy techniques into decision-making yields very good results. Fuzzy consistent matrix has many excellent characteri... Fuzziness is one of the general characteristics of human thinking and objective things. Introducing fuzzy techniques into decision-making yields very good results. Fuzzy consistent matrix has many excellent characteristics, especially cen- ter-division transitivity conforming to the reality of the human thinking process in decision-making. This paper presents a new approach for creating fuzzy consistent matrix from mutual supplementary matrix in fuzzy decision-making. At the same time, based on the distance between individual fuzzy consistent matrix and average fuzzy consistent matrix, a kind of combined opera- tion for several fuzzy consistent matrixes is presented which reflects most opinions of experienced experts. Finally, a practical example shows its flexibility and practicability further. 展开更多
关键词 Fuzzy consistent matrix Fuzzy consistent relation Compound operation
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Semi-Analytical Solution of the 1D Helmholtz Equation, Obtained from Inversion of Symmetric Tridiagonal Matrix 被引量:1
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作者 Serigne Bira Gueye 《Journal of Electromagnetic Analysis and Applications》 2014年第14期425-438,共14页
An interesting semi-analytic solution is given for the Helmholtz equation. This solution is obtained from a rigorous discussion of the regularity and the inversion of the tridiagonal symmetric matrix. Then, applicatio... An interesting semi-analytic solution is given for the Helmholtz equation. This solution is obtained from a rigorous discussion of the regularity and the inversion of the tridiagonal symmetric matrix. Then, applications are given, showing very good accuracy. This work provides also the analytical inverse of the skew-symmetric tridiagonal matrix. 展开更多
关键词 HELMHOLTZ Equation TRIDIAGONAL matrix Linear HOMOGENEOUS RECURRENCE relation
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Effect of sintering on the relative density of Cr-coated diamond/Cu composites prepared by spark plasma sintering 被引量:4
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作者 Wei Cui Hui Xu +3 位作者 Jian-hao Chen Shu-bin Ren Xin-bo He Xuan-hui Qu 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2016年第6期716-722,共7页
Cr-coated diamond/Cu composites were prepared by spark plasma sintering. The effects of sintering pressure, sintering temperature, sintering duration, and Cu powder particle size on the relative density and thermal co... Cr-coated diamond/Cu composites were prepared by spark plasma sintering. The effects of sintering pressure, sintering temperature, sintering duration, and Cu powder particle size on the relative density and thermal conductivity of the composites were investigated in this paper. The influence of these parameters on the properties and microstructures of the composites was also discussed. The results show that the relative density of Cr-coated diamond/Cu reaches ~100% when the composite is gradually compressed to 30 MPa during the heating process. The densification temperature increases from 880 to 915℃ when the diamond content is increased from 45vol% to 60vol%. The densification temperature does not increase further when the content reaches 65vol%. Cu powder particles in larger size are beneficial for increasing the relative density of the composite. 展开更多
关键词 metal matrix composites copper diamond relative density spark plasma sintering
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PDRK:A General Kinetic Dispersion Relation Solver for Magnetized Plasma 被引量:1
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作者 谢华生 肖湧 《Plasma Science and Technology》 SCIE EI CAS CSCD 2016年第2期97-107,共11页
A general,fast,and effective approach is developed for numerical calculation of kinetic plasma linear dispersion relations.The plasma dispersion function is approximated by J-pole expansion.Subsequently,the dispersion... A general,fast,and effective approach is developed for numerical calculation of kinetic plasma linear dispersion relations.The plasma dispersion function is approximated by J-pole expansion.Subsequently,the dispersion relation is transformed to a standard matrix eigenvalue problem of an equivalent linear system.Numerical solutions for the least damped or fastest growing modes using an 8-pole expansion are generally accurate;more strongly damped modes are less accurate,but are less likely to be of physical interest.In contrast to conventional approaches,such as Newton's iterative method,this approach can give either all the solutions in the system or a few solutions around the initial guess.It is also free from convergence problems.The approach is demonstrated for electrostatic dispersion equations with one-dimensional and twodimensional wavevectors,and for electromagnetic kinetic magnetized plasma dispersion relation for bi-Maxwellian distribution with relative parallel velocity flows between species. 展开更多
关键词 plasma physics dispersion relation kinetic waves instabilities linear system matrix eigenvalue
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