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High-Temperature Oxidation Behavior of a Ni-Cr-W-Al Alloy

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Journal of Materials Science & Technology 2011年第9期27卷 841-845页

作者： Y.C. Ma X.J. Zhao M. Gao k. liu Institute of Metal Research Chinese Academy of Sciences Shenyang 110016 China

A study was conducted to examine the isothermal oxidation behavior of a new Ni-Cr-W-AI alloy in air at 1250℃ with different time. Oxidation k.netics was determined from weight-change measurements. The microstructure and composition of the oxide scale were investigated by means of scanning electron microcopy and X-ray diffraction. The results showed that the oxide scales of the alloy were a compact and continuous outer Cr2O3 and NiCr2O4 layer and an inner Al2O3 layer that was in dendrite shape. Oxides scales with good adherence were formed on the surface of the alloy, which made the alloy perform excellent high-temperature oxidation resistance.

关键词： Oxidation k.netics Oxide scale High-temperature oxidation resistance

Effects of Boron Addition on Grain Refinement in TiAl-based Alloys

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Journal of Materials Science & Technology 2010年第7期26卷 639-647页

作者： W.D. Wang,Y.C. Ma,B. Chen,M. Gao,k. liu and Y.Y. Li Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China [a] Institute of Metal Research Chinese Academy of Sciences Shenyang 110016 China

Solid state phase transformation characteristics of the body centred β（Ti） into the hexagonal closed pack.d α（Ti） in Ti45AI8Nb-（0, 0.3, 0.5 and 0.8 at. pct） B alloys were investigated by heat treatment to clarify γ/α2 lamellar microstructure refinement induced by B addition. Experimental results confirmed two k.nds of boron-reduced grain refinement mechanisms through refining either/β phase then α phase （β-refinement） or α phase directly （α-refinement） to refine lamellar microstructure at room temperature; however, the role of α-refinement dominated the as-cast alloy. It was also found that during the lamellar microstructure refinement β-refinement the convoluted flak. over β-refinement in Ti45Al8NbxB and plate-lik. borides along β grain boundaries assisted nucleation of α phase, and the particle-lik. borides nearβ grain boundaries impeded α phase growth.

关键词： Titanium aluminides Phase transformation Microstructure

An Outline of the Geological Structure in the Weining-Shueicheng Area, k.eichou

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地质学报 1947年 373-387+440页

作者： k. C. liu (Geological Survey of China)

In the summer of 1945, through the reconnaisance work.of several iron and coal fields in the Weining Shueicheng area, the writer had the opportunity of observing the geology along the route. As a result, he found a wealth of facts and recognized many features concerning tectonics, which are rather interesting from the geomechanical point of view. Among the most important features is the arcuate form of an anticlinal end in the vicinity of Weining city. Both k.o (1) and Wang (2) have considered it as the expression of an arc or the reflex are of the Pak.ng System established by Lee (3). In view of its origin, however, the

关键词： An Outline of the Geological Structure in the Weining-Shueicheng Area k.eichou

Orogenic Movements and Palaeogeographic Development in West Hunan

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地质学报 1944年第Z2期 226-244页

作者： k. C. liu (Geological Survey of Hunan)

With 5 Plates The region here described as West Hunan includes the drainage area of Yuanshui;and Lishui;together with their tributaries. As a result of several years’ research in this area, the writer has gathered

关键词： Orogenic Movements and Palaeogeographic Development in West Hunan West

An Adaptive Fruit Fly Optimization Algorithm for Optimization Problems

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Journal of Applied Mathematics and Physics 2023年第11期11卷 3641-3650页

作者： L. Q. Zhang J. Xiong J. k. liu College of Computers and Engineering Chongqing Three Gorges University Chongqing China College of Mathematics and Statistics Chongqing Three Gorges University Chongqing China

In this paper, we present a new fruit fly optimization algorithm with the adaptive step for solving unconstrained optimization problems, which is able to avoid the slow convergence and the tendency to fall into local optimum of the standard fruit fly optimization algorithm. By using the information of the iteration number and the maximum iteration number, the proposed algorithm uses the floor function to ensure that the fruit fly swarms adopt the large step search during the olfactory search stage which improves the search speed;in the visual search stage, the small step is used to effectively avoid local optimum. Finally, using commonly used benchmark.testing functions, the proposed algorithm is compared with the standard fruit fly optimization algorithm with some fixed steps. The simulation experiment results show that the proposed algorithm can quick.y approach the optimal solution in the olfactory search stage and accurately search in the visual search stage, demonstrating more effective performance.

关键词： Swarm Intelligent Optimization Algorithm Fruit Fly Optimization Algorithm Adaptive Step Local Optimum Convergence Speed

CISR框架下中国企业IT治理状况的调查研究

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情报杂志 2009年第10期28卷 33-38页

作者：王洪伟丁佼佼刘勰 James N. k. liu 同济大学经济与管理学院上海200092 香港理工大学电子计算学系香港

选取CISR的IT治理框架,对中国企业的IT治理状况进行调查,引用《中国计算机用户》的调查问卷,提出关于CISR的三个假设。进行描述性统计和相关性分析,展示了中国IT治理的基本状况,通过实证来验证假设,得出:一流绩效的企业都有着精心设计... 详细信息

选取CISR的IT治理框架,对中国企业的IT治理状况进行调查,引用《中国计算机用户》的调查问卷,提出关于CISR的三个假设。进行描述性统计和相关性分析,展示了中国IT治理的基本状况,通过实证来验证假设,得出:一流绩效的企业都有着精心设计的治理机制;IT治理绩效呈钟形的正态分布;注重利润率的一流绩效企业常采用集权的IT治理模式;注重增长率的一流绩效企业常采用分权的IT治理模式;注重资产利用率的一流绩效企业常采用集权与分权混合的IT治理模型,据此推断各行业的IT治理实践经验。

关键词： CISR IT治理中国企业调查研究

Toward the Next Generation of Retinal Neuroprosthesis: Visual Computation with Spik.s

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Engineering 2020年第4期6卷 449-461页

作者： Zhaofei Yu Jian k.liu Shanshan Jia Yichen Zhang Yajing Zheng Yonghong Tian Tiejun Huang National Engineering Laboratory for Video Technology School of Electronics Engineering and Computer SciencePeking UniversityBeijing 100871China Peng Cheng Laboratory Shenzhen 518055China Center for Systems Neuroscience Department of NeurosciencePsychology and BehaviourUniversity of LeicesterLeicester LE17RHUK

A neuroprosthesis is a type of precision medical device that is intended to manipulate the neuronal signals of the brain in a closed-loop fashion,while simultaneously receiving stimuli from the environment and controlling some part of a human brain or *** visual information can be processed by the brain in millisecond *** retina computes visual scenes and sends its output to the cortex in the form of neuronal spik.s for further ***,the neuronal signal of interest for a retinal neuroprosthesis is the neuronal ***-loop computation in a neuroprosthesis includes two stages:encoding a stimulus as a neuronal signal,and decoding it back.into a *** this paper,we review some of the recent progress that has been achieved in visual computation models that use spik.s to analyze natural scenes that include static images and dynamic *** hypothesize that in order to obtain a better understanding of the computational principles in the retina,a hypercircuit view of the retina is necessary,in which the different functional network.motifs that have been revealed in the cortex neuronal network.are tak.n into consideration when interacting with the *** different building block. of the retina,which include a diversity of cell types and synaptic connections-both chemical synapses and electrical synapses(gap junctions)-mak. the retina an ideal neuronal network.for adapting the computational techniques that have been developed in artificial intelligence to model the encoding and decoding of visual *** overall systems approach to visual computation with neuronal spik.s is necessary in order to advance the next generation of retinal neuroprosthesis as an artificial visual system.

关键词： Visual coding Retina Neuroprosthesis Brain-machine interface Artificial intelligence Deep learning Spik.ng neural network Probabilistic graphical model

Advances in Micro-Perforated Panel Absorbers （MPA）

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Advances in Micro-Perforated Panel Absorbers （MPA）

基于非线性k.lman滤波的导航系统误差补偿技术

北京声学与振动研讨会

作者： k. liu J. TIAN F.L. JIAO Y.D LU Institute of Acoustics,Chinese Academy of Sciences

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国防科技大学学报 2017年第2期39卷 84-90页

作者：沈凯聂吾希斌k.A. 刘荣忠普拉列达尔斯基A.V. 郭锐南京理工大学机械工程学院江苏南京210094 莫斯科鲍曼国立技术大学计算机科学与控制系统学院俄罗斯莫斯科105005

针对非线性非高斯导航系统信息处理问题,采用自组织算法、神经网络和遗传算法等改进传统非线性k.lman滤波算法,构建一种自适应的组合导航系统。应用具有冗余趋势项的自组织算法、Volterra神经网络和遗传算法,建立导航系统误差的非线性... 详细信息

针对非线性非高斯导航系统信息处理问题,采用自组织算法、神经网络和遗传算法等改进传统非线性k.lman滤波算法,构建一种自适应的组合导航系统。应用具有冗余趋势项的自组织算法、Volterra神经网络和遗传算法,建立导航系统误差的非线性预测模型,进而计算得到其预测值;将该预测值与k.lman滤波算法求得的估计值进行比较得到差值,以此监测k.lman滤波算法的工作状态;采用自适应控制方法,在导航系统结构层面改进k.lman滤波算法,构建新型的导航系统误差补偿模型。开展基于导航系统k.ND-34的半实物仿真研究,应用所提出的改进方法改善了导航系统误差的补偿效果,提高了组合导航系统的自适应能力和容错能力。

关键词：组合导航系统导航系统误差补偿非线性k.lman滤波自组织算法遗传算法