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Lifetime prediction of electrical connectors under multiple environment stresses of temperature and particulate contamination

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The Journal of China Universities of Posts and Telecommunications 2016年第5期23卷 61-67,81页

作者： Li Qingya Gao Jinchun xie gang Jin Qiuyan Ji Rui School of Electronic Engineering Beijing University of Posts and Telecommunications Beijing Key laboratory of Work Safety Intelligent Monitoring Beijing University of Posts and Telecommunications School of Information and Communication Engineering Beijing University of Posts and Telecommunications

Electrical connectors play a significant role in the electronic and communication systems. As they are often exposed in the atmosphere environment, it is extremely easy for them to cause electrical contact failure. It is essential to carry out the reliability modeling and predict the lifetime. In the present work, the accelerated lifetime testing method which is on account of the uniform design method was designed to obtain the degradation data under multiple environmental stresses of temperature and particulate contamination for electrical connectors. Based on the degradation data, the pseudo life can be acquired. Then the reliability model was established by analyzing the pseudo life. Accordingly, the reliability function and reliable lifetime function were set up, and the reliable lifetime of the connectors under the multiple environment stresses of temperature and particulate contamination could be predicted for electrical connectors,

关键词： electrical connectors accelerated lifetime testing lifetime prediction

Optimal power and subcarrier allocation with partial side information for downlink OFDMA system

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The Journal of China Universities of Posts and Telecommunications 2010年第5期17卷 50-57页

作者： ZENG Ling-kang LIU Yuan-an xie gang CHANG Ling-jun Key Laboratory of Universal Wireless Communications Ministry of Education Beijing University of Posts and Telecommunications Beijing 100876 China

In this paper,we investigate the power and subcarrier allocation issue in the case of partial side information for downlink orthogonal frequency division multiple access （OFDMA） *** method is utilized to characterize the necessary conditions of the optimal solution and the uniqueness of the optimal solution is *** game theoretical concept,surplus function is also introduced to analyze the optimal *** on the theoretical analysis,we propose iterative surplus balancing algorithm （ISBA） that can jointly assign the power and subcarriers in multiple rounds,and then the optimality of ISBA is *** results are presented to show the characteristics of the theoretical analysis and ISBA.

关键词： resource allocation partial side information OFDMA surplus function game theory

Improving amplify-and-forward relay selection algorithm based on partial relay link

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The Journal of China Universities of Posts and Telecommunications 2010年第1期17卷 56-61页

作者： WANG Fei-fei LIU Yuan-an LIN Xiao-feng xie gang Key Labomty of Universal Wireless Communications Ministry of Education Beijing University of Posts and Telecommunications Beijing 100876 China

This article addresses the design problem of selecting an appropriate relay in amplify-and-forward （AF） cooperative diversity systems. In this regard, this article focuses on relay selection based on partial channel knowledge only across the source and relay links. In particular, the two fundamental questions will be answered, that is, whether to cooperate and whom to cooperate with. Through answering these two questions, an improved relay selection strategy based on partial relay link, which emphasizes that cooperation happens when necessary, is proposed to aim at maximizing the average mutual information. Then a joint optimization, in terms of power allocation and relay selection, is employed to guarantee a robust performance for relay selection based on partial relay link. Optimum power is allocated between the source and the selected relay to maximize the output signal-to-noise （SNR） at the destination. Simulation results turn out that the improved scheme can achieve better performance than previous work and the robust performance can be guaranteed by employing joint optimization.

关键词： cooperative diversity amplify-and-forward relay relay selection average mutual information

A CFD model for gas uniform distribution in turbulent flow for the production of titanium pigment in chloride process

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Chinese Journal of Chemical Engineering 2016年第6期24卷 749-756页

作者： Yadong Li gang xie Ting Lei Chongjun Bao Lin Tian Yanqing Hou State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization Kunming University of Science and Technology Kunming 650093 China Faculty of Metallurgical and Energy Engineering Kunming University of Science and Technology Kunming 650093 China Kunming Metallurgical Research Institute Kunming 650031 China Key Laboratory of Pressure Hydrometallurgy Technology Associated Non-Ferrous Metal Resources Kunming 650031 China Kunming Metallurgy College Kunrning 650-033 China

The fluid dynamic behavior of feeding gas(Ti Cl4) in an annular channel affects the combination of O2 and Ti Cl4 in an oxidation reactor, a key piece of equipment in titanium pigment production. The numerical procedure was validated by a 3-dimensional gas flow in the annular channel. Applying the validated model, the flow characteristics of Ti Cl4 in the oxidation reactor with a tangential inlet were simulated and characterized. The flow distribution with five rectifying rings of different structure was simulated and analyzed. The results showed that the rectifying ring improved the distribution uniformity of the pressure and outlet velocity. Compared to the original case without a rectifying ring, the non-uniformity of the pressure and outlet velocity could be reduced by up to91% and 69% respectively. The rectifying ring #5, which can be installed and adjusted easily, is more effective in realizing even distribution. In addition, installation of the rectifying ring effectively reduced the circulating flow in an annular channel as well as the total energy loss.

关键词：流体力学模型数值计算程序气体流动均匀分布生产过程湍流流动钛白粉 TiCl4

Theoretical Calculation for the Dip Feature in Tunnelling Experiment on Bi2212

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Chinese Physics Letters 2001年第9期18卷 1256-1257页

作者：谢刚韩汝珊 Mesoscopic Physics Laboratory and Department of Physics Peking UniversityBeijing 100871

We generalize a model, which was presented by Norman [Phys. Rev. Lett. 79 (1997) 3506], to calculate the Bi2Sr2CaCu2Os+δ (Bi2212) single-electron tunnelling conductance. In our calculation result, the dip feature appears which has been widely observed in tunnelling experiments. It is found that this dip feature in tunnelling experiments and the dip/hump feature in angle-resolved photoemission experiments have a common physics. Moreover, it is shown from our numerical calculation method that if the spectral function A(κ, ω) is known, the tunnelling conductance can be obtained.

关键词： conductance Bi2212 calculation

融合MobileNetv3与Transformer的钢板缺陷实时检测算法

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计算机集成制造系统 2023年第12期29卷 3951-3963页

作者：张林谢刚谢新林张涛源太原科技大学电子信息工程学院山西太原030024 先进控制与装备智能化山西省重点实验室山西太原030024

钢板表面的缺陷检测是分析和判断钢板质量的基础和关键。针对钢板表面龟裂等小缺陷检测效率低、精度差的问题,提出一种融合Transformer的钢板表面缺陷实时检测算法。首先,融合协调注意力(CA)模块以及最大动态转移(DY)激活函数构建CA-Bn... 详细信息

钢板表面的缺陷检测是分析和判断钢板质量的基础和关键。针对钢板表面龟裂等小缺陷检测效率低、精度差的问题,提出一种融合Transformer的钢板表面缺陷实时检测算法。首先,融合协调注意力(CA)模块以及最大动态转移(DY)激活函数构建CA-Bneck模块,提高缺陷特征的表示能力;其次,将MobileNetV3、CA-Bneck以及Transformer编码模块相融合,构建一种新的主干特征提取网络MobileNetV3-CATr,用于减轻模型的复杂度;最后,提出一种BiFPN-Lite模块,使得模型复杂度不增加的条件下融合更多缺陷特征;并通过YOLO Head输出缺陷的信息。在热轧钢公开数据集NEU-DET上实验结果表明,所提算法在性能和速度之间取得了平衡,mAP值相较于YOLOv4提升了5.96%,速度达到了20.1FPS,能够有效地完成钢板表面缺陷的实时和高精度检测。

关键词：机器视觉缺陷检测 MobileNetv3网络 Transformer模块

基于高分辨率T2WI的影像组学对直肠癌EGFR表达的预测价值

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川北医学院学报 2024年第3期39卷 358-362页

作者：胡友强罗敏董小娟邹龙权谢刚张远林刘文军姜萍自贡市第四人民医院放射科四川自贡643000 自贡市第四人民医院病理科四川自贡643000 自贡市第三人民医院放射科四川自贡643020

目的:探讨基于高分辨率T2WI的影像组学对直肠癌EGFR表达状态的预测价值。方法:回顾性分析经术后病理确诊且在接受治疗前行MRI检查的208例直肠癌患者的临床及影像资料,根据EGFR表达水平不同将患者分为阳性组和阴性组。在高分辨率T2WI图... 详细信息

目的:探讨基于高分辨率T2WI的影像组学对直肠癌EGFR表达状态的预测价值。方法:回顾性分析经术后病理确诊且在接受治疗前行MRI检查的208例直肠癌患者的临床及影像资料,根据EGFR表达水平不同将患者分为阳性组和阴性组。在高分辨率T2WI图像上勾画病灶的三维容积兴趣区(VOI)并提取影像组学特征,将208例患者分为训练集(n=145)和测试集(n=63),并对特征进行降维,将降维后的特征建立支持向量机(SVM)、逻辑回归(LR)、随机森林(RF)及线性判别分析(LDA)四种分类器学习模型,分别绘制训练集和测试集的受试者工作特征(ROC)曲线,并获得曲线下面积(AUC)。结果:208例患者中,EGFR阳性表达99例(47.6%)。二元Logistic回归分析显示示低分化和淋巴结转移是EGFR阳性表达的独立危险因素(P0.05)。4种影像组学模型均有一定的预测效能,其中SVM模型训练集与测试集的诊断效能均为最高,在训练集和测试集中的AUC分别为0.803、0.725。结论:基于高分辨率T2WI图像构建的影像组学模型对直肠癌EGFR表达状态具有一定预测价值。

关键词：直肠肿瘤影像组学磁共振成像 EGFR

Kinetics of austenite grain growth in medium-carbon niobium-bearing steel

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2011年第3期12卷 171-176页

作者： Ying-li ZHAO Jie SHI Wen-quan CAO Mao-qiu WANG gang xie School of Material and Metallurgy Engineering Kunming University of Science and Technology Kunming 650093 China Institute for Structural Materials Central Iron and Steel Research Institute Beijing 100081 China

In order to locate a reasonable heating system,the austenite grain growth behavior of Nb microalloyed medium carbon steel has been experimentally studied at various austenitizing temperatures and for different holding *** is indicated that austenite grain growth increases with increasing austenitizing temperatures and holding *** when the austenitizing temperature was above 1100 ℃,austenite grains grew rapidly,and an abnormal austenite grain growth was *** the austenitizing temperature was lower than 1100 ℃,austenite grain size and growth rate were *** activation energy of grain growth in the tested steel is 397 679.5 J/*** ensure an absence of coarse grains in microstructures,the heating technology of the tested steel should be controlled for 1 h at 1100 ℃.The relationships of austenite average grain size with soaking temperature and time of tested steel were obtained by mathematical calculation,and austenite average grain size was found to be in agreement with the measured size for different holding times.

关键词： Microalloyed steel Grain growth Modeling

Effect of direct quenching on microstructure and mechanical properties of medium-carbon Nb-bearing steel

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2010年第10期11卷 776-781页

作者： Ying-li ZHAO Jie SHI Wen-quan CAO Mao-qiu WANG gang xie School of Material and Metallurgy Engineering Kunming U~iversity of Scienee and Technology Kunming 650093 China Institute for Structural Materials Central Iron and Steel Research Institute Beijing 100081 China

The influence of direct quenching (DQ) on microstructure and mechanical properties of 0.19C-1.7Si-1.0 Mn-0.05Nb steel was studied. The microstructure and mechanical properties of reheat quenched and tempered (RQ&T) steel plate were compared with those of direct quenched and tempered (DQ&T) steel plates which were hot rolled at different finish rolling tem-peratures (1173 K and 1123 K), i.e., recrystallization-controlled-rolled direct-quenched (RCR&DQ) and controlled-rolled direct-quenched (CR&DQ), respectively. The strengths generally increased in the following order: RQ&T

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