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A high strength pH responsive supramolecular copolymer hydrogel

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Science China(Technological Sciences) 2017年第1期60卷 78-83页

作者： WANG Qing ZHANG YinYu DAI xiyang SHI XiaoHuan liu WenGuang School of Materials Science and Engineering Tianjin Key Laboratory of Composite and Functional Materials Tianjin University Tianjin 300354 China

Constructing high strength pH sensitive supramolecular polymer hydrogel remains very challenging due to the unavoidable network swelling caused by ionization of acid or basic groups at a specified *** this work,we proposed a simple and very convenient approach to fabricate high strength pH responsive supramolecular polymer(SP) hydrogels by one-pot copolymerization of N-acryloyl glycinamide(NAGA) and 2-vinyl-4,6-diamino-1,3,5-triazine(VDT),two feature hydrogen bonding *** these PNAGA-PVDT SP hydrogels obtained,the hydrogen bonding of NAGA was shown to play a dominant role in reinforcing strength,while the hydrogen bonding of diaminotriazine served as a pH sensitive *** pH 3,the mechanical properties of PNAGA-PVDT hydrogels decreased to a different extent due to the breakup of hydrogen bonding;in contrast,the hydrogel resumed the original strength while pH was raised to 7.4 because of reconstruction of hydrogen *** the selected pH range,the PNAGA-PVDT hydrogels exhibited up to 1.25 MPa tensile strength,845% breaking strain,69 kPa Young's modulus and 21 MPa compressive *** novel high strength pH-responsive SP hydrogels may find applications in biomedical and industrial fields.

关键词： high strength pH responsive supramolecular polymer hydrogel

Printed Circuit Board (PCB) Surface Micro Defect Detection Model Based on Residual Network with Novel Attention Mechanism

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Computers, Materials & Continua 2024年第1期78卷 915-933页

作者： Xinyu Hu Defeng Kong xiyang liu Junwei Zhang Daode Zhang School of Mechanical Engineering Hubei University of TechnologyWuhan430068Chain

Printed Circuit Board(PCB)surface tiny defect detection is a difficult task in the integrated circuit industry,especially since the detection of tiny defects on PCB boards with large-size complex circuits has become one of the *** improve the performance of PCB surface tiny defects detection,a PCB tiny defects detection model based on an improved attention residual network(YOLOX-AttResNet)is ***,the unsupervised clustering performance of the K-means algorithm is exploited to optimize the channel weights for subsequent operations by feeding the feature mapping into the SENet(Squeeze and Excitation Network)attention network;then the improved K-means-SENet network is fused with the directly mapped edges of the traditional ResNet network to form an augmented residual network(AttResNet);and finally,the AttResNet module is substituted for the traditional ResNet structure in the backbone feature extraction network of mainstream excellent detection models,thus improving the ability to extract small features from the backbone of the target detection *** results of ablation experiments on a PCB surface defect dataset show that AttResNet is a reliable and efficient *** Torify the performance of AttResNet for detecting small defects in large-size complex circuit images,a series of comparison experiments are further *** results show that the AttResNet module combines well with the five best existing target detection frameworks(YOLOv3,YOLOX,Faster R-CNN,TDD-Net,Cascade R-CNN),and all the combined new models have improved detection accuracy compared to the original model,which suggests that the AttResNet module proposed in this paper can help the detection model to extract target *** them,the YOLOX-AttResNet model proposed in this paper performs the best,with the highest accuracy of 98.45% and the detection speed of 36 FPS(Frames Per Second),which meets the accuracy and real-time requirements for the detection of tiny defect

关键词： Neural networks deep learning ResNet small object feature extraction PCB surface defect detection

Analysis on Lean Blowout of Swirl Cup Combustor at Atmospheric Pressure Condition

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Journal of Thermal Science 2011年第4期20卷 349-354页

作者： Yixiang Yuan Hailin Fan xiyang liu Qi Dong Chunqing Tan Baoting Guo Institute of Engineering Thermophysics Chinese Academy of Sciences Beijing 100190 China Graduate University of the Chinese Academy of Sciences Beijing 100190 China

The experimental data of lean blowout fuel/air ratio of a rectangular swirl cup combustor with different inlet temperatures was obtained at atmospheric pressure *** simulations both burning and non-burning were performed corresponding to the experimental data at lean *** indicated that the size of the recirculation region in the primary zone was obviously smaller when burning than non-burning,but the locations of the cores of their recirculation regions were almost the *** increase of inlet air temperature didn't mean the rise of the temperature of recirculation region *** location of the maximum temperature in the primary zone was not the same as that one of the core temperature of the recirculation *** more,the reasons were analyzed how the lean blowout fuel/air ratio changed with the inlet temperature increasing under the actions of factors both positive and negative to combustion,and this would be helpful to deepen the understanding of the lean blowout process of swirl cup combustor.

关键词： swirl cup combustor lean blowout primary zone recirculation region gas turbine

Experimental investigation on unsteady pressure fluctuation of rotor tip region in high pressure stage of a vaneless counter-rotating turbine

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Science China(Technological Sciences) 2009年第6期52卷 1478-1483页

作者： ZHAO QingJun liu xiyang WANG HuiShe ZHAO XiaoLu XU JianZhong Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing 100190China

An experimental investigation has been performed to study the unsteady pressure fluctuation of rotor tip region in high pressure stage of a vaneless counter-rotating *** experiment is carried out on a blow-down short duration turbine *** investigation indicates that the blow-down short duration turbine facility is capable of substituting continuous turbine facilities in most turbine *** this experimental investigation,a distinct blade-to-blade variation is *** results indicate that the combined effects of vane wake,tip leakage flow,complicated wave systems and rotor wake induce the remarkable blade-to-blade *** results also show that the unsteady effect is intensified along the flow direction.

关键词： counter-rotating turbine pressure fluctuation unsteady effect short duration experiment

High Dielectric Constant and Low-loss Dielectric Ceramics of Sr_5 LnTi_3Ta_7O_(30)(Ln=La,Nd,Sm and Y)

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Journal of Wuhan University of Technology(Materials Science) 2008年第2期23卷 218-221页

作者： TU Wenmao CHEN Pu PENG xiyang liu Ting School of Resource and Environmental Engineering Wuhan University of Technology Wuhan 430070 China

Polycrystalline Sr5LnTi3Ta7O30 （Ln=La, Nd, Sm and Y） ceramics were prepared as single-phase materials through conventional solid-state ceramics method. The structure was characterized by X-ray diffraction method and scanning electron microscopy （SEM）. The dielectric properties were measured from room temperature to 400℃. All compounds are paraelectric phases adopting the filled tetragonal tungsten bronze （TB） structure at room temperature. At 1 MHz their dielectric constant （ετ） varied from 109 to 139, dielectric loss changed from 0.003 3 to 0.005 8, and the temperature coefficients of the dielectric constant （τε） moved from -710 to -880×10^-6℃^-1.

关键词： dielectric properties paraelectric tungsten bronze tantalates

The enhanced genomic 6mA metabolism contributes to the proliferation and migration of TSCC cells

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International Journal of Oral Science 2022年第1期14卷 100-112页

作者： Lei Xi Ying Yang Ying Xu Fangming Zhang Jinghui Li xiyang liu Zhenxi Zhang Quan Du State Key Laboratory of Natural and Biomimetic Drugs School of Pharmaceutical SciencesPeking UniversityBeijingChina Department of Stomatology Beijing Friendship HospitalCapital Medical UniversityBeijingChina

In contrast to the well-established genomic 5-methylcytosine(5mC),the existence of N^(6)-methyladenine(6 mA)in eukaryotic genomes was discovered only *** studies found that it was actively regulated in cancer cells,suggesting its involvement in the process of ***,the contribution of 6 mA in tongue squamous cell carcinoma(TSCC)still remains *** this study,a pan-cancer type analysis was first performed,which revealed enhanced 6mA metabolism in diverse cancer *** study was then focused on the regulation of 6 mA metabolism,as well as its effects on TSCC *** these aspects,genome 6mA level was found greatly increased in TSCC tissues and cultured *** knocking down 6mA methylases N6AMT1 and METTL4,the level of genomic 6mA was decreased in TSCC *** led to suppressed colony formation and cell *** contrast,knockdown of 6mA demethylase ALKBH1 resulted in an increased 6 mA level,enhanced colony formation,and cell *** study suggested that regulation of the NF-κB pathway might contribute to the enhanced migration of TSCC ***,in the case of TSCC,we have shown that genomic 6mA modification is involved in the proliferation and migration of cancer cells.

关键词： metabolism involvement cancer

碳纤维增强环氧树脂基复合材料圆管轴向压溃分层失效仿真

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机械工程学报 2020年第12期56卷 107-115页

作者：庄蔚敏刘洋刘西洋吉林大学汽车仿真与控制国家重点实验室长春130022

为了模拟单向碳纤维增强复合材料圆管的压溃失效形式及吸能特性,对圆管进行轴向压溃试验,获得圆管的压溃失效形式及压溃载荷-位移曲线。采用单层壳单元模型进行压溃仿真,确定MAT54材料模型中非试验可测量参数。建立多层壳单元模型,基于T... 详细信息

为了模拟单向碳纤维增强复合材料圆管的压溃失效形式及吸能特性,对圆管进行轴向压溃试验,获得圆管的压溃失效形式及压溃载荷-位移曲线。采用单层壳单元模型进行压溃仿真,确定MAT54材料模型中非试验可测量参数。建立多层壳单元模型,基于Tiebreak接触模拟分层失效,研究网格划分尺寸及壳单元层数对压溃失效形式的影响,通过与试验结果对比验证所建立模型的准确性。研究表明参数YCFAC和SOFT影响压溃载荷-位移曲线的峰值载荷和平均压溃载荷。网格尺寸和壳单元层数影响圆管的失效形式,网格尺寸越小,分层失效和基体开裂现象越明显。随着壳单元层数增加,初始峰值载荷呈递减趋势,所需计算时间呈指数型增长趋势。综合考虑计算成本和预测准确性,采用4层壳单元模型能够准确预测碳纤维圆管的轴向压溃性能和分层失效。

关键词：碳纤维增强复合材料压溃仿真吸能特性分层失效

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检方施治:防疫方书与清代的疫情防控

清史研究 2022年第1期129卷 47-57页

作者：刘希洋中国海洋大学中国社会史研究所青岛266100

抄录、编撰、刊印、传播、参阅防疫方书,是清代疫情期间常见的医疗实践活动。防疫方书的大量涌现是一次次疫病流行激发的结果,是疫情防控实践本身的重要组成部分。它们在染疫病人救治、防疫力量动员、防疫知识整合和普及等方面发挥着独... 详细信息

抄录、编撰、刊印、传播、参阅防疫方书,是清代疫情期间常见的医疗实践活动。防疫方书的大量涌现是一次次疫病流行激发的结果,是疫情防控实践本身的重要组成部分。它们在染疫病人救治、防疫力量动员、防疫知识整合和普及等方面发挥着独特的媒介作用,是相关人、事、物实现链接和互动的一种重要途径,是人们积极主动地应对疫病、控制疫情、维护生命健康的一种"原动力"。相较于其他常见防疫举措,防疫方书深度参与到多种疫情防控实践中,实际构成了一种自发性、分散性、非制度性的疫病应对机制,具有成本低廉、传导性强、覆盖面广、溢出效应大等特征。

关键词：清代防疫方书疫情防控知识传播医疗实践

基于改进自适应小生境遗传算法的机械臂逆运动学求解

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西北工业大学学报 2019年第3期37卷 488-495页

作者：杨惠珍刘西洋西北工业大学航海学院陕西西安710072 水下信息与控制重点实验室陕西西安710072

逆运动学求解对机械臂位姿控制和轨迹规划具有重要意义,针对逆运动学求解存在多解及通用性差的问题,提出了一种基于改进自适应小生境遗传算法的逆运动学求解算法。适应度函数融合位姿误差和“最柔顺”原则,不存在多解及奇异解问题;引入... 详细信息

逆运动学求解对机械臂位姿控制和轨迹规划具有重要意义,针对逆运动学求解存在多解及通用性差的问题,提出了一种基于改进自适应小生境遗传算法的逆运动学求解算法。适应度函数融合位姿误差和“最柔顺”原则,不存在多解及奇异解问题;引入减法聚类分析,提升算法通用性;对遗传算法进行改进,提升了算法收敛速度及精度。利用六自由度机械臂进行仿真实验,结果表明该算法收敛快、精度高,可求得唯一解。

关键词：逆运动学自适应小生境遗传算法