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Simulation and Verification of Machining Deformation for Composite Materials

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Journal of Wuhan University of Technology(Materials Science) 2014年第5期29卷 917-922页

作者：刘凯叶金蕊 TANG Zhanwen liu weiping ZHANG Boming School of Materials Science and Engineering Beihang University Aeronautical Manufacturing Technology Institute Shanghai Aircraft Manufacturing CO

Prepreg properties including cure kinetics, cure shrinkage, and coefficient of thermal expansion were analyzed. A simulation method based on ＂element birth and death＂ method of Finite element analysis （FEA） was presented to simulate the cutting process and predict the machining deformation for composite laminates and stiffened panels. The comparisons between the simulation results and experimental data showed good agreement. It is found that residual stresses are the main source of machining deformation for composites and machining deformation is expected to happen only if there are stress gradients along the machining direction. There is no machining deformation for composite laminates due to its uniform stresses distribution in plane, while machining deformation can be observed obviously for T-shape stiffened composite panels. Attention should be paid to machining deformation to avoid the mismatch during assembly.

关键词： composite machining deformation residual stress finite element analysis (FEA)

Study on Sensitivity Improving of Fiber Bragg Grating Based pH Sensor

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Photonic Sensors 2014年第1期4卷 28-33页

作者： Xiongchang Liang Shun’er Chen Hongbin Huang weiping liu Department of Electronic Engineering Jinan UniversityGuangzhou510632China Key Laboratory of Optoelectronic Information and Sensing Technologies of Guangdong Higher Educational Institutes Jinan UniversityJinan510632China Optoelectronic and Fiber Sensing Institute of Beijing Pioptics Beijing100176China

The key factor of the sensitivity in the FBG-based pH sensor is analyzed in detail. A multi-thin-layer structure of the gel coated cover was proposed and implemented with a special process. The sensors with the coated thickness of 420 ~m, 500 ~m, and 580 ~m were built up, respectively. The corresponding spectral shifts of 0.08nm, 0.13nm, and 0.22nm were detected when the pH sensors were soaked in the pH value of 3-9. Meanwhile, the sensor with the gel layer thickness of 580 ~tm was measured in the optimum measurement time period with the pH value changing from 3-12, in which the detected sensitivity of 52pm/pH was achieved in the pH range of 6-12.

关键词： Fiber Bragg grating hydrogel pH sensor sensitivity

Facile shape and size-controlled growth of uniform magnetite and hematite nanocrystals with tunable properties

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Science China Chemistry 2011年第6期54卷 923-929页

作者： CHEN LiQiao liu weiping CHEN JiaLin YANG XianFeng liu Jia FU XiongHui WU MingMei Key Laboratory of Bioinorganic and Synthetic Chemistry Ministry of Education' State Key Laboratory of Optoelectronic Materials and Technologies' School of Chemistry and Chemical Engineering Sun Yat-Sen (Zhongshan) University Guangzhou 510275 China State Key Lab of Advanced Technology for Comprehensive Utilization of Platinum Metals ' Kunming Institute of Precious Metals Kunming 650106 China

Monodispersed magnetite Fe3O4 and hematite α-Fe2O3 nanocrystals have been grown in co-solvents of alcohol and water. Either the shape or the size of the nanocrystals could be easily controlled. Both the phases and nanostructures have been characterized by powder X-ray diffraction patterns and electron microscopy. The magnetic and catalytic properties of these products were investigated and compared with each other. The obtained results clearly demonstrate that these iron oxide nanocrystals are soft ferromagnetic at room temperature and α-Fe2O3 has a more effective catalytic property on the thermal decomposition of ammonium perchlorate than Fe3O4. Based on the experimental data, it is proposed that the magnetic and catalytic properties of these nanocrystals are dependent not only on the size and shape, but also on the surface structure of the nanocrystals. The nanoplates with significant anisotropic nanostructure demonstrate a highly enhanced performance as compared to nanoparticles.

关键词： iron oxide nanocrystals growth properties

Cooperative coupling of photocatalytic production of H_(2)O_(2) and oxidation of organic pollutants over gadolinium ion doped WO_(3) nanocomposite

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Chinese Chemical Letters 2023年第9期34卷 258-263页

作者： Jiaying Wang Jiejie Wang Sijin Zuo Jianchuan Pei weiping liu Juan Wang Institute of Environmental Health MOE Key Laboratory of Environmental Remediation and Ecosystem HealthCollege of Environment and Resources ScienceZhejiang UniversityHangzhou 310058China College of Environment and Resources Zhejiang A&F UniversityHangzhou 311300China

This work reported the lanthanide ion(Gd^(3+))doped tungsten trioxide(Gd-WO_(3))nanocrystal for remarkable promoted photocatalytic degradation of organic pollutants and simultaneous in-situ H_(2)O_(2)*** doped lanthanide ion(Gd^(3+)),Gd-WO_(3)showed a much broad and enhanced solar light absorption,which not only promoted the photocatalytic degradation efficiency of organic compounds,but also provided a suitable bandgap for direct reduction of oxygen to H_(2)O_(2).Additionally,the isolated Gd^(3+)on WO_(3)surface can efficiently weaken the*OOH binding energy,increasing the activity and selectivity of direct reduction of oxygen to H_(2)O_(2),with a rate of 0.58 mmol L^(-1)g^(-1)h^(-1).The in-situ generated H_(2)O_(2)can be subsequently converted to·OH based on Fenton reaction,further contributed to the overall removal of organic *** results demonstrate a cascade photocatalytic oxidation-Fenton reaction which can efficiently utilize photo-generated electrons and holes for organic pollutants treatment.

关键词： Lanthanide ion Photocatalytic oxidation Photocatalytic generation of H_(2)O_(2)in situ Cascade reaction

Manganese catalyzed urea and polyurea synthesis using methanol as C1 source

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Chinese Chemical Letters 2023年第4期34卷 304-308页

作者： Jiaxin Guo Jun Tang Hui Xi Sheng-Yin Zhao weiping liu Key Laboratory of Science and Technology of Eco-Textile Ministry of EducationCollege of ChemistryChemical Engineering and BiotechnologyDonghua UniversityShanghai 201620China Key Laboratory of Tobacco Flavor Basic Research of CNTC Zhengzhou Tobacco Research Institute of CNTCZhengzhou 450001China

The manganese-catalyzed dehydrogenative coupling between methanol and amines for the synthesis of ureas and polyureas is described. Importantly, catalytic efficiency can be improved by the newly synthesized MACHO ligands. Furthermore, this highly atom-economical protocol demonstrates a broad substrate scope with good functional group tolerance, producing H_(2)as the sole byproduct. Mechanistic studies disclose that formamide is formed through manganese-catalyzed formylation of amine with *** dehydrogenation affords a transient isocyanate, which is attacked by another equivalent of amine to provide the final product.

关键词： Manganese Homogeneous catalysis Urea synthesis Polyurea synthesis Methanol as C1 source

Determination of Four Chiral Pesticides in Soil by QuEChERS-Ultra Performance Liquid Chromatography-Tandem Mass Spectrometry

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Wuhan University Journal of Natural Sciences 2018年第5期23卷 369-375页

作者： YAO Xiaoshan YANG Fangxing liu weiping JIN Shiwei College of Chemistry and Materials Science South-Central University for Nationalities Wuhan 430074 Hubei China College of Environmental & Resource Sciences ZhejiangUniversity Hangzhou 310058 Zhejiang China

The enantiomer residues of metalaxyl, napropamide, triticonazole and metconazole were detected in soil by Qu EChERS-ultra performance liquid chromatography-tandem mass spectrometry（UPLC-MS/MS）. The soil sample was extracted with acetonitrile containing 1% acetic acid and purified using Qu ECh ERS method. Quantitative analysis for the enantiomers of these four chiral pesticides was performed in MS in multi-response monitoring（MRM） mode by external standard method. All enantiomers showed good linearity in the range of 0.5 to 50 μg/L. The average recoveries of enantiomers in soil were 81.74% to 105.79% with relative standard deviations（RSDs） from 3.69% to 7.86%. The method quantitative limit（MQL） was 5.3-30.3 ng/kg. The method can be used for rapid screening and determination of chiral pesticides in soil.

关键词： ultra performance liquid chromatography-tandemmass spectrometry QuEChERS soil chiral pesticide enantiomersresidues

Primary gastrointestinal mantle lymphoma with massive bleeding: a case report and literature review

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Chinese Journal of Cancer Research 2013年第2期25卷 250-253页

作者： Wen Zheng Yuqin Song Ningjing Lin Meifeng Tu weiping liu Jun Zhu Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education) Department of Lymphoma Peking University Cancer Hospital & Institute

The incidence of primary gastrointestinal lymphomas （PGILs） has been increasing. The clinical presentation and treatment of PGIL are distinct from those of nodular lymphomas. Symptoms include abdominal pain, abdominal mass, changes in bowel habits, obstruction, and bleeding. Less life- threatening gastrointestinal bleeding occurs after chemotherapy and few reports have focused on the bleeding of PGILs. We report a case of severe gastrointestinal bleeding caused by low-dose chemotherapy, which was dramatically improved by rituximab monotherapy treatment. The prevention and treatment of gastrointestinal bleeding in PGIL should be given much attention.

关键词： Gastrointestinal tract mantle lymphoma bleeding

取代基团修饰苯基吡啶类铱磷光配合物的合成、结构及光物理性能

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无机化学学报 2025年第2期41卷 235-244页

作者：常桥稳张柯黄光英李诺楠刘伟平白福全晏彩先冯洋洋左川昆明贵金属研究所稀贵金属综合利用新技术国家重点实验室云南省贵金属实验室有限公司贵研化学材料(云南)有限公司昆明650106 昆明理工大学材料科学与工程学院昆明650093 吉林大学化学学院理论化学研究所长春130023

为研究取代基对铱磷光配合物光物理性质的影响,以2,4-二(2,4-二取代基苯基)吡啶[2,4-(2,4-2R-phenyl)2py,R=甲基(HL1)、甲氧基(HL2)、氟(HL3)、三氟甲基(HL4)]为主配体,即在主配体上2个苯基的2位和4位同时引入4个相同的甲基、甲氧基、... 详细信息

为研究取代基对铱磷光配合物光物理性质的影响,以2,4-二(2,4-二取代基苯基)吡啶[2,4-(2,4-2R-phenyl)2py,R=甲基(HL1)、甲氧基(HL2)、氟(HL3)、三氟甲基(HL4)]为主配体,即在主配体上2个苯基的2位和4位同时引入4个相同的甲基、甲氧基、氟或三氟甲基,同时以乙酰丙酮(Hacac)为辅助配体,合成出4个铱磷光配合物(Ln)2Ir(acac)[n=1(Ir1)、2(Ir2)、3(Ir3)、4(Ir4)]。通过元素分析、核磁共振谱(1H NMR和13C NMR)和单晶X射线衍射表征了铱磷光配合物的组成、空间结构和分子堆积。通过溶液和固态光致发光光谱、紫外可见吸收光谱、荧光寿命和理论计算对铱磷光配合物的光物理性能进行了深入和系统的研究。结果表明:4个铱磷光配合物均呈稍微扭曲的八面体构型,中心IrⅢ分别与2个主配体的C和N原子配位形成五元螯合环,同时和辅助配体acac-的2个氧原子配位形成稳定的六元螯合环。配合物Ir1、Ir2、Ir3和Ir4在溶液状态下的发射波长分别为537、515、514和553 nm,溶液中量子产率分别为68%、83%、88%和81%,荧光寿命分别为26.75、163.93、64.50和330.39 ns。4个铱磷光配合物具有不同的电子云分布特征,取代基能够调控电子云在苯环上的分布,进一步实现发射波长、发光颜色,荧光寿命和分子堆积的调控。

关键词：铱(Ⅲ)配合物磷光材料取代基苯基吡啶光物理性能

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基于多尺度序列特征融合的林区害虫检测算法

林业科学 2025年第2期61卷 21-30页

作者：唐延龄韩巧玲赵玥刘卫平郑一力赵燕东徐钐钐北京林业大学工学院北京100091

【目的】针对虫情测报灯采集到的林区害虫样本种类多、尺寸复杂及密集遮挡问题,提出了一种多尺度序列特征融合检测算法(MPD-YOLO),用于提升林区害虫检测的精确度,为林区害虫监测和防护提供了新的技术路径。【方法】首先,以采集于北京、... 详细信息

【目的】针对虫情测报灯采集到的林区害虫样本种类多、尺寸复杂及密集遮挡问题,提出了一种多尺度序列特征融合检测算法(MPD-YOLO),用于提升林区害虫检测的精确度,为林区害虫监测和防护提供了新的技术路径。【方法】首先,以采集于北京、河北、山西等地的林区害虫图像为基础,构建包含18类林区害虫的数据集。数据集涵盖不同场景下的害虫图像,为算法的训练与测试提供了可靠的数据支撑。其次,为提高小目标害虫的检测效果,利用3D卷积对小目标进行更为深入的尺度序列特征提取,MPD-YOLO方法引入尺度序列特征融合模块(SSFF),有效提升模型对小目标的感知能力。最后,为解决密集遮挡和多尺度害虫并存情况下的模型检测能力,MPD-YOLO方法提出了三重特征编码高效聚合模块(TFE-ELAN),通过将不同尺寸特征图进行特征融合,增强多层特征图之间信息的关联性,提升了模型的检测性能。【结果】在相同试验条件下,本研究在构建的数据集上对MPD-YOLO进行大量试验,并与主流的目标检测算法(YOLO系列、Faster-CNN等)进行对比分析。MPD-YOLO方法具有最佳的害虫识别精度,其F1-score和m AP分别达到88.43%和91.92%,比次优方法YOLOv8x分别高1.45%和1.22%。相比于原网络模型YOLOv7,MPD-YOLO的F1-score与mAP分别比YOLOv7高0.72%和2.8%,证明了本文所提方法在处理复杂目标检测任务中的优势。此外,本研究中消融试验,分析了尺度序列特征融合模块和三重特征编码高效聚合模块对整体性能的贡献,验证了各模块设计的有效性。【结论】本文提出的MPD-YOLO算法,有效提升了复杂环境下多尺度害虫的检测性能,在处理复杂环境下的检测任务时表现出较高的鲁棒性。

关键词：林区害虫防控林区生态系统小目标检测 YOLOv7 特征融合

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