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LD-pumped acousto-optic 2-switched Pr:YLF pulsed laser at 604 nm

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Chinese Optics Letters 2024年第8期22卷 77-81页

作者： Wei yuan Canlin Jiang Huiying xu Zhiping Cai School of Electronic Science and Engineering Xiamen UniversityXiamen 361005China Center for Modern Educational Technology Guizhou Normal UniversityGuiyang 550001China Fujian Key Laboratory of Ultrafast Laser Technology and Applications Xiamen UniversityXiamen 361005China

We demonstrated an actively acousto-optic Q-switched pulsed laser based on Pr:YLF at 604 nm.A 604 nm continuous-wave(CW)laser with a maximum output power of 3.84 W was achieved for the first time,to the best of our *** Q-switched laser with a maximum average output power of 0.384 W,a narrowest pulse duration of 44.5 ns,a maximum single pulse energy of~64.1μJ,and a maximum peak power of~1.44 kW was obtained at a repetition rate of 6 *** far as we know,this was the first report of such a narrow pulse duration,high-power,and high-energy Q-switched pulsed laser at604 *** beam quality factors M_x~2and M_y~2were measured to be 2.87 and 2.40,*** results show that acousto-optic Q-switching is a promising method for obtaining pulsed lasers.

关键词： 604 nm acousto-optics Q-switching pulsed laser Pr:YLF crystal

Improved Convolutional Neural Network for Traffic Scene Segmentation

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Computer Modeling in Engineering & Sciences 2024年第3期138卷 2691-2708页

作者： Fuliang xu Yong Luo Chuanlong Sun hong Zhao College of Mechanical and Electrical Engineering Qingdao UniversityQingdao266071China

In actual traffic scenarios,precise recognition of traffic participants,such as vehicles and pedestrians,is crucial for intelligent *** study proposes an improved algorithm built on Mask-RCNN to enhance the ability of autonomous driving systems to recognize traffic *** algorithmincorporates long and shortterm memory networks and the fused attention module(GSAM,GCT,and Spatial Attention Module)to enhance the algorithm’s capability to process both global and local ***,to increase the network’s initial operation stability,the original network activation function was replaced with Gaussian error linear *** were conducted using the publicly available Cityscapes *** the test results,it was observed that the revised algorithmoutperformed the original algorithmin terms of AP_(50),AP_(75),and othermetrics by 8.7%and 9.6%for target detection and 12.5%and 13.3%for segmentation.

关键词： Instance segmentation deep learning convolutional neural network attention mechanism

Impaired pericyte-Müller glia interaction via PDGFRβsuppression aggravates photoreceptor loss in a rodent model of light-induced retinal injury

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International Journal of Ophthalmology(English edition) 2024年第10期17卷 1800-1808页

作者： Wei xu Li-Jin Cui Xiao-Ying Yang Xiao-yuan Cui Jian Guo Guo-Xing xu Department of Ophthalmology the First Affiliated Hospital of Fujian Medical UniversityFuzhou 350001Fujian ProvinceChina Department of Ophthalmology National Regional Medical CenterBinhai Campus of the First Affiliated Hospital of Fujian Medical UniversityFuzhou 350212Fujian ProvinceChina Fujian Institute of Ophthalmology Fuzhou 350001Fujian ProvinceChina

AIM:To investigate the involvement of pericyte-Müller glia interaction in retinal damage repair and assess the influence of suppressing the platelet-derived growth factor receptorβ(PDGFRβ)signaling pathway in retinal pericytes on photoreceptor loss and Müller glial ***:Sprague-Dawley rats were exposed to intense light to induce retinal *** antibody against PDGFRβwere deployed to block the signaling pathway in retinal pericytes through intravitreal *** histology and Müller glial reaction were assessed following light *** vitro,normal and PDGFRβ-blocked retinal pericytes were cocultured with Müller cell line(rMC-1)to examine morphological and protein expression changes upon supplementation with light-injured supernatants of homogenized retinas(SHRs).RESULTS:PDGFRβblockage 24h prior to intense light exposure resulted in a significant exacerbation of photoreceptor *** upregulation of GFAP and p-STAT3,observed after intense light exposure,was significantly inhibited in the PDGFRβblockage *** ther upregulation of cytokines monocyte chemoattractant protein 1(MCP-1)and interleukin-1β(IL-1β)was also observed following PDGFRβ*** the in vitro coculture system,the addition of light-injured SHRs induced pericyte deformation and upregulation of proliferating cell nuclear antigen(PCNA)expression,while Müller cells exhibited neuron-like morphology and expressed ***,PDGFRβblockage in retinal pericytes abolished these cellular responses to light-induced damage,consistent with the in vivo PDGFRβblockage ***:Pericyte-Müller glia interaction plays a potential role in the endogenous repair process of retinal *** of this interaction exacerbates photoreceptor degeneration in light-induced retinal injury.

关键词： pericyte Müller glia light-induced retinal injury platelet-derived growth factor receptorβ signal pathway

Boosting oxygen reduction activity and CO_(2) resistance on bismuth ferrite-based perovskite cathode for low-temperature solid oxide fuel cells below 600℃

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Journal of Energy Chemistry 2024年第3期90卷 600-609,I0013页

作者： Juntao Gao Zhiyun Wei Mengke yuan Zhe Wang Zhe Lü Qiang Li Lingling xu Bo Wei School of Physics Harbin Institute of TechnologyHarbin 150001HeilongjiangChina Key Laboratory of Functional Inorganic Material Chemistry Ministry of EducationSchool of Chemistry and Materials ScienceHeilongjiang UniversityHarbin 150080HeilongjiangChina School of Physics and Electronic Engineering Harbin Normal UniversityHarbin 150025HeilongjiangChina

Developing efficient and stable cathodes for low-temperature solid oxide fuel cells(LT-SOFCs) is of great importance for the practical ***,we propose a series of Sm-modified Bi_(0.7-x)Sm_xSr_(0.3)FeO_(3-δ) perovskites as highly-active catalysts for *** doping can significantly enhance the electrocata lytic activity and chemical stability of *** 600℃,Bi_(0.675)Sm_(0.025)Sr_(0.3)FeO_(3-δ)(BSSF25) cathode has been found to be the optimum composition with a polarization resistance of 0.098 Ω cm^2,which is only around 22.8% of Bi_(0.7)Sr_(0.3)FeO_(3-δ)(BSF).A full cell utilizing BSSF25 displays an exceptional output density of 790 mW cm^(-2),which can operate continuously over100 h without obvious *** remarkable electrochemical performance observed can be attributed to the improved O_(2) transport kinetics,superior surface oxygen adsorption capacity,as well as O_(2)p band centers in close proximity to the Fermi ***,larger average bonding energy(ABE) and the presence of highly acidic Bi,Sm,and Fe ions restrict the adsorption of CO_(2) on the cathode surface,resulting in excellent CO_(2) *** work provides valuable guidance for systematic design of efficient and durable catalysts for LT-SOFCs.

关键词： Low-temperature solid oxide fuel cell Perovskite cathode DFT calculations CO_(2) tolerance

Ecosystem service multifunctionality of mixed conifer-broad-leaved forests under climate change and forest management based on matrix growth modelling

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Forest Ecosystems 2024年第5期11卷 743-757页

作者： xue Du Xiangdong Lei Xiao He Jie Lan hong Guo Qigang xu State Key Laboratory of Efficient Production of Forest Resources Key Laboratory of Forest Management and Growth ModellingNational Forestry and Grassland AdministrationInstitute of Forest Resource Information TechniquesChinese Academy of ForestryBeijing 100091China College of Forestry and Horticulture Hubei Minzu UniversityEnshi 445000China East China Academy of Inventory and Planning National Forestry and Grassland AdministrationHangzhou 310000China

Climate change and forest management are recognized as pivotal factors influencing forest ecosystem services and thus ***,the magnitude and the relative importance of climate change and forest management effects on the multifunctionality remain unclear,especially for natural mixed *** this study,our objective is to address this gap by utilizing simulations of climate-sensitive transition matrix growth models based on national forest inventory plot *** evaluated the effects of seven management scenarios(combinations of various cutting methods and intensities)on the future provision of ecosystem services and multifunctionality in mixed conifer-broad-leaved forests in northeastern China,under four climate scenarios(SSP1-2.6,SSP2-4.5,SSP5-8.5,and constant climate).Provisioning,regulating,cultural,and supporting services were described by timber production,carbon storage,carbon sequestration,tree species diversity,deadwood volume,and the number of large living *** findings indicated that timber production was significantly influenced by management scenarios,while tree species diversity,deadwood volume,and large living trees were impacted by both climate and management *** storage and sequestration were notably influenced by both management and the interaction of climate and *** findings emphasized the profound impact of forest management on ecosystem services,outweighing that of climate scenarios *** found no single management scenario maximized all six ecosystem service *** upper story thinning by 5%intensity with 5-year interval(UST5)management strategy emerged with the highest multifunctionality,surpassing the lowest values by more than 20%across all climate *** conclusion,our results underlined the potential of climate-sensitive transition matrix growth models as a decision support tool and provided recommendations for long-term strategies for multifunctional forest management

关键词： Multifunctional forest management Thinning Transition matrix growth model Carbon sink Timber production

Nitric oxide removal from flue gas coupled with the Fe^(Ⅱ)EDTA regeneration by ultraviolet irradiation

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Chinese Journal of Chemical Engineering 2024年第4期68卷 133-143页

作者： yuan xu Ziwei Liu Ying Dai Jinbo Ouyang Zhuyao Li Yuling Zhu Jianhua Ding Feiqiang He School of Chemistry and Materials Science East China University of TechnologyNanchang 330013China

During wet complexation denitrification of flue gas,Fe^(Ⅱ)EDTA regeneration,also known as reducing Fe^(Ⅱ)EDTA and Fe^(Ⅱ)EDTA-nitric oxide(NO)to Fe^(Ⅱ)EDTA,is *** this paper,ultraviolet(UV)light was used for the first time to reduce Fe^(Ⅱ)*** experimental result demonstrated that Fe^(Ⅱ)EDTA-NO reduction rate increased with UV power increasing,elevated temperature,and initial Fe^(Ⅱ)EDTA-NO concentration ***^(Ⅱ)EDTA-NO reduction rate increased first and then decreased as pH value increased(2.0-10.0).Fe^(Ⅱ)EDTA-NO reduction with UV irradiation presented a first order reaction with respect to Fe^(Ⅱ)*** with other Fe^(Ⅱ)EDTA regeneration methods,Fe^(Ⅱ)EDTA regeneration with UV show more superiority through comprehensive consideration of regeneration rate and ***,NO absorption experiment by Fe^(Ⅱ)EDTA solution with UV irradiation confirmed that UV can significantly promote the NO removal performance of Fe^(Ⅱ)*** oxygen concentration(3%(vol))and acidic environment(pH=4)was favorable for NO *** UV power increasing as well as temperature decreasing,NO removal efficiency *** addition,the mechanism research indicates that NO from flue gas is mostly converted to NO_(2)-,NO_(3)-,NH_(4)^(+),N_(2),and N_(2)O with Fe^(Ⅱ)EDTA absorption liquid with UV *** strengthens NO removal in Fe^(Ⅱ)EDTA absorption liquid by forming a synergistic effect of ***,compared with NO removal methods with Fe^(Ⅱ)EDTA,Fe^(Ⅱ)EDTA combined UV system shows prominent technology advantage in terms of economy and secondary pollution.

关键词： Fe^(II)EDTA Ultraviolet Flue gas Nitric oxide Regeneration Absorption

Low-firing and temperature stability regulation of tri-rutile MgTa_(2)O_(6)microwave dielectric ceramics

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International Journal of Minerals,Metallurgy and Materials 2024年第8期31卷 1935-1943页

作者： Chengzhi xu hongyu Yang hongcheng Yang Linzhuang Xing yuan Wang Zhimin Li Enzhu Li Guorui Zhao School of Advanced Materials and Nanotechnology Xidian UniversityXi’an 710071China Academy of Advanced Interdisciplinary Research Xidian UniversityXi’an 710071China School of New Energy and Materials Southwest Petroleum UniversityChengdu 610500China National Engineering Research Center of Electromagnetic Radiation Control Materials and Key Laboratory of Multi-Spectral Absorbing Materials and Structures of Ministry of Education University of Electronic Science and Technology of ChinaChengdu 610054China Songshan Lake Materials Laboratory A1 Building University Innovation ParkDongguan 523808China

A glass frit containing Li_(2)O-MgO-ZnO-B_(2)O_(3)-SiO_(2)component was used to explore the low-temperature sintering behaviors and microwave dielectric characteristics of tri-rutile MgTa_(2)O_(6)ceramics in this *** good low-firing effects are presented due to the high matching relevance between Li_(2)O-MgO-ZnO-B_(2)O_(3)-SiO_(2)glass and MgTa_(2)O_(6)*** pure tri-rutile MgTa_(2)O_(6)structure remains unchanged,and high sintering compactness can also be achieved at 1150℃.We found that the Li_(2)O-MgO-ZnO-B_(2)O_(3)-SiO_(2)glass not only greatly improves the low-temperature sintering characteristics of MgTa_(2)O_(6)ceramics but also maintains a high(quality factor(Q)×resonance frequency(f))value while still improving the temperature ***,great microwave dielectric characteristics when added with 2wt%Li_(2)O-MgO-ZnO-B_(2)O_(3)-SiO_(2)glass can be achieved at 1150℃:dielectric constant,ε_(r)=26.1;Q×f=34267 GHz;temperature coefficient of resonance frequency,τ_(f)=-8.7×10^(-6)/℃.

关键词： MgTa_(2)O_(6) ceramic microwave dielectric characteristics glass

Sn-decorated CeO_(2) with different morphologies for direct dehydrogenation of ethylbenzene

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Journal of Rare Earths 2024年第1期42卷 102-109,I0004页

作者： Kai Zhang Guoju Cui Mengzhen yuan Huiwen Huang Ning Li Jiale xu Guowei Wang Chunyi Li State Key Laboratory of Heavy Oil Processing China University of Petroleum(East China)Qingdao266580China Petrochemical Plant of Sinopec Shengli Oilfield Company Dongying257237China College of Chemical and Biological Engineering Shandong University of Science and TechnologyQingdao266590China

Three Sn-decorated ceria catalysts with various morphologies(rods,particles,and cubes)were prepared and applied to the direct dehydrogenation of ***-technology characterizations,including X-ray photoelectro n spectroscopy(XPS),H_(2)-tempe rature programmed reduction(H_(2)-TPR),and Raman spectroscopy,prove that the oxygen vacancies are the active sites for ethylbenzene dehydrogenation,which can be regulated by engineering CeO_(2) morphology and enhanced via introducing metal *** the results of activity test,the catalytic activities for ethylbenzene dehydrogenation over different samples are closely dependent on the amount of oxygen *** reduced Sn-decorated CeO_(2) catalyst with nanoparticles morphology exhibits better dehydrogenation performance than the other two studied catalysts at 600℃.This work provides an effective approach to regulate the active oxygen vacancies and further enhance the dehydrogenation activities through engineering the surface morphology of the catalyst and introducing suitable additives.

关键词： Ethylbenzene dehydrogenation CeO_(2) Sn Morphology Oxygen vacancy Rare earths

On the low cycle fatigue behaviour of an Al-Zn-Mg-Cu alloy processed via non-isothermal ageing

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Journal of Materials Science & Technology 2024年第1期168卷 227-238页

作者： Guangyi Guo Guofu xu yuan Tang Zhihao Zhao Zhihao Yi Haoran Li Ruohan Wang Xiaoyan Peng School of Materials Science and Engineering Central South UniversityChangsha 410083China Key Laboratory of Nonferrous Materials Science and Engineering of Ministry of Education Changsha 410083China

The low cycle fatigue behaviour of an Al-Zn-Mg-Cu alloy processed via non-isothermal ageing(NIA)was examined at different strain *** showed that NIA improved the low cycle fatigue life(more than 7000 cycles)by optimising the precipitate configuration within 5.5 h while maintaining comparable mechanical properties(570 MPa for tensile strength)and conductivity(nearly 39%IACS)to conventional isothermal ageing,*** observation combined with molecular dynamic simula-tion revealed that precipitation configuration manipulated by NIA had a crucial effect on fatigue resis-tance.A great number of repeatedly sheared and locally destructed GP zones enhanced co-planar slip and slip localisation in the under-aged alloy during the early stage of NIA,responsible for the dramatic displacement steps on the surface and resultant poor fatigue *** the NIA further proceeded,moderately coarsened precipitates with an average dimension of 6.0 nm and elevated number density ef-fectively impeded the dislocation movement and weaken the slip localisation to a great extent,improving the fatigue performance within a few hours.

关键词： Non-isothermal ageing Fatigue Al-Zn-Mg-Cu alloy Precipitate manipulation Slip localization