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Emission characteristics of biogenic volatile organic compounds in a subtropical pristine forest of southern China

Journal of Environmental Sciences 2025年第2期148卷 665-682页

作者： Xi Chen Daocheng Gong Youjing Lin qiao xu Yujin Wang Shiwei Liu Qinqin Li Fangyuan Ma Jiangyong Li Shuo Deng Hao Wang Boguang Wang Institute for Environmental and Climate Research Jinan UniversityGuangzhou 511443China Guangdong Provincial Observation and Research Station for Atmospheric Environment and Carbon Neutrality in Nanling Forests China Australia-China Centre for Air Quality Science and Management(Guangdong) Guangzhou 511443China Hainan Provincial Ecological and Environmental Monitoring Center Haikou 571126China

Emission characteristics of biogenic volatile organic compounds(BVOCs)from dominant tree species in the subtropical pristine forests of China are extremely *** we conducted in situ field measurements of BVOCs emissions from representative mature evergreen trees by using dynamic branch enclosures at four altitude gradients(600-1690ma.s.l.)in the Nanling Mountains of southern *** characteristics as well as seasonal and altitudinal variations were *** emission rates and canopyscale emission factors were then *** showed that BVOCs emission intensities in the wet season were generally higher than those in the dry *** were the dominant BVOCs emitted from most broad-leaved trees,accounting for over 70%of the *** superba,Yushania basihirsuta and Altingia chinensis had relatively high emission intensities and secondary pollutant formation *** localized emission factors of isoprene were comparable to the defaults in the Model of Emissions of Gases and Aerosols fromNature(MEGAN),while emission factors of monoterpenes and sesquiterpenes were 2 to 58 times of those in the *** results can be used to update the current BVOCs emission inventory in MEGAN,thereby reducing the uncertainties of BVOCs emission estimations in forested regions of southern China.

关键词： Biogenic volatile organic compounds(BVOCs) Dynamic enclosure system Nanling Mountains Emission factors Emission rates Chemical reactivity

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基于非线性分析的无线通信识别系统优化研究

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农机化研究 2025年第1期47卷 125-129页

作者：王永虎乔旭安重庆交通大学重庆402265 重庆城市职业学院重庆402160

为了进一步提升插秧机的通信效率及整机作业效率,以无线通信识别模块为研究对象,基于非线性分析控制理论展开优化研究。结合插秧机的作业环境特征和各组件协调作业特点,从通信信号的非线性处理和保证抗干扰能力角度入手,建立通信识别系... 详细信息

为了进一步提升插秧机的通信效率及整机作业效率,以无线通信识别模块为研究对象,基于非线性分析控制理论展开优化研究。结合插秧机的作业环境特征和各组件协调作业特点,从通信信号的非线性处理和保证抗干扰能力角度入手,建立通信识别系统的非线性控制器模型,并针对系统的输入输出和接口模块完成电路控制与程序优化布局。同时,进行插秧作业通信监测验证试验,结果表明:此非线性分析应用机理下,插秧机作业的智能性与精准性得到显著提高,通过非线性控制实现了细致有效的数据计算分析,通信传输效率相对提升了5.69%,插秧深度合格率可达96.78%,满足智能插秧设计要求。

关键词：智能插秧无线通信识别非线性分析电路控制通信传输效率

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Towards Optimization and Assessment of the Chinese New-generation VLBI Network for Earth Orientation Parameters Monitoring

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Research in Astronomy and Astrophysics 2025年第2期 256-268页

作者： Hao Xiang Zhong-Kai Zhang Lan Du Ze-Jun Liu xu-qiao Wang College of Geospatial Information Information Engineering University Henan Industrial Technology Academy of Spatio-Temporal Big Data College of Geography and Environmental Science Henan University

The Earth Orientation Parameters(EOP) provide a time-varying transition relationship between the International Terrestrial Reference Frame and the International Celestial Reference Frame. To support deep space exploration and the Beidou Navigation Satellite System, the Chinese New-generation Very Long Baseline Interferometry Network(CNVN) is under construction for independent monitoring of the EOP. This paper evaluates the performance of existing 4-antenna CNVN through a batch generated observation schedules followed by extensive Monte Carlo simulations. The optimal positions of the fifth and sixth antennas of CNVN are found from 24hypothetical antenna positions uniformly distributed in China. In this process, the weighted parameters are optimized, which not only reduce the possibility of large error of EOP estimation accuracy due to unreasonable combination, but also greatly reduce the calculation cost.

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A pilot exploration with Posiphen to normalize amyloid precursor protein in Down syndrome

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Neural Regeneration Research 2021年第12期16卷 2420-2421页

作者： xu-qiao Chen Department of Neurosciences University of California San DiegoLa JollaCAUSA

Down syndrome(DS)pathology:DS is the most common cause of Alzheimer’s disease(AD)and has a known AD-causing genetic variation which is trisomy of the whole or part of Homo sapiens chromosome 21(HSA21)(Chen and Mobley,2019a).Compared with AD,DS usually present with various symptoms and manifestations which are related to dysfunction of multiple body systems;the extra copies of the many genes present in HSA21 in DS can cause various developmental problems including neurodevelopmental deficits,which underlie the physical features in DS and may also contribute to the ADrelated neurological symptoms of DS like cognition decline(Antonarakis et al.,2020).

关键词： al. amyloid pathology

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The Average Errors for Lagrange Interpolation on the Wiener Space

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Acta Mathematica Sinica,English Series 2012年第8期28卷 1581-1596页

作者： Gui qiao xu Department of Mathematics Tianjin Normal University

For the weighted approximation in Lp-norm, we determine the asymptotic order for the p- average errors of Lagrange interpolation sequence based on the Chebyshev nodes on the Wiener space. We also determine its value i... 详细信息

关键词： Chebyshev polynomial Lagrange interpolation weighted Lp-norm Wiener space

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Synaptic dysfunction in Down syndrome:an emerging role for circulatingβ2-microglobulin

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Signal Transduction and Targeted Therapy 2023年第6期8卷 2445-2446页

作者： xu-qiao Chen Department of Neurosciences University of California San DiegoLa JollaCA92093USA

Recent research by Gao et *** in Cell proposes that circulatingβ2-microglobulin impairs synaptic function through antagonizing NMDA receptors in two mouse models of Down syndrome(DS),providing a potentially novel the... 详细信息

关键词： microglobulin al. β2

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Study on tidal gravity observations obtained at stations Zhongshan and Changcheng, Antarctic

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Acta Seismologica Sinica(English Edition) 2001年第3期14卷 325-332页

作者： xu Jian-qiao Laboratory of Dynamic Geodesy Institute of Geodesy and Geophysics Chinese Academy of Sciences

Based on the international tidal gravity reference values at station Wuhan, the tidal gravity parameters, including the amplitude factors and phase differences are determined accurately by using the observations with three La-Coste-Romberg (LCR) gravimeters (G-589, ET-20 and ET-21) at stations Zhongshan and Changcheng in the Antarctic, respectively. The standard deviations of the determined amplitude factors of the main tidal waves are better than 0.5%. The amplitude of each tidal wave observed at station Zhongshan is much less than that of the same wave at station Changcheng. The differences of amplitude factors in the diurnal band (O1) at these two stations are less than 7% while those in the semi-diurnal band (M2) are larger than 40%. The influences of meteorology factors, such as atmospheric pressure and temperature, on the tidal gravity observations are very obvious. The oceanic loading effects on the tidal gravity are also very prominent. It is found that the amplitude of the final residual vector of every tidal wave reduces significantly after oceanic correction based on the Schwiderski's global co-tides. However, because the local oceanic loading is not taken into account, the discrepancies of amplitude factors of wave O1 observed at Zhongshan from the corresponding values of theoretical tidal model are about 4%, and 9% at Changcheng.

关键词： stations Zhongshan and Changcheng Antarctic tidal gravity observations international tidal gravity reference values theoretical tidal model P223.9

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超高效液相色谱-串联质谱法测定水体沉积物中17种新烟碱类杀虫剂及代谢物的残留量

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现代化工 2025年第1期45卷 261-265页

作者：徐彦杨继伟李剑徐巧俞晓峰姜佳钦杭州谱育科技发展有限公司浙江杭州310000 浙江工业大学化学工程学院浙江杭州310000

建立了基于全自动加速溶剂萃取-超高效液相色谱-串联质谱法检测水体沉积物中17种新烟碱类杀虫剂及代谢物残留的分析方法,17种目标物的质量浓度在一定范围内与对应的峰面积呈线性关系,该方法的检出限(3.143s)为0.0007~0.0022μg/kg。在0... 详细信息

建立了基于全自动加速溶剂萃取-超高效液相色谱-串联质谱法检测水体沉积物中17种新烟碱类杀虫剂及代谢物残留的分析方法,17种目标物的质量浓度在一定范围内与对应的峰面积呈线性关系,该方法的检出限(3.143s)为0.0007~0.0022μg/kg。在0.02、0.2、1.5μg/kg加标水平下的平均回收率为82.70%~114.30%,日内精密度和日间精密度的相对标准偏差分别为1.4%~9.4%和3.8%~9.7%。

关键词：全自动加速溶剂萃取新烟碱类杀虫剂超高效液相色谱-串联质谱法水体沉积物

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观音寺长江大桥索塔静力性能研究及其基础等效刚度计算

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科技通报 2025年第2期41卷 98-105页

作者：刘子牛许巧长沙理工大学土木工程学院长沙410114

观音寺长江大桥的索塔采用A型塔结构,其塔柱向两侧倾斜,导致传递至基础的荷载存在一定的偏心效应,准确的等效耦合承台基础的各向刚度,对提升整体结构有限元分析的精度具有重要意义。基于承台-桩基体系刚度与有限元等效刚度相等的原理,... 详细信息

观音寺长江大桥的索塔采用A型塔结构,其塔柱向两侧倾斜,导致传递至基础的荷载存在一定的偏心效应,准确的等效耦合承台基础的各向刚度,对提升整体结构有限元分析的精度具有重要意义。基于承台-桩基体系刚度与有限元等效刚度相等的原理,利用三杆系单元模拟承台-桩基体系,本文采用结构力学的位移法推导得到承台桩基的等效刚度矩阵,提出了一种在荷载作用下求解承台-桩基等效单元特性的方法。在此基础上,通过有限元分析,研究了分离式承台与一体式承台对观音寺长江大桥A型塔静力性能的影响,并对不同承台形式在塔柱应力分布和承台抗推刚度方面的差异进行了对比分析。研究结果表明:使用等效刚度法对群桩基础进行模拟的有限元模型,其计算结果与实测结果吻合较好,满足工程精度需求;分离式承台能显著改善该A型塔塔柱根部的应力,相较于一体式承台的最大拉应力2.3 MPa,分离式承台的最大拉应力仅为0.6 MPa。此外,分离式承台具有足够的抗推刚度,有效承担A型塔的荷载,确保其结构位移保持在允许范围内。

关键词： A型塔等效基础静力性能分离式承台一体式承台

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Involvement of T-complex protein 1-ring complex/chaperonin containing T-complex protein 1(TRiC/CCT) in retrograde axonal transport through tau phosphorylation

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Neural Regeneration Research 2019年第4期14卷 588-590页

作者： xu-qiao Chen Department of Neurosciences University of California San Diego

The cytosolic chaperonin T-complex protein 1-ring complex(TRiC)or chaperonin containing T-complex protein 1(CCT)is essential in de novo folding of approximately 10%of the eukaryotic,newly translated polypeptides as well as misfolded *** is a close link between the TRiC/CCT cytosolic chaperonin and neurodegenerative diseases(Lopez et al.,2015).A lot of research suggests that CCT plays neuroprotective roles in neurodegenerative diseases including Huntington’s disease(Lopez et al.,2015).Either overexpression of a single or all eight subunits(CCT1-8)or treatment of the substrate-binding apical domain of yeast CCT1(ApiCCT1)prevented mutant Huntingtin aggregation and improved cellular and neuronal functions(Zhao et al.,2016).Importantly,our recent study has demonstrated that both CCT and ApiCCT could reduce mutant Huntingtin level and enhance both anterograde and retrograde axonal transport of brain-derived neurotrophic *** results led to restoration of the trophic status of striatal neurons from a bacterial artificial chromosome transgenic mouse model of Huntington’s disease(Zhao et al.,2016).Axonal transport is regulated by many factors including microtubule-associated protein tau,which promotes tubulin polymerization and stabilizes *** interaction between tau and microtubules plays a vital role in the pathogenesis of multiple neurodegenerative diseases(Wang and Mandelkow,2016).Interestingly,tau phosphorylation is also observed in brains of several Huntington’s disease mouse models and Huntington’s disease patients(Gratuze et al.,2016).In a recent study,we explored if CCT subunit has any effect on axonal transport in a tau-dependent pathway(Chen et al.,2018b).We focused on the retrograde axonal transport of brain-derived neurotrophic factor,as neurotrophic factor-mediated signaling in the form of signaling endosome is essential in both the developing and the mature nervous system and dysregulation of trafficking of neurotrophic fact

关键词： T-complex protein 1-ring complex(TRiC) chaperonin containing T-complex protein 1(CCT) Involvemen

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