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Seasonal variation and sources of low molecular weight organic acids in precipitation in the rural area of Anshun

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Chinese Science Bulletin 2011年第10期56卷 1005-1010页

作者： ZHANG YanLin LEE xinqing CAO Fang HUANG DaiKuan State Key Laboratory of Organic Geochemistry Guangzhou Institute of Geochemistry Chinese Academy of Sciences Guangzhou 510640 China State Key Laboratory of Environmental Geochemistry Institute of Geochemistry Chinese Academy of Sciences Guiyang 550002 China

Low molecular weight (LMW) organic acids are important and ubiquitous chemical constituents in the atmosphere.A comprehensive study of the chemical composition of precipitation was carried out from June 2007 to June 2008 at a rural site in Anshun,in the west of Guizhou Province,*** this period,118 rainwater samples were collected and the main LMW carboxylic acids were determined using ion *** average pH of rainwater was 4.89 which is a typical acidic *** most abundant carboxylic acids were formic acid (volume weight mean concentration:8.77 μmol L-1) and acetic acid (6.90 μmol L-1),followed by oxalic acid (2.05 μmol L-1).The seasonal variation of concentrations and wet deposition fluxes of organic acids indicated that direct vegetation emissions were the main sources of the organic *** concentrations were observed in winter and were ascribed to the low winter rainfall and the contribution of other air pollution sources northeast of the study *** ratio of formic and acetic acids in the precipitation ([F/A] T) was proposed as an indicator of pollution *** suggested that the pollution resulted from direct emissions from natural or anthropogenic *** with acid precipitation in other urban and rural areas in Guizhou showed that there was a decreasing contribution of LMW organic acids to free acidity and all anions in rainwater from urban to remote rural ***,it is necessary to control emissions of organic acids to reduce the frequency of acid rain,especially in rural and remote areas.

关键词：低分子量有机酸农村地区季节变化降水安顺平均浓度化学成分污染来源

Deposition of duststorm particles during 2000–2012 in the South Yellow Sea,China based on satellite data

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Acta Oceanologica Sinica 2017年第4期36卷 46-53页

作者： YANG Dingtian YIN Xiaoqing ZOU xinqing GAO Jianhua SHAN Xiujuan State Key Laboratory of Oceanography in the Tropics South China Sea Institute of OceanologyChinese Academy of Sciences School of Geographical and Oceanographic Sciences Nanjing University Shandong Provincial Key Laboratory of Fishery Resources and Ecological Environment Yellow Sea Fisheries Research InstituteChinese Academy of Fishery Sciences

In this study,about 220 satellite images between 2000 and 2012 were obtained from FY-series,MODIS,CBERS,HJ-1A and HJ-1B to estimate the impact of duststorms on the South Yellow Sea（SYS）,which serve as an important source of particles *** analyzing results from the images support a total occurrence of 88 duststorms（including the locally-generated dusty weather） that affected the SYS during 2000–*** annual occurrence was about 4–10 times（10 times in 2000 and 2004;four times in 2009 and 2012）,predominantly in March（29%）,April（33%） and May（22%）.By mapping the distribution of their frequency,the duststorms influencing the SYS were found primarily moving from the northwest（39 times,44.3%） and west（37 times,42%） to the study region with only 11 duststorms（12.5%） coming from the north and 1 duststorm（1%） from the *** estimated that an annual amount of 0.5–3.5 million tons of sediment particles was brought to the SYS by the duststorms during 2000–2012.

关键词： duststorm particle deposition satellite data South Yellow Sea

An infrared target intrusion detection method based on feature fusion and enhancement

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Defence Technology（防务技术） 2020年第3期16卷 737-746页

作者： Xiaodong Hu xinqing Wang Xin Yang Dong Wang Peng Zhang Yi Xiao College of Field Engineering Army Engineering University of PLANanjing210007China

Infrared target intrusion detection has significant applications in the fields of military defence and intelligent *** view of the characteristics of intrusion targets as well as inspection difficulties,an infrared target intrusion detection algorithm based on feature fusion and enhancement was *** algorithm combines static target mode analysis and dynamic multi-frame correlation detection to extract infrared target features at different *** them,LBP texture analysis can be used to effectively identify the posterior feature patterns which have been contained in the target library,while motion frame difference method can detect the moving regions of the image,improve the integrity of target regions such as camouflage,sheltering and *** order to integrate the advantages of the two methods,the enhanced convolutional neural network was designed and the feature images obtained by the two methods were fused and *** enhancement module of the network strengthened and screened the targets,and realized the background suppression of infrared *** on the experiments,the effect of the proposed method and the comparison method on the background suppression and detection performance was evaluated,and the results showed that the SCRG and BSF values of the method in this paper had a better performance in multiple data sets,and it’s detection performance was far better than the comparison *** experiment results indicated that,compared with traditional infrared target detection methods,the proposed method could detect the infrared invasion target more accurately,and suppress the background noise more effectively.

关键词： Target intrusion detection Convolutional neural network Feature fusion Infrared target

Impact of EBG Structures' Positions on the Performance of an EBG Antenna

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Journal of Beijing Institute of Technology 2017年第1期26卷 95-99页

作者： Zijian Han Wei Song xinqing Sheng Center for Electromagnetic Simulation School of Information and ElectronicsBeijing Institute of TechnologyBeijing 100081China

Six circularly polarized patch antennas with electromagnetic band gap（EBG）arranged at different locations were *** EBG antennas were compared in terms of impedance bandwidth,axial ratio（AR）bandwidth and radiation *** the EBG cells were placed closer to the edge of the substrate,the EBG antenna had a larger front radiation and a narrower *** the EBG cells closer to the center of the patch resulted in a wider impedance bandwidth,a wider axial ratio bandwidth and a decreased front gain.

关键词： electromagnetic band gap (EBG) structure circularly polarized patch antenna imped-ance bandwidth

Robust Topology Optimization of Periodic Multi-Material Functionally Graded Structures under Loading Uncertainties

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Computer Modeling in Engineering & Sciences 2021年第5期127卷 683-704页

作者： xinqing Li Qinghai Zhao Hongxin Zhang Tiezhu Zhang Jianliang Chen College of Mechanical and Electrical Engineering Qingdao UniversityQingdao266071China Power Integration and Energy Storage System Engineering Technology Center Qingdao UniversityQingdao266071China

This paper presents a robust topology optimization design approach for multi-material functional graded structures under periodic constraint with load *** characterize the random-field uncertainties with a reduced set of random variables,the Karhunen-Lo`eve(K-L)expansion is *** sparse grid numerical integration method is employed to transform the robust topology optimization into a weighted summation of series of deterministic topology *** dividing the design domain,the volume fraction of each preset gradient layer is *** on the ordered solid isotropic microstructure with penalization(Ordered-SIMP),a functionally graded multi-material interpolation model is formulated by individually optimizing each preset gradient *** periodic constraint setting of the gradient layer is achieved by redistributing the average element compliance in ***,the method of moving asymptotes(MMA)is introduced to iteratively update the design *** numerical examples are presented to verify the validity and applicability of the proposed *** results demonstrate that the periodic functionally graded multi-material topology can be obtained under different numbers of sub-regions,and robust design structures are more stable than that indicated by the deterministic results.

关键词： Multi-material topology optimization robust design periodic functional gradient sparse grid method

Flexible Vis/NIR wireless sensing system for banana monitoring

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Food Quality and Safety 2023年第3期7卷 492-502页

作者： Meng Wang Bingbing Wang Ruihua Zhang Zihao Wu xinqing Xiao College of Engineering China Agricultural UniversityBeijingChina

Objectives:The quality of the fruit seriously affects the economic value of the *** quality is related to many ripening parameters,such as soluble solid content(SSC),pH,and firmness(FM),and is a complex *** methods are inefficient,do not guarantee quality,and do not adapt to the current rhythm of the fruit *** this paper,a was designed and implemented for quality prediction and maturity level classification of Philippine Cavendish *** and Methods:The quality changes of bananas in different stages were *** light intensity reflectance values for each maturity stage were compared to conventionally measured SSC,FM,PH,and color ***:Our device can be compared with traditional forms of quality *** experimental results show that the established predictive model with specific preprocessing and modeling algorithms can effectively determine various banana quality parameters(SSC,pH,FM,L^(*),a^(*),and b^(*)).The RPD values of SSC and a^(*)were greater than 3.0,the RPD values of L^(*)and b^(*)were between 2.5 and 3.0,and the pH and FM were between 2.0 and *** addition,a new banana maturity level classification method(FSC)was proposed,and the results showed that the method could effectively classify the maturity level classes(*** maturity levels)with an accuracy rate of up to 97.5%.Finally,the MLR and FSC models are imported into the MCU to realize the near-range and long-range real-time display of ***:These methods can also be applied more broadly to fruit quality detection,providing a basic framework for future research.

关键词： Banana Vis/NIR flexibility ripening classification chemometrics

Urban expansion and intra-urban land evolution as well as their natural environmental constraints in arid/semiarid regions of China from 2000–2018

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Journal of Geographical Sciences 2023年第7期33卷 1419-1441页

作者： PAN Tao KUANG Wenhui SHAO Hua ZHANG Chi WANG Xiaoyu WANG xinqing School of Geography and Tourism Qufu Normal UniversityRizhao 276826ShandongChina Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources ResearchCASBeijing 100101China State Key Laboratory of Desert and Oasis Ecology Xinjiang Institute of Ecology and GeographyCASUrumqi 830011China Shandong Provincial Key Laboratory of Water and Soil Conservation and Environmental Protection College of Resources and EnvironmentLinyi UniversityLinyi 276000ShandongChina

Rapid urbanization has occurred in arid/semiarid China,threatening the sustainability of fragile dryland ecosystems;however,our knowledge of natural environmental constraints on multiscale urban lands in this region is still *** solve this issue,this study retrieved 15-m multiscale urban *** indicated that urban area increased by 68%during 2000–2018,and one-third of the increase was contributed by only three large *** coverage of impervious surface area(ISA) and vegetated area(VA) increased by 16.6%and 1.38%,*** land-cover change may be helpful in suppressing wind erosion and sand *** also found that the newly urban lands had relatively lower ISA and higher VA than the old urban lands,indicating an improved human settlement *** environmental constraints on urban expansion were identified,with cities in oasis urban environments(OUEs) that had water supply expanding 150% faster than cities in desert urban environments(DUEs).Urban development was also constrained by terrain,with 73% of the ISA expansion occurring in relatively flat ***,the aggregated pattern of urbanization and the increase in ISA and VA in the newly urbanized lands have improved water-use efficiency and ecological services and benefited desert ecosystem protection in arid/semiarid China.

关键词： urbanization natural environmental constraints pixel and subpixel land change arid and semiarid regions of China

A β-type TiNbZr alloy with low modulus and high strength for biomedical applications

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Progress in Natural Science:Materials International 2014年第2期24卷 157-162页

作者： Qingkun Meng Shun Guo Qing Liu Liang Hu xinqing Zhao School of Materials Science and Engineering Beihang University Institute for Advanced Materials Jiangsu University

The effect of thermo-mechanical treatment on the mechanical properties of a novel β-type Ti–36Nb–5Zr(wt%) alloy has been *** solution treated alloy consists of β and α″ phases and exhibits a two-stage yielding with a low yield stress(around 100 MPa). After cold rolling at a reduction of 87.5% and subsequent annealing treatment at 698 K for 25 min, a fine microstructure with nanosized α precipitates distributed in small β grains as well as high density of dislocations was obtained to achieve a yield strength of 720 MPa and a ultimate tensile strength of 860 MPa. In spite of the formation of α precipitates, the β-stabilizers are not enriched in the parent β matrix due to the short duration and low temperature of the thermal treatment, resulting in a low chemical stability of β phase. The low stability of β phase and the small volume fraction of α precipitates produce a low Young’s modulus of 48 GPa. Such an excellent combination of low elastic modulus and high strength in mechanical properties indicates great potential for biomedical applications.

关键词： β-type Ti alloy Ti–Nb–Zr Chemical stabilization Young’s modulus Biomedical

Analysis of Large Slotted-Waveguide Antenna Arrays Using the Parallel DDA-FE-BI-MLFMA

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Journal of Beijing Institute of Technology 2017年第1期26卷 84-89页

作者： Xumin Sun Minglin Yang Hongwei Gao xinqing Sheng Center for Electromagnetic Simulation School of Information and Electronics Beijing Institute of Technology Beijing 100081 China

An efficient analyzing approach is presented for large slotted-waveguide antenna arrays by using hybrid finite element-boundary integral-multilevel fast multipole algorithm（FE-BI-MLFMA）in this paper.A simple computation model for slotted-waveguide antenna is presented by using thin current probe excitation and perfectly matched layer（PML）*** each slotted-waveguide antenna can be considered as a single sub-domain,the domain decomposition algorithm（DDA）can be applied to FE-BI-MLFMA to greatly reduce the computation resources and achieve high *** DDA-FE-BI-MLMFA is parallelized to further strength its *** comparisons of the computed radiation patterns with measured data and results from the commercial software show that our method has good accuracy for slottedwaveguide *** the influence of mutual coupling between adjacent slotted-waveguides is *** demonstrate capability of the presented method,a carefully designed large X-band slotted-waveguide antenna array containing eighteen waveguides with Taylor amplitude and inverse phase excitation distribution are analyzed in the paper.

关键词： large slotted-waveguide antenna array perfectly matched layer domain decompositionalgorithm parallel FE-BI-MLFMA