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Climate change filtered out resource-acquisitive plants in a temperate grassland in Inner Mongolia,China

Science China(Life Sciences) 2024年第2期67卷 403-413页

作者： Heying Jing Xingshuo Xiong Feng Jiang Xucai Pu wenhong ma Daijiang Li Zhongling Liu Zhiheng Wang Institute of Ecology and Key Laboratory for Earth Surface Processes of the Ministry of Education College of Urban and Environmental SciencesPeking UniversityBeijing 100871China Ministry of Education Key Laboratory of Ecology and Resource Use of the Mongolian Plateau School of Ecology and EnvironmentInner Mongolia UniversityHohhot 010021China Department of Biological Sciences Louisiana State UniversityBaton RougeLA 70803USA

Global climate change has led to the decline of species and functional diversity in ecosystems,changing community composition and ecosystem ***,we still know little about how species with different resource-use strategies(different types of resource usage and plant growth of plants as indicated by the spectrum of plant economic traits,including acquisitive resource-use strategy and conservative resource-use strategy)would change in response to climate change,and how the changes in the diversity of species with different resource-use strategies may influence community-level ***,using long-term(1982–2017)observatory data in a temperate grassland in Inner Mongolia,we investigated how climate change had affected the species richness(SR)and functional richness(FRic)for the whole community and for species with different resource-use ***,based on data for four traits representing leaf economics spectrum(leaf carbon concentration,leaf nitrogen concentration,leaf phosphorus concentration,and specific leaf area),we divided 81 plant species appearing in the grassland community into three plant functional types representing resource-acquisitive,medium,and resource-conservative *** then analyzed the changes in community-level productivity in response to the decline of SR and FRic at the community level and for different resource-use *** found that community-level SR and FRic decreased with drying climate,which was largely driven by the decline of diversity for resource-acquisitive ***,community-level productivity remained stable because resource-conservative species dominating this grassland were barely affected by climate *** study revealed distinctive responses of species with different resource-use strategies to climate change and provided a new approach based on species functional traits for predicting the magnitude and direction of climate change effects on ecosystem functions.

关键词： biodiversity ecological strategy functional diversity functional trait long-term change species diversity

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基于改进YOLOv8n的香梨目标检测方法

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农业工程学报 2024年第11期40卷 178-185页

作者：谭厚森马文宏田原张茜李梦瑶李孟卿杨旭海石河子大学机械电气工程学院石河子832003 农业农村部西北农业装备重点试验室石河子832003 现代农业机械兵团重点试验室石河子832003

针对非结构化环境下香梨识别准确率低,检测速度慢的问题,该研究提出了一种基于改进YOLOv8n的香梨目标检测方法。使用Min-max归一化方法,对YOLOv3-tiny、YOLOv5n、YOLO6n、YOLOv7-tiny和YOLOv8n评估选优;以YOLOv8n为基线,进行以下改进:1... 详细信息

针对非结构化环境下香梨识别准确率低,检测速度慢的问题,该研究提出了一种基于改进YOLOv8n的香梨目标检测方法。使用Min-max归一化方法,对YOLOv3-tiny、YOLOv5n、YOLO6n、YOLOv7-tiny和YOLOv8n评估选优;以YOLOv8n为基线,进行以下改进:1)使用简化的残差与卷积模块优化部分C2f(CSP bottleneck with 2 convolutions)进行特征融合。2)利用simSPPF(simple spatial pyramid pooling fast)对SPPF(spatial pyramid pooling fast)进行优化。3)引入了PConv(partial convolution)卷积,并提出权重参数共享以实现检测头的轻量化。4)使用Inner-CIoU(inner complete intersection over union)优化预测框的损失计算。在自建的香梨数据集上,指标F_(0.5)分数(F_(0.5-score))和平均精度均值(mean average precision, maP)比原模型分别提升0.4和0.5个百分点,达到94.7%和88.3%。在GPU和CPU设备上,检测速度分别提升了34.0%和24.4%,达到了99.4和15.3帧/s。该模型具有较高的识别准确率和检测速度,为香梨自动化采摘提供了一种精确的实时检测方法。

关键词：图像处理图像识别香梨目标检测 YOLOv8 轻量化消融试验

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Vibration and Sound Radiation of Cylindrical Shell Covered with a Skin made of Micro Floating Raft Arrays Excited by Turbulence

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Computer Modeling in Engineering & Sciences 2023年第3期134卷 2041-2055页

作者： Dan Zhao Qiong Wu Minyao Gan Ke Li wenhong ma Qun Wu Liqiang Dong Shaogang Liu College of Mechanical and Electrical Engineering Harbin Engineering UniversityHarbin150001China Shanghai marine Equipment Research Institute Shanghai200031China

To reduce the vibration and sound radiation of underwater cylindrical shells,a skin composed of micro floating raft arrays and a compliant wall is proposed in this paper.A vibroacoustic coupling model of a finite cylindrical shell covered with this skin for the case of turbulence excitation is established based on the shell theories of *** model is solved with the modal superposition method to investigate the effects of the structural parameters of micro floating raft elements on the performance of reducing vibration and sound radiation of the cylindrical shell of this *** results indicate that increasing the stiffness ratio,damping ratio,mass ratio,or decreasing the interval betweenmicro floating raft elements can improve the vibration and sound radiation reduction performance of this skin over the frequency range 0∼2000 ***,the mean quadratic velocity level and sound radiation power level of the finite cylindrical shell with this skin can be reduced by 12.00 dB and 9.65 dB respectively compared to the finite cylindrical shell with homogeneous viscoelastic coating in the frequency range from0∼2000Hz,implying a favorable performance of this skin for reducing the vibration and sound radiation of cylindrical shells.

关键词： Finite cylindrical shell vibration and sound radiation noise reduction turbulent pulsating pressure micro floating raft

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The relationship between species richness and productivity in four typical grasslands of northern China

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Frontiers in Biology 2007年第3期2卷 318-323页

作者： ma wenhong Department of Ecology College of Environmental SciencesCenter for Ecological Research&Educationand Key Laboratory for Earth Surface Processes of the Ministry of EducationPeking UniversityBeijing 100871China School of Environment&Urban Study Peking University Shenzhen Graduate SchoolShenzhen 518055China

The relationship between plant species richness and primary productivity has long been a central topic in bio-diversity *** this paper,we examine the relationship between species richness and productivity in four typical grasslands of Northern China at different spatial *** the community scale,a positive correlation was found for six of seven communities.A unimodal pattern was found only for one community(Stipa glareosa community),while at a large scale(vegetation type or landscape/region),the relationship was also found significantly *** richness ranged from 4 to 35 species,and community aboveground producti-vity from 13 to 368 g·m^(-2)·a^(-1).The highest species richness and aboveground productivity were found in alpine meadow,followed by meadow steppe,typical steppe and desert steppe.

关键词： species richness productivity grasslands scale

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Community phylogenetic structure of grasslands and its relationship with environmental factors on the Mongolian Plateau

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Journal of Arid Land 2019年第4期11卷 595-607页

作者： DONG Lei LIANG Cunzhu LI Frank Yonghong ZHAO Liqing ma wenhong WANG Lixin WEN Lu ZHENG Ying LI Zijing ZHAO Chenguang Indree TUVSHINTOGTOKH Ministry of Education Key Laboratory of Ecology and Resource Use of the Mongolian Plateau&Inner Mongolia KeyLaboratory of Grassland Ecology School of Ecology and EnvironmentInner Mongolia UniversityHohhot010021China Forestry and Desert Control Research Institute of Alagxa League Bayanhot750306China Institute of General and Experimental Biology Mongolian Academy of SciencesUlaanbaatar-51Mongolia

The community assembly rules and species coexistence have always been interested by ecologists. The community phylogenetic structure is the consequence of the interaction process between the organisms and the abiotic environment and has been used to explain the relative impact of abiotic and biotic factors on species co-existence. In recent years, grassland degradation and biodiversity loss have become increasingly severe on the Mongolian Plateau, while the drivers for these changes are not clearly explored, especially whether climate change is a main factor is debated in academia. In this study, we examined the phylogenetic structure of grassland communities along five transects of climate aridity on the Mongolian Plateau, and analyzed their relations with environmental factors, with the aims to understand the formation mechanism of the grassland communities and the role of climatic factors. We surveyed grassland communities at 81 sites along the five transects, and calculated their net relatedness index(NRI) at two different quadrat scales(small scale of 1 m2 and large scale of 5 m2) to characterize the community phylogenetic structure and analyze its relationship with the key 11 environmental factors. We also calculated the generalized UniFrac distance(GUniFrac) among the grassland communities to quantify the influence of spatial distance and environmental distance on the phylogenetic β diversity. The results indicated that plant community survey using the large scale quadrat contained sufficient species to represent community compositions. The community phylogenetic structure of grasslands was significantly overdispersed at both the small and large scales, and the degree of overdispersion was greater at the large scale than at the small scale, suggesting that competitive exclusion instead of habitat filtering played a major role in determination of community composition. Altitude was the main factor affecting the community phylogenetic structure, whereas climati

关键词： phylogenetic overdispersion environmental factors phylogenetic β diversity spatial scale environmental distance climate change Mongolian Plateau

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DEVELOPMENT　OF　A　NEW　GENERATION　OF　ADDITIVES　FOR　ALUMINIUM　ROLLING　LUBRICATION

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中国有色金属学会会刊：英文版 1996年第2期6卷 138-143页

作者： mao Daheng Xiao Gang ma wenhong(College of Electro- mechanical Engineering ,Central South University of Technology, Changsha 410083 Northwest Aluminium Fabrication Plant, Longxi, Gansu 748111) College of Electro-mechanical Engineering Central South University of Technology Changsha 410083 China Northwest Aluminium Fabrication Plant Longxi Gansu 748111 China

ＤＥＶＥＬＯＰＭＥＮＴＯＦＡＮＥＷＧＥＮＥＲＡＴＩＯＮＯＦＡＤＤＩＴＩＶＥＳＦＯＲＡＬＵＭＩＮＩＵＭＲＯＬＬＩＮＧＬＵＢＲＩＣＡＴＩＯＮＭａｏＤａｈｅｎｇ；ＸｉａｏＧａｎｇ；ＭａＷｅｎｈｏｎｇ（ＣｏｌｌｅｇｅｏｆＥｌ... 详细信息

ＤＥＶＥＬＯＰＭＥＮＴＯＦＡＮＥＷＧＥＮＥＲＡＴＩＯＮＯＦＡＤＤＩＴＩＶＥＳＦＯＲＡＬＵＭＩＮＩＵＭＲＯＬＬＩＮＧＬＵＢＲＩＣＡＴＩＯＮＭａｏＤａｈｅｎｇ；ＸｉａｏＧａｎｇ；ＭａＷｅｎｈｏｎｇ（ＣｏｌｌｅｇｅｏｆＥｌｅｃｔｒｏ－ｍｅｃｈａｎｉｃａｌＥ...

关键词： aluminium rolling lubricity additives compound mechanisms

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Increasing terrestrial vegetation activity in China, 1982—1999

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Science China(Life Sciences) 2004年第3期47卷 229-240页

作者： FANG Jingyun PIAO Shilong HE Jinsheng ma wenhong Department of Ecology College of Environmental Sciences and Key Laboratory for Earth Surface Processes of the Ministry of Education Peking University Beijing 100871 China Department of Ecology College of Environmental Sciences and Key Laboratory for Earth Surface Processes of the Ministry of Education Peking University Beijing 100871 China Department of Ecology College of Environmental Sciences and Key Laboratory for Earth Surface Processes of the Ministry of Education Peking University Beijing 100871 China Department of Ecology College of Environmental Sciences and Key Laboratory for Earth Surface Processes of the Ministry of Education Peking University Beijing 100871 China

Variations in vegetation activity during the past 18 years in China were investigated using the normalized difference vegetation index (NDVI) derived from the 3rd generation time series dataset of NOAA-AVHRR from 1982 to 1999. In order to eliminate the effects of non-vegetation factors, we characterized areas with NDVI marked increases. Such a pattern was due primarily to urbanization, agricultural activity, regional climate characteristics, and different vegetation responses to regional climate changes.

关键词： China, NDVI, vegetation activity, climate change, agricultural production, urbanization.

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内蒙古温带草原的根冠比及其影响因素

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北京大学学报（自然科学版） 2006年第6期42卷 774-778页

作者：马文红方精云北京大学环境学院生态学系生态学研究与教育中心地表过程分析与模拟教育部重点实验室北京100871

温带草地大部分生物量分布在地下,地下生物量在草地生态系统碳循环中起着重要作用。利用根冠比(R∶S)和地上生物量来估算地下生物量是目前常用的方法,但目前缺乏根冠比的数据。本研究利用内蒙古温带草原的生物量实测数据,分析了R∶S及... 详细信息

温带草地大部分生物量分布在地下,地下生物量在草地生态系统碳循环中起着重要作用。利用根冠比(R∶S)和地上生物量来估算地下生物量是目前常用的方法,但目前缺乏根冠比的数据。本研究利用内蒙古温带草原的生物量实测数据,分析了R∶S及其影响因素。结果显示(1)内蒙古温带草原地上和地下生物量分别为135.3、775.2g.m-2,不同草原类型生物量差异显著,荒漠草原、典型草原和草甸草原的地上生物量分别为56.6、133.4和196.7g.m-2,地下生物量分别为301.0、688.9和1385.2g.m-2。(2)研究区3种草原类型的R∶S差异较小,荒漠草原、典型草原和草甸草原R∶S中值分别为6.7、5.3和5.2,总体上,内蒙古温带草地的R∶S为6.3。(3)R∶S与年均温、年降水和土壤含水率之间没有显著相关关系。

关键词：温带草原根冠比年均温年降水土壤含水率

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中国土壤磷库的大小、分布及其影响因素

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北京大学学报（自然科学版） 2008年第6期44卷 945-952页

作者：汪涛杨元合马文红北京大学城市与环境学院生态学系地表过程分析与模拟教育部重点实验室北京100871 北京大学深圳研究生院环境与城市学院深圳518055

基于第二次土壤普查资料,估算了中国土壤磷库,揭示了其空间分布规律,并探讨了土壤磷库与环境因子的关系。结果表明,中国土壤实际剖面深度的全磷和有效磷库分别为5.3Pg和3.0Tg,对应的磷密度为0.60kg/m2和3.4g/m2。土壤全磷密度自湿润区... 详细信息

基于第二次土壤普查资料,估算了中国土壤磷库,揭示了其空间分布规律,并探讨了土壤磷库与环境因子的关系。结果表明,中国土壤实际剖面深度的全磷和有效磷库分别为5.3Pg和3.0Tg,对应的磷密度为0.60kg/m2和3.4g/m2。土壤全磷密度自湿润区向干旱、半干旱地区和自热带地区向温带、寒温带地区呈增加趋势。土壤全磷密度随着年均降水量和年均温的增加而显著降低。在不同的土壤地球化学类型中,硅铝型的有效磷密度明显高于石膏及碳酸盐型和铁铝及富铝型。上述结果表明气候和土壤的地球化学类型是中国土壤磷素分布的重要因素。

关键词：地球化学类型空间分布土壤磷库气候

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中国北方典型草地物种丰富度与生产力的关系

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生物多样性 2006年第1期14卷 21-28页

作者：马文红方精云北京大学环境学院生态学系北京大学生态学研究与教育中心北京大学地表过程分析与模拟教育部重点实验室北京100871

利用2002–2004年内蒙古和甘肃南部几种典型草地的实测资料,研究了不同尺度物种丰富度与生产力的关系,并初步探讨了其形成机制。结果显示,温带草地的物种丰富度随生产力的增加而增加,但受空间尺度影响。在群落尺度(同一群落),在7种样方... 详细信息

利用2002–2004年内蒙古和甘肃南部几种典型草地的实测资料,研究了不同尺度物种丰富度与生产力的关系,并初步探讨了其形成机制。结果显示,温带草地的物种丰富度随生产力的增加而增加,但受空间尺度影响。在群落尺度(同一群落),在7种样方数大于15的群落中,仅沙生针茅(Stipaglareosa)群落物种丰富度与生产力呈现单峰型关系,其余均呈现线性正相关关系;在植被类型尺度,物种丰富度–生产力之间表现为显著的正相关关系;在研究区尺度,物种丰富度随生产力的增加而显著增加。研究还表明,研究区群落生产力的变化范围为13–368g·m–2·yr–1,物种丰富度为4–35种;生产力从高到低的顺序为:高寒草甸>草甸草原>典型草原>荒漠草原。

关键词：物种丰富度生产力典型草地尺度

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