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Spatiotemporal patterns of precipitation based on the Bayesian maximum entropy method in a typical catchment of the Heihe River watershed,northwest China

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International Journal of Digital Earth 2022年第1期15卷 911-933页

作者： Hong Wang Chuanyan Zhao Fei Zang zhanlei rong Yapeng Chang Youyan Liu State Key Laboratory of Grassland Agro-ecosystems Key Laboratory of Grassland Livestock Industry InnovationMinistry of Agriculture and Rural AffairsCollege of Pastoral Agriculture Science and TechnologyLanzhou UniversityLanzhouPeople’s Republic of China College of Geographical Science Qinghai Normal UniversityXiningPeople’s Republic of China Academy of Plateau Science and Sustainability People’s Government of Qinghai Province & Beijing Normal UniversityXiningPeople’s Republic of China Qinghai Research Centre of Qilian Mountain National Park Qinghai Normal UniversityXiningPeople’s Republic of China

Precipitation patterns are vital to water resource management and hydrological research,especially in the upper reaches of inland rivers in arid and semiarid ***,estimating spatiotemporal precipitation patterns at a basin scale is challenging due to limited *** this study,spatiotemporal patterns of precipitation amount,frequency,duration,and intensity at different time scales from 2014 to 2019 are estimated using the Bayesian maximum entropy method in the Tianlaochi catchment of the Heihe River watershed,northwest *** study's results show that the annual average precipitation amount was 535.9 mm from 2014 to 2019,with precipitation amount between May and September accounting for 85.9%of the annual precipitation *** daily precipitation,the average frequency rate of light precipitation is highest at 59.55%,however,the average contribution rate of moderate precipitation is highest at 50.33%.The spatial distribution of precipitation is characterized by high-value areas concentrated in the central valley and low-value areas located at the catchment's *** most important driving factors of precipitation patterns are elevation,relative humidity,and wind *** outcomes can be used to establish accurate hydrological models in the catchment and provide support for water resource management in the Heihe River watershed.

关键词： Geostatistics precipitation patterns spatial estimation cross-validation grey relational analysis

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Actual evapotranspiration of subalpine meadows in the Qilian Mountains, Northwest China

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Journal of Arid Land 2019年第3期11卷 371-384页

作者： GAO Yunfei ZHAO Chuanyan Muhammad W ASHIQ WANG Qingtao rong zhanlei LIU Junjie MAO Yahua GUO Zhaoxia WANG Wenbin State Key Laboratory of Grassland and Agro-Ecosystems School of Life SciencesLanzhou UniversityLanzhou 730000China State Key Laboratory of Grassland and Agro-Ecosystems College of Pastoral Agriculture Science and TechnologyLanzhou UniversityLanzhou 730000China Ministry of Natural Resources and Forestry Timmins District5520 Hwy 101 ESouth PorcupineONPON 1 HOCanada

As a main component in water balance,evapotranspiration(ET)is of great importance for water saving,especially in arid and semi-arid *** this study,the FAO(Food and Agriculture Organization)Penman-Monteith model was used to estimate the magnitude and temporal dynamics of reference evapotranspiration(ET0)in 2014 in subalpine meadows of the Qilian Mountains,Northwest ***,actual ET(ETc)was also investigated by the eddy covariance(EC)*** indicated that ETc estimated by the EC System was 583 mm,lower than ET0(923 mm)estimated by the FAO Penman-Monteith model in ***,ET0 began to increase in March and reached the peak value in August and then declined in September,however,ETc began to increase from April and reached the peak value in July,and then declined in *** ETc and ET0 values during the growing season(from May to September)were 441 and 666 mm,respectively,which accounted for 75.73%of annual cumulative ETc and 72.34%of annual cumulative ET0,respectively.A crop coefficient(kc)was also estimated for calculating the ETc,and average value of kc during the growing season was 0.81(ranging from 0.45 to 1.16).Air temperature(Ta),wind speed(u),net radiation(Rn)and soil temperature(Ts)at the depth of 5 cm and aboveground biomass were critical factors for affecting kc,furthermore,a daily empirical kc equation including these main driving factors was *** result demonstrated that the ETc value estimated by the data of kc and ET0 was validated and consistent with the growing season data in 2015 and 2016.

关键词： actual evapotranspiration reference evapotranspiration crop coefficient meteorological factors biotic factors

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Leaf gas exchange and photosynthesis curves of Elymus nutans and Potentilla anserina under fencing and grazing conditions in the Qilian Mountains, Northwest China

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Journal of Arid Land 2019年第3期11卷 431-445页

作者： LIU Junjie WANG Xiaoping GAO Yunfei rong zhanlei ZHANG Guangde WANG Wenbin GE Lijuan MAO Yahua GUO Zhaoxia ZHAO Chuanyan State Key Laboratory of Grassland Agro-ecosystems School of Life SciencesLanzhou UniversityLanzhou 730000China Institute of Arid Meteorology China Meteorological AdministrationLanzhou 730020China

Potentilla anserina *** Elymus nutans *** dominant species in the subalpine meadows of *** is one of the most important factors that influence community structure and productivity of subalpine *** how grazing changes photosynthetic capability is essential for preservation and restoration of ***,information about the effects of grazing on photosynthetic capability remains *** were conducted in fencing and grazing areas in the Qilian Mountains,Northwest *** leaf gas exchange and photosynthetic curves of *** and *** were measured at different growth *** showed that grazing decreased the values of leaf gas exchange parameters,such as net photosynthetic rate,stomatal conductance,transpiration rate,and intercellular CO2 concentration of *** and *** addition,grazing decreased the values of net photosynthetic rate-photosynthetically active radiation(PN-PAR)curve parameters,such as light-saturated net photosynthetic rate,apparent quantum efficiency,light compensation point,light saturation point,and dark respiration *** results demonstrated that grazing was the primary limiting factor for photosynthesis of dominant grassland species in the study area.

关键词： grazing diurnal variation gas exchange Potentilla anserina Elymus nutans photosynthetic capacity

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Modified non-rectangular hyperbola equation with plant height for photosynthetic light-response curves of Potentilla anserina and Elymus nutans at various growth phases in the Heihe River Basin, Northwest China

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Journal of Arid Land 2019年第5期11卷 764-773页

作者： LIU Junjie WANG Xiaoping rong zhanlei GAO Yunfei ZHANG Guangde WANGWenbin GE Lijuan MAO Yahua GUO Zhaoxia WANG Qingtao ZHAO Chuanyan State Key Laboratory of Grassland Agro-ecosystems School of Life SciencesLanzhou UniversityLanzhou 730000China Institute of Arid Meteorology China Meteorological AdministrationLanzhou 730020China College of landscape and Ecological Engineering Hebei University of EngineeringHandan 056000China

The non-rectangular hyperbola(NRH)equation is the most popular method that plots the photosynthetic light-response(PLR)curve and helps to identify plant photosynthetic ***,the PLR curve can't be plotted well by the NRH equation at different plant growth phases due to the variations of plant ***,plant physiological parameters have been considered into the NRH equation to establish the modified NRH equation,but plant height(H),an important parameter in plant growth phases,is not taken into *** this study,H was incorporated into the NRH equation to establish the modified NRH equation,which could be used to estimate photosynthetic capability of herbage at different growth *** explore photosynthetic capability of herbage,we selected the dominant herbage species Potentilla anserina *** Elymus nutans *** the Heihe River Basin,Northwest China as the research ***,twenty-four PLR curves and H at different growth phases were measured during the growing season in *** showed that the maximum net photosynthetic rate and the initial slope of PLR curve linearly increased with *** modified NRH equation,which is established by introducing H and an H-based adjustment factor into the NRH equation,described better the PLR curves of *** and *** than the original *** results may provide an effective method to estimate the net primary productivity of grasslands in the study area.

关键词： plant height modified non-rectangular hyperbola equation Potentilla anserina Elymus nutans photosynthetic light-response curve Qilian Mountains

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基于Maxent模型的冬虫夏草中国潜在适生区预测

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生态科学 2023年第2期42卷 202-210页

作者：喻洁曹广超戎战磊李华非青海师范大学地理科学学院西宁810008 青藏高原地表过程与生态保育教育部重点实验室西宁810008 青海师范大学青海省自然地理与环境过程重点实验室西宁810008

冬虫夏草(Ophiocordyceps sinensis)是分布在青藏高原高寒地区稀缺的可再生生物资源,是我国传统名贵中药材,具有很高的药用价值和经济价值。目前对冬虫夏草的潜在适生区研究较少,对虫草资源的空间分布格局尚不清晰。明确冬虫夏草在我国... 详细信息

冬虫夏草(Ophiocordyceps sinensis)是分布在青藏高原高寒地区稀缺的可再生生物资源,是我国传统名贵中药材,具有很高的药用价值和经济价值。目前对冬虫夏草的潜在适生区研究较少,对虫草资源的空间分布格局尚不清晰。明确冬虫夏草在我国的地理分布,对其保护及有效利用具有重要意义。研究共收集了175个分布点及24个环境因子数据,最终筛选出12个环境变量数据参与模型训练,利用Maxent模型预测冬虫夏草中国潜在适生区,通过ROC曲线分析模型预测效果,结合贡献率、置换重要值和刀切法检验分析环境变量对冬虫夏草分布的影响。结果显示:我国虫草主要分布于西藏、青海、甘肃、四川和云南五省,适生区总面积(高适宜分布区与中适宜分布区)为8.82927×10^(5)km^(2)。ROC评价结果显示,Maxent模型训练数据的AUC值高达0.959,表明预测结果准确度极高。对环境变量进行分析,影响冬虫夏草地理分布的主要环境因子是海拔,最暖季度平均温度,最暖季度降水量。本研究明确了冬虫夏草在我国的潜在适生分布区,为虫草的资源明确及生境保护提供了理论依据。

关键词：冬虫夏草 Maxent模型潜在适生区

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2000-2020年青藏高原土地利用时空动态变化研究

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青海科技 2023年第3期30卷 31-43页

作者：毛宇昕戎战磊蒋刚青海师范大学地理科学学院青海省自然地理与环境过程重点实验室西宁810008 青藏高原地表过程与生态保育教育部重点实验室西宁810008

土地利用/覆盖变化是反映区域生态环境是否健康的重要指标之一。本研究以青藏高原为例,基于2000-2020年的GlobeLand30数据集,使用土地利用转移矩阵及动态度等方法揭示了区域土地利用/覆盖的空间分布格局的动态变化。研究表明:(1)青藏高... 详细信息

土地利用/覆盖变化是反映区域生态环境是否健康的重要指标之一。本研究以青藏高原为例,基于2000-2020年的GlobeLand30数据集,使用土地利用转移矩阵及动态度等方法揭示了区域土地利用/覆盖的空间分布格局的动态变化。研究表明:(1)青藏高原区域内草地分布最广,其次是裸地、林地,2000年分别为59.52%、23.61%和9.05%;2010年依次为57.87%、24.59%和8.99%;2020年则为54.67%、26.67%和9.19%。(2)2000-2020年,湿地、水体、人造地表、裸地及冰川和永久性积雪的分布面积增加,其中湿地、水体和冰川的增长比例依次约为36.18%、24.79%、32.07%;人造地表与裸地的增长比例为242.86%、12.97%;而草地的面积呈下降趋势,下降百分比为8.15%。(3)土地覆盖类型中人造地表的动态度属于快速变化型,其余类型都属于极缓慢变化型。(4)2000-2020年间,耕地主要转换成草地(742.31 km^(2))、林地(374.92 km^(2))和人造地表(636.85 km^(2));灌木地约6128.03 km^(2)转换成了草地,1128.74 km^(2)转换成了林地。表明生态保护政策的实施对青藏高原草地和林地的恢复具有明显的推动作用。该研究对生态修复和促进区域的可持续发展具有重要意义。

关键词：土地利用/覆盖转移矩阵时空变化青藏高原 GlobeLand30

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基于MaxEnt模型的天峻县放牧家畜生境适宜区估计

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中国草食动物科学 2023年第2期43卷 16-22页

作者：张振西林扎西尖措高太侦华旦仁青牟丹戎战磊谢久祥青海大学农牧学院西宁810016 天峻县林业和草原站天峻817200 天峻县国有林场天峻817200 青海师范大学地理科学学院西宁810008

天峻县是青海省海西州唯一的纯牧业县,预估放牧家畜在天峻县的生境适宜区,对合理放牧和保护大型野生草食动物栖息地具有重要意义。利用MaxEnt模型和地理空间分析技术,结合放牧家畜分布数据和主要环境数据,预测了天峻县放牧家畜(牦牛、... 详细信息

天峻县是青海省海西州唯一的纯牧业县,预估放牧家畜在天峻县的生境适宜区,对合理放牧和保护大型野生草食动物栖息地具有重要意义。利用MaxEnt模型和地理空间分析技术,结合放牧家畜分布数据和主要环境数据,预测了天峻县放牧家畜(牦牛、绵羊、马)适宜区分布及其生态特征。结果表明,距居民点的距离和距道路的距离两个变量对放牧家畜生境适宜区分布影响最为显著;天峻县牦牛的适宜区面积18857.22 km^(2),占天峻县总面积的79.89%,主要分布在苏里乡、龙门乡、木里镇;绵羊的适宜区面积18908.73 km^(2),占天峻县总面积的80.11%,主要分布在苏里乡、龙门乡、木里镇、舟群乡、阳康乡;马的适宜区面积13690.18 km^(2),占天峻县总面积的58.00%,主要分布在龙门乡、舟群乡、木里镇。

关键词： MaxEnt模型天峻县放牧家畜适宜区估计

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高寒草甸群落结构对不同氮素添加的响应分析

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华侨大学学报（自然科学版） 2022年第6期43卷 790-798页

作者：刘俊杰王娟袁顺捷韩亚南刘超戎战磊高云飞赵传燕新疆大学生态与环境学院新疆乌鲁木齐830046 新疆大学绿洲生态教育部重点实验室新疆乌鲁木齐830046 新疆大学新疆精河温带荒漠生态系统教育部野外科学观测研究站新疆乌鲁木齐830046 兰州市食品药品检验检测研究院甘肃省兰州730050 青海师范大学高原科学与可持续发展研究院青海省西宁810008 海南师范大学热带岛屿生态学教育部重点实验室海南省海口571158 兰州大学草地农业生态系统国家重点实验室甘肃省兰州730020

为研究全球气候背景下氮沉降对高寒草甸物种组成、种内-种间关系,以及群落结构的影响,在青藏高原研究区开展不同氮素添加水平下的控制实验.设置对照(CK,0 g·m^(-2))、低氮(L-N,5 g·m^(-2))、中氮(M-N,10 g·m^(-2))和高氮(H-N,15 g·m... 详细信息

为研究全球气候背景下氮沉降对高寒草甸物种组成、种内-种间关系,以及群落结构的影响,在青藏高原研究区开展不同氮素添加水平下的控制实验.设置对照(CK,0 g·m^(-2))、低氮(L-N,5 g·m^(-2))、中氮(M-N,10 g·m^(-2))和高氮(H-N,15 g·m^(-2))4个氮素添加水平,探讨不同氮素添加水平下群落物种空间分布格局和物种多样性的关系.结果表明:随着氮素添加水平的增加,垂穗披碱草聚集程度出现逐渐增强的趋势,条叶银莲花聚集程度出现逐渐减少的趋势,垂穗披碱草的正相互作用逐渐增强,条叶银莲花的负相互作用逐渐增强.

关键词：氮添加高寒草甸群落结构种内-种间关系响应机制

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Research on Muster-Based 3Dmax Network Rendering

Research on Muster-Based 3Dmax Network Rendering

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第十二届全国青年通信学术会议

作者： Tan Guoxin~1 Deng zhanlei~(1 2) Zhang Jing~(1 2) Li rong~(1 3) 1.Engineering Research Center for Education Information Technology Huazhong Normal Univ.Wuhan China 430079 2.Dept.of Computer Science Huazhong Normal Univ.Wuhan China 430079 3.Dept.of Information Technology Huazhong Normal Univ.Wuhan China 430079

＜正＞Toe principal of network rendering is presented in this paper,in which the inferiority and superiority of backburner are analyzed,in order to overcome the inferiority of backburner,virtual vertex muster is bring forward. On computational grid which consists of various heterogeneous machines,a series of experiments are done to testify our conclusion,and it is shown that Muster has relatively good speedup due to the well organized dynamic load balancing and the high utilization of the resources,machines with different operating system can be integrated into seamless system.

关键词： Network Rendering Backburner Virtual Vertex Muster(Muster)

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工频轨道电路叠加闭环电码化改造的试验

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铁道通信信号 2007年第5期43卷 25-25页

作者：朱蓉赵占雷宁波城市职业技术学院信息学院讲师315100 浙江宁波中铁七局电务工程有限公司

结合既有线闭环电码化改造施工情况,对工频轨道电路叠加闭环电码化的改造试验进行了总结.

关键词：闭环电码化轨道电路改造施工改造试验叠加工频既有线

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