检索结果-南通市图书馆

The urgent need to develop a new grassland map in China:based on the consistency and accuracy of ten land cover products

在线全文

学校读者我要写书评

暂无评论

Science China(Life Sciences) 2023年第2期66卷 385-405页

作者： Mengjing Hou Jing Ge Yangjing Xiu Baoping Meng Jie Liu qisheng feng Tiangang Liang State Key Laboratory of Grassland Agro-Ecosystems Key Laboratory of Grassland Livestock Industry InnovationMinistry of Agriculture and Rural AffairsEngineering Research Center of Grassland IndustryMinistry of EducationCollege of Pastoral Agriculture Science and TechnologyLanzhou UniversityLanzhou 730000China Institute of Fragile Eco-Environment Nantong UniversityNantong 226007China

Grasslands are the most dominant terrestrial ecosystem in China, but few national grassland maps have been generated. The grassland resource map produced in the 1980s is widely used as background data, but it has not been updated for almost 40 ***, a reliable map depicting the current spatial distribution of grasslands across the country is urgently needed. In this study, we evaluated the grassland consistency and accuracy of ten land cover datasets(GLC2000, GlobCover, CCI-LC,MCD12Q1, CLUD, GlobeLand30, GLC-FCS30, CGLS-LC100, CLCD, and FROM-GLC) for 2000, 2010, and 2020 based on extensive fieldwork. We concluded that the area of these ten grassland products ranges from 107.80×10^(4)to 332.46×10^(4)km^(2), with CLCD and MCD12Q1 having the highest area consistency. The spatial and sample consistency is highest in the regions of eastcentral Inner Mongolia, the Qinghai-Tibet Plateau and northern Xinjiang, while the distribution of southern grasslands is scattered and differs considerably among the ten products. MCD12Q1 is significantly more accurate than the other nine products,with an overall accuracy(OA) reaching 77.51% and a kappa coefficient of 0.51;CLCD is slightly less accurate than MCD12Q1(OA=73.02%, kappa coefficient=0.45) and is more conducive to the fine monitoring and management of grassland because of its30-meter resolution. The highest accuracy of grassland was found in the Inner Mongolia-Ningxia region and Qinghai-Tibet Plateau, while the accuracy was worst in the southeastern region. In the future grassland mapping, cartographers should improve the accuracy of the grassland distribution in South China and regions where grassland is confused with forest, cropland and bare land. We specify the availability of valuable data in existing land cover datasets for China’s grasslands and call for researchers and the government to actively produce a new generation of grassland maps.

关键词： grassland land use and land cover MCD12Q1 CLCD consistency comparison accuracy assessment

基于UPLC-Q-Orbitrap HRMS代谢组学和16S rRNA基因测序探讨骨疏丹补肾机制

在线全文

学校读者我要写书评

暂无评论

沈阳药科大学学报 2024年第6期41卷 675-685,698页

作者：佟琳冯啟圣张静陆晴石伟赵龙山熊志立沈阳药科大学药学院辽宁沈阳110016

目的整合代谢组学和肠道微生物组学的研究策略探讨骨疏丹(Gushudan, GSD)预防氢化可的松诱导的肾阳虚证(kidney-yang deficiency syndrome, KYDS)大鼠的补肾作用机制。方法分别采用超高效液相色谱-四级杆/静电场轨道阱高分辨质谱(UPLC... 详细信息

目的整合代谢组学和肠道微生物组学的研究策略探讨骨疏丹(Gushudan, GSD)预防氢化可的松诱导的肾阳虚证(kidney-yang deficiency syndrome, KYDS)大鼠的补肾作用机制。方法分别采用超高效液相色谱-四级杆/静电场轨道阱高分辨质谱(UPLC-Q-Orbitrap HRMS)的非靶向代谢组学和16S rRNA基因测序分析的肠道微生物组学方法,分析正常对照组、肾阳虚证模型组、骨疏丹给药组和阳性对照组大鼠粪便代谢物谱与肠道菌群组成,采用Pearson相关分析探讨内源性差异代谢物与差异菌群之间的相关性。结果基于UPLC-Q-Orbitrap HRMS的代谢组学方法在正负离子模式下共发现骨疏丹参与调控肾阳虚症的22种差异代谢物,如色氨酸、鹅去氧胆酸、肌酐和油酸酰胺等,主要涉及氨基酸代谢、胆汁酸代谢、能量代谢和脂质代谢。基于16S rRNA测序分析发现骨疏丹在属水平显著上调普雷沃氏菌(Prevotellaceae)的相对丰度(P<0.05),显著下调颤杆菌(Oscillibacter)的相对丰度(P<0.05)。相关性分析结果表明甘胆酸和鹅去氧胆酸与在属水平显著改变的普雷沃氏菌(Prevotellaceae)显著正相关(P<0.05),而与考拉杆菌(Phascolarctobacterium)显著负相关(P<0.05)。二十二碳六烯酸与毛螺菌(Lachnospiraceae)显著负相关(P<0.05)。结论骨疏丹通过良性调节内源性代谢和肠道菌群结构发挥补肾作用,为中药通过肠-肾轴治疗疾病提供新的思路和方法。

关键词：肾阳虚证骨疏丹代谢组学肠道菌群 UPLC-Q-Orbitrap HRMS 16S rRNA基因测序

Characterizing the spatiotemporal variations of evapotranspiration and aridity index in mid-western China from 2001 to 2016

在线全文

学校读者我要写书评

暂无评论

Journal of Arid Land 2021年第12期13卷 1230-1243页

作者： MU Le LU Yixiao LIU Minguo YANG Huimin feng qisheng State Key Laboratory of Grassland Agro-ecosystems College of Pastoral Agriculture Science and TechnologyLanzhou UniversityLanzhou 730020China

Mid-western China is one of the most sensitive and fragile areas on the ***(ET)is a key part of hydrological cycle in these areas and is affected by both global climate change and human *** dynamic changes in ET and potential evapotranspiration(PET),which can reflect water consumption and demand,are still unclear,and there is a lack of predictive capacity on drought *** this study,we used global MODIS(moderate-resolution imaging spectroradiometer)terrestrial ET(MOD16)products,Morlet wavelet analysis,and simple linear regression to investigate the spatiotemporal variations of ET,PET,reference ET(ET0),and aridity index(AI)in mid-western pastoral regions of China(including Gansu Province,Qinghai Province,Ningxia Hui Autonomous Region,and part of Inner Mongolia Autonomous Region)from 2001 to *** results showed that the overall ET gradually increased from east to southwest in the study *** ET showed an increasing trend,whereas PET tended to decrease from 2001 to *** change in ET was affected by vegetation *** the study period,the average annual ET0 and AI tended to *** the monthly scale within a year,AI value decreased from January to July and then *** interannual variations of ET0 and AI showed periodicity with a main period of 14 a,and two other periodicities of 11 and 5 *** study showed that in recent years,drought in these pastoral regions of mid-western China has been ***,it is foreseeable that the demand for irrigation water for agricultural production in these regions will decrease.

关键词： evapotranspiration aridity index climate change human activities vegetation cover arid areas

Accuracy assessment of four cloud-free snow cover products over the Qinghai-Tibetan Plateau

在线全文

学校读者我要写书评

暂无评论

International Journal of Digital Earth 2019年第4期12卷 375-393页

作者： Xiaohua Hao Siqiong Luoa Tao Che Jian Wang Hongyi Li Liyun Dai Xiaodong Huang qisheng feng Northwest Institute of Eco-Environment and Resources Chinese Academy of SciencesLanzhouGansuPeople’s Republic of China Heihe Remote Sensing Experimental Research Station Chinese Academy of SciencesLanzhouPeople’s Republic of China CAS Center for Excellence in Tibetan Plateau Earth Sciences BeijingPeople’s Republic of China Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application Nanjing Normal UniversityNanjingPeople’s Republic of China State Key Laboratory of Grassland Agro-ecosystems College of Pastoral Agriculture Science and TechnologyLanzhou UniversityLanzhouGansuPeople’s Republic of China

Four up-to-date daily cloud-free snow products–IMS(InteractiveMultisensor Snow products),MOD-SSM/I(combination of the MODIS andSSM/I snow products),MOD-B(Blending method basing on the MODISsnow cover products)and TAI(Terra–Aqua–IMS)–with high-resolutionsover the Qinghai-Tibetan Plateau(QTP)were comprehensively *** of the IMS,MOD-SSM/I,MOD-B and TAI cloud-free snowproducts against meteorological stations observations over 10 snowseasons(2004–2013)over the QTP indicated overall accuracies of 76.0%,89.3%,92.0%and 92.0%,*** Khat values of the IMS,MODSSM/I,MOD-B and TAI products were 0.084,0.463,0.428 and 0.526,*** TAI products appear to have the best cloud-removalability among the four snow products over the *** on theassessment,an I-TAI(Improvement of Terra–Aqua–IMS)snow productwas proposed,which can improve the accuracy to some ***,the algorithms of the MODIS series products show instabilitywhen identifying wet snow and snow under forest cover over the *** snow misclassification is an important limitation of MODIS snowcover products and requires additional improvements.

关键词： MODIS IMS snow-covered area cloud removal TAI

Changes in global potential vegetation distributions from 1911 to 2000 as simulated by the Comprehensive Sequential Classification System approach

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2012年第11期57卷 1298-1310页

作者： LIANG TianGang feng qisheng CAO JianJun XIE HongJie LIN HuiLong ZHAO Jun REN JiZhou State Key Laboratory of Grassland Agro-ecosystems College of Pastoral Agriculture Science and TechnologyLanzhou UniversityLanzhou 770020 China State Key Laboratory for Information Engineering in Surveying Mapping and Remote SensingWuhan UniversityWuhan 430079China Basic Geographic Information Center of Gansu Province Lanzhou 730000China University of Texas at San Antonio Department of Geological SciencesLaboratory for Remote Sensing and GeoinformaticsSan AntonioTexas78249USA College of Geography and Environmental Science Northwest Normal UniversityLanzhou 730070China

Vegetation classification models play an important role in studying the response of the terrestrial ecosystem to global climate change. In this paper, we study changes in global Potential Natural Vegetation (PNV) distributions using the Comprehensive Sequential Classification System (CSCS) approach, a technique that combines geographic information systems. Results indicate that on a global scale there are good agreements among maps produced by the CSCS method and the globally well-accepted Holdridge Life Zone (HLZ) and BIOME4 PNV models. The potential vegetation simulated by the CSCS approach has 6 major latitudinal zones in the northern hemisphere and 2 in the southern hemisphere. In mountainous areas it has obvious altitudinal distribution characteristics due to topographic effects. The distribution extent for different PNV classes at various periods has different characteristics. It had a decreasing trend for the tundra and alpine steppe, desert, sub-tropical forest and tropical forest categories, and an increasing trend for the temperate forest and grassland vegetation categories. The simulation of global CSCS-based PNV classes helps to understand climate-vegetation relationships and reveals the dynamics of potential vegetation distributions induced by global changes. Compared with existing statistical and equilibrium models, the CSCS approach provides similar mapping results for global PNV and has the advantage of improved simulation of grassland classes.

关键词：植被分布分类系统模拟全球气候变化亚热带森林陆地生态系统地理信息系统高山草原

A new MODIS daily cloud free snow cover mapping algorithm on the Tibetan Plateau

在线全文

学校读者我要写书评

暂无评论

Research in Cold and Arid Regions 2014年第2期6卷 116-123页

作者： XiaoDong Huang XiaoHua Hao qisheng feng Wei Wang TianGang Liang State Key Laboratory of Grassland Agro-ecology Systems College of Pastoral Agriculture Science and TechnologyLanzhou University Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences

Because of similar reflective characteristics of snow and cloud, the weather status seriously affects snow monitoring using optical remote sensing data. Cloud amount analysis during 2010 to 2011 snow seasons shows that cloud cover is the major limitation for snow cover monitoring using MOD10A1 and MYD10A1. By use of MODIS daily snow cover products and AMSR-E snow wa- ter equivalent products （SWE）, several cloud elimination methods were integrated to produce a new daily cloud flee snow cover product, and information of snow depth from 85 climate stations in Tibetan Plateau area （TP） were used to validate the accuracy of the new composite snow cover product. The results indicate that snow classification accuracy of the new daily snow cover product reaches 91.7% when snow depth is over 3 cm. This suggests that the new daily snow cover mapping algorithm is suitable for monitoring snow cover dynamic changes in TP.

关键词： MODIS snow cover cloud contamination elimination Tibetan Plateau

Modification of Hydration Resistance of SrO with ZrO_(2) Addition

在线全文

学校读者我要写书评

暂无评论

China's Refractories 2022年第4期31卷 16-21页

作者： CHEN Guangyao LIU Jian YU Feihai HOU Xiao feng qisheng PENG Jun WANG Enhui HOU Xinmei LU Xionggang LI Chonghe State Key Laboratory of Advanced Special Steel&Shanghai Key Laboratory of Advanced Ferrometallurgy&School of Materials Science and Engineering Shanghai UniversityShanghai 200072China Shanghai Special Casting Engineering Technology Research Center Shanghai 201605China China Northwest Architecture Design and Research Institute Co. LtdXi’an 710018China Beijing Advanced Innovation Center for Materials Genome Engineering Collaborative Innovation Center of Steel TechnologyUniversity of Science and Technology BeijingBeijing 100083China

Considering the high melting point and high stability of SrO,it has potential applications in the field of the preparation of titanium *** improve the hydration resistance,SrO samples with different ZrO_(2)additions were fabricated after firing at 1750℃for 6 *** phase,the microstructure,and the hydration resistance of the samples were *** results show that the sample with 33 mol%ZrO_(2)addition possesses good hydration resistance with the mass gain after hydration for 13 days of less than 0.42 mass%.The SrO crucible with 33 mol%ZrO_(2)addition does not react with TiNi alloy melt during melting,which provides a support for searching new refractories with good hydration resistance for induction melting titanium alloys.

关键词： strontium oxide hydration resistance titanium-nickel alloy induction melting

MODIS和VIIRS植被指数产品在估算甘南草地生物量的适用性

在线全文

学校读者我要写书评

暂无评论

草业科学 2023年第9期40卷 2199-2212页

作者：张忠雪冯琦胜王瑞泾金哲人梁天刚兰州大学草地农业科技学院甘肃兰州730020

目前中分辨率成像光谱仪(MODIS)传感器处于超期服役阶段,可见光红外成像辐射仪(VIIRS)传感器是MODIS传感器的继承和发展。本研究以甘南地区为例,选用MODIS的4种植被数据产品和VIIRS的两种植被数据产品提供的增强型植被指数(EVI)和归一... 详细信息

目前中分辨率成像光谱仪(MODIS)传感器处于超期服役阶段,可见光红外成像辐射仪(VIIRS)传感器是MODIS传感器的继承和发展。本研究以甘南地区为例,选用MODIS的4种植被数据产品和VIIRS的两种植被数据产品提供的增强型植被指数(EVI)和归一化植被指数(NDVI),对比分析了MODIS与VIIRS在草地地上生物量估测方面的差异。主要结论如下:1)与VIIRS相比较,基于MODIS的甘南地区草地地上生物量反演模型的精度更高,MODIS MOD13A1产品更适合甘南地区草地地上生物量的估算。2)甘南地区草地地上生物量较大的区域(>3000 kg·hm^(-2))主要分布于玛曲县、碌曲县和合作市,草地地上生物量较小的区域(<1500 kg·hm^(-2))主要分布于夏河县和迭部县。西部地区的草地地上生物量较高,东部地区的非草地区域比较多,且生物量较低。3)生物量增加幅度较大的区域主要分布于夏河县北部、玛曲县西北部以及碌曲县中部,生物量减少幅度较大的区域主要分布于玛曲县东南部和碌曲县南部。

关键词：地上生物量植被指数产品对比甘南反演空间分布

跳出历史周期率“两个答案”的科学内涵、内在价值与实践要求

在线全文

学校读者我要写书评

暂无评论

河南科技大学学报（社会科学版） 2023年第4期41卷 1-6页

作者：王洪彬冯奇升河南科技大学马克思主义学院河南洛阳471023

中国共产党的伟大之处不在于不犯错误,而在于犯了错误之后能够及时地发现错误、承认错误、改正错误。在建党百年历史进程中,中国共产党人探索出了跳出治乱兴衰历史周期率的“两个答案”——民主监督和自我革命:民主监督通过外部向党内... 详细信息

中国共产党的伟大之处不在于不犯错误,而在于犯了错误之后能够及时地发现错误、承认错误、改正错误。在建党百年历史进程中,中国共产党人探索出了跳出治乱兴衰历史周期率的“两个答案”——民主监督和自我革命:民主监督通过外部向党内提出建议和批评,促使中国共产党保持自身先进性;自我革命则强调通过刀刃向内加强党的自身建设;二者统一于跳出历史周期率的伟大实践过程中。中国共产党在特定历史条件下探索出的跳出历史周期率的“两个答案”在新时代仍具有重要的实践意义。

关键词：历史周期率 “两个答案” 民主监督自我革命