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| 1 | The relationship between NDVI and precipitation on the Tibetan Plateau显示文摘西藏的高原上的 NDVI 的时间、空间的变化,以及在 NDVI 和降水之间的关系,在这份报纸被讨论,由使用 8-km 分辨率从 1982 ~ 1999 的多时间的 NOAA AVHRR-NDVI 数据。每月最大的 NDVI 和每月的降雨被用来分析季节的变化,和年度最大值 NDVI,年度有效降水和成长季节降水(从 4 月到 8 月) 被用来讨论 interannual 变化。在 NDVI 和降雨之间的 NDVI 和关联系数的动态变化为每个象素被计算。结果如下:(1 ) NDVI 在种季节到达了山峰(从 7 月到 9 月) 在西藏的高原上。在高原的北、西方的部分,成长季节是很短的(大约二或三个月) ;但是在里面南部,植被几乎所有一年周围成长了。每月最大的 NDVI 和每月的降雨的关联在不同区域变化了。它在西方、北、南部的部分是弱的,但是在中央、东方的部分强壮。(2 ) NDVI interannual 的空间分发动态变化也是不同的。增加区域主要在南部的西藏山区的灌木大草原地区,西方的四川东方的西藏山区的具球果的森林地区的西方的部分, Kunlun 山区的荒芜的地区的北斜坡的西方的部分和 Himalaya 的南部的斜坡的东南的部分被散布山区常绿树阔叶的森林地区;减少区域主要在 Qaidam 山区的荒芜的地区,东方 Qinghai-Qilian 山区的大草原地区的西方、北的部分,南部的 Qinghai 高冷的草地大草原地区和 Ngari 被散布山区的荒芜大草原、荒芜的地区。在年度有效降雨和年度最大的 NDVI 之间的关联系数的空间分发类似于成长季节降雨和年度最大的 NDVI ,并且与中等植被盖子在草地和草地在 NDVI 和降雨之间有好关系,并且植被上的降雨的效果在森林和荒芜的区域里是小的。 | DING Mingjun ZHANG Yili LIU Linshan ZHANG Wei WANG Zhaofeng BAI Wanqi | 2007 | Journal of Geographical Sciences2007，17，3： | 45 |
| 2 | Spatiotemporal variation in alpine grassland phenology in the Qinghai-Tibetan Plateau from 1999 to 2009显示文摘Plant phenology is the most salient and sensitive indicator of terrestrial ecosystem response to climate change.Studying its change is significantly important in understanding and predicting impressively changes in terrestrial ecosystem.Based on NDVI from SPOT VGT,this paper analyzed the spatiotemporal changes in alpine grassland phenology in Qinghai-Tibetan Plateau from 1999 to 2009.The results are enumerated as follows:(1) The spatial distribution of the average alpine grassland phenology from 1999 to 2009 is closely related to water and heat conditions.Accompanying the deterioration in heat and water conditions from southeast to northwest,the start of growth season(SOG) was delayed gradually,the end of growth season(EOG) advanced slowly,and the length of growth season(LOG) shortened gradually.Elevation played an important role in the regional differentiation of phenology,but a dividing line of approximately 3500 m existed.Below this line,the phenology fluctuated irregularly with altitude change,whereas above the line,the phenology is closely related to altitude change.(2) From 1999 to 2009,SOG of the alpine grassland came earlier by six days per decade(R2=0.281,P=0.093),EOG was late by two days per decade(R2=0.031,P=0.605),and LOG lengthened by eight days per decade(R2=0.479,P=0.018).The early SOG,the late EOG,and the extended LOG mainly occurred at the center and east of the Plateau.SOG in most of the Plateau advanced significantly,especially in the eastern Plateau.(3) The inter-annual phenology changes of the alpine grassland in the Qinghai-Tibetan Plateau exhibited significant differentiation at different elevation and natural zones.The inter-annual changes at high altitude were more complicated than that at low altitude.The most significant phenology changes were found in the eastern Qinghai-Qilian montane steppe zone,and non-significant changes occurred in the Southern Tibet montane shrub-steppe zone. | DING MingJun ZHANG YiLi SUN XiaoMin LIU LinShan WANG ZhaoFeng BAI WanQi | 2013 | Chinese Science Bulletin2013，58，3： | 44 |
| 3 | Spatial and temporal variability in the net primary production of alpine grassland on the Tibetan Plateau since 1982显示文摘基于 GIMMS AVHRR NDVI 数据( 8 km 空间分辨率)为 19822000 , SPOT 植被 NDVI 数据( 1 km 空间分辨率)为 19982009 ,并且观察植物生物资源数据, CASA 模型习惯于在高山的草地的变化在西藏的高原( TP )上让主要生产( NPP )赚的模型。这研究将帮助评估高山的草地生态系统的健康条件,并且对高原牧场并且到 TP 上的国家生态的安全躲蔽处的函数的理解的持续开发的提升很重要。NPP 变化的时间空间的特征用空间统计分析被调查,独立根据 physico 地理的因素(自然地区,高度,纬度和经度) ,河盆,和县级的行政区域。处理的数据用一个 ENVI 4.8 平台被执行,当一个 ArcGIS 9.3 和 ANUSPLIN 平台被用来进行空间分析并且印射时。主要结果如下:(1 ) TP 上的高山的草地的 NPP 逐渐地从东南减少到西北,它在降水和温度对应于坡度。从 1982 ~ 2009,在 TP 高山的草地的平均年度全部的 NPP 是 177.2 ?? ?? ? | ZHANG Yili QI Wei ZHOU Caiping DING Mingjun LIU Linshan GAO Jungang BAI Wanqi WANG Zhaofeng ZHENG Du | 2014 | Journal of Geographical Sciences2014，24，2： | 47 |
| 4 | Alpine wetlands in the Lhasa River Basin, China显示文摘拉萨河盆是西藏的高原上的高山的沼泽地的典型分发区域之一。为监视,保护和利用得到背景的更好的理解和高山的沼泽地的特征是很重要的。在盆的沼泽地建设和分发包括域调查数据, CBERS 遥感数据和 3S 技术提供的另外的题目的数据基于多来源数据被分析。结果是(1 ) 沼泽地的全部的区域是 209,322.26 hm2,为盆的 6.37% 全部的陆地区域的财务。沼泽地被自然沼泽地主要统治,与仅仅占据 1.09% 沼泽地区域的人工的沼泽地;沼泽地沼泽地是自然沼泽地的主要部分,由 Kobresia littledalei 统治了在河来源区域分布式的沼泽的草地并且 Chali, Damshung 和 Medro 在上游 Gongkar 县。在不同的县的沼泽地的比率和类型显著地不同,它在 Chali 和 Damshung 县(为 62% 全部的沼泽地区域的财务) 是广泛地分布式的。(2 ) 沼泽地的集中的垂直分发在 36005100 m 的举起。沼泽地广泛地从河来源在整个 Yarlung Zangbo 河山谷被散布到河嘴进 Yarlung Zangbo 河。沼泽地沼泽地在来源区域是主导的并且河在上游与湖的马赛克分发, Kobresia littledalei 和 Carex moorcroftii 沼泽的草地,灌木状的沼泽地和河;至于中间下面流,主要类型是河沼泽地并且充满沼泽地。分发在河,小而淡的 Kobresia 和 Carex moorcroftii 的一个马赛克模式沼泽的草地, Phragmites 南极光和辅助的草沼泽地,充满的沼泽地和人工的沼泽地。 | ZHANG Yili WANG Chunlian BAI Wanqi WANG Zhaofeng TU Yanli YANGJAEN Dor Gka | 2010 | Journal of Geographical Sciences2010，20，3： | 32 |
| 5 | A reversed CD4/CD8 ratio of tumor-infiltrating lymphocytes and a high percentage of CD4^(+)FOXP3^(+) regulatory T cells are significantly associated with clinical outcome in squamous cell carcinoma of the cervix显示文摘In this study,40 biopsy samples collected from cervical cancer patients at the First Affiliated Hospital of Xi’an Jiaotong University,China,were retrospectively assessed using immunohistochemistry for CD4^(+) and CD8^(+) tumor-infiltrating lymphocytes(TILs)and were analyzed for the expression of FOXP3,OX40,granzyme B(GrB)and perforin(Prf).The proliferating index of the TILs was determined by assessing Ki67 expression.We determined the prognostic value of low and high numbers of TILs on survival by performing Kaplan–Meier analysis using median values as the cut-off points.Except for the number of CD4^(+)FOXP3^(+) regulatory T cells(Tregs)and the CD4/CD8 ratio,none of the CD4^(+),CD8^(+),OX401,GrB^(+) or Prf^(+) TILs were associated with the overall 5-year survival rate.The 5-year survival rate was significantly lower in patients who had a high percentage of Tregs as compared with the those who had a lower percentage(35.3%versus 88.9%,P50.001),while the 5-year survival rate was significantly higher in patients with a high CD4/CD8 ratio as compared with patients who had a low CD4/CD8 ratio(82.4%versus 44.4%,P50.029).When we considered the deaths and surviving cases as separate groups,we found that both the number of CD4^(+) T cells and the CD4/CD8 ratio were significantly lower in patients who died as compared with those who survived(26.33±11.80 versus 47.79±38.18,P=0.023 and 0.60±0.25 versus 1.17±1.02,P=0.019,respectively).In conclusion,decreased proportions of tumor-infiltrating CD4^(+) T cells with high percentages of Tregs and reversed CD4/CD8 ratios were significantly associated with the clinical outcome of patients with cervical carcinoma. | Walayat Shah Xiaofei Yan Li Jing Yi Zhou Hongwei Chen Yili Wang | 2011 | Cellular & Molecular Immunology2011，8，1： | 24 |
| 6 | Characteristics of grassland degradation and driving forces in the source region of the Yellow River from 1985 to 2000显示文摘The source region of the Yellow River is located in the middle east of the Tibetan Plateau in northwest China. The total area is about 51,700 km2, mainly covered by grassland (79%), unused land (16%) and water (4%). The increasing land utilization in this area has increased the risk of environmental degradation. The land use/cover data (1985 and 2000) provided by the Data Center of Resources and Environment in the Chinese Academy of Sciences were used to analyze the land cover change in the source region of the Yellow River. DEM (1:250,000) data, roads and settlement data were used to analyze the spatial characteristics of grasslands degradation. The ArcGIS 9 software was used to convert data types and do the overlay, reclassification and zonal statistic analysis. Results show that grassland degradation is the most important land cover change in the study area, which occupied 8.24% of the region’s total area. Human activities are the main causes of the grassland degradation in the source region of the Yellow River: 1) the degradation rate is higher on the sunny slope than on the shady slope; 2) the grassland degradation rate decreases with an increase in the elevation, and it has a correlation coefficient of -0.93; 3) the nearer to the settlements the grassland is, the higher the degradation rate. Especially within a distance range of 12 km to the settlements, the grassland degradation rate is highly related with the distance, with a coefficient of -0.99; and 4) in the range of 4 km, the degradation rate decreases with the increase of distance to the roads, with a correlation coefficient of -0.98. Besides some physical factors, human activities have been the most important driving forces of the grassland degradation in the source region of the Yellow River since 1985. To resolve the degradation problems, population control is essential, and therefore, it can reduce the social demand of livestock products from the grassland. To achieve sustainable development, it needs to improve the management of grassland ecosystem. | LIU Linshan ZHANG Yili BAI Wanqi YAN Jianzhong | 2006 | Journal of Geographical Sciences2006，16，2： | 22 |
| 7 | Livelihood diversification and cropland use pattern in agro-pastoral mountainous region of eastern Tibetan Plateau显示文摘这研究在 Keerma 村庄里检验了生计多样化和农田使用模式,在 Jinchuan 定位了县,东方西藏的高原。通过成层的随机的采样调查,提供参加机会的农村估价。 | ZHANG Liping ZHANG Yili YAN dianzhong WU Yingying | 2008 | Journal of Geographical Sciences2008，18，4： | 23 |
| 8 | Glacial change in the vicinity of Mt. Qomolangma (Everest), central high Himalayas since 1976显示文摘冰河是在高山的区域的最重要的陆地封面之一并且对全球气候特别敏感变化。遥感证明了是在遥远的多山的区域调查冰川的变化的程度的最好的方法。用 Landsat 题目的印射(TM ) 并且从科莫朗马山(珠穆琅玛) 的 multi-spectral-scanner (女士) 图象国家自然保存(QNNP ) ,为 1976, 1988 和 2006 的中央高喜马拉雅山脉,我们为这三个时期导出冰川的程度。面向对象的图象解释方法,专家知识规则和域调查的联合被采用。结果证明(1 ) 在 2006 的冰川的区域是 2710.17 卤 0.011 km2 (大约 7.41% 整个学习区域) ,并且主要定位了到南方并且在 4700 m 之间到上面的 6800 m 海水平;(2 ) 从 1976 ~ 2006, 0.035 km2 和冰川的湖由 36.88 卤扩展了的 501.91 卤减少的冰河 0.035 km2;冰河撤退的率比在北斜坡(14.40%) 上在喜马拉雅山脉的南部的斜坡(16.79%) 上的亚盆是更高的;大多数冰河在 4700 鈥 ? 的举起撤退了,并且主要发生了 400 m,和撤退地区的估计的上面的限制在 6600 m 和 6700 m 之间;(3 ) 温度的增加和在在学习时期上的降水的减少是驾驶撤退的关键因素。 | NIE Yong ZHANG Yili LIU Linshan ZHANG Jiping | 2010 | Journal of Geographical Sciences2010，20，5： | 22 |
| 9 | Livelihood diversification of farmers and nomads of eastern transect in Tibetan Plateau显示文摘在西藏的高原的农民和流浪者的生计被草地和草药的资源退化严重地影响。怎么帮助他们完成生计多样化是一个关键持续发展问题。这份报纸在西藏的高原在东方横断的 3 个区域检验生计财产,生计多样化水平和农民和流浪者的生计策略。结果证明生计多样化是流行策略。从高山塞满区域到山高原区域和高原区域,生计多样化水平被减少,并且扩大生计的生计活动和比例也减少。有举起的增加的生计财产和生计多样化水平减少,主要出现在人的财产和自然财产。生计多样化水平是高度有生计财产的关联词,主要出现在自然财产,人的财产和社会财产。仍然基于存在生计财产,农民和流浪者的生计改进策略主要正在提起家畜和挖的植物,并且更少的农民和流浪者认为离开农场是雇用或做的生意。在高原区域的流浪者应该在高山峡区域和山高原区域从人的扩大生计的经验学习大部分。因此,政府的帮助应该集中于减轻生计多样化的限制因素并且帮助他们改进他们的能力建立扩大类型生计。 | YAN Jianzhong WU Yingying ZHANG Yili ZHOU Shaobin | 2010 | Journal of Geographical Sciences2010，20，5： | 22 |
| 10 | Ten cities cross-sectional questionnaire survey of children asthma and other allergies in China显示文摘Asthma,rhinitis and eczema(allergic or non-allergic)have increased throughout the world during the last decades,especially among children.Changes in the indoor environment are suspected to be important causes.China has experienced a dramatic change in indoor environmental exposures during the past two decades.However,such changes and their associations with children’s asthma and other health aspects have not been thoroughly studied.China,Children,Homes,Health(CCHH),Phase I,was a cross-sectional questionnaire survey of 48219 children 1–8 years old in 10 Chinese cities during 2010–2012.The questionnaire includes the International Study of Asthma and Allergies in Childhood(ISAAC)core health questions and additional questions regarding housing,life habits and outdoor environment.In health analyses,children aged 3–6 years old were included.The prevalences of doctor diagnosed asthma varied from 1.7%to 9.8%(mean 6.8%),a large increase from 0.91%in 1999 and 1.50%in2000.The prevalence of wheeze,rhinitis and atopic eczema(last 12 months)varied from 13.9%to 23.7%,24.0%to 50.8%and4.8%to 15.8%,respectively.Taiyuan had the lowest prevalences of all illnesses and Shanghai the highest,except for wheezewhere the highest value was for Urumqi.We found(1)no obvious association between disease prevalences and ambient PM10concentrations and(2)higher prevalences of disease in humid climates with hot summers and cold winters,but with no centrally heated buildings.Associations between the diseases and economic status as indexed by Gross Domestic Product(GDP)requires further study. | ZHANG YinPing LI BaiZhan HUANG Chen YANG Xu QIAN Hua DENG QiHong ZHAO ZhuoHui LI AnGui ZHAO JiaNing ZHANG Xin QU Fang HU Yu YANG Qin WANG Juan ZHANG Ming WANG Fang ZHENG XiaoHong LU Chan LIU ZhiJian SUN YueXia MO JinHan ZHAO YiLi LIU Wei WANG TingTing NORBCK Dan BORNEHAG Carl-Gustaf SUNDELL Jan | 2013 | Chinese Science Bulletin2013，58，34： | 22 |
| 11 | Sensitivity of surface air temperature change to land use/cover types in China显示文摘Using CRU high resolution grid observational temperature and ERA40 reanalysis surface air temperature data during 1960-1999, we investigated the sensitivity of surface air temperature change to land use/cover types in China by subtracting the reanalysis from the observed surface air temperature (observation minus reanalysis, OMR). The results show that there is a stable and systemic impact of land use/cover types on surface air temperature. The surface warming of each land use/cover type reacted differently to global warming. The OMR trends of unused land (≥0.17℃/decade), mainly comprised by sandy land, Gobi and bare rock gravel land, are obviously larger than those of the other land use/cover types. The OMR over grassland, farmland and construction land shows a moderate decadal warming about 0.12℃ /decade, 0.10℃/decade, 0.12 ℃ /decade, respectively. Woodland areas do not show a significant warming trend (0.06 ℃ /decade). The overall assessment indicates that the surface warming is larger for areas that are barren and anthropogenically developed. The better the vegetation cover, the smaller the OMR warming trend. Responses of surface air temperature to land use/cover types with similar physical and chemical properties and biological processes have no significant difference. The surface air temperature would not react significantly until the intensity of land cover changes reach a certain degree. Within the same land use/cover type, areas in eastern China with intensive human activities exhibit larger warming trend. The results provide observational evidence for modeling research on the impact of land use/cover change on regional climate. Thus, projecting further surface climate of China in regional scale should not only take greenhouse gas increase into account, but also consider the impact of land use/cover types and land cover change. | YANG XuChao ZHANG YiLi LIU LinShan ZHANG Wei DING MingJun WANG ZhaoFeng | 2009 | Science China Earth Sciences2009，52，8： | 21 |
| 12 | The impacts of climate change on the Neolithic cultures of Gansu-Qinghai region during the late Holocene Megathermal显示文摘Holocene Megathermal 被划分成早、中间、迟了的时期,各由于他们改变趋势的不同气候在过时的文化上有不同影响。这研究基于在金海·莱克,记录的环境进化信息的比较分析黄土高原和 Zoige 和 Gansu-Qinghai 区域的过时的地点的空间分发的西方的边。结果证明早、中间的时期向温暖、潮湿在 Gansu-Qinghai 区域作为主要扇区与农业支持了过时的文化的开发,而且, Yangshao 文化繁荣的一个全盛时期出现了。Holocene 在 Gansu-Qinghai 区域在 5.9 ka BP 在冷气候事件以后进入了迟了的时期。后来,气候开始变得冷。然而,在 5.84.2 ka BP,相对稳定的温暖、潮湿的气候在这个区域为过时的年龄的 Majiayao 文化的发展创造了条件,因此,它的文化遗产地点的分发向高高度和高纬度膨胀了。从 4.2 ka BP 向前,气候变得冷、干燥,它在 Gansu-Qinghai 区域的过时的文化上有重要影响,在 4.2 ka BP 附近在文化人物和 Qijia 文化的空间分发导致一个戏剧的变化。在以后一将近 300 年冷、干燥的时期,统一过时的耕作文化完全崩溃了。以后,畜牧和耕作和地区性的多重文化的一个工业部门形成了,并且最终导致了原始社会并且开始一个使文明的社会的结束。 | LIU Fenggui ZHANG Yili FENG Zhaodong HOU Guangliang ZHOU Qiang ZHANG Haifeng | 2010 | Journal of Geographical Sciences2010，20，3： | 18 |
| 13 | The trend on runoff variations in the Lhasa River Basin显示文摘作为一个学习区域在西藏的高原在拉萨水文学车站上面拿拉萨河盆,年度、每月的吝啬的流量的特征在 1956 ¨ C 期间, 2003 被分析。 | LIN Xuedong ZHANG Yili YAO Zhijun GONG Tongliang WANG Hong CHU Duo LIU Linshan ZHANG Fei | 2008 | Journal of Geographical Sciences2008，18，1： | 18 |
| 14 | Start of vegetation growing season on the Tibetan Plateau inferred from multiple methods based on GIMMS and SPOT NDVI data显示文摘在这研究,我们使用了四个方法从 1982~2012 在西藏的高原( TP )上调查成长季节( SGS )的开始,用从全球库存为研究建模并且印射获得的规范的差别植被索引( NDVI )数据( GIMSS , 19822006 )并且点植被( SPOT-VGT , 19992012 )。用四个方法估计的 SGS 价值沿着纬度或高度的坡度显示出类似的空间模式,但是与在 SGS 日期的重要变化。最大的差异主要在这些区域被发现与最高或最低植被范围。在 1982 和 1998 之间,然而,从四个方法导出的 SGS 值都根据更最近的点 VGT 数据(19992012 ) 显示一个进展趋势,没有 TP 上的 SGS 的连续地进展的趋势。在价值从在 1999 和 2006 之间的 GIMMS 和点导出的 SGS 之间的关联的分析数据来源与问候在趋势表明一致性到并且到使用的四个分析方法。与另外的方法相比,最大的一致性在之间在里面 situ 数据和检索的 SGS 值与方法 3 被获得(NDVI 比率的阀值) 。避免错误在有多样的植被类型和物理环境的一个广阔区域,知道不同植被类型的季节的变化特征是批评的,特别地在有稀少的草地的区域或常绿树森林。 | DING Mingjun LI Lanhui ZHANG Yili SUN Xiaomin LIU Linshan GAO Jungang WANG Zhaofeng LI Yingnian | 2015 | Journal of Geographical Sciences2015，25，2： | 17 |
| 15 | Disentangling the effects of topography and space on the distributions of dominant species in a subtropical forest显示文摘Topography and space are two important factors determining plant species assemblages in forest communities.Quantification of the contribution of these two factors in determining species distribution helps us to evaluate their relative importance in determining species assemblages.This study aims to disentangle the effect of topography and space on the distributions of 14 dominant species in a subtropical mixed forest.Spearman correlation analysis and the torustranslation test were used to test the species–habitat associations.Variation partitioning was used to quantify the relative contributions of topography and space at three sampling scales and three life stages.Correlation analyses and torus-translation tests showed species abundance was mostly correlated with topographic wetness index,vertical distance from the channel network and convexity.Variation partitioning showed that pure topography,pure space and spatially structured topography explained about 2.1 %,41.2 % and 13.8 %of the variation in species distributions,respectively.For nine species,total topography fractions peaked in 20 m quadrats.For ten species,the pure space fractions peaked in 50 m quadrats.For many species,the total topography fraction andthe pure space fraction were larger for the most abundant life stages,which reflected the importance of sampling effect.However,some cases did not follow this trend suggesting that the effects of ecological processes such as habitat filtering,density dependence or dispersal limitation may exceed the sampling effects.In conclusion,we found that spatially structured topography and pure space primarily shaped the distribution of dominant tree species.Furthermore,their effects were both scale- and life stage-dependent. | Qinggang Wang Yaozhan Xu Zhijun Lu Dachuan Bao Yili Guo Junmeng Lu Kuihan Zhang Haibo Liu Hongjie Meng Xiujuan Qiao Handong Huang Mingxi Jiang | 2014 | Chinese Science Bulletin2014，59，35： | 16 |
| 16 | Crop cover reconstruction and its effects on sediment retention in the Tibetan Plateau for 1900-2000显示文摘地理上明确的历史的陆地使用和陆地盖子数据集逐渐地在人的活动的气候、生态的效果的研究被要求。在这研究,把历史的人口数据用作一个代理, Qinghai 省的省的农田区域和西藏为 1900, 1930,和 1950 的自治区域(tar ) 被估计。为 1980 和 2000 的 Qinghai 和 TAR 的农田区域与修订从出版统计数据被获得。用为耕作模型的陆地适用性,为第 20 世纪的省的农田区域与 1 | LI Shicheng WANG Zhaofeng ZHANG Yili | 2017 | Journal of Geographical Sciences2017，27，7： | 16 |
| 17 | Land cover change along the Qinghai-Tibet Highway and Railway from 1981 to 2001显示文摘Based on the NOAA AVHRR-NDVI monthly data from 1981 to 2001, the spatial distribution and dynamic change of land cover along the Qinghai-Tibet Highway and Railway were studied. The results of the analytical data indicate that the NDVI values in July, August and September are rather high during a year, and a linear trend by calculating NDVI of each pixel computed based on the average values of NDVI in July, August and September were obtained. The results are as follows: 1) Land cover of the study area by NDVI displays high at two sides of the area and low in the center, and agriculture area > alpine meadow > alpine grassland > desert grassland. 2) In the study area, the amount of pixels with high increase, slight increase, no change, slight decrease and high decrease account for 0.29%, 14.86%, 67.61%, 16.7% and 0.57% of the whole area, respectively. The increase of land cover pixels is mainly in the agriculture and alpine meadow and the decrease pixels mainly in the alpine grassland, desert grassland and hungriness. Grassland and hungriness contribute to the decrease mostly and artificial land and meadow contribute to the increase mostly. 3) In the area where human beings live, the changing trend is obvious, such as the valleys of Lhasa River and Huangshui River and area along the Yellow River; in the high altitude area with fewer people living, the changing trend is relatively low, like the area of Hoh Xil. 4) Human being’s behaviors are a key factor followed by the climate changes affecting land cover. | DING Mingkun ZHANG Yili SHEN Zhenx LIU Linshan ZHANG Wei WANG Zhaofeng BAI Wanqi ZHENG Du | 2006 | Journal of Geographical Sciences2006，16，4： | 15 |
| 18 | Predicting Potential Distribution of Tibetan Spruce (Picea smithiana) in Qomolangma (Mount Everest) National Nature Preserve Using Maximum Entropy Niche-based Model显示文摘Tibetan spruce (Picea smithiana) is an endemic species of the Himalayas,and it distributes only in a re-stricted area with very low number.To address the lack of detailed distributional information,we used maximum en-tropy (Maxent) niche-based model to predict the species' potential distribution from limited occurrence-only records.The location data of P.smithiana,relative bioclimatic variables,vegetation data,digital elevation model (DEM),and the derived data were analyzed in Maxent.The receiver operating characteristic (ROC) curve was applied to assess the prediction accuracy.The Maxent jackknife test was performed to quantify the training gains from data layers and the response of P.smithiana distribution to four typical environmental variables was analyzed.Results show that the model performs well at the regional scale.There is a potential for continued expansion of P.smithiana population numbers and distribution in China.P.smithiana potentially distributes in the lower reaches of Gyirong Zangbo and Poiqu rivers in Gyirong and Nyalam counties in Qomolangma (Mount Everest) National Nature Preserve (QNNP),China.The species prefers warm temperate climate in mountain area and mainly distributes in needle-leaved evergreen closed to open forest and mixed forest along the river valley at relatively low altitudes of about 2000-3000 m.Model simulations suggest that distribution patterns of rare species with few species numbers can be well predicted by Max-ent. | ZHANG Jiping ZHANG Yili LIU Linshan NIE Yong | 2011 | Chinese Geographical Science2011，21，4： | 15 |
| 19 | Unbalance Vibratory Displacement Compensation for Active Magnetic Bearings显示文摘As the dynamic stiffness of radial magnetic bearings is not big enough,when the rotor spins at high speed,unbalance displacement vibration phenomenon will be produced.The most effective way for reducing the displacement vibration is to enhance the radial magnetic bearing stiffness through increasing the control currents,but the suitable control currents are not easy to be provided,especially,to be provided in real time.To implement real time unbalance displacement vibration compensation,through analyzing active magnetic bearings(AMB) mathematical model,the existence of radial displacement runout is demonstrated.To restrain the runout,a new control scheme-adaptive iterative learning control(AILC) is proposed in view of rotor frequency periodic uncertainties during the startup process.The previous error signal is added into AILC learning law to enhance the convergence speed,and an impacting factor influenced by the rotor rotating frequency is introduced as learning output coefficient to improve the rotor control effects.As a feed-forward compensation controller,AILC can provide one unknown and perfect compensatory signal to make the rotor rotate around its geometric axis through power amplifier and radial magnetic bearings.To improve AMB closed-loop control system robust stability,one kind of incomplete differential PID feedback controller is adopted.The correctness of the AILC algorithm is validated by the simulation of AMB mathematical model adding AILC compensation algorithm through MATLAB soft.And the compensation for fixed rotational frequency is implemented in the actual AMB system.The simulation and experiment results show that the compensation scheme based on AILC algorithm as feed-forward compensation and PID algorithm as close-loop control can realize AMB system displacement minimum compensation at one fixed frequency,and improve the stability of the control system.The proposed research provides a new adaptive iterative learning control algorithm and control strategy for AMB displacement minimum compensation,and provides some references for time-varied displacement minimum compensation. | GAO Hui XU Longxiang ZHU Yili | 2013 | Chinese Journal of Mechanical Engineering2013，26，1： | 14 |
| 20 | Risk analysis of snow disaster in the pastoral areas of the Qinghai-Tibet Plateau显示文摘雪灾难是顶之一世界范围的十自然灾难,和最严重的自然灾难到影响 Qinghai 西藏高原的牧剧区域。基于从历史的记录收集的危险伤害数据和从这危险在 2010 影响的实体收集的数据,Qinghai西藏高原上的雪灾难的 18 个索引的全面分析被进行,包含危险伤害,物理暴露的数量忍受危险的实体脸,敏感到危险,和能力到对灾难作出回应。分析显示那:(1 ) 区域在 Qinghai 西藏高原上的雪灾难高风险在 Xinjiang 区域位于 Yecheng 和 Pishan 的县的某些区域;(2 ) 区域在雪中等风险灾难在 Qinghai 西藏高原,和南部的 Qinghai 高原的东南的部分的中央西方的部分在 Gangdise 山和喜马拉雅山脉之间被发现;(3 ) 雪灾难的风险在整个到 30 ‰ ? ? 的南方的大区域通常是低的 ????????????? ?? 吗?? | LIU Fenggui MAO Xufeng ZHANG Yili CHEN Qiong LIU Pei ZHAO Zhilong | 2014 | Journal of Geographical Sciences2014，24，3： | 13 |
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