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浅谈“拔高”教师如何成功转型
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作者 王俊 《当代教育论坛(教学版)》 2011年第1期37-38,共2页
成为一名合格的"拔高"教师,需要社会各方力量的共同支持,教育部门的宏观调控,学校的校本培训以及"拔高"教师的自我完善,三者缺一不可,相辅相成。
关键词 “拔高”教师 转型 初中教育 校本培训
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美术教学中“拔高”策略对优等生的影响
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作者 蔡飞平 《少儿美术》 2018年第10期36-37,共2页
“导优辅差”一直是一线教师采用的教学举措,在日常的课堂教学中,作为教师更多的是关注学困生的辅导,比较少地去对优等生采取相应的措施。如何在美术课堂教学中对优等生进行“拔高”,对于教师来讲少人问津,较少关注。那么在美术教... “导优辅差”一直是一线教师采用的教学举措,在日常的课堂教学中,作为教师更多的是关注学困生的辅导,比较少地去对优等生采取相应的措施。如何在美术课堂教学中对优等生进行“拔高”,对于教师来讲少人问津,较少关注。那么在美术教学中“拔高”策略对优等生影响几何?主要采取“大虚大实”“欲擒故纵”“愚公移山”等三大教学策略,对优等生进行“拔高”。 展开更多
关键词 美术教学 “拔高” 优等生 策略
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Effects of Enhanced Ultraviolet Radiation-B on Maize in Arid Regions of Middle-high Elevation 被引量:13
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作者 张磊 王连喜 +2 位作者 李福生 车晶晶 杜宏娟 《Agricultural Science & Technology》 CAS 2009年第1期11-14,73,共5页
[Objective] The experiment aimed to explore the influence of enhanced ultraviolet radiation-B on maize in arid regions of middle-high elevation for correct assessing the influence of enhanced ultraviolet radiation-B o... [Objective] The experiment aimed to explore the influence of enhanced ultraviolet radiation-B on maize in arid regions of middle-high elevation for correct assessing the influence of enhanced ultraviolet radiation-B on maize and providing scientific reference to make proper countermeasures. [ Method] The location test in field and lift lamp of UV-B were used to observe the changes of maize height, leaf area and number of green leaves under influences of different UV-B radiation. [ Result] In arid regions of middle-high elevation, enhanced ultraviolet radiation-B could dwarf maize plant, decrease leaf area, decline number of green leaves and yield. The reason of decreasing leaf area was that enhanced ultraviolet radiation-B shortened leaf length and leaf width while the reason of declining yield was that yield components were all negatively influ- enced and with the increase of ultraviolet radiation-B, the yield declined dramatically. [ Concluslonl The result of this experiment would be good for maize production in arid regions of middle-high elevation. 展开更多
关键词 UV-B Middle-high elevation Arid area MAIZE
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Study on Species Diversity of Alpine Vegetation with Different Altitudes in Daban Mountain 被引量:1
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作者 周芸芸 赵敏杰 +2 位作者 李熙萌 马帅 冯金朝 《Agricultural Science & Technology》 CAS 2011年第3期313-316,332,共5页
[Objective] The aim of this study is to investigate species diversity of alpine vegetation in different altitudes of Daban mountain. [Method] Plant communities were surveyed in three different altitudes (3 025 m,3 40... [Objective] The aim of this study is to investigate species diversity of alpine vegetation in different altitudes of Daban mountain. [Method] Plant communities were surveyed in three different altitudes (3 025 m,3 405 m,3 813 m) of Daban mountain,the eastern Qilian,and the richness or diversity index of vegetation in three different altitudes was comparatively analyzed. [Result] The species richness decreased with the gradual increase of altitude,and species diversity of plant communities was relatively lower in medium altitude. Furthermore,community similarity also decreased with the increase of altitude,and β diversity of communities had a significant change. [Conclusion] Environmental factor change caused by different altitudes and human disturbance are important reasons for the change of species distribution pattern in different altitudes. 展开更多
关键词 Daban Mountain Alpine vegetation Altitude gradient Species diversity
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Cultivation of Black Fungus under Forest in Middle-high Altitude Areas
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作者 袁长波 徐延熙 +5 位作者 王艳芹 姚利 付龙云 田叶 李瑞琴 曹德宾 《Agricultural Science & Technology》 CAS 2016年第10期2358-2361,共4页
[Objective] The study was to solve the contradiction between fungus and forest during the production of black fungi, and to obtain relatively high economic benefits and ecological benefits. [Method] Black fungi were c... [Objective] The study was to solve the contradiction between fungus and forest during the production of black fungi, and to obtain relatively high economic benefits and ecological benefits. [Method] Black fungi were cultivated in forest with middle-high altitude of 500-1 600 m. The germination time of fungus stick, germination days of buds, growth days of fruiting body, commodity exterior, marketing effect and biological efficiency of black fungi were investigated. [Result] Compared with traditional cultivation, black fungus products cultivated under forest had the taste and flavor of wild black fungus. Fungus chaff wastage was directly decomposed by the roots in forest land, improving the soil structure of forest land. The need of moisture retention and the frequent access of administrative staff reduced the probability of forest fire occurrence. [Conclusion] Cultivation of black fungus under forest saves more than 70% fixed-asset investment on fungus shed, and the biological efficiency reached 12.2%. 展开更多
关键词 Forest area in middle-high altitude Under forest Black Fungus
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Local Variability in Temperature, Humidity and Radiation in the BaekduDaegan Mountain Protected Area of Korea 被引量:5
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作者 CHAE Heemun LEE Hyunju +4 位作者 LEE Sangsin CHEONG Yukyong UM Gijeung MARK Bryan PATRICK Nathan 《Journal of Mountain Science》 SCIE CSCD 2012年第5期613-627,共15页
A novel embedded sensor network records changes in key climatic-environmental variables over a range of altitude in the BaekduDaegan Mountain (BDM) of Gangwon Province in Korea, a protected mountain region with uniq... A novel embedded sensor network records changes in key climatic-environmental variables over a range of altitude in the BaekduDaegan Mountain (BDM) of Gangwon Province in Korea, a protected mountain region with unique biodiversity undergoing climate change research. The investigated area is subdivided into three horizontal north-south study areas. Three variables, temperature (T, °C), relative humidity (RH, %), and light intensity (LI, lumens m-2, or lux, lx), have been continuously measured at hourly intervals from June, 2olo to September, 2011 using HOBO H8 devices at lO fixed study sites. These hourly observations are aggregated to monthly, seasonal and annual mean values, and results are summarized to inaugurate a long-term climate change investigation. A region wide T difference in accordance with altitude, or lapse rate, over the interval is calculated as o.4°C l00 m-1. T lapse rates change seasonally, with winter lapse rates being greater than those of summer. RH is elevated in summer compared to other seasons. LI within forestland is lower during summer and higher during other seasons. The obtained results could closely relate to the vegetation type and structure and the terrain state since data loggers were located in forestland. 展开更多
关键词 Embedded sensors Temperature lapserates Relative humidity Light intensity FOREST Climate change BaekduDaegan Mountain
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Trends in extreme high temperature at different altitudes of Southwest China during 1961–2014 被引量:5
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作者 XUE Yuting CHEN Quanliang +1 位作者 ZHANG Jiayu HUANG Ping 《Atmospheric and Oceanic Science Letters》 CSCD 2020年第5期417-425,共9页
This study analyzed the trends in extreme high temperature in Southwest China based on the observed daily maximum temperature and average temperature data from 410 Chinese stations recently released by the China Meteo... This study analyzed the trends in extreme high temperature in Southwest China based on the observed daily maximum temperature and average temperature data from 410 Chinese stations recently released by the China Meteorological Administration.The authors found that the trends in extreme high temperature at different altitudes of Southwest China exhibit staged variations during a recent 50-year period(1961–2014).The trends in mean temperature and maximum temperature also exhibit phase variation.All temperature-related variables increase gently during the period 1975–94,whereas they increase dramatically during the recent period of 1995–2014,with a rate that is approximately two to ten times more than that during 1975–94.In addition,the trends in mean temperature,maximum temperature,and the frequency of extreme high temperature in the low altitudes transit from negative to positive in the two periods,while they increase dramatically in the mid-and high-altitude areas during 1995–2014,the well-known global warming hiatus period.In particular,the maximum temperature increases much faster than that of average temperature.This result implies that the regional temperature trend could be apparently different from the global mean temperature change. 展开更多
关键词 Southwest China extreme high temperature trend change ALTITUDE
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Effect of Altitude and Latitude on Surface Air Temperature across the Qinghai-Tibet Plateau 被引量:8
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作者 WANG Keli SUN Jia +1 位作者 CHENG Guodong JIANG Hao 《Journal of Mountain Science》 SCIE CSCD 2011年第6期808-816,共9页
The correlation between mean surface air temperature and altitude is analyzed in this paper based on the annual and monthly mean surface air temperature data from 106 weather stations over the period 1961-2003 across ... The correlation between mean surface air temperature and altitude is analyzed in this paper based on the annual and monthly mean surface air temperature data from 106 weather stations over the period 1961-2003 across the Qinghai-Tibet Plateau. The results show that temperature variations not only depend on altitude but also latitude, and there is a gradual decrease in temperature with the increasing altitude and latitude. The overall trend for the vertical temperature lapse rate for the whole plateau is approximately linear. Three methods, namely multivariate composite analysis, simple correlation and traditional stepwise regression, were applied to analyze these three correlations. The results assessed with the first method are well matched to those with the latter two methods. The apparent mean annual near-surface lapse rate is -4.8 ℃ /km and the latitudinal effect is -0.87 ℃ /°latitude. In summer, the altitude influences the temperature variations more significantly with a July lapse rate of -4.3℃/km and the effect of latitude is only -0.28℃ /°latitude. In winter, the reverse happens. The temperature decrease is mainly due to the increase in latitude. The mean January lapse rate is -5.0℃/km, while the effect of latitude is -1.51℃ /°latitude. Comparative analysis for pairs of adjacent stations shows that at a small spatial scale the difference in altitude is the dominant factor affecting differences in mean annual near-surface air temperature, aided to some extent bydifferences of latitude. In contrast, the lapse rate in a small area is greater than the overall mean value for the Qinghai-Tibet Plateau (5 to 13℃ /km). An increasing trend has been detected for the surface lapse rate with increases in altitude. The temperature difference has obvious seasonal variations, and the trends for the southern group of stations (south of 33 o latitude) and for the more northerly group are opposite, mainly because of the differences in seasonal variation at low altitudes. For yearly changes, the temperature for high-altitude stations occurs earlier clearly. Temperature datasets at high altitude stations are well-correlated, and those in Nanjing were lagged for 1 year but less for contemporaneous correlations. The slope of linear trendline of temperature change for available years is clearly related to altitude, and the amplitude of temperature variation is enlarged by high altitude. The change effect in near-surface lapse rate at the varying altitude is approximately 1.0℃ /km on the rate of warming over a hundred-year period. 展开更多
关键词 Qinghai-Tibet Plateau Surface airtemperature Vertical lapse rate ALTITUDE LATITUDE
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Mountain Effect and Differences in Storm Floods between Northern and Southern Sources of the Songhua River Basin 被引量:6
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作者 LI Hongyan WU Ya'nan LI Xiubin 《Journal of Mountain Science》 SCIE CSCD 2012年第3期431-440,共10页
In this study, the differences in annual rainstorm changes in the Second Songhua River Basin and the Nenjiang River basin and their causes were compared from the perspective of mountain effects. The following results ... In this study, the differences in annual rainstorm changes in the Second Songhua River Basin and the Nenjiang River basin and their causes were compared from the perspective of mountain effects. The following results were drawn: (1) Altitude effect is the primary factor leading to increased rainstorms in the southern source; (2) Slope effect primarily leads to differences of the weather systems in the two sources, and thus cause the difference of the rainstorms; (3) Slope effect is responsible for the greater fluctuation in the observed floods in the southern source. These landform differences eventually lead to the differences in the characteristics of floods in the southern and northern sources. Commensurability method was used to identify the period of rainstorms in the southern and northern sources. The results showed that although rainstorms do not appear at the same time in the two sources they are characteristic of a 10 years' period in both areas. These results can serve as hydrological references for flood control and long-term flood disaster predictions. 展开更多
关键词 Mountain effect Songhua River Basin Nenjiang River Basin the Second Songhua RiverBasin Storm flood
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Vegetation-environment Relationships Between Northern Slope of Karlik Mountain and Naomaohu Basin,East Tianshan Mountains 被引量:8
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作者 ZHANG Haiyan QIAN Yibing +1 位作者 WU Zhaoning WANG Zhongchen 《Chinese Geographical Science》 SCIE CSCD 2012年第3期288-301,共14页
Based on data from 22 sample plots and applying the Canonical Correspondence Analysis (CCA), this paper discusses the vegetation-environment relationships between the northern slope of Karlik Mountain and Naomaohu B... Based on data from 22 sample plots and applying the Canonical Correspondence Analysis (CCA), this paper discusses the vegetation-environment relationships between the northern slope of Karlik Mountain and Naomaohu Ba- sin, which is situated in the easternmost end of the Tianshan Mountains, Xinjiang Uygur Autonomous Region, China. For the zonal vegetation, community diversity of mountain vegetation is higher than that of the desert vegetation due to environmental factors. The CCA ordination diagram revealed that the composition and distribution of vegetation types are mainly determined by altitude, soil pH and soil salt content. With increasing elevation, the soil pH and total salt content decrease but the contents of soil organic matter, soil water, total nitrogen and total phosphorus increase gradu- ally. In the CCA ordination diagrams, the sample plots and main species can be divided into five types according to their adaptations to the environmental factors. Type Ⅰ is composed of desert vegetation distributed on the low moun- tains, hills, plains and deserts below an elevation of 1900 m; type Ⅱ is distributed in the mountain and desert ecotone with an elevation of 1900-2300 m, and includes steppe desert, desert steppe and wetland meadow; type Ⅲ is very sim- ply composed of only salinized meadow; type Ⅳ is distributed above an elevation of 2300 m, containing mountain steppe, meadow steppe, subalpine meadow and alpine meadow; type Ⅴ only contains salinized meadow. The results show that with increasing elevation, species combination changes from the xerophytic shrubs, semi-shrubs and herbs distributed in the low altitude zone with arid climate to the cold-tolerant perennial herbs growing in the high altitudinal zone with cold climate. 展开更多
关键词 vegetation pattern environmental factors canonical correspondence analysis (CCA) vegetation-environment relationships Tianshan Mountains XINJIANG
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Effect of Topography and Accessibility on Vegetation Dynamic Pattern in Mountain-hill Region 被引量:8
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作者 QIU Bingwen ZHONG Ming +2 位作者 ZENG Canying TANG Zhenghong CHEN Chongcheng 《Journal of Mountain Science》 SCIE CSCD 2012年第6期879-890,共12页
Knowledge of both vegetation distribution pattern and phenology changes is very important.Their complicated relationship with elevation and accessibility were explored through a geographically weighted regression(GWR)... Knowledge of both vegetation distribution pattern and phenology changes is very important.Their complicated relationship with elevation and accessibility were explored through a geographically weighted regression(GWR) framework in Fujian province,China.The 16-day time series of 250 m Moderate Resolution Imaging Spectroradiometer(MODIS) Enhanced Vegetation Index(EVI) dataset from 2000 to 2010 was applied.Wavelet transform method was adopted to decompose the original time series and construct the annual maximum EVI and amplitude of the annual phenological cycle(EVI).Candidate explaining factors included topographic conditions,accessibility variables and proportions of primary vegetation types.Results revealed very strong positive influence from parameters of elevation and accessibility to big rivers and negative effect from accessibility to resident on both maximum EVI and phenological magnitude through ordinary linear least square(OLS) regression analysis.GWR analysis revealed that spatially,the parameters of topography and accessibility had a very complex relationship with both maximum EVI and phenology magnitude,as a result of the various combinations of environmental factors,vegetation composition and also intensive anthropogenic impact.Apart from the continuously increasing trend of phenology magnitude with increasing altitude,the influence of topography and accessibility on maximum EVI and phenological magnitude generally decreased,even from strongly positive to negative,with increasing altitude or distance.Specially,the most rapid change of correlation coefficient between them was observed within a low elevation or close distance;less variation was discovered within a certain range of medium altitude or distance and their relationship might change above this range.Non-stationary approaches are needed to better characterize the complex vegetation dynamic pattern in Mountain-hill Region. 展开更多
关键词 Vegetation phenology Elevation gradient ACCESSIBILITY Geographic weighted regression Enhanced Vegetation Index Spatial non-stationality
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Extracting Vegetation Phenology Metrics in Changbai Mountains Using an Improved Logistic Model 被引量:4
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作者 LI Ming WU Zhengfang +1 位作者 QIN Lijie MENG Xiangjun 《Chinese Geographical Science》 SCIE CSCD 2011年第3期304-311,共8页
Remotely sensing images are now available for monitoring vegetation dynamics over large areas.In this paper,an improved logistic model that combines double logistic model and global function was developed.Using this m... Remotely sensing images are now available for monitoring vegetation dynamics over large areas.In this paper,an improved logistic model that combines double logistic model and global function was developed.Using this model with SPOT/NDVI data,three key vegetation phenology metrics,the start of growing season (SOS),the end of growing season (EOS) and the length of growing season (LOS),were extracted and mapped in the Changbai Mountains,and the relationship between the key phenology metrics and elevation were established.Results show that average SOS of forest,cropland and grassland in the Changbai Mountains are on the 119th,145th,and 133rd day of year,respectively.The EOS of forest and grassland are similar,with the average on the 280th and 278th,respectively.In comparison,average EOS of the cropland is relatively earlier.The LOS of forest is mainly from the 160th to 180th,that of the grassland extends from the 140th to the 160th,and that of cropland stretches from the 110th to the 130th.As the latitude increases for the same land cover in the study area,the SOS significantly delays and the EOS becomes earlier.The SOS delays approximately three days as the elevation increases 100 m in the areas with elevation higher than 900 m above sea level (a.s.l.).The EOS is slightly earlier as the elevation increases especially in the areas with elevation below 1200 m a.s.l.The LOS shortens approximately four days as the elevation increases 100 m in the areas with elevation higher than 900 m a.s.l.The relationships between vegetation phenology metrics and elevation may be greatly influenced by the land covers.Validation by comparing with the field data and previous research results indicates that the improved logistic model is reliable and effective for extracting vegetation phenology metrics. 展开更多
关键词 logistic model SPOT/NDVI phenology metrics Changbai Mountains
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Changing human-environment interactions in medium mountains:the Apuseni Mts(Romania)as a case study 被引量:4
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作者 TELBISZ Tamas IMECS Zoltan +1 位作者 MARl Laszlo BOTTLIK Zsolt 《Journal of Mountain Science》 SCIE CSCD 2016年第9期1675-1687,共13页
The study of human-environment relationships in mountain areas is important for both theoretical and practical reasons, as many mountain areas suffer similar problems, such as depopulation, unemployment and natural ha... The study of human-environment relationships in mountain areas is important for both theoretical and practical reasons, as many mountain areas suffer similar problems, such as depopulation, unemployment and natural hazards. Medium mountains constitute a special case within mountains, because they are more populated but less attractive as tourist destinations than high mountains. In this context, the Apuseni Mts (Romania) are considered as a ease study. In this paper, we apply GIS-based, quantitative methods to characterize the strength and dynamics of human-environment interactions, taking into consideration some environmental factors (elevation, relative height, slope, river distance, lithology, land cover, natural attractions) as well as historical population and recent tourism data. We found that population density has strong (r2〉0.8) relationships with all relief factors (elevation, relative height, slope, river distance), and that best-fit functions are nonlinear. We outlined the varying demographic scenarios by elevation zones and interpreted the historically switching sign of population change versus elevation relationship. We demonstrated that lithology also has an impact on the spatial distribution of population, although it is not independent from the relief effect. The land cover of the mainly cultural landscape is very strongly correlated with relief parameters (especially slope), which suggests good adaptation. We pointed out the dominance of karst objects in the natural tourism potential of the Apuseni Mts and also explored further components of real tourism (spas, heritage, towns). Finally, we concluded that the environmental settings investigated do in fact constrain the spatial framework of society, but soeio-economic changes in history can be explained from the side of society, which conforms to the theory of cultural possibilism. 展开更多
关键词 Human-environment relations ApuseniMountains Geographical information system (GIS) Possibilism TOURISM KARST
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Area-corrected species richness patterns of vascular plants along a tropical elevational gradient 被引量:3
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作者 XU Xiang ZHANG Hua-yong +2 位作者 LUO Jian ZHANG Dong-jie MAAthen 《Journal of Mountain Science》 SCIE CSCD 2017年第4期694-704,共11页
The relationship and elevation is a hot issue between species richness in ecology and has been documented extensively. It is widely accepted that area size can significantly affect this relationship and thus mask the ... The relationship and elevation is a hot issue between species richness in ecology and has been documented extensively. It is widely accepted that area size can significantly affect this relationship and thus mask the effects of other predictors. Despite the importance of the relationship between species richness and elevation while accounting for the area effect, it is insufficiently studied. Here, we evaluated area-corrected species richness patterns of all vascular plants as well as six vascular plant subgroups (seed plants, ferns, trees, shrubs, herbs and vines) along a tropical elevational gradient (Hainan Island, China). If assessed in equal-elevation bands, uncorrected species richness showed bell-shaped curves, while area-corrected species richness assessed in equal-area bands appeared to increase monotonically due to the small proportion of highlands on Hainan Island. The mid-domain effect (MDE) was significantly correlated with both uncorrected and area-corrected species richness. On Hainan Island, the use of equal-area elevational bands increased the explanatory power of MDE.These findings provide useful insights to adjust for the area effect and highlight the need to use equal- area bands along the elevational gradient. 展开更多
关键词 Hainan Island Species-area relationship Mid-domain effect Vascular plant diversity Growthform
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Relationship between autonomic nervous system function and acute mountain sickness 被引量:4
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作者 Long Min Huang Lan +3 位作者 Tian Kaixin Yu Shiyong Yu Yang Qin Jun 《Journal of Medical Colleges of PLA(China)》 CAS 2008年第5期276-282,共7页
Objective: To elucidate the role of the autonomic nervous system (ANS) in acute mountain sickness (AMS) during the initial phase at acute high-altitude exposure. Methods: Ninety-nine healthy sea-level residents rapidl... Objective: To elucidate the role of the autonomic nervous system (ANS) in acute mountain sickness (AMS) during the initial phase at acute high-altitude exposure. Methods: Ninety-nine healthy sea-level residents rapidly ascended to Tibet plateau (3 675 m altitude) by airplane from Chengdu plain (560 m altitude). ANS function was tested in plain and day 2–4 in Tibet by heart rate variability (HRV), cold pressor test (CPT). AMS was evaluated by clinic symptomatic scores. All subjects were divided into non-AMS group (57, scores≤4) and AMS group (42, scores>4). Results: Compared with non-AMS group, AMS group had higher standard deviation of normal to normal intervals (SDNN), root mean square of delta RR (rMSSD), low-frequency (LF) power, and normalized low-frequency (LFnu) power in plain (P<0.05). After arrival at 3 675 m altitude, AMS group had greater reduction in percentage of delta RR>50 ms(PNN50), rMSSD (P<0.01) and SDNN, LF, total power (TP) (P<0.05). Although no significant differences in the increase of SP and DP during CPT were found between 2 groups in plain, the SP increase during CPT of AMS group was less than non-AMS group (P<0.05) at 3 675 m altitude. AMS symptomatic scores was not only positively correlated with SDNN, rMSSD, LF/HF in plain (P<0.05), but also negatively correlated with HFnu in plain (P<0.05). Conclusion: During the initial high altitude exposure, ANS modulation is generally blunted, but the relatively predominant sympathetic control is enhanced, and this characteristic change of ANS function is positively correlated with the development of AMS. 展开更多
关键词 High altitude Autonomic nervous system Acute mountain sickness Heart rate variability Cold pressor test
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Responses of Leaf Functional Traits of Torreya fargesii to the Altitudinal Variation 被引量:3
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作者 Jin SHANG Bo JIANG +3 位作者 Yonghong ZHENG Jianhua WANG Xianrong ZHOU Jianhui LI 《Agricultural Science & Technology》 CAS 2017年第11期2179-2184,共6页
[Objective] To reveal the leaf functional traits and adaptive strategy of Torreya fargesii at different altitude gradients.[Method] Leaves of T. fargesii were selected from the altitudes of 1 570, 1 700, 1 900, 2 125 ... [Objective] To reveal the leaf functional traits and adaptive strategy of Torreya fargesii at different altitude gradients.[Method] Leaves of T. fargesii were selected from the altitudes of 1 570, 1 700, 1 900, 2 125 and 2 360 m in Jiajinshan forest area of Sichuan Baoxing County, and the altitudes of 1 000, 1 200, 1 450, and 1 700 m in Hua'eshan Mountain Nature Reserve of Sichuan Wanyuan County as the research materials. Leaf blade traits such as leaf length, leaf width, leaf girth, leaf area and leaf dry weight were determined, and the influence of altitude on each index and correlation between characters were analyzed. [Result] For the leaves from both Baoxing County and Wanyuan County, leaf length, leaf width, leaf girth, leaf aspect ratio and leaf area decreased with the increase of altitude. There was no significant difference in the changes of leaf width, leaf girth and leaf aspect ratio among different altitudes(P>0.05), while the difference was significant in leaf length between high altitude and low attitude(P<0.05), and the difference was also significant in leaf area for the leaves from Baoxing County between high altitude and low altitude. However, there was no obvious correlation between leaf width and altitude, which could be considered as a relatively stable parameter. Leaf thickness and leaf dry weight increased first and then decreased with altitude,while the specific leaf area decreased first and then increased. In leaf length, leaf girth, leaf width and leaf area parameters, except for leaf width and leaf area for the T. fargesii from Wanyuan County, any two parameters reached significant or very significant positive correlation level(P<0.01). Leaf dry weight and leaf thickness had significant or very significant positive correlation, leaf dry weight and leaf area had a certain positive correlation but not significant. There existed no significant positive correlation between specific leaf area and leaf area, while specific leaf area was in negative correlation with leaf dry weight, and the negative correlation of specific leaf area with leaf area of T. fargesii from Wanyuan County reached the significant level.[Conclusion] T. fargesii adapted to different altitudes by changing leaf dry weight, leaf area and leaf area ratio, and the most suitable altitudes for the growth of T. fargesii were 1 900 and 1 450 m in Baoxing and Wanyuan area respectively. 展开更多
关键词 Torreya fargesii Franch. Altitude gradient Leaf traits CORRELATION
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Altitudinal trends in δ^13C value,stomatal density and nitrogen content of Pinus tabuliformis needles on the southern slope of the middle Qinling Mountains,China 被引量:2
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作者 LIU Xian-zhao GAO Chang-chun +2 位作者 SU Qing ZHANG Yong Song Yan 《Journal of Mountain Science》 SCIE CSCD 2016年第6期1066-1077,共12页
In this study,a coniferous tree species(Pinus tabuliformis Carr.) was investigated at a moderate-altitude mountainous terrain on the southern slope of the middle Qinling Mountains(QLM) to detect the trends in carbon i... In this study,a coniferous tree species(Pinus tabuliformis Carr.) was investigated at a moderate-altitude mountainous terrain on the southern slope of the middle Qinling Mountains(QLM) to detect the trends in carbon isotope ratio( δ^(13)C),leaf nitrogen content(LNC) and stomatal density(SD) with altitude variation in northsubtropical humid mountain climate zone of China.The results showed that LNC and SD both significantly increased linearly along the altitudinal gradient ranging from 1000 to 2200 m,whereas leafδ^(13)C exhibited a significantly negative correlation with the altitude.Such a correlation pattern differs obviously from that obtained in offshore low-altitude humid environment or inland high-altitude semi-arid environment,suggesting that the pattern of increasing δ^(13)C with the altitude cannot be generalized.The negative correlation between δ ^(13)C and altitude might be attributed mainly to the strengthening of carbon isotope fractionation in plants caused by increasing precipitation with altitude.Furthermore,there was a remarkable negative correlation between leaf δ ^(13)C and LNC.One possible reason was that increasing precipitation that operates to increase isotopic discrimination with altitude overtook the LNC in determining the sign of leaf δ ^(13)C.The significant negative correlation between leaf δ ^(13)C and SD over altitudes was also found in the present study,indicating that increases in SD with altitude would reduce,rather than enhance plant δ^(13)C values. 展开更多
关键词 Carbon isotope ratio Nitrogen content Stomatal density Altitudinal variation QinlingMountains
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Soil Nutrient Distribution in Two Typical Paddy Terrace Wetlands Along an Elevation Gradient During the Fallow Period 被引量:2
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作者 WANG Qinggai BAI Junhong +3 位作者 HUANG Laibin DENG Wei XIAO Rong ZHANG Kejiang 《Journal of Mountain Science》 SCIE CSCD 2011年第3期476-483,共8页
Soil nutrient concentrations in the top soils from two paddy terraces were determined in order to investigate spatial distributions of soil nutrients along the elevations on the Yunnan plateau of China during the fall... Soil nutrient concentrations in the top soils from two paddy terraces were determined in order to investigate spatial distributions of soil nutrients along the elevations on the Yunnan plateau of China during the fallow period.Results showed that soil nutrients in both terraces were higher than the reference concentrations except for SOC,TN,TP and Fe.Soil macronutrients didn't show significant differences in both terraces except for Mg and Ca,so did soil micronutrients except for Mn.Spatial distribution patterns of soil nutrients along the increasing elevations were different in both terraces.However,soil nutrients in both terraces were generally not significantly influenced by the elevations and soil pH values.The findings of this study can contribute to soil fertility management and ecological protection of Hani terraces. 展开更多
关键词 Spatial distribution MACRONUTRIENTS MICRONUTRIENTS Hani terrace Elevations
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Geodetic Height Determination in 2005 Qomolangma Survey 被引量:1
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作者 DANG Yamin CHENG Chuanlu CHEN Junyong ZHANG Peng 《Geo-Spatial Information Science》 2007年第2期79-84,共6页
Determining the geodetic height of Mount Qomolangma was one of the very important missions in the 2005 Qomolangma height survey. There were three GPS networks in the survey: regional GPS crustal deformation network, g... Determining the geodetic height of Mount Qomolangma was one of the very important missions in the 2005 Qomolangma height survey. There were three GPS networks in the survey: regional GPS crustal deformation network, geodetic GPS control network, and GPS measurement on the mountain summit. Data collection and processing were introduced. The final data processing strategy and reasonable geodetic height were fairly determined based on careful data analysis. 展开更多
关键词 Qomolangma geodetic height GPS MEASUREMENT
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Plant Communities and Factors Responsible for Vegetation Pattern in an Alpine Area of the Northwestern Himalaya 被引量:2
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作者 Man S.RANA S.S.SAMANT Y.S.RAWAT 《Journal of Mountain Science》 SCIE CSCD 2011年第6期817-826,共10页
The study intended to describe the alpine vegetation of a protected area of the northwestern Himalaya and identify the important environmental variables responsible for species distribution.We placed random plots cove... The study intended to describe the alpine vegetation of a protected area of the northwestern Himalaya and identify the important environmental variables responsible for species distribution.We placed random plots covering different habitats and altitude to record species composition and environmental variables.Vegetation was classified using hierarchical cluster analysis and vegetation-environment relationships were evaluated with Canonical Correspondence Analysis.Four communities,each in alpine shrub and meadows were delineated and well justified in the ordination plots.Indicator species for the different communities were identified.Maximum species richness and diversity were found in community IV among shrub communities and community II among the meadows.Studied environmental variables explained 61.5% variation in shrub vegetation and 59.8% variation in meadows.Soil variables explained higher variability (~35%) than spatial variables (~21%) in both shrubs and meadows.Altitude,among the spatial variables and carbon/nitrogen ratio and nitrogen among the soil variables explained maximum variation.About 40% variations left unexplained.Latitude and species diversity among the other variables had significant correlation with ordination axes.Study showed that altitude and C/N ratio played a significant role in species composition.Extensive sampling efforts and inclusion of other non-studied variables are also suggested for better understanding. 展开更多
关键词 Species diversity Indicator species Environmental variable ORDINATION Explainedvariation
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