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61.
2012、2013和2015年夏季,对湖北三潭风景区鸟类群落及多样性进行了调查.结果表明,该景区夏季分布鸟类66种,隶属11目31科.鸟类多样性指数为1.464,均匀度指数为0.884.鸟类种类年间变化不明显,但鸟类数量有减少的趋势.尽管总的鸟类种类与景区改造前变化不大,但每年到景区繁殖的鸟类种数有明显减少,说明景区大型的改造工程对鸟类群落组成和多样性造成一定的负面影响.  相似文献   
62.
亚洲季风区平均雨季起始期的时空分布特征   总被引:6,自引:0,他引:6  
 利用1961~1990年平均的降水资料,计算了亚洲季风区内91个测站的相对降水指数.在定义相对降水指数大于147作为雨季开始的标志后发现,亚洲季风区中最早进入雨季的地区位于青藏高原东南侧的纵向岭谷北部地区.该地区在3月份进入雨季,即纵向岭谷北部地区著名的“桃花汛”.在此基础上初步讨论了“桃花汛”形成的原因是由于青藏高原大地形作用下,暖湿西南气流沿纵向岭谷向着低纬高原的爬坡抬升作用,结合来自青藏高原的偏北气流带下的冷平流沿纵向河谷的下楔作用最终导致了该地区雨季的开始.  相似文献   
63.
Based on geographic division over the western North Pacific (WNP), the interdecadal relationships between summer monsoon, sea surface temperature (SST) and tropical cyclones activity (including number, track and intensity) are examined. In the past several decades, the western Pacific subtropical high (WPSH) and tropical westerlies contribute to the interdecadal variation of TC number in the northwest and southeast of WNP respectively. The increased TC occurrence density to the east of Philippines related to TC track appears during the 1990s, in terms of both steer flow induced by WPSH and genesis location. From the interdecadal viewpoint, the tendency of TC intensity, measured by averaged accumulated cyclone energy, does well agree with that of SST, implying that SST plays an important role in TC intensity. Supported by Special Scientific Research Project for Public Interest (Grant No. GYHY200806009) and National Basic Research Program of China (Grant No. 2009CB421505)  相似文献   
64.
Analysis of daily precipitation samples for stable oxygen isotopes (δ^18O) collected at the Shiquanhe and Gerze (Gaize, Gertse) stations in the Ngari (Ali) region on the western Tibetan Plateau indicates that air temperature affects the δ^18O variations in precipitation at these stations. In summer, Shiquanhe and Gerze show strongly similar trends in precipitation δ^18O, especially in simultaneous precipitation events. Moreover, both stations experienced low δ^18O values in precipitation during the active monsoon period, resulting from the southwest monsoon (the summer phase of the Indian monsoon). However, during the break monsoon period (during the summer rainy season, when the monsoon circulation is disrupted), δ^18O values in summer precipitation remain relatively high and local moisture recycling generally controls the moisture sources. Air temperature correlations with δ^18O strengthen during the non-monsoon period (January--June, and October--December) due to continental air masses and the westerlies. In addition, evaporation also influences the δ^18O variations in precipitation. The observed temporal and spatial variations of δ^18O in precipitation on the western Tibetan Plateau and adjacent regions show that the late May and early June-the late August and early September time frame provides an important period for the transportation of moisture from various sources on the Tibetan Plateau, and that the region of the West Kunlun-Tanggula Ranges acts as a significant climatic divide on the Plateau, perhaps for all of western China.  相似文献   
65.
Wang  Jing  He  JinHai  Liu  XuanFei  Wu  BinGui 《科学通报(英文版)》2009,54(4):687-695
Meiyu onset (MO) over Yangtze-Huaihe River Valley (YHRV) possesses obvious characteristics of interannual variations. Based on NCEP/NCAR reanalysis data sets, NOAA OLR and ERSST data, the in-terannual variability of MO(IVMO) and its previous strong influence signal (PSIS) are investigated. The possible mechanisms that the PSIS affecting IVMO are also discussed. The results show that the pre-vious CP-ENSO (Central Pacific El Nio/Southern Oscillation) event is the PSIS affecting IVMO and it has a better accu...  相似文献   
66.
以封丘县潮土为研究对象,结合当地常规施肥和不施肥(对照)处理,在大田条件下研究了在200kg/hm^2供氮水平下金阳牌有机无机肥料、金正大控释肥、红四方纳米控失肥3个新型肥料对夏玉米籽粒产量和蛋白质产量的影响.结果表明,在3种新型肥料中,红四方纳米控失肥对提高玉米产量和玉米籽粒蛋白质效果最明显,分别较常规施肥提高16.2%和18.9%;其次为金阳牌有机无机复合肥,其效果仅次于红四方纳米控失肥;最后是金正大控释肥.以上结果表明,在3种新型肥料中,红四方纳米控失肥对夏玉米增产和改善品质效果最好,而其他肥料(金阳有机无机肥、金正大控释肥)的缓控效果不能在当季显现,可能主要是由于夏玉米生育期相对较短引起的.  相似文献   
67.
暑期社会实践是高校学生社会实践的重要组成部分,是大学生思想政治教育、素质教育的重要途径,但目前仍有一些薄弱环节影响其作用的发挥。结合工作实际,以及2008年上海大学暑期社会实践的启示,着重分析暑期社会实践的“时政教育”功能,指出目前社会实践中存在的与专业结合不够紧密等问题并提出建议,以便今后将暑期社会实践更好地与时代热点结合、充分发挥其“时政教育”功能。  相似文献   
68.
结合高斯混合模型(GMM)和嗓音起始时间(VOT)特征的普通话音素发音错误检测,提出了一种结合语音声道特征信息和音源特征信息的发音错误检测方法。其中GMM用于反映声道特征信息的MFCC参数的建模与评测,并直接对大部分音素的发音质量直接进行错误检测。对于少数通过MFCC参数和GMM难于检测区分的辅音音素,则通过反映VOT信息的音源特征参数进行区分。实验表明,该方法在训练数据有限的情况下取得了较好的性能,非常适合用于聋人语言康复的计算机辅助训练。  相似文献   
69.
By applying a regional integrated environmental model system (RIEMS), a virtual numerical experiment is implemented to study the impacts of recovering natural vegetation on the regional climate and environmental conditions. The results show that recovering the natural vegetation in large scale could have significant influence on summer climate in East Asia. Not only would it be able to change the surface climate, but also to modify to certain extent the intensity of monsoon circulation. Although this is a virtual experiment at an extremely ideal condition, the implication of the simulating results is that the on-going nation-wide activities to recover the crop land for forest and pasture must be managed according to the local natural climate, hydrological and soil conditions. Only under such a condition, would the recovering of natural vegetation bring about significant climate and environmental benefits at regional scale.  相似文献   
70.
Based on the observational data analyses and numerical simulations with the air-sea coupled model (CGCM), a new perspective on the occurrence mechanism of ENSO is advanced in this paper. The continuous strong (weak) East Asian winter monsoon will lead to continuous westerly (easterly) wind anomalies over the equatorial western Pacific region. The anomalous equatorial westerly (easterly) winds can cause eastward propagation of the subsurface ocean temperature anomalies (SOTA) in the warm pool region, the positive (negative) SOTA have been in the warm pool region for quite a long time. The eastward propagating of positive (negative) SOTA along the thermocline will lead to positive (negative) SSTA in the equatorial eastern Pacific and the occurrence of El Niño (La Niña) event. After the occurrence of ENSO, the winter monsoon in East Asia will be weak (strong) due to the influence of El Niño (La Niña).  相似文献   
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