湖南高温日时空分布特征及高温日数气候预测   总被引：1，自引：0，他引：1  

罗伯良  李易芝 《气象科技》2015,43(6):1110-1115

利用1961—2013年湖南74个气象观测站逐日高温观测资料,建立了较完整的湖南高温日时间序列,分析了湖南高温日时空分布及变化趋势。结果表明,湖南高温日呈增加趋势,每10年增加2天左右,湘北高温日增加趋势显著;高温最长持续日数总体上湘南大部呈弱的减少趋势,每10年减少0.5天左右,湘中及湘北则呈较强的增加趋势,每10年增加1天左右。20世纪90年代以来,湖南高温天气显著增多、增强。利用最优子集回归构建气候预测模型,预测湖南高温平均出现日数,预测效果较好,可在业务中应用。  相似文献   

基于SOA的平度市国土资源一张图平台设计与应用          下载免费PDF全文

孙中原  綦春峰  焦俊超 《山东国土资源》2015,31(9)

国土资源“一张图”综合监管平台的建设是有效利用全国二调成果和提升国土管理部门行政服务能力的重要工程。该文设计并实现了基于SOA的搭建式开发平台,实现了集工作流、业务建模于一体的可视化的搭建式开发平台,并对平台进行了实际应用。  相似文献   

在空间数据库课程中采用开源软件实验的教学实践     

熊伟  陈荦  吴秋云  景宁 《地理信息世界》2015,(1):73-76

对比分析了国内外空间数据库课程现状。针对开源地理空间信息软件体系在空间数据库实验课程中的教学特点,探讨了开源软件应用于空间数据库课程实验的教学实践,提出了分阶段实验教学方法,在实际教学中取得了好的效果。  相似文献   

Indication of paleoecological evidence on the evolution of alpine vegetation productivity and soil erosion in central China since the mid-Holocene     

Cheng  Ying  Liu  Hongyan  Wang  Hongya  Chen  Deliang  Ciais  Philippe  Luo  Yao  Wu  Xiuchen  Yin  Yi 《中国科学:地球科学(英文版)》2021,64(10):1774-1783

Although alpine ecosystems have been commonly recognized as sensitive to recent climate change, few studies have examined its impact on the long-term productivity of vegetation and soil erosion. Using paleoecological records, these two aspects were examined in the alpine zone of the Taibai Mountains(elevation, 3767 m) in monsoon-dominated East Asia since the middle Holocene. Proxies for the productivity of vegetation and severity of soil erosion from high-resolution alpine lacustrine records show that the productivity and soil erosion were closely related to mean annual temperature and summer precipitation from the East Asian Summer Monsoon(EASM), respectively. Specifically, when the mean annual temperature was low and precipitation was abundant, during 5800–4000 calendar years before the present(cal. yr BP), the alpine ecosystem was characterized by low vegetation productivity and severe soil erosion. However, the productivity increased and soil erosion decreased from 4000 cal. yr BP onwards. These results highlight the role of paleoecological evidence in studying ecosystem services on longer time scales, which is significant in making policies for sustainable development under climate change in regions for which such long-term monitoring data are not available.  相似文献   

Size variation of the end Permian conodont <Emphasis Type="Italic">Neogondolella</Emphasis> at Meishan Section,Changxing, Zhejiang and its significance     

Luo?Genming  Lai?Xulong?Email author  Jiang?Haishui  Zhang?Kexin 《中国科学D辑(英文版)》2006,49(4):337-347

This study is based on both a generic and species level investigation of the individual size of the latest Permian conodont Neogondolella Pa elements collected from Meishan Section A, Changxing, Zhejiang Province. In this study, an obvious size reduction of Neogondolella Pa elements within bed 24e of the upper Changxing Limestone is recognized. The size variation of the Neogondolella occurs simultaneously with some important events including the negative shift of δ ¹³C, change in the ratio of the abundance of cyanobacterial biomarkers versus that of other general bacterial biomarkers and the shallowing of the sea water. Through the investigation of the paleoenvironmental changes and the analysis of the paleoecology of the conodont genus Neogondolella, the authors propose that the major factors for the size reduction of species of the conodont genus Neogondolella are food shortages caused by the mass extinction, the shallowing of the sea water as well as the increase in opacity of the sea water during the end Permian. The same phenomenon of Neogondolella size reduction is also observed in preliminary research from the same horizon at Shangsi Section, Sichuan Province. All the evidence suggests that there was a mass extinction that occurred at the horizon of bed 24e, and the evidence supports the viewpoint of a multi-phase mass extinction during the Permian and Triassic transition in South China.  相似文献   

Two possible mechanisms for vortex self-organization   总被引：3，自引：0，他引：3  

Luo?Zhexian  Zhou?Xiuji?Email author  Gao?Shouting 《中国科学D辑(英文版)》2006,49(2):202-211

Since the 21st century, the self-organization phe-nomenon has drawn a wide attention of Chinese sci-ence and technology researchers, and the study fields involve silicate chemistry[1, 2], the classification of re-mote sensing data[3], nanometer material[4―6], medium resistance to discharges[7], forest fires[8], mud-rock flow[9], sandpile formation[10, 11], urban geography[12], economic geography[13], intense storms over the Loess Plateau[14] and vortices over the Tibetan Plateau[15], etc. Re…  相似文献   

恢复高考以来我国地理高考学术研究特色演变及启示     

余中元 《地域研究与开发》2012,31(5)

根据CNKI和维普网查询1979-2010期间地理高考学术研究文献,在Spss 15.0,Excel 2003和ArcGIS 9.3平台下,计算文献学术分值,分析恢复高考以来我国地理高考研究特色的演变特征和发展趋势.研究发现:我国的地理高考学术研究地域差异明显,集中在少数省市区;研究重心游移波动,渐趋稳定;刊物、文献数量猛增,质量鱼龙混杂;强调方法论及实战操作研究,应试指导和答题分析日益受到重视;文献呈不正常的增长态势,研究机构混杂,中学唱主曲;地理高考学术研究带有明显功利性,高考是指挥棒.最后,对我国地理高考改革和学术研究得出了启示和提出了建议.  相似文献   

Probability distributions for carbon emissions and atmospheric response     

Clifford E. Singer  T. S. Gopi Rethinaraj  Samuel Addy  David Durham  Murat Isik  Madhu Khanna  Brandon Kuehl  Jianding Luo  Wilma Quimio  Kothavari Rajendran  Donna Ramirez  Ji Qiang  Jürgen Scheffran  T. Nedjla Tiouririne  Junli Zhang 《Climatic change》2008,88(3-4):309-342

Probability distributions for carbon burning, atmospheric CO₂, and global average temperature are produced by time series calibration of models of utility optimization and carbon and heat balance using log-linear production functions. Population growth is used to calibrate a logistically evolving index of development that influences production efficiency. Energy production efficiency also includes a coefficient that decreases linearly with decreasing carbon intensity of energy production. This carbon intensity is a piecewise linear function of fossil carbon depletion. That function is calibrated against historical data and extrapolated by sampling a set of hypotheses about the impact on the carbon intensity of energy production of depleting fluid fossil fuel resources and increasing cumulative carbon emissions. Atmospheric carbon balance is determined by a first order differential equation with carbon use rates and cumulative carbon use as drivers. Atmospheric CO₂ is a driver in a similar heat balance. Periodic corrections are included where required to make residuals between data and model results indistinguishable from independently and identically distributed normal distributions according to statistical tests on finite Fourier power spectrum amplitudes and nearest neighbor correlations. Asymptotic approach to a sustainable non-fossil energy production is followed for a global disaggregation into a tropical/developing and temperate/more-developed region. The increase in the uncertainty of global average temperature increases nearly quadratically with the increase in the temperature from the present through the next two centuries.  相似文献   

导线积冰的云雾特征观测研究   总被引：11，自引：2，他引：9       下载免费PDF全文

罗宁  文继芬  赵彩  唐磊 《应用气象学报》2008,19(1):91-95

导线积冰在贵州山区是常见的气象灾害, 导线积冰增长率与气象云雾因子密切相关。研究选择贵州西部、北部、中部3个积冰区进行了专门外场观测, 观测项目有:云滴谱、含水量、气温、风向、风速、导线上积冰的长径、短径。观测分析表明:贵州云滴浓度、特征平均直径没有显著性地区差异; 云滴平均浓度140~312个/cm3, 云滴算术平均直径、均立方根直径、中值体积直径分别为7.5 μm, 11.3 μm和20 μm; 14 μm以上大云滴浓度平均占云滴总浓度的12.5%, 但对含水量的贡献高达78%, 大滴与导线碰撞效率高, 大滴是导线积冰的关键因子; 云雾含水量平均0.20 g/m3; 在0~-6 ℃之间, 含水量随温度的降低而降低; 南北向导线积冰比东西向的积冰多; 导线积冰增长率与含水量的大小成正比, 风速超过3 m/s时, 积冰增长率与风速有较明显的正比关系。  相似文献   

一次中-β尺度局地大暴雨对流系统的雷达回波特征   总被引：5，自引：0，他引：5  

冯晋勤  童以长  罗小金 《气象》2008,34(10):50-59

利用新一代天气雷达产品对2006年6月18日永定一次中-β尺度大暴雨对流系统的雷达回波特征进行分析,探讨短时大暴雨的回波特征.结果表明:有利的大尺度环流、充足的水汽条件和较强的上升运动是产生强降水有利的天气背景.新一代天气雷达资料分析表明,强降水是由局地发展的对流回波加强合并产生的;中低层冷平流的入侵触发了强对流的产生,对流单体有明显的典型的液态强降水系统特征;逆风区及良好的垂直运动使对流单体发展加强,强降水区域尺度较大,与回波移向一致产生"列车效应",同时系统移动较慢,导致了强降水的持续.  相似文献