博斯腾湖滨柽柳(Tamarix ramosissina)生长对湖水位的敏感性     

侯佳文  海米提·依米提  叶茂 《中国沙漠》2015,35(3)

基于博斯腾湖1955—2012年湖水位变化资料,利用树木年轮法分析了博斯腾湖年和月水位变化与湖滨柽柳(Tamarix ramosissina)年轮生长关系,利用敏感度指数得出博斯腾湖滨柽柳年轮生长的敏感水位范围。结果表明:(1)1955—2012年博斯腾湖年平均水位经历了3个明显变化阶段,即1955—1987年下降至最低,1987—2002年上升至最高。受向下游生态输水影响,2002—2012年博斯腾湖水位快速下降。输水对博斯腾湖月平均水位和季节性水位变化有影响。(2)博斯腾湖滨柽柳年轮指数与当年的湖水位变化和前1年的湖水位变化均显著相关(p0.05)。柽柳年轮指数与前1年10月至当年4月各个月份的湖水位表现出显著相关(p0.05)。柽柳年轮指数与前1年冬季湖水位相关显著(p0.05),与当年春季3—4月月平均湖水位相关性显著,与当年夏季和秋季湖水位的相关性不显著。(3)博斯腾湖滨柽柳年轮生长对月湖水位变化响应比较敏感。当湖水位在1045.3m时,柽柳年轮指数灵敏度指数(Sk)存在最低值;当湖水位在1 046.3m时,Sk出现最高值。  相似文献   

Accuracy evaluation of two precipitation datasets over upper reach of Heihe River Basin, northwestern China   总被引：1，自引：0，他引：1  

SiWei He  ZhuoTong Nan  YuTing Hou 《寒旱区科学》2015,7(2):157-169

As an important forcing data for hydrologic models, precipitation has significant effects on model simulation. The China Meteorological Forcing Dataset (ITP) and Global Land Data Assimilation System (G...  相似文献   

Kinematic features of a bow echo in southern China observed with doppler radar     

彭新东  张人禾  王红艳 《大气科学进展》2013,30(6):1535-1548

A bow echo is a type of mesoscale convective phenomenon that often induces extreme weather and appears with strong reflectivity on radar images. A strong bow echo that developed from a supercell was observed over Foshan City in southern China on 17 April 2011. The intense gusty winds and showers caused huge losses of property and severely affected human lives. This paper presents an analysis of this strong meso- n-scale convective system based on Doppler radar observations. The isolated bow echo exhibited a horizontal scale of about 80 km in terms of reflectivity above 40 dBZ, and a life span of 8 hours. The system originated from the merging of a couple of weakly organized cells in a shear line, and developed into an arch shape as it moved through the shear zone. Sufficient surface moisture supply ensured the convective instability and development of the bow echo. The low-altitude winds retrieved from single Doppler radar observations showed an obvious rear-inflow jet along the notch area. Different from the conventional definition, no book- end anticyclone was observed throughout the life cycle. Very strong slantwise updrafts and downdrafts were recognizable from the retrieved winds, even though the spatial scale of the bow echo was small. Strong winds and induced damage on the surface are considered to have been caused by the mid-level rear-inflow jet and intense convective downdrafts.  相似文献   

同步辐射标定平面镜反射率不确定度分析方法研究   总被引：1，自引：0，他引：1  

陈伯伦  杨正华  曹柱荣  董建军  侯立飞  崔延莉  江少恩  易荣清  李三伟  刘慎业  杨家敏 《海洋学报》2010,32(10):7078-7085

为了提高多通道软X射线能谱仪的测量精度,2009年在北京同步辐射(BSRF)软X束线源上对多种材料的掠入射平面镜的反射率进行了标定.在标定实验的基础上,对光源的单色性、高次谐波以及源强稳定性、探测器响应一致性和数据采集统计误差等多项不确定因素进行了评估,给出了反射率的修正方法和相应的不确定度分析结果.  相似文献   

Effect of slow-solvent-vapour treatment on performance of polymer photovoltaic devices     

冯志慧  侯延冰  师全民  刘小君  滕枫 《海洋学报(英文版)》2010,29(9)

In this work, enhanced poly(3-hexylthiophene):[6,6]-phenyl-C61-butyric acid methyl ester (P3HT:PCBM) bulk-heterojunction photovoltaic devices are achieved via slow-solvent-vapour treatment. The correlations between the morphology of the active layer and the photovoltaic performance of polymer-based solar cell are investigated. The active layers are characterized by atomic force microscopy and optical absorption. The results show that slow-solvent-vapour treatment can induce P3HT self-organization into an ordered structure, leading to the enhanced absorption and efficient charge transport.  相似文献   

Noah-MP模型中积雪模拟对参数化方案的敏感性评估     

尤元红  黄春林  张莹  侯金亮 《地球科学进展》2019,(4):356-365

针对Noah-MP模型多参数化方案、模拟结果不确定性范围难以确定的特点,选取北疆地区具有代表性的阿勒泰站气象资料作为模型驱动数据,探讨了积雪对多参数化方案的敏感性。在不考虑模型参数和驱动数据不确定性的条件下,设计了集合数为13824的多参数化方案集合模拟试验。选用Natural selection方法对物理过程的敏感性进行分析,并在敏感性分析结果的基础上进一步讨论了模拟结果的不确定性。结果表明:积雪对地表热交换、雨雪分离、土壤温度底层边界条件和第一层积雪或土壤时间方案4个物理过程敏感;在不考虑驱动数据和模型参数不确定性的条件下,多参数化方案集合模拟试验中的不确定性主要来源于敏感物理过程。去除敏感物理过程中能够明显降低模拟性能的参数化方案后,集合模拟结果的不确定性大幅减小。最后,根据分析结果构建了该站雪深和雪水当量模拟的最优参数化方案组合。  相似文献   

Progress of Long-Chain Alkyl Diols in Marine Environmental Reconstruction     

Di Hou  Junjie Zhang  Lei Xing  Yang Zhou 《地球科学进展》2019,34(2):140-147

Long-chain alkyl diols contain an alkyl chain with alcohol groups at C1 and at the middle position of carbon chain, which exist widely in seas, rivers and lakes. It has been proven that these compounds are relatively resistant to degradation and have an extended occurrence in the geological record. In addition, they are relatively easy to identify. Therefore, long-chain alkyl diols can be used as potential biomarkers to trace the past change in paleoenvironment and paleoclimate. Although the sources of long-chain alkyl diols are still uncertain, the studies indicate that 1, 13 and 1, 15-diols are mainly produced by eustigmatophytes, while 14-diols are mainly from diatom Proboscia. So far, some proxies based on long-chain alkyl diols have been established to indicate the change in diatom productivity, upwelling intensity, salinity, sea surface temperature, riverine organic matter input and surface seawater nutrient concentration, which are significant for paleoenvironmental reconstruction. Current research and application of long-chain alkyl diols proxies were summarized, which would be helpful for further studying the source of long-chain alkyl diols and the application of relevant proxies in China’s marginal sea.  相似文献   

云南鲁甸6.5级地震灾害特点浅析   总被引：5，自引：4，他引：1  

帅向华  姜立新  侯建盛  延旭东  宋立军  刘爱文 《震灾防御技术》2014,9(3):340-358

通过对2014年8月3日云南鲁甸6.5级地震震害开展实地调查,对灾区破坏情况进行总体介绍,并就各烈度区特征和建筑物震害、地震地质灾害、工程结构震害进行分析,初步得出本次地震的一些震害特点.一是灾区人口密度大,人员死亡较集中.人员死亡主要集中在Ⅷ和Ⅸ度区.二是地震振动强,灾区破坏严重.本次地震震源深度12km,极震区烈度高达Ⅸ度,震源破裂在11s内集中释放.三是抗震能力弱,房屋破坏严重.灾区属国家级贫困区,农村民居抗震能力弱,且多数民房坐落在河谷陡坡上,边坡效应加重房屋震害,重灾区砖木和土木房屋成片损毁、倒塌.四是灾区条件恶劣,救灾难度大.震区活动断裂密集发育、地质破碎疏松、地形崎岖不平,又恰值雨季,诱发极其严重次生地质灾害,导致人员伤亡,造成灾区大面积交通、通信、电力中断,救援物资与救援力量无法及时发挥作用.  相似文献   

Tropical storm-forced near-inertial energy dissipation in the southeast continental shelf region of Hainan Island   总被引：1，自引：0，他引：1  

ShuWen Zhang  LingLing Xie  Hui Zhao  YiJun Hou 《中国科学:地球科学(英文版)》2014,57(8):1879-1884

Near-inertial motion is an important dynamic process in the upper ocean and plays a significant role in mass, heat, and energy transport across the thermocline. In this study, the dissipation of wind-induced near-inertial energy in the thermocline is investigated by using observation data collected in July and August 2005 during the tropical storm Washi by a moored system at (19°35′N, 112°E) in the continental shelf region off Hainan Island. In the observation period, the near-inertial part dominated the observed ocean kinetic energy and about 80% of the near-inertial energy dissipated in the upper layer. Extremely strong turbulent mixing induced by near-inertial wave was observed in the thermocline, where the turbulent energy dissipation rate increased by two orders of magnitude above the background level. It is found that the energy loss of near-inertial waves in the thermocline is mainly in the large-scales. This is different from the previous hypothesis based on “Kolmogorov cascade” turbulence theory that the kinetic energy is dissipated mainly by small-scale motions.  相似文献   

Vertical Distribution and Mobility of Heavy Metals in Agricultural Soils along Jishui River Affected by Mining in Jiangxi Province,China   总被引：1，自引：0，他引：1       下载免费PDF全文

Guannan Liu  Wei Xue  Li Tao  Xinhui Liu  Jing Hou  Meaghan Wilton  Ding Gao  Anjian Wang  Ruiping Li 《洁净——土壤、空气、水》2014,42(10):1450-1456

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