The decadal variability of the tropical Indian Ocean SST–the South Asian High relation: CMIP5 model study     

X. Qu  G. Huang 《Climate Dynamics》2015,45(1-2):273-289

  相似文献   

基于广义回归神经网络的全球表层海水1°×1°二氧化碳分压数据推演     

钟国荣  李学刚  曲宝晓  王彦俊  袁华茂  宋金明 《海洋学报》2020,42(10):70-79

表层海水二氧化碳分压是评估海洋碳源汇强度的关键参数，但其实测数据较少、时空分布极不均匀，导致二氧化碳交换通量的估算有很大的不确定性，海洋源汇特征就不能确切获取。为了解决这个难题，在收集的表层大洋二氧化碳地图(Surface Ocean CO₂ Atlas，SOCAT)实测数据集基础上，运用广义回归神经网络建立二氧化碳分压与经纬度、时间、温度、盐度和叶绿素浓度间的非线性关系，构建了1998?2018年间全球1°×1°经纬度的表层海水二氧化碳分压格点数据，其标准误差为16.93 μatm，平均相对误差为2.97%，优于现有研究中的前反馈神经网络、自组织映射神经网络和机器学习算法等方法。根据构建的数据所绘制的全球表层海水二氧化碳分压的分布与现有研究有较好的一致性。  相似文献   

新疆三塘湖盆地牛圈湖区块异常低压成因及压力演化定量分析     

康媛  孙卫  盛军  时建超  刘艳妮  赵婷 《地质论评》2016,62(1):103-110

三塘湖盆地牛圈湖区块中生界侏罗系西山窑组储层具有典型的异常低压油藏特征,晚白垩末期储层达到最大埋深,此时下部芦草沟组烃源岩演化程度达到最大,随着油气持续向储层充注,此时地层压力达到最大,可达30.33~50.74MPa。本文从引起油藏异常低压的主要因素入手,定量分析了构造抬升与地层剥蚀、地层温度降低、成岩作用中的"耗水作用"以及矿物蚀变引起的自生体积缩小等因素对地层压力的影响。这些因素共同作用导致了地层压力降低,其中溶蚀作用中矿物蚀变所形成的"耗水作用",使地层压力下降24.4%~37.1%,是造成储层异常低压的首要因素,同时矿物蚀变导致自身体积缩小并导致储层压力下降16.5%~24.8%,地层温度降低和构造运动对储层压力降低影响相对较弱,降低幅度分别为7.9%~8.6%和4.8%~8.1%。以上种种因素的共同作用,使得地层压力下降17.45~37.85MPa,最终形成现今异常低压的分布格局。  相似文献   

Short-term variability in the dates of the Indian monsoon onset and retreat on the southern and northern slopes of the central Himalayas as determined by precipitation stable isotopes     

Wusheng Yu  Tandong Yao  Lide Tian  Yaoming Ma  Rong Wen  Lochan P. Devkota  Weicai Wang  Dongmei Qu  Tek B. Chhetri 《Climate Dynamics》2016,46(1-2):159-176

  相似文献   

Shallowness of tropical low clouds as a predictor of climate models’ response to warming     

Florent Brient  Tapio Schneider  Zhihong Tan  Sandrine Bony  Xin Qu  Alex Hall 《Climate Dynamics》2016,47(1-2):433-449

  相似文献   

低空航测的系统工程问题分析     

田慧  林宗坚  文曲 《北京测绘》2016,(1)

当前低空航测工程实践中的许多技术问题,仅靠个别研究是不够的,必须运用系统工程学的方法进行研究。低空航测系统由飞行平台、成像传感器和航测处理等技术部分构成,各部分间存在相互关联、相互制约的关系,必须进行系统分析和系统优化的研究。同时,系统还受外部环境的制约,必须研究如何在不可改变的外部制约条件下,优化系统,达到系统目标的方法。  相似文献   

Strength Behavior of Shanghai Clayey Soil Reinforced with Wheat Straw Fibers     

Jili Qu  Zhongming Sun 《Geotechnical and Geological Engineering》2016,34(2):515-527

It is generally recognized that the low strength and high compressibility are the characteristics of soft soil. In addition to other techniques, reinforcement can also be used in increasing the strength and decreasing the deformation of this kind of soil. The results of an investigation into the effects of a natural fiber on the consolidation and shear strength behavior of Shanghai clayey soil reinforced with wheat straw fibers are presented in this paper. A series of one dimensional consolidation and triaxial tests were conducted on samples of unreinforced and reinforced Shanghai clayey soil with different percentages of randomly distributed wheat straw fibers. The results show that the preconsolidation pressure decreases and the coefficient of swelling and compression generally increase with increasing the fiber content until a optimum content value. Furthermore, the addition of wheat straw fiber leads to a significant increase in shear strength and friction angle of the natural soil and there is an optimum wheat fiber content that makes this increase maximal.  相似文献   

Application of 2D numerical model to unsteady performance evaluation of vertical-axis tidal current turbine     

Zhen Liu  Hengliang Qu  Hongda Shi  Gexing Hu  Beom-Soo Hyun 《中国海洋大学学报(英文版)》2016,15(6):977-986

Tidal current energy is renewable and sustainable, which is a promising alternative energy resource for the future electricity supply. The straight-bladed vertical-axis turbine is regarded as a useful tool to capture the tidal current energy especially under low-speed conditions. A 2D unsteady numerical model based on Ansys-Fluent 12.0 is established to conduct the numerical simulation, which is validated by the corresponding experimental data. For the unsteady calculations, the SST model, 2×10~5 and 0.01 s are selected as the proper turbulence model, mesh number, and time step, respectively. Detailed contours of the velocity distributions around the rotor blade foils have been provided for a flow field analysis. The tip speed ratio(TSR) determines the azimuth angle of the appearance of the torque peak, which occurs once for a blade in a single revolution. It is also found that simply increasing the incident flow velocity could not improve the turbine performance accordingly. The peaks of the averaged power and torque coefficients appear at TSRs of 2.1 and 1.8, respectively. Furthermore, several shapes of the duct augmentation are proposed to improve the turbine performance by contracting the flow path gradually from the open mouth of the duct to the rotor. The duct augmentation can significantly enhance the power and torque output. Furthermore, the elliptic shape enables the best performance of the turbine. The numerical results prove the capability of the present 2D model for the unsteady hydrodynamics and an operating performance analysis of the vertical tidal stream turbine.  相似文献   

Impacts of agricultural water saving practice on regional groundwater and water consumption in an arid region with shallow groundwater   总被引：1，自引：0，他引：1  

Hang Chen  Zhongyi Liu  Zailin Huo  Zhongyi Qu  Yuhong Xia  Alexander Fernald 《Environmental Earth Sciences》2016,75(16):1204

  相似文献   

CO2浓度增加背景下季风区大气辐射加热响应的差异          下载免费PDF全文

Xia Qu  Gang Huang  Xiaocong Wang 《大气和海洋科学快报》2021,14(3):19-24

大气CO2浓度增加,大气辐射平衡调整,将影响到大气的辐射加热,对季风环流的产生影响.CMIP6结果显示,大气CO2浓度增加,可减弱季风区主雨季对流层高,低层的辐射加热,加强对流层中层的辐射加热.各季风区加热响应的峰值层次不同:亚洲季风区平均层次最高(500-775 hPa),北非,南美,澳洲季风区次之(550-600 hPa),北美(600hPa)和南非季风区(600-775 hPa)较低.各季风区水云的垂直分布及其长波辐射效应的变化是形成峰值层次差异的主因.  相似文献