The influences of environmental factors on the air-sea coupling coefficient     

Yanmin Zhang  Yifan Wang  Yunhua Wang  Yining Bai  Chaofang Zhao 《海洋学报(英文版)》2022,41(2):147-155

The response relationship between equivalent neutral wind speed anomaly(ENWSA) and sea-air temperature difference anomaly(SATDA) has been analyzed over four typical sea regions, i.e., the Kuroshio Extension, the Gulf Stream, the Brazil-Malvinas Confluence and the Agulhas Return Current. The results show that ENWSA is more sensitive to SATDA than sea surface temperature anomaly(SSTA), which implies that SATDA seems to be a more suitable parameter than SSTA to analyze the mesoscale air-sea interac...  相似文献   

震前多种前兆异常形态特征及预测意义   总被引：1，自引：0，他引：1  

薛艳  张永仙 《地震》2004,24(1):145-154

对1970年以来华北地区31次M_S≥5.0地震前多种前兆异常形态特征进行了系统研究, 结果认为: ① 在强震前短临阶段, 普遍存在垂直形变和水位异常形态的四象限性分布, 且这种象限分布特征与主震震源机制解具有一定的相关性。 即在压缩区, 垂直形变上升, 水位亦上升。 在膨胀区, 垂直形变和水位都下降; ② 地倾斜异常在近源区与远源区具有明显的差异, 其中多数强震前表现为距离震中近的台站向与震中相反的方向倾斜, 而远离震中的台站, 其倾斜方向指向震中; ③ 地电阻率异常形态以下降为主; 多数水化异常(气体)表现为短期上升而临震转平或下降; 电磁波通常为短临异常。 基于上述前兆异常形态特征, 特别是垂直形变和水位异常形态的四象限分布特点, 提出了根据前兆场异常特征判断发震地点和孕震状态的思路。  相似文献   

水中填筑围堰边坡稳定的流-固耦合分析   总被引：1，自引：1，他引：0  

李树忱  李术才  邹淑平 《岩土力学》2004,25(1):82-86

详细地介绍了在流-固耦合分析过程中,特征时间和渗透边界条件的给定方法。并将其应用到泰安抽水蓄能电站围堰的流-固耦合分析中,同时,分析了基础开挖过程对围堰和基础边坡稳定性的影响。在开挖过程中,由于给定了透水边界和较合理的特征时间,最终结果表明,围堰和基础内的孔隙水压力明显下降,是由于开挖后透水边界增长,以及计算流体的特征时间增长的缘故。说明了用FLAC进行流-固耦合分析时,考虑特征时间和渗透边界条件是很重要的。  相似文献   

热-水-应力耦合弹塑性二维有限元程序的开发与应用尝试   总被引：5，自引：3，他引：2  

张玉军 《岩土力学》2005,26(2):19-174

从已有的应力平衡方程、水连续性方程、能量守恒方程和弹塑性矩阵入手,使用Galerkin方法将各控制方程分别在空间域和时间域进行离散,初步开发出了一个用于分析饱和岩土介质中热-水-应力耦合弹塑性问题的二维有限元程序,并通过2个算例进行了应用尝试。  相似文献   

高放废物深地质处置中的多场耦合与核素迁移   总被引：8，自引：3，他引：5  

罗嗣海  钱七虎  李金轩  周文斌 《岩土力学》2005,26(Z1):264-270

概括了深地下工程的深地质处置库的若干特点,简要介绍了多场耦合的机理与类型,论述了高放废物深地质处置多场耦合与核素迁移问题的特点及研究现状,最后提出了高放废物深地质处置多场耦合与核素迁移所需研究的主要问题。  相似文献   

中国区域城市化与生态环境耦合的关联分析   总被引：124，自引：7，他引：117  

刘耀彬  李仁东  宋学锋 《地理学报》2005,60(2):237-247

以定性与定量分析相结合的方法建立了耦合系统的评价指标体系,运用灰色关联分析法构建出区域城市化与生态环境交互作用的关联度模型和耦合度模型,定量揭示出中国省区城市化与生态环境系统耦合的主要因素,并从时空角度分析了区域耦合度的空间分布及演变规律。研究结果表明：(1) 城市化与生态环境系统要素之间的耦合是复杂的,总体上表现在城市化对生态环境的胁迫作用和生态环境对城市化的约束作用两个方面。通过关联度计算遴选出作用于生态环境的16项城市化指标和影响城市化的10项生态环境指标,它们较为全面反映出系统交互耦合的机理;(2) 中国区域城市化与生态环境耦合度分布基本符合东、中西空间分异的规律。根据耦合度大小并结合区域城市化与经济发展阶段,大致将全国省区划分为协调、磨合、拮抗和低水平耦合等4种类型,其中以拮抗类型为主;(3) 中国城市化与生态环境耦合度的时序变动表现出明显的阶段性和波动性。  相似文献   

溴、碘的半熔法-电感耦合等离子质谱(ICP-MS)测定   总被引：1，自引：0，他引：1  

曹萍  郁萍  邢飞  张丽 《吉林地质》2005,24(3):84-87

样品用碳酸钠和氧化锌混合熔剂半熔,用80℃～100℃水提取,用强酸型阳离子树脂分离溶液中的大量钠等阳离子,采用电感耦合等离子质谱直接测定溶液中的溴和碘。测定下限溴为0．15μg／g,碘为0．028μg／g。  相似文献   

塔里木盆地与天山山脉晚新生代盆山耦合机制   总被引：10，自引：0，他引：10  

卢华复  王胜利  贾东  王良书  刘绍文 《高校地质学报》2005,11(4):493-503

根据塔里木盆地北缘地质构造几何学和运动学资料、油气勘探地震剖面、人工地震测深、地震层析成像以及地热资料,提出了塔里木盆地、准噶尔盆地岩石圈地幔在天山岩石圈之下碰撞并发生拆沉的盆山耦合机制的概念模型。由于印藏碰撞,青藏高原的北部前缘岩石圈地幔与塔里木盆地岩石圈地幔形成V字形碰撞结构,推动塔里木地块的高强度岩石圈向北运动并俯冲到天山岩石圈之下,以水平俯冲作用在中天山北缘岩石圈之下与准噶尔盆地向南俯冲的岩石圈地幔碰撞,并发生后剥拆离。塔里木岩石圈俯冲的过程中,形成库车再生前陆盆地和再生前陆冲断带以及再生天山山脉。冲断量约为塔里木俯冲量的20％。这一盆山耦合模型可以解释盆地构造、盆地沉降、山脉隆升、岩石圈深部构造和热特征。  相似文献   

Are spatial patterns of soil moisture at plot scales generalisable across catchments,climates, and other characteristics? A synthesis of synoptic soil moisture across the Mid-Atlantic     

Charles I. Scaife  Jonathan M. Duncan  Laurence Lin  Christina Tague  Colin D. Bell  Lawrence Band 《水文研究》2021,35(9):e14313

The spatial variation of soil moisture over very small areas (<100 m²) can have nonlinear impacts on cycling and flux rates resulting in bias if it is not considered, but measuring this variation is difficult over extensive temporal and spatial scales. Most studies examining spatial variation of soil moisture were conducted at hillslope (0.01 km²) to multi-catchment spatial scales (1000 km²). They found the greatest variation at mid wetness levels and the smallest variation at wet and dry wetness levels forming a concave down relationship. There is growing evidence that concave down relationships formed between spatial variation of soil moisture and average soil moisture are consistent across spatial scales spanning several orders of magnitude, but more research is needed at very small, plot scales (<100 m²). The goal of this study was to characterise spatial variation in shallow soil moisture at the plot scale by relating the mean of measurements collected in a plot to the standard deviation (SD). We combined data from a previous study with thousands of new soil moisture measurements from 212 plots in eight catchments distributed across the US Mid-Atlantic Region to (1) test for a generalisable mean–SD relationship at plot scales, (2) characterise how landcover, land use, season, and hillslope position contribute to differences in mean–SD relationships, and (3) use these generalised mean–SD relationships to quantify their impacts on catchment scale nitrification and denitrification potential. Our study found that 98% of all measurements formed a generalised mean–SD relationship like those observed at hillslope and catchment spatial scales. The remaining 2% of data comprised a mean–SD relationship with greater spatial variation that originated from two riparian plots reported in a previous study. Incorporating the generalised mean–SD relationship into estimates of nitrification and denitrification potential revealed strong bias that was even greater when incorporating mean–SD observations from the two riparian plots with significantly greater spatial variation.  相似文献   

Contributing sources to baseflow in pre‐alpine headwaters using spatial snapshot sampling          下载免费PDF全文

Benjamin M. C. Fischer  Michael Rinderer  Philipp Schneider  Tracy Ewen  Jan Seibert 《水文研究》2015,29(26):5321-5336

Mountainous headwaters consist of different landscape units including forests, meadows and wetlands. In these headwaters it is unclear which landscape units contribute what percentage to baseflow. In this study, we analysed spatiotemporal differences in baseflow isotope and hydrochemistry to identify catchment‐scale runoff contribution. Three baseflow snapshot sampling campaigns were performed in the Swiss pre‐alpine headwater catchment of the Zwäckentobel (4.25 km²) and six of its adjacent subcatchments. The spatial and temporal variability of δ²H, Ca, DOC, AT, pH, SO₄, Mg and H₄SiO₄ of streamflow, groundwater and spring water samples was analysed and related to catchment area and wetland percentage using bivariate and multivariate methods. Our study found that in the six subcatchments, with variable arrangements of landscape units, the inter‐ and intra catchment variability of isotopic and hydrochemical compositions was small and generally not significant. Stream samples were distinctly different from shallow groundwater. An upper spring zone located near the water divide above 1,400 m and a larger wetland were identified by their distinct spatial isotopic and hydrochemical composition. The upstream wetland percentage was not correlated to the hydrochemical streamflow composition, suggesting that wetlands were less connected and act as passive features with a negligible contribution to baseflow runoff. The isotopic and hydrochemical composition of baseflow changed slightly from the upper spring zone towards the subcatchment outlets and corresponded to the signature of deep groundwater. Our results confirm the need and benefits of spatially distributed snapshot sampling to derive process understanding of heterogeneous headwaters during baseflow. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献