基于非均匀水体对比度传输方程的海水透明度计算试验          下载免费PDF全文

李妍  陈希  于斌  钟奕飞 《大气科学学报》2014,37(6):767-771

针对均匀水体假设的海水透明度经验计算公式不具有普适性的缺点,将海水在垂直方向上分为若干光学性质相近的均匀层,推导出非均匀水体中目标对比度传输方程,在此基础上,建立了海水透明度的计算模型。利用BROKE_WEST_ACS实测的海水固有光学性质数据和透明度盘观测数据,对计算模型进行了数值试验和效果分析。结果表明:模型计算值与透明度盘实测值平均相对误差为9.1%;该模型既克服了透明度盘测量易受天气状况和人眼差异影响较大的缺点,又突破了均匀水体透明度计算方法的局限性。  相似文献   

Calcium,Na, K and Mg Concentrations in Seawater by Inductively Coupled Plasma‐Atomic Emission Spectrometry: Applications to IAPSO Seawater Reference Material,Hydrothermal Fluids and Synthetic Seawater Solutions     

Philippe Besson  Jefferson Degboe  Benjamin Berge  Valérie Chavagnac  Sébastien Fabre  Gilles Berger 《Geostandards and Geoanalytical Research》2014,38(3):355-362

We report a measurement procedure to determine simultaneously the major cation concentrations (Na, Ca, K and Mg) of seawater‐derived solutions by inductively coupled plasma‐atomic emission spectrometry. The best results were obtained when the IAPSO (‘standard’) seawater reference material was diluted by thirty times with Milli‐Q^® water. We obtained an average reference value r_K (the ratio of the mass fraction of potassium to that of chlorine, i.e., (g kg^?1)/(g kg^?1)) for IAPSO seawater of 0.0205 ± 0.0006 (2.9% RSD), not significantly different from 0.0206 ± 0.0005 (2.4% RSD) for seawater composition reported in the literature. The measured Na, Ca and Mg concentrations correspond to r_Na, r_Ca and r_Mg values of 0.5406 ± 0.0026 (0.5% RSD), 0.02192 ± 0.00048 (2.2% RSD) and 0.06830 ± 0.00047 (0.7% RSD), respectively, in line with previous values measured by wet‐chemistry and atomic absorption spectrophotometry or wet‐chemical titration. Our measurement procedure was used successfully on synthetic seawater solutions and high‐temperature hydrothermal fluids.  相似文献   

Emplacement of the La Peña alkaline igneous complex,Mendoza, Argentina (33° S): Implications for the early Miocene tectonic regime in the retroarc of the Andes     

《Journal of South American Earth Sciences》2014

The La Peña alkaline complex (LPC) of Miocene age (18–19 Ma) lies on the eastern front of the Precordillera (32°41ʹ34ʺS, 68°59ʹ48″W, 1400–2900 m a.s.l.), 30 km northwest of Mendoza city, Argentina. It is a subcircular massif of 19 km² and 5 km in diameter, intruded in the metasedimentary sequence of the Villavicencio Formation of Silurian-Devonian age. It is the result of integration of multiple pulses derived from one or more deep magma chambers, which form a suite of silicate rocks grouped into: a clinopyroxenite body, a central syenite facies with a large breccia zone at the contact with the clinopyroxenite, bodies of malignite, trachyte and syenite porphyry necks, and a system of radial and annular dikes of different compositions. Its subcircular geometry and dike system distribution are frequent features of intraplate plutons or plutons emplaced in post-orogenic settings. These morphostructural features characterize numerous alkaline complexes worldwide and denote the importance of magmatic pressures that cause doming with radial and annular fracturing, in a brittle country rock. However, in the LPC, the attitude of the internal fabric of plutonic and subvolcanic units and the preferential layout of dikes match the NW–SE extensional fractures widely distributed in the host rock. This feature indicates a strong tectonic control linked to the structure that facilitate space for emplacement, corresponding to the brittle shear zone parallel to the N–S stratigraphy of the country rock. Shearing produced a system of discontinuities, with a K fractal fracture pattern, given by the combination of Riedel (R), anti-Riedel (R′), (P) and extensional (T) fracture systems, responsible for the control of melt migration by the opening of various fracture branches, but particularly through the NW–SE (T) fractures. Five different pulses would have ascent, (1) an initial one from which cumulate clinopyroxenite was formed, (2) a phase of mafic composition represented by dikes cross-cutting the clinopyroxenite, (3) a malignite facies that causes a small breccia in the clinopyroxenite, (4) a central syenite facies that develops breccias at the contact with the clinopyroxenite and, finally, (5) porphyry necks and a system of radial dikes intruding all units. At the moment of the emplacement different mechanisms would have acted, they summarized in: 1) opening of discontinuities synchronous to the magma circulation as the principal mechanism for formation of dikes and conduits; 2) stoping processes, that play an important role in the development of the breccia zone and enabling an efficient transference of material during the emplacement of the syenitic magma and 3) shear-related deformation (regional stress), affected the internal fabric of the facies, causing intracrystalline deformation and submagmatic flow, which is very evident in the central syenite intrusive. The kinematic analysis of shear planes allows proposing that emplacement of the LPC took place in a transtensive regime, which would have occurred in the back-arc of the Andes orogen, during a long period spanning from Miocene to the present, of the compressive deformation responsible, westward and at the same latitude, for the development of the Aconcagua fold and thrust belt.  相似文献   

特色保护类村域农村居民点空间重构探析   总被引：1，自引：0，他引：1  

冯德东  冯应斌  赵玲珑  龙花楼  徐雨利 《地理科学进展》2022,41(5):825-837

快速城镇化进程中中国乡村聚落空间面临剧烈分化和重组,农村居民点空间重构有利于乡村转型发展。论文基于系统理论,梳理了特色村落农村居民点空间系统形成机制,提出“遵循有序性—延续精神性—落脚物质性”的重构框架,并以贵州省江口县坝梅村为例,选用规模指数、基因分析及空间分析等方法解译了村域居民点系统内、外部特征,提出重构模式。研究表明：① 行为主体、文化基因及民居建筑构成坝梅村居民点内部系统,并分别呈“多元主体行为诱发空间变化、文化基因丰富但延续较差、用地结构与功能多样化”的特征;② 坝梅村居民点系统外部特征体现在外部环境对居民点起约束和导向作用,表现为距离点状、线状基础设施及河流越近,村域居民点数量、规模越大;③ 基于特征认知和重构框架,按照“分区—分类”方法,划分了核心区、重点区、提升区和保育区4种治理区以及完好型、受损型、缺失型、失真型4类民居提升类型,并提出了自组织和他组织2种模式下的居民点空间重构策略,为推动特色村落空间治理与转型提供参考。  相似文献   

连云港临洪河口水体中重金属的化学形态与分布特征研究   总被引：1，自引：0，他引：1  

李玉  李谷祺  冯志华 《海洋科学》2010,34(10):33-37

对连云港海域临洪河口水体中重金属元素Cu,Zn,Pb,Cd的主要存在形态及悬浮颗粒态重金属元素的赋存形态进行了分析。结果表明:悬浮态重金属Cu,Zn,Pb,Cd的含量在调查海域内空间分布基本均衡,Zn、Cu、Cd主要以溶解态形式存在,而Pb则主要以颗粒态形式存在。对悬浮态重金属元素的赋存形态分析表明,Cu主要富集在有机-硫化物态、Zn主要富集在残渣态、Pb主要富集在铁锰氧化物态和碳酸盐结合态、Cd主要富集在可交换态和碳酸盐结合态。  相似文献   

The impact of highly permeable layer on hydraulic system in a coastal aquifer     

Kue‐Young Kim  Weon Shik Han  Eungyu Park 《水文研究》2013,27(22):3128-3138

This study is aimed to understand the hydraulic mechanism of coastal aquifer systems that include highly permeable layers (HPLs). These hydrologic conditions can be found in many volcanic islands that are composed of a series of lava flows discharged into sea or other standing body of water. In the first part, we developed a numerical model based on the geologic and hydrologic data obtained from the eastern Jeju Island, Korea, of which the aquifer contains clinker and hyaloclastite layers. The simulation results reproduced spatial location of fresh‐saline water interface, especially the abrupt decline of interface at the inland part and the thickness variation of transition zone along the cross‐section observed at the eastern Jeju coastal aquifer. We were able to find out that these phenomena are strongly related to the presence of the HPL. In the second part, quantitative analyses were conducted with the use of hypothetical models in order to understand the dynamic characteristics of coastal system that includes HPLs. A series of sensitivity studies were conducted to assess the effect of the horizontal length and vertical depth of HPL on the spatial location of the interface toe and the configuration of transition zone. Various case studies have shown that the seawater intruded into the inland more as the horizontal length of HPL was increased and its vertical depth was decreased. In other simulations including two HPLs, the vertical distance between these two HPLs primarily controlled the flow regime, flux variations, and the configuration of the transition zone. Finally, we performed simulations to evaluate the effect of a rising sea‐level. This study provides more understanding of how the presence of HPL controls the seawater intrusion processes, and the spatial configurations of fresh‐saline water interface at coastal aquifers. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

海水拌养混凝土耐久性试验与应用   总被引：1，自引：0，他引：1  

陈兆林  唐筱宁  孙国峰  柳玉良 《海洋工程》2008,26(4)

通过对海水拌养混凝土耐海水侵蚀试验和海水中化学成分对水泥胶砂与骨料的影响分析,以及海水拌养混凝土的工程应用与调查结合长龄期强度跟踪观测,研究了海水拌养素混凝土的耐久性.旨在为淡水资源匮乏的海岛工程建设应用海水拌养混凝土,减少从大陆船运施工用淡水,节省工程投资提供资料.  相似文献   

Comprehensive Assessment of Seawater Quality on an Improved Attribute Recognition Model     

ZHANG Libing CHENG Jilin JIN Juliang JIANG Xiaohong 《中国海洋大学学报(英文版)》2006,5(4):300-304

The attribute recognition model （ARM） has been widely used to make comprehensive assessment in many engineering fields, such as environment, ecology, and economy. However, large numbers of experiments indicate that the value of weight vector has no relativity to its initial value but depends on the data of Quality Standard and actual samples. In the present study, the ARM is enhanced with the technique of data driving, which means some more groups of data from the Quality Standard are selected with the uniform random method to make the calculation of weight values more rational and more scientific. This improved attribute recognition model （IARM） is applied to a real case of assessment on seawater quality. The given example shows that the IARM has the merits of being simple in principle, easy to operate, and capable of producing objective results, and is therefore of use in evaluation problems in marine environment science.  相似文献   

Field Detection of Chiorophyll-a Concentration in the Sea Surface Layer by an Airborne Oceanographic Lidar   总被引：2，自引：0，他引：2  

LIU Zhishen MA Sen WANG Xin LI Zhigang 《中国海洋大学学报(英文版)》2008,7(1):108-112

An airborne oceanographic lidar, with a frequency-tripled Q-switched Nd： YAG laser of 355 nm, has been designed to measure chlorophyll-a （Chl-a） concentration in the sea surface layer by the Ocean Remote Sensing Institute, OUC. The field experiment was carried out in the bay which is located south of the Liaodong Peninsula on the 10th of September 2005. After the flight, the raw data were processed and analyzed by the fluorescence-to-Raman ratio method with seawater attenuation coefficients calculated from signal profiles. The results of Chl-a concentration sea water were also compared with those of Chl-a concentration by measurements by lidar are shown. The measurements in clear a Moderate Resolution Imaging Spectroradiometer （MODIS）.  相似文献   

胶州湾海水中悬浮颗粒对溶解态微量元素的影响   总被引：3，自引：0，他引：3       下载免费PDF全文

刘刚  瞿成利  常凤鸣  赵永芳  路波 《海洋科学》2008,32(3):55-61

运用离子色谱离线螯合结合ICP-MS的方法,对胶州湾海水中的微量元素(V,Co,Ni,Cu,Mo,Cd,Pb,U,REEs)进行了精确的定量分析。在测试前对在同一站位不同层位采集的平行海水样品进行了两种不同的酸化处理:一份采取先过滤后酸化的方式,以获得海水中溶解态微量元素的含量;另一份采取直接酸化后分析的方式,以评估悬浮颗粒中的可交换态微量元素对溶解态微量元素测定结果可能造成的影响。通过对比研究发现,不同处理方法得到的V、Ni、Cu、Co、Pb以及稀土元素(REEs)的质量浓度存在很大差异,说明悬浮颗粒物质可能对海水中相应元素的测定产生较大的影响。各种微量元素之间的差异和相应离子或离子团的电荷性质、在海水中的配位作用以及悬浮颗粒物质的表面电荷性质有关。初步研究结果表明,在类似于胶州湾这样的近海海域,悬浮颗粒物质是控制微量元素分布特征的一个重要因素。  相似文献