Modification of North Pacific Intermediate Water around Mixed Water Region     

Ryuichiro Inoue  Jiro Yoshida  Yutaka Hiroe  Kousei Komatsu  Kiyoshi Kawasaki  Ichiro Yasuda 《Journal of Oceanography》2003,59(2):211-224

The mixing processes in the Mixed Water Region (MWR) that lead to changes in the properties of North Pacific Intermediate Water (NPIW) have been studied using observational data sets obtained in May–June 1998. Neutral surfaces, the equation of water mass conversion rate on neutral surfaces and the equation of vertical velocity across neutral surfaces have been used to distinguish dominant processes by assuming the horizontal scale to be the streamer scale (under 100 km). The possibility of double diffusive convection is also discussed in relation to the density ratio. These results may be summarized as follows: (1) the difference between the potential density surface and the neutral surface may rise to −0.04 kg/m³ around the source water of NPIW; (2) horizontal diffusion causes strong modifications of the source water of NPIW; (3) the density range within which strong modification of the source water of NPIW occurs becomes dense from the northern part of MWR near the Oyashio Front to the southern part near the Kuroshio Front, and to the eastern part. Our modeling of these processes shows that cabbeling has effects on the density increment of the source water of NPIW in the northern and southern part of MWR. Double diffusive convection has effects on the density increment of the source water of NPIW, mainly in the northern part of MWR. The possible density increment due to cabbeling in these areas is estimated to be 0.01≈0.03 kg/m³. The possible density increment due to double diffusive convection is 0.01≈0.03 kg/m³. The total density increment due to cabbeling and double diffusive convection amounts to 0.06 kg/m³. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

钒钛磁铁矿中钛铁连测方法研究     

凌学芳 《矿物岩石》1990,10(2):105-107

本文采用中性红和二苯胺磺酸钠作指示剂,以重铬酸钾标准溶液对钒钛磁铁矿中钛铁连测.经对介质、指示剂、催化剂加入量等的优选试验和分析结果时照,本方法终点敏锐,操作简便、快速,结果可靠.  相似文献   

An investigation of the dependence of structural parameters of the middle atmosphere on the intensity of photochemical and dynamical processes     

V. V. Koshelev  N. N. Kolpakidi 《Pure and Applied Geophysics》1988,127(2-3):381-401

Using a numerical model for temperature and neutral and ion composition behaviour at middle atmospheric heights, an analysis has been made of the dependence of atmospheric structural parameters on temperature, solar activity, and on turbulent transfer intensity. For mesospheric heights, an inverse dependence of the nitric oxide density on the temperature has been found. It is thus possible to explain experimentally obtained temperature variations over a cyclc of solar activity at mesospheric and lower thermospheric heights. Numerical simulation results indicate that the temperature in the height range 75–120 km depends considerably on both the absolute values of turbulent transfer coefficients and their vertical gradients.  相似文献   

弱光层异养过程对海洋储碳的影响:进展、挑战和展望          下载免费PDF全文

徐超  柳欣  黄毅彬  肖武鹏  黄邦钦 《大气科学学报》2022,45(3):357-363

海洋是地表系统最大的碳库和重要碳汇区。海洋生物泵通过一系列复杂的生物地球化学过程将CO₂转化成颗粒有机碳（Particulate Organic Carbon,POC）并输送到深海,是海洋储碳的重要途径。弱光层（真光层底部到1 000 m）的生物异养过程消耗了超过70%从真光层输出的POC通量,决定了生物泵的储碳效率,因此准确定量弱光层的再矿化速率对评估海洋碳汇有重要意义。本文针对海洋生物泵储碳问题,聚焦弱光层异养过程对海洋储碳的影响机制,对全球弱光层再矿化定量工作进行评述,综合分析弱光层POC的衰减、再矿化等问题,并展望了相关新技术的应用。  相似文献   

用软锰矿直接制备高纯高比表面四氧化三锰   总被引：1，自引：0，他引：1  

田甜  罗红玉  杨超  皮振邦  田熙科 《地球科学》2007,32(1):119-122

软锰矿经中性浸出,通过除杂净化,制备出高纯硫酸锰溶液;碱化沉淀,采用微波加热进行控制氧化合成四氧化三锰,确定了该方法的最佳工艺参数.分别用扫描电镜、透射电镜、X射线衍射仪和全自动氮吸附比表面仪对样品进行了检测,结果表明:该方法成功制备了高纯四氧化三锰,比表面积高达28.27 m2/g.  相似文献   

接触应变作用   总被引：1，自引：0，他引：1  

蔡学林 《地球科学进展》1993,8(3):58-62

接触应变作用已成为构造地质学研究褶皱形态及其形成机制的新领域和新方向之一。综述了接触应变作用的研究现状、研究内容、研究进展以及今后的研究方向。  相似文献   

Carbon neutral policy in action: the case of Bhutan     

Dorji Yangka  Vanessa Rauland  Peter Newman 《Climate Policy》2019,19(6):672-687

Climate policy across the world is proceeding at a highly variable pace, with some places very committed to decarbonizing their economies and others just beginning. Emerging nations are generally just starting along this journey. However, among the few nation states that have pledged to achieve carbon neutrality, is Bhutan, a least developed country. Carbon neutrality is an ambitious climate policy that is increasingly being recognized as necessary in order to stabilize global temperature rise at 1.5°C. However, Bhutan is likely to face significant challenges in maintaining this status as the country balances its desire to grow in economic opportunities (GDP) and in human happiness (GNH). Little research has been conducted inside the policy processes to better understand how Bhutan will maintain carbon neutrality. Through open-ended, semi-structured interviews with key stakeholders, this study provides an inside view on the current situation and future challenges that Bhutan may face, along with the complexities associated with implementing and maintaining an ambitious carbon neutral policy. The paper highlights Bhutan's story and how it could be useful for policy learning and knowledge sharing, especially in the context of emerging nations’ climate governance.  相似文献   

中性大气对非差伪距定位的影响及其模型改正分析   总被引：2，自引：1，他引：1  

高星伟  陈锐志  李夕银 《测绘学报》2007,36(2):134-140

中性大气包括对流层和平流层,它们对GPS信号造成的延迟影响是GPS定位的一个主要误差源。与电离层的影响相比,消除中性大气的延迟影响更复杂,只能用经验模型进行改正。本文就中性大气对GPS定位的影响进行详细地分析和说明,对中性大气改正模型及其相关问题进行明确地论述。最后以中国IGS跟踪站一年中不同季节的观测数据为基础,通过对相同的数据采用不同的中性大气改正模型分别进行相同的定位解算,并对不同模型的定位结果进行分析,得出有关中性大气模型改正与GPS定位之间及改正模型间的定性和定量的关系。  相似文献   

金铜精矿中性催化加压浸出预处理工艺     

李滦宁  梁宏伟  赵淑杰  刘娟丽  陈博  王岚  崔玉果  于长江 《吉林大学学报(地球科学版)》2011,41(4):1186-1191

针对金铜精矿采用中性催化加压预处理工艺,经试验,在温度180 ℃、氧分压1.8 MPa、催化剂0.14 mol/L的基本条件下,Cu浸出率为99.4%,浸液中残留∑Fe质量浓度仅为3.52 g/L,对后续回收Cu的精炼工艺非常有利。氧化渣以氯化浸金工艺浸出Au、Ag,浸出率分别为98.2%、90.3%,有价元素回收率高,工艺简单,环境效益好。  相似文献   

Behaviour of piles in consolidating soil     

Yue Choong Kog 《Geomechanics and Geoengineering》2019,14(1):1-11

The development of negative skin friction on circular piles in a consolidating layered soil is investigated by an elasto-plastic load transfer theory which accounts for slippage of the soil. The elastic load transfer theory is premised on the compatibility condition that the vertical displacement of the ‘pile’ is equal to the summation of the vertical displacement of the layered soil due to the consolidation of the upper soil layer and the vertical displacement in the ‘soil layers’ along the pile’s centroidal axis caused by a system of pile-soil interactive forces. Slippage of the soil is accounted for by imposing the shear strength of the clay layer as the limit of the pile-soil interface shear stress. The saturated upper clay is consolidating under a uniform surcharge in accordance with Terzaghi’s one-dimensional consolidation theory. The validity of the proposed solution is confirmed by comparison with field measurements. Extensive parametric studies with regard to the effect of pile-soil slip on pile behaviour are presented.  相似文献