Changes in mixed layer depth and spring bloom in the Kuroshio extension under global warming

The mixed layer is deep in January–April in the Kuroshio Extension region. This paper investigates the response in this region of mixed layer depth(MLD) and the spring bloom initiation to global warming using the output of 15 models from CMIP5. The models indicate that in the late 21 st century the mixed layer will shoal, and the MLD reduction will be most pronounced in spring at about 33?N on the southern edge of the present deep-MLD region. The advection of temperature change in the upper 100 m by the mean eastward flow explains the spatial pattern of MLD shoaling in the models. Associated with the shoaling mixed layer, the onset of spring bloom inception is projected to advance due to the strengthened stratification in the warming climate.     

Gender and local soil knowledge: Linking farmers' perceptions with soil fertility in two villages in the Philippines

Scientists often turn to farmers to understand soil management. This process reveals differences and overlaps between local and scientific soil knowledge but rarely considers women and gender issues. This paper examines men's and women's local knowledge of soils in upland, smallholder farms in two villages in Mindanao, the Philippines, using focus group discussions, semi‐structured household interviews, field visits, GIS and soil testing. Farmers' field areas were calculated and delineated based on their perceptions of the different types of soils on their land. Men and women chose the same plots for what they considered their best soil but differed on what they felt were their worst. The fertility of the soils that women considered to be the best and worst was not significantly different from that of the men's respective choices. There was a difference in fertility, however, between the best and worst soils regardless of gender. Although soil fertility analyses showed that the women's chosen soils were similar to men's, analyses of qualitative data showed that their knowledge of soils was different and was based in part on a gendered division of labour. A multidisciplinary approach helped bridge the gap between sociocultural and physical research.     

滇中荒田铅锌矿床Rb-Sr同位素年代学与C-O-S-Pb同位素地球化学特征

滇中荒田铅锌矿床赋存于下二叠统碳酸盐岩与上二叠统峨眉山玄武岩接触界面上,矿体主要呈似层状、透镜状产出。矿石矿物组合以闪锌矿、方铅矿为主,脉石矿物以石英、方解石、白云石为主。热液方解石C、O同位素组成表明荒田铅锌矿床成矿流体中CO_2的碳具有多元性,主要来源于幔源与海相碳酸盐岩的混合碳;硫化物硫同位素组成表明荒田铅锌矿床硫以岩浆硫为主,可能混有其他硫源(可能包括地层硫酸盐),铅同位素表明赋矿围岩、玄武岩和燕山期花岗岩均有可能为成矿提供了成矿物质,是多源混合后的产物;闪锌矿Rb-Sr同位素等时线年龄为(83.2±3.4)Ma,指示荒田铅锌矿床形成于晚燕山期,荒田铅锌矿床成矿动力学背景可能与右江褶皱带在中生代末期发生了大规模的岩石圈伸展有关。而晚二叠世海相喷发火山岩对矿区铅锌矿床的形成起了重要的盖层、赋矿层及矿化作用。综上,荒田铅锌矿床成矿流体中的不同组分来源不同,矿床类型为沉积-改造型矿床。     

Modeling of dynamic cohesive fracture propagation in porous saturated media

In this paper, a mathematical model is presented for the analysis of dynamic fracture propagation in the saturated porous media. The solid behavior incorporates a discrete cohesive fracture model, coupled with the flow in porous media through the fracture network. The double‐nodded zero‐thickness cohesive interface element is employed for the mixed mode fracture behavior in tension and contact behavior in compression. The crack is automatically detected and propagated perpendicular to the maximum effective stress. The spatial discretization is continuously updated during the crack propagation. Numerical examples from the hydraulic fracturing test and the concrete gravity dam show the capability of the model to simulate dynamic fracture propagation. The comparison is performed between the quasi‐static and fully dynamic solutions, and the performance of two analyses is investigated on the values of crack length and crack mouth opening. Copyright © 2010 John Wiley & Sons, Ltd.     

基于C#与Fortran混合编程技术实现法方程系数阵求逆

开发控制网平差软件时,需要进行界面、算法优化设计等等。开发人员往往喜欢用图形化编程语言,但图形化编程语言在科学计算方面往往不够突出。测量平差需要进行很多的矩阵运算,如法方程系数阵的求逆计算等。Fortran语言是目前流行较广的适用于科学计算的程序开发语言,但是它的图形界面开发功能较弱。C#是新一代面向对象开发语言,擅长于图形界面系统开发。本文采用C#与Fortran混合开发,发挥两者的优点,实现法方程系数阵的快速求逆。     

应用VB实现地形图数据格式转换

运用VB开发软件,针对由矢量化大比例地形图生成的数据,格式转换为电力架空送电线路常用的SL-CAD架空送电线路平断面图,处理及定位CAD系统的数据格式,进行程序设计,经过实际应用,减少了数据处理时间,大大提高了工作效率。     

2008年孟加拉湾春季暖池生消过程的热收支诊断分析

在夏季风爆发前孟加拉湾会出现季节性暖池,在季风爆发后它则快速消失。本文利用RAMA浮标阵列中孟加拉湾中部浮标的观测资料,通过进行混合层热收支诊断,对2008年孟加拉湾春季暖池的生消过程进行了分析。结果表明:热通量项主导了暖池的生成和消亡过程,它在暖池生成期表现为强加热效应,而在暖池消亡期变为强冷却效应;垂向卷夹的冷却作用在暖池生成阶段比较突出;温度平流项的冷却作用在冬季较强。对热通量项的进一步分析表明:短波辐射平均热效应在暖池生成期高达0.32℃/d,而在暖池消亡期降低一半,这是使热通量项在两个时期有不同表现的根本原因;潜热通量在各阶段的平均冷却效应基本保持不变,都在-0.14℃/d左右;长波辐射的冷却效应在暖池生成期比较显著,一定程度上减缓了海温的上升速度;感热通量的热效应相对较小。     

渤海海域A构造区沙二段混合沉积特征及储层研究

渤海海域A构造区沙二段高孔高渗型混合岩类储层的发现改变了此区缺乏优质储层的认识.以钻井取心化验资料为基础,综合分析了该类储层的岩石学特征、沉积成因、储层特征及影响因素.研究认为该类储层是受间歇性陆源供给影响的混合沉积产物,沉积相带是影响储层质量的主要因素,后期混合白云石化对储层质量保护及改善具有积极作用.     

Estimation of canopy drying time after rainfall using sap flow measurements in an emergent tree in a lowland mixed‐dipterocarp forest in Sarawak,Malaysia

This study emphasizes the importance of canopy drying time (CDT) after rainfall in a lowland tropical rain forest. In this study, we estimate CDT using sap flow velocities measured by a heat‐pulse method in an emergent tree in a lowland mixed‐dipterocarp forest. Estimated CDT (ECDT) for each rain event has been defined as the time from rainfall cessation to the specific time derived from the difference between diurnal courses of sap flow velocities on a rainy day versus bright days. ECDT could be derived for 22 rain events that were grouped into two types, depending on whether rainfall ceased before or after noon. The ECDTs were distributed more widely and with greater values when rainfall ceased before noon (Type 1) than after noon (Type 2). The ECDTs of both Type 1 and Type 2 decreased with increases in net radiation (Rn) and vapour pressure deficit (VPD) after rainfall. This result shows that ECDT is determined mainly by post‐rainfall evaporation rates. The sap flow velocity as a detector of canopy wetness worked out well because of the specific rainfall characteristics at this site. The practical limitations of the method using sap flow velocities are discussed in relation to rainfall characteristics and time lags between transpirations and sap flow velocities. Copyright © 2005 John Wiley & Sons, Ltd.     

RESPONSE OF THE OCEAN UPPER MIXED LAYER TO ATMOSPHERIC FORCING

Using a one-dimension Turbulence Kinetic Energy(TKE)mixed layer model based on a simple eddyKinetic energy parameterization of the ocean upper mixed layer,some numerical examinations are intro- duced in this paper.These examination results show that the TKE ocean mixed layer model can respondwell to the effect of atmospheric forcing on the ocean upper mixed layer.The joint effect of wind stressand heat exchange on the ocean upper layer has nonlinear characteristics.The adjustment time of the re-sponse of the ocean upper mixed layer to the atmospheric forcing is about 12 hours in this model.