海-陆-气全球耦合模式能量收支的误差

通过分析GOALS模式两个版本GOALS 1.1和GOALS 2的能量收支 ,并与观测对比 ,结果表明 :模式模拟的地表净短波辐射通量在高纬地区偏低 ,而净长波辐射通量又偏高 ,导致极地表面温度偏低 ,感热通量在高纬地区为很高的负值。而在陆地上感热加热作用显著偏强 ,使地表有较大的向上净能量给大气 ,引起陆地上有些暖中心也偏强 ,这也解释了模式模拟地表面空气温度场的误差原因。海洋上潜热通量偏低 ,特别是在副热带洋面上偏少更明显。陆地上的欧亚和北美大陆大部分地区潜热通量仍偏低。这也是模式降水在大部分地区偏少的重要原因。两模式大气顶OLR偏低的模拟主要是在中低纬度 ,大气顶净短波辐射通量的模拟在中低纬度虽然与NCEP结果接近 ,但与地球辐射收支试验ERBE资料比较仍偏小较多 ,说明改进中低纬度云 辐射参数化方案对改进全球能量收支的模拟有重要意义。GOALS 2模式中诊断云方案模拟的云量除赤道地区外普遍偏小 ,尤以中纬度为甚 ,造成那里能量收支出现大的误差 ,这表明了更好的云参数化方案的引入是今后模式发展的重要任务之一     

等离子质谱(ICP-MS)对高含量元素硫样品中的微量元素分析前处理方法初探

用等离子质谱(ICP-MS)分析一些特殊样品的时候,前处理方法成为分析样品成功与否的关键,对于高基质含量的样品测量其微量元素含量更是如此。元素硫超过99%的自然硫样品中微量元素的测定一般使用燃烧的方法去除自然硫,但是一些易挥发性的元素也因此失去而测不出来。作者试图采用硫升华的方法去除硫基质,通过在原样品中加入内标,分析测定后计算内标的回收率确定出元素Be,Sn,Sc,U和稀土元素(REE)的回收率都在90%以上,可以用升华硫方法很好地测定,而元素Tl,Hf,W,Nb,Zr,Ta等的回收率则在75%以下,不适合用该种方法测定。     

横向同性地层中井间电磁响应的三维频域耦合势正演模拟研究

本文针对电导率横向同性地层中三轴发射-接收线圈系的井间电磁响应,开展三维正演算法及模拟研究.首先将发射线圈简化为三轴正交磁偶极子源.为克服低频电磁产生的数值迭代收敛缓慢问题,利用低感应数预处理方法将频域Maxwell方程组转化为基于矢势与标势的Helmholtz方程.采用非等间距的Yee氏交错网格、电导率的体积加权平均技术以及积分形式的有限差分格式实现对控制方程的离散化.借助于不完全LU分解预处理的稳定双共轭梯度法计算井间电磁响应的数值解,并通过与有限元软件COMSOL的数值结果对比验证本文模型与算法的有效性.数值计算结果表明：在横向同性地层的垂直井模型中,测井响应横向分量xx和yy能反映出地层电导率各向异性信息,但横向探测能力较差.轴向分量zz虽只反映地层水平电阻率信息,但具有较好的横向探测能力,且对地层中异常体非常敏感,而交叉分量xz、zx则具备较强的层边界识别能力.     

Physical and coupled fully three-dimensional numerical modeling of pressurized bottom outlet flushing processes in reservoirs

Sediment deposition in reservoirs is an important research topic in engineering practice. Reservoir sedimentation has the potential to affect ood levels, drainage for agricultural land, pump station and hydropower operation as well as navigation. This paper describes the development of a coupled fully three-dimensional (3D) numerical model for the prediction of the local sediment ushing scour upstream of the bottom outlet. The presented numerical model solves the Navier-Stokes equations in conjunction with the k- turbulence model which includes both sediment transport and hydrodynamic parameters. The proposed coupled fully 3D numerical model is used to simulate experimental tests based on non-cohesive sediment. The geometric features of the scour hole (temporal and spatial hole devel- opment) upstream of the bottom outlet were reasonably well predicted compared to the experimental data. Furthermore, the velocity eld upstream of the bottom outlet was in good agreement with mea- surements. The proposed numerical model for bottom outlet ushing was, therefore, validated because of its ability to accurately predict the scour hole development during the ushing process. The proposed numerical model can be considered reliable provided that the model is correctly calibrated and set up to re ect the conditions of a particular case study.     

耦合魔方——一个分析人地系统耦合机理的多维框架

Understanding the interactions between humans and nature in the Anthropocene is central to the quest for both human wellbeing and global sustainability.However,the time-space compression,long range interactions,and reconstruction of socio-economic structures at the global scale all pose great challenges to the traditional analytical frameworks of human-nature systems.In this paper,we extend the connotation of coupled human and natural systems(CHANS)and their four dimensions—space,time,appearance,and organization,and propose a novel framework:“Coupled Human and Natural Cube”(CHNC)to explain the coupling mechanism between humans and the natural environment.Our proposition is inspired by theories based on the human-earth areal system,telecoupling framework,planetary urbanization,and perspectives from complexity science.We systematically introduce the concept,connotation,evolution rules,and analytical dimensions of the CHNC.Notably there exist various“coupling lines”in the CHNC,connecting different systems and elements at multiple scales and forming a large,nested,interconnected,organic system.The rotation of the CHNC represents spatiotemporal nonlinear fluctuations in CHANS in different regions.As a system continually exchanges energy with the environment,a critical phase transition occurs when fluctuations reach a certain threshold,leading to emergent behavior of the system.The CHNC has four dimensions—pericoupling and telecoupling,syncoupling and lagcoupling,apparent coupling and hidden coupling,and intra-organization coupling and inter-organizational coupling.We mainly focus on the theoretical connotation,research methods,and typical cases of telecoupling,lagcoupling,hidden coupling,and inter-organizational coupling,and put forward a human-nature coupling matrix to integrate multiple dimensions.In summary,the CHNC provides a more comprehensive and systematic research paradigm for understanding the evolution and coupling mechanism of the human-nature system,which expands the analytical dimension of CHANS.The CHNC also provides a theoretical support for formulating regional,sustainable development policies for human wellbeing.     

南海上层对台风响应的模拟研究

利用中尺度海气耦合模式对2006年第1号台风Chanchu海气相互作用的模拟结果.分析了南海上层海洋对台风的热力和动力响应特征.研究发现:模拟的chanchu影响下南海SST分布与观测较为符合;与SST降低相对应的是混合层深度普遍增加,较大的海面冷却对应了较大的混合层加深;在台风作用下,海面上产生了一个气旋式环流,随着台风中心的移动而移动.流场呈现明显的不对称结构;模拟结果表明南海对台风的响应具有很明显的近惯性振荡特征.     

高围压条件下孔隙介质渗透特性试验研究

为研究不同围压条件下孔隙介质的渗透性能,利用新研制的高压渗流仪,对大尺寸低渗透性软弱岩进行了系统的试验测试。试验渗透压差波动幅度仅为0.02MPa,渗出端溶液体积变化量测试精度可达0.03mL。通过溶液体积变化与时间的线性关系,稳定渗流量大小可以精确测定。以稳定压差、流量法(即稳压法),试验验证了岩石的渗透系数随着围压的增加而下降,当围压降低时,岩石渗透系数回升,但回升路径低于原始路径。根据轴向应变的变化情况,提出了室内试验应力-渗流耦合过程中渗透性的变化主要是侧向压力使孔隙、喉道产生压缩变形所致。     

极地科考影音技术研究

极地科考影像资料是通过胶片模拟图像信号形式存储的。为了后期进行非线性编辑制作,有必要把胶片上存储的模拟图像信号转换为磁带录像电信号。通过深入地对比与研究,利用胶转磁技术完成这个工作是一个有效的方法。本文通过CCD胶转磁设备对极地科考影像资料进行胶转磁处理,并对转换后的影像资料与声音进行影音同步处理。     

二根耦合振动弦的边界反馈稳定化问题(Ⅰ)

本文讨论了二根耦合振动弦边界反馈的数学模型,讨论了相应的一阶线性双曲系统及谱的特征。