对流层低层的季风

文章提出一种对流层低层季风定义的新方法。通过大量的资料分析,作者认为:对流层低层的风可以近似地看作是二部分的线性组合。一部分是非季风的行星风,这部分代表大气对海陆地形的动力强迫的响应;另一部分则是季风,这部分是大气对海陆地形的热力强迫响应。作者用多年平均的年平均风来代表行星风,这样分离出来的季风与经典季风相比有很多优点:1.计算简单;2.物理图象清楚;3.便于划分季风区。     

鲤JAK2基因分子克隆及组织表达分析

采用同源克隆策略和RACE-PCR技术,克隆得到可能的鲤(Cyprinus carpio)两面神激酶2(JAK2)基因的c DNA全长序列,包括3 378 bp的开放阅读框,732 bp的5'-非编码区,529 bp的3'-非编码区,总长度达4 639bp。开放阅读框可编码1 125个氨基酸,推测分子质量和理论等电点分别为129.33 ku和6.99。同源性分析显示,克隆的鲤鱼基因与斑马鱼(Danio rerio)JAK2同源性最高,其氨基酸序列同一性和相似度分别达89%和95%。结构域预测表明,所编码氨基酸序列包含FERM、SH2及两个酪氨酸激酶结构域,这4个结构域也保守地存在于其他脊椎动物的JAK分子中。高级结构预测显示,鲤JAK2主要包括α-螺旋(α-helix)、β-折叠(β-sheet)和连接环(loop)等3类结构元件。脊椎动物JAK分子系统进化树显示,JAK1、JAK2、JAK3和TYK2等4类JAK分子分别聚类,鲤JAK2处于JAK2支系中,与所有其他的鱼类JAK2聚为一大支,并与两栖类和哺乳类组成的另一大支构成姊妹群,表明它们具有共同的祖先基因,为直系同源关系。实时荧光定量PCR检测结果表明,鲤JAK2在皮肤中表达量最高,其次是肠、血液和脑,而在肌肉、鳃、头肾、心、肝、脾中表达量较低;鲤JAK3在脾中表达量最高,在其他组织中表达量均很低,甚至未检出。     

基于FME的天地图水系显示级别检查方法

利用FME对地理空间数据的几何和属性处理功能,设计与实现了一种针对天地图水系数据显示级别合理性的检查方法.该方法可对水系线、水系面及二者之间显示级别的合理性进行快速检查,实际生产表明,该方法提高了水系数据融合更新的生产效率和质量.     

A Prediction Method of Internal Solitary Wave Loads on the Semi- Submersible Platform

An investigation into the prediction method for internal solitary waves (ISWs) loads on the columns and caissons of the semi-submersible platform found on three kinds of internal solitary wave theories and the modified Morison Equation is described. The characteristics of loads exerted on the semi-submersible platform model caused by the ISWs have been observed experimentally, and the inertial and drag coefficients in Morison Equation are determined by analyzing the forces of experiments. From the results, it is of interest to find that Reynolds number, KC number and layer thickness ratio have a considerable influence on the coefficients. The direction of incoming waves, however, is almost devoid of effects on the coefficients. The drag coefficient of columns varies as an exponential function of Reynolds number, and inertia coefficient of columns is a power function related to KC number. Meanwhile, the drag coefficient of caissons is approximately constant in terms of regression analysis of experimental data. The results from different experimental conditions reveal that the inertia coefficient of caissons appears to be exponential correlated with upper layer depths.

     

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海底双相随机介质声反射的SVM神经网络分类识别研究

考虑海底沉积介质为双相介质,为了更好地模拟实际海底底质的不均匀性,将随机介质理论引入双相介质理论。首先,通过基于随机-双相介质理论的高阶有限差分数值技术模拟计算海底底质分别为泥质砂、泥、泥质砾时的地震反射波信号。然后利用小波变换分别求取不同底质的一次反射波的包络作为其特征向量,最后利用基于粒子群智能算法优化的支持向量机神经网络对这些反射波信号进行分类识别。为了进一步考察所用方法的抗噪能力,对正演得到的海底底质反射波信号分别加入10%、30%、50%的高斯白噪音之后再进行分类,支持向量机仍然取得了较好的分类预测效果。基于上述正演模拟及分类识别方法的论证,提出了一套行之有效的微机软件模拟海底沉积物分类识别的一般化流程,这将有利于开展海底沉积物反射特征的进一步研究。     

基于 TEQC 的 GPS 观测数据质量分析

介绍了TEQC在GPS测量数据预处理中的基本功能,包括：格式转换、数据编辑和质量检核,结合实例对T EQC在GPS数据质量检核中的应用进行了分析,并将其结果可视化,最后,利用TEQC计算了伪距单点定位的结果,并与已公布的ITRF2005值进行了比较。     

Present and projected degree days in China from observation,reanalysis and simulations

Degree days are usually defined as the accumulated daily mean temperature varying with the base temperature, and are one of the most important indicators of climate changes. In this study, the present-day and projected changes of four degree days indices from daily mean surface air temperature output simulated by Max Planck Institute, Earth Systems Model of low resolution (MPI-ESM-LR) model are evaluated with the high resolution gridded-observation dataset and two modern reanalyses in China. During 1979–2005, the heating degree days (HDD) and the numbers of HDD (NHDD) have decreased for observation, reanalyses (ERA-Interim and NCEP/NCAR) and model simulations (historical and decadal experiments), consistent with the increasing cooling degree days (CDD) and the numbers of CDD (NCDD). These changes reflect the general warming in China during the past decades. In most cases, ERA-Interim is closer to observation than NCEP/NCAR and model simulations. There are discrepancies between observation, reanalyses and model simulations in the spatial patterns and regional means. The decadal hindcast/forecast simulation performance of MPI-ESM-LR produce warmer than the observed mean temperature in China during the entire period, and the hindcasts forecast a trend lower than the observed. Under different representative concentration pathway (RCP) emissions scenarios, HDD and NHDD show significant decreases, and CDD and NCDD consistently increase during 2006–2100 under RCP8.5, RCP4.5 and RCP2.6, especially before the mid-21 century. More pronounced changes occur under RCP8.5, which is associated with a high rate of radiative forcing. The 20th century runs reflect the sensitivity to the initial conditions, and the uncertainties in terms of the inter-ensemble are small, whereas the long-term trend is well represented with no differences among ensembles.