“菲特”台风路径和强度预报难点分析

利用1°×1°NCEP再分析资料、NOAA海温资料对其进行分析,结果表明:(1)副高突然加强西进,中低层高压带加强,在台风北侧形成高压坝和强盛偏东气流,是台风路径突然西折的主要原因;(2)"丹娜丝"的活动在一定程度上阻止了副热带高压的南落,有利于副高南侧偏东急流的维持和加强,对"菲特"路径的突然西折起一定作用。敏感性数值试验结果表明"双台风"效应对"菲特"登陆前进一步西折具有决定作用;(3)高低空急流的配置,产生了动力场的耦合作用,加强了台风的对流活动,所释放的潜热可以补偿海温降低的影响,对"菲特"在近海强度维持起到了重要作用;(4)"菲特"的强度和环境风垂直切变的演变规律基本一致,较低的环境风垂直切变是"菲特"在近海强度维持的重要原因。     

3种海洋微藻微胶囊培养的初步研究

用12mg/mL羧甲基纤维素钠(CMC)、10mg/mL海藻酸钠(SA)和0.5mmol/mL CaCl2制备亚心形扁藻、绿色杜氏藻和球等鞭金藻8701的中空海藻酸钙微胶囊,3种微藻在微胶囊内生长表现突出,最高细胞密度亚心形扁藻为70.4×106/mL,绿色杜氏藻为100.9×106/mL,球等鞭金藻8701为264.1×106/mL,分别是悬浮培养微藻最高密度的35倍、27倍和84倍,结果说明微胶囊化培养是微藻高密度培养的有效方式。     

长江口洪水期潮波变形数值模拟研究

由长江口现场水文测验资料分析知,洪水期潮波上溯过程中,潮波变形具有先加剧后趋缓的特点。基于非结构网格FVM方法建立大通至外海的大范围数学模型,复演长江口潮波传播过程,以此为基础,研究长江口洪水期潮波变形特征的形成原因。研究认为:洪水期长江口潮波变形转折点位于潮流界上游;转折点下游潮波变形逐渐加剧是由于高低潮位潮波传播速度差异造成的;转折点上游潮波变形趋缓是由于高潮位重力引起的潮波传播阻力对潮波传播影响大于高低潮位潮波传播速度差异造成的。     

Experimental Study on Response Performance of VIV of A Flexible Riser with Helical Strakes

Laboratory tests were conducted on a flexible riser with and without helical strakes. The aim of the present work is to further understand the response performance of the vortex induced vibration (VIV) for a riser with helical strakes. The experiment was accomplished in the towing tank and the relative current was simulated by towing a flexible riser in one direction. Based on the modal analysis method, the displacement responses can be obtained by the measured strain. The strakes with different heights are analyzed here, and the response parameters like strain response and displacement response are studied. The experimental results show that the in-line (IL) response is as important as the cross-flow (CF) response, however, many industrial analysis methods usually ignore the IL response due to VIV. The results also indicate that the response characteristics of a bare riser can be quite distinct from that of a riser with helical strakes, and the response performance depends on the geometry on the helical strakes closely. The fatigue damage is further discussed and the results show that the fatigue damage in the CF direction is of the same order as that in the IL direction for the bare riser. However, for the riser with helical strakes, the fatigue damage in the CF direction is much smaller than that in the IL direction.     

�������編ʱ��InSAR�������У�������о�

????????λ???????????????3????????????????????編???н??????????????????????????????????2007~2010?????20??ENVISAT ASAR?????÷????????????????????Э??????????У?????????????????й????????????Э?????????????????????3.1 mm²??????0.6mm²????????80%??e-folding???????????1.5 km?????0.21 km????????86%????????編??????Ч??У????????е??????λ?????     

����ؿǴ�ֱ�˶��о��е�ģ������Ӱ��

???????????????????о??м????????????ε??????????????????????????????????????????????????????Э??????????????????????????б????????С??????????????????????????????????????????????о??????????????????????????????????????Σ?????б?????????????     

Seismic data reconstruction based on iterative linear expansion of thresholds

Based on the compressive sensing,a novel algorithm is proposed to solve reconstruction problem under sparsity assumptions.Instead of estimating the reconstructed data through minimizing the objective function,the authors parameterize the problem as a linear combination of few elementary thresholding functions,which can be solved by calculating the linear weighting coefficients.It is to update the thresholding functions during the process of iteration.The advantage of this method is that the optimization problem only needs to be solved by calculating linear coefficients for each time.With the elementary thresholding functions satisfying certain constraints,a global convergence of the iterative algorithm is guaranteed.The synthetic and the field data results prove the effectiveness of the proposed algorithm.     

基于变分模态分解与相关向量机的变形特征提取及智能分析研究

建筑物、大型工程结构、边坡等受到内在与外在的复杂因素影响下,产生不同程度的变形.通过变形监测及变形数据分析,可及时、准确地掌握形变过程信息.变形特征提取与分析是变形数据处理的核心内容之一,是建筑物与工程结构精确健康监测、预报预警的关键,是变形灾害防治的重要理论与实践基础.由于变形体变形过程及变形数据采集过程中受到多种不确定性环境因素与人为因素的影响,变形数据具有显著的非线性、非平稳、高噪声和多尺度等特点,导致传统的变形数据分析方法存在诸多不足之处.     

面向城市精细化治理的"地楼房权人"实体构建

构建基础时空信息底板,是实现智慧城市内部多源、异构、海量数据间的关联与融合,保障各类智慧应用正常运转,实现城市精细化治理的前提.文中提出"地楼房权人"多层次城市实体模型,并基于该模型设计并实现"地楼房权人"实体建库、城市多源信息关联融合的业务框架,并通过应用展望,从教育学位配置和医疗资源管理等方面举例说明基于"地楼房权人"实体模型的多源信息关联在城市精细化治理中的应用价值.研究表明,通过构建"地楼房权人"等城市实体数据,并基于此关联集成各类城市数据,最终形成面向城市精细化治理的基础时空信息底板,将为智慧城市的各类应用提供基础支撑.