桑美台风决策服务分析

从桑美台风实况、台风登陆环流背景、数值预报降水、预报情报服务等方面分析回顾了2006年8号桑美台风影响期间的预报服务情况,并以碧利斯热带风暴作为参照分析,以期为各级台站做好决策气象服务提供一些宝贵的经验。     

"纳沙"台风对乌石渔港引起的台风浪的数值研究

利用MIKE21 SW波浪模型,对台风"纳沙"过境期间台湾宜兰县乌石渔港附近波浪特征进行数值模拟。结果表明,在"纳沙"影响下,在渔港近岸海域形成了最大有效波高超过5.5 m的巨浪,持续时间长达12 h。乌石渔港在多级防波堤的掩护下,港内有效波高逐渐减小,乌石渔港内有效波高低于0.5 m的有效避风面积达到总港域面积的24.2%。     

沿浦镇台风灾害与林业持续发展建议

随着全球温度的不断攀升，气候问题已席卷全球。伴随着全球气温的升高，对于沿海地区来说，台风发生得越来越频繁，台风带来的破坏程度也越来越大。通过对台风多发地苍南县沿浦镇的实地调查，针对台风带来的损失（特别是2006年的8号“桑美”台风）进行了分析、总结，并就如何更好地应对台风，推动台风多发区林业经济发展提出一些建议。     

台风“鲇鱼”环流的风矢量结构变化对其路径突变的影响

[目的]研究1013号强台风＂鲇鱼＂的风矢量结构变化及其对台风路径突变的影响。[方法]根据台风涡旋非对称结构对台风运动产生影响理论,对以1013号超强台风＂鲇鱼＂中心为坐标原点,300～500 km内850、500 hPa切向旋转速度分解成u、v分量,分析台风的合力运动倾向,探讨1013号强台风＂鲇鱼＂的风矢量结构变化及其对台风路径突变的影响。[结果]1013号强台风在快速移动阶段时,风矢量存在明显不对称结构;而在原地打转时,风矢量呈对称结构;当ΔU、ΔV及合成风矢出现明显的变化时,表明台风的合力出现变化,台风移动方向将出现突变。500和850 hPa台风中心周围300～500 km附近风速的不对称结构也有利于移动路径的趋向性;ΔU、ΔV及合成风矢,其指向可以作为台风合力运动的方向。[结论]该研究为台风的预防提供参考依据。     

海南省清澜渔港近岸台风浪数值模拟及波高重现值的推算

选取1980—2010年在海南省东海岸登陆的、每年强度等级最高的31个台风数据,应用MIKE21Spectral Wave计算模型,模拟清澜渔港台风浪的全过程,并对其中3个台风浪进行模型率定,计算结果与海南省清澜渔港近岸30 m水深处波浪实测数据相吻合。应用皮尔逊Ⅲ型频率曲线软件进行分析,清澜渔港近岸30 m水深处最大有效波高出现在N至NE方向,百年一遇的有效波高为5.78 m,50年一遇的有效波高为5.3 m,20年一遇的有效波高为4.6 m。本研究结果可对渔港的规划设计、防灾减灾提供有效参考,特别对缺少波浪实测资料的近岸工程具有实际应用价值。     

台风“碧利斯”与“桑美”路径相似的成因分析

利用1°×1°的NCEP全球再分析资料和实时高空、地面加密探测等资料,综合分析了环流背景、海表面温度和850 hPa的涡度变化对"碧利斯"和"桑美"台风的路径的影响。结果表明:它们在500 hPa的引导气流相似,都是受副高南侧的偏东气流的影响;在台风发展的过程中,在它们的西北方向都有暖舌稳定存在;在台风运动过程中,在850 hPa上总有一个正的涡度中心在它们的西北方向,引导它们向西北方向运动。     

热带气旋(台风)预报服务的有关技术浅析

就厦门市热带气旋(台风)预报服务的有关问题(台风预防发布注意事项及主要考虑的预报因子,天气雷达的应用)进行了探讨。     

福鼎市灾后水稻细菌性褐条病的发生与防治

2006年福鼎市遭受历史上罕见的超强台风"桑美"和多次强台风等洪涝灾害侵袭,台风带来强降雨,又遇到天文大潮,造成沿海大片稻区严重受淹。由于受淹时间长,稻苗损伤严重,极有利于病菌直接从伤口侵入,导致沿海稻区水稻细菌性褐条病爆发流行,同时引发白叶枯病、细条病、基腐病等其它细菌性病害发生。据统计,2006年全市水稻     

灾后水稻细菌性褐条病的发生与防治

2006年．福鼎市遭受历史上罕见的超强台风“桑美”和多次强台风等洪涝灾害侵袭，台风带来强降雨，又遇到天文大潮，造成沿海大片稻区严重受淹。由于受淹时间长．稻苗损伤严重，极有利于病菌直接从伤口浸入，导致沿海稻区水稻细菌性褐条病暴发流行，同时引发白叶枯病、细条病、基腐病等其它细菌性病害发生。     

基于GM（1，1）模型的台风灾害救灾物资需求量预测

针对福建省台风灾害频发，需要根据气象等部门的有关信息对台风灾害救灾物资的种类和数量进行预测的需求，在对随机强烈振荡的受灾情况原始数据序列进行修正的基础上，应用GM（1，1）模型对受灾人口数量进行预测，然后根据受灾人口数量推算生活类救灾物资需求量．该方法经实例验证，可应用于不确定性较大的台风灾害救灾物资需求量的预测．     

The Earth as a seismic absorption band

Attenuation of seismic waves indicates that the earth is not perfectly elastic. Dispersion accompanying absorption gives frequency-dependent "elastic" moduli, a fact that must be taken into account when inverting seismic data. Normal mode data are reinverted after correcting for absorption. The correction removes the discrepancy between body wave and free oscillation interpretations of earth structure.     

Propagation of seismic ground motion in the Kanto Basin, Japan

The pattern of ground motion for a magnitude 5.7 earthquake near Tokyo was captured by 384 strong ground motion instruments across the Kanto sedimentary basin and its surroundings. The records allow the visualization of the propagation of long-period ground motion in the basin and show the refraction of surface waves at the basin edge. The refracted wave does not travel directly from the earthquake epicenter, but traverses the basin obliquely to the edge. The surface wave inside the basin propagates more slowly than that outside such that the wavefronts separate from each other, and the refracted wave heals the discrepancy in the speed of advance of the wavefronts inside and outside the basin. The refracted arrival is dominant near the edge of the Kanto basin.     

Origin of the low rigidity of the Earth's inner core

Earth's solid-iron inner core has a low rigidity that manifests itself in the anomalously low velocities of shear waves as compared to shear wave velocities measured in iron alloys. Normally, when estimating the elastic properties of a polycrystal, one calculates an average over different orientations of a single crystal. This approach does not take into account the grain boundaries and defects that are likely to be abundant at high temperatures relevant for the inner core conditions. By using molecular dynamics simulations, we show that, if defects are considered, the calculated shear modulus and shear wave velocity decrease dramatically as compared to those estimates obtained from the averaged single-crystal values. Thus, the low shear wave velocity in the inner core is explained.     

A cellular automation model of excitable media including curvature and dispersion

Excitable media are spatially distributed systems characterized by their ability to propagate signals undamped over long distances. Wave propagation in excitable media has been modeled extensively both by continuous partial differential equations and by discrete cellular automata. Cellular automata are desirable because of their intuitive appeal and efficient digital implementation, but until now they have not served as reliable models because they have lacked two essential properties of excitable media. First, traveling waves show dispersion, that is, the speed of wave propagation into a recovering region depends on the time elapsed since the preceding wave passed through that region. Second, wave speed depends on wave front curvature: curved waves travel with normal velocities noticeably different from the plane-wave velocity. These deficiencies of cellular automation models are remedied by revising the classical rules of the excitation and recovery processes. The revised model shows curvature and dispersion effects comparable to those of continuous models, it predicts rotating spiral wave solutions in quantitative accord with the theory of continuous excitable media, and it is parameterized so that the spatial step size of the automation can be adjusted for finer resolution of traveling waves.     

浮绳式网箱框架纲波浪力特性的初步试验研究

结合生产的实际需要,沿海浮绳式网箱生产的作用日益突出,因而研究其水动力特性非常重要。根据这一需要,采用预加张力的直交系泊方法,依据目前柔性浮绳式网箱尺寸和渔具模型试验方法设计、制作了一个柔性浮绳式网箱模型（1 m×1 m×1 m）,并进行了水槽试验。试验工况为规则波,周期为0.8～2.0 s（间隔0.2 s）,波高为50～250 mm（间隔40 mm）。在不同波浪周期、波高下,根据测量数据,分析研究作用在浮绳式网箱框架纲上波浪力的特性。试验结果表明：波浪力的变化与波浪特性相似,呈周期性、不对称变化,垂直于波浪方向的2根框架纲的波浪力峰值比与波浪方向平行的2根框架纲的稍小。框架纲上的波浪力不是同步变化的,存在一定相位差,但由于框架纲是柔性绳索制成的,因而能承受由于不同相位波浪力产生的扭矩剪切作用,证明了波浪作用下HDPE网箱常受到破坏而浮绳式网箱安然无恙的事实。最后,就水流和波浪共同作用下的网箱水动力学进行了试验研究,发现波流共同作用下的水动力值并不是单独在纯流和纯波下的水动力的值的简单相加,而存在一修正项。     

The spectral-element method,Beowulf computing,and global seismology

The propagation of seismic waves through Earth can now be modeled accurately with the recently developed spectral-element method. This method takes into account heterogeneity in Earth models, such as three-dimensional variations of seismic wave velocity, density, and crustal thickness. The method is implemented on relatively inexpensive clusters of personal computers, so-called Beowulf machines. This combination of hardware and software enables us to simulate broadband seismograms without intrinsic restrictions on the level of heterogeneity or the frequency content.     

嫩江佰大街防浪林消浪机理物理实验研究

目的以嫩江佰大街堤防为研究对象,研究不同因素对嫩江干流防浪林消浪效果的影响以及合理设计防浪林优化布局。方法根据重力相似准则,通过合理的比尺缩放将研究区防浪林缩小至实验室水槽中,构建合适的防浪林物理模型,模拟防浪林植被与波浪的作用过程。其中波浪由造波机生成,防浪林采用模型树模拟。物理模型的实施方案,主要采用控制变量法,即通过单因素变化的方法,选取防浪林林带宽度、排列方式、密度、树型、滩地波高作为消浪影响因素,进行分组实验,模拟某一因素变化下,防浪林消浪效果的变化,确定各个影响因素对防浪林消浪效果的影响;并根据实验结果,综合一些较为复杂的影响因素,提出防浪林优化设计方案。结果实验结果表明:合理的防浪林树型条件下,30 ~ 40 m的防浪林林带宽度的消浪系数在30%以上,继续增大防浪林林带宽度,消浪系数增加并不显著。考虑到经济合理等因素,40 m的防浪林带宽度较为合理;等边三角形的排列方式的防浪林消浪效果相对较优,并且能满足更大的行株距,更适于防浪林生长的光照条件。植被密度的增加能够提高消浪系数,但当防浪林密度大于0.17株/m2时,消浪系数提高不显著,当防浪林密度采用0.17株/m2时能够充分的保证行株距,更有利于林带的生长。同时防浪林树冠部分的消浪效果最佳,并且当波高处于树冠位置时,波高越大,消浪效果越好。结论因此,在合理的树型条件下,研究区防浪林林带宽度采用40 m,排列方式为等边三角形,密度为0.17株/m2左右时为防浪林优化布局。      

San andreas fault zone head waves near parkfield, california

Microearthquake seismograms from the borehole seismic network on the San Andreas fault near Parkfield, California, provide three lines of evidence that first P arrivals are "head" waves refracted along the cross-fault material contrast. First, the travel time difference between these arrivals and secondary phases identified as direct P waves scales linearly with the source-receiver distance. Second, these arrivals have the emergent wave character associated in theory and practice with refracted head waves instead of the sharp first breaks associated with direct P arrivals. Third, the first motion polarities of the emergent arrivals are reversed from those of the direct P waves as predicted by the theory of fault zone head waves for slip on the San Andreas fault. The presence of fault zone head waves in local seismic network data may help account for scatter in earthquake locations and source mechanisms. The fault zone head waves indicate that the velocity contrast across the San Andreas fault near Parkfield is approximately 4 percent. Further studies of these waves may provide a way of assessing changes in the physical state of the fault system.     

绕组匝间绝缘测试研究

匝间绝缘测试仪在电机行业中得到了广泛的应用。分析匝间绝缘测试电路原理，用Matlab搭建仿真模型，获得电容放电波形。用LabVIEW测得正常波形和故障波形，对波形进行分析，阐明波形比较的重要性。     

细胞内钙离子形成的波形图案

目的利用包含缓冲和扩散影响的钙离子Shuai—Jung振荡模型，研究细胞内和钙库上不同的释放位置分布．方法研究细胞内钙离子振荡形成的波形结构，得到细胞内的钙波图案和细胞内一点的钙信号发放．结果细胞内的钙波信号具有各类实验出现的波形结构，细胞内固定点的钙波变化显示钙信号具有传递信使的特性．结论钙离子是细胞内重要的第二信使，其振荡传播可直接传导生理信息．