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61.
厦门连续性暴雨天气气候特征   总被引:1,自引:0,他引:1  
1956~2002年厦门降水资料和相应天气图资料分析结果表明:厦门连续性暴雨天气过程主要产生在台风季和雨季;雨季间连续性暴雨环流背景是500hPa的阻塞形势,分单阻和双阻两型,850hPa形势特征则表现为低涡切变偏南和低空西南急流两型;台风连续性暴雨的台风路径主要有台湾类和南海类两类,所对应的主要登陆地段分别是厦门至福清和厦门至珠江口,500hPa环流形态有台风倒槽、台风后部、槽台迎近和北槽南台4类。  相似文献   
62.
本文通过泉州地磁台重建工程中的工作实践 ,阐述了G85 6磁力仪在建筑材料磁性检测、施工过程中磁性跟踪监测的应用与实践。  相似文献   
63.
Construction of access tracks in national parks and other reserves in the south-west of Western Australia is an essential feature of park management. However, their construction was often carried out with little or no appreciation of soil and slope characteristics and potential erodibility, or the effect of slope and stream sedimentation on terrestrial and aquatic flora and fauna. This paper reports on the findings of a study carried out in Kalamunda National Park, a small reserve in the Darling Ranges east of Perth. Tracks were surveyed and the extent of erosion and sedimentation measured. Erosion-indicating and erosion-influencing variables were measured. Track alignment angle (to the contour) and track gradient were the two site variables most significantly correlated with measures of erosion severity. The most important upslope (on-track) factor was track length, and the most important upslope (off-track) factor was the abundance of granite outcrops. Seasonal conditions were important, particularly in relation to soils with relatively high clay contents. When wet, these soils were more likely to suffer from surface drainage problems and increased runoff, associated with decreased cohesion. On the other hand, the more common sand-textured soils are generally more erodible when wet. Several management measures are recommended. These fall into three categories: those relating to track closure or realignment (to avoid the most erosion-susceptible sites); those relating to actual track design and maintenance, or site management; and those relating to modification of visitor behaviour .  相似文献   
64.
A Bogus Typhoon Scheme and Its Application to a Movable Nested Mesh Model   总被引:1,自引:0,他引:1  
ABogusTyphoonSchemeandItsApplicationtoaMovableNestedMeshModelWangGuomin(王国民)(DepartmentofAtmosphericSciences,NamingUniversity...  相似文献   
65.
热带气旋路径强度预报——SAPC法   总被引:6,自引:1,他引:6       下载免费PDF全文
SAPC——逐段相似气候持续性热带气旋路径、强度预报方法,既考虑了热带气旋的气候持续性规律,又考虑了与现时热带气旋状态特别相似的历史热带气旋路径、强度变化规律,用不同的相似条件和权重,把气候路径、相似路径和持续性路径作了有机的统一。该方法克服了预报路径的大曲率变化,考虑了随时间、地点变化的热带气旋的气候规律,根据热带气旋的现时状态,即可随时制作路径、强度预报。历史资料和实际应用表明该方法有实用价值。  相似文献   
66.
热带气旋路径的模糊概率预报   总被引:5,自引:1,他引:4  
根据南海及其附近区域热带气旋路径左、右折突变与持续稳定的类型预报判据,应用模糊数学原理,建立了路径变化类型模糊概率预报方法,此方法具有48小时的预报时效和预报路径突变或稳定的性能,还能给出预报轨迹的模糊概率,便于预报决策使用。业务试验表明,该方法操作简便、显示直观、客观定量、结论明确、效果良好。特别是当模糊概率大于70%时,方向误差和48小时平均距离误差都明显小于国内、凶各主要预报台相应时次综合预  相似文献   
67.
The paper proposes an alternative approach to dispersion curves to analyse resonant phenomena in the context of wave propagation induced by a harmonic load moving over a railway track coupled to a multilayered poroviscoelastic medium. It consists of a shading representation of the spectral response in the frequency–wavenumber domain. Unlike the usual dispersion curves, it can take into account both the damping and the coupled system. Specific attention is paid to the first mode contribution. Critical ranges are determined from this shading representation: (i) for the load frequency when the load moves at a fixed constant speed, and (ii) for the load speed when the load frequency is constant. Both sub-Rayleigh and super-Rayleigh regimes are studied.  相似文献   
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