一种非对称台风Bogus方法的数值模拟应用

前人研究中BDA方法采用的轴对称Bogus台风不能反映个别台风具体特征,也弃掉了背景场的合理成分,有必要改用更精细的非对称台风Bogus模型对BDA方案做出改进。因此,提出一种充分融合分析场信息和实际观测信息并考虑副高影响的非对称台风Bogus方法,针对0613、0704台风个例,通过4DVAR技术,利用MM5模式及其伴随模式对此Bogus资料进行BDA同化试验和模拟预报,数值结果表明:BDA方法同化非对称台风Bogus模型,其路径预报效果优于同化轴对称台风模型,同化两种Bogus资料都使台风强度模拟效果得到极大改善,但改善程度相当,故台风的非对称结构及副高等外围环境场及背景场弱台风中合理信息对台风的准确模拟起到关键作用,同时,Bogus资料同化方法用于远洋上的台风时,需注意台风模型与副高的配置关系。     

CG-5重力仪零漂特性现况分析

为研究CG-5相对重力仪目前的零点漂移特性,为数据处理提供依据,拟基于河北省流动重力测区2019年2期资料及测试数据资料,对2台重力仪进行零点漂移的相关计算及分析.结果表明:①两台CG-5重力仪静态观测数据均呈现良好的线性零点漂移特性;②重力仪在静态、动态以及混合零漂分析中得到的零漂率数据平均值接近,仪器依然具有较好的...     

镉暴露对文蛤和四角蛤蜊血细胞功能及DNA损伤影响

为研究镉暴露对文蛤和四角蛤蜊血细胞功能及DNA损伤水平的影响,在实验室条件下将文蛤和四角蛤蜊暴露于镉离子浓度分别为0.05 mg·L-1、0.10 mg·L-1和0.25 mg·L-1的海水中,用流式细胞仪测定两者血细胞的死亡率和活性氧含量,用溶酶体荧光探针和碱解旋法测定其溶酶体含量和DNA损伤.结果显示,在0.05 ...     

应用线性合成概率方法探讨青藏高原北部地区强震趋势

基于周期谱分析基础上的线性合成概率预测方法,对青藏高原北部地区Ms≥7.0、Ms≥6.5强震进行了试验性研究,并利用其结果作为预测依据,对青藏高原北部地区强震趋势做了初步估计.利用该方法,本文还对东昆仑断裂带1900年以来的Ms≥7.0强震进行了研究.     

Loss of energy dissipation capacity from the deadzone in linear and nonlinear viscous damping devices

In a viscous damping device under cyclic loading, after the piston reaches a peak stroke, the reserve movement that follows may sometimes experience a short period of delayed or significantly reduced device force output. A similar delay or reduced device force output may also occur at the damper’s initial stroke as it moves away from its neutral position. This phenomenon is referred to as the effect of “deadzone”. The deadzone can cause a loss of energy dissipation capacity and less efficient vibration control. It is prominent in small amplitude vibrations. Although there are many potential causes of deadzone such as environmental factors, construction, material aging, and manufacture quality, in this paper, its general effect in linear and nonlinear viscous damping devices is analyzed. Based on classical dynamics and damping theory, a simple model is developed to capture the effect of deadzone in terms of the loss of energy dissipation capacity. The model provides several methods to estimate the loss of energy dissipation within the deadzone in linear and sublinear viscous fluid dampers. An empirical equation of loss of energy dissipation capacity versus deadzone size is formulated, and the equivalent reduction of effective damping in SDOF systems has been obtained. A laboratory experimental evaluation is carried out to verify the effect of deadzone and its numerical approximation. Based on the analysis, a modification is suggested to the corresponding formulas in FEMA 356 for calculation of equivalent damping if a deadzone is to be considered.     

Estimation of peak relative velocity and peak absolute acceleration of linear SDOF systems

In the seismic analysis and design of structures, the true velocity and absolute acceleration are usually approximated by their corresponding pseudo-values. This approach is simple and works well for structures with small damping (say, less than 15%). When the damping of a structure is enhanced for the purpose of response reduction, it may result in large analysis and design errors. Based on theory of random vibration and the established mechanism of seismic response spectra analysis, a method is developed (1) to predict the relative velocity spectra with any damping ratio level directly from the 5% standard pseudo-acceleration spectrum; and (2) to estimate the peak absolute acceleration. The accuracy of both is validated by using two selected ensembles of ground motion records.     

基于ZigBee的四线制PT100温度传感器采集节点设计

文章以STM32芯片为核心处理器,设计了一种基于ZigBee无线网络传输的温度采集节点,该模块采用气象业务中使用的PT100温度传感器进行温度检测,通过ZigBee网络进行数据传输,多个节点通过ZigBee网络组网实现固定区域的多点温度检测。经试验比对,表明该节点的检测最大误差小于0.2℃。     

2001年四川雅江MS 6.0地震前地脉动参数异常变化

<正>1研究背景冯德益等（1994）研究发现,在中强地震发生前后地震波参数和地脉动参数都会有各种异常形态出现,且短周期地脉动参数异常可用于地震短期预报。李志雄等（2008）编制了海南数字地脉动参数处理系统,系统自动计算2005—2007年海南地震台网各个台站的地脉动参数,发现在海南及邻区显著地震前和地震活动活跃时,地脉动参数有一定异常变化。2研究内容和方法研究主要采用地脉动运动学参数,如地脉动的视出射角、方位角、时间线性度、空间线性度、频谱参数等,其中频谱参数包含卓越频率或顶峰频率、最大谱值、最大频率、最小谱值、高频衰减系数等,上述各种地脉动参数的定义详见参考文献。     

The REM Adjoint System and Its 4DVar Data Assimilation Experiments

The Regional Eta-coordinate Model(REM) has performed well in forecasting heavy rainfalls in China in recent years.A four-dimensional variational assimilation system(4DVar) is developed to improve the forecast skill of the REM.The tangent linear model and adjoint model codes are written according to thecode to coderule,and the establishment of the REM adjoint modeling system is introduced in detail in this paper.The tangent linear and adjoint models of the REM are validated against the observational data,...