CYP1A mRNA expression in redeye mullets (Liza haematocheila) from Bohai Bay, China     

An L  Hu J  Yang M  Zheng B  Wei A  Shang J  Zhao X 《Marine pollution bulletin》2011,62(4):718-725

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Novel integrated system calibration method for impulse ground penetrating radar     

Chunlin Huang Min Lu  Shiping Zhu 《Journal of Applied Geophysics》2011,75(3):565-572

This paper proposes a new method of integrated system calibration that uses the transmitting and receiving signals from the impulse ground penetrating radar itself. In order to eliminate the influence from each subsystem or part including antenna, transmitter, receiver, signal processing circuits and transmission cables, two new calibration parameters that are different from the conventional S-parameters are introduced. The characteristic and influence of all parts in the transmitting and receiving channels are incorporated into the calibration equation through the new parameters. The calibration results of the radar detection data show that the new integrated system calibration can improve the quality of the data greatly in many aspects. It removes direct coupled waves, suppresses wave distortion and tail oscillation, and improves the quality of waveform and signal-clutter-ratios. It also compresses the pulse width and enhances resolution.  相似文献   

基于等效单自由度体系的结构地震输入能量的研究     

杜敏  林玮  郭晓云 《地震工程与工程振动》2011,31(3):77-82

通过对多自由度体系结构在地震作用下的能量分析,考虑地震动因素和结构自身特性,提出一种框架结构地震总输入能量的简化求解方法.实例计算结果表明:基于等效单自由度体系来估计多自由度体系的地震总输入能,是一种计算简便且较为准确的方法.  相似文献   

地面高精度磁测在蒙古13451矿区地质填图中的应用     

郭志华  张宝林  祁民  贾文臣  沈晓丽  黄雪飞 《地球物理学进展》2011,26(5):1802-1811

研究区内岩石物性差异明显,为进行高精度磁测提供了可靠的地球物理依据.本次工作利用Hc-95型手持式氦(4 He)光泵磁力仪在13451矿区进行了高精度磁法扫面,在划定岩性界线的同时,还识别出了隐伏的中基性火山岩.通过磁法资料的延拓处理,指出了重要的构造边界.磁法数据与地质填图的完美耦合,不仅使物探方法更好地为覆盖区地质...  相似文献   

约束优化的微分进化算法在波动方程反问题中的应用     

闵涛  张敏  李浩 《地球物理学进展》2011,26(3):1052-1056

本文提出了一种约束优化的微分进化算法,该算法使得种群在演化过程中能保持较好的多样性,且参数设置简单,不容易陷入局部最优,并能在较短时间内找到约束优化问题的最优解.结合有限元法对波动方程反问题进行研究,在对一维及二维波动方程反问题的数值模拟中都得到了较好的结果,表明了该算法具有较好的稳定性和较强的抗噪能力.  相似文献   

Research on seismic performance of shear walls with concrete filled steel tube columns and concealed steel trusses   总被引：1，自引：1，他引：0  

Wanlin Cao  Jianwei Zhang  Hongying Dong  Min Wang 《地震工程与工程振动(英文版)》2011,10(4):535-546

In order to further improve the seismic performance of RC shear walls, a new composite shear wall with concrete filled steel tube (CFT) columns and concealed steel trusses is proposed. This new shear wall is a double composite shear wall; the first composite being the use of three different force systems, CFT, steel truss and shear wall, and the second the use of two different materials, steel and concrete. Three 1/5 scaled experimental specimens: a traditional RC shear wall, a shear wall with CFT columns, and a shear wall with CFT columns and concealed steel trusses, were tested under cyclic loading and the seismic performance indices of the shear walls were comparatively analyzed. Based on the data from these experiments, a thorough elastic-plastic finite element analysis and parametric analysis of the new shear walls were carried out using ABAQUS software. The finite element results of deformation, stress distribution, and the evolution of cracks in each phase were compared with the experimental results and showed good agreement. A mechanical model was also established for calculating the load-carrying capacity of the new composite shear walls. The results show that this new type of shear wall has improved seismic performance over the other two types of shear walls tested.  相似文献   

天气形势影响对流层顶高度分析     

刘敏  薛小宁 《陕西气象》2011,(1):7-10

针对寒潮、梅雨锋个例采用全国120个探空站2000—2007年探空资料,根据对流层顶的热力学定义计算对应的天气形势下各站点的对流层顶高度,利用一元线性回归等统计学方法分析不同天气系统控制下的对流层顶高度的变化规律。结果表明:寒潮爆发,对流层顶高度下降,850、700、500 hPa 3层平均温度每下降1oC,对流层顶高度下降2.486 m,位相差为-6.85 m,温度改变对对流层顶改变量的方差贡献率达56.36%,冷高压系统造成控制区气流下沉、对流层顶高度下降。梅雨锋形成期间和暴雨前期,对流层内以上升运动为主,对流层顶高度上升;暴雨结束,对流层顶高度较暴雨前上升30~50 m,幅度与天气形势有关。  相似文献   

2011年4月江西降水异常偏少的初步诊断分析   总被引：1，自引：0，他引：1  

马锋敏  张超美  张传江  廖敏 《气象与减灾研究》2011,(4):16-22

利用1959-2011年北半球500 hPa高度格点资料、74项环流特征量资料和1974-2011年NOAA OLR月平均资料,结合江西83个气象观测站的1959-2011年4月降水资料,对2011年4月江西降水异常偏少成因进行了初步诊断分析.结果表明:江西省4月降水有一定的周期性,2011年4月降水处于少雨期;La ...  相似文献   

正压准平衡海洋模型及其解Ⅱ:中纬度自由涡旋波动   总被引：3，自引：1，他引：2  

路凯程  张永垂  张铭 《气象科学》2011,31(1):17-23

本文研究了正压准平衡海洋模型中的自由涡旋波.得到的主要结论有:该模型中的解为波包,其载频都是西传的.在仅考虑大洋西海岸时其载频频率是连续谱;而同时考虑大洋东、西海岸时则其为离散谱;且均有其载频频率越高(周期越短)其水平尺度越大的特点,对过分低频的波动,则会使准平衡的假定不再适用.模型中波包载频的周期约在26 d至24 ...  相似文献   

Assessment of probability multimodel seasonal forecast based on the APCC model data     

A. Yu. Bundel  V. N. Kryzhov  Young-Mi Min  V. M. Khan  R. M. Vilfand  V. A. Tishchenko 《Russian Meteorology and Hydrology》2011,36(3):145-154

The probability multimodel forecast system based on the Asia-Pacific Economic Cooperation Climate Center (APCC) model data is verified. The winter and summer seasonal mean fields T ₈₅₀ and precipitation seasonal totals are estimated. To combine the models into a multimodel ensemble, the probability forecast is calculated for each of single models first, and then these forecasts are combined using the total probability formula. It is shown that the multimodel forecast is considerably more skilful than the single-model forecasts. The forecast quality is higher in the tropics compared to the mid- and high latitudes. The multimodel ensemble temperature forecasts outperform the random and climate forecasts for Northern Eurasia in the above- and below-normal categories. Precipitation forecast is less successful. For winter, the combination of single-model ensembles provides the precipitation forecast skill exceeding that of the random forecast for both Northern Eurasia and European Russia.  相似文献