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191.
采用统一的分析方法和标准从北天山地区的地磁场总强度资料中提取异常信息.结果表明,在区内发生的一些中强地震前,震中周围的台站存在较明显的中、短期异常. 相似文献
192.
本文描述了11个铀酰矿物加热后的显微荧光特征,并对实验结果进行了初步探讨。随着温度的升高,其相对荧光强度均有不同程度的衰减直至猝灭,但衰减的速度和猝灭的温度是各不相同的。热至200℃时测量的荧光光谱和常温下的荧光光谱相比,不同矿物变化也各不相同。本文根据实验结果绘制了荧光和温度关系曲线及加热至200℃时的荧光光谱曲线。这种荧光变化可能与加热后矿物失水和晶体结构变化有关。对鉴定铀酰矿物具有重要的意义。 相似文献
193.
The change in atmospheric relative humidity affects the physical and optical properties of aerosol particles. It would be
interesting to study the effect of an increase in relative humidity on the angular scattering of light by aerosols (by incorporating
the changes due to it as the complex refractive index and the parameters of the size distribution function). In the present
paper we have computed the angular scattering function for rural and urban aerosols, for light of wavelength 0.55 μn. The
results obtained for these two models, representative of different environments, are interesting and show some discriminating
features. 相似文献
194.
Survey Group of Wuzhai Earthquake 《山西地震》1995,(2):42-47
本文介绍了对1993的9月11日五寨4.8ML地震的考察情况,确定宏观震中在五寨县丰兑坡与河曲县土沟村一带,震中烈度为6度。计算得出本次地震的总经济损失约15万元。 相似文献
195.
北半球4月份500hPa月平均场遥相关型及其与我国降水异常的关系 总被引:5,自引:2,他引:5
用一点相关法计算了春季4月份北半球500hPa遥相关型,得出4月存在5个遥相关型。它们的中心位置与冬季相比已有了较大的改变。计算了1951 ̄1990年各遥相关型的逐年强度指数。研究了它们的年际变化,指出4月的西太平洋型(WP)、欧亚型(EU)的强、弱是我国4月份大范围旱涝的主要原因。 相似文献
196.
冬季青藏高原对东移大槽动力影响的研究:Ⅲ.模拟试验结果的分析 总被引:3,自引:3,他引:3
具体分析了本文Ⅱ的模拟试验结果。结果表明,该试验较清楚地再现了青藏高原地形对西风气流的影响,也显示了不同地形、急流的有无、强度和位置以及初始槽强度和基本气流斜压性的强度对东移槽的影响。这些结果有的清楚地再现了过去熟知的或还不很清楚的地形影响事实,有的可为东移槽的预报提供着眼点。 相似文献
197.
D. Albarello A. Berardi C. Margottini M. Mucciarelli 《Pure and Applied Geophysics》1995,145(2):297-312
A multi-parametric study of empirical relationships between macroseismic data and magnitude is presented for the Italian region by the analysis of a new extended data set concerning 146 earthquakes. The available magnitude determinations include all of the most intense earthquakes which occurred in Italy in the last century and have been obtained by an accurate revision of original instrumental data. Intensity data have been revised and upgraded on the basis of the most recent studies: only local intensities directly documented have been used. Macroseismic determinations ofM
s
,m
B
andM
wa
magnitudes have been performed. The empirical relationships between maximum felt intensity (I
max
) and magnitude have been determined by the use of a distribution-free approach and a linear regression analysis. This last parameterization allows for the explanation of more than 60% of the variation in magnitude. In order to improve these results, the linear dependence between magnitude,I
max
and average distances (in logarithm) corresponding to fixed attenuation values has been explored. The comparison between instrumental magnitudes and corresponding macroseismic estimates obtained from empirical relationships shows that the respective uncertainties are comparable. 相似文献
198.
In this paper,we use a two-dimensional primary equation model which contains (1) heating ofradiation,(2) heating of condensation,and (3) transfers of sensible and latent heat between air andthe underlying surface.To investigate the causes for the formation of the eastern North Pacific sum-mer monsoon,the data at 110°W are obtained and winds at underlying surface and at 200 hPa aremodified under the conditions (1) removing topography and (2) changing meridional sea surface tem-perature (SST) gradient.In the numerical modification,we find that by removing the topography,the center's location ofthe eastern North Pacific summer monsoon does not change,but the intensity of the summer monsoonis weakened.Also the onset of the summer monsoon is delayed to the end of May.The tropical east-erly jet is weakened obviously,even changes to westerly wind.On the other hand,we find that theSST gradient along 110°W influences the eastern North Pacific summer monsoon distinctly.If theSST gradient is decreased,the center of the southwest wind near 12°N does not exist any more.theintensity of the whole summer monsoon becomes very weak and the circulation pattern of the summermonsoon also changes a lot.Finally,we indicate that both topography and meridional SST gradient play important roles inthe occurrence of the eastern North Pacific summer monsoon.The meridional SST gradient is themost important factor that triggers the summer monsoon and the topography along 110°W influencesthe intensity and the onset time of the summer monsoon there mostly. 相似文献
199.
200.
The Relative Impact of Regional Scale Land Cover Change and Increasing CO2 over China 总被引:2,自引:0,他引:2
A series of 17-yr equilibrium simulations using the NCAR CCM3 (T42 resolution) were performed to investigate the regional scale impacts of land cover change and increasing CO2 over China. Simulations with natural and current land cover at CO2 levels of 280,355, 430, and 505 ppmv were conducted. Results show statistically significant changes in major climate fields (e.g. temperature and surface wind speed) on a 15-yr average following land cover change. We also found increases in the maximum temperature and in the diurnal temperature range due to land cover change. Increases in CO2 affect both the maximum and minimum temperature so that changes in the diurnal range are small. Both land cover change and CO2 change also impact the frequency distribution of precipitation with increasing CO2 tending to lead to more intense precipitation and land cover change leading to less intense precipitation-indeed, the impact of land cover change typically had the opposite effect versus the impacts of CO2. Our results provide support for the inclusion of future land cover change scenarios in long-term transitory climate inodelling experiments of the 21st Century. Our results also support the inclusion of land surface models that can represent future land cover changes resulting from an ecological response to natural climate variability or increasing CO2. Overall, we show that land cover change can have a significant impact on the regional scale climate of China, and that regionally, this impact is of a similar magnitude to increases in CO2 of up to about 430 ppmv. This means that that the impact of land cover change must be accounted for in detection and attribution studies over China. 相似文献