云体併合及雹云形成   总被引：3，自引：1，他引：3  

王昂生  赵小宁 《气象学报》1983,41(2):204-210

云体併合是冰雹云形成的重要原因之一。 文章提出了五种併合类型,给出了它们的特征和模式。最后讨论了饼合成雹云的若干条件。  相似文献   

气压变化对石英弹簧重力仪读数的影响          下载免费PDF全文

赵炜  孙大武  童欣生  李春明  张凌  朱朗宁  果有文  孟祥霞  夏岩 《地震工程学报》1983,5(3):63-70

根据我们在低压仓中对国产ZSM—Ⅲ型(简称Z)、美国Wodnre(简称W)及加拿大Scintrex CG—2型(简称C)8台重力仪进行气压实验的结果,气压变化和重力仪读数呈极好的线性关系,但每台仪器有不同的回归系数,因此在以地震预报为目的的高精度重力测量中,应该对野外观测的结果进行气压改正。用高差所建立的重力基线场的数值是否准确有进一步考虑的必要。  相似文献   

X-ray flurorescene (XRF) determination of trace rare-earth elements in geological samples using ion-exchange-resin membrane technique     

Liangyuan Feng  Ruoling Li  Yawen Zhang  Yixian Wang  Zhixin Qian  Zhenghua Zhao 《中国地球化学学报》1983,2(2):153-169

Rare-earth elements in samples of geological interest were separated from other elements and concentrated onto ion-exchange membrane through ion-exchange procedures. The membrane was then used to determine the REE by X-ray fluorescence spectrography. In comparison with the traditional “thick-specimen” approach, the requirement of sample (REE oxides) in this method was reduced from 10 to 1 mg. Variable-internal-standard-quantification method was adopted to determine the relative concentrations of REE collected on the membrane. The area density of the sample was controlled at about 0.0003 g/cm², so that the matrix effect could be eliminated to a satisfactory extent. Interference calibration between the spectro-lines and the background determination was also improved, with the detection limit reaching 2.5×10^?6g.  相似文献   

山东归来庄金矿区g(Au/Ag)的空间信息统计学特征     

肖斌  潘懋  赵鹏大  侯景儒 《地质科学》2001,36(4):500-508

空间信息统计学是一门集数学、空间信息科学及计算机技术于一体,在时空域内对区域化变量的随机性与结构性进行定量研究的技术。以山东归来庄金矿床为例,对其g(AuAg)异常进行空间信息统计学研究。利用指示克立格法研究g(AuAg)的空间变异结构特征,建立空间结构模型。在对结构模型和估计方案进行交叉验证后,对g(AuAg)的空间分布进行估计。根据g(AuAg)的空间分布规律,探讨其与Au空间分布的关系,并对今后该区的找金工作提出建议。  相似文献   

Comment on “Silicic melts produced by reaction between peridotite and infiltrating basaltic melts: ion probe data on glasses and minerals in veined xenoliths from La Palma,Canary Islands” by Wulff-Pedersen et al.     

Andreas?KlügelEmail author 《Contributions to Mineralogy and Petrology》2001,141(4):505-510

  相似文献   

Tectono-thermal modeling of the Yinggehai Basin,South China Sea   总被引：1，自引：0，他引：1  

Lijuan?HeEmail author  Liangping?Xiong  Jiyang?Wang  Jihai?Yang  Weiliang?Dong 《中国科学D辑(英文版)》2001,44(1):7-13

Based on the observed data, the average value of surface heat flow in the Yinggehai Basin is calculated and it turns out to be 84.1 mW/m². The thermal evolution of the basin since the Cenozoic era has been attempted by tectono-thermal modeling. Three-phase extension made the basin become hotter and hotter, reaching its climax in paleo-temperature history since 5.2 Ma. And nowadays, the basin is in the heat flow decreasing period. During the Cenozoic era, the basement heat flow remained at 50–70 mW/m² all the time. This is related to the degree of each extension phase, stretching rate mode and also the limited basin scale. Modeling results also show that, the surface heat flow is controlled mainly by the basement heat flow, and less than 20% comes from radiogenic heat production in the sediments of the basin  相似文献   

油气储运系统钢结构设备地震火灾效应研究   总被引：3，自引：0，他引：3  

李天祺  赵振东 《地震工程与工程振动》2005,25(6):118-121

预防和减轻油气储运系统地震火灾危险性是防震减灾中的重要课题。本文论述了油气储运系统的地震火灾特征及防火要求，对钢结构的防火涂料在遭到破坏和平时情况下的抗火性能进行了对比分析，并应用有限元法对油气储运系统中典型钢结构设备在地震火灾荷载作用下的抗火性能进行了数值模拟。研究结果表明，防火涂料遭到强地震荷载破坏后，钢结构的抗火性能大大降低。  相似文献   

The Relative Impact of Regional Scale Land Cover Change and Increasing CO2 over China   总被引：2，自引：0，他引：2  

Mei ZHAO  Andrew J. PITMAN 《大气科学进展》2005,22(1):58-68

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   

东昆仑活动断裂带东段古地震活动特征   总被引：12，自引：0，他引：12       下载免费PDF全文

李春峰  贺群禄  赵国光 《地震学报》2005,27(1):60-67

东昆仑活动断裂托索湖——玛曲以东肯定那一带， 可据阿尼玛卿玛积峰为界再分为花石峡段和玛沁段两个在几何上不连续的段落. 两段在表征断层全新世活动特征的古地震事件方面有明显差异， 花石峡段的地震活动性明显高于玛沁段的地震活动性. 古地震研究表明， 花石峡段上3次强震活动相邻两次地震发生的时间间隔分别约为500 a和640 a， 玛沁段上最近两次古地震事件间大致有1 000 a左右的时间间隔. 根据断层平均滑动速率计算的花石峡段7.5级地震的平均复发间隔为411~608 a， 相对应的同震平均水平位错约为（5.75plusmn;0.57）m. 虽然玛沁段的地震活动性较弱， 但由于该段上最近一次地震事件离现在较为久远， 已经积累的应变能应该使我们对其未来地震危险性的分析有足够重视.   相似文献   

水文时间系列周期分析方法探讨   总被引：15，自引：2，他引：15  

易淑珍  王钊 《水文》2005,25(4):26-29

以分析广东省降水周期变化规律为例，探讨了最大熵谱方法在提取水文时间系列的主次周期上以及小波变换方法在分析水文时间系列的多时间尺度演变规律上的应用。由计算结果分析得到广东省降水过程主要存在的周期特性和旱涝变化趋势，为广东省降水趋势预测提供了重要信息。  相似文献