地震前氡衰变引起大气温度与湿度异常问题讨论          下载免费PDF全文

谭延亮  屈景年  肖德涛  丘寿康 《地震学报》2010,32(1):88-93

强地震前地震区域会出现卫星热红外增温异常现象,S A Pulinets提出了一种新的解释,认为是震前地表大量析出的222Rn衰变产生的高能α粒子使得空气电离,这些离子很容易吸附水蒸气分子,导致大气中潜热的释放,使得空气温度、湿度发生显著变化.本文分析了高能α粒子对空气辐射电离后的主要物理、化学作用,估算了放热和吸附水蒸气分子数量的极大值,结果表明空气温度、湿度的变化是微不足道的.由此认为,地震前出现的温度升高、湿度下降的现象可能与氡浓度变化无关.  相似文献   

背景场项目中iDirect卫星通信系统设计   总被引：1，自引：1，他引：0  

杨乐  谭颖  章静  曾薇 《地震地磁观测与研究》2015,(2):114-117

介绍背景场项目中i Direct卫星通信系统,主要从背景场项目对卫星通信的需求、系统设计、数据接入、系统应用等方面进行阐述,具体介绍卫星信系统为行业网备份的数据接入方案以及数据应用案例,可独立为国家测震台提供数据传输信道,保障测震速报业务的正常开展。  相似文献   

宁夏不同强度沙尘天气动力机制   总被引：1，自引：0，他引：1  

陈豫英  陈楠  谭志强 《中国沙漠》2015,35(2):438-447

利用常规气象观测资料和ECMWF逐6 h 0.25°×0.25°再分析资料,对宁夏2013年5月18日雷暴大风、2月28日大风沙尘和3月9日大风强沙尘天气过程的环流形势和高、低空急流的耦合作用进行了对比分析。结果表明:在“西高东低”环流形势下,受蒙新高压脊、西风槽、地面气旋和冷锋、高低空急流的共同影响,在中低层90°-110°E形成次级环流,对流层中上部高空急流和高位涡通过次级环流动量下传使中低层形成低空急流,同时在边界层发生强烈湍流混合,产生地面强风及沙尘,但由于冷空气强度及南下方式、高压脊线位置及强度、高低空急流活动的区域、低空急流南下位置、高空强风速下传的高度、次级环流的强弱不同,高层高位涡和低层850 hPa低空急流在宁夏上空活动与否,是导致宁夏出现不同强度风沙天气的重要动力因素。  相似文献   

Earthquake-related Electric Field Changes Observed in the Ionosphere and Ground     

Yingying Fan  Xuebin Du  Zhanghui An  Jun Liu  Dacheng Tan  Junying Chen 《Acta Geophysica》2015,63(3):679-697

The changes of the ionospheric electric field before and after four huge earthquakes, which include the Ms 8.7 earthquake of 2004 and the Ms 8.5 earthquake of 2005 in Sumatra of Indonesia, the Ms 8.0 Wenchuan earthquake of 2008 in China, the Ms 8.8 earthquake of 2010 in Chile, and their strong aftershocks are studied in this paper. The significant results revealed that the power spectral density of low-frequency electric field below 20 Hz in the ionosphere, a kind of electromagnetic radiation phenomena, increased abnormally before and after the earthquakes and partially corresponded to the increased power spectral density of the low-frequency geoelectric field in time. This research preliminarily indicates that the low-frequency electromagnetic radiation during the imminent stages before such earthquakes could be detected by the observation of the ionospheric electric field. However, the spatial, temporal, and intensive complexities of the electric field anomalies in the ionosphere before earthquakes have come in sight also.  相似文献   

Multi-disciplinary earthquake researches in Western Turkey: Hints to select sites to study geochemical transients associated to seismicity     

Sedat İnan  Kadriye Ertekin  Cemil Seyis  Şakir Şimşek  Furkan Kulak  Aynur Dikbaş  Onur Tan  Semih Ergintav  Rahşan Çakmak  Ahmet Yörük  Muhiddin Çergel  Hakan Yakan  Hüseyin Karakuş  Ruhi Saatçilar  Zafer Akçiğ  Yıldız İravul  Bekir Tüzel 《Acta Geophysica》2010,58(5):767-813

Warm and hot spring water as well as soil gas radon release patterns have been monitored in the Aegean Extensional Province of Western Turkey, alongside regional seismic events, providing a multi-disciplinary approach. In the study period of 20 months, seven moderate earthquakes with M _L between 4.0 and 4.7 occurred in this seismically very active region; two earthquakes with magnitude 5.0 also occurred near the study area. Seismic monitoring showed no foreshock activity. By contrast, hydro-geochemical anomalies were found prior to these seismic events, each lasting for weeks. The anomalies occurred foremost in conjunction with dip-slip events and seem to support the dilatancy and water diffusion hypothesis. Increased soil gas radon release was recorded before earthquakes associated with strike-slip faults, but no soil radon anomalies were seen before earthquakes associated with dip-slip faults. Geochemical anomalies were also noticeably absent at some springs throughout the postulated deformation zones of impending earthquakes. The reason for this discrepancy might be due to stress/strain anisotropies.  相似文献   

Removal of Cr(VI) by Zero‐valent,Iron‐encapsulated Alginate Beads     

Xue Song Wang  Yu Jun Tang  Li Fang Chen  Fei Yan Li  Wen Ya Wan  Ye Bin Tan 《洁净——土壤、空气、水》2010,38(3):263-267

Zero‐valent, iron‐encapsulated alginate beads were synthesized and were applied for the removal of Cr(VI) from aqueous solutions. The effects of several important parameters including solution pH, contact time, initial concentration and reaction temperature on Cr(VI) removal levels were investigated in batch studies. An initial solution pH of 1.0 was seen to be most favorable for Cr(VI) removal. The removal process was quick and almost 80% of the removal was attained within 60 min. The kinetic data followed the second‐order equation well. The Cr(VI) removal was almost reaction temperature‐independent and decreased with an increase in Cr(VI) initial concentration. The removal of Cr(VI) by iron‐encapsulated alginate beads was found to be significantly higher than that of non‐encapsulated alginate beads.  相似文献   

Nickel effects on growth and antioxidative enzymes activities in desert plant Zygophyllum xanthoxylon （Bunge） Maxim     

Yan Lu  XinRong Li  MingZhu He  ZhengNing Wang  HuiJuan Tan 《寒旱区科学》2010,2(5):0436-0444

One-month old Zygophyllum xanthoxylon seedlings were grown under five different Ni concentrations (0, 50, 150, 450 and 900 mg/kg). Growth parameters, tissues Ni accumulation, soluble protein content, photosynthetic pigment content, lipid peroxidation, antioxidative enzyme activities, and proline content were studied after one month of Ni exposure. The significant reduction in fresh biomass in the shoot and roots was detected at high Ni concentrations (≥450 mg/kg), whereas dry biomass was not significantly affected in both organs by any of the Ni doses tested. The Ni contents in the shoots and roots increased in a dose-dependent manner, and Ni contents in roots were higher than that in shoots at all treatments. The high Ni doses elevated soluble protein contents in leaves and roots. No visible symptoms of chlorosis were observed in leaves of plants grown in presence of Ni. Malondialdehyde (MDA) contents significantly increased in leaves and roots at high Ni treatments (≥450 mg/kg), indicating that Ni induces oxidative stress. Enzyme activities might play a central role in cellular protection against the Ni induced oxidative stress. Proline contents proportionally increased with the elevated Ni concentrations. Zygophyllum xanthoxylon revealed moderate Ni tolerance under tested culture conditions, and could be used as tools for revegetation for erosion control in moderate Ni contaminated sites.  相似文献   

Physiological responses and adjustment mechanisms of the dominate species of natural vegetation of Eastern Tengger Desert     

HaiYan Zhou  HuiJuan Tan  ZhiShan Zhang  XiaoHong Ji  HengWen Fan  JianLi Yuan 《寒旱区科学》2010,2(5):0455-0463

Reaumuria soongorica and Salsola passerina have significant differences in ecophysiological characteristics, which change with the environmental variations. Although they live together for a long period of time, their adaptive mechanisms to environmental stresses are very different. As two extreme xerophytes, Reaumuria soongorica and Salsola passerina differ significantly from other psammophytes in ecophysiological characteristics; they can survive in lower water potential, and can even grow in piedmont areas. Low water potential may be related to the existence of osmosis-regulating substance, such as praline, which can strengthen the capacity of water absorption. Compared to other psammophytes, Reaumuria soongorica and Salsola passerina have a higher degree of photo-inhibition under the same condition, and the photo-inhibition can lead to destruction of the photosynthetic pigment, nevertheless, this photo-inhibition can be repaired under suitable conditions in the morning and evening.  相似文献   

扬子地块北缘晚二叠世长兴期岩相古地理   总被引：1，自引：0，他引：1       下载免费PDF全文

牟传龙  王瑞华  谭钦银  付建元  程锦翔  王正和 《地学前缘》2011,18(4):1-8

扬子地块北缘与秦岭接壤,晚二叠世长兴期岩石地层单元为长兴组和大隆组。长兴组为一套碳酸盐岩沉积,沉积单元包括台地相、台地边缘礁滩相以及台地边缘斜坡相等;而大隆组则主要为一套灰黑至黑色薄层硅质岩、炭质页岩夹薄层泥晶灰岩,为一套较深水盆地沉积的产物。研究结果表明,这一深水盆地环境大致从西边的广元开始,向东经旺苍、南江与鄂西地区相连成为一广阔海域,扬子地块与华北地块隔海相望。这一沉积格局不仅为油气勘探工作的部署奠定了坚实的基础,而且可能反映出扬子地块与华北地块在此之前已经成为统一陆块。  相似文献   

深圳城市地面塌陷灾害特征及其成因分析     

施秋华  魏会龙  谭飞  周金文  朱江皇 《地质科技情报》2022,41(2):123-129

为了查明深圳市地面塌陷成因并提出防治措施,收集整理了深圳市2016-2020年地面塌陷灾害事故数据,通过现场调查、数据统计分析以及GIS空间分析,研究了深圳市地面塌陷灾害的时空分布、灾害危害程度以及塌陷成因等.结果表明:深圳市地面塌陷灾害正处于持续增长阶段,绝大多数属于小规模塌陷,且绝大多数发生在雨季,其中5-8月尤为...  相似文献