气象卫星条件植被指数监测土壤状况

本文介绍用1985-1991年NOAA卫星标准化植被指数(NDVI)资料进行处理生成的条件植被指数(VCI),研究我国土壤的湿度状况,并阐述了应用VCI,结合常规资料进行综合分析,监测由于干旱或大范围洪涝所造成的宏观植被状况变化的情况。研究结果表明,用气象卫星资料可以对我国的干旱、洪涝状况进行宏观动态监测。     

鄂尔多斯高原及周边地区地面温度的计算研究

采用一种分裂窗方法，利用ＮＯＡＡ－ＡＶＨＲＲ资料计算了鄂尔多斯高原及周边地区的地面温度。用３、４、５通道的数据计算地面发射率，其以发射率和４、５通道亮温结合计算地面温度。通过与当地气象站接近时次的实测资料相比，夜间计算差值在±１℃以内的占８０％，白天占６７％，最大差值－３．８℃。作为一种宏观地表监测手段，该方法是可行的。     

沙尘暴同一化监测模型与灾害评估研究

阐述了将GIS/RS(地理信息系统/遥感)一体化技术应用在沙尘暴灾害的监测与评估工作中的方法,提出利用不同遥感数据源建立同一化的沙尘暴监测模型的方法,将沙尘暴监测由定性研究转变为定量特征参数计算.引入GIS技术建立了可业务使用的沙尘灾害评估模型,通过对下垫面数据的集成与叠合分析,可以快速、机动、准确、可靠和多层次进行沙尘暴的灾后评估.     

Characterization of organic matter in sediment cores of the Todos os Santos Bay, Bahia, Brazil, by elemental analysis and 13C NMR

The impact of human activity on the sediments of Todos os Santos Bay in Brazil was evaluated by elemental analysis and ¹³C Nuclear Magnetic Resonance (¹³C NMR). This article reports a study of six sediment cores collected at different depths and regions of Todos os Santos Bay. The elemental profiles of cores collected on the eastern side of Frades Island suggest an abrupt change in the sedimentation regime. Autoregressive Integrated Moving Average (ARIMA) analysis corroborates this result. The range of depths of the cores corresponds to about 50 years ago, coinciding with the implantation of major onshore industrial projects in the region. Principal Component Analysis of the ¹³C NMR spectra clearly differentiates sediment samples closer to the Subaé estuary, which have high contents of terrestrial organic matter, from those closer to a local oil refinery. The results presented in this article illustrate several important aspects of environmental impact of human activity on this bay.     

2000年春季沙尘天气的监测、评估与对策

前　言2 0 0 0年入春以来 ,我国北方地区天气晴朗 ,光照充足 ,气温偏高 ,而且冷空气活动活跃 ,造成十分频繁和强烈的大风天气。特别是 3～ 4月 ,大风引发了 1 0余次不同强度的沙尘天气 ,严重影响到北京、天津等地的正常社会生活和环境质量 ,引起了党中央、国务院、全国人大和广大群众的高度重视 ,我们向国务院有关部门提供上百份沙尘暴监测和分析材料 ,为决策服务提供了依据。本文介绍了利用气象卫星对主要沙尘过程的监测、影响北京的沙尘路径分析及影响评估情况 ,最后提供了减轻沙尘过程的危害对策。1　 2 0 0 0年主要沙尘过程的卫星监测1 …     

Bacterial mineralization patterns in basaltic aquifers: implications for possible life in martian meteorite ALH84001

To explore the formation and preservation of biogenic features in igneous rocks, we have examined the organisms in experimental basaltic microcosms using scanning and transmission electron microscopy. Four types of microorganisms were recognized on the basis of size, morphology, and chemical composition. Some of the organisms mineralized rapidly, whereas others show no evidence of mineralization. Many mineralized cells are hollow and do not contain evidence of microstructure. Filaments, either attached or no longer attached to organisms, are common. Unattached filaments are mineralized and are most likely bacterial appendages (e.g., prosthecae). Features similar in size and morphology to unattached, mineralized filaments are recognized in martian meteorite ALH84001.