A Database for Volatile Organic Compounds     

K. Mannschreck  K. Bächmann  K. H. Becker  Th. Heil  R. Kurtenbach  M. Memmesheimer  V. Mohnen  A. Obermeier  D. Poppe  R. Steinbrecher  Th. Schmitz  A. Volz-Thomas  F. Zabel 《Journal of Atmospheric Chemistry》2002,42(1):281-286

The database for volatile organic compounds (VOC data base) was created with the aim of providing an overview of tropospheric hydrocarbon measurements. The data base contains 202 substances, for which atmospheric and useful kinetic data such as rate coefficients, photolysis frequencies, mixing ratios, emission data and ozone formation potentials are compiled from available literature. The database file can be downloaded without charge from http://www.physchem.uni-wuppertal.de/voc-database. Registered users will be informed about the appearance of updates.  相似文献   

Short-Term Ozone Forecasting with a Network Model System during Summer 1999     

Hermann J. Jakobs  Stefan Tilmes  Andre Heidegger  Klaus Nester  Gerhard Smiatek 《Journal of Atmospheric Chemistry》2002,42(1):23-40

Within the framework of the Tropospheric Research Programme (TFS) four working groups in Germany (University of Stuttgart, University of Cologne, Research Center Karlsruhe, German Weather Service) formed a network developing a model system for chemistry transport calculations on different scales. The network was optimized, based on each module and combined for the different interfaces in order to perform daily preoperational ozone forecasts and its precursors at the German Weather Service in summer 1999 (May through September). The setup of the model system, the interfaces and changes of each module are described. The results of the whole preoperational episode are displayed and discussed. Main efforts were done analyzing the model climate statistics and the verification of the predictions with an extensive data base of observations at stations in Germany. The results of this extensive verification demonstrate the relatively good performance of the entire forecast system.  相似文献   

On the Measurement of PANs by Gas Chromatography and Electron Capture Detection     

Frank?M.?FlockeEmail author  Andrew?J.?Weinheimer  Aaron?L.?Swanson  James?M.?Roberts  Rainer?Schmitt  Stephen?Shertz 《Journal of Atmospheric Chemistry》2005,52(1):19-43

A fast, automated, gas chromatographic system for the airborne measurement of PAN and a series of its homologues is described and its performance is evaluated. Response factors for PAN, PPN, APAN, PiBN, and MPAN have been determined and are discussed with regard to ECD response and to potential losses in the analytical system. Calibration methods used for these tasks are described and compared. The results from this work should help investigators who are employing the widely used GC/ECD method for the measurement of peroxyacyl nitrates to evaluate peaks of PAN homologues that cannot be calibrated for by using the reported response factors.  相似文献   

Oscillations of optical emission from flare stars and coronal loop diagnostics     

A. V. Stepanov  Yu. G. Kopylova  Yu. T. Tsap  E. G. Kupriyanova 《Astronomy Letters》2005,31(9):612-619

Based on an analogy between stellar and solar flares, we investigate the ten-second oscillations detected in the U and B bands on the star EV Lac. The emission pulsations are associated with fast magnetoacoustic oscillations in coronal loops. We have estimated the magnetic field, B ≈ 320 G; the temperature, T ≈ 3.7 × 10⁷ K; and the plasma density, n ≈ 1.6 × 10¹¹ cm^?3, in the region of energy release. We provide evidence suggesting that the optical emission source is localized at the loop footpoints.  相似文献   

Uranium Isotopes, Metals and Other Elements in Lichens and Tree Barks Collected in Bosnia–Herzegovina     

S. Rosamilia  S. Gaudino  U. Sansone  M. Belli  Z. Jeran  S. Ruisi  L. Zucconi 《Journal of Atmospheric Chemistry》2004,49(1-3):447-460

The United Nations Environment Programme (UNEP) performed field surveys at 15 sites in Bosnia–Herzegovina where depleted uranium (DU) ammunition was used by the North Atlantic Treaty Organization (NATO) during the Balkans conflict (1994–1995). During the field missions, the Italian Environmental Protection Agency (APAT) evaluated airborne contamination due to DU dusts or aerosol particles, generated at the time of the conflict by the impact of DU ammunition on hard targets, using lichens and tree barks as biomonitors. Each sample was analyzed by alpha-spectrometry for DU determination. The ²³⁴U/²³⁸U activity concentration ratios were used to distinguish natural from anthropogenic uranium. This paper reports the data obtained by the UNEP investigation, including (non-radioactive) metal and other element concentrations in lichen and tree bark samples measured by instrumental neutron activation analysis (INAA). The results indicated: (i) lichens and tree barks are sensitive bio-accumulators of past airborne contamination by depleted uranium dusts; (ii) 8 years after the conflict, environmental DU contamination is still present at some of the target sites; and (iii) the highest concentrations of most non-radioactive elements were found at sites used for ammunition destruction.  相似文献   

西部特殊景观区钻探取样技术展示     

王达 《探矿工程》2005,32(1):1-5

针对西部特殊景观区海拔高、地势险峻、地形地质条件复杂、自然条件恶劣、地理位置偏远、交通不便等问题，我国科研人员经过多年努力，开发并完善了一批适合于特殊景观区的钻探技术——空气组合钻探技术、水文水井泡沫增压钻探技术、复杂地层钻探取样新技术、液动潜孔锤钻进技术、特殊地层取样钻机及钻探工艺、节水钻探新技术、新疆吐鲁番铀矿勘探及罗布泊环境科学钻探用取样工艺、西部特殊景观区资源勘查及重大建设工程中地质灾害监测和防治新技术、存储式多点连续测斜仪等，介绍了各项新技术的原理、研究进展及取得的成果。  相似文献   

大口径瓦斯地质孔钻探技术          下载免费PDF全文

马沈岐  刘凤琴  张艳菊 《探矿工程》2005,32(11):44-47

运用非平衡钻探工艺理论，对煤矿瓦斯地层进行大口径钻孔的钻探，使目标层富集的高压瓦斯经抽放后得到释压，确保煤矿安全生产。在针对小构造带形成的角砾岩、松散煤层、不稳定地层等瓦斯地质条件下，采用中压风作为冲洗介质进行钻探中所存在的问题，重新设计了新型的钻具级配、正反向一体化钻头等，并且对风介质的排渣机理进行了阐述和分析。同时，就实践中遇到的问题和解决方法进行了总结。  相似文献   

地面加热对飞机颠簸影响的动力学初步分析   总被引：2，自引：0，他引：2  

邹波 《南京气象学院学报》2004,27(4):527-531

用积分变换法求解考虑了地面加热作用的中尺度二维不可压缩流体的Boussinesq方程，得到一组描述地面加热作用激发的垂直风场、水平扰动风场、扰动气温场的解析解，进而用动力学分析的观点定性讨论了飞机颠簸与地面加热场、风场、温度场空间分布及时间变化的关系，对动力和热力性气象因子对于飞机颠簸的影响进行了初步分析。  相似文献   

潍坊市区近10年空气质量与气象条件的关系   总被引：15，自引：0，他引：15  

山义昌  徐太安  王善芳  徐文正  曲廉峰 《气象》2004,30(10):47-51

运用潍坊市环境监测中心站 1 993～ 2 0 0 2年的潍坊市区空气质量逐日监测资料与潍坊市气象局气象观测资料 ,分析了 1 0年间潍坊市区空气质量的时空特征、变化趋势及与气象条件的关系。结果表明 ,在影响潍坊市区空气质量的主要三种污染物———二氧化硫 (SO2 )、氮氧化物 (NOX)和总悬浮颗粒 (TSP)中总悬浮颗粒是首要污染物 ;三种污染物随季节的分布规律是 :冬半年 ( 1 1～ 4月 )偏多 ,夏半年 ( 5～ 1 0月 )偏少 ;三种污染物的变化趋势是随年代减少 ,年减少率SO2 为 0 0 0 54mg·m- 3,NOX 为0 0 0 1 6mg·m- 3,TSP为 0 0 0 6 2mg·m- 3。按国家标准分级 ,空气质量 3级以上 (API>1 0 0 )的日数占 33 5% ,年递减率为 5 96天。针对市区空气质量特征又重点分析了混合层高度、雾与其它天气现象 (烟尘、浮尘、扬沙 )与空气污染的关系。  相似文献   

气温数据栅格化中的几个具体问题   总被引：22，自引：3，他引：22  

廖顺宝  李泽辉 《气象科技》2004,32(5):352-356

用地理信息系统软件ARC／INFO及4种空间插值方法，对中国617个气象站30年平均气温数据和1961年平均气温数据的栅格化试验发现，克立格插值方法的精度最高，反距离权重法次之，样条插值法的精度第三，趋势面插值方法的精度最低。利用多年平均气温数据和年平均气温的距平值进行气温数据的栅格化，虽然可以减少分析和计算量，但栅格化结果的精度比利用年平均气温数据直接进行栅格化的精度要低。气象站的实际高程与气象站经纬度对应的数字高程(DEM)上的高程不完全一致，但气温数据的栅格化完全依赖于DEM，用气象站实际高程建模进行气温数据栅格化的精度比用与气象站经纬度对应的DEM上的高程建模进行气温数据栅格化的精度要高。  相似文献