基于Landsat时间序列遥感数据的华北平原农田火烧迹地检测与制图

以河南省漯河市、周口市和驻马店市交界处为研究区,基于2000年10月~2011年12月间的101幅图像,采用谐波模型和断点识别算法拟合Landsat时间序列实现对过火像元的检测,并将结果与目视解译结果、MODIS火烧迹地产品MCD64A1检测结果对比进行精度分析。结果表明：① 随着燃烧面积指数BAI (Burned Area Index)异常值阈值增大,焚烧火点误判误差减小,漏判误差增大,火烧迹地制图的总体精度先增大后减小;② 当BAI异常值阈值2.9×RMSE（Root Mean Square Error）时,该方法总体精度达到最高93.25%,MCD64A1产品总体精度为70.25%;③ 本文算法的漏判误差和误判误差相对平衡,而MCD64A1产品的漏判误差远大于误判误差。研究表明,相比MODIS火烧迹地产品数据,Landsat时间序列火烧迹地法可更有效地检测农田火烧迹地。     

粘土沙障及麦草沙障合理间距的调查研究

确定机械沙障障间距的基本原理是障间风蚀沙量等于积沙量。障间凹曲面面积与障间距及沙面坡度之间存在着显著的回归关系,运用这种回归关系就可以建立障间风蚀沙量等于积沙量的等式方程。在民勤沙区取样分别建立粘土沙障和麦草沙障的风蚀沙量等于积沙量的等式方程,计算出沙面坡度0°~8°和0°~10°的粘土沙障和麦草沙障间距分别是253.1~185.9 cm和261.4~155.0 cm;粘土沙障高度应为适宜高度范围内的最小值;粘土沙障在障高为15 cm、沙面坡度>8°时障间没有风蚀。麦草沙障在坡度>10°时障间没有风蚀;15 cm高的粘土沙障和固沙有效高度13 cm的麦草沙障的最小间距分别是185.9 cm和155.0 cm;若需要在固定就地沙面的基础上接纳外来流沙或者需要风蚀部分就地沙粒时,可将接纳沙量或风蚀沙量的平均厚度作为参数之一计算障间距;按照风蚀沙量≤积沙量的障间距设置的沙障,其方格形式只适合在害风方向多变的地段设置。     

Preparation of adsorbent with magnesium sulfate and straw pulp black liquor and its phenol adsorption properties

A magnesia adsorbent was prepared from straw pulp black liquor and magnesium sulfate for the first time, and its adsorption of phenol from aqueous solution was examined. The characteristics of the adsorbent were tested through chemical analysis, surface analysis, X-ray diffraction and FT-IR spectroscopy. The effects of various factors, such as dose, adsorption time and adsorption temperature, on phenol adsorption behavior were studied. The results show that the adsorption processes can be fitted to the isotherm Langmuir model very well. It was found that the adsorption process was strongly influenced by temperature and the optimal temperature for phenol removal was 40 °C. The optimum adsorption time was 10 min, and desorption would happen afterwards. Between the models of Langmuir and Freundlich, the adsorption process of phenol onto magnesia fitted the Langmuir equation better.     

随钻监测技术在气体钻井中的应用

气体钻井是近年来兴起的一种实用钻井技术,具有保护油气产层、提高钻速、缩短建井周期及处理井漏事故等优点,应用范围越来越广泛。与常规钻井液钻井相比,气体钻井是单向循环,使用气体作为循环介质来携带岩屑、清洗井眼,使得现有录井监测系统还不能满足气体钻井现场参数监测需要,易出现钻具失效、井下燃爆、地层出水及井壁坍塌等复杂钻井问题,影响气体钻井的安全性。基于井下燃爆理论和监测监控系统技术,开展了随钻监测基本原理研究,形成了UBD气体监测系统及分析技术;通过在多口井气体钻井现场服务,验证了气体监测系统及分析技术的合理性和实用性,为安全顺利实施气体钻井提供了有力的技术支持。     

CALIOP对一次秸秆焚烧后气溶胶光学特性的探测分析

采用星载激光雷达(Cloud-Aerosol LIdar with Orthogonal Polarization,CALIOP)资料研究了2008年6月2日华东秸秆焚烧排放气溶胶的光学特性,并与2006~2008年统计结果进行了对比。结果表明:1)CALIOP能够有效探测到气溶胶层,探测结果符合生物质燃烧气溶胶的典型特征;气溶胶分布及廓线特点可以由火点分布及大气环流形势做出解释。2)个例中气溶胶光学特性廓线与该地区2006~2008年全年平均和夏季平均都存在一定差异。个例中后向散射系数廓线的峰值显示出气溶胶垂直分布结构,对应高度上的退偏振率比平均偏大而双波长比则偏小,表明秸秆焚烧源气溶胶层由大量非球形的细粒子组成。3)个例中气溶胶粒子谱特征与3年夏季平均接近而与3年平均差别很大,显示出个例的季节特征。更多个例的统计分析和地基观测的验证有助于了解秸秆焚烧源气溶胶的普遍规律。     

Emissions of Polycyclic aromatic hydrocarbons by savanna fires

Although Polycyclic aromatic hydrocarbons (PAH) are known as anthropogenic compounds arising from the combustion or the pyrolysis of fossil fuels, they may be also emitted by the combustion of vegetation. A field study was carried out in January 1991 at Lamto (Ivory Coast) as part of the FOS DECAFE experiment (Fire Of Savanna). Some ground samplings were devoted to the qualitative and quantitative characterization of atmospheric emissions by savanna fires during prescribed burns and under background conditions. Specific collections for gaseous and particulate PAHs have shown that the African practice of burning the savanna biomass during the winter months is an important source of PAHs. These compounds are emitted mainly in gaseous form but a significant fraction, essentially heavy PAHs, is associated with fine carbonaceous particles and can therefore represent a hazard for human health, since some of these compounds are mutagenic and carcinogenic. Twelve compounds were identified during the fire episodes and in the atmospheric background. The total concentration in the fires is of the order of 10 ng m^–3 for the gas phase and from 0.1 to 1 ng m^–3 in the aerosols. In the atmospheric background the mean concentrations are regular, 0.15 ng m^–3 and 2 pg m^–3, respectively. These concentrations are comparable with what is observed in European rural zones. The particulate emissions of PAHs by the savanna fires are distinguished by the abundance of some compounds which can be considered as tracers, although they are also slightly emitted by fossil fuel sources. These compounds are essentially pyrene, chrysene and coronene. In the gas phase, although no individual PAH may be considered as specific of the biomass combustion emissions, the relative abundances of the main PAHs are characteristic of the biomass burning. The concentrations of pyrene and fluorene are always predominant; these compounds could be considered as characteristic emission products of smoldering and flaming episodes, respectively. In the background the PAH composition shows that in a tropical region the air consists of a mixture coming from the various sources, but the biomass combustion is by far the most important source.The fluxes of total PAH emitted by savanna biomass burning in Africa were estimated to be of the order of 17 and 600 ton yr^–1, respectively, for the particulate PAHs and the gaseous PAHs, respectively.     

石家庄市周边秸杆焚烧导致云凝结核变化的特征

利用DMTCCN仪定点观测的云凝结核（cloud condensation nuclei,CCN）粒子浓度资料,对2007年6月11—13日石家庄市出现的一次空气质量和能见度均十分差的灾害性极端天气事件进行了分析。结果表明,这次极端事件与周边地区焚烧秸杆的人为活动密切相关;对流层中、高层维持的下沉气流,迫使烟雾聚集在近地面层而使得CCN粒子数相对增加;垂直湍流交换微弱抑制了近地面层烟雾的垂直扩散,从而加剧低能见度的恶化,并导致霾天气形成;逆温层的厚度和地面静风、风速偏小同样使形成的烟雾在特殊地形作用下聚集     

采用偏心楔侧钻处理坚硬地层烧钻事故

介绍了一种取出式改进型偏心楔的侧钻方法、工艺措施及侧钻效果。与传统偏心楔侧钻法比较,具有偏孔速度快、可取出斜面岩心、无专程扩孔工序、不留事故隐患、不影响后续绳索取心钻进、偏心楔可重复使用等优点。解决了某矿区ZK901孔在坚硬岩中侧钻处理烧钻事故的关键技术难题。     

燃烧麦秸对大气颗粒物中多环芳烃含量的影响

通过对集中燃烧麦秸前后北京市大气颗粒物中多环芳烃的分析，结合麦秸燃烧排放气体中相关成分的测试，说明燃烧麦秸对大气中多环芳烃的含量有很大的影响，提示有关部门应对之采取措施，防止大气环境质量因此而受到破坏。     

利用正构烷烃单分子碳同位素组成对兰州大气污染源的探讨

本文以兰州大气环境为试点,收集西固工业区、铁路商业-居民混合区和盘旋路交通要道区①取暖期（1994 年 3 月)和非取 暖期( 1994 年 8 月）的大气飘尘样品,固定污染源烟尘和汽车尾气样以及选择石油和煤的端元样品,利用MAT-252(GC-C-MC)仪进行正构烷烃单分子碳同位素测定。研究了大气飘尘、烟尘和尾气排放物中正构烷烃单分子碳同位素组成特征及分布规律,结合化石燃料（石油和煤）的分析结果提出了结果提出了冬季δ13C值高于夏季,西固工业区冬季、夏两季相似。经选择nC₂₁～nC₂₃单分子碳同位素值用二元复合估算结果,西固工业区大气污染主要为燃油源,市区内取暖期燃煤源输入率高,非取暖期主要来自燃油源,以汽车尾气为主,兰州市大气污染物中燃油源占60 %以上,这与用石油作为主要能源所造成的大气环境污染密切相关。