多尺度空气质量模式系统及其验证Ⅱ.东亚地区对流层臭氧及其前体物模拟

利用一个多尺度空气质量模式系统对东亚地区2001年春季对流层臭氧及其前体物的输送与演变过程进行了模拟.为了检验模式系统模拟臭氧演变过程的能力,将模拟的臭氧浓度及其与之紧密相关的化学物种浓度,如OH自由基、HO2自由基、一氧化氮、二氧化氮、一氧化碳、乙烷和乙烯,与TRACE-P期间两架飞机在西北太平洋上空获取的大量观测资料进行了比较.比较结果表明,模拟值的平均值与相应的观测值具有相当好的一致性,且绝大多数模拟值在相应观测值的2倍范围之内;模拟的化学物种浓度的时空分布与观测结果基本相符;模式系统对于非甲烷烃中不同化学物种的输送与转化过程的处理是基本合理的,反映了光化学生成和平流层输送等过程对对流层臭氧浓度分布的影响.     

Mapping as a Means of Farmworker Education and Empowerment

Abstract

Mapping is a simple activity that can be effectively linked to popular education of non-students. Mapping exercises have the potential to contribute to profound shifts in thought because the activity simultaneously draws on and challenges deep-seated experiential knowledge. The transformative potential of mapping is illustrated with health-promoter workshops for Latino migrant farmworkers in Benson, North Carolina, that took place in 1998 and 1999. The workshops are part of a larger project designed to reduce pesticide exposure by using community participatory research to develop and disseminate culturally appropriate teaching materials among Latino workers.     

利用自由基浓度研究盆地古地温的方法

主要讨论了利用自由基浓度研究盆地古地温的三种方法，并结合实测的自由基浓度值估算了塔里木盆地ＴＺ１井的古地温梯度和反演了琼东南盆地单井的热流变化历史．     

甲基绿-高碘酸钾催化光度法测定痕量铂

利用痕量铂 (IV)在稀磷酸介质中对高碘酸钾氧化甲基绿褪色反应的催化作用 ,建立了测定痕量铂 (IV)的催化动力学光度法。方法检出限为 3.4× 10 - 1 0 g/mL ,线性范围为 0～ 2 4μg/L。用于催化剂及矿石中铂的测定 ,结果满意。     

Kinetics and Products of the Gas-Phase Reaction of OH Radicals with 5-Hydroxy-2-Pentanone at 296± 2 K

The 1,4-hydroxycarbonyl 5-hydroxy-2-pentanone is an important product of the gas-phase reaction of OH radicals with n-pentane in the presence of NO. We have used a relative rate method with 4-methyl-2-pentanone as the reference compound to measure the rate constant for the reaction of OH radicals with 5-hydroxy-2-pentanone at 296 ± 2 K. The carbonyls were sampled by on-fiber derivatization using a Solid Phase Micro Extraction (SPME) fiber coated with O> -(2,3,4,5,6-pentafluorobenzyl)hydroxylamine hydrochloride with subsequent thermal desorption of the oxime derivatives and quantification by gas chromatography with flame ionization detection. For comparison, the reference compound was also analyzed following sample collection onto a Tenax adsorbent cartridge. Products of the reaction were investigated using coated-fiber SPME sampling with gas chromatography-mass spectrometry analysis as well as by using in situ atmospheric pressure ionization mass spectrometry. A rate constant for the reaction of OH radicals with 5-hydroxy-2-pentanone of (1.6 ± 0.4) × 10^–11 cm³ molecule^–1 s^–1 was obtained at 296 ± 2 K. Two dicarbonyl products, of molecular weight 86 and 100, were observed and are attributed to CH₃C(O)CH₂CHO and CH₃C(O)CH₂CH₂CHO, respectively. Reaction schemes leading to these products are presented.     

窑街三矿矿井水文地质特征及防治措施研究

根据生产实践总结，对窑街三矿矿井危害最大的是位于煤二层上部的第四系砾石层潜水，其次是烧变岩孔隙水与地表塌陷区积水，经多年水文地质资料分析，认为砾石层与地表水大通河水力联系密切，如采用帷幕注浆，打放水孔或泄水巷都不会取得好的效果，切断大通河与砾石层的水力联系，是根治砾石层最有效的方法，故要在充分研究大通河补给范围的情况下有目的地修筑拦河提与地下挡水墙，烧变岩孔隙水已利用打泄水巷，放水孔的方式排完，目前主要是严防地表水重新灌入，对塌陷区复垦，修筑防洪渠是防止大气降水进入塌陷区及防止地表水溃入矿井的有效途径。     

Evaluation of the Salicylic Acid—Liquid Phase Scrubbing Technique to Monitor Atmospheric Hydroxyl Radicals

A novel method has been examined for monitoring tropospheric hydroxyl radicals (OH), the most important oxidant in tropospheric chemistry. Aqueous phase salicylic acid reacts with atmospheric OH to produce 2,5-dihydroxy benzoic acid (2,5-DHBA) and other products. High Performance Liquid Chromatography (HPLC) is used to separate the post-reaction solution and the products are quantified using fluorescence detection. Unlike other methods, it has been reported to be inexpensive, portable and relatively simple. Although the sensitivity was sufficient to measure typical daytime OH concentrations of 0.04–0.4 ppt., the method was hindered by numerous interferences. Successive identification and elimination of these still resulted in a signal that was much larger than expected. Tests showed that this was not likely to be due to ozone, HO₂, NOx, H₂O₂, aerosols, light or bacteria. Experimental and numerical studies suggest that the interference could be due to methyl peroxy radicals. The effect of many other components in the atmosphere, both individual and combined, must also be tested before the method can be used reliably in the field. The validity of previous reports of ambient hydroxyl measurements using this technique is therefore brought into question.     

铀矿石菌浸液中硫酸根测定方法的研究

研究了铀矿石菌浸液中大量铁存在下测定SO4^2-的问题。利用743阳离子交换树脂吸附阳离子，而SO4^2-不被吸附的特性。随流出液出柱。使铁与SO4^2-分离。消除铁对SO4^2-测定的干扰。采用铬酸钡光度法测定SO4^2-经合成标准样品验证测定结果与理论值相符。样品加标回收率为96％和98％。实验表明，本方法可以用来准确测定菌浸液中SO4^2-含量。     

苏北盆地部分古生界原油来自第三系源岩的证据

苏北盆地LT1井、D7井、7．43井和L1井等古生界原油的地球化学特征研究表明，它们来自古新统阜宁组源岩。“新生石储”现象主要是新生界源岩与古生界储层呈断层接触造成的。