Studying air pollution with kitt peak solar flux atlas — analysis method and results of observation

For the measurement of atmospheric NO2 vertical column density (VCD), Kitt Peak Solar Flux Atlas can be substituted as an extraterrestrial solar radiation. Compared with differential analysis method, the Taylor expansion of integrated transfer equation underestimates the VCD. This underestimation is as large as 35% when the amount of NO2 is 1 × 1017 cm－2 and observation is conducted with an air mass factor of 10. Even when the VCD is 2 × 1016 cm－2 and the air mass factor is 4, the relative error of the retrieved VCD is still no less than 3%. If the observation is restricted under the small air mass factor condition (≤4), with Kitt Peak Solar spectrum as an extraterrestrial solar radiation, only an atmospheric layer of 2 km thick from ground can be studied, which will make the absorption too weak to be detected by normal instruments.The VCD in winter Tokyo area was observed and analyzed by differential method, which shows a good precision even when the absorption is as low as 3%. The largest average VCD was about 1.3 × 1017 cm－2, and the lowest was about 1.3 × 1016 cm－2. The trend of its variation was almost the same as the ground level observation by Saltzman reagent method.     

Factors influencing the release of dissolved organic carbon and dissolved forms of nitrogen from a small upland headwater during autumn runoff events

We identify and assess the relative importance of the principal factors influencing the release of dissolved organic carbon (DOC) and dissolved forms of nitrogen (N) from a small upland headwater dominated by podzolic soils during a sequence of autumn runoff events. We achieve this by subjecting high‐resolution hydrometeorological and hydrochemical data to an R‐mode principal component factor analysis and a stepwise multivariate regression analysis. We find that the release of DOC and N is influenced by four principal factors, namely event magnitude, soil water flow through the Bs horizon, the length of time since the soil profile was last flushed, and rewetting of the H horizon. The release of DOC and dissolved organic nitrogen (DON) is most strongly influenced by the combination of event magnitude and soil water flow through the Bs horizon, and to a lesser extent by the length of time since the soil profile was last flushed. Rewetting of the H horizon also influences the release of DOC, but this is not the case for DON. The release of nitrate (NO₃‐N) is most strongly influenced by the combination of the length of time since the soil profile was last flushed and rewetting of the H horizon, and to a lesser extent by event magnitude. Soil water flow through the Bs horizon does not influence the release of NO₃‐N. We argue that the mechanisms by which the above factors influence the release of DOC and N are probably strongly associated with moisture‐dependent biological activity, which governs the turnover of organic matter in the soil and limits the availability of NO₃‐N in the soil for leaching. We conclude that the release of DOC and N from upland headwaters dominated by podzolic soils is largely controlled by the variable interaction of hydrometeorological factors and moisture‐dependent biological processes, and that a shift in climate towards drier summers and wetter winters may result in the release of DOC and N becoming increasingly variable and more episodic in the future. Copyright © 2006 John Wiley & Sons, Ltd.     

Nitric oxide concentration near the mesopause as deduced from ionospheric absorption measurements

Nitric oxide concentration in the upper D-region is estimated by comparing empirically derived ratios of Lyman- and X-ray contributions to the total radio-wave absorption (2775 kHz. A3 method) in medium latitudes with model ratios. Typical NO concentrations are about 8.5×10¹³ m^–3, at 90 km and 6.5×10¹³ m^–3 at 78 km. These values are higher than generally accepted model NO concentrations, but lie within the broad range of experimental values.     

龙凤山大气近地层O3浓度变化及与其它因素的关系

研究首次在龙凤山区域大气本底站测得的地面Ｏ３浓度及其变化的资料表明,中国东北农村地面大气Ｏ３浓度总体水平不很高,但在少数特殊的天气条件下,时均浓度可超过国家二级标准。Ｏ３浓度存在明显的季节和日变化,其月平均浓度１９９５年１月最低（２７．５ｐｐｂ）,１９９４年１１月最高（４３．２ｐｐｂ）。Ｏ３日变化幅度夏季的晴天最大（２８ｐｐｂ）,冬季的阴天最小（８ｐｐｂ）。气象要素（尤其是风速、气温和相对湿度等）和ＮＯｘ与地面Ｏ３浓度有较密切的关系。用多变量分析法探讨了地面Ｏ３各指标随气象因子和ＮＯｘ共同变化的规律,并拟合了寒冷和温暖期里与地面Ｏ３日最高浓度、日最低浓度及日变化幅度有关的方程。     

NO冷却率在连续磁暴中对热层密度的影响

基于CHAMP卫星加速度计数据,对2002年4月和2004年11月两个连续磁暴事件期间400 km高度热层大气密度时空变化特征进行了分析,结果表明,地磁扰动相近的连续磁暴发生时,热层密度对第一个磁暴的响应幅度明显大于后续磁暴;磁暴间歇期有时会出现密度低值;磁暴恢复相,热层密度先于ap指数快速恢复至暴前水平,甚至更低;热层大气经验模式NRLMSISE00的预测结果中没有包含这些现象.利用TIMED卫星SABER辐射计数据进一步分析同时段100~155 km高度NO冷却率的变化特点,NO冷却率在暴时的增大滞后热层密度2~6 h;磁暴恢复相,NO冷却率保持在较高水平,弛豫时间远大于热层密度.暴时增强的NO冷却率及其缓慢的恢复是导致热层密度响应幅度变小的原因,间歇期是否出现热层密度异常低值也与NO冷却率的增幅有关.     

Removal of NO3– from Drinking Water by Electrocoagulation – An Alternate Approach

The present study provides an electrocoagulation method, for the removal of NO₃^– from drinking water using magnesium as the anode and cathode. The experiments are carried out as a function of pH, temperature, and current density. The results show that the maximum removal efficiency of 95.8% was achieved at a current density of 0.25 A/dm², at a pH of 7.0. The adsorption of NO₃^– preferably fitting the Langmuir adsorption isotherm suggests monolayer coverage of the adsorbed molecules. The adsorption process follows a second‐order kinetics model. Thermodynamic studies show that the adsorption was exothermic and spontaneous in nature.     

硝酸盐中~(15)N和~(18)O测试新技术

最近 40年 ,硝酸盐 (NO-3 )已成为最常见的地下水污染源之一。本文介绍了用CaO除去CO2 与H2 O的测定氮同位素比值的燃烧管方法和用AgNO3 +C(石墨 )生成CO2 的测定NO-3 中氧同位素比值的燃烧法 ,它们是 1995年以后发展起来的最新测试技术。     

排水条件下化肥流失的研究——现状与展望

探讨排水对化肥流失的影响;减少排水条件下化肥流失的合理施肥措施及排水方式。根据现有研究成果,从排水条件下化肥流失的野外试验研究和数值模拟研究两方面进行了论述,在此基础上提出该项研究需进一步探讨和解决的问题,为该课题的深入研究提供了有利条件。     

两种海参对实验性高脂血症大鼠治疗作用的比较研究

比较研究菲律宾刺参（Pearsonothuria graeffei）和日本刺参（Apostichopus japonicus）对实验性高脂血症大鼠血脂水平和抗氧化能力的影响。结果表明，菲律宾刺参和日本刺参均能明显降低高脂血症大鼠血清TC（P〈0．01），LDL—C（P〈0．01）含量及LDL—C／HDL．C比值（P〈0．01），提高HDL—C及NO（P〈0．01）含量；显著降低血清和肝脏中MDA含量（P〈0．05，P〈0．01），并提高其SOD和GSH-PX活性（P〈0．05，P〈0．01）。其中，日本刺参对血清TC，LDL-C，LDL—C／HDL—C及肝脏MDA水平降低作用和NO含量提升作用显著优于菲律宾刺参（P〈0．05）。提示了菲律宾刺参和日本刺参对大鼠实验性高脂血症均具有显著的治疗作用，日本刺参的治疗效果优于菲律宾刺参。     

r-干扰素对溶藻弧菌(Vibrio alginolyticus)在青石斑鱼(Epinephelus awoara)巨噬细胞胞内存活的影响

采用大肠杆菌重组?-干扰素(rIFN-gamma)单独和联合处理青石斑鱼(Epinephelus awoara)头肾巨噬细胞的方法, 进行了重组?-干扰素对溶藻弧菌(Vibrio alginolyticus)在巨噬细胞内存活研究。结果表明, 溶藻弧菌感染巨噬细胞后暴露于?-干扰素的细胞内细菌存活数量[(1380±80)CFU/mL]明显降低。然而, 在24h, ?-干扰素及脂多糖联合处理组巨噬细胞内溶藻弧菌的存活数量[(463±32)CFU/mL]比暴露于含有或者不含有脂多糖, NG-单甲基-L-精氨酸(NMMA)和过氧化氢酶的?-干扰素处理组少。采用?-干扰素, ?-干扰素和脂多糖, ?-干扰素、脂多糖和NMMA, ?-干扰素、脂多糖和过氧化氢酶四种方式处理24h能提高巨噬细胞过氧化氢的释放, 而不能提高NO2?的产物。另外, 经过?-干扰素处理能够明显降低巨噬细胞对溶藻弧菌的的吞噬作用, 但不影响对溶藻弧菌的杀伤作用。本文数据表明, 过氧化氢的释放和细胞吞噬作用能明显减少溶藻弧菌在巨噬细胞内存活的数量。