臭氧和氮氧化物四季浓度特征及其相关性

根据５ａ来Ｏ３－ＮＯｘ四季的观测资料，计算了各季Ｏ３和ＮＯｘ的浓度特征及两者之间的线性回归方程。其日平均值的相关显著性，以夏季最强，冬季其次，春秋季畸差。     

大气环境中氮氧化物的监测与控制探讨

氮氧化物的超标排放不仅会对所涉区域的大气环境质量造成直接影响,导致一系列环保问题涌现,而且还会通过长距离扩散从而对全国甚至是全球对流层大气环境质量产生一定负面影响,导致环保压力剧增,因此,加强对大气中氮氧化物的监测与控制极为关键.文章对大气环境中氮氧化物的监测与控制展开全面探讨,以期可对各地方环保工作的更好开展有所裨益...     

大连市实验区大气中氮氧化物现状及变化趋势

实验区是在连市重要的工业城区之一，位于大连市西部，自１９８８年以来，在整个实验区四十一平方公里实施烟法、大气污染控制工程由此全区内大气质量发生了很大改观，尤其是大气中氮氧化物浓度明显有所下降。但是由于生产的发展，车流量的增加今后还会使大气中氮氧化物浓度有所增加，因此我们必须提高认识，尽最大努力减轻大气中氮氧化物的污染程度。     

不同的监测方法对大气中二氧化硫氮氧化物监测结果的影响

本篇论文主要引用徐州市环境监测站在1988年6月至1989年12月，对连续采样法与间断采样法所测定的二氧化硫、氮氧化物监测结果，进行对比分析。可知连续采样法比间断来样法的监测结果偏低，同时对其偏低的主要原因进行了探讨。     

提高空气中氮氧化物监测质量的方法

大气监测质量保证是一项室内外密切配合的系统工程，每一个步骤对测值都有影响。为提高大气中氮氧化物测定值的准确性，我站采用双管平行对比采样，在长期实践中总结出从室外采样到室内样品分析质量保证方法和经验，以保证大气中氮氧化物测值准确可靠。     

大气氮氧化物监测中空白控制图的应用

根据对氮氧化物空白值连续四年的累积和统计，阐述了对使用中的空白控制图要不断加以修正和完善的必要性。     

浅谈玻璃块熔窑氮氧化物排放浓度执行标准

玻璃块生产熔窑产生的氮氧化物浓度较高,通过对乌海市一家生产玻璃块企业的2台熔窑进行监测可知,氮氧化物产生浓度均大于1500mg/m~3。玻璃块生产原理和使用原料与电子玻璃工业及平板玻璃工业相似,故玻璃块熔窑氮氧化物排放浓度应参照《电子玻璃工业大气污染物排放标准》或《平板玻璃工业大气污染物排放标准》执行700mg/m~3限值要求。     

空气中臭氧浓度与氮氧化物浓度及气象因子的相关研究

本文对绵阳城区开展的空气中臭氧监测，以及同步监测的氮氧化物、气象因子进行了一些研究。结果表明：绵阳城区空气中臭氮深度均低于国家二级标准，未受到臭氧的污染；臭氧浓度与氮氧化物浓度、气温、气压、相对湿度具有较好的相关性，可建立四元线性回归预测模型。     

唐山市区大气环境中氮氧化物的监测与分析

通过使用分光光度法测定大气中氮氧化物浓度,采集样品分析得出唐山市西道大气中氮氧化物污染现状,了解大气中氮氧化物污染水平。由实验数据分析可知,路段中间的监测点的氮氧化物日小时均值浓度大约为0．037mg／m^3,氮氧化物浓度值受风力影响大于车流量的影响,路口监测点由于车流量大,其氮氧化物浓度值也对应升高,大约为0.046mg/m^3,其受车流量的影响大于风力影响,说明当车流量超过一定值时,风力的影响就会战弱。结果表明,唐山市新华西道氮氧化物日均值浓度大于0.05mg／m^3,氮氧化物污染指标的平均值均超过国家环境空气质量二级标准。因此,此道路属于污染区。还提出了减轻氮氧化物污染状况的几点建议。     

锅炉烟尘浓度监测误差因素分析

烟尘作为国家规定的重要污染控制指标,要求其排放浓度和总量全部达标排放。但在锅炉烟尘测试过程中目前还存在很多问题,如锅炉烟尘浓度监测采用瞬时监测法,它受各种因素的影响,监测结果误差很大。正确分析引起锅炉烟尘浓度监测误差的因素,对于消除误差,获取代表性样品,正确、客观、真实地反映污染源排放状况,对于控制污染、改善环境质量有着十分重要的意义。     

基于QAR数据的发动机LTO阶段氮氧化物排放量计算与分析

氮氧化物是发动机运行过程中产生的一种主要污染物,对于航空器氮氧化物排放量的准确计算是控制排放和评估其环境影响的基础.本文依据BM2流量修正方法对机载快速存取记录器(QAR)数据中的燃油流量值进行标准化修正,并根据低压转子转速、空地传感器指示、油门杆解算器角度、飞行高度,对起飞着陆循环(LTO)进行更精确的阶段划分.同时,参考国际民航组织公布的特定发动机机型的分阶段排放指数,对PW-4077D发动机某次LTO阶段的氮氧化物排放量进行计算.结果表明,通过精准飞行阶段划分,结合QAR实测数据估算的LTO分阶段(起飞、爬升、进近、慢车)氮氧化物排放量分别达到3415.87、7574.57、3019.98、1721.33 g,与标准LTO估算方法相比,相差30%以上.这种发动机LTO阶段实际排放量的计算方法,可为近地面航空器乃至不同地区整个机场氮氧化物污染评估提供更加准确的依据.     

The influence of source and timing of nitrogen fertilizers on yield and nitrogen use efficiency of four sweet potato cultivars

Nitrogen (N) availability is a very important determinant of crop yield. It is also one of the most expensive inputs in crop production. Thus, the efficient management of N by farmers with limited resource is a very important part of successful soil and crop management system. A field study was conducted on a Norfolk sandy loam soil at the George Washington Carver Agricultural Experiment Station, Tuskegee, AL, to evaluate the influence of fertilizer source and timing on the yield of four sweet potato [Ipomoea batatas (L.)] cultivars. Two N sources (urea, CO(NH₂)₂ and ammonium nitrate, NH₄NO₃), four sweet potato cultivars (‘Georgia Jet’, GA-Jet; ‘TU-82-155’, TU-155; ‘TU-1892’; and ‘Rojo Blanco’, Rojo-Bl) and three times (zero, single, and split applications) were used in a factorial designed experiment. Plants were harvested after 80 and 120 days and total and marketable yields determined. Nitrogen recovery efficiency, yield efficiency and physiological efficiency were also determined. Total and marketable yields of early maturing cultivars were significantly higher than of late maturing cultivars (P<0.05). The single application of N resulted in significantly higher yield in storage roots than split application (P<0.05). Physiological efficiency values were highly correlated with total marketable yields. Recovery rates increased with time. Late maturing cultivars tended to have higher N recovery and physiological efficiency than early maturing cultivars. These results suggest that cultivar maturity group should play an important part in N fertilization recommendations for sweet potato.     

The culture of compound bioflocculant and the analysis of its activated components

利用农业固体废弃物秸秆类纤维素为原料制备复合型生物絮凝剂（CBF）,优化了CBF的培育条件。同时解析了CBF活性物质在发酵液中的分布,并对CBF的活性组分进行了研究。结果表明,在高效纤维素降解菌HIT-3的作用下,秸秆类纤维素发酵3天产糖量达到高峰,此时接入CBF产生菌于灭菌后的纤维素发酵液中,在30℃、140r/min的旋转式摇床上培养36h,整个过程中只需将纤维素发酵培养基的pH值调节到7.2。在上述条件下CBF可获得较优的絮凝效果;多糖是CBF的主要组成成分,CBF的热稳定性良好。其絮凝活性物质主要分布在上清液中。     

机动车氮氧化物污染现状与减排措施

汽车尾气对空气的污染越来越严重,影响人们的健康生活,破坏生态环境。机动车尾气中的氮氧化物是大气污染的主要污染物之一,采取有效措施减少机动车氮氧化物排放对于空气质量的改善具有重要意义。     

Effects of cracks and some key factors on emissions of nitrous oxide in paddy fields

IntroductionNitrousoxide,N2Oisofenvironmentalimportancebecauseitcontributestoglobalwarmingandthedepletionofthestratosphericozonelayer(Smith,1982).Itsatmosphericconcentrationisstillincreasingatarateof025%—031%peryear(Rodhe,1990).SignificantsourcesofN2Oarefoundinterrestrialecosystemsasaresultofnitrificationanddenitrificationprocessinsoils(Bouwman,1993).Globally,anthropogenicactivityaccountsfor64%oftotalN2Oemissions,towhichagriculturecontributes92%(Duxbury,1982).Therearesomedifferencesbetwe…     

Comprehensive analysis of nitrogen distributions and ammonia nitrogen release fluxes in the sediments of Baiyangdian Lake, China

The condition of Baiyangdian Lake(BYDL) will improve as the Xiongan New Area evolves and fulfills its role of easing overcrowding and supporting economic growth. Water and sediment samples from BYDL were analyzed to provide information on nitrogen(N) contamination in BYDL. The mean ammonium N(NH_4~+-N), nitrate N, and total N concentrations in the water samples were 0.36, 0.12, and 2.22 mg/L, respectively, and the ranges were 0.003–8.38, 0.06–0.30,and 1.25–10.34 mg/L, respectively. The N concentrations in water gradually increased from the north to the south of BYDL. Sediment at 90% of the sampling sites was in or above the moderately contaminated class(1000–2000 mg/kg) defined in US Environmental Protection Agency total N pollution standards. Positive NH_4~+-N fluxes were found for 28 of the 34 sediment core samples, so the potential for NH_4~+-N being released from sediment was relatively high. The NH_4~+-N fluxes were 5.35–48.76 mg/m~2/day, and the mean and maximum fluxes were 8.71 and 48.76 mg/m~2/day, respectively. Benthic organisms will be affected more by NH_4~+-N and NH_3·H_2O in the surface sediment pore water(mean concentrations 4.93 and 0.13 mg/L, respectively) than by the other forms of N.     

复合型生物絮凝剂成分分析及其絮凝机理的研究

蒽酮反应、考马斯亮蓝、紫外扫描等测定结果表明,絮凝剂CBF的主要成分为多糖类物质．红外光谱扫描分析CBF中含有羧基,分别以-COO^-和COOH的形式存在．用凝胶色谱柱测其相对分子量为10^5-10^6．Zeta（ζ）电位测定及氢键和离子键检验结果表明,CBF与高岭土等无机颗粒之间的作用力为离子键,絮凝过程中存在架桥作用．利用原子力显微镜观察其絮凝形态发现絮体结构密实,有利于絮体沉降．其絮凝机理为絮凝剂和高岭土以离子键的形式结合,之后通过架桥作用絮凝沉淀．     

徐州市三环西路硝基苯泄漏事故应急监测案例分析及研究

2006年4月徐州市三环西路发生一起硝基苯泄漏事故。通过对该环境应急监测案例的分析与研究,认识到我们在突发性污染事故环境监测与管理方面的不足,提出了加强与改进的措施,使环境应急监测系统更完善。     

氮在富营养化湖泊沉积物-水界面的释放

湖泊沉积物-水界面中的氮在特定条件下通过形态变化、界面特性和释放等途径影响湖泊水体质量。文章阐述了氮在湖泊沉积物-水界面的释放特征,并对影响氮在沉积物-水界面释放的因素进行了简要概述,并提出了几点控制水体释氮的建议。     

Competitive role of nitrogen functionalities of N doped GO and sensitizing effect of Bi2O3 QDs on TiO2 for water remediation

The promising solar irradiated photocatalyst by pairing of bismuth oxide quantum dots (BQDs) doped TiO₂ with nitrogen doped graphene oxide (NGO) nanocomposite (NGO/BQDs-TiO₂) was fabricated. It was used for degradation of organic pollutants like 2,4-dichlorophenol (2,4-DCP) and stable dyes, i.e. Rhodamine B and Congo Red. X-ray diffraction (XRD) profile of NGO showed reduction in oxygenic functional groups and restoring of graphitic crystal structure. The characteristic diffraction peaks of TiO₂ and its composites showed crystalline anatase TiO₂. Morphological images represent spherical shaped TiO₂ evenly covered with BQDs spread on NGO sheet. The surface linkages of $\text{NO}?\mathrm{O}?\text{Ti}$, $\mathrm{C}?\mathrm{O}?\text{Ti}$, $\mathrm{B}\mathrm{i}?\mathrm{O}?\text{Ti}$ and vibrational modes are observed by Fourier transform infrared spectroscopy (FTIR) and Raman studies. BQDs and NGO modified TiO₂ results into red shifting in visible region as studied in diffused reflectance spectroscopy (DRS). NGO and BQDs in TiO₂ are linked with defect centers which reduced the recombination of free charge carriers by quenching of photoluminescence (PL) intensities. X-ray photoelectron spectroscopy (XPS) shows that no peak related to $\mathrm{C}?\mathrm{O}$ in NGO/BQDs-TiO₂ is observed. This indicated that doping of nitrogen into GO has reduced some oxygen functional groups. Nitrogen functionalities in NGO and photosensitizing effect of BQDs in ternary composite have improved photocatalytic activity against organic pollutants. Intermediate byproducts during photo degradation process of 2,4-DCP were studied through high performance liquid chromatography (HPLC). Study of radical scavengers indicated that ${\mathrm{O}}_2^{·?}$ has significant role for degradation of 2,4-DCP. Our investigations propose that fabricated nanohybrid architecture has potential for degradation of environmental pollutions.