北京太阳能气象指数预报研究与应用

利用统计方法制作出逐日太阳能的短期预报模型,并将其预报产品指数化,编制了日太阳能指数预报系统,可逐日制作并发布次日的太阳能指数预报,有利于充分利用太阳能,节约电能,最大程度发挥效益。     

边界层方案对华北低层O3垂直分布模拟的影响

利用WRF-Chem模式,采用3种边界层参数化方案 (YSU, MYJ和ACM2),针对1个晴空、静稳日 (2013年8月26日20:00—27日20:00(北京时)) 进行模拟,着重分析不同边界层参数化方案对夜间残留层形成及日出前后O₃浓度垂直分布形式的模拟效果,并与固城站地面及垂直同步观测资料进行对比。结果表明:3种边界层参数化方案均能够模拟出温度及风速的区域分布形式以及风温垂直结构的变化特征;相比之下,MYJ方案模拟的夜间边界层高度较YSU方案和ACM2方案明显偏高,该对比结果可能是导致近地面污染物浓度模拟差异的重要原因;在夜间稳定层结至日出后稳定状态打破的边界层结构演变过程中,采用YSU方案和ACM2方案模拟的温度和风速垂直扩线形式与观测结果更为接近;同样采用非局地闭合的YSU方案和同时考虑局地和非局地闭合的ACM2方案,对于边界层高度内O₃浓度垂直分布形式的模拟效果具有明显优势。     

Stable Carbon Isotope Ratios and the Photochemical Age of Atmospheric Volatile Organic Compounds

Abstract

The dependence of ozone formation on the mixing ratios of volatile organic compounds (VOCs) and nitrogen oxides (NO_x) has been widely studied. In addition to the atmospheric levels of VOCs and NO_x, the extent of photochemical processing of VOCs has a strong impact on ozone levels. Although methods for measuring atmospheric mixing ratios of VOCs and NO_x are well established and results of those measurements are widely available, determination of the extent of photochemical processing of VOCs, known as photochemical age (PCA), is difficult. In this article a recently developed methodology for the determination of PCA for individual compounds based on the change in their stable carbon isotope composition is used to investigate the dependence between ozone and VOC or NO_x mixing ratios at a rural site in Ontario, Canada, during fall and winter. The results show that under these conditions the variability in VOC mixing ratios is predominantly a result of the varying impact of local emissions and not a result of changes in the extent of atmospheric processing. This explains why the mixing ratio of ozone shows no systematic dependence on the mixing ratios of VOCs or NO_x in this environment and at this time of the year.     

TCA2003全站仪自动识别系统ATR的实测三维精度分析

简述智能型全站仪TCA2003的自动目标识别(ATR)功能及其二次开发的机载测量软件的特点,以琅琊山抽水蓄能电站大坝变形监测网应用ATR功能三维测量实例,基于对其测量平差成果的评定精度,分析ATR三维测量的精度,比较ATR测量与常规的人工测量的功效,并给出有益的结论,为同类工程的应用以及拓展ATR全站仪应用领域提供技术依据。     

用TOPCON-GTS311S型全站仪测量数字地形图

随着计算机技术的普及及测绘仪器自动化水平的提高，数字化地形图比模拟线划地形图具有种种优点，使传统手工白纸测图的方法将被全站仪、成图软件完成的数字化地形图所替代。在数字地形图测量模式中，选择无码作业的方法，由1人或多人现场绘地形草图，将被测碎部点的坐标存人全站仪内存器中，利用清华山维的EPSW 98成图软件在QBASIC的平台上实现与计算机数据传输，编制成图。     

热电离质谱法测定国际比对氧化铀芯块中的铀同位素比值

采用全蒸发-热电离质谱技术测量了国际比对二氧化铀样品中的铀同位素比值。比对结果表明,本实验室提交的²³⁴U/²³⁸U、²³⁵U/²³⁸U和²³⁶U/²³⁸U值与IAEA公布的参考值偏差分别为0.02%、-0. 003%和0. 97%,在实验室间分析测试能力评价中, Z (或ζ)分数分别是0.03(或0.05)、-0.05(或-0.07)和0.15(或0.25),均被评价为满意。     

Observed surface ozone trend in the year 2012 over Nairobi,Kenya

Clean air is a basic requirement for human health and wellbeing. The Kenya Meteorological Department has established air pollution monitoring activities in various sites in Nairobi, at Dagoretti Corner meteorological station and at Mount Kenya. Different pollutants are measured including ozone. The increased concentration of greenhouse gases in the atmosphere has influenced the weather and climate. This study examined the variations of surface ozone over Dagoretti Corner, Nairobi for a 12-month period ending July 2013, exactly one year after the start of data acquisition. The trend was studied using time series analysis of ozone concentration on both an hourly and monthly basis. The ozone data was then combined with meteorological data and temperature to find correlations between the two. Overall, the air quality of Nairobi, represented by Dagoretti Corner meteorological station is good as compared to the World Meteorological Organization ozone standards. The highest concentration of ozone is observed in the afternoon and the minimum at dawn on a daily basis. On seasonal scale, the highest levels are recorded in the cold months. This information helps to reduce exposure to the gas and thus to reduce its impacts on living things. The study recommends the reduction of exposure to the gas during the times when it has been observed to be highest in order to minimize its impacts.     

Surface ozone measurements in the Venezuelan tropical savannah

A one-year set of surface ozone measurements in a four-station network located in the Venezuelan savannah is reported. The diurnal ozone variation is typical of continental stations with a maximum in the afternoon, when vertical turbulent mixing is strongest. The annual O₃ average concentration, based on the monthly averages of daily maxima, was 17±2 ppb, which is in good agreement with values reported for similar latitudes. The boundary-layer ozone levels did not fall below 8 ppb, in contrast with previous sporadic measurements made in tropical latitudes. No evidence was found that mesoscale O₃ downdrafts in the ITCZ in the South American continent are an important source of surface ozone. Finally, it is suggested that the relatively high ozone levels observed at the end of the dry season are probably of photochemical origin.     

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织锦巴非蛤不同组织及性别总类胡萝卜素含量比较分析

本文分析了织锦巴非蛤(Paphia textzle)斧足、外套膜、闭壳肌、鳃、性腺5个组织以及不同性别的总类胡萝卜素含量(TCC),结果显示:织锦巴非蛤5个组织的总类胡萝卜素含量除鳃与性腺之间没有显著性差异之外(P0.05),其它各组织之间差异均达到极显著水平(P0.01),各组织总类胡萝卜素含量从高到低依次为:斧足性腺鳃外套膜闭壳肌;不同性别织锦巴非蛤的斧足、外套膜、闭壳肌、鳃中总类胡萝卜素的含量没有显著差异(P0.05),但精巢与卵巢中的总类胡罗卜素含量有极显著性差异(P0.01),精巢中总类胡萝卜素的含量高于卵巢。本研究结果初步揭示了织锦巴非蛤中总类胡萝卜素含量的分布规律。