常规施肥条件下农田不同途径氮素损失的原位研究:以长江中下游地区夏玉米季为例

为了解农田常规施肥条件下的不同途径氮素损失特征,本文通过田间原位试验同步研究了长江中下游地区夏玉米生长季氮肥施用后的农田N2O排放、NH3挥发、氮渗漏和地表径流的变化.结果表明,在复合肥为基肥,尿素为追肥,基追肥氮素水平均为150 kg·hm-2的条件下,整个玉米生长季N2O排放系数为3.3%,NH3挥发损失率为10.2%,氮渗漏和地表径流损失率分别为11.2%和5.1%.此外,基肥施用以氮素渗漏损失为主,而追肥氮素损失以氨挥发和渗漏为主,表明不同途径化肥氮素损失主要受氮肥品种影响,玉米季追肥可改用低氨挥发氮肥品种以减少氮素损失.     

Preliminary report on methane emissions from the Three Gorges Reservoir in the summer drainage period

Considerable variations may exist in CH4 emissions from the Three Gorges Reservoir.     

汽车道路试验安全管理体系建设研究

为了保障汽车道路试验安全、提高安全管理水平,设计提出汽车道路试验安全管理体系(SMS)总方案。根据OHSAS 18001和安全标准化规范的特点分析,论证了融合两种体系建立道路试验SMS的适用性。并从政策与目标、风险管理、安全保证和安全促进四个模块阐述了该体系的搭建思路、框架内容和搭建步骤。最后,以某自主品牌车企研发中心道路试验的应用情况为例进行效果评估,结果表明:汽车道路试验SMS能有效防控风险、提升试验安全管理水平。     

Attitudes towards relocation following Hurricane Sandy: should we stay or should we go?

This study explores the dilemma of whether to rebuild or relocate from the areas devastated by Hurricane Sandy in 2012. Since disasters represent the discernible manifestation of other complex coastal hazards, they offer a window of opportunity to engage residents in the dialogue on relocation as sometimes the most effective risk reduction strategy. The following research evaluates attitudes towards relocation and willingness to consider buyout among 46 surveyed households located in highly‐affected communities five months after Sandy. It also gauges perceptions of coastal risks and recovery concerns as drivers of relocation, the level of support for different adaptation strategies, and preferences related to the relocation process itself on how and where to relocate and with what type of assistance. Responses indicate that, even though residents prefer structural solutions to address coastal hazards, they are not fully opposed to the possibility of relocation mostly for personal health and safety reasons.     

北方蚕区夏秋蚕病的防范对策

夏秋蚕病是北方蚕桑生产上存在的主要问题,对蚕桑的危害不断扩大。为此,笔者根据多年调查研究,试验摸索出了北方蚕区夏秋蚕病的防范对策。     

印度夏季风降水周期性研究

印度夏季风降水(ISMR)在南亚气候系统中是一个非常重要的内容,近年来对它的研究日益受到人们的重视。为了深入认识ISMR的变化特征,主要利用Scargle周期图和小波变换研究了1871-2004年间ISMR变化的周期性。结果表明,ISMR的周期性波动非常复杂,相应的周期参数具有明显的时变特征。文中还简单讨论了ISMR周期时变的可能原因。     

The impact of heat waves on daily mortality in Belgrade (Serbia) during summer

In this paper, we are dealing with two extreme events in temperature and population – heat wave and mortality. Our aim is to assess the relation between high temperatures and daily mortality counts during the summer months in the period 2000–2010 in Belgrade (Serbia). In order to establish this connection, we used Poisson regression and two different measures of heat wave: Warm Spell Duration Index (WSDI) and apparent temperature (T _app). As mean daily temperature increases over 90th, 95th and 99th percentiles, average number of deaths increases for 15.3% (p?<?.01), 22.4% (p?<?.05) and 32.0% (insignificant for p?<?.1). We tested three different thresholds (90th, 95th, 99th) for WSDI and T _app in order to separate the hottest heat-wave episodes. On average, mortality is higher than expected for 13.4%, 16.7% and 28.3% (90th, 95th and 99th percentiles for WSDI) and 16.1%, 17.3% and 32.5% (90th, 95th and 99th percentiles for T _app). Estimated mortality excess with heat-wave indices is in accordance with regression output, meaning that WSDI and T _app are good tools for heat-wave identification. During the most severe episode in July 2007, absolute temperature maximum (43.6°C) and daily maximum mortality counts (94 dead) were recorded in the same day (24 July 2007).     

天津市郊夏季VOCs化学特征及其时间精细化的来源解析

夏季为环境空气中臭氧污染事件的频发时期,针对挥发性有机化合物(VOCs)及其臭氧生成潜势(OFP)的时间精细化的来源解析研究,对有效地进行臭氧污染防控具有非常重要的作用.利用2019年夏季(6～8月)天津市郊区点位监测的小时分辨率VOCs在线数据,分析臭氧污染事件和非臭氧污染时期环境受体中VOCs及其OFP的变化特征,并利用正定矩阵因子分解(PMF)模型进行精细化的来源解析研究.结果表明,夏季环境受体中VOCs平均体积分数为24.42×10-9,臭氧污染事件中的VOCs平均体积分数为27.72×10-9,较非臭氧污染时期增加15.69％.夏季总VOCs(TVOCs)的OFP为87.92×10-9,其中烯烃的OFP最高,对TVOCs的OFP的贡献达58.28％.臭氧污染事件中TVOCs的OFP为102.68×10-9,较非臭氧污染时期增加19.59％.臭氧污染事件中VOCs的来源分别为石化工业及汽油挥发(29.44％)、柴油车尾气(23.52％)、液化石油气及汽油车尾气(22.00％)、天然气及燃烧(13.41％)、溶剂使用(6.14％)和植物排放(5.49％).相比于非臭氧污染时期,液化石油气及汽油车尾气和柴油车尾气分别增长4.84％和5.29％.石化工业及汽油挥发和植物排放的贡献均表现为08:00开始上升,11:00达到最高,这与太阳辐射增强和温度不断上升密切相关.液化石油气及汽油车尾气和柴油车尾气均具有明显的早晚高峰特征,并在夜间(00:00～06:00)保持较高贡献水平.根据PMF结果并结合OFP的计算方法,解析了不同源类对臭氧生成潜势的 贡献.石化工业及汽油挥发(31.01％)和柴油车尾气(36.64％)是较高贡献源类,相比非臭氧污染时期分别增加了 1.74％和8.27％;并且石化工业及汽油挥发贡献率在臭氧污染事件发生过程的上升阶段显著增加,而在下降阶段明显下降.     

Effects of the Anthropogenic Factor on Bats (Chiroptera: Vespertilionidae) in the Volga Region

Using the example of bats inhabiting the Volga region, the cases in which the anthropogenic factor creates favorable conditions for these animals or significantly reduces their diversity of their fauna are considered. In this context, an opinion concerning the approaches to the conservation of bats is formulated.     

全新世青藏高原东部西南季风的演变

本研究报道一组新的西南季风代用指标,即泥炭中单一种属植物———木里苔草残体纤维素和泥炭混合植物残体纤维素的δ13C时间序列,所记录的青藏高原东部全新世气候变化。两记录表明,该区全新世的下限年龄约11200aBP(14C年龄约9900aBP);从约11200aBP起该区迅速进入湿暖的全新世阶段,季风活动迅速增强;在约10800～5500aBP期间,季风总体保持在强盛状态,但其间有4次突然减弱,气候变干冷;约从5500aBP起季风活动在波动中逐渐减弱,其中有4次减弱最明显。所有这8次气候的突然变化都与北大西洋浮冰事件一一对应。这种密切的相关关系表明,西南季风强度的波动可能是对全球变化,特别是对海洋热盐环流引起的地球南北方气候波动的所谓"跷跷板效应"的响应。