寡照对温室黄瓜花果期生长及产量品质影响研究

为了探讨寡照对日光温室黄瓜花果期生长发育、产量和品质的影响,以黄瓜品种“德瑞特L108”(Cucumis sativusL. cv.Derit L108)为试材,通过不同遮阴日数（1 d、3 d、5 d、7 d、9 d）及恢复控制试验,研究寡照对日光温室黄瓜生长及果实品质的影响。结果表明：1）持续寡照日数超过5 d,黄瓜株高和茎粗生长受到显著影响,尤其是茎粗存在变细现象,7 d以上对植株生长影响不可逆。2）黄瓜果实横径、长度生长速率和果重受寡照影响程度存在一定差异,果实上下两端横径长势对寡照较为敏感,连续寡照3 d时影响即达显著水平,可导致上端横径生长速率降低0.87 mm·d-1,下端为0.73～0.99 mm·d-1;果实中部横径和长度增长速率在寡照5 d以上时影响达显著水平,生长速率降低0.88 mm·d-1和0.87～1.00 cm·d-1;与对照（以CK表示）相比,寡照3 d的单果重降低18.7 g,寡照日数每延长1 d,单果重降低2～3 g。3）果实的外观等级受寡照影响较大,1～5 d寡照,特级果比例降低9.4%～43.0%;持续寡照5 d以上二级果和坏果比例明显升高,连续寡照9 d,二级果和坏果比例达到20%和25%;寡照3 d以上,果实含水率与CK差异即达到显著性差异;维生素含量对寡照影响反映敏感,1～5 d寡照,果实维生素含量降低6%左右,7 d以上的寡照日数,则降低10%～13%;寡照持续日数超过5 d,花青素和有机酸含量影响较大;持续寡照日低于7 d时,可溶性糖含量对寡照影响敏感度相对较低,超过7 d其含量达到显著性差异,且寡照日每延长1 d,其含量降低4%。     

两种不同减排情景下21世纪气候变化的数值模拟

利用国家气候中心最新发展的气候系统模式BCC-CSM1.0模拟了相对于B1排放情景,两种不同减排情景(De90和De07,表示按照B1情景排放到2012年,之后线性递减,至2050年时CO_2排放水平分别达到1990和2007年排放水平一半的情景)对全球和中国区域气候变化的影响.结果表明:两种减排情景下模式模拟的全球平均地表气温在21世纪40年代以后明显低于Bl情景,比减排情景浓度低于B1的时间延迟了20年左右;尽管De90减排情景在2050年所达到的稳定排放水平低于De07情景,但De90情景下的全球增温在2070年以后才一致低于De07情景,这种滞后町能与耦合系统(主要足海洋)的惯性有关;至21世纪末,De90和De07情景下的全球增温幅度分别比B1情景降低了0.4和0.2℃;从全球分布来看,B1情景下21世纪后30年的增温幅度在北半球高纬度和极地地区最大,减排情景能够显著减少这些地区的增温幅度,减排程度越大,则减少越多;在中国区域,B1情景下21世纪末平均增温比全球平均高约1.2℃,减排情景De90和De07分别比B1情景降低了0.4和0.3℃,中国北方地区增温幅度高于南方及沿海地区,减排情景能够显著减小中国西部地区的增温幅度;B1情景下21世纪后30年伞球增温在冬季最高,De90和De07情景分别能够降低各个季节全球升温幅度的17%和10%左右.     

内蒙古草原温室气体排放日变化规律研究

采用静态值－气相色谱法研究内蒙古草原温室气体N2O、CO2、CH4与大气交换的日变化规律。CO2日排放变化形式基本相同，和大气交换的总结果是向大气排放，影响草原N2O排放日变化形式的关键是土壤含水量和表层土壤理化特性，日温变化主要影响其日变化强度；影响草原CH4日变化形式的关键因子是土壤水分和供氧状况，而温度和植物的生长状况则影响吸收强度，利用内蒙古草原温室气候排放相对固定的日变化形式，可以对相同生产季内每周1次的观测结果进行矫正。     

Aerosol spectra and new particle formation observed in various seasons in Nanjing

The aerosol number spectrum and gas pollutants were measured and the new particle formation （NPF） events were discussed in Nanjing. The results showed that the size distributions of aerosol number concen- trations exhibited distinct seasonal variations, implying the relations of particle sizes and their sources and sinks. The number concentrations of particles in the nuclei mode （10-30 nm）, Aitken mode （30-100 nm）, accumulation mode （100 -1000 nm） and coarse mode （〉1μm） varied in the order of summer 〉 spring 〉 autumn, summer 〉 autumn 〉 spring, autumn 〉 summer 〉 spring, and spring 〉 autumn 〉summer, re- spectively. The diurnal variation of total aerosol number concentrations showed three peaks in all observed periods, which corresponded to two rush hours and the photochemistry period at noon. In general, the NPF in summer occurred under the conditions of east winds and dominant air masses originating from marine areas with high relative humidity （50%-70%） and strong solar radiations （400 -700 W m-2）. In spring, the NPF were generally accompanied by low relative humidity （14%-30%） and strong solar radiations （400-600 W m-2）. The new particle growth rates （GR） were higher in the summertime in the range of 10- 16 nm h-1. In spring, the GR were 6.8-8.3 nm h-1. Under polluted air conditions, NPF events were seldom captured in autumn in Nanjing. During NPF periods, positive correlations between 10- 30 nm particles and 03 were detected, particularly in spring, indicating that NPF can be attributed to photochemical reactions.     

Micrometeorological Observations of a Microburst in Southern Finland

On the afternoon of 3 July 2004 in Hyytiälä (Juupajoki, Finland), convective cells produced a strong downburst causing forest damage. The SMEAR II field station, situated near the damage site, enabled a unique micrometeorological analysis of a microburst with differences above and inside the canopy. At the time of the event, a squall line associated with a cold front was crossing Hyytiälä with a reflectivity maximum in the middle of the squall line. A bow echo, rear-inflow notch, and probable mesovortex were observed in radar data. The bow echo moved west-north-west, and its apex travelled just north of Hyytiälä. The turbulence data were analysed at two locations above the forest canopy and at one location at sub-canopy. At 1412 EET (Eastern European Time, UTC+2), the horizontal and vertical wind speed increased and the wind veered, reflecting the arrival of a gust front. At the same time, the carbon dioxide concentration increased due to turbulent mixing, the temperature decreased due to cold air flow from aloft and aerosol particle concentration decreased due to rain scavenging. An increase in the number concentration of ultra-fine particles (< 10 nm) was detected, supporting the new particle formation either from cloud outflow or due to rain. Five minutes after the gust front (1417 EET), strong horizontal and downward vertical wind speed gusts occurred with maxima of 22 and 15 m s^?1, respectively, reflecting the microburst. The turbulence spectra before, during and after the event were consistent with traditional turbulence spectral theory.     

水库温室气体净通量评估模型(G-res Tool)及在长江上游典型水库初步应用

目前准确量化温室气体排放量已成为气候变化研究和政策制定的关键.在IPCC水库温室气体净通量的概念性框架下,国际水电协会汇总分析了全球223座水库的CO₂和CH₄研究成果,构建了G-res Tool,其可以用于评估已建或待建水库在长时间尺度下的温室气体净通量.本文介绍了G-res Tool模型的基本原理与模型框架,利用模型内置数据库中所涉及的中国长江上游12座典型水库数据进行初步应用分析,12座水库温室气体净通量平均值为88.17 g CO₂e/（m²·a）,在全球约7000座水库中所处水平为11.67%,处于低阈值范围.在水库温室气体净通量分析结果中,其他非相关人类活动产生的水库温室气体通量（UAS）在蓄水后总通量（Post）中所占比重远高于蓄水前温室气体通量（Pre）.长江上游水库蓄水后的CH₄和CO₂通量对于温室效应的贡献量相当.通过将G-res Tool模型蓄水后的温室气体通量评估结果和所涉及到的12座水库中已发表的数据对比分析发现,G-res Tool具有简便、适用面广等特点.但G-res Tool毕竟仍为经验性模型,其基本原理和模块设计上的内在缺陷在很大程度上限制了其应用范围并造成了一定的不确定性.对个案水库而言,长期跟踪观测与机理研究仍是未来减少水库温室气体净通量不确定性的关键.     

阜康日光温室内温湿度与外界气象要素的相关性分析

根据2011—2012年阜康六运温室内温湿度和附近气象站观测资料,利用相关和逐步回归分析,对不同天气状况下阜康地区日光温室内温湿度变化特征及其与外界气象要素的关系进行了研究。结果表明,不同天气状况下温室内的气温和空气相对湿度均有明显的日变化。影响日光温室内温湿度的主要因子为外界的日照时数、平均气温、最高气温、最低气温、空气湿度以及温室内前一天的温度和空气湿度等。建立了日光温室内外气象要素的相关模型,经拟合检验和应用检验,不同天气状况下日光温室内日平均气温、最高气温、最低气温、空气平均相对湿度、空气最小相对湿度的平均绝对误差分别在1.5℃、2.6℃、2.0℃、6.2%、9.6%以内,平均相对误差大部分在10%以内,具有较高的精度。确定了温室生火增温、移栽定植、通风及覆盖保温等气象服务指标。     

MODELING THE EFFECTS OF ANTHROPOGENIC SULFATE IN CLIMATE CHANGE BY USING A REGIONAL CLIMATE MODEL

1 INTRODUCTION Being an important composition of the atmosphere, aerosol attracts increasing attention from the scientific community in recent years, together with the radiative forcing it causes and effects it imposes on the climate system. The anthropogenic aerosol affects the climate both directly and indirectly. The climate is directly affected when solar shortwave radiation is scattered and absorbed in what is known as the 搖mbrella effect? which can be dated back to as early as mor…     

The importance of sewage effluent discharge in the export of dissolved organic carbon from U.K. rivers

The flux of fluvial carbon from the terrestrial biosphere to the world's oceans is known to be an important component of the global carbon cycle, but within this pathway, the flux and return of carbon to the river network via sewage effluent has not been quantified. In this study, monitoring data from 2000 to 2016 for the dissolved organic carbon (DOC) concentration, biochemical oxygen demand, and chemical oxygen demand of the final effluent of sewage treatment works from across England were examined to assess the amount of DOC contributing to national‐scale fluvial fluxes of carbon. The study shows that the median concentration of DOC in final effluent was 9.4 compared with 4.8 mg C/L for all surface waters for the United Kingdom over the study period and that the DOC in final effluent significantly declined over the study period from 11.0 to 6.4 mg C/L. Rivers receiving sewage effluent showed a significant, on average 19%, increase in DOC concentration downstream of sewage discharges. At the scale of the United Kingdom, the flux of DOC in final effluent was 31 ktonnes C/year with a per capita export of 0.55 kg C/year and compared with an average annual flux of DOC from the United Kingdom of 859 ktonnes C/year, that is, only 3.6% of national‐scale flux. The lability of this DOC was limited, with only 7.4% loss of final effluent DOC concentration over in‐stream residence times of up to 5 days. The direct decline in DOC concentration from sewage treatment works was not large enough on its own to explain the declines observed in DOC concentration in U.K. rivers at their tidal limit.     

BOOK REVIEWS

Books Reviewed in this article: Lob Trees in the Wilderness . Clifford and Isabel Ahlgren . Satellite Microwave Remote Sensing . T. D. Allan , ed. Sunbelt Cities: Politics and Growth Since World War II . Richard M. Bernard and Bradley R. Rice , eds. Legacy of Minneapolis: Preservation Amid Change . John R. Borchert , David Gebhard , David Lanegran , and Judith A. Martin . Bloomington, MN: Preparing a Historic Preservation Ordinance. Richard J. Roddewig . The Mountains of Northeastern Tasmania, A Study of Alpine Geomorphology . Nel Caine . Introductory Cartography . John Campbell . Englewood Cliffs, NJ: Changing Climate . Manual of Remote Sensing, Second Edition . 2 Vols. Robert N. Colwell , ed.-in-chief; David S. Simonett and John E. Estes , vol. eds. Remote Sensing in Meteorology, Oceanography and Hydrology . A. P. Cracknell , ed. Multidimensional Scaling . Mark L. Davison . Environmental Karst . Percy H. Dougherty , ed. The Urban Environment . Ian Douglas . Geomorphology of Europe . Clifford Embleton , ed. An Introduction to South Asia . B. H. Farmer . Great Geological Controversies . A. Hallam . Hazardous Waste Management: In Whose Backyard? Michalann Harthill , ed. Energy for Subsistence . Margaret Haswell . Perspective on Ratzel's Political Geography . James M. Hunter . Economic Deposits and their Tectonic Setting . Charles S. Hutchison . Energy Risk Assessment . Herbert Inhaber . Discovering the Vernacular Landscape . John Brinckerhoff Jackson . Climate and Energy Systems: A Review of Their Interactions . Jill Jäger . Dilemmas in Regional Policy . Antoni Kuklinski and J. G. Lambooy , eds. California Farmland: A History of Large Agricultural Landholdings . Ellen Liebman . The Spatial Organization of New Land Settlement in Latin America . Jacob O. Maos . Dark Continent: Africa as Seen by Americans . Michael McCarthy . Westport, CT: Climatology: An Introduction . John E. Oliver and John J. Hidore . Columbus, OH: The Geography of Warfare . Patrick O'Sullivan and Jesse W. Miller . The Expanding City. Essays in Honour of Professor Jean Gottmann . John Patten , ed. Scotland's Environment During the Last 30,000 Years . Robert J. Price . Integrated Urban Models . S. H. Putman . Development and the Environmental Crisis: Red or Green Alternatives? Michael Redclift .