不同季节生态型大白菜光合作用对夏季高温强光的响应

分别以春季品种强势、夏季品种夏珍白1号和秋季品种鲁白8号大白菜（Brassica campestrisL.ssp.Pekinesis(Lour)Olsson）为试材，研究了不同季节生态型大白菜在莲座末期或结球初期，叶片光合作用对夏季高温、强光胁迫的响应。结果表明，不同季节生态型大白菜在高温、强光下的光合特性存在明显差异，夏珍白1号的光合速率（Pn）、蒸腾速率（Tr）、气孔导度（Gs）的极值明显高于强势和鲁白8号，光合“午休“现象较轻；中午12：00时光系统Ⅱ的光化学效率（Fv/Fm）夏珍白1号、强势较高，鲁白8号较低；室内人工控制高温、强光下，夏珍白1号的光合速率较高，鲁白8号较低；利用直线方程求得大白菜的温度补偿点为55℃左右，品种略有差异，夏珍白1号（56.97℃）高于强势（54.81℃）和鲁白8号（54.40℃）。图5参13。     

长江三角洲地区土地利用分区及其特征

通过对长江三角洲地区土地利用结构类型和社会经济发展等指数的数据的调研和整理，采用多元统计分析方法，结合区域发展战略，初步研究了长江三角洲地区土地利用分区类型及其特征，以期为科学合理地利用土地资源提供参考。因子分析结果表明，经主成分分析法进行降维处理，18项分区指标可由4个主因子代表，其特征值累计贡献率为89．72％，且其与各指标、各单元之间存在较强的相关关系；基于因子分析结果，采用层次聚类分析方法和K-Means聚类方法进行评价分区，遵照区域整体性等分区原则，经归并和调整，将长江三角洲地区16个主要城市划分为6大类土地利用类型区，并讨论了不同类型区的区域特征、土地利用特征及其存在的问题。     

湿热流域化学风化与水化学组成季节变化——以西枝江流域为例

为研究湿热中小流域岩石化学风化与化学径流组成的关系，选取硅酸盐岩为主的东江一级支流西枝江流域，分别于2011年1月和7月采集干流和支流水样品并测量其化学组成，运用图解法和正演模型对西枝江流域水化学组成进行分析和定量计算。结果表明，Na⁺和HCO₃^-为西枝江流域水体的主要阳离子和阴离子，两者分别占总阳离子和总阴离子的55%以上。硅酸盐矿物的化学风化对水体阳离子的贡献最大（45.8%），其次是人类活动和碳酸盐矿物风化的贡献（分别是24.7%和22.0%），大气输入对阳离子的贡献相对较少（7.5%）。受碳酸盐矿物风化和人类活动影响较大的支流水化学组成季节变化较大，受硅酸盐矿物化学风化影响的河流水化学组成季节变化不明显。西枝江流域硅酸盐矿物和碳酸盐矿物化学风化速率分别是8.27和56.95 t/（km²·a），二者化学风化对大气CO₂的消耗速率分别为0.80×10⁵和8.52×10⁵ mol/（km²·a）。     

西部地区公路建设区划理论研究

从以大区域进行规划的经济发展思路出发,提出公路建设区划的概念和公路建设区划理论基础,并建立西部公路网合理规模评价指标体系,利用主成分分析方法将指标进行降维,避免了多指标间存在的相关性及信息重叠性的不足,并对西部地区的公路发展水平进行评价。再利用降维后新的互不相关的综合主成分指标体系替代原先存在较多的信息重叠及相关关系的评价指标,对西部各省区的公路发展进行聚类分析。聚类分析结果可用于西部地区公路网合理规模的确定。该方法不但能够使原来复杂的问题简单化,而且所得结论具有客观、可信、较有说服力,使西部地区公路网合理规模的确定具有针对性和可操作性。     

Sedimentation and seasonal variation of hexachlorocyclohexanes in sediments in a eutrophic lake,China

Hexachlorocyclohexane (HCH) concentrations in sediments and sediment trap fluxes of particulate organic carbon and HCHs were measured bi-weekly from March 31 to October 18, 2006 in an urban eutrophic lake in Tianjin, China, in order to investigate sedimentation and seasonal variation of HCHs in sediments. HCH concentrations (dry weight basis) ranged from 2.2 to 20.2 ng/g (mean 7.7 ng/g) in surface sediments and from 26.6 to 972.7 ng/g (mean 187.0 ng/g) in settling particles, respectively. A clear seasonal variation in HCH sedimentation and HCH concentrations in sediments was observed. The maximal HCH deposition occurred following a spring phytoplankton bloom. The average flux of HCHs to sediment was approximately 21-fold higher in April to mid-June as compared to late June to October. This was attributed to the high vertical fluxes at the end of the spring phytoplankton bloom. The maximum values of HCH concentrations in sediments were observed in mid-June to late July. Concentrations of HCHs in sediments from the eutrophic lake were well-correlated with organic carbon contents in sediments. The annual sediment trap flux of HCHs in the eutrophic lake, which was estimated using data obtained in the eutrophic lake, was 117 μ g/m² yr, about 72% of which was attributed to the sedimentation corresponding to spring bloom phytoplankton deposition in late May to mid-June. The high sediment trap flux of HCHs in the eutrophic lake was related to serious local contamination.     

Benthic Infaunal Composition and Distribution at an Intertidal Wetland Mudflat

Benthic infaunal communities at Mai Po Inner Deep Bay mudflat, Hong Kong were investigated between August 2002 and August 2003. A total of 55 species belonging to 8 Phyla from more than 99,074 specimens were recorded. The species richness varied between 13 at Station B in August 2002 and 28 at Station D in August 2003 with an average of 21 across the mudflat and the species diversity was low [H′(log₂) = 0.7–3.5 with an average H′ = 2.4]. Seasonal variations were also observed through abundance and biomass across the mudflat among the seasons. The abundance density was between 8,977 individuals m⁻² at Station D in February 2003 and 77,256 individuals m⁻² at Station B in November 2002 and the overall average density was 25,274 individuals m⁻² for the four stations. The benthic infauna were dominated by pollution tolerant species at this wetland mudflat.     

基于模糊可拓方法的泥石流危险度区划研究

泥石流危险度区划是一个复杂的问题，影响泥石流危险度的诸多因素中既有定性描述的，也有定量描述的，因此，必须将定性与定量描述有机地结合起来，才能获得较为合理的区划结果。本文将模糊数学与可拓方法相结合，在物元理论、可拓集合论和关联函数的基础上，利用区域泥石流危险度等级分类和区划指标隶属度化使其无量纲化，构造了经典物元和节域物元，并建立了泥石流危险度区划的模糊可拓模型。实例应用表明该方法能较真实地反映实际区域的泥石流危险度等级．     

WATER RESOURCE MANAGEMENT AND DROUGHT FORECASTS IN SOUTH CAROLINA1

ABSTRACT: Despite potential benefits for resource planning, community water systems managers have not used seasonal climate forecasts extensively. Obstacles to forecast use include a lack of awareness of their existence, distrust of their accuracy, perceived irrelevance to management decisions, and competition from other technological innovations. In this paper, ways in which seasonal forecasts might be extended to address more directly some concerns of South Carolina community water systems managers are explored. From May 1998 through August 2002, this group experienced drought conditions that threatened water quality and supply and required restrictions on water consumption. Methods for incorporating long lead forecasts with joint probabilities of monthly temperature and precipitation to produce drought forecasts are demonstrated. When tailored to specific places, such forecasts show the likelihood of exceeding drought thresholds that would trigger water use restrictions. The methods illustrate how long lead forecasts can be extended and customized into secondary products that address issues of greater relevance to water resource managers.     

中国城市自然灾害区划编制

依据灾害系统理论和中国自然灾害数据库,构建了综合城市化水平(C1)指标和综合自然灾害强度(QC)指标;运用数字地图技术,在模型与图谱互馈过程中,实现了中国城市承灾体与致灾因子的综合定量评价,编制了中国城市自然灾害区划图.将中国区划为3个一级区,即沿海城市灾害区、东部城市灾害区和西部城市灾害区,以及15个二级区和22个三级区,为城市灾害风险管理和中国自然灾害救助区划提供了科学依据.     

Characterisation of particulate matter for toxic metals in ambient air of Kochi City, India

Measurement of respirable suspended particulate matter (RSPM) and analysis of toxic metals in air of Kochi city was carried out for a period of one year, 1997. Seasonal variations of RSPM and toxic metals are analysed to identify the influence of meteorological parameters. The air pollution problem with respect to RSPM and lead is moderately significant especially in winter season. The profile of other toxic metals in RSPM is not much significant. Domestic fuel used mainly coal/wood and petrol/diesel fueled motor vehicles are the major contributors to the RSPM and toxic metals. Various control strategies are delineated for reduction of ambient RSPM and toxic metals in air of Kochi city.