基于对应分析法的吉林西部地下水化学特征时空演化研究

运用对应分析方法,分析了吉林西部地下水化学特征随时间、空间的变化.对研究区进行了分区,分别确定了各区的主要影响因子,并分析了各区的主要因子随时间的变化趋势.最后,结合吉林西部的水文地质条件与人类活动,分析了地下水化学成分的来源及成因.结果显示,吉林西部地下水按照其水质特征可分为3个区:Ⅰ区,位于山前平原的通榆北部、长岭南部等地及盐碱区,阴离子主要为HCO-3,总碱度大,动态变化平稳;Ⅱ区,位于西部山前平原与中部低平原区间过渡带的洮南中部、通榆东北部等地,Ca2+、Mg2+含量高,硬度大,NO-3-N含量较高,且有增大趋势;Ⅲ区,位于低平原区的乾安、前郭、大安地区,主要为高矿化度水,阴离子主要为SO2-4、Cl-,阳离子为Na+,矿化度有增大趋势.上述分析结果符合当地实际.研究表明,地下水化学特征时空演化研究可为地下水污染的防治、生态环境的改善提供重要依据.     

HPLC-MS/MS测定城市废水中的10种药物与个人护理用品

采用固相萃取技术对水样进行预处理,结合液相色谱-串联质谱分析方法(HPLC-MS/MS),建立了同时检测城市废水中包括扑热息痛、萘普生、磺胺甲恶唑、磺胺二甲嘧啶、三氯生、双氯芬酸钠、三氯卡班、盐酸四环素、盐酸土霉素、吉非罗平在内共计10种药物与个人护理用品(PPCPs)的分析检测方法。采用中性条件萃取水样,控制上样流速为3—5 mL?min~(–1),用甲醇溶液洗脱。纯水的平均加标回收率为40.8%—104.5%,相对标准偏差为5.0%—25.5%(n=3)。应用所建立的分析方法,对西安浐河表层水进行了分析。结果表明:该方法可用于城市废水PPCPs的检测。10种目标物质中,共检测到4种,其含量为1.4—15.0 ng?L~(–1)。     

封管法制备有机碳稳定同位素样品存在的问题和改进

有机碳稳定同位素的高精度测定是利用地质样品有机碳同位素研究气候和植被变化等的基础。通过实验发现低有机碳含量样品同位素测定误差相对较大,其中样品收集过程是主要的影响因素之一。本文针对这个问题,主要从杂质气体干扰入手,在一步冷冻分离CO_2和H_2O,或分步冷冻分离CO2和H2O的收集方法,以及改变收样管体积三方面进行条件实验研究,讨论了封管法制备有机碳稳定同位素样品气体收集过程对有机碳稳定同位素组成的影响。结果表明:(1)CO_2气体的纯化收集是封管法制备有机碳稳定同位素样品的一个重要步骤,收集时杂质气体含量越高,对样品有机碳稳定同位素组成的影响越大;(2)在相同的杂质气体背景条件下,与一步冷冻分离CO_2和H_2O的方法相比,分步冷冻CO2和H2O的方法能够显著减小杂质气体对有机碳稳定同位素测定的影响;(3)小体积收样管能够显著提高有机碳稳定同位素样品的离子流强度,进而提高低有机碳含量样品的稳定碳同位素测定精度。     

不同入口位置的行人进入流实验研究

为了研究行人进入流运动规律,寻找合理的入口位置,对不同入口位置(中间、右侧)进行了不同人数(10人、20人、30人、40人)的可控实验。分析了行人进入流的时间、速度和空间分布,并统计了空间分布影响因素——入口避让、边界吸引、分布角度和空间关系的规律。结果表明,入口位于中间的设计更好,进入时间和稳定时间较短,速度更快,空间分布更合理。这些影响因素的统计,也为行人进入流的模型建立提供了实验基础。     

Sustainability of rice production systems: an empirical evaluation to improve policy

An evaluation is needed to monitor the progress of sustainable development (SD) in rice production systems. The purpose of this study is to provide policy inputs, examine the sustainability of rice production, and determine major policy areas. A requisite set of 12 indicators of three dimensions of SD, namely economic, was generated by employing an assemblage of top–down and bottom–up approaches. The data were gathered from farm households’ survey as well as in-depth discussion with stakeholders from the regions that represent irrigated, rain-fed lowland, rain-fed upland, flood-prone, and saline-prone rice-growing ecosystems in Bangladesh. By constructing composite indicators, the results revealed that 44 % of rice growers were economically viable, environmentally sound, and socially developed. The irrigated rice production system was found to be the most sustainable. The path analysis measured the contribution of the indicators to the index, and results highlighted that rice growers’ knowledge, skills, and social networks development, improving land productivity, and integrated nutrient management were essential for promoting sustainable rice production. However, the study findings suggest that pluralistic (i.e., government and non-government) agricultural advisory services can serve as an engine of transition to rice production sustainability in which a multi-year planning and strategy formulation are crucial besides investing in the modernization of extension services. Overall and ecosystem-specific policy implications that emerged from the findings of this study are outlined.     

黑龙江、松花江航道疏浚工程对水生生物环境影响研究

针对黑龙江、松花江航道疏浚工程对水生生物环境影响问题,提出了疏浚工程对水生生物的影响,包括对浮游植物的影响、对浮游动物的影响、对底栖动物的影响和对水生植物的影响,将产生泥沙、悬浮物、噪音、底质改变及机械废水、固体垃圾等,进而对鱼类资源的影响分析,包括施工噪音对鱼类的影响,如对鱼类栖息地的影响、对鱼类摄食生长的影响、对鱼类产卵行为的影响、悬浮物对鱼类生存的影响、对鱼类卵、苗的影响和对鱼类洄游通道的影响。     

Tie them up tight: wrapping by Philoponella vicina spiders breaks, compresses and sometimes kills their prey

We show that uloborid spiders, which lack the poison glands typical of nearly all other spiders, employ thousands of wrapping movements with their hind legs and up to hundreds of meters of silk line to make a shroud that applies substantial compressive force to their prey. Shrouds sometimes break the prey’s legs, buckle its compound eyes inward, or kill it outright. The compressive force apparently results from the summation of small tensions on sticky lines as they are applied to the prey package. Behavioral details indicate that wrapping is designed to compact prey; in turn, compaction probably functions to facilitate these spiders’ unusual method of feeding. This is the first demonstration that prey wrapping by spiders compacts and physically damages their prey, rather than simply restraining them.     

建设海峡西岸高效持续农业示范区的基本思路与技术对策——以福建省龙海市为例

本文以福建省龙海市为例,分析了龙海市农业发展优势与存在的问题,提出了建设海峡西岸高效持续农业示范区的基本思路与技术对策     

Institutional Arrangements for Flood Hazards in Malaysia: An Evaluation Using the Criteria Approach

Institutional aspects of flood hazards significantly affect their outcomes in Malaysia. Institutional arrangements to deal with floods include: legislative activity, organisational structures, attitudes and sub-culture, and policies and instruments. When assessed in terms of four specific criteria, institutional aspects of flood hazards are found to be largely inadequate. Disaster reduction programmes are over-dependent on a reactive approach based largely on technology and not even aimed at floods specifically. Structual flood reduction measures are the predominant management tool and, although the importance of non-structural measures is recognised, thus far they have been under-employed. Current laws and regulations with regard to flood management are also insufficient and both the financial and human resources of flood hazard organisations are generally found to be wanting. Finally, economic efficiency, equity and public accountability issues are not adequately addressed by institutional arrangements for flood hazards.