我国土壤受试植物筛选与毒性预测

生态毒性数据缺乏是我国土壤基准与生态风险评估研究中一直存在的问题,开展本土受试植物的筛选可提供更多的生态毒理试验选材,从而获得不同物种的生态毒性数据.鉴于植物对土壤污染物的敏感性,从被子植物中依据分布范围、代表性和易于获得性等原则,对我国潜在的受试植物进行筛选,结果发现,13科53种被子植物分布广泛且易于获取,可作为本土受试植物;结合生态毒性数据的搜集与分析,其中12种受试植物的生态毒性数据相对丰富,并对部分典型污染物表现高敏感.此外在受试植物生态毒性预测模型研究方面,对12种受试植物两两进行建模预测,共得到132个物种种间关系估算模型(Interspecies Correlation Estimation,ICE),其中88个为显著性模型(F检验P<0.05);此处,回归分析了已构建ICE模型的评价参数,得出预测效果较好的ICE模型应满足交叉验证成功率≥ 80.00%、MSE ≤ 0.62、R² ≥ 0.76和分类学距离≤ 4的标准.最终筛选出25个符合上述标准的ICE模型,涉及禾本科-禾本科、十字花科-十字花科的相互预测,其中当燕麦Avena sativa、芜青Brassica rapa、普通小麦Triticum aestivum、玉蜀黍Zea mays和黑麦草Lolium perenne等作为替代物种时,预测物种的实际生态毒性值与预测值较为接近.受试植物的筛选与生态毒性预测模型的建立有助于生态毒性数据的产生,并为土壤污染管理和生态风险评估提供科学依据.     

Transparency and Control in Engineering Integrated Assessment Models

Better software engineering such as archiving releases with version control, writing portable code, publishing documentation and results closely tied to the code improves integrated assessment models' transparency and control. A case study of four climate change policy analysis models found that source code and data was generally available, but for larger models licenses were more restrictive with respect to modification and redistribution. It is suggested that Free software licenses such as the GNU GPL would improve transparency and control. Moreover, opening the source allows opening the development process, a potentially important tool to improve collaboration, data sharing and models integration. This revised version was published online in July 2006 with corrections to the Cover Date.     

Synthesis and application of insect attractants in Vietnam

Detrimental effects of synthetic pesticides on health, environment and organisms have necessitated the exploration of alternative strategies for insect control. The insect attractants represent an important link within these systems. In Vietnam, since 1970, methyleugenol and its analogues have been synthesized for mass trapping of the fruitfly Daccus dorsalis Hendel. This chemical reduced the damage on the oranges of many plantations in our country. In the period 1978–1980, for the first time some selected types of pheromones were tested. The trials verified and provided evidence of the occurrence of six species of moth in southeast Vietnam: Archips micaceanus, Archips seminubilus, Cadra caustella, Spodoptera exigua, Chysodeixis eriosoma and Parapoynx sp. The last decade has seen intense activity in the elaboration and application of some complex systems of fighting plant pests. Pheromones of moth and weevils have been prepared in the Institute of Agrochemistry and the Institute of Tropical Biology NCST: Ostrinia nubilalis Hbn, Heliothis armigera Hbn, Plutella xylostella Curt, Adoxophyes sp, Lyonetia clerckella, Trogoderma granarium, Diabrotica virgifera virgifera, Diabrotica undecimpunctata, Blattela germanica, Diprion, Neodiprion, Scolytus multistriatus, Scolytus scolytus, Lasioderma sericorne, Tribolium cofusum. Some synthetic aspects of these pheromones are described. The use of pheromone traps for monitoring and mass trapping the Scolytus multistriatus, Tribolium confusum, Plutella xylostella Curt, Heliothis armigera Hbn, Cylas formicarius elegantulus will be discussed.     

基于TM数据北京城区水体叶绿素a浓度反演方法研究

叶绿素是城市水体富营养化的重要表征参数.以北京城区重点水体为研究对象,利用2011年6月8日TM遥感影像及同步获取的实测数据,在对TM数据进行几何校正和大气校正等预处理的基础上,选取相关性最大的TM2/(TM1 +TM4)波段组合进行叶绿素a浓度反演;利用2008 ～ 2010年的历史TM影像及人工水质站点准同步的实测数据,对模型的精度及适用性进行分析得出:回归模型适用于30 m以上的北京城区水体叶绿素a浓度监测,相对误差为17.04％.     

模拟氮沉降对中亚热带森林土壤中可溶性氮含量的影响

通过野外模拟试验,研究CK〔对照,0 kg(hm2.a)〕、LN〔低氮,30 kg(hm2.a)〕和HN〔高氮,100 kg(hm2.a)〕处理3个氮沉降水平对亚热带针叶(杉木)和阔叶(浙江桂、罗桴栲)森林土壤中可溶性氮含量的影响.结果表明:施氮后3 d,土壤中的w(SIN)(可溶性无机氮含量)在CK和LN处理之间差异不显著,仅发现HN处理与LN及CK处理之间的差异显著.施氮后3个月,各处理之间差异不显著;与施氮后3 d相比,土壤中的w(NH4+-N)在CK处理显著增加了42%～68%(P<0.05),而HN处理则显著降低了45%～58%(P<0.05);土壤中的w(NO3--N)平均降低了24%～88%,其中HN处理降幅最大也最显著;杉木林土壤降幅最大.施氮后3 d,随着施氮水平的提高土壤尤其是杉木林土壤中的w(SON)(可溶性有机氮含量)增加,其占w(TSN)(可溶性总氮含量)的比例降低.然而3个月后,施氮影响趋缓甚至相反;与施氮后3 d比较,HN处理下w(SON)降低,而其占w(TSN)的比例却有所升高,表明SON损失仍低于SIN.阔叶天然林土壤中的w(SON)显著高于杉木人工林,表明凋落物性质差异造成的影响与w(SON)变化有关.     

论环境保护与可持续发展

在市场经济影响下,很多人过分追求经济的快速增长,而忽略对环境和后代产生的影响,使得环境问题日益突出,也使得资源短缺的情形越来越为严重,为了缓解或是遏制这样的不良现象,对环境保护和可持续发展的需求愈来愈迫切,所以环境保护和可持续发展的概念被提出了。     

加速自然环境试验装置中太阳跟踪系统研究

自然环境加速试验是自然环境试验发展的一个重要方向,对新材料的研究具有推动作用。太阳跟踪装置是自然加速试验中的一种重要设备,文中介绍了一种太阳自动跟踪系统,有效地结合了日点轨迹跟踪方式,并采用双轴式跟踪调整装置,实现了对太阳全天候的实时跟踪。     

填方边坡变形机制研究

在对西南地区某800 kV换流站填方边坡现场进行工程地质调查的基础上,通过对经过先期治理但仍发生变形的填方边坡的变形特征和监测数据进行分析,总结边坡稳定性影响因素,并结合FLAC3D数值模拟对边坡变形破坏机制进行了研究.结果表明:该填方边坡破坏模式为整体滑移破坏,导致边坡经过治理但仍发生变形的主要诱因是强降雨,但边坡的前期治理设计也存在不足;由于降雨导致边坡重度增大,底部强风化泥岩软化,填土抗剪强度降低,在边坡内形成贯通的滑动面,滑动面绕过加筋土挡土墙的加筋带,边坡顺着强风化层从软化的坡脚剪出;位移监测显示边坡处于加速变形阶段;边坡应急治理措施应重点放在控制边坡继续沿软弱面的滑移变形上,并加强坡体排水,该边坡变形控制的治理方案对同类工程的设计与应急治理具有一定的参考价值.     

Spectrophotometric analyses of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) in water

A simple and accurate spectrophotometric method for on-site analysis of royal demolition explosive(RDX) in water samples was developed based on the Berthelot reaction. The sensitivity and accuracy of an existing spectrophotometric method was improved by:replacing toxic chemicals with more stable and safer reagents; optimizing the reagent dose and reaction time; improving color stability; and eliminating the interference from inorganic nitrogen compounds in water samples. Cation and anion exchange resin cartridges were developed and used for sample pretreatment to eliminate the effect of ammonia and nitrate on RDX analyses. The detection limit of the method was determined to be 100 μg/L. The method was used successfully for analysis of RDX in untreated industrial wastewater samples. It can be used for on-site monitoring of RDX in wastewater for early detection of chemical spills and failure of wastewater treatment systems.