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1.
多环芳烃是倍受关注的环境污染物.不同样品基质中多环芳烃的样品处理和HPLC分析方法在EPA标准方法中都有明确的描述(见表1).  相似文献   

2.
大熊猫肌肉氨基酸含量的初步研究   总被引:3,自引:0,他引:3  
测定了3只大熊猫的头部、背部和腿部等10个肌肉样品中17种氨基酸(AA)含量,并分析了各样品AA与Lys含量的比值.结果表明:对同一只大熊猫,不同部位的肌肉样品中各AA含量无明显差异;对同一个肌肉样品,17种AA含量比较,Glu含量最高,Asp、Arg、Lys、Leu、Ala、Gly、Val、Pro、Thr、Phe等含量较高;不同年龄大熊猫肌肉AA含量有差异,除极少数AA外,未成熟雄性大熊猫肌肉AA含量高于成熟和老龄雌性大熊猫,且有显著性差异(P<0.05或P<0.01);成熟雌性大熊猫肌肉中,除Pro外,其余所有AA含量与其年龄无显著差异(P>0.05);除极少数AA外,不同年龄、性别大熊猫肌肉样品中各AA与Lys含量的比值无明显差异  相似文献   

3.
应用ICP-MS技术和EPA200.8标准方法分析饮用水和污水样品   总被引:3,自引:0,他引:3  
Elzbieta 《环境化学》2001,20(6):616-619
EPA200.8方法叙述了水和污水中痕量元素的ICP-MS多元素测定方法.本文是参照EPA200.8方法No.5.4版本所叙述的方法编制的.该方法提供了适用于地下水、地表水和饮用水中可溶性元素的分析步骤.测定可溶性元素之前,水样需适当过滤并酸化.方法也可用于地下水、地表水、饮用水以及污水、淤泥和固体废弃物样品中可溶解元素总浓度的测定.为了测定水样及固体样品中可溶解元素的  相似文献   

4.
煤飞灰环境标准参考中PAHs的表征   总被引:3,自引:0,他引:3  
曹学丽  习志群 《环境化学》1996,15(2):127-137
本文采用不同提取方法以及不同溶剂对煤飞灰环境标准参考物质样中PAHs的提取效率进行了考察,采用HPLC,毛细管GC以及GC-MS对飞灰样品中的PAHs进行了分析表生对前两种分析方法的精密度、准确性和所得结果的一致性进行了研究。  相似文献   

5.
PACS的结构特征及絮凝性能研究   总被引:11,自引:0,他引:11  
高宝玉  于慧 《环境化学》1994,13(2):113-118
制备了碱化度及Al^3+/SO^2-4摩尔比不同的系列PACS,分别进行常压(干燥温度105℃)及真空干燥(真空度为-0.098MPa、干燥温度65℃)制备固体产品。用红外光谱及X-射线衍射谱研究了碱化度、Al^3+/SO^2-4摩尔比、干燥温度对PACS的结构影响,比较了干燥温度不同对PACS固体样品的溶解度及絮凝效果的影响,借助于显微电泳测定技术研究不同碱化度及不同Al^3+/SO^2-4摩尔  相似文献   

6.
采用^27Al-NMR法比较研究了PASC与PAC中铝的形态分布。实验结果表明,在PASC中,由于聚硅酸与铝水解聚合物产物间的相互作用,使得铝的水解聚合形态分布及转化情况发生了变化。在相同B值条件下,PASC中Al单和Al13的含量低于PAC中相应Al单和Al13的含量,而PASC中Al其它的含量大于PAC中Al其它的含量,其差值随着碱化度(B)和Al/Si摩尔比的减小而增大。  相似文献   

7.
Umak.  RR 《产业与环境》1998,20(3):43-46
4年多来,以马德拉斯附近的马纳利-恩诺尔工业我中实施APEEL/LAMP计划所取得的经验,为进一步发展提供了一良好的基础,在APELL方法的成功实施方面,特别重要的两步是1993年在国家安全理事会与世界环境中心之间签署一项为期4年的京解备记录,和建立一个国家顾问委员会, 利于计划成功的因素,遇到的和身心健康为止的一些成线。  相似文献   

8.
大气中PAN的测定及其与前体物的关系   总被引:3,自引:0,他引:3  
对北京中关村地区大气PAN的监测结果表明:在强日照条件下,PAN浓度随汽车等排放和NO2浓度的增加而增加,高PAN浓度水平与高O3浓度相关联;夏季的PAN浓度明显高于春季。模拟实验的结果证实:C3H6是大气中重要的PAN前体物,在一定范围内,其浓度越高,PAN浓度越大;C2H4生成PAN是困难的,H2O2的存在对C2H4反应生成PAN有促进作用;大气中SO2的存在可降低PAN的生成速率。在〈400  相似文献   

9.
聚合氯化铝铁絮凝剂的性能研究   总被引:32,自引:2,他引:32  
高宝玉  王秀芬 《环境化学》1994,13(5):415-420
煤矸石是采煤过程之废料。本文利用煤矸石制备出了聚合氯化铝铁(PAFC):一种新型无机高分子絮凝剂,探讨了Fe^3+的稳定性与溶液离子强度之间的关系,发现溶液的离子强度越大,则产生Fe(OH)3沉淀时的PH越高。研究了PAFC水解产物的ζ电位及絮凝效果随PH的变化情况,比较了PAFC、PAC和PFS的除浊性能,PAFC在PH为7.0-8.2范围内除浊效果最佳,PAFC的除浊效果优于PAC。  相似文献   

10.
用^32P后标记方法测定典型有毒污染物的DNA加合物   总被引:1,自引:0,他引:1  
刘淑芬  尹秀琴 《环境化学》1996,15(4):320-331
^32P后标记方法测定生物样品里的有毒污染物-DNA加合物的过程是用小球菌核酸酶和脾核酸酶将DNA及加合物酶解成为2‘-脱氧核苷3’-单磷酸,以它为底物,在T4多核到激酶的催化下,与γ^32PATP进行文笔磷的转移反应,形成带放射磷的2‘-脱氧核苷3’,5‘-二磷酸酯ODS-TLC吸附薄层板和PEI-TLC阴离子交换薄层板将标记过的带放射磷的^*3’,5‘-二磷酸酯分离分辨,然后用自显影技术制成加  相似文献   

11.
Conservation science is a crisis discipline in which the results of scientific enquiry must be made available quickly to those implementing management. We assessed the extent to which scientific research published since the year 2000 in 20 conservation science journals is publicly available. Of the 19,207 papers published, 1,667 (8.68%) are freely downloadable from an official repository. Moreover, only 938 papers (4.88%) meet the standard definition of open access in which material can be freely reused providing attribution to the authors is given. This compares poorly with a comparable set of 20 evolutionary biology journals, where 31.93% of papers are freely downloadable and 7.49% are open access. Seventeen of the 20 conservation journals offer an open access option, but fewer than 5% of the papers are available through open access. The cost of accessing the full body of conservation science runs into tens of thousands of dollars per year for institutional subscribers, and many conservation practitioners cannot access pay‐per‐view science through their workplace. However, important initiatives such as Research4Life are making science available to organizations in developing countries. We urge authors of conservation science to pay for open access on a per‐article basis or to choose publication in open access journals, taking care to ensure the license allows reuse for any purpose providing attribution is given. Currently, it would cost $51 million to make all conservation science published since 2000 freely available by paying the open access fees currently levied to authors. Publishers of conservation journals might consider more cost effective models for open access and conservation‐oriented organizations running journals could consider a broader range of options for open access to nonmembers such as sponsorship of open access via membership fees. Obtención de Acceso Abierto a la Ciencia de la Conservación  相似文献   

12.
A bioblitz inexpensively and quickly generates biodiversity data, but bioblitzes are often conducted with haphazard, unreplicated sampling. Results tend to be taxonomically, geographically, or temporally biased, lack metadata, and consist of lists of observed taxa that do not enable further analyses or correction for imperfect detection. A rapid, recurring, structured survey (RRSS) uses a structured sampling design and temporal and spatial replication to survey randomly selected sites on a conservation property. We participated in a loosely structured bioblitz and a subsequent RRSS at Big Canoe Creek Nature Preserve in Springville (St. Clair County), Alabama (USA) to compare observed richness derived from the 2 survey approaches. The RRSS data structure enabled us to fit models that accounted for imperfect detection to estimate abundances, occupancy probabilities, and habitat associations. The loosely structured bioblitz data could not be used in such models. We present a new integrated multispecies abundance model that we applied to avian RRSS data. Our model extension enables estimation for the community, employs data augmentation to estimate the number of undetected species, and incorporates covariates. The RRSS generated a more comprehensive and less biased list of observed taxonomic richness than the loosely structured bioblitz (e.g., 73 vs. 45 bird species and 104 vs. 63 insect families from the RRSS vs. loosely structured bioblitz, respectively). Models fit to the RRSS data identified seasonal patterns in avian community composition and allowed for estimation of habitat–occupancy relationships for insect taxa. The RRSS protocol has potential for broad transferability as a standardized, quick, and inexpensive way to inventory biodiversity and estimate ecological parameters while providing an outreach opportunity.  相似文献   

13.
Land-use change via human development is a major driver of biodiversity loss. To reduce these impacts, billions of dollars are spent on biodiversity offsets. However, studies evaluating offset project effectiveness that examine components such as the overall compliance and function of projects remain rare. We reviewed 577 offsetting projects in freshwater ecosystems that included the metrics project size, type of aquatic system (e.g., wetland and creek), offsetting measure (e.g., enhancement, restoration, and creation), and an assessment of the projects’ compliance and functional success. Project information was obtained from scientific and government databases and gray literature. Despite considerable investment in offsetting projects, crucial problems persisted. Although compliance and function were related to each other, a high level of compliance did not guarantee a high degree of function. However, large projects relative to area had better function than small projects. Function improved when projects targeted productivity or specific ecosystem features and when multiple complementary management targets were in place. Restorative measures were more likely to achieve targets than creating entirely new ecosystems. Altogether the relationships we found highlight specific ecological processes that may help improve offsetting outcomes.  相似文献   

14.
Summary Interactions were studied among alkaloid-containing legumes (Erythrina corallodendrum andSpartium junceum) and non-toxic plants (Citrus sinensis, Cucurbita moschata andEuphorbia tirucalli), several polyphagous homopterans,Aphis craccivora (Aphididae),Icerya purchasi, I. aegyptiaca (Margarodidae),Lepidosaphes ulmi (Diaspididae) andPlanococcus citri (Pseudococcidae), and some major natural enemies of these homopterans. Significant reductions in survival due to negative effects of alkaloid containing as compared with non-alkaloidal plants were recorded for the predatorsRodolia cardinalis andChilocorus bipustulatus, but not forCryptolaemus montrouzieri (Coleoptera: Coccinellidae),Chrysoperla carnea (Neuroptera: Chrysopidae) andSympherobius sanctus (Neuroptera: Sympherobiidae). The development time of the larvae or pupae ofR. cardinalis, C. carnea andS. sanctus was longer on the toxic plants than on the non-toxic ones. The percentage of parasitism ofA. craccivora collected from the non-alkaloidal plantsVicia palaestina andMelilotus albus was much higher than that onS. junceum. The parasitoid complexes ofA. craccivora differed between both plant groups. The nutritive value of honeydew ofI. purchasi andA. craccivora, as expressed by the life span ofEncyrtus infelix (Hymenoptera: Encyrtidae) adults, was also investigated. Life spans were significantly longer when the wasps fed on honeydew produced on non-alkaloidal plants (C. sinensis andPittosporum tobira) than on alkaloid containing plants whenI. purchasi — but notA. craccivora — was the producer. It is suggested that the chemical defense ofE. corallodendrum andS. junceum is exploited by polyphagous phytophages to reduce predation. In nature, population growth and density of four of the investigated homopterans are conspicuously high when they developed on the alkaloid containing plant species, and very low on non-alkaloid plants. The efficiency of their natural enemies may be reduced by sequestration of alkaloids (or other toxic plant compounds) or their transfer into excreted honeydew. Therefore it is assumed that a generalist phytophagous homopteran may be protected from its natural enemies, although at different rates of efficiency, if it can safely sequester the host allelochemical when it develops on toxic species within its host range.  相似文献   

15.
An argument is presented in which areas of natural arsenic contamination of modern groundwaters throughout Asia have a common origin. Arsenic originally accumulated in oceanic ferro-manganoan sediments of the eastern Palaeo-Tethys. This was further concentrated through oceanic crustal extinction in what later became the south-east Chinese accreted mineralised terrain. Proto-Himalayan uplift of this area created the palaeo-drainage systems of the Ganges – Brahmaputra, Irrawaddy, Mekong, and Red Rivers, with consequent headwater erosion of arsenic-rich sediments. Their downstream deposition as immature and easily redistributed Neogene sandstones, silts, and iron-rich clays has created secondary and tertiary reservoirs of adsorbed and authigenic arsenic, from which the current arsenic-rich groundwaters have evolved. Considering river basins within the above palaeo-hydrogeological framework provides a basis for assessing the risk of arsenic in groundwater basins of south and south-eastern Asia.  相似文献   

16.
Summary Two South American polyphagous leaf beetles,Diabrotica speciosa andCerotoma arcuata, selectively accumulated the bitter tasting compound 23,24-dihydrocucurbitacin D in their body after ingesting root tissues of cucurbit plants. Similarly, three Asian Cucurbitaceae-feeding specialists in the genusAulacophora were found to sequester the same compound. Cucurbitacin analogs were shown to deter feeding by a bird predator, indicating an allomonal role for these compounds in cucurbitacin-associated chrysomelid leaf beetles both of New and Old Worlds. The strong affinity to cucurbitacins, selective sequestration of the analogs and consequent protection from predators suggested an ecological adaptation mechanism developed in common among these two geographically isolated subtribes in the Luperini.  相似文献   

17.
Large, intact areas of tropical peatland are highly threatened at a global scale by the expansion of commercial agriculture and other forms of economic development. Conserving peatlands on a landscape scale, with their hydrology intact, is of international conservation importance to preserve their distinctive biodiversity and ecosystem services and maintain their resilience to future environmental change. We explored threats to and opportunities for conserving remaining intact tropical peatlands; thus, we excluded peatlands of Indonesia and Malaysia, where extensive deforestation, drainage, and conversion to plantations means conservation in this region can protect only small fragments of the original ecosystem. We focused on a case study, the Pastaza‐Marañón Foreland Basin (PMFB) in Peru, which is among the largest known intact tropical peatland landscapes in the world and is representative of peatland vulnerability. Maintenance of the hydrological conditions critical for carbon storage and ecosystem function of peatlands is, in the PMFB, primarily threatened by expansion of commercial agriculture linked to new transport infrastructure that is facilitating access to remote areas. There remain opportunities in the PMFB and elsewhere to develop alternative, more sustainable land‐use practices. Although some of the peatlands in the PMFB fall within existing legally protected areas, this protection does not include the most carbon‐dense (domed pole forest) areas. New carbon‐based conservation instruments (e.g., REDD+, Green Climate Fund), developing markets for sustainable peatland products, transferring land title to local communities, and expanding protected areas offer pathways to increased protection for intact tropical peatlands in Amazonia and elsewhere, such as those in New Guinea and Central Africa which remain, for the moment, broadly beyond the frontier of commercial development.  相似文献   

18.
19.
Abstract: In East Africa fire and grazing by wild and domestic ungulates maintain savannas, and pastoralists historically set fires and herded livestock through the use of temporary corrals called bomas. In recent decades traditional pastoral practices have declined, and this may be affecting biodiversity. We investigated the effects of prescribed fires and bomas on savanna bird communities in East Africa during the first and second dry seasons of the year (respectively before and after the rains that mark the onset of breeding for most birds). We compared abundance, richness, and community composition on 9‐ha burned plots, recently abandoned bomas, and control plots in the undisturbed matrix habitat over a 3‐year period. Generally, recently burned areas and abandoned bomas attracted greater densities of birds and had different community assemblages than the surrounding matrix. The effects of disturbances were influenced by interactions between primary productivity, represented by the normalized difference vegetation index, and time. Bird densities were highest and a greater proportion of species was observed on burned plots in the months following the fires. Drought conditions equalized bird densities across treatments within 1 year, and individuals from a greater proportion of species were more commonly observed on abandoned bomas. Yearly fluctuations in abundance were less pronounced on bomas than on burns, which indicate that although fire may benefit birds in the short term, bomas may have a more‐lasting positive effect and provide resources during droughts. Several Palearctic migrants were attracted to burned plots regardless of rainfall, which indicates continued fire suppression may threaten their already‐declining populations. Most notably, the paucity of birds observed on the controls suggests that the current structure of the matrix developed as a result of fire suppression. Traditional pastoralism appears critical to the maintenance of avian diversity in these savannas.  相似文献   

20.
How should managers choose among conservation options when resources are scarce and there is uncertainty regarding the effectiveness of actions? Well‐developed tools exist for prioritizing areas for one‐time and binary actions (e.g., protect vs. not protect), but methods for prioritizing incremental or ongoing actions (such as habitat creation and maintenance) remain uncommon. We devised an approach that combines metapopulation viability and cost‐effectiveness analyses to select among alternative conservation actions while accounting for uncertainty. In our study, cost‐effectiveness is the ratio between the benefit of an action and its economic cost, where benefit is the change in metapopulation viability. We applied the approach to the case of the endangered growling grass frog (Litoria raniformis), which is threatened by urban development. We extended a Bayesian model to predict metapopulation viability under 9 urbanization and management scenarios and incorporated the full probability distribution of possible outcomes for each scenario into the cost‐effectiveness analysis. This allowed us to discern between cost‐effective alternatives that were robust to uncertainty and those with a relatively high risk of failure. We found a relatively high risk of extinction following urbanization if the only action was reservation of core habitat; habitat creation actions performed better than enhancement actions; and cost‐effectiveness ranking changed depending on the consideration of uncertainty. Our results suggest that creation and maintenance of wetlands dedicated to L. raniformis is the only cost‐effective action likely to result in a sufficiently low risk of extinction. To our knowledge we are the first study to use Bayesian metapopulation viability analysis to explicitly incorporate parametric and demographic uncertainty into a cost‐effective evaluation of conservation actions. The approach offers guidance to decision makers aiming to achieve cost‐effective conservation under uncertainty.  相似文献   

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