四种~(14)C标记农药在某些海洋动物中的积累和降解     

钟创光  赵小奎  陈舜华  符云 《热带海洋学报》1998,(4)

对14C－六六六、14C-毒死蝉、14C-敌百虫和14C-久效磷在几种海洋动物中的积累和降解进行了比较研究。结果表明,4种农药在实验动物中被积累的能力由大至小顺序为：14C－六六六和14C－毒死蝉,14C－敌百虫,14C－久效磷。而实验动物对农药的积累能力由大至小顺序为：小弹涂鱼Periophthalmuscantonensis,实验贝类,褶痕相手蟹Sesarma（Parasearma）plicata。不同动物对毒死蜱的降解能力各不相同：弹涂鱼的降解能力最强,其主要降解产物为三氯代吡啶酚（TCP）;毛蚶Scapharcasuberenata次之,主要降解产物为极性未知物;褶牡蛎AlectryonellaPlicatula和翡翠贻贝Pernaviridis的降解率也在30％以上,降解产物为TCP和极性未知物;波纹巴非蛤Pophia（Paphia）undulata和文蛤Meretrixmereitrix的降解能力较差。对14C－六六六和14C－毒死蜱在生物中的结合态比例有很大的差异。  相似文献   

震旦纪生命大爆炸!──浅论地史早期动物的演化     

陈孟莪 《华北地质》1999,(3)

本文列举了晚前寒武纪特别是震旦纪动物化石的记录。阐述了地史早期动物演化的主要研究成果及存在的问题,预测在不久的将来该领域定会取得突破性进展。  相似文献   

Relationships between sediment contamination and toxicity in San Francisco Bay     

B. Thompson  B. Anderson  J. Hunt  K. Taberski  B. Phillips 《Marine environmental research》1999,48(4-5)

Sediment contamination and toxicity were monitored at 14 sites in San Francisco Bay between 1991 and 1996. Sediment contamination patterns were different in the major reaches of the Bay, and at each site. Several contaminants were consistently above concentrations previously associated with toxicity at most sites. Bulk sediment bioassays using the amphipod Eohaustorius estuarius and sediment elutriate bioassays using larval bivalves (Mytilus spp., Crassostrea gigas) also indicated different patterns of sediment toxicity in space and time. Sediments were most toxic to the amphipods at Redwood Creek (90% of the tests), and were toxic in at least half the tests conducted at five other sites. Sediment elutriates severely reduced normal bivalve larval development at the San Joaquin and Sacramento Rivers in all samples, but toxicity occurred in less than a third of the tests in the Central and South Bays. Toxicity could not be statistically related to seasonal freshwater flow or rainfall in the Bay, but seasonal variation in contaminant concentrations and toxicity was observed. Amphipod toxicity was inversely and significantly related to the mean effects range-median quotient, suggesting that cumulative concentrations of several contaminants were related to toxicity. Further analysis identified suites of specific contaminants at each site that were variably related to amphipod toxicity at each site. Chlordanes, cadmium, and silver were significantly related to amphipod survival in the North Bay. Seasonal patterns in low, and high molecular weight polycyclic aromatic hydrocarbons (PAHs) were related to toxicity at Alameda, and metals and PAHs were related to toxicity at Castro Cove. Larval bivalve toxicity was associated with metals in bulk sediments, but elutriate chemistry was not measured, and relationships with toxicity could not be examined. Hypotheses about effective concentrations of several individual contaminants and mixtures of contaminants were posed.  相似文献   

组合型浮床生态系统的构建及其改善湖泊水源地水质的效果   总被引：14，自引：0，他引：14  

李先宁  宋海亮  朱光灿  李大成  吕锡武 《湖泊科学》2007,19(4):367-372

研究开发了一种由水生植物、水生动物及微生物膜构建的组合型浮床生态系统.在野外条件下,考察了该浮床对富营养化湖泊水在静态条件下的净化效果.结果表明,20 d内TN、TP的去除率分别为83.7%和90.7%,透明度也有大幅提高.而且,组合型浮床系统对有机物尤其是难降解有机物的去除能力较强,在25 d内,对r-BHC、HE、DDE、DDD、DDT的去除率分别为25.2%、63.8%、42.1%、71.6%和27.6%,氯苯、阿特拉津的去除率达55.9%和72.1%.水生动物的代谢活动提高了有机物的生物可降解性和氮磷的植物可利用性.该新型浮床可用于水源地水质改善、污水净化生态工程、富营养水体的生态恢复等.  相似文献   

富营养化浅水湖泊生态修复中背角无齿蚌(Anodonta woodiana)对水质改善的影响   总被引：2，自引：0，他引：2  

吴中奎  邱小常  张修峰  刘正文  唐雅丽 《湖泊科学》2018,30(6):1610-1615

滤水速率的快慢是决定滤食性河蚌对水质改善与否的关键,但受蚌龄大小、食物多少和季节变化的影响.以背角无齿蚌（Anodonta woodiana）为研究对象,设置幼龄蚌组、成年蚌组和无蚌对照组,在惠州西湖生态修复后的清水态和未修复的富营养化水体同时进行中型系统原位实验,测定了各处理组水层中氮、磷、总悬浮物（TSS）浓度和浮游藻类生物量（用叶绿素a（Chl.a）浓度表示）的季节变化,以研究蚌龄、食物和季节变化对背角无齿蚌水质改善的影响.结果表明,与对照组相比,背角无齿蚌提高了清水态水体总磷（TP）和铵态氮浓度,但对总氮（TN）、TSS和浮游藻类Chl.a浓度的影响不显著,表明其不能有效改善清水态水体水质;富营养化水体中,背角无齿蚌虽对水中TN浓度影响不显著,但显著降低了TP浓度、浮游藻类Chl.a浓度和TSS浓度;表明背角无齿蚌可改善富营养化水体水质;且富营养化水体中幼龄蚌的滤水速率显著高于成年蚌;幼龄蚌的滤水速率春季最大（0.132±0.018 L/（g·h））,夏季最小.因此,在富营养化水体修复前期,可通过放养本地滤食性河蚌,如背角无齿蚌,以改善水质,春季放养幼龄蚌更佳,为接下来的修复创造有利条件;而在生态修复后期的清水态水体中,单独的河蚌对水质改善效果不明显.本研究可为水生态系统保护和富营养化水体生态修复提供参考.  相似文献   

黑土肥力质量评价的生物指标研究进展   总被引：1，自引：0，他引：1  

房娜娜  刘凯  刘国栋  许江  张一鹤  杨泽  陈江  戴慧敏 《地质与资源》2020,29(6):518

由于受到自然因素和人类掠夺式开发利用的影响,黑土肥力下降不断加剧,对国家粮食安全构成重大威胁,黑土肥力质量评价指标已成为当今土壤学的研究热点.传统的研究涉及较多化学和物理指标,近年来生物检测技术迅猛发展,土壤生物指标因其灵敏性较高已逐渐成为土壤肥力质量评价的重要参数,但还没有形成统一的标准,因此有必要梳理一下土壤生物指标.本文对近些年土壤微生物、酶活性及动物等土壤肥力质量评价的生物指标的研究进展进行了综述,为黑土肥力质量评价提供新的研究思路和手段.  相似文献   

沙质草地土壤动物的研究进展及建议   总被引：6，自引：1，他引：6  

刘任涛  赵哈林 《中国沙漠》2009,29(4):656-662

中国北方农牧交错带,生态背景脆弱,在自然因素和人为活动的严重干扰下,生态系统遭到了严重破坏,草地面临严重沙化的威胁。而土壤动物是沙质草地生态系统物质循环和能量流动的不可或缺的一环,对保护和改善土地资源,控制由于各种原因而导致的土地退化、土地沙漠化有着重要意义。从沙质草地土壤动物的物种组成、研究方法、时空动态变化及其对生态系统的作用等方面进行了总结,分析了当前沙地土壤动物研究中存在的问题,并为未来沙地土壤动物研究提出了一些建议,从而为沙质草地生态系统恢复和重建及沙漠化逆转等提供了基础资料。  相似文献   

中国卤虫(Artemia sinica)早期胚胎发育相关基因表达序列标签(ESTs)分析          下载免费PDF全文

侯林  邹向阳  姚锋  林盛国  徐明玉  陈志娟  姜丽娟  孙文静 《海洋与湖沼》2008,39(2):139-144

以mRNA差异显示技术分析了中国两性生殖卤虫早期胚胎发育相关基因的表达序列标签(ESTs),共回收了2000条差异条带并进行了克隆、测序,在GenBank/DDBJ/EMBL数据库中用BLASTX和BLASTN软件分别与NCBI上的非冗余核酸序列数据库进行同源性比对,得到分值较高、长度在100bp—2kb以内的ESTs序列133条。所发现的133条ESTs的生物学功能分类为:能量代谢占24%、细胞生长、分裂相关基因占23%、RNA相关占17%、体节形成占12%、蛋白质合成占3%、转录因子占3%、离子转运占5%、细胞信号转导占4%、未知占9%。对所发现的ESTs进行了RT-PCR测定,排除假阳性能够提供足够数量的信息用于获取其全长cDNA,进而获得其全长基因序列以用于功能研究。另外,研究发现了包括小热休克蛋白基因家族、Hox基因家族的abdA和Dfd基因、A-trh基因(排盐器官及盐调节基因)、HIF(缺氧诱导因子)、CK-M2(肌肉型磷酸激酶基因)和GRP基因(富甘氨酸蛋白基因)等20个具有明显功能的相关基因的ESTs和完整基因序列和开放阅读框(ORF)。经初步推断这些ESTs和基因的功能大多为与卤虫发育的生理、生化相关的基因有关。所研究的133条ESTs基本代表了卤虫早期胚胎发育相关功能基因的表达谱。  相似文献   

Aeolian construction and alluvial dismantling of a fault‐bounded intracontinental aeolian dune field (Teruel Basin,Spain); a continental perspective on Late Pliocene climate change and variability     

JUAN PEDRO RODRÍGUEZ‐LÓPEZ  CARLOS L. LIESA  JAN VAN DAM  PALOMA LAFUENTE  LUIS ARLEGUI  LOPE EZQUERRO  POPPE L. DE BOER 《Sedimentology》2012,59(5):1536-1567

An aeolian dune field migrating to the east encroached on the toes of alluvial fans in the Teruel Basin (eastern Spain) during a short interval in the Late Pliocene (ca 2·9 to 2·6 Ma), when Northern Hemisphere glaciation and strong glacial–interglacial cycles began. Preservation of the dune field was controlled by syn‐sedimentary activity of a normal fault. Ephemeral water discharge eroded aeolian sands and formed V‐shaped channels in which aeolian sandstone blocks accumulated. The incorporation of loose aeolian sand in wadi waters modified the sediment/water ratio, changing the physical properties of the flows as they penetrated the aeolian dune field. The erosion and cover of aeolian dune foresets by sheetflood deposits suggest that dune‐damming caused the intermittent ponding of water behind the dunes and its flashy release. The arid climate in the Late Pliocene western Mediterranean realm favoured the transport of windblown sediments from northern Africa and western Mediterranean land masses into the Mediterranean. The formation of the studied aeolian dune field (2·9 to 2·6 Ma) and possibly others (for example, the Atacama, Namib and Sahara deserts) correlates with a strong increase of the influence of obliquity, which can be attributed to the combination of a regional expression related to the reduced effect of precession due to a minimum in the long‐period (2·3 Ma) eccentricity cycle and a remote expression of the onset of the Northern Hemisphere glaciation.  相似文献   

变蛋中微量铅的催化示波极谱法测定     

谢娟  兰斌明 《地球科学与环境学报》2000,22(2):96-98

用催化示波极谱法测定变蛋中微量铅 ,提出在HCl-酒石酸 -KI -抗坏血酸体系中 ,用催化示波极谱法测定变蛋中微量铅。在此体系中 ,Pb(ⅠⅠ )于 -0 54V处产生一个非常灵敏的吸附催化波。铅含量在 0 0 2 5～ 3 μg·mL-1 范围内波高与浓度呈良好线型关系 ,相关系数r为 0 9976,检测限为0 0 2 5μg·mL-1 。样品经HNO3 -HClO4消化和分解 ,蒸至近干后 ,再用HCl溶解 ,在HCl-酒石酸 -KI体系中测定 ,回收率为 ( 98± 2 ) %。此方法具有灵敏、准确、快速等特点 ,适用于变蛋及其他食品、人发等样品中微量铅的测定  相似文献