Effect of Cu toxicity at different salinity on selective group of juvenile pompano Trachinotus ovatus

Effects of copper toxicity and salinity shock on selective group of juvenile pompano Trachinotus ovatus were investigated.The fish were exposed to different Cu2+ concentrations of 0(blank),0.02(C1),0.05(C2),0.10(C3),and 0.15 mg·L–1(C4)at a salinity of 10‰ or 40‰ for 96 h,with the salinity of 29‰ as the control.The results showed that the effects of the acute salinity stimulation to survival rates of pompano between control(29‰)and lower or higher salinity for 96 h were not significant(p0.05).However,the survival rates in each treatment were decreased with the increase of Cu2+ concentration.The dominant factor influencing body moisture of the fish was salinity,and there was no sign that body moisture was correlated with exposure to Cu2+.The gill lamellas in high level of Cu2+ concentration(C4 treatments)were abnormal under the salinity of 40‰ and extremely curly under the salinity of 10‰.Hemorrhage in gill was observed in the two C4 treatments.Under transmission electron microscope,pillar cells in gill lamellas appeared deformed and ruptured in some areas of the epithelia in the higher concentration of Cu2+,resulting in the death of the fish due to the destruction of gill tissue,elevation of the arithmetic mean distance from water to blood,the decrease of oxygen diffusion capacity,and other physiological functions.These findings indicate that the pompano might suffer much more pressure when encountered with Cu2+ pollution and low salinity.     

Vertical mixing of gravel over a long flood series

Vertical sediment exchange is a fundamental component of bedload transport in gravel‐bed channels. This paper describes the characteristic depth of exchange achieved over a long flood series. Analysis is based on 11 recoveries of magnetically tagged gravels deployed in Carnation Creek, Canada, completed between 1990 and 2008. Vertical grain exchange mixes gravels throughout the streambed relatively rapidly. Within one to eight floods the mean burial depth approaches two times the surface layer thickness, quantified by the 90th percentile of the size distribution. Finer gravels are mixed more rapidly into the bed than coarser gravels. Both active and passive grain exchanges throughout most of the bed produce the overall vertical distribution of marked grains. Gravel exchanges exhibit fairly consistent patterns once tracers are well mixed by large floods. Results highlight the role of flood sequence in determining exchange depths, support the notion of an upper limit to exchange, and underscore the importance of passive grain exchange. Copyright © 2011 John Wiley & Sons, Ltd.     

铼-锇同位素分析样品预处理研究进展

文章评述并归纳了近年来地质样品中Re-Os同位素分析的化学前处理方法研究进展。总结了锍镍火试金法、碱熔法、Carius管溶样法以及HPA-S高温高压釜溶样法等常用的Re-Os同位素样品消解方法。归纳了离子交换、溶剂萃取富集Re以及蒸馏、萃取等分离富集Os的方法。由于地质样品的复杂性,Re、Os含量的不均一性及测试方法的多样性,要求在具体分析过程中不同的样品使用不同的消解方法和分离富集方法。当前国内应用较成熟的Re、Os分离方法是Carius管逆王水分解样品,原位蒸馏或CCl4萃取方法分离Os,阴离子交换法或丙酮萃取分离Re。     

池养条件下军曹鱼仔鱼的消化道内容物

采用光镜解剖观察的方法对池塘培育的1-20日龄军曹鱼仔鱼消化道内容物的种类、数量和大小进行研究。结果显示：军曹鱼仔鱼于2日龄开口，主要摄食桡足类无节幼体和桡足幼体及枝角类；在2～20日龄阶段，桡足类在军曹鱼仔鱼食谱中占据主要成分；从13日龄开始摄食虾、蟹类幼体等大型浮游动物，两个阶段的食物选择性指数存在显著差异。     

POTENTIOMETRIC TITRATION OF CALCIUM IN SEAWATER

Atpasent,thestandardmethodfordetendningcalciuminseawateriscomPlexometrictitrationusingEGTA[ethyleneglycol-bis(2-adrinoethylether)-N,N,N',N'-tetraaceticacid]andGHAtelyoxal-bis(2-hydroxyanil)].ThisInethodwasfirStdeveopedbyTSunogaietal.(l968),sumrnarindbyKremling,andeditalinMethodsofSeawaterAnalySisbyGrasshoff(l983).AlthoughtheendpointreadingsinthismethodarenotquitCsharp,andrnaybeaffCCtedbyoveanstweather,withtheuseofcalctumISEasindicatingeledrode,SCEasreferenceeledrodeanddigitalvoltme…     

中国典型有机污染场地土层岩性和污染物特征分析

目前我国存在大量待修复场地,其分布具有一定的规律性和区域性,场地地层系统结构复杂、渗透性空间异质性显著,污染物种类复杂。总结场地典型土层结构和典型污染物有助于有针对性地开展修复技术的研发。为此,本文收集并整理了全国136处有机污染场地相关资料,对其地域性、地层及污染物特征总结如下:目前我国已经开展调查与修复的有机污染场地主要集中在京津冀和沪宁杭地区;有机污染场地土层基本都含有黏土等低渗透介质,而且都具有非均质性,其中67%场地土层有强非均质性;沪宁杭地区场地土层渗透性总体低于京津冀和辽中南地区,此外我国京津冀和辽中南地区场地调查深度(20.3 m)总体大于沪宁杭地区(12.8 m);我国有机污染场地地下水中最常见的有机污染物种类为氯代溶剂,依次为氯代烷烃类(场地数量占比84%)、氯代苯类(场地数量占比46%)和氯代烯烃类(场地数量占比33%);最常见的3种氯代溶剂依次为二氯乙烷、一氯苯和三氯甲烷。     

New Extraction System for Lithium from Brine with High Magnesium Content

正Lithium is an important element with a wide variety of applications,especially in lithium ion batteries and in the exploration of nuclear energy.Salt lake brine is the most abundant lithium source available in world,comp-rising70%~80%of all known lithium deposits.Lithium can be abstracted from brines with low magnesium content and processed into kinds of lithium compound in Atacama and Hombre Muerto of South America(Nie et al.,2013).     

调剖技术在埕岛油田的应用及效果分析

基于埕岛油田的油藏特征及海上条件限制,依据PI决策理论,选用酚醛树脂交联体系冻胶,高黏的聚合物乳液为过顶替液,通过分轮次注入对4口井进行了深部堵水调剖。堵水调剖后,油藏水驱效果明显改善。通过对堵水调剖效果的分析研究,对深度调剖技术实施过程中堵剂的用量、冻胶凝固时间及施工轮次进行了总结和探索,对其他海上油田开展堵水调剖具有指导意义。     

Hydrology of Okarito Lagoon and the inferred effects of selective logging in Okarito Forest

Okarito Lagoon (43° 11′S, 170° 14′E) is a small (20 km²) shore‐parallel, predominantly subtidal estuary, deepest near the landward end, and linked to the sea by two subtidal channels incised through shallow subtidal and intertidal flats which occupy the southern third of the lagoon. Tides at sea vary from 2.1m (spring) to 1.2 m (neap), but in the lagoon the tidal range is constant through the lunar cycle and varies from 0.80 m at the entrance to 0.17 m in the upper lagoon. Tidal water level and flow asymmetries in the subtidal channels are separated by a 1.7 h phase difference. Variations in the net discharge through the inlet result from changing flow cross‐sections rather than from variations in current velocities. Both the tidal‐averaged volume and the tidal compartment of the lagoon vary through the lunar cycle, from maxima at spring tides to minima at neap tides.

Freshwater inflows vary from less than 11 m³.s^‐1 to more than 750 m³.s^‐1. During storms, water level in the lagoon rises rapidly by 2–3 m, then declines to normal over several days. Three water masses, two with salinity and turbidity largely controlled by antecedent rainfall, normally occur in the lagoon. Suspended sediment concentrations in both freshwater inflows and lagoon waters are normally low but increase during floods. Most sediment is supplied by the Waitangi‐taona River or by erosion of tidal channel margins. The lagoon is floored with organic‐rich mud and sandy mud, deposited predominantly from suspension. Surface sediment is consistently muddier than subsurface sediment, probably reflecting an increase in the mud supply since diversion of the Waitangi‐taona River in 1967.

Comparisons of the estimated sediment yield and water inflow effects of the 1967 river diversion with short‐term observations during selective logging suggest that the effects of logging on sediment yield, water balance of the lagoon, and dissolved solids inputs will be small compared with changes caused by diversion of the Waitangi‐taona River.