Enzymatic activities in spermatozoa and butyltin concentrations in Baltic turbot (Scophthalmus maximus)

Spermatozoal enzymes of fish (NAD+- and NADP-dependent dehydrogenases and creatine kinase (CK)) were previously determined to be sensitive to tributyltin (TBT) in laboratory experiments and were thus indicated for use as biomarkers for TBT exposure. However, the potential ability of spermatozoal enzymes as biomarkers of TBT exposure has never been recapitulated in a field study. For this purpose, the kinetic activities of spermatozoal enzymes of the natural turbot Scophthalmus maximus population from the Gulf of Gdańsk (GDA) and the Pomeranian Bay (POM) in the southern Baltic Sea were measured. Gas chromatography/high-resolution mass spectrometry was used to determine the concentrations of TBT and its breakdown products, dibutyltin (DBT) and monobutyltin (MBT), in the muscle, liver and testes of the male turbot. Males from GDA had significantly higher enzymatic activities and butyltin (BT) content in tissues than those from POM. A general linear model (GLM) showed that lactate dehydrogenase (LDH), malate dehydrogenase (MDH), glucose-6-phosphate dehydrogenase (G6PDH) and CK activities increased significantly with BT concentration in the testes and liver. We indicate the potential effects of TBT pollution on the spermatozoal enzymes of Baltic turbot.     

Directional Spectrum of Wind Waves: Part Ⅰ- Model and Derivation

1　Introduction　Numerousinvestigationsondeepwaterwindwavespectrumhavebeen performed (Phillips ,195 8;Bretschneider,195 9;PiersonandMoscowitz ,196 4;Hasselmannetal.,1973;Donelanetal.,1985 ;Ban ner ,1990 ;Wenetal.,1999) .Ondimensionalground ,Phillips (195 8)suggestedthattheequilibriumfre quencyspectrumofwindwavesfordeepwatershouldbe proportionaltoω- 5,andthecorrespondingwavenumberspectrumshouldbe proportionaltok- 4,whereωistheangularfrequencyandkisthewavenumber.Forfully developedwindwaves…     

Directional Spectrum of Wind Waves: Part Ⅱ- Comparison and Confirmation

1　Introduction1.1　Proposed ModelonDirectionalFrequencySpec trum　ThisisthePartⅡofthetwo papersetondirection alspectraofwindwaves.Anewmodelonthedirec tionalspectrumofwindwavesfordeepwaterispro posedbasedonthestatisticsofwindwavesinthePartⅠ .Substituting (4 5 )ofPartⅠinto (4 0 )andaddingapeak enhancementitemγΓ,weobtainS(ω ,) =0 .0 0 93αaαwD( ,k) ωpω2 ξ- 4g2ω5×exp - 2 ξ+14[bωp +(1-b)ωp]4ω4 γΓ. (1)Here ,αaisthewaveagefactorofspectralcoefficientdefinedbyαa = ω0 .55…     

月球伽玛射线谱仪的研制及其性能

介绍将用于中国第一颗月球探测卫星主载荷之一的伽玛射线谱仪的结构设计, Monte Carlo模拟结果和原理样机性能测试结果等．该探测器采用CsI(T1)晶体作为闪烁体和反符合技术抑制本底,可探测的射线能量范围为0．3-9．0 MeV,仪器能量分辨率是9．0％(662 keV)．     

绳索式方便提引器

自从有了“关门山提引器”以来,起下钻就不用攀登钻塔摘、挂提引环了。但是挂“立袖管”仍要上塔,进行高空作业。我队杜选银同志,在机长和技术员的帮助下,试验成功了绳索式方便提引器,钻工可不上高空操作,而且结构简单,容易加工,深受现场欢迎。该提引器是在原“关门山提引器”的基础上增添了一个滚轮支架,并在水接头的提梁上联接一个蘑菇头,在蘑菇头内固定一根φ5mm、长约8～9m的     

糯扎渡、景洪水库地震监测台网修复重建

糯扎渡、景洪水库地震监测台网于2008年建成,用于监测糯扎渡、景洪水电站周边水库地震活动,受历史原因影响,监测设备老旧,设备用房破损,截至2016年,该水库地震监测台网基本处于停测状态。2017年,华能澜沧江水电股份有限公司对整个水库地震监测台网进行设计优化、修缮,对15个台站及中心机房设备进行维修、更换,恢复台站网地震监测。修缮以后,水库地震台网考核运行率达95%以上,可满足监测M_L≥0.5地震的需求,台网观测的动态范围优于恢复重建前水平。此次糯扎渡、景洪水库地震台网的恢复重建,不仅对水库地震监测起到保障作用,也是对防震减灾事业的重要推进。     

老寨湾金矿控矿层位时代及控矿因素新认识

矿区主要金矿化层为下奥陶统老寨组(O1l),而非下泥盆统坡松冲组。金矿化主要受断裂构造+岩浆活动+不整合面+岩性等多因素的综合控制,矿体富集的空间部位与断裂构造及深部岩浆活动有密切的关系。丰富和扩展了滇东南地区加里东不整合面控矿理论的内涵,明确矿区深部及外围找矿空间。