环境因素对富硒锌纯顶螺旋藻生化特性的影响

研究３种环境因素ｐＨ、光照强度、锌盐对富硒锌钙螺旋藻叶绿素ａ、硝酸还原酶的影响,实验结果表明,在实验的光强范围内随着光强度增大,硝酸还原酶和叶 纱ａ呈同步增加的态势;等量不同种类锌盐对硝酸还原酶和叶绿素ａ含量影响较小’ｐＨ对硝酸还原酶和叶绿素ａ的影响出现不同步的变化。     

饲料添加剂硒和谷胱甘肽对微囊藻毒素胁迫下罗非鱼肝脏去毒相关基因诱导表达的影响

为从分子水平探讨饲料添加剂硒(Se)和谷胱甘肽(GSH)对淡水养殖鱼类肝脏微囊藻毒素胁迫下去毒分子机理的影响,实验杂交罗非鱼一组喂食含0.15 mg/kg Se的富硒酵母粉饲料,一组喂食含普通酵母粉的饲料,喂食一个月以上;实验尼罗罗非鱼一组喂食含1 g/kg GSH的饲料,一组喂食普通饲料,两组均饱食10 d.所有实验组再均分两组,一组腹腔注射磷酸缓冲液(PBS),一组按体质量注射腹腔注射50μg/kg微囊藻毒素-LR(MC-LR),24 h后分离肝脏组织.以β-肌动蛋白作为外参照,采用半定量RT-PCR方法研究Se和GSH分别对罗非鱼肝脏去毒相关基因转录水平的诱导改变.结果表明,未喂食Se的实验组,杂交罗非鱼肝脏alpho-可溶性谷胱甘肽S-转移酶(sGSTA)和谷胱甘肽过氧化物酶(GPX)基因mRNA表达水平在腹腔注射50μg/kg MC-LR 24 h后,均较PBS组有诱导趋势;Se+MC-LR组sGSTA和GPX基因mRNA表达水平,均较Se+PBS组略低,可能与添加剂的低剂量添加相关.喂食GSH的实验组,尼罗罗非鱼腹腔注射MC-LR组,肝脏sGSTA基因mRNA表达水平较PBS组有诱导趋势;Se+MC-LR组GPX基因mRNA表达水平,较Se+PBS组有升高趋势,而sGSTA和rho-可溶性谷胱甘肽S-转移酶(sGSTR)基因mRNA表达水平则轻微降低.本实验首次从基因表达水平比较研究了Se和GSH对罗非鱼微囊藻毒素压力情况下,肝脏去毒酶基因表达的影响变化,为Se和GSH饲料添加剂在鱼类饲料中的合理添加提供分子水平的理论依据.     

The isotopic abundance and atomic weight of natural uranium

Conclusion The published measurement data of atomic weight of uranium are shown in table 4^[9]. The best results are those measured by Smith and Cowanet al. A _r (U) = 238.028 79–238.028 90(3), their result error being ISD. The evaluated value of IUPAC-CAWIA is A_r(U)=238.028 9(1). In this work, the result is A_r(U) = 238.028 91(4). The combined uncertainty has been given according to 2SD of the measurement data through the calibration of a series of standard materials of uranium isotopes. It is reasonable to conclude that in this work the uncertainty which characterizes the measurement quality is better than other published data.     

西藏地壳模型及其化学成分初探

西藏地壳是指西藏高原内中-新生代造山带的地壳。其面积210万km~2,地壳平均厚度63.5km,地壳体积1.32亿km~3,地壳内的岩石平均密度2.775g/cm~3,地壳质量3663地克(=3.663×10~(17)吨)。西藏地壳由五个槽壳构成。它们是松潘甘孜槽壳、三江槽壳,喀拉昆仑唐古拉槽壳,冈底斯念青唐古拉槽壳和喜马拉雅槽壳。根据现有的地质学、地球物理学、地球化学和地理学资料,本文概略地给出了西藏地壳模型及其化学成分。     

乌岩岭自然保护区两栖动物垂直分布的研究

乌岩岭自然保护区位于浙江省南部,1975年建立保护区,嗣后对区内动植物资源进行了全面调查和研究,本文就两栖动物种类和垂直分布研究结果作一报导。保护区内两栖动物计有5科26种,种类随海拔高度的不同而变化,以海拔500—600米区内数量和种类最为丰富,600米以上随海拔高度的升迁而递减,1400米以上最为贫乏。     

蓬莱19-3平台溢油事故对渤海大型底栖生物群落结构的长期影响

【目的】研究渤海海域底栖生物群落状况,探明2011年发生的蓬莱19-3平台溢油事故对该海域底栖生物群落结构的长期影响。【方法】根据2014年夏季对渤海海域32个站位底栖生物的采样调查资料,并与历史数据进行比较,分析渤海海域底栖生物的群落结构、物种组成和底质状况。【结果】渤海海域32个站位共鉴定出大型底栖生物191种,其中多毛类环节动物83种,甲壳动物40种,软体动物42种,棘皮动物15种,其它类群动物11种。优势种为凸壳肌蛤(Musculus senhousei)。调查海域大型底栖生物平均丰度为676.88ind/m2,变化范围为15~11 555ind/m2,低于溢油前水平;平均生物量为30.77g/m2,变化范围为0.09~141.55g/m2,高于溢油前水平。生物量的主要贡献者为棘皮动物,丰度的主要贡献者为软体动物,底栖生物群落结构的小型化有减缓趋势。Shannon-Wiener物种多样性指数、Margalef物种丰富度指数和Pielou物种均匀度指数平均值分别为3.11±1.20,2.89±1.40和0.82±0.22。ABC曲线显示渤海海域正处于中度扰动状态,溢油区各站位ABC曲线均显示底质状况较好,但个别站位生物量起点较低且曲线整体偏左,说明有向中度干扰发展的趋势。【结论】溢油事故3年后,受溢油影响的底栖生物群落已得到不同程度的恢复。     

Abundance and diversity of decapod crustaceans in the deep-Catalan Sea (Western Mediterranean)

The deep-slope decapod fauna of the Catalan Sea was extensively sampled with an OTSB-14 bottom trawl. A total of 67 bottom tows were taken from 1985 to 1989 at bottom depths ranging from 552 to 2261 m. Species in which abundance decreased with depth were Plesionika acanthonotus, Polycheles typhlops, Calocaris macandreae and Geryon longipes. Highest densities of Acanthephyra eximia, Stereomastis sculpta, and Nematocarcinus exilis were attained at the greatest depths studied. Total abundance, biomass and species richness for decapod crustaceans as a whole decreased with depth. Maximum decapod biomass and diversity occurred on the upper-middle slope on soft bottoms in the Catalan Sea and in all regions for which data were available. In the Catalan Sea, an oligotrophic area, the abundance of decapods as a group seemed to be higher than in north-Atlantic eutrophic regions. In these latter areas, other deep-sea benthic invertebrate groups, particularly ophiuroids, predominate.     

Spatial–temporal composition of Chrysomelidae (Insecta: Coleoptera) communities in southern Brazil

We examined the Chrysomelidae communities from representative sites of different ecosystems in Paraná State, Brazil, comparing their spatial and temporal changes. Sampling was undertaken using malaise traps at eight sites during a 2-year period. Chrysomelidae represented 19.1% of all the Coleoptera sampled, with a total of 7611 specimens and 465 species. Galerucinae was the most abundant and richest subfamily. Ponta Grossa was the most abundant site, São José dos Pinhais the richest, Fênix the poorest, Jundiaí do Sul the most uniform, and Antonina had the highest dominance of just a single species. Approximately 79% of the species were represented by fewer than 10 specimens and the 10 most abundant species represented 44.7% of all chrysomelids collected. None of the species were collected at all of the sites, but 325 were unique, reflecting the low similarity among sites. Sites with similar phytophysiognomies were more similar in terms of their Chrysomelidae species compositions. Similarities between years were slightly higher than similarities between sites.     

不同烤烟品种对硒的富集能力及动态研究

分析了不同烤烟品种对微量元素硒的富集能力差异及动态变化,结果表明:①K326具有较强的富硒能力,红大富集硒的能力则相对较弱;在烟草大田生育期,中烟103、云烟87叶片中硒的富集动态呈现出"持续上升—下降"的趋势,红大、K326、NC82则表现为"下降—上升—下降".②土壤强化供硒易促进硒往上部叶中富集;中烟103和云烟87相比其他品种对硒肥的利用率高;各烤烟品种对硒肥的敏感程度不同,土壤强化供硒改变了红大、K326、NC82叶片中硒的富集动态,表明红大、K326、NC82对硒肥较为敏感.     

AGB星He壳层内重元素丰度的变化

采用新的s-过程核合成模型和分叉s-过程反应通道，计算了太阳金属丰度3MTP-AGB星He壳层内重元素核合成，结果表明，中子辐照量小于标准情况时，丰度不能达到渐近分布，中子辐射量子大于标准情况时，达到渐近分布所需的脉冲数为5－10个，中子辐射量参数的合理取值范围为标准情况的0．5－2．5倍。