130 resultados para 14-137


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The geneswere cloned for the two apoprotein subunits, alpha and beta, of phycocyanin from the cyanobacterium Spirulina maxima (=Arthrospira maxima) strain F3. The alpha- and beta-subunit gene-coding regions contain 489 bp and 519 bp, respectively. The beta-subunit gene is upstream from the alpha-subunit gene, with a 111-bp segment separating them. Similarities between the alpha-subunits of S. maxima and nine other cyanobacteria were between 58% and 99%, as were those between the beta-subunits. The maximum similarity between the alpha- and beta-subunits from S. maxima was 27%.

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遗传力是数量遗传学的重要参数,对鱼类良种选育具有重要意义。可靠的遗传力估计值可以为合理制定育种计划提供宝贵信息,同时可以预测选择反应。本文按照10×3因子设计方法,10尾雄鱼与3尾雌鱼两两授精,产生10个父系半同胞、3个母系半同胞及30个全同胞家系,以微卫星分子标记为家系鉴定手段,对40日龄牙鲆生长相关性状遗传力进行了估计;同时,初步探讨了因子交配设计及人工控制条件下,亲本对子代遗传贡献率差异及有效群体大小。主要结论包括:1.初步筛选的14个微卫星位点中,有9个(Po91、Po1、Po56、Po20、Poli23、Po89、Poli121、Po42、Po13)在亲本中呈现中、高度多态性:平均等位基因9.4个;平均亲本特异性等位基因4个。用5个位点(Po91、Po1、Po56、Po20、Poli23)为346个子代中的227个个体找到所属家系;继续用另外4个位点(Po89、Poli121、Po42、Po13)分型,成功鉴定72个个体。鉴定率约86%,其中,亲本特异性等位基因的存在使鉴定效率大大提高。以上9个位点可为该群体良种选育工作提供技术支持。2. 发生降解的DNA与完整的DNA,在相同引物、相同PCR体系、相同模板浓度下扩增的带型一致。该结果证实了微卫星分型对降解的DNA同样稳定。3. 亲本对子代的遗传贡献率存在差异。雄亲的贡献率为5.8—14.3%,除3号、9号子代数较少,5号、6号子代数较多外,其它父本基本一致;母本对子代的贡献率差异较大(18.5%—50.6%),这与人工授精前雌亲发育状况、卵子质量检测结果基本一致,在一定程度上说明,母本尤其是卵子质量对鱼类早期存活具有较大影响。4. 家系内子代数目的不平衡导致实际有效群体大小下降。Ne=7.44,比理论有效群体大小(9.23)下降约19%。但与自然交配相比(有效群体下降可达75%),人工控制下的交配在一定程度上可有效限制遗传多样性的下降。5. 基于父本方差组分,40日龄生长相关性状遗传力估计值(h2s±S.E.)为(0.157±0.052)-(0.440±0.137)。加性遗传方差在表型方差中所占的比例,在一定程度上表明该牙鲆群体生长性状具有一定的选择力度。

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对产自青海的以礼草属一新种——长芒以礼草(Kengyilia longiaristata),进行了描述。

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本论文选取我国的典型玛珥湖-湖光岩玛珥湖为研究对象,在国内外率先系统开展湖泊沉积物硅藻硅同位素研究。为获取过去2000a来的气候环境记录,对原有沉积物-水界面采样装置进行了改进,将沉积物柱芯无扰动采集深度从60cm提高到150cm。建立了一套有效的五阶段硅藻提纯方法,成功从初始硅藻含量大于7%的沉积物中提取出纯度达90%以上的硅藻样品,为广泛开展沉积物硅藻硅氧同位素研究奠定了基础。放射性核素Pb-210、Cs-137、C-14计年结果表明,该湖沉积物堆积速率稳定,具连续、稳定的堆积特点,是气候和环境变化的良好记录体。湖光岩玛珥湖沉积物硅藻硅同位素记录了硅藻利用水体溶解硅的比例变化。沉积物硅藻硅同位素与生物硅含量的变化关系为揭示湖泊古环境提供了重要线索。当硅藻硅同位素组成与生物硅含量呈正相关变化时,湖水溶解硅利用比例主要受温度控制,硅藻硅同位素可反映古温度变化。当硅藻硅同位素组成与生物硅含量不呈相似变化时,湖水溶解硅利用比例主要受有效养分控制,沉积物硅藻硅同位素仅仅反映硅藻利用水体溶解硅的比例,不反映古温度变化。湖光岩玛珥湖沉积物柱芯硅藻硅同位素组成的变化范围为 -0.6‰~1.1‰,其最小值出现于1580~1920年间,指示了1580~1920年为湖光岩地区过去2000年来最冷的时期,为中国南方热带地区现代小冰期的存在提供了新的证据。

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保存在湖泊沉积物~(137)Cs剖面中的环境信息记录,可能因~(137)Cs沉积后的再迁移作用而失真。~(137)Cs吸附动力学及离子交换实验表明红枫湖沉积物中的~(137)Cs绝大部分处于固定态,少量处于交换态和造反性吸附态。同时Cs~(+)浓度很低时,高Cs~(+)浓度下在各吸附态与粘土矿物表面的特定吸附部位之间,通常比较明确的对应关系变得有些模糊。本文以界面过程的数学模型为核心,通过模式分析,重建了红枫湖地区历年的~(137)Cs大气沉降通量值,获得了红枫湖集水区 ~(137)Cs流域侵蚀寄宿时间,约为550年。 ~(137)Cs的扩散和其它沉积后再迁移作用。虽然导致~(137)Cs剖面发生了一些变化,但通过适当的数据处理,仍可从中提取出有价值环境信息。

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A novel and ideal dense catalytic membrane reactor for the reaction of partial oxidation of methane to syngas (POM) was constructed from the stable mixed conducting perovskite material of BaCo0.4Fe0.4Zr0.2O3-delta and the catalyst of LiLaNiO/gamma-Al2O3. The POM reaction was performed successfully. Not only was a short induction period of 2 h obtained, but also a high catalytic performance of 96-98% CH4 conversion, 98-99% CO selectivity and an oxygen permeation flux of 5.4-5.8 ml cm(-2) min(-1) (1.9-2.) mumol m(-2) S-1 Pa-1) at 850 degreesC were achieved. Moreover, the reaction has been steadily carried out for more than 2200 h, and no interaction between the membrane material and the catalyst took place.

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Is prosocial behavior of supernormal children distinguished from normal children? Is there any difference between the supernormal children’s prosocial behavior from different educational placement? What are the mechanisms underlying the difference? The aim of this study was to examine these issues. With multiple methods of prosocial behavior, including other-rating, self-rating and hypothetical dilemma, we investigated the 10 to 14 year-old children. Firstly, the development of prosocial behavior and its relationship with prosocial behavior was examined. Secondly, we investigated the features of supernormal children’s prosocial behavior and analysed its difference with normal children. Finally, we tried to find the difference of supernormal children’s prosocial behaviour from different educational placement, and the mechanisms underlying the difference, such as social value orientation and peer relation. The results are as follows: 1)The altruistic and compliant prosocial tendency of 14 year-old children was obviously lower than those younger children. Intelligence was positively related with altruistic and emotional prosocial tendency for 10 year-olds, and with prosocial behaviour of peer nominated for 12 year-olds. 2)There was no significant difference of prosocial behaviour between supernormal and normal children. The peer nominated prosocial behaviour of 12 year-old supernormal children was higher than of 11 and 13 years old supernormal children. In addition, girls’ other-rating prosocial behaviour was significantly higher than boys’, but no gender difference was detected in the prosocial behaviour of self-rating and hypothetical dilemma. 3)With regard to the supernormal children’s prosocial behaviour in different educational placement, we found that the prosocial degree of the supernormal children of homogeneous groups was higher than that of heterogeneous groups in the role-change of ultimatum game. 4)The supernormal children from different educational placement had different social value orientation. More supernormal children of homogeneous groups belonged to the type of group enhancement, while more supernormal children of heterogeneous groups belonged to the type of equality. The types of social value orientation did not have impact on the supernormal children’s prosocial behaviour from different educational placement. 5)Peer relation moderated the impact of different educational placement on supernormal children’s prosocial behaviour.