莱州湾东岸三山岛段砂质海岸沉积物运移动力机制

通过对三山岛岸段冬夏重复的地形测量和表层沉积物的粒度分析,研究了其地貌特征与地形变化规律、沉积物类型、粒度特征、运移趋势,并探讨了沉积物运移的动力机制。结果表明:该岸段可根据1985黄海高程-1.2m(低潮水位)和-6.5m(闭合深度)平面划分为海滩、水下岸坡和浅海陆架三个地貌单元,各地貌单元表层沉积物分布规律与地形变化特征区别显著。其中水下岸坡和浅海陆架地貌单元主要受潮流作用,海滩地貌单元主要受波浪作用。在西向落潮流和西南向潮余流的作用下,水下岸坡地貌单元发育一个中等规模潮流通道-沙脊沉积系统。表层沉积物以向西运移的趋势为主,少数滞留于西部潮流沙脊处,与地形"东侵西淤"的变化规律相符,这些西向运移的沉积物最终离开研究区,补给莱州浅滩。     

论“中国肯氏兽动物群”的多样性及生存时代

地质历史上的二叠纪、三叠纪,正是爬行动物和两栖动物多样辐射的时期,也是低等四足类相互更替的时期。那时地球上只有一个大陆—盘古大陆,中国所处的位置是南海北陆的格局。山西位于华北古陆上,这片土地出露着大面积的三叠纪陆相地层,无数的科研机构、专家学者都曾来这儿工作过,并在这里发现大量的脊椎动物化石,其中最具特色的就是"中国肯氏兽动物群"。本文简要介绍了该动物群的研究历史、多样性概况、时代讨论及在生命演化史上的意义等情况。     

王世元:透视国情数据 增强忧患意识

正作为一次重大国情国力调查,第二次全国土地调查主要数据成果去年12月底发布。为什么每组数据都饱含渗透纸背的忧患感?就相关问题,国土资源部副部长、国务院第二次全国土地调查领导小组办公室主任王世元接受了记者专访。     

Fully coupled time-domain simulation of dynamic positioning semi-submersible platform using dynamic surface control

A fully coupled 6-degree-of-freedom nonlinear dynamic model is presented to analyze the dynamic response of a semi-submersible platform which is equipped with the dynamic positioning （DP） system. In the control force design, a dynamic model of reference linear drift frequency in the horizontal plane is introduced. The dynamic surface control （DSC） is used to design a control strategy for the DP. Compared with the traditional back-stepping methods, the dynamic surface control combined with radial basis function （RBF） neural networks （NNs） can avoid differentiating intermediate variables repeatedly in every design step due to the introduction of a first order filter. Low frequency motions obtained from total motions by a low pass filter are chosen to be the inputs for the RBF NNs which are used to approximate the low frequency wave force. Considering the propellers’ wear and tear, the effect of filtering frequencies for the control force is discussed. Based on power consumptions and positioning requirements, the NN cen-ters are determined. Moreover, the RBF NNs used to approximate the total wave force are built to monitor the disturbances. With the DP assistance, the results of fully coupled dynamic response simulations are given to illustrate the effectiveness of the proposed con-trol strategy.     

四川盆地东部垫江盐盆早三叠世嘉陵江组四段杂卤石成因及对成钾的指示

四川盆地三叠纪是主要的成钾期,目前发现的主要含钾矿物为杂卤石,有关早三叠世嘉陵江组四段石盐岩中杂卤石成因一直存在争议.采用薄片鉴定、扫描电镜、稀土元素和锶同位素等手段,分析了四川盆地东部垫江盐盆长寿地区嘉陵江组四段石盐岩中杂卤石矿物形态特征,初步探讨了该杂卤石成因及对寻找海相钾盐的指示意义.扫描电镜下与石盐岩共生的杂卤...     

动力学模型预测泥鳅(Misgurnus anguillicaudatus)半干制品的货架期

以泥鳅(Misgurnus anguillicaudatus)半干制品为研究对象,测定和分析其在不同贮藏温度(4°C、20°C、30°C和40°C)下,菌落总数、挥发性盐基氮(TVBN)、脂肪氧化程度(TBA值)与感官评分各项指标随贮藏时间的变化。结果表明,泥鳅半干制品在不同贮藏温度下,随着贮藏时间的延长品质逐渐下降,贮藏温度越低,品质指标变化越缓慢。经Pearson相关性分析,确定影响泥鳅半干制品品质变化的关键因子为菌落总数;基于Arrhenius方程,进一步建立菌落总数与贮藏时间、贮藏温度之间的动力学模型,该模型中活化能Ea为26.5 kJ/mol,反应速率常数k0为3186.6,推算得出泥鳅半干制品货架期预测值与实测值相对误差较小,该动力学模型可准确预测泥鳅半干制品在4—40°C贮藏温度下的货架期。本研究可为泥鳅半干制品的开发、流通奠定理论基础。     

青蛤(Cyclina sinensis)TLR2基因的克隆与表达分析

利用转录组文库分析得到青蛤(Cyclina sinensis)的Toll样受体2(Toll-like receptor 2,TLR2)基因序列,采用荧光定量PCR法分析该基因的表达过程。结果显示,青蛤TLR2基因的cDNA开放阅读框为2082bp,编码693个氨基酸,具典型的LRRs、单次跨膜区和TIR结构域。该基因在血淋巴中的表达量最高,与肝脏、鳃、外套膜、闭壳肌和性腺有显著性差异(P0.05)。在鳗弧菌和Poly I:C刺激下,青蛤血淋巴中TLR2基因3h开始升高,48h达到最大值,与对照组和空白组有极显著性差异(P0.01);藤黄微球菌刺激下,血淋巴中CsTLR2基因3h开始升高,48h亦达到最大值,实验组与对照组有显著性差异(P0.05)。     

半滑舌鳎(Cynoglossus semilaevis Günther)生长激素体外重组表达及活性分析

根据半滑舌鳎(Cynoglossus semilaevis Günther)生长激素(GH)基因的c DNA全长序列设计引物克隆得到其全长552个碱基成熟肽序列。利用RT-PCR方法将扩增片段克隆到原核表达载体p ET-28a上,实现了GH成熟肽在大肠杆菌BL21(DE3)中的融合表达。融合蛋白分子量为26 k Da,在IPTG诱导4h时目的蛋白表达量最高,占细菌总蛋白的41.5%,主要以包涵体形式存在。Western-blotting分析表明GH融合蛋白可特异性地被6×His抗体识别。诱导表达后的菌液沉淀经纯化和复性后,获得大小为26 k Da的纯化GH融合蛋白。以ELISA方法检测纯化后的GH融合蛋白显示其具有免疫学活性。本研究为认识半滑舌鳎生长轴的调控机制提供了基础资料。     

Phylogenomic analysis of transcriptomic sequences of mitochondria and chloroplasts for marine red algae (Rhodophyta) in China

The chloroplast and mitochondrion of red algae （Phylum Rhodophyta） may have originated from different endosymbiosis. In this study, we carried out phylogenomic analysis to distinguish their evolutionary lin-eages by using red algal RNA-seq datasets of the 1 000 Plants （1KP） Project and publicly available complete genomes of mitochondria and chloroplasts of Rhodophyta. We have found that red algae were divided into three clades of orders, Florideophyceae, Bangiophyceae and Cyanidiophyceae. Taxonomy resolution for Class Florideophyceae showed that Order Gigartinales was close to Order Halymeniales, while Order Graci-lariales was in a clade of Order Ceramials. We confirmed Prionitis divaricata （Family Halymeniaceae） was closely related to the clade of Order Gracilariales, rather than to genus Grateloupia of Order Halymeniales as reported before. Furthermore, we found both mitochondrial and chloroplastic genes in Rhodophyta under negative selection （Ka/Ks〈1）, suggesting that red algae, as one primitive group of eukaryotic algae, might share joint evolutionary history with these two organelles for a long time, although we identified some dif-ferences in their phylogenetic trees. Our analysis provided the basic phylogenetic relationships of red algae, and demonstrated their potential ability to study endosymbiotic events.