基于FY-4A卫星数据的短时强降水监测预警指标

选取2018—2021年汛期短时强降水天气过程,利用相关性分析、箱线图法和极值统计法,尝试研究FY-4A卫星产品在短时强降水天气过程中的监测预警指标。研究表明：(1)FY-4A卫星多通道数据可以作为短时强降水监测预警的定量化指标予以应用。(2)筛选出相关性较好的13项产品统计出短时强降水的监测预警指标,其中赋值类指标4项,数值判别类指标9项(含辅助指标3项);初步设定13项指标中有9项达标时,短时强降水会发生。(3)在评估基础上完善了指标,监测预警效果有所提高,TS评分提高5.4%,空报率降低2.7%,漏报率降低1.9%。     

Cloning and phylogenetic analysis of a fatty acid elongase gene from Nannochloropsis oculata CS179

Nannochloropsis oculata CS179, a unicellular marine microalga, is rich in long-chain polyunsaturated fatty acids (LCPUFAs). Elongase and desaturase play a key role in the biosynthesis of PUFAs. A new elongase gene, which encodes 322 amino acids, was identified via RT-PCR and 5′ and 3′ RACE. The sequence of the elongase gene was blast-searched in the NCBI GenBank and showed a similarity to those of the cryptosporidium. But the NJ-tree revealed that the N. oculata CS179 elongase clustered with those of the microalgae Phaeodactylum tricornutum, Ostreococcus tauri and Thalassiosira pseudonana.     

Sediment texture and grain-size implications: the Changjiang subaqueous delta

Sediment cores were collected from the subaqueous delta of the Changjiang Estuary. Sediment grain-size profiles and their fractal dimensions were analyzed, to elucidate responses to long-term sedimentary processes. In addition, the environmental sensitive populations of grain size have been extracted. The sediment cores can be divided into two parts, according to the sedimentary structures present. The upper part (0-12 cm) is interpreted as being the active layer, which is influenced frequently by changes i...     

海洋毒素大田软海绵酸完全抗原的制备与分析

为了建立大田软海绵酸(Okadaic acid,0A)的免疫学检测方法,利用活泼酯法将OA分子中的羧基与栽体蛋白上的氨基偶联,人工制备OA的免疫抗原(OA-IgG)和检测抗原(OA-BSA),经电泳、动物实验及ELISA法进行了鉴定,完全抗原的偶联成功,为利用杂交瘤技术制备OA的单克隆抗体和海产品OA免疫学检测方法奠定了良好的基础.     

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沉积物粒度参数的无偏估计及其在长乐海岸的应用

根据数理统计方法对粒度参数进行无偏估计,使之较以往参数估计更符合无系统误差的这一估计量的评选标准,并用这一方法对长乐东部海岸的风沙进行了系统的粒度参数分析,结果表明长乐海岸风沙沉积物的主要粒级为细沙,分选好,偏度为近对称,峰态很窄等特征,说明研究区域海岸风沙的搬运风动力主要为NE向、而且动力强度较稳定。     

海湾扇贝微卫星标记开发及其分离方式分析

利用尼龙膜吸附杂交法构建了海湾扇贝的(AC)_(15)、(AG)_(15)微卫星富集文库,随机挑取3 000个克隆,经菌落原位杂交二次筛选共获得阳性克隆1 268个(42.3%).经序列测定和生物信息学分析后得到521个独立的阳性克隆,其中微卫星506个,小卫星15个.微卫星中,完美型248个,占总数的49.0%;非完美型216个,占42.7%;复合型42个,占8.3%;其中AG/TC重复占70.4%(356个),AC/TG重复29.6%(150个).选择其中的55条序列设计引物,筛选出其中的20对引物检测它们在海湾扇贝CC10家系的双亲和94个子代个体中的分离情况,结果表明:(1) 其中6个位点在母本和子代中发生分离,10个位点在父本和子代中发生分离,4个为双亲共享位点;(2) 2个位点存在无效等位基因;(3) 16个位点符合孟德尔遗传定律,4个位点的子代个体基因型频率偏离孟德尔遗传定律.上述结果表明,这些微卫星引物可以用于构建海湾扇贝的遗传连锁图谱,并且所构建的富集文库适用于微卫星标记的大规模开发.     

Environmental impact of fluidized solidified silt casting on surrounding water bodies

Abstract

With the growing demand for underwater refill engineering, the construction technology of implementing fluidized solidification in underwater pouring has recently received increased attention. However, the environmental impact of underwater casting on surrounding water bodies, especially when the silt is polluted, is still unclear. In this study, a simulated underwater pouring test and a static immersion release test were conducted separately to study the quality of the surrounding water during and after pouring. The results showed that fluidized-solidified silt casting could increase the pH of the surrounding water, even after the pouring had stopped, by approximately 1.0 and the turbidity could reach 200 NTU. No diffusion of Zn and Cu into the surrounding water was observed and while Ni and Cr exhibited slight diffusion, this was at a level well below international water quality standard. During construction, reducing the distance from the seafloor to the bottom of the pouring catheter could reduce the level of pollution. After construction, the use of neutral solidified materials can effectively reduce the pH of the surrounding water and the potential risk of heavy metal dissolution.     

机载LiDAR地形特征信息快速提取

为更有效地获取地形特征信息,提出一种机载LiDAR地形特征信息快速提取算法。首先,通过构建二次曲面拟合模型,建立实测LiDAR地形数据与拟合曲面的几何规则;然后,采用LM算法迭代参数寻优,获得最优化结果下的地形拟合参数,计算拟合时间及拟合精度;最后,以地形拟合模型为基础,进行地形特征信息的快速提取。通过机载LiDAR实测数据验证,当最优搜索半径为2 m时,地形曲面的拟合时间仅为0.02 s,RMSE仅为5.09 cm。该算法保证了地形特征信息提取效率和精度,能够有效满足机载LiDAR科学研究和工程应用的技术需求。     

1605年海南岛琼州大地震及其发震构造的初步探讨

琼北地区铺前−清澜断裂是一条关系到1605年琼山7½级大地震发震构造判断的重要断裂。为准确厘定该断裂的最新活动特征,针对琼北地区第四纪玄武岩盖层和巨厚海相砂沉积等地质条件,采用大吨位震源的浅层人工地震勘探和小间距钻孔联合地质剖面探测相结合的方法,分别在海口江东三江镇岐山头村和东寨村展开探测。结果表明：(1) 铺前−清澜断裂断错了多个标志地层,最浅断错至全新统烟墩组淤泥层,上断点埋深10 m左右,钻探所揭示的断层面明显具有走滑兼具逆冲性质,是一条具有一定宽度、多分支、多期次活动的大规模断裂带;(2)钻孔联合地质剖面所揭示的地层深度范围内,被断错地层的位移量随着深度增加而加大,铺前−清澜断裂自8 346~7 153 a cal BP以来有过活动,全新世累计垂直位移量4~5 m,垂直位移速率为0.53~0.63 mm/a,推断其为1605年琼山大地震的发震断裂。本研究取得的铺前−清澜断裂全新世活动的新证据,为国土空间规划和区域地震危险性评价提供了科学依据。