人工诱导栉孔扇贝雌核发育胚胎的SNP标记分析

利用紫外线照射灭活的同源精子,激活栉孔扇贝(Chlamys farreri)卵子分裂,获得雌核发育胚胎,流式细胞仪检测胚胎细胞平均单倍体率为82.5%。对获得的胚胎进行全基因组扩增,获得足量的基因分型模板,利用高分辨率溶解曲线(HRM)技术对其进行96个单核苷酸多态性(SNP)位点分型。结果显示,诱导雌核发育胚胎的位点检出率为96.27%,其中99.06%的位点分型结果与相应雌性亲本相符;单个胚胎中只表现一种等位形式的位点占91.67%~96.88%,平均为94.81%,较雌性亲本的纯合位点比例(64.25%)明显提高。本研究利用灭活同源精子诱导获得栉孔扇贝雌核发育胚胎,并利用单个胚胎的全基因组扩增产物进行基因位点分析,为扇贝人工诱导雌核发育个体的早期多基因位点检测和评价提供参考。     

Sediment records of environmental changes in the south end of the Zhejiang-Fujian coastal mud area during the past 100 years

Previous studies carried out in the East China Sea （ECS） mud area focused on long-term environmental changes in sedimentary records during the Holoeene, especially during the mid-Holocene high-stand water levels period. These results indicate that sensitive grain size groups can be used as a sedimentary proxy to reconstruct the evolution of the East Asian Winter Monsoon （EAWM）. The studies have been carried out mainly in the northern and middle portions of the Zhejiang-Fujian coastal mud, however, similar research in the southern portion and the comparison between sedimentary proxy and modern measured data of EAWM are lacking. In this paper, we focused on a sedimentary record of the past 100 years with an enhanced resolution of 1.8 years. Investigations of the southern end of the Zhejiang-Fujian coastal mud area were conducted on the basis of 21~Pb chronology, grain-size analysis and chemical element analysis. The correspondence between the mean grain size （Mz） of sediment sensitive grain size and the measured EAWM was confirmed for the first time. We found that during the recent 100 years, the variation of the mean grain size of the sensitive population in the southern portion of the Zhejiang-Fujian mud was mainly controlled by the EAWM intensity changes; and not directly related to changes in the sediment discharge from Datong station of the Changjiang River （DTSD）. Finally, recent changes in the content of heavy metals in study area reflect the impact of human activities on the environment.     

Evaluation of the biological toxicity of fluorine in Antarctic krill

Antarctic krill is a potentially nutritious food source for humans, but fluorine(F) toxicity is a matter of concern. To evaluate the toxicity of F in Antarctic krill, 30 Wistar rats were divided into three groups with different dietary regimens: a control group, a krill treatment group(150 mg·kg-1 F), and a sodium fluoride(NaF) treatment group(150 mg·kg-1 F). After three months, F concentrations in feces, plasma, and bone were determined, and the degree of dental and skeletal fluorosis was assessed. The F concentrations in plasma and bone from the krill treatment group were 0.167 0±0.020 4 mg.L-1 and 2 709.8±301.9 mg·kg-1, respectively, compared with 0.043 8±0.005 5 mg·L-1 and 442.4±60.7 mg·kg-1, respectively, in samples from the control group. Concentrations of F in plasma and bone in the krill treatment group were higher than in the control group, but lower than in the NaF treatment group. The degree of dental fluorosis in the krill treatment group was moderate, compared with severe in the NaF treatment group and normal in the control group. The degree of skeletal fluorosis did not change significantly in any group. These results showed that the toxicity of F in Antarctic krill was lower than for an equivalent concentration of F in NaF, but it was toxic for rats consuming krill in large quantities. To conclude, we discuss possible reasons for the reduced toxicity of F in Antarctic krill. The present study provides a direct toxicological reference for the consideration of Antarctic krill for human consumption.     

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风廓线雷达垂直径向速度应用初探

利用北京风廓线雷达五波束探测中的垂直波束资料,进行了垂直速度在预报中的应用研究。通过对垂直速度的分级显示,配合地面气象记录,对不同的天气个例进行分析,结果表明:平稳晴空的天气风廓线雷达所测量的垂直速度很小,基本上在±1m·s~(-1)范围内;而有降水时,风廓线雷达所测得边界层的垂直速度基本上都是朝向地面的,不同相态降水粒子的垂直下落速度有明显的差别。分析表明风廓线雷达垂直速度的探测对研究晴空大气的垂直运动、判断降水粒子相态和降水预报有应用价值。     

1330号台风海燕强烈发展和快速移动原因分析

本文运用NCEP再分析资料(水平分辨率1°×1°,垂直层次26层)和各种常规观测资料以及中央气象台台风实时定位定强数据对2013年全球最强台风海燕的特点和极端性展开分析,并运用天气学分析和动力学诊断的方法探讨"海燕"强度发展的动力机制和快速移动的原因,同时发掘预报着眼点,以提高中央气象台对类似台风的综合预报能力。本文主要研究结论为:(1)"海燕"在登陆菲律宾之前的持续加强和高强度维持发生在副热带西风急流加强南压和副热带高压南侧对流层各层低纬东风同时加强的条件下。(2)副热带西风急流加强南压是导致西太平洋副热带高压加强和副热带高压南侧对流层各层低纬东风加强及"海燕"高速靠近并登陆菲律宾的重要原因。(3)"海燕"的水平风速分布存在明显不对称,呈现台风北侧东风大于南侧西风、台风东侧南风大于西侧北风的特点,其中纬向风的不对称更显著。而由台风海燕东西两侧经向风和南北两侧纬向风的不对称分布导致的切变正涡度的增加可能是台风强度持续增强的重要原因之一。(4)对流层低层水平辐合的显著加强和台风海燕南北两侧经向垂直环流圈的加强和建立也是"海燕"强度持续加强的重要原因之一。(5)台风海燕持续加强和高强度维持的主要动力机制为内核区对流层低层水平辐合和对流层中低层涡度的持续增长以及台风所处环境的高层辐散的明显增加和高低层垂直切变的减小。(6)预报启示为:对于秋冬季的台风而言,除了西太平洋副热带高压、西风槽、对流层低层偏东风、越赤道气流外,还需关注对流层上层副热带西风急流的变化,特别是对于偏西行台风而言,副热带西风急流的加强南压可能会导致台风移速的加快和强度的明显加强。另外对流层上层不光是台风的出流层,能影响台风高层出流的变化,对流层上层的环流还可能对台风移动造成一定影响。     

以黑体为目标的能见度参考标准试验研究

黑体为目标的能见度测量是从科西米德定律出发,通过工业相机对黑体目标物进行拍摄,建立黑体和背景天空的数学模型,求得能见度。分析表明:当能见度小于30 km,黑体黑度和CCD(change-coupled device)工业相机的面非均匀性对该方法测得的能见度造成的误差约为3.7%。该方法与前向散射能见度仪测量进行对比,能见度变化趋势上具有一致性;但在高能见度时,黑体能见度测量值大于前向散射能见度测量值,低能见度时,黑体测量值小于前向散射能见度测量值。     

广域滑坡灾害隐患InSAR显著性形变区深度学习识别技术

全面识别和发现地质灾害隐患,已成为我国地质灾害防治的重大实际需求。目前,基于InSAR技术和深度学习相结合用于广域尺度下地质灾害隐患智能识别应用效果与适用性还需要进一步探索与研究。本文基于Stacking InSAR技术获得地表形变相位数据,利用深度学习检测识别正在变形的滑坡隐患位置与分布,确定显著性形变区边界,探索将上述技术方法推广到一定的广域范围和动态更新数据集。结果显示,测试数据集显著性形变区平均识别精度为0.69,召回率为0.67,F₁ score为0.67,动态更新数据集识别精度为0.85,召回率为0.58,F₁ score为0.68。研究表明,本文方法在广域地灾隐患识别中具有应用可行性,可为地质灾害监测预警提供理论基础与技术支撑。