潮滩围垦对海岸环境的影响研究进展

潮滩围垦是沿海国家拓展陆域, 缓解人地矛盾的最主要方式之一。潮滩围垦通过对潮滩高 程、水沙动力条件、沉积物特征等多种环境因子的改变, 促进生物演替, 并通过垦区土地的人为利 用, 对海岸环境演变产生重要影响。文章从围垦工程对水沙环境的影响、围垦对海岸带物质循环 的影响、围垦对潮滩生物生态学的影响和盐沼恢复与生态重建等4 方面探讨了不同学科学者对 围垦环境影响的主要研究进展及存在的问题, 并指出应加强多学科合作的综合研究, 探讨潮滩围 垦对海岸环境的影响机制, 以寻求兼顾围垦土地需求与海岸带生态保护的持续发展之路。     

我国海洋放射性监测技术体系现状及展望

随着我国滨海核设施和核技术利用项目的大力建设与发展,迫切需要建立一套统一、规范的海洋放射性监测技术体系,以保障和应对我国海洋放射性环境安全与风险.本文分别对当前海洋放射性样品采集规范体系、海洋放射性监测技术规范体系、海洋放射性监测分析方法体系、海洋放射性质量评价体系和质量保证体系进行梳理,提出海洋放射性监测技术体系的发...     

三丁基氟化锡对内刺盘管虫的实验性中毒研究

评价防污涂料的毒效，通常采用以附着生物的幼虫作室内药物筛选和外海挂板检验的方法，前者常在解剖镜下检查幼虫是否变态，后者是检查附着的成体数量，但这两者都不能说明药物进入附着生物体内的途径及其作用机制。 本文通过有机锡药物——三丁基氟化锡(tributyltin fluoride)对内刺盘管虫Hydroides ezoensis的实验性中毒观察，试图解答上述问题。     

基于MODIS的沿海带状植被NDVI/EVI季节变化研究——以江苏沿海互花米草盐沼为例

植被指数的时空变化是目前全球变化研究的热点问题。该文以江苏沿海互花米草盐沼为例,运用MODIS数据探索沿海带状植被NDVI/EVI的季节变化规律。结果表明,互花米草的返青(出苗)、抽穗、种子成熟等主要物候期在VI曲线上均能得到很好体现。本研究可为监测互花米草盐沼扩展趋势、加强管理、趋利避害提供基础数据,同时也为沿海其它带状植被监测提供借鉴。     

Optimization of ice cuttings transportation by cable-suspended core auger drills

Ice cores contain an abundance of information about the Earth''s climate in the past,and recovered from shallow drilling down to 300--350 m give sufficient information for reconstructing of the last climatic chan- ges and for monitoring of pollution from human being． Cable-suspended core auger drills use an armored cable with a winch to provide power to the down-hole motor system and to retrieve the down-hole unit． Because of their lightweight,convenient transportation and installation,high penetration rates and low power consumption, core auger drills are widely used for shallow drilling in ice． Nowadays at least 14 types of auger electromechani- cal drills were designed and tested in different foreign and national glaciological laboratories． However,auger options were usually determined by experience,and the main parameters (helix angle of the fights and rotational speed) are varied in a wide range from drill to drill． If parameters of auger are not chosen properly,poorly en- gineered drills had troubles with low efficiency of cuttings transportation,jam of ice cuttings,repeated fragmen- tation,cutters icing and stop penetration,abnormal power consumption,high rotation torques,and so on． Thus,this paper presents the method of optimization of ice cuttings transportation of cable-suspended core auger drill on the base of the theory of rotary auger． As the result,the optimal helix angle was determined correspond- ing to the rotational speed from the transportation efficiency point of view．     

Distribution Patterns of Synechococcus Indicated Their Environmental Constraints and Related Geochemical Processes in the Yellow Sea

Synechococcus is a widely distributed photosynthetic pico-phytoplankton,which contributes mainly to carbon fixation and maintains the stability of the marine ecosystem.To investigate its distribution patterns in the Yellow Sea,seawater samples were collected during September 2018.Results of flow cytometry analysis showed that the Synechococcus abundance ranged from 6.36×10² to 4.51×10⁴ cells mL^?1,which correlated with salinity(P<0.01)and temperature(P<0.05).At deeper off-shore sites,Synecho-coccus showed high abundance at the subsurface thermo-halocline,which was in accordance with chlorophyll a(Chl a)content along the vertical column.Based on the high-throughput sequencing data of rpoC1(partial gene encoding RNA polymerase),two Synechococcus subclusters,S5.1 and S5.2,were found to coexist in the studied area.Several clades of S5.1,including Clades I,II,and III,were the dominant components,accounting for 6.63%,26.11%,and 45.5%of the total genus,respectively.Redundancy analysis(RDA)showed that nitrite was the main environmental factor that explained the genus composition among samples.Fur-thermore,co-occurrence network revealed that the main phyla that coexisted with Synechococcus were Proteobacteria,Bacteroidetes,Actinobacteria,Planctomycetes,and Verrucomicrobia,which were involved in the carbon(C),nitrogen(N),sulfur(S),and manga-nese(Mn)cycles.Overall,Synechococcus exhibited biogeographic distribution correlated with temperature-salinity and nitrite in the Yellow Sea,and their geochemical function showed diverse but should be further verified in the future.     

精密时频传递技术综述

精密时间频率传递技术在当今众多领域中发挥基础支撑作用,同时也是UTC(coordinated universal time)、TAI(international atomic time)等国际时间标准建立和维持的关键技术之一。本文对3类主流的精密时频传递技术进行了研究。结果表明,卫星时频传递发展最为成熟,应用最为广泛,但同时也面临性能提升瓶颈及安全性、环境适应性等隐患;光纤时频传递利用先进的光纤传输技术,在传递性能方面具有一定的优越性,但易受环境温度等因素的影响,且在铺设范围、成本及灵活性方面存在局限性;激光时频传递利用卫星激光测距技术实现星地时钟的高精度比对,但该技术实施需要专用系统及设备,应用领域有限,目前主要应用于卫星导航系统性能增强。本文研究可为建设满足精度、稳定性、可靠性及安全性要求的国家时频体系提供参考。     

山东郯城和江苏东海早白垩世晚期恐龙足迹化石新发现及古环境*

首次在山东郯城早白垩世晚期地层中发现恐龙足迹化石,分属蜥脚类和兽脚类恐龙足迹,足迹大小差异较大。通过对山东省郯城县新发现的2处恐龙足迹化石点和江苏省东海县南古寨恐龙足迹化石点的对比研究,探讨了足迹类型、大小、速度与足迹深度的关系,发现同等条件下,蜥脚类恐龙足迹通常较兽脚类足迹深,而蜥脚类恐龙足迹深度随着足迹大小的增加有变深的趋势;波痕、雨痕和泥裂等沉积构造以及足迹回填和叠覆现象对足迹化石保存形态和细节有较大影响,而构造变形对足迹形态和行迹并无明显影响,但高角度的构造变形会加速差异风化,使足迹化石更易暴露而被破坏。对研究区古环境与古生态的研究表明,早白垩世晚期研究区经历了水体逐渐变浅、气候由湿到干并伴随短暂间歇性干旱的过程,沉积环境由河湖演变为三角洲前缘、并逐渐过渡到三角洲平原,生态环境逐渐恶化,动植物由兴而衰、逐渐减少。     

9015号台风登陆后其周围的若干中尺度特征

利用加密观测资料详细分析了登陆并穿过浙江省的９０１５号台风所造成的风雨分布及其变化与台风周围的一些中尺度特征以及地形作用的关系。分析表明：台风登陆后气压眼与风眼存在偏高，这种偏离状况是与风雨强度相对应的。此外，在台风登陆后不久，由于入流增强，中心眼区范围内降雨会突然增强；台风造成的雨区成带状分布，带宽约４０─６０ｋｍ，间隔为３０─１００ｋｍ，雨带内主要雨团相对于台风中心的移动轨迹大都呈顺时针旋转；较强的风雨区往往出现在台风周围的中尺度低压和中尺度涡旋及辐合线附近，前者易在倒槽内生成，后者则与地形影响有关。