Pb distribution and translocation in Jiaozhou Bay

The trends of distribution, translocation and seasonal change of heavy metal Pb were studied based on the surface and bottom water sampling in Jiaozhou Bay in 1979, and compared with those in 1990＇s. The results showed that the source of Pb in the bay was from wastewater and sewage in the east of Jiaozhou Bay from ocean vessels. Pb concentration was higher in spring and lower in summer and autumn, and remained stable through sedimentation in the bottom layer. The overall water quality was good in 1970＇s. Compared with the environmental monitoring data of 1995-1999, Pb pollution had become serious. Therefore, more efforts should be made to protect the bay from Pb pollution.     

Optimum temperature for the growth performance of juvenile orange-spotted grouper （Epinephelus coioides H.）

Effects of water temperature （17, 21, 25, 30 and 35℃） and body size （14.75-281.41 g initial body weight） on food consumption, growth, feed conversion, and dry matter content in orange-spotted grouper fed to satiation were investigated. The combined effect of temperature （T, ℃） and body weight （W, g） on maximum food consumption （Cmax, g/day） was described as： InCmax=-7.411＋0.828 InW＋0.317T4）.004 7T2, and the optimum feeding temperature was 33.9℃. The combined effect of temperature and body weight on growth （G） was described as： lnG=-4.461-0.2081nW＋0.394T-0.006 3T^2. The optimum growth temperature was 31.4℃, whereas overall growth rates were high at 25, 30 and 35 ℃. Feed conversion efficiencies （FCE, %）, increasing first and then decreasing with increasing temperature, averaged from 1.8 to 2.1 in terms of dry weight of food fish. The optimum temperature for FCE tended to be lower than that for growth or feeding. Dry matter content increased with both increasing water temperature （17, 25, 30 and 35℃） and body weight, and the combined effect of temperature and body weight on dry matter content （DM, %） was described as： lnDM =3.232＋0.01 4 lnW-0.004 4T＋0.001 2TInW.     

Uncertainty representation of ocean fronts based on fuzzy-rough set theory

Analysis of ocean fronts' uncertainties indicates that they result from indiseemibility of their spatial position and fuzzi-ness of their intensity. In view of this, a flow hierarchy for uncertainty representation of ocean fronts is proposed on the basis of fuzzy-rough set theory. Firstly, raster scanning and blurring are carried out on an ocean front, and the upper and lower approximate sets, the indiscernible relation in fuzzy-rough theories and related operators in fuzzy set theories are adopted to represent its uncer-tainties, then they are classified into three sets: with members one hundred pereent belonging to the ocean front, belonging to the ocean front's edge and definitely not belonging to the ocean front. Finally, the approximate precision and roughness degree are util-ized to evaluate the ocean front's degree of uncertainties and the precision of the representation. It has been proven that the method is not only capable of representing ocean fronts' uncertainties, but also provides a new theory and method for uncertainty representation of other oceanic phenomena.     

Understanding the dynamical-microphysical-electrical processes associated with severe thunderstorms over the Beijing metropolitan region

The Dynamical-microphysical-electrical Processes in Severe Thunderstorms and Lightning Hazards(STORM973)project conducted coordinated comprehensive field observations of thunderstorms in the Beijing metropolitan region(BMR)during the warm season from 2014 to 2018.The aim of the project was to understand how dynamical,microphysical and electrical processes interact in severe thunderstorms in the BMR,and how to assimilate lightning data in numerical weather prediction models to improve severe thunderstorm forecasts.The platforms used in the field campaign included the Beijing Lightning Network(BLNET,consisting of 16 stations),2 X-band dual linear polarimetric Doppler radars,and 4 laser raindrop spectrometers.The collaboration also made use of the China Meteorological Administration’s mesoscale meteorological observation network in the Beijing-Tianjin-Hebei region.Although diverse thunderstorm types were documented,it was found that squall lines and multicell storms were the two major categories of severe thunderstorms with frequent lightning activity and extreme rainfall or unexpected local short-duration heavy rainfall resulting in inundations in the central urban area,influenced by the terrain and environmental conditions.The flash density maximums were found in eastern Changping District,central and eastern Shunyi District,and the central urban area of Beijing,suggesting that the urban heat island effect has a crucial role in the intensification of thunderstorms over Beijing.In addition,the flash rate associated with super thunderstorms can reach hundreds of flashes per minute in the central city regions.The super(5%of the total),strong(35%),and weak(60%)thunderstorms contributed about 37%,56%,and 7%to the total flashes in the BMR,respectively.Owing to the close connection between lightning activity and the thermodynamic and microphysical characteristics of the thunderstorms,the lightning flash rate can be used as an indicator of severe weather events,such as hail and short-duration heavy rainfall.Lightning data can also be assimilated into numerical weather prediction models to help improve the forecasting of severe convection and precipitation at the cloud-resolved scale,through adjusting or correcting the thermodynamic and microphysical parameters of the model.     

Parametric vibration of submerged floating tunnel tether under random excitation

For the study of the parametric vibration response of submerged floating tunnel tether under random excitation,a nonlinear random parametric vibration equation of coupled tether and tube of submerged floating tunnel is set up.Subsequently,vibration response of tether in the tether-tube system is analyzed by Monte Carlo method.It may be concluded that when the tube is subjected to zero-mean Gaussian white noise random excitation,the displacement and velocity root mean square responses of tether reach the peak if the circular frequency of tube doubles that of tether;the displacement and velocity root mean square responses of tether increase as the random excitation root mean square increases;owing to the damping force of water,the displacement and velocity root mean square responses of tether decrease rapidly compared with tether in air;increasing the damping of the tether or tube reduces the displacement and velocity root mean square responses of tether;the large-amplitude vibration of tether may be avoided by locating dampers on the tether or tube.     

象山港潮波响应和变形研究 Ⅱ.象山港潮波数值研究

通过象山港水域的潮波运动数值模拟,分析了象山港M4分潮的生成和增长机制．结果说明,潮波传播中的非线性底摩擦效应是M4分潮生成和增长的主要控制因子,M4分潮在湾内的共振现象也起着重要的放大作用二平流效应在绝大部分区域中抑制了M4分潮的发展,只有在佛渡水道中一些岛屿周围极小区域内对M4分潮有增强作用．潮滩在湾内对M4分潮的影响极其微弱．     

用模糊集合观点讨论水团的有关概念

本文将划分水团的基本原则,概括为水团内部特征的相对均一性及其与外部海水的明显差异性。用模糊集合讨论了水型、水团和水系等有关概念。提出了用模糊集合观点定义水团及其核心、本体、边界与混合区的建议,并以1979年8月黄海和东海表层为例,给出了各水团的隶属函数。计算了其核心、本体、边界、混合区及贴近度,按其模糊性排出了顺序。     

气候变化中海洋和冰冻圈的变化、影响及风险

本文系统梳理了IPCC 《气候变化中的海洋和冰冻圈特别报告》(SROCC)的主要结论,并对主要观点进行了解读。报告主要关注全球变暖背景下高山、极地、海洋和沿海地区现在和未来的变化及其对人类和生态系统的影响,以及实现气候适应发展路径的方案。在全球变暖背景下,冰冻圈大面积萎缩,冰川冰盖质量损失,积雪减少,北极海冰范围和厚度减小,多年冻土升温,全球海洋持续增温,1993年以来,海洋变暖和吸热速度增加了一倍以上。同时,海洋表面酸化加剧,海洋含氧量减少。全球平均海平面呈加速上升趋势,2006—2015年全球海平面上升速率为3.6 mm/yr,是1901—1990年的2.5倍,但存在区域差异。高山、极地和海洋的生态系统的物种组成、分布和服务功能均发生变化,并对人类社会产生了显著负面影响。极端海洋气候事件发生频率增多,强度加大。1982年以来,全球范围内海洋热浪的发生频率增加了一倍,且范围更广,持续时间更长。海平面持续上升加剧了洪涝、海水入侵、海岸侵蚀等海岸带灾害,并影响沿海生态系统。海洋及冰冻圈的变化及其影响在未来一定时期仍将持续,应对这些影响而面临的挑战,应加强基于生态系统的适应和可再生能源管理,强化海岸带地区的海平面上升综合应对,打造积极有效、可持续和具有韧性的气候变化应对方案。     

基于GIS的武汉市公共信息服务系统的研制

介绍了武汉市公共服务系统项目研制的目的——通过网络电子地图、触摸屏电子地图、光盘电子地图搭建公共服务系统平台,服务于公众。阐述了系统的内容,并着重分析了系统功能实现中数据库和功能模块的设计。     

遥感影像混合像元分解中的端元选择方法综述

端元选择是进行遥感影像混合像元分解的首要步骤,也是最关键的步骤,其直接影响混合像元分解的精度。该文对遥感影像混合像元分解中端元产生的特定背景、当前存在的端元选择途径和端元选择方法进行综述,并通过对当前端元选择方法的分析,提出了选择或构造端元选择方法应遵循的几个原则。