海雾生成过程中平流、湍流、辐射效应研究

推导出一个相对湿度方程,分析了在海雾生成过程中平流、湍流和辐射的效应.     

Fifty-five-year longevity for the largest member of the family Sparidae: the endemic red steenbras Petrus rupestris from South Africa

A previous study that explored the age and growth of red steenbras Petrus rupestris (Valenciennes, 1830), a large sparid (family Sparidae, seabreams or porgies) endemic to South Africa and reported to approach 2 m in length, provided estimates as a moderately slow-growing species with a maximum age near 30 years. The stock is considered collapsed and a fishing moratorium was imposed in 2012, resulting in this species being assessed as Endangered by the IUCN. One consideration in addressing population status is validation of life-history traits. In this study, estimates of age for red steenbras from thin-sectioned otoliths were reassessed visually in terms of both the original ages and revised estimates using a different age-reading pattern. The revised ages exceeded the original ages by up to 30 years, with a maximum estimated age of 55 years from a well-defined otolith section that provided a basis for the revised age-reading procedure. Bomb radiocarbon (¹⁴C) dating revealed there was an offset in the timing of the ¹⁴C rise on the Agulhas Bank that, when coupled with considerations for regional oceanography, provided support for the revised age-reading pattern and an estimated longevity that exceeds 50 years. These findings were further supported by the fortuitous recapture of a tagged red steenbras that was at liberty for 22 years.     

论VAM的适宜时间

垂直角观测(vAM)的质量与作业时间有关.通过对大气折光角及其起伏的日变化规律的分析,提出了一种根据动态照准误差确定vAM的有利与不利时间的方法.与传统的观点相比较,采用该法确定的适宜时间将具有更高的参考价值.     

南海台风边界层湍流小波分析

利用小波变换（WT）对香港天文台飞机观测台风“妮妲”（1604）资料进行分析,研究在不稳定、不均匀的台风边界层中湍流涡旋的垂直传输作用。在0.1～5 Hz惯性子区内横风和顺风分量功率谱密度能较好符合-5/3幂律。小波分析显示：横风的小波功率谱峰值集中在1 km之下,顺风分量的小波功率谱峰值集中在1～6km之间;眼区动量通量的主要贡献尺度为2.3 km,眼区外主要贡献尺度在1～2 km,中低层为较小尺度（<1.0km）;湍流功能(TKE)的生成尺度主要集中在4 km之下。这项研究定量描述了南海北部台风边界层各个区域湍流结构的差异特征,讨论了对台风边界层通量参数化的可能影响。     

连续闭合钢箱接头地下连续墙施工技术

目前许多深基坑工程对于超深地下连续墙的刚度及防渗性能要求较高。在分析传统常用的接头形式在施工过程中存在问题的基础上,提出了一套行之有效的施工方法——连续闭合钢箱接头。详细介绍了连续闭合钢箱接头地下连接墙施工技术及其施工效果。     

Numerical Experiment on Two-Dimensional Line Thermal

The time evolution of a two-dimensional line thermal-a turbulent flow produced by an initial element with signifi-cant buoyancy released in a large water body, is numerically studied with the two-equation k - e model for turbulence closure. The numerical results show that the thermal is characterized by a vortex pair flow and a kidney shaped concentra-tion structure with double peak maxima; the computed flow details and scalar mixing characteristics can be described by self-similar relations beyond a dimensionless time around 10. There are two regions in the flow field of a line thermal: a mixing region where the concentration of tracer fluid is high and the flow is turbulent and rotational with a pair of vortex eyes, and an ambient region where the concentration is zero and the flow is potential and well-described by a model of doublet with strength very close to those given by early experimental and analytical studies. The added virtual mass coeffi-cient of the thermal motion is found to be approximat     

凹坑地形风流结构对污染物散布的模拟研究

利用建立的三维非静力高分辨率高阶湍流闭合模式与随机游动扩散模式研究了一个深凹露天矿区污染物散布的规律,同时在风洞中进行了示踪实验。结果表明,由于凹坑内复环流结构的存在,使得坑内污染物浓度较大,且浓度最大值出现在源的上风侧。数值试验与风洞试验结果吻合较好。     

SPECTRAL CHARACTERISTICS OF SURFACE-LAYER TURBULENCE OVER THE SUBURBS OF TIANJIN*

The paper computed the spectra of velocity and temperature,and the cospectra of velocity and temperature by the observational data of July,1990 in the suburbs of Tianjin.The results show that the characteristics of the atmospheric turbulence spectra over the suburbs are basically in accordance with some typical results over the flat terrain.But the scale,on which turbulence can satisfy the isotropic condition,over the suburbs is larger than over the flat terrain.The spectrum peak frequency range is a bit narrower.The feature of the spectrum range in low frequency(LF) is out of accordance with that of the flat terrain either.     

Flexibility in temporary fisheries closure legislation is required to maximise success

Temporary closures have been used for centuries in many parts of the world as a tool for fisheries management and restoration. The length of time that a closure is in place can play a determinative role in the effectiveness of the closure as a means of restoring stock biomass and diversity. For species that are slow growing and slow to reproduce, closures shorter than a decade are unlikely to be sufficient for the effects of restoration to accrue. New Zealand has two legislative mechanisms specifically designed to establish temporary closures: sections 186A and 186B of the Fisheries Act 1996. These provisions were created to respond to localised depletion and to provide for the use and management practices of Māori (New Zealand’s Indigenous People). There is currently a two-year time limit on temporary closures applied for by the community. By defining a time limit for temporary closures legislators have failed to account for the ecology of many of the species targeted for protection that require longer periods of protection for restoration. Furthermore, the way in which the final decision making power is vested with central government is also inconsistent with the original purpose of the provisions. An amendment to the temporary closure provisions is suggested to provide greater flexibility for users and to better recognise the non-commercial fishing rights provided for by the Fisheries Act 1996, of local communities seeking to apply this tool.     

一次暴雪过程前后近地层物理量场特征分析

利用铁塔风梯度观测资料和超声风温仪观测资料,对2008年1月18—21日暴雪前后,湖北黄石长江岸边近地层风场和湍流作了计算分析,探索其异常变化特征,为认识黄石地区暴雪近地层发生发展的物理过程提供依据。结果表明,暴雪前,风向转变,水平风速和垂直风速明显增大,湍流通量的输送较活跃,湍流动能和湍流强度有显著峰值出现;降雪过程结束后,湍流动能再次增大后缓慢减弱。可见此次暴雪过程前后近地层物理量场有异常变化