混合智能优化算法的SAR图像特征选择

为提高SAR图像自动目标识别的准确率及实时性,提出了一种基于混合智能优化的SAR图像特征选择算法。首先,采用分形特征对SAR图像进行增强,基于分割后的图像提出了一种基于图像矩的方位角估计方法。然后基于未校正和校正后的图像分别提取Zernike矩、Gabor小波系数和灰度共生矩阵构成候选特征集合,使用遗传算法结合二值粒子群的混合优化算法实现SAR图像特征选择。最后,采用MSTAR数据库验证本文算法的有效性。实验结果表明,优化后的特征集合具有一定泛化能力,一方面提高了SAR目标识别的准确率,另一方面减小了SAR图像目标识别的时间。     

气象卫星发展回顾与展望

回顾了国际气象卫星和中国风云气象卫星的发展,综述了气象卫星在图像解译、定量产品应用和数据同化方面的成就以及辐射校正技术的进步。围绕大气科学,特别是数值天气预报对天基观测的需求,展望了未来气象卫星的技术发展方向。     

Spatio-Temporal Characteristics of Heavy Precipitation Forecasts fromECMWF in Eastern China

This study examines the spatio-temporal characteristics of heavy precipitation forecasts in eastern China fromthe European Centre for Medium-Range Weather Forecasts (ECMWF) using the time-domain version of the Method forObject-based Diagnostic Evaluation (MODE-TD). A total of 23 heavy rainfall cases occurring between 2018 and 2021 areselected for analysis. Using Typhoon “Rumbia” as a case study, the paper illustrates how the MODE-TD method assessesthe overall simulation capability of models for the life history of precipitation systems. The results of multiple tests withdifferent parameter configurations reveal that the model underestimates the number of objects’ forecasted precipitationtracks, particularly at smaller radii. Additionally, the analysis based on centroid offset and area ratio tests for differentclassified precipitation objects indicates that the model performs better in predicting large-area, fast-moving, and long lifespan precipitation objects. Conversely, it tends to have less accurate predictions for small-area, slow-moving, and short lifespan precipitation objects. In terms of temporal characteristics, the model overestimates the forecasted movement speedfor precipitation objects with small-area, slow movement, or both long and short lifespans while underestimating it forprecipitation with fast movement. In terms of temporal characteristics, the model tends to overestimate the forecastedmovement speed for precipitation objects with small-area, slow movement, or both long and short lifespans while un derestimating it for precipitation with fast movement. Overall, the model provides more accurate predictions for theduration and dissipation of precipitation objects with large-area or long-lifespan (such as typhoon precipitation) whilehaving large prediction errors for precipitation objects with small-area or short-lifespan. Furthermore, the model’s simu lation results regarding the generation of precipitation objects show that it performs relatively well in simulating thegeneration of large-area and fast-moving precipitation objects. However, there are significant differences in the forecastedgeneration of small-area and slow-moving precipitation objects after 9 hours.     

海绵铁对活性艳红K-2BP废水的脱色动力学研究

为了开发新型的脱色填料,进行海绵铁对活性艳红K-2BP的脱色动力学研究。试验结果表明,海绵铁对活性艳红K-2BP具有较高的脱色率,在10min,30min和60min脱色率分别为58.78%,85.2%和93.89%。在海绵铁表面衰减分析的基础上,建立了脱色动力学模型,并研究了pH值、温度、粒径和投加量对反应速度常数K和表面衰减系数Ka的影响。     

利用UNIX平台对多波束测深系统进行监测

根据多波束测深系统存在着“工作站有时会停机”和“测深软件有时会退出”的问题,利用UNIX中的SHELL编写了两个程序,它们可以对多波束测深系统可能出现的故障进行实时监测。     

三沙湾海域沉积物中甲藻休眠孢囊的初步研究

通过对福建三沙湾海域50个站位海底沉积物进行研究，共发现9属20种甲藻休眠孢囊。其中，有毒种类2种：Alexandrium minutun、A.tamarense,有害种类4种：Alexandrium affine、Gonyaulax spinifera、Lingulodinium polyedraum、Scripp-siella trochoidea。文中对孢囊的形态与丰度、分布特征进行了初步研究。     

黄河源地区水文水资源及生态环境变化研究

本文通过实地查勘调查、依据多年积累的原型观测资料，在分析可源地区基本情况、水文气候特征的基础上，揭示了近年来黄河源地区水文水资源及生态环境变化的特点；解答了这种变化所产生的结果和影响；得出了在河源地区封山育林植草，涵养水源，防止水土流失的初步对策；提出了河源地区水资源开发利用纳入全河统一调度、开发、利用规划的建议；以期找出对付生态环境恶化的根本途径。     

东海西湖凹陷浙东中央背斜带烃源岩生排烃史研究

为了深化西湖凹陷浙东中央背斜带油气成藏过程的研究，优化勘探目标选择，在烃源岩特征分析的基础上，应用动态数值模拟技术，定量恢复了研究区主要烃源岩层系的生排烃历史，研究表明，浙东中央背斜带主要发育4套烃源岩系，其中始新统平湖组泥岩与煤层为主力烃源岩，具较高的有机质丰度=生烃强度与排烃效率，烃类排出具阶段性、多期次幕式排烃的特点汉平湖组为源岩的油气系统应是本区油气勘探的主要目标。     

Trial and Numerical Analysis of Specimen Pipelay

Subsea pipelay has a relatively long history. In recent years, there has been a domestic need for the laying of large diameter thin wall pipes. A land-based trial for the large diameter thin wall specimen pipe is described in this paper. Re-gression analysis is performed for the trial data and the formula derived can express the trial data very well. Numerical analysis is adopted to compute various trial conditions. Then the numerical model is revised with the trial results, which are consistent with each other. After summarization of the results of trial and numerical analysis, the characteristics are described of the spatial configuration during the laying of the pipe and it is concluded that the maximum strain appears around the center of the raised pipeline. In the end, a reference Standard, which limits the maximum stress below the yield stress is provided.