大连地区伏期旱涝指数EOF分析和预测

从大连地区气候规律及农业生产实际出发，制定出客观定量表征伏期旱涝特征的旱涝指数；用EOF方法对大连地区1961～2000年伏期旱涝指数进行了分析，在此基础上提出一种伏期旱涝预测方法。     

天然沸石负载二氧化钛光催化剂的制备与性能研究

以钛酸丁酯为钛源，天然沸石为载体，用溶胶．凝胶法制备了天然沸石负载TiO2光催化剂，用紫外可见吸收光谱、比表面积、红外光谱和X射线衍射等分析技术对沸石负载TiO2光催化剂进行了表征，以甲基橙为目标降解染料，考察了TiO2负载量、催化剂用量、热处理温度等不同条件下催化剂的光催化活性，结果表明，用天然沸石为载体所制得的TiO2光催化剂对于甲基橙具有较好的光催化降解效果。     

作物生长期水分条件对大连地区粮食产量的影响

利用1961～2000年大连主要产粮地区旅顺、金州、瓦房店、普兰店、庄河粮食产量资料和5个不同时段的水分条件指数资料。分析了粮食作物生长期水分条件对大连地区粮食气象产量的影响关系。结果表明，偏湿年份利于粮食增产，偏干年份粮食减产。     

大连地区主汛期多、少雨年同期大气环流场的差异

大连地区主汛期降水异常是该地区大气环流异常直接影响的结果,本文用1961~2000年各层大气环流场资料来分析对比多、少雨年同期大气环流的情况。揭示出大连地区主汛期多雨年和少雨年同期的海平面气压场、850 hPa大气环流场、500 hPa西风带槽脊和高度场都存在显著差异。多雨年较少雨年该地区低层的辐合上升运动加强,850 hPa盛行西南气流,水汽输送旺盛。同时,500 hPa西风带的槽脊波动加深,高空西风急流增强。     

Numerical Study of Submerged Vertical Plane Jets Under Progressive Water Surface Waves

When wastewater is discharged into a coastal area through an ouffall system, it will always be subjected to the action of waves. It is important to study and quantify the mixing of the discharge with the ambient water so that accurate environmental impact assessment can be made for such discharge conditions. The present work aims to study the phenomenon of a plane jet discharged into water environment with regular waves. A 3D numerical model based on the full Navier- Stokes equations （NSE） in the a-coordinate is developed to study the present problem. Turbulence effects are modeled by a subgrid-scale （SGS） model using the concept of large eddy simulation （LES）. The operator splitting method is used to solve the modified NSE. The model has been applied to the simulation of three different eases of submerged plane jets with surface waves： jet with strong waves, jet with weak waves and jet without waves. Numerical results show that the waves enhance the mixing of the jet with the ambient fluid, and cause a periodic deflection of the jet. The size of the recirculation is about 1.5- 2.4 h （water depth） . The velocity profile of the jet is serf-similar in the zone of established flow for both the pure jet and jet in wave circumstances. The spreading characteristic constant a is 0. 100 and 0. 105 for pure momentum jets with Re numbers 1025 and 2050. The value of a increases from 0. 130 to 0. 147 for a jet in weak and strong wave circumstances, showing that waves have an obvious effect on the mixing and dilution properties of jets. Numerical results are in good agreement with the experimental data for the cases of pure jets and jets with waves.     

Simulation of Surface Wave with Large Eddy Simulationin in δ-Coordinate System

A three-dimensional numerical model in the δ-coordinate system is developed to study the problem of waves. Turbulence effects are modeled by a subgfid-scale (SGS) model with the concept of large eddy simulation (LES). The δ-coordinate transformation is introduced to map the irregular physical domain of the wavy free surface and uneven bottom onto the regular computational domain of the shape of rectangular prism. The operator splitting method, which splits the solution procedure into the advection, diffusion, and propagation steps, is used to solve the modified Navier-Stokes Equation.The model is used to simulate the propagation of solitary wave and wave passing over a submerged breakwater. Numerical results are compared with available analytical solutions and experimental data in terms of velocity profiles, free surface displacement, and energy conservation. Good agreement is obtained. The method is proved to be of high accuracy and efficiency in simulating surface wave propagation and wave-structure interaction. It is suitable for the large and irregular physical domain, and requiring the non-uniform grid system. The present work provides a foundation for further studies of random waves, wave-structure interaction, wave-discharge interaction, etc.     

波浪能振荡浮子转换方式实验装置的研究与设计

针对阵列式振荡浮子波浪能转换设备,提出一种在实验室进行测试研究的实验装置。该实验装置由一组阵列柱形水槽组成,水槽液面在水动力系统的驱动下,按照计算机设定的函数做升降运动;对该装置模型——柱形阵列水槽的假设,依据波浪理论进行了论证;对装置的工作原理、结构设计、技术参数、控制电路和操作运行等做了较详细的说明;对实验装置实际运行和测试情况做了介绍。结果表明:该实验装置设计合理可行,模拟波浪高度,远高于现有的造波水池,构成了一种专用的模拟造波装置;该装置为不同形式振荡浮子式波浪能转换设备的研制提供了一种多功能、大振幅、高效灵活的实验平台。     

中国海水养殖生态系统服务价值评估研究进展

中国是海水养殖大国,海水养殖生态系统服务价值评估可促进海水养殖密度合理化,为推进海水养殖高质量发展提供科学依据。与其他国家相比,中国对海水养殖生态系统服务价值评估的研究文献数量较多。文章基于“中国知网”数据库中1979-2020 年相关主题的文献样本数据,利用CiteSpace文献计量软件分析海水养殖生态系统服务价值评...     

Numerical Investigating of Vertical Turbulent Jets in Different Types of Waves

The effects of various types of waves on vertical plane turbulent jets are studied numerically in the paper. A three-dimensional numerical model in σ -coordinate is developed to study these problems by use of large eddy simulation method. Turbulence is modeled by a dynamic coherent eddy model. Numerical results including the distribution of velocity, the decay law of the mean velocity along axis, the turbulent Reynolds stresses and the volume flux per unit width without wave, in the first-order Stokes waves, in the second-order Stokes waves, in the fifth-order Stokes waves, in the solitary waves and in random waves are compared and analyzed. A focus on coherent structures, probability density functions and correlation functions of jets is also investigated. The numerical results are of great theoretical importance for understanding jet turbulent behaviors in different types of waves.     

2000—2017年湖南省土地耕作适宜性、气候生产潜力与LUCC过程动态特征

定量分析土地耕作适宜性、气候生产潜力与土地利用/土地覆盖变化(LUCC)的动态特征是科学规划土地利用、有效保护耕地资源的基础。本文基于湖南省气候、土地覆被、地形等数据,采用气候生产潜力估算和趋势分析方法,以300 m×300 m栅格为计算单元,获得湖南省2000—2017年耕地气候生产潜力的变化趋势,并分析湖南省土地耕作适宜性、气候生产潜力与LUCC过程的关系。结果显示:湖南省最适宜耕作的土地主要分布在北部平原、中部和南部盆地、丘陵区,气候生产潜力为19 530~40 375 kg/ha,整体呈现东南部高西北部低。北纬28°以南的中部、中东部丘陵盆地区,是土地耕作适宜性和气候生产潜力组合最好的区域。86.5%的新增人造地表为最适宜耕作的耕地,说明新增人造地表主要以牺牲优良的耕地为代价。气候变化、气候生产潜力变化与LUCC过程密切相关,LUCC过程中流向耕地多为气候生产潜力增加区,而耕地转为林地等土地类型则属于气候生产潜力下降区,指示气候变化在驱动不同类型土地相互转变中的作用。上述结果可望为湖南省土地规划整治及山地资源开发等提供决策参考。