海水淡化浓盐水太阳能加热性能研究

实验采用真空管太阳能集热器系统,研究了太阳能对6波美度海水淡化浓盐水的加热性能。实验采用了自动采集与监测系统,主要考察了太阳能辐照度、环境温度、湿度、风速等四个气象因子以及进水流量、温度单因素对浓盐水太阳能集热性能的影响。研究结果表明,浓盐水的集热速率与太阳辐照强度关系最为密切,其他因子对浓盐水太阳能集热性能无显著影响。     

Variability of turbulence dispersion characteristics during heavy haze process: A case study in Beijing

The turbulent standard deviations and the turbulent third-order and fourth-order moments are the key turbulence dispersion parameters in Lagrangian dispersion models. However, the characteristics of these parameters under heavy haze conditions in urban areas have not been fully investigated, and the commonly used similarity relations of these parameters in models were based on observations in highly flat and sparsely populated areas. In this paper, the vertical profiles of these parameters and their local similarity relations under heavy haze conditions in the wintertime of Beijing have been analyzed by using data collected at a 325-m meteorological tower. The heavy haze process has been divided into three stages: transport stage (TS), cumulative stage (CS), and dispersion stage (DS). Results show that the turbulent dispersion parameters behave differently during three stages. In the TS and DS, the maxima appear in the profiles of the turbulent standard deviations above the urban canopy; in the CS, the turbulent standard deviation are almost constant with height. The analysis of the third and fourth order moments shows that the wind velocities above the urban canopy in the TS deviate from the Gaussian distribution more significantly than those in the CS and DS. The local similarity relations of the turbulent dispersion parameters in the TS, especially for the longitudinal wind components, are normally different from those in the CS and DS. Thus, different from the common assumptions in Lagrangian models, the turbulence dispersion in horizontal directions is anisotropic and should be parameterized by multiple similarity relations under heavy haze conditions.     

利用风场资料研究中距离大气扩散规律

本文提出了一个利用气象观测网取得的测风资料研究中距离大气扩散规律的方法。根据常规的风场观测资料和高空风观测资料,用插值公式计算地面和200m高度的水平轨迹以及水平风纵向分量和横向分量的脉动时间序列,进而用相继两条轨迹的横向距离和风脉动滑动平均法求得各类稳定度下的大气扩散参数。计算结果与同时进行的SF_6示踪实验结果和不同时进行的平衡球双经纬仪定位结果基本符合。     

河谷型城市风场及污染物扩散的CFD数值仿真

为研究河谷型城市地形及其引起的风场和污染物扩散的复杂问题,利用CFD（计算流体力学）方法和复杂地形网格生成技术,建立河谷型城市风场及大气污染分布的数值仿真模型,实现CFD方法在复杂地形空气运动和污染物扩散方面的应用.分别使用LES（large eddy simulation）模型和mixture模型研究兰州市地面风场特征和污染物扩散形态,计算得到的污染物分布结果与实测结果分布一致.结果表明:复杂地形对空气运动的影响很大,如风速因山体屏障作用会呈现带状分布特征,山体后侧易出现弱风区域;同时,风场会密切影响污染物扩散,决定了污染物扩散形态,如幅散能够影响污染物扩散范围及污染水平.而给定西北风条件下,如地面以上10 m、风速为5 m/s、不受地形阻挡情况下,工业区污染物浓度被稀释10倍,约扩散2.2 km;山体阻挡会抑制污染物纵向扩散,表现在山体阻挡情况下污染物稀释100倍时的扩散长度约为相对平坦区域的1/3.此外,不同的入口风向会引起空气运动与山体相互作用发生变化,进而会使得地面风速、局部风场存在差异,造成污染物扩散及分布形态差异.研究显示,CFD方法可行,模型可靠,可以用来研究地形对风场和污染物扩散的影响.      

中国风电的时空分布特征和发展趋势

利用1990-2005年中国和英国风电发展数据,对两国风电的时空分布特征和发展趋势进行了比较分析。据英国风电发展的阶段性,把中国风电发展划分为试验性发展、规模发展、过渡发展3个阶段,并预测到2007年步入大规模发展阶段。因此,未来几年,中国风电场数目和规模将会快速增长,并且由集中走向高密度集中分布。据对影响风电场省级时空分布的自然、市场和政策共8个选择因子的主成分分析和系统聚类分析结果,将中国风电场按省级划分为3个区域和8个亚区域,对聚类结果进行逐步判别回判,结果表明准确率达92.6%。     

Reduction of the environmental impact of coal storage piles: A wind tunnel study

This paper presents an application of scale model wind tunnel tests to reduce the environmental pollution provoked by fugitive dust from coal storage piles. The effectiveness of different types of wind breaks, shelter belts and coating chemicals has been tested under different wind speeds and pile layouts. Most of the results presented in this paper are of general significance and demonstrate the usefulness of comparative simulations in reducing real pollution impact problems. The best reductions in dust deposition (up to 85%) have been assured by using chemical additives spread over the pile surface, whose coating action remained nearly unvaried up to 5 days or more, and wind breaks provided with suitable baffles for wind deviation.     

东莞市夏季大气边界层风、温场结构与特征研究

利用2008年5月4-20日东莞市探空观测资料,分析该地区夏季大气边界层内的风场、温度场特征进行研究,结果表明:1)各规定层高度主导风向为WNW,其风向频率值大于15%;2)风速随高度的增加而增大;3)接地逆温大约在20:00左右生成,02:00以后逐渐消失,从06:00到17:00没有观测到接地逆温,一天中接地逆温大约维持12 h左右;4)混合层高度在清晨厚度较薄,午后混合层厚度较厚,有利于污染物的扩散。     

天津市郊区冬季大气边界层风、温场结构与特征

利用天津市郊区探空观测资料,对该地区冬季大气边界层内的风场、温度场结构与特征进行研究.结果表明,测试期间风向随着高度增加呈顺时针旋转, 由东风、东南风逐渐右转,转为西南风、西风,遵循Eckman螺线的规律;不同高度层风速日变化规律不同.一般来说,在较低高度风速白天变大,夜晚变小,而较高处则相反;接地逆温大约在20:00开始生成,随着时间的增加,逆温逐渐加强,平均逆温厚度在02:00达到最大值;混合层高度在早晨厚度较薄,午后混合层厚度较厚,有利于污染物的扩散;天津市市区10m和100m高度层风速的日变化规律与郊区相同,200m高度层风速日变化规律不同;市区与郊区相比,不同高度层风速随着时间起伏变化较小.     

The effect of a precipitation gauge orifice rim on the wind field deformation as investigated in a wind tunnel

The ASTA precipitation gauge has shown systematically less precipitation than the Hellmann gauge. To explain the deficit, wind speed and turbulence intensity profiles above the orifice of both gauges have been measured in a wind tunnel. They showed greater values of wind speed increment and smaller values of intensity of turbulence for the ASTA gauge. This indicates that the deficit is due to the larger wind field deformation above the ASTA gauge. The reasons for this are the bigger orifice rim and the bird protection ring used occasionally on this gauge. The effect of turbulence intensity with respect to the deficit has not been explained as yet.     

The determinants of support levels for wind energy in the European Union. An econometric study

The aim of this paper is to identify the factors that drive support levels for wind on-shore electricity in the Member States of the European Union (EU) with the help of econometric techniques. The econometric analysis is based on cross-section linear regressions with ordinary least squares. Four alternative specifications of the model have been estimated. The estimates comply with the basic hypotheses of the lineal model, i.e., absence of multicollinearity, accurate functional form, homokedasticity and normality in the distribution of errors. Thus, the estimations are unbiased, efficient and consistent. The results show that countries with higher wind energy generation costs have higher support levels. The higher support levels in countries with higher carbon intensities suggest that wind energy deployment is regarded as effective to mitigate carbon emissions. The type of support scheme also influences support levels, with feed-in tariffs leading to lower levels of support than other instruments. In addition, a general good investment climate in the country makes higher support levels less necessary, stressing the importance of lowering risks in order to reduce support levels and, thus, financial transfers from consumers to producers. Thus, providing stable regulatory frameworks should be a priority of policy-makers. The rest of variables (renewable energy resource potentials, administrative barriers, energy import dependency, interest rates, share of wind energy in total electricity generation as a proxy of lobbying pressures and electricity demand) are not statistically significant in most specifications and some of them do not have the expected sign.     

湖北省风能资源的高分辨率数值模拟试验

利用边界层模式CALMET耦合中尺度模式MM5对湖北省的风能资源分布特征进行数值模拟,得到水平分辨率1 km、 垂直高度10~150 m覆盖全省的风能资源分布。通过与测风塔对比发现,模式对九宫山7月、 11月的逐时有效风速的模拟相关系数分别为0.59、 0.57;受下垫面复杂地形的影响,10 m高度上的误差最大,50 m高度的模拟效果好于其他高度。70 m高度上数值模拟风速年均误差为7.21%,逐月平均风速误差范围在6.62%~7.30%之间。全省风能资源的总体分布特征是:中东部大于西部,西部的等值线相对凌乱且密集,冬、 春季风速、 风功率大于秋季,西部地区为风资源较贫乏地区。数值模拟结果虽然存在一定的误差,但模拟得到的风能资源分布趋势是符合本地区气候和地形特征变化规律的,可以作为制定区域风电发展规划的科学依据。在进行风电场选址时,对于误差大于平均水平的地区需要多布设测风塔。     

Wind field and dispersion in a built-up area—A comparison between field measurements and wind tunnel data

The dispersion of accidentally released gases from sources near the ground in built-up areas is determined by the complex flow conditions around the buildings. Wind tunnel experiments must be performed to obtain detailed information on the diffusion of pollutants. In order to show that the wind tunnel results are transferable to nature, parallel measurements in a wind tunnel and for prototype conditions of wind direction, wind velocity, and gas dispersion have been carried out in an industrial plant. The results show excellent agreement of model and prototype for properly scaled conditions.     

论风力发电建设项目的环境监理

目前,随着国家清洁能源的政策支持,风力发电项目已在内蒙古地区普遍发展。风力发电项目对生态环境影响范围大、污染分散,环境监理内容较多,因此做好风力发电建设项目的环境监理工作是十分重要的。本文简述了这方面的环境监理内容。     

棘洪滩水库典型风况分析及其应用研究

棘洪滩水库的源水是水库流场变化的主要动力,风力状况也是影响棘洪滩水库流场况变化的重要因素,当水库处于非调水期,风力状况的作用尤为明显。本论文整理了棘洪滩水库1989-2008年20年间气象资料,统计得出水库年际和四个季度的风向、风力变化情况。结果表明,棘洪滩水库常年盛行风向是南风和西北风。春季和冬季以西北风为主,夏季和秋季以东风和东南风为主。通过sMs软件建立的水质模型可以验证,不同的风向与风力大小对水库流场的变化有着显著的影响。     

基于全天空 FPI 的临近空间中性风场研究

目的对临近空间大气中性风场进行监测与分析。方法借助法布里-珀罗干涉仪(Fabry-Perot Interferometer,FPI)观测临近空间顶层的大气中性风场。针对北极黄河站(78.92°N,11.93°E)临近空间顶层的大气中性风场,介绍全天空FPI测风的基本原理,通过对2016年11月25日全天空FPI设备观测的OI557.7 nm气辉干涉图进行分析,反演得到极光亚暴期间的内5级环的水平风场和视线风场。结果极地地区临近空间顶层的水平风速基本保持在-200~200 m/s之间,极光亚暴使得中性风场呈现出一定的方向性,并且风场增大的方向垂直于极光弧。结论利用全天空FPI设备可以对临近空间顶层的大气中性风场进行探测和分析,有助于认识和理解临近空间大气环境。     

中国东南沿海风能资源评价

本文选取322个气象台站(自记158个,非自记174个)10年(1971—1980)风速资料统计计算了3.5—20.4m/s有效风速出现的小时数,年(月)风能和风能密度,风速、风能变化规律;绘制了年有效风能和有效风速频率分布图,进而按风能资源分布规律做出风能区划及风能的高度变化。其次,结合实际风能资料,阐明风能与风力机输出能量转换关系,从而测算出该地区农田灌溉和风力发电的风能资源利用转换值。最后,根据当地实际风能资源、环境、地形及地下水位高低,为选择合理的设计风速或引进适合当地的风力机以及解决当地部分能源提供合理化建议和对该区发展风力机的前景提出了看法。实践证明具有一定的实际应用价值。     

青岛冬季PM2.5持续重污染天气的大气边界层特征

鲜有出现空气质量问题的北方沿海城市青岛近年来也频频出现重污染天气. 2014年1月青岛市总计出现7 d重污染天气,其中1月15-18日是持续4 d的PM_2.5重污染,其余的则分别出现在1月6日、11日和30日.为了获得气象条件对持续重污染天气发展、维持和消除的影响机制,利用激光雷达、大气稳定度仪探测数据以及地面、高空气象观测和空气质量监测数据,重点分析了1月15-18日持续重污染期间青岛市大气边界层气象要素的时间和空间特征.结果表明,2014年1月影响青岛冷空气势力弱、青岛近地面低于3 m/s的风速不利于污染物扩散,66%以上的相对湿度有利于污染物浓度增大.在污染源稳定的背景下,气象要素的差异性导致了污染物浓度时空分布的差异.在持续的弱偏北风下污染物浓度居高不下;在偏南风影响下,污染物浓度趋于下降.边界层内存在高层干冷弱北风和低层暖湿弱南风的风切变、稳定层结、低层相对湿度为70%的高湿大气以及交替出现的近地面南北风是此次重污染持续的主要原因.大气边界层高度变化对污染物浓度具有6 h左右的延迟影响;而低边界层高度、大稳定度因子,低云的存在和较高的污染物浓度之间具有较好的一致性变化趋势.当近地面温度升高、相对湿度减小以及增大的偏南风和存在弱不稳定层结时,有利于提高青岛局地大气扩散能力.      

Wind and sky as compass cues in desert ant navigation

While integrating their foraging and homing paths, desert ants, Cataglyphis fortis, depend on external compass cues. Whereas recent research in bees and ants has focused nearly exclusively on the polarization compass, two other compass systems—the sun compass and the wind (anemo) compass—as well as the mutual interactions of all these compass systems have received little attention. In this study, we show that of the two visual compass systems, it is only the polarization compass that invariably outcompetes the wind compass, while the sun compass does so only under certain conditions. If the ants are experimentally deprived of their polarization compass system, but have access simultaneously to both their sun compass and their wind compass, they steer intermediate courses. The intermediate courses shift the more towards the wind compass course, the higher the elevation of the sun is in the sky.     

Soil erosion in Denmark: processes and politics

Denmark has been dealing seriously with wind erosion problems for the past 125 years whereas water erosion did not come into focus until serious euthrophication appeared in the coastal waters in 1986. This paper describes the problems and processes of soil erosion in Denmark and how these are inter-linked with the political system through subsidies, production systems, etc. The dominant soil erosion processes in Denmark are wind, sheet, rill, tillage and bank erosion. Whereas wind erosion is predominant on sandy soils with low soil fertility, sheet, rill and tillage erosion are mainly on till from the last glaciation and is largely caused by snowmelt events and prolonged rain on saturated and/or partly frozen soil. Danish laws and subsidies have played a major role in managing soil erosion. This has for instance been manifested by the extensive planting of windbreaks and the establishment of buffer zones along water courses. On the other hand, the focus on reducing nitrate leaching has led to increased sheet and rill erosion resulting from a larger number of fields with winter crops. When it comes to reducing phosphorous transport to the aquatic environment, soil erosion has been recognized as an important process but a thorough understanding of the mechanisms are lacking. Finally, the case study of the Water Environmental Protection Plan I shows that both the media and NGOs can play an important role in pushing environmental problems associated with soil erosion onto the political agenda and with the NGOs having a great say in the actual shaping of the laws.     

太湖悬浮物分布的现场监测研究

于2005年8月25日至8月28日对太湖进行现场监测,得到了太湖梅梁湾到大太湖的悬浮物、浊度数据,分析得出:(1)光照强度较高时,对应于微囊藻峰值的出现,浊度在水深0.5m处出现最高值,光照强度较弱时,浊度的分布在垂直方向上趋于均匀;(2)悬浮物浓度与浊度具有较高的相关性,悬浮物浓度值可以用浊度的测定值换算得到;(3)河流流入、风浪条件和湖内藻类繁殖等影响着太湖悬浮物的垂直和纵向空间分布,出现梅梁湾到大太湖不同的悬浮物垂直和纵向分布。