传承陶瓷文化，启迪智慧大门

转变科普教育的观念与提高科学传播素养是实施科技兴国的保障。陶瓷这种既古老又极具生命力的文化推动科学传播创新走向何方？国际科普教育正在为文化的传承努力着。在中国这个具有悠久历史文化的国度,科普教育如何将传统陶瓷文化与现代高科技陶瓷完美融合？陶瓷文化在科普实践教育中的探索与创新或许能为我们开辟新的科学传播创新的前景。结合现代科技的陶瓷科技工艺,将承载着华夏文化的陶瓷用到科普实践教育中,使其成为科学传播创新中科普实践新课题,让陶瓷文化成为传承中国悠久历史文化并引领科普实践的载体。     

继承与创新:Innovasic Fido微控制器

上世纪最早出现的CISC(复杂指令集计算机)计算机结构,现又悄然兴起--Xilinx,Tensilica,Sun Microsystems和Power联盟等组织带头复兴CISC计算机结构.     

网络时代媒体如何继承普利策奖传统

网络和纸张对于媒体而言只是一个介质，普利策奖只是证明了，同样的传统和专业精神得以在不同的介质上延续。自1917年起每年颁发的美国普利策新闻奖早已成为全球知名的专业新闻奖，与美国新闻界和美国乃至世界的命运紧紧相连。它代表着世界上最高品质的新闻专业主义，为无数后来人和仿效者树立了标杆。     

Harnessing the wind

Wind power is now recognized as the one renewable-energy source on the verge of being economically viable. For developing countries, in fact, the technology is already practical for bringing pollution-free electricity to areas off the power grid. The author discusses the economic benefits of wind power and then discusses the basic principle involved in generating electricity from wind. The use of wind power by developing countries is outlined with particular reference to projects in Mexico and Indonesia     

Reap the wild wind [offshore wind farm]

The worlds largest offshore wind farm is being built at Horns Rev (Reef) in the often turbulent seas off Denmark. The 80 towers in 20 km/sup 2/ of sea will be capable of generating 160 MW of power. Elsam expects Horns Rev to make 600 GWh of electricity a year, 2% of the country's consumption. This paper discusses the construction of the wind farm.     

顺风飞扬

初识广东科达的老总杨勇刚是在本社举办的“信息安全发展与趋势高层研讨会”上,当时他正跟一个业内颇有影响力的老专家谈得投机,他的风趣幽默、博闻强记给记者留下了深刻的印象。我当时想,广东企业的老板确实头脑灵活,善于运筹帷幄。但不久之后我对他进行了专访,使我对他有了进一步的了解。     

世界数码相机逆风飞扬

市场概况纵观电子产业发展史，电子手表取代传统机械手表是手表领域一场典型的电子革命，今天手上还带机械手表的人已是寥若晨星。当前在相机业，正在掀起一场席卷全球的同样的电子革命风暴，技术走向成熟的数码相机已更具相机味，发展迅速，引领时尚，用户不断扩大，世界销量不久即将超过传统的胶卷相机。数码相机兴起于上世纪90年代，它将拍摄的图像聚焦于CCD(电荷耦合器件)或CMOS技术的光敏半导体上，生成彩色图像，随之转换为数字数据，最后压缩到相机的存储器中。拍摄时的影像可在相机的液晶显示屏上显示出来。随着数字化环境不断改…     

不同风向下城市街区风环境的模拟

利用CFD软件Fluent建立了一个三维城市街区十字路口模型,模拟了3种风向条件,在沙尘天气下街区速度场以及粒子浓度场的分布情况。结果表明,街区的建筑物布局与风向共同作用,会对街区的风环境及室内空气品质（IAQ）产生很大影响。     

激光测风雷达分析典型高原机场风场特征

为了对激光测风雷达在民用机场的运行环境适应性及综合保障能力进行评估,采用国产自研激光测风雷达在典型高原机场为期3个月的风场联合监测试验数据,结合同址相关气象资料,分晴、多云、阴、雾及降水等不同气象条件,对激光测风雷达的风场数据进行了分析,以揭示典型高原机场的风场特征,检验国产激光测风雷达的综合保障能力。结果表明,在不同天气类型下,激光雷达的测风性能存在明显的差异,其在晴、多云、阴天整体表现较优,水平最大探测距离最远可达6623m,垂直最高可达2895m;同时,激光测风雷达能精准捕捉到高原机场的风场在时间尺度和空间尺度上的典型变化特征。该研究为雷达在民航的应用提供了参考。     

瑞利测风激光雷达夜间准零风层观测结果分析

一台用于观测对流层和平流层风场的车载瑞利测风激光雷达于安徽合肥建成,该雷达使用双边缘技术,设计探测高度10~40 km,距离分辨率分别为100 m(20 km高度以下)和500 m(20 km高度以上)。在2011年夏季该雷达于新疆乌鲁木齐地区(42.1N,87.1E)进行了风场观测实验并成功观测到了平流层准零风层大气结构,给出了几组夜间典型的风场数据,根据观测结果得出:准零风层底部高度稳定在17~18 km高度而不随时间变化,而准零风层厚度则随时间有一个先增大后减小的趋势,并在北京时间凌晨0点~3点期间达到最大值。在观测中出现的准零风层厚度最大值超过15 km,最小值则仅有约2~3 km。分析认为:准零风层厚度的变化与夜间平流层接收到的紫外线辐射强度变化有关,同一时刻不同纬度上的平流层接收的紫外线辐射强度变化程度不同,导致平流层温度梯度继而大气环流的速度发生变化,从而引起准零风层厚度变化。     

机动型激光测风雷达倾斜风场修正算法研究

为了解决激光测风雷达处于倾斜放置的情况下测出的风场信息与实际风场之间存在的误差,分析了激光雷达的测量原理、放置情况以及存在的问题,采用空间坐标变换的方法对雷达倾斜状态进行理论计算并给出了修正计算公式。对比了水平放置和横向倾斜7.2°放置的激光雷达的实测数据,发现修正前由于倾斜放置导致雷达所测垂直气流数据间产生的误差较大,加入修正算法进行仿真后,数据曲线吻合良好,修正效果明显。结果表明,空间坐标变换的修正算法可使激光雷达在处于非特定位置时仍能正确地反映实际风场信息,从而验证了该修正算法的正确性和可行性。     

Assimilating wind [wind energy contribution to UK energy needs]

The belief that wind energy can make only a marginal contribution to the UK's energy needs is based on fundamental misconceptions. The DTI suggests that up to half of the 2010 target for renewable electricity (10%) could be met by wind energy. The British Wind Energy Association argues that this is quite feasible and has carried out a detailed analysis, suggesting possible regional distributions. The industry struggles, however, to overcome misconceptions. 'What happens when the wind stops blowing?' is a frequent question, and even power engineers suggest-quite erroneously-that thermal plant must be held in readiness to pick up any reductions in output. It is also argued that electricity distribution systems, designed to cope with power flows from central power stations, cannot easily cope with power from wind farms flowing in the opposite direction. Although this may be true in some locations, wind is no different from any other form of generation-welcome in some locations, but more difficult to assimilate in others. Experience in Denmark suggests such problems can be overcome, with wind now accounting for more than a third of the generation capacity in Jutland. This paper discusses the issues and involved in overcoming the misconceptions. No matter how strong the engineering argument for wind energy, as with any other energy option, wind power will only be deployed on a significant scale if it can generate electricity at a cost comparable to alternative forms of generation technology. The latest figures suggest that wind is more than equal to this challenge     

关于风电场风电机组中风力发电机的运行维护分析

本文通过风电机组中风力发电机的常见故障分析,针对故障诊断难点问题,优化风力发电机的运行维护环节,重点加强故障难点的维护工作,为风电场风电机组的运行维护提供新的思路.     

多普勒测风激光雷达与 L 波段探空对比分析

利用北京国家基本气象站内多普勒测风激光雷达和 L 波段探空系统在 2020 年 1 月 1 日至 5 月 31 日期间进 行了同步观测试验, 在经过观测数据时间和空间匹配的基础上, 以后者测风数据为参照标准, 从探测风廓线的高度、 风向和风速三个方面的一致性分析了激光雷达的测风数据质量。结果显示: 在观测试验期间, 激光雷达 56.5% 的观测 时间里最大探测高度不低于 2000 m, 2.9% 的观测时间最大探测高度不足 1000 m; 激光雷达探测获取的水平风向、风 速与 L 波段探空系统具有较好的一致性, 针对匹配得到的 8491 组对比观测数据, 其风向和风速数据拟合总相关系数 分别为 0.965 和 0.986; 总体风向、风速的平均偏差和均方根误差分别为 −1.3◦ 和 16.1◦、0.21 m·s −1 和 1.06 m·s −1 ; 在 2000 m 以上高度, 由于激光雷达观测数据的信噪比偏弱, 获得可信的观测数据量减少, 会对风向、风速一致性比对造 成不利影响。     

小型风机最大功率点快速跟踪策略的仿真研究

风力发电系统的输出功率受外界因数和风速的影响。为了提高小型风机发电机组的转换效率,文中采用一种最大功率优化跟踪算法。以变步长来跟踪风速变化,当功率变化小于一个阈值时停止搜索,来实现最大功率收索的快速性和稳定性。以带齿轮箱6 kW的鼠笼异步式风力发电并网为基础,通过Matlab/Simulink软件仿真结果证实此种方法与定步长爬山法相比,能够达到快速跟踪最大功率点和避免达到最大功率点附近的时候频繁波动。     

Model-based estimation of wind fields over the ocean from windscatterometer measurements. I. Development of the wind field model

For pt.II see ibid., vol.28, no.3, p.361-373 (1990). A parametric model for near-surface mesoscale wind fields suitable for use in a model-based approach to estimate the wind field over a large region of the scatterometer measurement swath from measurements of the radar backscatter of the ocean's surface is discussed. The assumptions made in developing the model are described, and the accuracy of the resulting model is evaluated. The model is based only on scatterometer data and is computationally tractable, consisting of a linear equation relating the near-surface wind field to a vector of model parameters which is estimated from the scatterometer measurements. Tradeoffs in the accuracy of the model and the number of unknown parameters are considered     

Running against the wind [sports prosthetics]

This paper discusses the implications of recent technological advances in sports prosthetics on the existing rules for various sporting events. The paper points to the record-breaking performance of the double-leg amputee from South Africa, Oscar Pistorius, at the 2004 Paralympic Games in Athens. Fitted with high-tech carbon-fiber artificial running legs, Pistorius became the first leg amputee to run the 200-meter dash in less than 22 seconds. Because it seems likely that Pistorius will one day qualify for able-bodied competitions, current rules may need to be reviewed.     

Determining land-surface parameters from the ERS wind scatterometer

The ERS-1 wind scatterometer (WSC) has a resolution cell of about 50 km but provides a high repetition rate (less than four days) and makes measurements at multiple incidence angles. In order to retrieve quantitative geophysical parameters over land surfaces using this instrument, a method is presented that applies a mixed-target modeling approach to estimate subpixel fractional vegetation cover at a regional scale. The model represents the footprint area as a combination of part dense, homogeneous vegetation and part bare soil (with homogeneous roughness and dielectric properties). Inversion of this model is then carried out using a retrieval procedure that incorporates a priori information in a quantitative manner The method is applied to the estimation of fractional cover over an area in Africa using WSC data from 1992 to 1995. Retrieved parameters are also compared to ground measurements made in the area during the 1992 HAPEX-Sahel campaign. The procedure illustrates the applicability of WSC data for measuring geophysical parameters over land and offers the potential of deriving a physically-based alternative to empirical indices for estimating regionally-variable parameters     

Levenberg-Marquardt算法在测风激光雷达中的应用

分析了直接探测测风激光雷达中的Fabry-Perot标准具透过率的非线性理论模型。根据实验测量数据,利用Levenberg-Marquardt算法对理论模型进行参数优化估值,获得测量数据的最佳拟合曲线。数值计算表明,pseudo-Voigt函数能快速且很好地近似计算Voigt线形。对于Fabry-Perot标准具的宽带光透过率频谱响应曲线,可以采用Voigt函数拟合,也可以采用pseudo-Voigt函数拟合;当透过率频谱响应曲线用于风速反演时,若采用pseudo-Voigt函数拟合会造成低于1 m/s的测速偏差,因此必须采用Voigt函数拟合。