能见度

Pilot Doug Roesch had passed all his tests for flying in normal visibility. But he wasn't experienced at coping with what pilots call inadvertent meteorological conditions – suddenly flying blind in cloud and relying only on instruments.

飞行员道格﹒罗什通过了正常能见度下的所有飞行考试，但对于应付飞行员们所说的因能见度低而失去方向感、只依靠仪表的情况还没有经验。

These lights increase the conspicuousness of the landing surface and "reach out" to the pilot thereby creating a seeing condition which is significantly better than the reported ground visibility or tower visibility.

这些灯光增加了着陆道面的醒目度并"伸向"飞行员，从而产生一个明显好于地面能见度或塔台能见度报告的目视条件。

Geographical distribution characteristics of urban visibility in Anhui province are analyzed using routine observational data at 17 urban stations during the period from 1980 to 2005. The visibility trends in 5 cities from 1955 to 2005 have been analyzed using the methods of Ridit analysis cumulative percentiles and frequency of "very good" visibility.

利用安徽省17个地级市气象站1980-2005年的能见度观测资料，分析了安徽省城市大气能见度的地理分布特征，并用Ridit、累积百分率和"非常好"能见度出现频率分析法分别对5个代表性城市1955-2005年的大气能见度进行了研究和分析。

Instrument Landing System with airports, aircraft while in the case of low visibility landing, but the world's larger airports, when the runway visual range less than 400 meters, vertical visibility is less than 30 meters, aircraft taking off or landing or hard of.

具有仪表着陆系统的机场，飞机虽然可以在低能见度的情况下着陆，但目前世界上较大的机场，当跑道视程小于400米，垂直能见度低于30米时，飞机还是难以起飞或着陆的。

The outfield intercomparison experiments with Belford show that the relative measurement error of lidar-visibility meter is within 20%.

与美国Belford能见度仪的外场对比实验表明，该激光雷达能见度仪相对测量误差在20%以内。

Two instruments for measure of atmospheric aerosol extinction coefficients characteristics were introduced,one is forward scatter visibility sensor,and the other is three-wavelength integrating nephelometer.

对比分析了两种设备测量结果，为提高探测精度，将两种仪器的测量结果放在一起进行了研究，获得了满足特殊试验要求的第一手数据，夏秋两季的能见度较高时，平均能见度的最大值超过10000m。

Because of the phenomenon, the impact of particulate matter light scattering to visibility is discussed, based on particulate matter light scattering b(subscript sp measured by a nephelometer (M9003) and contamination concentration and meteorological data.

就近年来天津市能见度逐渐降低的现象，利用M9003浊度计并辅以同期观测的污染物浓度和气象因子资料，考察了颗粒物散射消光对能见度的影响。

The relative humidity for those matters is approximately 80%, so it is suggested that the weather phenomena, the visibility deterioration caused by atmospheric turbidness resulting in blur of visual field, is determined as haze when relative humidity is less than 80%, while as fog when relative humidity is large than 90%, and as the mixture of haze and fog the main constitutes are still haze when the relative humidity is between 80% and 90%.

建议将相对湿度小於80%时的大气混浊视野模糊导致的能见度恶化的天气现象确定为霾，相对湿度大於90%时的大气混浊视野模糊导致的能见度恶化确定为雾，相对湿度介於80%~90%之间时的大气混浊视野模糊导致的能见度恶化是霾和雾的混合物共同造成的，但其主要成分应该是霾。

All the analysis was done using SAS EM 4.1 software. The prevalence of tracheobronchitis were higher in spring and autumn. Average atmospheric pressure, average temperature, highest air temperature, lowest air temperature, water-vapour pressure, degradation of visibility were positively correlated with the prevalence of tracheobronchitis. Factors that affected the incidence of tracheobronchitis were average atmospheric pressure, degradation of visibility, daily temperature difference and water-vapour pressure.

结果］湖州市气管支气管炎门诊人数存在明显的季节分布差异，夏季和冬季是此类疾病的2个高发季节，而春季和秋季门诊人数较少；其门诊人数与平均气压、平均气温、最高气温、最低气温、水汽压、大气能见度等气象条件存在较好相关性；影响气管支气管炎门诊人数的主要气象因子有平均气压、能见度、日较差和水汽压，当平均气压≥1020.33hPa且能见度＜6.2km时，气管支气管炎门诊人数最高。

The article research the relative project about visibility, it discussed the principle, it introduced the new measuring method opposite the foreword scattering visibility meter and design the transmit and incept devices of foreword scattering visibility for keystone, it is advanced the characteristics of the light source which is should be possess , it show the advantage of the LED used to the light source and selected PIN LED which matching with it, the article is discussed the optics system and design the reasonable object lens structure, measuring and controlling system and the relative design idea ,design method and the accuracy analyzing etc.

本文研究了能见度测量仪器的有关问题，系统地论述了能见度测量仪器的理论，然后以前向散射式能见度仪为研究对象，论述一种新的测量方法，提出了理想光源应具备的特点，说明了采用LED 发光二极管做光源的优越性，并选择了合适的PIN 光电二极管与之匹配，对光学系统作了全面讨论，设计出合理的物镜结构、机械结构、并详细论述了与之有关的设计思想、设计方法和精度分析等问题。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。