Spectral intensity distribution in a hydrogen discharge

A cold cathode discharge tube has an auxiliary tube attached from which cathode-rays are projected against the main cathode. A photo-electric cell, attached to a monochromatic illuminator, is used to measure relative intensity distribution of H_γ and H_δ respectively, from the main cathode through the cathode dark space into the negative glow with and without excitation of the auxiliary tube. When the main cathode is bombarded by the electron stream the intensity of spectral illumination in the negative glow is increased by about 20 per cent. This increase does not result from the mere addition of an illumination, which appears when the auxiliary tube is alone excited, to the illumination of the main discharge, but may be attributed to the production of soft X-rays in the gas which are capable of exciting the gas molecules.R. Seeliger and co-workers have investigated spectrophotometrically the several characteristic sections of a cold cathode discharge tube. Their method consisted of an examination, with a microphotometer, of spectrograms taken at points along the discharge. The intensity distribution of any spectral line was found continuous in passing from one portion of the discharge to another, e.g., from the Faraday dark space into the positive column, and that the maxima of illumination for different lines appeared displaced relative to one another.A. Wehnelt and A. Jachan demonstrated with several experimental arrangements the effect of bombarding the cold cathode of an ordinary discharge tube with a beam of cathode-rays. There resulted an increase in the total intensity of illumination in the tube together with a shrinkage of the cathode dark space.The purpose of the present investigation was to examine the effect such an electronic bombardment would produce upon the spectral intensity distribution near the cathode of a hydrogen discharge in Hγ and Hδ alone were capable of investigation.     

高频无极灯原理和发展前景及在实际工程中的应用

节能、长寿命和环保是高频无极灯的三大优势.本文从高频无极灯的基本原理、技术发展现状,较全面地分析了作为21世纪绿色新光源高频无极灯的技术特点、发展趋势和它的广阔应用前景,将它与半导体发光LED灯作了比较,最后展示若干工程应用实例.     

高频无极灯原理和发展前景及在实际工程中的应用

节能、长寿命和环保是高频无极灯的三大优势。本文从高频无极灯的基本原理、技术发展现状，较全面地分析了作为21世纪绿色新光源高频无极灯的技术特点、发展趋势和它的广阔应用前景，将它与半导体发光LED灯作了比较，最后展示若干工程应用实例。     

The phenomenon of eye glow

The coloured eye glow of animals, seen at night when their eyes are caught in a strong light, is a matter of common experience. It is caused by a reflecting layer known as the tapetum lucidum. A similar eye glow is seen in butterflies and apparently serves to enhance vision by increasing contrast and reducing glare.     

西伯利亚淡水资源格局与合作开发潜力分析

淡水是人类生存的基础,也是全球战略性资源。总面积为969万km²的俄罗斯西伯利亚地区,拥有蓄水量占全球地表淡水资源总量约22%的贝加尔湖,以及总长度约500万km的河流和多座大型水库,其中叶尼塞河、勒拿河、鄂毕河等大型河流的水资源量极为丰富。据分析,该地区多年平均地表水资源量为2.35万亿m³,占全俄水资源总量的55%;水能资源蕴藏量为1.556万亿kW·h,占全俄65%;水运资源量为5.65万km,占全俄55.8%。尽管该地区水资源丰富,但由于人口稀少（不足2400万人,仅占全俄总人口的16%左右）,水资源利用程度低,具有很大的开发潜力。西伯利亚山区河流水量丰沛,水能开发及水电发展具有广阔的前景。随着全球变暖,西伯利亚平原区河流的结冰期变短,航运价值不断提高。同时,在俄罗斯西伯利亚周边地区严重缺水的背景下,通过虚拟水贸易或跨流域调水,向中亚、蒙古和中国北方地区输送淡水资源具有重要的战略意义,将推动这一地区的经济与社会协同发展。随着“一带一路”倡议和“中蒙俄经济走廊”的规划实施,中蒙俄三方在水资源与水电能源等方面的合作具有广阔的前景。     

中国陆地风能资源开发潜力区域分析

本文从风能资源的丰富度、稳定度、人文环境对风能资源开发适宜度和自然环境适宜度等四个方面,分别选取了较有代表性的有效风能密度、风能可用时数、人口密度、森林郁闭度四项量化指标,利用综合指数法对我国陆地10m高度风能资源开发潜力进行了综合评价和分析。结果表明:内蒙古中部和西部、河西走廊、青藏高原中北部、东北平原南部、山东和辽东半岛,以及江苏、浙江、福建和海南的沿海地带,风力资源优越,环境因子限制小,是风能规模开发潜力最高的地区;内蒙古锡林郭勒高原、呼伦贝尔高原、新疆东部和西北克拉玛依地区、东北平原、河北北部和东部沿海(除了最高潜力地区)为次高潜力区;大兴安岭、山东西北部、河南北部、江苏大部、安徽中部、新疆北部和东南部、西藏中西部和云南东部属中级开发潜力区;其它地区因风能资源贫乏或环境因子限制大,风能开发潜力较低。