北京地区中小学及高校教室照明改造频闪实测研究

光源频闪是指亮度或光谱随时间波动的光刺激引起观察者视觉感知的变化,也是光环境质量评价的重要指标之一,教室照明中过度的频闪很容易诱发学生视觉疲劳.本文通过对北京地区十所学校教室照明节能改造示范工程现场监测,使用传统频闪评价指标频闪比MD和目前国际上认可度较高的频闪效应可视度SVM指标对比评估教室照明现状,发现将荧光灯替换为LED灯具后教室照明频闪并未得到显著改善,现场测试LED面板灯频闪性能明显优于LED灯管.频闪对人视力及健康影响不容忽视,而我国教室照明相关标准中对频闪的评价方法及限值处于滞后状态,未来应尽快完善频闪评价体系,明确对灯具频闪的控制要求,以标准引领行业健康发展.     

北京地区中小学及高校教室照明改造频闪实测研究

光源频闪是指亮度或光谱随时间波动的光刺激引起观察者视觉感知的变化,也是光环境质量评价的重要指标之一,教室照明中过度的频闪很容易诱发学生视觉疲劳.本文通过对北京地区十所学校教室照明节能改造示范工程现场监测,使用传统频闪评价指标频闪比MD和目前国际上认可度较高的频闪效应可视度SVM指标对比评估教室照明现状,发现将荧光灯替换为LED灯具后教室照明频闪并未得到显著改善,现场测试LED面板灯频闪性能明显优于LED灯管.频闪对人视力及健康影响不容忽视,而我国教室照明相关标准中对频闪的评价方法及限值处于滞后状态,未来应尽快完善频闪评价体系,明确对灯具频闪的控制要求,以标准引领行业健康发展.     

教室及实验室照明设计中几个问题的探讨

通过分析频闪效应在视觉上产生的不利因素、弦光产生的原因及单面采光对教室照明均匀度的影响，提出在考室、实验室照明设计中避免频闪效应、减小弦光、提高照度均匀度的具体方法。     

教室照明设计研究

介绍教室照明设计研究内容,指出教室照明设计研究的重点是光环境与视觉健康;梳理教室照明的国内外设计标准;分析教室照明设计参数,提出适合的照明指标及光源指标;分析教室光环境,天然光与人工照明的关系,提出健康的教室光环境的设计要素,介绍光环境评价标准;提出普通教室照明计算要点.     

学校教室电气照明工程设计相关问题的探讨

学校教室的照明设计是一个很重要,但并不简单,却又被常常忽视的问题。文章从照明标准,灯具布置及控制和减少眩光及频闪效应等三方面探讨了教室照明设计的新思路。文中提出的改善教室照明的办法已在工程设计中采用。作者呼吁修订现行照度标准。作者还认为,随着现代教学设备的广泛应用,在教室照明设计中应充分重视灯具(含镇流器)的选择,布置和控制。     

学校教室电气照明工程设刮相关问题的探讨

学校教室的照明设计是一个很重要,但并不简单,却又被常常忽视的问题。文章从照明标准,灯具布置及控制和减少眩光及频闪效应等三方面探讨了教室照明设计的新思路。文中提出的改善教室照明的办法已在工程设计中采用。作者呼吁修订现行照度标准。作者还认为,随着现代教学设备的广泛应用,在教室照明设计中应充分重视灯具（含镇流器）的选择,布置和控制。     

LED灯在民用建筑中的应用探讨

LED技术进步,带动了LED灯的飞速发展,由于LED灯质量不断提高,使用寿命越来越长,价格也越来越优惠,所以它快速应用到各类场所。然而,LED灯具灯光存在眩光限制、过度蓝光、电磁辐射、频闪效应和谐波等问题,限制了LED灯的发展和应用,对LED灯引起的谐波对功率因数(λ)的影响进行研究和探讨,并结合照明设计标准和LED产品标准,采取一系列措施,实现LED健康照明。     

探讨大功率LED在Ⅵ级体育场馆场地照明中的应用

通过对比学习新旧版行业标准《体育场馆照明设计及检测标准》的相关规定,结合现阶段几个Ⅵ级体育场馆场地照明设计的实际工程案例,总结得出Ⅵ级体育场馆照明中应用LED必须要重视的R_9和频闪比两个指标,浅谈两个参数各自的涵义及其对LED照明带来的影响。根据相关规范及设计经验,提出Ⅵ级比赛场地照明的配电方案,同时考虑大功率LED灯的启动特性及其对电压偏差的要求,探讨了末端场地照明配电箱"单灯单回路"的出线形式,为日后大功率LED在体育场馆照明中的应用推广提供参考。     

浅谈LED在室内照明中的应用

本文简述了LED在室内的应用依据和技术条件,分析了LED灯在室内可应用的场所,并对LED灯所存在的问题进行说明,得出了诸多结论：尽快制定、完善LED灯的相关标准,并紧盯国际LED技术的新动态;努力提高LED灯的性价比;现阶段室内可以采用LED筒灯、射灯等,非人员长期停留、工作场所也可使用LED灯,如车库、走廊、楼梯间等：疏散照明可以采用LED照明技术：鉴于LED光健康问题尚处在研究之中,有人员长期停留、工作场所需慎重使用LED灯。     

大功率LED照明产品关键技术指标研究

LED应用于体育照明已是大势所趋,大功率LED照明产品的性能指标如何确定,目前国内外尚缺乏系统性研究。本文通过大量的实测分析,提出了大功率LED照明产品的关键技术指标,为相关标准的制订提供了依据,对于冬奥会和亚运会等高级别赛事的体育照明设计及应用具有重要的指导意义。     

Vanadium in foods and in human body fluids and tissues

Using neutron activation analysis, vanadium was analysed in a range of foods, human body fluids and tissues. On the basis of these results and those of other workers, it was concluded that daily dietary intake amounts to some tens of micrograms. Analysis of body fluids (including milk, blood and excreta) and organs and tissues provided an estimate for the total body pool of vanadium in man of about 100 μg. Vanadium was not detectable in blood and urine at the level of 0.3 ng/g, while low levels were found in muscle, fat, bone, teeth and other tissues. The relationship between dietary intake to pulmonary absorption is discussed in relation to the occurrence of vanadium in man-made air particulates. The very low levels found in milks and eggs suggest minimal vanadium requirements in growth. The findings are discussed in the light of previous results and also in relation to the possible essentiality of vanadium.     

Iodine-129 in thyroid and urine in Ukraine and Denmark

Human thyroids collected from Gomel in Belarus, sheep thyroid from Jutland and human urine from Zealand in Denmark were analysed for 129I and 127I concentrations. The ratios of 129I/127I in human thyroid in Gomel are 2.65-11.0 x 10(-9) with an average of 7.21 x 10(-9), which is one order of magnitude higher than those from Asia and South America (10(-10)), but significantly lower than those observed in west Europe (10(-8)). A weak negative correlation (P < 0.05) between 129I/127I ratio in human thyroid and the age of the subjects was observed in Gomel. The average ratio of 129I/127I in sheep thyroids from Jutland of Denmark is 1.81 x 10(-7), which is two orders of magnitude higher than those in south hemisphere, and Asia. It is also significantly higher than those observed in other west European countries before 1984 and that in human thyroid in Gomel. The high thyroid 129I level in Jutland is attributed to the release of reprocessing plants in France and UK. The 129I/127I ratios in human urine in Zealand of Denmark are 0.86-2.86 x 10(-8). The possibility of using urine 129I to evaluate the thyroid exposure to 129I is investigated.     

儿童青少年近视的防控研究进展

儿童青少年近视率一直处于高位并持续上升,严重影响了我国儿童青少年的学习和生活,本研究通过查阅国内外治疗儿童青少年近视相关著作及文献,针对目前儿童青少年近视防控手段的进展,对各治疗方案进行分析和研究。     

德国城乡景观与中国景观问题

2003年,笔者获得德国DAAD(德国国际学术交流基金会)奖励资助,作为访问学者在德国逗留了4个月(4月～8月).在这期间,笔者还考察了法国、丹麦、瑞典和意大利,但我认为还是德国的景观最为优雅和美丽.     

广义文脉与规划设计教育

城市规划设计教育不仅应关注历史化,还应关注自然、社会和经济;不仅应关注地方和传统,还应关注全球和未来。城市规划教育应掌握正确的发展观和方法论,肩负起发展地万脉的历史使命,保护社会公众的利益,推动城市持续发展。     

Perchlorate in raw and drinking water sources in England and Wales

A well‐known use of perchlorate is as a rocket fuel propellant; however, more widespread uses include in munitions and fireworks, and it also occurs naturally. Perchlorate suppresses the thyroid, which can lead to a variety of adverse effects. It is a widespread contaminant in the United States, but limited occurrence data in the United Kingdom exist, and even less for drinking water. Monitoring of 20 raw and treated drinking water sites in England and Wales, covering four seasonal periods, showed that perchlorate is a low‐level background contaminant of raw and treated drinking water. Low concentrations (treated drinking water: <0.020–2.073 μg/L, mean 0.747 μg/L) were detected at every higher‐risk site. The concentrations were comparable in each of the four sampling exercises and no significant trends were apparent relating to the time of year, the type of risk or the method of chlorination. Limited data showed that removal by ion exchange and granular‐activated carbon may occur.     

Lead and cadmium contents in cereals and pulses in north-eastern China

It is known that, unlike Japanese, Koreans or southern Chinese who depend on rice as a major source of energy for daily life, people in north-eastern China rely not only on rice, but on wheat and other cereals and to a lesser extent also on pulses. Cereal and pulse samples were collected from open markets in north-eastern China, and analyzed by inductively-coupled plasma spectrometry (ICP-MS) for two potentially hazardous heavy metals — lead (Pb) and cadmium (Cd). The average Pb level in cereals (31.3 ng Pb/g as a geometric mean) and that of pulses (25.7 ng Pb/g) were similar to each other with no significant difference. Among the cereals, Pb contents were higher in foxtail millet (54.3 ng/g) and lower in maize (35.4 ng Pb/g; grain and flour in combination), wheat flour (28.8 ng Pb/g) and rice flour (22.7 ng Pb/g). Lead levels in two important types of pulses, kidney bean and soybean (24.6 and 30.8 ng Pb/g, respectively), were comparable to the levels in rice and wheat. In contrast, Cd levels were substantially higher in pulses (55.7 ng Cd/g) than in cereals (9.2 ng Cd/g), and among the pulses, Cd in soybean (55.7 ng Cd/g) was significantly higher than that in kidney bean (23.8 ng Cd/g). The possible public health implication of the Pb and Cd levels, especially the high Pb level in foxtail millet (54.3 ng Pb/g) and the high Cd level in soybean (73.5 ng Cd/g), is discussed.     

武汉城市景观文化生态保护建设的问题与对策

城市文化生态是形成城市特色的文化要素。历史古迹,优秀建筑,空间形态,环境特色,作为城市文化生态的显现部分,既是城市文化底蕴直观生动的反映,也是市民的情感港湾和精神家园。理应得到珍惜和保护。该文在系统地概括武汉景观文化生态特点的基础上,重点分析了当前武汉城市景观规划建设中的文化生态问题,提出了武汉今后改进城市景观文化生态规划建设的对策建议。     

创新创业教育在高校实践教学中的研究与探索

大学生创新创业教育的开展对高校人才培养体系的完善具有非常重要的意义。针对目前我国高校创新创业教育模式的问题与不足进行探讨,分析研究了创新创业教育的实质,最后重点阐述了在实践教学中如何加强创新思路的引导,建立有效激励机制,开展创新及创业教育的应对策略,促进对大学生实践创新能力、创业就业能力和持续发展能力的培养。