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Correlations for estimating solar radiation using sunshine hours and temperature measurement in Osogbo

O. S. OHUNAKIN, M. S. ADARAMOLA, O. M. OYEWOLA, R. O. FAGBENLE

《能源前沿（英文）》 2013年第7卷第2期页码 214-222 doi: 10.1007/s11708-013-0241-2

摘要： In this study, the global solar radiation on horizontal surface in Osogbo, Osun state, Nigeria was analyzed using 11-year data (1997–2007). Correlations using linear and quadratic expressions were developed to relate the global solar radiation on horizontal surface based on relative sunshine hours and temperature measurements for evaluating the monthly average daily global solar radiation. The calculated monthly clearness index values indicate that the prevailing weather condition in Osogbo is heavily overcast. All the developed quadratic correlations gave better correlation coefficients (0.834, 0.872 and 0.823 respectively) than the linear models. However, the Hargreaves and Samani related based quadratic model gave the best among the three developed quadratic expressions and is therefore suggested for estimating the monthly global radiation in this site and its surroundings.

关键词： global solar radiation Hargreaves model sunshine hour ambient temperatures Osogbo

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Effects of modafinil on vestibular function during 24 hour sleep deprivation

ZHAN Hao, XIE Sujiang, JIA Hongbo, WEI Sihuang, JING Baisheng

《医学前沿（英文）》 2007年第1卷第2期页码 226-229 doi: 10.1007/s11684-007-0044-0

摘要： The aim of this research was to investigate the effects of modafinil, a new wake-promoting agent, on vestibular function during 24 h sleep deprivation (SD) so as to provide experimental evidence for the rational use of this drug among air crew. Eight young, healthy male volunteers were exposed to two 24 h periods of continuous wakefulness during the crossover experiment. Initially, 200 mg dose of modafinil was given, and one week later, a matching placebo was administered. The SD time started from 08:00 of the first day to 08:00 of the second day. Drugs were given at 0:00 on the second day. Vestibular function was tested at 21:00 on the first day and 1, 3, 5, 7 h after drug administration. The accuracy of saccade tracking and gains in visual-vestibular optokinetic reflex (VVOR) and optokinetic nystagmus (OKN) in the placebo group decreased during 24 h SD, especially at 01:00 05:00 on the second day, while OKN gains in the modafinil group increased significantly. There were no significant differences in the other vestibular functional indices between the modafinil group and placebo group. The 24 h SD can influence vestibular function to a certain degree, but modafinil may improve OKN.

关键词： VVOR modafinil Vestibular function vestibular functional Initially

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“信息阳光”——无冲突共享结构

李幼平

《中国工程科学》 2000年第2卷第1期页码 24-27

摘要：

文章探讨一种非Internet原理的无冲突信息共享结构——“信息阳光”。“信息阳光”包含“数据流环境”和“个人需求代码”两个新概念。所谓“数据流环境”，是利用DVB技术，营造一种普照天下的高速数据流，每天都有数百GB的数据流经家庭。其流量如此之大，足以把上千种报纸、期刊、网站、课程的内容每天反复传播几十遍。所谓“个人需求代码”用来在上述数据流中辨认并下载用户有兴趣的内容，实现无需远程互联的交互选择。由于只需单向广播，大大降低了成本，也从原理上消除了互联结构固有的带宽冲突。

关键词：数据广播 DVB 网络无冲突

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新京沪铁路最优化选择——时速200公里快速轮轨

李玉山

《中国工程科学》 2004年第6卷第12期页码 7-12

摘要：

从中国13亿人口的有效需求出发，汲取“铱星”通讯系统和超声速“协和”号飞机运营失败的教训，提出了新京沪铁路投资建设必须选择“最优化"而不是“最高速”；在中长距离上，选择8～12h旅行时间的“夕发朝至"列车具有最优化性价比；论述了中国铁路发展目标的最优化选择——时速200 km的电气化快速轮轨技术，符合幅员辽阔的中国现实社会经济基础发展的需要，符合中国的国情；分析了在能源危机日益深重的历史时代，时速400 km的“磁悬浮”和时速300 km的“高速轮轨”将造成国家难以承受的社会经济资源的巨大浪费和运营亏损。

关键词：京沪铁路最优化选择磁悬浮高速轮轨时速200 km快速轮轨

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Potential and economic viability of standalone hybrid systems for a rural community of Sokoto, North-west Nigeria

O. D. OHIJEAGBON,Oluseyi. O AJAYI

《能源前沿（英文）》 2014年第8卷第2期页码 145-159 doi: 10.1007/s11708-014-0304-z

摘要： An assessment of the potential and economic viability of standalone hybrid systems for an off-grid rural community of Sokoto, North-west Nigeria was conducted. A specific electric load profile was developed to suite the community consisting 200 homes, a school and a community health center. The data obtained from the Nigeria Meteorological Department, Oshodi, Lagos (daily mean wind speeds, and daily global solar radiation for 24 years from 1987 to 2010) were used. An assessment of the design that will optimally meet the daily load demand with a loss of load probability (LOLP) of 0.01 was performed, considering 3 stand-alone applications of photovoltaic (PV), wind and diesel, and 3 hybrid designs of wind-PV, wind-diesel, and solar-diesel. The diesel standalone system (DSS) was taken as the basis of comparison as the experimental location has no connection to a distribution network. The HOMER® software optimizing tool was engaged following the feasibility analysis with the RETScreen software. The wind standalone system (WSS) was found to be the optimal means of producing renewable electricity in terms of life cycle cost as well as levelised cost of producing energy at $0.15/(kW·h). This is competitive with grid electricity, which is presently at a cost of approximately $0.09/(kW·h) and 410% better than the conventional DSS at a levelized cost of energy (LCOE) of $0.62/kWh. The WSS is proposed for communities around the study site.

关键词： photovoltaic (PV) power wind power solar-wind hybrid cost per kilowatt-hour clean energy

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综合使用飞行小时在飞机构件腐蚀疲劳寿命分析中的应用

林明,金平,孙明礼

《中国工程科学》 2001年第3卷第3期页码 65-67

摘要：

飞机使用环境谱中飞行环境谱和停放环境谱的组合就是飞行─停放─飞行环境谱。大多数军用飞机地面停放时间占飞机使用寿命的90％以上。海军飞机所处的高温、高湿、高盐雾腐蚀环境对飞机使用寿命有很大影响。腐蚀疲劳直接影响疲劳裂纹形成寿命。飞机使用寿命必须应用飞机使用环境谱，考虑飞行小时、日历时间和综合使用飞行小时。列举海军某直升机主桨毂轴向铰轴颈裂纹故障，通过波音公司飞机结构疲劳分析方法，在飞行小时、日历时间和综合使用飞行小时方面对其翻修期进行了探讨。

关键词：腐蚀腐蚀疲劳飞行小时日历时间综合使用飞行小时