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波长可调谐深紫外窄带光源模块的设计及验证 被引量:1
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作者 俞凯雄 朱星玥 吴锜 《光电工程》 CAS CSCD 北大核心 2021年第8期66-74,共9页
本文提出了一种中心波长连续可调的光源模块,实现了深紫外光源的窄带输出。设计的光源模块由氘灯、角度旋转台、滤光片旋转轮、不同中心波长的滤光片(220 nm,230 nm,240 nm,250 nm,260 nm,270 nm,280 nm)和光学透镜组成。基于多光束干... 本文提出了一种中心波长连续可调的光源模块,实现了深紫外光源的窄带输出。设计的光源模块由氘灯、角度旋转台、滤光片旋转轮、不同中心波长的滤光片(220 nm,230 nm,240 nm,250 nm,260 nm,270 nm,280 nm)和光学透镜组成。基于多光束干涉理论,通过分析出射光的中心波长和入射角度之间的关系,得到了由每个滤光片出射的中心波长和角度旋转台旋转角度之间的定标关系式。实验结果表明,当角度旋转台入射角范围在0∼30°时,每个滤波片的可调谐范围可达到10 nm,实现紫外光源模块的单色光可调谐范围212 nm∼280 nm,能满足海水中硝酸盐浓度的测量要求。 展开更多
关键词 窄带光源 紫外波长可调 滤光片 多光束干涉 硝酸盐测量
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Physico-Chemical Analysis of Korapuzha River and Estuaries
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作者 Subburaj M Mity Thambi Mahesh G 《Journal of Shipping and Ocean Engineering》 2015年第3期131-135,共5页
Korapuzha is a short river of 40 km with a drainage area of 624 km^2, flowing from dense forest and empties into the Arabian sea. It is formed by the confluence of two streams Agalapuzha and Punnoorpuzha. In this stud... Korapuzha is a short river of 40 km with a drainage area of 624 km^2, flowing from dense forest and empties into the Arabian sea. It is formed by the confluence of two streams Agalapuzha and Punnoorpuzha. In this study the samples were collected from Agalapuzha, Punnoorpuzha and Korappuzha, Korapuzha estuaries. The temperature and pH were monitored on the site and the remaining parameters were analyzed in the laboratory. The physical quality parameters such as color, odor, appearance and chemical quality parameters such as pH, alkalinity, chloride, nitrate, nitrite, sulphate, ammonia, dissolved oxygen, total solids, total hardness, and iron have been evaluated. Compare the physical and chemical parameters. The physico-chemical analysis shows that the samples have high level of salinity, sulphate, total solids and total hardness. The results show that the water is affected by the intrusion of sea water into the river by excess excavation of sands from river for the construction of buildings and other anthropogenic activities which leads to environmental destruction. 展开更多
关键词 Korapuzha River PHYSICO-CHEMICAL POLLUTION degradation.
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Development Trends and Evaluation of Egbe Reservoir Water Nutrient Status in Ekiti State, Nigeria
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作者 Josephine Bolaji Edward Adiaha Aldah Alex Ugwumba 《Journal of Life Sciences》 2010年第1期7-16,共10页
A study about some physicochemical parameters of Egbe reservoir was carried out from September 2005 to December 2006. The parameters include mean temperature, pH, conductivity, alkalinity, TSS, TDS, DO and BOD which h... A study about some physicochemical parameters of Egbe reservoir was carried out from September 2005 to December 2006. The parameters include mean temperature, pH, conductivity, alkalinity, TSS, TDS, DO and BOD which have values of 28.7±0.9 ℃ ; 8.3±0.3; 831±172.5 μS/cm; 165.4±18.3 mg/L; 0.06±0.1 mg/L; 0.4±0.6 mg/L; 7.8±2.4 mg/L and 5.2±1.6mg/L, respectively. Temperature and pH were measured in the field using mercury-in-glass thermometer calibrated in degrees Celsius and pH meter, respectively. TSS and TDS were measured by grayimetric methods, while alkalinity was measured titrimetrically and DO and BOD were measured by Winkler's method. For the nutrients, nitrate was measured color±metrically, phosphate by Stannous Chloride method and sulphate by turbidimetric method. Mean concentration of nitrate, phosphate, and sulphate were 15.6±8.6 rag/L; 42.5±19.4 mg/L and 72.3±14.7 mg/L respectively. Nowadays, eutrophication of natural waters is one of the most significant causes of deterioration of water quality, and nitrates and phosphates are probably the key nutrients in controlling the growth of aquatic plants. Though the mean concentration of nitrates and phosphates in the reservoir water were within the acceptable limit, yet their concentrations in some locations of reservoir were high enough to encourage the growth of aquatic macrophytes which would increase productivities. Hence, it is necessary to check their further increase, and periodic monitoring and preventive measures must be adopted to save the reservoir from eutrophication. 展开更多
关键词 Physico-chemical parameters development trends NUTRIENTS Egbe reservoir.
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