排序方式: 共有49条查询结果,搜索用时 625 毫秒
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BiologicaleffectsofindoorsunlightinruraldwelinghousesChenGuifu,QiuShicong(WannanMedicalCollege,Wuhu241001,China)Biologicaleff... 相似文献
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为了探明自然光和紫外光(UV)对二级处理出水中溶解性有机物(DOM)及其毒性效应的削减特性,研究了在自然光和UV两种不同光源的辐照条件下,二级处理出水中DOM的光谱特性、遗传毒性和植物毒性变化,阐明了毒性效应变化的成因.结果表明:相比于自然光照,UV辐照可以明显降低二级处理出水的UV254,并达到21%矿化.自然光和UV均可降低二级处理出水中有色溶解性有机物(CDOM),但去除的组分有所差异.同时,自然光照与UV辐照均可降低二级处理出水的遗传毒性,其削减率分别达到92%和61%.遗传毒性的变化与CDOM荧光强度变化有显著相关性.UV辐照可降低二级处理出水的植物毒性,削减率达到81%,而自然光照对二级处理出水植物毒性的削减率仅为19%,削减效果较差.利用UPLC-MS检测二级出水中的除草剂,发现植物毒性削减的差异主要是由于自然光照下二级处理出水中的阿特拉津降解缓慢,表观降解速率常数为0.0033h-1;但是UV辐照下二级处理出水中的阿特拉津可快速降解,其表观速率常数为0.2225h-1.这为污水厂排放水毒性效应控制及生态安全保障提供了一定的依据. 相似文献
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Kais Elghniji Sabrine Salem Mongi ben Mosbah Elimame Elaloui Younes Moussaoui 《毒物与环境化学》2013,95(6):869-879
The mineralization and detoxification of 4-chlorophenol (4-CP) were studied using a TiO2-paper/sunlight system. The possibility of reusing the photocatalyst was examined to determine the cost effectiveness of the method. Experiments were performed to establish optimum conditions for 4-CP removal. Phytotoxicity of photo-treated and raw 4-CP (100 mg L?1) solutions on seed germination and plant growth were carried out with the aim of water reuse and environment protection. The seeds irrigated with raw 4-CP solution showed lower sprout length while increase in sprout length was observed with the photo-treated solution for tomato (Lycopersicon esculentum), lettuce (Lactuca sativa), onion (Allium cepa), and turnip (Brassica rapa). Plant growth tests with the photo-treated 4-CP solution did not affect the leaf numbers compared to those irrigated with tap water. Photo-treated 4-CP solution can be used for irrigation in agriculture. 相似文献
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Chlorimuron-ethyl, a post-emergent herbicide selectively used in soybean and maize, degrades mainly through chemical hydrolysis. Photolysis has also an important role in the degradation of this compound. Phototransformation of chlorimuron-ethyl takes place through the cleavage of the sulfonylurea bridge, dechlorination, de-esterification and cyclization. Enzymatic de-esterification usually takes place in plant system to liberate the free acid, chlorimuron, which, in fact, inhibits the acetolactate synthase enzyme. In the non-enzymatic environment, de-esterification generally does not occur at normal pH and in moisture-free medium. But on the leaf surface of maize crop de-esterification of chlorimuron-ethyl takes place. The moisture deposited on leaf surfaces by virtue of evapo-transpirational loss of water may cause the de-esterification of chlorimuron-ethyl to the free acid, chlorimuron. 相似文献
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Cloud optical depth, as it is derived from the King's method, is compared with that deduced from the simple two stream approximation for the greater Athens, Greece area. The results show that King's method overestimates the cloud optical thickness, in comparison to the two stream approximation. These estimations were also compared with satellite observations provided by the International Satellite Cloud Climatology Project. This comparison showed that there are large deviations between ground‐based and satellite observations. These deviations are probably due to the uncertainty introduced by the integration procedure of the satellite spatial analyzing resolution (distinctness). Furthermore, values of the simple scattering albedo were calculated by employing a recently proposed theoretical method and using the solar ultraviolet irradiance measurements performed at the Athens University on a routine basis. These results are of great importance for the densely populated areas like Athens, in a sense of health impacts, from enhanced incident solar ultraviolet radiation. 相似文献
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通过建立"腐蚀环境综合试验仓"、"温度、湿度、日照、淋雨综合试验仓"、"高原环境试验仓"三个大型试验仓,构建成可模拟我国不同地域大气环境,可针对大尺寸工程构件,系统开展环境适应性评价的实验装置. 相似文献
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目的 找出太阳跟踪反射聚能户外加速曝晒方法的特点和价值。方法 基于几种典型的透明高分子材料试样,分别在佛罗里达典型亚热带潮湿环境自然曝晒、汽车外饰实验室氙灯加速耐候试验及亚利桑那太阳跟踪反射聚能户外加速曝晒黄变结果相关性、加速性和区分度的对比分析,来比较这几种试验方法的特点。结果 户外加速曝晒和自然曝晒的相关性高于氙灯加速试验和自然曝晒的相关性。与自然曝晒相比,户外加速曝晒的平均加速倍率及不同试样的加速倍率的相对差异明显小于氙灯加速试验。自然曝晒和户外加速曝晒的区分度也明显大于实验室氙灯加速试验。结论 户外加速曝晒方法较好地均衡了相关性、加速性、加速一致性及区分度,适合高分子材料的验证性试验。 相似文献
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