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971.
Lim CY Yoo YH Sidharthan M Ma CW Bang IC Kim JM Lee KS Park NS Shin HW 《Journal of environmental biology / Academy of Environmental Biology, India》2006,27(3):461-466
In copper based antifouling (AF) paints Cu (I) oxide was largely used as booster biocide. In this study effect of Cu (I) oxide on two marine microalgae, Tetraselmis suecica and Dunaliella tertiolecta was demonstrated. EC50 (96 hr) concentrations estimated for T. suecica and D. tertiolecta were 1.3 mg l(-1) and 1.34 mg l(-1), respectively. Copper (I) oxide induced changes in growth, chlorophyll, carbohydrate and protein contents were observed in T. suecica and D. tertiolecta. At low concentration of 0.0625 mg l(-1), 3-26% and 1-16% growth stimulation was observed in T. suecica and T. tertiolecta respectively. Increasing Cu (I) oxide concentrations proportionately decreased the carbohydrate and protein contents. This study clearly indicates the toxicity of excessive Cu (I) oxide on growth and biochemical compositions of T. suecica and D. tertiolecta. 相似文献
972.
The levels of extractable aluminum (Al) in soils of tea plantations, Al concentrations in tea leaves and the impact of nitrogen
fertilization on these two parameters were investigated. In addition, the properties of soils from tea plantations were compared
to those from soils of adjacent non-tea fields to evaluate the effect of land use conversion (from non-tea soils to tea soils).
Exchangeable Al (extracted in 1 mol l−1 KCl) ranged from 0.03 to 7.32 cmolc kg−1 in 94 tea fields and decreased rapidly with increasing soil pH. In comparison with non-tea soils, tea soils had a significantly
lower pH and exchangeable Mg2+ concentration but higher organic matter contents and exchangeable K+ concentration. Contents of extractable Al were not different (P > 0.05) between these two soils. The concentrations of Al in mature tea leaves correlated significantly with exchangeable
Al in soil samples taken at a depth of 20–40 cm and with exchangeable Al saturations in soil sampled at␣depths of 0–20 and
20–40 cm. In the pot experiment, nitrogen fertilization significantly increased extractable Al levels but decreased soil pH
and the levels of exchangeable base cations. Nevertheless, the levels of Al in mature leaves and young shoots were significantly
reduced by the application of large amounts of N fertilizer. 相似文献
973.
Kaduka MV Shutov VN Bruk GY Balonov MI Brown JE Strand P 《Journal of environmental radioactivity》2006,89(3):199-211
The influence of agrochemical properties of forest soils and growth conditions on 137Cs aggregated transfer factors from soil to different species of forest mushrooms have been analysed. Statistically significant correlations between 137Cs soil to mushroom aggregated transfer factors and agrochemical soil properties have been revealed. The experimental data show that 137Cs aggregated transfer factors depend on the mushroom's trophic group, biological family, genus and species. They also strongly depend on forest soil properties and their values can be estimated with the use of multiple regression equations constructed from agrochemical soil parameters which most closely correlate with the 137Cs transfer parameters for particular mushroom groups. 相似文献
974.
为了统一规范环境实验室仪器设备期间核查工作,分析了环境实验室仪器设备期间核查对象、主要内容、核查方法,提出了具体实施流程和结果处理方法.应加快期间核查相关标准的制定,以便统一规范环境仪器设备期间核查方法和要求,及时评价仪器设备的运行状态,增强检测数据的准确性,提高检测质量. 相似文献
975.
Mathilde Stomp Maël Leroux Marjorie Cellier Séverine Henry Martine Hausberger Alban Lemasson 《Die Naturwissenschaften》2018,105(9-10):57
While the vocal coding of human and animal internal states has been widely studied, the possible acoustic expression of “positive” emotions remains poorly known. Recent studies suggest that snorts (non-vocal sounds produced by the air expiration through the nostrils) appear to be reliable indicators of positive internal states in several ungulate species. Here, we hypothesised in horses that the acoustic structure of the snort could vary with the subjects’ current emotional state. Indeed, a preliminary sound analysis of snorts let us suggest structure variations related to the presence of pulsations. We recorded snorts from 20 horses living in a riding center. Auditory playbacks run with 20 humans first confirmed the existence of two snort subtypes, i.e. one pulsed and one non-pulsed. Observations were then conducted to compare the distribution of these two subtypes according to the location (stall/pasture) of the signaller as a contextual determinant of its internal state and to its ears’ position as a reflection of its emotional state. We found that both subtypes were preferentially observed in positive contexts, but that pulsed snorts were even more associated with highly appreciated situations (in pasture and with ears forward). This study is a step further in the identification of indicators of positive emotions in horses and more generally in the understanding of the acoustic emotions’ coding. 相似文献
976.
从现行规范存在的问题入手,提出了确定炼化企业职业健康监护项目与周期的建议,旨在科学合理地指导炼化企业职业健康监护工作的运行操作。 相似文献
977.
978.
979.
本文从数字图像的特点引出图像讯号压缩技术,并介绍了不同压缩方式的特点及其最佳使用场合.同时引入统计概念来估算数字硬盘录像单位时间所需的平均容量和评估图像质量,为合理正确选用何种数字硬盘录像设备和选用何种工作方式提出了一些有益的看法. 相似文献
980.
Rong Li Jing Wang Ailing Gu Yan Xu Jing Guo Jiafu Pan Yanhong Zeng Yuanlin Ma Canquan Zhou Yanwen Xu 《黑龙江环境通报》2021,41(6):681-689