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排序方式: 共有1305条查询结果,搜索用时 15 毫秒
871.
David C. Bull Peter W. Harland Claire Vallance Garry J. Foran 《Journal of Wood Science》2000,46(3):248-252
Copper and arsenic K-edge X-ray absorption fine structure spectroscopy (EXAFS) of pine wood (Pinus radiata) treated with chromated copper arsenate (CCA) timber preservative have been measured. Refinement of the data is consistent with arsenate anions bound to chromium and copper ions isolated from other heavy elements, regardless of depth into the wood. This constitutes the first substantive analysis of CCA's fixation products and has a number of implications for models of fixation. 相似文献
872.
873.
《Communications in Soil Science and Plant Analysis》2012,43(19-20):2887-2905
Abstract To evaluate contributions of organic matter, oxides, and clay fraction to copper (Cu) adsorption in six characterized soils, adsorption isotherms and distribution coefficients were obtained by a batch experimental method. Copper adsorption isotherms from untreated soil, organic matter removed from samples, and organic‐matter‐ and oxide‐removed samples were compared with curve patterns and correlated to Langmuir and Freundlich models. Copper sorption data on untreated soils described L or H‐curves, whereas in soils deprived of any component, their curves were S‐type. Distribution coefficients allowed knowing Cu adsorption capacity of untreated soil and of organic matter, oxides, and clay fraction. Soil organic matter is the main component that affects Cu adsorption as long as soil pH is near neutrality. At acid pH, oxides are the main component that affects Cu adsorption, although to a much smaller extent than organic matter near neutral conditions. Soil pH is the main soil factor that determines Cu adsorption. 相似文献
874.
David L. Straus 《Journal Of Applied Aquaculture》2013,25(4):272-284
ABSTRACT Fingerling channel catfish Ictalurus punctatus were exposed to Ichthyophthirius multifiliis-infested fish until immature trophonts developed. The fish were transferred to individual static fiberglass tanks filled with 600 L of pond water (total alkalinity and total hardness was 220 mg/L and 101 mg/L, respectively) and were treated with 0, 1.1, 2.2, 3.3, or 4.4 mg/L copper sulfate (CuSO4 · 5H2O) every other day for four treatments to evaluate its effectiveness to control mortality associated with ichthyophthiriasis. Water temperature was maintained at 18 ± 1°C. Fish were observed for ten days post-treatment and mortalities were recorded. Results indicate that half of the recommended dose (1.1 mg/L CuSO4) is needed to effectively control an occurrence of ichthyophthiriasis under the conditions of this study. However, fish culturists should be aware that effective CuSO4 treatment of ichthyophthiriasis on channel catfish raised in ponds may be influenced by water chemistry characteristics and suspended materials such as pond sediments. 相似文献
875.
Li Hua‐Tao Lu Lei Zhang Rong‐Mei Luo Lan Yuan Zhi Zhang Shan‐Fu Jiang Jun Liu Si‐Miao Dong Ting‐Ting Liang Qi He Si‐Pei 《Aquaculture Nutrition》2019,25(1):119-133
The study explored the effects of ethyl ether extract, ethyl acetate extract (EAE), acetone extract, ethanol extract and aqueous extract of Angelica sinensis (EAs) and ethoxyquin (EQ) on lipid oxidation in erythrocytes and growth, digestive, absorptive and antioxidant capacity in carp (Cyprinus carpio var. Jian). The results indicated that EAs and EQ respectively at the concentrations of 0.5 and 0.25 mg/ml suppressed lipid oxidation by decreasing the generation of ROS and restoring the activities of antioxidants in hydroxyl radical‐treated erythrocytes. Of all of the examined EAs, EAE showed the strongest protective effects against lipid oxidation in carp erythrocytes. The antioxidant effects of EQ at the concentration of 0.25 mg/ml were stronger than that of EAE at the concentration of 0.5 mg/ml in fish erythrocytes. The antioxidative activities of EAs in carp erythrocytes were positively correlated with their phenols content. Moreover, dietary EAE raised growth performance in fish. The appropriate concentration of EAE for the growth of fish was estimated to be 3.544 g/kg diet. Dietary EAE increased digestive and absorptive capacity in carp and improved antioxidant capacity in copper‐treated carp. So, EAE could be used as a potential natural antioxidant and inhibitor of copper stress in fish. 相似文献
876.
为了评价铜合金围栏养殖大黄鱼(Larimichthys crocea)海域的水质状况,通过大黄鱼养殖期与非养殖期的4次调查,分析评价了调查海域海水中的p H、溶解氧、铜、锌、无机氮、活性磷酸盐等指标的区域分布、季节变化及污染水平,并利用内梅罗指数对调查海域水体进行了质量综合评价。结果表明:调查海域大黄鱼非养殖时间段的海水综合质量整体上属于清洁或者较清洁状态,大黄鱼养殖时间段的海水综合质量下降,分布趋势是以养殖网箱为高值中心,向外缘逐渐下降。 相似文献
877.
In this study, an effective method to enrich the rotifer Brachionus plicatilis with copper was developed as a feed for the Chinese mitten crab Eriocheir sinensis zoea larvae. Changes in the concentrations of other minerals in rotifers were also examined when copper was added for rotifer enrichment. The ability of Chlorella to absorb waterborne copper is much higher than that of rotifers, and hence, copper was preaccumulated in Chlorella before its ingestion by rotifers. The copper content in rotifers was comparable to the dietary copper requirement of the crab larvae when the rotifers were enriched with 0.1 mg Cu g−1 Chlorella for 12 h. Further enrichment in rotifers with Cu‐enriched Chlorella and lipid emulsions did not significantly change the profile of major fatty acids and mineral composition in the rotifers. Evidence shows the feasibility of copper enrichment in rotifers using microalgae that can accumulate copper. This study indicates that copper in rotifers can be enriched by feeding copper‐enriched algae at a concentration of 0.1–0.2 mg Cu g−1 Chlorella. The developmental rates of E. sinensis can be improved by feeding zoea larvae with copper‐enriched rotifers, but survival rates were not affected by dietary copper enrichment. 相似文献
878.
铜合金网衣在海水养殖中的应用研究进展 总被引:3,自引:0,他引:3
铜合金网衣在渔业工程领域特别是网箱和围栏网海水养殖中得到了广泛的应用,并取得良好效果。铜合金网衣具有"0"生物附着、高效低碳、健康环保等特点。本文结合国内外在海洋、环境和金属材料等领域对铜合金研究已取得的成果,探讨了铜合金网衣在海洋中的抗污、耐腐蚀机理;通过介绍几种铜合金网衣类型,描述了两种结构类型的铜合金网衣网箱的制作方法以及在网箱养殖应用中常见的问题,并分析了其结构、力学特性和抗风浪能力等作业性能的关系,对铜合金网衣网箱在渔业上的应用情况及研究进展进行了梳理,以期为铜合金网衣网箱的进一步研究和应用提供参考。 相似文献
879.
实验采用RT-PCR和RACE克隆fzd2、fzd3a、fzd4和fzd10基因,其c DNA全长分别为2 176、3 243、2 509和3 021 bp,其中ORF长度分别为1 652、2 084、1 649和2 161 bp,编码551、695、550和586个氨基酸。氨基酸序列比对和系统树分析显示,4种基因十分保守,黄颡鱼与斑点叉尾鲖亲缘关系最近。组织表达分析显示,4种基因的m RNA在脑、脾脏、肾脏、鳃、心脏、肌肉、脂肪、肝脏及卵巢等组织中都有表达,而其表达量不尽相同。FZD家族基因对铜的响应研究表明,在暴露28 d时,fzd3a m RNA水平随着铜浓度的增加而增加,但是fzd2、fzd4和fzd10基因表达各个处理组无显著性差异;在56 d,fzd2m RNA水平在30μg Cu/L组最高,其他2个组差异不显著,fzd3a、fzd4和fzd10的基因表达在3个铜暴露组中均无显著差异,表明fzd家族这些基因的功能发生了分化,部分成员介导了铜影响黄颡鱼卵巢发育的调控。 相似文献
880.
Evangelia Gouva Cosmas Nathanailides Ioannis Skoufos Ioannis Paschos Fotini Athanassopoulou Ioannis S. Pappas 《Aquaculture Research》2020,51(8):3255-3267
This study aimed to investigate the effects of heavy metals, such as copper, zinc, iron, cobalt, chromium, aluminium, manganese and molybdenum, on zebrafish egg hatching rate and the subsequent survival rate of the larvae. Each metal was used in the various concentrations of0.05 mg/L, 50 mg/L and 500 mg/L to detect the threshold limit of tolerance. The study's results showed significant differences in the hatching and survival rate of larvae between the control group and most of the experimental groups when adding heavy metals in various concentrations. The highest concentration (500 mg/L) of the induced heavy metals tested in this study resulted in total egg or larval mortality within 96 hr and significantly lower egg or larval life expectancy. Among the tested metals, zinc and molybdenum had the most significant impact on hatching time, in contrast to iron that did not differentiate the results from the control group. Copper, cobalt, chromium, aluminium and manganese did affect zebrafish eggs depending on their exposure concentrations, which differentiated the results from the control group. Also, the study's findings demonstrate a significant dependence of the hatched egg heart rate on the metal concentration, and in particular, higher concentrations of metals correspond to higher heart rate. Zinc, Molybdenum and copper was proved to be the most toxic heavy metals causing increased hazard rate to mortality up to 96 hr and shorter life expectancy. Finally, skeletal deformities that occasionally observed did not significantly affect the total life expectancy of the hatched eggs. 相似文献