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221.
从我国20个省市采集176份土壤中分离出苏云金芽孢杆菌51株.以cry1,cry2,cry3,cry4,cry-n,cry7,cry8,cry11,cry13和cyt的引物作PCR分析.结果表明:4株含有cry4,12株含有cry7,4株含有cry8,4株含有cry1,2株同时含有cry1和cry2,27株无PCR产物.未检测到其它基因型.经电镜扫描伴胞晶体形态多种多样,主要有菱形、球形、方形、多边形和不规则形.图3表3参15 相似文献
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Acetochlor is a widely used herbicide all over the world. Similarly to other organic pollutants, the environmental fate of the acetochlor is strongly related to its adsorption properties. Static adsorption equilibrium measurements were carried out at 25 degrees C on different types of Hungarian soils characterized by varying amounts of organic matter and pH values. Isotherms obtained under different conditions, as well as on various soils, exhibit a similar shape, thus indicating a two-step adsorption process. The plots cannot be interpreted according to the classes of isotherms suggested by Giles. The adsorption coefficients (K) were estimated from the initial slope of the curves. These values were determined not only by the type of the soil, but also by the composition of the aqueous media. The organic matter adsorption coefficients (Kom) were also calculated and they were approximately identical for soils of high organic matter. Due to the low value of the adsorption coefficients, the acetochlor is a rather mobile pollutant of the soil posing a potential danger to the aquatic environment. For soils with high organic content, the Kom values are similar to each other and, due to the significant coverage of the inorganic surfaces, the adsorption is controlled by the solute-organic substance interactions. The adsorption of weakly polar compounds, however, is remarkable even on those soils where the organic content is low. In this case, the binding is governed by the solute-inorganic surface interactions. This conclusion is nicely proved by the adsorption of the acetochlor on quartz. According to our hypothesis, the second part of the adsorption step is controlled by the solute-adsorbed solute interactions. The role of the organic matter in this region of the isotherm is probably negligible. As the organic matter content of the soils plays an important role in the acetochlor adsorption, humic substances must have a strong influence upon the transport of this compound. Experiments to obtain adsorption isotherms of further pesticides and the development of a quantitative model are in progress. 相似文献
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Development of GC capillary column for isomer-specific separation of toxic isomer of PCDDs and PCDFs in environmental samples 总被引:1,自引:0,他引:1
Analysis of polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF) has been performed using gas chromatography mass spectrometry (GC-MS). Analysis of the most toxic isomers, in particular, 2,3,7,8-substituted PCDD/PCDF in the presence of other isomers requires a special isomer specific capillary column or high performance liquid chromatography (HPLC) fractionation prior to GC-MS analysis. Commercially available long (>50 m) polar columns can separate 2,3,7,8-TCDD from other tetra isomers. However, those columns are not satisfactory for the analyses of total PCDD/PCDF in the environmental samples. Gas chromatography -high resolution mass spectrometry (GC-HRMS) and GC-MS/MS techniques are not helpful in the analysis of 2,3,7,8-TCDD unless it is separated from the other tetra isomers. The analysis of 2,3,7,8-TCDD and total PCDD and PCDF in a single GC-MS run can ease the laborious techniques presently used. In this study we have developed a new stationary phase for the GC capillary column. The capillary column developed using this new stationary phase showed unsurpassed selectivity for the separation of 2,3,7,8-TCDD from other tetra isomers. There are several advantages of the newly developed GC capillary column. 相似文献
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考虑到机械行业磷化废水的特点 ,利用混凝沉淀与结晶除磷的原理 ,设计成 2t h的磷化废水处理成套设备 相似文献
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染料结晶紫降解菌分离及其特性研究 总被引:2,自引:0,他引:2
从印染废水中筛选分离得到结晶紫(CV)降解菌株H,并对其脱色条件和机理进行了研究。结果表明,在外加生长基质条件下,菌株H不仅对CV降解脱色而且能降解中间产物。在pH7.0、35℃、摇床转速180r/min条件下,菌株H有最佳的脱色效果。对于20mg/L CV溶液,生长细胞降解0.5h,脱色率可达95%。休眠细胞对CV的降解规律也进行了对比探讨。菌株H对CV脱色过程遵循一级动力学方程,脱色速率常数k随CV浓度升高而降低,生长细胞的k值约为休眠细胞的6~7倍。 相似文献
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刘昭云 《湖南环境生物职业技术学院学报》2005,11(1):40-43,72
知识经济时代,企业最宝贵的财富是知识型员工。知识型员工是生产力的代表。知识型员工的工作效率决定了企业的竞争能力.因此。如何激励知识型员工成为企业探讨的一个重要问题.本文从知识型员工的特点入手。按有关知识管理专家提出的激励因素,从四个方面阐述了对知识型员工的激励策略。并提出了对知识型员工的管理对策. 相似文献