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991.
研究了利用聚酯下脚料生产对苯二甲酸型不饱和聚酯树脂的方法。分析了原料配比及工艺参数对产品性能的影响,将对苯二甲酸型不饱和聚酯的性能与邻苯二甲酸型不饱和聚酯及间苯二甲酸型聚酯的性能进行了比较。结论认为对苯二甲酸型不饱和聚酯树脂是一种性能良好的耐腐蚀树脂。 相似文献
992.
993.
采用平衡振荡法研究腐植酸对毒死蜱水解的影响和毒死蜱在腐植酸上的吸附特征及其影响因素.结果表明,在试验浓度范围内腐植酸可促进毒死蜱的水解,腐植酸浓度为120 mg/L时,毒死蜱的水解速率常数k明显增大,为不加腐植酸时的2.53倍,腐植酸浓度增加毒死蜱的水解速率降低.毒死蜱在腐植酸上的吸附行为均可用Linear方程和Freundlich方程来描述,拟合效果均达到显著水平;试验条件下温度为15℃时毒死蜱在腐植酸上的吸附量最大,随温度的升高吸附量呈现出先降低后增大的趋势;pH值减小,腐植酸对毒死蜱的吸附能力增大;而离子强度对毒死蜱的吸附影响不明显;腐植酸添加量越大,吸附量越大,但单位质量的腐植酸吸附量越小. 相似文献
994.
995.
996.
Organic compounds dissolved in water can be decomposed on a layer of n-TiO2 particles irradiated by u.v. light, which generates holes and electrons in the TiO2 material. Dissolved oxygen was used as electron scavenger and holes reacted with water to give OH radicals. The rate of degradation of the dissolved organic compounds by OH radicals is limited by the transfer of either oxygen or of theorganic compounds to the surface of n-TiO2 particles. The consequence of these limits is that, in the batch mode reactor with recirculation of the liquid, the dependence of the concentration of an organic compound on time has either a linear or an exponential form. Experiments with decomposition of oxalic acid in aqueous solutions using a plate reactor (60 cm × 120 cm) confirmed the analysis. Equations for evaluation of the mass transfer coefficient of the dissolved species to the surface of the plate reactor with a moving liquid fil m were developed for the case of the thickness of the Nernst diffusion layer being thinner than the thickness of the liquid. The experimentally obtained decomposition rate of oxalic acid was about 60 to 80% of the theoretical decomposition rate limited by oxygen flux through the film of a moving liquid. The present theory neglects the diffusion of oxygen into the porous layer of n-TiO2. 相似文献
997.
Adsorption of benzoic acid by CTAB exchanged montmorillonite 总被引:1,自引:1,他引:1
Liang-Guo Yan Jin Wang Hai-Qin Yu Qin Wei Bin Du Xiao-Quan Shan 《Applied Clay Science》2007,37(3-4):226-230
This paper reports the adsorption of benzoic acid from water on cetyl trimethylammonium exchanged montmorillonite (CTAB-montmorillonite). Important factors are the adsorbent concentration, ionic strength, equilibrium time and pH. The largest adsorption is at pH 9. The adsorption kinetics data fitted the pseudo-second-order equation. The adsorption isotherms at different pH were linear indicating a partition mechanism. Up to about 61% of the dissolved benzoic acid was adsorbed by CTAB-montmorillonite. These results indicate that CTAB-montmorillonite is a potential adsorbent for benzoic acid. 相似文献
998.
999.
SSS Rajan 《Nutrient Cycling in Agroecosystems》1986,8(3):219-229
Four greenhouse experiments were conducted using three soils to determine the availability to plants of P from unground North Carolina phosphate rock (PR) treated with 20% to 50% of the H3PO4 required for complete acidulation. The influences of soil P retention, P status, the method of preparation of partially acidulated phosphate rocks (PAPRs) and the granule size of the products were investigated. Perennial ryegrass was grown as the test plant for up to 8 months. Triple superphosphate (TSP) was used as the standard fertilizer and unground North Carolina rock was included for comparison.The dry matter yield and P uptake response curves showed that in all experiments PAPRs were markedly superior to the PR. P status of soils appeared to influence the effectiveness of PAPRs to a greater extent than P retention. In soils of low P status the degree of acidulation required for PAPR to be nearly or as effective as TSP was 50% whereas in a soil of high P status even 30% PAPR applied as a maintenance fertilizer was effective. There was a significant positive correlation between water soluble P of fertilizers and P uptake by ryegrass. However, in general PAPRs were more effective per unit of water soluble P than TSP. Granule size (< 1 mm and 1–2 mm) and method of preparation of PAPRs did not alter the effectiveness of PAPRs. 相似文献
1000.
采用GC-900气相色谱仪、3%PEG-12000/Chromosorb880AWDMCS填充柱和FID检测器,以水杨酸甲酯为内标物测定N-氰基乙亚胺酸乙酯含量,回收率在98.5%—101.8%之间,标准偏差为0.27%,变异系数为0.27%。 相似文献