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Kenzo KōBō 《Soil Science and Plant Nutrition》2013,59(1):91-93
It has been considered by investigators, no matter whether they stand by the lignin-protein complex theory or not, that lignin plays an important role in the humus formation of plant residues. When plant residues are added to the soil, though almost all the plant constituents are decomposed, only lignin accumulates in the soil as a component of humus, as it is resistant to the microbial decomposition. However, lignin does not remain unchanged in this case and is thought to be modified, either through chemical agencies or as a result of specific microbial action. Though it is not yet fully clarified what changes it undergoes in the humification process, at least it is indicated that the methoxyl, as a characteristic radical of lignin, is attacked during the process. 相似文献
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[目的]改进赤霉素废水处理工艺。[方法]采用"混凝气浮+UASB厌氧+AO+接触氧化+沉淀"的处理工艺。[结果]处理后的出水水质优于《污水综合排放标准》(GB8978-1996)1级标准。[结论]改造后的工艺处理赤霉素废水效果较好,同时有效地节省了投资,降低了整个系统的冲击负荷。 相似文献
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After an analysis of the characteristics of impulse electro flotation wastewater treatment equipment, we discussed the factors affecting the efficiency of this technology. A simplified steel ball model was used in the construction of the free particle flotation removal model based on the kinematical theory of flocculation processes. Variation of the concentration of a free particle over time was stimulated. This mathematical model showed a significant role in the design of the flocculator parameter, and provided theoretical guidance on the choice of electric flotation parameters and the design of the electric flotation treatment equipment. The simulated results suggest that when the treatment time was between 20 and 25 minutes, the free particle removal rate could exceed 90%, a finding consistent with the experimental data. 相似文献
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文章分析了KYF系列和JJF-130系列浮选机研制过程中要解决的关键技术,详细阐述了在设计过程中整机的主要结构和参教的选择,以及槽体、叶轮、定子等关键部件的结构和参数选择. 相似文献
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J. Hummel K.‐H. Südekum D. Bayer S. Ortmann W. J. Streich J.‐M. Hatt M. Clauss 《Journal of animal physiology and animal nutrition》2009,93(2):209-220
The stratification of reticulorumen (RR) contents has been described in domestic ruminants, but suspected to be absent in certain wild ruminant species. To investigate how such stratification could be quantified, we tested variables indicating stratification in three oxen with rumen cannulae, fed once daily for 3 h, one of three different forages (fresh grass FG, grass hay GH, lucerne hay LH). Ingesta samples from dorsal rumen (DR), ventral rumen (VR) and reticulum (RET) were taken at 0, 3, 6, 12 and 24 h after the last meal and analyzed for dry matter (DM) concentration, mean particle size and proportion of floating/sedimenting particles. Viscosity was measured in centrifuged RR fluid. There was no relevant variation in rumen fluid viscosity over time or with feeding regime. Dry matter content in DR was always higher than in VR or RET and increased after feeding. When LH and FG were fed, DR always contained larger particles than VR, except at 6 and 12 h of feeding GH. The proportion of floating particles was higher in DR than VR except at GH 6 h and GR between 6 and 12 h. The floating particle fraction mostly contained larger particles, except for GH 3 h in both DR and VR and for FG 3–12 h in DR. Changes in the distribution of particle size and proportion of floating particles over time comply with the theoretical course of fermentative digestion for different forages, but make these variables unreliable indicators of stratification in less controlled settings, such as investigations in wild ruminants. In contrast, viscosity of rumen fluids appears constant over time and feeding regime and might be used as a species‐specific variable. The difference in DM content in DR and VR is a reliable indicator for RR contents stratification characterized by an oversaturation of the contents with fluid, leading to lower VR DM contents. 相似文献
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