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针对牙齿组织形态学研究的难点,选择适宜固定液,用EDTA-2Na进行脱钙,完成了牙齿组织石蜡切片的制作。通过确定染色程序及各种染料的最佳作用时间,分别利用Masson三色染色法、传统的苏木精和伊红（HE）染色法对牙齿组织切片进行了染色观察。染色结果表明,与HE染色法相比,Masson三色染色更能使牙齿的各主要成分以不同颜色显现出来,色彩对比鲜明,亮丽润眼,为牙齿组织生理及病理组织形态学研究奠定了基础。针对机体中硬组织的相似特性,该试验方法可以在骨骼、软骨等硬组织的形态学研究中参考、改进并推广使用。 相似文献
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Long‐term soil acidification leads to lower pH values and to a concomitant decrease in base saturation (BS). The relationship between pH and base saturation (BS) in acidified forest soils can be disturbed by processes such as nutrient cycling by vegetation, temporary saturation by ground water that comes into contact with calcareous material, or by upward diffusion of base cations from deeper horizons. This paper examines the relationship between pH and BS in Swiss forest soils developed from calcareous and noncalcareous parent material and identifies some of the factors that can affect the BS in the decalcified parts of soils derived from calcareous parent material. The decalcified zone in the latter soils has a higher BS on average compared to soils from noncalcareous parent material, but their pH values are identical. In the pH range 4.0–4.5, the difference in BS may vary by a factor of three. The mean BS in the decalcified zone tends to decrease with increasing depth of the calcareous layer. The water regime also affects the BS in soils on calcareous parent material. In soils temporarily saturated by groundwater (gleysols), the BS in the decalcified zone is always high (85%–100%) because of the continuous contact between the soil water and the calcareous parent material. In addition, the inhibited drainage impedes the depletion of base cations in these soils. In contrast, soils that are temporarily saturated by rainwater are depleted in base cations due to the alternating wetting‐and‐drying regime and the associated leaching of dissolved ions. In such soils, the depletion of base cations is strongly related to the extent of hydromorphy. Stagnogleyic soils, with the longest period of water saturation, have the highest depletion levels. We conclude that in such soils, the diffusion of base cations from deeper zones is strongly compensated by leaching from the very acidic soil horizons. The pH–base saturation anomaly has consequences for some of the methods used to calculate the critical loads of acidity for forest soils in Switzerland, with many soils being less sensitive than previously reported. 相似文献
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陈日春 《农产品加工．学刊》2013,(3):42-44
研究了EDTA螯合脱除鲢鱼鱼鳞中钙离子的工艺条件。在单因素试验基础上,采用正交试验优化得到最优的脱钙工艺条件:鱼鳞与EDTA料液比1:30,EDTA溶液浓度0.17 mol/L,浸泡时间30 h;在该最优条件下,脱钙率为94.11%,表明EDTA脱钙效果良好,脱钙工艺条件切实可行。 相似文献
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以羊软骨为试验材料,对前处理工艺-脱脂、脱钙工艺进行了改进.经过单因素实验筛选确定了较为理想的脱脂剂为氯仿:甲醇:水=1:2:0.8,脱脂条件是温度为25℃、时间为48 h、固液比1:10时其脱脂率为最高,达55.88％;选择0.5mol/LEDTA为脱钙试剂时脱钙率最高,达29.16％;SDS-PAGE电泳结果表明:用前处理改进后提取的的胶原蛋白与sigma公司的Ⅱ型标准品相一致,证明羊软骨中存在的蛋白主要是Ⅱ型胶原蛋白.紫外光谱分析结果显示:所提胶原的最大吸收峰为230nm左右,与Ⅱ型标准品最大相一致. 相似文献
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The knowledge about element leaching and biogeochemical cycles during initial stages of soil development is very limited. Therefore, we studied the effects of parent material characteristics and plant litter addition on element leaching from young sandy soils in a microcosm experiment. Our objective was to evaluate the function of young soils as a source and/or sink for nutrients during initial pedogenesis and to identify main processes which are involved in the initial development of biogeochemical cycles. The main research questions were: (1) How do differences in parent material characteristics affect nutrient leaching?; and (2) How is nutrient leaching of young soils influenced by litter addition of different plant functional groups (e.g., legume and grass species)? Combined treatments of two minimally weathered parent materials (pure sand and loamy sand) with plant litter of two plant species (Lotus corniculatus L. and Calamagrostis epigejos L.) were investigated in a soil column experiment. In addition, control columns with parent material or plant litter only were included. Carbonate weathering as a main source for calcium leaching was induced by the moderately acidic irrigation solution used in the experiment. It was 7.5 fold greater for the loamy sand parent material compared to the pure sand despite lower carbonate contents in the loamy sand. Leaching of K was very low for both parent materials but greater for the loamy sand parent material, likely due to transfer processes from fixed to exchangeable potassium forms in the clay minerals of the loamy sand. Plant litter addition generally increased leaching losses. Carbonate dissolution was intensified by both plant litter types, especially by L. corniculatus, very likely due to H+ released during nitrification of N released from plant litter and an increase in partial pressure of CO2 from microbial respiration. In contrast, K was largely retained in the soils, probably due to fixation by clay minerals and microbial immobilization. Only the pure sand treated with L. corniculatus litter leached K, resulting in 4–6 fold greater leaching losses compared to all other treatments. Nitrogen released from L. corniculatus litter was almost completely nitrified and was nearly doubled as compared to that from C. epigejos, resulting in greater N leaching. The results of our study allow identifying the general function and processes of vegetation patches in young ecosystems formed as a result of initial parent material characteristics and invading vegetation with respect to litter decomposition, soil solution composition, nutrient retention and leaching, and effects on the soil mineral phase. These patterns are not mere additive effects of parent materials plus plant litter, but reflect differences in biogeochemical process intensities and could result in an increasing heterogeneity of soil properties, nutrient availability, and element leaching fluxes with time. 相似文献
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该研究以风积沙粉体为水泥替代材料的风积沙粉体混凝土为研究对象,设计风沙冲蚀-碳化、碳化-风沙冲蚀2种工况,探讨其在风沙冲蚀、碳化环境下的劣化机理及耐久性能。结果表明,风沙冲蚀时,90o冲蚀角作用时以撞击作用为主,产生冲蚀坑洞,45°冲蚀角作用时以削切作用为主,产生冲蚀沟壑,且风沙冲蚀破坏混凝土表面水泥石结构,可使碳化深度增加3倍以上;碳化作用时,普通混凝土碳化时是由于氢氧化钙和水化硅酸钙发生脱钙反应,风积沙粉体混凝土则是由于氢氧化钙、水化硅酸钙和钙矾石发生脱钙反应,且由于碳化产物自身的膨胀作用使混凝土变的疏松,使风沙冲蚀后质量损失增加1.6倍以上;风积沙粉体混凝土内部孔径在20 nm以下的无害孔的比例多于普通混凝土21.37个百分点,200 nm以上多害孔少于普通混凝土13.93个百分点,其劣化显著性低于普通混凝土;相对于单一工况,风沙冲蚀、碳化耦合作用下劣化显著性更高,且风沙冲蚀-碳化耦合作用劣化显著性低于碳化-风沙冲蚀耦合作用,风沙冲蚀-碳化耦合作用后的10~15 mm范围内出现碳化区域、碳化产物发生变化(生成硫酸钙)及非碳化区域的混合区,且风沙冲蚀-碳化耦合作用后风积沙粉体混凝土孔隙度下降0.47%,20 nm以下的无害孔的比例高出普通混凝土25.15%。 相似文献
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