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81.
82.
喀斯特洼地退耕和耕作土壤优先流特征 总被引：2，自引：8，他引：2
应用亮蓝染色示踪技术,研究了喀斯特洼地退耕封育区土壤和耕作土壤的优先流类型及其特征,分析2种土地利用方式下的土壤优先流路径分布特征以及影响因素,并结合去除耕作层的对比试验,阐述了耕作层对优先流发生及其优先流路径发育的重要影响。结果表明,喀斯特洼地优先流类型为大孔隙流、裂隙流;耕地与自然封育区的优先流程度差异显著(P0.01),虽然其剖面染色总面积并无明显差异,但耕地染色区域主要集中在表层土壤,0—20cm范围内染色面积占染色总面积的91%,而自然封育区染色面积比仅为60%;耕地的水分入渗深度小于自然封育区,耕作层阻碍了水分入渗及优先流的产生并加强了孔隙中水分与基质的交换;耕作层以下土壤优先流程度与自然封育区差异不明显,但其优先流路径分布特征具有明显差异,自然封育区的孔隙、裂隙发育程度高于耕地,但是最大入渗深度大于退耕封育区,表明封育区更能有效的蓄持水分;植被覆盖及其根系生长通过影响土壤理化性质及其优先流路径分布导致优先流特征差异,而同时耕作层的存在对于耕作层以下部分优先流路径的发育起到关键作用。 相似文献
83.
为建立酸性测定平贝母中总生物碱含量的方法,采用乙醇溶液反复提取总生物碱及用酸性染料比色法测定提取物总生物碱含量.采用本方法测定结果为:贝母中总生物碱含量为0.236%,加样回收率为97.5%,RSD为1.21%.本法不需要复杂仪器,可作为平贝母中总生物碱含量测定的实用技术. 相似文献
84.
The nature of subsurface flow depends largely on hydraulic conductivity of the vadoze zone, permeability of the underlying bedrock, existence of soil layers differing in hydraulic properties and macropore content, soil depth, and slope angle.Quantification of flow pathways on forested hillslopes is essential to understand hydrological dynamics and solute transport patterns.Acrisols, with their argic Bt horizons, are challenging in this respect.To further elucidate flow pathways of water and short-term variability of soil moisture patterns in Acrisols, a field study was conducted on a forested hillslope in a sub-catchment of the Tie Shan Ping(TSP)watershed, 25 km northeast of Chongqing City, China.This catchment is covered by a mixed secondary forest dominated by Masson pine(Pinus massoniana).Soil saturated hydraulic conductivity(K sat) was significantly reduced at the interface between the AB and Bt horizons(2.6 × 10~(-5) vs.1.2 × 10~(-6) m s~(-1)), which led to that the flow volume generated in the Bt horizon was of little quantitative importance compared to that in the AB horizon.There was a marked decrease in porosity between the OA and AB horizons, with a further decrease deeper in the mineral subsoil.Especially, the content of soil pores 300 μm was higher in the AB horizon(14.3%)than in the Bt horizon(6.5%).This explained the difference in soil K sat values.This study showed that Bt horizon had limited water transport capability, forcing part of the infiltrated rainwater as interflow through the OA and AB horizons.Thus, the topsoil responded quickly to rainfall events, causing frequent cycles of saturation and aeration of soil pores. 相似文献
85.
基于探索桑叶综合利用新途径以及开发无公害染色丝绸织物的目的,以沸水及微波提取法获得的桑叶提取液作为丝绸织物的染料。采用不同提取剂对桑叶染料的萃取效果显示,以碱液提取最为有效,桑叶染色液的最大吸收峰值在420~450 nm间,且高浓度碱液提取桑叶染色液的染色效果好、耐贮藏。桑叶染色液的黄酮含量与明度值呈负相关,与偏绿值呈正相关。对染色丝织物的性能测试表明:桑叶提取液染色丝织品的耐皂洗牢度及湿牢度好,但耐光牢度较差;染色丝织物的色谱为黄绿色系,媒染不能改变色谱性质,仅有颜色深浅的变化。试验表明,桑叶提取液可作为丝绸织物染色的天然植源性黄绿色染料,建议应用于丝织品染色的工艺条件为:温度60~80℃,时间60 m in,pH 6.5~7.5。 相似文献
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88.
[目的]研究富油微藻的分离与筛选,探讨其油脂提取的最佳工艺条件。[方法]采用尼罗红荧光染料对分离自海南淡水水体的微藻进行初筛,得到油脂含量较高的Monoraphidium sp.,采用Bligh-Dyer超声法提取该微藻的油脂.以提取溶剂比例、超声功率、提取温度、提取时间为因子,通过单因子试验研究其对出油率的影响,并通过正交试验优化微藻油脂提取的工艺条件。[结果]Monoraphidiumsp经尼罗红染色后荧光强度高,表明该微藻富含油脂,具有作为能源微藻的潜力。正交试验表明,从Monoraphidium sp.提取油脂的最佳工艺条件为：溶剂氯仿、甲醇和水的比例为10∶10∶9,超声功率600 W、提取温度50℃、提取时间30 min。优化后的工艺条件与未优化的相比,该微藻出油率提高了29.01%。[结论]该研究为快速筛选富油微藻及Monoraphidium sp.的应用提供科学依据。 相似文献
89.
抗草甘膦转基因大豆PCR定量检测研究 总被引：15，自引：1，他引：15
试验建立大豆中转基因成分的定量测定方法。采用双链DNA SYBR Green I结合染料实时荧光定量PCR技术，扩增编码大豆凝集素的内参照基因lec和抗草甘膦转基因大豆中的外源花椰菜花叶病毒CaMV35s基因。绘制2种基因扩增的循环数一拷贝数标准曲线图，根据标准曲线方程计算样品中的转基因含量；并作重现性和熔解曲线分析。结果表明，lec和CaMV35s基因标准曲线方程线性好，R^2值分别达到0．9997和0．9992。不同转基因含量的标准及模拟大豆样品定量显示，实测值与实际值接近，相对偏差5％～11％。SYBR Green I实时定量PCR方法可用于定量测定大豆中转基因品种的含量。 相似文献
90.
Development of A Real-Time PCR Assay for Plasmodiophora brassicae and Its Detection in Soil Samples 总被引：1，自引：0，他引：1
A SYBR Green I real-time PCR assay was developed to detect and quantify Plasmodiophora brassicae ribosomal DNA(rDNA) and internal transcribed spacer(ITS).A pair of primers PBF1/PBR1 was designed based on the conservative region of rDNA-ITS of P.brassicae.The positive plasmid pB12 was obtained and used as the template to create standard curve.The specificity,sensitivity,and reproducibility of real-time PCR were evaluated respectively.Naturally and artificially infested soil samples containing different concentrations of P.brassicae were detected.The results demonstrated that standard curve established by recombinant plasmid was shown a fine linear relationship between threshold cycle and template concentration.The melting curve was specific with the correlation coefficient of 0.995 and that the amplification efficiency was 93.8%.The detection limit of P.brassicae genomic DNA was approximately 40 copies per 25 μL.The sensitivity of the assay was at least 100-fold higher than conventional PCR.Only DNA from P.brassicae could be amplified and detected using this assay,suggesting the highly specific of this assay.The coefficient of variation was less than 3%,indicating the PCR method revealed high reproducibility.The detection limit in soil samples corresponded to 1 000 resting spores g-1soil.Bait plants were used to validate the real-time PCR assay.This developed real-time PCR assay allows for fast and sensitive detection of P.brassicae in soil and should be useful in disease management and pest interception so as to prevent further spread of P.brassicae. 相似文献