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61.
Gamma‐ray spectrometry is an established method in geo‐sciences. This article gives an overview on fundamentals of gamma‐ray spectrometry that are relevant to soil science including basic technical aspects, and discusses influencing factors, inconsistencies, limitations, and open questions related to the method. Gamma‐ray spectrometry relies on counting gamma quanta during radionuclide decay of 40K, 238U, and 232Th, but secular equilibrium for the decay series of U and Th must be given as decays of their respective daughter radionuclides are used for determination. Secular equilibrium for U and Th decay series, however, is not always given leading to, e.g., anomalies in U concentration measurements. For soil science, gamma‐ray spectrometry is of specific value since it does not only detect a signal from the landscape surface, but integrates information over a certain volume. Besides, different spatial scales can be covered using either ground‐based or airborne sensing techniques. Together with other remote sensing methods, gamma signatures can provide completive information for understanding land forming processes and soil properties distributions. At first, signals depend on bedrock composition. The signals are in second order altered by weathering processes leading to more interpretation opportunities and challenges. Due to their physico‐chemical properties, radionuclides behave differently in soils and their properties can be distinguished via the resulting signatures. Hence, gamma signatures of soils are specific for local environments. Processes like soil erosion can superimpose gamma signals from in situ weathering. Soil mappings, available K and texture determination, or peat and soil erosion mapping are possible applications being discussed in this review. 相似文献
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D. Fowler R. I. Smith M. Coyle K. J. Weston T. D. Davies M. R. Ashmore M. Brown 《Water, air, and soil pollution》1995,85(3):1479-1484
Surface ozone concentrations show very large local variability. This, in rural areas, is largely a consequence of the degree to which the surface air is decoupled from the bulk of the atmosphere by nocturnal and winter stability effects and of the aerodynamic roughness and topography of the countryside. Procedures have been developed to simulate these effects and have been used with O3 data from a regional monitoring network to quantify exposure of vegetation to mean and peak O3 concentrations. The index of exposure to potentially phytotoxic O3 concentrations is the AOT40 (accumulated exposure over a threshold of 40 ppb) expressed in ppb.h. The accumulated exposure of crop and forest surfaces to ozone is shown to increase approximately linearly with altitude and along a gradient from 3000 ppb.h in north west Scotland to 7000 ppb.h in the south of England. The area of UK forest which exceeds the critical level for ozone effects (104 ppb.h above 40 ppb) totals 2.0 × 104 km2 and represents 47% of afforested land. The areas affected include most of southern and central England and Wales and large plantation forests of Northumberland and the Scottish borders. 相似文献
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为进一步认识微咸水的入渗规律,采用室内土柱入渗试验,对比分析了不同矿化度(0,1,3,5g/L)的NaCl溶液加入湿润剂进行灌溉后盐碱土累积入渗量和入渗率随时间的变化,验证了在盐碱土中微咸水加湿润剂情况下不同公式描述入渗过程的适应性,并分析了全盐量和氯离子的剖面分布。结果表明:NaCl溶液添加湿润剂灌溉后,盐碱土的入渗能力随NaCl溶液矿化度的增加呈先增加后减小的趋势,入渗能力在NaCl溶液矿化度为3g/L时达到最大,超过3g/L后随NaCl溶液矿化度的增大而减小。湿润土层剖面含盐量及Cl-浓度在相同湿润锋随NaCl溶液矿化度的增加而增大,在湿润锋前达到最大。NaCl溶液矿化度为3g/L时,剖面含水率最大,其次是5,1,0g/L。4种不同矿化度NaCl溶液添加湿润剂条件下,Kostiakov公式的入渗率拟合值和实测值最为接近。 相似文献
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Genome-wide identification and analysis of the regulation wheat DnaJ family genes following wheat yellow mosaic virus infection
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LIU Ting-ting XU Miao-ze GAO Shi-qi ZHANG Yang HU Yang JIN Peng CAI Lin-na CHENG Ye CHEN Jian-ping YANG Jian ZHONG Kai-li 《农业科学学报》2022,21(1):153-169
The co-chaperone DnaJ plays an important role in protein folding and regulation of various physiological activities, and participates in several pathological processes. DnaJ has been extensively studied in many species including humans,drosophila, mushrooms, tomatoes, and Arabidopsis. However, few studies have examined the role of DnaJ in wheat(Triticum aestivum), and the interaction mechanism between TaDnaJs and plant viruses. Here, we identified 236 TaDnaJs and performed a comprehensive genome... 相似文献
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Duchêne S Métayer S Audouin E Bigot K Dupont J Tesseraud S 《Domestic animal endocrinology》2008,34(1):1-13
p70 S6 kinase (p70S6K) is a key enzyme involved in the control of protein synthesis. We have previously shown that this kinase is insulin sensitive in chicken muscle despite a relative insulin resistance in the early steps of insulin receptor signaling in this tissue, particularly with no change in tyrosine phosphorylation of the insulin receptor substrate 1 (IRS1). The aim of the present study is to further study the p70S6K pathway in chicken muscle. By analyzing in silico several kinases involved in the protein kinase B (PKB also called AKT)/target of rapamycin (TOR)/p70S6K pathway in the chicken, we showed that the amino acid sequence of the proteins exhibited a very high identity with their homologs in mammalian species and Drosophila. We investigated the regulation of these kinases in vivo or in vitro. Refeeding and insulin treatment significantly (P<0.05) increased the phosphorylation and/or activity of kinases upstream of p70S6K such as AKT and TOR. Similarly, refeeding and insulin increased the phosphorylation of p70S6K on key residues (i.e. T389, T229 and T421/S424) and the phosphorylation of a p70S6K downstream target, the ribosomal protein S6 (by 3-10-fold, P<0.05). Interestingly, we also showed an increase in the phosphorylation level of IRS1 on S632/S635, sites involved in insulin resistance. In conclusion, the AKT/TOR/p70S6K pathway is activated by refeeding and insulin injection, which might negatively regulate IRS1 tyrosine phosphorylation. These results indicate some particularities of the insulin signaling in chicken muscle and suggest the involvement of p70S6K in these features. 相似文献
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采用石蜡切片技术研究甘蓝白化种荚材料alb1的细胞学特征,结果表明白化种荚细胞形态发育异常,细胞壁畸形、细胞界限不明显。遗传分析结果表明,绿荚∶白荚的分离比为3∶1,白荚性状是由1对隐性基因控制的。利用转录组测序技术分析白化种荚突变体alb1及绿荚芥蓝TO1000的基因表达情况,筛选获得4 530个差异表达基因,其中2 569个基因上调表达,1 961个基因下调表达;这些基因主要涉及核糖体、植物激素信号转导、脂肪酸链伸长等生物学过程,植物激素信号转导对细胞形态建成尤为重要,可能是引起细胞发育畸形,出现白化种荚的重要原因。 相似文献
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