Gamma‐ray spectrometry as versatile tool in soil science: A critical review     

Nadja Reinhardt  Ludger Herrmann 《植物养料与土壤学杂志》2019,182(1):9-27

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   

Monacolin K转化产物对HMG-CoA酶的抑制作用     

于海  方慧英  诸葛健  吴华俊  徐鑫  汪志君 《扬州大学学报(农业与生命科学版)》2008,29(2)

采用分光光度法测定HMG-CoA还原酶的酶活性,探讨Monacolin K 微生物转化产物与普伐他汀、辛伐他汀对HMG-CoA还原酶抑制作用的关系.结果表明:Monaeolin K 微生物转化产物的IC50为377.69μg·mL-1,显著低于Monacolin K 和普伐他汀,而与辛伐他汀的IC50差异不显著.  相似文献   

Preparation of high surface area activated carbons from tobacco stems with K₂CO₃ activation using microwave radiation   总被引：1，自引：0，他引：1  

Wei Li  Li-bo Zhang  Jin-hui Peng  Ning Li  Xue-yun Zhu 《Industrial Crops and Products》2008,27(3):341-347

In this paper, activated carbons with high surface area from carbonized tobacco stems with K₂CO₃ activation by microwave radiation were investigated. Effects of microwave radiation time and K₂CO₃/C ratio on the yield and adsorption capacities of activated carbons were evaluated. Experimental results indicated that the optimum conditions were as follow: microwave power 700 W; microwave radiation time 30 min; K₂CO₃/C ratio 1.5:1. Iodine number, amount of methylene blue adsorption and the yield of activated carbon prepared under optimum conditions were 1834 mg/g, 517.5 mg/g and 16.65%, respectively. Surface area, micropore volume and pore size distribution (PSD) of the carbons were determined by the BET, H-K and DFT methods. Results showed that activated carbons had a micropore content about 59.98% and a small number of mesopores and macropores; BET specific surface area and total pore volume were 2557 m²/g and 1.647 cm³/g, respectively.  相似文献   

湖北省油菜钾肥效应及推荐用量研究   总被引：19，自引：2，他引：17  

李银水  鲁剑巍  邹娟  李小坤  黄和平  余勇  姚忠清  彭文勇  李彬 《中国油料作物学报》2008,30(4)

通过22个田间试验研究湖北省油菜主产区钾肥效应和适宜用量。结果表明,适量施用钾肥对油菜具有明显的增产增收效果,21个试验施钾比不施钾对照增收油菜籽70~1 091kg/hm2,平均增产337kg/hm2,增产幅度在2.5%~68.6%之间,平均增产率为18.6%;纯利润平均为871元/hm2,产投比平均达3.91;钾肥偏生产力和农学利用率平均分别为34.8kg/kg K2O和4.2kg/kg K2O。根据肥料效应方程,在当前生产条件下,油菜生产的钾肥最佳经济用量平均为82.7kg K2O/hm2,推荐幅度为0~150.2kg K2O/hm2。土壤速效钾含量与油菜钾肥最佳推荐用量呈极显著负相关(r(-0.789 6**,n(20),根据土壤速效钾含量(x,单位为mg/kg)水平,湖北省目前油菜生产适宜用钾量(y,单位为kg/hm2)可通过公式y(366.28-62.646Ln(x)求得。  相似文献   

氮营养对甜菜K^＋含量及K^＋选择吸收的影响     

于海彬  阮凤 《中国糖料》1998,(2):20-23

试验结果表明,在亩秋施Ｐ２Ｏ５７．５ｋｇ,Ｋ２Ｏ５．０ｋｇ基础上,随施Ｎ水平提高,各生育时期块根中的Ｎ含量和Ｋ＋含量均呈正相关,而叶片中呈负相关;幼苗期特别是糖分积累期,随施Ｎ水平提高,Ｎ对Ｋ＋选择性向地上部运输比率ＳＲＫ．Ｎ值有提高趋势,而在叶丛快速生长期和块根糖分增长期,则呈降低趋势;随生育进程,块根糖分增长期和糖分积累期较苗期和叶丛快速生长期,ＳＲＫ．Ｎ值高出１倍以上;从苗期至块根糖分增长期,ＳＲＫ．Ｎ值与叶片中Ｋ＋含量呈正相关,与块根中Ｋ＋含量呈负相关;在块根糖分增长期,ＳＲＫ．Ｎ值与块根和叶片中Ｎ含量,与叶丛快速生长期叶片中Ｎ含量均呈负相关。各生育时期,块根和叶片的生长量与其中的Ｋ＋含量均呈负相关。  相似文献   

莲藕施用钾肥试验   总被引：1，自引：0，他引：1  

武如心 《山西农业科学》1998,26(1):59-62

两年试验结果表明,种植在沼泽土和草甸土的莲藕,每公顷施K2O75－300kg,产量分别增加2235－3480kg／hm2和3420－4530kg／hm2。钾肥能明显增强莲藕的抗病性,改善莲藕品质。  相似文献   

减蛋综合征病毒33K蛋白基因克隆及结构分析   总被引：2，自引：0，他引：2  

李茂祥  李红卫  金奇  章金刚  余兴龙  吕宗吉  侯云德  殷震 《中国兽医学报》1999,19(3):221-225

纯化的减蛋综合征病毒（ＥＤＳＶ）ＤＮＡ经ＨｉｎｄⅢ水解、０．８％琼脂糖电泳后,回收各ＤＮＡ条带并克隆至ｐＢｌｕｅｓｃｒｉｐｔＫＳ载体,建立了ＥＤＳＶ基因文库,对３３Ｋ蛋白基因进行了分析。本研究证实,ＥＤＳＶ３３Ｋ蛋白基因含有２个外显子,与羊腺病毒（ＯＡＶ）３３Ｋ蛋白比较,Ｎ端编码产物的同源性为３０．８％,Ｃ端的为６０％。用ＲＴ－ＰＣＲ扩增３３ＫｍＲＮＡ和ｃＤＮＡ克隆及序列分析证实,ＥＤＳＶ３３Ｋ蛋白含有８２碱基（ｎｔ）的内含子,去掉内含子３３Ｋ蛋白基因能形成完整的ＯＲＦ,其编码产物由１７７氨基酸（ａａ）组成,推测分子质量为２．０６×１０４,与人５型腺病毒和ＯＡＶ的同源性分别为２８．１％和４４．７％。  相似文献   

Influence of dietary menadione nicotinamide bisulphite (vitamin K3) and phylloquinone (vitamin K1) on Atlantic salmon (Salmo salar L.) tissue levels,determined by high‐performance liquid chromatography with fluorescence detection     

I.E. GRAFF  C. KROSSØY  K. GJERDEVIK  K. JULSHAMN 《Aquaculture Nutrition》2010,16(6):637-647

The aim of the present study was to investigate the retention of menadione nicotinamide bisulphite (MNB; vitamin K₃) and phylloquinone (vitamin K₁) in Atlantic salmon (Salmo salar L.). Another objective was to find a reliable method for determination of menadione in fish feed, and to include and validate more matrices in the methods for phylloquinone and menaquinones (vitamin K₂). Duplicate tanks of Atlantic salmon (～93 g) were fed four levels (0–1000 mg menadione kg^?1 feed) of MNB for 9 weeks. The concentration of menadione and phylloquinone in the feed and the concentration of phylloquinone and menaquinone‐4 (MK‐4) in the tissues were determined. The analysed concentration of dietary menadione found in feed indicated a substantial loss of MNB during feed production. This assumption was supported by screening 15 commercial fish feed samples which also revealed menadione concentrations far below the recommended level. MNB fed salmon showed only a minor increase in liver MK‐4 concentration, compared to salmon fed phylloquinone which had a considerably higher level of liver phylloquinone, indicating a higher retention of phylloquinone compared to menadione in Atlantic salmon. Due to highly varying stability and bioavailability of the different vitamin K derivatives, vitamin K supplementation in fish feed needs a revision.  相似文献   

Vitamin K in fish nutrition     

C. KROSSØY  R. WAAGBØ  R. ØRNSRUD 《Aquaculture Nutrition》2011,17(6):585-594

Vitamin K belongs to the lipid soluble vitamins, and occurs naturally as phylloquinone (vitamin K₁) and menaquinone (vitamin K₂). In addition, there is a synthetic provitamin, menadione (vitamin K₃), primarily used as a vitamin K source in animal feed. Menadione is unstable during feed processing and storage and the dietary content may reach critically low levels. Recent publications also question the availability of menadione in feed for salmonids. Vitamin K plays vital roles in blood coagulation and bone mineralization in fish, but the suggested minimum requirement varies considerably depending on the vitamin K source used. Vitamin K deficiency is characterized by mortality, anaemia, increased blood clotting time and histopathological changes in liver and gills. However, one should assess both inherent and supplemented forms of vitamin K in feeds for exact determinations, as relevant novel feed ingredients of plant origin may be sufficient to meet the requirement for vitamin K. The current review gives an overview of the biochemical role of vitamin K, and discusses vitamin K requirement in fish in light of updated literature, with special emphasis on salmonids.  相似文献   

普通小麦籽粒硬度的全基因组关联分析     

胡文静  张晓  刘巧  方正武  高德荣 《麦类作物学报》2021,41(2):157-163

籽粒硬度是小麦品质评价的重要指标。为挖掘控制小麦籽粒硬度的重要基因/位点,以国内外171个小麦品种组成的自然群体为材料,在4个环境下利用小麦90K SNP芯片对籽粒硬度进行全基因组关联分析(genome-wide association study, GWAS)。171个小麦品种籽粒硬度变异系数为56.59%～66.80%,相关系数为0.88～0.92。GWAS结果表明,共检测到20个与小麦籽粒硬度显著相关的SNPs,其中,14个SNPs(7个位点)在2个及以上环境中能被检测到,分别位于1A、1B、1D、2A、5A和7A染色体上,可解释6.76%～11.79%的表型变异。表型贡献率超过10%的SNPs有4个(3个位点),分布在1D、2A和5A染色体上,其中,1D染色体上的标记wsnp_Ku_c19622_29138795在3个环境中能被检测到,可解释9.08%～11.79%的表型变异;2A染色体上的标记Excalibur_c12675_1789在4个环境中均能被检测到,可解释9.10%～10.86%的表型变异;5A染色体上的标记wsnp_Ra_c24707_34262900和BS00041219_51在2个环境中能被检测到,可解释6.76%～10.35%的表型变异。在所有环境下均与小麦籽粒硬度显著相关的位点有4个,分别位于1A、1B、2A和7A染色体上。  相似文献