荧光光度法测定饲料中微量硒的探讨     

李晓亮  王伟 《华南农业大学学报》1994,15(3):163-165

本文在前人研究的基础上对荧光测定微量硒作了进一步的改进与简化，结果表明，操作简便易行。硒与２，３－二氨基萘在酸性条件及适当的温度下，形成络合物。用ＥＤＴＡ掩蔽干扰离子，以环己烷萃取，取其有机相直接在ＨＩＴＡＣＨＩ６５０－１０ＬＣ荧光检测器５５５ｎｍ处（发３７４ｎｍ）测荧光强度。避光保存时络合物至少稳定２４ｈ。相对标准差在３％－５％之间。  相似文献   

硒的作用与硒资源开发利用Ⅱ.硒在农业上的开发利用     

金明珠  邢丹英  胡蔚红  黄飞跃  邓端富 《湖北农学院学报》2003,23(5):392-396

硒在自然界稀少，分散，它在地壳的丰度为O．08μg／g，在地球内部为13μg／g，在地壳中呈一定的带状分布。从农业生产的角度，可以在植物、动物和微生物等方面进行研究开发。  相似文献   

石泉县中部地区土壤硒分布特征及影响因素   总被引：1，自引：0，他引：1       下载免费PDF全文

郑新如  潘爱芳  马润勇  魏萌初 《中国土壤与肥料》2022,(1):131-138

石泉县是我国富硒(Se)的重点地区,研究其土壤Se元素的分布特征及影响因素,对特色农业资源的开发利用具有重要意义。为开发富硒土地,以1个·km;的采样密度对石泉县研究区土壤的Se分布特征及其影响因素进行分析。结果表明:石泉县研究区表层土壤中Se含量为0.06~12.8 mg·kg^-1,平均值为0.678 mg·kg^-1,以足Se(0.175~0.40 mg·kg^-1)或富Se(0.40~3 mg·kg^-1)为主,其分布面积达到80.28%,Se中毒(>3mg·kg^-1)区域仅为3.83%,缺Se(<0.175 mg·kg^-1)面积仅为15.88%。成土母质是影响石泉县Se含量的主要因素,高Se土壤主要分布在以页岩、板岩为母质的古生代地层区;Se含量与主要重金属As、Cd、Cr、Cu、Hg、Ni、Zn、Pb等元素存在着较强的伴生关系;海拔、坡度等地形地貌因素对Se的含量无明显影响;另外,Se含量与p H存在一定正相关关系,与Mg、Al、Fe之间均具有极显著的负相关关系,与K关系不显著。  相似文献   

植物中硒的含量、影响因素及形态转化研究     

刘媛媛  孟凡乔  吴文良  周越 《农业环境与发展》2014,(6)

综合近年来国内外的研究文献,从硒对植物的生理作用、植物含硒量和影响因素以及植物硒形态分布和转化等方面进行了系统分析。今后应该继续对硒在植物体内的作用进行深入分析,结合分子和基因手段以及硒同位素技术,探索培育富硒作物品种的可能性以及在生产实践中应用的价值。继续在自然土壤条件下加强富硒作物生产技术的开发,为合理利用硒资源提供可持续技术保障。  相似文献   

新疆伊犁土壤硒资源分布及与土壤性质的关系分析     

王琪  刘禹含  杨景娜  黄青青  吴文良  李花粉 《农业环境与发展》2014,(6)

调查研究了伊犁州土壤中硒资源的分布特征,为该地区富硒农产品的开发提供理论指导。用原子荧光光度法测定了新疆伊犁州6个县158个农田土壤样品的全硒含量,并运用统计分析方法对伊犁州土壤硒资源的分布特征及与土壤理化性质的关系进行了分析。结果表明,伊犁州6个县土壤中全硒含量范围为0.14~2.75 mg·kg-1,几何均值为0.33 mg·kg-1,其中昭苏县土壤全硒含量均值最高,巩留县最低。所检测的土壤样品中有2.38%属于少硒土壤,78.57%属于足硒土壤(0.175~0.45 mg·kg-1),19.05%属于高硒土壤(0.45~3.00 mg·kg-1)。统计分析的结果表明,有机质、速效钾、碱解氮与全硒含量呈极显著正相关(P0.01),p H值与硒含量成显著负相关(P0.01)。伊犁州土壤中硒的含量水平偏高,可以优先考虑富硒农业的开发建设。  相似文献   

Advanced Treatment Technologies in the Remediation of Seleniferous Drainage Waters and Sediments     

W.T. Frankenberger Jr.  C. Amrhein  T.W.M. Fan  D. Flaschi  J. Glater  E. Kartinen Jr.  K. Kovac  E. Lee  H.M. Ohlendorf  L. Owens  N. Terry  A. Toto 《Irrigation and Drainage Systems》2004,18(1):19-42

Bioaccumulation of selenium (Se) in wetlands and evaporation ponds has created serious hazards to fish and waterfowl in the western United States. Agricultural drainage water is the main source for Se contamination in this region. Treatment technologies currently being evaluated to reduce the Se load in agricultural drainage water include physical, chemical and biological methods. This article focuses on ion-exchange, reverse osmosis, solar ponds, chemical reduction with iron, microalgal-bacterial treatment, volatilization, biological precipitation, and flow-through wetlands to remove Se in water. Advantages and disadvantages of each technology are evaluated and assessed in terms of cost-effectiveness and practical applications in dealing with large volumes of drainage water. With intense research in treatment technologies, it is feasible that a combination of biological, chemical and physical techniques may be employed in the development of a cost-effective strategy to treat agricultural drainage water.  相似文献   

若尔盖高原湿地土壤性质对硒有效性的影响   总被引：1，自引：0，他引：1  

田应兵 陈芬熊明彪  宋光煜 《水土保持学报》2004,18(5):15-18

用等温吸附的方法研究了若尔盖高原广泛分布的泥炭土、沼泽土和风沙土对硒的吸附与解吸,以探讨湿地土壤因素对硒有效性的影响。结果表明,3种土壤还原状态下硒的吸附量均大于氧化态,水溶性硒和交换态硒的解吸量均为氧化态高于还原态,潜在有效硒与此相反,氧化状态有助于提高土壤硒的有效性。土壤pH升高,泥炭土对SeO_3~(2-)-Se的吸附量降低,水溶态硒增加,交换态硒降低,潜在有效硒变化不明显。土壤有机质能大量吸持硒降低其有效性,泥炭土去有机质后对硒的吸附量大幅度下降,水溶性硒和交换态硒量增加,潜在有效性硒量则明显降低。  相似文献   

Composition and functional properties of unprocessed and locally processed seeds from three underutilized food sources in Nigeria     

S. Y. Giami  O. C. Wachuku 《Plant foods for human nutrition (Dordrecht, Netherlands)》1997,50(1):27-36

Chemical and functional properties of unprocessed (raw) and locally processed seeds ofBrachystegia eurycoma, Detarium microcarpum andMucuna sloanei that affect their utilization as sources of human food were investigated. The seeds, which are underutilized food sources in Nigeria, were subjected to local processing methods which included roasting, boiling, dehulling/shelling, soaking and the changes in composition and functional properties were estimated. Chemical analyses showed that the crude protein contents of the raw seeds ranged from 12.2 to 23.2%; fat varied from 4.9 to 12.0%. The level of phytic acid in the raw seeds (192.4–215 mg/100 g) was observed to be lower than the levels found in some commonly consumed pulses in Nigeria. There were no significant differences (p>0.05) between crude protein contents and the least gelation concentrations of the raw and processed samples, but processing (roasting, boiling, dehulling and soaking) significantly (p=0.011) improved in vitro protein digestibility, water and fat absorption capacity and decreased the bulk density, nitrogen solubility and the phytic acid and polyphenol contents of the samples. Processed samples had high water (3.4–3.8 g/g) and fat (1.8–2.1 g/g) absorption capacities and hence may be useful as functional agents in fabricated foods such as bakery products and ground meat formulations.  相似文献   

Flexural characteristics of coir fiber reinforced cementitious composites     

Zhijian Li  Lijing Wang  Xungai Wang 《Fibers and Polymers》2006,7(3):286-294

This study has examined the flexural properties of natural and chemically modified coir fiber reinforced cementitious composites (CFRCC). Coir fibers of two different average lengths were used, and the longer coir fibers were also treated with a 1 % NaOH solution for comparison. The fibers were combined with cementitious materials and chemical agents (dispersant, defoamer or wetting agent) to form CFRCC. The flexural properties of the composites, including elastic stress, flexural strength, toughness and toughness index, were measured. The effects of fiber treatments, addition of chemical agents and accelerated ageing of composites on the composites’ flexural properties were examined. The results showed that the CFRCC samples were 5–12 % lighter than the conventional mortar, and that the addition of coir fibers improved the flexural strength of the CFRCC materials. Toughness and toughness index, which were associated with the work of fracture, were increased more than ten times. For the alkalized long coir fiber composites, a higher immediate and long-term toughness index was achieved. SEM microstructure images revealed improved physicochemical bonding in the treated CFRCC.  相似文献   

不同处理对椰肉贮藏期间酶活性的影响     

沈晓君  王辉  李晓煜  陈卫军  夏秋瑜  赵松林 《热带作物学报》2014,34(8):86-90

为明确椰肉中酶活性的影响因素,有针对性地控制酶的活动,研究低温、巴氏、80℃烘干、超高温及微波处理对椰肉贮藏期内中脂肪酶(LPS)、过氧化物酶(POD)和多酚氧化酶(PPO)活性的影响。结果表明：-25℃、低温、巴氏、80℃烘干、超高温和微波处理均对椰肉中的LPS、PPO和POD活性有一定抑制作用。对椰肉进行6 d以内的短期贮藏时,80℃烘干处理对脂肪酶、过氧化物酶和多酚氧化酶抑制作用明显;而对椰肉进行6～12 d长期贮藏时,超高温处理效果显著。通过对新鲜椰肉进行不同的处理,可以达到抑制椰肉内酶活性,提高椰肉品质的目的。  相似文献