基于便携式X射线荧光光谱法的土壤重金属快速检测     

杨桂兰  倪晓芳  张长波 《浙江农业学报》2019,31(11):1903

考查便携式X射线荧光光谱(PXRF)法对6类典型土壤中重金属Cr、Cu、Zn、As、Pb、Ni进行检测的精密度和准确度,探究其适用性。结果表明,在一定前处理条件下,PXRF法对6类土壤的检测精密度在0.14%~11.40%。以电感耦合等离子体发射光谱(ICP-OES)法的检测结果作为参考,PXRF法对其中5类土壤中重金属元素的检测准确度在75%~125%,基本可以满足土壤重金属快速检测要求,但是对于砖红壤中Cr和低浓度As的检测准确度较低,不能满足实验要求,有必要做进一步研究。  相似文献   

不同朝天椒种质资源维生素C的含量测定     

任朝辉  田浩 《现代农业科技》2019,(10)

为了探索不同朝天椒种质资源维生素C的含量。以50份不同朝天椒种质为材料,采用高效液相色谱法(HPLC)测定不同朝天椒维生素C的含量。结果表明,不同朝天椒种质之间维生素C的含量差异较大,最高达233.2 mg/100g,最低达64.1 mg/100g。维生素C的含量与品种密切相关,为朝天椒种植时种质资源的选择以及新品种选育提供了理论参考。  相似文献   

基于漏磁内检测的管道补口失效识别与判定方法     

杨辉  王富祥  王婷  玄文博  曹京刚  雷铮强  李明菲  陈振海 《油气储运》2019,(5):516-521

管道补口一旦发生失效,腐蚀介质自破损处渗入,将会严重影响管道完整性。基于漏磁内检测原理和管道补口失效形式,提出了补口防腐失效的识别与判定流程:通过分析管道补口结构特点、失效形式、可能产生腐蚀缺陷的位置与形貌特征,明确管道补口失效导致外腐蚀特征及其与漏磁内检测信号特征之间的对应关系,从而识别可能已经失效的管道补口。通过对多条管道的开挖验证,得出采用漏磁内检测技术识别与判定补口失效准确率,并验证了该方法的准确性,为基于漏磁内检测的补口失效识别与判定技术的工业化应用奠定了基础。(图7,表1,参20)  相似文献   

盐岩变形参数确定方法     

马纪伟  孟涛  李文婧  任世杰  宋素芳 《油气储运》2019,(7):822-826,833

为更加准确地确定盐岩变形参数,利用弹性力学理论推导出常规三轴压缩试验确定盐岩变形参数的计算公式。对某地下盐穴储气库区盐岩试样进行单轴、三轴压缩试验,对比分析两种试验方法获取的盐岩变形参数结果;并研究以单轴压缩试验为依据确定盐岩变形参数时,应力-应变曲线不同变形段的选择对变形参数的影响。结果表明:当采用初始弹性变形阶段的应力-应变增量求取盐岩变形参数时,利用三轴压缩试验方法所得到的结果更接近实际;以单轴压缩试验为依据确定的盐岩弹性模量及剪切模量与实际有较大误差,对应抗压强度5%~10%弹性变形段参数结果较10%~30%弹性变形段参数结果更为准确。研究成果可为合理确定盐岩变形参数提供参考依据。  相似文献   

茶树鲜叶抗坏血酸过氧化物酶活性的变化规律及测定方法   总被引：3，自引：0，他引：3  

孙云  江春柳  赖钟雄  邵巍  王秀英 《热带作物学报》2008,29(5):562-566

探讨茶树鲜叶抗坏血酸过氧化物酶(APX)活性的测定条件,分析不同茶树品种以及茶树鲜叶不同叶位APX活性的变化.结果表明:聚乙烯聚吡咯烷酮(PVPP)加入量约为鲜叶重的1.5倍,酶提取液pH为7.8.反应液pH为7.O,抗坏血酸(AsA)浓度为0.50 mmol/L时茶树鲜叶APX活性最高;茶树鲜叶APX活性随冷藏时间的延长呈下降趋势;福建7个主要茶树品种以福鼎大白茶的APX活性最高,铁观音的APX活性最低;茶树鲜叶不同叶位APX活性变化趋势为:芽>第一叶>第二叶>第三叶>老叶>嫩茎.  相似文献   

茶叶中的氟含量及测定方法研究   总被引：7，自引：0，他引：7  

刘超  吴方正  傅柳松  陈雪松 《农业环境科学学报》1998,(3)

采用氟离子选择电极法测定了茶叶中氟的含量,根据测定结果讨论了茶叶含氟量与产地、等级和季节的关系,发现茶叶中的氟以水溶性为主,其溶出率与水温有关。在此基础上,提出了沸水冲泡法作为测定茶叶中氟的新方法。  相似文献   

A rapid latex agglutination test for gender identification in the Atlantic bluefin tuna,Thunnus thynnus (Linnaeus)     

Elisabetta Micera  Rosa Zupa  Antonia Zarrilli  Antonio Camarda  Angela M Moramarco  Franca Acone  Gregorio De Metrio  Aldo Corriero 《Aquaculture Research》2010,41(9):1396-1401

A rapid, one‐step agglutination assay has been developed, based on latex particles sensitized with antibodies against vitellogenin (Vtg), aimed at Atlantic bluefin tuna, Thunnus thynnus (Linnaeus) (ABFT), gender identification. The egg‐yolk precursor protein Vtg was used as a gender marker for the assay as it is a female‐specific protein synthesized during reproductive maturation. The presence of Vtg in the plasma was revealed in 60–120 s through an agglutination reaction by mixing small volumes of ABFT plasma and an anti‐Vtg antibody‐latex suspension on a microscope slide. The effectiveness of the present test was restricted to the months of May and June, concomitant with high circulating Vtg levels. Because of its rapidity and ease of performance in the field, the present gender identification assay could be useful for broodstock management in the aquaculture industry as well as in tagging studies on wild populations.  相似文献   

Induction of meiotic gynogenesis in the stinging catfish Heteropneustes fossilis (Bloch) and evidence for female homogamety     

John Samuel Godwin Christopher  Arunachalam Ganesan Murugesan  Natarajapillai Sukumaran 《Aquaculture Research》2010,42(1):129-138

This study reports the results on induced meiotic diploid gynogenesis and female homogametic nature in the Indian catfish, Heteropneustes fossilis. The eggs of H. fossilis were inseminated with conspecific sperm. The sperm suspension was diluted to 1 × 10⁷ sperm mL⁻¹ in Hanks balanced salt solution. Sperm were irradiated under UV light, with the exposure time ranging from 15 to 360 s (7500 ergs mm⁻² for 60 s). The genetic inactivation of paternal chromosomes was confirmed by chromosome counting from the larval cells and the larvae also had a characteristic haploid syndrome. A typical ‘Hertwig effect’ in the yield of hatched larvae was observed with doses of UV exposure >75 s (9375 ergs mm²). Larvae resulting from sperm UV irradiated above 120 s (15 000 ergs mm²) were 100% haploids. Application of heat shock to the activated eggs was effective in suppressing the release of the second polar body (meiotic gynogenesis) and resulted in diploid gynogenetic larvae morphologically identical to those of the control. The best yield of diploid gynogens (49.3% with respect to the control) was found to be at 6 min after egg activation and the heat shock at 41 °C for a 1-min duration, at an ambient water temperature of 27 °C. A total of 113 diploid gynogenetic fry from seven different female fish were reared and subjected to sexing. All gynogenetic fish were female in contrast to the control, which had a mean sex ratio of 56.7% females (which was not significantly different from 50% female). From these results, the sex determination mechanism in H. fossilis was presumed to be female homogamety.  相似文献   

淬灭酶AiiO-AIO6酶学性质及对嗜水气单胞菌毒力因子的表达调控   总被引：2，自引：1，他引：1  

张美超  曹雅男  姚斌  白东清  周志刚 《水产学报》2011,35(11):1720-1728

将N-乙酰高丝氨酸内酯酶基因(aiiO-AIO6)插入表达载体pET28a构建了原核表达载体pET28a/ aiiO-AIO6.转化大肠杆菌后筛选具有活性的重组子并对纯化的目的蛋白AiiO-AIO6的酶学性质进行了研究,同时研究了纯化的酶液对嗜水气单胞菌ATCC7966溶血素( Hemolysin,Hem)、细胞肠毒素(Cytotonic enterotoxin,Ast)、胞外蛋白酶(Extracellular protease,Ep)、丝氨酸蛋白酶(Serine protease,Sp)及磷脂酶Pho( Phospholipase Al,Pho)等5个毒力因子表达的影响.结果表明,pET28a/aiiO-AIO6在大肠杆菌中大量表达N-乙酰高丝氨酸内酯酶,纯化后的N-乙酰高丝氨酸内酯酶的最适作用条件为pH8.0,30℃,在pH 6.0 ～11.0的范围内能够稳定的存在,在80℃条件下保温30 min后酶活力能够维持在65％以上;且该酶对多种金属离子、化合物和中性蛋白酶都具有很好的抗性;该酶对多种底物都具有一定的降解作用;以3-oxo-C8-HSL为底物时的km值为0.015 mmol/L;比活力为583.33 U/mg.N-乙酰高丝氨酸内酯酶在培养8h及12 h时对嗜水气单胞菌5个毒力因子的表达量都具有明显的下调趋势(P＜0.05).本实验通过测定AiiO-AIO6的酶学性质及证明AiiO-AIO6可以通过降解嗜水气单胞菌产生的信号分子来抑制其毒力因子的表达,从而为将其应用于水产环境及致病性嗜水气单胞菌的生物防治奠定理论基础.  相似文献   

伊维菌素注射液含量测定的兽药检测实验室能力比对结果分析     

戴青  王轩  赵晖  韩宁宁  杨秀玉  张秀英 《中国兽药杂志》2022,56(4):17-21

为加强兽药检验检测机构能力建设,进一步提升检测技术水平,组织开展了全国省级兽药检验机构伊维菌素注射液含量测定的能力比对。依据《中国兽药典》2020年版一部附录0512高效液相色谱法以及中国合格评定国家认可委员会(CNAS)规定的程序进行本次能力比对。采用单因子方差分析对制备的测试样品进行均匀性检验,采用t检验对样品进行稳定性考察,采用Z比分数评价各参加实验室的测试结果,以稳健统计的平均值作为指定值。参加本次能力比对的34家兽药检测实验室中,32家结果为满意,满意率94.1%。  相似文献