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1.
提出用硫化铵-氨水-过氧化氢分解硫磺试样,在0.63 mol/L醋酸—0.60 mol/L溴化钾—0.14 mol/L盐酸羟胺—0.30 mol/L硫酸铵体系中以单扫描极谱测定微量铅的方法.铅极谱峰电位为—0.48 V(相对饱和甘汞电极).铅浓度在0.2~1μg/mL范围内与峰电流成良好的分段线性关系.检出限为0.16 ng/mL.RSD为3.6%~5.6%.加标回收率为86%~93%.此法操作快速简单,用于硫磺中铅的测定,结果满意.  相似文献   

2.
利用微分电位溶出分析法,以0.09 mol/L草酸、7.5×10-5mol/L中性红为底液,同时测定了4种样品中的铅、锡含量,二元素峰电位分别为-0.52 V和-0.62 V(vs SCE),铅、锡的线性范围分别为2.0~100.0 ng/mL、5.0~250.0 ng/mL.当富集时间为60 s时,铅、锡的检出限分别为2 ng/mL和5 ng/mL.将此法应用于测定食品中痕量铅和锡,结果满意.  相似文献   

3.
研究了二苯并吡喃类染料吡口罗红Y(PY)与核酸作用的共振光散射光谱,在pH11.5~12.0Tris-NaOH缓冲溶液中,1.75×10-5mol/L的PY溶液加入核酸后,体系的共振光散射增强,在364.0nm处,存在一共振光散射增强峰,其增强强度(△IRLS=I-I0)与核酸浓度呈线性关系,据此建立了一种测定纳克级核酸的简便灵敏的方法.对于fsDNA,方法的线性范围为27.0~625ng/mL,检出限为8.1ng/mL;对于ctD NA,方法的线性范围为39.0~500ng/mL,检出限为11.7ng/mL;对于yRNA,方法的线性范围为59.0~375ng/mL,检出限为17.7ng/mL.建立的方法已用于六种合成样品的测定,结果令人满意.  相似文献   

4.
螺旋藻中痕量硒的示波极谱测定   总被引:4,自引:1,他引:3  
建立了测定螺旋藻中痕量硒的简便快速的示波极谱法.在0.6 mol·L-1醋酸介质中,硒(Ⅳ)-对氨基苯磺酸配合物于0.63 V处产生一敏锐的单扫描示波极谱波.硒质量浓度在0~80 ng·(mL)-1范围内与波高呈线性关系.Se的质量浓度检测限为1.5 ng·(mL)-1.本法测定螺旋藻中痕量硒的回收率为98%.与荧光法测定结果相比,方法对比的相对误差为12.0%.  相似文献   

5.
建立了超高效液相色谱-三重四极杆复合线性离子阱质谱快速筛查确证全血中49种安眠镇静类药物.样品前处理采用固相支撑液液萃取法.色谱条件:色谱柱为Waters C18(2.1 mm×50 mm, 1.7μm),以5 mmol/L乙酸铵-(体积分数为0.1%)甲酸水溶液(A),甲醇(B)为流动相,进行梯度洗脱.在0.1~200.0 ng/mL内,49种常见药物展现出良好的线性关系(R2>0.99),最高检出限为0.1 ng/mL;最高定量限为0.5 ng/mL;全血基质中50、100、200 ng/mL 3个加标水平下回收率为65.9%~109.0%,日内精密度为2.0%~17.6%、日间精密度为2.0%~16.3%.该方法可应用于生物检材中49种常见安眠镇静物质的检测.  相似文献   

6.
研究了meso-四(4-氯-3-磺酸钠基苯基)卟啉与铅的显色反应.结果表明:不需加热即可完成络合,表观摩尔吸光系数为2.51×105L/(mol·cm),线性范围为0~0.6靏/mL,抗干扰能力强.用该方法测定人发中痕量铅,结果令人满意.  相似文献   

7.
石墨炉原子吸收法测定黄芪甘草和广藿香中的铅   总被引:2,自引:0,他引:2  
用硝酸-高氯酸混合酸(4∶1)消化黄芪、甘草和广藿香,用石墨炉原子吸收光谱法测定黄芪、甘草和广藿香中的铅.在选定实验条件下,线性范围为0 ng/mL~20 ng/mL检出限为0.113 ng/mL,回收率为98.2%~100.9%,相对标准偏差为0.2%.  相似文献   

8.
对荨麻青霉原生质体的高效制备以及再生方法进行了探索.结果显示荨麻青霉较为适合的原生质体制备及再生条件的组合:菌龄为28 ℃恒温下培养20~22 h,DTT预处理0.5 h,以7 mg/mL的纤维素酶,7 mg/mL蜗牛酶,5 mg/mL溶菌酶为混合酶,0.6 mol/L的NaCl作为渗透压稳定剂,28 ℃恒温酶解3.5 h,PDA高渗双层培养基再生.该组合制备原生质体形成量达到1.59×107~1.89×107/mL,其再生率达到16.24%~19.25%.  相似文献   

9.
采用EDC法制备卡那霉素(KAN)完全抗原、卡那霉素-牛血清白蛋白(KAN-BSA)、卡那霉素-鸡卵清蛋白(KAN-OVA).用KAN-BSA完全抗原免疫BALB/c小鼠,并通过杂交瘤技术制备能够稳定分泌抗KAN单克隆抗体的杂交瘤细胞(1E1).通过体内诱生腹水大量制备单克隆抗体,鉴定1E1单克隆抗体,其效价为8×10~5,亲和力为2. 8×10~9L/mol,半数抑制浓度(IC50)为1. 09 ng/mL,与妥布霉素(TOB)的交叉反应率为53. 4%,与其他氨基糖苷类化合物没有交叉反应性.利用该单克隆抗体,建立KAN间接竞争酶联免疫吸附试验(ciELISA).ciELISA检测KAN在牛奶中的回收率为64. 4%~89. 6%,最低检测限为1. 92 ng/mL.  相似文献   

10.
垃圾渗滤液总氮含量的流动注射化学发光法分析   总被引:1,自引:0,他引:1  
垃圾渗滤液是一种含有多种有机物和无机物的高浓度废水,氨氮浓度高是垃圾渗滤液的重要特征,也是导致垃圾渗滤液处理难度增大的重要原因.研究了垃圾渗滤液中含氮物质消解处理的影响因素.垃圾渗滤液样品100 mL,加5 mL浓磷酸作消解剂,加8 g K2SO4作增温剂,消解时间从沸腾开始加热维持30 min,然后自然冷却至室温.消解处理样品在碱性条件下蒸馏,用1 mol/L的盐酸吸收形成铵根离子.结合流动注射化学发光法进行了垃圾渗滤液总氮含量的测定,是基于在1×10-2 mol/L NaOH溶液的碱性条件下,N-溴代丁二酰亚胺在二氯荧光素作为能量转移剂的增敏作用下氧化氯化铵,产生强烈的化学发光信号.NBS的优化浓度为3×10-3mol/L,二氯荧光素的优化浓度为2×10-5mol/L.本化学发光体系的检出限(3σ)为3×109 g/mL,测定的线性范围为7.0×10-9~9.0×10-6g/mL(r=0.9964,n=7).使用本法测定垃圾渗滤液样品总氮含量为8.2×10-3g/mL,回收率大于92.5%,RSD范围为2.9%~4.2%.本法分析结果与常规方法进行对比,结果令人满意.  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

14.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

15.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

16.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

17.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

18.
For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the  相似文献   

19.
Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of  相似文献   

20.
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with  相似文献   

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