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1.
NBS-NH+4-荧光素体系流动注射化学发光法测定铵   总被引:7,自引:0,他引:7  
在0.1mol/L的碱性条件下,NBS(N-溴代琥珀酸亚胺)在荧光素的增敏作用下氧化氯化铵,产生强的化学发光,基于此详细研究了其反应的特性和影响因素,在优化的实验条件下体系对氯化铵的测定范围为0.1-15mg/L,检出限为0.036mg/L,对5.0mg/L氯化铵进行11次平行测定,其RSD为2.8%,将本法用于环境水样中NH4^ -的分析,并与常规的方法进行对照,获得了满意的结果。  相似文献   

2.
研究了HCl溶液中KBrO3-KBr紫外分光光度法测定苯酚的条件.建立了测定痕量苯酚的新方法.结果表明,在0.6 mol/L HCl,4.6×10-5 mol/L KBrO3,5.1×10-4mol/L KBr,5.7×10-4mol/L KI溶液中测定苯酚,其线性范围为0~120 mg/L,表观摩尔吸光系数为4.58×104L@mo1-1@cm-1,Sandell灵敏度为0.001 9μg/cm2.本法用于废水中苯酚的测定,结果满意.  相似文献   

3.
室温下,用1500倍速克灵、3000mg/L硝酸稀土、1500倍速克灵+3000mg/L硝酸稀土、2000倍速克灵+3000mg/L硝酸稀土、2500倍速克灵+3000mg/L硝酸稀土、3000倍速克灵+3000mg/L硝酸稀土的混剂喷施番茄幼苗,间隔不同时间接种番茄灰霉病菌,测定其防病效果及番茄叶片内丙二醛含量和多酚氧化酶活性。结果表明:不同处理在喷施后第15天时,对番茄灰霉病的防病效果最为理想,其中1500倍速克灵+3000mg/L硝酸稀土的混剂的效果最好,防效达96.10%,1500倍速克灵、3000mg/L硝酸稀土和2000倍速克灵+3000mg/L硝酸稀土、2500倍速克灵+3000mg/L硝酸稀土、3000倍速克灵+3000mg/L硝酸稀土的混剂次之。喷施1500倍速克灵+3000mg/L硝酸稀土混剂的植株丙二醛含量最低,为30.54(mmol·g),多酚氧化酶活性最高,为73(0.01A/min)。说明稀土与速克灵混合具有良好的抑菌和增抗作用。  相似文献   

4.
本文编制了选择固相吸光光度测定的最佳等吸收波长对的计算程序。以钴-硫氰酸盐-CTMAB-明磁、稀土-硝酸根-三溴偶氮胂两个固相显色体系为例,阐明了选择“波长对”的方法。本法在选择“波长对”方面,比作图法更具优越性。  相似文献   

5.
本文采用火焰原子吸收光谱法测定血清中锌含量。样品经用0.16mol/L硝酸5倍稀释后,直接上机测定。采用黏度与稀释了的血清样相近的锌标准溶液(含10%甘油基质)。本法血清锌检出限为0.03mg/L,取低、中、高三种浓度血清分别进行六次测定,变异系数为1.5%-3.2%,用标准加入法进行回收实验,得回收率为99.0-100.2%,人体血清中存在一定浓度的无机组分不干扰测定。  相似文献   

6.
采用离子色谱法,通过试验确定了优化的色谱条件。硝酸根的检出限为0.01mg/L,方法精密度(RSD)为0.79%,方法的线性范围是1.0~100mg/L,样品的平均加标回收率为96.8%。通过对校正曲线的检验、回收率试验和不同方法的比对确认该分析方法是可靠的。  相似文献   

7.
在HAc-NH4Ac缓冲介质中,乳化剂OP存在下,铝与CAS形成灵敏度很高的绿色络合物,测定波长624nm,ε624=1.09×10^5。碳酸铸中除Fe^3 对测定有干扰外,其它杂质元素均不干扰,方法具有较好的选择性。Fe^3 的干扰采用抗坏血酸还原Fe^3 成Fe^2 消除。0.1mg以下Co量对测定无明显影响,但当Co量大于此量时,络合物吸光度上升,产生正干扰。本法采用在6-8mol/L的盐酸介质中,用乙酸乙酯-苯甲酸萃取微量铝使之与基体钴分离的方法消除基体钴的干扰。对碳酸钴中微量铝测定经与ICP-AES法对照,结果良好。  相似文献   

8.
利用聚乙烯系大孔聚合物与间氨基苯硼酸偶联制备亲和介质,配基密度为每克湿胶0.92mmol。最佳吸附条件为pH9.0和2.0mol/LNaCl;最佳洗脱条件为0.1mol/LHCl。测定了吸附等温线,算得解离常数Kd为0.155mol/L,最大吸附量qm为每克湿胶78.8mg。将含有胸腺嘧啶的5-甲基尿苷溶液进行亲和层析,5-甲基尿苷收率为56.3%。  相似文献   

9.
建立了食用植物油样品皂化后显色-分光光度法测定总黄酮含量的方法。样品在80℃水浴条件下用氢氧化钾-乙醇溶液皂化后直接以亚硝酸钠-硝酸铝溶液显色,选择353 nm波长用分光光度法测定吸光度。以芦丁为标样,用测定过含量的脱色油样制备标准溶液,显色后测定标准曲线。实验显示,测定大豆油样品的日内精密度相对标准偏差(RSD)为0.82%,日间精密度RSD为1.8%。食用油中的抗氧化剂、甾醇、多酚类成分对本法没有干扰。加标回收率99.1%±0.7%。用于实际样品测定市售大豆油样品中总黄酮含量为10.1 mg/L,大豆油样品中总黄酮含量为13.1 mg/L。通过对样品皂化处理,避免了实验过程中的乳化现象,精密度较好且操作简便。可用于植物油中总黄酮的测定。  相似文献   

10.
基于NO3^-在酸性介质中被锌粉还原后,溶液紫外吸收光谱将发生显著变化的原理,建立了测定水中NO3^-浓度的还原-紫外分光光度法,该方法采用的波长为202.0nm,水样的pH值控制为7,以试样还原前后在该条件下的吸光度变化值ΔA对NO3^-溶液的浓度进行标定,还原-紫外分光光度法测定NO3^-浓度的线性范围为0-8.5mg/L,最低检出限为0.02mg/L,且F^-,Cl^-以及HCO3^-等常见离子对温室不产生干扰,地下水,自来水,雪水以及湖水等实际水样的测定结果及加标回收实验结果表明,该方法的相对标准偏差小于2.5%,加标回收率在96.3%-103.1%,相对于标准方法(紫外分光光度法)的偏差为4.0%-4.0%,该方法的精密度,准确度和灵敏度均较高,且操作简便,适用于饮用水以及污染较轻的湖水和地下水中NO3^-含量的测定。  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.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

15.
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   

16.
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   

17.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

18.
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   

19.
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   

20.
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   

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