共查询到20条相似文献,搜索用时 62 毫秒
1.
《广西师范大学学报(自然科学版)》2004,22(4):57-60
在8.0×10-3
mol/L HCl-2.0×10-3 mol/L KI介质中,吖啶橙(AO)在515 nm处有1个同步荧光峰.当有NO-2存在时,NO-2与过量的I-反应生成I-3,I-3与AO形成缔合微粒,在320,560
nm处产生2个共振散射(RS)峰,在470 nm处产生1个同步散射峰.NO-2浓度在0.068~7.36
mg/L范围内与320 nm波长处的共振散射光强度成线性关系.据此建立了一个测定水中NO-2的共振散射光谱分析法.光谱研究结果表明,(AO-I3)n缔合微粒和界面的形成是导致体系RS增强的根本原因. 相似文献
2.
在过量的I-存在的稀盐酸介质中,当有IO3-存在时,IO3-与过量的I-反应生成I3-,I3-与吖啶红、吖啶橙染料均可形成离子缔合微粒。吖啶红、吖啶橙分别在540、480 nm有较强吸收峰,在550、520 nm有较强荧光峰,吖啶红体系在605 nm处产生1个较强的共振散射(RS)峰,IO3-浓度在1.0×10-7~4.0×10-6mol/L与605nm波长处的共振散射光强度成线性关系。吖啶橙体系在560 nm处产生1个较强的共振散射(RS)峰,碘酸根浓度在2.0×10-7~1.2×10-5mol/L与560 nm波长处的共振散射光强度成线性关系。据此建立测定食盐中碘酸根的一种共振散射光谱法。采用此体系测定食盐中碘酸根,结果满意。 相似文献
3.
以银原子团簇 (主 )共振散射峰作为共振散射光谱分布理论研究模型 ,采用密度矩阵法研究液相银原子团簇 (主 )共振散射峰 (7.0 6× 10 1 4 Hz,42 5 nm)和 1/2分频共振散射峰 (1/2× 7.0 6× 10 1 4 Hz,85 0 nm)的频率和强度分布。银原子团簇 (r =12 nm)溶液呈黄色 ,在 415 nm处有 1个吸收峰 ;在 470 nm处产生吸收谷 ,在485 nm处产生吸收峰 ,最大共振散射波长为 42 5 nm (× 10 1 4 Hz)。当 λex=42 5 nm时 ,在 42 5 nm处产生 1个主共振峰 ,在 85 0 nm (1/2× 10 1 4 Hz)处产生 1个 1/2分频共振峰。对于不同浓度的银原子团簇 (0~ 1.0× 10 - 5 mol/LAg) ,两散射峰的半峰宽度之比 (△ λ) 42 5 /(△ λ) 85 0 =2 /3,其散射光强度之比 I42 5 / 4 2 5 /I42 5 / 85 0 ≈ 3/1。在理想条件(真空 )下 ,理论推导出共振散射光中心峰带与两边峰带谱线的强度比为 1/3;中心峰与边峰的高度比为 3:1;边峰宽与中心峰宽之比为 3:2 相似文献
4.
在HCl介质中,AuI-2与阳离子表面活性剂可形成较稳定的缔合微粒,它在560nm产生一个吸收峰,在320,470nm产生2个同步散射峰,在580nm产生1个共振散射峰.在一定条件下,阳离子表面活性剂浓度在0~7.0×10-5mol/L范围内遵循比尔定律,摩尔吸光系数高达1.904×104L·mol-1·cm-1.用于合成样和新洁尔净样品中阳离子表面活性剂的测定,结果满意. 相似文献
5.
《广西师范大学学报(自然科学版)》2004,22(4):61-64
在HCl介质中,AuI-2与阳离子表面活性剂可形成较稳定的缔合微粒,它在560
nm产生一个吸收峰,在320,470 nm产生2个同步散射峰,在580 nm产生1个共振散射峰.在一定条件下,阳离子表面活性剂浓度在0~7.0×10-5
mol/L范围内遵循比尔定律,摩尔吸光系数高达1.904×104 L·mol-1·cm-1.用于合成样和新洁尔净样品中阳离子表面活性剂的测定,结果满意. 相似文献
6.
在乙酸钠-盐酸缓冲液中,ClO2能氧化I-生成I2,过量的I-与I2形成I3-,阳离子表面活性剂(CS)十四烷基二甲基苄基氯化铵(TDMBA)、溴代十四烷基吡啶(TPB)、十六烷基三甲基溴化铵(CTMAB)、四丁基碘化铵(TBAI)等分别能与I3-形成缔合物微粒,分别在320、467、480、530 nm处产生共振散射效应.激光散射法测得(TDMBA-13).缔合物微粒的平均粒径为347 nm.ClO2分别在0.009 92~0.546、0.010 2~1.024、0.026 9~0.538和0.017 8~1.095 mg/L范围内与TDMBA、TPB、CTMAB及TBAI缔合微粒体系在467nm处共振强度成线性关系,各体系的检测限分别为0.005 93、0.006 00、0.019 8和0.064 5 mg/L ClO2.其中TDMBA体系最稳定,且灵敏度较高,用于水中ClO2的测定,结果满意. 相似文献
7.
催化共振散射光谱法测定木瓜蛋白酶活力 总被引:1,自引:1,他引:0
木瓜蛋白酶催化水解酪蛋白生成小分子氨基酸和肽,剩余底物酪蛋白与三氯乙酸结合形成粒径约为1740nm的缔合物微粒。该微粒在360、400、420、470、520nm处产生5个共振散射峰,其中最强峰位于470nm。在选定条件下,随着木瓜蛋白酶量的增加,体系中剩余酪蛋白浓度降低,470nm处的共振散射光强度,Ⅰ470nm降低。木瓜蛋白酶的酶活力在0.024~4.8 USP/mL范围内与470nm处的共振散射光强度降低值△Ⅰ470nm呈现良好线性关系,检出限为0.0083 USP/mL。该共振散射光谱法用于嫩肉粉中木瓜蛋白酶活力测定,结果满意。 相似文献
8.
二氧化锰纳米微粒的制备及其共振瑞利散射光谱研究 总被引:6,自引:0,他引:6
基于KMnO4 与NH3 ·H2 O反应 ,用微波高压液相合成技术制备了粒径为 12 5nm的二氧化锰纳米微粒。二氧化锰纳米微粒的稳定性实验发现 ,微量NaNO3 和TritonX 10 0对二氧化锰纳米微粒的稳定起一定作用 .二氧化锰纳米微粒在 34 2nm处有特征吸收峰 .它的共振瑞利散射峰分别位于 410nm ,470nm ,5 30nm ,共振瑞利散射强度I4 70 与二氧化锰浓度在 2× 10 -7~ 4× 10 -5mol/L范围内呈线性关系 ,相关系数 0 9987.还研究了二氧化锰米微粒的非线性散射现象 . 相似文献
9.
采用分光光度法研究了小檗碱-氯金酸-卤化钾等5个缔合微粒体系.结果表明,4.0×10-2 mol/L HCl-2.8×10-3 mol/L KI-2.4×10-4 mol/L HAuCl4体系的最大吸收峰在370 nm,当有盐酸小檗碱(BH)存在时,由于形成(BH-AuI2)n缔合微粒,在550 nm处有一吸收峰,BH浓度在0.16~24 mg/L范围遵循Lamber-Beer定律,其摩尔吸光系数ε550 nm为1.71×104 L·mol-1·cm-1.据此建立了一个测定中药及其制剂中的盐酸小檗碱含量的分光光度法,平均回收率为100.5%,相对标准偏差RSD为1.00%(n=5). 相似文献
10.
甲基橙-阳离子表面活性剂缔合微粒体系的光谱特性与变色效应 总被引:4,自引:1,他引:3
在pH2.56,4.10和5.72的Britton-Robinson介质中,甲基橙(MO)分别呈红色(λmax=510nm)、橙色(λmax=470nm)和黄色(λmax=460nm).分别加入十六烷基溴化铵(CTAB),甲基橙在510,470和460nm处吸收峰降低,这是由于形成CTAB—MO缔合物分子并可聚集形成(CTAB—MO)。缔合微粒将吸光分子MO包裹所致.(CTAB—MO)。在pH2.56,4.10和5.72的Britton-Robinson介质中,缔合微粒体系分别呈浅红色、橙色和亮黄色,在470和570,370和530,370和540nm处各有2个共振散射峰.当[CTAB]≤[MO]时,该缔合微粒体系分别呈浅红色、橙色和亮黄色;在pH2.56的介质中,当[CTAB]≥2[MO]时;及在pH4.10和5.72Britton-Robinson介质中,[CTAB]≥1.5[MO]时,体系的吸收峰首先紫移到356nm再红移到425nm且逐渐增强,经过一系列颜色变化,最终都变黄绿色.共振散射光谱、扫描电镜、透析和乙醇浓度的影响等实验结果表明,(CTAB—MO)。缔合有机微粒是产生其减色效应和增色效应及共振散射效应的根本原因.[(CTAB—MO)n]nucleus[CTABm]shell有机微粒形成和界面反应导致该微粒体系的变色效应. 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.
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.
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.
Miao Maosheng 《华南师范大学学报(自然科学版)》2014,(6)
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
18.
Yang Weitao 《华南师范大学学报(自然科学版)》2014,46(6):137-138
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
19.
Bernard Kirtman 《华南师范大学学报(自然科学版)》2014,(6)
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
20.
《上海师范大学学报(自然科学版)》2014,(5):550
<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