975 resultados para Rb-
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This work initiated the development of operating envelopes for stabilised/solidified contaminated soils. The operating envelopes define the range of operating variables for acceptable performance of the treated soils. The study employed a soil spiked with 3,000 mg/kg each of Cd, Cu, Pb, Ni and Zn, and 10,000 mg/kg of diesel. The binders used for treatment involved Portland cement (CEMI), pulverised fuel ash (PFA), ground granulated blast furnace slag (GGBS) and hydrated lime (hlime). The specific binder formulations were CEMI, CEMI/PFA = 1:4, CEMI/GGBS = 1:9 and hlime/GGBS = 1:4. The water contents employed ranged from 13 % to 21 % (dry weight), while binder dosages ranged from 5 % to 20 % (w/w). We monitored the stabilised/solidified soils for up to 84 days using different performance tests. The tests include unconfined compressive strength (UCS), hydraulic conductivity, acid neutralisation capacity (ANC) and pH-dependent leachability of contaminants. The water content range resulted in adequate workability of the mixes but had no significant effect on leachability of contaminants. We produced design charts, representing operating envelopes, from the results generated. The charts establish relationships between water content, binder dosage and UCS; and binder dosage, leachant pH and leachability of contaminants. The work also highlights the strengths and weaknesses of the different binder formulations. © 2013 Springer-Verlag Berlin Heidelberg.
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A new Enzyme ImmunoAssay (EIA) for PCDD/F TEQ measurement in extracts of environmental samples was described. The bioassay TEQ which derived from EIA and EROD were compared with each other and with results from chemical analysis. For all environmental samples, the EROD-TEQ is higher than the value from chemical analysis. However, the EIA-TEQ is much more identical with the value from chemical analysis. Our results indicate that the EIA assay is a complementary method to the EROD assay and should be useful as a rapid and sensitive screening tool for environmental samples in many situations. (C) 1999 Elsevier Science Ltd. All rights reserved
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We demonstrate in theory that it is possible to all-electrically manipulate the RKKY interaction in a quasi-one-dimensional electron gas embedded in a semiconductor heterostructure, in the presence of Rashba and Dresselhaus spin-orbit interaction. In an undoped semiconductor quantum wire where intermediate excitations are gapped, the interaction becomes the short-ranged Bloembergen-Rowland superexchange interaction. Owing to the interplay of different types of spin-orbit interaction, the interaction can be controlled to realize various spin models, e.g., isotropic and anisotropic Heisenberg-like models, Ising-like models with additional Dzyaloshinsky-Moriya terms, by tuning the external electric field and designing the crystallographic directions. Such controllable interaction forms a basis for quantum computing with localized spins and quantum matters in spin lattices.
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Self-assembled InAs quantum dots were prepared on GaAS(100)) substrate in a solid source molecular beam epitaxy system The distribution and topographic images of uncapped dots were studied by atomic force microscope. The statistical result shows that the quantum dots are bimodal distribution. The photoluminescence spectrum results shows that the intensity of small size quantum dots dominated, which may be due to: (1) the state density of large quantum dots lower than that of small quantum dots; (2) the carriers capture rate of large size quantum dots is small relative to that of small ones; (3) there is a large strain barrier between large quantum dots and capping layer, and the large strain is likely to produce the defect and dislocation, resulting in a probability carriers transferring from large quantum dots to small dots that is very small with temperature increasing.
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We obtained the high mobility Of mu(2K) = 1.78 x 10(6) cm(2)/V . s in Si-doped GaAs/AlGaAs two-dimensional electron gas (2DEG) structures. After the sample was illuminated by a light-emitting diode in magnetic fields up to 6 T at T = 2K, we did observe the persistent photoconductivity effect and the electron density increased obviously. The electronic properties of 2DEG have been studied by Quantum-Hall-effect and Shubnikov-de Haas (SdH) oscillation measurements. We found that the electron concentrations of two subbands increase simultaneity with the increasing total electron concentration, and the electron mobility also increases obviously after being illuminated. At the same time, we also found that the electronic quantum lifetime becomes shorter, and a theoretical explunation is given through the widths of integral quantum Hall plateaus.
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We report on a detailed investigation on the temperature-dependent behavior of photoluminescence from molecular beam epitaxy (MBE)-grown chlorine-doped ZnSe epilayers. The overwhelming neutral donor bound exciton ((ClX)-X-0) emission at 2.797 eV near the band edge with a full-width at half-maximum (FWHM) of similar to 13 meV reveals the high crystalline quality of the samples used. In our experiments, the quick quenching of the (ClX)-X-0 line above 200 K is mainly due to the presence of a nonradiative center with a thermal activation energy of similar to 90 meV, The same activation energy and similar quenching tendency of the (ClX)-X-0 line and the I-3 line at 2.713 eV indicate that they originate from the same physical mechanism. We demonstrate for the first time that the dominant decrease of the integrated intensity of the I, line is due to the thermal excitation of the "I-3 center"-bound excitons to its free exciton states, leaving the "I-3 centers" as efficient nonradiative centers. The optical performance of ZnSe materials is expected to be greatly improved if the density of the "I-3 center" can be controlled. The decrease in the luminescence intensity at moderately low temperature (30-200 K) of the (ClX)-X-0 line is due to the thermal activation of neutral-donor-bound excitons ((ClX)-X-0) to free excitons. (C) 2000 Published by Elsevier Science B.V.
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A novel AC driving configuration is proposed for biased semiconductor superlattices, in which the THz driving is provided by an intense bichromatic cw laser in the visible light range. The frequency difference between two components of the laser is resonant with the Bloch oscillation. Thus, multi-photon processes mediated by the conduction (valence) band states lead to dynamical delocalization and localization of the valence (conduction) electrons, and to the formation and collapse of quasi-minibands. Thus, driven Bloch oscillators are predicted to generate persistent THz emission and harmonics of the dipole field, which are tolerant of the exciton and the relaxation effects.
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Within the one-dimensional tight-binding model;rnd chi-3 approximation, we have calculated four-wave-mixing (FWM) signals for a semiconductor superlattice in the presence of both static and high-frequency electric fields. When the exciton effect is negligible, the time-periodic field dynamically delocalizes the otherwise localized Wannier-Stark states, and accordingly quasienergy band structures are formed, and manifest in the FWM spectra as a series of equally separated continua. The width of each continuum is proportional to the joint width of the valence and conduction minibands and is independent of the Wannier-Stark index. The realistic homogeneous broadening blurs the continua into broad peaks, whose line shapes, far from the Lorentzian, vary with the delay time in the FWM spectra. The swinging range of the peaks is just the quasienergy bandwidth. The dynamical delocalization (DDL) also induces significant FWM signals well beyond the excitation energy window. When the Coulomb interaction is taken into account, the unequal spacing between the excitonic Wannier-Stark levels weakens the DDL effect, and the FWM spectrum is transformed into groups of discrete lines. Strikingly, the groups are evenly spaced by the ac field frequency, reflecting the characteristic of the quasienergy states. The homogeneous broadening again smears out the line structures, leading to the excitonic FWM spectra quite similar to those without the exciton effect. However, all these features predicted by the dynamical theory do not appear in a recent experiment [Phys. Rev. Lett. 79, 301 (1997)], in which, by using the static approximation the observed Wannier-Stark ladder with delay-time-dependent spacing in the FWM spectra is attributed to a temporally periodic dipole field, produced by the Bloch oscillation of electrons in real space. The contradiction between the dynamical theory and the experiments is discussed. In addition, our calculation indicates that the dynamical localization coherently enhances the time-integrated FWM signals. The feasibility of using such a technique to study the dynamical localization phenomena is shown. [S0163-1829(99)10607-6].
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The photoluminescence (PL) properties of nitrogen-doped ZnSe epilayers grown on semi-insulating GaAs(100) substrates by MBE using a rf-plasma source for N doping were investigated. The PL peak which can be related to N acceptor was observed in the PL spectra of ZnSe:N smaples. At 10K, as the excitation power density increases, the energy of donor-acceptor pair(DAP) emission shows a blue-shift and its intensity tends to saturate. As the temperature increases over a range from 10K to 300K, the relative PL intensity of donor bound exciton to that of the acceptor bound exciton increases due to the transfer between two bound excitons.
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本文内容包括Tb~(3+)、Pr~(3+)、Ce~(3+)的光氧化。研究了各种因素对氧化率或四价离子生成量的影响。在Tb~(3+)光氧化的基础上,建立了混合钇族稀土中Tb的光化学分析法及混合稀土中Tb的化学氧化分析方法。Tb~(3+)、Pr~(3+)的光氧化是开创性的工作,Tb的分析方法具有一定的应用价值。1 Ce~(3+)d HZO_3-HClO_4体系中的光氧化 用低压汞灯(254nm)、高压汞灯(366nm)和氩离子激光器(351/364nm, 458 nm, 477nm, 502 nm, 514, nm)光辐照Ce~(3+)-HZO_3-HClO_4溶液,Ce~(3+)发生光氧化反应,生成Ce(ZO_3)_4沉淀 。在低压汞灯254 nm波段可获得较高的氧化率,具它波段下的氧化率低,以低压汞灯为光源辐照。研究了温度、光强、酸度、Ce~(3+)初始浓度及辐照时间对氧化率的影响。降低酸度,选择较高的温度和较大的光强,有利于Ce~(3+)的光氧化。2 Tb~(3+)在KIO_4-KOH体系中的光氧化 用高压汞灯(366nm)光辐照Tb~(3+)-KIO_4-KOH溶液,首次实现了Tb~(3+)的光氧化。研究了碱度、络合剂浓度,Tb~(3+)初始浓度、辐照面积,光强和辐照时间等因素对Tb~(4+)生成的影响。测定了Tb(IV)/Rb(III)的氧化还原电势。适宜的KOH浓度应大于0.3M,KIO_4的浓度要比Tb~(3+)初始浓度大几个数量级。当KOH=0.6M, KIO_4=0.22M, 温度为13 ℃时。E_(Tb(IV)/Tb(III))=0.68优,生成的Tb~(4+)可溶性络离子为红棕色,最大吸收峰在420nm附近,比较稳定。3 用光氧化法分析钇族混合稀土中的Tb 根据Tb~(3+)在KIO_4-KOH体系中的光氧化反应,建立了钇族混合稀土中Tb的分光光度分析方法。在高压汞灯366nm的光辐照不无色的Tb~(3+)转变为红棕色的Tb~(4+),其谱带的吸收峰值在420nm,其它三价钇族稀土无此反应,故无千扰,在Tb的分析浓度范围为1*10~(-5)M - 1*10~(-3)M时,符合Beer定律,Tb在钇族混合稀土中含量的分析最低限为0.2%。此方法可用于萃取钇族稀土过程中Tb的分析,方法简便快速。4 用化学氧化法分析混合稀土中的Tb 根据Tb~(3+)在KIO_4-KOH-K_2S_2O_8体系中的氧化反应,建立了混和稀土中Tb的分光光度分析方法。Tb~(3+)-KzO_4-KOH-K_2S_2O_8溶液加热,Tb~(3+)被氧化的Tb~(4+),其颜色由无色转变为红棕色,最大吸收峰在420nm。Ce~(3+)加入KIO_4-KOH溶液后,立即被完全氧化为Ce~(4+), Ce~(4+)在420nm也有吸收,其干扰可以在本底中排除,其它三价稀土离子在此体系中不能发生氧化反应,故无干扰。在Tb的分析浓度范围为5*10~(-5)-5*10~(-4)M时,符合Beer定律,Tb在混合稀土中含量分析的最低限为1%。此方法可用于萃取稀土过程中Tb的分析和监控,方法简便快速。5 Pr~(3+)在KZO_4-KOH体系中的光氧化用高压汞灯光辐照Pr~(3+)-KZO_4-KOH溶液,首次实现了Pr~(3+)的光氧化。生成的Pr~(4+)为棕褐色,最大吸收峰在400nm附近,稳定性较差,在水溶液中发生自还原反应。按Pr~(4+)在400nm的吸收峰值,研究了辐照时间,Pr~(3+)初始浓度,KOH浓度、KZO_4浓度及Ce~(4+)共存时对Pr~9(4+)生成的影响。相应增加KOH及KZO_4用量,有利于Pr~(4+)的生成,Ce~(4+)对Pr~(3+)的光氧化无所谓的“带同氧化作用”。
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稀土离子的敏化发光早在1942年就被Weissiman发现了,后来,人们对这一现象作了大量的研究工作,并且,开始用于稀土离子的测试。高灵敏度和好的选择性一直是分析工作者追求的真正目的。为此,很长时间以来,人们从化学体系上入手,不断地在配体种类;配体条件;溶剂作用;第二配体影响;胶束;表面活性剂等方面入手,来寻找可获得高的灵敏度和好的选择性的测试体系,并取得了一定的成绩,但还远远满足不了分析工作者的要求。近年来,随着仪器设备的不断改进,人们想到,能否通过新的仪器的出现来改善分析测试的灵敏度和选择性。时间分辨光谱法就是在这种条件下产生的,并且,初步的实验就得到了令人十分满意的结果。时间分辨光谱法顾名思义是以时间做为分辨量的一种方法,是一种多维萤光技术,它采用脉冲激光做为光源和门控检测系统相结合,因此,不但获得了高子常规法的灵敏度,而且还解决了光谱峰有干扰的发光组分的测定,提高了选择性。为了有效地应用时间分辨光谱法即获得更高的灵敏度和更好的选择性,时间分辨光支要求:①待测定的物质必须有较强的发光,这是提高灵敏度的前提:②待测定的物质的寿命必须合适(如测单组分时是通过延迟消除噪声,则被测组分的寿命至少要比噪音信号长;若是二组分的分辨光谱法测定,就要求二组分间寿命差要尽可能大),这样才可能效分辨;③适合彼此间有光谱干扰的多组分中单一组分的测定,这是时间分辨光谱法优于常远见二维光法的最为突出的一点。Eu-TTA_3和SmTTA_3是较合适时间分辨测定体系。Eu_TTA_3和S_m-TTA_3 二元络合物不但有较强的萤光,而且寿命差较大,EuTTA_39寿命400微秒)。SmTTA_3(寿命21微秒),并且Eu和Sm间有光谱干扰,因此在混合体系下,时间分辨光谱法测定Eu和Sm才充分显示了伏越性。为此,为了研究稀土元素的时间分辨光谱测定,本论文分三部分完成。第一部分:几种稀土离子萤光络合物体系的选择通过对Eu~(3+)、Tb~(3+)、Dy~(3+)络合体系最强发光的条件实验,期望找到一系列既有较强的发光,元素间又存在着光谱干扰。而常规法又难以测试的络合物体系。为此,在现有条件下,做了TTA、DBM、Phen、AAE、Sal五种配体Eu~(3+)、Sm~(3+)、Tb~(3+)、Py~(3+)四种稀土离子所有可能的络合物组成的发光条件试验,主要为配体浓度和PH值的影响。确定了不同络合物的最佳组成条件。并且考虑到苯的毒性和萃取的繁琐性。选用乙醇做为溶剂。最后得到TTA、DBM是Eu、Sm较好的络合剂,而且它们与Phen的三元络合物也具有强的发光。Sml:是Tb和Dy的较好络合剂,并且它们与Phen形成三元络合物也具有较强的萤光,AAE、Phen是选择性最差的络合剂,它们与Tb、Eu、Sm、Dy都能形成有一定发光强度的络合剂Eu和Sm以及Tb和Dy之间是无论配体息样变化都有光谱干扰的两对元素。第二部分;发光络合物的萤光寿命的测试:除了要求从化学体系入手,得到具有较强的发光络合物之外,时间分辨光谱法还要求;待分辩的物质间有较大的寿命差异。寿命τ是进行时间分辨光谱法的理论基础。为此,在本室和11室自己安装的仪器上做了已讨论的最佳条件下合成的络合物萤光寿命的测试,并给出了许多络合物的寿命数据。同时还讨论了配体种类,稀土离子浓度,对寿命大小的影响,得出不同的稀土离子络合物寿命差异很大,即使是相同的稀土离子,配体不同,寿命也是不同的,一般而言,Eu,Tb寿命较长,达几百微秒,Dy、Sm寿命较短,一般仅为几微秒或几十微秒,并总有寿命Tb > Eu > Sm > Dy。为了讨论稀土离子浓度对寿命的影响。选Eu. Sm-TTA和Tb. Dy-Sal-乙醇溶液为例,进行了浓度影响实验,得到浓度粹灭的同时,不仅萤光强度减弱,而且寿命缩短,最后总结出: Eu. Sm-TTA(Phen)二元(或三元)络合物和Tb. Dy-Sal(Phen)二元(或三元)络合物彼此间寿命差最大。第三部分:时间分辨光谱法研究在前二部分准备工作完成后,基本上就确定了可供时间分辩的最佳体系,即Eu. Sm-TTA二元络合物(或它与Phen形成的三元络合物)和Tb、Dy-Sal二元络合物(或与Phen形成的三元络合物)-乙醇体系。关于Eu.Sm-TTA体系的时间分辨光谱法测定,已有过研究并得到了十分满意的结果,因此,本论文选不曾有过报导的Tb、Dy-Sal 乙醇体系为时间分辨光谱法研究的对象。首先在本室和11室自建的时间分辨光谱仪上进行了仪器测量参数的选择,然后,对Tb、Dy-sal的时间分辨光谱法给以原理性的讨论,得到在延迟大于30微秒后,可消除Dy对Tb测定的干扰的结果,之后,又作了当延迟大于100微秒的条件下的时间分辩光谱法在Dy存在下测定Rb[Sal]_3的检测限的探索,并与MPF-4型萤光分光光度计的测试结果做了比较,得到了可高于常规法三个数量级的灵敏度的初步结果。本论文建立了寿命测量和激光时间分辨的实验装置,并且完成了原理性实验,在选择体系测定寿命和利用时间分辨排除稀土离子干扰方面得到了较好的初步结果,积累了大量数据完成了本论文目的要求。
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本工作研究了X荧光光谱进行痕量元素分析,谱线重迭干扰校正及基体效应的校正方法,共分六个部分。一.X荧光光谱滤纸片法分析痕量稀土元素。为了降低XRF滤纸片法的检出限,分析痕量稀土,我们对XRF的制样方法,标准工作曲线的制作,谱线干扰校正,背景扣除等进行研究,将滤纸片法应用到分析痕量稀土,方法准确可靠、快速、简便,测定精度优于1%,检出限为0.X-X微克,特别适合萃取分离流程中低含量稀土的测定。二.XRF中谱线重迭干扰的校正方法。在J. L. Brandle 假定合成峰的强度是各了成份的线性迭加的基础上,引入非零截距,提出了用线性规划法校正稀土元素谱线重迭的方法,其中R_i为第i个元素衍射角(20)处测量的谱线强度,C_i为浓度,K_(ij)为衍射角处的特性常数。通过实验求出K_(ij),然后求出在[1]式约束条件下,使目标函数E = Σ from i=1 to n|Σ from j=1 to n of (k_(ij)(j+b_i)-R_i|(i,j=1,…n)为最小的C_i值。为了证明方法的有效性,实验中选用了干扰较大的分析线。本文对Eu Lβ, (56.96°)和Dy Lα_1 (56.58°);Ho Lβ_1, (48.28°),和Lu Lα, (47.40°);Ho Lα, (54.52°)和Gd Lβ_1, (54.56°)的谱峰重迭进行校正,取得满意结果。三.XRF测定土壤中痕量铬钒时谱线干扰校正方法:在研究了薄样中稀土元素谱线重迭问题的同时,还研究了土壤直接压片时,Cr的K_α线(69.35°)和V的K_β线(69.12°)的谱线重迭问题。由于Cr的K_α线和V的K_β均处于铁的K系吸收限的长波侧,铁的基体效应是不可忽略的。同时,由于谱线的相互重迭,使得元素间不存在简单的线性关系,本文提出一种新的数模来校正Cr和V的谱线干扰及Fe的基体效应:C_i = K_0 + K_1R_1 + K_2R_2 + K_3R_3 + K_4R_1~2 + K_5R_1R_2 + K_6R_1R_3 + K_7R_2~2 + K_8R_1R_3 + K_9R_3~2 其中C_i(i = 1,2)分别为Cr, V 的浓度,单位为ppm;R_i(i = 1,2,3)分别为Cr、V和Fe的峰/背比值,K_i(i = 0,…,9)为参数。通过几种常用校正模型的比较表明,本文所提模型的剩余标准差最小。说明由于该模型同时考虑了基体的影响及谱线重迭而产生的非线性影响因素,用交叉项表示非线性项,对谱线重迭及基体效应的校正是有效的。四.土壤中常量元素的XRF测定:在XRF中,选择影响元素,解决元素间的基体效应是极其重要的问题。一般采用Plesch判据来选择影响元素,但该法需要知道主要基体和干扰元素对分析元素的质量吸收系数及干扰元素含量变化范围。本文采用逐步回归方法,对共存元素进行筛选,根据每个共存元素对分析元素的方差贡献大小选择影响元素,并以散射内标与经验系数相结合校正基体效应的影响。同时,对几种常用的经验校正模型进行比较。利用最小剩余标准作为判据。结果表明,几种常用的数模没有明显差别,当分析范围比较窄时,强度模型较好,当分析范围宽时,浓度模略优。同时用微型计算机,以基本参数法和若干标样,直接与X荧光谱仪进行联机分析,显示了基本参数法和经验系数法相结合解决实际问题的优越性。五.土壤中十三种痕量元素的XRF测定:用逐步回归方法选择基体元素,以散射内标和强度校正模型分析了土壤中十三种痕量元素。六.土壤中Cu、Zn、Rb、y的XRF测定:以相干/非相干散射之比为内标分析了Cu、Zn、Rb和y, 并考察了基体的影响,对参考标样的分析结果表明,结果满意。
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本论文由六部分组成第一部分文献综述,对近年来碱性染料-元素杂多酸显色反应的研究及其应用的进展情况作了介绍。第二部分研究了乙基罗丹明B与硅钼杂多酸 PVA存在下的显色条件,缔合物的最大吸收波长为584nm,在测量波长586nm处,ε_(586) = 3.4 * 10~5lmol·cm~(-1), 缔合物至少可稳定1小时,0~1.3μg Si(IV)/25ml Beer定律,只有P(V)、A(s)、Ge(IV)等离子干扰严重,可采用酒石酸掩蔽之。从而提出了测定硅的高灵敏光度法。本法可不经分离直接用于水样及NaOH、NH_4G、NH_4NO_3等试剂分析,检测下限分别为10ppb(水样,5ml) 1 * 10~(-5)%(试剂,1g)。第三部分研究了乙基罗丹明B-磷钼杂多酸-PVA新的显色体系的光度测定条件,缔合物的最大吸收波长为584nm,在工作波长586nm下,ε_(586) = 3.2 * 10~5l·mol~(-1)·cm~(-1),配合物至少可稳定1小时,0~1.5μgP(V)/25ml服从Beer定律。藉提高酸度和还原剂以消除Si(IV)、As(V)等离子的干扰。本法可不经分离直接用于钢样及硫酸钠、硫酸镁试剂中痕量磷的测定,检测下限达1 * 10~(-5)%(试剂1g)。第四部分研究了乙基罗丹明B-锗钼杂多酸在PVA存在下的显色条件,缔合物最大吸收波长为584nm,在测量波长588nm下,缔合物的表观摩尔吸光系数ε_(588) = 3.8 * 10~5l·mol~(-1)·cm~(-1),0~1.5μg Ge(IV)/25ml服从Beer定律,缔合物至少可稳定2小时,仅P(V)、As(V)、 Si(IV)等离子严重干扰。第五部分研究了缔合物的形成机理。我们用摩尔比法,等摩尔连续变化法及摩尔吸光系数对比法分别研究呈溶液或结晶状的缔合物组成比,所得结果一致,即Si(或 P、Ge):ERB=1:4。由红外光谱的研究证明,染料ERB~+的结构未受缔合物形成的影响。ERB~+阳离子与杂多酸阴离子是藉离子链力结合成离子对缔合物,并讨论了本类显色反应的历程。第六部分是罗丹明类碱性染料中取代基对缔合的稳定性及萃取率的影响的研究。对用苯萃取罗丹明类碱性染料-高氯酸缔合物体系,进行了吸收光谱、酸度影响、表现摩尔吸光系数、萃取率和萃取平衡常数的测定实验,各种缔合物的最大吸收波长分别为:BRB, 567nm; ERB, 567nm; R6G, 536nm; RB, 563nm。表观摩尔吸光系数分别为(l·mol~(-1)·cm~(-1):BRB, 9.86 * 10~4; ERB, 8.82*10~4;R6G, 4·0.3 * 10~4。萃取率分别为:BRB, 91.9%, ERB, 79.2%; R6G, 45.7%。萃取平衡常数分别为:BRB, 1.32 * 10~4; ERB, 1.14 * 10~3; R6G, 6.06 * 10~2。并用平衡移动法测定缔合物组成均为1:1。根据上述实验结果,从离子体积、憎水和亲水基、取代基的酸碱性及染料阳离子的正电性等四个方面对染料分子上不同取代基对缔合物稳定性、可萃性和溶解度影响进行了讨论,得到了一些规律性的认识:随着取代基体积增大、憎水基的引入和加重、碱性减弱、染料阳离子正电性的增加,均能使形成缔合物的稳定性和可萃性增加,其增加顺序为BRB > ERB > R6G > RB。
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本工作合成了MF_2:Eu~(2+)(M = Mg、Ca、Sr、Ba); AlF_3:Eu~(2+); Ax:Eu~(2+) (A = Na、k; x = Cl. Br); A_2BeF_4:Eu~(2+) (A = Na、k); ABF_4:Eu~(2+)、A_2SiF_6:Eu~(2+) (A = Na、k、Rb、Cs); NasAl_3F_(14):Eu~(2+)、Na_3AlF_6:Eu~(2+)、K_2MgF_4:Eu~(2+); Al_2O_3:Eu~(2+)、BeAl_2O_4:Eu~(2+)化合物。测定了所含成化合物的晶体结构、荧光光谱、光电子能谱。第一次在AlF_3:Eu~(2+)、 Al_2O_3:Eu~(2+)、BeAl_2O_4:Eu~(2+)中观察到Eu~(2+)的f→f跃迁发射。据我们所知,在单一氧氟化物、单一氧化物中观察到Eu~(2+)的f→f跃迁发射,还是首次。第一次在强晶场、低配位数体系(如:NaBF_4A:Eu~(2+)、Na_2SiFe_6:Eu~(2+)、Na_2BeF_4:Eu~(2+)-K_2BeF_4:Eu~(2+)、Na_5Al_3F_(14):Eu~(2+))中观察到了Eu~(2+)的f→f跃迁发射。这与Blasse、Fouassier 的观点是不相符的。讨论了Eu~(2+)在所合成化合物中的价态稳定性。Eu~(2+)在所合成化合物中价态是稳定的,从光电子能谱看出尾有少量Eu~(2+)与Eu~(2+)光存。研究了Eu~(2+)的光谱结构与其所处晶场环境、化学键性质的关系。Eu~(2+)的光谱结构由晶场:化学键性质所产生的影响的共同结果来决定。晶场强度是键长的函数,Eu-L化学键的性质除同L有关外,还与邻近的Eu~(2+)的阳离子有关,邻近Eu~(2+)阳离子电负性的大小对Eu-键的共价作用产生很大的影响。采用Sanderson电负性标度计算了 Eu在 MF_2:Eu~(2+)(M = Mg、Ca、Sr、Br)。AlF_3:Eu~(2+)中所带分电荷,以及Eu-F键的离子性、共价成份。
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本论文“痕量生命活性之素高灵敏分光光度法的研究”,包括五部分内容:一、文献综述 二、钼(VI)-硫氰酸盐-乙基罗丹明B体系。本工作首次在钼的碱性染料光度法中仅引入Cu~(2+)离子作催化剂以促进硫氰酸盐还原Mo(VI)为Mo(VI),研究了钼(VI)-硫氰酸盐-乙基罗丹明B体系的光特征。三、钼(VI)-硫氰酸盐-罗丹明B体系。四、钼超高灵敏显色反应机理探讨。本工作通过吸收光谱研究及 合物组成比的测定,对显色反应的机理作了初步探讨。五、锌-硫氰酸盐-罗丹明B体系。锌是重要的生命活性之素之一,对人的生长发育起着重要的作用。目前尚缺少高灵敏 度的光度测锌方法。本工作研究了Zn~(2+)-SCN~--RB体系和光度特性。