功能离子液体复配溶液吸收CO_2性能研究

采用酸碱中和一步法制备出四甲基铵甘氨酸([N1111][Gly])功能离子液体,并进行~1H NMR和TGA表征。通过[N_(1111)][Gly]与单乙醇胺(MEA)水溶液复配成混合吸收剂,研究了不同复配浓度、温度、压力对CO_2的吸收性能的影响。结果表明;在MEA溶液中添加[N_(1111)][Gly]功能离子液体可以提高吸收CO_2的速率,在本文采用的5种吸收剂中,0.3mol·L-[N_(1111)][Gly|与0.7 mol·L~(-1)MEA复配形成的吸收剂具有较高的吸收容量和较大的吸收速率。温度升高,混合吸收剂吸收CO_2的速率增加,但平衡时的吸收容量减小。混合吸收剂的CO_2吸收速率和吸收容量均随压力的升高而增加。     

复合胺砜溶液吸收CO_2传质动力学研究

利用湿壁塔法测量复合胺砜溶液吸收CO_2的动力学特性,实验工况包括不同的反应温度(293.15～323.15 K)和不同的溶液浓度(0.5～6.6 mol/L)。本文简化了气液传质模拟,计算了不同工况下的吸收速率常数、总反应速率常数、二级反应速率常数及增强因子等动力学参数,同时根据实验结果拟合得到了二级反应速率常数和增强因子的经验公式,并得到了复合胺砜溶液与CO_2反应的表观反应活化能为为20.38 kJ/mol。     

胺溶液吸收CO_2的量子化学分析

胺溶液吸收燃煤电厂烟气中CO_2是目前减少CO_2排放的有效技术途径。采用真实溶剂似导体屏蔽模型COSMO-RS结合密度泛函理论DFT预测了多种伯胺和仲胺溶液的pK_a值,计算中采用了不同的密度泛函和基组方法,表明在BLYP/TZP方法下得到的pK_a值与已有实验值符合最好。在BLYP/TZP方法下计算了各组分的吉布斯自由能,评估了胺溶液吸收CO_2后溶液中氨基甲酸离子与碳酸氢根离子的比率。此外,通过液相状态下的DFT计算研究了氨甲基丙醇(AMP)溶液吸收CO_2过程中碳酸氢根离子生成的反应机理,结果表明碳酸氢根离子更有可能是由胺、H_2O和CO_2直接反应生成,而不是由氨基甲酸离子水解生成。     

紫外薄层色谱法分离C15H18N4SO2和C13H19N3SO4

采用紫外薄层色谱法在硅胶GF254板上分离N-{2-[(2,2-二氰基-乙烯基)-甲基-氨基]-丙基}-4-甲基-苯磺酰胺(C_(15)H_(18)N_4SO_2)和4-甲基-N-{2-[甲基-(2-硝基-乙烯基)-氨基]-丙基}-苯磺酰胺(C_(13)H_(19)N_3SO_4)二种有机物的方法。硅胶GF254板由0.27mol/L,pH=7的EDTA溶液修饰,避免了这两种样品与板上少量无机金属离子发生络合作用;展开剂为乙酸乙酯-石油醚-乙醇-37.5%氨水(体积比为10∶10∶1∶1)。C_(15)H_(18)N_4SO_2和C_(13)H_(19)N_3SO_4的Rf值分别为0.64和0.48。用紫外薄层色谱法分离C_(15)H_(18)N_4SO_2和C_(13)H_(19)N_3SO_4具有操作简单,灵敏,准确的特点。     

[APMim]Br离子液体溶液水含量对CO_2溶解度影响

1-氨丙基-3-甲基咪唑溴([APMim]]Br)功能型离子液体对CO_2具有良好的选择吸收特性,在二氧化碳吸收工程领域将有较好的应用前景。对于[APMim]Br离子液体水溶液体系,只有当水含量足够大才能有效地实现流体对CO_2的有效吸收,而且在有效吸收区间(水含量大于55%)水含量多少对溶液体系CO_2吸收效率有着非常显著的影响。为此在密闭石英玻璃反应釜内,测定5~75℃,0.1~7.6 MPa范围内,CO_2在水的质量分数w(H_2O)为0.5590、0.6578、0.7680和0.8576的[APMim]Br水溶液中的溶解特性。实验结果表明,低压下化学吸收占主导作用,随水含量增大,溶液体系对CO_2溶解度成倍增加,而且产生的物理吸收效应远大于离子液体本身的化学吸收能力。在水的质量分数在0.65~0.85区间,[APMim]Br水溶液在相当大的温度和压力范围内具有优良的CO_2吸放气特性,显示出良好的工程应用前景。     

N-烯丙基-N''-(氨基对苯磺酸钠)硫脲光度法测定微量银

本文研究了显色剂N-烯丙基-N'-(氨基对苯磺酸钠)硫脲(ASATu)与银的显色反应.在0.3mol/L的氨水溶液中,银(Ⅰ)与ASATu形成稳定的1 1茶色水溶性配合物,最大吸收波长为410nm,表观摩尔吸收系数为4.5×104L@mol-1@cm-1;银的浓度在0-0.6mg/L范围内服从比耳定律.本法具有显色稳定.选择性好,操作简单等优点.可用于阳极泥和地质样品中银的测定,其结果及回收率令人满意.     

复合胺砜溶液同时吸收并分部解吸CO_2/SO_2/NO_x循环实验研究

在同一系统中联合脱除CO_2/SO_2/NO_x并实现溶液的解吸再生,不仅能够减少气体污染物的排放,而且具有系统简单、经济性高等优点。自行设计了同时吸收一分部解吸CO_2/SO_2/NO_x循环实验系统,以N一甲基二乙醇胺和二甲基亚砜配制成的复合胺砜溶液为吸收剂,在不同解吸温度和解吸气液比条件下,考察了富液中各组分的解吸情况,确定了CO_2和NO的最佳解吸条件。在整体循环实验中,考察了系统的可行性和稳定性,并考察不同浓度溶液的吸收、解吸特性。在整体循环实验中,实现了CO_2、SO_2、NO、NO_2的同时吸收和CO_2、NO的分部解吸,各组分的吸收速率逐渐减小,解吸速率逐渐增加,最终吸收一解吸达到平衡,平衡时吸收、解吸速率与吸收液浓度无关。     

N-烯丙基-N′-(氨基对苯磺酸钠)硫脲光度法测定微量银

本文研究了显色剂 N-烯丙基 - N′- (氨基对苯磺酸钠 )硫脲 (ASATu)与银的显色反应。在 0 .3mol/ L的氨水溶液中 ,银 ( )与 ASATu形成稳定的 1∶ 1茶色水溶性配合物 ,最大吸收波长为 4 10 nm,表观摩尔吸收系数为 4 .5× 10 4 L· mol-1· cm-1;银的浓度在 0— 0 .6 mg/ L范围内服从比耳定律。本法具有显色稳定 ,选择性好 ,操作简单等优点。可用于阳极泥和地质样品中银的测定 ,其结果及回收率令人满意。     

一种新的芴类衍生物的三光子吸收诱导荧光和光限幅效应研究

通过对新合成的芴的一种具有对称性衍生物4-2-(7-(4-氨基苯乙烯基)-9，9-二(2-乙基己基)-9H-芴-2-)乙烯基)苯胺(BASF)的DMF溶液的研究，发现其具有很强三光子吸收频率上转换荧光发射特性，实验测出上转换荧光的波长范围是456—775nm，在510nm处的荧光强度与入射光强的三次方成正比.在0.03mol/L的浓度下就有明显的三光子吸收诱导的光限幅效应.非线性吸收系数和吸收截面分别为γ=4.34×10^-20cm³/W²和σ₃＝2.4×10^-39cm⁶/W². 关键词： 三光子吸收 光限幅 上转换荧光 吸收截面     

轴向嘧啶衍生物修饰硅酞菁的光谱性质、光动力抗癌活性及与白蛋白相互作用的研究

研究了一种新型轴向修饰硅酞菁,即二(2-氨基-6-三氟甲基-4-嘧啶氧基)硅酞菁(SiPcF)的光物理光化学性质、离体光动力抗癌活性以及与白蛋白的相互作用。结果表明,SiPcF的Q带最大吸收峰波长686 nm,摩尔吸光系数为2.3×105 mol-1·L ·cm-1,荧光发射峰694 nm,荧光量子产率为0.46,光敏化产生单线态氧的量子产率为0.38,是有效的1O₂光敏剂。SiPcF与牛血清白蛋白(BSA)具有较强的相互作用,两者的结合常数为4.33×105mol·L-1,结合位点数为1。离体细胞实验表明,SiPcF具有较高的光动力抗癌活性,对人肝癌细胞HepG2的IC₅₀值为5×10-7mol·L-1。     

Guided-Wave Two-Dimensional Acousto-Optic Scanner Using Proton-Exchanged Lithium Niobate Waveguide

Two-dimensional scanning of a 0.6328 mum guided-light beam has been realized using noncolinear acousto-optic (AO) coplanar Bragg diffraction together with colinear AO guided-mode to substrate radiation-mode conversion in a Z-cut Xpropagation LiNbO3 proton-exchanged (PE) waveguide. The two surface acoustic (SAW) waves utilized are at the center frequencies of 500 and 200 MHz, propagating in the Y and X axes, respectively. Two-dimensional scanning of approximately 720 resolvable light beam spots, namely, 18 40 (horizontal vertical) scanning, has been demonstrated using a light beam of 1.0 mm aperture. The total number of resolvable beam spots can be greatly increased from 720 by simply utilizing SAW transducers of larger bandwidth and a light beam of greater aperture. It should also be possible to significantly increase the diffraction efficiency from 3 % by optimizing the parameters of the PE waveguide and the SAWs.     

Effect ofγ-radiation on the spectral luminescence characteristics of impure cadmium tungstate crystals

Results of a study of the effect of γ-radiation on the spectral luminescence properties of cadmium tungstate crystals doped with silver, bismuth, and molybdenum cations are presented. Spectral characteristics of the nondnnnoped crystals are briefly described. Absorption and photo and X-ray luminescence spectra of the crystals taken before and after exposure to γ-radiation (5.5·10⁴ Gy) are compared. It is found that the spectral characteristics of the crystals doped with silver, bismuth, and molybdenum cations do not change markedly after the exposure. The relation between the type of impurity-induced defects, individual characteristics of the impurity cations, and the character of the effect of γ-radiation on the spectral luminescence properties of impure crystals is analyzed (preliminarily). Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 1, pp. 55–60, January–February, 1997.     

Femtosecond Transform-Limited Pulse Generation by Compensating for the Linear Chirp of SPM Spectra in Dispersion Shifted Fibers

A simple technique of pulse compression, based on the linear chirp compensation of self-phase modulation (SPM) spectra in dispersion shifted fibers, is demonstrated. The optimization procedure is carried out, for a short span of a single-mode fiber, using a parabolic law, which describes the behavior of the squared output pulse width versus the pump peak power in the case of Gaussian pulses. The experimental results give a minimum pulse duration of 233 fs, which is in good agreement with the model. Shorter and coherent pulses, down to 90 fs, have been obtained by inserting an interference filter at the optical output.     

Theoretical analysis and simulation of conjugate heights for dual-conjugate AO system in lidar

A multi-conjugate adaptive optics （MCAO） can offer a possibility of widening field of view （FOV） characterized by the isoplanatic angle, and the choose of conjugate height becomes a basic problem for MCAO, which influences the size of iosplanatic angle. Considering the application of lidar, the isoplanatic angle＇s expressions of two deformable mirrors （DMs） MCAO for uplink and downlink are deduced. The effects of conjugate heights for dual-conjugate AO are thoughtfully discussed, and the isoplanatic angles are further analyzed. The results show that the isopanatic angle varies with the conjugate height and reaches the maximum as the conjugate height is at the optimal altitude. Moreover, the optimal conjugate height changes with the propagation distance.     

Quick single-photon detector with many avalanche photo diodes working on the time division

Due to the limit of response speed of the present single-photon detector, the code rate is still too low to come into practical use for the present quantum key distribution (QKD) system.A new idea is put up to design a quick single-photon detector.This quick single-photon detector is composed of a multi-port optic-fiber splitter and many avalanche photo diodes (APDs).Au of the ports with APDs work on the time division and cooperate with a logic discriminating and deciding unit driven by the clock signal.The operation frequency lies on the number N of ports, and can reach N times of the conventional single-photon detector.The single-photon prompt detection can come true for high repetition-rate pulses.The applying of this detector will largely raise the code rate of the QKD, and boost the commercial use.     

Sorting of bending magnets for the SSRF booster

The Shanghai Synchrotron Radiation Facility(SSRF)booster ring,a full energy injector for the storage ring,is deigned to accelerate the electron beam energy from 150MeV to 3.5GeV that demands high extraction efficiency at the extraction energy with low beam loss rate when electrons are ramping.Closed orbit distortion(COD)caused by bending magnet field uniformity errors which affects the machine performance harmfully could be effectively reduced by bending magnet location sorting.Considering the affections of random errors in measurement,both ideal sorting and realistic sorting are studied based on measured bending magnet field uniformity errors and one reasonable combination of bending magnets which can reduce the horizontal COD by a factor of 5is given as the final installation sequence of the booster bending magnets in this paper.     

Improvement of four-wave mixing-based wavelength conversion efficiency in dispersion shifted fiber by 40-GHz clock pumping

40-GHz clock modulated signal as a pump to improve the efficiency of four-wave mixing (FWM)-based wavelength conversion in a 26.5-km dispersion shifted fiber (DSF) is investigated. The experimental results demonstrate that the conjugated FWM component has higher intensity with the clock pumping than that with the continuous-wave (CW) light pumping. The improvement of FWM-based wavelength conversion efficiency is negligible when the pump power is less than Brillouin threshold. But when the pump power is greater than Brillouin threshold, the improvement becomes significant and increases with the increment of pump power. The improvement can increase up to 9 dB if pump power reaches 17 dBm.     

Characterization of PolyA and PolyC mismatches by Raman spectroscopy

A.C mismatches are studied by Raman spectral characterization of PolyA, PolyC, and their equimolar complex in solution of 0.14 mol/L Na ,pH7.0.Experimental results show that A·C mismatches occur to be A/B (mainly A) conformers, and unlike Watson-Crick base pairing, this kind of mismatches is stabilized by only one hydrogen bond involving cytosine N4H2 and adenine N7.The formation of A·C complex makes the base stacking interactions much stronger, and conformation of the backbone more ordered, which leads to obvious Raman hypochromic effect with some shifts in corresponding bands.