Photophysical properties of borondipyrromethene analogues in solution

The photophysical properties of seven new 8-(p-substituted)phenyl analogues of 4,4-difluoro-3,5-dimethyl-8-(aryl)-4-bora-3a,4a-diaza-s-indacene (derivatives of the well-known fluorophore BODIPY) in several solvents have been studied by means of absorption and steady-state and time-resolved fluorimetry. For each compound, the fluorescence quantum yield and lifetime are lower in solvents with higher polarity owing to an increase in the rate of nonradiative deactivation. Increasing the electron withdrawing strength of the p-substituent on the phenyl group in position 8 also leads to lower fluorescence quantum yields and lifetimes. When the p-substituent on the phenyl group in position 8 is a tertiary amine [8-(4-piperidinophenyl), 8-(4-N,N-dimethylaminophenyl), and 8-(4-morpholinophenyl)], the low quantum yields of these compounds in more polar solvents can be rationalized by the inversion of the energy levels of an apolar, highly fluorescent and a polar, nonfluorescent excited state, where charge transfer from the tertiary amine to the BODIPY unit occurs. These amine analogues can be protonated at low pH in aqueous solution. Fluorescence titrations yielded pK(a) values of their conjugate ammonium salts which are in agreement with the electron donating tendency of the amine group: piperidino (4.15) > dimethylamino (2.37) > morpholino (1.47), with the pK(a) values in parentheses. The rate constant of radiative deactivation (k(f)) is the same for all compounds in all solvents studied (k(f) = 1.4 x 10(8) s(-1)).     

Synthesis of multi-hydroxyl and sulfonyl dual-functionalized room temperature ionic liquids

Starting from the hydroxylamine (dimethyl amino ethanol, triethanolamine) and 1,3-propane sultone, a series of hydroxyl and sulfonyl dual-functionalized zwitterionic salts and corresponding acidic room temperature ionic liquids have been synthesized. The hydroxyl groups of the synthesized substances were confirmed by the 1H NMR measurement. These zwitterionic salts and ionic liquids may be used for synthesizing other functionalized ionic liquids or ionic liquid-polymer (polyelectrolyte).     

Studies on synthesis and infrared and fluorescence spectra of new europium and terbium complexes with an amide-based open-chain crown ether

An amide-based open-chain crown ether ligand and its complexes with europium and terbium were synthesized. The complexes were characterized by elemental analysis, infrared spectra and conductivity. The europium and terbium ions were found to coordinate to the C=O oxygen atoms and pyridine nitrogen atoms. The fluorescence properties of these complexes in DMF and CH3OH/CHCl3 were studied. Under the excitation of UV light, these complexes exhibit characteristic fluorescence of europium and terbium ions. The solvent factors influencing the fluorescent intensity are discussed.     

NOx在固体电解质电解池上的电化学消除

 综述了近年来利用固体电解质电解池消除NO的研究进展．重点总结了电化学消除NO研究体系、电化学消除NO分解机制、O2－在固体电解质电解池中传导的控速步骤、电极种类和形态对NO分解性能的影响以及直流与交流电作用的差异等几个方面的研究结果．在RuO2—Ag—YSZ—Pd电解池上实现的NO选择性分解是迄今为止的最佳结果，500℃下NO的转化率为31．8％，NO的分解活性是O2的分解活性的13倍．该领域今后研究的主要方向是，进一步提高NO分解相对于共存O2离子化的选择性、降低O2－在阴极界面处的传导阻力和探寻可在更低温度传导O2－的新的固体电解质     

Quantitative study on selective stacking of zwitterions in large-volume sample matrix by moving reaction boundary in capillary electrophoresis

The paper advanced the theoretical procedures for quantitative design on selective stacking of zwitterions in full capillary sample matrix by a cathodic-direction moving reaction boundary (MRB) in capillary electrophoresis (CE) under control of electroosmotic flow (EOF). With the procedures, we conducted the theoretical computations on the selective stacking of two test analytes of L-histidine (His) and L-tryptophan (Trp) by the MRB created with 30 mM pH 3.0 formic acid-NaOH buffer and 2-80 mM sodium formate. The results revealed the following three predictions. At first, the MRB cannot stack His and Trp plugs if less than 12.5 mM sodium formate is used to form the MRB and prepare the sample matrix. Second, the MRB can stack His and/or Trp sample plugs completely if higher than 50 mM sodium formate is chosen to form the MRB. Third, the MRB can only focus His plug completely, but stack Trp plug partially if 20-50 mM sodium formate is used; this implied the complete MRB-induced selective stacking to His rather than Trp. All the three predictions were quantitatively proved by the experiments. With great dilution of sample matrix and control of EOF, controllable, simultaneous and MRB-induced selective stacking and separation of zwitterions were achieved. The theoretical results hold evident significances to the quantitative design of selective stacking conditions and the increase of detection sensitivity of zwitterions in CE. In addition, the control of EOF by cetyltrimethylammonium bromide (CTAB) can evidently improve the stacking efficiency to both His and Trp.     

镧与镍共沉积的研究

由于含稀土的合金新材料具有多种特殊功能，因此，其制备技术已为人们所关注．制备含稀土合金的方法有高温烧结法、真空蒸发法、离子溅射法及电化学法等．其中电化学法设备简单，容易获得不同组份的表层材料，但是，由于稀土元素的电位很负，从电解质水溶液中沉积稀土及其合金是相当困难的，以往曾有采用熔融盐电解质或非水电解质制备稀土合金的一些报导[1，2]，而从电解质水溶液中电沉积稀土合金的报导甚少．本研究采用适宜的络合剂，实现了从电解质水溶液中电沉积Ni－La合金，镀层中钠含量最高达22．58％（质量分数，下同）．通过XPS及…     

轻希土硫氰酸盐与2,3,11,12,-四苯基-1,4,7,10,13,16-六氧-2,11-十八环二烯配合物的合成及XPS研究

合成了六种轻希土硫氰酸盐与标题不饱和冠醚的新固体配合物,进行了元素分析,摩尔电导率、DTA、UV、IR和XPS等表征。对Ln(NCS)_3·L和Ln(NCS)_3的XPS研究中,得到它们组成原子芯能级电子(Ln3d_(5/2),Ols,Nls,S2p)的结合能信息;观察到除Y3d_(5/2)外Ln3d_(5/2)(Ln=La、Ce、Pr、Nd、和Sm)的伴峰结构,Ln3d_(5/2)结合能与原子序数呈线性关系,并推断类似化合物Pm3d_(5/2)结合能在1035eV附近.     

Studies on the Spectral Behavior between Protein with Poniacyl Carmine 2B and its Analytical Application

In this paper, the spectral behavior of protein and Poniacyl Carmine 2B (PC 2B) has been studied by spectrophotometric method. The conditional constants, apparent combination constant K and maximum binding number n, were used to express the combination ability of the reactions between PC 2B and protein under a set of given conditions. The Sandell index s was used to express the sensitivity of the determination of protein. The factors, acidity, PC 2B concentration and the ionic strength, were discussed by the change of apparent combination constant and maximum binding number. It was found that acidity of the solution, PC 2B concentration and ionic strength had a significant effect on the sensitivity of the assay of protein. Under the optimal conditions, the apparent combination constant K and the maximum binding number n were 2.36 × 10⁶ L mol^?1 and 95, respectively. With further investigation, it was found that the Scatchard model was suitable in treating the data obtained in the experiments. In the buffer medium of HCl‐KCl at 1.87, the addition of protein made the maximum absorption of the system move from 527 nm to 513 nm. Its apparent molar absorptivity is 4.46 × 10⁵ Lmol^?1 cm^?1 at 513 nm. Beer's law is obeyed in the range of 0 ? 55 μg mL^?1. The system developed in this paper has been used for the determination of protein in milk powder successfully.     

微合金钢中稀土对沉淀相和性能的影响

在Nb(Ti,V）微合金钢中，主要沉淀相分别为Nb(C,N),(Nb,Ti)(C,N)和V（C，N）。稀土降低沉淀相完全溶解的温度，增大奥氏体中沉淀相析出的孕育期，降低析出速率，抑制奥氏体中沉淀相的析出，在铁素体相区，稀土提高沉淀相的析出速率和数量，促进沉淀相的析出，其中稀土对铌沉淀相析出的作用影响最强。锻态钢中，稀土有促进细化球化析出相的作用，随稀土含量增加，沉淀相析出数量增加，但过量稀土，促进作用又减弱，稀土在保持微合金钢强度的情况下，显著改善其冲击韧性，尤其是低温韧性，微合金钢中添加适量稀土可获得更佳的综合性能。