天然竹红菌素粗品的光物理特性及机理分析

用SP-2558型光谱实验系统测得了天然竹红菌素粗品的三维荧光光谱,给出其随样品浓度变化的规律,进而利用软件和理论分析提出,天然竹红菌素粗品荧光光谱主要是竹红菌甲素（HA）和竹红菌乙素（HB）荧光光谱的贡献,HA的荧光光谱受其他成分影响较大,造成了短波峰的蓝移和长波峰的红移;HA与HB之间的辐射能量转移导致其荧光光谱中长波成分增加,从而形成较宽的谱段;由分子间氢键形成的多聚体会导致天然竹红菌素粗品溶液的发射峰随浓度的增加而红移,因而通过对天然竹红菌素粗品的浓度调控,可以在一定的范围内实现对发射光波段的调控,这对指导临床上的应用具有较高的参考价值。     

Luminescence investigation of red phosphors Ca0.54Sr0.34−1.5xEu0.08Smx(MoO4)y (WO4)1−y for UV-white LED device

Ca_0.54Sr_0.34−1.5xEu_0.08Sm_x(MoO₄)_y (WO₄)_1−y red phosphors were prepared by solid-state reaction using Na⁺ as a charge compensator for light-emitting diodes (LED). The effects of Na⁺ concentration, synthesis temperature, reaction time and Eu³⁺ concentration were studied for the properties of luminescence and crystal structure of red phosphors. The results show that the optimum reaction condition is 6%, 900 °C, 2 h and 8%. The photoluminescence spectra show that red phosphors are effectively excited at 616 nm by 292, 395 and 465 nm. The wavelengths of 465 nm nicely match the widely applied emission wavelengths of blue LED chips.     

磺基水杨酸-溴邻苯三酚红-溴化十六烷基吡啶分光光度法测定食品中钼的研究

研究了在pH5.6的HAc NaAc缓冲溶液中,溴化十六烷基吡啶(CPB)存在下,钼(Ⅵ)与溴邻苯三酚红及磺基水杨酸形成多元配合物的显色反应,建立了测定食品中微量钼的新方法。该配合物的最大吸收波长为λmax=620nm,表观摩尔吸光系数ε620=1.84×105L·mol-1·cm-1。钼(Ⅵ)浓度在0～0 80μg mL范围内符合比尔定律。应用于粮食作物中微量钼的测定,相对标准偏差小于4 8%,回收率为95.2%～100.5%。     

DODAB and DODAC bilayer-like aggregates in the micromolar surfactant concentration domain

In the millimolar concentration domain (typically 1 mM), dioctadecyldimethylammonium bromide and chloride (DODAX, X representing Br⁻ or Cl⁻ counterions) molecules assemble in water as large unilamellar vesicles. Differential-scanning calorimetry (DSC) is a suitable technique to obtain the melting temperature (T _m) characteristic of surfactant bilayers, while fluorescence spectroscopy detects formation of surfactant aggregates, like bilayers. These two techniques were combined to investigate the assembly of DODAX molecules at micromolar concentrations, from 10 to 100 μM. At 1 mM surfactant, T _m ≈ 45 °C and 49 °C, respectively, for DODAB and DODAC. DSC and fluorescence of Nile Red were used to show the formation of DODAX aggregates, at the surfactant concentration as low as 10 μM, whose T _m decreases monotonically with increasing DODAX concentration to attain the value for the ordinary vesicles. The data indicate that these aggregates are organized as bilayer-like structures.     

Conformational changes of strong polycations in the presence of divalent counterions and their influence upon the flocculation efficiency

The interaction between strong polycations, which possess the ammonium quaternary centers attached to an acrylic macromolecular chain derived from poly(N,N-dimethylaminoethyl methacrylate) (polycations Q_x), and divalent counterions was investigated by viscometry and turbidimetry. Conformational changes of polycations were influenced by the polycation charge density, counterion nature (SO₄²⁻ or S₂O₈²⁻) and concentration. The morphology of the polycation layers deposited onto silicon wafers has been studied by tapping mode atomic force microscopy, a strong influence of the polycation and ammonium persulfate concentration on the surface topography being observed. The optimum flocculation concentration of polycation decreased and the flocculation window increased in the presence of S₂O₈²⁻, in the destabilization of kaolin model dispersion. Removal of Congo Red from aqueous solution by the complex system formed between polycations and divalent counterions was also investigated. The behavior of polycations Q_x in separation processes was compared with that of one polycation containing 95 mol% N,N-dimethyl-2-hydroxypropyleneammonium chloride units in the backbone (PCA₅).     

Fluorenyl dendrimer porphyrins: synthesis and photophysical properties

New symmetrical dendrimeric type super-porphyrin bearing sixteen fluorenyl donor groups sixteen fluorenylporphyrin SOFP (1) have been synthesized and characterized. Preliminary photophysical properties are reported; in comparison to the references first generation dendrimer tetrafluorenylporphyrin TOFP (2) bearing four peripheral fluorenyl and second generation dendrimer octafluorenylporphyrin OOFP (3) bearing eight peripheral fluorenyl, the luminescence properties are slightly improved. It is found that the excitation energy transfer occurs from the sixteen fluorenyl units to the porphyrin core, following what the porphyrin emits intense red light.     

Removal of phenol from aqueous phase by using neutralized red mud

The objective of this study is to remove the phenol from aqueous solution by using the neutralized red mud in batch adsorption technique. The study was carried out as functions of contact time, pH, initial phenol concentration, red mud dosage and effect of salt addition. The experiments demonstrated that maximum phenol removal was obtained in a wide pH range of 1-9 and it takes 10 h to attain equilibrium. The adsorption data was analyzed using the Langmuir and the Freundlich isotherm models and it was found that the Freundlich isotherm model represented the measured sorption data well. The influence of addition of salt on phenol removal depends on the relative affinity of the anions for the red mud surface and the relative concentrations of the anions.     

Convenient synthesis and anion recognition properties of N-flurobenzoyl-N′-phenylthioureas in water-containing media

Novel artificial anionic receptors N-flurobenzoyl-N′-phenylthioureas were synthesized by simple steps in good yields. The binding properties for anions of these N-flurobenzoyl-N′-phenylthioureas and 2N-benzoyl-N′-phenyl thiourea were examined by UV-vis and ¹H NMR spectroscopy. By fluorination of the benzoyl chromophore, the receptors had higher binding affinity for tested anions than the receptor 2. Especially, we studied the anion binding efficiency of the receptors 1N-(3-flurobenzoyl)-N′-phenylthiourea and 2 in dimethyl and dimethyl sulfoxide-water binary solutions in detail respectively. In pure dimethyl sulfoxide, the receptors 1 and 2 had higher binding affinity for F⁻ over AcO⁻. However, as the ratio of water to dimethyl sulfoxide increases, we found the binding properties for tested anions of 1 and 2 changed in dimethyl sulfoxide-water binary solutions. The receptor 1 showed high binding affinity and selective ability for AcO⁻ in dimethyl sulfoxide containing water with varied ratios.     

Adsorption of Anionic Dyes onto Chitosan-modified Diatomite

The purpose of this work is to study the possibility of anionic dyes Reactive Red M-8B(RR) and Direct Green B(DG) adsorbed on chitosan-modified diatomite. The characteristics of adsorbent, adsorption isotherms and the influence of adsorption time, temperature and pH were researched in this work. The results show that the mo- dified diatomite had a much better adsorption capability than the natural diatomite. The adsorption capacities of chitosan-modified diatomite for RR and DG were 94.46 and 137.0 mg/g, respectively. Both adsorption time and adsorption temperature provided a positive effect on the dye adsorption. Within the experimental pH range, the adsorbance was enhanced at lower pH but reduced sharply at high pH. On the basis of the experimental results and discussion, electrostatic attraction is considered as the main mechanism of this chemisorption.     

UV/乙酰丙酮法降解脱色蒽醌类染料茜素红

染料废水由于色度高,成份复杂,是一种较难处理的工业废水. 本研究以茜素红为蒽醌类染料的代表,研究了UV/乙酰丙酮（简称UV/AA）法中茜素红浓度、乙酰丙酮用量、溶液初始pH对降解脱色效率的影响. 实验结果表明,UV/AA法在中、酸性条件下对茜素红具有显著的降解脱色效果,其脱色过程符合准一级动力学,降解速率常数远高于UV/H₂O₂法. 基于溶液pH对UV/AA法脱色效果以及乙酰丙酮紫外吸收光谱的影响,推测在UV/AA法降解脱色染料的过程中起主导作用的是乙酰丙酮的烯醇式异构体. 尽管UV/AA法对总有机碳和化学耗氧量的去除率不高,但是显著提高了溶液的可生化性. 因此,UV/AA法有望作为预处理工艺与传统的生物处理法相结合,以较低的成本实现染料废水的达标处理. 这一工作为小分子双酮在染料废水处理中的应用研究提供了新的思路.