三价铕离子配合物的激光光谱研究

利用高灵敏度的时间辨激光光谱技术研究了在配位场作用下Ｅｕ＾３＾＋的直接激发与发特性。Ｅｕ＾３＾＋的直接激发光谱（特别是７Ｆ０－５Ｄ０的超灵敏跃迁）及其发射光谱随不同的配合物的变化，同时观测到与配位对称性及配位强度有联系的７Ｆ１－５Ｄ０磁偶极跃 迁的分裂。在对７Ｆ０－５Ｄ０跃迁共振与非共振的１０ｐｓ激光脉冲的激励下，都可以立即观察到５Ｄ０－７ＦＪ（Ｊ＝２，３，４）的发射，说明Ｅｕ＾３＾＋的５Ｄ０能态     

D2EHPA萃取稀土的有机相红外光谱及添加DMHPA的影响

本文研究了部分皂化的二（２－乙基己基）磷酸（Ｄ２ＥＨＰＡ）－正庚烷体系萃取稀土离子Ｙ＾３＋，Ｐｒ＾３＋，Ｎｄ＾３＋，Ｅｕ＾３＋后有机的傅里叶变换红外光谱（ＦＴ－ＩＲ）。发现不同稀土离子与萃取剂的配位能力有差异，并且皂化度对萃取有机相中的Ｐ＝Ｏ谱带的频率和吸收强度皆有影响，在Ｄ２ＥＨＰＡ中加入二（１－甲基庚基）磷酸（ＤＭＨＰＡ）导致Ｐ＝Ｏ谱带形状和吸收强度发生变化。     

d^10组态金属离子与邻菲罗啉衍生物配位反应的^1H NMR研究

通过研究ｄ＾１０组态金属离子Ｚｎ＾２＋，Ｃｄ＾２＋，Ｈｇ＾２＋与邻菲罗啉及其衍生物发生配位时配体的＾１Ｈ ＮＭＲ谱的变化，对配离子的种类进行了讨论，给出了配离子中配键稳定性的比较，提出了一种通过实验直接研究溶液中的ｄ＾１０组态离子为中心离子的配合物的方法。     

铝对掺铽硅基玻璃发光强度的影响

本文通过溶胶－凝胶方法法制备了掺Ｔｂ＾３＋和Ａｌ＾３＋的硅基玻璃,并研究了Ａｌ＾３＋对Ｔｂ＾３＋发光性能的影响,结果显示Ａｌ＾３＋对Ｔｂ＾３＋的发射峰的位置没有明显影响,但通过溶胶－凝胶方法掺Ａｌ＾３＋后,所有样品中Ｔｂ＾３＋的发光强度都明显增加,掺８％－１０％的Ａｌ＾３＋的Ｔｂ－硅基玻璃中Ｔｂ＾３＋的发光强度是不掺Ａｌ＾３＋的Ｔｂ－硅基玻璃中的５倍,我们推测Ｔｂ＾３＋和Ａｌ＾３＋能级之间的关系对于能量传递是比较合适的,Ａｌ＾３＋的作用是更有效地吸收能量并完全地转移给Ｔｂ＾３＋。     

稀土离子与二棕榈酰磷脂酰胆碱相互作用的FT—IR研究

利用傅里叶变换红外光谱法研究了稀土离子Ｓｍ＾３＋，Ｇｄ＾３＋，Ｅｒ＾３＋和Ｙｂ＾３＋与二棕榈酰磷脂磷胆碱脂质体的相互作用，结果表明：稀土离子间磷脂极性头部的ＰＯ＾－２和Ｎ＾＋（ＣＨ３）３基闭间有较强的静电作用，而且这些作用随着稀土子摩尔比例的增大而加强，稀土离子与磷脂相互作用程度按稀土离子原子序数增大即Ｓｍ＾３＋＜Ｇｄ＾３＋＜Ｙｂ＾３＋的顺序排列。     

铜基催化剂表面缺陷对催化性能的影响

用顺磁共振谱研究外来离子含量与由这些正三价金属离子在ＺｎＯ表面诱导出一的正一价缺位数量之间的关系。结果表明，Ａｌ＾３＋和Ｓｃ＾３＋对ＺｎＯ表面的正一价缺位都有诱导作用，其中Ｓｃ＾３＋的掺杂对正一价缺位的诱导更有效。ＴＰＲ结果显示，随着样品中Ｓｃ＾３＋含量的增加，归属于Ｃｕ＾２＋→Ｃｕ＾＋和Ｃｕ＾＋→Ｃｕ＾０ ＴＰＲ谱最高峰温分别向低温和高温方向移动。     

稀土（La^3＋,Pr^3＋）—DBS—偶氮胂有色配合物组合和稳定常数的吸收光谱法测定

稀土（Ｌａ＾３＋,Ｐｒ＾３＋）在酸性条件下与ＤＢＳ－偶氮胂发生配位反应,首先对光谱数据进行因子分析法处理从而判断出只生成一类配合物,进而采用线性回归法计算配合物组成,摩尔吸光系数,表观稳定常数及配位体浓度,实验结果表明,在１ｍｏｌ．Ｌ＾－１ＨＣｌ介质中,Ｌａ＾３＋、Ｐｒ＾３＋与ＤＢＳ－偶氮胂形成Ｍ：Ｌ＝１：３的配合物,其摩尔吸光系数分别为１．３９９＊１０＾５和１．１５１７＊１０＾５Ｌ．ｍｏｌ＾－１．ｃｍ＾－１,表观稳定常数ｌｏｇβ３分别为１５．３６和１５．３４。     

2-氨基-4-磺酸基-丁酸及其金属离子络合物的光谱研究

本处次对２－氨基－４－磺酸基－丁酸的红外光谱作了初步指认,并早此对其存在形式作出判断、同时,合成了２－氨基－４－磺酸基－丁酸与Ｎａ＾＋、Ｋ＾＋、Ｃａ＾２＋形成的络合物,对其红外光谱及拉曼光谱进行了分析讨论,并对其配位方式进行了比较。结果表明形成络合物后,羟基、磺酸基均参与配位,且破坏了原有分子间的氢键网络,进行了分子间的重新组合。     

同步辐射EXAFS研究FeCl3溶液中Fe离子的区域结构

ＥＸＡＦＳ研究ＦｅＣｌ３溶液中Ｆｅ＾３＋的区域环境结构随溶液浓度的变化，Ｆｅ＾３＋的径向结构函数表明，随着ＦｅＣｌ３溶液的浓度降低，第一配位峰的距离逐渐缩短，当溶液浓度从３．０ｍｏｌ／Ｌ降到０．２ｍｏｌ／Ｌ时，配位距离减小到０．０１４ｎｍ，但振幅峰强度以０．８ｍｏｌ／Ｌ浓度为最小，其强度比浓的或稀的ＦｅＣｌ３溶液的低约３０％，结构参数拟合结果表明，０．２ｍｌ／Ｌ，ＦｅＣｌ３稀溶液中Ｆｅ＾３＋的近邻     

海藻酸钠溶液溶胶—凝胶相转变过程的光谱学研究

以粘度法和＾１３Ｃ－ＮＭＲ、ＵＶ、Ｒａｍａｎ光谱学方法研究了海藻酸钠溶液胶－凝胶相结转变过程，结合体系的光谱学特征，分析了体系相转变过程中海藻酸单体官能基与二价铜离子间的结合情形、分子链的构型变化以及与它紧密相关溶剂行为，进一步探讨了天然高分子电南海藻酸钠在重金属离子Ｃｕ＾２＋作用下的凝胶化机理。     

Effect of ultrasound pretreated hydrocolloid batters on quality attributes of fried chicken nuggets during post-fry holding

In this study, batters formulated with different hydrocolloids (i.e., pectin, locust bean gum, xanthan gum, guar gum, hydroxypropyl methylcellulose and methylcellulose) were treated with ultrasound as edible coatings for fried chicken nuggets. Quality characteristics (i.e., batter pickup, flow behaviours, thermal properties, moisture loss, color and textural properties) in chicken nuggets coated with ultrasound treated batters were evaluated before and after post frying exposure to heat lamp. Ultrasonication significantly reduced batter pickup, flow behavior and gelatinization enthalpy, revealing its tendency to alter functional properties of batter systems. Rheological evaluation of all batter samples revealed a pseudoplastic (shear thinning) flow characteristic when fitted to power law model, with ultrasonicated (US) samples exhibiting a significant reduction in viscosity over non-ultrasonicated (NUS) samples. Compared to the control NUS, fat content of chicken nuggets coated with US-treated batters decreased by 39.0, 60.9, 62.87, 64.1, 65.7, and 65.0 % for pectin, locust bean gum, xanthan gum, guar gum, hydroxypropyl methylcellulose and methylcellulose, respectively. Finally, chicken nuggets coated with US and NUS treated batters exhibited greater cutting force values immediately after frying but declined within the first 10 min of heat lamp exposure and increased subsequently with extended heat lamp holding time. Furthermore, NUS-treated guar gum resulted in chicken nuggets with the most minimal variability in cutting force during post-frying holding, indicating that crispiness was maintained. Overall, application of ultrasound as a batter pretreatment technique can be exploited by the frying food industry as an alternative approach to producing low fat chicken nuggets with appreciable quality attributes.     

高压对食品胶溶液流变特性的影响

 经高压处理后,卡拉胶、琼胶、高甲氧基果胶、海藻酸钠、黄原胶和瓜尔豆胶等六种食品胶溶液的粘度变化不同。卡拉胶和琼胶溶液的粘度显著增加,高甲氧基果胶、海藻酸钠和瓜尔豆胶溶液的粘度变化较小,而黄原胶溶液的粘度明显降低。动态粘弹性测量表明,卡拉胶和琼胶溶液的贮藏模量（G′）在高压处理后明显减小,而且G′变得小于G″,这表明卡拉胶和琼胶溶液的弹性变小。高甲氧基果胶、海藻酸钠和瓜尔豆胶溶液的损耗正切值（tan δ=G″/G′）在处理后几乎没有变化,黄原胶溶液的tan δ略微减小。高压处理后食品胶溶液流变特性的不同变化表明,高压处理对食品胶的影响因其种类、胶分子的结构和胶在水溶液中的构象而异。文中对造成这些变化差异的可能原因进行了探讨。     

Determination of the charge state of chromium in Cr:Bi<Subscript>12</Subscript>GeO<Subscript>20</Subscript> single crystals by spectral luminescence methods

The valence state and structural localization of Cr ions in Cr:Bi₁₂GeO₂₀ single crystals grown by the Czochralski method in air and annealed in argon or UV-irradiated have been determined in the spectral luminescence study. It is established that chromium is in the state of tetrahedrally coordinated Cr⁴⁺ ions in the samples studied. Octahedrally coordinated Cr²⁺ and Cr³⁺ ions and tetrahedrally coordinated Cr⁵⁺ ions were not revealed.     

镱铒共掺硼硅酸盐玻璃可见光波段扎得-奥菲而特理论分析

采用高温烧结工艺制备了多种掺杂浓度的掺铒硼硅酸盐玻璃、镱铒共掺硼硅酸盐玻璃样品.依据扎得-奥菲而特(Judd-Ofelt,J-O)理论计算了三价铒离子扎得-奥菲而特强度参量Ωk(k=2,4,6)和自发辐射寿命、自发辐射跃迁几率、荧光分支比、谱线强度等参量.用麦克库玻(McCumber)理论分析了镱铒共掺硼硅酸盐玻璃铒离子上转换红光(4F9/2→I15/2)、绿光(2>H11/2→I15/2)的受激发射截面.结果表明,随着掺铒硼硅酸盐玻璃中铒离子浓度的增加,扎得-奥菲而特参量Ω2变小;镱铒共掺硼硅酸盐玻璃的Ω2则随掺镱浓度的提高而增大,且高于已有的硅酸盐、氟化物、铋酸盐玻璃的相应值,同时上转换红光和绿光的受激发射截面略有增加.     

Ultrasound assisted enzymatic depolymerization of aqueous guar gum solution

The present work investigates the effectiveness of application of low intensity ultrasonic irradiation for the intensification of enzymatic depolymerization of aqueous guar gum solution. The extent of depolymerization of guar gum has been analyzed in terms of intrinsic viscosity reduction. The effect of ultrasonic irradiation on the kinetic and thermodynamic parameters related to the enzyme activity as well as the intrinsic viscosity reduction of guar gum using enzymatic approach has been evaluated. The kinetic rate constant has been found to increase with an increase in the temperature and cellulase loading. It has been observed that application of ultrasound not only enhances the extent of depolymerization but also reduces the time of depolymerization as compared to conventional enzymatic degradation technique. In the presence of cellulase enzyme, the maximum extent of depolymerization of guar gum has been observed at 60 W of ultrasonic rated power and ultrasonic treatment time of 30 min. The effect of ultrasound on the kinetic and thermodynamic parameters as well as the molecular structure of cellulase enzyme was evaluated with the help of the chemical reaction kinetics model and fluorescence spectroscopy. Application of ultrasound resulted in a reduction in the thermodynamic parameters of activation energy (E_a), enthalpy (ΔH), entropy (ΔS) and free energy (ΔG) by 47%, 50%, 65% and 1.97%, respectively. The changes in the chemical structure of guar gum treated using ultrasound assisted enzymatic approach in comparison to the native guar gum were also characterized by FTIR. The results revealed that enzymatic depolymerization of guar gum resulted in a polysaccharide with low degree of polymerization, viscosity and consistency index without any change in the core chemical structure which could make it useful for incorporation in food products.     

Interactions between Diamagnetic Metal Ions and pH-Sensitive Nitroxides

Specific interactions between pH-sensitive nitroxide radicals and selected diamagnetic metal ions were investigated. To this end, the influence of different metal salts at varying concentrations on the continuous-wave electron paramagnetic resonance spectra of two imidazoline nitroxides was studied. Among the screened metal ions, Zn(II) most significantly affected the spectral profile, analogous to the effect attributed to protonation of the nitroxide imino nitrogen known from pH studies. Simulations showed the acquired spectra to result from the superposition of the signals of the coordinated and the uncoordinated species. The complex formation between Zn(II) and (4-amino-2,5-dihydro-2,2,5,5-tetramethyl-3-imidazoline-1-yloxyl) was modelled by theoretical methods revealing the rather specific selectivity of the nitroxide toward Zn(II). The results suggest imidazoline nitroxides as promising candidates for the development of new specific metal ion probes.     

Inelastic collisions of slow electrons with yttrium trichloride molecules

Inelastic collisions of electrons with YCl₃ molecules are investigated by the method of extended crossing beams. As in the case of LaCl₃ molecules, only the spectral lines of singly charged metal ions are found, with the lines of yttrium atoms and the spectral bands of yttrium monochloride being absent. The excitation cross sections of the energy levels of Y(II) and the contribution of the cascade population are calculated using the results obtained. Possible reaction channels upon dissociative excitation are discussed.     

偕胺肟纤维与Fe(Ⅲ),Co(Ⅱ),Ni(Ⅱ),Cd(Ⅱ),Hg(Ⅱ)配合物的红外光谱研究

用聚丙烯腈纤维 (PAN)改性制备的偕胺肟纤维 (AOCF)分别与三氯化铁、氯化钴、氯化镍、氯化镉和氯化汞在酸性介质中反应 ,制备偕胺肟 铁 (Ⅲ )、偕胺肟 钴 (Ⅱ )、偕胺肟 镍 (Ⅱ )、偕胺肟 镉 (Ⅱ )和偕胺肟 汞 (Ⅱ ) 5种偕胺肟 重金属配合物 (用通式M AOCF表示 )。用红外分光光度计分别对偕胺肟纤维和 5种配合物在 4 0 0 0～ 4 0 0cm- 1 范围进行傅里叶变换红外吸收 ,对各M AOCF的FTIR主要吸收峰做了经验归属 ,并将各M AOCF的特征吸收峰与AOCF的相应吸收峰作对比分析 ,结果表明 :配合物中C—N ,CN ,N—O等键的吸收峰位置均向高波数方向移动 ,且峰的强度增加。说明纤维材料中的偕胺肟基团与重金属离子在酸性介质中进行了配位反应 ,偕胺肟基团与重金属离子之间形成了配位键。     

金属离子对纳米TiO2悬浊液的光催化性能影响的光谱研究

以钛氧有机物为前驱体,利用微乳液法制备了纳米TiO2微晶。用X射线衍射(XRD)和红外光谱(FTIR)等测试技术对产物进行了表征,并就纳米TiO2悬浊液中加入金属离子后光催化降解甲基橙溶液进行了初步的研究。光谱分析表明,纳米TiO2悬浊液中加入Bi3 离子后对甲基橙溶液的光催化降解有很大的促进作用,Bi3 与TiO2质量比为1∶8及TiO2的浓度为1.6g·L-1时光催化活性最佳。     

丙二醇甲醚中超痕量金属杂质元素的ICP-MS/MS分析

基于电感耦合等离子体串联质谱(ICP-MS/MS)建立了准确测定丙二醇甲醚中超痕量金属杂质元素的分析方法,提出了利用混合反应气消除质谱干扰的新策略.丙二醇甲醚经超纯水稀释后直接采用IC P-MS/MS测定其中具有挑战性的超痕量金属元素Mg,Al,K,Ti,V,Cr,Fe,Ni,Cu和Zn,在MS/MS模式下,选择混合气...