Potentiometric determination of iron using a fluoride ion-selective electrode-the application of the Apple II-ISE intelligent ion analyzer

A new method for determining iron is based on both nonlinear regression calibration plots and parabolic interpolation using a fluoride ion-selective electrode (ISE) and the Apple II-ISE intelligent ion Analyzer developed by ourselves. The experimental conditions for determining iron are discussed. The appropriate acidity of the experimental solution is pH 3, controlled by total ionic strength adjustment buffer (TISAB) that is composed of glycine (aminoacetic acid), nitric acid and sodium nitrate. The suitable total concentration of fluoride is equal to the highest concentration of iron in the standard series. Because the mathematical model of the method coincides with the experimental data the Apple II-ISE intelligent ion Analyzer can perform data acquisition and data processing, and the performance of fluoride electrode is excellent, the new method for determination of iron is fast and accurate. This method has been used successfully in the determination of iron in mineral samples.     

Energy Spectrum and Its Pressure-Induced Shift and g Factor of ZnS:Mn2+

By using strong-field scheme, the complete d⁵ energy matrix with D_2d symmetry has been constructed. Then, by diagonalization of this matrix at normal and various pressures,the whole energy spectrum [including the ground-state zero-field-splitting (GSZFS)], its PS and the g factor of the ground state for zns:Mn²⁺ have uniformly been calculated. According to the eigenfunctions and PS, the new assignments of five absorption bands have been given.The variation of tetragonal field with pressure makes a main contribution to the pressureinduced shift (PS) of GSZFS of zns:Mn²⁺, which supports the existence of tetragonal Jahn-Teller distortion in zns:Mn²⁺. It is found that when P≥62 kbar, t₂⁴(³T₁)e⁴T₁ merges with t₂e^{4 2}T₂, which has to be taken into account in the calculation of PS of the fifth band in the range of 1 bar ~ 95 kbar. It is demonstrated that the Mn²⁺ ions in ZnS:Mn²⁺ have tetrahedral coordination, and the difference between ζ and ζ' caused by the covalency effect is very important for GSZFS. The physical essentials of typical levels, GSZFS and their PS have been revealed. By taking into account the influence of covalency on t₂³(⁴A₂)e²(³A₂)⁴A₁ and t₂³(²E)e²(³A₂)⁴E, the positon of the third absorption band at normal pressure has been estimated.     

光学自由曲面数控化加工方法

在光学系统中，为了满足特殊的成像要求，需要使用自由曲面光学零件，但由于自由曲面是一类非常复杂的曲面，用传统的光学加工方法很难加工。本文概要介绍了光学非球面的多种加工方法，探索了这些方法加工光学自由曲面的可能性，提出了用数控化加工方法加工光学自由曲面，并利用这种方法加工了一块自由曲面透镜。     

Quality assessment of Cortex Phellodendri by high‐performance liquid chromatography coupled with electrospray ionization mass spectrometry

A simple method based on liquid chromatography coupled with diode array detection and electrospray ionization mass spectrometry (LC‐DAD‐ESI‐MS) was developed for the quality assessment of Cortex Phellodendri (CP), which was mainly derived from two species of Phellodendron chinense Schneid and Phellodendron amurense Rupr. Total 41 compounds, including 14 phenols, 24 alkaloids and three liminoidal triterpenes were identified or tentatively characterized from the 75% methanol extract of CP samples by online ESI‐MSⁿ fragmentation and UV spectra analysis. Among them, two phenols and six alkaloids were simultaneously quantified using HPLC‐DAD method. The validated HPLC‐DAD method showed a good linearity, precision, repeatability and accuracy for the quantification of eight marker compounds. Furthermore, the plausible fragmentation pathway of the representative compounds were proposed in the present study. The differences of the chemical constituents content and the comprehensive HPLC profiles between the two CP species using LC‐DAD‐ESI‐MS method are reported for the first time, indicating that the CP drugs from different resources should be used separately in the clinic. Copyright © 2009 John Wiley & Sons, Ltd.     

CPT symmetry in honeycomb lattices and quantum brachistochrone problem

In this paper, we have provided a matrix Hamiltonian model for honeycomb lattices and subsequently obtained the dispersion relation. Furthermore, we have constructed the C operator for the given non-Hermitian Hamiltonian model. The quadratic surfaces are sketched and the quantum Brachistochrone problem is discussed for the given honeycomb lattice model.     

Conjugated copolymers comprised cyanophenyl‐substituted spirobifluorene and tricarbazole‐triphenylamine repeat units for blue‐light‐emitting diodes

A series of conjugated blue‐light‐emitting copolymers, PTC‐1 , PTC‐2 , and PTC‐3, comprised different ratios of electron‐withdrawing segments (spirobifluorene substituted with cyanophenyl groups) and electron‐donating segments (tricarbazole‐triphenylamines), has been synthesized. The structures of these polymers were characterized and their thermal, photophysical, electrochemical, and electroluminescence properties were measured. Incorporation of rigid spirobifluorene units into the copolymers led to blue‐shifted absorption peaks in dilute toluene solution. Cyclic voltammetric measurement indicated the bandgaps of the polymers were in the range of 2.77–2.94 eV. It was found that increasing cyanophenyl‐spirobifluorene content in the polymer backbone lowered both the HOMO and LUMO energy levels of the copolymers, which was beneficial for electron injection/transporting in the polymer layer of the device. OLED device evaluation indicated that all the polymers emitted sky blue to deep blue light when the pure polymers were used as the emissive layers in the devices with a configuration of ITO/PEDOT:PSS/polymers/CsF/Ca/Al. The devices have been optimized by doping 30 wt % PBD into the polymer layers. Among the doped devices, PTC‐2 showed the best performance with the turn‐on voltage of 3.0 V, maximum brightness of 7257 cd/m², maximum current efficiency of 1.76 cd/A, and CIE coordinates of (0.15, 0.14). © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 292–301, 2010     

脂质组成对硫辛酸脂质纳米粒的制备及其稳定性的影响

采用高压均质法制备硫辛酸(ALA)脂质纳米粒(ALA-NLC),确定了负载ALA的最佳体系。通过高效液相色谱、动态光散射、流变等测试研究了脂质成分、含量对ALA负载、ALA-NLC稳定性和分散液流变性质的影响,并用原子力显微镜观察了ALA-NLC的形貌。结果表明,脂质/ALA质量比在4.5∶1～6∶1之间,得到的脂质纳米粒分散均匀,颗粒规则;脂质中液态油脂的增加有利于保持ALA-NLC的粒径,储存稳定性和分散液的低粘度,并得到两个有望用于食品工业的ALA-NLC配方。