Spectral characterization of diffusion with chemical shift resolution: Highly concentrated water-in-oil emulsion

We present a modulated gradient spin-echo method, which uses a train of sinusoidally shaped gradient pulses separated by 180° radio-frequency (RF) pulses. The RF pulses efficiently refocus chemical shifts and de-phasing due to susceptibility differences, resulting in undistorted, high-resolution diffusion weighted spectra. This allows for the simultaneous spectral characterization of the diffusion of several molecular species with different chemical shifts. The technique is robust against susceptibility artifacts, field inhomogeneity and imperfections in the gradient generating equipment. The feasibility of the technique is demonstrated by measuring the diffusion of water, oil, and water-soluble salt in a highly concentrated water-in-oil emulsion. The diffusion of water and salt reveal precise information about the droplet size distribution below the μm-range. Common droplet size distribution explains both the data for water with finite long-range diffusion and the data for salt with negligible long-range diffusion. The results of water diffusion show that the technique is efficient in deconvolving the effects of molecular exchange between droplets and restricted diffusion within droplets. The effects of water exchange suggest that droplets of different sizes are uniformly distributed within the sample.     

以香草素为内标之气相层析光谱法定量牛樟木精油指标成分松油醇的快速分析方法

牛樟精油具有独特浓郁的香气,其中以α-松油醇(α-terpineol)为牛樟精油主要成分。由于樟树精油制品可依种类、变种、亚种等不同而有不同成分,以松油醇最具独特性,可作为牛樟木精油品质重要指标成分,应用以区别牛樟树与冇樟以及香樟等木材精油的方法,因此建立市售牛樟木精油指标成分α-松油醇含量的简便快速又准确的检验方法便有其必要性。该研究拟以市售精油液体样品,不经任何前处理,加入适当之内标准溶液溶解后,直接注入气相层析光谱仪中,配合适当的分离管柱及气相层析条件,以期建立简便快速又准确的牛樟木精油指标成分α-松油醇之定量方法。毛细管柱气相层析具有高解析度及高灵敏度等优点,仍为现代最重要分析技术之一,因此研究建立了以香草素为内标准定量牛樟木精油指标成分α-松油醇(α-terpineol)之气相色谱层析法的快速分析方法。牛樟木精油液体样品,加入适当量之香草素内标准溶液混合溶解后,即可直接注入配有广口径之毛细管柱(megabore column)气相色谱仪中分析,相当简便,每分析一个样品仅需约30 min。结果显示松油醇之最低定量浓度（limit of quantitation, LOQ）为1 μg·mL-1左右。在添加回收试验中添加松油醇1.0及10.0 mg 于市售冇樟精油及牛樟精油中,其回收率在98%~103%,变异系数均在10.8%以下,显示该方法的精密度相当高。以该研究建立的方法分析15件市售牛樟精油中松油醇含量,结果显示,市售牛樟木精油的松油醇含量最高约51.6%及最低为21.3%左右,此结果显示以定量松油醇作为市售牛樟精油品质指标是一快速、准确且可行的方法。     

汞光谱色散曲线实验研究

在现有理论基础上,利用汞光谱色散实验测出汞光谱8条谱线对棱镜的折射率后,通过多项式拟合得到了波长和折射率的经验关系,即色散特性函数,并由此得到了汞光谱的角色散率.本文有助于人们更深入认识色散现象.     

Spectroscopy Study on Cobalt EDTA Complexes

The photoacoustic spectra of Co(H2EDTA)·3H20, Ca[Co(EDTA)H20]·4H20, Sr[Co(HEDTA)H20]2·4H20, Ba[Co(HEDTA)H20]2·4H20 complexes crystal are determined in the region of 300–800nm. In these spectra, the separations of absorption bands observed at 510nm and 650nm, the peak widths of 510nm band are variable in this series complexes. It is explained by the electron mutual effect, strength of ligand field and the symmetry of coordination group. The structure characters of these series complexes are also discussed.     

Spectroscopic Properties and Electronic Structure of (L-Glutamato)(2, 2′-Bipyridine) copper(II)

Cu(L-glu)(bpy)(L-glu = L-glutamato; bpy = 2, 2′-bipyridine) was prepared. Its electronic absorption spectrum and photoacoustic spectrum were recorded at room temperature. They were compared with each other and compared quantitatively with ligand field theory(LFT) and the radical wave function of non-free ions^[1–3]. Therefore, the electronic structure was also investigated with its spectrum behaviors and PLFT^[1–3].     

An Overview of The Photoacoustic Phase Spectra of Rare Earth Complexes

Abstract

The photoacoustic(PA) amplitude and phase spectra of several kinds of rare earth (RE) complexes are reported and summarized briefly. It is observed that both the amplitude and phase spectra well characterize the different energy levels of the RE complexes. The phase angle of the RE complexes is associated with the relaxation time τ and the optical absorption coefficient β concerning with the π-π? transition and the f-f transitions, respectively. After individual detailed discussion of the phase spectra, a reasonable theoretical consideration is given to interpret the results.     

SPECTROSCOPIC PROPERTIES AND ELECTRONIC STRUCTURE OF [CuCl(L-PROLINATO)(H2O)]

ABSTRACT

[CuCl(L-Prolinato)(H₂O)] was prepared. Its electronic absorption spectrum and photoacoustic spectrum were recorded at the room temperature. A semi-empirical method of ligand-field-theory PLFT was utilized to calculate the d-d transition energy. According to the results, the spectrum was explained satisfactorily.     

Singular spectrum analysis and Fisher–Shannon analysis of spring flow time series: An application to Anjar Spring,Lebanon

In this study, the time dynamics of water flow from Anjar Spring was investigated, which is one of the major issuing springs in the central part of Lebanon. Likewise, many water sources in Lebanon, this spring has no continuous records for the discharge, and this would prevent the application of standard time series analysis tools. Furthermore, the highly nonstationary character of the series implies that suited methodologies can be employed to get insight into its dynamical features. Therefore, the Singular Spectrum Analysis (SSA) and Fisher–Shannon (FS) method, which are useful methods to disclose dynamical features in noisy nonstationary time series with gaps, are jointly applied to analyze the Anjar Spring water flow series. The SSA revealed that the series can be considered as the superposition of meteo-climatic periodic components, low-frequency trend and noise-like high-frequency fluctuations. The FS method allowed to extract and to identify among all the SSA reconstructed components the long-term trend of the series. The long-term trend is characterized by higher Fisher Information Measure (FIM) and lower Shannon entropy, and thus, represents the main informative component of the whole series. Generally water discharge time series presents very complex time structure, therefore the joint application of the SSA and the FS method would be very useful in disclosing the main informative part of such kind of data series in the view of existing climatic variability and/or anthropogenic challenges.     

Study on High-Temperature Spectra of Asymptotic Asymmetric-Top Molecule O3

The line intensities of 001-000 transition of the asymptotic asymmetric-top O₃ molecule at several temperatures are calculated by directly calculating the partition functions and regarding the rotationless transition dipole moment squared as a constant. The calculated values of the total internal partition sums (TIPS) are consistent with the data of HITRAN database with -0.61% at 296 K. The calculated line intensity data at 500 K and 3000 K are also in excellent agreement with the data in HITRAN database with less than 0.659% and 5.458% at 500 K and 3000 K, which provide a strong support for the calculations of partition function and line intensity at high temperature. Then we extend the calculation to higher temperatures. The line intensities and simulated spectra of ν₃ band of the asymptotic asymmetric-top O₃ molecule at 4000 and 5000 K are reported. The results are of significance for the studying of the molecular high-temperature spectrum including experimental measurements and theoretical calculations.