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1.
Guang Pu Xue Yu Guang Pu Fen Xi ; 35(1): 122-7, 2015 Jan.
Artículo en Zh | MEDLINE | ID: mdl-25993833

RESUMEN

In recent years, with frequent domestic food safety incidents related to the plasticizing agent, the detection of plasticizers in food research becomes increasingly urgent. DEHP is one of the plasticizer. In the present paper, theoretical Raman spectrum and experimental Raman spectrum of DEHP were given. DEHP molecular structure was optimized by DFT(B3LYP) method. DEHP molecular Raman spectra and infrared spectra were calculated with. HF theory and DFT theory based on 3-2G level. The analytical reagent level DEHP Raman spectra was measured, and was compared with theoretical spectra, and good agreements were obtained between the theoretical and experimental results. Because of different calculation methods, we can see that both the wave number and relative intensity of peaks have small differences. DEHP structure parameters were also given in the paper including bond lengths and bond angles etc. Vibrational modes were assigned to all bands between 400 and 3 500 cm-1. Raman spectroscopy study of the commonly used plasticizer dioctyl phthalate was reported in this paper for the first time. This effort will contribute to the research and application of Raman spectroscopy in the field of food testing.


Asunto(s)
Dietilhexil Ftalato/análisis , Embalaje de Alimentos , Plastificantes/análisis , Espectrometría Raman
2.
Guang Pu Xue Yu Guang Pu Fen Xi ; 35(6): 1464-8, 2015 Jun.
Artículo en Zh | MEDLINE | ID: mdl-26601348

RESUMEN

The high precision scattering spectrum of spatial fragment with the minimum brightness of 4.2 and the resolution of 0.5 nm has been observed using spectrum detection technology on the ground. The obvious differences for different types of objects are obtained by the normalizing and discrete rate analysis of the spectral data. Each of normalized multi-frame scattering spectral line shape for rocket debris is identical. However, that is different for lapsed satellites. The discrete rate of the single frame spectrum of normalized space debris for rocket debris ranges from 0.978% to 3.067%, and the difference of oscillation and average value is small. The discrete rate for lapsed satellites ranges from 3.118 4% to 19.472 7%, and the difference of oscillation and average value relatively large. The reason is that the composition of rocket debris is single, while that of the lapsed satellites is complex. Therefore, the spectrum detection technology on the ground can be used to the classification of the spatial fragment.

3.
Guang Pu Xue Yu Guang Pu Fen Xi ; 34(12): 3218-23, 2014 Dec.
Artículo en Zh | MEDLINE | ID: mdl-25881412

RESUMEN

The authors have investigated the optical properties of core-shell structure of mist wrapped dust particles based on the method of discrete dipole approximation (DDA). The influence on the thickness of the elliptical core-shell structure were calculated which the ratio of long axis and short axis is 2:1, and the change of scattering angle for scattering characteristics. The results shows that the thickness of outer layer increase from 1.2 to 4.8 µm with the scattering and extinction coefficient of double core-shell layers particles decrease from 3.4 and 3.43 to 2.543 and 2.545, when the size of inner core isn't change. And scattering relative strength also increased obviously. The thickness of inner core increase from 0.6 to 2.4 µm with the of scattering and extinction coefficient change from 2.59 and 2.88 to 2.6 and 2.76 when thickness of outer remain constant. Effect of the thickness of visible outer layer on the scattering characteristics of double core-shell layers particles is greater, because of the interaction between scattering light and outer materials. The scattering relative intensity decrease with wavelength increased, while increased with the scale of core-shell structure increase. The results make a promotion on the study of the transportation characteristics of laser and scattering characteristics when the atmospheric aerosol and water mist interact together.

4.
Front Pharmacol ; 14: 1229963, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37719857

RESUMEN

Curcumae Longae Rhizoma (turmeric), Curcumae Radix and Curcumae Rhizoma are derived from the Curcuma species, and have gradually become three of the most commonly used medicinal herbs in China due to their different origins, processing methods and medicinal part. These three herbs have certain similarities in morphology, chemical composition, and pharmacological effects. All three of these herbs contain curcuminoids and volatile oil compounds, which exhibit anti-inflammatory, anti-tumor, antioxidant, and neuroprotective properties, although modern clinical applications have their own requirements. At present, there is no systematic guidelines for the clinical application of these three of Curcuma species; consequently, there is a high risk of unwanted phenomena associated with the mixing and indiscriminate use of these herbs. In this review, we focus predominantly on morphology, chemical composition, and the pharmacological activity of these three Curcuma herbs and summarize the current status of research in this field. Our goal is to provide a better understanding of clinical value of these Curcuma species so that we can provide reference guidelines for their further development, utilization and rational clinical application.

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