[Analysis of tobacco site features using near-infrared spectroscopy and projection model].

In this paper, total of 5170 flue-cured tobacco samples collected from 2003 to 2012 in the domestic and foreign origin by Shanghai Tobacco Group Technical Center were tested by near infrared spectroscopy, including the typical upper leaves 1394, central 2550, the lower part of 1226. Using projection model of based on principal component and Fisher criterion (PPF), follow the projected results to get no statistically significant differences at adjacent principal components, and the number of principal components as little as possible, in this paper, four main components to build projection analysis model, the model results show that: the near-infrared spectral characteristics of the upper and lower leaves have a significant difference that can be achieved almost entirely distinguished; while the middle leaves with upper and lower have a certain degree of overlap, which is consistent to the actual situation of the continuity of tobacco leaf. At the same time, Euclidean distance between the predicted sample projection values and the mean projection values of each class in the model, a description is given for the prediction samples to quantify the extent of the site features, and its first and second close categories. Using the dispersion of projected values in model and the given threshold value, prediction results can be refined into typically upper, upper to central, central to upper, typical central, central to the lower, the lower to central, typically the lower, or super-model range. The model was validated by 34 tobacco samples obtained from the re-drying process in 2012 with different origins and parts. This kind of analysis methods, not only can achieve discriminant analysis, and get richer feature attribute information, can provide guidance on the raw tobacco processing and formulations.

The photochemistry properties on interaction silver with tryptophan.

UV-vis and fluorescence spectra for interaction silver(I) ion with tryptophan (Trp) have been studied. The influence of pH of media, multicomponent concentration, including amino acids, silver(I) ion, formaldehyde, sodium dodecyl sulfate (SDS), and trihydroxymethylaminomethane (Tris) as well as temperature, illumination, time, etc. on reaction were investigated, and the mechanism of reaction has been explored. The results shown that the optimum condition for the interaction between tryptophan and silver(I) ion were found.

Preparation of Cu-Ni alloy nanocrystallites in water-in-oil microemulsions.

The well-mixed copper-nickel nanoparticles were prepared when the molar ratio of Cu2+ to Ni2+ was 1:1 by simultaneous reduction of CuSO4 and NiCl2 with hydrazine in the microemulsion of SDS/n-butanol/n-heptane/water at 70 degrees C, and was characterized by TEM, ED, TGA, EDS, and XRD. ED analysis and XRD patterns suggest the formation of the homogeneous alloy structure in the bimetallic nanoparticles. Average size of the sample calculated from the full width at medium height of peak 111 in the XRD patterns using Scherrer formula is 5.53 nm. TEM photographs show a narrow distribution of Cu-Ni nanoparticles that essentially are monodispersed and the mean diameter is 12 nm. The results indicate that the composition and size of alloy nanoparticles depend on the mole ratio of H2O to SDS, the method of addition of Cu2+ and Ni2+, and the mole ratio of Cu2+ and Ni2+ in the initial precursor solution.

[The preparation of NiFe2O4 composite nanoparticles and spectral properties].

The composite nanoparticles of Ni-ferrite with coated gelatin were prepared with the gel-microemulsion chemical tailoring method. The gelatin FeCl2 and NiCl2 were used to prepare gel, which was tailored to be particles in micellar of microemulsion, and the particles were reduced, compounded and nucleated. Surveying by XRD, TEM, IR and EDS showed that the particles formed were coated by gelatin protein and their mean sizes are in the range of 10-100 nm, and particle sizes are 3.3-4.6 nm. There are about 3-22 NiFe2O4 particles on each spheroid. The measurement of magnetic parameters indicated that the specific saturation magnetization was sigma(s) = 36.31 x 10(3)/4pi(A x m(-1) x g(-1)), coercivity was H(c) = 6750 A x m(-1), and residual magnetism B(r) = 4.39 x 10(3)/4pi(A x m(-1) x g(-1)).

[Preparation and characterization of polymeric ultrafine particles on Hb-SDS-Ag hydrogeles (I)].

Preparation and characterization of polymeric particles ultrafine on Hb-SDS-Ag have been reported. (Taking fixed quantity of Hb, SDS to be putting in a beaker, then Ag(NH3)2NO3 solution, pH--12 buffer, n-heptane and iso-amyl-alcohol were added. And fixed quantity formaldehyde, n-heptane and iso-amyl-alcohol were added in another beaker. They were stirred emulsification respectively, both of mixture were mixed in a three-well flask and which were reacted for 1.5 h at 60 +/- 0.5 degrees C. After cooling, the precipitation was separated and washed once and again, it was dried) The structure of surface have been investigated by XRD, TEM and FT-IR for this polymeric ultrafine particles, and size of diameter is about 120 nm. It is shown that Ag+ ion first formed chemical binding with Hb, then reduced to Ag particles and finally collected to a network polymers of coated by Hb.