The analysis of fingerprint chemical composition is a meaningful way to excavate the multidimensional information of fingerprint, including the donor profiling information and the age of a fingerprint, which broadens the evidential values of fingerprint, especially for the partial and distorted fingerprint. But the research remains still in the pilot phases or is ongoing. Amino acids are the dominant organic substances in latent sweat fingerprint and influenced by many donor factors.
View Article and Find Full Text PDFTime-of-flight secondary ion mass spectrometry (TOF-SIMS) has been applied in forensic science for fingerprint detection. However, due to limitations of the instrument, it is not always possible to directly sample fingerprints on certain substrates. In this report, we indirectly sampled fingerprints using transfer films.
View Article and Find Full Text PDFPhotonic crystal fibers with three and four zero-dispersion wavelengths are presented through special design of the structural parameters, in which the closing to zero and ultra-flattened dispersion can be obtained. The unique phase-matching properties of the fibers with three and four zero-dispersion wavelengths are analyzed. Variation of the phase-matching wavelengths with the pump wavelengths, pump powers, dispersion properties, and fiber structural parameters is analyzed.
View Article and Find Full Text PDFGuang Pu Xue Yu Guang Pu Fen Xi
January 2015
In order to grasp the inner wall condition of ring forgings, an inner wall condition monitoring method based on infrared spectra for ring forgings is proposed in the present paper. Firstly, using infrared spectroscopy the forgings temperature measurement system was built based on the three-level FP-cavity LCTF. The two single radiation spectra from the forgings' surface were got using the three-level FP-cavity LCTF.
View Article and Find Full Text PDFThe dispersion and mode characteristics in a dual-concentric-core photonic crystal fiber, based on pure silica, are simulated by the multipole method. The fiber exhibits very large negative dispersion due to anticrossing of two individual inner core and outer core modes. Near the wavelength of 1.
View Article and Find Full Text PDFIn the simulation of photonic crystal fibers, the fixed value of the normalized equivalent core radius (p/Lambda) in the fully vectorial effective index method is inaccurate. For what is believed to be the first time, the relation of p/Lambda with normalized frequency (Lambda/lambda) and hole-to-pitch ratio (d/Lambda) is obtained. The improved fully vectorial effective index method (IFVEIM) is proposed.
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