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1.
Lanthanide ions doped luminescent materials are widely studied for latent fingerprint detection. However, most of these materials are synthesized at very high temperatures and use UV C light for visualization, which is harmful to eye, skin, etc. Herein, the Gd0.95Eu0.05PO4 nanorods synthesized by a simple co-precipitation method at 185 °C were reported for latent fingerprint visualization under 395 nm light. The Gd0.95Eu0.05PO4 nanomaterial has monoclinic crystal structure and shows rod-shaped morphology. Further, these Gd0.95Eu0.05PO4 nanorods exhibit excellent photoluminescence properties and strong fuchsia emission under UV light. These nanorods have been employed for developing latent fingerprints on various porous and non-porous substrates by the powder dusting technique, which exhibits clear and well defined details with high contrast, selectivity and sensitivity under 395 nm UV light. Latent fingerprints developed after 72 h of their deposition also show clear contrast with these nanorods. Therefore, the Gd0.95Eu0.05PO4 nanorods can be used for latent fingerprint visualization applications.  相似文献   

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Photographic images obtained by the Kirlian technique are principally a record of corona activity during an exposure interval. Most of the variations in the images of the corona of a living subject who is in contact with the photographic film can be accounted for by the presence of moisture on or within the subject's surface. During exposure, moisture is transferred from the subject to the emulsion surface of the photographic film and causes an alteration of the electric charge pattern on the film, hence the electric field at the surface of the subject. As a result, large variations in the density of corona images, corona streamer trajectories, and image coloration can be brought about. The radial extent of corona images--that is, the range of corona streamers--is an inverse function of the resistance in the circuit formed by the high-voltage supply, the subject, and the film-electrode configuration. This is because the voltage at which corona is initiated is dependent on the rate of rise of the voltage impressed between the subject and the electrode, and the rate of rise is governed by the applied voltage waveform and the voltage drop across the resistance. The range of streamers is proportional to the corona onset voltage. However, we have not seen any influence of large changes in skin resistance on streamer range. Presumably, this is due to the shunting effect of skin capacitance. In general, the photographic response to moisture suggests that corona discharge photography may be useful in the detection and quantification of moisture in animate and inanimate specimens through the orderly modulation of the image due to various levels of moisture.  相似文献   

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Latent fingerprints (LFPs) were the most significant identification method for individualization. Most commonly available fingerprints (FPs) in crime spot investigation were latent and patent types. Generally,LFPs were invisible and thus the effective visualization technique necessitates for the analysis of such FPs. In the past years, many traditional visualization techniques have been employed, but suffered with low resolution, sensitivity, contrast and high background noise. To overcome such limitations, we synthesized Sm~(3+) doped CaSiO_3 nanophosphors (NPs) via an ultrasound irradiation route using mimosa pudica (m. p.)leaves extract as a bio-surfactant. The morphological behavior of the prepared samples was extensively studied by varying the concentration of the m. p. extract, ultrasound irradiation duration, pH level of the precursor solution and sonication power. The photoluminescence (PL) emission spectra exhibit characteristic peaks at~561,601 and 647 nm, which were attributed to~5G_(5/2)→~6H_J(J=5/2,7/2 and 9/2) transitions of Sm~(3+) ions.The Judd-Ofelt(J-O) intensity parameters and other radiative properties were estimated using PL data. The Commission International de I'Eclairage (CIE) color coordinates were positioned in orange-red region shows average correlated color temperature (CCT) value of~3576 K. The optimized samples can be used as a labeling agent for the visualization of LFPs on various porous and non-porous surfaces under normal light irradiation. The visualized FPs reveals well defined ridge characteristics, namely whorl, loop,arch, bifurcation, eye, island, bridge, sweat pores, etc, with high sensitivity, selectivity, low contrast and background hindrance. Aforementioned results evidence that the prepared CaSiO_3:Sm~(3+) NPs were promising luminescent materials for solid state lighting and forensic applications.  相似文献   

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The human "fingerprints" detected by the phage M13 DNA probe from 40 simple families with some presumably genetic malformations were observed. When only one parent had a specific band, the mean segregation frequency of all the electrophoretic bands detected was equal to 0.485, which confirmed the hypothesis about the Mendelian inheritance and high level of heterozygosity of hypervariable loci. The mean new measure of similarity between the parents calculated by Li C.C. was 0.54 (this measure within only fathers and only mothers was equal to the mean population level of similarity 0.41).  相似文献   

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In the present work, TiO2:Eu3+ (1 mol%–11 mol%) nano powders (NPs) were prepared via a facile one-pot hydrothermal method by using Epigallocatechin Gallate (EGCG) as bio-surfactant. The optimized TiO2:Eu3+ (5 mol%) NPs can be used as fluorescent labeling agent for visualizing of latent fingerprints (LFPs) on various porous and non-porous surfaces. The obtained results exhibit well defined ridge details with high sensitivity, selectivity, and low background hindrance which show greater advantages as compared to conventional powders. We demonstrated the viability of high-performance security labels thorough excellent luminescence for practical anti-mimetic applications. Morphology of the prepared samples is highly dependent on pH, concentration of the bio-surfactant, temperature and time durations. Photoluminescence (PL) emission spectra exhibit intense red emission at ~ 615 nm due to electric dipole transition (5D07F2). Photometric (CIE and CCT) results clearly show the intense warm red emission of the optimized samples. Therefore, this work offers a superior and universal luminescent label, which can be applied to visualize miniature LFPs particulars for individualization and consequently display great prospective in forensic investigation.  相似文献   

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A new process for modifying a metallic surface in a vacuum arc discharge plasma using thermally stimulated ion diffusion is considered. The effect of the bias voltage (negative substrate potential) on the processes that occur on the surface of a treated part is studied when the substrate material interacts with an accelerated metallic-ion flow. The phase and elemental compositions of the modified layer are studied for substrates made of nickel-based superalloys, austenitic and martensitic steels, and titanium-based alloys. The heat resistance, the salt corrosion resistance, and the corrosion cracking resistance of steels and titanium-based alloys are investigated after their modification in vacuum arc plasmas of pure metals (Ti, Zr, Al, Cr, Y) and related alloys. The surface modification caused by the thermally stimulated ion saturation of the surfaces of parts made from structural materials is shown to change the structural-phase states of their surfaces and, correspondingly, the properties of these materials in relation to the state of the surface.  相似文献   

9.
Carbon Nanotubes (CNTs) are of significant research interest due to their significant electrical, mechanical, electro-mechanical and thermal properties. This enables CNT to be used in advanced bio-medical, electronics and materials technological applications. CNTs can be synthesized by various methods such as Arc-discharge, Chemical Vapor Deposition (CVD), Laser ablation etc. Still challenge exists when it comes to the yield. In general CNTs are commercially synthesized by Arc-discharge and CVD techniques. In both the cases the defect intensity differs according to the atmosphere which prevails in the production chamber. In the case of CVD the defect intensity is mainly due to pentagons of carbon, which cause curved faces whereas in the case of arc discharge, broken bonds can result at the surfaces. In general, the production of CNTs requires the presence of a controlled atmosphere inside the reaction chamber. Recent research has shown that CNTs can also be produced in open atmosphere but with a significant reduction in the yield. In the present work, a jet of nitrogen gas is applied between the arcing interfaces. As a consequence there is a significant change in the yield and defect density. Characterization techniques such as XRD, FEG-SEM, TEM and Raman spectroscopy confirm the same.  相似文献   

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To assess how reliably hospitals report serious, uncommon communicable diseases to the Department for Public Health, we searched the 1995 hospital discharge data set (HDDS) collected by the Kentucky Health Policy Board for cases of 11 diseases. Of 17 case records found, 4 represented disease occurrences that had been reported to the Department; 6 represented coding errors in the HDDS; 4 were instances where a reportable disease had been suspected but not confirmed by subsequent workup; 1 case was a resident of another state; and 2 were cases of invasive Hemophilus influenzae infection in adults that should have been reported to the Department. The study found no evidence that hospitals failed to report vaccine-preventable diseases. There was evidence that the HDDS needs improved accuracy to maximize its usefulness for public health purposes.  相似文献   

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During storage of prerigor freeze-dried beef, glycogen is not broken down even at 97.5% r.h. (moisture content of the meat about 30%). However, the metabolites of glycogen -- glucose, fructose, and their phosphoric acid esters -- are changed during storage at r.h. greater than 25%, mainly by the effect of glycolytic enzymes. Also nonenzymic reactions of the Maillard type seem to occur. An accelerated breakdown of these carbohydrates with increasing water activity was found. Even though the sugar monophosphates are broken down, no increase in C3 metabolites was found. The reason for this could be that the energy-rich compounds glyceraldehyde phosphate and dihydroxyacetone phosphate form complexes with some proteins. It is suggested that also pyruvate reacts with free amino groups of proteins. The breakdown of carbohydrates increases in uncooked freeze-dried samples above 60% r.h. whereas nonenzymatic reactions of the Maillard type reach a maximum rate at nonenzymatic reactions of the Maillard type reach a maximum rate at 60% r.h. This also shows that the disappearance of carbohydrates during storage of freeze-dried prerigor beef is mainly due to enzymatic processes.  相似文献   

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Prior research has focused on the latent structure of endophenotypic markers of schizophrenia liability, or schizotypy. The work supports the existence of 2 relatively distinct latent classes and derives largely from the taxometric analysis of psychometric values. The present study used finite mixture modeling as a technique for discerning latent structure and the laboratory-measured endophenotypes of sustained attention deficits and eye-tracking dysfunction as endophenotype indexes. In a large adult community sample (N=311), finite mixture analysis of the sustained attention index d′ and 2 eye-tracking indexes (gain and catch-up saccade rate) revealed evidence for 2 latent components. A putative schizotypy class accounted for 27% of the sample. A supplementary maximum covariance taxometric analysis yielded highly consistent results. Subjects in the schizotypy component displayed higher rates of schizotypal personality features and an increased rate of treated schizophrenia in their 1st-degree biological relatives compared with subjects in the other component. Implications of these results are examined in light of major theories of schizophrenia liability, and methodological advantages of finite mixture modeling for psychopathology research, with particular emphasis on genomic issues, are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

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The chemical nature of essential oils makes them suitable for analysis using a gas chromatography-mass selective detector (GC-MSD). Mass spectra (MS) libraries can not be used as unique and absolute criteria for the identification of chromatogram peaks. The wide variety of MS of the libraries, recorded in different conditions, can lead us to erroneous results. In order to increase the reliability of the analytical results, we used as identity criteria, both GC fingerprints resulted from the relative retention indices (RRI) and the recorded MS of the separated compounds. The two criteria have been quantified by their correlation with the standards. A new parameter called global composition evaluation index (I(GCMS)), which resulted from a well-balanced average of the two criteria, has been defined. Because the comparison of the results of the MS with databases is more accurate than the RRI, we considered that the ratio of the two criteria must be at least GC:MS 1:2. A database containing RRI of about 600 components, widely found in essential oils composition and separated on HP-5 column, was created. Two macros based on the Microsoft Excel spreadsheet were also created. The program offers the best 20 matches of each compound with the combined MS and RRI library. The composition of Romanian Acorus calamus L. essential oil was established and the results were compared with those obtained by 'classical' methods.  相似文献   

19.
Results from a longitudinal correlational study of 244 children from kindergarten through 2nd grade indicate that young children's phonological processing abilities are well-described by 5 correlated latent abilities: phonological analysis, phonological synthesis, phonological coding in working memory, isolated naming, and serial naming. These abilities are characterized by different developmental rates and remarkably stable individual differences. Decoding did not exert a causal influence on subsequent phonological processing abilities, but letter-name knowledge did. Causal relations between phonological processing abilities and reading-related knowledge are bidirectional: Phonological processing abilities exert strong causal influences on word decoding; letter-name knowledge exerts a more modest causal influence on subsequent phonological processing abilities. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

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Heart transplantation causes sympathetic cardiac denervation. Measurements of plasma concentrations of the main presynaptic noradrenaline metabolite, dihydroxyphenylglycol (DOPEG, the plasma pool of which is exclusively neuronal in origin), were used to examine sympathetic reinnervation of the transplanted human heart. We determined arterial and coronary-venous plasma concentrations of DOPEG in 27 heart transplant recipients (transplant age ranging from 0.5 to 5 years) and in 9 control patients. In each of the control patients the DOPEG concentration was higher in coronary venous plasma than in arterial plasma (mean arterio-venous increment: 57.3 +/- 8.7%; p < 0.001). However, in heart transplant recipients, 18 out of 27 patients showed an arteriovenous increment in plasma DOPEG (mean increment in all patients 12.6 +/- 2.0%; p < 0.05). The ratio of the coronary-venous to arterial DOPEG concentration was positively correlated with the time after transplantation (p = 0.02 for individual results and p < 0.01 for mean group results). Thus, our data provide evidence for a time-dependent partial sympathetic reinnervation of the transplanted heart.  相似文献   

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