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101.
Recently, a new technique for unique non-iterative multi-exponential fitting of time domain NMR data was proposed. The method was termed SLICING, because an intrinsic part of the method consisted of taking different parts (slices) of the original matrix data and rearranging the slices into a three-way box of data. Subsequently, a directly calculated model of this box provided T(2)-estimates and corresponding amplitudes. The most critical part of this method is the choice of how to slice the original data. In this paper, a new general scheme for this slicing is proposed which (1) is shown to provide more accurate T(2)-estimates and (2) leads to a significant speed improvement compared to earlier approaches. The method is called PowerSlicing, because it takes slices of lag 2(x) (x=0,1,..,N) where 2(N) < or =J/2 and J is the number of bins on the time axis. This approach ensures a reasonably high amount of direct constraints and an appropriate representation of both short and long time decays in the decomposition. 相似文献
102.
Jaromír Bro 《Czechoslovak Journal of Physics》1954,4(1):96
103.
An unstable perminvar effect was found in magnesium manganese ferrite at a temperature of –195°C and its connection with the magnetic after-effect was investigated. The analysis carried out on the basis of Néel's theory showed that both effects are a result of the same diffusion process. The experimental results also show that 180° Bloch walls are displaced when the sample is magnetized.
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- – 195° C qe, , . , - . , 180- .相似文献
104.
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106.
de la Mata-Espinosa P Bosque-Sendra JM Bro R Cuadros-Rodríguez L 《Analytical and bioanalytical chemistry》2011,399(6):2083-2092
This work presents a method for an efficient differentiation of olive oil and several types of vegetable oils using chemometric
tools. Triacylglycerides (TAGs) profiles of 126 samples of different categories and varieties of olive oils, and types of
edible oils, including corn, sunflower, peanut, soybean, rapeseed, canola, seed, sesame, grape seed, and some mixed oils,
have been analyzed. High-performance liquid chromatography coupled to a charged aerosol detector was used to characterize
TAGs. The complete chromatograms were evaluated by PCA, PLS-DA, and MCR in combination with suitable preprocessing. The chromatographic
data show two clusters; one for olive oil samples and another for the non-olive oils. Commercial oil blends are located between
the groups, depending on the concentration of olive oil in the sample. As a result, a good classification among olive oils
and non-olive oils and a chemical justification of such classification was achieved. 相似文献
107.
Bro?ek-Mucha Z 《Microscopy and microanalysis》2011,17(6):972-982
Persistence of gunshot residue (GSR) simultaneously collected from hands, face and hair, and clothing of the shooting person was examined. Samples were collected from five shooters in nine time intervals after a single shoot with a Luger 9 mm pistol, in the range of 0-4 h and examined with scanning electron microscopy and energy dispersive X-ray spectrometry. Numbers of particles, frequencies of occurrence of certain compositions of particles, and their sizes in function of the time intervals were inspected. The greatest numbers of particles were observed in samples collected from hands right after shooting, but they decrease quickly with time. In samples collected from the face smaller initial numbers of particles were found, but they lasted at a similar level longer. The estimated half-life times of particles were less than 1 h for samples taken from the hands, over 1 h for clothing and about 2-3 h for the face. In samples collected at longer intervals after shooting, there were particles present of small sizes and irregular shapes. The results demonstrate that including evidence collected from the suspect's face and hair may increase the probability of detection of GSR in cases when the suspect has not been apprehended immediately after the investigated incident. 相似文献
108.
Jiří Brožek Václava Benešová Lenka Malinová Radka Kalousková Karel Šanda Zdeňka Ledrová 《先进技术聚合物》2014,25(9):934-939
The present paper is focused on the use of promising bio‐based thermoplastic—poly(l ‐lactic acid)—in textile applications and with possible limits related to its enhanced sensitivity to (bio)degradation. Linear and planar fabrics made of staple were exposed to standard washing cycles imitating the maintenance of textile materials. The effect of temperature and pH of the washing bath on the degradation rate of poly(l ‐lactic acid) was monitored by the abiotic hydrolysis test. The properties of the fabrics after carrying out the tests were evaluated from the changes of mass per areal weight, strength, and morphology of the fabrics. The changes of the structure of the polymer chains were assessed by differential scanning calorimetry, by the decrease of molar masses (determined using size exclusion chromatography) and of the viscosity of the polymer solutions, and by infrared spectroscopy. Poly(l ‐lactic acid) fabric finds application for various kinds of garments, and untreated fabric reliably tolerates 60 standard washing cycles. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
109.
For 0 < p < 1 and q > 0 let Gq(n,p) denote the random graph with vertex set [n]={1,…,n} such that, for each graph G on [n] with e(G) edges and c(G) components, the probability that Gq(n,p)=G is proportional to . The first systematic study of Gq(n,p) was undertaken by 6 , who analyzed the phase transition phenomenon corresponding to the emergence of the giant component. In this paper we describe the structure of Gq(n,p) very close the critical threshold. © 2005 Wiley Periodicals, Inc. Random Struct. Alg., 2006 相似文献
110.
Neda Neykova Antonín Bro?Zdeněk Remeš Karel HruškaMarie Kalbá?ová Alexander KromkaMilan Vaně?ek 《Applied Surface Science》2012,258(8):3485-3489
Growth of biocompatible zinc oxide hedgehog-like structures on glass substrates using hydrothermal method at low temperature is demonstrated. The as-grown samples are characterized by scanning electron microscopy and Raman spectroscopy. The optical absorption of the as-grown ZnO microstructures measured with photothermal deflection spectroscopy showed very low optical absorption and strong scattering making ZnO microrods an ideal diffuser in the visible and near IR regions. In addition, the effect of ZnO microstructures on the cultivation of osteosarcoma cells (SAOS-2) is presented. During the 48 h cultivation period, no toxic effect of ZnO as a chemical agent on SAOS-2 cells was observed. 相似文献