HAXPES （hard X-ray photoelectron spectroscopy） is a powerful emerging instrument in surface analysis. It extended the photoelectron energy range up to 15,000 eV and opened the possibility to study much thicker films...HAXPES （hard X-ray photoelectron spectroscopy） is a powerful emerging instrument in surface analysis. It extended the photoelectron energy range up to 15,000 eV and opened the possibility to study much thicker films, buried layers and bulk electronic properties. In order to study these features, data for the electron IMFP （inelastic mean free path） at these energies is needed. To date, only calculated IMFP are available at energies above 5,000 eV and therefore experimental validation of these calculations are essential. In this paper, a new approach for using the HAXPES spectra is presented. This approach, treats the attenuated part of the electron spectrum as a whole to calculating the average electron energy loss. This average electron energy loss is the result of inelastic collisions in the material and hence, carry with it information about the electron transport poses. Carbon layers with thicknesses between 20 and 75 nanometer deposited over copper substrate were used to test this approach at the Spanish beam-line （Spline） in the ESRF （European synchrotron radiation facility）. The measured results showed good agreement with the predictions of the multiple inelastic scattering theory. In addition, an algorithm for the experimental evaluation of electron IMFP, using the measured energy loss, is proposed.展开更多
The magnetic properties of a mixed spin-3/2 and spin-2 and a mixed spin-3/2 and spin-5/2 Ising ferromag- netic system with different anisotropies are studied by means of mean-field theory （MFT）. The dependence of th...The magnetic properties of a mixed spin-3/2 and spin-2 and a mixed spin-3/2 and spin-5/2 Ising ferromag- netic system with different anisotropies are studied by means of mean-field theory （MFT）. The dependence of the phase diagram on single-ion anisotropy strengths is studied too. In the mixed spin-3/2 and spin-2 Ising model, besides the second-order phase transition, the first order-disorder phase transition and the tricritical line are found. In the mixed spin-3/2 and spin-5/2 Ising model, there is no first-order transition and trieritical line.展开更多
The properties of neutron stars are studied in a relativistic mean-field model with SU(2) chiral symmetry spontaneous breaking being considered. The calculation results indicate that the effects of the chiral symmetry...The properties of neutron stars are studied in a relativistic mean-field model with SU(2) chiral symmetry spontaneous breaking being considered. The calculation results indicate that the effects of the chiral symmetry spontaneous breaking are not negligible.展开更多
The aim was to characterize thyroid function in Hispanic hypertensive population. Retrospective study of 1,023 individuals was performed, in which 68.23% had hypertension （74.21% women） and 37.25% had thyroid pathol...The aim was to characterize thyroid function in Hispanic hypertensive population. Retrospective study of 1,023 individuals was performed, in which 68.23% had hypertension （74.21% women） and 37.25% had thyroid pathology. Age, weight, blood pressure, biochemical measurements were recorded, mean age： 53.02 ± 14.80 yr, mean weight： 83.05 ±16.95 kg, thyrotropin-stimulating hormone （TSH） hypertensive patients： 5.55±1.63 μUI/mL and without hypertension： 3,72 ± 1.60 μUI/mL. TSH range concentration distributed by sex indicates： 1.50-2.49 μUI/mL men, 2.50-5.01 μUI/mL women. TSH categories vs. age were positively associated （r = ＋ 0.114, P = 0.044） and hypertension by age was also correlated （r = ＋ 0.178, P = 0.0001）. Significant positive association we found between TSH and diastolic blood pressure （r = ＋ 0.197, P = 0.008）. Systolic and diastolic blood pressure vs. age were positively increasing （r = ＋ 0.410,p = 0.0001; r = ＋0.285, P = 0.0001, respectively）. Prevalence of thyroid pathology in hypertensive subjects are hyperthyroidism 5.87%; hypothyroidism 20.34% （5.73% subclinic） and autoimmune disease 6.25%. High percentage of hypertensive population has concomitant thyroid diseases, more common in women （50-70 years）. Systematic surveillance for occult thyroid dysfunction in patients with hypertension could prevent future cardiovascular disease.展开更多
An appropriate acquisition configuration in terms of signal quality can optimize the acquisition performance. In view of this, a new approach of acquisition assisted by the control voltage of automatic gain control(AG...An appropriate acquisition configuration in terms of signal quality can optimize the acquisition performance. In view of this, a new approach of acquisition assisted by the control voltage of automatic gain control(AGC) is proposed. This approach judges the signal power according to the AGC control voltage and switches the working modes correspondingly and adaptively. Non-coherent accumulation times and the detection threshold are reconfigured according to the working mode. Theoretical derivation and verification by simulation in typical situations are provided, and the algorithm is shown to be superior in terms of the mean acquisition time, especially in strong signal scenarios compared with the conventional algorithm.展开更多
The trimmed mean is one of the most common estimators of location for symmetrical distributions, whose effect depends on whether the trim rate matches the proportion of contaminated data. Based on the geometric charac...The trimmed mean is one of the most common estimators of location for symmetrical distributions, whose effect depends on whether the trim rate matches the proportion of contaminated data. Based on the geometric characteristics of the curve of the trimmed variance function, the authors propose two kinds of adaptive trimmed mean algorithms. The accuracy of the estimators is compared with that of other often-used estimates, such as sample mean, trimmed mean, trimean, and median, by means of simulation method. The results show that the accuracy of the adaptive derivative optimization trimmed mean method is close to the optimum performance in case of medium contamination （the contamination rate is less than 50%）. Under high contamination situation （the contamination rate equals 8070）, the performance of the estimates is comparable to that of the median and is superior to other counterparts.展开更多
文摘HAXPES （hard X-ray photoelectron spectroscopy） is a powerful emerging instrument in surface analysis. It extended the photoelectron energy range up to 15,000 eV and opened the possibility to study much thicker films, buried layers and bulk electronic properties. In order to study these features, data for the electron IMFP （inelastic mean free path） at these energies is needed. To date, only calculated IMFP are available at energies above 5,000 eV and therefore experimental validation of these calculations are essential. In this paper, a new approach for using the HAXPES spectra is presented. This approach, treats the attenuated part of the electron spectrum as a whole to calculating the average electron energy loss. This average electron energy loss is the result of inelastic collisions in the material and hence, carry with it information about the electron transport poses. Carbon layers with thicknesses between 20 and 75 nanometer deposited over copper substrate were used to test this approach at the Spanish beam-line （Spline） in the ESRF （European synchrotron radiation facility）. The measured results showed good agreement with the predictions of the multiple inelastic scattering theory. In addition, an algorithm for the experimental evaluation of electron IMFP, using the measured energy loss, is proposed.
文摘The magnetic properties of a mixed spin-3/2 and spin-2 and a mixed spin-3/2 and spin-5/2 Ising ferromag- netic system with different anisotropies are studied by means of mean-field theory （MFT）. The dependence of the phase diagram on single-ion anisotropy strengths is studied too. In the mixed spin-3/2 and spin-2 Ising model, besides the second-order phase transition, the first order-disorder phase transition and the tricritical line are found. In the mixed spin-3/2 and spin-5/2 Ising model, there is no first-order transition and trieritical line.
文摘The properties of neutron stars are studied in a relativistic mean-field model with SU(2) chiral symmetry spontaneous breaking being considered. The calculation results indicate that the effects of the chiral symmetry spontaneous breaking are not negligible.
文摘The aim was to characterize thyroid function in Hispanic hypertensive population. Retrospective study of 1,023 individuals was performed, in which 68.23% had hypertension （74.21% women） and 37.25% had thyroid pathology. Age, weight, blood pressure, biochemical measurements were recorded, mean age： 53.02 ± 14.80 yr, mean weight： 83.05 ±16.95 kg, thyrotropin-stimulating hormone （TSH） hypertensive patients： 5.55±1.63 μUI/mL and without hypertension： 3,72 ± 1.60 μUI/mL. TSH range concentration distributed by sex indicates： 1.50-2.49 μUI/mL men, 2.50-5.01 μUI/mL women. TSH categories vs. age were positively associated （r = ＋ 0.114, P = 0.044） and hypertension by age was also correlated （r = ＋ 0.178, P = 0.0001）. Significant positive association we found between TSH and diastolic blood pressure （r = ＋ 0.197, P = 0.008）. Systolic and diastolic blood pressure vs. age were positively increasing （r = ＋ 0.410,p = 0.0001; r = ＋0.285, P = 0.0001, respectively）. Prevalence of thyroid pathology in hypertensive subjects are hyperthyroidism 5.87%; hypothyroidism 20.34% （5.73% subclinic） and autoimmune disease 6.25%. High percentage of hypertensive population has concomitant thyroid diseases, more common in women （50-70 years）. Systematic surveillance for occult thyroid dysfunction in patients with hypertension could prevent future cardiovascular disease.
基金supported by the National Natural Science Foundation of China(Grant No.61401026)the National High Technology Research and Development Program of China(Grant No.2014AA1070)
文摘An appropriate acquisition configuration in terms of signal quality can optimize the acquisition performance. In view of this, a new approach of acquisition assisted by the control voltage of automatic gain control(AGC) is proposed. This approach judges the signal power according to the AGC control voltage and switches the working modes correspondingly and adaptively. Non-coherent accumulation times and the detection threshold are reconfigured according to the working mode. Theoretical derivation and verification by simulation in typical situations are provided, and the algorithm is shown to be superior in terms of the mean acquisition time, especially in strong signal scenarios compared with the conventional algorithm.
基金supported in part by the National Basic Research Program of China under Grant No. 2010CB950703the Natural Science Foundation of China under Grant No.10901020the Fundamental Research Funds for the Central Universities
文摘The trimmed mean is one of the most common estimators of location for symmetrical distributions, whose effect depends on whether the trim rate matches the proportion of contaminated data. Based on the geometric characteristics of the curve of the trimmed variance function, the authors propose two kinds of adaptive trimmed mean algorithms. The accuracy of the estimators is compared with that of other often-used estimates, such as sample mean, trimmed mean, trimean, and median, by means of simulation method. The results show that the accuracy of the adaptive derivative optimization trimmed mean method is close to the optimum performance in case of medium contamination （the contamination rate is less than 50%）. Under high contamination situation （the contamination rate equals 8070）, the performance of the estimates is comparable to that of the median and is superior to other counterparts.
