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[en] The inductance of a thin film inductor with magnetic core is much less than μ'(magnetic core's permeability) times that of inductor without magnetic core due to the complicated magnetic structure in the scaled-down magnetic elements. Therefore, it is very important to optimize the micro-scale magnetic structure for improving the inductance value of the thin film inductor with magnetic core. In this paper, the magnetization dynamics and magnetic structure have been investigated using micromagnetic simulation method, in which the additional internal boundaries are considered. The simulated results show that the permeability of structured micromagnetic core is promoted 32.5% than that of magnetic element without slits. It opens a new way to improve the dynamic high frequency characteristics of micro-scale magnetic element, which can be used in a thin film inductor. - Highlights: • Simulate the magnetic element with dimensions of 2 μm×1 μm×100 nm with slits using micromagnetic simulation method. • The dynamic characteristics of micro-scale magnetic element can be improved when adding appropriate slits. • Give the corresponding area for different resonance frequency
[en] Inversion quality of T2 spectrum determines the application effect of NMR data. It is necessary to study influence factors of the inversion for improving inversion quality. Firstly, to classify the influence factors of inversion, then to do numerical experiment of each influence factor by means of forward and inversion numerical simulation technique. The results show that the parameters and quality of echo acquisition, such as echo numbers, echo spacing and SNR, have the great influence on the inversion quality of T2 spectrum, the assigned parameters of T2 spectrum inversion, such as numbers and range of T2 value, has the little influence on the inversion quality, and the shape of T2 spectrum also has impact on the inversion. Therefore, In order to improve the application effect of NMR, it should optimize the parameter of echo acquisition besides improving echo SNR. As for the assigned parameters of T2 spectrum inversion, it could be selected flexibly according to the actual conditions. (authors)
[en] Supply chain management directly affect the safe and stable operation of nuclear power plants. China's nuclear power production management information system N1-EAM covers supply chain management business. This paper firstly N1-EAM supply chain management functions, advanced analysis of business processes, Qinshan area combined with supply chain management situation, the initial application of the proposed solutions. (authors)
[en] To investigate the value of MRI radiomics based on T2-weighted (T2W) images in predicting preoperative synchronous distant metastasis (SDM) in patients with rectal cancer. This retrospective study enrolled 177 patients with histopathology-confirmed rectal adenocarcinoma (123 patients in the training cohort and 54 in the validation cohort). A total of 385 radiomics features were extracted from pretreatment T2W images. Five steps, including univariate statistical tests and a random forest algorithm, were performed to select the best preforming features for predicting SDM. Multivariate logistic regression analysis was conducted to build the clinical and clinical-radiomics combined models in the training cohort. The predictive performance was validated by receiver operating characteristics curve (ROC) analysis and clinical utility implementing a nomogram and decision curve analysis. Fifty-nine patients (33.3%) were confirmed to have SDM. Six radiomics features and four clinical characteristics were selected for predicting SDM. The clinical-radiomics combined model performed better than the clinical model in both the training and validation datasets. A threshold of 0.44 yielded an area under the ROC (AUC) value of 0.827 (95% confidence interval (CI), 0.6963–0.9580), a sensitivity of 72.2%, a specificity of 94.4%, and an accuracy of 87.0% in the validation cohort for the combined model. A clinical-radiomics nomogram and decision curve analysis confirmed the clinical utility of the combined model. Our proposed clinical-radiomics combined model could be utilized as a noninvasive biomarker for identifying patients at high risk of SDM, which could aid in tailoring treatment strategies.
[en] We describe uniform and high-temperature-stable mesoporous TiO_2 beads functionalized with gold nanoparticles (AuNPs-TiO_2) for use in conductometric sensing of gases and organic vapors. The size of the interconnected main mesopores of the TiO_2 beads ranges from 8 to 15 nm, and the AuNPs have diameters between 8 and 10 nm. The mesoporous TiO_2 beads are formed during calcination while the structure-directing template agent is removed. Monodispersed AuNPs are formed by reduction in-situ and are placed inside the mesoporous TiO_2 framework. This prevents aggregation of the AuNPs even at 500 °C. The materials were characterized by UV–vis spectroscopy, scanning and transmission electron microscopy, nitrogen adsorption-desorption, and X-ray diffraction. Comb-type gold electrodes were then fabricated on an alumina substrate and are shown to display excellent properties in terms of sensing ammonia, ethanol, methanol or acetone. The sensitivity (defined as the ratio of resistivities under vapor and air) of a typical AuNPs(0.5 %)-TiO_2 gas sensor for ethanol reached up to 5.65 at above 600 ppm at 75 °C. Response time and recovery times (t_9_0 ≤ 20 s) are faster than (or comparable to) other metal-doped TiO_2 sensors, and working temperatures are much lower. An interesting observation was made in that the changes in the conductivity of the sensor change with temperature. The sensor prepared with AuNPs(0.5 %)-TiO_2 is of the p-type (in its response to ammonia gas) at 45 °C, but becomes n-type at 20 °C. Obviously, rather slight changes in temperature lead to a complete change in the direction of the conductometric signal change. This may provide a new aspect in terms of selective and highly sensitive detection of ammonia at ambient and slightly elevated temperatures. (author)
[en] As the basis method for the pollution source apportionment, the isotope ratios were applied for analysis Pb isotopes in coal to explore the feasibility of coal pollution source apportionment. A method was established to analysis Pb isotopes in coal. First, the coal samples were dissolved by the combination of ashing and microwave digestion. Then by using PB resin extraction chromatography, Pb and a large number of matrix elements were effectively separated. After separation, the Pb isotope ratios were determined by multi-collector inductively coupled plasma mass spectrometry. The Pb isotopic ratios of natural Pb solution were calibrated with NIST 981. Using established analytical method, the measured relative error of 208Pb/207Pb, 206Pb/207Pb in natural Pb solution were less than 0.03%, the decontamination coefficients of sodium, magnesium, aluminium, iron, titanium and manganese were more than 400. The results showed that the method was effective and reliable. By measuring the standard coal samples (NIST 1635a, NIST 1632d), Shanxi Datong and Panzhihua coal samples, it was found that the relative standard deviation of 208Pb/207Pb, 206Pb/207Pb were less than 0.2%. The ratio difference of 208Pb/207Pb and 206Pb/207Pb between Datong coal and Panzhihua coal was about 6%∼10%. Such a big difference proved that it was feasible to establish a Pb isotope background database about the coal in China. (authors)
[en] In this paper, we have proposed a novel type of fiber amplifier by filling the PbS semiconductor quantum dots into the holes of photonic crystal fibers (PCFs) for the first time. Based on simulation results, we have found that the loss of PCF filled with PbS is slightly increased compared with the one without PbS at wavelength of 1310 nm. Furthermore, we have successfully fabricated the PbS-filled PCF with selective air-hole cladding by a new perfusion technique that can optimize the overall loss. (paper)
[en] To investigate the repeatability, reproducibility, and staging and monitoring of the performance of native T1 mapping for noninvasively assessing liver fibrosis in comparison with acoustic radiation force impulse (ARFI) elastography. The repeatability and reproducibility were explored in 8 male Sprague-Dawley rats with intraclass correlation coefficient (ICC). Different degrees of fibrosis were induced in 52 rats by carbon-tetrachloride (CCl4) insult. Another 16 rats were used to build fibrosis progression and regression models. The native T1 values and shear wave velocity (SWV) were quantified by using native T1 mapping and ARFI elastography, respectively. The METAVIR system (F0–F4) was used for the staging of fibrosis. The area under the receiver operating characteristic curve (AUC) was determined to assess the performance of quantitative parameters for staging and monitoring fibrosis. Native T1 values shared similar good repeatability (ICC = 0.93) and reproducibility (ICC = 0.87) with SWV (ICC = 0.84–0.93). The AUC of native T1 values were 0.84, 0.84, and 0.75 for diagnosing significant fibrosis (≥ F2) and liver cirrhosis (F4) and detecting fibrosis progression, and those of SWV were 0.81, 0.86, and 0.7, respectively. No significant difference in performance was found between the two quantitative parameters (p ≥ 0.496). For detecting fibrosis regression, native T1 values had a better accuracy (AUC = 0.99) than SWV (AUC = 0.56; p = 0.002). Native T1 mapping may be a reliable and accurate method for noninvasively assessing liver fibrosis. Compared with ARFI elastography, it provides similar good repeatability and reproducibility, a similar high accuracy for staging fibrosis, and a better accuracy for detecting fibrosis regression.
[en] A fiber-optic refractive index (RI) sensor was proposed and demonstrated by using a double-cladding fiber (DCF). The DCF consists of a core, inner cladding and outer cladding. The RI of the core and outer cladding is higher than that of the inner cladding. Through evanescent wave coupling, the cladding mode of the DCF can be excited by the core mode resonantly at the phase-matching wavelength. By splicing a section of the DCF into a standard single mode fiber (SMF), a SMF–DCF–SMF structure was constructed to detect the resonant band-rejection filter spectrum. Based on the coupled mode theory, we found that the phase-matching wavelength is at a near modal cut-off wavelength. Under this condition, the cladding mode is more sensitive to the variation of the ambient RI. A resonant wavelength shift of 65 nm was achieved by changing the ambient RI from 1 to 1.4525
[en] Monoclinic vanadium dioxide (M-VO) is a kind of typical thermal phase change materials, but its relatively high phase transition temperature (68 °C) and low solar modulation efficiency greatly hinder the applications as energy materials. In this work, well-crystalline M-VO were prepared by pulsed laser deposition (PLD) under the adjustable oxygen pressure range. By fine adjusting the low oxygen pressure (0.1–0.9 Pa), VO maintain the monoclinic crystal and excellent photoelectrical properties, even if oxygen deficiency and other defects exist. Results indicate that the phase-transition temperature (T) decreases with the decrease of oxygen pressures while the solar modulation efficiency (ΔT) increases with the decrease of oxygen pressures. Moreover, the M-VO thin films prepared with 0.3 Pa oxygen pressure showed the best photoelectric performance, in which the sheet resistance changes up to three orders of magnitude, the phase-transition temperature is 61 °C and the ΔT is as high as 8.3%. This work has demonstrated the role of moderate oxygen defects in optimizing the photoelectric properties of M-VO, also provided a feasibility study on how to deposit pure M-VO by PLD.