Search

We have developed a sensitive interferometric technique for measuring the temperature derivative of the refractive index of liquids with an accuracy of 0.5% as illustrated by measurements with mixtures of liquid n-hexane and toluene. In addition the concentration dependence of the refractive index of these mixtures has been measured with refractometry. The experimentally observed temperature dependence of the refractive index appears to be consistent with a modification of the Lorentz–Lorenz relation proposed by Looyenga. [ABSTRACT FROM AUTHOR]

An optimized model is established to improve the accuracy and efficiency of lifetime estimation for LED-based light bars. A Weibull function is used to fit test data of remaining luminance under two groups of accelerated stresses, and a method for determining the optimal test time is put forward. The results show that the optimized model for lifetime prediction best reflects the characteristic of luminance degradation. Furthermore, the error of the accelerated lifetime first decreases and then increases, finally decreasing again, which confirms that the method for determining the optimal test time is feasible given the level of accuracy required. [ABSTRACT FROM AUTHOR]

The effects of the initiation diameter and synchronicity error on the formation of fins and stable-flight velocity of an explosively formed projectile (EFP) with three-point initiation are investigated. The pressure and area of the Mach wave acting on the metal liner at different initiation diameters are calculated employing the Whitham method. LS-DYNA software is used to investigate the asymmetric collision of detonation waves resulting from three-point initiation synchronicity error, the distortion characteristics of the liner resulting from the composite detonation waves, and the performance parameters of the EFP with fins. Results indicate that deviations of the Y-shaped high-pressure zone and central ultrahigh-pressure zone from the liner center can be attributed to the error of three-point initiation, which leads to the irregular formation of EFP fins. It is noted that the area of the Mach wave decreases, but the pressure of the Mach wave and the final speed and length-to-diameter (L/D) ratio of the EFP increase, benefiting the formation of the EFP fins, as the initiation diameter increases. [ABSTRACT FROM AUTHOR]

Seed shape (SS) affects the yield and appearance of soybean seeds significantly. However, little detailed information has been reported about the quantitative trait loci (QTL) affecting SS, especially SS components such as seed length (SL), seed width (SW) and seed thickness (ST), and their mutual ratios of length-to-weight (SLW), length-to-thickness (SLT) and weight-to-thickness (SWT). The aim of the present study was to identify QTL underlying SS components using 129 recombinant inbred lines derived from a cross between Dongnong46 and L-100. Phenotypic data were collected from this population after it was grown across nine environments. A total of 213 simple sequence repeat markers were used to construct the genetic linkage map, which covered approximately 3623·39 cM, with an average distance of 17·01 cM between markers. Five QTL were identified as being associated with SL, five with SW, three with ST, four with SLW, two with SLT and three with SWT. These QTL could explain 1·46–22·16% of the phenotypic variation in SS component traits. Three QTL were identified in more than six tested environments three for SL, two for SW, one for ST, two for SLW and one for SLT. These QTL have great potential value for marker-assistant selection of SS in soybean seeds. [ABSTRACT FROM PUBLISHER]

The bundled lipped channel-concrete composite wall is an innovative structural wall. This wall has a series of advantages, such as convenient construction and high bearing capacity. Seven full-scaled specimens were tested and subjected to cyclic lateral loads. ABAQUS, which is a finite-element software, was used to simulate the test process. Hysteretic curves and skeleton curves were obtained. This process proved that the simulation effect of finite element was good. A parametric analysis was conducted on this composite shear wall to determine the effect of the wall under different parameters, such as the axial load ratio, the shear span ratio and the intensity of steel and concrete. The formula for the bending capacity of normal section was deduced. The failure mode and factors that affect the shear capacity of the composite shear wall at a low shear span ratio were analyzed to obtain the composition of the shear capacity. Based on the superposition theory and statistical regression, the formula for the shear capacity of the inclined section was obtained. [ABSTRACT FROM AUTHOR]

Purpose We explored the patterns of sentinel node metastasis and investigated the prognostic value of sentinel node necrosis (SNN) in patients with nasopharyngeal carcinoma (NPC), based on magnetic resonance imaging (MRI). Methods This retrospective study enrolled 252 patients at our institution who had metastatic lymph nodes from biopsy-confirmed NPC and who were treated with definitive radiation therapy, with or without chemotherapy. All participants underwent MRI before treatment, and the resulting images were reviewed to evaluate lymph node status. The patients were divided into SNN and NON-SNN groups. Overall survival (OS), tumour-free survival (TFS), regional relapse--free survival (RRFS), and distant metastasis--free survival (DMFS) were calculated by the Kaplan--Meier method, and differences were compared using the log-rank test. Factors predictive of outcome were determined by univariate and multivariate analysis. Results Of the 252 patients, 189 (75%) had retropharyngeal lymph node metastasis, and 189 (75%) had level IIA or IIB lymph node necrosis. The incidence of SNN was 43.4% (91 of 210 patients with lymph node metastasis or necrosis, or both). After a median follow-up of 54 months, the 5-year rates of OS, TFS, RRFS, and DMFS in the SNN and NON-SNN groups were, respectively, 79.4% and 95.3%, 73.5% and 93.3%, 80.4% and 96.6%, and 75.5% and 95.3% (all p < 0.01). Age greater than 40 years, SNN, T stage, and N stage were significant independent negative prognostic factors for OS, TFS, RRFS, AND DMFS. Conclusions Metastatic retropharyngeal lymph nodes and necrotic level ii nodes both seem to act as sentinels. Sentinel node necrosis is an negative prognostic factor in patients with NPC. Patients with SNN have a worse prognosis. [ABSTRACT FROM AUTHOR]

The corrosion behavior of two cast Fe-xCr-5Si (x = 0, 5 at.%) alloys has been studied at 800°C in H2-CO2-H2S mixture. The addition of 5 at.% Cr improved the corrosion resistance of the Fe-5Si alloy by forming a protective scale of mixed Cr2O3 and SiO2 at the bottom of a non-uniform scale. The corrosion resistance of the cast Fe-5Cr-5Si alloy was further improved by a magnetron-sputtered film of identical composition that promoted the formation of a protective scale of a Cr2O3-SiO2 mixture at the coating/alloy interface. The mechanisms of forming the protective scales are examined and analyzed. [ABSTRACT FROM AUTHOR]

Rod-like copper manganese mixed oxides (CuMnx-NR) have been synthesized from copper manganese mixed oxide particles by sodium hydroxide hydrothermal treatment, and a higher BET surface area of 221 m2 g−1 is obtained on the nanorod-like sample, which exhibits superior catalytic activity toward toluene combustion at 210 °C due to the increase in its oxygen mobility of the chemisorbed oxygen species as well as the increase in surface concentrations of higher valance cations, Cu2+, Mn3+ and Mn4+, in the samples. [ABSTRACT FROM AUTHOR]

In this paper, we report results on two-colour above-threshold ionisation, where extreme ultraviolet pulses of femtosecond duration were synchronised to intense infrared laser pulses of picosecond duration, in order to study the laser-assisted photoelectric effect of atomic helium, neon, krypton and xenon which leads to the appearance of characteristic sidebands in the photoelectron spectra. The observed trends are found to be well described by a simple model based on the soft-photon approximation, at least for the relatively low optical intensities of up toemployed in these early experiments. [ABSTRACT FROM AUTHOR]