Search

The performances of a multi-spectral fit for the spectra of pressure-broadened overlapping lines (R9F1, R9F2) of 12CH4 in binary mixtures with N2 were studied by applying different lineshape models, from the simplest Voigt profile (VP) to the Harmann-Tran profile (HTP). Line-mixing was approximated in the first order in the spectral fits. Data were acquired using a high-resolution cavity ring-down spectrometer of minimum detectable absorption coefficient of 2.8 × 10−12 cm−1. The lines were observed with a signal-to-noise ratio of 19 365 for pressures from 5 to 40 kPa. The study reveals that the multi-spectral fits using the HTP and the speed-dependent Nelkin–Ghatak profile (SDNGP) yield the best among all tested. The two models gave the maximum relative residuals of less than 0.065 %. All things considered, the HTP and the SDNGP appear to be the most reliable models for treating the present case of multi-spectral fitting of unresolved dual-component spectra.

Refractive index gas thermometry (RIGT) uses the dependence of the relative dielectric permittivity on the density of a noble gas (He), typically measured with a temperature-controlled resonator. On an isotherm, to a good approximation, the slope of the dielectric permittivity versus pressure gives the thermodynamic temperature T. To measure T with a low uncertainty, one must measure the absolute value of the pressure with a low uncertainty and know the compressibility of the resonator wall. This article shows how to use RIGT in a novel way between 5 K and 25 K. Instead of changing the pressure on an isotherm (Schmidt et al., 2007), a constant pressure of pure helium gas is maintained at multiple temperatures. After calibration of the resonator under vacuum at different temperatures, all thermometry is performed at a single pressure and referred to a fixed point of the International Temperature Scale of 1990 (ITS-90) (here the neon triple point at 24.5561 K). The quantity that yields the temperature is the ratio of the resonance frequencies of a microwave mode in the resonator measured at the fixed point and at the unknown temperature. This paper describes the theoretical model of Single-Pressure Refractive Index Gas Thermometry (SPRIGT) and analyses the shifts and broadenings due to non-ideal behaviour. The technique should enable a helium-based measurement of thermodynamic temperature with a resolution better than 25 μK and an uncertainty of around 250 µK.

Coiled two-capillary viscometers can measure gas viscosities with high accuracy over a wide temperature range. The authors built a two-capillary viscometer and used it to measure the zero-density viscosity of Kr and Xr at temperatures from 243.15 K to 393.15 K with relative standard uncertainties of 0.10% and 0.11%, respectively. Additional measurements on Ar were used to understand and avoid the error due to inadequate preheating or precooling of the gas entering the viscometer. The error, which occurred at volume flow rates above 4 m3 s−1, was approximately proportional to the temperature difference between the reference capillary and the probe capillary.

The Weinan-Jingyang fault is one of the southern boundary faults of the Gushi secondary depression of the Weihe Basin, China. Geophysical exploration work and field geological surveys have demonstrated that this fault system has a length of approximately 105 km, and extends at least 5 km into the subsurface, with a northerly dip that shallows with depth. Under the influence of long-term displacement on the fault zone, the strata on the north side of the fault within the fault zone dip to the south, and the subsidence centre of the Gushi depression has migrated continuously southward. The Cenozoic activity of the Weinan-Jingyang fault has resulted in a significant dislocation between Paleozoic and Cenozoic strata on either side of the fault. This fault has been active during the Quaternary, especially the late Quaternary, in some places offsetting strata formed during the Ming Dynasty(1368–1644 CE), suggesting that this fault can reliably be regarded being active during Holocene time. Comprehensive re-examination of historical earthquake records, combined with field studies, confirm that the Weinan-Jingyang fault is likely the fault that slipped during a magnitude ~7 earthquake in northeast Xi'an, China in 1568 CE. That earthquake is here re-named the Shaanxi Gaoling Earthquake.

A destructive earthquake occurred in Northeast Xi'an, Shaanxi province, on May 25th, 1568 AD, causing many casualties, severe damage to property, and significant disruption to livelihoods. This earthquake has been chosen as a plausible basis for calculating a seismic scenario for the modern city of Weinan, and its surrounding urban areas. Previous studies agreed in assigning a magnitude 6 ¾ to the earthquake but yielded differing epicentral locations and isoseismal intensity maps. We combine textual research on historical earthquake reports with field investigations to reduce the uncertainties, and to place constraints on the ground shaking that would be experienced if such an earthquake were to recur. We show that the counties of Jingyang, Gaoling, and Xianning were the worst hit by the earthquake, with the townships of Yongle, Huijun, Pisha, and Fengzheng (present-day Gaozhuang and Zhangbu township), likely being in the mesoseismal area of this earthquake. Reinterpretation of the historical texts, combined with field observations, indicates that the epicenter of the earthquake was at about 34°28′N and 108°59′E, with an epicentral intensity of Ⅸ+ and an estimated magnitude of 7. The isoseismal contours have major axes-oriented WNW-ESE, in contrast to the more NS alignment inferred from the earlier study of the historical documents. The isoseismal of intensity VIII+encloses, and has its major axis parallel to, the active Weinan-Jingyang fault, which we infer to be the fault that slipped in the May 25th, 1568 earthquake.

The 2v3 R6 manifold of methane is important for remote sensing. The positions of 96 lines in this manifold were determined by both Lamb-dip spectroscopy and linear absorption spectroscopy using a cavity ring-down spectrometer.

Martensitic phases are intermediate phases in Ti alloys and have obvious effects on microstructure and properties of heat treated specimens. The martensitic transformation and phase stability of Ti alloys with high content Zr were investigated. The addition of high content Zr was found to greatly modify the β phase stability and martensitic transformation of Ti alloys. The β transus temperature of Ti–50Zr binary alloy is about 616 °C. Simultaneously, the phase composition of the β quenched Ti–50Zr binary alloy is composed of whole α′ martensitic phase. Reversely, the Ti–30Zr–10Al–3.5V and Ti–50Zr–10Al–3.5V quaternary alloys have the higher β transus temperatures 779 and 636 °C, respectively. However, phase composition is major α″ martensitic phase in β quenched Ti–30Zr–10Al–3.5V alloy and is major β phase in β quenched Ti–50Zr–10Al–3.5V alloy, respectively. This interesting martensitic transformation phenomenon does not conform to previous wide accepted martensitic transformation theories and laws of Ti alloys. The delayed martensitic transformation of aforementioned two quaternary alloys was considered to be caused by the local stresses resulting from the extra additions of Al and V alloying elements.

This paper introduces a method to measure the online strain in the plate shell forming process. It solves the problem that the inside stress online is almost impossible measured in the process of the upper and lower molds forming. The key technology is the design of the moving test frame. This frame can move with the plate’s movement to protect the sensors and ensure the output of the test signal, at the same time, it does not interfere with the shell’s process conditions. It is the first time to apply this method to the large-sized high-strength steel ball shell plate, and it could accurately measure the stress distribution and changes laws within the shell plate under certain specific condition in the process of punching to online stress test and analysis during the punching forming process. The test results show that the periphery of each pressure point is residual tensile stress, and the inside is the residual compressive stress, more evenly distributed. The existence of residual compressive stress is in favor of the anti-fatigue capacity of the plate.

The polyaniline/polysulfone (PAN/PSF) composite films were prepared by electropolymerization, and then platinum was deposited into this composite film to obtain the platinum-modified polyaniline/polysulfone(Pt/PAN/PSF) composite film electrodes. Their component, morphology and structure were characterized by FTIR spectra, scanning electron microscopy and energy dispersive X-ray spectroscopy. The results show that the composite film has a bi-layer structure with asymmetrical pores, and the platinum particles are homogeneously dispersed in the modified film electrodes. The cyclic voltammetry and electrochemical impedance spectroscopy techniques were applied to investigate the electrochemical properties and the electrocatalytic activity of the modified film electrodes, which show a promotive action for methanol oxidation and the methanol oxidation under a diffusion-controlled process. Keywords: PAN/PSF composite film, Pt/PAN/PSF electrode, Preparation, Methanol oxidation, Electrocatalytic activity

One of the most important development directions of the Ti and its alloys is the applications in medical field. Development of new Ti alloys with low elastic modulus and/or favorable biocompatibility plays an important role for promoting its application in medical field. In this work, a new β Ti alloy (Ti-31Nb-6Zr-5Mo, wt.%) was designed for implant material using d-electron alloy design method. Microstructure and tensile properties of the designed alloy after hot rolling (HR) and solution followed by aging treatments (SA) were investigated. Results show that the designed alloy is composed of single β phase. However, microstructural analysis shows that the β phase in the designed alloy separates into Nb-rich and Nb-poor phase regions. The Nb-rich regions in HR specimen are typical elongated fiber texture, but are equiaxed particles with several micrometers in SA specimen. Tensile results show that the designed alloy has low Young's modulus of 44 GPa for HR specimen and 48 GPa for SA specimen which are very close to the extreme of Young's modulus of bulk titanium alloys. At the same time, the designed alloy has favorable plasticity in term of elongation of 26.7% for HR specimen and 20.6% for SA specimen, and appropriate tensile strength over 700 MPa. In short, the designed alloy has low elastic modulus close to that of bone and favorable plasticity and strength which can be a potential candidate for hard tissue replacements.

Aluminum and aluminum-magnesium alloys were prepared by direct current electro-deposition and pulse electro-deposition in AlCl3-LiAlH4-benzene-tetrahydrofuran (THF) system. Electrochemistry experiment was conducted by three electrode system and analyzed by Chronoamperometic plots. The surface morphology, composition and content of aluminum and aluminum magnesium alloys were studied by scanning electron microscope (SEM) and energy spectrum (EDS). The results show that the coatings of aluminum and aluminum magnesium are superior when the pulse duration ratio (ton:toff) is 0.08s:0.02s. The coatings are best when DC deposition current density in 14.89mA/cm2. SEM shows that by DC deposition the grain sizes are thick and the surface is rough. But the coatings obtained by pulse electro-deposition are more uniform, thinner and the surface is flatter than obtained by DC deposition.

UNLABELLED Thirty strains of lactic acid bacteria (LAB) were isolated from herders' traditional dairy products collected from Xinjiang, China. The species Lactobacillus, Lactococcus, Enterococcus, Pediococcus and Leuconostoc were identified by 16S ribosomal RNA gene sequencing analysis and conventional observation. The strains' fermentation characteristics, including milk acidification, proteolysis, autolysis, antimicrobial activity and diacetyl production, were assayed and compared. Strains NL24 and NL31 showed the highest proteolytic activity-2·75 and 2·08 mmol Phe l(-1) milk, respectively. Strains C, NL41, SW2, Z3-11, NL42 and Z2-91 had high autolytic activity. In addition, most of the wild strains produced diacetyl, half of them to high levels. This study provides a clue to LAB biodiversity in traditional dairy foods produced by herders in the western Tianshan Mountains. High-performing strains should be further evaluated for practical application in value-added fermented dairy products. SIGNIFICANCE AND IMPACT OF THE STUDY Our results reveal a certain variety of lactic acid bacteria (LAB) in traditional dairy products from Xinjiang. Some of the LAB strains, such as Lactobacillus rhamnosus NL24 and Lactobacillus paracasei SW2, possess excellent functional properties and have the potential for application in indigenous fermented dairy products. Performance of the newly isolated strains in cheese or yogurt manufacturing was further evaluated. Application of the high-performing strains to enrich the flavour of fermented dairy products is highly desirable and holds great commercial potential.

A simple and rapid method is described for the determination of trace amounts of arsenic, antimony, selenium, tellurium and bismuth in nickel metal by hydride generation atomic fluorescence spectrometry (HGAFS). The five elements are coprecipitated simultaneously with lanthanum hydroxide and separated quantitatively from a nickel matrix and other interfering elements prior to the determination. The detection limits of arsenic, antimony, selenium, tellurium and bismuth in samples are 0.10, 0.15, 0.11, 0.10 and 0.45 μg g −1 , respectively.