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In this study, synchrotron radiation X-ray diffraction is used to study the equation of state of vanadium nitride in a diamond anvil cell at room temperature. Experimental results reveal the high stability of the cubic structure up to 76 GPa pressure. In addition, the bulk modulus of vanadium nitride derived from XRD data is K0 = 328.4(2.8) GPa with K0′ = 5.86(0.14). Finally, the high pressure compression behavior is investigated to 80 GPa using density functional theory of first-principle calculations, and the obtained bulk elastic modulus is 316 GPa. Vanadium nitride is not magnetic in the whole pressure range and is metallic. Highlights • We have investigated the equation of state of VN under high pressure with silicone oil as the pressure transmitting medium to 76 GPa. • It was found that the face-centred cubic structure of VN maintains the maximum pressure of 76 GPa. • We have carried out first-principles calculations and obtained the equation of state, band structure, and electronic density of state of VN to 80 GPa. [ABSTRACT FROM AUTHOR]

To remove the limitation that the plane stress problem cannot be considered using cylindrical cavity expansion and to explore surface response of cylinder expansion in shallow soil, a semi-analytical undrained solution is developed for cylindrical cavity expansion in anisotropic modified Cam-clay model soils under the plane stress condition. The constitutive relationship is described by the K0-consolidated anisotropic modified Cam-clay (K0-AMCC) model, which can properly simulate the mechanical behaviour of the K0-consolidated natural clays. The problem is equivalent to solving ordinary differential equations to determine the effective stresses, vertical strain, and excess pore water pressure (EPWP). Parametric analyses are conducted to investigate the effective stresses, vertical strain, and EPWPs around the expanded cavity under plane stress condition. The results show a clear influence of over-consolidation ratio on the stresses, vertical strain, EPWP around the cavity, and effective stress paths for a soil particle at the cavity wall. Axial expansion or uplift of soil and negative pore water pressure are observed during cavity expansion under the plane stress condition. There are obvious differences in effective stress components around the cavity under two plane conditions. The effective axial stress around the cavity wall is generally smaller than that under the plane strain condition. [ABSTRACT FROM AUTHOR]

We have designed and implemented a novel DLD for controlling pressure and compression/decompression rate. Combined with the use of the symmetric diamond anvil cells (DACs), the DLD adopts three piezo-electric (PE) actuators and three static load screws to remotely control pressure in accurate and consistent manner at room temperature. This device allows us to create different loading mechanisms and frames for a variety of existing and commonly used diamond cells rather than designing specialized or dedicated diamond cells with various drives. The sample pressure compression/decompression rate that we have achieved is up to 58.6/43.3 TPa/s, respectively. The minimum of load time is less than 1 ms. The DLD is a powerful tool for exploring the effects of rapid (de)compression on the structure of materials and the properties of materials. [ABSTRACT FROM PUBLISHER]

Primary objective: To investigate the epidemiological characteristics of paediatric inpatients with traumatic brain injury (TBI) in China.Research design: The Chinese Trauma Database (CTD), a nationwide register system based on hospital admission data, contains diagnosis and treatment information for trauma inpatients in over 200 military-managed public-service hospitals in China. Using the ICD-9 coding, the data for children with TBI aged 0–17 years between 2001 and 2007 were retrieved.Methods and procedures: The demographic characteristics, admission time, injury cause, severity and treatment outcomes of paediatric inpatients with TBI were analysed.Main outcomes and results: A total of 26,028 paediatric inpatients with TBI (69.52% male, 30.48% female) were included in the CTD. Motor vehicle traffic (MVT) accidents, falls and assaults were the primary causes of injury. Falls were the leading cause of TBI in children aged 0–4 years, and MVT was the leading cause of TBI in children aged 5–17 years. According to the abbreviated injury scale, 37.20% of the TBI cases were mild, 25.15% were moderate, 24.81% were severe and 12.84% were critically severe.Conclusion: Chinese authorities should develop targeted measures to reduce children injuries based on the leading causes of TBI in the different age groups, particularly MVT, falls and assaults. [ABSTRACT FROM PUBLISHER]

Static aeroelastic and flutter characteristics of an aircraft composite wing with high aspect ratio were analysed by an effective Computational Fluid Dynamics and Computational Structure Dynamics coupled method. Effects of stiffness distribution on aeroelastic characteristics were considered. Honeycomb core sandwich composite was considered to be equivalent to an orthotropic material by stiffness and inertance equivalent method to allow highly efficient numerical simulation, which was used for analysis of bending and torsional stiffness distribution. The results showed that the redistributed aerodynamic load leads to a decrease of pressure difference between the upper and lower airfoils. The flutter speed of the composite wing is near 0.64 Ma. Both bending and torsional stiffness increases with a small increase of beam size. Stiffness of the wing root has a major influence generally on the static aeroelastic characteristics. Both the lift coefficient and the loss percent decrease with a small increase of beam size. Effects of stiffness distribution on frequency are not obvious. Flutter speed remains close to the initial value when the beam size is changed. [ABSTRACT FROM PUBLISHER]