A review of neck injury and protection in vehicle accidents

Neck injury is one of the most common types of injury in vehicle accidents. The mechanisms of neck injury remain controversial due to the complex structure of the cervical spine and various impact conditions. The aim of the present study is to provide a summary of recent research on neck injury mechanisms, neck injury criteria and neck injury prevention measures. The main types of neck injury resulting from vehicle accidents, including whiplash injury, cervical bone fractures and spinal cord injury, are introduced. Neck injury mechanisms are summarized according to load directions, test or simulation methods, and thresholds by means of impact intensity, load intensity and stress/strain conditions. Neck injury criteria are introduced, including NIC, N and LNL. Passive and active technologies for neck injury prevention are described and the challenge of neck injury prevention for future intelligent vehicles is discussed

CARDIOPROTECTIVE ROLES OF THE CHINESE MEDICINAL FORMULA BAO-XIN-TANG ON ACUTE MYOCARDIAL INFARCTION IN RATS

Background: Bao-Xin-Tang (BXT) is a traditional Chinese medicinal formula used for the treatment of coronary heart disease and known to have favorable therapeutic benefits. The current study was designed to determine whether BXT has a cardioprotective role for acute myocardial infarction. The underlying mechanisms were also explored. Materials and Methods: The Sprague-Dawley rat model of acute myocardial infarction was established by occluding the left anterior descending branch of the coronary artery. After a 3-h ischemic period, we determined the myocardial infarction size, inflammatory components, and antioxidant activities. Results: The data showed that BXT could reduce the infarction size and lower the levels of C-reactive protein, interleukin-6, and myeloperoxidase, and increase the activities of superoxide dismutase and the anti-inflammatory cytokine, interleukin-10. These results indicate that administration of BXT, following acute myocardial infarction, could reduce infarct size. Conclusion: The effects of BXT may be related to its anti-inflammatory and anti-oxidative properties

Numerical Simulation of Internal Flow and Performance Prediction of Tubular Pump with Adjustable Guide Vanes

Aiming at the performance defect of tubular pump with fixed guide vanes, a design scheme of tubular pump with adjustable guide vanes is proposed, so that the inlet setting angle of guide vanes can be flexibly adjusted to coordinate with the operation conditions of pump, to ensure the inlet setting angle of guide vanes changing with the outlet flow angle of the impeller. The three-dimensional time-averaged incompressible Navier-Stokes equations are adopted to numerically simulate the internal flow field of a tubular pump with fixed and adjustable guide vanes, respectively. Computed results indicate that with the design of adjustable guide vanes and at off-design flow rates the flow conditions inside the diffuser of tubular pump can be improved effectively, and its hydraulic losses can be reduced. When the impeller blade angles are fixed the best efficiency points are within 0.51% while adjusting setting angles of guide vanes within a certain range. Under off-design conditions the hydraulic efficiency of tubular pump with adjustable guide vanes can be obviously improved by 1.70% at 0.75 Q 0 and 2.19% at 1.20 Q 0 , when the blade angle is 0 degrees and the angle of guide vanes is adjusted to be 2 degrees smaller and larger, respectively

On-Orbit Vicarious Radiometric Calibration and Validation of ZY1-02E Thermal Infrared Sensor

The ZY1-02E satellite carrying a thermal infrared sensor was successfully launched from the Taiyuan Satellite Launch Center on 26 December 2021. The quantitative characteristics of this thermal infrared camera, for use in supporting applications, were acquired as part of an absolute radiometric calibration campaign performed at the Ulansuhai Nur and Baotou calibration site (Inner Mongolia, July 2022). In this paper, we propose a novel on-orbit absolute radiometric calibration technique, based on multiple ground observations, that considers the radiometric characteristics of the ZY1-02E thermal infrared sensor. A variety of natural surface objects were selected as references, including bodies of water, bare soil, a desert in Kubuqi, and sand and vegetation at the Baotou calibration site. During satellite overpass, the 102F Fourier transform thermal infrared spectrometer and the SI-111 infrared temperature sensor were used to measure temperature and ground-leaving radiance for these surface profiles. Atmospheric water vapor, aerosol optical depth, and ozone concentration were simultaneously obtained from the CIMEL CE318 Sun photometer and the MICROTOP II ozonometer. Atmospheric profile information was acquired from radiosonde instruments carried by sounding balloons. Synchronous measurements of atmospheric parameters and ECMWF ERA5 reanalysis data were then combined and input to an atmospheric radiative transfer model (MODTRAN6.0) used to calculate apparent radiance. Calibration coefficients were determined from the measured apparent radiance and satellite-observed digital number (DN), for use in calculating the on-orbit observed radiance of typical surface objects. These values were then compared with the apparent radiance of each object, using radiative transfer calculations to evaluate the accuracy of on-orbit absolute radiometric calibration. The results show that the accuracy of this absolute radiometric calibration is better than 0.6 K. This approach allows the thermal infrared channel to be unrestricted by the limitations of spectrum matching between a satellite and field measurements, with strong applicability to various types of calibration sites

Absolute Radiometric Calibration of ZY3-02 Satellite Multispectral Imager Based on Irradiance-Based Method

In this paper, an irradiance-based absolute radiometric calibration campaign at Baotou calibration site during June and July 2018 was described. This radiometric calibration campaign made use of six radiometric calibration tarps. The synchronous measurements of parameters such as surface reflectance, atmospheric parameters, and diffuse-to-global irradiance ratio were collected at the satellite overpass. The top-of-atmospheric radiance was predicted by radiative transfer model with these synchronous measurements. The linear relationship between DNs of satellite sensor and band-specific top-of-atmospheric spectral radiance was established, and a stable and reliable absolute calibration coefficient of ZY3-02 MUX was determined in this campaign. We compared the calibration results of the irradiance-based method with those of the reflectance-based method. The results suggested that the irradiance-based method is better than reflectance-based method

Ceria Quantum Dot Filler-Modified Polymer Electrolytes for Three-Dimensional-Printed Sodium Solid-State Batteries

Solid polymer electrolytes have been considered as promising candidates for solid-state batteries (SSBs), owing to their excellent interfacial compatibility and high mechanical toughness; however, they suffer from intrinsic low ionic conductivity (lower than 10−6 S/cm) and large thickness (usually surpassed over 100 μm or even 500 μm), which has a negative influence on the interface resistance and ionic migration. In this work, ceria quantum dot (CQD)-modified composite polymer electrolyte (CPE) membranes with a thickness of 20 μm were successfully manufactured via 3D printing technology. The CQD fillers can reduce the crystallinity of the polymer, and the oxygen vacancies on CQDs can facilitate the dissociation of ion pairs in the NaTFSI salt to release more free Na+, improving the ionic conductivity. Meanwhile, tailoring the thickness of the CPE-CQDs membrane via 3D printing can further promote the migration and transport of Na+. Furthermore, the printed NNM//CPE-CQDs//Na SSB exhibited outstanding rate capability and cycling stability. The combination of CQD modification and thickness tailoring through 3D printing paves a new avenue for achieving high performance solid electrolyte membranes for practical application in Na SSBs

Mechanically Robust and UV-Curable Shape-Memory Polymers for Digital Light Processing Based 4D Printing

4D printing is an emerging fabrication technology that enables 3D printed structures to change configuration over “time” in response to an environ-mental stimulus. Compared with other soft active materials used for 4D printing, shape-memory polymers (SMPs) have higher stiffness, and are compatible with various 3D printing technologies. Among them, ultraviolet (UV)-curable SMPs are compatible with Digital Light Processing (DLP)-based 4D printing to fabricate SMP-based structures with complex geometry and high-resolution. However, UV-curable SMPs have limitations in terms of mechanical performance, which significantly constrains their application ranges. Here, a mechanically robust and UV-curable SMP system is reported, which is highly deformable, fatigue resistant, and compatible with DLP-based 3D printing, to fabricate high-resolution (up to 2µm), highly complex 3D structures that exhibit large shape change (up to 1240%) upon heating. More importantly, the developed SMP system exhibits excellent fatigue resistance and can be repeatedly loaded more than 10000 times. The development of the mechanically robust and UV-curable SMPs significantly improves the mechanical performance of the SMP-based 4D printing structures, which allows them to be applied to engineering applications such as aerospace, smart furniture, and soft robots