10 research outputs found
Development of an incoherent broad-band cavity-enhanced aerosol extinction spectrometer and its application to measurement of aerosol optical hygroscopicity
We report on the development of a blue light-emitting-diode-based incoherent broad-band cavity-enhanced absorption spectroscopy (IBBCEAS) instrument for the measurement of the aerosol extinction coefficient at \u1d706=461âânm. With an effective absorption path length of 2.8 km, an optimum detection limit of 0.05ââMmâ1 (5Ă10â10ââcmâ1) was achieved with an averaging time of 84 s. The baseline drift of the developed spectrometer was about ±0.3ââMmâ1 over 2.5 h (1\u1d70e standard deviation). The performance of the system was evaluated with laboratory-generated monodispersed polystyrene latex (PSL) spheres. The retrieved complex refractive index of PSL agreed well with previously reported values. The relative humidity (RH) dependence of the aerosol extinction coefficient was measured using IBBCEAS. The measured extinction enhancement factor values for 200 nm dry ammonium sulphate particles at different RH were in good agreement with the modeled values. Field performance of the aerosol extinction spectrometer was demonstrated at the Hefei Radiation Observatory site
Data-driven capacity estimation of commercial lithium-ion batteries from voltage relaxation
Accurate capacity estimation is crucial for the reliable and safe operation of lithium-ion batteries. In particular, exploiting the relaxation voltage curve features could enable battery capacity estimation without additional cycling information. Here, we report the study of three datasets comprising 130 commercial lithium-ion cells cycled under various conditions to evaluate the capacity estimation approach. One dataset is collected for model building from batteries with LiNiCoAlO-based positive electrodes. The other two datasets, used for validation, are obtained from batteries with LiNiCoMnO-based positive electrodes and batteries with the blend of Li(NiCoMn)O - Li(NiCoAl)O positive electrodes. Base models that use machine learning methods are employed to estimate the battery capacity using features derived from the relaxation voltage profiles. The best model achieves a root-mean-square error of 1.1% for the dataset used for the model building. A transfer learning model is then developed by adding a featured linear transformation to the base model. This extended model achieves a root-mean-square error of less than 1.7% on the datasets used for the model validation, indicating the successful applicability of the capacity estimation approach utilizing cell voltage relaxation
Research on Novel Flexible High-Saturation Nanocrystalline Cores for Wireless Charging Systems of Electric Vehicles
TRIM25 Suppresses Rabies Virus Fixed HEP-Flury Strain Production by Activating RIG-1-Mediated Type I Interferons
Rabies remains a great threat to public health worldwide. So far, the mechanism of rabies virus (RABV) infection is not fully understood, and there is no effective treatment for rabies. Identifying more host restriction factors of RABV will spur the development of novel therapeutic interventions against rabies. Accumulating studies suggest that tripartite motif-containing (TRIM) proteins have great effects on virus replication. TRIMs control the antiviral responses through either direct interaction with viral proteins or indirect regulation of innate immune signaling molecules in the host. The role of TRIM25 in rabies virus (RABV) infection is poorly understood. Using next-generation sequencing, we found that TRIM25 is upregulated during HEP-Flury infection. Knockdown of TRIM25 enhances HEP-Flury production, while overexpression of TRIM25 suppresses HEP-Flury replication. Knockdown of interferon α and interferon ÎČ weakens the anti-RABV response induced by TRIM25 overexpression, and potentiates RABV production. Furthermore, we found that TRIM25 regulates type-I interferon response by targeting retinoic acid-inducible gene I (RIG-I) during HEP-Flury infection. Knockdown of RIG-I weakens the anti-HEP-Flury response induced by TRIM25 overexpression, indicating that TRIM25 regulates RABV production via the RIG-I-IFN axis. In addition, we observed that TRIM25 does not directly interact with HEP-Flury structural proteins, suggesting that TRIM25 regulates HEP-Flury production indirectly. Taken together, our work identifies TRIM25 as a new host factor involved in HEP-Flury infection, which may be a potential target for the development of antiviral drugs against RABV
Real-time retrieval of aerosol chemical composition using effective density and the imaginary part of complex refractive index
International audienceKnowledge of aerosol chemical composition is essential for the research on aerosol climate effect, air quality and health issues. With the development of optical remote-sensing technology, numerous aerosol chemical composition retrieval methods based on optical properties were developed. However, the existing algorithms lack the verification with similar measurements of aerosol chemical composition. In this work, a novel algorithm based on effective density (Ïe) and imaginary part (k) of the complex refractive index (CRI) at λ = 365 and 532 nm was developed to retrieve four main aerosol components, including black carbon (BC), organic matter (OM), mineral dust (MD), and sum of sulfate, nitrate and ammonium (SNA). Ïe was derived by converting aerodynamic to electrical mobility diameter. CRI was retrieved from Mie code and simultaneous measurement of particle number size distribution (PNSD) and the extinction and scattering coefficients (bext and bscat). Comprehensive sensitivity tests were performed to estimate the retrieval uncertainties from the measurements and a priori inputs. Validation of the algorithm was demonstrated using a series of observations at Shouxian (China) from November 30 to December 12, 2016. The measured and retrieved aerosol chemical compositions were compared and the two results showed good agreements, proving the reliability of the method. During one clean and two pollution periods, the variation of measured aerosol physical and optical properties and retrieved chemical composition were analyzed. The aerosol chemical composition changes can be well described by the transition of air mass sources for different pollution levels. This study provides a reliable, in-situ method for better constraining the relationship between aerosol chemical compositions and optical properties. This method will help monitor the pollution event, identify aerosol sources and verify the retrievals from remote sensing data