Study on emotion recognition and companion Chatbot using deep neural network

Multimedia Tools and Applications - With the development of technology, the importance of the research on speech emotion recognition and semantic analysis has increased. The research is primarily...     

Li0.95Na0.05MnPO4/C nanoparticles compounded with reduced graphene oxide sheets for superior lithium ion battery cathode performance

Sodium-substituted LiMnPO₄/C/reduced graphene oxide (LNMP@rGO) was synthesized in this study via freeze drying and carbon thermal reduction method with graphene oxide as carbon source. Sodium ion doping is optimized and rGO effects are evaluated by XRD, SEM, TEM, BET, Raman, and electrochemical performance measurements. Well-distributed nanoparticles with average size of ~50?nm are evenly distributed on the surface or intercalation between rGO layers, resulting in a porous ion/electronic conductive network. Compared to 122.3?mA?h?g^?1 in unmodified LNMP, the best LNMP@rGO (20?mg rGO) exhibits an excellent initial discharge capacity of 150.4?mA?h?g^?1 at 0.05?C at 122.9% of the initial capacity. The capacity retention rate is 95.8% of the initial capacity after 100 cycles at 1?C. Capacity of 101.2?mA?h?g^?1 is preserved even at rates as high as 10?C.     

Promoting the Li storage performances of Li2ZnTi3O8@Na2WO4 composite anode for Li-ion battery

In this work, a reasonable strategy for the construction of Li₂ZnTi₃O₈@Na₂WO₄ composite was employed to promote the Li storage performances of Li₂ZnTi₃O₈. The Li₂ZnTi₃O₈@Na₂WO₄ composites (5, 10, and 15 wt%) were then prepared by a solution dispersion method. The introduction of Na₂WO₄ does not change the structures of the samples and they show similar morphologies with particle sizes from 100 to 200 nm. Suitable amount of Na₂WO₄ modification effectively improves the electrochemical performance of Li₂ZnTi₃O₈. Li₂ZnTi₃O₈@Na₂WO₄ composites (0, 5, 10, and 15 wt%) deliver the discharge/charge capacities of 137.4/136.4, 164.2/162.3, 189.2/188.1, and 154.5/153.3 mAh g^?1 at 0.5 A g^?1 after 100 cycles, respectively. Li₂ZnTi₃O₈@Na₂WO₄ composites (10 wt%) has the highest reversible capacities among all samples. The Na₂WO₄ shell with an excellent electronic conductivity can reduce electrode polarization, decrease the charge transfer resistance, enhance the Li-ion diffusion coefficient of Li₂ZnTi₃O₈, and then improve the electrochemical kinetics of composites. In addition, the formation of Ti–O bonds at the interface can be helpful for the stabilization of the composite, being beneficial for the improvement of their cycling stabilities. These results reveal that Na₂WO₄ coating is a facile and effective strategy to promote the Li storage performance of Li₂ZnTi₃O₈.     

Yield ratios and directed flows of light particles from proton-rich nuclei-induced collisions

The neutron-to-proton and3 H-to-3 He yield ratios, and the directed flows of particles dependent on a reduced rapidity, the transverse momentum per nucleon,and a reduced impact parameter are investigated for ~(28)S+~(28)Si and ~(32)S+~(28)Si systems at 50 and 400 MeV/u using an isospin-dependent quantum molecular dynamics model.The results show that these yield ratios of projectile-like fragments are approximately equal to the constituent neutron-to-proton ratio of the projectile. There are clear differences of the directed flows for isospin-related fragments neutron and proton,~3H and ~3He from ~(28)S+~(28)Si collisions.The differences in directed flows for neutrons and protons and ~3H–~3He from a proton-rich nucleus ~(28)S- induced collisions are noticeably larger than those from a stable nucleus ~(32)S- induced reactions under medium impact parameters. Thus, the yield ratios and differences in directed flows for the neutrons and protons and ~3H–~3He under medium impact parameters are proposed as possible observable items for studying isospin physics.     

Facile strategy to fabricate Na2Li2Ti6O14@Li0.33La0.56TiO3 composites as promising anode materials for lithium-ion battery

A robust strategy has been developed to fabricate Na₂Li₂Ti₆O₁₄@Li_0.33La_0.56TiO₃ composites as promising anode materials for lithium-ion battery. Li_0.33La_0.56TiO₃ modification does not change the basic structure of Na₂Li₂Ti₆O₁₄ but enhances the lattice parameter because few trivalent lanthanum ions enter the crystal lattice of Na₂Li₂Ti₆O₁₄. All samples show similar morphology with a narrow size distribution ranged from 100 to 500?nm. HRTEM test demonstrates that a good conductive connection between the Na₂Li₂Ti₆O₁₄ and Li_0.33La_0.56TiO₃ layer is successfully formed. The electrochemical tests show that Na₂Li₂Ti₆O₁₄@Li_0.33La_0.56TiO₃ (5?wt%) sample exhibits the lowest charge-transfer resistance, highest reversibility of lithium insertion/extraction, and the largest Li-ion diffusion coefficient among all samples, and then shows the best electrochemical activity. Hence, the Na₂Li₂Ti₆O₁₄@Li_0.33La_0.56TiO₃ (5?wt%) electrode reveals the largest lithiation and delithiation capacities at each current density. The Na₂Li₂Ti₆O₁₄@Li_0.33La_0.56TiO₃ (5?wt%) shows excellent cycling stability with a delithiation capacity of 166.8?mAh?g^?1 at 500?mA?g^?1 after 100 cycles. However, the corresponding delithiation capacity of pristine Na₂Li₂Ti₆O₁₄ is only 136.9?mAh?g^?1 after 100 cycles. Li_.33La_.56TiO₃ modification is a direct and powerful design method to enhance the delithiation and lithiation capacities and cycling stability of Na₂Li₂Ti₆O₁₄.     

Chemical Composition and Immunohistological Variations of a Growing Bamboo Shoot

Abstract

Ma bamboo (Dendrocalamus latiflorus Munro) is the most distributed bamboo species in Taiwan, and its newly grown biomass within one growing season is the highest compared to the other local bamboo species. However, little is known about the cell wall chemical composition variations and distributions in Ma bamboo during its growth. In this study, we use chemical analyses along with lignin staining and immunolocalization to characterize the distributions of cell wall components from a Ma bamboo shoot at different growing stages. The results show that lignin, crystalline cellulose, and xylan are preferentially accumulated at later stage of developments. Lignin heterogeneity varies among different growing stages, and their lignins contain significant amounts of acylated p-coumaric acid and ferulic acid. Depositions of xyloglucan in differentiating cell walls are associated with that of pectin and xylan; they might be masked with each other. Galactan and mannan are minor constituents of bamboo shoots, and galactan is potentially masked by other polysaccharides in specific growing stages.     

Enhanced cycling stability of microsized LiCoO2 cathode by Li4Ti5O12 coating for lithium ion battery

The effect of Li₄Ti₅O₁₂ (LTO) coating amount on the electrochemical cycling behavior of the LiCoO₂ cathode was investigated at the high upper voltage limit of 4.5 V. Li₄Ti₅O₁₂ (≤5 wt.%) is not incorporated into the host structure and leads to formation of uniform coating. The cycling performance of LiCoO₂ cathode is related with the amount of Li₄Ti₅O₁₂ coating. The initial capacity of the LTO-coated LiCoO₂ decreased with increasing Li₄Ti₅O₁₂ coating amount but showed enhanced cycling properties, compared to those of pristine material. The 3 wt.% LTO-coated LiCoO₂ has the best electrochemical performance, showing capacity retention of 97.3% between 2.5 V and 4.3 V and 85.1% between 2.5 V and 4.5 V after 40 cycles. The coulomb efficiency shows that the surface coating of Li₄Ti₅O₁₂ is beneficial to the reversible intercalation/de-intercalation of Li⁺. LTO-coated LiCoO₂ provides good prospects for practical application of lithium secondary batteries free from safety issues.     

Synthesis and electrochemistry of 5 V LiNi0.4Mn1.6O4 cathode materials synthesized by different methods

Spinel LiNi_0.4Mn_1.6O₄ has been successfully synthesized by ultrasonic-assisted co-precipitation (UACP) method. The structure and physicochemical properties of this as-prepared powder compared with the LiNi_0.4Mn_1.6O₄ synthesized by co-precipitation method were investigated by powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and galvanostatic charge–discharge test in detail. XRD and SEM show that all samples have high phase purity, and ultrasonic process plays an important role in controlling morphology; FT-IR reveals that the Mn(III)–O stretching band at 511 cm^?1 has a red shift to 503 cm^?1, and the Mn(IV)–O stretching band at 612 cm^?1 has a blue shift to 622 cm^?1 because of the doped Ni. CV confirms that the LiNi_0.4Mn_1.6O₄ sample (UACP) has bigger area of the reduction peaks than that of sample synthesized by co-precipitation method, indicating that the former has higher discharge capacity than that of the latter. Galvanostatic charge–discharge test indicates that the initial discharge capacities for the LiNi_0.4Mn_1.6O₄ (UACP) at C/5 and 1C are 129 and 116 mAh g^?1, respectively. After 100 cycles, their capacity retentions are 94.6% and 85.3%, respectively. EIS indicates that LiNi_0.4Mn_1.6O₄ samples synthesized by UACP method have smaller charge transfer resistance than that of samples synthesized by co-precipitation method corresponding to the extraction of Li⁺ ions.     

Effects of different particle sizes on electrochemical performance of spinel LiMn<Subscript>2</Subscript>O<Subscript>4</Subscript> cathode materials

Spinel LiMn₂O₄ were prepared by adipic acid-assisted sol–gel method at 800 °C, and the cathode materials with different particle sizes were obtained through ball milling. The effects of different particle sizes on electrochemical performance of LiMn₂O₄ sample were investigated by X-ray diffraction (XRD), galvanostatic charge–discharge test, cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS), respectively. XRD data exhibits that all samples exhibit the same pure spinel phase; EIS and CV indicate that LiMn₂O₄ samples with smaller particle size have higher charge transfer resistance and oxidation potential than that of other samples corresponding to the extraction of Li⁺ ions, respectively; galvanostatic charge–discharge test shows that the particle size has significant effects on the electrochemical performance of spinel LiMn₂O₄ cathode materials.