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Abstract: Multi-walled carbon nanotubes (MWCNTs) were filled into polycarbonate (PC) by large scale extruder, and some studies were carried out on as-produced composite. The results showed PC composite containing 1wt.% of MWCNTs had a tensile strength 4.5% higher than neat PC, and the elastic modulus of PC/MWCNTs composite increased obviously with MWCNTs loadings. The electrical resistivity measurements indicated a percolation of MWCNTs near 5wt.% (3.4vol.%) for the composite. Either the decrease in the fluidity of the composite melts with the increase of carbon nanotubes (CNTs) loadings or the unexpected shortening of CNTs in extrusion was supposed to have weakened the effects of CNTs as a reinforcing agent or a conductive filler. [Copyright &y& Elsevier]

Abstract: Manganese oxide/multiwalled carbon nanotubes (MWNTs) composite was prepared by mixing manganese oxide and MWNTs through a means of ultrasonic vibration in ethanol solution. A nonaqueous hybrid supercapacitor using manganese oxide/MWNTs (M/M) composite and MWNTs as positive and negative electrodes, respectively, has been designed and investigated by constant current charge/discharge tests. The asymmetric hybrid capacitor has better capacitance and energy characteristics than those of the symmetric ones based on individual M/M composite and MWNTs electrodes. The energy density of the hybrid capacitor can reach 32.91 W h/kg even at a current density of 10 mA/cm2 in 1.0 M LiClO4 electrolyte, which is comparable to that of a manganese oxide/activated carbon hybrid capacitor. [Copyright &y& Elsevier]

The commercial Li 4 Ti 5 O 12 (LTO) is successfully modified by SrF 2 via a low temperature coprecipitation process. The results indicate that Sr 2+ and F − do not co-dope into the bulk phase of the LTO, but instead form a SrF 2 coating layer on the surface of the LTO. The suitable SrF 2 buffer layer could cover the catalytic active sites of the LTO and suppress the electrolyte reduction decomposition on the surface of the LTO, which means that the SrF 2 modification is favorable to suppress gas generation of the LIBs using LTO as anode material during charge/discharge cycles and storage. Moreover, according to optimized the amount of SrF 2 , the 2 wt% of SrF 2 in the SrF 2 modified LTO composites exhibits the best rate capability and an excellent cyclic performance. [ABSTRACT FROM AUTHOR]

Abstract: The influences of LiBF4, LiClO4, lithium bis(oxalato) borate (LiBOB), LiPF6 with VC and without VC, and the mixed electrolytes composed of different ratios of LiBOB and LiPF6 or LiClO4 on the electrochemical properties of Si/graphite/disordered carbon (Si/G/DC) composite electrode were systematically investigated by constant current charge–discharge and electrochemical impedance spectra (EIS) techniques. Scanning electron microscopy (SEM) was used to observe the change of electrodes in morphology after given cycle numbers. X-ray photoelectron spectroscopy (XPS) was employed to understand the influences of different mixed electrolytes on the composition of SEI layers. The results showed that Si/G/DC composite electrode in the mixed electrolytes presented better electrochemical performance than in single electrolyte. The compactness and compositions of SEI layers intensively influenced the cycle performance of Si/G/DC composite materials. LiBOB and additive VC had a good synergistic effect on the formation of the dense SEI layers. In particular, Si/G/DC in 0.5M LiBOB+0.38M LiPF6 electrolytes containing VC exhibited a high reversible capacity and excellent cycle performance. [Copyright &y& Elsevier]

Abstract: Binary conductive additives (BCA), formed by sonication of mesoporous carbon (MC) and acetylene black (AB), were used as conductive additives to improve the electrochemical performance of a LiCoO2 composite cathode. The electrochemical performance of the LiCoO2 composite cathode dispersed with BCA was investigated. The results showed that the electrochemical performance (including the discharge capacity, the discharge voltage and the total internal resistance) of a BCA loaded LiCoO2 composite cathode was better than that of a cathode loaded with AB. The possible mechanism is that the MC in BCA can adsorb and retain electrolyte solution, which allows an intimate contact between the lithium ions and the cathode active material LiCoO2 due to its large mesopore specific surface area. A simplified model was also proposed. [Copyright &y& Elsevier]

Abstract: Silicon/graphite/disordered carbon (Si/G/DC) is coated by Li2ZrO3 using Zr(NO3)4·5H2O and CH3COOLi·2H2O as coating reagents. X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) are used to characterize Li2ZrO3-coated Si/G/DC composite. The Li2ZrO3-coated Si/G/DC composite exhibits a high reversible capacity with no capacity fading from 2nd to 70th cycle, indicating its excellent cycleability when used as anode materials for lithium ion batteries. A compact and stable solid-electrolyte interphase (SEI) layer is formed on the surface of Li2ZrO3-coated Si/G/DC electrode. Analysis of electrochemical impedance spectra (EIS) shows that the resistance of the coated material exhibits less variation during cycling, which indicates the integrity of electrode structure is kept during cycling. XPS shows that F and P elements do not appear in the SEI layers of Li2ZrO3-coated Si/G/DC electrode, while they have a relatively high content in SEI layers of Si/G/DC electrode. The improvement of Li2ZrO3-coated Si/G/DC is attributed to the decrease of lithium insertion depth and the formation of stable SEI film. [Copyright &y& Elsevier]

Abstract: Modified natural graphite is synthesized by surface coating and graphitizing process on the base of spherical natural graphite. The modified natural graphite is examined discharge capacity and coulombic efficiency for the initial charge–discharge cycle. Modification process results in marked improvement in electrochemical performance for a larger discharge capacity and better coulombic efficiency. The mechanism of the enhancement are investigated by means of X-ray powder diffraction, scan electron microscopy, and physical parameters examination. The proportion of rhombohedral crystal structure was reduced by the heat treatment process. The modified natural graphite exhibits 40mAhg−1 reduction in the first irreversible capacity while the reversible capacity increased by 16mAhg−1 in comparison with pristine graphite electrode. Also, it has an excellent capacity retention of ∼94% after 100 cycles and ∼87% after 300 cycles. [Copyright &y& Elsevier]

Abstract: Thin carbon nanotubes were synthesized by catalytic decomposition of CH4 over MoCoMgO catalyst. We obtained bundles of ordered nanotubes under hydrogen gas and disordered nanotubes under nitrogen gas over the same catalyst. The formation mechanism of nanotube bundles was discussed. The number of the tube walls was 2–5 with the corresponding diameters of 3–6 nm. We obtained a high production yield of 500 wt.% for the thin carbon nanotubes compared to the weight of the supplied catalyst. Moreover the duration of the hydrogen pretreatment was also found to have different effects on the yield of nanotubes under different carrier gases. [Copyright &y& Elsevier]

Abstract: Cutting carbon nanotubes is an important issue encountered in many potential applications. It was found that multi-walled carbon nanotubes(MWNTs) could be cut short efficiently by a two-roller mill. The addition of poly (methyl methacrylate) (PMMA) could increase the cutting efficiency and make the lengths of as shortened carbon nanotubes more uniform. Both the milling times and MWNTs'' content in PMMA composite had positive effects on the final lengths of as shortened MWNTs. The shortened MWNTs obtained from PMMA composites containing 25% MWNTs after being milled for 20 times showed a narrow length distribution of 250–300 nm and could form a homogeneous and stable dispersion in H2CCl2. [Copyright &y& Elsevier]

Abstract: Polycarbonate(PC) layer was introduced onto the surface of the purified carbon nanotubes(CNTs) by solution mixing. The as encapsulated nanotubes can be effectively cut short by ball milling for several hours. The average length of carbon nanotubes after 10 h of ball milling is about 60 nm. The polymer layer acts as a micro-cutting medium and stimulates shortening the carbon nanotubes. [Copyright &y& Elsevier]

• CpMADS4 was decreased during fruit ripening. • CpMADS4 could interact with NAC transcription factor CpNAC3. • Both CpMADS4 and CpNAC3 had transcriptional activation activities. • Both CpMADS4 and CpNAC3 co-regulate ethylene signal genes CpERF9 and CpEIL5. MADS box transcription factors (TFs) play important roles in different biological processes, for example, fruit ripening. However, the roles of MADS box TFs in papaya fruit ripening remain a little know. In this study, a novel MADS-box gene was found, named as CpMADS4 , and its expression level was decreased during fruit ripening. Protein-protein interaction assays proved that CpMADS4 interacted with CpNAC3. Both CpMADS4 and CpNAC3 had transcriptional activation activities. Moreover, CpMADS4 and CpNAC3 could specifically bind to and activate the promoters of ethylene signal genes CpERF9 and CpEIL5 , and the activate activities would be enhanced when both CpMADS4 and CpNAC3 existed at the same time. Our results suggested that CpMADS4 might function in fruit ripening through interacting with CpNAC3 and regulating ethylene signal genes CpERF9 and CpEIL5 , which provided new views about the functions of papaya MADS box TFs in regulating fruit ripening. [ABSTRACT FROM AUTHOR]

Abstract: Carbon nanotubes-based TiO2 composites were fabricated by hydrolysis, and the transmission electron microscopy(TEM) results showed that carbon nanotubes were partly coated with TiO2. X-ray photoelectron spectroscopy (XPS) results of purified carbon nanotubes indicated that there were some polar oxygenated groups such as C–O, C=O and O–C=O which might stimulate formation of the composites, and enhance the interfacial combination of TiO2 with carbon nanotubes. The formation of TiO2 and its compounding with CNTs happened almost simultaneously in this process. The method is a convenient route to fabricate CNTs-based TiO2 composites with different ratios. [Copyright &y& Elsevier]