Production of Large Specific Capacitance by Electrodes with Low Active Mass and Synergistic Mechanisms.

Decoration of vanadium nitride nanoparticles on carbon nanotubes creates electrodes with three different energy storage mechanisms that operate synergistically to give a high specific capacitance with a low active mass. Calculation and measurements further indicate the power and energy density to be as high as 105-106 W/kg and 102 Wh/kg, respectively. Particle attachment also greatly improves the capacitive coefficient, including ionic transmittance, charge transfer, porosity, and conductivity. Corrosion tests based on the Tafel method reveal the corrosion potential and current of electrodes as low as -0.721 V and 7.53 × 10-4 A, respectively.

Carbon nanotube papers with p-n junctions along the thickness direction.

Conductive papers made from carbon nanotubes and wood fibers exhibit a p-type character. N2 plasma treatment converts paper into n-type and conversion is verified by elemental analyses, work function and Hall-effect measurements. By screening one face of p-type paper in plasma, the p-n junctions are successfully created along the thickness direction and electrical rectification is evident by current-voltage measurement.

Effects of Cordyceps militaris fermentation products on reproductive development in juvenile male mice.

Cordyceps militaris (CM) is a popular medicinal fungus; however, few studies have focused on its impact on the male reproductive system. We evaluated the effects of CM fermentation products on the reproductive development of juvenile male (JM) mice. Mice were divided into four experimental groups, each fed 5% CM products (weight per weight (w/w) in normal diet): extracellular polysaccharides (EPS), fermentation broth (FB), mycelia (MY), and whole fermentation products (FB plus MY, FBMY) for 28 days, while mice in the control group (CT) were fed a normal diet. Basic body parameters, testicular structure, sperm parameters, and sex hormones concentrations were analyzed. Compared to the CT group, mice in the EPS, MY, and FBMY groups showed a significantly increased mean seminiferous tubule area (p < 0.05), mice in the FB and MY groups had significantly higher sperm concentrations (p < 0.05), and mice in the EPS, FB, and FBMY groups showed significantly increased ratios of motile sperm (p < 0.05). Meanwhile, EPS significantly promoted the ability of JM mice to synthesize testosterone (p < 0.05). Furthermore, all CM products significantly increased the food intake of JM mice (p < 0.05) but did not significantly change their water intake and body weight gain (p > 0.05). In conclusion, CM products, especially EPS, exhibit strong androgen-like activities that can promote male reproductive development.

Electric field created p-n junction in composite films made from carbon nanotubes, iron (III) sulfate and polyvinyl alcohol.

Suspension made of Fe2(SO4)3(aq), polyvinyl alcohol and carbon nanotubes is placed in electric field to separate charges. Charges remain separated as suspension solidifies, forming composite films with cations and anions enriched at opposite sides. Polarized films behave as junction diodes with forward current and threshold voltage found to be 10-4-10-5 A and 2.4-2.6 V at ± 5 V. Rectification is preserved in strained composite films.

Synthesis of SiC/SiO2 core-shell nanowires with good optical properties on Ni/SiO2/Si substrate via ferrocene pyrolysis at low temperature.

In this study, the high-density SiC/SiO2 core-shell nanowires were synthesized on the nickel coated SiO2 (100 nm)/Si substrate by chemical vapor deposition (CVD) method with ferrocene precursor at temperature 1000 °C compared to previous studies (1300-1600 °C). The present work provides an efficient strategy for the production of SiC/SiO2 nanowires with uniform morphology and good optical properties, where the Ni layer plays important roles for this fabrication at low temperature which reduces the decomposition temperature of hydrocarbon gases and improves the growth quality of SiC nanowires. The as-synthesized SiC/SiO2 nanowires consist of single crystal 3C structures as well as 3C structures with defects along [111] direction. In the photoluminescence (PL) spectrum, the SiC/SiO2 core-shell nanowires revealed an obvious blueshift. The blueshift is due to the formation of nanoscale silicon carbide polytypism caused by the stacking faults in 3C-SiC and the nanoscale polytypism also caused the transition from indirect to direct bandgap which explains why the stacking faults percentage in SiC confirmed from X-ray diffraction (XRD) is 19%, but ultimately makes the strongest emission intensity. Finally, the PL characteristics are further improved by changing the diameter of the SiC nanowire and etching and an approximate model followed by the vapor-liquid-solid (VLS) mechanism was proposed to explain the possible growth mechanism of the SiC/SiO2 nanowires.

Production of nitrogen-doped carbon quantum dots with controllable emission wavelength, excellent sensing of Fe3+ in aqueous solution, and potential application for stealth quick response coding in the visible regime.

Nitrogen-doped carbon quantum dots (N-CQDs) exhibit a high quantum yield with controllable emission wavelength and intensity in the blue-green regime. N-CQDs were tested and determined to be thermally and optically stable during 150 °C heat treatment and prolonged UV irradiation. Potential applications of N-CQDs were demonstrated, including excellent Fe3+ sensing in aqueous solution, fluorescent polymer fibres, and stealth quick response coding at visible wavelengths.

Structural equation modelling of the complex relationship between toothache and its associated factors among Indonesian children.

The Indonesian family life survey (IFLS) is used for formulating various government policies. Our preliminary study using data from the IFLS showed increase in the prevalence of toothache from 2007 to 2014. Hence, a need to analyse the factors associated with toothache using structural equation modelling (SEM) for identifying the direct and indirect association of factors with toothache was evident. The objective of this study is to analyse the complex relationships between toothache and its associated risk factors. This cross-sectional study was conducted on the data obtained from the IFLS in 2014. The IFLS data pertaining to toothache and its prevalence were analysed using the STATA software, and the multifaceted relationship was analysed using SEM. The prevalence of toothache among Indonesian children was 15.55% (1,959 of 12,595). SEM showed the direct association between toothache and age (p < 0.001) and parent awareness of children's health conditions (p < 0.005) and food consumption frequency (p < 0.001). Parents' education level and residential area showed an indirect association with toothache, mediated by socio-economic status and parent awareness of children's health conditions (p < 0.001). We identified the multifaceted relationship between toothache and the social covariates. Parents' awareness of their children's health conditions mediated several indirect associations, highlighting its importance.

Selective modification of aligned carbon nanotubes by N2 plasma and their diode behavior.

Aligned carbon nanotubes made by pyrolysis of ferrocene are selectively treated with N2 plasma at various durations. Raman spectra reveal that polar bonds form at treated regions and result in increased Raman breathing mode. XPS support Raman and verify the C-O/C-N formations in carbon lattices. Electrical measurements show an unipolar p-type character as probes are placed in contact with untreated regions of nanotubes. Reposition of probes at untreated and treated regions respectively produces a current-voltage profile that resembles a p-n junction diode with forward current reaching a value as high as 100 mA at 3 V. Ab initio calculations confirm the on-tube junction and creation of a donor state is owing to C-N formations.

Hexagonal Boron Nitride Coated Carbon Nanotubes: Interlayer Polarization Improved Field Emission.

Coating of h-BN onto carbon nanotubes induces polarization at interfaces, and charges become localized at N and C atoms. Field emission of coated tubes is found to be highly stable, and current density fluctuates within 4%. Study further reveals that the electric field established between coatings and tubes facilitates charge transfer across interfaces and electrons are emitted through occupied and unoccupied bands of N and B atoms.

Extraction of intercalated O2 from aligned carbon nanotubes: the breaking of intertube paths and exponential changes in resistance.

In carbon nanotube films, the alignment of carbon nanotubes creates Lennard-Jones potentials at intertube junctions and trapped O2 appears to oscillate at elevated temperatures. Electrical measurements reveal a low hopping barrier along the transverse direction and an underlying mechanism that involves intercalated molecules acting as charge carriers between tubes. Ab initio calculations support dynamic intercalation and charge transfer through O2 bouncing between tubes.

Carbon nanotubes enhanced Seebeck coefficient and power factor of rutile TiO2.

The Seebeck coefficient, according to Ioffe's approximation, is inversely proportional to carrier density and decreases with doping. Herein, we find that the incorporation of multi-walled carbon nanotubes into rutile TiO2 improves the electrical conductivity and Seebeck coefficient at a low filling fraction of tubes; moreover, the former was due to the lengthening of the mean free path and doping modified carrier mobility for the latter. Tube-oxide mixing also causes significant phonon drag at the interfaces and the reduced thermal conductivity was verified by the promoted figure of merit.

ZnO-coated carbon nanotubes: inter-diffusion of carboxyl groups and enhanced photocurrent generation.

ZnO is a defect-governed oxide and emits light at both visible and UV regimes. This work employs atomic layer deposition to produce oxide particles on oxygenated carbon nanotubes, and the composites only show emission profiles at short wavelengths. The quenching of defect-related emissions at long wavelengths is verified, owing to carboxyl diffusion into oxygen vacancies, and doping is supported by ZnCO3 formation in oxide lattice. Fully coated tubes display an increased photocurrent and the quantum efficiency increases by 22 % relative to the bare nanotubes.

Carbon nanotube alignment driven rapid actuations.

Suspended micro-beams made from aligned carbon nanotubes and parylene deflect reversibly in an ac field and the deflection rate is three orders of magnitude greater than those for existing devices. The direction of beam deflection is determined by the area moment of inertia and the actuation mechanism involves rapid accumulation of charges at tube surfaces, the creation of Coulomb repulsive forces between tubes, beam dilation and the formation of compressive stresses at beam ends. Tube alignment plays a crucial role in the first step as is verified by experimental data and calculation.

Separation, purification, and α-glucosidase inhibition of polysaccharides from Coriolus versicolor LH1 mycelia.

Intracellular polysaccharides (iPs) were separated and purified from Coriolus versicolor LH1 mycelia and characterized for their α-glucosidase inhibitory properties. Three iP fractions (iPL-F5-2-1, iPL-F5-4-1, and iPL-F5-5-1) were extracted, separated, and purified from LH1 mycelia using microwave extraction technology, a DEAE-Sepharose CL-6B column, a Diaion HP20 macroporous adsorption column, and a Sephadex™ G-50 gel-permeation column. The principal constituents of iPL-F5-2-1, iPL-F5-4-1, and iPL-F5-5-1 were saponins and polyphenoic compound mixtures. The enzyme inhibition activity, IC(50) values, of these three fractions were 1.7, 1.8, and 0.8 mg/mL, respectively. The α-glucosidase inhibitory properties were related to the presence of α-(1,4) glycosidic linkages in the polysaccharide structure and the total relative percentage of d-glucose and d-galactose in the structure of polysaccharides, other than triterpenoids.

Supersensitive, ultrafast, and broad-band light-harvesting scheme employing carbon nanotube/TiO2 core-shell nanowire geometry.

We demonstrate a novel, feasible strategy for practical application of one-dimensional photodetectors by integrating a carbon nanotube and TiO(2) in a core-shell fashion for breaking the compromise between the photogain and the response/recovery speed. Radial Schottky barriers between carbon nanotube cores and TiO(2) shells and surface states at TiO(2) shell surface regulate electron transport and also facilitate the separation of photogenerated electrons and holes, leading to ultrahigh photogain (G = 1.4 × 10(4)) and the ultrashort response/recovery times (4.3/10.2 ms). Additionally, radial Schottky junction and defect band absorption broaden the detection range (UV-visible). The concept using metallic core oxide-shell geometry with radial Schottky barriers holds potential to pave a new way to realize nanostructured photodetectors for practical use.

Why aggregated carbon nanotubes exhibit low quantum efficiency.

Aggregation of carbon nanotubes reduces quantum efficiency and the phenomenon is found to be related to photocurrent leakage through oxygenated lattices acting as low barrier intertube channels. This outcome is supported by calculation and optical excitation experiments.

The zone-refine driven growth of jellyfish-like core-shell nanowires.

Thermal evaporation of a Sn-silica mixture produces core-shell nanowires assembled into jellyfish-like structures. The growth mechanism involves zone-refine driven phase separation at the solid-liquid interface. The materials emit blue and red lights; the luminescence centers are discussed and verified.

Oscillation induced worm-like locomotion of carbon nanotubes.

Harmonic oscillation of a doubly clamped single-walled carbon nanotube rope is significantly damped by the resistive force of friction at intertube contacts and the energy transmission rate has been estimated to be lower than that on a metal wire excited at similar frequency and vibrating length by one order of magnitude.

Creation of interfacial phonons by carbon nanotube-polymer coupling.

Incorporation of carbon nanotubes into nylon-6 creates interfacial phonons; phonon occupation at low frequency regime is therefore enhanced, leading to thermal conductivity improvement by 74-78%.