Interfacial chemical oxidative synthesis of multifunctional polyfluoranthene.

A novel polyfluoranthene (PFA) exhibiting strong visual fluorescence emission, a highly amplified quenching effect, and widely controllable electrical conductivity is synthesized by the direct cationic oxidative polymerization of fluoranthene in a dynamic interface between n-hexane and nitromethane containing fluoranthene and FeCl3, respectively. A full characterization of the molecular structure signifies that the PFAs have a degree of polymerization from 22-50 depending on the polymerization conditions. A polymerization mechanism at the interface of the hexane/nitromethane biphasic system is proposed. The conductivity of the PFA is tunable from 6.4 × 10-6 to 0.074 S cm-1 by doping with HCl or iodine. The conductivity can be significantly enhanced to 150 S cm-1 by heat treatment at 1100 °C in argon. A PFA-based chemosensor shows a highly selective sensitivity for Fe3+ detection which is unaffected by other common metal ions. The detection of Fe3+ likely involves the synergistic effect of well-distributed π-conjugated electrons throughout the PFA helical chains that function as both the fluorophore and the receptor units

Facile Synthesis and Versatilities of Polyanthraquinoylamine Nanofibril Bundles with Self Stability and High Carbon Yield

A facile synthesis for nanosized conducting polymers with inherent self-stability and multi-functionalities is a main challenge. Here we simply synthesize intrinsically self-stabilized nanofibril bundles of poly(1-anthraquinoylamine) (PAQ) by a template-free method. The critical polymerization parameters were studied to significantly optimize the synthesis, size, properties, and functionalities of the resulted fine nanofibrils with a diameter of ca. 30 nm and length of ~6 μm. The PAQ obtained with ammonium persulfate possesses higher polymerization yield, purer composition, higher conductivity, better melting behaviour, higher thermostability, lower burning enthalpy, and slower degradation than that with other oxidants. Furthermore, the polymer nanofibrils exhibit high self-stability, powerful redispersibility, high purity, and clean surface because of a complete avoidance of the contamination from external stabilizer. The PAQ exhibits widely controllable conductivity moving across ten orders of magnitudes from 10^-9^ to 50 S/cm, photoluminescence, lead-ion adsorbability, very high thermostability in air and extremely high char yield in nitrogen at 1000˚C. These materials would be useful as advanced materials including photoluminescent materials, highly cost-effective carbon precursors, sorbents of toxic metal ions, and cost-efficient conductive nanocomposite with low percolation threshold

Graviton-Photon Conversion in Atoms and the Detection of Gravitons

We study graviton-photon conversion in ground-based experiments. From graviton to photon tran- sition, we calculate the cross section of graviton-atom interaction in the presence of spherical atomic electric fields; the obtained results hold for graviton energy around 100 keV - 1 GeV and would be enhanced by crystal structures, thus it gives a chance to catch MeV level gravitons from the universe with current neutrino facilities. From photon to graviton transition, we propose an experiment using entangled pho- ton pairs to count missing photons passing through transverse magnetic tunnel, which could be used to verify the energy quantization of gravitational field

Solar Instrumentation Lab

This project is a mobile platform that will allow experiments on different solar panels to be done easily while keeping the cost of the lab to a minimum. California Polytechnic State University’s motto is ‘learn by doing’ and this lab structure will allow students to get practical experience with photovoltaic cells and the instruments that are required to take measurements. The solar instrumentation lab is a potential hardware lab for the electrical engineering department’s Sustainable Electric Energy Conversion class EE 420 and Solar-Photovoltaic Systems Design EE 520. This group took the current solar structure as a base for the lab’s functions and also the input from professors who would be running these solar labs as to what they would like to see in future labs and incorporated their suggestions into the solar structure capabilities. The result will be a user friendly mobile solar lab on which students can perform experiments that is affordable for the electrical engineering department

Human Disturbance Reduces Plant Species Diversity and Stability of Phyllostachys pubescens Forests

Plant species diversity is an important index reflecting the functional complexity and stability of ecosystems. Human activity can completely alter plant species diversity and cause serious degradation of ecosystems but its impact on bamboo forest still lacks of systematic evaluation. In this study, we performed a field investigation to reveal the influences of human disturbances on the plant diversity and stability of Moso bamboo forests at Southern China. The selected bamboo fields contained different intensities of human activities that could be classified as slight, moderate and severe disturbance level. Species richness index S, Shannon-Wienner index H, Simpson index D, Pielou index Jsw, community similarity index IS and community stability index were employed to quantitatively evaluate the plant species diversity and stability. The survey revealed that there were 203 species belonging to 83 families and 108 genera in Moso bamboo forests. The number of plant species in the Moso bamboo forests decreased with the increasing of disturbance intensity. The species diversity indexes generally followed the order of slight > moderate > severe disturbance, as well as the richness index S, Shannon-Wienner index H and Pielou index Jsw. The similarity and species stability of the bamboo forest communities also decreased with the increase of the disturbance intensity. Under the severe disturbance, plant species replacement occurred strongly. The obtained results provide some a guideline for the sustainable management of bamboo forest