Improved asymmetric electrochemical capacitor using Zn-Co co-doped Ni(OH)2 positive electrode material

The performance of Ni-foam pasted Ni(OH)₂ prepared from co-precipitated Ni(OH)₂ with Zinc (Zn) and Cobalt (Co) as the positive electrode active material of an asymmetric electrochemical capacitor (EC) is studied for the enhancement of the capacitor’s specific energy and power densities. A co-precipitated Ni(OH)₂/activated carbon (AC) composite material and AC were used as a positive and negative electrode material. The AC in the positive electrode is used as an electrolyte reservoir to reduce ionic diffusion resistance regardless of charge/discharge current density. In addition, the simultaneous presence of Zn and Co ions in the Ni(OH)₂ layer improves the efficiency of the active material and reduces the resistance of the unit cell. It was observed that through the effects of the additives in the positive electrode, the asymmetric EC exhibits a high energy density with 35.7 Wh/kg, based on the active material. Furthermore, the energy density decreasing behavior at a high discharge current density was retarded. PACS 81.20.Ev; 73.40.Mr; 66.30.Pa; 66.30.Dn     

Transmission of 40 Gb/s × 8 WDM channels with 100 GHz spacing using short-period dispersion-managed fiber

We report on the 320 Gb/s (40 Gb/s × 8 channels) WDM transmission experiment using short-period dispersion-managed fiber. After 320-km transmission, the average Q-factor was measured to be better than 20.4 dB. In addition, we compared the performances of various types of fibers in 40-Gb/s based systems. The results show that the SPDMF was robust to both the intra-channel and inter-channel nonlinearities due to its small average dispersion and large local dispersion.     

弱L^p的对偶空间的一个注记

本文证明了非自反弱序列完备Ｂａｎａｃｈ格在它的二次对偶空间中的正交补是非自反映的，从而证明了Ｃｗｉｋｅｌ的关于弱Ｌ＾ｐ的对偶空间的奇异部的表示定理是错误的。     

Organic electroluminescence using polymer networks from smectic liquid crystals

We report the synthesis of a red light-emitting and photopolymerizable smectic liquid crystal (reactive mesogen). We investigate the suitability of polymer networks formed from smectic reactive mesogens for use in organic light-emitting diodes (OLEDs). The use of mixtures of smectic reactive mesogens is shown to lower the processing temperature for the fabrication of OLEDs to room temperature. We also report efficient energy transfer from a nematic polymer network host to a smectic light-emitting dopant and polarized emission from a polymer network formed from an aligned smectic reactive mesogen.     

Novel Variable PDL Emulator Based on LiNbO3 Modulator

We propose and demonstrate a novel variable PDL emulator based on a LiNbO3 modulator. The proposed emulator could vary the PDL values simply by adjusting the bias voltage of modulator. The results show that the proposed PDL emulator could generate a wide range of PDL values (0 ～ 35 dB). The generated PDL value could be maintained within ± 0.02 dB for ＞70 minutes. The wavelength dependency was about 0.03 dB in the range of 1520nm ～ 1590 nm.     

Synthesis and properties of chitosan‐based thermo‐ and pH‐responsive nanoparticles and application in drug release

In this research, thermo‐ and pH‐responsive nanoparticles with an average diameter of about 50–200 nm were synthesized via the surfactant‐free emulsion polymerization. The thermal/pH dual responsive properties of these nanoparticles were designed by the addition of a pH sensitive monomer, acrylic acid (AA), to be copolymerized with N‐isopropylacrylamide (NIPAAm) in a chitosan (CS) solution. The molar ratio of CS/AA/NIPAAm in the feed was changed to investigate its effect on structure, morphology, thermal‐ and pH‐responsive properties of the nanoparticles. It was found that CS‐PAA‐PNIPAAm nanoparticles could be well dispersed in the aqueous solution and carried positive charges on the surface. The addition of thermal‐sensitive NIPAAm monomer affected the polymerization mechanism and interactions between CS and AA. The particle size of the nanoparticles was found to be varied with the composition of NIPAAm monomer in the feed. The synthesized nanoparticles exhibited stimuli‐responsive properties, and their mean diameter thus could be manipulated by changing pH value and temperature of the environment. The nanoparticles showed a continuous release of the encapsulated doxycycline hyclate up to 10 days during an in vitro release experiment. The environmentally responsive nanoparticles are expected to be used in many fields such as drug delivery system. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 2798–2810, 2009     

Templated synthesis of silver nanoparticles in amphiphilic poly(vinylidene fluoride‐co‐chlorotrifluoroethylene) comb copolymer

In this study, poly(vinylidene fluoride‐co‐chlorotrifluoroethylene)‐graft‐poly(oxyethylene methacrylate), P(VDF‐co‐CTFE)‐g‐POEM, an amphiphilic comb copolymer with hydrophobic P(VDF‐co‐CTFE) backbone and hydrophilic POEM side chains at 73:27 wt % was synthesized. The POEM side chains were grafted from the P(VDF‐co‐CTFE) mainchain backbone via atom transfer radical polymerization (ATRP) using direct initiation of the chlorine atoms in CTFE units. Synthesis of microphase‐separated P(VDF‐co‐CTFE)‐g‐POEM comb copolymer was successful, as confirmed by nuclear magnetic resonance (¹H NMR), FTIR spectroscopy, and transmission electron microscopy (TEM). Nanocomposite films were prepared using the comb copolymer as a template film and the in situ reduction of AgCF₃SO₃ precursor to silver nanoparticles under UV irradiation. Silver nanoparticles with 4–8 nm in average size were in situ created in the solid state template film, as revealed by TEM, UV–visible spectroscopy, and wide angle X‐ray scattering (WAXS). Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) presented the selective incorporation and the in situ growth of silver nanoparticles within the hydrophilic POEM domains of microphase‐separated comb copolymer film. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 702–709, 2008