Synthesis and characterization of novel polyamide‐imides containing noncoplanar 2,2′‐dimethyl‐4,4′‐biphenylene unit

A new diimide‐dicarboxylic acid, 2,2′‐dimethyl‐4,4′‐bis(4‐trimellitimidophenoxy)biphenyl (DBTPB), containing a noncoplanar 2,2′‐dimethyl‐4,4′‐biphenylene unit was synthesized by the condensation reaction of 2,2′‐dimethyl‐4,4′‐bis(4‐minophenoxy)biphenyl (DBAPB) with trimellitic anhydride in glacial acetic acid. A series of new polyamide‐imides were prepared by direct polycondensation of DBAPB and various aromatic diamines in N‐methyl‐2‐pyrrolidinone (NMP), using triphenyl phosphite and pyridine as condensing agents. The polymers were produced with high yield and moderate to high inherent viscosities of 0.86–1.33 dL · g⁻¹. Wide‐angle X‐ray diffractograms revealed that the polymers were amorphous. Most of the polymers exhibited good solubility and could be readily dissolved in various solvents such as NMP, N,N‐dimethylacetamide (DMAc), N,N‐dimethylformamide (DMF), dimethyl sulfoxide, pyridine, cyclohexanone, and tetrahydrofuran. These polyamide‐imides had glass‐transition temperatures between 224–302 °C and 10% weight loss temperatures in the range of 501–563 °C in nitrogen atmosphere. The tough polymer films, obtained by casting from DMAc solution, had a tensile strength range of 93–115 MPa and a tensile modulus range of 2.0–2.3 GPa. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 63–70, 2001     

Outlook for photovoltaic developments in Taiwan

This paper describes the various aspects of photovoltaic developments in Taiwan, which include applications of space and terrestrial solar cells, solar cell production and research on advanced thin-film solar cell materials. The advanced materials are hydrogenated polycrystalline silicon films deposited at low substrate temperatures and ternary chalcopyrite films with the potential for intrinsically stable and ultra-high-efficiency solar cells having a conversion efficiency in the vicinity of AMI 35%. © 1998 John Wiley & Sons, Ltd.     

A Chemoimmunotherapy Nanogel Enables Efficient Delivery of Interleukin-2 and Induction of Immunogenic Cell Death for Effective Cancer Therapy

Interleukin-2 (IL-2) is one of the first FDA-approved immunotherapeutics, but its use is limited by toxicity and low efficacy. In addition, all immunotherapies are limited by the immunosuppressive and desmoplastic microenvironment of “immunologically cold” tumors, such as pancreatic ductal adenocarcinoma (PDAC) or hepatocellular carcinoma (HCC) with advanced liver fibrosis. Here, a new chemoimmunotherapy nanogel (IL2-Pt@Nanogel) for dual delivery of IL-2 and the type II immunogenic cell death inducer Pt-NHC that reduces the immunosuppressive phenotype of tumor-associated macrophages and diminishes regulatory T cell infiltration by inducing the production of type I interferon (IFN) by cancer cells is reported. Combining the angiotensin II receptor blocker losartan with IL2-Pt@Nanogel treatment reduces desmoplasia and reprogrammes the microenvironment of PDAC and HCC toward an immunostimulatory one. These effects result in potent anti-tumor efficacy in models of primary and metastatic PDAC and HCC with underlying liver fibrosis. This study presents a strategy for IL-2-based chemoimmunotherapy with the potential for clinical translation to treat solid tumors.     

Dual-band CPW-fed Y-shaped monopole antenna for PCS/WLAN application

A rectangular notch is introduced to expand the impedance bandwidth of a dual-band planar monopole antenna for application in PCS/WLAN systems. The antenna is fed by a CPW line and resembles the shape of the letter 'Y'. Prototypes of the proposed antenna have been constructed and tested. Good measured radiation characteristics of monopole-like patterns, 14.4 and 34.1% bandwidths, and 3 and 4.3 dBi peak antenna gains for the lower (1.95 GHz) and upper (5.45 GHz) bands have been obtained.     

Investigation on vortex shedding of a swept-back wing

Effects of Reynolds number and angle of attack on the vortex shedding of a finite swept-back wing are experimentally studied. The cross-sectional profile of the wing is NACA 0012, and the sweep-back angle is 15° The time series signals detected by hot-wire in the wake region shows four distinct behaviors: laminar, subcritical, transitional, and supercritical. The derived Strouhal number curves are significantly different in these four behaviors. In addition, the statistical properties of turbulence, that is, the power spectrum density function, probability density function, correlation coefficient, Lagrangian integral time scales, and length scales are also presented in this paper.     

Microstructure and protonic conductivity of H3PO4‐doped polyethylenimine–siloxane chemically covalently organic–inorganic hybrids

The chemically covalent polyethylenimine–siloxane hybrids doped with various amounts of ortho‐phosphoric acid (H₃PO₄) were prepared and characterized by FTIR, DSC, TGA, and solid‐state NMR spectra. The protonic conduction behavior of these materials was also investigated by means of impedance measurements. These observations indicate that the hydrogen bonding and protonic interactions exist between the dopant H₃PO₄ and the hybrid host, resulting in an increase in T _g of polyethylenimine segments. These hybrids are thermally stable up to 200 °C from TGA analysis. Conductivity studies show an Arrhenius behavior characteristic and the Grotthus‐like proton conduction, and a high conductivity of 10^?2–10^?3 S cm^?1 at 110 °C in dry atmosphere for the hybrid membrane with H₃PO₄/EI of 0.5. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 2135–2144, 2006     

An asymmetric two-side program with one-side read (ATPOR) device for MultiBit per cell MLC nitride-trapping flash memories

An asymmetric two-side program with one-side read (ATPOR) Flash memory device is proposed. In this nitride-trapping device, the interaction of stored charges in the two sides (second-bit effect) is utilized to achieve multilevel cell (MLC) V/sub t/ levels with the advantages of relatively small total charge. The small total charge can enhance both programming and erasing efficiency. The ATPOR device with programming and erasing times within 100 ns and 40 /spl mu/s are demonstrated. Excellent read disturb immunity of ATPOR device can provide high scaling capability. In addition, good data retention and P/E cycling endurance and reliability are achieved. For 2-bit/cell and 3-bit/cell MLC applications, the ATPOR device with tight level distributions less than 100 mV is illustrated.     

A high efficient 820 nm MOS Ge quantum dot photodetector

A Ge quantum dot photodetector has been demonstrated using a metal-oxide-semiconductor (MOS) tunneling structure. The oxide film was grown by liquid phase deposition (LPD) at 50/spl deg/C. The photodetector with five-period Ge quantum dot has responsivity of 130, 0.16, and 0.08 mA/W at wavelengths of 820 nm, 1300 nm, and 1550 nm, respectively. The device with 20-period Ge quantum dot shows responsivity of 600 mA/W at the wavelength of 850 nm. The room temperature dark current density is as low as 0.06 mA/cm/sup 2/. The high performance of the photodetectors at 820 nm makes it feasible to integrate electrooptical devices into Si chips for short-range optical communication.     

A Novel Low-Cost Multi-Mode Reed Solomon Decoder Design Based on Peterson-Gorenstein-Zierler Algorithm

Reed-Solomon (RS) codes play an important role in providing error protection and data integrity. Among various Reed-Solomon decoding algorithms, the Peterson-Gorenstein-Zierler (PGZ) algorithm in general has the least computational complexity for small t values. However, unlike the iterative approaches (e.g., Berlekamp-Massey and Euclidean algorithms), it will encounter divided-by-zero problems in solving multiple t values. In this paper, we propose a multi-mode hardware architecture for error numbers ranging from zero to three. We first propose a cost-down technique to reduce the hardware complexity of a t = 3 decoder. A Finite-field Inversion (FFI) elimination scheme is also proposed in our PGZ kernel. Next, we perform an algorithmic-level derivation to identify the configurable feature of our design. With those manipulations, we are able to perform multi-mode RS decoding in one unified VLSI architecture with very simple control scheme. The very low cost and simple data-path make our design a good choice in small-footprint embedded VLSI systems such as Error Control Coding (ECC) in memory/storage systems.