High-field Magnetization of SrMn3P4O14 Having Magnetization Plateau and Ferrimagnetic Long-range Order

It has not been studied sufficiently whether quantum-mechanical character can exist in classical magnetic long-range order of systems with large spins. Very recently, it has been shown that a quantum-mechanical 1/3 magnetization plateau and classical ferrimagnetic long-range order coexist in SrMn₃P₄O₁₄ possessing spin-5/2 [T. Yang et al. in Inorg. Chem. 47:2562, 2008]. Magnetism of this substance has not been explained quantitatively, although the origin of the plateau is inferred to be a trimerized spin chain. We performed high-field magnetization measurements on SrMn₃P₄O₁₄ powders. We consider a spin system in this substance.     

Preparation and characterization of poly(9-hexylcarbazole-3,6-diylbutadiynylene)

Oxidative polymerization of 3,6-diethynyl-9-hexylcarbazole with oxygen in the presence of copper complex affords soluble poly(9-hexylcarbazole-3,6-diylbutadiynylene) in good yield. Irradiation with UV-vis. light and annealing under nitrogen lead to photochemical and thermal cross-linking and insolubilization of the polymer film. Received: 24 July 1997/Revised: 27 August 1997/Accepted: 7 September 1997     

Influence of Aluminum Titanate Formation on Sintering of Bimodal Size-Distributed Alumina Powder Mixtures

The sintering behavior of green compacts, in which coarse alumina particles formed a skeletal structure and fine alumina and/or fine titania particles filled the voids of the skeletal structure, was investigated. Sinterability of the green compacts changed according to the titania content in the fine powder. The titania content of 33 mol% was the most effective for the densification. The volume expansion due to the aluminum titanate formation occurred in the voids of the skeletal structure, and the densification of the skeletal structure progressed more because the grain growth between the fine and coarse alumina particles did not proceed. As the titania content decreased, the densification did not progress more than that of the compact with 33 mol% titania content because the grain growth proceeded more. As the titania content increased, the expansion of the compacts was larger, and large grains were formed by the reaction between the titania and coarse alumina particles. Therefore, densification became difficult.     

Tribological Behavior of a Si3N4/Carbon Short Fiber Composite under Water Lubrication

The tribological behavior of monolithic Si₃N₄ and a Si₃N₄/carbon fiber composite has been assessed under high load and low speeds in an aqueous environment. The results showed that the friction coefficient of the Si₃N₄ was not significantly reduced when compared with dry sliding, and this was attributed to the failure to maintain a lubricating layer between the solid–solid surfaces. In the case of the composite, the initial high friction coefficient was reduced shortly after the beginning of the wear test and maintained a low value (about 0.03) throughout. This was attributed to the solid lubricating effect of the composite resulting in lower stress at the contact asperities, preventing the removal of the lubricating layer.     

Room-Temperature Freeze Casting for Ceramics with Nonaqueous Sublimable Vehicles in the Naphthalene–Camphor Eutectic System

Freeze casting for Al₂O₃ was accomplished at room temperature with nonaqueous sublimable vehicles in the naphthalene–camphor eutectic system with a eutectic temperature of 31°C. A fully dense sintered body (>99.5% of theoretical density (T.D.)) was obtained with a eutectic composition vehicle, whereas at most 90% T.D. was obtained with an off-eutectic (i.e., hypo- or hypereutectic) composition vehicle due to formation of large uniquely shaped voids. Microstructural observation suggested that growing pro-eutectic crystals rejected the suspended Al₂O₃ particles to form large voids during the solidification process. At the eutectic composition, formation of fine lamellar microstructure in a solidified vehicle is considered to inhibit particle rejection resulting in large voids.     

Fabrication of Elongated α-SiAlON via a Reaction-Bonding Process

A reaction-bonding process, which offers low sintering shrinkage and is a low-cost process, was applied to fabricate Y–α-SiAlON ceramics. The green compacts composed of Si, Y₂O₃, Al₂O₃, and AlN were nitrided and subsequently postsintered. Dense single-phase Y–α-SiAlON with elongated grain morphology could be achieved in the specimen postsintered at 1900°C. The material exhibited high hardness (1850 HV10) and high fracture toughness (5.1 MPa·m^1/2).     

MAS NMR Evidence for the Presence of Silicon in the Alumina Spinel from Thermally Transformed Kaolinite

Georgia kaolinite dehydroxylated at 950°C for 24 h, then leached with KOH at 90°C for 1 h, shows a well-resolved ²⁹Si MAS NMR resonance at −77.5 ppm, within 2 ppm of the calculated position for Si incorporated in γ-alumina spinel. From a knowledge of the total SiO₂ in the leached sample and its partitioning between the spinel and residual grain boundary phases, a maximum of 3.9 wt% is estimated to be present in the spinel.     

Molecular-weight-controlled polymerization of styrene with Mn(acac)3 in combination with organic halides

Summary The control of molecular weight of polymers in polymerization of styrene (St) with manganese(III) acetylacetonate [Mn(acac)₃] in the presence of organic halides (RX) in toluene at 80°C was investigated. In the polymerizations of St with Mn(acac)₃ in combination with benzyl bromide (BzBr) as RX, the molecular weight of the polymer increased with polymer yields, and the relationships between the molecular weight of polymer and polymer yield gave a straight line passing through the original point. However, the molecular weight distribution was not narrow, but kept almost constant (M_w/M_n was about 2) throughout the polymerization. The mechanism of the polymerization of St with Mn(acac)₃-BzBr was also discussed. Received: 18 December 2000/Revised version: 19 April 2001/Accepted: 25 April 2001     

Preparation of epoxy resin/acrylic composite latexes by miniemulsion polymerization method

Epoxy resin/acrylic composite latexes were prepared by miniemulsion polymerization. Epoxy resins have a functional epoxy group in them and excellent characteristics, such as heat resistance and good adhesion. Acrylic latexes have weather and water resistance. Combining the epoxy resin and the acrylic latex was an attempt to actualize these advantages. The miniemulsion polymerization method was effective in obtaining the composite latex. A less than 500‐nm droplet size for the monomer preemulsion was necessary to obtain the latex in a stable manner. Dimethylaminoethylmethacrylate and methacrylic acid as the reactive functional monomer with an epoxy group were introduced to the latexes. The effect of the polymerization method of these functional groups on the properties of latexes and their films was investigated. The latex prepared by the two‐stage polymerization method had good polymerization stability, storage stability, and solvent resistance. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 128–133, 2001     

MALDI-MS derived prognostic protein markers for resected non-small cell lung cancer

Protein signals obtained directly from frozen lung tissue sections using MALDI-MS were used to predict nodal involvement and survival in resected non-small cell lung cancer (NSCLC). We have identified a list of these protein signals and further evaluated their prognostic values for NSCLC using immunohistochemistry (IHC). Kaplan-Meier analysis was used to assess the mortality risk associated with the prognostic protein IHC-staining intensities. The combined IHC scores of calmodulin, thymosin β4, and thymosin β10 were found to be correlated with NSCLC patient survival (p = 0.004). Furthermore, low cofilin-1 IHC-staining intensity was found to be correlated with a better outcome for patients with negative lymph node status (p = 0.006) while high cofilin-1 IHC-staining intensity was found to be correlated with a better outcome for patients with positive node status (p = 0.034). In conclusion, the prognostic protein signals selected using MALDI-MS can be identified and tested by IHC in formalin-fixed tissue samples. MALDI-MS-derived protein signals can be potentially translated to a conventional clinical setting to aid in the prognosis of patients with NSCLC at the molecular level.