Reversible polycolour change of viologens from violet through transparent to white

The electrochromic properties of 1,1′-dibenzyl-4,4′-bipyridinium and 1,1′-diheptyl-4,4′-bipyridinium were investigated in the presence of MBr (M = Li⁺, Na⁺, and K⁺). The cyclic voltammograms of these viologens showed a white-coloured state in addition to the usual violet one-electron reduction state and the colourless divalent state. Chemical analyses (FT-IR and XPS spectra) of the white film and some control experiments with different supporting electrolytes, MX (X = Cl⁻ and I⁻), revealed that the viologens formed water-insoluble ion pairs with tribromide generated by the electrooxidation of monobromide to produce a white film. The film was reversibly decolourized electrochemically to the initial transparent state, providing the polyelectrochromism using the simple viologen/MBr systems. The colouration efficiencies for the violet and the white-coloured states were 170 cm²/C and 104 cm²/C, respectively.     

利用固体废弃物制备干粉砂浆的应用研究

用矿渣、粉煤灰等固体废弃物为主要原材料,制备性能满足GB175-2007标准要求的生态型胶凝材料,代替425#普通硅酸盐水泥;利用矿山尾矿部分代替河砂,添加以改性膨润土为主的保水增稠剂,成功开发了系列干粉砂浆产品。固体废弃物利用率高达70%～90%,各项性能指标符合标准DBJ/T01-73-2003《干拌砂浆应用技术规程》的要求。     

Synthesis of poly(1,3-phenyleneethynylenes) membranes having one-handed helical conformation without any chiral side groups by in-situ desubstitution of d-menthoxy groups

In this study, we synthesized four chiral helical poly(phenyleneethynylenes) having optically active menthoxycarbonyl groups and desubstituted the chiral groups in membrane state. Polycondensations of (+)-menthyl 3,5-diethynylbenzoate with (+)-menthyl 3,5-diiodobenzoate, 1,2-diiodobenzenen, 1,3-diiodobenzene, and 1,4-diiodobenzene using PdCl₂(PPh₃)₂–PPh₃–CuI were afforded helical polymers in good yields (named as PMtMt, o-PMtH, m-PMtH, and p-PMtH, respectively). Among them, PMtMt in a mixture of chloroform/benzene showed the largest Cotton effect in absorption region and gave self-supporting membrane by solvent-casting method. PMtMt membrane also showed a Cotton signal similar to that observed in solution. Desubstitution of PMtMt proceeded quantitatively by immersing the membrane into alkaline solution at room temperature for 3 days. The desubstituted PMtMt membrane showed circular dichroism (CD) signals similar shape to that of the original membrane in the UV region in despite of the polymer having no chiral moieties except for helical conformation. This is the first example of synthesis of chiral helical poly(phenyleneethynylenes) without the coexistence of any other chiral moieties.     

Crosslinked Structure of Polyacrylic Acid Affects Pulmonary Fibrogenicity in Rats

We conducted intratracheal instillations of polyacrylic acid (PAA) with crosslinking and non-crosslinking into rats in order to examine what kinds of physicochemical characteristics of acrylic-acid-based polymers affect responses in the lung. F344 rats were intratracheally exposed to similar molecular weights of crosslinked PAA (CL-PAA) (degree of crosslinking: ~0.1%) and non-crosslinked PAA (Non-CL-PAA) at low and high doses. Rats were sacrificed at 3 days, 1 week, 1 month, 3 months, and 6 months post-exposure. Both PAAs caused increases in neutrophil influx, cytokine-induced neutrophil chemoattractants (CINC) in the bronchoalveolar lavage fluid (BALF), and heme oxygenase-1 (HO-1) in the lung tissue from 3 days to 6 months following instillation. The release of lactate dehydrogenase (LDH) activity in the BALF was higher in the CL-PAA-exposed groups. Histopathological findings of the lungs demonstrated that the extensive fibrotic changes caused by CL-PAA were also greater than those in exposure to the Non-CL- PAA during the observation period. CL-PAA has more fibrogenicity of the lung, suggesting that crosslinking may be one of the physicochemical characteristic factors of PAA-induced lung disorder.     

Performance as electrode of electrical double layer capacitor of activated carbon prepared from bamboo using guanidine phosphate and CO<Subscript>2</Subscript> activation

The electrochemical performances of an electrical double layer capacitor were investigated regarding the activated carbon prepared from bamboo by a new approach, that is, the combination of delignification, addition of guanidine phosphate, and CO₂ activation. In this study, a 1 M H₂SO₄ aqueous solution was used as the electrolyte of the capacitor. The physical properties, such as the BET specific surface area of the carbon material, depend on the preparation conditions of the activated carbon. A TEM image indicated that the addition of guanidine phosphate did not facilitate the graphitization and did not prevent activation by CO₂. The apparent reaction equation for the CO₂ activation was first-order, which is reasonable for physical activation. The electrochemical performances of the carbon material depended on the preparation conditions of the carbon material, such as the heat treatment temperature, amount of added guanidine phosphate, and CO₂ activation time. The sample prepared under the following conditions (the amount of added guanidine phosphate: 9 wt%, the heat treatment temperature: 800 °C, CO₂ activation time: 3 h) had the highest performance (153 F g^?1 at 1000 mA g^?1) because the sample had the highest BET specific surface area (2001 m² g^?1).     

Increasing chemisorbed silane coupling agents in surface-treated layer of silica particles

In the surface treated inorganic particles with silane coupling agent (SCA), chemisorbed and physisorbed molecules are present in the treated layer. Increasing the amount of chemisorption by increasing the molecular weight of SCAs was investigated. Oligomers formed via self-condensation during storage more than 10 days at room temperature for 3-methacryloxypropyltrimethoxysilane-treated silica particles. Monomeric SCA evaporates easily by heating. The oligomers restrict evaporation, and heating increases the chemisorption. The influence of molecular weight of SCA was investigated. In the case of amino group, the amount of chemisorbed was greater for aminoethylaminooctyltrimethoxysilane with high molecular weight than for 3-aminopropyltriethoxysilane. For SCAs with hydrocarbon chains, the amount of chemisorption was lower for both low molecular weight molecules and decyltrimethoxysilane (D) with a high molecular weight. For fluorocarbon chains, the amount of chemisorption was lower for low molecular weight molecules, whereas it increased significantly by heating for high molecular weight type of 1H,1H,2H,2H-heptadecafluorodecyltriethoxysilane (F). Wide-angle X-ray diffraction analysis of F-treated silica particles showed that the fluorocarbon chains formed an ordered structure. There was no such indication for the D-treated system. This ordered structure seems to influence on higher chemisorption for F-treated systems.     

Three‐Dimensional Stereolithography of Alumina Photonic Crystals for Terahertz Wave Localization

Using stereolithography as an additive manufacturing (AM) process, photonic crystals, with a diamond‐like structure composed of alumina microlattices, were fabricated and their electromagnetic band gap profiles, in terahertz frequency ranges, were investigated. Acrylic resins with dispersed alumina particles were fabricated by stereolithography with micrometer‐order accuracy. After dewaxing and sintering processes, alumina lattices were obtained with high relative densities that reflected the terahertz waves, through Bragg diffraction, perfectly in all directions. Twinned crystal structures with mirror symmetric diamond lattices were designed to introduce defect interfaces. Double‐cavity defects consisting of unit cells hollowed from the diamond lattices formed the coupled resonation modes.     

Plasma behavior and characteristics of a pulsed‐laser‐driven MHD electrical power generation

The fundamental electrical power generation experiment of a pulsed‐laser‐driven magnet hydrodynamics generator with a divergent channel and segmented electrodes has been conducted with a rough estimate of gas heating efficiency of laser energy. The output energy is increased with the decrease in the initial filling gas pressure because of the increase in the gas velocity and the electrical conductivity with the gas temperature. The output power is surely improved in comparison with the previously examined generator with constant height channel and continuous electrode. About 70% of the incident laser energy is absorbed and less than 20% is transferred to the blast wave energy at low initial filling gas pressure in the present experimental setup.     

Effect of the growth rate of Pseudomonas aeruginosa biofilms on the susceptibility to antimicrobial agents: beta-lactams and fluoroquinolones

The combined effects of meal cost and food flavor on meal size were studied with a method that avoided the covariation of nutrient composition and caloric density with palatability. As rats (Rattus norvegicus) drank flavored fluids (unpalatable 0.05% sucrose octaacetate [SOA], neutral 0.05% saccharin, and palatable 2% Polycose + 0.2% saccharin [P + S]), liquid diet was infused intragastrically. Relative to saccharin, rats with free access ate 10% more calories in larger meals while consuming P + S and initially ate fewer calories in smaller but more frequent meals while drinking SOA. Other rats lever-pressed to begin meals, which halved meal number and doubled meal size relative to the free-access group. Although foraging rats also ate larger P + S meals and smaller SOA meals, the changes did not affect total intake. Without the usual differential postingestive effects of foods that differ in palatability, making food more costly blunts rats' response to its flavor.