植物蛋白质凝胶光学性质研究的进展(一)

论述了主要食用植物蛋白（大米蛋白、芝麻蛋白、大豆蛋白等）凝胶的光学性质及其研究发展。通过讨论和分析这些蛋白凝胶光学性质的特点、影响光学性质的主要因素、分子结构、分子间作用力与蛋白质凝胶光学性质的关系，为蛋白透明凝胶的进一步研究和应用提供理论依据。     

Investigation of positive electrodes after cycle testing of high-power Li-ion battery cells: I. An approach to the power fading mechanism using XANES

Cylindrical lithium-ion (Li-ion) cells with a nickel-cobalt oxide (LiNi_0.73Co_0.17Al_0.10O₂) positive electrode and a non-graphitizable carbon (hard carbon) negative electrode were degraded using cycle tests. The degraded cells were disassembled and examined; most attention was paid to the positive electrodes in order to clarify the origin of the power fade of the cells. X-ray absorption near-edge structure (XANES) analysis demonstrated that the crystal structure of the electrode at the surface changed from rhombohedral to cubic symmetry. Furthermore, a film of lithium carbonate (Li₂CO₃) covered the surface of the positive electrode after the cycle tests. Using a combination of X-ray photoelectron spectroscopy (XPS), infrared spectroscopy (IR), and glow discharge optical emission spectrometry (GD-OES) measurements, a schematic model of the changes occurring in the surface structure of the positive electrode during the cycle tests was constructed. The appearance of both an electrochemically inactive cubic phase and lithium carbonate films at the surface of the positive electrode are important factors giving rise to power fade of the positive electrode.     

Effects of humic substances on the pattern of oxidation products of pentachlorophenol induced by a biomimetic catalytic system using tetra(p-sulfophenyl)porphineiron(III) and KHSO5

In the presence of humic substances (HSs), the oxidative conversion of pentachlorophenol (PCP) was found to be efficiently catalyzed by tetra(p-sulfophenyl)porphineiron(III) (Fe(III)-TPPS) using KHSO5 as an oxygen donor. Ortho-tetrachloroquinone (o-TeCQ), 2-hydroxyl-nonachlorodiphenyl ether (2H-NCDE), 4-hydroxyl-nonachlorodiphenyl ether (4H-NCDE), and octachlorodibenzo-p-dioxin (OCDD) were identified as the major byproducts of the reaction. Decreased amounts of these byproducts were produced in the presence of HS. In particular, the addition of HSs with a lower degree of humification resulted in a large decrease in the formation of dimers, such as 2H-NCDE, 4H-NCDE, and OCDD. More than 60% of the chlorine, which was released from PCP, was found in the HS fractions after the reaction. This suggests that chlorinated intermediates from PCP were incorporated into the HS. Pyrolysis-GC/MS and 13C NMR studies confirmed that the binding of the chlorinated intermediates was covalent in nature and that the intermediates were copolymerized with HS via oxidative coupling reactions. A Microtox test demonstrated that the toxicity of the HS fraction containing PCP-derived intermediates was much lower than that of the mixture of PCP and HS in the absence of a catalytic reaction.     

Fast cycling of Li/LiCoO2 cell with low-viscosity ionic liquids based on bis(fluorosulfonyl)imide [FSI]

A charge–discharge cycling test of a Li/LiCoO₂ cell containing ionic liquids based on bis(fluorosulfonyl)imide ([FSI]⁻) as the electrolyte media, revealed significantly better rate properties compared to those of cells using conventional ionic liquids. The use of an 1-ethyl-3-methylimidazolium (EMI⁺) salt permitted the retention of 70% of the discharge capacity at a 4 C current rate. In contrast, similar performance of cells containing N-methyl-N-propylpyrrolidinium (Py₁₃⁺) and N-methyl-N-propylpiperidinium (PP₁₃⁺) salts of [FSI]⁻ was limited to operation at 2 and 1 C current rates, respectively. However, the charge/discharge cycling stability of the cell with Py₁₃[FSI] was much better than that of the cell using EMI[FSI].     

Thermal reliability of gold–aluminum bonds encapsulated in bi-phenyl epoxy resin

Bond degradation of Au wire/Al pad has become a major problem, because of the use of molding resin with low thermal stability (e.g. bi-phenyl epoxy resin) and the use of the IC devices under high thermal environments. It is therefore important to insure the thermal reliability at Au/Al bonds. The lifetime to bond failure of bi-phenyl epoxy molding became shorter than that for cresol novolac epoxy. The failures were caused by the corrosion reaction of Au–Al intermetallics with bromine (Br) contained in the resin compounds. It was clarified that the reactive intermetallic was Au₄Al phase formed in the bond interface.The governing factors of the bond corrosion were investigated such as resin compound and gold wire material. Especially some impurities in gold wire could affect the Au–Al intermetallic growing and therefore retard the corrosion. The use of the alloyed wire was effective in improving the bond reliability.     

Solution combustion synthesis of Ce0.6Mn0.3Fe0.1O2 for anode of SOFC using LaGaO3-based oxide electrolyte

This paper describes the potential of solution combustion synthesis (SCS) method for preparing Ce_0.6Mn_0.3Fe_0.1O₂ (CMF) as the anode material for solid oxide fuel cells (SOFC). The stability, crystallinity, morphology, and surface area of the products were depended on the fuel ratio used in SCS as investigated by TGA, XRD, SEM, and BET, which correspondingly influenced their electrochemical properties. The SCS-derived products were directly used for preparing anodes by sintering the screen-printed powders on the electrolyte membrane, and were evaluated from power generation performance, which were compared with the conventional solid-state-reaction (SSR) sample. Significantly, under configuration of the cell of CMF/La_0.8Sr_0.2Ga_0.8Mg_0.15Co_0.05O₃/Sm_0.5Sr_0.5CoO₃ using humidified hydrogen gas as a fuel and O₂ as an oxidizing agent, the maximum power densities obtained were 1.23 W/cm² at 1000 °C for the SCS product (CMF1) obtained at ? = 0.5. This value was higher than 1.09 W/cm² for the SSR-derived sample under the same evaluation conditions. The results appealed benefits of SCS method for preparing CMF as the anode material with high power generation performance for SOFC, due to its large surface area and nanosized grains, in which fuel ratio was a key parameter for its synthesis.     

On the Electronic Origins of a Novel Transoid Structure of 1,3-Diene-zirconocene Complexes

Coordinations of conjugated 1,3-dienes to a transition metal had been considered to occur only in a s-cis geometry, until the recent discovery of Cp₂Zr(s-trans-diene), diene = butadiene and trans, trans-1,4-diphenylbutadiene. A molecular orbital analysis of metal-butadiene interactions is carried out, for the specific cases of Fe(CO)₃ (butadiene) and Cp₂Zr(butadiene), to discern the electronic origin of the novel transoid geometry. Stability of the s-cis and s-trans structures of Cp₂Zr(butadiene) is found to be well balanced and we show how the geometrical choice is affected by substitution on butadiene.     

Synthesis and solid-state polymerization of a methylene-chain-modified butadiyne derivative

5,7-Dodecadiyn-1,12-diyl bis[N-(butoxycarbonylmethyl)carbamate] abbreviated as 4BCMU is one of the typical monomers for solid-state polymerization to form polydiacetylene. In this study, we modified 4BCMU by substituting methylene groups to oxygen atoms. Namely, 3,10-dioxa-5,7-dodecadiyn-1,12-diyl bis[N-(butoxycarbonylmethyl)carbamate] (DO-4BCMU) was synthesized and the replacement effects on the monomer properties were investigated. In powder X-ray diffraction experiments, spacings for the layered structure in 4BCMU and DO-4BCMU crystals were found to be 2.74 nm and 3.56 nm, respectively, and large crystal structural difference was confirmed. The polymer absorption maxima of 4BCMU and DO-4BCMU were observed at 630 nm and 580 nm, respectively. Since conversions of these monomers were similar, butadiyne moieties are aligned in polymerizable stacks and the different spacings seemed to be caused by folding structure differences in substituents. We also prepared mixed crystals of 4BCMU and DO-4BCMU with mixing ratio of 3:7 by melt crystal growth. In this crystal, the layered-structure spacing was 2.31 nm, and their similar molecular structures may be responsive for mixed crystal formation with a new phase. However, it was strangely observed that absorption spectrum of the polymer from the mixed crystals corresponded to summation of the spectra of original polymers from 4BCMU and DO-4BCMU.     

Direct Decomposition of NO on Ba/Ba–Y–O Catalyst

Direct decomposition and storage of nitric oxide (NO) on Ba–Y mixed oxide with four different catalysts, Ba₃Y₄O₉, BaY₂O₄, BaO/Y₂O₃ and Ba_0.5/BaY₂O₄ were investigated. Among the examined phases, it was found that Ba_0.5/BaY₂O₄ which is obtained by decomposition of Ba₃Y₄O₉ in helium at 1123 K shows relatively high NO decomposition activity at high temperature and a large capacity for NO storage at low temperature. XRD measurement suggests the formation of nano sized barium particles on BaY₂O₄ and it is suggested that Ba nano size particles play an important role for NO storage and the direct decomposition activity.     

Ag current collector for honeycomb solid oxide fuel cells using LaGaO3-based oxide electrolyte

Honeycomb type solid oxide fuel cell (SOFC) using a Ag mesh as a current collector and La_0.9Sr_0.1Ga_0.8Mg_0.2O₃ (LSGM) as an electrolyte was studied for reducing production cost. When an Ag mesh was used as a current collector, the power density of the cell became lower than that of a cell using a Pt mesh due to the relatively worse contact caused by the lower calcination temperature, particularly in the case of the anode. The preparation method and the electrode structure were investigated for the purpose of increasing the power density of the cell using the Ag current collector. It was found that an interlayer of Ni–Sm_0.2Ce_0.8O_1.9 (1:9) between the NiFe–LSGM cermet anode and the LSGM electrolyte was effective for decreasing the pre-calcination temperature for anode fabrication. Much higher power densities of 300 mW cm⁻² and 140 mW cm⁻² at 1073 K and 973 K, respectively, were achieved by inserting an interlayer. These results for the power density of the cell using the Ag mesh current collector after the optimization of the electrode structure and the preparation procedure are close to those of the cell using the Pt mesh current collector cell presented in our previous work.