Possibilities of the Formation of Enol-Ethers in Lignin by Soda Pulping

In the alkaline decomposition of a β-O-4 type lignin model compound (erythro-guaiacylglycerol-β-guaiacyl ether, compound 1), an isomeric pair of C₆C₂ enol-ether (2-methoxy-4-[2-(2-methoxyphenoxy)-vinyl]-phenol, compound 2) was detected as the main decomposition product with no trace of C₆C₃ enol-ether (4-[3-hydroxy-1-(2-methoxyphenoxy)-propenyl]-2-methoxy-phenol, compound 3) or other dimers. In contrast, compound 2 was not detected in the alkaline decomposition products of compound 3. Under alkaline conditions, the γ-hydroxymethyl group of compound 3 was reduced to form 2-methoxy-4-[1-(2-methoxyphenoxy)-propenyl]-phenol (compound 4). In the HSQC analysis of soda lignin, the formation of substructures of C₆C₂ type enol-ether (related to compound 2) was confirmed. However, no substructures related to compound 4, which could be formed if a substructure of C₆C₃ type enol-ether was formed under alkaline conditions, were detected. Therefore, it could be concluded that C₆C₃ type enol-ethers could not be intermediates of alkaline decomposition products of lignin.     

Porous cellulose acetate membrane prepared by thermally induced phase separation

Microporous cellulose acetate membranes were prepared by a thermally induced phase separation (TIPS) process. Two kinds of cellulose acetate with acetyl content of 51 and 55 mol % and two kinds of diluents, such as 2‐methyl‐2,4‐pentandiol and 2‐ethyl‐1,3‐hexanediol, were used. In all polymer‐diluent systems, cloud points were observed, which indicated that liquid–liquid phase separation occurred during the TIPS process. The growth of droplets formed after the phase separation was followed using three cooling conditions. The obtained pore structure was isotropic, that is, the pore size did not vary across the membrane. In addition, no macrovoids were formed. These pore structures were in contrast with those usually obtained by the immersion precipitation method. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3951–3955, 2003     

Fabrication of an Anode-Supported Gadolinium-Doped Ceria Solid Oxide Fuel Cell and Its Operation at 550°C

Ce_0.9Gd_0.1O_{2− x} (CGO) layers were deposited onto nonconductive porous NiO–CGO supports by electrophoretic infiltration, and then compacted by isostatic pressing to achieve a high packing density of the deposited layer. The bilayers were sintered to give dense CGO layers at 1290°C in air. A fuel cell comprising an La_0.6Sr_0.4Co_0.2Fe_0.8O_{3− x} cathode, a 10-μm CGO electrolyte, and a Ni–CGO anode was tested at 550°C with humidified 10% H₂ and air. The cell showed an open circuit voltage of 0.86 V and delivered a steady current of about 470 mA/cm² at a terminal voltage of 0.24 V.     

Acid catalyst influence on the polymerization time of polyfurfuryl alcohol and on the porosity of monolithic vitreous carbon

This study compares the influence of different acid catalysts on the polymerization rate of polyfurfuryl alcohol (PFA) precursor and especially on the respective porosity of Monolithic Vitreous Carbon (MVC) produced from that. Five acid catalysts commonly used were compared: p‐toluenesulfonic (PTLS), hydrochloric, sulfuric, nitric, and phosphoric. A fixed molar concentration of catalyst was diluted in PFA resin under room pressure and temperature. The time dependence of PFA resin polymerization was investigated by optical transmittance of PFA films, and the polymerization degree, characterized by ATR spectroscopy and thermogravimetry. MVC samples prepared with the same PFA resin and each catalyst were carbonized up to 1200 °C, under inert atmosphere. MVC porosity was studied by nitrogen adsorption/desorption, and by SEM and optical microscopy. Higher polymerization degree and higher residual mass were obtained with faster catalysts. No direct relation between the polymerization rate and the acid force was observed. PTLS promoted the fastest PFA polymerization process and the sulfuric acid, the slowest one. MVC samples were obtained by slow carbonization. MVC presented low specific surface S_BET from 1.4 to 7.4 m²/g. Nitric acid catalyst contributed the most to micropores formation. Micrometric apparent porosity was smaller for the catalysts having longer polymerizations times, such as phosphoric and sulfuric acid. Phosphoric catalyst corresponded to the lowest porosity in MVC. As the polymerization time increased, the average size of the micrometric surface pores tended to augment. The MVC macroscopic porosity increased with the S_BET increment. Acid catalysts choice exerted a fundamental role on the porosity of MVC. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43272.     

Smart polyion complex micelles for targeted intracellular delivery of PEGylated antisense oligonucleotides containing acid-labile linkages

A novel pH-sensitive and targetable antisense ODN delivery system based on multimolecular assembly into polyion complex (PIC) micelles of poly(L-lysine) (PLL) and a lactosylated poly(ethylene glycol)-antisense ODN conjugate (Lac-PEG-ODN) containing an acid-labile linkage (beta-propionate) between the PEG and ODN segments has been developed. The PIC micelles thus prepared had clustered lactose moieties on their peripheries and achieved a significant antisense effect against luciferase gene expression in HuH-7 cells (hepatoma cells), far more efficiently than that produced by the nonmicelle systems (ODN and Lac-PEG-ODN) alone, as well as by the lactose-free PIC micelle. In line with this pronounced antisense effect, the lactosylated PIC micelles showed better uptake than the lactose-free PIC micelles into HuH-7 cells; this suggested the involvement of an asialoglycoprotein (ASGP) receptor-mediated endocytosis process. Furthermore, a significant decrease in the antisense effect (27 % inhibition) was observed for a lactosylated PIC micelle without an acid-labile linkage (thiomaleimide linkage); this suggested the release of the active (free) antisense ODN molecules into the cellular interior in response to the pH decrease in the endosomal compartment is a key process in the antisense effect. Use of branched poly(ethylenimine) (B-PEI) instead of the PLL for PIC micellization led to a substantial decrease in the antisense effect, probably due to the buffer effect of the B-PEI in the endosome compartment, preventing the cleavage of the acid-labile linkage in the conjugate. The approach reported here is expected to be useful for the construction of smart intracellular delivery systems for antisense ODNs with therapeutic value.     

Synthesis and application of fluorescein- and biotin-labeled molecular probes for the chemokine receptor CXCR4

The design, synthesis, and bioevaluation of fluorescence- and biotin-labeled CXCR4 antagonists are described. The modification of D-Lys8 at an epsilon-amino group in the peptide antagonist Ac-TZ14011 derived from polyphemusin II had no significant influence on the potent binding of the peptide to the CXCR4 receptor. The application of the labeled peptides in flow cytometry and confocal microscopy studies demonstrated the selectivity of their binding to the CXCR4 receptor, but not to CXCR7, which was recently reported to be another receptor for stromal cell-derived factor 1 (SDF-1)/CXCL12.     

Hydrometallurgical process for the recycling of copper using anodic oxidation of cuprous ammine complexes and flow-through electrolysis

Flow-through electrolysis for copper electrowinning from cuprous ammine complex was studied in order to develop a hydrometallurgical copper recycling process using an ammoniacal chloride solution, focusing on the anodic oxidation of cuprous to cupric ammine complexes. The current efficiency of this anodic oxidation was 96% at a current density of 200 A m⁻² under a batch condition. In a flow-through electrolysis using a sub-liter cell and a carbon felt anode, the anodic current efficiency increased with the flow rate and was typically higher than 97%. This tendency was explained by the backward flow of the cupric ammine complex, which was formed on the anode, through the diaphragm. The anodic overpotential was lower than 0.3 V even at an apparent current density of 1500 A m⁻². A similar current efficiency and overpotential were also achieved in a liter scale cell, which indicates the scale flexibility of this electrolysis. The power consumption requirements for copper electrowinning in this cell were 460 and 770 kWh t⁻¹ at the current densities of 250 and 500 A m⁻², respectively, which were much lower than that of the conventional copper electrowinning despite the longer interpolar distance.     

特大型零件热处理工艺模拟用试验设备的设计

简述热处理模拟设备研制的由来及其技术特色、结构系统与技术优势,并以具体的模拟试验过程来说明热处理工艺模拟验证实验炉的实际应用情况.     

Preparation of Cu2ZnSnS4 thin films by sulfurizing electroplated precursors

Cu₂ZnSnS₄ (CZTS) thin films were prepared by sulfurizing precursors deposited by electroplating. The precursors (Cu/Sn/Zn stacked layers) were deposited by electroplating sequentially onto Mo-coated glass substrates. Aqueous solutions containing copper sulfate for Cu plating, tin sulfate for Sn plating and zinc sulfate for Zn plating were used as the electrolytes. The precursors were sulfurized by annealing with sulfur at temperatures of 300, 400, 500 and 600 °C in an N₂ gas atmosphere. The X-ray diffraction peaks attributable to CZTS were detected in thin films sulfurized at temperatures above 400 °C. A photovoltaic cell using a CZTS thin film produced by sulfurizing an electroplated Sn-rich precursor at 600 °C exhibited an open-circuit voltage of 262 mV, a short-circuit current of 9.85 mA/cm² and an efficiency of 0.98%.     

Mixture distribution measurement using laser induced breakdown spectroscopy in hydrogen direct injection stratified charge

Reduction in cooling loss due to the heat transfer from burning gas to the combustion chamber wall is very important for improving the thermal efficiency in hydrogen engines. The previous research has shown that the direct injection stratified charge can be a technique to reduce the cooling loss and improve thermal efficiency in hydrogen combustion. For effective reductions in cooling loss by the stratified charge, it is very important to know the relation between the fuel injection conditions and mixture distribution. The current research employs the laser induced breakdown spectroscopy as a method to measure the hydrogen concentration distribution in the direct injection stratified charge. Measurement of instantaneous local equivalence ratio by the method clears the characteristics of mixture formation in hydrogen direct injection stratified charge. This research also tries to actively control the mixture distribution using a split fuel injection.