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101.
In the presence of α-SiMo12O404− ions dissolved in acidic solution and under laser irradiation, the electroless photoetching of n-type InP is achieved. At the laser impact, the semiconductor is oxidized while SiMo12O404− species are reduced. The shape of the pit formed, due to the photoanodic dissolution of the material, depends on the experimental conditions, notably on the presence or not of Cl ions in the medium. It can have either a Gaussian shape or a flat bottom. To specify the charge transfer which occurs at the n-InP/solution illuminated interface, some electrochemical studies were performed on n- and p-type InP electrodes. In fact, the reduction of SiMo12O404− ions occurs by capture of electrons from the InP conduction band. Considering the energetic situation at the InP/electrolyte interface and some electrochemical results, it is concluded that the electron transfer from InP to SiMo12 is mediated by surface states. The influence of Cl ions on the n-InP photodissolution process is also discussed.  相似文献   
102.
The group of conjugated fatty acids known as conjugated linoleic acid (CLA) isomers have been extensively studied with regard to their bioactive potential in treating some of the most prominent human health malignancies. However, CLA isomers are not the only group of potentially bioactive conjugated fatty acids currently undergoing study. In this regard, isomers of conjugated α‐linolenic acid, conjugated nonadecadienoic acid and conjugated eicosapentaenoic acid, to name but a few, have undergone experimental assessment. These studies have indicated many of these conjugated fatty acid isomers commonly possess anti‐carcinogenic, anti‐adipogenic, anti‐inflammatory and immune modulating properties, a number of which will be discussed in this review. The mechanisms through which these bioactivities are mediated have not yet been fully elucidated. However, existing evidence indicates that these fatty acids may play a role in modulating the expression of several oncogenes, cell cycle regulators, and genes associated with energy metabolism. Despite such bioactive potential, interest in these conjugated fatty acids has remained low relative to the CLA isomers. This may be partly attributed to the relatively recent emergence of these fatty acids as bioactives, but also due to a lack of awareness regarding sources from which they can be produced. In this review, we will also highlight the common sources of these conjugated fatty acids, including plants, algae, microbes and chemosynthesis.  相似文献   
103.
The preparation of an antimicrobial nylon material and its properties are discussed. Biocidal cyclic N‐chloramine moieties were covalently bonded to Nylon 66. These moieties, which included hydantoins, oxazolidinones, and imidazolidinones, were stable during at least 3 months of dry storage, and their antimicrobial activities, once lost by reaction with reducing sodium thiosulfate, could be regenerated by exposure to free chlorine. Biocidal swatch tests showed that the nylon fabrics containing N‐chlorinated hydantoin functional groups provided a 7.2 log reduction of Staphylococcus aureus and a 7.1 log reduction of Escherichia coli at a contact time of only 10 min. Antimicrobial nylon should find a variety of important uses such as in clothing, carpets, sutures, brushes, and so forth. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 943–947, 2001  相似文献   
104.
As a part of research work to elaborate polymeric materials for metal corrosion protection, we have developed a new family of phosphonic acid‐containing polymers. The synthesis and the characterization of polysulfones bearing alkyl phosphonate ester side groups are first described. These polymers are synthesized by direct polycondensation of a phosphonate ester‐containing bisphenol by aromatic nucleophilic substitution. The physicochemical properties of the resulting polymers are described. Acidic hydrolysis of phosphonate esters results in the formation of phosphonic acid groups. A series of phosphonic acid‐containing polysulfones is therefore obtained and characterized. A preliminary evaluation of the anticorrosive properties of these polymers is described. In 0.25M Na2SO4 solution, the corrosion rate of a polymer‐coated mild steel sample is much lower than of the free metal substrate. These results suggest that phosphonic acid‐containing polysulfones might be interesting as anticorrosive coatings. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41890.  相似文献   
105.
The ever‐growing number of pathogenic bacteria resistant to treatment with antibiotics call for the development of novel compounds with as‐yet unexplored modes of action. Here, we demonstrate the in vivo antibacterial activity of carba‐α‐d ‐glucosamine (CGlcN). In this mode of action study, we provide evidence that CGlcN‐mediated growth inhibition is due to glmS ribozyme activation, and we demonstrate that CGlcN hijacks an endogenous activation pathway, hence utilizing a prodrug mechanism. This is the first report describing antibacterial activity mediated by activating the self‐cleaving properties of a ribozyme. Our results open the path towards a compound class with an entirely novel and distinct molecular mechanism.  相似文献   
106.
107.
This research investigates the long‐term shrinkage and Relative Mass Loss (RML) of mature Portland concretes (pure CEMI and blended CEMV/A), at temperatures of 20°C and 80°C. When placed at 80°C and at relative humidities (RH) below 50‐60%, concrete shrinkage increases with very slow stabilization kinetics by several hundreds of μm/m, while RML remains of about 0.2%. The origins of this continued shrinkage, simultaneously with limited RML, are investigated through the changes in (i) the pore structure of the concretes (by Mercury Intrusion Porosimetry and nitrogen adsorption) and in (ii) their solid phases (by TGA/DTA, FTIR spectroscopy coupled to DVS, quantitative X‐Ray Diffraction by Rietveld analysis, and 29Si and 27Al MAS NMR). While the pore structure coarsens during continued shrinkage, several phase transformations occur, namely ettringite decomposition and changes in the silicate chain length of the C–A–S–H. While these structural changes are documented, their relationship with shrinkage/RML and to the pore structure is novel.  相似文献   
108.
According to the principle of sustainability, modern industry should preserve nonrenewable energy sources and develop more efficient processes, especially in terms of energy consumption. The depletion of fossil energy reserves, the environmental impact of greenhouse gases, and the possible threats of environmental taxes are the main reasons to develop new processes in general, and new drying processes in particular, for the existing industries. Using superheated steam as a drying medium instead of hot air can improve the energy efficiency by reusing the energy from exhausted steam and prevent gas emission into the atmosphere by condensation. The present review is focused on both lab-scale pilots—including impingement jet, fluid bed, kiln, fixed bed, and flash drying—described in the literature and existing industrial facilities, with a specific analysis focused on energy efficiency. The usefulness of superheated steam drying pilots for experimental research and for the design of industrial dryers is analyzed. The impact on quality specifications of the dried product for different operating conditions is also presented. Documentation on industrial superheated steam dryers is very rare. Nevertheless, this work presents and analyses the key data available for superheated steam drying of beet, alfalfa, industrial pulp, and paint sludge. Energy recovery and process integration, with a focus on specific technological challenges for industrial dryer implementation, are also presented. This document will result in a discussion of some new ideas for possible R&D in superheated steam drying.  相似文献   
109.
110.
This paper reports the structural investigation of a series of in situ spruce lignins in wood, thermomechanical pulp (TMP) and the corresponding bleached (BTMP) and photoyellowed (YBTMP) samples. This was achieved by using an original two-step degradative technique, thioacidolysis followed by Raney nickel desulfuration. The determination of thioacidolysis monomeric and dimeric products allowed an estimate of various lignin building units and interunit bonds, respectively. It was observed that the thermomechanical and bleaching treatments did not affect spruce lignin structure to an appreciable extent. On the contrary, the photoyellowing treatment caused marked structural changes in lignin, particularly when run in severe conditions. These changes were essentially a decrease in the amount of β-O-4 and β-1 interunit bonds and a relative increase in catechol units and in vanillin end-groups.  相似文献   
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