Applied Mechanics and Materials Vol. 662

Abstract: Possible ways to remove fluoride from phosphoric acid are extraction,but there are always generated a second organic phase ,where still have small amounts of impurities such as fluoride,sulfate,iron,aluminum and heavy metals. The traditional process using pure water or dilute phosphoric acid washing the organic phase to get phosphoric acid ,but the impurities removing rate is not obvious.This study explore a new way to changes the washing detergent,using dilute alkali solution to reduce fluoride content of stripping in phosphoric acid.The optimization of experimental conditions is dilute alkali mass fraction 20%,dosage 0.4%,temperature 45°C,the defluorization rate can be 67.75% and phosphorus pentoxide yield rise to 95.50%.This study provides a new idea to improve defluorination rate in industrial production.

Abstract: The author finds problems of fire chemical detection equipment based on material properties in the process of the actual application through learning and exploration, and puts forward the solving method to explain the misunderstanding when fire officers and soldiers use detection equipment based on material properties

Abstract: A new ZrCl₄-catalyzed method for the preparation of an asymmetrical benzimidazole derivative has been developed. Further alkylation of the benzimidazole precursor with methyl iodide afforded a new monomethine cyanine derivative. The photophysical evaluation showed that the newly synthesized monomethine cyanine compound was non-fluorescent.

Abstract: A facile and efficient method for the synthesis of P¹,P³-dizidovudine-5′,5′-triphosphate has been developed. The coupling of zidovudine diphosphate with zidovudine phosphoropiperidate based on the DCI activation of P-N bond afforded the desired product in good yield.

Abstract: A three-component solvent-free method for the synthesis of a series of bis-α-aminophosphonate-modified butanes has been developed. The experimental results showed that the solvent-free reaction conditions without catalyst were optimal for the preparation of this type compounds. The synthesized title compounds were characterized by ¹H, ¹³C, and ³¹P NMR and mass spectroscopy.

Abstract: A series of α-aminophosphonate-functionalized 3-aminopropanols have been efficiently prepared and characterized by ¹H, ¹³C, and ³¹P NMR and mass spectroscopy. The reaction conditions such as solvent and temperature were thoroughly investigated based on the three-component Kabachnik-Fields reaction. The experimental results revealed that moderate elevation of reaction temperature under solvent-free conditions was optimal for the synthesis of these types of compounds without forming the cyclized byproduct.

Abstract: Two adenosine-containing asymmetrical dinucleoside triphosphates were synthesized via the P(V)–N activation method. The key adenosine 5ʹ-phosphoropiperidate intermediate was obtained by a redox condensation method. The reaction of adenosine phosphoropiperidate with uridine 5ʹ- and cytidine 5ʹ-diphosphates in the presence of 4,5-dicyanoimidazole (DCI) afforded the desired dinucleoside triphosphates in good isolated yields.

Abstract: The surface properties of W-implanted H13 steel are investigated using pulse multi-charged ion implantation. Computer simulations based on the binary collision approximation, TRIDYN, have been applied to calculate the concentration depth profiles of implanted tungsten ions in H13 steel. The calculated result by TRIDYN program is compared with that from experimental results. The factors affecting the surface properties of W-implanted H13 steel have been discussed. The radiation enhanced diffusion induced by spike is the main factor affecting the concentration depth profile. Compared with single energy ion implantation, the multi-charged ion implantation will make the concentration gradient become small, which is conducive to the formation of a kind of relatively uniform surface structure, and further improve the wear resistance of H13 steel.

Abstract: A new unsymmetrical photochromic diarylethene 1o, which contains condensed nucleus was synthesized. Its photochromic both in hexane solution and in PMMA film and kinetics experiment were investigated in detail. The result indicated that this diarylethene had reversible photochromism, changing the color from colorless to purple in hexane solution upon appropriate irradiation with 297 nm UV light, respectively. What’s more, The kinetic experiments showed that the cyclization and cycloreversion processes were zeroth and first order reaction, respectively. This new photochromic system also exhibited fluorescence switching in acetonitrile solution.

Abstract: A new asymmetrical photochromic diarylethene 1-(2-cyano-1,5-dimethyl-4-pyrryl)-2-{2-methyl-[5-(4-methylene-hydroxyl) phenyl]-3-thienyl} perflu-orocyclopentene (1o) was synthesized and its photochromic properties were investigated systematically. Upon irradiation with 297 nm UV light, 1o exhibited photochromism in acetonitrile solution and in a PMMA amorphous film. The kinetic experiments showed that the cyclization and cycloreversion processes were zeroth and first order reaction, respectively. In addition, diarylethene 1o also exhibited obvious fluorescence switches along with the photochromism.