In this paper, we describe a simple and efficient synthesis of gold nanoparticles (GNPs) of various shapes (spherical, rod-like, hexagonal, truncated triangular, and triangular) using Au(III) reduction in aqueous solutions by l-tryptophan. We evaluated the influences of reaction temperature, foreign metal ions Ag (I), and surfactants of nonionic (polyethylene glycol, PEG), anionic (sodium dodecyl sulfate, SDS), and cationic (cetyltrimethyl ammonium bromide, CTAB) on GNPs synthesis. We characterized the resultant GNPs using UV–visible adsorption spectroscopy, transmission electron microscopy/high-resolution transmission electron microscopy, scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, selected-area electron diffraction, and Fourier-transform infrared spectroscopy. We fabricated the variously sized GNPs by controlling the rate of the reduction of gold ions in aqueous solution by varying the reaction temperature: the higher the temperature, the smaller the gold nanospheres. We found the existence of Ag(I) to reinforce the reduction of Au(III) and to correspond with the appearance of some amorphous bimetallic Au/Ag nanoparticles. Additionally, we found the presence of surfactants to greatly influence the shape of the formed GNPs, especially the presence of CTAB, which results in the anisotropic growth of gold nanocrystals into hexagonal, truncated triangular, and triangular nanoplates. In addition, with the increase in CTAB concentration, we found the amount of gold nanoplates to first increase and then decrease. Finally, we performed preliminary explorations of the reduction process and morphological evolution to propose possible corresponding reduction and morphological evolution pathways.

Response surface methodology (RSM) was employed to optimize the control parameters of TiO₂/graphene with exposed {001} facets during synthesis, and its enhanced photocatalytic activities were evaluated in the photodegradation of toluene. Experimental results were in good agreement with the predicted results obtained using RSM with a correlation coefficient (R ²) of 0.9345. When 22.06 mg of graphite oxide (GO) and 2.09 mL of hydrofluoric acid (HF) were added and a hydrothermal time of 28 h was used, a maximum efficiency in the degradation of toluene was achieved. X-ray diffraction (XRD), transmission electron microscopy (TEM), and scanning electron microscopy (SEM) were employed to characterize the obtained hybrid photocatalyst. The electron transferred between Ti and C retarded the combination of electron–hole pairs and hastened the transferring of electrons, which enhanced the photocatalytic activity.

In this study, we used a mixture of organic liquid propane-1,3-diol and ionic liquid 1-ethyl-3-methylimidazolium chloride ([emim]Cl) as the entrainer to separate tert-butyl alcohol (TBA) + water. We measured the isobaric vapor–liquid equilibrium (VLE) for the quaternary system TBA + water + propane-1,3-diol + [emim]Cl at 101.3 kPa, and found the VLE data to be well correlated with the nonrandom two-liquid model. These results show that the mixed solvent of propane-1,3-diol + [emim]Cl can increase the relative volatility of TBA to water and break the azeotropic point. We found no notable synergetic effect between them, and observed that the liquid mixed solvent of propane-1,3-diol and [emim]Cl had lower viscosity than [emim]Cl, which makes it a promising entrainer for separating the TBA + water azeotrope in industrial applications.

Graft-modified polybutadiene (PB) latex was synthesized and used as an admixture to improve the performance of oilwell cement. Results showed that the addition of latex to pure cement slurry can significantly reduce the fluid loss of the cement slurry. When the dosage was 8%, the fluid loss was only 38 mL, and the fluidity of the cement slurry was improved. With an increasing amount of latex, the fluidity of the cement slurry increased continuously. The toughness of cement was significantly enhanced, whose average elastic modulus was 4.2 GPa. Scanning electron microscopy revealed that the filter cake of the cement slurry with latex was thin and dense, and the surface was coated with a layer of latex film. The microstructure of the cement stone showed a high density, and an interweaving mesh network formed in the cement. The results of cement hydration heat analysis and X-ray diffraction showed that latex inhibited the hydration of cement; the effect was stronger under a larger amount of latex. It is indicated that the graft-modified PB latex has great potential to replace the conventional styrene-butadiene rubber (SBR) latex for cementing in the future.

The effect of non-reactive powder particle properties on the detergent dry agglomeration process in a high shear mixer was investigated. Three types of micron-scale silica were chosen as the non-reactive fine powders and a semi-solid alkyl ethyl ethoxy sulfate (AES) paste with ultra-high viscosity was chosen as the binder. The granules were characterized using mass-based granule size distribution, scanning electron microcopy, and bulk density tests. The results revealed that powder particle size plays a leading role in agglomeration behavior. A decrease in the median particle size results in enhanced dispersion of silica particles in the AES paste binder droplets, which leads to the formation of uniform granules that are slightly affected by compacting forces. Agglomerate quality, using silica with high oil absorption as well as optimum particle size, was satisfactory, and the product exhibited a smaller median particle size, narrower size distribution, and superior anti-caking capacity under the same liquid-to-solid ratio (L/S).

The addition of substituents at the 6,13-position improved the solubility and stability of pentacene, making it possible to use the derivatives in spin coating of organic field-effect transistors (OFETs). Three pentacene derivatives, 6,13-bis(m-tolyl)pentacene (MP), 6,13-bis(4-butylphenyl)pentacene (BP), and 6,13-bis((4-butylphenyl)ethynyl)pentacene (BPEP) were synthesized, and their properties were investigated. 6,13-Pentacenequinone and organolithium were used in the preparation of 6,13-dihydropentacene at 0 °C, and pentacene derivatives were synthesized with SnCl₂/HCl as reducing agent, to reduce 6,13-dihydropentacene at room temperature. The structure of the derivatives was characterized using NMR. The thermal stability, photochemical properties, and electronic structure of the three compounds were investigated using TGA, cyclic voltammetry, and UV–Vis. BPEP was also characterized using X-ray diffraction and atom force microscopy. BPEP was used to fabricate an OFET device using spin coating. The device showed a mobility of 0.07 cm² V s⁻¹ at V _th = − 10 V and I _ON/I _OFF = 10².

TS-1/SiO₂ extrudate was post-treated with mixed solution of tetrapropyl ammonium hydroxide (TPAOH) and various ammonium salts solution (NH₄F, (NH₄)₃PO₄, (NH₄)₂CO₃, (NH₄)₂SO₄, NH₄CH₃CO₂, NH₄NO₃, NH₄Cl and (NH₄)₂TiF₆). The obtained hierarchical TS-1 catalysts were characterized by many techniques and tested for propylene epoxidation using hydrogen peroxide as an oxidant in a fixed-bed reactor. It was shown that the physicochemical and catalytic properties of the treated TS-1/SiO₂ extrudate depended on the types of ammonium salts added. Compared to the treatment with TPAOH alone, the treatment with a mixed solution of TPAOH and some ammonium salts can greatly improve the catalytic properties of the treated TS-1/SiO₂ extrudate. Some of these ammonium salts were favorable for the incorporation of titanium in the framework, and the beneficial effect depended on the types of ammonium salt. TS-1/SiO₂ extrudate treated with a mixed solution of TPAOH and (NH₄)₃PO₄ exhibited the highest catalyst stability in propylene epoxidation. Such catalytic property can be correlated to high crystallinity, more framework titanium, large specific surface area and large external surface area.

A series of Ni/ZrO₂ catalysts were synthesized by urea combustion method for CO₂ methanation. The effects of zirconium precursors and urea dosage on the structure and catalytic performance of the catalysts were tested. Results showed that the Ni/ZrO₂–O catalyst derived from zirconium oxynitrate hydrate exhibited better catalytic activity than the Ni/ZrO₂ catalyst because of its higher Ni dispersion and smaller Ni particle size. In addition, the urea dosage significantly influenced the low-temperature activity of the catalysts by affecting the metal–support interaction, Ni dispersion, and Ni particle size. The Ni/ZrO₂–O-0.4 catalyst with a urea-to-nitrate molar ratio of 0.4 exhibited the best catalytic activity owing to its moderate metal–support interaction, highest Ni dispersion, and smallest Ni particle size, achieving 69.2% CO₂ conversion and 100% CH₄ selectivity at 300 °C, 0.1 MPa, and a weight hour space velocity (WHSV) of 50,000 mL/(g·h). Moreover, the urea combustion method can lead to the entire phase transformation from monoclinic ZrO₂ to tetragonal ZrO₂ accompanied by the incorporation of oxygen vacancies in the ZrO₂ lattice. This phenomenon can also be related to the high catalytic activity of the as-prepared catalysts.

The blind-hole method is the most widely used approach to experimentally determine the distribution of residual stress. This paper aims to improve test accuracy of welding residual stress and conducts an experimental study on the strain release factors involved when using the blind-hole method for Q235 and Q345, two steels commonly used in building structures. The ranges of strain release factors A and B in the elastic stage, the effects of strain release factors on residual stress calculated values, and the plastic corrected strain release factors are analyzed considering of the effect of plastic deformation around the blind hole on measurement accuracy. Finally, a simplified calculation formula to determine strain release factors is proposed for use with the blind-hole method. Results show that in the elastic stage, strain release factor A for Q235 and Q345 ranges from −0.399 to −0.525 and strain release factor B from −0.791 to −0.960. Changing the strain release factors A and B shows that calculated residual tensile stress varies in relation to a decrease in both factor values. However, there is a increase in calculated residual compressive stress with a decrease in the strain release factor A value, but there is an decrease with a decrease in strain release factor B value. Calculated residual stress applied to elastic strain release factors is compared with that applied to amended plastic strain release factors for Q235 steel. The maximum deviation between calculated residual stress and test stress is reduced from 21.1 to 1.0%, and for Q345 steel from 26.5 to 1.2%. It is thus evident that the plastic correction formula proposed in this paper can be used in calculations when conducting a residual stress test.

To analyze the effects of width and thickness of each composition element of mixed steel U-rib-stiffened plates on the welding residual stress distribution, the distribution of the U-rib and the plate residual stress was calculated using a simplified calculation method. The method involved welding the mixed steel U-rib-stiffened plates for a structure with different sizes and different strength ratios of U-rib to plate. Based on a welding residual stress numerical simulation method validated by the blind hole method test, the distribution law of the mixed steel U-rib stiffened plate was studied. The results showed that the change of plate width has little impact on the welding residual stress and that the ratio of the thicknesses of the plate to U-rib stiffeners, the thickness of the plate, and the thickness of the U-rib has a great influence on the distribution of the welding residual stress. The thickness of plate and steel strength also greatly influenced the distribution width of the residual tensile stress. While analyzing the compression capacity of U-rib-stiffened plates, the simplified distribution of welding residual stress was used.