Search

Aluminum nitride (AlN) thin film of thickness 300 nm grown on sapphire substrate was annealed by a nanosecond laser at a wavelength of 532 nm. The laser energy values were 2 J, 3 J, 4 J, and 4.5 J, respectively. In order to increase the absorption of laser energy by the sample, 50 nm thick tungsten films were deposited on the left half of the sample. Surface morphology and Raman spectrum of AlN films were characterized before and after annealing using scanning electron microscope (SEM) and Raman spectrometer, respectively. The SEM micrographs have shown that the surface of AlN film had a large number of voids before annealing. After annealing, the size of the voids becomes smaller and their number decreases with the increase of laser energy density. The full width at half maximum (FWHM) of AlN film was roughly 6-10 cm−1before annealing and 4-8 cm−1after annealing. The results showed that the surface morphology and FWHM of the AlN films were improved after laser annealing compared with those before annealing. Finally, COMSOL Multiphysics simulated the temperature field change of AlN film after laser irradiation and the evolution of its surface.

This study was devoted to compare ternary and binary deep eutectic solvents (DESs) with aqueous two-phase systems (ATPSs) to extract proteins. Four types of binary DESs and four ternary DESs, composed of a hydrogen bond acceptor (tetramethylammonium chloride, TMAC) and hydrogen bond donors, were synthesized. The phase diagrams of the studied DESs demonstrated that binary DESs were more amenable to producing a two-phase split. Afterwards, their ability to extract four different substances was further evaluated. It was found that the systems based on ternary DESs showed a better potential in the field of extraction. Two types of DESs with ATPS, involving TMAC–urea (TMAC–U) and TMAC–glycerol–urea (TMAC–G–U), were investigated for five influence factors such as the amount of DES, concentration of salt, mass of BSA, temperature and pH, on the extracting of bovine serum albumin (BSA). Under the optimal conditions, the values of their respective extraction efficiency were up to 99.31% and 98.95%. Moreover, the back extraction efficiencies were discussed, which indicated that the ternary DESs reached up to 71.89%, remarkably different from binary DES (21.02%). Finally, UV-vis, Fourier transform infrared spectrometry (FT-IR), circular dichroism (CD), dynamic light scattering (DLS), conductivity measurements and transmission electron microscopy (TEM) were utilized to study the extraction mechanism. This study reveals the outstanding feasibility of TMAC–G–U based DES with an ATPS for the protein extraction process, providing significant information for designing task-specific DESs.

A surface molecularly imprinted polymer (MIP-Fe3O4@AA) was prepared on a magnetic material (Fe3O4@AA) surface for the selective recognition and adsorption of bovine hemoglobin (BHb). The acrylic acid (AA) monomer was directly grafted to the surface of Fe3O4through a simple coordination reaction between the carboxyl group of AA and unsaturated iron ions (Fe3O4@AA). Then the composite of MIP-Fe3O4@AA based on BHb was successfully synthesized by the surface grafting copolymerization method. The amounts of raw materials were optimized. The characteristics of the obtained MIP-Fe3O4@AA were determined by Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), vibrating sample magnetometry (VSM) and thermogravimetric analysis (TGA). The adsorption capacity of MIP-Fe3O4@AA was evaluated and well fitted by the Langmuir model. The maximum theoretical adsorption capacity (Qmax) was calculated to be 117.27 mg g−1for MIP-Fe3O4@AA. The selectivity experiment showed that the MIP-Fe3O4@AA had an outstanding selectivity toward the template protein (BHb) with an imprinting factor of 4.43. The MIP-Fe3O4@AA was also used to capture BHb from the protein mixture and real sample with satisfactory results, which demonstrated its potential practical analytical performance.

A highly selective surface molecularly imprinted inorganic polymer composed of tetraethoxysilane and 3-aminopropyltriethoxysilane has been prepared by a sol–gel process on silica submicroparticles in aqueous solution under simple and mild conditions. Lysozyme (Lyz, pI 11, MW 14.4 kDa) is used as the template protein. The product polymers were characterized by FT-IR, TEM, and TG techniques to verify the successful synthesis of the MIP on the surface of silica submicroparticles. The adsorption behavior of the MIP was evaluated by adsorption capacity, imprinting factor and adsorption model. It was found that both MIP and NIP could adsorb the template protein quickly and easily owing to the low mass transfer resistance of the thin shell and their adsorption equilibrium could be reached in 5 h. Compared with the NIP, the MIP showed stronger adsorption capacity for template protein Lyz under all experimental conditions. The mechanism for static adsorption of Lyz onto the MIP was found to follow the Langmuir adsorption model which was further used to calculate the maximum adsorption capacity Qmaxand gave a result of 90.33 mg g−1in theory. The MIP adsorbent could be reused twice without significant loss in adsorption capacity. The MIP indicated excellent recognition and binding affinity toward Lyz, whose selectivity factor βfor Lyz relative to reference proteins bovine serum albumin (BSA, pI 4.9, MW 69.0 kDa), bovine hemoglobin (BHb, pI 6.9, MW 65.0 kDa) and ovalbumin (OVA, pI 4.7, MW 43.0 kDa) were 2.36, 2.22, and 2.24, respectively. It was shown that the shape memory and the size effect were the major factors for the recognition. This imprinted inorganic polymer was used to specifically adsorb the Lyz from the protein mixture, which demonstrated its potential selectivity.

In this paper, an ionic liquid-based aqueous two-phase system (ATPs) has been developed for the effective extraction of bovine serum albumin (BSA). Compared with the effects of three different ionic liquids used in an aqueous two-phase system, a choline-like ionic liquid was selected as the suitable solution for bovine serum albumin. Extraction efficiencies of BSA were found to be dependant on the temperature, time, IL mass and the salt content. Based on single-factor experiments, these significant operating parameters of the ILs-ATP were respectively optimized. Experimental results show that 92.03–100.03% of the proteins could be extracted into the ionic liquid-rich phase in a single-step extraction. Repeatability, precision and stability experiments were investigated and the RSDs are lower than 2.3%, 1.7% and 4.7% respectively. Experiments indicated that intermolecular forces, the micelle phenomenon and the salting-out effect play important roles in the transfer process, and the aggregation phenomenon was the main driving force for the separation. Conformation of the protein was not affected after extraction into the upper ionic liquid-rich phase according to the determination by UV-visible (UV-vis), fluorescence spectra, dynamic light scattering (DLS), Fourier transform infrared (FT-IR) spectroscopy and TEM. It is suggested that the method of choline-like ILs-based ATPs for the selective separation of protein would have potential applications in bio-analysis and bio-separation.

In this paper, Incoloy800 and 304 stainless steel (SS304) were clad by explosive welding. Accordingly, hardness, tensile strength, shearing strength, bending properties and microstructure of the clad plates were evaluated. The bonding interface showed a wavy morphology. Line scanning results indicated that there was no diffusion area through the bonding interface. Whereas, a colorful zone was observed at the wave ridge of the base metal (white area in optical microscopy and black area in scanning electronic microscopy). Energy dispersive spectroscopy analysis indicated that compositions and contents of the colorful zone were the same as that in the base metal. Hardness testing showed that the highest value of hardness was obtained in the colorful zone. Thus, the colorful zone was an intensive deformation area in SS304, which was produced by shock pressure from collision. Mechanical tests showed that the clad plate was acceptable according to ASTM specification.

In the boiler combustion of power plants, the smoke loss is the main combustion heat loss of the boiler. Reducing the exhaust gas temperature is one of the main means to reduce the heat loss of the exhaust gas, and it is also the main measure for improving the thermal efficiency of the boiler in each power plant. This paper summarizes and discusses the application and economics of installing composite phase change heat exchangers for coal-fired boilers.