Search

In this study, the feasibility of using ZrO2coatings, fabricated through the atmospheric pressure plasma jet technique, as top coats in thermal barrier systems was explored. Inconel 617 was used as the substrate material, and sputtered laminated RuAl/RuAlZr/Ru was used as the bond coat. >20-μm-thick ZrO2coatings were deposited through several iterations of deposition at 500 °C and annealing at 600 °C; here, ZrO2existed in the tetragonal phase. The tetragonal ZrO2was stable after annealing at up to 700 °C but transformed into a mixture of tetragonal and monoclinic ZrO2phases when annealed at >800 °C. The thermal stability of the ZrO2/RuAl/RuAlZr/Ru/Inconel 617 assembly was evaluated at 800–900 °C in air. The variations in volumetric fractions of the tetragonal and monoclinic ZrO2phases were recorded; 44% of the tetragonal phase remained after 100 h of annealing at 800 °C, whereas 80% of the tetragonal phase had transformed into the monoclinic phase after 4 h of annealing at 900 °C. Observation of BC after annealing at 800 °C indicated that a dense thermally grown oxide scale, comprising O and Al, formed between the ZrO2and RuAl layers, which impeded the inward diffusion of O. The inhibition of O diffusion declined with the crystallization of the thermally grown oxide scale into the δ-Al2O3phase when the annealing time was extended.

Two-dimensional (2-D) polymer has properties that are attractive for energy storage applications because of its combination of heteroatoms, porosities and layered structure, which provides redox chemistry and ion diffusion routes through the 2-D planes and 1-D channels. Here, conjugated aromatic polymers (CAPs) were synthesized in quantitative yield viasolid-state polymerization of phenazine-based precursor crystals. By choosing flat molecules (2-TBTBP and 3-TBQP) with different positions of bromine substituents on a phenazine-derived scaffold, C–C cross coupling was induced following thermal debromination. CAP-2 is polymerized from monomers that have been prepacked into layered structure (3-TBQP). It can be mechanically exfoliated into micrometer-sized ultrathin sheets that show sharp Raman peaks which reflect conformational ordering. CAP-2 has a dominant pore size of ∼0.8 nm; when applied as an asymmetric supercapacitor, it delivers a specific capacitance of 233 F g–1at a current density of 1.0 A g–1, and shows outstanding cycle performance.

The gene (CcLcc2) encoding laccase from the basidiomycete Coprinopsis cinereaOkayama-7 #130 was synthesized by polymerase chain reaction-based two-step DNA synthesis, and heterologously expressed in Pichia pastoris. The recombinant protein was purified by ammonium sulphate precipitation and nickel nitrilotriacetic acid chromatography. The molecular mass of CcLcc2 was estimated to be 54 kDa by denaturing polyacrylamide gel electrophoresis. The optimum pH and temperature for laccase catalysis for the oxidation of 2,2ʹ-azino-bis(3-ethylbenzothiazoline-6-sulphonate) (ABTS) were 2.6 and 45 °C, respectively. The Kmvalues of the enzyme towards the substrates ABTS, 2,6-dimethoxyphenol (2,6-DMP) and guaiacol were 0.93, 1.02 and 28.07 mmol·L−1, respectively. The decolourization of methyl orange, crystal violet and malachite green, commonly used in the textile industry, was assessed. The decolourization percentage of crystal violet and malachite green was 80% after 4 h of reaction, and that of methyl orange was 50% at 4 h. These results show that the CcLcc2 has enormous potential for the decolourization of highly stable triphenylmethane dyes.

Ti-15V-3Cr-3Al-3Sn, β-phase titanium alloy, is subjected to study the microstructure and mechanical behavior after thermohydrogen processing. It aims to study the relationship between microstructure modification and notched tensile test at room temperature. Meanwhile, the notched tensile test and fracture features of Ti-15-3 alloy without THP is also discussed. It follows that the hardness of Ti-15V-3Cr-3Al-3Sn would be clearly enhaced up to Hv 499 after thermohydrogen processing due to grain refinement. Besides, the notched tensile strength of the as-received specimen is about 904 MPa, and is increased to 959 MPa after THP, that is, Ti-15-3 alloy after THP shows higher hardness and notched tensile strength than as-received alloy. The enhanced high hardness does not induce a significant notched embrittlement effect.

Ti-15V-3Cr-3Al-3Sn, β-phase titanium alloy, is subjected to study the temperature effects on microstructure and mechanical behavior by using different aging temperature (426 ∼ 600 oC) and high temperature (450oC) notched tensile test. It follows that the highest hardness of Ti-15V-3Cr-3Al-3Sn would be got up to 420 Hv after 426 oC aging. Afterward, the hardness is decreasing with increasing aging temperature. By means of microstructure analyses, it reveals that the narrow and intragranular α-phase precipitates with lamella-shape in the grains at 426 oC aging treatment caused the age hardening of the titanium alloy. Subsequently, the α-phase precipitates were coarsening with increasing the aging temperature and showed the thick morphologies distributed along grain boundaries, which results in overaging. In the notched tensile test at 450oC, the highest notched tensile strength (1160 MPa) is also obtained after 426oC aging treatment, and then decreasing with increasing aging temperature. Its mechanical behavior is different from the room temperature notched tensile test, which demonstrates the lowest notched tensile strength (813 MPa) after 426 oC aging treatment due to the notched embrittlement effect. According to microstructure study, it suggests that the environment temperature effect enhanced the toughness of the alloy and terminated the notched embrittlement effect resulted from the 426oC aging treatment.

A multienergy oxygen ion implantation process was demonstrated to be compatible with the processing of high-power microwave AlGaN/GaN high electron mobility transistors (HEMTs). A high sheet resistivity and thermally stable isolation were demonstrated. The microstructures of implanted and postannealed specimens were investigated by transmission electron microscopy (TEM). The dependences of the sheet resistivity and different postannealing temperatures were correlated with the defect clusters and microstructure of lattice stacking faults. After 300 \mbox{\circC} annealing, the sheet resistivity was higher than $10^{12}$ $\Omega$/square, which was attributed to the severe defect interaction eliminating the trapping centers and reducing the leakage current. A maximum output power density of 5.3 W/mm at $V_{\text{gs}}=-4$ V and $V_{\text{ds}}=50$ V at 3 GHz was demonstrated on lag-free HEMTs without field plates on sapphire substrate.

In product concept design, not only designers with professional CAD skills, but also final customers take part in the design and evaluation of product shape styling. Because customers usually lack surface modelling background and are not familiar with concrete operations of commercial CAD systems, it is difficult for them to express their change intentions of product shape through professional CAD tools if they are not satisfied with the current shape design. This paper puts forward a method for creating, dragging and manipulating constraint and load represented in form of icon entity in interactive sculpting of product shape in virtual environment. The method supports customers manipulation of sculpting constraints or loads on sculpting shapes in virtual reality interaction, to control the deformation of product shape. Constraints management based on icon entity is similar to spline lofting operation that is familiar to engineers, so users do not need to know surface details or have any professional knowldege of surface modelling, by only using their physical and engineering experience, they can manipulate the sculpting of product shape intuitively.

In product concept design, not only designers with professional CAD skills, but also final customers take part in the design and evaluation of product shape styling. Because customers usually lack surface modelling background and are not familiar with concrete operations of commercial CAD systems, it is difficult for them to express their change intentions of product shape through professional CAD tools if they are not satisfied with the current shape design. This paper puts forward a method for creating, dragging and manipulating constraint and load represented in form of icon entity in interactive sculpting of product shape in virtual environment. The method supports customers manipulation of sculpting constraints or loads on sculpting shapes in virtual reality interaction, to control the deformation of product shape. Constraints management based on icon entity is similar to spline lofting operation that is familiar to engineers, so users do not need to know surface details or have any professional knowldege of surface modelling, by only using their physical and engineering experience, they can manipulate the sculpting of product shape intuitively.

In an attempt to overcome barriers to trade posed by numerous and: often contradictory national-level environmetral requirements, the international Organization Tor Standardization (ISO) has created a voluntary set of uniform envirnmental management system guidelines for firms, formally known as ISO 14001. Firms may decide 10 implement an ISO environmental management system (EMS) and become third-party certified in order to improve their environmental management and to increase their marketability. This study examines the relative costs, benefits, and motivations for ISO certification for China compared to other economically developing and developed countries. These comparisons allow to better understand the ways in which the unique economic and potilical conditions within China affect the incentives for Chinese firms to join in vuluntary self-regulatory measures. Survey results indicate that ISO 14001 cerlified firms in China are experiencing benefits equal to or greater than their peers in other countries. Benefits to environmental management appear to be significant and they generally outweigh (he costs of implementation and certification. However, as with most voluntary, the potential for abuse remains. Therefore regulators and policy makers are advised not to grant regulatory relief or inspections except on a case-by-case basis.

This work evaluated the kinetic behavior of fluoxetine O-dealkylation in human liver microsomes from different CYP2C19 genotypes and identified the isoenzymes of cytochrome P450 involved in this metabolic pathway. The kinetics of the rho-trifluoromethylphenol (TFMP) formation from fluoxetine was determined in human liver microsomes from three homozygous (wt/wt) and three heterozygous (wt/m1) extensive metabolizers (EMs) and three poor metabolizers (PMs) with m1 mutation (m1/m1) with respect to CYP2C19. The formation rate of TFMP was determined by gas chromatograph with electron-capture detection. The kinetics of TFMP formation was best described by the two-enzyme and single-enzyme Michaelis-Menten equation for liver microsomes from CYP2C19 EMs and PMs, respectively. The mean intrinsic clearance (V(max)/K(m)) for the high- and low-affinity component was 25.2 microl/min/nmol and 3.8 microl/min/nmol of cytochrome P450 in the homozygous EMs microsomes and 12.8 microl/min/nmol and 2.9 microl/min/nmol of cytochrome P450 in the heterozygous EMs microsomes, respectively. Omeprazole (a CYP2C19 substrate) at a high concentration and triacetyloleandomycin (a selective inhibitor of CYP3A4) substantially inhibited O-dealkylation of fluoxetine. Furthermore, fluoxetine O-dealkylation was correlated significantly with S-mephenytoin 4'-hydroxylation at a low substrate concentration and midazolam 1'-hydroxylation at a high substrate concentration in liver microsomes of 11 Chinese individuals, respectively. Moreover, there were obvious differences in the O-dealkylation of fluoxetine in liver microsomes from different CYP2C19 genotypes and in microsomal fractions of different human-expressed lymphoblast P450s. The results demonstrated that polymorphic CYP2C19 and CYP3A4 enzymes were the major cytochrome P450 isoforms responsible for fluoxetine O-dealkylation, whereas CYP2C19 catalyzed the high-affinity O-dealkylation of fluoxetine, and its contribution to this metabolic reaction was gene dose-dependent.

It has been a hot spot in the area of material science that how to design an experiment to produce a kind of ceramic matrix composites (CMCs) which possesses ideal performances. An approach is to build models with data from previous experiments recorded in published papers and predict the experiment parameters needed by the ideal CMCs. According to the database of CMCs funded by the National Material Genome Engineering, 8 factors were considered to affect the tensile property of CMCs, which were the basis, the reinforcement fiber type, the reinforcement fiber volume content, the perform type, the porosity, the interface type, the interface thickness and the density. Among the data we collected from papers, however, only few of pieces contained all the 8 factors, most were incomplete, some of them even lacked multiple factors. This paper's work mainly researched how to take advantage of the incomplete data to build an effective model to predict the tensile property of CMCs. We proposed a model to predict the tensile property of CMCs based on a 1-D convolution neural network (CNN), the training data of which were all from papers. To decrease the influences of the incompleteness of data, we tried several methods to process the missing data, such as the mean imputation, the K-Means clustering imputation, the Hot-Deck Imputation and the regression imputation. The results showed that the regression imputation with a dual-hidden-layer feedforward network performed better and improved the performance of the CNN tensile property prediction model.

Silver nanoparticles (AgNPs) were successfully synthesized via a rapid and convenient electrochemical method using sodium montmorillonite (MMT), a naturally occurring mineral, as both a stabilizer and a carrier. X-ray diffraction results showed that the AgNPs had face-centered cubic crystal structure. Inductively coupled plasma-atomic emission spectral analysis indicated that the AgNP yield increased with increasing the reduction potential. UV-vis absorption curves demonstrated that the AgNPs had optical absorbance at ca. 412 nm and showed a spectral blue-shift resulting from a decrease in the particle size. Transmission electron microscopy confirmed that after a centrifugation clarification process, the AgNPs formed in the aqueous solutions at reduction potentials of 5, 10, 15, and 20 V had average sizes of 4.2, 5.6, 15.3, and 20.5 nm, respectively. In contrast, in the as-prepared AgNP/MMT aqueous solutions, the AgNPs on the MMT surface had average sizes of 5.1, 8.0, 17.0, and 25.0 nm at reduction potentials of 5, 10, 15, and 20 V, respectively. Measurement of the inhibition area of antibacterial activity demonstrated that the AgNP/MMT nanocomposites had promising antibacterial applications.