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Although an increasing number of studies have examined issues relating to the preservation and development of intangible cultural heritage (ICH), there has been limited research on how tourists perceive ICH. Moreover, UNESCO asserts that the concept of "authenticity" is not applicable to ICH, and so far, no valid instrument for measuring tourists' subjective perceptions of ICH has been developed, even though their perceptions play a very important role in the preservation and development of ICH. Therefore, this paper aims to develop a measurement scale for ICH image, using both qualitative and quantitative research methods. Participant observation, semi-structured in-depth interviews, secondary data collection, and a literature review were conducted to generate the initial scale items, and then the main surveys were conducted to collect data for the model tests. Four dimensions were extracted by exploratory factor analysis: transmission, localization, vitality, and association. The reliability and validity of the measurement model were demonstrated through confirmatory factor analysis. We further determined that the transmission, vitality, and association of ICH image have a positive impact on tourists' revisit intention. The paper highlights the crucial role of ICH image in sustainable tourism development. The theoretical and managerial implications of the study are discussed, followed by suggestions for future research. [ABSTRACT FROM AUTHOR]

In this paper, the transient ignition process of an annular combustor with 16 centrally staged swirling burners is experimentally investigated to study the mechanism of burner–burner flame propagation. The flame propagation patterns are studied by high-speed imaging. Three typical patterns of the burner–burner flame propagation are identified: the kindled-swirling pattern, entrained-swirling pattern, and sweeping pattern. The patterns are featured with different flame paths of motion. For fixed flow rates, the paths of motion are mainly determined by the overall equivalence ratio Φ. Furthermore, during the burner–burner flame propagation, the effect of the flow field on the local flame fronts is analyzed by Mie scattering and particle image velocimetry (PIV) methods. The PIV results show that the flame paths of motion are greatly influenced by the flow structure of the annular combustor. The optical diagnosis of the flame–flow interaction provides new insights into the ignition dynamics of the centrally staged annular combustor. [ABSTRACT FROM AUTHOR]

Fuel injection and distribution play an important role in the formation and migration of hot streaks in gas turbine combustors and determine the exit temperature uniformity especially for modern low emission combustors that have little or no primary and dilution air flows. To better understand the underlying mechanism of the formation and evolution of hot streak, both experimental and numerical investigations have been carried out in a centrally staged tri-sector model combustor. Flow, spray, and flame have been investigated by particle image velocimetry and planar laser-induced fluorescence. The exit temperature distributions are also measured and analyzed with both laser diagnostics and simulation results. The results show that increasing fuel-to-air ratio (FAR) or fuel staging ratio enhances the formation of high temperature hot streak and leads to high overall temperature distribution factor and radial temperature distribution factor at the combustor exit. It is found that the high temperature zone is formed through the non-premixed combustion of pilot stage and resides in the shear layer of pilot stage and primary circulation zone. Increasing FAR at low power conditions and increasing SR at high power conditions promote the formation of a large hot streak area through pilot stage combustion and thus deteriorate the uniformity of temperature distribution at the combustor exit. [ABSTRACT FROM AUTHOR]

Lean premixed prevaporized combustors with a centrally staged scheme are capable to reduce NOx emissions. Ignition is one of the key performances of the centrally staged combustor. The present study proposes a novel method to improve ignition performance by using a flow deflector. The effects of various flow deflector lengths and pressure drops on ignition performance and flame kernel propagation are investigated in this work. It is found that ignition performance is significantly improved by the flow deflector. The ignition process is obtained using a high-speed camera under different operating conditions. The timescale of the successful ignition process is analyzed using a statistical method, revealing the effects of the flow deflector length and pressure drop on the timescale of each phase of ignition. The flame kernel propagation trajectory is extracted and analyzed by combining the flow and spray fields. The mechanism of the flow deflector is analyzed by numerical simulation. It is found that with the flow deflector, the local fuel/air ratio and droplet diameter are both improved, which benefits ignition performance. This work proves that the flow deflector is a potential method to improve ignition. [ABSTRACT FROM AUTHOR]

The ignition behaviors of an annular combustor consisting of 16 centrally staged swirling burners are experimentally investigated in this work. This research is mainly focused on the light-round mechanism of burner-burner flame propagation. The swirling flow structure of the staged burner and the flow interaction between multiple burners in the annular combustor are well measured via the particle image velocimetry method. Two high speed cameras are applied to analyze the light-round process from the side view and the top view. The light-round time, ignition and extinction limits, flame propagating pattern, and dynamics of flame leading point are analyzed. Increasing the equivalence ratio, the light-round time decreases gradually. A more complicated "sawtooth" pattern of flame propagation is discovered during the burner to burner flame propagation, compared to that with non-staged burners. The trajectories of the flame leading points are moving in a "zigzag" pattern during the light-round process. The trajectories of the anti-clockwise leading point are near the inside wall, while the trajectories of the clockwise one are closer to the outside wall. For various equivalence ratios and airflow rates, the circumferential flame speeds of the clockwise flame front are constantly faster than the anti-clockwise one. In addition, the two flame speeds and their differences increase with larger equivalence ratio. These characteristics are very different from those in an annular combustor with non-staged burners. [ABSTRACT FROM AUTHOR]

Due to the battery voltage performance of the dual power supply open-winding permanent magnet synchronous motor (OW-PMSM) system in electric vehicles, the dc bus voltages of the dual power supply varies and the traditional direct torque control (DTC) method will not be suitable and may lead to obvious torque ripples. Thus, in this article, based on the analysis of the effect of voltage vector on torque variation, a bus voltage ratio is employed in the switching table optimization strategy of DTC for OW-PMSM, the voltage vector selection method is also modified according to different voltage ratio, and then, the optimized control scheme for OW-PMSM over a wide bus voltage ratio is achieved to diminish the torque ripples. Finally, simulation models of the proposed method are built to verify the theory, and the corresponding experiments are also conducted to verify the feasibility and effectiveness of the proposed optimized control strategy. [ABSTRACT FROM AUTHOR]

Mechanically responsive materials (MRMs) usually showing observable changes in emission intensity (mechanochromic) under force stimuli have garnered increasing interest due to their broad range of potential applications. Relative to usual mechanochromic materials, a kind of alternative MRMs with changeable lifetime upon force stimuli in terms of mechanodecay is proposed. A catalog of novel MRMs with both mechanochromic and mechanodecay characteristics is reported. Halogen‐free semicrystalline polymers doped with chromophores showing bright and ultralong room‐temperature phosphorescence (RTP) under ambient conditions are facilely fabricated through melt blending approaches. Upon being stretched or compressed, the RTP polymers show abundant changes in fluorescence intensity, emission color, RTP intensity, and RTP lifetime. Such RTP polymers with multiple strain‐responsive visual signals offer a kind of new MRMs useful for visually sensing the deformation of materials. Leveraging remarkable change in RTP lifetime under force stimuli, deformation process of polymers is investigated through phosphorescence lifetime and image analysis. Early damage warning for engineering polymers is achieved. Given the merits of high sensitivity, multiple visual signals, low cost, and simple operation, such RTP polymers provide a class of new MRMs useful for deformation sensing and early damage reporting of engineering materials. [ABSTRACT FROM AUTHOR]

A novel metal‐organic framework (MOF) containing one‐dimensional, Fe2+ chains bridged by dipyrazolate linkers and N,N‐dimethylformamide (DMF) ligands has been synthesized. The unusual chain‐type metal nodes feature accessible coordination sites on adjacent metal centers, resulting in motifs that are reminiscent of the active sites in non‐heme diiron enzymes. The MOF facilitates direct reduction of nitric oxide (NO), producing nearly quantitative yields of nitrous oxide (N2O) and emulating the reactivity of flavodiiron nitric oxide reductases (FNORs). The ferrous form of the MOF can be regenerated via a synthetic cycle involving reduction with cobaltocene (CoCp2) followed by reaction with trimethylsilyl triflate (TMSOTf). [ABSTRACT FROM AUTHOR]

A novel metal‐organic framework (MOF) containing one‐dimensional, Fe2+ chains bridged by dipyrazolate linkers and N,N‐dimethylformamide (DMF) ligands has been synthesized. The unusual chain‐type metal nodes feature accessible coordination sites on adjacent metal centers, resulting in motifs that are reminiscent of the active sites in non‐heme diiron enzymes. The MOF facilitates direct reduction of nitric oxide (NO), producing nearly quantitative yields of nitrous oxide (N2O) and emulating the reactivity of flavodiiron nitric oxide reductases (FNORs). The ferrous form of the MOF can be regenerated via a synthetic cycle involving reduction with cobaltocene (CoCp2) followed by reaction with trimethylsilyl triflate (TMSOTf). [ABSTRACT FROM AUTHOR]

Background: Increasing evidence has demonstrated the critical roles of mRNA modification regulators on multiple types of cancers. However, it is still poorly known about the prognostic and therapeutic value of mRNA modification regulators in HNSCC. Methods: The gene expression profile of 36 mRNA modification regulators and their corresponding clinical data were obtained from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO). Stepwise regression in R with both directions was used to construct a model for the prognosis of HNSCC. Univariate Cox regression survival analysis was performed to identify the most significant risk gene. Gene set enrichment analysis (GSEA) was applied to determine the cancer-associated pathways with NAT10. Immunohistochemistry (IHC) staining was performed to evaluate the expression of NAT10 in formalin fixed paraffin-embedded (FFPE) samples of HNSCC. Univariate and multivariate Cox regression survival analysis performed to identify the independent risk factors associated with the OS of patients with HNSCC. HNSCC cell lines (Cal-27, FaDu, and Detroit-562) were transfected with short interfering RNA (siRNA) targeting NAT10 or treated with Remodelin, a small-molecule inhibitor of NAT10. Knockdown efficiency of siRNA was assessed by quantitative real-time PCR (qRT-PCR) and western blotting. In addition, CCK-8 assay, scratch assay and transwell assay were used to examine the proliferation, migration, and invasion abilities of the three HNSCC cell lines after NAT10 was inhibited genetically and pharmaceutically. Cell cycle and cell apoptosis assays were performed by flow cytometry. Finally, the therapeutic value of Remodelin in HNSCC was evaluated via a patient-derived xenograft (PDX) model. The statistical analysis was performed with SPSS 23.0. Results: A risk prediction model containing 10 mRNA modification regulators was constructed and showed prognostic value in HNSCC. NAT10 was further identified as a key risk gene and independent prognostic factor in TCGA HNSCC dataset. The GSEA analysis suggested that high NAT10 expression was associated with MYC, E2F, G2M checkpoint, mTORC1, DNA repair and oxidative phosphorylation pathways. NAT10 protein expression was significantly up-regulated in tumour cells compared to normal epithelial cells in FFPE samples and increased NAT10 protein expression was correlated with poor overall survival of 267 HNSCC patients. Genetic depletion of NAT10 using siRNA or chemical inhibition of NAT10 using Remodelin resulted in reduced cell proliferation, migration and invasion abilities in Cal-27, FaDu and Detroit-562 cells. Knockdown of NAT10 using siRNA significantly increased cell cycle arrest in S/G2-phase. Remodelin significantly inhibited tumour growth and tumour cell proliferation in the PDX model of HNSCC. Conclusions: NAT10 could be a potential prognostic marker and a therapeutic target for HNSCC. [ABSTRACT FROM AUTHOR]

A redox‐neutral S‐nitrosation of thiol has been achieved at a dicopper(I,I) center. Treatment of dicopper (I,I) complex with excess NO. and thiol generates a dicopper (I,I) di‐S‐nitrosothiol complex [CuICuI(RSNO)2]2+ or dicopper (I,I) mono‐S‐nitrosothiol complex [CuICuI(RSNO)]2+, which readily release RSNO in 88–94 % yield. The S‐nitrosation proceeds by a mixed‐valence [CuIICuIII(μ‐O)(μ‐NO)]2+ species, which deprotonates RS‐H at the basic μ‐O site and nitrosates RS− at the μ‐NO site. The [CuIICuIII(μ‐O)(μ‐NO)]2+ complex is also competent for O‐nitrosation of MeOH. A rare [CuIICuII(μ‐NO)(OMe)]2+ intermediate was isolated and fully characterized, suggesting the S‐nitrosation may proceed through the intermediary of analogous [CuIICuII(μ‐NO)(SR)]2+ species. This redox‐ and proton‐neutral S‐nitrosation process is the first functional model of ceruloplasmin in mediating S‐nitrosation of external thiols, with implications for biological copper sites in the interconversion of NO./RSNO. [ABSTRACT FROM AUTHOR]

A redox‐neutral S‐nitrosation of thiol has been achieved at a dicopper(I,I) center. Treatment of dicopper (I,I) complex with excess NO. and thiol generates a dicopper (I,I) di‐S‐nitrosothiol complex [CuICuI(RSNO)2]2+ or dicopper (I,I) mono‐S‐nitrosothiol complex [CuICuI(RSNO)]2+, which readily release RSNO in 88–94 % yield. The S‐nitrosation proceeds by a mixed‐valence [CuIICuIII(μ‐O)(μ‐NO)]2+ species, which deprotonates RS‐H at the basic μ‐O site and nitrosates RS− at the μ‐NO site. The [CuIICuIII(μ‐O)(μ‐NO)]2+ complex is also competent for O‐nitrosation of MeOH. A rare [CuIICuII(μ‐NO)(OMe)]2+ intermediate was isolated and fully characterized, suggesting the S‐nitrosation may proceed through the intermediary of analogous [CuIICuII(μ‐NO)(SR)]2+ species. This redox‐ and proton‐neutral S‐nitrosation process is the first functional model of ceruloplasmin in mediating S‐nitrosation of external thiols, with implications for biological copper sites in the interconversion of NO./RSNO. [ABSTRACT FROM AUTHOR]

Nonreacting swirling flow behavior through a novel double swirl burner has been investigated in this paper using Detached Eddy Simulation (DES) calculations and experimental measurements. The effect of mixing both the swirling flow of the inner jet (primary air or inner swirler) and the swirling flow of the annular jet (secondary air or outer swirler) on the flow structure has been analyzed. Moreover, pressure losses and flow field characteristics have been investigated at different inlet air mass flow rates and combustor diameters. Due to the drawbacks of general pressure loss to predict the pressure drop through high turbulence swirl flow as well as the complex geometry, the time-averaged viscous dissipation field function is used to predict the pressure drop through the burner. This function is based on the relationship between viscous dissipation and pressure losses. DES flow fields are compared with high-speed particle image velocimetry measurements at different inlet air mass flow rates. It is found that there is good agreement between numerical and experimental results, and both the central toroidal recirculation zone and the corner recirculation zone are well captured. In the case of a single inner swirler, the general pressure drop is very high compared to single outer and double swirl generators, and 84% of the inlet air pass through the outer swirler and just 16% of the air pass through the inner swirler in the case of a double burner (partially premixed). The time-averaged viscous dissipation field function is very important to identify the locations that lead to pressure drop inside the burner, which induces to select the appropriate design for the best performance. In addition, it is concluded that the performance of the double swirl burner is more efficient compared with the other two single swirlers in terms of pressure losses and flow structure. [ABSTRACT FROM AUTHOR]

Herein, we report the synthesis of palladium complexes bearing an N‐heterocyclic carbene (NHC)‐sulfonamide bidentate ligand and their application in ethylene oligomerization and ethylene/polar monomer cooligomerization. These catalysts could smoothly catalyze ethylene oligomerization and ethylene/methyl acrylate cooligomerization albeit the performance was lower compared to that of a NHC–phenoxide catalyst. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 474–477 Palladium complexes bearing an N‐heterocyclic carbene–sulfonamide bidentate ligand were synthesized, characterized, and applied to ethylene oligomerization and ethylene/polar monomer cooligomerization. [ABSTRACT FROM AUTHOR]

A novel fault-tolerant inverter topology of the multiport dual-stator doubly salient electromagnetic machine (MDDSEM) drive is proposed in this paper for high reliability applications such as automotive and aerospace industries. The proposed topology adopts four diverter switches to reconnect the floating phase windings under the fault conditions and reconfigures the dual inverter to be a five-leg inverter; the output performance could be maintained after a single-phase open-circuit or short-circuit fault of the dual inverter. Compared with the traditional fault-tolerant method of the dual inverter for the MDDSEM, the lower cost and smaller volume of the proposed fault-tolerant system can be achieved. The operation principle and the optimized commutation method of the five-leg inverter for the MDDSEM are analyzed to eliminate the unexpected phase current drop so that the torque performance in the fault-tolerant mode could be improved. The effectiveness and feasibility of the proposed fault-tolerant topology and control strategies are verified by the simulation and experimental results of a 24/16-pole MDDSEM that includes both steady-state and dynamic processes with the standard angle control method and the advanced angle control method. [ABSTRACT FROM AUTHOR]

In this paper, an integrated motor-drive and battery-charging (IMB) system with a doubly salient electromagnetic machine (DSEM) is proposed to be implemented for electric vehicles. In the driving mode, the front-end dc/dc converter is employed to boost the battery voltage to improve the speed range and acceleration ability of the DSEM. The field windings distribution of a 12/10-pole DSEM is arranged for the constant self-inductance, and adopted as the inductance of the front-end dc/dc converter to eliminate the traditional filter inductance and excitation loss of the machine. In the charging mode, the windings of DSEM could be exploited as the filter inductances to obtain the unity power factor operation and constant current charging ability. The simulations and experiments have been accomplished to verify the feasibility of the independent field current control method for the proposed IMB system. [ABSTRACT FROM AUTHOR]

The Al-Si coating of ultra-high strength steel has been applied to hot stamping more and more widely, owing to solving the problem of oxidation and decarburization. However, the evolution of Al-Si coating during the heating process was rarely studied in the previous study. The tests about the influence of heating parameters, such as heating temperature, heating rates and dwell time, on properties of the Al-Si coating were carried out on the Gleeble-3500 thermal simulator. The properties of the Al-Si coating, for instance, volume fraction of FeAl intermetallics, α-Fe layer as well as porosity and 3D surface topography, were explored in the study. Results showed that more and more Kirkendall voids and cracks appeared in the Al-Si coating when the heating temperature exceeded 600°C. The heating rates almost had no influence on properties of the Al-Si coating when the temperature was equal to or lower than 500°C. The volume fraction of FeAl intermetallics in the coating with dwell time from 3 s to 8 min at 930°C was 0, 6.19%, 17.03% and 20.65%, separately. The volume fraction of the α-Fe layer in the coating changed from zero to 31.52% with the prolonged dwell time. The porosity of the coating ranged from 0.51% to 4.98% with the extension of dwell time. The unsmooth degree of the surface of the coating rose gradually with the increasing of heating rates and the extension of dwell time. The 3D surface topography of the coating was determined by the comprehensive effect of atoms diffusion, new formed phases, surface tension and the degree of oxidation of the coating surface. Experiments indicated that rapid heating was not suitable for the coating when the temperature exceeded 500°C. Experiments also demonstrated that enough dwell time was essential to obtain the superior properties of the coating. [ABSTRACT FROM AUTHOR]

In this study, the compaction characteristics of recycled hot-mix asphalt (RHMA) were evaluated using the void content (VV), compaction energy index (CEI), slope of accumulated compaction energy (K), and lock point (LP). Then, the effects of the compaction parameters, including the gradation of the RHMA, reclaimed asphalt pavement (RAP) content, temperature of gyrations, and number of gyrations, on the compaction characteristics of RHMA were investigated. An orthogonal experiment was designed and the data collected were analyzed via range analysis; then, a regression model was generated relying on a quadratic polynomial. Furthermore, the regression model was used for the comparison and prediction of the mixture's compactability during the material design. Finally, the compaction mechanism of RHMA was discussed from the perspective of the void content of RAP particles. The results showed that a finer aggregate gradation, a higher gyration temperature, a greater number of gyrations, and a higher RAP content were effective for increasing the compactability of RHMA. The range analysis results suggest that the gradation of RHMA has the greatest influence on compactability, followed by the RAP content. The RAP aggregate cannot diffuse to a new mixture completely, so the remained RAP particle reduces the void content of RHMA. Therefore, a higher RAP content up to 50% can help RHMA to achieve the designed void content with higher efficiency. [ABSTRACT FROM AUTHOR]