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This paper aims to establish a photoacoustic detection system for SO₂ using UV-LED and testify its feasibility for sensitive measurement. The work in this paper can avoid potential crossover interference in infrared (IR) range and also balance the capability and cost of feasible excitation for photoacoustic detection system.

In this experimental work, a cantilever-enhanced–based photoacoustic SO₂ detection system using an ultraviolet (UV) LED light source with a light power of 4 mW as the excitation was established.

A feasible photoacoustic detection system for SO₂ using UV-LED was established. Experimental results demonstrate that the detection limit of the system can reach the level of 0.667 ppm, which can serve as a reference for the application of PAS in insulation fault diagnosis.

This work investigated the potential of using ultraviolet photoacoustic spectroscopy to detect trace SO₂, which provided an ideal replacement of infrared-laser-based detection system. In this paper, a photoacoustic detection system using LED with a low light power was established. Low light power requirement can expand the options of light sources accordingly. In this paper, the absorption characteristics of SO₂ in the presented detection system and ultraviolet range were studied. And the detection limit of the presented system was given. Both of which can provide reference to SO₂ detection in ambient SF₆.

Building on social media and destination brand-related literature, this study aims to explore World Heritage Sites’ (WHSs) brand diffusion and formation process from long-term and short-term perspectives, which includes brand diffusion, user-generated content (UGC), opinion leaders and brand events’ impact.

This study uses a mixed-method including text mining, keyword analysis and social network analysis to explore the brand formation process of four popular WHSs in Beijing, namely, the Palace Museum, Great Wall, Summer Palace and Temple of Heaven and more than 10,000,000 users’ data on Sina Weibo has been implemented to uncover the underlying social media branding mechanism.

The results show that the number of postings keeps in a stable range in most months, but, in general, there are no common rules for changing trends among the four WHSs; long-term high-frequency keywords related to history and culture account for a higher percentage; different kinds of accounts have varying impacts on information diffusion, in which media accounts lead to a bigger influence. However, more followers do not necessarily mean more interactions and most of the interaction ratio is much lower than 0.01000; brand events facilitate brand dissemination and have an impact on the creation of UGC.

This study is valuable for destination marketers to deeper understand brand diffusion and formation and provides valuable insights for developing effective destination marketing strategies.

Unlike previous studies that only concern a few parts of destination brand formation via social media (e.g. brand diffusion, brand events or opinion leaders’ impact), this study takes a more comprehensive perspective by systematically analyzing the brand formation process of WHSs on social media. By considering both long-term diffusion and short-term representative events, this study provides a more holistic understanding of the branding mechanism.

The purpose of this study is to propose an adaptive fault-tolerant control approach based on output feedback for a class of quadrotor unmanned aerial vehicles system. In the event of a controlled actuator failure, a stable flying of the aircraft can be achieved by selecting an appropriate sliding mode surface.

Aiming at the actuator failure of quadrotor aircraft during flight in the controllable range, a dynamic surface sliding mode passive fault-tolerant controller based on output feedback is designed based on the strong robustness of sliding mode method. Due to the unknown nonlinearity dynamics and parameter uncertainties in the system, a nonlinear observer is used to estimate them online.

The stability of the suggested algorithm is established using appropriate Lyapunov functions, and the performance of the proposed control approach is demonstrated using hardware-in-the-loop simulation.

An error performance function is introduced into the controller to ensure the convergence speed and accuracy of errors are within the predetermined range. By using the norm estimation method, there is only one parameter that needs to be updated in each step of the control process, which considerably minimizes the calculation burden. Finally, the validity of the proposed control scheme is verified on the hardware-in-the-loop simulation, and the results show that the proposed control method has achieved the desired results.

With the development of science and technology, more creators are trying to use new crafts to represent the cultural trends of the social media era, which makes cultural heritage innovative and new genres emerge. This compels the academic community to examine craft from a new perspective. It is very helpful to understand the hidden representational structure of craft more deeply and improve the craft innovation system of cultural and creative products that we deconstruct the craft based on Complex Network and discover its intrinsic connections.

The research crawled and cleaned the craft information of the top 20% products on the Forbidden City’s cultural and creative products online and then performed Complex Network modeling, constructed three craft representation networks among function, material and technique, quantified and analyzed the inner connections and network structure of the craft elements, and then analyzed the cultural inheritance and innovation embedded in the craft representation networks.

The three dichotomous craft representation networks constructed by combining function, material and technique: (1) the network density is low and none of them has small-world characteristics, indicating that the innovative heritage of the craft elements in the Forbidden City’s cultural and creative products is at the stage of continuous exploration and development, and multiple coupling innovation is still insufficient; (2) all have scale-free characteristics and there is still a certain degree of community structure within each network, indicating that the coupling innovation of craft elements of the Forbidden City’s cultural and creative products is seriously uneven, with some specific “grammatical combinations” and an Island Effect in the network structure; (3) the craft elements with high network centrality emphasize the characteristics of decorative culture and design for the masses, as well as the pursuit of production efficiency and economic benefits, which represent the aesthetic purport of contemporary Chinese society and the ideological trend of production and life.

The Forbidden City’s cultural and creative products should continue to develop and enrich the multi-coupling innovation of craft elements, clarify and continue their own brand unique craft genes, and make full use of the network important nodes role.

Five different structural reactive dyes (Reactive Brilliant Blue K-3R, Everacion Blue H-ERD, Moderzol Blue FBR, Atuzol Black B and Moderzol Blue HEGN) were treated with laccase (Denilite II US) in order to determine the optimum decolouration conditions. The experiments showed that laccase had distinct decolouration effects on these five dyes. Under optimum conditions, the colour removal rates of Everacion Blue H-ERD and Moderzol Blue HEGN were over 90%. Furthermore, the effects of different additives, such as acid ion, metal ion, and surfactants on the decolouration rate of Reactive Brilliant Blue K-3R were discussed. The results show that the decolouration rate is significantly promoted through the addition of Cu²⁺ and Al³⁺, while it is inactivated with Fe²⁺ and ion surfactants. Moreover, the COD removal rates of the five dyes are more than 75%.

Sedimentary facies type of the Shanxi Formation in northeastern Ordos Basin is an ongoing debate. Based on field measurements, sample collection and identification, and laboratory analysis, we systematically evaluated the sedimentary characteristics of the sandstone bodies of Shanxi Formation of Chengjiazhuang section in Liulin. Analysis included identifying sample composition, grain size, texture, sedimentary structure and spatial distribution. We came to the conclusion that the sedimentary environment of Shanxi Formation is deltaic. This deltaic environment included deltaic front and deltaic plain. It can be further divided into five sedimentary microfacies: subfluvial distributary channel, subfluvial distributary interchannel, distributary channel, levee, and peat bog. And lastly, the evolution of sedimentary environment of Shanxi Formation is discussed.

The coal bed methane resources distribution of Handan - Fengfeng Mining area has the features of "richness in the midland and north while poorness in the south, and richness in the east while poorness in the west. Through the analysis of the geological factors causing the above phenomena, we get that: the coal metamorphism and hydrogeological condition are the major controlling factors, the former controls the north and south difference of coal bed methane resources distribution from the two aspects covering gas-generated quantity and adsorption capacity, while the latter controls the east and west difference of coal bed methane resources distribution; syncline and good cap rock conditions are necessary conditions for coal bed methane enrichment, but not the reason for causing the difference of coal bed methane resources distribution.

The paper aims to contribute to the current research on China's Belt and Road Initiative (BRI) from a historical point of view. The paper investigates why the history of the Silk Roads is important to the BRI, what is in the guiding thought underpinning China's Silk Roads narrative and how this narrative is presented transnationally, through an insightful analysis of the Communist Party of China's (CPC) view of the Silk Roads history, as well as its perception of the connections between the Silk Roads history and the BRI.

The paper sits in the interface between history, heritage and state power. The argument is framed in concepts of historical constructionism and soft power. It is based on the discourse analysis of China's official narrative of Silk Roads and a case study of the planning for the World Heritage nomination of the Maritime Silk Routes (MSR) (China section). The case study is conducted through a qualitative analysis of academic publications, media reports and programs, official speeches and documents that are available to the public in hardcopy or on the Internet.

The paper reveals the relationship between the state-endorsed Silk Roads narrative and the BRI. The paper argues that the state-backed Silk Roads narrative as well as the planning for the World Heritage nomination of the MSR (China section) is guided by the Chinese Communist Party's perception of the BRI. In this respect, the Silk Roads-associated history, heritage and memory are shaped and deployed to serve as a convenient platform for the promotion of the BRI. The Party leaders' perception of the BRI is in large part about the revival of China's past glory, its national rejuvenation and the demonstration of China's soft power.

The paper contributes to the existing literature on the BRI through its enquiries into how the CPC reconcile nationalist ambitions with notions of peace, harmony and cosmopolitanism and how CPC's view of the Silk Roads history shapes its vision of the BRI. The paper examines the role of the state in the construction and articulation of the Silk Roads-associated history, heritage and memory. It investigates how China's official interpretation of the Silk Road heritage serves China's BRI.

Integrating complementary information with high-quality visual perception is essential in infrared and visible image fusion. Contrast-enhanced fusion required for target detection in military, navigation and surveillance applications, where visible images are captured at low-light conditions, is a challenging task. This paper aims to focus on the enhancement of poorly illuminated low-light images through decomposition prior to fusion, to provide high visual quality.

In this paper, a two-step process is implemented to improve the visual quality. First, the low-light visible image is decomposed to dark and bright image components. The decomposition is accomplished based on the selection of a threshold using Renyi’s entropy maximization. The decomposed dark and bright images are intensified with the stochastic resonance (SR) model. Second, texture information-based weighted average scheme for low-frequency coefficients and select maximum precept for high-frequency coefficients are used in the discrete wavelet transform (DWT) domain.

Simulations in MATLAB were carried out on various test images. The qualitative and quantitative evaluations of the proposed method show improvement in edge-based and information-based metrics compared to several existing fusion techniques.

In this work, a high-contrast, edge-preserved and brightness-improved image is obtained by the processing steps considered in this work to get good visual quality.

In this study, engineering stress-strain relationships considering an effect of strain rate on steel materials at elevated temperatures were formulated and a simplified analytical model using a two-dimensional beam element to analytically examine the effect of strain rate on the load-bearing capacity and collapse temperature was proposed.

The stress-strain relationships taking into account temperature, strain, and strain rate were established based on the past coupon test results with strain rate as the test parameter. Furthermore, an elasto-plastic analysis using a two-dimensional beam element, which considered the effect on strain rate, was conducted for both transient- and steady-state conditions.

The analytical results agreed relatively well with the test results, which used small steel beam specimens with a rectangular cross-section under various heating rates (transient-state condition) and deformation rates (steady-state condition). It was found that the bending strength and collapse temperature obtained from the parametric analyses agreed relatively well with those evaluated using the effective strength obtained from the coupon tests with strain equal to 0.01 or 0.02 under the fast strain rates.

The effect of stress degradation, including the stress-strain relationships at elevated temperature, was mitigated by considering the effect of strain rate on the analytical model. This is an important point to consider when considering the effect of strain rate on steel structural analysis at elevated temperatures to maintain analytical stability unaccompanied by the stress degradation.