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Aluminum foam-filled thin-walled unit structures have received much attention for their excellent energy absorption properties. To improve the energy absorption effect of car energy absorption box under axial compression, this paper optimizes the fiber lay-up sequence, fiber angle and aluminum foam density of aluminum foam filled carbon fiber reinforced plastic (CFRP) thin-walled square tubes.

Design of sample points required to construct the proxy model using design of experiments (DOE) method, and the data sample points of different models are obtained through Abaqus simulation and test. A double high-precision proxy model with the maximum specific energy absorption (SEA) and the minimum initial peak crash force (PCF) as the evaluation index is constructed based on the response surface function method. The NSGA-II multi-objective genetic algorithm was used to optimize the design parameters and obtain the optimal solution for the Pareto front, and the results were verified by using the multi-objective optimization toolbox in design-expert.

The results show that the optimal solution to the multi-objective optimization problem with the inclusion of the lay-up sequence is ρ = 0.5g/cm3 for a fiber lay-up angle varying in the range ±15–90° and an aluminum foam density varying in the range 0.2g/cm3-0.5g/cm3, with a lay-up method of [±87°/±16°/±15°/±89°]. The two optimization methods correspond to SEA and PCF errors of 2.109% and 4.1828%, respectively. The optimized SEA value is 18.2 J/g and the PCF value is 18,230 N. The optimized design reduces the peak impact force and increases the specific energy absorption, which improves the energy absorption effect of thin-walled energy-absorbing boxes for automobiles.

In this paper, the impact resistance of CFRP thin-walled square tubes filled with aluminum foam is optimized. Based on numerical simulations and experiments to obtain the sample point data for constructing the dual-agent model, we investigate the effect of filling with different densities of aluminum foam under the simultaneous change of fiber lay-up angle and order on its mechanical properties in this process, and carry out the multi-objective optimization design with NSGA-II algorithm.

Thailand has served as a major outbound tourist destination for Chinese tourists for decades. Behaviours demonstrated by Chinese tourists in Thailand are believed to have created an image of Chinese outbound tourists among the residents and have impacted on the sustainability of Thai tourism. This study aims to contribute a more comprehensive and nuanced understanding of the image of Chinese outbound tourists from the perspective of Thai residents’.

In-depth interviews were conducted with 15 Thai residents who have frequent contact with Chinese tourists.

The results reveal that Thai residents’ perceptions of Chinese tourists include both positive and negative images. Positive images consist of being filial and friendly (e.g. taking good care of the elderly and having close emotional ties within their touring group) and being wealthy and auspicious (e.g. having a lot of money to spend and tipping generously). Negative images include moral norms (e.g. making loud noises and jumping into a queue), hygiene habits (e.g. littering and spitting) and religious culture (e.g. touching and climbing Buddha statues).

This qualitative research promotes the study of destination residents’ perceptions of tourists’ in the context of outbound tourism and enriches the application of social representation theory from the perspective of residents in the field of tourism marketing. It generates a more nuanced comprehension of Thai residents’ perceptions of Chinese tourists, contributes to the government’s formulation of guidelines for civilised tourism and has benefits to the sustainable development of tourism destinations.

泰国居民对中国游客的形象感知

摘要

几十年来, 泰国一直是中国游客的主要出境旅游目的地。中国游客在泰国表现出的行为在居民中创造了中国出境游客的形象, 并影响了泰国旅游业的可持续性。这项研究旨在从泰国居民的感知出发, 对中国出境游客的形象进行更全面、细致的了解。

对15位经常与中国游客接触的泰国居民进行了深入访谈。

结果表明, 泰国居民对中国游客形象的感知既包括正面形象也包括负面形象。正面的形象包括孝顺和友善（例如, 照顾老人, 并在其旅行团中保持紧密的情感联系）, 富有和吉祥（例如, 有很多钱可花, 并慷慨地付小费）, 而负面的形象则包括道德规范（例如, 大声喧哗, 并插队）, 卫生习惯（例如, 乱扔垃圾和随地吐痰）以及宗教文化（例如, 触摸和爬到佛像上）。

这项定性研究弥补了出境旅游背景下目的地居民对游客形象的感知的差距, 并且从居民的角度出发丰富了社会表象理论在旅游营销领域的应用。它使泰国居民对中国游客的认识更加细致, 有助于政府制定有针对性的文明旅游指导方针, 有利于旅游目的地未来的可持续发展。

Percepción de los residents tailandeses sobre el comportamiento de los turistas chinos

Por décadas, Tailandia ha sido un principal destino tulístico de turismo emisor para los turistas chinos.El comportamiento de los turistas chinos en Tailandia ha impresionado las imagenes de los turistas chinos emisores a los habitantes, y ha afectado la sostenibilidad de la industria turística de Tailandia. Esta investigación tiene como objetivo comenzar con la percepción de los habitantes tailandeses para conocer una comprensión más completa y detallada de las imagenes de los turistas chinos emisores.

Entrevisitar en profundidad a 15 habitantes tailandeses que a menudo contactan con los turistas chinos.

Los resultados muestran, las percepciones de los habitantes tailandeses de las imagenes de los turistas chinos contienen las imagenes positivas y negativas. Los imágenes positivas incluyen fiedad filial y amabilidad (por ejemplo, cuida a los ancianos y mantiene una estrecha conexión emocional con su grupo de viaje), riqueza y buena suerte (Por ejemplo, tiene mucho dinero para gastar y propina generosa.) pero las imagenes negativas incluyen las normas étias (por ejemplo, hace ruido fuerte y corta en línea.) los hábitos de higienes (por ejemplo, tira basura al azar y escupiendo por todas partes.) y cultura religiosa (por ejemplo, toca y trepa los estatuas de Buda.)

Esta investigación cualitativa cierra la brecha en los percepciones de los habitantes de desino de las imagenes de turistas en el contexto del turisimo emisor y comenza con los aspectos de los habitantes enriquece la aplicación de la teoría de la representación social en el campo de marketing turístico. Deja los habitantes tailanteses conocer a los turistas chinos más detallada y ayuda al gobierno a desarrollar pautas específicas de turismo civilizado y es benificioso para el futuro desarrollo sostenible de los destinos turísticos.

The purpose of this study is to develop luminescence sensors for the detection of nitroaromatic compounds (NACs) and metal ions to protect human health and prevent environmental pollution.

The composition and morphology of Eu-metal-organic frameworks (MOF) (1) were well characterized by powder X-ray diffraction, elemental analyses, Fourier-transform infrared spectroscopy, thermogravimetric analysis, X-ray photoelectron spectroscopy and scanning electron microscopy. The emission spectrum displays that 1 has significant characteristic emission bands of Eu(III) ions. The authors further investigated the fluorescence sensing performances of 1 to NACs and metal ions.

The results show that Eu-MOF (1) exhibits significant fluorescence quenching effect toward p-nitroaniline and Fe³⁺ ions with good stability and recyclability. This means that 1 can be used as a multifunctional sensing material for the detection of p-nitroaniline and Fe³⁺ ions.

The authors have successfully synthesized a fluorescence Eu-based sensing material under hydrothermal conditions. In addition, the fluorescence property and sensing performances for detecting NACs and metal ions were studied. The results suggest that 1 has highly selective fluorescence quenching toward p-nitroaniline and Fe³⁺ ions with not only high sensitivity and selectivity but also excellent stability and recyclability. Furthermore, this study has confirmed that the multifunctional MOF material is very useful in environment pollutants’ detection and monitoring.

Since their inception in late 2007, the Qualified Domestic Institutional Investor (QDII) funds, which help Chinese investors to invest in foreign capital markets, have experienced significant portfolio losses and persistent fund outflows. While these losses are large in absolute terms, QDII funds, on average, performed better than Chinese A-share funds, but slightly worse than a group of foreign mutual funds. Our study focuses on the QDII industry, and asks three interrelated questions: (1) why have there been large fund outflows from the industry? (2) what explains QDII funds’ poor performance? and (3) why have QDII funds been so heavily exposed to the Hong Kong market? Our empirical analysis shows that the persistent capital outflows were primarily a result of disappointing fund performance. This poor performance can, in turn, be explained by the deficiency of knowledge required of QDII fund managers to successfully invest in foreign capital markets and manage global portfolios. Finally, our study goes some way to explain the phenomenon of QDII funds’ large asset allocation in the Hong Kong market. This ‘Hong Kong bias’ is shown to be consistent with the well-documented ‘home bias’ behaviour in cross-border portfolio investment, but is greatly exacerbated by the lack of global investing experience of QDII managers.

We seek to quantify the relationship between urbanization and economic growth in China using recent advances in econometric techniques.

This study adopts a smoothed instrumental variables quantile regression (SIVQR) estimator to obtain consistent estimates of the effects of urbanization on economic growth in China. Our approach accounts for the differential impacts of urbanization across the conditional distribution of economic growth while allowing for an identification strategy that addresses the endogeneity of urbanization. Our main findings reveal that ignoring urbanization endogeneity leads to inconsistent estimates of urbanization effects. Further, we find a positive relationship between urbanization and growth resembling an inverted U-shape. This supports the hypothesis that the beneficial effects of urbanization intensify at initial stages while diminishing beyond a certain threshold, due perhaps to weakening scale economies.

Our main results indicate that the individual productivity gains brought by urbanization outweigh the negative effects thereof that impede productivity, thus contributing to the economic growth in China. Further, we find that ignoring differential impacts of urbanization underestimates the beneficial effects of urbanization for provinces whose quality of governance is in the vicinity of the center of quality distribution. Ignoring the endogeneity of urbanization generates inconsistent estimates of the elasticity of economic growth with respect to urbanization. Finally, we estimate an inverted U-shape resembling relationship between urbanization and growth.

First, future studies would benefit from incorporating more data as provinces further east on the mainland become more urbanized and urbanization runs its course. Second, controlling the barriers to rural-urban mobility would contribute to the robustness of the estimated relationship between urbanization and growth once such data became available. Unveiling the impact of government-imposed barriers is key to designing optimal policies that help fuel economic growth in the country. Finally, future research could benefit from information on urbanization sources not considered here such as inter-provincial migration, as such data become publicly available.

Quantifying the beneficial effects of urbanization on economic growth can help guide the government in China to further fuel the growth through a set of relevant policy tools that promote urbanization.

Rural-urban migration in China lays the groundwork for economic advancement in recipient cities and economies, as it may induce scale economies. This can benefit both the economy at large and the migrants.

The SIVQR estimator accounts for potential heterogeneous effects of urbanization across the entire conditional distribution of growth while allowing for an identification strategy that addresses the endogeneity of urbanization. An additional distinguishing feature of the current study is our use of the most recent novel, provincial-level data obtained from the National Bureau of Statistics of China. Our focus on a single country allows sidestepping issues arising from the inconsistency of the definition of urban across different countries while accounting for intra-country urbanization drivers intrinsic to China, such as natural features and geographic characteristics. Therefore, our approach has the potential to sidestep the bias resulting from the differences in mechanisms behind urbanization-growth relationships across different countries.

The potential implications of the three-dimensional printing (3DP) technology are growing enormously in the various health-care sectors, including surgical planning, manufacturing of patient-specific implants and developing anatomical models. Although a wide range of thermoplastic polymers are available as 3DP feedstock, yet obtaining biocompatible and structurally integrated biomedical devices is still challenging owing to various technical issues.

Polyether ether ketone (PEEK) is an organic and biocompatible compound material that is recently being used to fabricate complex design geometries and patient-specific implants through 3DP. However, the thermal and rheological features of PEEK make it difficult to process through the 3DP technologies, for instance, fused filament fabrication. The present review paper presents a state-of-the-art literature review of the 3DP of PEEK for potential biomedical applications. In particular, a special emphasis has been given on the existing technical hurdles and possible technological and processing solutions for improving the printability of PEEK.

The reviewed literature highlighted that there exist numerous scientific and technical means which can be adopted for improving the quality features of the 3D-printed PEEK-based biomedical structures. The discussed technological innovations will help the 3DP system to enhance the layer adhesion strength, structural stability, as well as enable the printing of high-performance thermoplastics.

The content of the present manuscript will motivate young scholars and senior scientists to work in exploring high-performance thermoplastics for 3DP applications.

Tour guides play a significant role in sustainable tourism development as leaders, mediators, resource managers and promoters of economic prosperity. This paper aims to show how local Tibetan tour guides practice sustainable tourism in their encounters with Western tourists.

The data consists primarily of 15 in-depth interviews with native Tibetan guides,Content analysis of the data were undertaken.

It was found that the guides adopt sustainable tourism practices based on their local religious wisdom and experiences as they try to establish harmonious host–guest relationships. Western clients also encourage guides to adopt more proenvironmental behaviors. The “hosts” live by Buddhist concepts such as samsara that are in line with concepts such as altruism and benevolence. Most “guests” are well-behaved and try to build sincere mutual relationships with local people. Host and guest cocreate value for local sustainable tourism practice.

Tour guides can practice sustainable tourism in a leadership role or as mediators, resource managers or promoters of economic prosperity. They also maintain a sincere and kind relationship with their guests that goes beyond the instrumental host–guest relationship and might help to cocreate value for local sustainable tourism practices.

Tour guides’ sustainable practices have been examined in the past based on their roles as leader, mediator, resource manager and promoter of economic prosperity. But researchers have seldom examined circumstances in which the tourists and tour guides were from different cultures. This paper addresses this gap.

导游作为领导者、中介者、资源管理者和经济繁荣的促进者, 在旅游可持续发展中发挥着重要的作用。本文展示了藏族导游在与西方游客的接触中如何实践可持续旅游。

深度访谈15个对当地藏族导游, 对收集的数据进行内容分析。

导游基于本土的宗教智慧和经验, 尝试与建立更加和谐的主客关系时, 从而实现可持续旅游实践。西方客户也鼓励导游采取更环保的行为。“主人” 的生活遵循佛教轮回等观念, 提倡“利他”、“仁爱”。大多数“客人” 都行为得体, 试图与当地人建立真诚的相互关系。主客共同为当地可持续旅游实践创造价值。

导游可以作为领导角色或中介、资源管理者或经济繁荣的促进者实践可持续旅游。他们还与客人保持真诚和友好的关系, 这超越了工具性的主客关系, 可能有助于共同为当地可持续旅游实践创造价值。

在过去的研究中, 导游的可持续实践基于他们作为领导者、中间人、资源管理者和经济繁荣的促进者。但研究人员对游客和导游来自不同文化的情境缺少关注, 我们的研究试图解答这一问题。

Los guías turísticos desempeñan un papel importante en el desarrollo del turismo sostenible como líderes, mediadores, administradores de recursos y promotores de la prosperidad económica. Este documento muestra, cómo los guías turísticos tibetanos locales practican el turismo sostenible en sus encuentros con turistas occidentales.

Los datos consisten principalmente en 15 entrevistas en profundidad con guías tibetanos nativos. Los datos fueron analizados mediante el método de análisis de contenido.

Se encontró que, los guías adoptan prácticas de turismo sostenible basadas en su sabiduría y experiencias religiosas locales, mientras intentan establecer relaciones armoniosas entre el anfitrión y el huésped. Los clientes occidentales, también alientan a los guías a adoptar comportamientos más proambientales. Los “anfitriones”, viven según conceptos budistas, como el samsara, que están en línea con conceptos como el altruismo y la benevolencia. La mayoría de los “visitantes” se comportan bien y tratan de construir relaciones mutuas sinceras con la gente local. El anfitrión y el huesped, co-crean valor para la práctica local de turismo sostenible.

Los guías turísticos pueden practicar el turismo sostenible en un papel de liderazgo o como mediadores, administradores de recursos o promotores de la prosperidad económica. También mantienen una relación sincera y amable con sus huéspedes que va más allá de la relación instrumental anfitrión-huésped y podría ayudar a co-crear valor para las prácticas locales de turismo sostenible.

Las prácticas sostenibles de nuestra guía han sido examinadas en el pasado en función de sus roles como líder, mediador, gestor de recursos y promotor de la prosperidad económica. Pero los investigadores, rara vez han examinado las circunstancias en las que los turistas y los guías turísticos eran de diferentes culturas. Abordamos esta brecha.

Fluted pumpkin seed shell, an abundant and inexpensive natural resource in Nigeria, was used as a precursor to adsorbent production for the removal of suspended and dissolved particle (SDP) from initially coagulated coal washery effluent (CWE). Key parameters such as contact time, adsorbent dose, pH and temperature were investigated using batch mode. The adsorption equilibrium, thermodynamics and kinetics of SDP on H₃PO₄ treated shell (FPA) and NH₄Cl treated shell (FPS) were examined at specified temperatures. Equilibrium data sufficiently fit the Langmuir isotherm model (R² > 0.99; SSE < 0.09). The pseudo-second order kinetic model provides the best correlation (R²>0.99;SSE<0.1) with the experimental data. The evaluated ΔG○ and ΔH○ indicate the spontaneous and endothermic nature of the process. This study demonstrates that pumpkin seed shell could be utilized as low cost, renewable, ecofriendly bioadsorbent for the removal of SDP from CWE.

This paper aims to provide an overview of the recent findings of the mechanical properties of parts manufactured by fused deposition modeling (FDM). FDM has become a widely used technique for the manufacturing of thermoplastic parts. The mechanical performance of these parts under service conditions is difficult to predict due to the large number of process parameters involved. The review summarizes the current knowledge about the process-property relationships for FDM-based three-dimensional printing.

The review first discusses the effect of material selection, including pure thermoplastics and polymer-matrix composites. Second, process parameters such as nozzle temperature, raster orientation and infill ratio are discussed. Mechanisms that these parameters affect the specimen morphology are explained, and the effect of each parameter on the strength of printed parts are systematically presented.

Mechanical properties of FDM-produced parts strongly depend on process parameters and are usually lower than injection-molded counterparts. There is a need to understand the effect of each parameter and any synergistic effects involved better.

Through the optimization of process parameters, FDM has the potential to produce parts with strength values matching those produced by conventional methods. Further work in the field will make the FDM process more suitable for the manufacturing of load-bearing components.

This paper presents a critical assessment of the current knowledge about the mechanical properties of FDM-produced parts and suggests future research directions.