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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.

Based on core description, gas logging and laboratory analysis, this paper aims to study the controlling effect of the types of shale sedimentary microfacies in coal formations over shale reservoirs using the example of Shanxi formation in Northern Ordos Basin.

According to core observation, the authors selected typical samples of rock types for thin section analysis to determine the micro features and compositions of rocks.

By using core observation, we found that fine lithology in Shanxi formation included major shale, carbonaceous shale, partially carbonaceous shale, partially silty shale and silty shale with colors of gray, dark gray, black and/or gray. Shanxi Formation shale are deposited in plant-rich and plant-poor swamps, interdistributary depressions of delta plains, interfluvial depressions of meandering rivers as well as microfacies environment of natural levees and the distal crevasse splay.

Currently, the research on the shale gas in Shanxi Formation in the Ordos Basin is still in its infancy. There is yet no research on the fine-grained partition of the sedimentary facies in coal accumulation environment of Shanxi formation and the controlling effect of sedimentary microfacies over shale reservoirs.

The purpose of this paper is to build a phase-type risk model with stochastic return on investment and random observation periods to characterize the ruin quantities under which the insurance company may take effective investment strategies to avoid bankruptcy.

By the Markov property and Ito’s formula, this paper derives the integro-differential equations in which the interclaim times follow a phase-type distribution. Using the sinc method, this paper obtains the approximate solutions of the expected discounted penalty function. The numerical examples are given to verify the robustness of the proposed sinc method.

This paper discloses the relationship between the investment strategy and initial surplus level. The insurance company with a high initial surplus level prefers high risk portfolios to earn more profit. Contrarily, the insurance company would invest low risk portfolios to avoid bankruptcy. In addition, this paper shows that a short observation period would bring higher ruin probability.

The risk model is distinct in that a phase-type risk model is constructed with stochastic return on investment and random observation periods. These considerations in the risk model are in sharp contrast to the setting in which the stochastic return on investment is observed continuously. In practice, the insurance company only can periodically observe the surplus level to check the balance of the book. This setting, therefore, is difficult to adopt. This paper develops a sinc method to solve the approximate solutions of the expected discounted penalty function.

This study aims to examine the significance of transformational leadership and social support for expatriate adjustment and performance. This study also extends relevant literature on expatriate management to examine the relationships among transformational leadership, social support, expatriate adjustment, and expatriate performance through a mechanism taking into account the moderating roles of cultural intelligence and socialization experience.

The sample was collected from 156 expatriate managers of Taiwanese multinational company (MNC) subsidiaries operating in China. Structural equation modeling (SEM) in AMOS 21 and hierarchical regression in SPSS 19 were used to test eight research hypotheses.

The SEM results indicated that transformational leadership and social support make significant contributions to expatriate adjustment and performance. The moderating roles of socialization experience and cultural intelligence were also confirmed in this study.

This study extends a theoretical model of transformational leadership and social support to examine expatriate adjustment and performance based on social learning and social exchange theories. Using a specific Chinese context, the current paper highlights the value and necessity of cross‐cultural adjustment for successful expatriation.

Polyetheretherketone (PEEK) is used to manufacture biomedical implants because it has a high strength-to-weight ratio and high strength and is biocompatible. However, the use of fused deposition modeling to print a PEEK results in low strength and crystallinity. This study aims to use the Taguchi method to optimize the printing factors to obtain the highest tensile strength of the printed PEEK object. The annealing effect on printed PEEK object and crystallinity are also investigated.

This study determines the printing factors including the printing speed, layer thickness, printing temperature and extrusion width. Taguchi experimental design with a L9 orthogonal array is used to print the tensile specimen and carried out the tensile test to compare the tensile strength and porosity. Analysis of variance (ANOVA) is used to determine the experimental error and to determine the optimization printing parameters to obtain the highest tensile strength. A multivariate linear regression analysis is used to obtain the linear regression equation for predicting the theoretical tensile strength. An X-ray analysis is achieved to evaluate the crystalline of printed object. The effect of annealing is investigated to improve the tensile strength of printed part. An intervertebral lumber device is printed to demonstrate the feasibility of the obtained optimization parameters for practical application.

Taguchi experiment designs nine sets of parameters to print the PEEK tensile specimen. The experimental results and the ANOVA present that the order in which the factors affect the tensile strength for printed PEEK parts is the layer thickness, the extrusion width, the printing speed and the printing temperature. The optimized printing parameters are a printing speed of 5 mm/s, a layer thickness of 0.1 mm, a printing temperature of 395 °C and an extrusion strand width of 0.44 mm. The average tensile strength of printed specimen with the optimized printing parameters is 91.48 MPa, which is slightly less than the theoretical predicted value of 94.34 MPa. After annealing, the tensile strength increases to 98.85 MPa, which is comparable to that for molded PEEK and the porosity decreases to 0.3 from 3.9%. X-ray diffraction results show that all printed and annealed specimens have a high degree of crystallinity. The printed intervertebral lumber device has ultimate compressive load of 13.42 kN.

The optimized printing parameters is suitable for low-price fused deposition modeling machine because it does not involve a table at high temperature and can print the PEEK object with high tensile strength and good crystalline. Annealing parameters offer a good solution for tensile strength improvement.

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.

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.

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.

Fused filament fabrication (FFF) is a type of additive manufacturing (AM) based on materials extrusion. It is the most widely practiced AM route, especially used for polymer-based rapid prototyping and customized product fabrication in relation to aerospace, automotive, architecture, consumer goods and medical applications. During FFF, part quality (surface finish, dimensional accuracy and static mechanical strength) is greatly influenced by several process parameters. The paper aims to study FFF parametric influence on aforesaid part quality aspects. In addition, dynamic analysis of the FFF part is carried out.

Interpretive structural modelling is attempted to articulate interrelationships that exist amongst FFF parameters. Next, a few specimens are fabricated using acrylonitrile butadiene styrene plastic at varied build orientation and build style. Effects of build orientation and build style on part’s ultimate tensile strength, flexure strength along with width build time are studied. Prototype beams (of different thickness) are fabricated by varying build style. Instrumental impact hammer Modal analysis is performed on the cantilever beams (cantilever support) to obtain the natural frequencies (first mode). Parametric influence on natural frequencies is also studied.

Static mechanical properties (tensile and flexure strength) are greatly influenced by build style and build orientation. Natural frequency (NF) of prototype beams is highly influenced by the build style and beam thickness.

FFF built parts when subjected to application, may have to face a variety of external dynamic loads. If frequency of induced vibration (due to external force) matches with NF of the component part, resonance is incurred. To avoid occurrence of resonance, operational frequency (frequency of externally applied forces) must be lower/ higher than the NF. Because NF depends on mass and stiffness, and boundary conditions, FFF parts produced through varying build style may definitely correspond to varied NF. This aspect is explained in this work.

The fused filament fabrication (FFF) process is an additive manufacturing technique used in engineering design. The mechanical properties of parts manufactured by FFF are influenced by the printing parameters. The mechanical properties of rigid thermoplastics for FFF are well defined, while thermoplastic elastomers (TPE) are uncommonly investigated. The purpose of this paper is to investigate the influence of extruder temperature, bed temperature and printing speed on the mechanical properties of a thermoplastic elastomer.

Regression models predicting mechanical properties as a function of extruder temperature, bed temperature and printing speed were developed. Tensile specimens were tested according to ASTM D638. A 3×3 full factorial analysis, consisting of 81 experiments and 27 printing conditions was performed, and models were developed in Minitab. Tensile tests verifying the models were conducted at two selected printing conditions to assess predictive capability.

Each mechanical property was significantly affected by at least two of the investigated FFF parameters, where printing speed and extruder temperature terms influenced all mechanical properties (p < 0.05). Notably, tensile modulus could be increased by 21%, from 200 to 244 MPa. Verification prints exhibited properties within 10% of the predictions. Not all properties could be maximized together, emphasizing the importance of understanding FFF parameter effects on mechanical properties when making design decisions.

This work developed a model to assess FFF parameter influence on mechanical properties of a previously unstudied thermoplastic elastomer and made property predictions within 10% accuracy.