Search results

Through the scientific and reasonable evaluation of the site selection of the emergency material reserve, the optimal site selection scheme is found, which provides reference for the future emergency decision-making research.

In this paper, we have chosen three primary indicators and twelve secondary indicators to construct an assessment framework for the determination of suitable locations for storing emergency material reserves. By mean of the improved entropy weight-order relationship weight determination method, the evaluation model of kullback leibler-technique for order preference by similarity to an ideal solution (KL-TOPSIS) emergency material reserve location based on relative entropy is established. On this basis, 10 regional storage sites in Beijing are selected for evaluation.

The results show that the evaluation model of the location of emergency material reserve not only respects the objective knowledge, but also considers the subjective information of the experts, which makes the ranking result of the location of the emergency material reserve more accurate and reliable.

Firstly, the modification factor is added to the calculation formula of traditional entropy weight method to complete the improvement of entropy weight method. Secondly, the order relation analysis method is used to assign subjective weights to the indicators. The principle of minimum information entropy is introduced to determine the comprehensive weight of the index. Finally, KL distance and TOPSIS method are combined to determine the relative entropy and proximity degree of alternative solutions and positive and negative ideal solutions, and the scientific and effective of the method is proved by case study.

In modern China, sports and nationalism always have close connection, and nationalism is the important reason for the promotion of Chinese sports. However, the relationship between Chinese sports and nationalism in globalised China could be much more examined by academics, as well as its influencing factors. This chapter selects the Beijing 2008 Olympic Games as the context and representative three Chinese sports heroes in the period of globalisation to study. The findings show that in some extent, Beijing 2008 Olympic Games and three Chinese sports heroes represent the national image of China in the globalised world, also bearing the burden of washing away historical humiliation and pursuing national glory. Furthermore, it is manifested that China have a complex nationalism in the process of hosting the 2008 Olympic Games. Under the influence of mass media, market economy and sports professionalisation, nationalism still exists in Chinese sports, but people gradually start to reflect on the ‘Juguo Tizhi’, the traditional Chinese sports system and the concept of ‘winning glory for the nation’. The relationship between Chinese nationalism and sports shows the important implications of rapid Chinese sports development.

This study aims to optimize the preparation conditions and modify the nanofiltration (NF) membranes to prepare high-performance polysulfone/sulfonated polysulfone composite nanofiltration (PSF/SPSF-NF) membranes through interfacial polymerization.

Investigating the impacts of anhydrous piperazine (PIP) concentration, trimesoyl chloride (TMC) concentration and basement membrane type on NF membrane performance, the optimal membrane was prepared. In addition, nano-SiO₂ was added to the active separation layer to modify the NF membranes.

The comprehensive performance of PSF/SPSF-NF membranes was optimized when the concentration of PIP was 0.75 Wt.% and the concentration of TMC was 0.15 Wt.%, at which time the water flux was 66.1 L·m⁻²·h⁻¹ and the retention rate of Na₂SO₄ was 98.1%. The comprehensive performance of polysulfone/sulfonated polysulfone-SiO₂ nanofiltration (PSF/SPSF-SiO₂-NF) membranes was optimized when the blending ratio of nano-SiO₂ to PIP was 2:3, with a pure water flux of 81.9 L·m⁻²·h⁻¹ and a Na₂SO₄ retention rate of 95.9%. Compared to polysulfone nanofiltration (PSF-NF) membranes and PSF/SPSF-NF membranes, NF membranes with nano-SiO₂ increased the flux recovery rate by 22.9% and 8.7%.

PSF/SPSF-SiO2-NF membrane exhibits excellent antifouling properties.

There is currently no literature available on the preparation of NF membranes using polysulfone/sulfonated polysulfone (PSF/SPFS) as a substrate. This provides a method for modifying NF membranes, starting with the modification of the basement membrane and then modifying the active separation layer.

Using the stimulus–organism–response (SOR) theoretical model, this empirical research aims to examine and validate how tourists’ interactions with 360-degree virtual reality (VR) videos incorporating Web navigability and visual interface design quality (stimulus) on travel websites can make tourists more engaged and then satisfied (organism), which could make them more likely to visit destinations and spread electronic word of mouth (e-WOM) (response).

Using the convenience sampling method, 975 responses were collected through a questionnaire. The data were analysed using Smart-PLS 4 software to investigate the hypothesised relationships.

The findings demonstrate that 360-degree VR videos significantly create Web user engagement, and Web user engagement is significantly associated with Web user satisfaction. The result shows that Web user engagement and satisfaction impact the intention to visit the tourist destination. Additionally, Web user satisfaction impacts e-WOM. Lastly, navigability and visual interface design quality are significantly moderated between 360-degree VR videos and Web user engagement.

This research only examined the tourists’ behavioural intentions with 360-degree VR videos during the pre-travel phase. In contrast, future research may investigate how tourists behave with VR during the on-site and post-travel phases.

Tourism marketers should not only adopt 360-degree VR but also integrate Web navigability and visual interface design to boost Web users’ engagement on tourism websites.

This study advances the study of VR from the tourists’ psychological perspective. Moreover, the SOR theory has been re-examined from the VR and technology tourism perspectives. It provides a general understanding of the behavioural aspects of tourists in developing countries.

利用刺激-有机体反应（SOR）理论模型, 本实证研究检验并验证了游客与旅游网站上结合了网络导航性和视觉界面设计质量（刺激）的360度虚拟现实(VR)视频的互动如何使游客更投入、更满意（有机体）, 这可能使他们更有可能访问目的地并传播电子口碑（响应）。

采用方便抽样法, 通过问卷调查收集了975份回复。使用Smart-PLS 4软件对数据进行分析, 以调查假设的关系。

研究结果表明, 360度虚拟现实(VR)视频显著提高了网络用户参与度, 网络用户参与与网络用户满意度显著相关。结果表明, 网络用户参与度和满意度对旅游目的地的访问意愿有影响。此外, 网络用户满意度也会影响电子口碑。最后, 在360度虚拟现实(VR)视频和网络用户参与度之间, 导航性和视觉界面设计质量显著适中。

这项研究只考察了游客在旅行前阶段使用360度虚拟现实(VR)视频的行为意图。相比之下, 未来的研究可能会调查游客在现场和旅行后阶段使用虚拟现实(VR)的行为。

旅游营销人员不仅应采用360度虚拟现实(VR), 还应将网络导航性和视觉界面设计相结合, 以提高网络用户对旅游网站的参与度。

本研究从游客的心理角度推进了虚拟现实(VR) 的研究。此外, 还从虚拟现实(VR)和科技旅游的角度重新审视了SOR 理论。它提供了对发展中国家游客行为方面的一般了解。

Utilizando el modelo teórico estímulo-organismo-respuesta (SOR), esta investigación empírica examinó y validó cómo las interacciones de los turistas con los vídeos de RV de 360 grados que incorporan la navegabilidad web y la calidad del diseño de la interfaz visual (estímulo) en los sitios web de viajes pueden hacer que los turistas se sientan más comprometidos y luego satisfechos (organismo), lo que podría hacerles más propensos a visitar los destinos y a difundir el e-WOM (respuesta).

Utilizando el método de muestreo por conveniencia, se recogieron 975 respuestas a través de un cuestionario. Los datos se analizaron mediante el software Smart-PLS 4 para investigar las relaciones hipotetizadas.

Los resultados demuestran que los vídeos de RV de 360 grados generan un compromiso significativo de los usuarios de la web y que el compromiso de los usuarios de la web se asocia significativamente con su satisfacción. El resultado muestra que el compromiso y la satisfacción del usuario web repercuten en la intención de visitar el destino turístico. Además, la satisfacción del usuario web influye en el e-WOM. Por último, la navegabilidad y la calidad del diseño de la interfaz visual son significativamente moderadas entre los vídeos de RV de 360 grados y el compromiso del usuario web.

Esta investigación sólo examinó las intenciones de comportamiento de los turistas con los vídeos de RV de 360 grados durante la fase previa al viaje. En cambio, en futuras investigaciones se podría estudiar cómo se comportan los turistas con la RV durante las fases in situ y posterior al viaje.

Los profesionales del marketing turístico no sólo deberían adoptar la RV de 360 grados, sino también integrar la navegabilidad web y el diseño de la interfaz visual para potenciar el compromiso de los internautas en los sitios web turísticos.

Este estudio avanza en el estudio de la RV desde la perspectiva psicológica del turista. Además, se ha reexaminado la teoría S-O-R desde las perspectivas de la RV y el turismo tecnológico. Proporciona una comprensión general del aspecto conductual de los turistas en los países en desarrollo.

The purpose of this study is to examine the impact of the (in)congruence between team leader self-evaluation and follower evaluation about the leader's transformation leadership (TL) on team performance, as well as the conditions under which the impact can be strengthened or weakened.

This study adopts a survey method to collect data from matched sales team leaders and sales team members in 81 teams. A multi-level polynomial regression analysis was conducted.

Team performance was higher in teams with balanced or high TL than with balanced or low TL. Among the teams with incongruence, no difference was found between leader underestimation and leader overestimation. TL congruence plays a moderating role in the relationship between team follower evaluation of TL and team performance, such that the relationship is stronger when team leader self-evaluation and follower evaluation are congruent than incongruent.

This study extends the authors' current understanding of TL literature by combining and contrasting the different perceptions of TL from both the leaders themselves and the followers towards leaders. The findings highlight the importance of congruence versus incongruence rather than just the high or low levels of follower TL evaluation. It provides a more complete understanding of the TL and team performance relationship than the traditional view that promotes a linear relationship between TL and performance.

Sodium alginate (Na-Alg) is a natural polysaccharide with a rich and renewable production that is widely used in the food, pharmaceutical and daily necessities industries, among other fields. The purpose of this study is to obtain a green and degradable shape memory material, calcium alginate (Ca-Alg) film was prepared and the mechanical properties, the shape memory effect of the film were investigated and confirmed.

The Ca-Alg films were prepared by Na-Alg, calcium chloride (CaCl₂) solution, and flow extension method. Dissolve sodium alginate powder, remove bubbles, pour into petri dish, dry at 60°C, add calcium chloride solution cross-linking and finally dry naturally. The effect of CaCl₂ solution concentration on the mechanical properties of the films were investigated and discussed by universal tensile tester. The shape memory behavior and degradation performance of thin films were verified and studied by the fold-deploy shape memory test and soil embedding method, respectively.

The Ca-Alg films exhibited good mechanical and shape memory properties, with a 72.2% shape memory fixity ratio and a 92.3% shape memory recovery ratio, respectively. For a period of 120 days, the film treated with a 6 wt% CaCl₂ solution degraded at a rate of approximately 53%.

Shape memory polymers (SMPs) as intelligent materials are an important research direction for the development of modern high-tech materials. On the other hand, plastic pollution is a major problem today; as a result, preparing green degradable SMPs is essential.

This study synthesized transparent and degradable shape memory Ca-Alg films using Na-Alg and CaCl₂ solution and the flow extension method.

This study’s aim is to introduce a high-performance sorbent for the removal of both anionic (Congo red; CR) and cationic (methylene blue; MB) dyes from aqueous solutions.

Sodium silicate is adopted as a substrate for GO and AgNPs with positive charge are used as modifiers. The synthesized nanocomposite is characterized by FTIR, FESEM, EDS, BET and XRD techniques. Then, some of the most effective parameters on the removal of CR and MB dyes such as solution pH, sorbent dose, adsorption equilibrium time, primary dye concentration and salt effect are optimized using the spectrophotometry technique.

The authors successfully achieved notable maximum adsorption capacities (Qmax) of CR and MB, which were 41.15 and 37.04 mg g⁻¹, respectively. The required equilibrium times for maximum efficiency of the developed sorbent were 10 and 15 min for CR and MB dyes, respectively. Adsorption equilibrium data present a good correlation with Langmuir isotherm, with a correlation coefficient of R2 = 0.9924 for CR and R2 = 0.9904 for MB, and kinetic studies prove that the dye adsorption process follows pseudo second-order models (CR R2 = 0.9986 and MB R2 = 0.9967).

The results showed that the proposed mechanism for the function of the developed sorbent in dye adsorption was based on physical and multilayer adsorption for both dyes onto the active sites of non-homogeneous sorbent.

The as-prepared nano-adsorbent has a high ability to remove both cationic and anionic dyes; moreover, to the high efficiency of the adsorbent, it has been tried to make its synthesis steps as simple as possible using inexpensive and available materials.

The purpose of this study is to evaluate the tannase-assisted extraction of tea stem pigment from waste tea stem, after which the stability of the purified pigment was determined and analyzed.

The extracting process was optimized using the response surface methodology (RSM) approach. Material-liquid ratio, temperature and time were chosen as variables and the absorbance as a response. The stability of the tea stem pigment at the different conditions was tested and analyzed.

The optimized extraction technology was as follows: material-liquid ratio 1:20 g/ml, temperature 50°C and time 60 min. The stability test results showed that tea stem pigment was sensitive to oxidants, but the reducing agents did not affect it. The tea stem pigment was unstable under strong acid and strong alkali and was most stable at pH 6. The light stability was poor. Tea stem pigment would form flocculent precipitation under the action of Fe²⁺ or Fe³⁺ and be relatively stable in Cu²⁺ and Na²⁺ solutions. The tea stem pigment was relatively stable at 60°C and below.

No comprehensive and systematic study reports have been conducted on the extraction of pigment from discarded tea stem, and researchers have not used statistical analysis to optimize the process of tannase-assisted tea stem pigment extraction using RSM. Additionally, there is a lack of special reports on the systematic study of the stability of pigment extracted from tea stem.

The aim of this study was to analyze the effects of carbon reduction efforts and preservation efforts on system benefits in the cold chain industry of fresh products.

This study develops an optimal decision game model for the fresh products in the cold chain, incorporating the retailer's preservation effort and the supplier's carbon emission reduction effort. It quantifies the relationship between carbon emission reduction effort, preservation effort and system profit. The model considers parameters like carbon trading price, consumer low-carbon preference and consumer freshness preference, reflecting real-world conditions and market trends. Numerical simulations are conducted by varying these parameters to observe their impact on system profit.

Under the carbon cap-and-trade policy, the profit of the fresh cold chain system is higher than that of the fresh cold chain system without carbon constraints, and the profit of the supplier under decentralized decision-making is increased by nine times in the simulation results. The increase in carbon trading prices can effectively improve the freshness level of fresh products cold chain, carbon emission reduction level and system profit.

This study comprehensively considers the factors of freshness and carbon emission reduction, provides the optimal low-carbon production decision-making reference for the fresh food cold chain and promotes the sustainable development of the fresh food cold chain.

The restoration and strengthening of QT600 is an industry bottleneck challenge. The Co-12 cladding layer has great wear and corrosion resistance. The purpose of this paper is to quantitatively reveal the transient evolution law of the corrosion process of Co-12 cladding layer on QT600 surface.

In this paper, a three-dimensional numerical model of the corrosion process of Co-12 cladding layer by QT600 laser cladding is established. The interaction between pitting pits and corrosion medium is considered to reveal the transient evolution of ion concentration, electrode potential, pH and corrosion rate at different locations.

The calculation shows that the ion concentration in pitting pit changes Cl⁻>Co²⁺>Na⁺, pH value decreases from top to bottom and corrosion rate at bottom is greater than that at top. The electrochemical corrosion test of Co-12 cladding layer was carried out. It is shown that the current density of QT600 increases by an order of magnitude compared to the Co-12 cladding layer, and the corrosion rate is 4.862 times higher than that of the cladding layer.

The results show that Co-12 cladding layer has great corrosion resistance, which provides an effective way for QT600 protection.