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.

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.

Rapid industrialization and construction generate substantial concrete waste, leading to significant environmental issues. Nearly 10 billion metric tonnes of concrete waste are produced globally per year. In addition, concrete also accelerates the consumption of natural resources, leading to the depletion of these natural resources. Therefore, this study uses artificial intelligence (AI) to examine the utilization of recycled concrete aggregate (RCA) in concrete.

An extensive database of 583 data points are collected from the literature for predictive modeling. Four machine learning algorithms, namely artificial neural network (ANN), random forest (RF), ridge regression (RR) and least adjacent shrinkage and selection operator (LASSO) regression (LR), in predicting simultaneously concrete compressive and tensile strength were evaluated. The dataset contains 10 independent variables and two dependent variables. Statistical parameters, including coefficient of determination (R²), mean square error (MSE), mean absolute error (MAE) and root mean square error (RMSE), were employed to assess the accuracy of the algorithms. In addition, K-fold cross-validation was employed to validate the obtained results, and SHapley Additive exPlanations (SHAP) analysis was applied to identify the most sensitive parameters out of the 10 input parameters.

The results indicate that the RF prediction model performance is better and more satisfactory than other algorithms. Furthermore, the ANN algorithm ranks as the second most accurate algorithm. However, RR and LR exhibit poor findings with low accuracy. K-fold cross-validation was successfully applied to validate the obtained results and SHAP analysis indicates that cement content and recycled aggregate percentages are the effective input parameter. Therefore, special attention should be given to sensitive parameters to enhance the concrete performance.

This study uniquely applies AI to optimize the use of RCA in concrete production. By evaluating four machine learning algorithms, ANN, RF, RR and LR on a comprehensive dataset, this study identities the most effective predictive models for concrete compressive and tensile strength. The use of SHAP analysis to determine key input parameters and K-fold cross-validation for result validation adds to the study robustness. The findings highlight the superior performance of the RF model and provide actionable insights into enhancing concrete performance with RCA, contributing to sustainable construction practice.

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 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.

Despite the knowledge transfer in project contexts which has been extensively studied by scholars, the study on inter-organizational knowledge transfer in international construction projects is still scattered and unsystematic. This research aims to explore the key factors influencing inter-organizational knowledge transfer of international construction projects and analyze how these factors interact to create a synthetic framework that enhances the effectiveness of knowledge transfer (EKT).

At first, eight factors influencing inter-organizational knowledge transfer within international construction projects were identified, which were from the four dimensions of subject, relationship, channel and context, namely cultural distance, connection strength, organizational climate, intercultural competence, information technology capability, transmit willingness, receive willingness and richness of transfer channels. Then, a conceptual model was developed and 13 hypotheses were formulated, which were derived from a literature review and in-depth survey. After that, data from 353 respondents were collected and analyzed, and the hypotheses were tested by structural equation modeling analysis and bootstrapping test.

The results suggest that cultural distance hinders transfer willingness, which further affects EKT. Connection strength affects EKT by positively influencing transfer willingness and channel. Besides, organizational climate and intercultural competence positively influence transfer willingness and further affect EKT, while information technology capability affects the richness of transfer channels.

This research gives a thorough examination of the determinants influencing inter-organizational knowledge transfer of international construction projects, thus formulating available approaches that project managers and personnel can employ to effectively facilitate EKT.

The purpose of this study is to explore the impact of online reviews on answer adoption in virtual Q&A communities, with an eye toward extending knowledge exchange and community management.

Online reviews contain rich cognitive and emotional information about community members regarding the provided answers. As feedback information on answers, it is crucial to explore how online reviews affect answer adoption. Based on signaling theory, a research model reflecting the influence of online reviews on answer adoption is established and empirically examined by using secondary data with 69,597 Q&A data and user data collected from Zhihu. Meanwhile, the moderating effects of the informational and emotional consistency of reviews and answers are examined.

The negative binomial regression results show that both answer-related signals (informational support and emotional support) and answerers-related signals (answerers’ reputations and expertise) positively impact answer adoption. The informational consistency of reviews and answers negatively moderates the relationships among information support, emotional support and answer adoption but positively moderates the effect of answerers’ expertise on answer adoption. Furthermore, the emotional consistency of reviews and answers positively moderates the effect of information support and answerers’ reputations on answer adoption.

Although previous studies have investigated the impacts of answer content, answer source credibility and personal characteristics of knowledge seekers on answer adoption in virtual Q&A communities, few have examined the impact of online reviews on answer adoption. This study explores the impacts of informational and emotional feedback in online reviews on answer adoption from a signaling theory perspective. The results not only provide unique ideas for community managers to optimize community design and operation but also inspire community users to provide or utilize knowledge, thereby reducing knowledge search costs and improving knowledge exchange efficiency.

This paper investigates the dual interactive effects of manufacturer encroachment on the supply chain and retailer provision of retail services.

Consider a supply chain dominated by manufacturers, retailers, and e-commerce platforms, with the manufacturers selling the same product online and offline. Utilizing Stackelberg’s game theory, examples of wholesale and retail prices and profits of participants in the supply chain under different channels are analyzed. An effective encroachment strategy for manufacturers facing different retail service investment strategies of traditional retailers is given.

When traditional retailers do not invest in retail services, they will lose more profit due to competition with the manufacturer. At this time, the retailer does not want the manufacturer to encroach. The traditional retailer’s investment in retail services will enhance its and the manufacturer’s profits, incentivizing the manufacturer to pursue an aggressive expansion strategy.

(1) Considers a situation where the selling efficiency of the manufacturer is lower than that of the traditional retailer. (2) The interaction between traditional retailers’ retail service investment strategies and manufacturers’ encroachment strategies is investigated where the manufacturer is the dominant player. The three modes of online direct sales, resale, and third-party platform agency are compared to provide a basis for decision-making on different types of manufacturers’ encroachment. (3) Offline retail services not only directly increase sales in the offline market but also indirectly have a negative effect on the online market.