XuDong Wang, Zhenbin Chen, Jiapeng Long, Chenglong Duan and Xueyan Du
The purpose of this paper is to separate and purify flavonoids from glycyrrhiza by macroporous adsorption resin (MAR) mixed-bed technology.
Abstract
Purpose
The purpose of this paper is to separate and purify flavonoids from glycyrrhiza by macroporous adsorption resin (MAR) mixed-bed technology.
Design/methodology/approach
The adsorption performance of MAR and MAR mixed bed for flavonoids was studied using ultraviolet-visible spectrophotometry.
Findings
The research shows that the MAR mixed bed of LZ-50+LZ-59 with a mass ratio of LZ-50:LZ-59(m:m) = 1:1 was the optimized combination with the optimal conditions of adsorption (pH = 6, T = 45°C) and desorption (liquid ratio R = 70%, T = 50°C, pH = 8) obtained, relatively.
Originality/value
This paper provides a novel way to separate flavonoids from glycyrrhiza. Under the optimal conditions, the adsorption rate (F) of MAR mixed-bed LZ-50+LZ-59 to the flavonoids was 62.5 per cent/g, the desorption rate (D) was 89.23 per cent and the purity was achieved at 80 per cent.
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Zhenbin Chen, Jiapeng Long, Lei Kang, Xueyan Du, Duolong Di and Jingbo Liu
The purpose of this paper is to prepare a higher chloromethylation degree (CD) modified macroporous adsorption resin (MAR, LX1180-Cl) and further study their adsorption…
Abstract
Purpose
The purpose of this paper is to prepare a higher chloromethylation degree (CD) modified macroporous adsorption resin (MAR, LX1180-Cl) and further study their adsorption performance.
Design/methodology/approach
CD and crosslinking degree were evaluated using stationary potential step and rotating-disk method, the adsorption performance of LX1180-Cl and LX1180 for flavonoids were studied using the UV-VIS spectrophotometry.
Findings
This research realized high CD (9.6 mass %) on high crosslinking MAR, LX1180. In tandem, the adsorption performance of them to flavonoids finds that the matching degree of polarity (presented with CD) and size were the critical factor to adsorption. It was also found that the reaction time had reduced to 24 h with the addition of iron particles into the zinc chloride (ZnCl2) catalyst.
Research limitations/implications
The study on reaction mechanism and the function principle of hybrid catalyst were speculated, but not the rigid experimental result.
Practical implications
This contribution can provide a rule for the separation and purification of natural products with the aim to improve food additive removal or isolation and purification of flavonoids used for healthcare applications.
Originality/value
This contribution provided a novel way to obtain high degree of CD with high crosslinking MAR, CD of commercially available MAR was improved by 2.5 times to 9.6 percent under crosslinking degree at 58.2 percent, compared with reported CD value (ca. 4.2 percent under crosslinking degree at 20.0 percent), which will be useful in the following further systematically research about the adsorption and separation selectivity of MAR. Besides, the primitive chosen principle of MAR according to the substrate was also presented. Moreover, the chloromethylation mechanism, although speculative, was briefly presented, which will stimulate the related study.
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Ting Huo, Zhenbin Chen, Jiapeng Long, Lei Kang, Duolong Di and Xueyan Du
This work focused on the sulphonation modification research of highly crosslinking non-polarity macroporous adsorption resin (MAR) LX1180; the adsorption behaviour of LX1180 and…
Abstract
Purpose
This work focused on the sulphonation modification research of highly crosslinking non-polarity macroporous adsorption resin (MAR) LX1180; the adsorption behaviour of LX1180 and its chloromethylation- and sulphonation-modified products (LX1180-Cl and LX1180-SO3−); and the influence of the structure parameters matching degree of MAR and flavonoids on the adsorption feature and adsorption kinetics.
Design/methodology/approach
LX1180-SO3− was obtained by the processes of chloromethylation first and then sulphonation. LX1180-Cl and LX1180-SO3− were prepared through the principle of substitution reaction from LX1180 and LX1180-Cl, respectively. First, Monochloromethyl ether (ME), pre-treated ZnCl2, NaCl and iron powder were added into the swollen LX1180 to obtain the chloromethylated LX1180. Thereafter, NaCl, NaOH and SAA were added into the swollen LX1180-Cl to obtain the sulphonation modification LX1180. The conditions were investigated and optimised; the structures of LX1180-Cl and LX1180-SO3− were characterised by Fourier transform infrared chromatography (FTIR) and a specific surface area instrument. Finally, the adsorption kinetics and adsorption isotherm were used to evaluate the adsorption capacity of LX1180-Cl and LX1180-SO3− for flavonoids, and the adsorptions and desorptions of LX1180-SO3− with different sulphonation degree on different flavonoids were investigated systemically.
Findings
Results showed that LX1180-Cl and LX1180-SO3− had been prepared successfully, and that after the sulphonation, the adsorption capacity tended to increase with the increase of adsorption time, and the equilibrium adsorption capacity of LX1180-SO3− was also higher than that of LX1180.
Research limitations/implications
The research only investigated the adsorption and desorption properties for only one kind of functional group, and other functional groups should also be studied in future work.
Practical implications
This contribution can provide a further base for the research of separation and purification of natural products with the aim to improve food additive removal or isolation and purification of flavonoids used for healthcare applications.
Originality/value
The adsorptions and desorptions of LX1180-SO3− with different sulphonation degree on different flavonoids were investigated. The relationship between sulphonation degree and the adsorption and desorption capacities of flavonoids were also explored, and the results showed that with the increase of sulphonation degree, the adsorption of LX1180-SO3− to rutin and cyanidin was maximum, while the desorption ratio was minimum at the same sulphonation degree; this phenomenon could be ascribed to the variation in the polarity matching degree.
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Jian Wang, Xinyi Zhang, Min Du, Xueyan Shan and Zhiyu Tian
The purpose of this study is to provide ideas and theoretical guidance for green, environmentally friendly and efficient “bacteriostasis with bacteria” technology.
Abstract
Purpose
The purpose of this study is to provide ideas and theoretical guidance for green, environmentally friendly and efficient “bacteriostasis with bacteria” technology.
Design/methodology/approach
In this paper, a beneficial strain of bacteria was extracted and purified from marine mud. Weight-loss test, morphological observation and electrochemical test were used to systematically study the effect of sulfate-reducing bacteria (SRB)-induced corrosion inhibition on X65 steel in simulated offshore oil field production water.
Findings
The results showed that a beneficial strain was selected and identified as Vibrio alginolyticus. Under the condition of co-culture of SRB, the average corrosion rate of X65 steel was significantly reduced. In the mixed bacterial system, the surface of X65 steel samples was relatively flat, and the structure of biofilm and corrosion product film was dense. The number of corrosion pits, the average diameter and depth of corrosion pits were significantly reduced. The localized corrosion of X65 steel was significantly inhibited.
Originality/value
The complex and changing marine environment makes the corrosion problem of marine steel increasingly severe, and the microbiologically influenced corrosion (MIC) caused by SRB is particularly serious. The research and development of environmentally friendly corrosion protection technology is a long-term and difficult problem. The use of beneficial microorganisms to control MIC is a green and efficient anticorrosion measure. Compared with terrestrial microorganisms, marine microorganisms can adapt to complex environments, and their metabolites exhibit special biological activities. The use of marine beneficial bacteria can inhibit SRB activity to achieve the corrosion inhibition effect.
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Xueyan Dong, Yuxin Tian, Mingming He and Tienan Wang
The purpose of this study was to investigate the impact of artificial intelligence (AI) adoption on knowledge workers' innovative work behaviors (IWB), as well as the mediating…
Abstract
Purpose
The purpose of this study was to investigate the impact of artificial intelligence (AI) adoption on knowledge workers' innovative work behaviors (IWB), as well as the mediating role of stress appraisal and the moderating role of individual learning abilities.
Design/methodology/approach
This study analyzed the questionnaire results of 313 knowledge workers, and data analysis was conducted by using SPSS 25.0, SPSS 25.0 macro-PROCESS and AMOS 28.0.
Findings
This study found that AI adoption has a double-edged sword effect on knowledge workers' IWB. Specifically, AI adoption can promote IWB by enhancing knowledge workers' challenging stress appraisal, while inhibiting IWB by fostering their hindering stress appraisal. Moreover, individual learning ability significantly moderated the relationship between AI adoption and stress appraisal, which further influenced IWB.
Originality/value
This study integrates the conflicting findings of previous studies and proposes a comprehensive theoretical model based on the theory of cognitive appraisal of stress. This study enriches the research on AI in the field of knowledge management, especially extending the understanding of the relationship between AI adoption and knowledge workers’ IWB by unraveling the psychological mechanisms and behavior outcomes of users' technology usage. Additionally, we provide new insights and suggestions for organizations to seek the cooperation and support of employees in introducing new technologies or driving intelligent transformation.
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Consumer adoption of shared products is a prerequisite for successful commercialization. The purpose of this paper is to explore what innovative characteristics of entity shared…
Abstract
Purpose
Consumer adoption of shared products is a prerequisite for successful commercialization. The purpose of this paper is to explore what innovative characteristics of entity shared products can accommodate consumers' concerns and are likely to motivate adoption of consumers.
Design/methodology/approach
This paper used a conceptual model that combined the innovation diffusion theory and technology acceptance model to explore shared products adoption. It identified the direct and indirect effects of perceived app ease of use/online, perceived convenience of access/offline, perceived utility advantages and personal innovativeness on shared products adoption intention. Structural equation modeling was used for analyzing the questionnaire data from a sample of 479 users who used entity shared products such as shared cars, shared bicycles and shared power banks for mobile phones.
Findings
The empirical tests indicate that perceived utility advantages based on market innovation, perceived accessibility of usage rights based on technology innovation (including perceived app ease of use/online and perceived convenience of access/offline) and consumer personal innovativeness are the key factors affecting consumer adoption.
Originality/value
This paper constructs an innovation-adoption coupling model of entity shared products to understand shared products usage. The findings provide useful practical guidance for the design and development of shared products and “usage rights economy” business applications.
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Xueyan Zhang, Xiaohu Zhou, Qiao Wang, Zhouyue Wu and Yue Sui
Based on social influence theory, this paper aims to explore the influence of academic entrepreneurs on team innovation activities. The innovation behavior of academic team…
Abstract
Purpose
Based on social influence theory, this paper aims to explore the influence of academic entrepreneurs on team innovation activities. The innovation behavior of academic team members is the key behavior in academic entrepreneurial activities. As a special entrepreneurial group, academic entrepreneurs' political skills play an important role in stimulating team innovative behaviors.
Design/methodology/approach
This paper adopts a multi-level study design and takes as samples the paired data of 91 academic entrepreneurial teams (n = 475). Based on team cognition, it constructs a model of the influence mechanism of academic entrepreneurs' political skills on team innovation behavior and explores the mechanism of transactive memory system in this influence effect. The authors use HLM and PROCESS macro to test our multilevel model.
Findings
The results show that academic entrepreneurs' political skills positively impact team innovation behavior, and a transactive memory system plays a mediating role between them. Team psychological safety significantly enhances the positive relationship of both academic entrepreneurs' political skills and a transactive memory system with team innovation behavior. Moreover, with enhanced perceptions of team psychological safety, academic entrepreneurs' political skills are more likely to improve team innovation behavior through the transactive memory system.
Originality/value
The study explores the influence of transactive memory system on the relationship between academic entrepreneurs' political skills and team innovation behavior, with the team cognitive perspective derived from social influence theory. This provides authors with new insights on the complex dynamics at place in the team innovation process and offers implications for how we can fruitfully manage this process.
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Ying Zhao, Wei Chen, Mehrdad Arashpour, Zhuzhang Yang, Chengxin Shao and Chao Li
Prefabricated construction is often hindered by scheduling delays. This paper aims to propose a schedule delay prediction model system, which can provide the key information for…
Abstract
Purpose
Prefabricated construction is often hindered by scheduling delays. This paper aims to propose a schedule delay prediction model system, which can provide the key information for controlling the delay effects of risk-related factors on scheduling in prefabricated construction.
Design/methodology/approach
This paper combines SD (System Dynamics) and BP (Back Propagation) neural network to predict risk related delays. The SD-based prediction model focuses on dynamically presenting the interrelated impacts of risk events and activities along with workflow. While BP neural network model is proposed to evaluate the delay effect for a single risk event disrupting a single job, which is the necessary input parameter of SD-based model.
Findings
The established model system is validated through a structural test, an extreme condition test, a sensitivity test, and an error test, and shows an excellent performance on aspect of reliability and accuracy. Furthermore, 5 scenarios of case application during 3 different projects located in separate cities prove the prediction model system can be applied in a wide range.
Originality/value
This paper contributes to academic research on combination of SD and BP neural network at the operational level prediction, and a practical prediction tool supporting managers to take decision-making in a timely manner against delays.
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– The purpose of this paper is to analyze the relationship between ownership concentration and company performance in China private listed companies.
Abstract
Purpose
The purpose of this paper is to analyze the relationship between ownership concentration and company performance in China private listed companies.
Design/methodology/approach
By taking into account of the difference of managerial positions of large shareholders in listed companies (whether they assume the posts as presidents or general managers), and based on the two agency theories, the paper analyzes the state dependency of the relationship between ownership concentration and the company performance of listed companies with the samples of China private listed companies from 2003 to 2011.
Findings
The paper finds that if the large shareholders assume no posts in the listed companies, there is an inverted U shape relation between shareholding ratio of the largest shareholders and the company performance. This result indicates the inadequate or excessive monitoring to the companies by the large shareholders according to different shareholding ratios. If large shareholders assume posts in the listed companies, there is a U shape relation between shareholding ratio of the largest shareholders and the company performance. This result indicates the tunneling and propping to the small shareholders by the large shareholders according to different shareholding ratios.
Research limitations/implications
This paper has not taken the influence of earnings management of the listed companies.
Practical implications
For strengthening the protection of investors, proper distinction shall be made among shareholders of different conditions, and difference of roles large shareholders play in the company under different conditions shall be understood correctly, so as to formulate and perfect market rules for corporate governance, rather than just restraining the power (rights) of large shareholders. The study in this paper is for helping understand the different roles large shareholders play under different corporate governance conditions.
Originality/value
First, different from the research paradigm of relationship between ownership concentration and company performance in existing literature, the paper discriminates the study background with the post-assuming conditions of large shareholders in listed companies and believes that relationship between ownership concentration and company performance shall be presented differently under different post-assuming conditions. Second, by using monitoring theory and tunneling and propping theory to explain the behaviors of large shareholders under different post-assuming conditions respectively, a new theory explanation view is provided for explaining the relation between ownership concentration and company performance.