Yinchun Fang, Xinhua Liu, Hailong Liu and Qian Wang
Cotton is one of the most common nature textile fiber that is widely used in clothing, bedding and decorative fields due to its comfort. However, the cellulosic cotton fiber has…
Abstract
Purpose
Cotton is one of the most common nature textile fiber that is widely used in clothing, bedding and decorative fields due to its comfort. However, the cellulosic cotton fiber has its own drawbacks. Cotton fiber belongs to flammable material with the limiting oxygen index (LOI) value about 18% that restricts its applications. Cotton fiber is easy to crease during the repeat wearing and laundering process that will influence the wearability. Therefore, it is very important to improve the flame retardancy and anticrease performance of cotton fabric.
Design/methodology/approach
In this study, flame retardant and anticrease multifunctional modifications of cotton fabric were conducted by one-step pad–dry–cure process using eco-friendly phytic acid and 1, 2, 3, 4-butanetetracarboxylic acid.
Findings
The results of limited oxygen index (LOI) values and vertical burning test indicate that the flame retardancy of modified cotton fabric was greatly improved. The LOI value of modified cotton fabric reached 30.8% when the usage of phytic acid was 12%. The crease recovery angle was over 250° of the modified cotton fabric revealing good anticrease performance.
Originality/value
This research provides a novel feasible cost-effective one-step method for the multifunctional modified cellulosic fiber using eco-friendly chemical agents.
Details
Keywords
Changfeng Cui, Hailong Liu and Yi Zhang
Credit spread change is a key issue for investors to earn the excess return from corporate bonds. Generally, there are two kinds of different effects that support the changing of…
Abstract
Purpose
Credit spread change is a key issue for investors to earn the excess return from corporate bonds. Generally, there are two kinds of different effects that support the changing of credit spread: asset allocation effect and credit risk change effect. The existing literature based on US data supports credit spread change is driven by credit risk change; however, this issue based on Chinese market data has not been investigated clearly. This paper seeks to address this issue.
Design/methodology/approach
The authors adopt Markov regime switching model to investigate the changing mode of the credit spread in the Chinese bond market. They select three kinds of variables: the credit risk variables, the asset allocation variables and the liquidity condition variables. With ML estimators, the authors can find the changing mode and further they study the relationship between the regime switching and some observed variables, such as macro economy variables and turnover of stock market.
Findings
The authors find it is driven by asset allocation effect in most time and by credit risk change only in shorter period. Empirical results show that the switching of dominance from one effect to another isn't closely related with macro‐economy variables, but related with the turnover of stock market.
Practical implications
These results indicate that in China the credit risk of corporate bonds is relatively low and the corporate bonds are still auxiliary asset for investors.
Originality/value
In this paper, the authors have the following two contributions: first, they discuss the asset allocation effect in the Chinese bond market and introduce the stock market variables and bank credit variable to describe the asset allocation effect; second, based on Chinese bond market data, they find different findings from the existing literature about US and European bond markets, showing that the changing of credit spread is mostly related with asset allocation effect but not credit risk change.
Details
Keywords
Tong Wen, Wen Chen, Liang Zhang and Xiaoming Liu
Under the background of rapid urbanization, all kinds of urban water problems have gradually come into being: local flooding frequently happens, water environment is deteriorated…
Abstract
Under the background of rapid urbanization, all kinds of urban water problems have gradually come into being: local flooding frequently happens, water environment is deteriorated, water-supply is in tension, etc. Meanwhile, with rapid development of higher education in China, campus area and scale are gradually expanding, but traditional campus construction has many drawbacks. In order to promote sponge campus planning and construction of universities in hilly areas and provide demonstration windows for sponge city construction, based on deficiencies of campus construction of Hunan City University in the aspect of water resource utilization, we used ArcGis spatial analysis method, simulation method and comparative analysis method on Storm Water Management Model (SWMM) to establish sponge campus construction indexes, content system and optimal design strategies with objectives of campus water safety, water environment and water resource utilization. Results indicate that: difference between sponge campus planning and traditional campus planning mainly lies in rainfall management. We combed the design process of sponge campus planning in hilly areas from the perspective of rainfall management, and simulated the process of sponge facilities controlling the rainfall in the campus via computer model to verify reasonability of sponge facility planning and select the optimal planning and construction plan. This study has defined design process of sponge campus planning in hilly areas to a certain degree and provided a research basis for sponge campus planning and construction of universities, setting up a typical example and driving effects on solving urban local flooding problem and rainfall resource utilization in hilly areas.
Details
Keywords
Peng Liu, Rong Zhang, Ya Wang, Hailong Yang and Bin Liu
In recent years, private brands for e-commerce platforms have experienced rapid growth. However, whether these platforms developing private brands should share their demand…
Abstract
Purpose
In recent years, private brands for e-commerce platforms have experienced rapid growth. However, whether these platforms developing private brands should share their demand information with others and how such information sharing affects the sales format selection of national brand manufacturers have puzzled firm managers in practice. This paper aims to investigate the information-sharing strategy for the e-commerce platform and its influence on the sales format selection in the presence of the private brand.
Design/methodology/approach
The authors use a game-theoretical model to examine the interaction between the information-sharing strategy and sales format selection in a supply chain consisting of a manufacturer and a platform that operates a private brand.
Findings
The equilibrium results show that when the commission rate is low, the manufacturer favors agency selling, and the platform shares demand information with the manufacturer; when the commission rate is high, the manufacturer prefers reselling, and the platform does not share the information. This preference is affected by information forecasting accuracy; as the information forecasting accuracy increases, the manufacturer prefers to adopt agency selling, and the platform tends to share the information. Interestingly, under agency selling, sharing information with the manufacturer can increase the platform’s profit from selling the private brand and achieve a win-win situation for them. Furthermore, we show that the manufacturer can inspire the platform to share the information with himself by adopting agency selling, whereas the platform sharing the information improves the probability that the manufacturer adopts agency selling. Moreover, the manufacturer may have a first-mover advantage. In particular, the manufacturer moving first increases the likelihood that the manufacturer chooses agency selling and the platform shares the information.
Originality/value
This paper contributes to sales format literature by exploring the effect of information sharing strategy on sales format selection in the presence of the private brand and can help manufacturers and platforms to make suitable decisions regarding information sharing and sales format selection.
Details
Keywords
Hailong Ju, Yiting Fang and Yezhen Zhu
Prior literature has long argued that knowledge networks contain great opportunities for innovation, and researchers can identify these opportunities using the properties of…
Abstract
Purpose
Prior literature has long argued that knowledge networks contain great opportunities for innovation, and researchers can identify these opportunities using the properties of knowledge networks (PKNs). However, previous studies have examined only the relationship between structural PKNs (s-PKNs) and innovation, ignoring the effect of qualitative PKNs (q-PKNs), which refer to the quality of the relationship between two elements. This study aims to further investigate the effects of q-PKNs on innovation.
Design/methodology/approach
Using a panel data set of 2,255 patents from the Chinese wind energy industry, the authors construct knowledge networks to identify more PKNs and examine these hypotheses.
Findings
The results show that q-PKNs significantly influence recombinant innovation (RI), reflecting the importance of q-PKNs analysed in this study. Moreover, the results suggest that the combinational potential of an element with others may be huge at different levels of q-PKNs.
Originality/value
This study advances the understanding of PKNs and RI by exploring how q-PKNs impact RI. At different levels of PKNs, the potential of the elements to combine with others and form innovation are different. Researchers can more accurately identify the opportunities for RI using two kinds of PKNs. The findings also provide important implications on how government should provide support for R&D firms.
Details
Keywords
Yue Wang, Longqing Zou, Hailong Fu, Congcong Huang and Jiaqi Liu
Wear failure happens frequently in rubber seal of high-speed rotating shaft because of the dry friction. Some traditional lubrication methods are not effective because of the…
Abstract
Purpose
Wear failure happens frequently in rubber seal of high-speed rotating shaft because of the dry friction. Some traditional lubrication methods are not effective because of the restrictions on the relative high speed, temperature and others. This paper aims to present a new method of lubrication with gas film for the rotation shaft seal based on the contact design.
Design/methodology/approach
To obtain the generation condition of gas film and good effect of lubrication in the contact gap between the shaft and its seal, a series of micro-spiral grooves are designed on the contact surface of rubber seal so as to obtain a continuous dynamic pressure difference.
Findings
The result is that the distribution of the gas film in the micro-gap is continuous under the design of the spiral grooves and the contact with eccentricity because of the deformation of rubber seal, which is verified through the simulation calculation and experiment test. It is confirmed that the lubrication method with gas film through designing micro-spiral grooves on the contact surface is effective, and can achieve self-adaptive air lubrication for the high-speed shaft under the premise of the reliable sealing.
Originality/value
The method of gas film lubrication is realized through designing a microstructure of spiral grooves on the rubber surface to change the contact status, which can form a mechanism of adaptive lubrication to reduce the dry friction automatically in the contact gap. For the cross-scale difference between the rubber seal and gas film, a new modeling method is presented by building the mapping relation for the split blocks and repairing technique with integrated computer engineering and manufacturing, to reduce the possibility of nonconvergence and improve the efficiency and accuracy of calculation.
Details
Keywords
Hailong Zhao, Lirong Luo, Fangwei Guo, Xiaofeng Zhao and Ping Xiao
The purpose of this paper is to investigate the tribological performance of Cr3C2–NiCr–Mo–BaF2 composite sliding against a Si3N4 ball at high temperatures.
Abstract
Purpose
The purpose of this paper is to investigate the tribological performance of Cr3C2–NiCr–Mo–BaF2 composite sliding against a Si3N4 ball at high temperatures.
Design/methodology/approach
A Cr3C2–NiCr composite and a Cr3C2–NiCr–Mo–BaF2 composite were prepared using spark plasma sintering. Tribological properties of the composites were investigated using a ball-on-disk type tribotester. The relationships among the microstructure, wear mechanism and tribological performance were determined by analyzing the wear track morphologies and the glaze layer’s phase composition.
Findings
The wear rate of the Cr3C2–NiCr–Mo–BaF2 composite was approximately one order of magnitude lower than that of the Cr3C2–NiCr composite from 700°C to 900°C when sliding against a Si3N4 ball. The favorable tribological performance of the Cr3C2–NiCr–Mo–BaF2 composite at high temperatures results from the synergistic lubrication of MoOx, BaF2 and BaMoO4.
Originality/value
This paper reports a new Cr3C2–NiCr matrix self-lubricating composite with better tribological properties than Cr3C2–NiCr composite at temperatures up to 900°C through Mo and BaF2 addition.
Details
Keywords
Hailong Du, Zengyao Chen, Xiyan Wang, Yongliang Li, Renshu Yang, Zhiyong Liu, Aibing Jin and Xiaogang Li
The purpose of this paper is to develop new types of anchor bolt materials by adding corrosion-resistant elements for alloying and microstructure regulation.
Abstract
Purpose
The purpose of this paper is to develop new types of anchor bolt materials by adding corrosion-resistant elements for alloying and microstructure regulation.
Design/methodology/approach
Three new anchor bolt materials were designed around the 1Ni system. The stress corrosion cracking resistance of the new materials was characterized by microstructure observation, electrochemical testing and slow strain rate tensile testing.
Findings
The strength of the new anchor bolt materials has been improved, and the stress corrosion sensitivity has been reduced. The addition of Nb makes the material exhibit excellent stress corrosion resistance under –1,200 mV conditions, but the expected results were not achieved when Nb and Sb were coupled.
Originality/value
The new anchor bolt materials designed around 1Ni have excellent stress corrosion resistance, which is the development direction of future materials. Nb allows the material to retain its ability to extend in hydrogen-evolution environments.
Details
Keywords
Changpeng Chen, Zhongxu Xiao, Gang Xue, Hailong Liao and Haihong Zhu
High temperature gradient induces high residual stress, producing an important effect on the part manufacturing during laser powder bed fusion (LPBF). The purpose of this study is…
Abstract
Purpose
High temperature gradient induces high residual stress, producing an important effect on the part manufacturing during laser powder bed fusion (LPBF). The purpose of this study is to investigate the effect of the molten pool mode on the thermal stress of Ti-6Al-4V alloy during different deposition processes.
Design/methodology/approach
A coupled thermal-mechanical finite element model was built. The developed model was validated by comparing the numerical results with the experimental data in the maximum molten pool temperature, the molten pool dimension and the residual stress described in the previous work.
Findings
For the single-track process, the keyhole mode caused an increase in both the maximum stress and the high-stress area compared with the conduction mode. For the multitrack process, a lower tensile stress around the scanning track and a higher compressive stress below the scanning track were found in the keyhole mode. For the multilayer process, the stress along the scanning direction at the middle of the part changed from tensile stress to compressive stress with the increase in the deposition layer number. As the powder layer number increased, the stress along the scanning direction near the top surface of the part decreased while the stress along the deposition direction obviously increased, indicating that the stress along the deposition direction became the dominant stress. The keyhole mode can reduce the residual stress near the top of the part, and the conduction mode was more likely to produce a low residual stress near the bottom of the part.
Originality/value
The results provide a systematic understanding of thermal stress during the LPBF process.
Details
Keywords
Baopeng Zhang, Xuesong Han, Changpeng Chen, Wenqi Zhang, Hailong Liao and Baijin Chen
The purpose of this study is to investigate the effect of the strut size and tilt angle on the densification behavior, surface roughness and dimensional accuracy of the selective…
Abstract
Purpose
The purpose of this study is to investigate the effect of the strut size and tilt angle on the densification behavior, surface roughness and dimensional accuracy of the selective laser melting AlSi10Mg lattice structure was investigated in this study. In this study, the characteristics such as the density, up-skin and down-skin roughness and dimensional accuracy of selective laser melting forming technology manufacturing (SLMed) AlSi10Mg cellular lattice structure were carried. This work reveals the effect of the strut size and tilt angle on the geometric characteristics of SLMed AlSi10Mg and is benefit for controlling the forming performance of the SLMed cellular lattice structure.
Design/methodology/approach
Based on AlSi10Mg powder, the influence of the tilt angle changed from 10° to 45° with an increment of 5° were investigated, the influence of the strut size was varied from 0.4 mm to 1.2 mm with an increment of 0.2 mm were investigated. The characteristics such as the density, up-skin and down-skin roughness, dimensional accuracy and mechanical properties of SLM-ed AlSi10Mg cellular lattice structure was carried.
Findings
Greater than 99% relative density can be achieved for different strut size when optimal process parameters are used. In the optimized process interval, the struts with a tilt angle of 10° can still be formed well, which is higher than the design limit of the inclined angle given in the related literature. The tilt angle has a significant effect on the surface roughness of the strut. The microhardness reached to 157 ± 3 HV, and the maximum compressive strength was 58.86 MPa, with the optimal process parameters.
Originality/value
In this study, the characteristics such as the density, up-skin and down-skin roughness and dimensional accuracy of SLMed AlSi10Mg cellular lattice structure were carried. With the optimal geometric parameters, the authors tested microhardness and compressive strength of the cellular lattice structure. The results of this study provide theoretical and experimental basis for the realization of high-quality manufacturing and optimization design of aluminum alloy cellular lattice structure, which will meet more diversified industrial needs.