Search results
11 – 20 of over 11000Guangxing Ji, Zhizhu Lai, Dan Yan, Leying Wu and Zheng Wang
The purpose of this study is to assess the spatiotemporal patterns of future meteorological drought in the Yellow River Basin under different representative concentration pathway…
Abstract
Purpose
The purpose of this study is to assess the spatiotemporal patterns of future meteorological drought in the Yellow River Basin under different representative concentration pathway (RCP) scenarios.
Design/methodology/approach
Delta method is used to process the future climate data of the global climate models, then analyzed the spatiotemporal variation trend of drought in the Yellow River Basin based on standardized precipitation evaporation index (SPEI) under four RCP scenarios.
Findings
This research was funded by the National Natural Science Foundation of China (41901239), Soft Science Research Project of Henan Province (212400410077, 192400410085), the National Key Research and Development Program of China (2016YFA0602703), China Postdoctoral Science Foundation (2018M640670) and the special fund of top talents in Henan Agricultural University (30501031).
Originality/value
This study can provide support for future meteorological drought management and prevention in the Yellow River Basin and provide a theoretical basis for water resources management.
Details
Keywords
Shan Li, Li Juan Zheng, Cheng Yong Wang, Bing Miao Liao and Lianyu Fu
In an integrated circuit (IC) substrate, more fillers, including talcum powder and aluminium hydroxide, are added, which leads to much higher rigidity and hardness compared with a…
Abstract
Purpose
In an integrated circuit (IC) substrate, more fillers, including talcum powder and aluminium hydroxide, are added, which leads to much higher rigidity and hardness compared with a traditional printed circuit board. However, the micro drilling of IC substrates is harder. This paper aims to test the drilling process of IC substrates to improve the drilling process and the micro hole quality.
Design/methodology/approach
Substrate drilling by a micro drill with 0.11-mm diameter was used under several drilling conditions. The influence of drilling conditions on the drilling process was observed. Drilling forces, drill wear and micro hole quality were also studied.
Findings
The deformation circle around holes, hole location accuracy, bugle hole and burrs were the major defects of micro holes that were observed during the drilling of the substrate. Reducing the drilling force and drill wear was the effective way to improve hole quality.
Originality/value
The technology and manufacturing of IC substrates has been little investigated. Research data on drilling IC substrates is lacking. The micro hole quality directly affects the reliability of IC substrates. Thus, improving the drilling technology of IC substrates is very important.
Details
Keywords
Viju Subramoniapillai and Govindharajan Thilagavathi
In recent years, oil spill pollution has become one of the main problems of environmental pollution. Recovering oil by means of sorbent materials is a very promising approach and…
Abstract
Purpose
In recent years, oil spill pollution has become one of the main problems of environmental pollution. Recovering oil by means of sorbent materials is a very promising approach and has acquired more attention due to its high cleanup efficiency. Compared to synthetic fibrous sorbents, the use of natural fibers in oil spill cleanups offers several advantages including environmental friendliness, degradable features and cost-effectiveness. Therefore, studies on developing sorbents using natural fibers for oil spill cleanup applications have become a research hotspot.
Design/methodology/approach
This paper reviews the work conducted by several researchers in developing oil sorbents from fibers such as cattail, nettle, cotton, milkweed, kapok, populous seed fiber and Metaplexis japonica fiber. Some featured critical parameters influencing the oil sorption capacity of fibrous substrates are discussed. Oil sorption capacity and reusability performance of various fibers are also discussed. Recent developments in oil spill cleanups and test methods for oil sorbents are briefly covered.
Findings
The main parameters influencing the oil sorption capacity of sorbents are fiber morphological structure, fiber density (g/cc), wax (%), hollowness (%) and water contact angle. An extensive literature review showed that oil sorption capacity is highest for Metaplexis japonica fiber followed by populous seed fiber, kapok, milkweed, cotton, nettle and cattail fiber. After use, the sorbents can be buried under soil or they can also be burned so that they can be vanished from the surface without causing environmental-related issues.
Originality/value
This review paper aims to summarize research studies conducted related to various natural fibers for oil spill cleanups, fiber structural characteristics influencing oil sorption and recent developments in oil spill cleanups. This work will inspire future researchers with various knowledge backgrounds, particularly, from a sustainability perspective.
Details
Keywords
Hui Jin and Zheng Wang
To reveal the effective ways for leaders to motivate employees' innovative behaviour in complex environmental situations, the leadership rapport orientation is subdivided into two…
Abstract
Purpose
To reveal the effective ways for leaders to motivate employees' innovative behaviour in complex environmental situations, the leadership rapport orientation is subdivided into two types of values-based/instrumental rapport orientation. The mechanism of supervisor developmental feedback in mediating between leadership rapport orientation and employees' innovative behaviour and the moderating effect of ambidextrous environments is explored. This paper aims to discuss the aforementioned objective.
Design/methodology/approach
Leadership rapport orientation is divided into value-based and instrumental rapport orientation to reveal effective ways for leaders to motivate employees' innovative behaviour in complex environmental situations.
Findings
The results show that the values-based (instrumental) rapport orientation of leaders impacts employees' innovative behaviour positively (negatively).
Originality/value
Leaders' values-based/instrumental rapport orientation indirectly influences employees' innovative behaviour through supervisor developmental feedback, which positively moderates the relationship between the values-based or instrumental rapport orientation of leaders and employees' innovative behaviour and further moderates the partially mediating role of supervisor developmental feedback between leaders' values-based/instrumental rapport orientation and employees' innovative behaviour.
Details
Keywords
Juanping Xu, Jinxu Li, Zheng Wang, Hao Fu and Ming Wu
The purpose of this paper is to investigate the effect of the soft annealing time on the microstructure and hydrogen embrittlement (HE) of Fe-0.22C-11.54Mn-2.05Al steels.
Abstract
Purpose
The purpose of this paper is to investigate the effect of the soft annealing time on the microstructure and hydrogen embrittlement (HE) of Fe-0.22C-11.54Mn-2.05Al steels.
Design/methodology/approach
Steels A and B with different morphologies were prepared by cold rolling after warm rolling, long/short softening annealing and finally annealing at 700 °C for 30 min. Uncharged and charged samples were subjected to tensile, and HE behavior was studied by electron backscattered diffraction, scanning electron microscopy and X-ray diffraction.
Findings
The two samples exhibited similar tensile strengths. The homogeneous equiaxed microstructure of steel B was found to be more conducive to relieve its HE sensitivity. Steel A exhibited bimodal-grained microstructures – blocky and lath. The formation of crack in the blocky grains of steel A resulted in a significant reduction in its plasticity and tensile strength.
Originality/value
The high HE susceptibility of steel A is mainly connected with the inhomogeneity of martensite transformation.
Details
Keywords
Zheng-Xin Wang, Ji-Min Wu, Chao-Jun Zhou and Qin Li
Seasonal fluctuation interference often affects the relational analysis of economic time series. The main purpose of this paper is to propose a new grey relational model for…
Abstract
Purpose
Seasonal fluctuation interference often affects the relational analysis of economic time series. The main purpose of this paper is to propose a new grey relational model for relational analysis of seasonal time series and apply it to identify and eliminate the influence of seasonal fluctuation of retail sales of consumer goods in China.
Design/methodology/approach
First, the whole quarterly time series is divided into four groups by data grouping method. Each group only contains the time series data in the same quarter. Then, the new series of four-quarters are used to establish the grey correlation model and calculate its correlation coefficient. Finally, the correlation degree of factors in each group of data was calculated and sorted to determine its importance.
Findings
The data grouping method can effectively reflect the correlation between time series in different quarters and eliminate the influence of seasonal fluctuation.
Practical implications
In this paper, the main factors influencing the quarterly fluctuations of retail sales of consumer goods in China are explored by using the grouped grey correlation model. The results show that the main factors are different from quarter to quarter: in the first quarter, the main factors are money supply, tax and per capita disposable income of rural residents. In the second quarter are money supply, fiscal expenditure and tax. In the third quarter are money supply, fiscal expenditure and per capita disposable income of rural residents. In the fourth quarter are money supply, fiscal expenditure and tax.
Originality/value
This paper successfully realizes the application of grey relational model in quarterly time series and extends the applicable scope of grey relational model.
Details
Keywords
Danna Tang, Yushen Wang, Zheng Li, Yan Li and Liang Hao
The low-temperature sintering of silica glass combined with additive manufacturing (AM) technology has brought a revolutionary change in glass manufacturing. This study aims to…
Abstract
Purpose
The low-temperature sintering of silica glass combined with additive manufacturing (AM) technology has brought a revolutionary change in glass manufacturing. This study aims to carry out in an attempt to achieve precious manufacturing of silicate glassy matrix through the method of slurry extrusion.
Design/methodology/approach
A low-cost slurry extrusion modelling technology is used to extrude silicate glassy matrix inks, composed of silicate glass powder with different amounts of additives. Extrudability of the inks, their printability window and the featuring curves of silicate glassy matrix are investigated. In addition, the properties of the low-temperature sintering green part as a functional part are explored and evaluated from morphology, hardness and colour.
Findings
The results showed that the particle size was mainly distributed from 1.4 µm to 5.3 µm, showing better slurry stability and print continuity. The parameters were set to 8 mm/s, 80% and 0.4 mm, respectively, to achieve better forming of three-dimensional (3D) samples. Besides, the organic binder removal step was concentrated on 200°C–300°C and 590°C–650°C was the fusion bonding temperature of the powder. The hardness values of 10 test samples ranged from 588 HL to 613 HL, which met the requirements of hard stones with super-strong mechanical strength. In addition, the mutual penetration of elements caused by temperature changes may lead to a colourful appearance.
Originality/value
The custom continuous AM technology enables the fabrication of a glass matrix with 3D structural features. The precise positioning technology of the glass matrix is expected to be applied more widely in functional parts.
Details
Keywords
Junru Zhang, Yumeng Liu and Bo Yan
This study aims to research the large cross-section tunnel stability evaluation method corrected after considering the thickness-span ratio.
Abstract
Purpose
This study aims to research the large cross-section tunnel stability evaluation method corrected after considering the thickness-span ratio.
Design/methodology/approach
First, taking the Liuyuan Tunnel of Huanggang-Huangmei High-Speed Railway as an example and taking deflection of the third principal stress of the surrounding rock at a vault after tunnel excavation as the criterion, the critical buried depth of the large section tunnel was determined. Then, the strength reduction method was employed to calculate the tunnel safety factor under different rock classes and thickness-span ratios, and mathematical statistics was conducted to identify the relationships of the tunnel safety factor with the thickness-span ratio and the basic quality (BQ) index of the rock for different rock classes. Finally, the influences of thickness-span ratio, groundwater, initial stress of rock and structural attitude factors were considered to obtain the corrected BQ, based on which the stability of a large cross-section tunnel with a depth of more than 100 m during mechanized operation was analyzed. This evaluation method was then applied to Liuyuan Tunnel and Cimushan No. 2 Tunnel of Chongqing Urban Expressway for verification.
Findings
This study shows that under different rock classes, the tunnel safety factor is a strict power function of the thickness-span ratio, while a linear function of the BQ to some extent. It is more suitable to use the corrected BQ as a quantitative index to evaluate tunnel stability according to the actual conditions of the site.
Originality/value
The existing industry standards do not consider the influence of buried depth and span in the evaluation of tunnel stability. The stability evaluation method of large section tunnel considering the correction of overburden span ratio proposed in this paper achieves higher accuracy for the stability evaluation of surrounding rock in a full or large-section mechanized excavation of double line high-speed railway tunnels.
Details
Keywords
Qianling Jiang, Zheng Wang and Jie Sun
The rise of interactive fitness games in the post-epidemic era has resulted in the need to establish a quality evaluation index system. This study aims to develop such a system…
Abstract
Purpose
The rise of interactive fitness games in the post-epidemic era has resulted in the need to establish a quality evaluation index system. This study aims to develop such a system and provide a reference for enhancing the quality of interactive fitness games.
Design/methodology/approach
To achieve this, interviews and questionnaires were conducted to identify the factors that influence the quality of interactive fitness games. The Kano model and SII (Satisfaction Increment Index)-Dissatisfaction Decrement Index (DDI) two-dimensional quadrant analysis were then used to explore differences in quality judgment between males and females, as well as their priorities for improving interactive fitness games.
Findings
The study revealed that males and females have different quality judgments for “rich and diverse content,” “motivational value,” “sensitive motion recognition detection” and “portability.” However, both genders share similar views on the other quality factors. In addition, the study identified differences in the priority of improvement between men and women. “Very interesting,” “effective fitness achievement,” “motivating fitness maintenance,” “sensitive motion recognition detection,” “portability” and “educational value” were found to be of higher priority for men than women.
Originality/value
These findings provide a valuable theoretical reference for developers and designers of interactive fitness games seeking to enhance the user experience.
Details