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1 – 10 of 12
Article
Publication date: 3 August 2021

Denglin Fu, Yanan Wen, Jida Chen, Lansi Lu, Ting Yan, Chaohui Liao, Wei He, Shijin Chen and Lizhao Sheng

The purpose of this paper is to study an electrolytic etching method to prepare fine lines on printed circuit board (PCB). And the influence of organics on the side corrosion…

Abstract

Purpose

The purpose of this paper is to study an electrolytic etching method to prepare fine lines on printed circuit board (PCB). And the influence of organics on the side corrosion protection of PCB fine lines during electrolytic etching is studied in detail.

Design/methodology/approach

In this paper, the etching factor of PCB fine lines produced by new method and the traditional method was analyzed by the metallographic microscope. In addition, field emission scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) were used to study the inhibition of undercut of the four organometallic corrosion inhibitors with 2,5-dimercapto-1,3,4-thiadiazole, benzotriazole, l-phenylalanine and l-tryptophan in the electrolytic etching process.

Findings

The SEM results show that corrosion inhibitors can greatly inhibit undercut of PCB fine lines during electrolytic etching process. XPS results indicate that N and S atoms on corrosion inhibitors can form covalent bonds with copper during electrolytic etching process, which can be adsorbed on sidewall of PCB fine lines to form a dense protective film, thereby inhibiting undercut of PCB fine lines. Quantum chemical calculations show that four corrosion inhibitor molecules tend to be parallel to copper surface and adsorb on copper surface in an optimal form. COMSOL Multiphysics simulation revealed that there is a significant difference in the amount of corrosion inhibitor adsorbed on sidewall of the fine line and the etching area.

Originality/value

As a clean production technology, electrolytic etching method has a good development indicator for the production of high-quality fine lines in PCB industry in the future. And it is of great significance in saving resources and reducing environmental pollution.

Details

Circuit World, vol. 49 no. 1
Type: Research Article
ISSN: 0305-6120

Keywords

Article
Publication date: 7 November 2016

Yanan Wu, Hongfang Liu, Bijuan Zheng, Shuang Qin and Lei Chen

The purpose of this paper was to study some effective evaluation methods for the biocide performance on sulfate-reducing bacteria (SRB) biofilm.

Abstract

Purpose

The purpose of this paper was to study some effective evaluation methods for the biocide performance on sulfate-reducing bacteria (SRB) biofilm.

Design/methodology/approach

The most probable number method, electrochemical impedance spectroscopy (EIS) measurements, scanning electron microscopy (SEM), three-dimensional (3D) photos and epifluorescent microscopy were used in this study.

Findings

The results showed that the minimum inhibitory concentrations and minimum bactericidal concentrations of them to sessile SRB were greatly more than planktonic SRB. The EIS of the two biocides indicated that the biofilm exposed to higher concentrations of biocide were much more compact and flat, which perfectly coincided with the SEM, 3D photos and the epifluorescent microscopies.

Originality/value

In this paper, it, thus, appears that these methods evaluating biocide performance on the SRB biofilm were really effective by comparing the performance of bis-quaternary ammonium salt (BAQS) and tetrakis hydroxymethyl phosphonium sulfate.

Details

Anti-Corrosion Methods and Materials, vol. 63 no. 6
Type: Research Article
ISSN: 0003-5599

Keywords

Article
Publication date: 1 March 1988

Patricia A. Maguire and Muzaffer Uysal

With the end of the Cultural Revolution and the rise of Deng Xiaoping, China began a new era of economic and political reform. In 1978 the open door policy was initiated. In…

Abstract

With the end of the Cultural Revolution and the rise of Deng Xiaoping, China began a new era of economic and political reform. In 1978 the open door policy was initiated. In October of 1984, Deng Xiaoping set in motion an ambitious program of financial and industrial reform aimed at eventually restructuring China's economy into a vaguely defined market system. This “second revolution” has run into difficulties because the Chinese officials lacked experience controlling a supply and demand economy and because of the opposition from conservative factions within the Chinese bureaucracy.

Details

The Tourist Review, vol. 43 no. 3
Type: Research Article
ISSN: 0251-3102

Article
Publication date: 28 February 2023

Yanan Wang, Yan Zhang, Wenkun Zhang and Tao Zhang

The aim of this paper is to investigate the factors influencing citizens' willingness to participate in the development of smart cities.

Abstract

Purpose

The aim of this paper is to investigate the factors influencing citizens' willingness to participate in the development of smart cities.

Design/methodology/approach

Citizens drawn from 30 second-tier cities in China were chosen as the research object for this empirical research. Based on citizenship behavior theory, research hypotheses were tested and analyzed using structural equation modeling (SEM).

Findings

The results indicated that information publicity has a direct and positive effect on residents' participation behavior. Perceived benefits, personal responsibility and subjective norms are positively associated with residents' citizenship. Additionally, citizenship was found to affect residents' participation intention positively. Finally, the moderating effect of information credibility in this context was also verified.

Originality/value

As one of the first empirical studies on this topic, this paper offers important guidance for future research regarding residents' participation in the development of smart cities. On this basis, the implications of this research with respect to policies that aim to encourage residents to participate in the construction of smart cities are discussed.

Details

Open House International, vol. 49 no. 1
Type: Research Article
ISSN: 0168-2601

Keywords

Article
Publication date: 30 November 2021

Junchao Li, Yanan Yang, Ze Zhao and Ran Yan

The purpose of this study is to establish a finite element (FE) model with the random distribution of the Nylon12/hydroxyapatite (PA12/HA) composite material in selective laser…

Abstract

Purpose

The purpose of this study is to establish a finite element (FE) model with the random distribution of the Nylon12/hydroxyapatite (PA12/HA) composite material in selective laser sintering (SLS) process for considering the material anisotropy, which aims to obtain the law of temperature and stress changes in PA12/HA sintering.

Design/methodology/approach

By using python script in Abaqus, the FE model is established in which the two materials are randomly distributed and are assigned to their intrinsic temperature-dependent physical parameters. Molten pool sizes at various process parameters were evaluated in terms of numerical simulation and scanning electron microscope analysis, identifying a good agreement between them. Evaluation of temperature and stress distribution under the condition of different HA contents was also conducted.

Findings

It shows that the uneven distribution and quantity of HA powder play a vital role in stress concentration and temperature increase. Additionally, the influence of HA addition on the mechanical performance of SLS-fabricated parts shows that it is conducive to improve compressive strength when the HA ratio is less than 5% because an excess of HA powder tends to bring about a certain amount of microspores resulting in a decrease in part density.

Originality/value

The FE model of the PA12/HA composite material with parameterized random distribution in SLS can be applied in other similar additive manufacturing technologies. It provides a feasible guideline for the numerical analysis of properties of composite materials.

Details

Rapid Prototyping Journal, vol. 28 no. 5
Type: Research Article
ISSN: 1355-2546

Keywords

Open Access
Article
Publication date: 7 May 2019

Yanan Wang, Jianqiang Li, Sun Hongbo, Yuan Li, Faheem Akhtar and Azhar Imran

Simulation is a well-known technique for using computers to imitate or simulate the operations of various kinds of real-world facilities or processes. The facility or process of…

1633

Abstract

Purpose

Simulation is a well-known technique for using computers to imitate or simulate the operations of various kinds of real-world facilities or processes. The facility or process of interest is usually called a system, and to study it scientifically, we often have to make a set of assumptions about how it works. These assumptions, which usually take the form of mathematical or logical relationships, constitute a model that is used to gain some understanding of how the corresponding system behaves, and the quality of these understandings essentially depends on the credibility of given assumptions or models, known as VV&A (verification, validation and accreditation). The main purpose of this paper is to present an in-depth theoretical review and analysis for the application of VV&A in large-scale simulations.

Design/methodology/approach

After summarizing the VV&A of related research studies, the standards, frameworks, techniques, methods and tools have been discussed according to the characteristics of large-scale simulations (such as crowd network simulations).

Findings

The contributions of this paper will be useful for both academics and practitioners for formulating VV&A in large-scale simulations (such as crowd network simulations).

Originality/value

This paper will help researchers to provide support of a recommendation for formulating VV&A in large-scale simulations (such as crowd network simulations).

Details

International Journal of Crowd Science, vol. 3 no. 1
Type: Research Article
ISSN: 2398-7294

Keywords

Abstract

Details

Advances in Librarianship
Type: Book
ISBN: 978-0-12024-615-1

Article
Publication date: 17 August 2012

Xin Chen and Xian Chen

The purpose of this paper is to examine long‐term return of new China collectible stamps after their issuance and how stamp characteristics affect the return.

Abstract

Purpose

The purpose of this paper is to examine long‐term return of new China collectible stamps after their issuance and how stamp characteristics affect the return.

Design/methodology/approach

The authors construct a model to analyze the determinants of stamps' long‐term return and test their hypotheses empirically in a sample of 1,201 sets of Chinese collectible stamps issued between 1949 and 2008.

Findings

The paper finds Chinese stamps provide decent returns for collectors in terms of exceeding comparable one‐year savings rates. Among factors affecting annual excess returns of Chinese stamps, variables related to usage are the most important; quantity issued has significantly negative impact on returns of early stamps, but its coefficient has weak economic implications and it is not significant for BianNian stamps issued in more recent years. In general, variables related to topic have weak influence on stamp returns, but the topics about the most significant events of China in recent years have huge impact on stamp returns; in addition, variables related to design and printing can influence stamp returns to some extent.

Research limitations/implications

Overall, the results reveal that variables related to usage are the most important determinants of long‐term stamp return.

Practical implications

There have been fierce disputes among stamp collectors about how stamp features affect returns. Nevertheless, no systematic empirical studies exist about the issue. This paper sheds light on the disputes by providing the first piece of empirical evidence.

Originality/value

Moreover, existing studies of stamps treat them as one asset, but often ignore different characteristics within the group. This paper systematically investigates the influence of stamp characteristics to stamp return, and thus fills the caveat in the literature.

Details

China Finance Review International, vol. 2 no. 4
Type: Research Article
ISSN: 2044-1398

Keywords

Article
Publication date: 25 November 2020

Carl Déry

This paper aims to explore various tensions related to the diffusion and reception of the New Qing History (NQH) in China, and more specifically, it aims at underlying a recurrent…

Abstract

Purpose

This paper aims to explore various tensions related to the diffusion and reception of the New Qing History (NQH) in China, and more specifically, it aims at underlying a recurrent tension within the core of this debate, between a Global and a Nationalist historical narrative.

Design/methodology/approach

The author’s focus is to analyze various texts published in China between 2006 and 2018.

Findings

The author argues that the intensity of the current debate is partly related on the one hand, to the fact that NQH undermines various aspects of China’s Nationalist teleology and territorial claims and, on the other hand, to the basic difficulty of accepting the coexistence of various historical representations that are risking to weaken contemporary’s justifications of its rising schemes.

Originality/value

The text presents an original reading of some important issues raised by the NQH debate.

Details

Social Transformations in Chinese Societies, vol. 16 no. 2
Type: Research Article
ISSN: 1871-2673

Keywords

Article
Publication date: 30 August 2021

Donghui Liu, Lingjie Meng and Yudong Wang

Oil is crucial for industrial development. This paper investigates the impacts of oil price changes on China's industrial growth and examines whether the impacts are asymmetric…

Abstract

Purpose

Oil is crucial for industrial development. This paper investigates the impacts of oil price changes on China's industrial growth and examines whether the impacts are asymmetric. The estimations can help determine how oil price shocks are transmitted throughout the economy.

Design/methodology/approach

This paper adopts West Texas Intermediate (WTI) crude oil price and industrial sector output and uses monthly data. The recently developed nonlinear autoregressive distributed lag (NARDL) model is employed to illustrate the effects in both the short term and long term. Importantly, under NARDL framework, this paper examines whether the impacts are asymmetric by decomposing oil price shocks into their positive and negative partial sums.

Findings

The empirical results prove clear evidence of asymmetries in the short term, long term or both terms. Specifically, some sectors benefit from, rather than suffer from higher oil prices, even some energy-intensive sectors, i.e. C31 (Smelting and Pressing of Ferrous Metals) and C32 (Smelting and Pressing of Non-ferrous Metals). However, the effects on some other energy-intensive sectors appear insignificant. Additionally, the results prove significantly negative responses in some sectors in the long term, and most of these sectors are in the top half of the ranking by energy consumptions.

Originality/value

This paper studies the economic responses at a disaggregated level by employing industry-level data. NARDL method is used to decompose oil price changes into their increases and decreases and investigate the asymmetries in the impacts of oil price changes.

Details

Kybernetes, vol. 51 no. 12
Type: Research Article
ISSN: 0368-492X

Keywords

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