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Article
Publication date: 1 January 2006

Guangshen Xu, Wanhua Zhao, Yiping Tang and Bingheng Lu

To satisfy the demands for rapid prototyped small‐size objects with intricate microstructures, a high‐resolution stereolithography (SL) system is developed.

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Abstract

Purpose

To satisfy the demands for rapid prototyped small‐size objects with intricate microstructures, a high‐resolution stereolithography (SL) system is developed.

Design/methodology/approach

This novel SL system consists of a single mode He‐Cd laser, an improved optical scanning system, a novel recoating system and a control system. The improved optical system consists of a beam expander, an acoustic‐optic modulator, a galvanometric scanner and an Fθ lens; the recoating system consists of roller pump, resins vat with an integrated high‐resolution translation stage and part building platform and a scraper. Experimental studies were performed to investigate the influences of building parameters on the cured line width and depth.

Findings

With the SL system, a laser light spot with a diameter of 12.89 μm on the focal plane and resin layers with a thickness of 20 μm have been obtained. The experimental results indicate that cured depth and width increase with the ratio of laser power to scanning speed, and cured line with a width of 12 μm and a depth of 28 μm was built, which showed the capability building microstructures with this new SL system.

Research limitations/implications

The building area limited to 65 × 65 mm, is smaller than that of current SL system.

Practical implications

Small objects with intricate microstructures can be fabricated with the SL system.

Originality/value

The high‐resolution SL system provides a solution to the problem that has hampered the progress of SL process into a high resolution ranges below 75 μm.

Details

Rapid Prototyping Journal, vol. 12 no. 1
Type: Research Article
ISSN: 1355-2546

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Article
Publication date: 17 June 2006

Nancy Ursel, Xiaohua Lin and Jessica Li

Chinese companies have recently started listing ADRs in North American stock exchanges and thus offered an alternative venue for Western investors whose access to the Chinese…

379

Abstract

Chinese companies have recently started listing ADRs in North American stock exchanges and thus offered an alternative venue for Western investors whose access to the Chinese market has largely been limited to the illiquid B shares. Are ADRs a good substitute for investing in Chinese B Shares? We examine characteristics of return distributions for indices of Chinese shares and an index of Chinese ADRs. We also compare efficient frontiers for portfolios including Chinese shares and Chinese ADRs and compute possible portfolio allocations. We find that investing in Chinese ADRs does not provide a risk/return tradeoff similar to direct investment in Chinese stock exchanges.

Details

Multinational Business Review, vol. 14 no. 2
Type: Research Article
ISSN: 1525-383X

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Article
Publication date: 9 March 2021

Qin Qin, Jigang Huang, Jin Yao and Wenxiang Gao

Scanning projection-based stereolithography (SPSL) is a powerful technology for additive manufacturing with high resolution as well as large building area. However, the surface…

267

Abstract

Purpose

Scanning projection-based stereolithography (SPSL) is a powerful technology for additive manufacturing with high resolution as well as large building area. However, the surface quality of stitching boundary in an SPSL system has been rarely studied, and no positive settlement was proposed to address the poor stitching quality. This paper aims to propose an approach of multi-pass scanning and a compensation algorithm for multi-pass scanning process to address the issue of poor stitching quality in SPSL systems.

Design/methodology/approach

The process of multi-pass scanning is realized by scanning regions repeatedly, and the regions can be cured simultaneously because of the very short repeat exposure time and very fast scanning. Then, the poor stitching quality caused by the non-simultaneous curing can be eliminated. Also, a compensation algorithm is designed for multi-pass scanning to reduce the stitching errors. The validity of multi-pass scanning is verified by curing depth test, while the performance of multi-pass scanning as well as proposed compensation algorithm is demonstrated by comparing with that of a previous SPSL system.

Findings

The results lead to a conclusion that multi-pass scanning with its compensation algorithm is an effective approach to improve the stitching quality of an SPSL system.

Practical implications

This study can provide advice for researchers to achieve the satisfactory surface finish with SPSL technology.

Originality/value

The authors proposed a process of multi-pass scanning as well as a compensation algorithm for SPSL additive manufacturing (system to improve the stitching quality, which has rarely been studied in previous work.

Details

Rapid Prototyping Journal, vol. 27 no. 3
Type: Research Article
ISSN: 1355-2546

Keywords

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Article
Publication date: 11 May 2015

Congsheng Wu and Ke Chen

A number of Chinese firms have dual-listed in USA and China. The US listing takes the form of American Depositary Receipts (ADRs) whereas the China listing in the form of…

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Abstract

Purpose

A number of Chinese firms have dual-listed in USA and China. The US listing takes the form of American Depositary Receipts (ADRs) whereas the China listing in the form of A-shares. Though ADRs and their underlying A-shares lack full fungibility due to regulatory constraints, they nevertheless represent the same claiming rights and hence should be affected by the same fundamentals or news. The purpose of this paper is to examine the mutual return influences between ADRs and A-shares of dual-listed Chinese firms, and whether and how the recent global financial crisis has altered the mutual feedback dynamics.

Design/methodology/approach

The paper uses the bivariate VAR approach to model the returns of ADRs and A-shares. The model is jointly estimated with the three-stage least squares (3SLS) method. It also accounts for the non-synchronous trading problem caused by the fact that the Chinese and US markets are located in different time zones and that the two market observe different national and religious holidays.

Findings

The authors find significant mutual return transmissions between ADRs and their A-share counterparts. In the absence of local market sentiments, the return transmission is more prevalent going from USA to China than it is the other way around. After the market factors are included in the models, the information flows between A-shares and ADRs become stronger and bidirectional. Additionally, both ADR and A-share returns are strongly affected by the market sentiment of the marketplace where they are traded. Lastly, the authors find evidence showing that the recent global financial crisis has enhanced the linkage between ADRs and their underlying A-shares.

Originality/value

This paper adopts a more rigorous approach to overcome the potential issue caused by non-synchronous trading. It investigates how the global financial crisis has altered the ADR and A-share return feedback dynamics.

Details

Managerial Finance, vol. 41 no. 5
Type: Research Article
ISSN: 0307-4358

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