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The structural and aerodynamic performance of the air inlet volute
has an important influence on the performance of the gas turbine. On one hand,
it requires the airflow flowing through inlet volute as even as possible, in
order to reduce the pressure loss, to avoid a decrease in the effective output
power and an increase of the fuel consumption rate of the internal
combustion engine which indicate the inefficiency of the entire power unit; On
the other hand, it requires the size of the inlet volute to be as small as
possible in order to save mounting space and production costs. The thesis
builds the structure model and develops flow fields numerical simulation of
several different sizes of the inlet volutes. Further, the unreasonable
aerodynamic structure is improved according to the flow field characteristics
and thereby, a better aerodynamic performance of the inlet volute is
We developed a nicking endonuclease
dependent DNA amplification (NDA), using Nt.BstNBI
to catalyze single-stranded nick on double-stranded DNA, and Bst DNA polymerase
to make extension while sealing the nick and displacing the downstream strand. The
displaced single-stranded DNA thereby serves as template for primers hybridization
and extension, resulting in exponential synthesis of target DNA under isothermal
condition. Over 105 folds target DNA amplification can be achieved
in 30 minutes, generating DNA product suitable for both diagnosis and DNA cloning.
This NDA strategy does not require thermal cycling or prerequisite nucleotides
modification, making it suitable for application in the field and at the point-of-care.
The marine and coastal intake filtration device is mainly used to filter out the salt spray aerosol particles. So, the laboratory studies of the intake filtration device need to simulate the salt spray aerosols state of the ocean environment. But the distribution of ocean salt spray aerosol particle of diameter is very wide, so the simulation device of salt spray aersol should produce a variety of salt spray aerosol particles. The paper is to mainly study the influencing factors of salt spray aerosol device to produce different particles diameter. And the investigation and study mainly include two aspects: numerical simulation and experimental study.
How fast do firms expand in a foreign market after their initial entry? Is faster better? Under what conditions is it beneficial or detrimental for a firm to move fast in a foreign market? This paper attempted to answer these questions by investigating the relationship between a firm’s pace of post-entry foreign expansion and its market share performance in a foreign market. The study is an attempt at filling a gap in the existing international business literature. Numerous researches have studied various point-of-entry decisions such as why (motivations), how (entry modes), where (location choices), and when (entry timing) firms make foreign entries. Studies have also investigated the consequences of internationalization, i.e., the relationship between degree of internationalization and firm performance. However, little is known about what happens after initial entry into a foreign market and before firms reach a certain degree of international diversity. As a step towards understanding the internationalization process, this study explores one important characteristic of post-entry foreign expansion—pace of expansion and its performance implications. Opposing hypotheses are developed from the perspectives of industrial organizational economics, and that of organizational learning, the resource-based view of the firm, and internationalization theory. The post-entry experiences of 214 foreign firms in China’s automobile market were examined in our sample. Results from multivariate regression show that greater firm performance is associated with greater expansion frequency and expansion magnitude. Furthermore, we found the inverted U shape relationship between expansion frequency and firm performance. J-shaped relationship between expansion magnitude and firm performance was also identified. We conclude this paper with implications for theory, research and management practice.