The graduation performance of technology business incubators in China's three tier cities: the role of incubator funding, technical support, and entrepreneurial mentoring

This study examines the effects of technology business incubator (TBI)’s funding, technical support and entrepreneurial mentoring on the graduation performance of new technology-based firms in China’s three tier cities. Using new dataset on all TBIs and incubated new technology-based firms from government surveys conducted over five consecutive years from 2009 to 2013 combined with archival and hand-collected data, we find the effects of incubator services on the early growth of new technology-based firms vary according to the local context. Technical support facilities and entrepreneurial mentoring from TBIs are found to have significantly and positively influenced the early development of the firms in the four most affluent tier 1 cities, whilst these effects become less pronounced for the tier 2 and tier 3 cities. These two services are also found to influence graduation performance in the government and university types of TBI respectively. Results support the notion that the effectiveness of an incubators services is shaped by the level of a city’s socio-economic development and that the city location of a TBI does impact the graduation performance of its incubatees

A theoretical investigation of the contribution of texture and dislocation sheets on strain path change effects in BCC metals

Softening/hardening effects are often observed in BCC polycrystals during changing strain paths. They can lead to premature failure of the material. Both the anisotropy due to microstructural features as well as due to the development of preferred crystallographic orientations are considered to be responsible for these effects. This paper addresses a methodology to incorporate cells and cell blocks at the grain scale in a full-constraints Taylor model. This allows the coupling of the full anisotropy due to basic slip processes, crystallographic texture and microstructure. It is demonstrated that the model is capable of simulating the complex softening/hardening effects during changing strain paths. It is shown that the cross effect and the Bauschinger effect are mainly caused by microstructural features and not by textural effects

The incorporation of dislocation sheets into a model for plastic deformation of b.c.c. polycrystals and its influence on r-values

Industrial forming processes usually involve complex strain paths, which are typically associated with softening/hardening effects. These can mainly be ascribed to the development of an 'intragranular microstructure' consisting of dislocation cells and cell blocks. This paper addresses a method to incorporate these microstructural details at the grain-scale in a full-constraints Taylor model. The dislocation cells and cell blocks have a significant influence on the anisotropic properties of the material, particularly the r-values. The trends arising from the simulations correspond well with experimental observations. (C) 2001 Elsevier Science B.V. All rights reserved.status: publishe

Work-hardening/softening behaviour of B.C.C. polycrystals during changing strain paths: I. An integrated model based on substructure and texture evolution, and its prediction of the stress-strain behaviour of an if steel during two-stage strain paths

For many years polycrystalline deformation models have been used as a physical approach to predict the anisotropic mechanical behaviour of materials during deformation, e.g. the r-values and yield loci. The crystallographic texture was then considered to be the main contributor to the overall anisotropy. However, recent studies have shown that the intragranular microstructural features influence strongly the anisotropic behaviour of b.c.c. polycrystals, as revealed by strain-path change tests (e.g. cross effect, Bausch-inger effect). This paper addresses a method of incorporating dislocation ensembles in the crystal plasticity constitutive framework, while accounting for their evolution during changing strain paths. Kinetic equations are formulated for the evolution of spatially inhomogeneous distributions of dislocations represented by three dislocation densities. This microstructural model is incorporated into a full-constraints Taylor model. The resulting model achieves for each crystallite a coupled calculation of slip activity and dislocation structure evolution, as a function of the crystallite orientation. Texture evolution and macroscopic flow stress are obtained as well. It is shown that this intragranular-microstructure based Taylor model is capable of predicting quantitatively the complex features displayed by stress-strain curves during various two-stage strain paths. (C) 2001 Acta Materialia Inc. Published by Elsevier Science Ltd. All rights reserved.status: publishe