290 research outputs found
Not looking for trouble: Understanding large-scale Chinese overseas investment by sector and ownership
This paper contributes to the systematic understanding of Chinese investment abroad, and particularly the role of state-owned enterprise (SOE) investors, in two ways. Firstly, we identify major problems in the literature stemming from wide-spread data deficiencies in data. Specifically, the reliability of previous research results has been limited by data sets that do not identify the final destination for Chinese investment, nor suitably differentiate between different ownership types. By augmenting the project-level data from the China Global Investment Tracker with detailed ownership information for each firm, this study reveals that large-scale investment in natural resource investment, which surged after 2008, is dominated by state-owned enterprises controlled by China's central government. But it also reveals a newer wave of non-resource investment after 2009 in which non-state enterprise plays the leading role.
Further, we investigate the destination selection of large-scale Chinese investment to 192 countries from 2005 to 2015 – to test the extent to which SOEs might be attracted to poorer institutional host environments. We find that Chinese SOE investment in resources, regardless of ownership type is attracted to countries with political stability, but is negatively related to the rule of law measure. For non-resource investment, we find no strong institutional preferences. We therefore suggest that previous findings of different investment motivations between state- and non-state investors likely reflects the dominance of state-ownership in resource sectors, rather than different investment behaviour based on ownership
Phase Synchronization In Three-dimensional Lattices And Globally Coupled Populations Of Nonidentical Rossler Oscillators
A study on phase synchronization in large populations of nonlinear dynamical systems is presented in this thesis. Using the well-known Rossler system as a prototypical model, phase synchronization in one oscillator with periodic external forcing and in two-coupled nonidentical oscillators was explored at first. The study was further extended to consider three-dimensional lattices and globally coupled populations of nonidentical oscillators, in which the mathematical formulation that represents phase synchronization in the generalized N-coupled Rossler system was derived and several computer programs that perform numerical simulations were developed. The results show the effects of coupling dimension, coupling strength, population size, and system parameter on phase synchronization of the various Rossler systems, which may be applicable to studying phase synchronization in other nonlinear dynamical systems as well
Photoconductivity of Single-crystalline Selenium Nanotubes
Photoconductivity of single-crystalline selenium nanotubes (SCSNT) under a
range of illumination intensities of a 633nm laser is carried out with a novel
two terminal device arrangement at room temperature. It's found that SCSNT
forms Schottky barriers with the W and Au contacts, and the barrier height is a
function of the light intensities. In low illumination regime below 1.46x10E-4
muWmum-2, the Au-Se-W hybrid structure exhibits sharp switch on/off behavior,
and the turn-on voltages decrease with increasing illuminating intensities. In
the high illumination regime above 7x10E-4 muWmum-2, the device exhibits ohmic
conductance with a photoconductivity as high as 0.59Ohmcm-1, significantly
higher that reported values for carbon and GaN nanotubes. This finding suggests
that SCSNT is potentially a good photo-sensor material as well we a very
effective solar cell material.Comment: 12pages including 5 figures, submitted to Nanotechnolog
The nanoscale phase distinguishing of PCL-PB-PCL blended in epoxy resin by tapping mode atomic force microscopy
In this work, we investigated the bulk phase distinguishing of the poly(ε-caprolactone)-polybutadiene-poly(ε-caprolactone) (PCL-PB-PCL) triblock copolymer blended in epoxy resin by tapping mode atomic force microscopy (TM-AFM). We found that at a set-point amplitude ratio (rsp) less than or equal to 0.85, a clear phase contrast could be obtained using a probe with a force constant of 40 N/m. When rsp was decreased to 0.1 or less, the measured size of the PB-rich domain relatively shrank; however, the height images of the PB-rich domain would take reverse (translating from the original light to dark) at rsp = 0.85. Force-probe measurements were carried out on the phase-separated regions by TM-AFM. According to the phase shift angle vs. rsp curve, it could be concluded that the different force exerting on the epoxy matrix or on the PB-rich domain might result in the height and phase image reversion. Furthermore, the indentation depth vs. rsp plot showed that with large tapping force (lower rsp), the indentation depth for the PB-rich domain was nearly identical for the epoxy resin matrix
Gain-gain and gain-lossless PT-symmetry broken from PT-phase diagram
Parity-time (PT) symmetry and broken in micro/nano photonic structures have
been investigated extensively as they bring new opportunities to control the
flow of light based on non-Hermitian optics. Previous studies have focused on
the situations of PT-symmetry broken in loss-loss or gain-loss coupling
systems. Here, we theoretically predict the gain-gain and gain-lossless
PT-broken from phase diagram, where the boundaries between PT-symmetry and
PT-broken can be clearly defined in the full-parameter space including gain,
lossless and loss. For specific micro/nano photonic structures, such as coupled
waveguides, we give the transmission matrices of each phase space, which can be
used for beam splitting. Taking coupled waveguides as an example, we obtain
periodic energy exchange in PT-symmetry phase and exponential gain or loss in
PT-broken phase, which are consistent with the phase diagram. The scenario
giving a full view of PT-symmetry or broken, will not only deepen the
understanding of fundamental physics, but also will promote the breakthrough of
photonic applications like optical routers and beam splitters
Impact of spatial resolution on air quality simulation: A case study in a highly industrialized area in Shanghai, China
AbstractThe air pollution contribution from highly industrialized areas has been a prominent issue in regional air quality control. Particular emphasis on local industrial emissions is necessary to understand the complexity of air pollution over highly industrialized areas. Baoshan District, one of the most important industrialized areas in China and the most competitive steel and iron production base worldwide, was selected as the study area in this work. The WRF/CMAQ modeling system with local emission profile was applied to study the impact of spatial resolution on air quality modeling. The simulation results for SO2, NO, NO2, CO and PM10 at both 3–km and 1–km resolutions were verified by ground level observations. The results showed that the allocation of the emission inventory is improved by using finer resolution grids, which allow the consideration of detailed emission features. The influence of model resolution was more significant for air quality than for meteorology simulation. The relative errors using the finer resolution method ranged from –25% to 59%, an obvious improvement over the error value of 26%–245% obtained using the coarse resolution method. The changing tendencies of air pollutants in urban and rural areas were generally better modeled at finer than coarser resolution. However, the detailed variation in the most heavily polluted areas was still difficult to capture, and the model performance was not evidently improved by the use of a fine resolution. To improve the model performance over highly industrialized areas for future studies, combining the dynamic emission profile with detailed industrial activities and accurate local meteorological fields is suggested
Programmable long period grating in a liquid core optical fiber
A programmable fiber long-period grating (LPG) is experimentally demonstrated in a liquid core optical fiber with a low insertion loss. The LPG is dynamically formed by a temperature gradient in real time through a micro-heater array. The transmission spectrum of the LPG can be completely reconfigured by digitally changing the grating period, index contrast, length, and design. The phase shift inside the LPG can also be readily defined to enable advanced spectrum shaping. Owing to the high thermo-optic coefficient of the liquid core, it is possible to achieve high coupling efficiencies with driving powers as low as a few tens of milliwatts. The proposed thermo-programmable device provides a potential design solution for dynamic all-fiber optics components
VCKSM: Verifiable conjunctive keyword search over mobile e-health cloud in shared multi-owner settings
- …