Banking reforms, performance and risk in China

We investigate the impact of the banking reform started from 2005 on ownership structures in China on commercial banks’ profitability, efficiency and risk over the period 2000–2012, providing comprehensive evidence on the impact of banking reform in China. We find that banks on average tend to have higher profitability, lower risk and lower efficiency after the reforms, and the results are robust with our difference-in-difference approach. Our results also show that the Big 5 state-owned banks (SOCB) underperform banks with other types of ownership when risk is measured by non-performing loans (NPLs) over the entire study period but tend to have fewer NPLs than other banks during the post-reform period. Our results provide some supporting evidence on the ongoing banking reforms in China, suggesting that attracting strategic foreign investors and listing SOCBs on stock exchanges appear to be effective ways to help SOCBs deal with the problem of NPLs and manage their risk

Semiconductor Nanomaterial Development For Photovoltaic And Thermoelectric Applications

Today\u27s world is frequently going through fossil energy shortage and environmental consequences brought by the over-emission of greenhouse gas from burning fossil fuels. Therefore, it is urgent now more than ever to discover or develop clean and sustainable power generation approaches. Among various approaches, photovoltaics and thermoelectrics have been more and more attentive both in academia and industry. Photovoltaic power generators can significantly decrease carbon dioxide emission by directly converting sunlight into electricity, and thermoelectric power generators can increase energy use efficiency by recycling waste heat into electricity. This research seeks to gain a better understanding of the mechanism that influences the energy conversion process in photovoltaic and thermoelectric materials and meanwhile use nano-engineering approaches to improve the performance of thermoelectric materials. For photovoltaic nanomaterials, we have first made progress in simulations of electron-phonon coupling, which is a major mechanism for efficiency loss, in CdSe quantum dots. Time-domain non-adiabatic ab initio simulations have been performed to study the phonon-assisted hot electron relaxation dynamics in CdSe nanocrystals. It is found that the shape of the nanocrystals has a strong impact on the electron decay dynamics. The electron-phonon coupling is generally stronger in elongated nanocrystal than in the spherical nanocrystal. The relaxation of hot electrons proceeds faster in the elongated nanocrystal than in the spherical nanocrystal, and it also shows stronger temperature dependence in the elongated nanocrystal. The hot electron decay rates calculated from non-adiabatic molecular dynamics show weaker temperature dependence than the T-1 trend in both elongated and spherical nanocrystals, which can be attributed to the thermal expansion effect. We then performed experiments to synthesize and characterize semiconductor nanocrystals. Monodisperse CdSe, PbSe, and PbTe nanocrystals of various morphologies have been synthesized by using different combinations of surfactant and solvent in the refined phosphonic-acid-assisted organometallic method. XRD spectra have confirmed the formation of desired crystal phase and size. SEM and TEM images have confirmed the morphology and crystallinity. UV-visible absorption spectra show that the bandgap decreases with increasing crystal size. With collaborators, we have characterized the hot electron relaxation dynamics using transient absorption spectroscopy. The results show that the hot electron relaxation can result from both electron-phonon coupling and the Auger process Raman spectroscopy has also been used to investigate the size, shape and temperature dependence of phonon vibrational modes, for the interest of Raman thermometry using NCs. For spherical CdSe NCs of diameters 2.8 nm, 3.6 nm, and 4.4 nm, the temperature sensitivities are -0.0131, -0.0171, and -0.0242 cm^-1/K, respectively. This trend indicates that as the diameter increases, the effect of increasing phonon anharmonicity dominates over the effect of the decreasing thermal expansion coefficient. On the other hand, triangular NCs with a size of 4.2 nm and elongated NCs of a dimension of 4.6 nm by 14 nm show temperature sensitivities of -0.0182 and -0.0176 cm^-1/K, respectively. This trend indicates that in non-spherical shape NCs, the effect of decreasing thermal expansion coefficient dominates over the effect of slightly increasing phonon anharmonicity. For thermoelectric nanomaterials, both material synthesis and device fabrication have been conducted. For the material synthesis part, Bi2Te3-based nanocrystals have been made using both pyrolysis of organometallic method and ball milling method. Experimental parameters have been optimized to make impurity-free Bi2Te3 nanocrystals of various morphologies. Raman spectroscopy has been used to investigate the morphology dependence of phonon modes. The A1u mode is invisible in bulk Bi2Te3, but becomes visible in Bi2Te3 nanocrystals no matter whether they are synthesized by wet-chemistry method or ball milling method. Furthermore, for wet-chemistry synthesized Bi2Te3 nanocrystals, the 2D nanostructure shows similar Raman features as those of few-quintuple-thick Bi2Te3 layers, while the 0D and 1D nanostructures show a blue-shifted A1g2 mode and a much stronger A1u mode, which is the first report regarding the morphology impact on the Raman modes of Bi2Te3 nanocrystals. We have also used ball milling and hot pressing to obtain nanostructured bulk and improve the figure of merit of Bi2Te3 based alloys. Nanostructured bulk pellets are fabricated by densifying nanocrystal powders into bulk using hot pressing method. Due to the increased phonon scattering at the grain boundaries introduced in nanostructured bulk process, significantly reduced thermal conductivities have been obtained on nanostructured bulk Bi2Te3 pellet samples. It is also observed that thermal conductivity decreases with decreasing average grain size. Several post-fabrication treatments, like removing surface oxide layer by Ar plasma and improving crystallinity by thermal annealing, have been used to further improve the thermoelectric properties of the samples. Ion bombardment by Ar plasma is found to improve the contact between the metal electrodes and the material. Thermal annealing is found to not only increase the electrical conductivity but also the increase the Seebeck coefficient. The improved figure of merit at room temperature is around 1.23 on the p-type Bi0.5Sb1.5Te3 sample and 0.32 on the n-type Bi2Te2.7Se0.3 sample. The value from the p-type sample is close to the state-of-the-art value and still has room for improvement

Regulation and corporate corruption: new evidence from the telecom sector

This paper examines how government regulation in developing countries affects the form of corruption between business customers and service providers in the telecom sector. We match the World Bank enterprise-level data on bribes with a unique cross-country telecom regulation dataset collected by Wallsten et al. (2004), finding that 1) strong regulatory substance (the content of regulation) and regulatory governance reduce corruption; 2) competition and privatization reduces corruption; 3) the effects of regulatory substance on corruption control are stronger in countries with state-owned or partially state-owned telecoms, greater competition, and higher telecommunication fees; and 4) bureaucratic quality exert substitution effects to regulatory substance in deterring corruption. Overall, our results suggest that regulatory strategies that reduce information asymmetry and increase accountability tend to reduce illegal side-payments for connections.Telecommunications; Regulation; Corruption

Quality evaluation based on color grading - relationship between chemical susbtances and commercial grades by machine version in Corni fructus

Purpose: To evaluate the correlation between the commercial grade of Corni fructus determined by machine vision technology, and its chemical composition. Methods: Loganin, morroniside, ursolic acid, water-soluble extractives, alcohol-soluble extractives, polysaccharides and total organic acids were quantitated in four Corni fructus grades classified by machine vision technology. The content of each component was determined and analyzed bymathematical statistics. Results: Compared with low-grade samples, higher-grade counterparts contained elevated concentrations of alcohol-soluble extractives, water-soluble extractives, loganin and morroniside. In addition, principal component analysis revealed a correlation coefficient of -0.723 between Corni fructus grade and Holistic Scoring based on chemical composition, indicating a significant correlation (p < 0.01). Conclusion: These findings indicated the rationality of the classification method based on machine vision, and further confirmed the notion of  "quality evaluation based on color" of traditional Chinese medicine. Keywords: Corni fructus, Commercial grade, Machine vision technology, Chemical substanc

On the natural frequency and vibration mode of composite beam with non-uniform cross-section

In this paper, the vibratory properties and expression of natural modes of laminated composite beam with variable cross-section ratios of elastic modulus and density along the axis of the beam have been investigated via theoretical analysis. Based on the generalized Hamilton principle, the longitudinal and transverse vibration equations have been deduced by the means of variational method. Then, the natural frequencies of longitudinal and transverse vibration modes have been obtained using the method of power series, which agree well with finite element simulations. The first-order natural frequencies of longitudinal and transverse of composite beams are plotted as a function of the elastic modulus or densities difference of two components. With distinct material characteristics, the effect of shape factor on the first and second order lateral modes of composite beam is also revealed. In addition, the study shows that the boundary conditions impose a strong effect on the shape factor. The method presented in this paper is not only suitable for the laminated composite beam with variable cross-section, but will also be applicable to more general cases of composite beams of complex geometry and component in vibration mechanics. This controllable vibration performance achieved in this paper may shed some light on and stimulate new architectural design of composite engineering structures

MODELLING AND DYNAMIC ANALYSIS OF THREE-DIRECTION GRID PRESTRESSED RETICULATED MEGA-STRUCTURE

In this paper, the generation way of three-direction grid prestressed reticulated mega- structure is studied, and the three-direction grid prestressed reticulated mega-structure composite joint specific formation ideas are proposed. The important control parameters of three-direction grid prestressed reticulated mega-structure are determined, and the geometric modelling method of hexagon across the middle joint and octagon across the side joint is proposed. Coordinate formula of hexagonal and octagonal joints are derived to ensure reasonable grid arrangement and uniform stress distribution of the structure. Combined with the geometric parameters of the mega grid, a new method for creating the geometric model of three-direction grid prestressed mega reticulated structure is realized. The quadrangular pyramid space grid structure with the same length, span, rise and grid size and the three-direction grid prestressed grid structure are calculated, and the advantages of three-direction grid prestressed grid structure in dynamic performance are compared and analyzed

Universal service subsidies and cost overstatement: Evidence from the U.S. telecommunications sector

Abstract Utility subsidies are often defended as promoting universal service. However, specific support formulas may be poorly targeted and/or designed. The U.S. high cost loop support (HCLS) program (formerly referred to as the Universal Service Fund (USF)), has been a key component of the FCC's USF program. With proposed initiatives for universal access to broadband, it is useful to critically evaluate how the HCLS creates a moral hazard problem. This study finds that companies receiving HCLS subsidies have an incentive to report high costs to the FCC in order to qualify for still higher support payments. Using data from 1,136 rural telecom firms in 50 states (1992)(1993)(1994)(1995)(1996)(1997)(1998)(1999)(2000)(2001)(2002), this study shows that some companies respond to current incentives by overstating costs (or incurring higher costs) as they approach the subsidy cutoff points. Compared to the no-subsidy group, companies at the point of greatest subsidy jump appear to overstate costs more due to larger marginal benefits. Such perverse incentives need to be recognized in future universal service initiatives