Essays on managerial foreign experience and corporate behaviours in China : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Finance at Massey University, Palmerston North, New Zealand

Managerial foreign experience is a type of resource which allows managers to think globally and act locally. This thesis contributes to the literature on how foreign experienced managers impact corporate behaviour in China, the world’s largest emerging market. The first essay examines how managers with foreign experience influence corporate risk-taking. I find that foreign experienced managers are positively associated with corporate risk-taking. This relationship only robustly exists among private firms rather than state-owned enterprises (SOEs). The excess risk-taking through foreign experienced managers is positively related to Tobin’s Q, indicating that foreign experienced managers increase firm value through value-enhancing projects, which benefits shareholders. The second essay concentrates on the relationship between managerial foreign experience and earnings quality. I find that foreign experienced managers improve corporate earnings quality, and this improvement is more pronounced in private firms. Moreover, I document that the improved earnings quality is an important mechanism for which foreign experienced managers increase stock returns and decrease agency costs. The third essay in the thesis investigates the relationship between foreign experienced managers and corporate labour investment. I find foreign experienced managers are more likely to recruit and retain high skilled employees, which in turn increases labour cost for firms in total. The positive relationship between managerial foreign experience and labour cost is significant in both SOEs and private firms. Foreign experienced managers may focus on employees’ well-being to complete political goals in SOEs while they are more likely to retain and attract high skilled employees to benefit shareholders’ value in private firms. I further document that the increased labour costs through managerial foreign experience can influence firm value positively. However, it also increases the labour stickiness cost. Overall, this thesis documents the benefits and costs of hiring foreign experienced managers in firms

Achieving low energy consuming bio-based piezoelectric nanogenerators via modulating the inner layer thickness for a highly sensitive pedometer

Considering their drawbacks of environmental pollution, biodegradable cellulose-based materials are becoming one of the most promising alternative candidates for conventional petroleum-based polymers, which are considered the fundamental materials for dynamical units in human-machine interaction systems. Using an up-to-date hydrogen bond replacement strategy, which means using the highly electronegative F− in polyvinylidene fluoride (PVDF) to replace the intramolecular hydrogen bonds in cellulose for weakening the self-assembly behavior, herein, multilayer-structured piezoelectric nanogenerators (PENGs) composed of cellulose, a small amount of PVDF, and Ba0.7Ca0.3Zr0.2Ti0.8O3 (BCZT) fillers were fabricated via modified tape-casting technology. Due to the hydrogen bond network, which was confirmed using multiple characterization methods, the fillers dispersed uniformly in the matrix. Through changing the inner layer thickness, the output performance of the PENGs can be subtly modulated, which is revealed to be caused by the synergistic effect between the trapped electrons and the inter-squeezing between adjacent particles by employing the band theory. When applied to a pedometer, one of the essential devices for monitoring human health, such a modulation can significantly improve its sensitivity. The water contact angle test also indicates their potential for use in humid environments. Compared with some typical cellulose-based PENGs, our device shows outstanding performance in PD/F, defined as the power density triggered by unit force, indicating our PENG's low energy consumption characteristic.</p

Revealing the effect of the Schottky barrier on the energy storage performance of ferroelectric multilayers

Different from most of the studies on dielectric energy storage thin films, which mainly talk about domain engineering or interface engineering, our work revealed the effect of the interaction between film and bottom electrode on the energy storage performance of ferroelectric multilayers by fabricating multilayers of BaTiO3 (BT) and SiO2-BaZr0.2Ti0.8O3 (S-BZT) with different layer sequences. With the same periodic number, the multilayers start with the S-BZT layer always have higher voltage endurance, and thus higher energy storage capacity(Wrec), than the multilayers start with BT. The highest Wrec was finally obtained to be 39.37 J/cm3 in BT/S-BZT//(2PN). Such a phenomenon was revealed to be related to the Schottky barrier, which was thought to be caused by the formation of the 2Ti3+-VO. dipoles, in the interface between the LSMO and the S-BZT. Such an assumption was finally proved by the combination of the I-E curves and the C-E curves, and the finite element simulation was also carried out to simulate the electric breakdown process. The result of the simulation fit very well with the experimental result. The reliability and power density of BT/S-BZT//(2PN) are also good. After all, our work opens up a new way to improve the energy storage capacity of dielectric thin films. In addition, the reliability and charge-discharge behavior of the BT/S-BZT//(2PN) is also in good performance.</p

A review in rational design of graphene toward advanced Li–S batteries

For lithium–sulfur (Li–S) batteries, the problems of polysulfides shuttle effect, slow dynamics of sulfur species and growth of lithium dendrite during charge/discharge processes have greatly impeded its practical development. Of core importance to advance the performances of Li–S batteries lies in the selection and design of novel materials with strong polysulfides adsorption ability and enhanced redox electrocatalytic behavior. Graphene, affording high electrical conductivity, superior carrier mobility, and large surface area, has presented great potentials in improving the performances of Li–S cells. However, the properties of intrinsic graphene are far enough to achieve the multiple management toward electrochemical catalysis of energy storage systems. In addition, a general and objective understanding of its role in Li–S systems is still lacking. Along this line, we summarize the design routes from three aspects, including defect engineering, dimension adjustment, and heterostructure modulation, to perfect the graphene properties. Thus-synthesized graphene materials are explored as multifunctional electrocatalysts targeting high-efficiency and long-lifespan Li–S batteries, based on which the regulating role of graphene is comprehensively analyzed. This project provides a perspective on the effective engineering management of graphene materials to boost Li–S chemistry, meanwhile promote the practical application process for graphene materials

Stabilizing Crystal Framework of an Overlithiated Li_1+xMn₂O₄ Cathode by Heterointerfacial Epitaxial Strain for High-Performance Microbatteries

To meet the increasing demands of high-energy and high-power-density lithium-ion microbatteries, overlithiated Li1+xMn2O4 (0 ≤ x ≤ 1) is an attractive cathode candidate due to the high theoretical capacity of 296 mAh g-1 and the interconnected lithium-ion diffusion pathways. However, overlithiation triggers the irreversible cubic-tetragonal phase transition due to Jahn-Teller distortion, causing rapid capacity degradation. In contrast to conventional lithium-ion batteries, microbatteries offer the opportunity to develop specific thin-film-based modification strategies. Here, heterointerfacial lattice strain is proposed to stabilize the spinel crystal framework of an overlithiated Li1+xMn2O4 (LMO) cathode by epitaxial thin film growth on an underlying SrRuO3 (SRO) electronic conductor layer. It is demonstrated that the lattice misfit at the LMO/SRO heterointerface results in an in-plane epitaxial constraint in the full LMO film. This suppresses the lattice expansion during overlithiation that typically occurs in the in-plane direction. It is proposed by density functional theory modeling that the epitaxial constraint can accommodate the internal lattice stress originating from the cubic-tetragonal transition during overlithiation. As a result, a doubling of the capacity is achieved by reversibly intercalating a second lithium ion in a LiMn2O4 epitaxial cathode with a complete reversible phase transition. An impressive cycling stability can be obtained with reversible capacity retentions of above 90.3 and 77.4% for the 4 and 3 V range, respectively. This provides an effective strategy toward a stable overlithiated Li1+xMn2O4 epitaxial cathode for high-performance microbatteries.</p

Solidification Enhancement in a Triple-Tube Latent Heat Energy Storage System Using Twisted Fins

Copyright: © 2021 by the authors. This work evaluates the influence of combining twisted fins in a triple-tube heat exchanger utilised for latent heat thermal energy storage (LHTES) in three-dimensional numerical simulation and comparing the outcome with the cases of the straight fins and no fins. The phase change material (PCM) is in the annulus between the inner and the outer tube, these tubes include a cold fluid that flows in the counter current path, to solidify the PCM and release the heat storage energy. The performance of the unit was assessed based on the liquid fraction and temperature profiles as well as solidification and the energy storage rate. This study aims to find suitable and efficient fins number and the optimum values of the Re and the inlet temperature of the heat transfer fluid. The outcomes stated the benefits of using twisted fins related to those cases of straight fins and the no-fins. The impact of multi-twisted fins was also considered to detect their influences on the solidification process. The outcomes reveal that the operation of four twisted fins decreased the solidification time by 12.7% and 22.9% compared with four straight fins and the no-fins cases, respectively. Four twisted fins improved the discharging rate by 12.4% and 22.8% compared with the cases of four straight fins and no-fins, respectively. Besides, by reducing the fins’ number from six to four and two, the solidification time reduces by 11.9% and 25.6%, respectively. The current work shows the impacts of innovative designs of fins in the LHTES to produce novel inventions for commercialisation, besides saving the power grid.Jiangsu Provincial Basic Research Program (Natural Science Fund); Natural Science Research Project of Jiangsu Province Colleges and Universities; Philosophy and Social Science Project of Jiangsu Province Colleges and Universitie

Achieving ultrahigh energy storage density in super relaxor BCZT-based lead-free capacitors through multiphase coexistence

Dielectric capacitors own great potential in next-generation energy storage devices for their fast charge-discharge time, while low energy storage capacity limits their commercialization. Enormous lead-free ferroelectric ceramic capacitor systems have been reported in recent decades, and energy storage density has increased rapidly. By comparing with some ceramic systems with fashioned materials or techniques, which lacks repeatability, as reported latterly, we proposed a unique but straightforward way to boost the energy storage capacity in a modified conventional ferroelectric system. Through stoichiometric ratio regulation, the coexistence of the C-phase and T-phase was obtained in 0.85(Ba1-xCax)(ZryTi1-y)O3-0.15BiSmO3-2 wt. % MnO ceramics with x = 0.1 and y = 0.15 under the proof of the combination of Rietveld XRD refinement and transmission electron microscope measurement. The Wrec of 3.90 J/cm3, an excellent value for BCZT-based ceramic at the present stage, was obtained because of the co-contribution of the optimization of electric field distribution and the additional interfacial polarization triggered at the higher electric fields. The finite element simulation and physical deduction, which fits very well with our experimental result, were also performed. As to the practical application, stable performance in a long-time cycle and frequency stability was obtained, and excellent discharge behaviors were also achieved.</p

Enhanced energy density with a wide thermal stability in epitaxial Pb0.92La0.08Zr0.52Ti0.48O3 thin films

High-quality epitaxial Pb0.92La0.08Zr0.52Ti0.48O3 (PLZT) films of thickness of 880 nm were fabricated using pulsed laser deposition on (001) Nb doped SrTiO3 (Nb:STO) substrates. Besides a confirmation of the epitaxial relationship [100]PLZT//[100]Nb:STO and (001)PLZT//(001)Nb:STO using X-ray diffraction, a transmission electron microscopy study has revealed a columnar structure across the film thickness. The recoverable energy density (Wrec) of the epitaxial PLZT thin film capacitors increases linearly with the applied electric field and the best value of 31 J/cm3 observed at 2.27 MV/cm is considerably higher by 41% than that of the polycrystalline PLZT film of a comparable thickness. In addition to the high Wrec value, an excellent thermal stability as illustrated in a negligible temperature dependence of the Wrec in the temperature range from room temperature to 180 C is achieved. The enhanced Wrec and the thermal stability are attributed to the reduced defects and grain boundaries in epitaxial PLZT thin films, making them promising for energy storage applications that require both high energy density, power density, and wide operation temperatures

Development of a 45K pepper GBTS liquid-phase gene chip and its application in genome-wide association studies

IntroductionPepper (Capsicum spp.) is a vegetable that is cultivated globally and has undergone extensive domestication, leading to a significant diversification in its agronomic traits. With the advancement of genomics in pepper and the reduction in sequencing costs, the high-throughput detection of single nucleotide polymorphisms (SNPs) and small insertions-deletions (indels) has become increasingly critical for analyzing pepper germplasms and improving breeding programs. As a result, there is a pressing need for a cost-effective, high-throughput, and versatile technique suitable for both foreground and background selection in pepper breeding.MethodsIn the present study, Python-based web scraping scripts were utilized to systematically extract data from published literatures and relevant sequence databases focusing on pepper genomes. Subsequent to data extraction, SNPs and indels were meticulously identified and filtered. This process culminated in the delineation of core polymorphic sites, which were instrumental in the development of specific probes. Following this, comprehensive phenotypic and genotypic analyses were conducted on a diverse collection of 420 pepper germplasms. Concurrently, a genome-wide association study (GWAS) was conducted to elucidate the genetic determinants of helical fruit shape in peppers.ResultsIn this study, a 45K pepper Genotyping-By-Target-Sequencing (GBTS) liquid-phase gene chip was developed on the GenoBaits platform. This chip is composed of 45,389 probes, of which 42,535 are derived from core polymorphic sites (CPS) in the background genetic landscape, while 2,854 are associated with foreground agronomic traits, spanning across 43 traits. The CPS probes are spaced at an average interval of 68 Kb. We have assessed the performance of this chip on 420 pepper germplasms, with successful capture of target DNA fragments by 45,387 probes. Furthermore, the probe capture ratio surpassed 70% in 410 of the 420 germplasms tested. Using this chip, we have efficiently genotyped 273 germplasms for spiciness levels and elucidated the genetic relationships among 410 pepper germplasms. Our results allowed for precise clustering of sister lines and C. chinense germplasms. In addition, through a GWAS for helical fruit shape, we identified three quantitative trait loci (QTLs): heli2.1, heli11.1, and heli11.2. Within the heli11.1 QTL, a gene encoding the tubulin alpha chain was identified, suggesting its potential role in the helical growth pattern of pepper fruits.DiscussionIn summary, the 45K pepper GBTS liquid-phase gene chip offers robust detection of polymorphic sites and is a promising tool for advancing research into pepper germplasm and the breeding of new pepper varieties