Effects of Long-Range Interactions on Magnetic Excitations and Phase Transition on a Magnetically Frustrated Square Lattice

We investigate the effects of long-range interaction on the magnetic excitations and the competition between magnetic phases on a frustrated square lattice. Applying the spin wave theory and assisted with symmetry analysis, we obtain analytical expression for spin wave spectrum of competing Neel and (pi, 0) stripe states of systems containing any-order long-range interactions. In the specific case of long-range interactions with power-law decay, we found surprisingly that staggered long-range interaction suppresses quantum fluctuation and enlarges the ordered moment, especially in the Neel state, and thus extends its phase boundary to the stripe state. Our findings only illustrate the rich possibilities of the roles of long-range interactions, and advocate future investigations in other magnetic systems with different structures of interactions.Comment: 9 pages, 9 figure

Cross-cultural adaptation of Chinese international students in Europe

Chinese students have increasingly chosen European countries as destinations for oversea education. Cross-cultural adaptation is a great challenge for Chinese international students in their oversea education endeavors in Europe. The study aims to understand cross-cultural adaptation challenge of Chinese students studying in Europe, and analyzes the main factors affecting their cross-cultural adaptation. Specifically, this study investigated the cross-cultural adaptation of Chinese international students in Europe on three dimensions of daily life, academic and communication. This study was conducted by semi-structured interviews of 20 Chinese students with studying experience in Europe. The study found the following results. Most respondents in this study have a high degree of cross-cultural adaptation. The respondents have higher socio-cultural adaptation than psychological adaptation in daily life and academics, but lower social-cultural adaptation than psychological adaptation in communication. Among the influencing factors, the purpose and expectation of coming to Europe have a significant impact on the cross-cultural adaptation of international students; economic factors are an important variable affecting cross-cultural adaptation of international students.Os estudantes chineses escolhem cada vez mais os países europeus como destino para os seus estudos no estrangeiro. A adaptação intercultural é um grande desafio para os estudantes chineses internacionais que estudam na Europa. Esta pesquisa teve como objetivo compreender os desafios da adaptação intercultural de estudantes chineses na Europa e analisar os principais fatores que influenciam a adaptação intercultural. Especificamente, a pesquisa analisou a adaptação intercultural de estudantes chineses na Europa, nas dimensões da vida cotidiana, acadêmica e comunicacional. Foram realizadas entrevistas semiestruturadas com 20 estudantes chineses com experiência de estudo na Europa. O estudo encontrou os seguintes resultados. Neste estudo, a maioria dos entrevistados apresentou um alto grau de adaptação transcultural. A adaptação psicológica na vida cotidiana e na academia fica atrás dos efeitos da adaptação sociocultural, interação social e adaptação psicológica e sociocultural. O estudo encontrou os seguintes resultados. Neste estudo, a maioria dos entrevistados apresentou alto grau de adaptação transcultural. A adaptação sociocultural dos entrevistados foi superior à adaptação psicológica na vida cotidiana e acadêmica, enquanto a adaptação sociocultural foi inferior à adaptação psicológica na comunicação. Entre os fatores de influência, o propósito e as expectativas de vir para a china tiveram um impacto significativo na adaptação intercultural dos estudantes estrangeiros; Fatores econômicos são importantes variáveis que influenciam a adaptação transcultural de estudantes estrangeiros

Return and Volatility Spillovers across Equity Markets in Mainland China, Hong Kong and the United States

Abstract: Examinations of the dynamics of daily returns and volatility in stock markets of the U.S., Hong Kong and mainland China (Shanghai and Shenzhen) over 2 January 2001 to 8 February 2013 suggest: (1) evidence of unidirectional return spillovers from the U.S. to the other three markets; but no spillover between Hong Kong and either of the two mainland China markets; (2) evidence of unidirectional ARCH and GARCH effects from the U.S. to the other three markets; (3) correlations of returns vary across markets, with the highest correlation of 93.5% between the two Chinese markets, medium correlation of 30% between mainland China and Hong Kong markets and low correlations of 6.4% and 7.2% between the U.S. and China's two markets; thus, international investors may benefit by allocating their assets in China's markets; (4) the patterns of dynamic conditional correlations from the DCC model suggest an increase in correlation between China and other stock markets since the most recent financial crisis of 2007

van der Waals Bonded Co/h-BN Contacts to Ultrathin Black Phosphorus Devices

Due to the chemical inertness of 2D hexagonal-Boron Nitride (h-BN), few atomic-layer h-BN is often used to encapsulate air-sensitive 2D crystals such as Black Phosphorus (BP). However, the effects of h-BN on Schottky barrier height, doping and contact resistance are not well known. Here, we investigate these effects by fabricating h-BN encapsulated BP transistors with cobalt (Co) contacts. In sharp contrast to directly Co contacted p-type BP devices, we observe strong n-type conduction upon insertion of the h-BN at the Co/BP interface. First principles calculations show that this difference arises from the much larger interface dipole at the Co/h-BN interface compared to the Co/BP interface, which reduces the work function of the Co/h-BN contact. The Co/h-BN contacts exhibit low contact resistances (~ 4.5 k-ohm), and are Schottky barrier free. This allows us to probe high electron mobilities (4,200 cm2/Vs) and observe insulator-metal transitions even under two-terminal measurement geometry

Tell Me What You Want: Exploring the Impact of Offering Option Repertoires on Service Performance in Gig Economy

Confronted with an increasingly competitive business landscape for credence goods in the gig economy, sellers in e-marketplaces must effectively design their services by configuring the service offering specification options to enhance the visibility of their service offerings. Motivated by the gap between the configuration of service offering specification options and its impact on service quality and sales, this study builds on the competitive repertoire theory to advance a research model that seeks to unveil how the volume, complexity, and heterogeneity of service offering specification option repertoires affect service quality and sales. We empirically examined our hypotheses with a dataset comprising 3,307 lifestyle-themed credence goods observations from Fiverr, one of the largest e-marketplaces for gig economy in the world. We discover that the repertoire volume increases both service quality and sales whereas repertoire complexity only increases service quality. Repertoire heterogeneity does not significantly impact on service quality and sales

Property Impacts on Performance of CO2 Pipeline Transport

AbstractCarbon Capture and Storage (CCS) is one of the most potential technologies to mitigate climate change. Usingpipelinesto transport CO2 from emission sources to storage sitesis one of common and mature technologies. The design and operation of pipeline transport process requires careful considerations of thermo-physical properties.This paper studied the impact of properties, including density, viscosity, thermal conductivity and heat capacity, onthe performance of CO2 pipeline transport. The pressure loss and temperature dropin steady state were calculated by using homogenous friction model and Sukhof temperature drop theory, respectively. The results of sensitivity study show thatover-estimating density and viscosity increases the pressure loss while under-estimating of density and viscosity decreases it. Over-estimating density and heat capacity leads to lower temperature drop while under-estimating of density and heat capacity result in higher temperature drop.This study suggests that the accuracy of property models for example, more accurate density model, should be developed for the CO2 transport design