2,616 research outputs found
Is checkout- free store a flash in the pan? Factors influencing Hong Kong people’s adoption intention of checkout-free stores
Last year, two checkout-free flash stores made their debut in Hong Kong. After the initial try, several companies followed up, and opened their own checkout-free stores or exhibitions, e.g., Sinopec’s easy joy, Watsons, and AlipayHK Futureland. The trial of these stores has aroused wide attentions and discussions on the possibility of new retailing format and experience in Hong Kong. From the consumers’ perspective, this study aims to understand whether the concept of checkout-free store is welcomed by the local people, and what are the factors influencing Hongkongers’ adoption intention toward checkout-free technologies and stores. To realize the above research objectives, we used theory of technology acceptance, UTAUT2, and their extension to build a theoretical model, and empirically tested it by focus groups. The qualitative study shows some initial results to address the research questions
Apparent horizon and gravitational thermodynamics of Universe in the Eddington-Born-Infeld theory
The thermodynamics of Universe in the Eddington-Born-Infeld (EBI) theory was
restudied by utilizing the holographic-style gravitational equations that
dominate the dynamics of the cosmical apparent horizon and the
evolution of Universe. We started in rewriting the EBI action of the Palatini
approach into the Bigravity-type action with an extra metric . With
the help of the holographic-style dynamical equations, we discussed the
property of the cosmical apparent horizon including timelike,
spacelike and null characters, which depends on the value of the parameter of
state in EBI Universe. The unified first law for the gravitational
thermodynamics and the total energy differential for the open system enveloped
by in EBI Universe were obtained. Finally, applying the
positive-heat-out sign convention, we derived the generalized second law of
gravitational thermodynamics in EBI universe.Comment: 23 pages, 0 figure
Void Generation Between Shell and Charge ofWarhead under the Projection Load
In the process of projecting, the coupled property of warhead shell and charge is an important issueof the launching safety study. To maintain charge in close contact with the shell is one of the requirementsfor quality. For solid-liquid mixed charge , its tensile strength is very small, the dynamic response characteristicbetween warhead shell and charge make it possible to form instantaneous void between the shell and charge.his paper studies the impact of factors of instantaneous void and its development law by numerical simulation.This work lays foundation for warhead charge quality control and projection safety.Defence Science Journal, 2008, 58(6), pp.715-720, DOI:http://dx.doi.org/10.14429/dsj.58.169
Properties of wire+ arc additively manufactured 2024 aluminum alloy with different solution treatment temperature
2024 aluminum alloy deposits were produced with wire + arc additive manufacturing procedure. Solution treatment + natural aging processes with different solution treatment temperature were conducted to improve the properties. The microstructure and mechanical properties were investigated. After heat treatment the distributing characteristic of the second phase changed to be dispersive from continuous in as-deposited condition. Solution treatment + natural aging process can significantly improve the properties of WAAM 2024 aluminum alloy. With higher solution treatment temperature, the micro hardness, tensile properties and elongation presented an increasing trend. After 503 °C solution treatment + natural aging process, the micro hardness, ultimate tensile strength, yield strength and elongation were 143HV, 497 MPa, 330 MPa and 16%, respectively, which can nearly meet the applying requirement
The Insect Fascicle Morphology Research and Bionic Needle Pierced Mechanical Mechanism Analysis
In this paper, mosquito and cicadas two kinds of insects fascicle were studied, and observed the fascicle surface morphology and distribution through scanning electron microscopy, discussed the height of the six parameters of sawtooth and analyzed quantitatively, compared the two types of fascicle in micro-structure size, and shape, the experiment results show that there are obviously different among the two mouth fascicle morphological structure. Triangular sawtooth are all clearly visible in the two kinds of insect fascicle, in which the mosquito has the small microstructure, and the cicada has the larger one; microstructure of mosquitoes tilt to the rear part of the fascicle, while the microstructure of cicada is symmetric on bottom corner. Based on non-smooth surface structure of fascicle obvious principles of drag reduction effect, the model of drag reduction bionic syringe is proposed, Designed a bionic drag painless needles, and simulated needle piercing power is also measured. Bionic needle surface microstructure can help reduce the needle to decrease the contact area, form rolling, friction, and thus reduce the resistance to needle piercing. Bionic needle has been proved that its puncture resistance is less than smooth one consequently has significant drag reduction effects. Keywords: Insects fascicle; surface morphology; bionic needles; drag reductio
Relationship and Contract Issues of IT Outsourcing – Descriptive Case Studies in China Regions
In spite of the continuous increase in IT outsourcing activities globally, a major percentage of outsourcing deals failed or suffered from serious problems. In China regions where IT outsourcing practice is still at its initial stage, the situation is even serious: there lacks systematic guidance in terms of how to negotiate decent contracts and how to develop sound relationships. In view of this, the current research develops a research framework based on the theories in Economics, Management and Marketing fields, and investigates the effects of both relationship and contract on IT outsourcing success. To support the research framework, evidence was collected from two descriptive case studies conducted in Hong Kong and Mainland China. The case analysis implies the dimensionalities of relationship and contract. What is more, IT outsourcing success is mainly evaluated from the technological benefits client company could gain. A significant contribution of this study to theory is to look into IT outsourcing phenomenon with a balanced view and through an integrated theoretical lens. For practitioners, this research removes executives’ doubts about simultaneously employing both relationship (soft side) and contract (hard side) as governance mechanisms in managing IT outsourcing deals
Dicke Superradiance in Solids
Recent advances in optical studies of condensed matter have led to the
emergence of phenomena that have conventionally been studied in the realm of
quantum optics. These studies have not only deepened our understanding of
light-matter interactions but also introduced aspects of many-body correlations
inherent in optical processes in condensed matter systems. This article is
concerned with superradiance (SR), a profound quantum optical process predicted
by Dicke in 1954. The basic concept of SR applies to a general -body system
where constituent oscillating dipoles couple together through interaction with
a common light field and accelerate the radiative decay of the system. In the
most fascinating manifestation of SR, known as superfluorescence (SF), an
incoherently prepared system of inverted atoms spontaneously develops
macroscopic coherence from vacuum fluctuations and produces a delayed pulse of
coherent light whose peak intensity . Such SF pulses have been
observed in atomic and molecular gases, and their intriguing quantum nature has
been unambiguously demonstrated. Here, we focus on the rapidly developing field
of research on SR in solids, where not only photon-mediated coupling but also
strong Coulomb interactions and ultrafast scattering exist. We describe SR and
SF in molecular centers in solids, molecular aggregates and crystals, quantum
dots, and quantum wells. In particular, we will summarize a series of studies
we have recently performed on quantum wells in strong magnetic fields. These
studies show that cooperative effects in solid-state systems are not merely
small corrections that require exotic conditions to be observed; rather, they
can dominate the nonequilibrium dynamics and light emission processes of the
entire system of interacting electrons.Comment: 23 pages, 26 figure
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