3,580 research outputs found
The Dual-channel Pricing Decision-making and Quality Information Disclosure under the Information Asymmetry
探讨了质量信息不对称下制造商与零售商联合披露、制造商披露以及零售商披露3种披露方式下的双渠道定价策略,得到不同披露方式下的质量信息披露条件。结果表明:3种披露方式下的质量信息披露阈值都与披露成本、交叉价格弹性、渠道的潜在需求量相关,且披露成本越大,质量披露的动机就越小。同时借助于数值分析发现,当产品质量较低或较高时,零售商披露方式最优;当产品质量中等时,制造商披露要相对优于零售商披露,但只有联合披露可以使双渠道供应链系统达到最优状态。Under the information a symmetry of product quality,this paper discusses three quality information disclosure strategies: joint disclosure between the manufacturer and retailer,manufacturer disclosure and retailer disclosure and the pricing strategy of the dual channel. And the conditions to disclose the product quality under different quality information disclosure strategies are analyzed. Our conclusions show that the quality disclosure threshold under three disclosure formats related to disclosure cost,potential demand and the cross price elasticity,and the higher disclosure cost,the less motivation to disclosure quality. Finally,by using the numerical analysis,the obtained results show that when the product quality is low or high,it is better to adopt retailer disclosure; when product quality is medium,manufacturer disclosure is relatively better than retailer disclosure,but joint disclosure can make dual channel supply chain system reach the optimal state.国家自然科学基金项目(71571151、71371159)
Transparent SiON/Ag/SiON multilayer passivation grown on a flexible polyethersulfone substrate using a continuous roll-to-roll sputtering system
We have investigated the characteristics of a silicon oxynitride/silver/silicon oxynitride [SiON/Ag/SiON] multilayer passivation grown using a specially designed roll-to-roll [R2R] sputtering system on a flexible polyethersulfone substrate. Optical, structural, and surface properties of the R2R grown SiON/Ag/SiON multilayer were investigated as a function of the SiON thickness at a constant Ag thickness of 12 nm. The flexible SiON/Ag/SiON multilayer has a high optical transmittance of 87.7% at optimized conditions due to the antireflection and surface plasmon effects in the oxide-metal-oxide structure. The water vapor transmission rate of the SiON/Ag/SiON multilayer is 0.031 g/m2 day at an optimized SiON thickness of 110 nm. This indicates that R2R grown SiON/Ag/SiON is a promising thin-film passivation for flexible organic light-emitting diodes and flexible organic photovoltaics due to its simple and low-temperature process
An Estimate of the Yield Displacement of Coupled Walls for Seismic Design
A formula to estimate the yield displacement observed in the pushover analysis of coupled wall lateral force-resisting systems is presented. The estimate is based on the results of an analytical study of coupled walls ranging from 8 to 20 stories in height, with varied amounts of reinforcement in the reinforced concrete coupling beams and walls, subjected to first-mode pushover analysis. An example illustrates the application of these estimates to the performance-based seismic design of coupled walls
Valley Polarization Enhancement Induced by a Single Chiral Nanoparticle
Valley polarization is amongst the most critical attributes of atomically
thin materials. However, achieving a high contrast from monolayer transition
metal dichalcogenides (TMDs) has so far been challenging. In this work, a giant
valley polarization contrast up to 45% from a monolayer WS2 has been achieved
at room temperature by using a single chiral plasmonic nanoparticle. The
increased contrast is attributed to the selective enhancement of both the
excitation and the emission rate having one particular handedness of the
circular polarization. The experimental results were corroborated by the
optical simulation using finite-difference time-domain (FDTD) method.
Additionally, the single chiral nanoparticle enabled the observation of
valley-polarized luminescence with a linear excitation. Our results provide a
promising pathway to enhance valley contrast from monolayer TMDs and utilize
them for nanophotonic devices
Ultrathin compound semiconductor on insulator layers for high performance nanoscale transistors
Over the past several years, the inherent scaling limitations of electron
devices have fueled the exploration of high carrier mobility semiconductors as
a Si replacement to further enhance the device performance. In particular,
compound semiconductors heterogeneously integrated on Si substrates have been
actively studied, combining the high mobility of III-V semiconductors and the
well-established, low cost processing of Si technology. This integration,
however, presents significant challenges. Conventionally, heteroepitaxial
growth of complex multilayers on Si has been explored. Besides complexity, high
defect densities and junction leakage currents present limitations in the
approach. Motivated by this challenge, here we utilize an epitaxial transfer
method for the integration of ultrathin layers of single-crystalline InAs on
Si/SiO2 substrates. As a parallel to silicon-on-insulator (SOI) technology14,we
use the abbreviation "XOI" to represent our compound semiconductor-on-insulator
platform. Through experiments and simulation, the electrical properties of InAs
XOI transistors are explored, elucidating the critical role of quantum
confinement in the transport properties of ultrathin XOI layers. Importantly, a
high quality InAs/dielectric interface is obtained by the use of a novel
thermally grown interfacial InAsOx layer (~1 nm thick). The fabricated FETs
exhibit an impressive peak transconductance of ~1.6 mS/{\mu}m at VDS=0.5V with
ON/OFF current ratio of greater than 10,000 and a subthreshold swing of 107-150
mV/decade for a channel length of ~0.5 {\mu}m
Impact of visceral fat on skeletal muscle mass and vice versa in a prospective cohort study: The Korean Sarcopenic Obesity Study (KSOS)
Objectives: Sarcopenia and visceral obesity have been suggested to aggravate each other, resulting in a vicious cycle. However, evidence based on prospective study is very limited. Our purpose was to investigate whether visceral fat promotes a decrease in skeletal muscle mass and vice versa. Methods: We observed changes in anthropometric and body composition data during a follow-up period of 27.6±2.8 months in 379 Korean men and women (mean age 51.9±14.6 years) from the Korean Sarcopenic Obesity Study (KSOS). Appendicular lean soft tissue (ALST) mass was calculated using dual-energy X-ray absorptiometry, and visceral fat area (VFA) was measured using computed tomography at baseline and follow-up examination. Results: ALST mass significantly decreased, whereas trunk and total fat mass increased in both men and women despite no significant change in weight and body mass index. In particular, women with visceral obesity at baseline had a greater decrease in ALST mass than those without visceral obesity (P=0.001). In multiple linear regression analysis, baseline VFA was an independent negative predictor of the changes in ALST after adjusting for confounding factors including age, gender, life style and body composition parameters, insulin resistance, high sensitivity C-reactive protein and vitamin D levels (P=0.001), whereas the association between baseline ALST mass and changes in VFA was not statistically significant (P=0.555). Conclusions: This longitudinal study showed that visceral obesity was associated with future loss of skeletal muscle mass in Korean adults. These results may provide novel insight into sarcopenic obesity in an aging society
Organically modified clay with potassium copper hexacyanoferrate for enhanced Cs + adsorption capacity and selective recovery by flotation
The selective capture of mobile radioactive nuclides, such as 137Cs+, is crucial to the clean-up and remediation of contaminated environments. While remediation remains a challenging task, the current study considers novel organo-clay composites containing potassium copper hexacyanoferrate (KCuHCF) as a viable option for large-scale clean-up. A three-step synthesis has been demonstrated whereby pristine montmorillonite clay was readily modified to incorporate KCuHCF nanoparticles for enhanced and selective Cs+ removal from aqueous environments. Alkyldiamine (DT) was used as an organic modifier to intercalate the clay and provided chelating sites to anchor copper onto the clay matrix, from which KCuHCF nanoparticles were subsequently grown in situ via the coordination of hexacyanoferrate precursors with the immobilized copper ions. The organo-clay–HCF composite particles exhibited a superior Cs+ adsorption capacity (qm = 206 mg g−1), twice that of the pristine clay. The enhanced performance also extended to high Cs+ selectivity in seawater, with the organo-clay–HCF composites demonstrating Cs+ selectivity values in excess of 105 mL g−1, two orders of magnitude greater than the pristine clay. Organo modification of the clay particles reduced the particle wettability, thus facilitating the separation of Cs-loaded composite particles from aqueous environments by collector-less flotation. Batch flotation experiments showed recovery efficiencies of the Cs-loaded composite particles of up to 90%, which was in great contrast to the low recovery of less than 15% for the Cs-loaded pristine montmorillonite. The current study provides a new concept for the treatment of contaminated aqueous environments
MDCK Cystogenesis Driven by Cell Stabilization within Computational Analogues
The study of epithelial morphogenesis is fundamental to increasing our
understanding of organ function and disease. Great progress has been made
through study of culture systems such as Madin-Darby canine kidney (MDCK) cells,
but many aspects of even simple morphogenesis remain unclear. For example, are
specific cell actions tightly coupled to the characteristics of the cell's
environment or are they more often cell state dependent? How does the single
lumen, single cell layer cyst consistently emerge from a variety of cell
actions? To improve insight, we instantiated in silico analogues that used
hypothesized cell behavior mechanisms to mimic MDCK cystogenesis. We tested them
through in vitro experimentation and quantitative validation. We observed novel
growth patterns, including a cell behavior shift that began around day five of
growth. We created agent-oriented analogues that used the cellular Potts model
along with an Iterative Refinement protocol. Following several refinements, we
achieved a degree of validation for two separate mechanisms. Both survived
falsification and achieved prespecified measures of similarity to cell culture
properties. In silico components and mechanisms mapped to in vitro counterparts.
In silico, the axis of cell division significantly affects lumen number without
changing cell number or cyst size. Reducing the amount of in silico luminal cell
death had limited effect on cystogenesis. Simulations provide an observable
theory for cystogenesis based on hypothesized, cell-level operating
principles
An observational study of patient characteristics associated with the mode of admission to acute stroke services in North East, England
Objective
Effective provision of urgent stroke care relies upon admission to hospital by emergency ambulance and may involve pre-hospital redirection. The proportion and characteristics of patients who do not arrive by emergency ambulance and their impact on service efficiency is unclear. To assist in the planning of regional stroke services we examined the volume, characteristics and prognosis of patients according to the mode of presentation to local services.
Study design and setting
A prospective regional database of consecutive acute stroke admissions was conducted in North East, England between 01/09/10-30/09/11. Case ascertainment and transport mode were checked against hospital coding and ambulance dispatch databases.
Results
Twelve acute stroke units contributed data for a mean of 10.7 months. 2792/3131 (89%) patients received a diagnosis of stroke within 24 hours of admission: 2002 arrivals by emergency ambulance; 538 by private transport or non-emergency ambulance; 252 unknown mode. Emergency ambulance patients were older (76 vs 69 years), more likely to be from institutional care (10% vs 1%) and experiencing total anterior circulation symptoms (27% vs 6%). Thrombolysis treatment was commoner following emergency admission (11% vs 4%). However patients attending without emergency ambulance had lower inpatient mortality (2% vs 18%), a lower rate of institutionalisation (1% vs 6%) and less need for daily carers (7% vs 16%). 149/155 (96%) of highly dependent patients were admitted by emergency ambulance, but none received thrombolysis.
Conclusion
Presentations of new stroke without emergency ambulance involvement were not unusual but were associated with a better outcome due to younger age, milder neurological impairment and lower levels of pre-stroke dependency. Most patients with a high level of pre-stroke dependency arrived by emergency ambulance but did not receive thrombolysis. It is important to be aware of easily identifiable demographic groups that differ in their potential to gain from different service configurations
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