Glass transitions in two-dimensional suspensions of colloidal ellipsoids

We observed a two-step glass transition in monolayers of colloidal ellipsoids by video microscopy. The glass transition in the rotational degree of freedom was at a lower density than that in the translational degree of freedom. Between the two transitions, ellipsoids formed an orientational glass. Approaching the respective glass transitions, the rotational and translational fastest-moving particles in the supercooled liquid moved cooperatively and formed clusters with power-law size distributions. The mean cluster sizes diverge in power law as approaching the glass transitions. The clusters of translational and rotational fastest-moving ellipsoids formed mainly within pseudo-nematic domains, and around the domain boundaries, respectively

The Development of the Risky Financial Behavior Scale: A Measure of Financial Risk Tolerance

There is an increasing need for a more comprehensive instrument to measure risk tolerance in human financial decision making studies. The traditional economic method and the more recent psychometric method of examining risk tolerance were both reviewed in the study. The purpose of this thesis was the initial development and validation of the Risky Financial Behavior Scale (RFBS), with items taken from four different domains noted in previous studies. Phase I and II consisted of item pool generation, construct determination from content experts\u27 review and cognitive interviews. Data from these stages were collected and used for item revision prior to final data collection. Phase III consisted of quantitative evaluation of the field administration data using factor analysis, item analysis, Rasch analysis, and final revision based on item meanings and factor loadings. Phase IV tested convergent validity and relationships with demographic variables. A final version of the 20-item survey showed low but acceptable internal consistency reliability for each of the subscales, and moderate convergent validity was found between RFBS scale and a commonly used risk tolerance measure, the GL-RTS. Reasons for lower than expected reliability and validity are discussed. Suggestions for improvement, implications for use, and future research are also discussed

Self-diffusion in two-dimensional hard ellipsoid suspensions

We studied the self-diffusion of colloidal ellipsoids in a monolayer near a flat wall by video microscopy. The image processing algorithm can track the positions and orientations of ellipsoids with sub-pixel resolution. The translational and rotational diffusions were measured in both the lab frame and the body frame along the long and short axes. The long-time and short-time diffusion coefficients of translational and rotational motions were measured as functions of the particle concentration. We observed sub-diffusive behavior in the intermediate time regime due to the caging of neighboring particles. Both the beginning and the ending times of the intermediate regime exhibit power-law dependence on concentration. The long-time and short-time diffusion anisotropies change non-monotonically with concentration and reach minima in the semi-dilute regime because the motions along long axes are caged at lower concentrations than the motions along short axes. The effective diffusion coefficients change with time t as a linear function of (lnt)/t for the translational and rotational diffusions at various particle densities. This indicates that their relaxation functions decay according to 1/t which provides new challenges in theory. The effects of coupling between rotational and translational Brownian motions were demonstrated and the two time scales corresponding to anisotropic particle shape and anisotropic neighboring environment were measured

Applications of Federated Learning in Smart Cities: Recent Advances, Taxonomy, and Open Challenges

Federated learning plays an important role in the process of smart cities. With the development of big data and artificial intelligence, there is a problem of data privacy protection in this process. Federated learning is capable of solving this problem. This paper starts with the current developments of federated learning and its applications in various fields. We conduct a comprehensive investigation. This paper summarize the latest research on the application of federated learning in various fields of smart cities. In-depth understanding of the current development of federated learning from the Internet of Things, transportation, communications, finance, medical and other fields. Before that, we introduce the background, definition and key technologies of federated learning. Further more, we review the key technologies and the latest results. Finally, we discuss the future applications and research directions of federated learning in smart cities

Recent progress in thermoelectric nanocomposites based on solution-synthesized nanoheterostructures

Thermoelectric materials, which can convert waste heat into electricity, have received increasing research interest in recent years. This paper describes the recent progress in thermoelectric nanocomposites based on solution-synthesized nanoheterostructures. We start our discussion with the strategies of improving the power factor of a given material by using nanoheterostructures. Then we discuss the methods of decreasing thermal conductivity. Finally, we highlight a way of decoupling power factor and thermal conductivity, namely, incorporating phase-transition materials into a nanowire heterostructure. We have explored the lead telluride–copper telluride thermoelectric nanowire heterostructure in this work. Future possible ways to improve the figure of merit are discussed at the end of this paper

Stepwise exhumation of the Triassic Lanling high-pressure metamorphic belt in Central Qiangtang, Tibet: Insights from a coupled study of metamorphism, deformation, and geochronology

The E-W trending Central Qiangtang metamorphic belt (CQMB) is correlated to the Triassic orogeny of the Paleo-Tethys Ocean prior to Cenozoic growth of the Tibetan Plateau. The well-exposed Lanling high-pressure, low-temperature (HP-LT) metamorphic complex was chosen to decipher the process by which it was exhumed, which thereby provides insights into the origin of the CQMB and Qiangtang terrane. After a detailed petrological and structural mapping, three distinct N-S-trending metamorphic domains were distinguished. Microscopic observations show that core domain garnet (Grt)-bearing blueschist was exhumed in a heating plus depressurization trajectory after peak eclogitic conditions, which is more evident in syntectonic vein form porphyroblastic garnets with zoning typical of a prograde path. Grt-free blueschist of the mantle domain probably underwent an exhumation path of temperature increasing and dehydration, as evidenced by pervasive epidote veins. The compilation of radiometric results of high-pressure mineral separates in Lanling and Central Qiantang, and reassessments on the published phengite data sets of Lanling using Arrhenius plots allow a two-step exhumation model to be formulated. It is suggested that core domain eclogitic rocks were brought onto mantle domain blueschist facies level starting at 244-230 Ma, with exhumation continuing to 227-223.4 Ma, and subsequently were exhumed together starting at 223-220 Ma, reaching lower greenschist facies conditions generally after 222-217 Ma. These new observations indicate that the CQMB formed as a Triassic autochthonous accretionary complex resulting from the northward subdcution of the Paleo-Tethys Ocean and that HP-LT rocks therein were very probably exhumed in an extensional regime.This work was jointly funded by the Young Scientist Fund of the National Natural Science Foundation of China (grant 41402177) and the Fundamental Research Funds for the Central Universities (2652014004). Our field work was supported by a project issued by the China Geological Survey (CGS): The integrated geological survey on the west part and central uplift of Qiangtang Block (grant 12120115026901)