DISCUSSION ON THE CHARACTERISTICS OF UU-XIANG'S HURDLING TECHNIQUES

By using the, methods of experiment and documentary, the data and motor photo of liu Xiang attending Olympic and pre-Olympic games were collected and digitized. Based on the sport training practice, Liu-Xiang 110m hurdle sport techniques were investigated. Results show that the performance showing the technique characteristics of short flight time, long offending hurdle distance, short landing distance, high sprint pace frequency and the hip-hurdling style which postponed hold-down-hurdle time, enhanced hold-downhurdle speed and decreased landing time. His knee conceding angle was small and pelvis swung rapidly

Ultrafast dynamics in semiconductor devices

This research focuses on three types of GaAs-based semiconductor devices, namely oxide confined vertical-cavity surface-emitting lasers (VCSEL), GaAs/AlGaAs quantum dots and GaAs microdisk lasers. An individual transverse mode distribution in a VCSEL has been resolved by a scanning confocal microscope in connection with an optical spectrum analyzer. With resonant femtosecond pulse injection, we directly perturb the cavity field of a VCSEL. After the injection, the lasing and nonlasing mode dynamics are measured. Spatio-temporal resolution of the VCSEL's modes helps us to understand how to lock transverse modes and work toward a new type of mode-locked pulse laser. By injecting cross-polarized laser pulses into a VCSEL cavity, we also studied the ultrafast polarization effects of a single-mode VCSEL. Based on time-resolved microscopic photoluminescence (μPL) from single self-assembled GaAs/AlGaAs quantum dots, we unambiguously identify one of the emission lines as arising from positive trions (two holes and one electron) in these nominally undoped quantum dots. The trion is formed via tunneling of one electron out of the dot after optical excitation of a biexciton. The rise time of the trion emission line matches the decay time of the biexciton due to electron tunneling. Time-resolved whispering-gallery modes (WGMs) of GaAs microdisk lasers show a redshift in time. After the fs laser pulse pump, there is a turn-on delay of the microdisk laser lasing emission. With the increasing pump power, the WGMs shift to shorter wavelength

THE EFFECTS OF DISTRIBUTOR DESIGN ON THE SOLIDS DISTRIBUTION IN A CFB RISER

The influence of gas distributor design on the gas-solids flow structure was investigated in a rectangular CFB riser. The gas distributor was altered five different ways. The results show that the distributor design had significant effects on the solids distribution. The changed flow structure was maintained from the entrance to the riser top. Altering the gas distributor was an effective and practical method to change the flow structure. This study may be beneficial to CFB design and operation

Reference point adaptation and air quality – Experimental evidence with anti-PM 2.5 facemasks from China

The formation of reference points has drawn increasing interest ever since the introduction of prospect theory. Given that most studies focus on tradable goods such as stocks, for which the prices are observable, while few have focused on environmental goods. This paper attempts to fill this gap in the literature in this regard. In our experiment, we divided the subjects into buyers and sellers and asked them to trade four PM 2.5 filters using the Becker–DeGroot–Marschak mechanism. We have two treatments in this experiment: a) the experience of seven weeks of heavy air pollution; and b) the receiving of information on the relationship between death rates and air pollution. The different bidding prices for the four PM 2.5 filters in these treatment groups make it possible to trace the adjustment of the reference points as a result of these treatments without having to know their precise values. Our results show that, for buyers, the heavy air pollution drives them to fully downwardly adjust their reference points on air quality. For sellers, however, the reference points adaptation caused by heavy pollution is not a full adaptation. Moreover, the new information on the damage to health from air pollution causes buyers to upwardly adjust their reference points on air quality but does not significantly change the sellers’ reference points. We show that, for both treatments, sellers are more reluctant to adjust their reference points on air quality than are buyers. Our results confirm the asymmetric reference point adaptation in that adaptation after a loss is harder than adaptation after a gain

Improving Scene Graph Generation with Superpixel-Based Interaction Learning

Recent advances in Scene Graph Generation (SGG) typically model the relationships among entities utilizing box-level features from pre-defined detectors. We argue that an overlooked problem in SGG is the coarse-grained interactions between boxes, which inadequately capture contextual semantics for relationship modeling, practically limiting the development of the field. In this paper, we take the initiative to explore and propose a generic paradigm termed Superpixel-based Interaction Learning (SIL) to remedy coarse-grained interactions at the box level. It allows us to model fine-grained interactions at the superpixel level in SGG. Specifically, (i) we treat a scene as a set of points and cluster them into superpixels representing sub-regions of the scene. (ii) We explore intra-entity and cross-entity interactions among the superpixels to enrich fine-grained interactions between entities at an earlier stage. Extensive experiments on two challenging benchmarks (Visual Genome and Open Image V6) prove that our SIL enables fine-grained interaction at the superpixel level above previous box-level methods, and significantly outperforms previous state-of-the-art methods across all metrics. More encouragingly, the proposed method can be applied to boost the performance of existing box-level approaches in a plug-and-play fashion. In particular, SIL brings an average improvement of 2.0% mR (even up to 3.4%) of baselines for the PredCls task on Visual Genome, which facilitates its integration into any existing box-level method

Numerical investigations on scour and flow around two crossing pipelines on a sandy seabed

When a pipeline is laid on the seabed, local scour often occurs below it due to sea currents. In practical engineering, there are some cases that two pipelines laid on the seabed need to cross with each other. The complex flow structures around two crossing pipelines make the scour characteristics different from that of an isolated single pipeline. In this study, scour below two crossing pipelines was simulated numerically using the CFD software Flow-3D. The study is focused on the effect of the intersecting angle on the equilibrium depth and time scale of scour below the crossing position. Five intersecting angles, i.e., α = 0◦ , 15◦ , 30◦ , 45◦ and 90◦ , are considered, where α = 0◦ and 90◦ represent two pipelines parallel and perpendicular to each other, respectively. The results show that the equilibrium depth and the time scale of scour below the two crossing pipelines are greater than those of an isolated single pipeline. The equilibrium depth and time scale of scour have the largest values at α = 0◦ and decrease with the increase of the intersecting angle. Finally, the flow structures around the crossing pipelines are presented to explain the scour process