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STUDY DESIGN An in vitro biomechanical study of the stabilizing effects of the body augmenter and posterior instrumentation on experimental thoracolumbar fractures with vertebral defects. OBJECTIVE To evaluate the effects of the body augmenter and instrumentation on the stability of the spine-device construct. SUMMARY OF BACKGROUND DATA Posterior(More)
STUDY DESIGN An in vitro biomechanical study of the stabilizing effects of a different combination of cages and transpedicular instrumentation on experimental degenerative disc disease. OBJECTIVES To evaluate the biomechanical efficacy of the interbody fusion cage and unilateral posterior instrumentation on the stability of the spine-device construct. (More)
The coverage problem is a fundamental and important issue with regard to wireless sensor networks. To reduce the number of sensor nodes, mobile nodes can be used to mitigate the sweep coverage problem. In this paper, a sweep coverage mechanism is proposed to keep the patrol times of mobile nodes approximate to one another. In simulation, various moving(More)
A Ge67Cu33 (16 nm) layer and a Ge (3 nm)/Ge67Cu33 (16 nm) bilayer were grown by sputtering at room temperature and used as the recording films for write-once blue laser media. In comparison to the crystallization temperature of Ge in a GeCu film (380.7 °C-405.1 °C), the crystallization temperature of Ge in a Ge/GeCu bilayer could be further decreased to(More)
In the process of mathematics learning, most elementary students never think but receive all the methods their teachers have taught. In other word, they don’t catch the basic concept in every unit. Based on the Petri-Net theory, this paper designs a guided learning system to correct the mis conception of elementary students. We expect to achieve the best(More)
In this study, a 3-μm-thick AlGaN film with an Al mole fraction of 10% was grown on a nanoscale-patterned sapphire substrate (NPSS) using hydride vapor phase epitaxy (HVPE). The growth mechanism, crystallization, and surface morphology of the epilayers were examined using X-ray diffraction, transmission electron microscopy (TEM), and scanning electron(More)
Approximately 4-µm-thick GaN epitaxial films were directly grown onto a GaN/sapphire template, sapphire, Si(111), and Si(100) substrates by high-temperature pulsed laser deposition (PLD). The influence of the substrate type on the crystalline quality, surface morphology, microstructure, and stress states was investigated by X-ray diffraction (XRD),(More)
A composite AlSi alloy substrate was fabricated to eliminate thermal expansion coefficient mismatch in high-power vertical light-emitting diodes (VLEDs). At 2000-mA injection current, the light output power performance of LED/sapphire, VLED/Si, and VLED/AlSi are 1458, 2465, and 2499 mW and the wall-plug efficiencies are 13.66%, 26.39%, and 28.02%,(More)