Recently, polymer‐coated magnetite (Fe3O4) nanoparticles (NPs) are extensively studied for applications in therapeutics or diagnostics using photothermal effect. Therefore, it is essential to understand the interactions between Fe3O4 NPs and polymers when optical stimuli are applied. Herein, the photonic reactions of Fe3O4 NPs and polymer composites upon application of a 780 nm multiphoton laser are analyzed. The photonic reactions produce unique results including fluorescence from conformationally changed polymer and low‐temperature phase transformation of Fe3O4 NPs. Typically, π‐conjugated chains are formed, inducing fluorescence through a series of main and side‐chain cleavage reactions of polymers with the aliphatic chain. In addition, fluorescence is detected in the cellular system by photonic reactions between Fe3O4 NPs and biomolecules. After multiphoton laser irradiation, light emission is detected near the intracellular Fe3O4 NPs, and a stronger intensity is observed in large‐sized NPs. 相似文献
The ability to predict performance of manufacturing equipment during early stages of process planning is vital for improving efficiency of manufacturing processes. In the metal cutting industry, measurement of machining performance is usually carried out by collecting machine-monitoring data that record the machine tool’s actions (e.g. coordinates of axis location and power consumption). Understanding the impacts of process planning decisions is central to the enhancement of the machining performance. However, current methodologies lack the necessary models and tools to predict impacts of process planning decisions on the machining performance. This paper presents the development of a virtual machining model (called STEP2M model) that generates machine-monitoring data from process planning data. The STEP2M model builds upon a physical model-based analysis for the sources of energy on a machine tool, and adopts STEP-NC and MTConnect standardised interfaces to represent process planning and machine-monitoring data. We have developed a prototype system for 2-axis turning operation and validated the system by conducting an experiment using a Computer Numerical Control lathe. The virtual machining model presented in this paper enables process planners to analyse machining performance through virtual measurement and to perform interoperable data communication through standardised interfaces. 相似文献
The aim of this study was to evaluate antiproliferative sirolimus- and antioxidative alpha-lipoic acid (ALA)-eluting stents using biodegradable polymer [poly-l-lactic acid (PLA)] in a porcine coronary overstretch restenosis model. Forty coronary arteries of 20 pigs were randomized into four groups in which the coronary arteries had a bare metal stent (BMS, n = 10), ALA-eluting stent with PLA (AES, n = 10), sirolimus-eluting stent with PLA (SES, n = 10), or sirolimus- and ALA-eluting stent with PLA (SAS, n = 10). A histopathological analysis was performed 28 days after the stenting. The ALA and sirolimus released slowly over 30 days. There were no significant differences between groups in the injury or inflammation score; however, there were significant differences in the percent area of stenosis (56.2 ± 11.78 % in BMS vs. 51.5 ± 12.20 % in AES vs. 34.7 ± 7.23 % in SES vs. 28.7 ± 7.30 % in SAS, P < 0.0001) and fibrin score [1.0 (range 1.0–1.0) in BMS vs. 1.0 (range 1.0–1.0) in AES vs. 2.0 (range 2.0–2.0) in SES vs. 2.0 (range 2.0–2.0) in SAS, P < 0.0001] between the four groups. The percent area of stenosis based on micro-computed tomography corresponded with the restenosis rates based on histopathological stenosis in different proportions in the four groups (54.8 ± 7.88 % in BMS vs. 50.4 ± 14.87 % in AES vs. 34.5 ± 7.22 % in SES vs. 28.9 ± 7.22 % in SAS, P < 0.05). SAS showed a better neointimal inhibitory effect than BMS, AES, and SES at 1 month after stenting in a porcine coronary restenosis model. Therefore, SAS with PLA can be a useful drug combination for coronary stent coating to suppress neointimal hyperplasia. 相似文献
Herein, hierarchically structured SnO2 microspheres are designed and synthesized as an efficient anode material for lithium-ion batteries using hollow SnO2 nanoplates. Three-dimensionally ordered macroporous (3-DOM) SnOx-C microspheres synthesized by spray pyrolysis are transformed into hierarchically structured SnO2 microspheres by a two-step post-treatment process. Sulfidation produces hierarchically structured SnS-SnS2-C microspheres comprising tin sulfide nanoplate and carbon building blocks. A subsequent oxidation process produces SnO2 microspheres from hollow SnO2 nanoplate building blocks, which are formed by Kirkendall diffusion. The discharge capacity of the hierarchically structured SnO2 microspheres at a current density of 5 A·g?1 for the 600th cycle is 404 mA·h·g?1. The hierarchically structured SnO2 microspheres have reversible discharge capacities of 609 and 158 mA·h·g?1 at current densities of 0.5 and 30 A·g?1, respectively. The ultrafine nanosheets contain empty voids that allow excellent lithium-ion storage performance, even at high current densities.
In this paper, an adaptive observer-based trajectory tracking problem is solved for nonholonomic mobile robots with uncertainties.
An adaptive observer is first developed to estimate the unmeasured velocities of a mobile robot with model uncertainties.
Using the designed observer and the backstepping technique, a trajectory tracking controller is designed to generate the torque
as an input. Using Lyapunov stability analysis, we prove that the closed-loop system is asymptotically stable with respect
to the estimation errors and tracking errors. Finally, the simulation results are presented to validate the performance and
robustness of the proposed control system against uncertainties. 相似文献
Abstract— A novel pixel design for vertical‐alignment LCDs with superior transmittance has been developed. The new liquid‐crystal mode, refered to as the hole‐induced vertical‐alignment mode (Hi‐VA), uses a via hole of an organic layer on a TFT substrate to achieve multi‐domain alignment. Compared to the conventional design, the Hi‐VA mode has a transmittance of up to 135% with a contrast ratio of 2000:1. Moreover, the new structure is free from ITO patterning or protrusion on the color‐filter side, which makes the fabrication process simple and low cost. 相似文献