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81.
Microsystem Technologies - This paper developed a robotics-assisted device for the stroke patients to perform the hand rehabilitation. Not only the system can perform passive range of motion... 相似文献
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Bo Zhao Baoqi Chang Lusheng Yuan Pengtao Li 《The International Journal of Advanced Manufacturing Technology》2020,106(3):891-905
This study aimed to investigate the problems of system detuning, amplitude attenuation, and even vibration stop after the load was applied to the acoustic system during ultrasonic-assisted vibration processing. In the theoretical part, the overall theoretical model of the ultrasonic longitudinal–torsional composite drilling system (ULTCDS), including the longitudinal–torsional composite horn, transducer, and load was established based on the four-terminal network, combined with the longitudinal and torsional vibration equations of the variable cross-section rod. Also, the influence of the load on the input impedance and output amplitude of the acoustic system was preliminarily analyzed. In the simulation part, the static and dynamic drilling force was simulated by the pre-stressed modal and transient dynamic analyses, and the influence of the force load on the resonant frequency and output amplitude of the system was further explored. In the experiment part, the static force loading test and the ultrasonic drilling test of titanium alloy were designed. The micro-morphology of drilling holes under different processing parameters was observed, and the influence of force load on the system characteristics and stability was explored. The results showed that when the system was subjected to a force load greater than 400 N, the system current and frequency were greatly offset, the electromechanical conversion efficiency reduced, and the amplitude was attenuated to below the amplitude at empty load. In the ultrasonic-assisted drilling of titanium alloy processing, the acoustic system undergoes an obvious detuning phenomenon and the drilling quality is attenuated when the current increased by more than 60% and the frequency changed by more than 350 Hz, affecting the stability of the system and the ultrasonic-assisted processing effect. 相似文献
84.
为缓解高产高效矿井采掘接续紧张局面,鄂尔多斯地区综采工作面多采用“两进一回”的巷道布置形式,辅运巷在回采结束后用作下一工作面的回风巷,两进风巷之间采用大煤柱护巷。但随着该地区采深600 m以上的深部矿井增多,冲击地压灾害问题逐渐显现,双巷大煤柱留设的弊端也暴露出来。针对此问题,以鄂尔多斯红庆河煤矿3-1101大采高综采工作面为例,对不同宽度煤柱留设的应力分布规律进行建模研究,提出了合理的煤柱留设宽度,为鄂尔多斯地区类似条件矿井的安全高效开采提供参考依据。 相似文献
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Journal of Mechanical Science and Technology - This work developed an efficient model for calculating the mesh stiffness of spur/helical internal gear pairs by combining the finite element method... 相似文献
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Journal of Mechanical Science and Technology - Rotating machines are one of the most common equipments in modern industry, effective fault detection and diagnosis methods are vital to equipment... 相似文献
89.
Ming Chang Fangcheng Qiu Niannian Lan Tao Zhang Xin Guo Qingzhe Jin Ruijie Liu Xingguo Wang 《Lipids》2020,55(4):353-363
In China, Camellia oleifera oil (COO) is not only a common edible oil but also a traditional remedy widely applied to ameliorate a variety of illnesses associated with inflammation, such as mouth ulcers, thrush, eczema, etc. However, there has been a lack of relevant biological research on the anti-inflammatory capacity of COO, and the specific bioactive lipid phytochemicals contributing to the anti-inflammatory effect need further research. In this study, the RAW 264.7 macrophages model was used to investigate the anti-inflammatory capacity of COO. Our data showed that 33–200 μg/mL COO markedly inhibited the lipopolysaccharide lipopolysaccharide (LPS)-stimulated nitric oxide (NO.) secretion via the suppression of Nos2 and Cox-2 expression. The enzyme immunoassay confirmed that COO also exhibited a strong suppressive effect on the expression of proinflammatory cytokines such as Tnf-α and Il-6. To further explore the correlation between the anti-inflammatory effects and the lipid phytochemicals in COO, 10 samples were collected and screened for their chemical compositions. It was interestingly demonstrated that the polyphenol extracts of COO play a vital role in its anti-inflammatory properties. In addition, an oil-in-water (O/W) emulsion-based system was also developed to deliver the liposoluble COO into the cells, and the feasibility of this system was confirmed. Our research confirms the anti-inflammatory potential of COO and highlights that the main functional ingredient is polyphenol extracts. This may provide a scientific basis for the comprehensive utilization and development of COO and related functional foods. 相似文献
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