Considering the wavelength characteristics of the pump high-power laser diode, a modified Fabry-Perot fiber laser resonator is designed. And a fiber laser with more than 10Watts output, near diffraction-limited and op...Considering the wavelength characteristics of the pump high-power laser diode, a modified Fabry-Perot fiber laser resonator is designed. And a fiber laser with more than 10Watts output, near diffraction-limited and operating in the 1110nm region is developed.展开更多
Ni-based composite coatings incorporated with nano/micron SiC particles were fabricated via electrochemical co-deposition in Watts bath,followed by the evaluation of their mechanical and anti-corrosion properties.The ...Ni-based composite coatings incorporated with nano/micron SiC particles were fabricated via electrochemical co-deposition in Watts bath,followed by the evaluation of their mechanical and anti-corrosion properties.The micrographic observations suggest that the SiC particles with various sizes can be well incorporated to the Ni substrate.X-ray diffraction(XRD)patterns indicate that SiC particles with smaller sizes could weaken the preferential growth of Ni along(200)facet.In addition,it is found that the incorporated SiC particles with medium micron sizes(8 and 1.5μm)could significantly enhance the micro-hardness of the Ni composite coatings.Nevertheless,electrochemical measurements demonstrate that micron-sized SiC particles would weaken the corrosion resistance of Ni composite coatings ascribed to the structure defects induced.In contrast,the combined incorporation of nanosized(50 nm)SiC particles with medium micron(1.5μm)ones is capable of promoting the compactness of the composite coatings,which is beneficial to the long-term corrosion resistance with negligible micro-hardness loss.展开更多
针对Watt型平面六连杆机构解域分析问题,提出了基于欧拉公式和判别法的平面四环链和平面六环链的奇异点识别方法,并结合平面四环链和平面六环链的运动特征,对Watt型平面六连杆机构进行了分支自动识别研究。首先,基于提出的识别方法并结...针对Watt型平面六连杆机构解域分析问题,提出了基于欧拉公式和判别法的平面四环链和平面六环链的奇异点识别方法,并结合平面四环链和平面六环链的运动特征,对Watt型平面六连杆机构进行了分支自动识别研究。首先,基于提出的识别方法并结合MFC(microsoft foundation classes,微软基础类库)设计了计算机辅助识别软件,实现对Watt型平面六连杆机构的分支、构型位置以及奇异点坐标的自动识别。然后,基于识别结果分析Watt型平面六连杆机构的可行域,再根据Watt型平面六连杆机构的可行域生成机构的运动仿真视频,并通过仿真视频分析其运动学特性。最后,结合实例演示Watt型平面六连杆机构分支的自动识别过程。结果显示该计算机辅助识别软件能够对该机构分支进行自动判别。研究结果表明利用所提出的Watt型平面六连杆机构分支自动识别方法可简便快捷地实现对机构的可行域分析和运动学分析,具有较强的工程实用性。展开更多
文摘Considering the wavelength characteristics of the pump high-power laser diode, a modified Fabry-Perot fiber laser resonator is designed. And a fiber laser with more than 10Watts output, near diffraction-limited and operating in the 1110nm region is developed.
基金This work was financially supported by National Natural Science Foundation of China(Nos.51901018 and 51771027)National Science and Technology Resources In-vestigation Program of China(No.2019FY101400)+3 种基金Funda-mental Research Funds for the Central Universities,China(Nos.FRF-MP-19-001 and FRF-AT-20-07)National Key Research and Development Program of China(No.2017YFB0702100)China Postdoctoral Science Foundation(No.2019M660456)Young Elite Scientists Sponsor-ship Program by China Association for Science and Techno-logy(YESS,No.2019QNRC001).
文摘Ni-based composite coatings incorporated with nano/micron SiC particles were fabricated via electrochemical co-deposition in Watts bath,followed by the evaluation of their mechanical and anti-corrosion properties.The micrographic observations suggest that the SiC particles with various sizes can be well incorporated to the Ni substrate.X-ray diffraction(XRD)patterns indicate that SiC particles with smaller sizes could weaken the preferential growth of Ni along(200)facet.In addition,it is found that the incorporated SiC particles with medium micron sizes(8 and 1.5μm)could significantly enhance the micro-hardness of the Ni composite coatings.Nevertheless,electrochemical measurements demonstrate that micron-sized SiC particles would weaken the corrosion resistance of Ni composite coatings ascribed to the structure defects induced.In contrast,the combined incorporation of nanosized(50 nm)SiC particles with medium micron(1.5μm)ones is capable of promoting the compactness of the composite coatings,which is beneficial to the long-term corrosion resistance with negligible micro-hardness loss.
文摘针对Watt型平面六连杆机构解域分析问题,提出了基于欧拉公式和判别法的平面四环链和平面六环链的奇异点识别方法,并结合平面四环链和平面六环链的运动特征,对Watt型平面六连杆机构进行了分支自动识别研究。首先,基于提出的识别方法并结合MFC(microsoft foundation classes,微软基础类库)设计了计算机辅助识别软件,实现对Watt型平面六连杆机构的分支、构型位置以及奇异点坐标的自动识别。然后,基于识别结果分析Watt型平面六连杆机构的可行域,再根据Watt型平面六连杆机构的可行域生成机构的运动仿真视频,并通过仿真视频分析其运动学特性。最后,结合实例演示Watt型平面六连杆机构分支的自动识别过程。结果显示该计算机辅助识别软件能够对该机构分支进行自动判别。研究结果表明利用所提出的Watt型平面六连杆机构分支自动识别方法可简便快捷地实现对机构的可行域分析和运动学分析,具有较强的工程实用性。
