Research on the effect of ultrasonic vibration on the roll-over during the fine blanking process

Yanxiong Liu,Tao Cheng,Lin Hua,Huajie Mao 대한기계학회 2017 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.31 No.2

Fine blanking process as an advanced sheet metal cutting process has been widely used in industry. However, the roll-over of the parts fabricated by this process weakens the performance. For some parts, i.e. gear, the size of the roll-over should be very small in some situation. Therefore, a lot of efforts have been made to reduce the roll-over size or even eliminate the roll-over. Since the high frequency vibration can greatly change the metal flow, the ultrasonic vibration was applied into the fine blanking process to eliminate the roll-over in this paper. A finite element model was created to investigate the roll-over forming mechanism in the ultrasonic vibration assisted fine blanking process. The forming force, metal flow and mean stress were analyzed and compared with the conventional fine blanking process, and the roll-over size variation mechanism of the ultrasonic vibration assisted fine blanking process was revealed. An experiment of ultrasonic vibration assisted fine blanking has been carried out in this paper, and the roll-over size variation during the conventional and ultrasonic vibration assisted fine blanking process were compared. The results show that the experiment result has a good agreement with that of the finite element simulation. From this research, it can get that the ultrasonic vibration can greatly reduce the roll-over size, and it has a promising future to be used in the fine blanking process.

Research on Rural E-commerce Development Strategies Based on Digital Marketing Context

Mou Huajie,Liu Jinyu 한중경제문화학회 2022 한중경제문화연구 Vol.20 No.-

Optimization and Experiment of Two-Dimensional Parallel Decoupling Image Stabilization Mechanism

Xiangqiang Zhong,Caixia Liu,Zhimin Di,Huajie Fang 한국정밀공학회 2020 International Journal of Precision Engineering and Vol.21 No.10

In order to improve the precision positioning accuracy of image stabilization mechanism, a two-dimensional image stabilization mechanism with parallel decoupling was proposed. Firstly, according to the principle of lever-half-bridge hybrid amplifi cation mechanism, the structure of two-dimensional image stabilization mechanism was designed, the working principle was analyzed, and natural frequency of the mechanism was calculated. Secondly, static analysis, modal analysis, and fl exure hinge parameter optimization of the mechanism based on ANSYS were carried out. The simulation results show that two-dimensional image stabilization mechanism can realize the micro-displacement positioning function in the X and Y directions. The resonance phenomenon does not occur when the mechanism works. The thickness and width are the sensitive parameters of fl exure hinge. Finally, the actuation performance of two-dimensional image stabilization mechanism was tested during the prototype, the relationship between the output displacement in the X and Y directions and the input voltage, frequency was tested, and the displacement coupling in the X and Y directions was tested. The experimental results show that the motion displacement of the mechanism is 103.9 × 104.8 μm, and the output displacement coupling does not exceed 7.5% of the stroke. The image stabilization mechanism can realize large stroke and precision positioning functions, and is feasible in engineering applications.

Dissecting Causal Relationships Between Gut Microbiota, Blood Metabolites, and Stroke: A Mendelian Randomization Study

Wang Qi,Dai Huajie,Hou Tianzhichao,Hou Yanan,Wang Tiange,Lin Hong,Zhao Zhiyun,Li Mian,Zheng Ruizhi,Wang Shuangyuan,Lu Jieli,Xu Yu,Liu Ruixin,Ning Guang,Wang Weiqing,Bi Yufang,Zheng Jie,Xu Min 대한뇌졸중학회 2023 Journal of stroke Vol.25 No.3

Background and Purpose We investigated the causal relationships between the gut microbiota (GM), stroke, and potential metabolite mediators using Mendelian randomization (MR). Methods We leveraged the summary statistics of GM (n=18,340 in the MiBioGen consortium), blood metabolites (n=115,078 in the UK Biobank), and stroke (cases n=60,176 and controls n=1,310,725 in the Global Biobank Meta-Analysis Initiative) from the largest genome-wide association studies to date. We performed bidirectional MR analyses to explore the causal relationships between the GM and stroke, and two mediation analyses, two-step MR and multivariable MR, to discover potential mediating metabolites. Results Ten taxa were causally associated with stroke, and stroke led to changes in 27 taxa. In the two-step MR, <i>Bifidobacteriales</i> order, <i>Bifidobacteriaceae</i> family, <i>Desulfovibrio</i> genus, apolipoprotein A1 (ApoA1), phospholipids in high-density lipoprotein (HDL_PL), and the ratio of apolipoprotein B to ApoA1 (ApoB/ApoA1) were causally associated with stroke (all <i>P</i><0.044). The causal associations between <i>Bifidobacteriales</i> order, <i>Bifidobacteriaceae</i> family and stroke were validated using the weighted median method in an independent cohort. The three GM taxa were all positively associated with ApoA1 and HDL_PL, whereas <i>Desulfovibrio</i> genus was negatively associated with ApoB/ApoA1 (all <i>P</i><0.010). Additionally, the causal associations between the three GM taxa and ApoA1 remained significant after correcting for the false discovery rate (all q-values <0.027). Multivariable MR showed that the associations between <i>Bifidobacteriales</i> order, <i>Bifidobacteriaceae</i> family and stroke were mediated by ApoA1 and HDL_PL, each accounting for 6.5% (<i>P</i>=0.028) and 4.6% (<i>P</i>=0.033); the association between <i>Desulfovibrio</i> genus and stroke was mediated by ApoA1, HDL_PL, and ApoB/ApoA1, with mediated proportions of 7.6% (<i>P</i>=0.019), 4.2% (<i>P</i>=0.035), and 9.1% (<i>P</i>=0.013), respectively. Conclusion The current MR study provides evidence supporting the causal relationships between several specific GM taxa and stroke and potential mediating metabolites.

Direct Palladium-Catalyzed C-4 Arylation of Tri-substituted Furans with Aryl Chlorides: An Efficient Access to Heteroaromatics

Hai Yang,Zhishuo Zheng,Jian Zeng,Huajie Liu,Bing Yi 대한화학회 2012 Bulletin of the Korean Chemical Society Vol.33 No.8

A series of functionalized furans were synthesized by way of a palladium -catalyzed coupling reaction of 2,3,5- trisubstituted furans with aryl chlorides through C-H bond cleavages at C-4 position. The feature of the reaction was facilitative preparation of furan derivatives with good functional group tolerance. All reactions gave the desired products in moderate to good yields in the presences of BuAd2P and t-BuOK in DMF at 120 oC after 15 h.

Direct Palladium-Catalyzed C-4 Arylation of Tri-substituted Furans with Aryl Chlorides: An Efficient Access to Heteroaromatics

Yang, Hai,Zheng, Zhishuo,Zeng, Jian,Liu, Huajie,Yi, Bing Korean Chemical Society 2012 Bulletin of the Korean Chemical Society Vol.33 No.8

A series of functionalized furans were synthesized by way of a palladium-catalyzed coupling reaction of 2,3,5-trisubstituted furans with aryl chlorides through C-H bond cleavages at C-4 position. The feature of the reaction was facilitative preparation of furan derivatives with good functional group tolerance. All reactions gave the desired products in moderate to good yields in the presences of $BuAd_2P$ and t-BuOK in DMF at $120^{\circ}C$ after 15 h.

Necessary Experimental Conditions for Single-Shot Diffraction Imaging of DNA-Based Structures with X-ray Free-Electron Lasers

Sun, Zhibin,Fan, Jiadong,Li, Haoyuan,Liu, Huajie,Nam, Daewoong,Kim, Chan,Kim, Yoonhee,Han, Yubo,Zhang, Jianhua,Yao, Shengkun,Park, Jaehyun,Kim, Sunam,Tono, Kensuke,Yabashi, Makina,Ishikawa, Tetsuya,So American Chemical Society 2018 ACS NANO Vol.12 No.8

<P>It has been proposed that the radiation damage to biological particles and soft condensed matter can be overcome by ultrafast and ultraintense X-ray free-electron lasers (FELs) with short pulse durations. The successful demonstration of the “diffraction-before-destruction” concept has made single-shot diffraction imaging a promising tool to achieve high resolutions under the native states of samples. However, the resolution is still limited because of the low signal-to-noise ratio, especially for biological specimens such as cells, viruses, and macromolecular particles. Here, we present a demonstration single-shot diffraction imaging experiment of DNA-based structures at SPring-8 Angstrom Compact Free Electron Laser (SACLA), Japan. Through quantitative analysis of the reconstructed images, the scattering abilities of gold and DNA were demonstrated. Suggestions for extracting valid DNA signals from noisy diffraction patterns were also explained and outlined. To sketch out the necessary experimental conditions for the 3D imaging of DNA origami or DNA macromolecular particles, we carried out numerical simulations with practical detector noise and experimental geometry using the Linac Coherent Light Source (LCLS) at the SLAC National Accelerator Laboratory, USA. The simulated results demonstrate that it is possible to capture images of DNA-based structures at high resolutions with the technique development of current and next-generation X-ray FEL facilities.</P> [FIG OMISSION]</BR>