Study of Material Removal Behavior during Laser-assisted Ultrasonic Dressing of Diamond Wheel

Zhibo Yang,Shiyu Zhang,Junchen Hu,Zhen Zhang,Kaiqiang Li,Bo Zhao 한국정밀공학회 2020 International Journal of Precision Engineering and Vol.7 No.1

Laser-assisted ultrasonic dressing (LUD) of the removal behavior of diamond wheel material is investigated by simulation and experimental method. The finite element model of diamond wheel is constructed for simulation during LUD. The effect of parameters of LUD process on the dressing force is discussed according to the simulation results. LUD experiments of diamond wheels are carried out after obtaining optimization of parameter. The dressing force obtained from simulation and experiments are compared. It is found that the variation tendency of simulated dressing force is in agreement with the experimental result. This indicates that the simulation results can be effectively used for the selection of process’ parameters.

Effect of Heat Treatment on Microstructure and Properties of FGH4096M Superalloy Processed by Selective Laser Melting

Zhibo Hao,Tian Tian,Shiqing Peng,Changchun Ge,Xinggang Li,Chonglin Jia,Chuan Guo,Qiang Zhu 대한금속·재료학회 2020 METALS AND MATERIALS International Vol.26 No.8

A self-designed nickel-based superalloy, designated as FGH4096M, was prepared by selective laser melting (SLM). Differentheat treatments were performed to improve the mechanical properties of the SLM alloy through optimizing the microstructuresand the features of γ′ precipitates. Compared with the as-deposited alloy, the columnar grains with dendritic structuresand equiaxed structures were retained in the alloy after direct aging, but a large amount of tertiary γ′ phase precipitated,especially around the sub-grain boundaries, resulting in the highest tensile strength but the lowest elongation. During solidsolution and aging treatment (SSA), the recovery and recrystallization occurring in the alloy facilitated the grains to beequiaxed with the increase of solution temperature. For lower solution temperature (below 1100 ℃), the secondary γ′ precipitatesdecreased with the increase of solution temperature, while the tertiary γ′ precipitates from the subsequent agingprocess gradually increased; for higher solution temperature over 1100 ℃, exceeding the complete dissolution temperatureof the γ′ phase, only tertiary γ′ precipitates from the subsequent aging process were uniformly distributed in the alloy. Afterdouble solid solution (1170 ℃ + 1050 ℃) + aging heat treatment (DSSA), there were three sizes of γ′ precipitates in thealloy. In general, the SLM + SSA (1130 ℃) alloy obtained the best comprehensive properties, which could be related tothe homogenized microstructures and the uniform and dense distribution of single sized tertiary γ′ precipitates in the alloy.

Predicting Web Service QoS via Combining Matrix Factorization with Network Location

Li Zhou,Zhibo Song,Suichu Zhai,Tan Xiao,Yuyu Yin 보안공학연구지원센터(IJUNESST) 2014 International Journal of u- and e- Service, Scienc Vol.7 No.3

Expression characterization and transcription regulation analysis of porcine Yip1 domain family member 3 gene

Ni, Dongjiao,Huang, Xiang,Wang, Zhibo,Deng, Lin,Zeng, Li,Zhang, Yiwei,Lu, Dongdong,Zou, Xinhua Asian Australasian Association of Animal Productio 2020 Animal Bioscience Vol.33 No.3

Objective: The Yip1 domain family (YIPF) proteins were proposed to function in endoplasmic reticulum (ER) to Golgi transport and maintenance of the morphology of the Golgi, which were homologues of yeast Yip1p and Yif1p. YIPF3, the member 3 of YIPF family was a homolog of Yif1p. The aim of present study was to investigate the expression and regulation mechanism of porcine YIPF3. Methods: Quantitative realtime polymerase chain reaction (qPCR) was used to analyze porcine YIPF3 mRNA expression pattern in different tissues and pig kidney epithelial (PK15) cells stimulated by polyinosine-polycytidylic acid (poly [I:C]). Site-directed mutations combined with dual luciferase reporter assays and electrophoretic mobility shift assay (EMSA) were employed to reveal transcription regulation mechanism of porcine YIPF3. Results: Results showed that the mRNA of porcine YIPF3 (pYIPF3) was widely expressed with the highest levels in lymph and lung followed by spleen and liver, while weak in heart and skeletal muscle. Subcellular localization results indicated that it expressed in Golgi apparatus and plasma membranes. Upon stimulation with poly (I:C), the level of this gene was dramatically up-regulated in a time- and concentration-dependent manner. pYIPF3 core promoter region harbored three cis-acting elements which were bound by ETS proto-oncogene 2 (ETS2), zinc finger and BTB domain containing 4 (ZBTB4), and zinc finger and BTB domain containing 14 (ZBTB14), respectively. In which, ETS2 and ZBTB4 both promoted pYIPF3 transcription activity while ZBTB14 inhibited it, and these three transcription factors all played important regulation roles in tumorigenesis and apoptosis. Conclusion: The pYIPF3 mRNA expression was regulated by ETS2, ZBTB4, and ZBTB14, and its higher expression in immune organs might contribute to enhancing ER to Golgi transport of proteins, thus adapting to the immune response.

Few-Layered MoS2 Nanoparticles Loaded TiO2 Nanosheets with Exposed {001} Facets for Enhanced Photocatalytic Activity

Chujun Chen,Xia Xin,Jinniu Zhang,Gang Li,Yafeng Zhang,Hongbing Lu,Jianzhi Gao,Zhibo Yang,Chunlan Wang,Ze He 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2018 NANO Vol.13 No.11

To improve the high charge carrier recombination rate and low visible light absorption of {001} facets exposed TiO2 [TiO2(001)] nanosheets, few-layered MoS2 nanoparticles were loaded on the surfaces of TiO2(001) nanosheets by a simple photodeposition method. The photocatalytic activities towards Rhodamine B (RhB) were investigated. The results showed that the MoS2–TiO2(001) nanocomposites exhibited much enhanced photocatalytic activities compared with the pure TiO2(001) nanosheets. At an optimal Mo/Ti molar ratio of 25%, the MoS2–TiO2(001) nanocomposites displayed the highest photocatalytic activity, which took only 30 min to degrade 50mL of RhB (50 mg/L). The active species in the degradation reaction were determined to be hþ and OH according to the free radical trapping experiments. The reduced charge carrier recombination rate, enhanced visible light utilization and increased surface areas contributed to the enhanced photocatalytic performances of the 25% MoS2–TiO2(001) nanocomposites.

Precise Modeling and Adaptive Feed-Forward Decoupling of Unified Power Quality Conditioners

Yingpin Wang,Rubangakene Thomas Obwoya,Zhibo Li,Gongjie Li,Yi Qu,Zeyu Shi,Feng Zhang,Yunxiang Xie 전력전자학회 2019 JOURNAL OF POWER ELECTRONICS Vol.19 No.2

The unified power quality conditioner (UPQC) is an effective custom power device that is used at the point of common coupling to protect loads from voltage and current-related PQ issues. Currently, most researchers have studied series unit and parallel unit models and an idealized transformer model. However, the interactions of the series and parallel converters in AC-link are difficult to analyze. This study utilizes an equivalent transformer model to accomplish an electric connection of series and parallel converters in the AC-link and to establishes a precise unified mathematical model of the UPQC. The strong coupling interactions of series and parallel units are analyzed, and they show a remarkable dependence on the excitation impedance of transformers. Afterward, a feed-forward decoupling method based on a unified model that contains the uncertainty components of the load impedance is applied. Thus, this study presents an adaptive method to estimate load impedance. Furthermore, simulation and experimental results verify the accuracy of the proposed modeling and decoupling algorithm.

Precise Modeling and Adaptive Feed-Forward Decoupling of Unified Power Quality Conditioners

Wang, Yingpin,Obwoya, Rubangakene Thomas,Li, Zhibo,Li, Gongjie,Qu, Yi,Shi, Zeyu,Zhang, Feng,Xie, Yunxiang The Korean Institute of Power Electronics 2019 JOURNAL OF POWER ELECTRONICS Vol.19 No.2

The unified power quality conditioner (UPQC) is an effective custom power device that is used at the point of common coupling to protect loads from voltage and current-related PQ issues. Currently, most researchers have studied series unit and parallel unit models and an idealized transformer model. However, the interactions of the series and parallel converters in AC-link are difficult to analyze. This study utilizes an equivalent transformer model to accomplish an electric connection of series and parallel converters in the AC-link and to establishes a precise unified mathematical model of the UPQC. The strong coupling interactions of series and parallel units are analyzed, and they show a remarkable dependence on the excitation impedance of transformers. Afterward, a feed-forward decoupling method based on a unified model that contains the uncertainty components of the load impedance is applied. Thus, this study presents an adaptive method to estimate load impedance. Furthermore, simulation and experimental results verify the accuracy of the proposed modeling and decoupling algorithm.

Numerical simulation on gas continuous emission from face during roadway excavation

Chen, Liang,Wang, Enyuan,Feng, Junjun,Li, Xuelong,Kong, Xiangguo,Zhang, Zhibo Techno-Press 2016 Geomechanics & engineering Vol.10 No.3

With the mining depth continuously increasing, gas emission behaviors become more and more complex. Gas emission is an important basis for choosing the method of gas drainage, gas controlling. Thus, the accurate prediction of gas emission is of great significance for coal mine. In this work, based on the sources of gas emission from the heading faces and the fluid-solid coupling process, we established a gas continuous dynamic emission model, numerically simulated and applied it to the engineering. The result was roughly consistent with the actual situation and shows the model is correct. We proposed the measures of reducing the excavation distance and borehole gas drainage based on the model. The measures were applied and the result shows the overproof problem of gas emission disappears. The model considered the influence factors of gas emission wholly, and has a wide applicability, promotional value. The research is of great significance for the controlling of gas disaster, gas drainage and pre-warning coal and gas outbursts based on gas emission anomaly at the heading face.