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115 results on '"Yuan, Qingyun"'

24. Self‐reduction and enhanced luminescence in transparent Mn2+‐doped mullite glass‐ceramics derived from EMT‐type zeolite.

Author

Geng, Rongrong, Zhou, Beiying, Wang, Jiancheng, Yuan, Qingyun, Pan, Zesheng, Zhao, Yuye, Wang, Lianjun, and Jiang, Wan

Subjects
MULLITE, GLASS-ceramics, LUMINESCENCE, ZEOLITES, RAYLEIGH scattering, ION migration & velocity
Abstract

Mn2+ activated glass‐ceramic (GC) has received tremendous attention in the exploration of luminescent materials for solid‐state lighting due to the high stability, broad red emission, and low toxicity. However, the doped Mn2+ ions still suffer from the oxidation and uncontrollable ions migration during the melting process of conventional preparation techniques, which is detrimental to the luminescence performance. Herein, transparent Mn2+‐doped mullite GCs have been prepared at low temperature (∼850°C) via the spark plasma sintering of EMT‐type zeolite. The GC samples show typical red emission peaking at 620 nm that can be assigned to spin‐forbidden 4T1(G)→6A1(S) transition of Mn2+ located in the octahedral coordination site of the host. Owing to the charge compensation mechanism and produced oxygen vacancies, the self‐reduction of Mn3+ to Mn2+ ions is realized and the oxidization is inhibited. The mullite nanocrystals acted as additional scattering centers introduce Rayleigh scattering to enhance the emission intensity. Moreover, benefitted from the established mullite nanocrystals network, the Mn2+‐doped GCs exhibit improved thermal conductivity up to 1.79 W K−1 m−1 and more excellent mechanical properties than conventional GCs, simultaneously. [ABSTRACT FROM AUTHOR]

Published
2022
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35. An Improved Plant-wide Hierarchical Optimization Method Based on Technical Indices Decomposition

Author

Liu Tan, Yuan Qingyun, and Wang Yonggang

Subjects
Measure (data warehouse), Mathematical optimization, Optimization problem, Computer science, Material consumption, Process (engineering), 010102 general mathematics, 02 engineering and technology, 01 natural sciences, Global optimum, 020401 chemical engineering, Coupling (computer programming), Decomposition (computer science), 0204 chemical engineering, 0101 mathematics
Abstract

Basing on the minimum material consumption models, the plant-wide hierarchical optimization method has been successful in determining technical indices and manipulated variables by solving a two-level optimization problem, including the procedure-level optimization and the process-level optimization. However, the performance of the method will deteriorate if there are numerous technical indices and coupling relationship between them in the procedure-level optimization problem. To address this problem efficiently, this paper presents an improved plant-wide hierarchical optimization method based on technical indices decomposition. In the method, the procedure-level optimization problem is decomposed into several easier solvable sub-problems based on technical indices grouping. Two metrics are defined to measure whether the technical indices is divided into groups or separate. Then, the global optimum of procedure-level optimization problem is found by successively solving the sub-problems. Finally, the presented optimization method is applied to the hydrometallurgy process of a gold smelter. The results verify the effectiveness of this method.

Published
2019

36. Experimental Investigation on Contaminated Friction of Hydraulic Spool Valve

Author

Yuan Qingyun, Shengqing Yang, Hong Ji, Fan Shuai, and Rui Xu

Subjects
Fluid Flow and Transfer Processes, 0209 industrial biotechnology, Test bench, contaminated friction, Materials science, integumentary system, Process Chemistry and Technology, General Engineering, hydraulic spool, 02 engineering and technology, Mechanics, Conical surface, Lower limit, Clamping, Computer Science Applications, stagnation-sensitive size, Spool valve, 020303 mechanical engineering & transports, 020901 industrial engineering & automation, 0203 mechanical engineering, General Materials Science, solid particulates, human activities, Instrumentation
Abstract

This paper focuses on the contaminated friction of fit clearance between the spool and valve body to explore the influence principles of clamping stagnation phenomenon. From the perspective of surface morphology and size of particulates in the clearance, designing and manufacturing the valve body, rough spool, conical spool, and standard morphology spool, the test bench was built up and the curves of real-time contaminated friction in the movement of spools were obtained through experiments. The curves show that the contaminated frictions have a feature of pulsation, meanwhile, the stagnation-sensitive size of particulates is between 0.7 and 0.9 times that of clearance. Compared to the ideal morphology spool within the range of sensitive size, the contaminated fiction of rough spool is increased, whereas the lower limit of stagnation-sensitive size range of particulates on conical spool is decreased. The contaminated friction is gradually increased on cis-conical spool but increased first and then decreased on invert cone spool.

Published
2019

45. An improved gradient-based NSGA-II algorithm by a new chaotic map model.

Author

Liu, Tan, Gao, Xianwen, and Yuan, Qingyun

Subjects
EVOLUTIONARY algorithms, GENETIC algorithms, PARETO analysis, EVOLUTIONARY computation, MATHEMATICAL optimization
Abstract

Gradient-based non-dominated sorting genetic algorithm II (G-NSGA-II) is successful for solving multi-objective optimization problems. However, the effectiveness of gradient-based hybrid operator is influenced by the distribution of individuals in the population. In order to solve the problem, based on the framework of G-NSGA-II, we propose an improved gradient-based NSGA-II algorithm by introducing a new chaotic map model named IG-NSGA-II. In this algorithm, a new hybrid chaotic map model is first established to initialize population for keeping the diversity of the initial population. Then, the substitution operation of chaotic population candidate is introduced to maintain the diversity and uniformity of the Pareto optimal solution set. Finally, the proposed algorithm is tested on several standard test problems and compared with other algorithms. The experimental results indicate that the proposed algorithm leads to better performance results in terms of the convergence to Pareto front or the diversity of the obtained non-dominated solutions. [ABSTRACT FROM AUTHOR]

Published
2017
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46. Correlation between coupled voltage and discharge current

Author

Yuan Qingyun, Ning Jianjian, and Wu Yong

Subjects
Physics, Electrostatic discharge, business.industry, Rise time, Electrode, Electrical engineering, Value (computer science), Mechanics, Repeatability, Derivative, Current (fluid), business, Voltage
Abstract

When the discharge voltage is +8kV and electrode approaching speed is 0.8m/s, the test results were sorted and investigated and several ideas are drawn as follows: there are better linear relations between the coupled voltage peak-to-peak value, discharge current peak value and current derivative maximum value. These three parameters are linear with the discharge current rise time. And the relative amplitude of several repeatable frequency points is not linear with these parameters at all.

Published
2009

49. Generation and Characterization of a Bispecific Antibody Targeting Both PD-1 and c-MET

Author

Wu, Yi, Yu, Min, Sun, Zujun, Hou, Weihua, Wang, Yuxiong, Yuan, Qingyun, and Mo, Wei

Abstract

Background: Bispecific antibodies, BsAbs, are molecules with the ability to bind to two different epitopes on the same or different antigens. c-MET, cellular-mesenchymal to epithelial transition factor, is deregulated in many types of human malignancies. Abnormal c-MET activation in cancer correlates with poor prognosis. PD-1, programmed death-1, is an additional inhibitory receptor expressed by T cells. Blocking the interactions between PD-1 and PD-L1 has emerged as a promising immunotherapy for treating cancer. Objectives: The goal of this study was to identify a novel bispecific antibody targeting both c-MET and PD-1 as an anti-cancer therapeutic candidate. Methods: The BsAb was produced using 293E expression system and purified by Protein A affinity chromatography. Then the binding specificity and affinity of the BsAb was examined by FACS and biolayer light interferometry. The ability of the BsAb to inhibit the proliferation of tuman cells was measured using the CellTiter 96 Aqueous One Solution Cell Proliferation Assay kit; the potential signaling pathway involved was identified by Western Blot. Cytokine secreted by PHA-L stimulated PBMC was measured by ELISA. Effects of BsAb on PBMC-mediated lysis of MKN45 cells was measured by LDH cytotoxicity assay. Results: Based on the original sequences of PD-1 and c-MET mAb, a BsAb gene was designed, cloned into pCEP4 vector for expression in 293E cells. The BsAb was obtained after purification of the cell culture supernatant. It can bind to PD-1 and c-MET simultaneously, the calculated affinity was 11.5 nM for PD-1 and 9.09 nM for c-MET. The BsAb enhanced IFN-γ production over control IgG by 2-3 folds. It also inhibit the c-MET pathway activation and the proliferation of tumor cells significantly, comparable to JnJ-38877605. The BsAb showed dose-dependent cytotoxic activity against MKN45 cells. Conclusion: Our results indicated that a novel BsAb recognizing PD-1 and c-MET was successfully generated. It could redirect T cells to kill tumor cells, while retaining its inherent ability to restore T cells and inhibit tumor cells. With this potential, this BsAb could be developed as a therapeutic candidate for the treatment of various solid tumors.

Published
2017
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50. Valve hall fire report and analysis for Gezhouba Converter Station

Author

Yuan Qingyun and Lou Dianqiang

Subjects
Fire control, Fire detection, education, HVDC converter station, Environmental science, Thyristor, Valve hall, Marine engineering
Abstract

A valve fire incident happened in the Gezhouba HVDC Converter Station in China on June 25, 1994. This paper reports on the investigation and analysis of the incident concerning a 12-pulse thyristor valve. Valve hall fire detection and fire control is also discussed in this paper.

Published
2002

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