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Your search keyword '"Wang, Fen-Fen"' showing total 31 results
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31 results on '"Wang, Fen-Fen"'

16. A real time on orbit calibration for redundant gyros of launch vehicle upper stage

Author

Wang Fen Fen and Zhang Tong

Subjects
Engineering, business.product_category, Spacecraft, business.industry, Kalman filter, Adaptive filter, Rocket, Control theory, Inertial measurement unit, Physics::Space Physics, Orbit (dynamics), Calibration, Ring laser gyroscope, business, Simulation
Abstract

With regards to the fourth stage rocket, upper stage flight time can be up to 48 hours. Volatile space environment leads parameters calibrated in ground do not meet the requirements of the spacecraft precise orbit. In this paper, a real-time on-orbit calibration method of redundant laser gyro inertial measurement unit for space transfer vehicle is proposed. We make use of the high precise attitude information from star sensor to design a calibration model with ten inertial instruments (five gyros and five accelerometers), which includes gyros drift, and scale factor error. The redundant gyros of strapdown inertial measurement unit parameters are estimated through Kalman filter and Sage-Husa adaptive filter. For this, we conduct numerical simulation. That the result of the parameters calibration precision is within 5% demonstrates the validity of this method on satisfying the navigation system's reliability and accuracy with the estimation and compensation for gyros error. The on-orbit calibration method provides a theoretical reference for the higher precise attitude determination of space transfer vehicle.

Published
2016

19. Research on organization and mohilization mechanism of rural revitalization in western region.

Author

LI Quan and WANG Fen-fen

Abstract

Constructing a modern organization and mohilization mechanism is an important guarantee for the implementation of rural revitalization strategy. In the face of the profound change in the social structure in the transformation of urban and rural areas and ihe major adjustment in the pattern of urban and rural interests in the process of comprehensively deepening reform, the existing organization and mobilization mechanisms in the western rural areas are facing severe challenges. The study is based on the positive role of the organization and mobilization mechanism to promote the rural revitalization in differenl fields for rural grassroots governments, agro-industrial enterprises, civil society organizations and the majority ol farmers to realize collective action, and combine the successful practice of organization and mobilization in rural revitalization at home and abroad. We analyze and compare the constituent elements and basic types of organization and mobilization mechanisms in rural revitalization in western China, and then propose that in perfecting the dynamic mechanism, the operation mechanism and the safeguard mechanism of the organization and mohilization in modernization, we should accelerate the training of grassroots governments, social and rural collectives, elites and other mobilization forces, and actively mobilize social resources in urban and rural areas and integrate different social organizations to work together to help the implement of the strategy for revitalizing rural areas in the western China and achieve the goal of building a moderately prosperous society in all respects. [ABSTRACT FROM AUTHOR]

Published
2019

31. [Phosphorylation of signal transducer and activators of transcription 3 induced by vascular endothelial growth factor in ovarian carcinoma cell line in vitro].

Author

Wang FF, Chen HZ, Xie X, Ye F, Ye DF, Lü WG, and Ding ZM

Subjects
Acute-Phase Proteins metabolism, Female, Humans, Ovarian Neoplasms pathology, Phosphorylation, STAT3 Transcription Factor, Signal Transduction physiology, Tumor Cells, Cultured, Vascular Endothelial Growth Factor A metabolism, DNA-Binding Proteins metabolism, Ovarian Neoplasms metabolism, Signal Transduction drug effects, Trans-Activators metabolism, Vascular Endothelial Growth Factor A pharmacology
Abstract

Objective: To observe phosphorylation of signal transducer and activators of transcription 3 (STAT3) in Caov-3 induced by vascular endothelial growth factor (VEGF), and to investigate molecular mechanisms of the effect of VEGF on ovarian carcinoma cells., Methods: The expressions of phosphorylated STAT3 in Caov-3 induced by VEGF were detected by immunocytochemistry and Western blot methods. Furthermore, the relationship between STAT3 phosphorylation and VEGF stimulation in ovarian carcinoma cells was investigated using a peptide which could specifically bind VEGFR2 and thus block the binding of VEGF to its receptors., Results: With VEGF stimulation, the expressions of phosphorylated STAT3 were significantly higher than those without VEGF stimulation in Caov-3. And 50 ng/ml was the effective dose resulting in a significant increase of phosphorylated STAT3 (2.20 +/- 0.28/1.37 +/- 0.17) compared to 0 ng/ml (0.56 +/- 0.15/0.47 +/- 0.19) (P < 0.001). Translocation into nuclei of activated STAT3 occurred after 30 min, while STAT3 phosphorylation decreased after 60 min of stimulation (0.95 +/- 0.18/0.66 +/- 0.20). A small peptide specific for VEGFR2, blocked the increase of STAT3 phosphorylation induced by VEGF in a dose dependent manner and 80 micro mol/L was the effective dose (P < 0.001)., Conclusions: VEGF could induce STAT3 phosphorylation and translocation into nuclei of activated STAT3 in Caov-3, and the small peptide could effectively inhibit these effects of VEGF. It suggests that STAT3 participates in the VEGF signal transduction mediated by VEGFR2 in ovarian carcinoma cells.

Published
2004

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