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1,384 results on '"ZHANG Yu-qing"'

1. Performance evaluation of titanium-based metal nitride coatings and die lifetime prediction in a cold extrusion process

Author

Shen Li, Zhao Jiang, Zhang Yu-Qing, and Quan Guo-Zheng

Subjects
titanium-based nitride coating, performance, finite element method, archard model, cold extrusion, Technology, Chemical technology, TP1-1185, Chemicals: Manufacture, use, etc., TP200-248
Abstract

Surface coating can greatly enhance the lifetime of cold extrusion die. It is a significant issue to evaluate the performance of coatings and even predict the lifetime of cold extrusion die. In this work, the titanium-based nitride coatings including TiN, TiAlN, and TiAlCrN were, respectively, deposited on the surface of high-speed steel substrate W6Mo5Cr4V2 (M2) by the physical vapor deposition technology. The hardness test, scratch test, Rockwell adhesion test, and pin-on-disc (POD) wear test were carried out aiming to investigate the performances of the three coatings including hardness, adhesion strength, and wear resistance. The results show that the TiAlCrN coating exhibits the highest hardness of 3,033 HV in comparison with TiN coating (1,222 HV) and TiAlN coating (1,916 HV), while it possesses poor adhesion strength and inferior wear resistance. Furthermore, the TiAlN coating presents the highest resistance to wear and spalling from the substrate. In addition, the Archard wear model of the coatings was solved and applied in the finite element model of cold extrusion to calculate the wear depth and lifetime of the cold extrusion dies. The results suggest that TiAlN coating is the optimal option for cold extrusion die as compared with TiAlCrN and TiN coatings. TiAlN coating can prolong the lifetime of the substrate die up to 260%.

Published
2021
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6. Design and implementation of national security vulnerability database

Author

ZHANG Yu-qing, WU Shu-ping, LIU Qi-xu, and LIANG Fang-fang

Subjects
information security, security vulnerability, security vulnerability database, vulnerability standard, Telecommunication, TK5101-6720
Abstract

Base on both domestic and overseas research on vulnerability database,considering our national conditions and the security requirements,a security vulnerability database model was proposed.It’s compatible with multiple stan-dards,and could be used to classify vulnerability attributes through groups.The national security vulnerability database was implemented based on the model and applied to security warning and emergency response.This work has brought satisfactory effects in practice.

Published
2011

7. Robust multi-dimensional trust model for improving the survivability of ad hoc networks

Author

CHEN Shen-long and ZHANG Yu-qing

Subjects
ad hoc networks, trust model, survivability, D-S theory, RMTM, Telecommunication, TK5101-6720
Abstract

Attackers could perform the blended attack against ad hoc networks through utilizing several attack methods together.Under this circumstance,a robust multi-dimensional trust model（RMTM） to improve the survivability of ad hoc networks was proposed.RMTM was based on D-S theory.Nodes’ attack evidences were classified into several dimen-sions and the trust of each dimension was computed according to basic probability assignment function.Then RMTM implemented the comprehensive evaluation through the multi-dimensional trust fusion.In order to resist the attacks against trust models themselves,the corresponding tolerant algorithms were designed to enhance the RMTM’s robustness.The simulations show that RMTM can effectively defense against both ad hoc network blended attack and trust model attacks with limited overload and consequently it significantly improves the survivability of ad hoc networks.

Published
2010

8. New signcryption algorithm for secure communication of ad hoc networks

Author

ZHANG Chuan-rong, ZHANG Yu-qing, LI Fa-gen, and XIAO Hong

Subjects
ad hoc networks, identity-based signcryption, bilinear pairing, provable security, share refreshing protocol, Telecommunication, TK5101-6720
Abstract

At first, a new identity based signcryption algorithm was proposed; its security and efficiency were analyzed. As a result, its provable security in the random oracle model is proved; compared with the previous identity based sign- cryption algorithms, the new algorithm has lower computation cost and communication overhead. It is very suitable for secure communication protocols of key management and secure routing in ad hoc networks. Finally, for showing the ap- plication methods and significance of new identity based signcryption algorithm in ad hoc networks, a share refreshing protocol of a serve node’s system private key in threshold key management of ad hoc networks is given.

Published
2010

9. Study of secret sharing schemes based on quantum theory

Author

ZHU Zhen-chao and ZHANG Yu-qing

Subjects
quantum secret sharing（QSS）, unconditional security, quantum cryptography, quantum entanglement, Telecommunication, TK5101-6720
Abstract

Quantum secret sharing（QSS） which is based on the laws of quantum mechanics,instead of mathematical assumptions can share the information unconditionally securely, according to the form of sharing information, quantum secret sharing can be divided into QSS of classical messages and QSS of quantum information,QSS of classical messages can be divided into QSS of classical messages based on entanglement and QSS of classical messages without entanglement, the representative protocols in three main branches of the quantum secret sharing schemes and its latest development were introduced, also prospect analysis of the schemes’ future development was given.

Published
2009

10. Design and realization of the real-time monitoring system for instant messenger

Author

FU An-min and ZHANG Yu-qing

Subjects
instant messenger, real-time monitor, protocol analysis, intercept, audio and video, Telecommunication, TK5101-6720
Abstract

On the base of the deep study and analysis of the various instant messengers’ transmission protocol of texts,files,audios and videos,A real-time monitoring system for instant messenger——IMmonitor was designed and realized.The system can not only real-timely monitor the text message of the instant messengers（such as MSN,Fetion,ICQ etc.） for multiple versions,but also monitor the transmission of any files（such as.doc,.jpg,.rar etc.）,audios and videos.The IMmonitor system has realized the comprehensive monitor of the all formats of information of the instant messengers,and has solved the problem of the upgrade of the monitor system,which is caused by the upgrade of the instant messenger.

Published
2008

16. Effects of Compound Danshen Dripping Pills on Ventricular Remodeling and Cardiac Function after Acute Anterior Wall ST-Segment Elevation Myocardial Infarction (CODE-AAMI): Protocol for a Randomized Placebo-Controlled Trial

Author

Wu, Yu-jie, Deng, Bo, Wang, Si-bo, Qiao, Rui, Zhang, Xi-wen, Lu, Yuan, Wang, Li, Gu, Shun-zhong, Zhang, Yu-qing, Li, Kai-qiao, Yu, Zong-liang, Wu, Li-xing, Zhao, Sheng-biao, Zhou, Shuang-lin, Yang, Yang, and Wang, Lian-sheng

Published
2023
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31. Metatranscriptome of human lung microbial communities in a cohort of mechanically ventilated COVID-19 Omicron patients

Author

Wang, Lin, Cao, Jia-Bao, Xia, Bin-Bin, Li, Yue-Juan, Zhang, Xuan, Mo, Guo-Xin, Wang, Rui-Juan, Guo, Si-Qi, Zhang, Yu-Qing, Xiao, Kun, Zhu, Guang-Fa, Liu, Peng-Fei, Song, Li-Cheng, Ma, Xi-Hui, Xiang, Ping-Chao, Wang, Jiang, Liu, Yu-Hong, Xie, Fei, Zhang, Xu-Dong, Li, Xiang-Xin, Sun, Wan-Lu, Cao, Yan, Wang, Kai-Fei, Zhang, Wen-Hui, Zhao, Wei-Chao, Yan, Peng, Chen, Ji-Chao, Yang, Yu-Wei, Yu, Zhong-Kuo, Tang, Jing-Si, Xiao, Li, Zhou, Jie-Min, Xie, Li-Xin, and Wang, Jun

Published
2023
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