http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Assembling Synthesis of Barium Chromate Nano-superstructures Using Eggshell Membrane as Template
Jinku Liu,Qingsheng Wu,Yaping Ding,Yu Yi 대한화학회 2004 Bulletin of the Korean Chemical Society Vol.25 No.12
The branch-like, feather-like BaCrO4 nano-superstructures were synthesized with bioactive eggshell membrane as directing and assembly template. Studies on the two products revealed that they formed through the self-assembly of nanoparticles, and that the optical properties of the products were different from BaCrO4 bulk materials.
An Approach for the Stability of Communication Constrained Networked Time-delay Control Systems
Siwei Qiao,Qingsheng Yang,Jie Wu,Xisheng Zhan,Huaicheng Yan 제어·로봇·시스템학회 2023 International Journal of Control, Automation, and Vol.21 No.4
This paper aims to solve the stability problem of networked time-delay systems by frequency-domain analysis. The communication network quality is affected by bandwidth, noise, and packet dropouts. The main techniques are spectral decomposition and frequency-domain analysis. By means of utilizing those techniques, the expression of minimum signal-to-noise ratio which stabilizes the networked time-delay systems is obtained. Further, it is shown that the minimum value of system stability depends on the certain constraints (bandwidth and packet dropout probability) of communication channel, the position of unstable poles and the non-minimum phase zeros of given model. Moreover, an acquired result clearly brings out the contact among the status of the researched system, communication channel parameters, and the structural property of the considered model. Some simulation examples are given to provide validation of the final result.
Qianhao Li,Qingsheng Yang,Xisheng Zhan,Jie Wu 제어·로봇·시스템학회 2024 International Journal of Control, Automation, and Vol.22 No.2
In this paper, we investigate the optimal regulation performance of networked time delay systems with limited bandwidth and interference signals. Communication networks are primarily influenced by parameters including bandwidth, packet dropouts, coding and decoding, interference signals, and channel noise. For a given system, non-minimum phase zeros, unstable poles, and time delay are considered. The corresponding regulation performance expressions are derived using coprime decomposition, spectral decomposition techniques, and norm correlation theory in the frequency domain. Results indicate that regulation performance is dependent on the location and direction of non-minimum phase zeros and unstable poles of a given system, as well as the internal time delay of the controlled plant. In addition, network communication parameters such as bandwidth, channel noise, packet dropouts, and external interference signals influence the performance of the regulation. Finally, simulation examples are provided to demonstrate the theory’s validity.
ULTRASONIC PREPARATION AND OPTICAL PROPERTIES OF HgWO4 NANOSHUTTLES
YAPING DING,RUNPING JIA,QINGSHENG WU 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2007 NANO Vol.2 No.1
A newly luminescent nanomaterial, monoclinic wolframite-type HgWO4 nanoshuttles (length: 200–300 nm; diameter: 100–150 nm) is prepared through ultrasonic method. For HgWO4 nanoshuttles, the fluorescent (FL) emitting peaks at 430 and 330 nm obviously blue shift compared with those of corresponding bulk crystals. Meanwhile, the latter almost disappear after ultrasonic irradiation procedure. A UV-visible blue-shifted (about 130 nm) absorption peak is observed at 280 nm and a new absorption peak is observed at 203 nm. FTIR results show all absorption peaks below 800 cm-1 shift to a longer wavenumber region, whereas those above 800 cm-1 remain invariable. All those unique optical performances might result from both quantum size effects and the involvement of the incompact d10 electrons. Moreover, the possible synthesis mechanism of HgWO4 nanoshuttles is also investigated.