New eremophilane-type sesquiterpenes from an Antarctic deepsea derived fungus, Penicillium sp. PR19 N-1

Aiqun Lin,Guangwei Wu,Qian Qun Gu,Tian-Jiao Zhu,De-Hai Li 대한약학회 2014 Archives of Pharmacal Research Vol.37 No.7

Chemical investigation of an Antarctic deepseaderived fungus Penicillium sp. PR19 N-1 yielded fivenew eremophilane-type sesquiterpenes 1–5 and a new rarelactam-type eremophilane 6, together with three knowncompounds 7–9. The structures of these diverse sesquiterpeneswere determined by extensive NMR and massspectroscopic analyses. Compounds 1, 2, 4–6, 8 and 9 wereevaluated for their cytotoxities against HL-60 and A-549human cancer cell lines, and 5 was the most active one withIC50 value of 5.2 lM against the A-549 cells.

Mechanism of Controllable Force Generated by Coupling Inverse Effect of Piezoelectricity and Magnetostriction

Aiqun Xu,Qianxing Gu,Haikuo Yu 한국정밀공학회 2021 International Journal of Precision Engineering and Vol.8 No.4

A method based on piezoelectric and magnetostrictive coupling inverse effect to generate precise controllable force is proposed to meet the requirement of manipulation force control in ultra-precision machining and assembly process. According to the principle of magnetic flux continuity, combine with the characteristics of piezoelectric and magnetostrictive inverse effects, the working mechanism of force generation is analyzed, and the theoretical model of the relationship between output force and parameters which include material characteristics, geometric parameters, working voltage of piezoelectric ceramics is established. An experimental device consisting of piezoelectric ceramic driving power supply, strain gauge, static strain tester, micro laser displacement sensor, force sensor, data acquisition card and magnetic force control component is developed. The relationship between output magnetic force and air gap or working voltage are studied by experiment and simulation. The results show that the output force variations of simulation and experiment are close. The output magnetic force fluctuation is small and with good stability. It verifies the consistency and correctness of the theoretical, simulation and experimental results.

New eremophilane-type sesquiterpenes from an Antarctic deep-sea derived fungus, Penicillium sp. PR19 N-1

Lin, Aiqun,Wu, Guangwei,Gu, Qianqun,Zhu, Tianjiao,Li, Dehai 대한약학회 2014 Archives of Pharmacal Research Vol.37 No.7

Chemical investigation of an Antarctic deep-sea derived fungus Penicillium sp. PR 19 N-1 yielded five new eremophilane-type sesquiterpenes 1-5 and a new rare lactam-type eremophilane 6, together with three known compounds 7-9. The structures of these diverse sesquiterpenes were determined by extensive NMR and mass spectroscopic analyses. Compounds 1, 2, 4-6, 8 and 9 were evaluated for their cytotoxities against HL-60 and A-549 human cancer cell lines, and 5 was the most active one with $IC_{50}$ value of $5.2{\mu}M$ against the A-549 cells.

ATMOSPHERIC REFRACTION EFFECTS ON LAMOST

SUN AIQUN,Hu JINGYAO The Korean Astronomical Society 1996 Journal of The Korean Astronomical Society Vol.29 No.suppl1

Large field spectrographs are severely influenced by atmospheric refraction. LAMOST is a large field multi-object spectroscopy telescope with $5^{\circ}$ field of view, f/5 focus ratio and 20m focal length. There will be 4000 fibers simultaneous on it's $\phi$1.75m focal plane. Here we discuss the atmospheric refraction effects on LAMOST in two hands. One is the effect of differential refraction across the field, another is the effect of atmospheric dispersion. According to the calculation, we find that: 1. The largest deviation from center within the field is 4.;32" during a 1.5-hour integration at $80^{\circ}$ declination. 2. The directions of deviation are complex, so the deviations can't be decreased by rotating the field. We also give out the atmospheric dispersions.

Study of the structural damage identification method based on multi-mode information fusion

Tao Liu,AiQun Li,YouLiang Ding,DaLiang Zhao 국제구조공학회 2009 Structural Engineering and Mechanics, An Int'l Jou Vol.31 No.3

Due to structural complicacy, structural health monitoring for civil engineering needs more accurate and effectual methods of damage identification. This study aims to import multi-source information fusion (MSIF) into structural damage diagnosis to improve the validity of damage detection. Firstly, the essential theory and applied mathematic methods of MSIF are introduced. And then, the structural damage identification method based on multi-mode information fusion is put forward. Later, on the basis of a numerical simulation of a concrete continuous box beam bridge, it is obviously indicated that the improved modal strain energy method based on multi-mode information fusion has nicer sensitivity to structural initial damage and favorable robusticity to noise. Compared with the classical modal strain energy method, this damage identification method needs much less modal information to detect structural initial damage. When the noise intensity is less than or equal to 10%, this method can identify structural initial damage well and truly. In a word, this structural damage identification method based on multi-mode information fusion has better effects of structural damage identification and good practicability to actual structures.

CDMA wireless computer LAN

Yun Shen,Aiqun Hu,Zhenya Ha 대한전자공학회 1996 대한전자공학회 워크샵 Vol.1996 No.-

Temperature-induced Variations of Measured Modal Frequencies of Steel Box Girder for a Long-span Suspension Bridge

YouLiang Ding,AiQun Li 한국강구조학회 2011 International Journal of Steel Structures Vol.11 No.2

This paper addresses the temperature-induced variations of measured modal frequencies of steel box girder for a suspension bridge using long-tem monitoring data. The output-only modal frequency identification of the bridge is effectively carried out using the Iterative Windowed Curve-fitting Method (IWCM) in the frequency-domain. The daily and seasonal correlations of frequency-temperature are investigated in detail and the analysis results reveal that: (i) the identified modal frequencies using IWCM provide an effective indication for changes of the bridge due to the ambient temperature variations; (ii) temperature is the critical source causing modal variability, and there is an overall decrease in modal frequency with temperature for all the identified modes; (iii) the random variations in measured modal frequencies mainly arise from the identification algorithm due to the nonstationary loadings, which can be effectively eliminated using multi-sample averaging technique; (iv) the daily averaged modal frequencies of vibration modes have remarkable seasonal correlations with the daily averaged temperature and the seasonal correlation models of frequency-temperature are suitable for structural damage warning if future seasonal correlation models deviate from these normal models.

Opportunities, Challenges and Tactics for Communication of Sports Academic Journals in the Era of AI and Multi-Media

Feifei Song,Aiqun Li,Yingya You 아시아건강운동학회 2023 Journal of Asian Society for Health & Exercise Vol.5 No.1

PURPOSE : With the advent of the AI and multi-media in 21st century, the innovation of media technology has brought new opportunities and challenges to the communication of academic journals. RESULTS : The study concluded that AI + multi-media can help sports academic journals realize the efficient production of academic papers, the diversified publication of academic achievements, and the precise distribution of academic ideas. CONCLUSIONS : It is also necessary to pay attention to the challenges, which are the accelerated imbalance in academic publishing ecology, slow enhancment of academic attractiveness, and becoming fomality in academic communication. The authors also puts forward the tactics, such as balancing technical rationality and value rationality, promoting the integration of technology and content, and strengthening the depth of accurate communication.

Preparation of NiO and CoO nanoparticles using M2+-oleate (M = NiCo) as precursor

Zhongping Chen,Aiqun Xu,Yu Zhang,Ning Gu 한국물리학회 2010 Current Applied Physics Vol.10 No.3

The preparation of NiO and CoO nanoparticles was reported. The dot-like NiO and flower-like CoO nanoparticles were obtained using M2+-oleate (M = Ni, Co) as precursor via thermal decomposition method. Transmission electron microscopic (TEM) images monitored the growth of NiO and CoO nanoparticles. When the reaction complex including M2+-oleate (M = Ni, Co) precursor, oleic acid and 1-octadecene was heated to the refluxing temperature (320 ℃), the formed NiO and CoO nanoparticles were needlelike and very small, indicating low growth speed. However, when the reaction complex was kept refluxing for 30 min, dot-like NiO and flower-like CoO nanoparticles were observed, suggesting the accelerated growth at this refluxing stage. The difference of the morphology of the resultant NiO and CoO nanoparticles resulted from the difference of their growth mode. Selected-area electron diffraction (SAED) patterns showed the face-centered cubic structures of NiO and CoO nanoparticles. The magnetic property of the nanoparticles was studied using vibrating sample magnetometer (VSM).

Effect of boundary conditions on modal parameters of the Run Yang Suspension Bridge

Zhijun Li,Aiqun Li,Jian Zhang 국제구조공학회 2010 Smart Structures and Systems, An International Jou Vol.6 No.8

Changes in temperature, loads and boundary conditions may have effects on the dynamic properties of large civil structures. Taking the Run Yang Suspension Bridge as an example, modal properties obtained from ambient vibration tests and from the structural health monitoring system of the bridge are used to identify and evaluate the modal parameter variability. Comparisons of these modal parameters reveal that several low-order modes experience a significant change in frequency from the completion of the bridge to its operation. However, the correlation analysis between measured modal parameters and the temperature shows that temperature has a slight influence on the low-order modal frequencies. Therefore, this paper focuses on the effects of the boundary conditions on the dynamic behaviors of the suspension bridge. An analytical model is proposed to perform a sensitivity analysis on modal parameters of the bridge concerning the stiffness of expansion joints located at two ends of bridge girders. It is concluded that the boundary conditions have a significant influence on the low-order modal parameters of the suspension bridge. In addition, the influence of vehicle load on modal parameters is also investigated based on the proposed model.