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Output characteristics and experiments of a novel low frequency rotary piezoelectric motor
Kang Liang,Chong Li,Yujian Tong,Jiwen Fang,Wei Zhong,Xiaorui Fu 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.3
In order to improve the output performance of a piezoelectric motor under low driving frequency, a novel rotary piezoelectric motor driven by two piezoelectric actuators is proposed that is actuated based on harmonic and friction driving mechanism. The motor uses two piezoelectric actuators to drive two amplifying mechanisms with π/2 phase difference to produce harmonic motion, and then drives the rotor to rotate through friction force. Based on the driving principle, the electromechanical coupling equations of the motor are established. And a test platform is built to test the output characteristics of the motor. The results show that fluctuation of harmonic force and output torque occurs when the motor operates at different positions. Under the driving voltage and frequency of 150 V and 5 Hz, the actual average output torque of the prototype is 3.08 Nmm. Moreover, fluctuation of harmonic force and output torque occurs when the motor operates at different positions.
Peng Chen,Kangliang Guo,Ning Li,Song Lu,Lili Lin 한국자원공학회 2019 Geosystem engineering Vol.22 No.6
Fractured horizontal wells have been widely used in tight reservoirs. The distribution of the formation pressure is related to the fracturing design, well pattern optimization and development effect. In addition, there is generally a stress sensitivity effect in tight reservoirs, which makes the pressure distribution more complex. Therefore, it is necessary to analyze the formation pressure distribution in the development process of tight reservoirs by fractured horizontal wells. In this paper, using the Pedrosa transform, perturbation transform, Green formula and boundary element method, a pressure calculation model is first built and solved for a stress-sensitive reservoir with a multistage fractured horizontal well. Second, comparing the bottom hole pressure of this method with those of existing tight reservoir models illustrates the accuracy of this model. Finally, pressure contours with different permeability moduli and boundaries are obtained by solving the seepage model. The results indicate that this model can conveniently calculate the pressure at any position in stress-sensitive reservoirs with arbitrary boundaries. The pressure contours show that the stress-sensitive effect occurs mainly near the wellbore and affects the pressure distribution of this region. The results have a certain significance for fracturing design and well pattern optimization, which is beneficial for improving the development efficiency of tight oil reservoirs.
Yue Liu,Xueqing Yang,Kangliang Peng,Qiong Wang,Jianzhen Huang,Zilin Zhang,Jiang Lu,Hao Xu,Jieguang Song,Lin Chen 한양대학교 세라믹연구소 2019 Journal of Ceramic Processing Research Vol.20 No.4
Yttrium aluminum garnet (YAG), which possesses excellent properties, is investigated and applied. The sintering technology of YAG porous ceramics is optimized. Results show that the porosity initially increases and then decreases with an increase of increasing temperature rate, the porosity are decreased with an increase of removing carbon temperature, the porosity are decreased with an increase of sintering temperature, the porosity are decreased with an increase of holding time. Meanwhile, the compressive strength constantly exhibits an opposite tendency. The optimization of the sintering technology of YAG porous ceramics is based on porosity and compressive strength. A good sintering technology are an increasing temperature rate of 8 oC/min, a removing carbon temperature of 800 oC, removing carbon time of 1 h, a sintering temperature of 1450 oC and holding time of 2 h. The porosity of the prepared YAG porous ceramics is 57.4%, and the compressive strength is 8.89 MPa.
Highly stable N-doped carbon dots as the sensitive probe for the detection of Fe3+
Zhao Youjun,Yu Lixin,Deng Yakun,Peng Kangliang,Huang Shuai 한국물리학회 2023 Current Applied Physics Vol.50 No.-
The nitrogen-doped carbon dots (NCDs) are facilely fabricated by a one-step hydrothermal strategy using citric acid and o-phenylenediamine as start ingredient. The as-synthesized NCDs with a high quantum yield of 38.63% at 370 nm excitation maintain significant fluorescence stability in various complex environments, indicating that NCDs have the possibility of application in harsh environments. Moreover, after adding the Fe3+ to this as-synthesized NCDs, the emission intensity at 446 nm is remarkably reduced and exhibits line-dependent relationship in the range of 0.5–90 μM with a detection limit of 0.37 μM. Meanwhile, the fluorescence lifetime and absorption characteristics are compared respectively, and Stern-Volmer is calculated. These results illustrate that the quenched fluorescence is attributed to the synergistic effect of internal filtration effect (IFE) and static quenching. Moreover, this carbon-based sensing material has elevated efficiency in detecting Fe3+ in practical samples, implying that the sensing probe provides a fast and accurate new technique for the detection of Fe3+.
Dong Xinyuan,Si Jiali,Zhang Guanghui,Shen Zhen,Zhang Li,Sheng Kangliang,Wang Jingmin,Kong Xiaowei,Zha Xiangdong,Wang Yongzhong 한국미생물학회 2021 The journal of microbiology Vol.59 No.8
Arthrobotrys oligospora is a model species of nematophagous fungi and has great potential for the biological control of nematode diseases. Lectin is a protein that binds to carbohydrates and their complexes with high specificity, which mediates recognition events in various physiological and pathological processes. This study aimed to investigate the role of the Jacalin-related lectin (JRL) gene, AOL_s00083g511, in A. oligospora development. Through a homology recombination approach, we obtained the AOL_s00083g511 knockout mutant strain (Δg511). Next, the biological characteristics of the Δg511 mutant strain, including growth rate, conidia germination rate, adaptation to environmental stresses, and nematocidal activity, were compared with those of the wild-type (WT) strain. The results showed that the JRL gene AOL_ s00083g511 did not affect fungal growth, conidia germination, 3D-trap formation, and the ability of A. oligospora to prey on nematodes significantly. We speculate that this phenomenon may be caused by a loss of the key β1–β2 loops in the AOL_ s00083g511-encoded JRL domain and an intrinsic genetic compensation of AOL_s00083g511 in this fungus. The growth rates of both strains on high salt or surfactant media were similar; however, in the strong oxidation medium, the growth rate of the Δg511 mutant was significantly lower than that of the WT strain, indicating that AOL_s00083g511 might play a role in oxidative stress resistance. These findings provide a basis for further analysis of the related functions of the JRL gene in A. oligospora and their potential roles in the biological control of nematodes in the future.