• 제목/요약/키워드: Qun

검색결과 163건 처리시간 0.03초

The Investigation of Electro-Oxidation of Methanol on Pt-Ru Electrode Surfaces by in-situ Raman Spectroscopy

  • She, Chun-Xing;Xiang, Juann;Ren, Bin;Zhong, Qi-Ling;Wang, Xiao-Cong;Tian, Zhong-Qun
    • 전기화학회지
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    • 제5권4호
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    • pp.221-225
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    • 2002
  • Assisted by the highly sensitive confocal microprobe Raman spectrometer and proper surface roughening procedure, the Raman investigation on the adsorption and reaction of methanol was performed on Pt-Ru electrodes with different coverages. A detailed description of the roughening process of the Pt electrodes and the underpotential deposition of the Ru was given. Reasonably good Raman signal reflecting the metal-carbon vibration and CO vibration was detected. The appearance of vibrations of the Ru oxides, together with the existence of Ru-C, Pt-C and CO bands, clearly demonstrates the participation of the bi-functional mechanism during the oxidation process of methanol on Pt-Ru electrodes. The Pt-Ru electrode was found to have a higher catalytic activity over Pt electrodes. This preliminary study shows that electrochemical Raman spectroscopy can be applied to the study of rough electrode surface.

Simultaneous Determination of Tin, Nickel, Lead, Cadmium and Mercury in Cigarette Material by Solid Phase Extraction and HPLC

  • Hu, Qun;Yang, Guangyu;Ma, Jing;Liu, Jikai
    • Bulletin of the Korean Chemical Society
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    • 제24권10호
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    • pp.1433-1436
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    • 2003
  • A new method for the simultaneous determination of heavy metal ions in cigarette material by microwave digestion and reversed-phase high-performance liquid chromatography (RP-HPLC) has been developed. The cigarette material was digested by microwave digestion. Lead, cadmium, mercury, nickel and tin ions in the digested samples were pre-column derivatized with tetra-(2-chlorophenyl)-porphyrin ($T_2$-CPP) to form color chelates, which were then enriched by solid phase extraction with a $C_{18}$ cartridge. The chelates were separated on a Waters Xterra$^{TM}RP_{18}$ column by gradient elution with methanol (containing 0.05 mol/L pyrrolidine-aceticacid buffer salt, pH = 10.0) and acetone (containin0.05 mol/L pyrrolidine-acetic acid buffer salt, pH = 10.0)as mobile phase at a flow rate of 0.5mL/min and analyzed with a photodiode array detector from 350-600 nm. The detection limits of lead, cadmium, mercury, nickel and tin were 4,3,3,8 and 5 ng/L, respectively, in the original samples. This method was afforded good results.

The nonconserved N-terminus of protein phosphatases 1 influences its active site

  • Xie, XiuJie;Huang, Wei;Xue, ChengZhe;Wei, Qun
    • BMB Reports
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    • 제41권12호
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    • pp.881-885
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    • 2008
  • Protein phosphatase 1 consists of a secondary structure arrangement, conserved in the serine/threonine protein phosphatase gene family, flanked by nonconserved N-terminal and C-terminal domains. The deletion mutant of PP1 with the 8 nonconserved N-terminal residues removed was designated PP1-(9-330). PP1-(9-330) had a higher activity and affinity than PP1 when assayed against four different substrates, and it also demonstrated a 6-fold higher sensitivity to the inhibitor okadaic acid. This suggested that the N-terminal domain suppresed the activity of PP1 and interfered with its inhibition by okadaic acid. The ANS fluorescence intensity of PP1-(9-330) was greater than that of PP1, which implies that the hydrophobic groove running from active site in the truncated PP1 was more hydrophobic than in PP1. Our findings provide evidence that the nonconserved N-terminus of PP1 functions as an important regulatory domain that influences the active site and its pertinent properties.

Four Butenolides are Novel Cytotoxic Compounds Isolated from the Marine-Derived Bacterium, Streptoverticillium luteoverticillatum 11014

  • Li, De-Hai;Zhu, Tian-Jiao;Liu, Hong-Bing;Fang, Yu-Chun;Gu, Qian-Qun;Zhu, Wei-Ming
    • Archives of Pharmacal Research
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    • 제29권8호
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    • pp.624-626
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    • 2006
  • Four known butenolides were isolated from the ethyl acetate extracts of the culture broth of the marine-derived bacterium, Streptoverticillium luteoverticillatum, by bioassay-guided fractionation. The structures were identified on the basis of spectral data. The absolute configuration of compound (1) was determined by CD spectrum for the first time. Compounds 1-4 showed in vitro cytotoxicity against the murine lymphoma P388 and human leukemia K562 cell lines. This is the first report on the isolation of butenolides from the marine bacterium, Streptoverticillium luteoverticillatum, and their cytotoxic activities.

Capacitive sensor for the detection of residual quantity of intravenous drip solution in a plastic intravenous bag

  • Wei, Qun;Woo, Sang-Hyo;Mohy-Ud-Din, Zia;Kim, Dong-Wook;Won, Chul-Ho;Cho, Jin-Ho
    • 센서학회지
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    • 제19권4호
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    • pp.271-277
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    • 2010
  • Intravenous(IV) drip therapy is extensively used for all kinds of treatments. It works by delivering medicine directly into the vein. When the medicine has been fully dispensed, a dangerous situation occurs since air in the IV drip bag could enter the patient's vein, which is hazardous to the patient’s safety. In this paper, using capacitive sensors to detect the residual quantity of a plastic IV drip pack is proposed. A simulation model of this technology was shown by a finite elements analysis(FEA) program to find out its feasibility and analyze the proper geometrical dimension of a capacitive sensor. According to the FEA simulation, 3 kinds of capacitive sensors were attached to the bottom surface of the plastic IV drip bag to detect the residual quantity in the experiment. Experimental data showed an agreement with the FEA simulation model estimation and confirmed that the sensor works.

Establishment of a Micro-Particle Bombardment Transformation System for Dunaliella salina

  • Tan Congping;Qin Song;Zhang Qun;Jiang Peng;Zhao Fangqing
    • Journal of Microbiology
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    • 제43권4호
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    • pp.361-365
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    • 2005
  • In this study, we chronicle the establishment of a novel transformation system for the unicellular marine green alga, Dunaliella salina. We introduced the CaMV35S promoter-GUS construct into D. salina with a PDS1000/He micro-particle bombardment system. Forty eight h after transformation, via histochemical staining, we observed the transient expression of GUS in D. salina cells which had been bombarded under rupture-disc pressures of 450 psi and 900 psi. We observed no GUS activity in either the negative or the blank controls. Our findings indicated that the micro-particle bombardment method constituted a feasible approach to the genetic transformation of D. salina. We also conducted tests of the cells' sensitivity to seven antibiotics and one herbicide, and our results suggested that 20 ${\mu}g$/ ml of Basta could inhibit cell growth completely. The bar gene, which encodes for phosphinothricin acetyltransferase and confers herbicide tolerance, was introduced into the cells via the above established method. The results of PCR and PCR-Southern blot analyses indicated that the gene was successfully integrated into the genome of the transformants.

A new perspective towards the development of robust data-driven intrusion detection for industrial control systems

  • Ayodeji, Abiodun;Liu, Yong-kuo;Chao, Nan;Yang, Li-qun
    • Nuclear Engineering and Technology
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    • 제52권12호
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    • pp.2687-2698
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    • 2020
  • Most of the machine learning-based intrusion detection tools developed for Industrial Control Systems (ICS) are trained on network packet captures, and they rely on monitoring network layer traffic alone for intrusion detection. This approach produces weak intrusion detection systems, as ICS cyber-attacks have a real and significant impact on the process variables. A limited number of researchers consider integrating process measurements. However, in complex systems, process variable changes could result from different combinations of abnormal occurrences. This paper examines recent advances in intrusion detection algorithms, their limitations, challenges and the status of their application in critical infrastructures. We also introduce the discussion on the similarities and conflicts observed in the development of machine learning tools and techniques for fault diagnosis and cybersecurity in the protection of complex systems and the need to establish a clear difference between them. As a case study, we discuss special characteristics in nuclear power control systems and the factors that constraint the direct integration of security algorithms. Moreover, we discuss data reliability issues and present references and direct URL to recent open-source data repositories to aid researchers in developing data-driven ICS intrusion detection systems.

수온 모니터링 기능을 탑재한 심장마비 방지용 목욕 보조 시스템 (Development of a Bath Assistive System with Water Temperature Monitoring to Prevent Heart Attack)

  • 강소명;웨이췬
    • 한국멀티미디어학회논문지
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    • 제22권2호
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    • pp.242-249
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    • 2019
  • Old people and patients with cardiovascular disease could die of a heart attack in the bath with heated water for a long time. Various researches have been studied to prevent these accidents from happening such as measuring the ECG signal when taking bath. However, these devices are hard to use and the higher price is not easily accepted by the public. In this paper, a low-cost and use-friendly, real time high precision water temperature monitoring device to prevent heart attack in the bath was developed. The device with waterproof design that lets the device can float on the surface of the water, and an accurate way to make water temperature measurement method was proposed by this paper that is immerging the sensor into water with 4cm depth to measure the temperature of underwater. The manufactured device was conducted to two experiments; one was to verify the basic functions of the device, and another one was for compare the proposed device with commercial products for monitoring the water temperature in the bathtub. As the experimental results shown, the proposed device has stable performance for the water temperature measurement and communicating with laptop in wireless.

A Video Expression Recognition Method Based on Multi-mode Convolution Neural Network and Multiplicative Feature Fusion

  • Ren, Qun
    • Journal of Information Processing Systems
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    • 제17권3호
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    • pp.556-570
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    • 2021
  • The existing video expression recognition methods mainly focus on the spatial feature extraction of video expression images, but tend to ignore the dynamic features of video sequences. To solve this problem, a multi-mode convolution neural network method is proposed to effectively improve the performance of facial expression recognition in video. Firstly, OpenFace 2.0 is used to detect face images in video, and two deep convolution neural networks are used to extract spatiotemporal expression features. Furthermore, spatial convolution neural network is used to extract the spatial information features of each static expression image, and the dynamic information feature is extracted from the optical flow information of multiple expression images based on temporal convolution neural network. Then, the spatiotemporal features learned by the two deep convolution neural networks are fused by multiplication. Finally, the fused features are input into support vector machine to realize the facial expression classification. Experimental results show that the recognition accuracy of the proposed method can reach 64.57% and 60.89%, respectively on RML and Baum-ls datasets. It is better than that of other contrast methods.

Radioactive gas diffusion simulation and inhaled effective dose evaluation during nuclear decommissioning

  • Yang, Li-qun;Liu, Yong-kuo;Peng, Min-jun;Ayodeji, Abiodun;Chen, Zhi-tao;Long, Ze-yu
    • Nuclear Engineering and Technology
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    • 제54권1호
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    • pp.293-300
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    • 2022
  • During the decommissioning of the nuclear facilities, the radioactive gases in pressure vessels may leak due to the demolition operations. The decommissioning site has large space, slow air circulation, and many large nuclear facilities, which increase the difficulty of workers' inhalation exposure assessment. In order to dynamically evaluate the activity distribution of radionuclides and the committed effective dose from inhalation in nuclear decommissioning environment, an inhalation exposure assessment method based on the modified eddy-diffusion model and the inhaled dose conversion factor is proposed in this paper. The method takes into account the influence of building, facilities, exhaust ducts, etc. on the distribution of radioactive gases, and can evaluate the influence of radioactive gases diffusion on workers during the decommissioning of nuclear facilities.