• 제목/요약/키워드: Ping

검색결과 1,340건 처리시간 0.022초

Cloning and Characterization of 6-Phosphogluconolactonase Gene in Silkworm Bombyx mori

  • Yang, HuaJun;Chen, KePing;Yao, Qin;Guo, ZhongJian
    • International Journal of Industrial Entomology and Biomaterials
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    • 제14권2호
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    • pp.69-74
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    • 2007
  • As the genome of B. mori is available in GenBank and the EST database of B. mori is expanding, identification of novel genes of B. mori was conceivable by datamining techniques and bioinformatics tools. In this study, we used the in silico cloning method to get the 6-Phosphogluconolactonase (6PGL) gene of B. mori and analysed with bioinformatics tools. The result was confirmed by RT-PCR and prokaryotic expression. The 6PGL cDNA comtains a 702 bp ORF. The deduced protein has 233 amino acid residues, with the predicted molecular weight of 25946. 72 Da, isoelectric point of 5.41, and contains conserved NagB domains. This gene has been registered in GenBank under the accession number EF198104.

Surface Modification of Titanium Based Biomaterials by Ion Beam

  • Liu, Xianghuai;Huang, Nan;Yang, Ping;Cai, Guanjun;Chen, Yuanru;Zheng, Zhi hong;Zhou, Zhuyao
    • 한국진공학회지
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    • 제4권S2호
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    • pp.8-19
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    • 1995
  • Ion beam enhanced deopsition(IBED) was adopted to synthesize biocompatible titanium oxide film. Structure characteristics of titanium oxide film were investigated by RBS, AES and XRD. The blood compatibility of the titanium oxide film was studied by measurements of blood clotting time and platelet adhesion. The results show that the anticoagulation property of titanium oxide film is improved significantly. The mechanism of anticoagulation of the titanium oxide film was discussed.

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자동차 공회전시 기어 치타음에 영향을 미치는 파라미터에 관한 연구 (A Study on the Parameters Influence upon Automotive Neutral Gear Rattle)

  • Hong, D.P.;Chung, T.J.;Ahn, B.M.;Jeon, B.H.
    • 한국정밀공학회지
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    • 제14권2호
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    • pp.74-83
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    • 1997
  • The non-periodic angular accelerations of engine are the major cause of gear rattle. This gear rattle is based on the existence of a backlash between the drive gear of input shaft and the free gear of output shaft in the gearbox. Especially, the neutral gear rattle have a very bad effect on the ride quality. Test-rig was constructed in order to evaluate the parameter influence upon the neutral gear rattle. Also, each different 4 type torsional characteristic of clutch was manufactured. Experimental conditions are the use of each different 4 type torsional characteristic of clutch and oil temperature variation in gearbox. In case of the same stiffiness of pre-damper type clutch at idling, the clutch of large hysteresis showed dam- ping effects at the 2nd input gear and the 2nd output gear. Also, the main-damper type clutch was shown to large resonance phenomenon at the 2nd input gear. Accordingly, main-damper type clutch was unapp- roriate at idling.

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Remarkable Productselectivity in Photocycloaddition of Diarl Compounds and in Photosensitized Oxidation of Alkenes within Supramolecular System

  • Chen-Ho Tung;Li-Zhu Wu;Zhen-Yu Yuan;Jing-Qu Guan;Hong-Wei Wang;Li-Ping Zhang
    • Journal of Photoscience
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    • 제6권3호
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    • pp.85-90
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    • 1999
  • Supramolecular photochemistry is concerned with systems where non-covalent interactions become significant or dominate in determining the chemistry of guest/host systems. The photocycloaddition of diaryl compounds and the photosensitized oxidation of alkenes included in zeolites, low-density polyethylene films and Nafion membranes is the subject of this report.

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A Comparison of Chinese Secondary School Mathematics In- and Pre-service teachers' beliefs about Mathematics, Mathematics Teaching and Learning

  • Jin, Meiyue;Guo, Yanmin;Dai, Feng;Jia, Ping
    • 한국수학교육학회지시리즈D:수학교육연구
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    • 제11권4호
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    • pp.221-234
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    • 2007
  • A comparison of mathematics teachers' personal beliefs between in- and pre-service teachers for Chinese secondary schools (grades 7-12) about mathematics theories, teaching and learning has been studied. In-service teachers' beliefs are close to constructivist's aspect and pre-service teachers' beliefs are close to absolutist's views. Based on the results, we give some suggestions to both teacher education and in-service teachers' training.

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The Third Wave: Chinese Students' Values in Effective Mathematics Teaching in Two Secondary Schools

  • Zhang, Qiao-Ping
    • 한국수학교육학회지시리즈D:수학교육연구
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    • 제18권3호
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    • pp.209-221
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    • 2014
  • In the last few decades there has been much interest in how mathematics can be effectively taught and learnt. The Third Wave is a unique ongoing international collaborative mathematics education research project, which aims to explore the relevant values of effective school mathematics teaching from both the teacher and student perspectives. As part of this project, this study investigates the related findings from students on the Chinese mainland. Multiple data were collected through classroom observations, focus group interviews, and written, open-ended questions. Twenty-four students from junior and senior secondary schools were invited to write down their views on an effective lesson, a good mathematics teacher, and how to do well in mathematics learning. Results showed that among the eight values determined in the study, the values of involvement, explanation, and examples were embraced by students across all grades. Students preferred teacher-led mathematics teaching. Junior secondary students placed more value on teachers' personalities, whereas senior students placed more value on teachers' teaching manners.

Secrecy Analysis of Amplify-and-Forward Relay Networks with Beamforming

  • Chen, Pu;Ouyang, Jian;Zhu, Wei-Ping
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제10권10호
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    • pp.5049-5062
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    • 2016
  • This paper analyzes the secrecy performance of an amplify-and-forward (AF) relay network, where a multi-antenna eavesdropper attempts to overhear the transmitted message from a multi-antenna source to a multi-antenna destination with a single antenna relay. Firstly, we derive the approximate analytical expressions for the secrecy outage probability (SOP) and average secrecy rate (ASR) of the relay network. Then, asymptotic expressions of SOP and ASR at high main-to-eavesdropper ratio (MER) are also provided to reveal the diversity gain of the secure communication. Finally, numerical results are given to verify the theoretical analysis and show the effect of the number of antennas in the considered relay network.

STABILITY OF POSITIVE STEADY-STATE SOLUTIONS IN A DELAYED LOTKA-VOLTERRA DIFFUSION SYSTEM

  • Yan, Xiang-Ping;Zhang, Cun-Hua
    • 대한수학회지
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    • 제49권4호
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    • pp.715-731
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    • 2012
  • This paper considers the stability of positive steady-state solutions bifurcating from the trivial solution in a delayed Lotka-Volterra two-species predator-prey diffusion system with a discrete delay and subject to the homogeneous Dirichlet boundary conditions on a general bounded open spatial domain with smooth boundary. The existence, uniqueness and asymptotic expressions of small positive steady-sate solutions bifurcating from the trivial solution are given by using the implicit function theorem. By regarding the time delay as the bifurcation parameter and analyzing in detail the eigenvalue problems of system at the positive steady-state solutions, the asymptotic stability of bifurcating steady-state solutions is studied. It is demonstrated that the bifurcating steady-state solutions are asymptotically stable when the delay is less than a certain critical value and is unstable when the delay is greater than this critical value and the system under consideration can undergo a Hopf bifurcation at the bifurcating steady-state solutions when the delay crosses through a sequence of critical values.

X. 25와 SDLC간 Protocol Converter의 성능 분석에 관한 연구 (Performance Analysis of A Protocol Converter Between X. 25 and SDLC)

  • 청해;은종관
    • 한국통신학회논문지
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    • 제16권9호
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    • pp.828-837
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    • 1991
  • 본 논문에서는 CCITT에서 채택된 X.2.5 network과 IBM이 채택한 System network architecture(SNA)의 synchronous data link control(SDLC)간의 protocol converter의 성능 분석을 한다. 여기서 protocol converter의 link level map-ping method를 사용하여 구현 되었다고 가정한다. 성능 분석을 통하여 각종 parameter에 대한 throughput과 mean waiting time을 구하며, 다양한 paramerter에 대하여 최적의 값을 조사한다. 특히 converter가 추정한 SDLC frame이 X.25. network packetizing과 규정한 최대 data packet size 보다 더 클 경우에 frame을 분할하게 되는데. 분할방식에 있어서 full and remainder packetzing과 equal packetizing 도입하여 서로간의 성능을 비교한다. message를 분할 할 때 조격으로 나누는 것이 frame의 오류를 줄일 수 있기 때문에 전자보다 후자가 성능면에서 우수함을 알 수 있다.

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Influence of fracture characters on flow distribution under different Reynold numbers

  • Wang, Jing;Li, Shu-Cai;Li, Li-Ping;Gao, Cheng-Lu
    • Geomechanics and Engineering
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    • 제14권2호
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    • pp.187-193
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    • 2018
  • Water inrush through the destruction of water resisting rock mass structure was divided into direct water inrush, key block water inrush and splitting water inrush. In the direct water inrush, the Reynolds numbers has a significant effect on the distribution of the water flow and vortex occurred in the large Reynolds numbers. The permeability coefficient of the fracture is much larger than the rock, and the difference is between 104 and 107 times. The traditional theory and methods are not considering the effect of inertia force. In the position of the cross fracture, the distribution of water flow can only be linearly distributed according to the fracture opening degree. With the increase of Reynolds number, the relationship between water flow distribution and fracture opening is studied by Semtex.