• 제목/요약/키워드: physics education

검색결과 947건 처리시간 0.035초

Atomistic simulations of defect accumulation and evolution in heavily irradiated titanium for nuclear-powered spacecraft

  • Hai Huang;Xiaoting Yuan;Longjingrui Ma;Jiwei Lin;Guopeng Zhang;Bin Cai
    • Nuclear Engineering and Technology
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    • 제55권6호
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    • pp.2298-2304
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    • 2023
  • Titanium alloys are expected to become one of the candidate materials for nuclear-powered spacecraft due to their excellent overall performance. Nevertheless, atomistic mechanisms of the defect accumulation and evolution of the materials due to long-term exposure to irradiation remain scarcely understood by far. Here we investigate the heavy irradiation damage in a-titanium with a dose as high as 4.0 canonical displacements per atom (cDPA) using atomistic simulations of Frenkel pair accumulation. Results show that the content of surviving defects increases sharply before 0.04 cDPA and then decreases slowly to stabilize, exhibiting a strong correlation with the system energy. Under the current simulation conditions, the defect clustering fraction may be not directly dependent on the irradiation dose. Compared to vacancies, interstitials are more likely to form clusters, which may further cause the formation of 1/3<1210> interstitial-type dislocation loops extended along the (1010) plane. This study provides an important insight into the understanding of the irradiation damage behaviors for titanium.

물리문제 해결에 관한 초심자의 프로토콜분석 연구 (A Study on Analysis of Novice's Protocol in Solving Physics Problems)

  • 박학규;권재술
    • 한국과학교육학회지
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    • 제10권1호
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    • pp.57-64
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    • 1990
  • In this study, novices' protocols were investigated on the basis of Mayer's analysis of mathematical problem solving. These protocols were obtained by Jae-Sool Kwon and Seong-Wang Lee(1988) by means of thinking aloud while 20 sophomore students in a department of physics education were solving physics problems on Newton's low of motion. The results of investiqation are as follows; (1) We proposed an effective method in analyzing protocols on physics porblem solving (2) We could find the defective types of knowledge of individuals who got an incorrect solution, through analyzing the cause of failure individually (3) The fact that many students considered first the frictional force as muntiplying the coefficient of friction by perpendicular force rather than as resistance of motion, was found And students' misconception on the coefficient of friction was found. (4) If such analyses of test items and protocols are used in physics education, they will be very useful for finding the faults of problem-solving process, and for setting and scoring subjective problems in physics

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물리보다 수학을 잘 해야 물리를 잘 한다: 입학 전 수학진단점수의 일반물리학 성취도 예측타당성 검증 (Mathematical Preparedness Predicts College Grades in Physics Better than Physics Preparedness: the Predictive Validity of the Mathematical Diagnostic Test on the Freshmen's Physics Grades)

  • 신윤경;박규열;이아름;정종원
    • 공학교육연구
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    • 제22권4호
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    • pp.22-31
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    • 2019
  • This study aims to elucidate the relationship between physics and mathematics to predict achievement for the college level of engineering courses. For the last 4 years, more than 3,000 engineering college freshmen of this study took the diagnostic tests on three subjects, which were physics, mathematics, and chemistry before enrollment. We studied how strongly these diagnostic scores can predict each general college course grades. The correlation between the physics diagnostic scores and the course grades in physics was .264, which was significantly lower than the correlation between the mathematics scores and the physics grades, .311. This stronger prediction of the mathematical diagnostic scores for the general course grades was not found when predicting the grades in chemistry. We therefore conclude that mathematical preparation can unexpectedly predict future achievement in physics better than physics preparation due to the academic interrelationships between mathematics and physics.

One-dimensional magnetic photonic crystals

  • Kim J.B.;Lee G.J.;Lee Y.P.;Rhee J.Y.;Kim K.W.;Yoon C.S.
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2006년도 제31회 학술논문발표회 초록집
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    • pp.91-91
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    • 2006
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