• Title/Summary/Keyword: Wuwei

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MBE-growth and Oxygen Pressure Dependent Electrical and Magnetic Properties of Fe3O4 Thin Films

  • Dung, Dang Duc;Feng, Wuwei;Sin, Yu-Ri-Mi;Thiet, Duong Van;Jo, Seong-Rae
    • Proceedings of the Korean Vacuum Society Conference
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    • 2011.02a
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    • pp.60-60
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    • 2011
  • Giant magnetoresistance (GMR), tunneling magnetoresistance (TMR), and magnetic random-access memory (MRAM) are currently active research areas in spintronics. The high magnetoresistance and the high spin polarization (P) of electrons in the ferromagnetic electrodes of tunnel junction or intermediate layers are required. Magnetite, Fe3O4, is predicted to possess as half-metallic nature, P ~ 100% spin polarization, and has a high Curie temperature (TC~850 K). Experiments demonstrated that the P~($80{\pm}5$)%, ~($60{\pm}5$)%, and ~40-55% for epitaxial (111), (110) and (001)-oriented Fe3O4 thin films, respectively. Epitaxial Fe3O4 films may enable us to investigate the effects of half metals on the spin transport without grain-boundary scattering.In addition, it has been reported that the Verwey transition (TV, a first order metal-insulator transition) of 120 K in bulk Fe3O4 is strongly affected by many parameters such as stoichiometry and stress, etc. Here we report that the growth modes, magnetism and transport properties of Fe3O4 thin films were strongly dependent on the oxygen pressure during film growth. The average roughness decreases from 1.021 to 0.263 nm for the oxygen pressure increase from $2.3{\times}10-7$ to $8.2{\times}10^{-6}$ Torr, respectively. The 120 K Verwey transition in Fe3O4 was disappeared for the sample grown under high oxygen pressure.

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Type Drive Analysis of Urban Water Security Factors

  • Gong, Li;Wang, Hong;Jin, Chunling;Lu, Lili;Ma, Menghan
    • Journal of Information Processing Systems
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    • v.16 no.4
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    • pp.784-794
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    • 2020
  • In order to effectively evaluate the urban water security, the study investigates a novel system to assess factors that impact urban water security and builds an urban water poverty evaluation index system. Based on the contribution rates of Resource, Access, Capacity, Use, and Environment, the study adopts the Water Poverty Index (WPI) model to evaluate the water poverty levels of 14 cities in Gansu during 2011-2018 and uses the least variance method to evaluate water poverty space drive types. The case study results show that the water poverty space drive types of 14 cites fall into four categories. The first category is the dual factor dominant type driven by environment and resources, which includes Lanzhou, Qingyang, Jiuquan, and Jiayuguan. The second category is the three-factor dominant type driven by Access, Use, and Capability, which includes Longnan, Linxia, and Gannan. The third category is the four-factor dominant type driven by Resource, Access, Capability, and Environment, which includes Jinchang, Pingliang, Wuwei, Baiyin, and Zhangye. The fourth category is the five-factor dominant type, which includes Tianshui and Dingxi. The driven types impacting the urban water security factors reflected by the WPI and its model are clear and accurate. The divisions of the urban water security level supply a reliable theoretical and numerical basis for an urban water security early warning mechanism.

A Study on the Excavated 『Liu Shi Bing Fang』 from the Lao Guan Shan Cemetery - focussed on Qi, Blood, and Attributive Channel Theory of Herbal Medicine - (노관산 한대 분묘 출토 의서 『육십병방(六十病方)』에 관한 고찰 - 기(氣), 혈(血), 본초 귀경(歸經)을 중심으로 -)

  • Jung, Seunghan;Kim, Kiwang
    • Journal of Korean Medical classics
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    • v.33 no.1
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    • pp.103-133
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    • 2020
  • Objectives : To determine the level of medicine in the Earlier Han period through 『Liushi Bing Fang』. Methods : Original texts were collected from previously published studies on 『Liushi Bing Fang』 and books to reconstruct the text of 『Liushi Bing Fang』. Results & Conclusions : 151 tablets out of the entire 213, a total of 4,084 characters out of the entire 9,000 were collected. This amounts to about 45% of the entire 『Liushi Bing Fang』. Based on this finding, we could summarize the following. First, the concept of Qi is used in the context of illness, indicating the usage of Qi as a medical concept to be much earlier than previously known, as it appears in a herbal treatment text. Second, on Blood, similarly to 『Wushier Bing Fang』 and 『Wuwei Handai Yijian』, it refers to the physical blood as well as name of disease. Moreover, the concept of stagnated blood is mentioned as 'neiyu(內瘀)' in 『Liushi Bing Fang』, meaning that the doctors of the time held this concept and also had the medicinal knowledge to treat this condition. Third, within 『Liushi Bing Fang』, there are contents on the body parts each medicinal mainly treats. This indicates to the understanding that not only were they at the level to connect each medicinals to its mainly applicable disease, but they were able to connect the herbal medicinals to the inner constructions of the body. Based on these findings, the first text to provide the base to the attributive channel theory of herbal medicinals, where each medicinal's properties and effects are connected to the Zangfu and body parts, needs to be newly acknowledged as 『Liushi Bing Fang』 instead of 『Shennongbencaojing』 as previously known.

The study of the Huang-Lao philosophy in the Wenzi (『문자(文子)』의 황노사상(黃老思想)에 대한 연구)

  • Kim, Yea-ho
    • The Journal of Korean Philosophical History
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    • no.39
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    • pp.169-194
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    • 2013
  • The Wenzi is the material criticized about the relation bamboo-slip literature and current literatures in the academic world. If is true or not, because we don't know the author and the records accurately. In this study, to sublate the researching method of HuangLao philosophy that vogues the boundary between Zajia, on the basis of volumes with bamboo-slip literature and the present literatures shared, I discuss the peculiarity of Wenzi HuangLao philosophy, comparing Dao-theory of Daoist. The Wenzi is HuangLao philosophy of Rujia pattern that doesn't understand as the Dao-Fa school. And its origin is Laozi philosophy. It accepts Zujia philosophy, putting first in importance about Rujia philosophy. In this study, the origin of the Wenzi is Laozi philosophy theoretically, but I discuss that the Wenzi is the early literature forming Rujia pattern HuangLao philosophy. And the Wenzi tries to combine the theory of Rujia in the social political category.

Military science's understanding on Daodejing of Wangzhen (왕진의 『도덕경』에 대한 병학적 이해)

  • Kim, Tae-yong
    • The Journal of Korean Philosophical History
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    • no.23
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    • pp.295-316
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    • 2008
  • This is to study the military philosophy of Wangzhen's Commentary on Daodejing written by a famous military officer in the end of Tang Dynasty, Wangzhen. Historically, many scholars consider Laozi's Daodejing as a book on military science. Wangzhen, however, is the only person to interpret Daodejing genealogically from a military perspective. Wangzhen thinks that the fact that human beings like competing naturally causes the constant competition in the world. Human beings are born with the most outstanding spirit among all beings. But, when God created human beings, they had greed and avarice in the middle of their heart. Accordingly, human beings look for a success and a profit, and follow the wicked way, leaving the right way. The contractions among each greed and avarice bring about small or big competitions. Human beings have greed and avarice. It means human beings have emotions. As a result, the competitions in the world are not able to disappear because human beings have emotions. To win the completion human beings use weapons. According to Wangzhen, the war is the most devilish deed due to the weapon's atrocious, dangerous quality. Yet, the world's interests are decided by how efficiently the weapons are used. Consequently, the weapon techniques are worthy and play an important role in the real world. Morality, however, should be in the first priority in ruling over a country and commanding the army. The national security and the war victory could be secured when civil and military affairs have a balance. Wangzhen thinks that Laozi emphasizes "Not-Competing" as a basic solution of competition. The competition is the root cause of war and disorder. Therefore, Not-Competing is the main idea of Daodejing. Not-Competiting is a basis of Wangzhen's military philosophy as well. For Wangzhen, Not-Competing is Wuwei. Wuwei has political and military meanings at the same time. Wangzhen build up the "Not-Competing" military philosophy by applying Loazi's Daodejing to his military philosophy.

Strain induced/enhanced ferromagnetism in $Mn_3Ge_2$thinfilms

  • Dung, Dang Duc;Feng, Wuwei;Thiet, Duong Van;Sin, Yu-Ri-Mi;Jo, Seong-Rae
    • Proceedings of the Korean Vacuum Society Conference
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    • 2010.02a
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    • pp.135-135
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    • 2010
  • In Mn-Ge equilibrium phase diagram, many Mn-Ge intermetallic phases can be formed with difference structures and magnetic properties. The MnGe has the cubic structure and antiferromagnetic(AFM) with Neel temperature of 197 K. The calculation predicted that the $MnGe_2$ with $Al_2Cu$-type is hard to separate between the paramagnetic(PM) states and the AFM states because this compound displays PM and AFM configuration swith similar energy. Mn-doped Ge showed the FM with Currie temperature of 285 K for bulk samples and 116 K for thin films. In addition, the $Mn_5Ge_3$ compound has hexagonal structure and FM with Curie temperature around 296K. The $Mn_{11}Ge_8$ compound has the orthorhombic structure and Tc is low at 274 K and spin flopping transition is near to 140 K. While the bulk $Mn_3Ge_2$ exhibited tetragonal structure ($a=5.745{\AA}$;$c=13.89{\AA}$) with the FM near to 300K and AFM below 150K. However, amorphous $Mn_3Ge_2$ ($a-Mn_3Ge_2$) was reported to show spin glass behavior with spin-glass transition temperature (Tg) of 53 K. In addition, the transition of crystalline $Mn_3Ge_2$ shifts under high pressure. At the atmospheric pressure, $Mn_3Ge_2$ undergoes the magnetic phase transition from AFM to FM at 158 K. The pressure dependence of the phase transition in $Mn_3Ge_2$ has been determined up to 1 GPa. The transition was found to occur at 1 GPa and 155 K with dT/dP=-0.3K/0.1 GPa. Here report that Ferromagnetic $Mn_3Ge_2$ thin films were successfully grown on GaAs(001) and GaSb(001) substrates using molecular beam epitaxy. Our result revealed that the substrate facilitates to modify magnetic and electrical properties due to tensile/compressive strain effect. The spin-flopping transition around 145 K remained for samples grown on GaSb(001) while it completely disappeared for samples grown on GaAs(001). The antiferromagnetism below 145K changed to ferromagnetism and remained upto 327K. The saturation magnetization was found to be 1.32 and $0.23\;{\mu}B/Mn$ at 5 K for samples grown on GaAs(001) and GaSb(001), respectively.

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Music, Language, and Life in Daoism and Confucianism (음악과 언어, 그리고 삶 - 도가와 유가를 중심으로 -)

  • Chung, Yong-Hwan
    • Journal of Korean Philosophical Society
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    • v.105
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    • pp.373-400
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    • 2008
  • This essay is an analysis on Daoist deconstructivism and Confucian constructivism about music and language. (1) Daoist criticizes that the Confucian constructive music and language fail to describe original sounds and original facts of doing nothing (wuwei, 無爲). According to Daoist, music and language can be an instrument to describe true facts in the world. So Daoists try to attain a state of 'seeing things as things themselves (yiwuguanwu, 以物觀物)' by 'forgetting oneself (wangwo, 忘我).' (2) However Confucian music and language is a part of one's life. Confucians try to get truth, goodness, and beauty by exercising one's music and language. Confucian music is associated with political and moral development in society. The Confucian genres of poetry (shi, 詩), appealing letter (shu, 疏), declaring writing (biao, 表), record (ji, 記), and written words (ci, 詞) are processes of developing one's life. Further, Confucian rhetoric of 'Xing (興)' in writing poem shows that one's language can be developed in contexts of one's life. (3) Although music and language is associated with human subjective narratives as if Confucians say, diverse narratives of different subjectivity cannot appear in one's lives if all kinds of narrative is absorbed in Confucian absolute ideological slogan to devide things into good and bad. Accordingly, the Confucian view of music and language can develop diverse narratives when it does not show an inclination toward moral dichotomy preunderstood by Confucian ideology.

Effect of Codonopsis pilosula polysaccharide on the quality of sheep semen preservation at 4℃

  • Yuqin Wang;Yanhong Zhao;Hua Chen;Tingting Lu;Rujie Yang;Xiuxiu Weng;Wanhong Li
    • Animal Bioscience
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    • v.37 no.6
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    • pp.1001-1006
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    • 2024
  • Objective: This study aimed to investigate the effect of Codonopsis pilosula polysaccharide (CPP) on the motility, mitochondrial integrity, acrosome integrity rate, and antioxidant ability of sheep sperm after preservation at 4℃. Methods: Semen from healthy adult rams were collected and divided into four groups with separate addition of 0, 200, 400, and 1,000 mg/L CPP. Sperm motility was analyzed using the Computer-Assisted Semen Analysis software after preservation at 4℃ for 24, 72, 120, and 168 h. Sperm acrosome integrity rate was analyzed by Giemsa staining at 24, 72, and 120 h, and mitochondrial membrane integrity was analyzed by Mito-Tracker Red CMXRos. The total antioxidant capacity (T-AOC) and malondialdehyde (MDA) content of spermatozoa were measured after 120 h of preservation. Results: The sperm viability and forward-moving sperm under 200 mg/L CPP were significantly higher than that in the control group at 72 h (61.28%±3.89% vs 52.83%±0.70%, 51.53%±4.06% vs 42.84%±1.14%), and 168 h (47.21%±0.85% vs 41.43%±0.37%, 38.68%±0.87% vs 31.68%±0.89%). The percentage of fast-moving sperm (15.03%±1.10% vs 11.39%±1.03%) and slow-moving sperm (23.63%±0.76% vs 20.29%±1.11%) in the 200 mg/L group was significantly higher than control group at 168 h. The mitochondrial membrane integrity of the sperm in the group with 200 mg/L CPP was significantly higher than those in the control group after storage at 4℃ for 120 h (74.76%±2.54% vs 65.67%±4.51%, p<0.05). The acrosome integrity rate in the group with 200 mg/L (87.66%±1.26%) and 400 mg/L (84.00%±2.95%) was significantly higher than those in the control group (80.65%±0.16%) after storage for 24 h (p<0.05). CPP also increased T-AOC and decreased the MDA concentration after preservation at 4℃ (p<0.05). Conclusion: Adding CPP could improve the T-AOC of sperm, inhibit lipid peroxidation, and facilitate semen preservation.