830 research outputs found

    Chemical Self Assembly of Graphene Sheets

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    Chemically derived graphene sheets were found to self-assemble onto patterned gold structures via electrostatic interactions between noncovalent functional groups on GS and gold. This afforded regular arrays of single graphene sheets on large substrates, characterized by scanning electron and Auger microscopy imaging and Raman spectroscopy. Self assembly was used for the first time to produce on-substrate and fully-suspended graphene electrical devices. Molecular coatings on the GS were removed by high current electrical annealing, which recovered the high electrical conductance and Dirac point of the GS. Molecular sensors for highly sensitive gas detections are demonstrated with self-assembled GS devices.Comment: Nano Research, in press, http://www.thenanoresearch.co

    Determinace kreditního rizika u portfolia dluhových aktiv

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    For managers, it is important to manage the risk in banks. Risk management include identify and prioritization of risks, then adjust the risks to make it minimize. The aim of risk management is to assure uncertainty does not influence the company’s business goal. It has many kinds of risks, but the most important risk is credit risk. The aim of this thesis is to determine the capital requirement for unexpected losses from credit risk of the portfolio under Basel agreement include Basel I, II, III and use CreditMetricTM model to determine the economic capital of the portfolio. There are three main chapter in this thesis, in chapter two and chapter three were both theory part. In chapter two was the description of the financial risk. It was include credit risk, market risk, liquidity risk, operational risk and other risks. In chapter three was the introduction of some models that can use to calculate credit risk, the main model is CreditMetricTM model and Basel agreement. Chapter four was the most important chapter, it was the calculation part in this thesis, we find ten bonds that trade on Frankfurt stock exchange with the nominal value of each bonds is 10 million euro. The capital requirement under the risk from unexpected loss, standard approach and foundation internal rating-based approach include in Basel agreement can be used. The economic capital of ten bonds portfolio was calculate by CreditMetricTM model. All the companies and individual need to have risk management as a planning, under risk management the unexpected loss can be prepared before the accident, make the loss and cost in the minimum value, all the management and how important it is we have been shown in this thesis.For managers, it is important to manage the risk in banks. Risk management include identify and prioritization of risks, then adjust the risks to make it minimize. The aim of risk management is to assure uncertainty does not influence the company’s business goal. It has many kinds of risks, but the most important risk is credit risk. The aim of this thesis is to determine the capital requirement for unexpected losses from credit risk of the portfolio under Basel agreement include Basel I, II, III and use CreditMetricTM model to determine the economic capital of the portfolio. There are three main chapter in this thesis, in chapter two and chapter three were both theory part. In chapter two was the description of the financial risk. It was include credit risk, market risk, liquidity risk, operational risk and other risks. In chapter three was the introduction of some models that can use to calculate credit risk, the main model is CreditMetricTM model and Basel agreement. Chapter four was the most important chapter, it was the calculation part in this thesis, we find ten bonds that trade on Frankfurt stock exchange with the nominal value of each bonds is 10 million euro. The capital requirement under the risk from unexpected loss, standard approach and foundation internal rating-based approach include in Basel agreement can be used. The economic capital of ten bonds portfolio was calculate by CreditMetricTM model. All the companies and individual need to have risk management as a planning, under risk management the unexpected loss can be prepared before the accident, make the loss and cost in the minimum value, all the management and how important it is we have been shown in this thesis.154 - Katedra financívelmi dobř

    A Comparison of Experiences and Preferences Regarding Classroom and Tutoring Feedback among Chinese and Saudi Learners of English

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    This report studies ESL tutoring feedback to Chinese and Saudi students. The objective is to research the reasons of feedback differences and similarities, which include previous and current English learning styles, habits, purposes for receiving tutoring, and evaluations of tutors. Faced with L2 learners who come from different cultural backgrounds, it is helpful for instructors and tutors to know L2 students’ previous English learning experiences in their home countries so that instructors and tutors can adjust teaching or tutoring for each student. In addition, students who speak the same L1 have common problems of English learning due to their L1. In this way, ESL tutors not only tutor English skills, but also promote cultural awareness. Meanwhile, knowing students’ cultural background is necessary to give tutoring for each L2 learner. The present study aims to explore L2 learners’ feedback from previous and current English learning experiences and will help L2 instructors and tutors to know some basic knowledge about two different language groups

    Translation of Culture-Loaded Words in the Ci-Poem Turn of Zui Hua Yin From the Perspective of Meaning in Semantics

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    Ci-poetry holds an important position in spreading Chinese literature and cross-cultural communication. It contains many culture-loaded words and because of this, the accurate translation of the meaning becomes a barrier during Ci-poetry rendering. This thesis is conducted from the perspective of the theory of meaning stated by Jeffery Leech in Semantics and selects Turn of Zui Hua Yin written by Li Qingzhao, a female poet in Song Dynasty, as a case study, placing its culture-loaded words into three categories according to the differences of their conceptual and associative meaning in Chinese and English cultures. Then, in each category, this thesis comparatively analyses the translation of the culture-loaded words in four English versions from Xu Yuan-zhong, Ding Zuxin, Kenneth Rexroth, and Gong Jinghao, and finally concludes proper translation methods and merits and demerits of each version at this point

    A comparison of experiences and preferences regarding classroom and tutoring feedback among Chinese and Saudi learners of English

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    Master of ArtsDepartment of Modern LanguagesEarl BrownThis report studies ESL tutoring feedback to Chinese and Saudi students. The objective is to research the reasons of feedback differences and similarities, which include previous and current English learning styles, habits, purposes for receiving tutoring, and evaluations of tutors. Faced with L2 learners who come from different cultural backgrounds, it is helpful for instructors and tutors to know L2 students’ previous English learning experiences in their home countries so that instructors and tutors can adjust teaching or tutoring for each student. In addition, students who speak the same L1 have common problems of English learning due to their L1. In this way, ESL tutors not only tutor English skills, but also promote cultural awareness. Meanwhile, knowing students’ cultural background is necessary to give tutoring for each L2 learner. The present study aims to explore L2 learners’ feedback from previous and current English learning experiences and will help L2 instructors and tutors to know some basic knowledge about two different language groups

    Character of frustration on magnetic correlation in doped Hubbard model

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    The magnetic correlation in the Hubbard model on a two-dimensional anisotropic triangular lattice is studied by using the determinant quantum Monte Carlo method. Around half filling, it is found that the increasing frustration t/tt'/t could change the wave vector of maximum spin correlation along (π,π\pi,\pi)\rightarrow(π,5π6\pi,\frac{5\pi}{6})\rightarrow(5π6,5π6\frac{5\pi}{6},\frac{5\pi}{6})\rightarrow (2π3,2π3\frac{2\pi}{3},\frac{2\pi}{3}), indicating the frustration's remarkable effect on the magnetism. In the studied filling region =1.0-1.3, the doping behaves like some kinds of {\it{frustration}}, which destroys the (π,π)(\pi,\pi) AFM correlation quickly and push the magnetic order to a wide range of the (2π3,2π3)(\frac{2\pi}{3},\frac{2\pi}{3}) 120120^{\circ} order when the t/tt'/t is large enough. Our non-perturbative calculations reveal a rich magnetic phase diagram over both the frustration and electron doping.Comment: 6 pages, 7 figure

    Simple spatial scaling rules behind complex cities

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    Although most of wealth and innovation have been the result of human interaction and cooperation, we are not yet able to quantitatively predict the spatial distributions of three main elements of cities: population, roads, and socioeconomic interactions. By a simple model mainly based on spatial attraction and matching growth mechanisms, we reveal that the spatial scaling rules of these three elements are in a consistent framework, which allows us to use any single observation to infer the others. All numerical and theoretical results are consistent with empirical data from ten representative cities. In addition, our model can also provide a general explanation of the origins of the universal super- and sub-linear aggregate scaling laws and accurately predict kilometre-level socioeconomic activity. Our work opens a new avenue for uncovering the evolution of cities in terms of the interplay among urban elements, and it has a broad range of applications.This work is supported by the National Natural Science Foundation of China under Grant Nos. 61673070, 61773069, 71731002 and the Fundamental Research Funds for the Central Universities with the Grant No. 2015KJJCB13, and also partially supported by NSF Grants PHY-1505000, CMMI-1125290, CHE-1213217, DTRA Grant HDTRA1-14-1-0017, DOE Grant DE-AC07-05Id14517. J.Z. acknowledges discussions with Prof. Bettencourt of the Santa Fe Institute, Dr. Lingfei Wu of Arizona State University, and Profs. Yougui Wang and Qinghua Chen of Beijing Normal University. R.L. acknowledges helpful discussions with and comments from Dr. Remi Louf in CASA, University College London, Dr. Longfeng Zhao from Huazhong (Central China) Normal University, and selfless help from Prof. Yougui Wang. R.L. is also supported by the Chinese Scholarship Council. (61673070 - National Natural Science Foundation of China; 61773069 - National Natural Science Foundation of China; 71731002 - National Natural Science Foundation of China; 2015KJJCB13 - Fundamental Research Funds for the Central Universities; PHY-1505000 - NSF; CMMI-1125290 - NSF; CHE-1213217 - NSF; HDTRA1-14-1-0017 - DTRA Grant; DE-AC07-05Id14517 - DOE; Chinese Scholarship Council)Published versio
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