Application and Progress of Confinement Synthesis Strategy in Electrochemical Energy Storage

Designing high-performance nanostructured electrode materials is the current core of electrochemical energy storage devices.Multi-scaled nanomaterials have triggered considerable interest because they effectively combine a library of advantages of each component on different scales for energy storage.However,serious aggregation,structural degradation,and even poor stability of nanomaterials are well-known issues during electrochemically driven volume expansion/contraction processes.The confineme...     

Energy Levels of Strong Coupling Magnetopolaron in Quantum Dot

By using variational method of Pekar type,we have studied the energy levels of strong coupling magnetopolaron in diskshape quantum dot(QD) and quantum well(QW),our esults show that ,with the increasing magnetic field and confinement strength,the magnetopolaron binding energy of QD and QW in the ground state and in the excited state is enhanced.The limiting results of bulk type and strict two-dimensional type are obtained.     

Mathematical Analysis of Energy Efficiency in IEEE 802.11 DCF

The standardized IEEE ,802. II distributed coordination function （ DCF） provides a contention-based distributed channel access mechanism for mobile stations to share the wireless medium. However, when stations are mobile or portable units, power consumption becomes a primary issue since terminals are usually battery driven. This paper proposes an analytical model that calculates the energy efficiency of both the basic and the RTS/CTS access mechanisms of the IEEE 802. II protocol. The model is validated with simulation results using NS-2 simulation package. The effects of the network size, the average packet length, the initial contention window and maximum backoff stages on the energy efficiency of both access mechanisms are also investigated. Results show that the basic scheme has low energy efficiency at large packet length and large network size, and depends strongly on the number of stations and the backoff procedure parameters. Conversely, the RTS/CTS mechanism provides higher energy efficiency when the network size is large, and is more robust to variations in the backoff procedure parameters.     

Atomic Energy

Scientistshadlongdreamedofsplittingtheatomandletoutsomeofitshugeenergy.Theydidntfindouthowtodoituntilthe1940s.Uraniumisoneofthematterswhoseatomscanbesplitfairlyeasily.Asmallparticle(粒子)isaddedtoatomofuranium,whichthenbreaksintosmalleratoms.Thechangehasotherresults.Itmakestheuraniumveryhot.Italsoproducestwoorthreeparticlesofthekindfirstadded.Thesefreeparticlesmovearound,splittingotheruraniumatoms,andsobeginsa“chainreaction”whichproducesmoreheatandmorefreeparticles.Boththeheatandthechainre…     

Energy Cycle

Do you find getting up in the morning so diffi-cult that it‘s painful? This might be called laziness,but Dr. Kleitman has a new explanation. He hasproved that everyone has a daily energy cycle.     

Secondary School Teachers’ Knowledge and Attitudes Towards Renewable Energy Sources

Investigating knowledge, perceptions as well as attitudes of public that concern various aspects of environmental issues is of high importance for Environmental Education. An integrated understanding of these parameters can properly support the planning of Environmental Education curriculum and relevant educational materials. In this survey we investigated knowledge and attitudes of secondary school teachers in Greece towards renewable energy sources, particularly wind and solar energy systems. A questionnaire with both open and close questions was used as the main methodological instrument. Findings revealed that although teachers were informed about renewable energy sources and well disposed towards these sources, they hardly expressed clear positions regarding several issues about wind and solar energy technologies and farms. Moreover such themes are limited integrated in teaching either as extra curricular educational programs or through the curriculum. These findings cannot confirm that teachers could influence students’ opinion towards renewable energy systems. Thus, authorities should invest more in Environmental Education and relevant Teachers' Education.     

Energy,Metaphysics, and Space: Ernst Mach’s Interpretation of Energy Conservation as the Principle of Causality

This paper discusses Ernst Mach’s interpretation of the principle of energy conservation (EC) in the context of the development of energy concepts and ideas about causality in nineteenth-century physics and theory of science. In doing this, it focuses on the close relationship between causality, energy conservation and space in Mach’s antireductionist view of science. Mach expounds his thesis about EC in his first historical-epistemological essay, Die Geschichte und die Wurzel des Satzes von der Erhaltung der Arbeit (1872): far from being a new principle, it is used from the early beginnings of mechanics independently from other principles; in fact, EC is a pre-mechanical principle which is generally applied in investigating nature: it is, indeed, nothing but a form of the principle of causality. The paper focuses on the scientific-historical premises and philosophical underpinnings of Mach’s thesis, beginning with the classic debate on the validity and limits of the notion of cause by Hume, Kant, and Helmholtz. Such reference also implies a discussion of the relationship between causality on the one hand and space and time on the other. This connection plays a major role for Mach, and in the final paragraphs its importance is argued in order to understand his antireductionist perspective, i.e. the rejection of any attempt to give an ultimate explanation of the world via reduction of nature to one fundamental set of phenomena.     

Students’ Energy Concepts at the Transition Between Primary and Secondary School

Energy is considered both a core idea and a crosscutting concept in science education. A thorough understanding of the energy concept is thought to help students learn about other (related) concepts within and across science subjects, thereby fostering scientific literacy. This study investigates students’ progression in understanding the energy concept in biological contexts at the transition from primary to lower secondary school by employing a quantitative, cross-sectional study in grades 3–6 (N?=?540) using complex multiple-choice items. Based on a model developed in a previous study, energy concepts were assessed along four aspects of energy: (1) forms and sources of energy, (2) transfer and transformation, (3) degradation and dissipation, and (4) energy conservation. Two parallel test forms (A and B) indicated energy concept scores to increase significantly by a factor of 2.3 (A)/1.7 (B) from grade 3 to grade 6. Students were observed to progress in their understanding of all four aspects of the concept and scored highest on items for energy forms. The lowest scores and the smallest gain across grades were found for energy conservation. Based on our results, we argue that despite numerous learning opportunities, students lack a more integrated understanding of energy at this stage, underlining the requirement of a more explicit approach to teaching energy to young learners. Likewise, more interdisciplinary links for energy learning between relevant contexts in each science discipline may enable older students to more efficiently use energy as a tool and crosscutting concept with which to analyze complex content.     

Seasonal Behavior of Pavement in Geothermal Snow-Melting System with Solar Energy Storage

* Due to snow accumulation and ice formation onhighways, traffic accidents happen frequently in win-ter, causing great losses of economy and lives. Soroad snowremoval has been given great concern[1]. Geothermal road snow-melting system (GRSS)with solar energy storage is an effective, non-pollutionapplied sustainable energy technology developed in re-cent years. Its prominent advantage is to realize sea-sonal thermal storage and improve energy efficien-cy[2]. In Sapporo of Japan, a GRSS sys…     

Energy Performance and Condensation Risk of DCDV System in Subtropical Hong Kong简

The combined use of dry cooling （DC） system and dedicated ventilation （DV） system to decouple cool-ing and dehumidification process for energy efficiency was proposed for subtropical climates like Hong Kong. In this study, the energy performance and condensation risk of the use of DCDV system were examined by analyzing its ap-plication in a typical office building in Hong Kong. Through hour-by-hour simulation using actual equipment per-formance data and realistic building and system characteristics, it was found that with the use of DCDV system, the annual energy consumption could be reduced by 54%in comparison with the conventional system （constant air vol-ume with reheat system）. In respect of condensation risk, it was found that the annual frequency of occurrence of con-densation on DC coil was 35 h. Additional simulations were conducted to examine the influence of different parame-ters on the condensation risk of DCDV system. Measures to ensure condensate-free on DC coil were also discussed.     

Trends and developments in postgraduate education and training in the UK†

This paper argues that ‘partnership’ is an essential part of the marketization of education. Whilst the market fragments and promotes individualism, ‘partnership’ promotes involvement, commitment and responsibility. It is, though, an involvement, commitment and responsibility based on individual vested interest; a necessary prerequisite to protect one's ‘investment’. In harnessing this, control upon the individual is exerted. ‘Partnership’ is presented here as double‐edged for both parents and teachers. Whilst parents may call teachers to account, ‘partnership’ acts as a form of control upon parents. Employing ‘surveillance’ as a conceptual framework, the nature and purpose of ‘partnership’, together with its management by teachers, is discussed. The paper argues that partnership serves as a device for monitoring parents and engendering what Foucault describes as ‘disciplinary power’ which is ensuring that parents learn to be ‘good’ parents as defined by the teachers and adopt a set of values that match those of the school.     

A Comparison of Thailand and New Zealand Students’ Ideas About Energy Related to Technological and Societal Issues

This study is a cross-cultural comparison between the ideas of 49 Thai Grade 9 students and the 30 New Zealand Grade 9 students (approximately 15 years old), about energy related to technological and societal issues. Students’ ideas were explored using the Questionnaire for exploring Students’ ideas about Energy, Technological, and Societal issues (QSETS). The QSETS questionnaire gave students the opportunity to express their ideas about energy related to societal and technological issues. Both groups of students were presented with the same set of issues, but specific places were related to each student’s own country. The study reveals some interesting student ideas that might be generated from engaging in different contexts. It seemed that the 15-year-old students had difficulty in perceiving the relationship between the study of society and energy. Around 50% of both groups of students did not understand, and did not know enough about, questions which referred to the relationship between society and energy. Thai and New Zealand students held different values in decision-making. Thai students placed value on decisionmaking concerning the development of the country. They strongly believed in scientific application for solving social problems. New Zealand students valued decision-making in relation to environmental issues. They were not quite sure that scientific knowledge could solve problems. They thought that science applications caused damage to the environment. This study has implications for the development of teaching approaches in different countries.     

Exploiting Sun’s Energy Effectively as a Source of Renewable Energy

Using Sun’s energy effectively to drive important, industrially relevant chemical reactions is currently an area of research that is attracting a large attention. This route circumvents our reliance on non-renewable sources of energy and more importantly prevents the release of hazardous pollutants as a byproduct. One such reaction that has a large industrial relevance is the splitting of water to release hydrogen and oxygen. This is a thermodynamically energy intensive reaction, and the most relevant aspect is that hydrogen gas is the product which is being touted as a fuel of the future. Its energy density value is higher than other commercially relevant fuels, and its combustion only produces water as a byproduct with zero carbon footprint. Presented here are the current routes being considered for effective water splitting and the fundamental principles that need to be considered when pursuing new directions in this area.     

Students’ classroom experience in foreign-faculty and local-faculty classes in public and private universities in Taiwan

This study investigates university students’ perceptions of classroom experience in foreign-faculty and local-faculty classes and their relations to the type of institution in which they studied. The sample included 714 undergraduate students from 14 universities in Taiwan. The instrument consisted of seven dimensions: peer supportiveness, peer pressure, teacher supportiveness, teacher approachability, study preparedness, class participation, and learning comprehensiveness. The results indicate that students in both types of universities are reluctant to participate, feel pressure, and experience difficulty comprehending course content in the foreign teacher’s class. However, they feel that foreign teachers are more supportive and approachable than local teachers, especially in private universities. Compared with local-faculty classes, private university students prepare more and obtain more peer support in foreign-faculty classes. They also participate more and feel more peer support; however, they comprehend less course content than their public university counterparts in foreign-faculty classes. Detailed discussions regarding the university classroom experience of Taiwanese students in local-faculty classes and foreign-faculty classes are provided.     

Life in the City and in the Country

Life is exciting and convenient in the city.People can enjoy all sorts of services and entertainments such as restaurants,shopping centers,hospitals,cinemas and so on.     

Education in China and America

My little brother is six years old, in his first grade. Yesterday, he gave Mum a letter from his teacher. "I got a red card today. Could you     

Examining Pre-Service Teachers’ Use of Atomic Models in Explaining Subsequent Ionisation Energy Values

Chemistry students’ explanations of ionisation energy phenomena often involve a number of non-scientific or inappropriate ideas being used to form causality arguments. Research has attributed this to many science teachers using these ideas themselves (Tan and Taber, in J Chem Educ 86(5):623–629, 2009). This research extends this work by considering which atomic models are used in pre-service teachers’ explanations and how that relates to the causality ideas expressed. Thirty-one pre-service teachers were interviewed. Each was asked to describe and explain four different atomic representations (Rutherford, Electron cloud micrograph, Bohr and Schr?dinger types) in as much detail as they could. They also provided an explanation for the subsequent ionisation energy values for an oxygen atom and identified which representations were helpful in explaining the values. Significantly, when pre-service teachers only used Bohr type representations, they did not use repelling electron ideas in their explanations. However, arguments that were based on electron–electron repulsion used features from Schr?dinger type atoms. These findings suggest that many pre-service teachers need to develop their atomic modelling skills so that they select and use models more expertly and that subsequent ionisation explanations offer a context in which to explore different atomic models’ limitations and their deployment as explanatory resources.