Definition of an Ellipse

If F1 （c, 0） and F2（ -c, 0） are two fixed points in the plane and a is a constant, 0〈c〈a, then the set of all points P in the plane such that ｜ PF1｜ ＋ ｜ PF2 ｜ = 2a is an ellipse. F1 and F2 are the loci of the ellipse.     

The Story of an Hour

本文是美国著名短篇小说家凯特·肖邦的作品,文中生动地描述了马拉德夫人在得知丈夫死讯后复杂的心情,以及事情真相给她带来的打击。     

Mycorrhizoremediation an enhanced form of phytoremediation

Study of plant roots and the diversity of soil micro biota, such as bacteria, fungi and microfauna associated with them, is important for understanding the ecological complexities between diverse plants, microbes, soil and climates and their role in phytoremediation of contaminated soils. The arbuscular mycorrhizal fungi （AMF） are universal and ubiquitous rhizosphere mi- croflora forming symbiosis with plant roots and acting as biofertilizers, bioprotactants, and biodegraders. In addition to AMF, soils also contain various antagonistic and beneficial bacteria such as root pathogens, plant growth promoting rhizobacteria including free-living and symbiotic N-fixers, and mycorrhiza helping bacteria. Their potential role in phytoremediation of heavy metal （HM） contaminated soils and water is becoming evident although there is need to completely understand the ecological complexities of the plant-microbe-soil interactions and their better exploitation as consortia in remediation strategies employed for contaminated soils. These multitrophic root microbial associations deserve multi-disciplinary investigations using molecular, biochemical, and physiological techniques. Ecosystem restoration of heavy metal contaminated soils practices need to incorporate microbial biotechnology research and development. This review highlights the ecological complexity and diversity of plant-microbe-soil combinations, particularly AM and provides an overview on the recent developments in this area. It also discusses the role AMF play in phytorestoration of HM contaminated soils, i.e. mycorrhizoremediation.     

An Australian''''s Perspective of an American University

Since high school I have always wanted to study in a country other than my own. However my parents always informed me that it was too expensive. This was until luck turned my way one day while I was at university. My advisor called me and asked me to go and see him as soon as possible. I just knew it had to be good news. I could barely stand the suspense and went to his office with a nervous happiness in my tummy My advisor told me that I had been offered a scholarship to study at Central W…     

Stylistic Analysis of an Unline Computer Advertisement

随着网络经济的发展,发布于互联网上的网络广告日益增长。网络广告已成为当今世界最热门的广告形态之一。而近年来,研究广告的虽然不少,但对这一新兴的文本形式从文体角度加以分析的研究并不多见。笔者根据Crystal和Davy(1969:84-85)对广告文体分析的观点,借鉴他们的分析方法,通过对dell计算机网络广告的文体分析,说明一个成功的网络广告,除了具有自身的特色之外,也必须具有传统广告的文体要素;通过本文的文体分析,使读者能更好地领略到网络广告的文体魅力。     

Sister Carrie, an Adherent of Desires

Sister Carrie is one of the most controversial characters in American literature.Thought as a "fallen woman" firstly,she was defined as a "new woman" by some critics later. However, by digging into the motivaton behind the whole process of Carrie's "success", the relationship between Carrie and her creator (the author), the social conditions of then American, it can be found that Carrie has never been free-standing on her thought and she has never found her real-sdf even after becoming a famous actress. In a society dominated by mass consumerism Carrie is only an adherent of her own desires. She also is a representative of all those country girls flooded into cities, a symbol and a sacrifice of the urbanization of America in a time countryside was overcome by cities.     

Stylistic Analysis of an Online Computer Advertisement

随着网络经济的发展，发布于互联网上的广告日益增长，网络广告已成为当今世界最热门的广告形态之一。而近年来，研究广告的虽然不少， 但对这一新兴的文本形式从文体角度加以分析的研究并不多见。笔者根据Cyrstal和Davy(1969:84-85)对广告文体分析的观点，借鉴他们的分析方法，通过对dell计算机网络广告的文体分析，说明一个成功的网络广告，除了具有自身的特色之外，也必须具有传统广告的文体要素，通过本文的文体分析，使读者能更好地领略到网络广告的文体魅力。     

Performance analysis of an iSCSI-based unified storage network

INTRODUCTIONNASisatermusedtorefertostorageele mentsthatconnecttoanetworkandprovidefileaccessservicestocomputersystems.Incommonusage ,aNASsystemisaspecial purposedevicethatisdesignedtoservefilestoclientsoveraLAN .Therearemanybenefitsinthearchitec ture:heterogeneousfilesharing ;internalre sourcepooling;exploitationoftheexistingin frastructure;simplicityofimplementation ;con nectivity;improvedmanageability;reductionoftotalcostofownership ;andsoon .Butinprac tice,therearestillmanydrawbacks…     

Educators‘ perceptions of an in-service training programme

Abstract

In-service training programmes for educators (INSET) in South Africa have a common objective, namely to support unqualified or underqualified educators to teach their subjects well. The Science, Technology, Environmental and Mathematics Education (STEME) outreach programme is an initiative of the University of South Africa to support these educators with skills and knowledge to teach these subjects efficiently. This article reports on an INSET programme for science teachers who took part in STEME and serves as a case study to investigate educators’ perceptions of the programme. The study, which involved a total of 13 educators, had two phases which were conducted during and after the INSET programme respectively. A focus group interview was conducted in the first phase while individual interviews were conducted in the second phase at the participants’ schools. Participants valued facilitators’ knowledge, continuous support and demonstration of new skills in practical real-life situations. Their main concern was applying the skills at their schools within present circumstances. This case study can serve to inform other service providers on what educators expect from INSET programmes.     

Towards an Understanding of Situated Learning：Students’Perceptions in an Interpretation Course

Situated learning approach has been applied in various teaching contexts, and increasing advocations have been shown in the particular context of language teaching. This study applied situated learning...     

A Universal Model of Giftedness – an adaptation of the Munich Model

The Munich Model of Giftedness (MMG) by Heller and his colleagues, developed for the identification of gifted children, is adapted and expanded, with the aim of making it more universally usable as a model for the pathway from talents to performance. On the side of the talent-factors, the concept of multiple intelligences is introduced, and the moderating factors proposed in the MMG are discussed and categorized. The environmental moderators are interpolated as to incorporate not only “school-settings” but also “work-settings”.     

Impact of an engineering design-based curriculum compared to an inquiry-based curriculum on fifth graders’ content learning of simple machines

Background: Elementary Science Education is struggling with multiple challenges. National and State test results confirm the need for deeper understanding in elementary science education. Moreover, national policy statements and researchers call for increased exposure to engineering and technology in elementary science education. The basic motivation of this study is to suggest a solution to both improving elementary science education and increasing exposure to engineering and technology in it.

Purpose/Hypothesis: This mixed-method study examined the impact of an engineering design-based curriculum compared to an inquiry-based curriculum on fifth graders’ content learning of simple machines. We hypothesize that the LEGO-engineering design unit is as successful as the inquiry-based unit in terms of students’ science content learning of simple machines.

Design/Method: We used a mixed-methods approach to investigate our research questions; we compared the control and the experimental groups’ scores from the tests and interviews by using Analysis of Covariance (ANCOVA) and compared each group’s pre- and post-scores by using paired t-tests.

Results: Our findings from the paired t-tests show that both the experimental and comparison groups significantly improved their scores from the pre-test to post-test on the multiple-choice, open-ended, and interview items. Moreover, ANCOVA results show that students in the experimental group, who learned simple machines with the design-based unit, performed significantly better on the interview questions.

Conclusions: Our analyses revealed that the design-based Design a people mover: Simple machines unit was, if not better, as successful as the inquiry-based FOSS Levers and pulleys unit in terms of students’ science content learning.     

Simulating the operation action of an asynchronized turbogenerator under loss of excitation

1.IntroductionWhentheexcitationfieldofaconventionalgenera-torislostandconsequentout-of-stepconditionsoccur,theresultanthighcurrentsandpulsatingtorquecandamagethegeneratorundersomeconditions.Alsothepowersystemcanbeimpactedbyabnormallevelsofcyclicswingsofpower,varsandvoltages.Butatthelossofexcitationatbothwindings(dandqaxes)oronewindingoftherotor,anasynchronizedturbo-generator(ASTG)canbeautomaticallydrivenintoanasynchronousmodeofoperationorintoasingleaxissynchronousmodeofoperationwithoutapower…     

Teachers’ perceptions of school climate as an indicator of their beliefs of effective teaching

The ability to express oneself clearly in both a mother tongue and a foreign language is a foundation principle of the new national curriculum in Estonia. Therefore, research was conducted to determine whether there was a possible relationship between English as a foreign language (EFL) teachers’ perceptions of effective teaching and the contextual evaluation of the school. The aim of this article is to describe the relationship between the perceptions of school climate and effective teaching among EFL teachers. The study revealed that EFL teachers’ perceptions of the school climate correlate to some extent with their perceptions of effective teaching practices, with some differences between teachers of Estonian-language schools compared with those of Russian-language schools. The research also highlighted that senior management should place more emphasis on creating a cooperative school climate for developing a learner-centred teaching approach as one of the foundation principles of the new national curriculum.     

Sinking in the sand? Academic work in an offshore campus of an Australian university

This research examines academic work in an offshore campus of an Australian university. The focus is on the external factors that influence academic practice, mainly in relation to assessment and the way academics perceive their role. The study is set within the wider context of transnational education and the changing nature of academic life and unlike some previous studies, it presents an entirely offshore perspective. The relationship with the home campus and the local educational and political context are found to be the major external influences on academic staff. Leading from the research, some suggestions for increasing the success of offshore campuses are offered. These include establishing strong channels of communication and well‐developed induction and professional development processes.     

Review:Mycorrhizoremediation—an enhanced form of phytoremediation

INTRODUCTION Biosphere pollution by heavy metals and nu-cleotides was accelerated dramatically during the last few decades due to mining, smelting, manufacturing, treatment of agricultural soils with agro-chemicals and soil sludge, etc. Problems associated with the contamination of soil and water such as animal wel-fare, health, fatalities and disruptions of natural eco-systems are well documented (He et al., 2005). Heavy metals such as Pb, Cr, As, Cu, Cd, and Hg, being added to our so…