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1.
Using SnxTi1-xO2 as carriers, CuO/Sn0.9Ti0.1O2 and CuO/Sn0.7Ti0.3O2 catalysts with different loading amounts of copper oxide (CuO) were prepared by an impregnation method. The catalytic properties of CuO/Sn0.9Ti0.1O2 and CuO/Sn0.7Ti0.3O2 were examined using a microreactor-gas chromatography (GC) NO CO reaction system and the methods of BET (Brun- auer-Emmett-Teller), TG-DTA (themogravimetric and differential thermal analysis), X-ray diffraction (XRD) and H2-temperature programmed reduction (TPR). The results showed that NO conversions of Sn0.9Ti0.1O2 and Sn0.7Ti0.3O2 were 47.2% and 43.6% respectively, which increased to 95.3% and 90.9% at 6 wt% CuO loading. However, further increase in CuO loading caused a decrease in the catalytic activity. The nitrogen adsorption-desorption isotherm and pore-size distribution curve of Sn0.9Ti0.1O2 and Sn0.7Ti0.3O2 represented type IV of the BDDT (Brunauer, Deming, Deming and Teller) system and a typical mesoporous sample. There were two CuO diffraction peaks (2θ 35.5° and 38.7°), and the diffraction peak areas increased with increasing CuO loading. TPR analysis also detected three peaks (α, β and γ) from the CuO-loaded catalysts, suggesting that the α peak was the reduction of the highly dispersed copper oxide, the β peak was the reduction of the isolated copper oxide, and the γ peak was the reduction of crystal phase copper oxide. In addition, a fourth peak (δ) of the catalysts meant that the SnxTi1-xO2 mixed oxides could be reductive.  相似文献   

2.
Hydroxyapatite bioceramics is simulated by using finite element method (FEM).The influences of porosity,hole shape,angle of crack and other parameters on the ceramics are analyzed.The results show that with the increase of the angle between crack and horizontal direction,the stress intensity factor KⅠdecreases gradually,but stress intensity factor K II increases at first and then it decreases.The value of K Ⅱ reaches maximum when the angle between crack and horizontal direction is 45°.KⅠ and K Ⅱ rise with the increase of porosity,and they are almost the same for the circular and hexagonal holes.For elliptical holes,KⅠand KⅡreach maximum when the long axis of ellipse is perpendicular to the loading direction and they reach minimum when the same axis is parallel to the loading direction.Moreover,with the increase of the angle between the long axis and loading direction,KⅠ and KⅡ increase gradually.  相似文献   

3.
Teaching and learning in higher education: Recent trends   总被引：1，自引：0，他引：1  
In the last decade, the questioning of traditional teaching and learning methods and instructional systems and the search for more effective alternatives have gained momentum in higher education. Recent trends can be grouped as follows:
–  -facilitation of student learning with an emphasis on individualizing instruction, and increased use of multi-media systems, learning resource centers, and peer teaching;
–  -evaluation of teaching: the widespread and systematic use of student evaluations by means of questionnaires and greater use of these data for purposes of faculty selection and promotion;
–  -university-teacher training including the creation of pedagogical service units on many campuses, courses and workshops on instruction for faculty and graduate students, and increased collaboration between content specialists and instructional and media consultants in curricular reforms;
–  -new systems of higher education, such as the Open University or the University Without Walls, designed to offer radical alternatives to new as well as traditional types of students.
These trends, which have been accompanied by intense research and evaluation efforts, will be described and assessed.  相似文献   

4.
Masculinity ideology is argued to be associated with academic outcomes. However, relatively few studies have examined these associations. This study examines the associations between masculinity ideology and academic skepticism, self‐presentation of low achievement, academic engagement, academic initiative, and self‐regulation, above and beyond academic self‐efficacy, among a diverse sample of urban youth. With a sample of 135 eighth‐grade students from a Northeastern middle school, 5 separate multiple hierarchical regression analyses were used to examine whether students’ endorsement of masculinity ideology predicted the criterion variables above and beyond academic self‐efficacy. The sample was comprised of 54 girls and 74 boys ages 12–14 years (M = 13.14; SD = .37). Results showed academic self‐efficacy significantly predicted academic engagement (B = 1.26; β = .53, p < .001; f2 = .39), academic initiative (B = .98; β = .37; p < .001, f2 = .16), and behavioral regulation (B = .61; β = .24; p < .05; f2 = .09) and explained an additional 8 and 10% of the variance in self‐presentation of low achievement (B = .54; β = .33; p = .001; f2 = .14) and academic skepticism (B = .56; β = .35; p < .001; f2 = .15), respectively, over and above academic self‐efficacy. Gender, which was dummy coded and entered as a covariate, only predicted self‐presentation of low achievement. Findings from this study point to the need to foster positive academic outcomes through bolstering academic self‐efficacy and, perhaps more important, addressing masculinity ideology.  相似文献   

5.
Wassell and LaVan (this issue) make strong arguments about the value of coteaching as a model for learning to teach. This response paper draws upon recent sociocultural conceptualizations of human nature and development as a process of contribution and shared contribution to extend Wassell and LaVan’s findings about teacher learning and to further illuminate evidence of the transformative potential of coteaching. It is argued that the beginning teachers in Wassell and LaVan’s study appropriated the cultural practices, and ontological and epistemological stances of coteaching and used these perspectives and practices to transform the cultures of their in-service classrooms as well as the roles and epistemic perspectives of their students.
Jennifer Gallo-FoxEmail:
Jennifer Gallo-Fox   is a PhD candidate at the Department of Teacher Education, Special Education, and Curriculum and Instruction in the Lynch School of Education at Boston College. She is also an educational researcher in the Department of Chemistry and Biochemistry at the University of Delaware. Her research interests include: teacher education research and practice; teacher learning and development; teaching, policy, and teachers’ work; and research methodology.  相似文献   

6.
This collection of historical accounts provides diverse perspectives on the structure and culture of the community of researchers who participate in activities of the Australasian Science Education Research Association (ASERA). It describes the formation of the Association, and identifies major changes and challenges for the ever growing and internationalisation of its membership.
Stephen M. RitchieEmail:
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7.
Pakistani wheat varieties are grown over a wide agro-climatic range and as such are anticipated to exhibit yield and quality differences. It is therefore necessary to investigate the nutritional status of wheat varieties in terms of biochemical and physiochemical characteristics available for food and nutritional purposes in Pakistan. The result shows that wheat grains of different varieties contain a net protein level of 9.15%～10.27%, 2.15%～2.55% total fats, 1.72%～1.85% dietary fibers,77.65×10^-6～84.25×10^-6 of potassium and 7.70× 10 6～35.90× 10^-6 of sodium ions concentration, 0.24× 10^-6～0.84× 10^-6 of phosphorus, 1.44%～2.10% ash, 31.108～43.602 g of thousand grain mass （TGM） and 8.38%～9.67% moisture contents. This study is significant in providing an opportunity to explore the available wheat varieties and to further improve their nutritional excellence and also essential for setting nutritional regulations for domestic and export purposes.  相似文献   

8.
The author analyzes two texts, Gloria Whelan’s Homeless Bird and Deborah Ellis’s Parvana’s Journey, in an attempt to explain some of the problems and difficulties associated with those texts. The author examines Whelan’s representations of India and finds troubling binaries associated with that text. In comparison, the author finds Ellis’s depictions of Afghanistan more nuanced and complex. The author also discusses student reception of both texts and offers ways to problematize some of their reactions.
Susan Louise StewartEmail:
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9.
Issues of equality and fairness and invasion of the personal domain, 2 previously identified topic areas of adolescent sibling conflict (N. Campione‐Barr & J. G. Smetana, 2010), were examined in 145 dyads (Mfirst‐born = 14.97, SD = 1.69 years; Msecond‐born = 12.20, SD = 1.90 years) for their differential effects on youths' emotional adjustment over 1 year. The impact of internalizing symptoms on later sibling conflicts also was tested. Invasion of the personal domain conflicts were associated with higher levels of anxiety and lower self‐esteem 1 year later, whereas Equality and Fairness issues were associated with greater depressed mood. Conversely, greater internalizing symptomatology and lower self‐esteem predicted more of both types of conflict. Moderating influences of gender and ordinal position were also examined.  相似文献   

10.
This study describes the sense-making behaviors of sixth- and seventh-grade students (n = 46 dyads) as they read and discussed expository articles in print and digital formats. Most dyads approached the digital text as if it were static and linear, despite the availability of hyperlinks. Reading through (or covering) the text was the most commonly observed behavior, occurring in 89% of the coded intervals in the print condition and 76% of intervals in the digital condition. Students were observed discussing a variety of cognitive and metacognitive strategies. The most common strategies were process monitoring, summarizing, connecting, and reacting. The dyads used at least one overt sense-making strategy in about 50% of the intervals when reading the print text and about 65% of the intervals with the digital text. Previewing and progress monitoring, which serve important planning and self-regulative functions, were used more frequently in the digital condition. Regression analyses show that several collaborative behaviors were associated with text comprehension, as measured by a researcher-designed multiple choice test, in the print condition but not in the digital condition. These included word recognition monitoring (β = 1.84; SE = 0.90; p = .05), summarizing (β = 2.43; SE = 1.21; p = .05), and connecting (β = −5.20; SE = 2.06; p = .02) at the student level and attending to illustrations (γ = −7.08; SE = 2.17; p = .003) at the dyad level. In both conditions, prior reading achievement and prior knowledge were strong predictors of comprehension.  相似文献   

11.
Heldal  Marit 《Interchange》2021,52(3):433-445

According to data from the Norwegian Refugee Council, more than 70 million people are refugees today. Approximately half of these are children, and every five seconds a new child becomes a refugee. An increasing large number of children live parts of their childhood in a refugee camp with limited opportunities for play. This article highlights the importance of play for children living as refugees. The study was conducted during the winter of 2017 in a refugee camp on the Greek island of Lesbos. The importance of a trusting relationship between children and adults is emphasised in the data regarding children’s play. Furthermore, the data stresses how adults can facilitate children to make experiences through play and create meaning in an everyday life controlled by factors outside the child and the child's family. An important issue is to highlight the opportunities children have to create meaning and experiences in a difficult life situation.

  相似文献   

12.
The authors discuss the factors which predetermine research into the effectiveness of education and the role of economics in educational research. Three fundamental research areas are identified: macroeconomic research into the relations between the national economy and culture and the educational system, economic aspects of the functioning of education, and cost-effectiveness in individual terms. The principles of planning and its implications for policy are discussed and the role of research on expenditure and costs defined. The effects of education are shown as being of two kinds, direct and indirect, and their relative importance for planning is considered and illustrated with examples from the authors' own research in Poland. Finally, the quantitative and qualitative aspects of extensive and intensive development policies and their relationship to overall national economic development are investigated and a number of conclusions drawn.
Résumé Les auteurs discutent les facteurs qui conditionnent la recherche consacrée au rendement de l'éducation ainsi que la rôle de l'économie dans la recherche sur l'éducation. Ils distinguent trois domaines fondamentaux de la recherche: premièrement, la recherche macro-économique portant sur les relations entre la culture ou l'économie nationale et le système d'éducation; deuxièmement les aspects économique du processus d'éducation; troisièmement les études de rendement en fonction du coût de l'éducation par téte. L'article discute les principes de la planification et ses implications en termes de politique de l'éducation et cherche à définir les effets de la recherche sur les dépenses et les coûts. On montre que les conséquences du processus d'éducation sont de deux types et leurs importance relative du point de vue de la planification est mise en évidence et illustrée par des exemples empruntés aux recherches des auteurs sur la Pologne. En conclusion, l'article éclaire les aspects tant quantitatifs que qualitatifs des politiques de développement extensif et intensif de l'éducation dans leurs relations au développement global de l'économie nationale pour en tirer un certain nombre de remarques finales. *** DIRECT SUPPORT *** A0010002 00003
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13.
BackgroundExposure to greater Adverse Childhood Experiences (ACEs) has been associated with increased likelihood of general and sex offending behaviors. However, few studies consider both the impact of varied ACE exposures and other early experiences on pathways to offending behaviors in adolescents who have engaged in sexually abusive behaviors.ObjectiveThe purpose of this study was to examine the impact of ACEs and sexual boundary problems within the home on the development of delinquent and sexually abusive behavior.Participants & settingData were collected from archival records of male adolescents (N = 285) who had received treatment for sexually abusive behavior at a youth facility.MethodsThis study investigated the effects of individual adverse experiences on delinquent nonsexual and sexually abusive behaviors through structural equation modeling.ResultsStructural equation modeling revealed a three-factor model for ACEs. Direction and significance of paths between ACEs and the onset, persistence, and nature of maladaptive behaviors differed. Household dysfunction was related to an earlier onset (β = 1.19, p = 0.013) and more persistent nonsexual delinquent offending (β = 1.05, p = 0.048) and contact sexual offending (β = 1.19, p = 0.010). Conversely, sexual abuse and exposure to sexual boundary problems were associated with an earlier onset of sexually abusive behavior (β = −1.08, p = 0.038) as well as indicators of adolescent-onset (β = −1.30, p = 0.002), less persistent (β = −1.53, p = 0.001), and nonviolent (β = −1.89, p = 0.001) delinquency.ConclusionsFindings suggest variations in ACE exposures differentially influence the onset, severity, and persistence of delinquent and sexually abusive behaviors among these youths.  相似文献   

14.
Defining what it means to be an “effective teacher” is a difficult, but necessary, undertaking, as research reveals a correlation between teacher qualities and student success (Buchel and Edwards 2005 Buchel, T., and F. Edwards. 2005. Characteristics of effective clinical teachers. Resid Educ. 37 (1):30–5. [Google Scholar]; Darling-Hammond 2000 Darling-Hammond, L. 2000. Teacher quality and student achievement: A review of state policy evidence. Center for the Study of Teaching and Policy. Seattle: University of Washington Press. doi: 10.1086/ahr/106.2.595-a.[Crossref] , [Google Scholar]; Lupascu, Pânisoa, and Pânisoar 2014; Stronge 2007 Stronge, J. H. 2007. Qualities of effective teachers. 2nd ed. Alexandria, VA: Association of Supervision and Curriculum Development. [Google Scholar]). The literature on this topic clearly demonstrates that there is no consensus on exactly what traits and characteristics truly define an effective teacher. Given this lack of agreement, the question for teacher educators becomes how do we prepare teacher candidates to be effective in the classroom when researchers, policymakers, and administrators can’t agree on the traits that encompass what the system has come to deem an “effective” teacher?

Throughout this article, we share our findings from an exploratory case study of National Teachers of the Year. Through an analysis of personal teacher of the year narratives and nomination letters, we learned that even in the ever-changing world of education, specific characteristics and philosophies which support and exemplify outstanding teaching have remained constant over the years. Award winning educators agree that teacher effectiveness is realized only through the intersection of curriculum, relationships, collaboration, engagement, and a commitment to further one’s learning. In this article, we offer insight into each of these ideological constants and discuss the implications they have for today’s teacher education programs.  相似文献   

15.
Nondeterminism is a fundamental concept in computer science that appears in various contexts such as automata theory, algorithms and concurrent computation. We present a taxonomy of the different ways that nondeterminism can be defined and used; the categories of the taxonomy are domain, nature, implementation, consistency, execution and semantics. An historical survey shows how the concept was developed from its inception by Rabin & Scott, Floyd and Dijkstra, as well as the interplay between nondeterminism and concurrency. Computer science textbooks and pedagogical software are surveyed to determine how they present the concept; the results show that the treatment of nondeterminism is generally fragmentary and unsystematic. We conclude that the teaching of nondeterminism must be integrated through the computer science curriculum so that students learn to see nondeterminism both in terms of abstract mathematical entities and in terms of machines whose execution is unpredictable.
Michal Armoni (Corresponding author)Email:
Mordechai Ben-AriEmail:
Michal Armoni   is a postdoctoral fellow at the Department of Science Teaching of the Weizmann Institute of Science. She received her PhD in science teaching from the Tel Aviv University, and her BA and MSc in computer science from the Technion. Her research interests are in the teaching and learning processes in computer science, in particular of fundamental concepts such as reduction and nondeterminism. She is currently on leave from the computer science department of the Open University of Israel. She has extensive experience in developing learning materials in computer science and in teaching the subjects at all levels from high school through graduate students. Mordechai Ben-Ari   is an associate professor in the Department of Science Teaching of the Weizmann Institute of Science. He holds a PhD in mathematics and computer science from the Tel Aviv University. In 2004, he received the ACM/SIGCSE Award for Outstanding Contributions to Computer Science Education. He is the author of numerous computer science textbooks and of Just a Theory: Exploring the Nature of Science (Prometheus 2005). His research interests include the use of visualization in teaching computer science, the pedagogy of concurrent and distributed computation, the application of theories of education to computer science education and the nature of science.  相似文献   

16.
Within the sphere of contemporary social sciences, the terms “modernity,” “post-modernity” and “globalization” have penetrated, as the core concepts, into various fields of social sciences in a logical way. In constituting the concept of “modernity,” sociology of education develops the educational theory, as sociological theory does, into a “grand narrative” and “foundationalist” theory; the contribution of post-modernity is pluralism and self-examination in an attempt to transcend modernity. Globalization, a kind of expanded modernity, makes education sociologists broaden their perspective from single and traditional “nationality,” “society” and “nation” to an international society and even to the global society, which has broken through the research paradigm of modernity with ethnocentrism, anthropocentrism and Euro-centrism. These changes have required urgent constitution of the conceptions and theoretical frameworks of sociology of education to be applied on a global level. __________ Translated from Peking University Education Review, 2006 (1)  相似文献   

17.
Objective: To investigate the influence of lead exposure on the immune function of lymphocytes and erythrocytes in preschool children. Materials and methods: A group of 217 children three to six years of age from a rural area were given a thorough physical examination and the concentration of lead in blood samples taken from each subject was determined. The indices of lymphocyte immunity (CD 3CD 4, CD 3CD 8, CD 4CD 8, CD-3CD 19) and erythrocyte immunity (RBC-C3b, RBC-IC, RFER, RFIR, CD35 and its average fluorescence intensity) of 40 children with blood lead levels above 0.483 μmol/L were measured and compared with a control group. Results: The blood lead levels of the 217 children ranged from 0.11 μmol/L to 2.11 μmol/L. The CD 3CD 4and CD 4CD 8 cells were lower (P＜0.01) and the CD 3CD 8 cells were higher in the lead-poisoned subjects than those in the control group (P＜0.05). CD 3 and CD-3CD 19 did not show significant differences. Although the RBC-C3b rosette forming rate was lower and the RBC-IC rosette forming rate was higher in the lead-poisoned group, this difference could not be shown to be statistically significant (P＞0.05). RFIR was found to be lower in the lead-poisoned group (P＜0.01). Compared with the control group, the positive rate of CD35 was not found to be significantly different in a group of 25 lead-poisoned children (P＞0.05), while the average fluorescence intensity was lower in the lead-poisoned group (P＜0.05). Conclusion: Lead exposure can result in impaired immune function of T lymphocytes and erythrocytes in preschool children.  相似文献   

18.
Enantiomers (R(+) and S(-)),RS-racemate (double compound) and (R+S)-conglomerate (mechanical mixture of enantiomers) of malic acid C 4 H 6 O 5 have been investigated by means of X-ray diffractometry and high temperature X-ray diffraction method.The RS-racemate was found to be able to form three polymorphic modifications,which we denominated as M1 (monoclinic,space group P2 1 /c),M2 (monoclinic,space group Cc),and Tc (triclinic,space group P-1),the latter modification having been unknown before.Modification Tc was also described,and its Xray diffraction characteristics,including interplanar spacings d,hkl indices,unit cell parameters,were defined.In addition,X-ray diffraction characteristics for both reported earlier M1 and M2 monoclinic polymorphic modifications were measured with higher accuracy.The ability of RS-racemate to form one of the above three modifications (M1,M2,and Tc) or their mixtures containing various proportions and combinations of the components (M1+M2,M1+Tc,or M2 +Tc) was found to depend on the type of crystallization medium (a melt,aqueous medium,ethanol or acetone solution),crystallization rate (from 2-3 minutes to 4 months),and crystallization temperature.Heating S-enantiomer and M1 RS-racemate up to their respective melting points (100 ℃ and 124 ℃,correspondingly) only made them undergo thermal deformations,while heating (R+S)-conglomerate in the temperature range of 96-110 ℃ resulted in its homogenization to form M2 RS-racemate,which,near the melting point (118 ℃),namely,in the range of 112-116 ℃,was transformed into M1 RS-racemate.  相似文献   

19.
困境与突破:论中国教育学范式   总被引：1，自引：0，他引：1  
In this paper, the paradigm of China’s pedagogy means a way of thinking followed and adhered to by Chinese educationists from the establishment of New China till now when they consider, study and conceive problems of pedagogy. This way of thinking guides educationists to have particular study directions, unique modes of pedagogy establishment and special framework of problem solving. And furthermore, it forms the study tradition of China’s pedagogy and stipulates the developing orientation of China’s pedagogy. From the establishment of New China till now, we have been edified by the paradigms in the Soviet Union and the Western countries and restricted by “Western paradigm” and “Soviet Paradigm”, without any paradigm of our own. The paradigm crisis in the development of China’ pedagogy has obstructed the healthy development of China’s pedagogy. The establishment of China’s pedagogy should start with establishing the subject-educationists and establishing the object-“paradigm system”. The establishment of China’s pedagogy paradigm will contribute greatly to the origination of China’s pedagogy and its academic schools. __________ Translated from Dongbei Shifan Daxue Xuebao (Zhexue Shehui Kexue Ban) 东北师范大学学 报(哲学社会科学版) (Journal of Northeast Normal University (Philosophy and Social Sciences)), 2007, (3): 5–12  相似文献   

20.
It has been over ten years since the Teacher’s Law took effect on January 1, 1994, and its promulgation and implementation have somewhat helped in protecting teachers’ legal rights and interests. Undeniably, however, the Teacher’s Law is defective in many aspects, such as the absence of teachers’ legal identity, its failure to safeguard a teacher’s essential interests and rights, serious laggardness of the teacher’s appointment system and obstacles to dealing with teachers’ complaints and litigations. All such defectiveness make the legislative purpose “to safeguard the teacher’s legal rights and interests” in Article 1 of the Teacher’s Law less effective in practice. Therefore, in order to judicially assist teachers in safeguarding their own legal rights and interests, it is necessary to modify the Teacher’s Law and especially give priorities to: (1) defining the identity of the state staff member for teachers; (2) treating teachers owed to in arrears as peasant-workers, and paying and remunerating them punctually (3) formulating detailed measures on the implementation of the teacher’s appointment system as soon as possible, solving problems of unemployment of teachers arising from the inequality between the teacher’s rights, the school’s power and the absence of the teacher’s identity; (4) establishing a lawsuit system connected with teachers’ complaints and personnel arbitration. __________ Translated from Theory and Practice of Education, 2005:2  相似文献   

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