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1.
Nine limiting binaries of Al2O3-SiO2-Re2O3(Re=Nd, Sm, Gd and La) system are assessed. The binary diagrams or experimental information from Toropov, Mizuno, Aramaki,
Bondar, Rolin and Coutures are optimized with the substitutional model of Kaufman and Nesor and the approximate formula of
fusion free energy for rare earth element oxides of Wu and Pelton. The extracted Gibbs free energies of pure solid oxides
and stoichiometric phases and the solution parameters are used to estimate the corresponding binaries, liquidus surfaces and
a series of isothermal sections of four ternaries Al2O3-SiO2-Nd2O3, Al2O3-SiO2-Sm2O3, Al2O3-SiO2-Gd2O3, and Al2O3-SiO2-La2O3. In the Al2O3-SiO2-Gd2O3 system samples as fired at exact temperature with different compositions were analyzed by X-ray diffractometer and the detected
results are fitted with the calculation of isothermal sections.
Supported by State Key Lab of High Performance Ceramics and Superfine Micro-structure (9517 and 9708) 相似文献
2.
This study examined differential and mediating relations between hot and cool self-regulation (Mage = 48.2 months; N = 1,155, 48% girls), first-grade (Mage = 77.5 months) maladjustment (externalizing [EXT] and internalizing [INT] behavior), and first- and second-grade (Mage = 89.5 months) academic competence (AC). Using teacher reported EXT, INT, and AC, partial support for the differential perspective was found in that only hot self-regulation was significantly related to EXT, whereas both hot and cool self-regulation was significantly related to AC. Moreover, hot self-regulation indirectly predicted second-grade AC through first-grade EXT, lending some support for the mediating perspective also. The findings contribute to an understanding of how self-regulation is related to academic and behavioral school adjustment. 相似文献
3.
LetH
n
be the set of real algebraic polynomials of degreen, whose zeros all lie in the interval [−1,1]. The well known Turán type inequalities tell us that forf(x)∈H
n
, it holds ‖f′‖≥C√n‖f‖. This note deals with the weighted Turán type inequalities with the weights having inner singularities underL
p
norm for 0<p≤∞. Our results essentially extend the result of Wang and Zhou (2002), and the method used in this paper is simpler and more
direct than that of Wang and Zhou (2002). The results and methods have their own values in approximation theory and computation. 相似文献
4.
LU Bao - qi 《上海大学学报(英文版)》2005,9(4):365-368
Infrared (IR) absorption spectra and X-ray powder diffraction (XRD) patterrns of sexpenfine cat's eye from Sichuan Province have been investigated, and infrared absorption bands of the serpentine have been assigned in this paper. The results indicate that the bands near 3 600 - 3 700 cm^-1 belong to the stretching absorption band VOH, the bands in 948 - 1 100 cm^-1 axe assigned to the stretching vibraling band Usvo, and the bands at 600 570 and 440 cm^-1 respectively belong to the bending vibration band VOH, δMg-O and δSi-O. The serpentine cat' s eye includes two types: chrysotile and antigorite. Chrysotile has a sharp and intensive band at 3 688 cm^-1 and a weak band at 3 643 cm^-1 , while antigorite has only one intensive band in the region. At vibration band VSi-O, chrysotile and antigorite have a similar feature at 1 071 cm^-1, but the band at 980 cm^-1 in anfigorite has been split into two bands in chrysotile - a strong one at 1 027 cm^-1 and a weak one at 949 cm^-1. In addition, antigorite has a characteristic bending vibrating band δMg-O at 570 cm^-1. Based on the analysis of the feature of crystal structure, their IR differences axe well explained. 相似文献
5.
Consider the positive d-dimensional lattice d (d≥2) with partial ordering ≤, let {XK; K ∈ d } be i.i.d. random vari- ables taking values in a real separable Hilbert space (H, ||·||) with mean zero and covariance operator ∑, and set partial sums SN =∑K≤NXK, K , N ∈ d . Under some moment conditions, we obtain the precise asymptotics of a kind of weighted infinite series for partial sums SN as ε 0 by using the truncation and approximation methods. The results are related to the convergence rates of the law of the logarithm in Hilbert space, and they also extend the results of (Gut and Spǎtaru, 2003). 相似文献
6.
The study investigated the within- and cross-language contribution of morphological awareness (MA) to vocabulary and reading comprehension among students learning to read two typologically different orthographies at the same time: Korean and English. Fifty Korean ESL learners in grades five and six were administered Korean and English measures of MA (derivational and compound morphemes), vocabulary, and reading comprehension (narrative and expository texts), in addition to measures of phonological awareness (PA) and orthographic awareness (OA). Information about home language environment was also obtained from a parental questionnaire. Path analysis showed that MA was the most significant contributor to vocabulary (β = 0.33, p < 0.05) and reading comprehension (β = 0.46, p < 0.01) in English; and in Korean (β = 0.62 and β = 0.54, respectively, all ps < 0.01), controlling for effects of PA and OA. Unidirectional cross-language transfer was found from Korean MA to English vocabulary (β = 0.27, p < 0.05) and reading comprehension (β = 0.22, p < 0.05) and multiple determining factors are discussed. Educational implications and research recommendations are also presented. 相似文献
7.
8.
ZHAO Li-li 《浙江大学学报(A卷英文版)》2007,8(6):957-962
In this paper, we consider some polynomial (α,β)-metrics, and discuss the sufficient and necessary conditions for a Finsler metric in the form F=α a1β a2β2/α a4β4/α3 to be projectively flat, where ai (i=1,2,4) are constants with a1≠0, α is a Riemannian metric and β is a 1-form. By analyzing the geodesic coefficients and the divisibility of certain polynomials, we obtain that there are only five projectively flat cases for metrics of this type. This gives a classification for such kind of Finsler metrics. 相似文献
9.
《About Campus》2004,8(6):1-32
- How Benchmarking Can Help Us Improve What We Do—Jodi Levine Laufgraben Talks to Joseph A. Pica and Randy L. Swing
- What is benchmarking and what can it help us achieve? An interview with Joseph Pica and Randy Swing, who have both been studying this approach and putting it into practice, sheds light on these and other questions.
- Helping Students Develop Vision and Voice—The Role Creativity Plays
- Michele M. Welkener
- Creativity is more than just a good thing, says the author, it is the cornerstone of learning and development.
- Leadership, Feminism, and Classroom Politics—Or, How I Gave Up the Fight and Learned to Love Resistance
- Lee Burdette Williams
- Resistance is not as bad as it seems. Indeed, argues the author, it may be the catalyst on which learning depends.
- Departments
- Letters—Plagiarism: Academic Dishonesty or Communication Problem?
- Barbara J. Moore, Juan Flores, and John Gunter
- In Practice—The Tensions of Creating a Good First‐Year Experience Program: The Alpha Seminar
- Jeanie K. Allen
- Good first‐year experience programs don't come easy. Here are some of the challenges and opportunities the Alpha Seminar presents to educators at Drury University.
- Campus Commons—One Day at Hartman Rocks
- Lee Burdette Williams
- Hanging above the chasm of uncertainty and other learning opportunities.
- What They're Reading—The Truth About Writing
- Paula Stacey
- A primer on writing, life, and lousy first drafts.
10.
David Winograd 《TechTrends》2002,46(5):53-57
Moderating computer conferences is both is challenging and stimulating. Knowledge of the dynamics of preparing an asynchronous conference and how the functions of moderators differ at different stages of a conference will help to make the process run smoothly and enjoyably. A few concepts to keep in mind are:
相似文献
– | • Technical problems are inevitable |
– | • A conference size of 10 - 15 students is optimal |
– | • Welcome messages are critical and should be carefully crafted |
– | • Use appropriate conferencing spaces for different discourses |
– | • Be responsive and clear |
– | • Be on the lookout for small problems and solve them promptly before they grow into larger problems. |
11.
Pan Jian-min 《浙江大学学报(A卷英文版)》2000,1(1):71-77
Consider the mixed-effect coefficient semiparametric regression modelZ=X'α+Y'β+g(T)+e, whereX, Y andT are random vectors onR
p×R
q×[0, 1], α is a p-dimensional fixed-effect parameter, β is a q-dimensional random-effect parameter (Eβ=b, Cov(β)=Σ),g(.) is an unknown function on [0, 1], e is a random error with mean zero and variance σ2, and (X, Y, T) and (β,e), β ande are mutually independent. We estimate α,b andg(.) by the nearest neighbor and the least square method. In this paper, we prove that estimations of α,b have asymptotic normality and obtain the best convergence raten
−1/3 for the estimation ofg(.).
Project supported by the NSFC and the Natural Science Foundation of Zhejiang Province. 相似文献
12.
Joby Gardner 《The Urban Review》2009,41(2):174-197
This article explores how incarcerated youth and adult supervisors contest claims to identity via language of “representing”.
Comparing how youth and adults “represent” in discussions of their own past and future selves sheds light on the constrained
universe of discourse within which both groups work to express identities and on the basis of which we counsel, mentor, and
educate young people. Acknowledging these constraints can contribute to understanding what I call exceptionalism—the idea that only exceptional poor and raced young men, through great personal effort and sacrifice, may resist the lure
of the “street”. I conclude by discussing implications of this work for education and youth development work both inside and
beyond the juvenile justice system as well as for research across lines of difference by committed “outsiders”.
相似文献
Joby GardnerEmail: |
13.
Mei-Shiu Chiu 《International Journal of Science and Mathematics Education》2012,10(1):163-191
The aim of the present study was to identify children’s conceptions of learning mathematics and to assess the identified conceptions.
Children’s conceptions are identified by interviewing 73 grade 5 students in Taiwan. The interviews are analyzed using qualitative
data analysis methods, which results in a structure of 5 major conceptions, each having 2 subconceptions: constructivist (interest and understanding), interpretivist (liberty and innovation), objectivist (academic goal and perseverance), nativist (confidence and anxiety (reverse)), and pragmatist (vocational goal and application). The conceptions are assessed with a self-developed questionnaire, titled “the Conception of Learning Mathematics Questionnaire”
(CLMQ), which is administered to 513 grade 5 students in Taiwan and examined with a reliability measure, confirmatory factor
analysis, and correlations with 2 criteria: mathematics achievement and approaches to learning mathematics. The results show
that the CLMQ has desirable internal consistency reliability and construct validity. The conceptions are also sensibly in
relation to the 2 criteria, suggesting that the CLMQ is a valid measure for evaluating the quality of children’s learning
mathematics in relation to teaching contexts. 相似文献
14.
Functions like loge x, e x , e z and loge z are defined and studied systematically. It is observed thate z is the only complex analytic extension of the real analytic functione x . It is also observed that the power (analyticity) of ez is by choice and the beauty (its derivative is itself) of ez is unexpected. 相似文献
15.
Ramya Chandrasekaran Shairah Radzi Peh Zhen Kai Preman Rajalingam Jerome Rotgans Sreenivasulu Reddy Mogali 《Anatomical sciences education》2022,15(5):850-862
Due to the modernization of the medical curriculum and technological advancements, anatomy education has evolved beyond cadaveric dissection alone. Plastination techniques, three-dimensional (3D) modeling, and 3D printing technologies have progressively gained importance. However, there are limited valid and reliable surveys to evaluate students' perceptions of these new anatomy tools. Hence, this study aimed to develop a validated instrument to measure students' learning satisfaction, self-efficacy, humanistic values, and perceived limitations of plastinated and 3D printed models. A 41-item survey (five-point Likert scale, 1 = strongly disagree to 5 = strongly agree) was administered to Year 1 undergraduate medical students following a randomized controlled crossover study that evaluated plastinated and 3D printed cardiac and neck models. Ninety-six responses were received, and a factor analysis was performed with the Kaiser–Meyer–Olkin sampling adequacy of 0.878. The confirmatory factor analysis yielded a 4-factor, 19 items model that had a good fit with the latent constructs of 2 (147) = 211.568, P < 0.001, root mean square error of approximation = 0.068, root mean square residual = 0.064, comparative fit index = 0.946, and Tucker Lewis index = 0.937. The Cronbach's alpha for the individual factors ranged from 0.74 to 0.95, indicating good internal consistency. This demonstrated a psychometrically valid and reliable instrument to measure students' perceptions toward plastinated and 3D printed models. 相似文献
16.
Effect of lead exposure on the immune function of lymphocytes and erythrocytes in preschool children
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
17.
We derive necessary and sufficient conditions for the existence and an expression of the (anti)reflexive solution with respect to the nontrivial generalized reflection matrix P to the system of complex matrix equations AX = B and XC = D. The explicit solutions of the approximation problem min x∈Ф ||X - E||F was given, where E is a given complex matrix and Ф is the set of all reflexive (or antireflexive) solutions of the system mentioned above, and ||·|| is the Frobenius norm. Furthermore, it was pointed that some results in a recent paper are special cases of this paper. 相似文献
18.
Christopher Day 《Journal of Educational Change》2008,9(3):243-260
This paper is based upon a unique mixed methods 4-year research project which focused upon the variations in teachers’ work,
lives, and effectiveness of 300 elementary and secondary school teachers in a range of 100 schools across seven regions of
England. Its findings challenge linear conceptions of teacher development and expertise and provide new understandings of
the effects of personal, school and broader policy contexts upon professional life phase trajectories and teachers’ emotional
identities. It finds connections between these and teachers’ commitment, resilience, and effectiveness. This paper discusses
these in relation to the school standards and teacher retention agendas.
相似文献
Christopher DayEmail: |
19.
Rene A. Gonzales Gordon Ferns Marc A. T. M. Vorstenbosch Claire F. Smith 《Anatomical sciences education》2020,13(6):707-720
Spatial ability (SA) is the cognitive capacity to understand and mentally manipulate concepts of objects, remembering relationships among their parts and those of their surroundings. Spatial ability provides a learning advantage in science and may be useful in anatomy and technical skills in health care. This study aimed to assess the relationship between SA and anatomy scores in first- and second-year medical students. The training sessions focused on the analysis of the spatial component of objects' structure and their interaction as applied to medicine; SA was tested using the Visualization of Rotation (ROT) test. The intervention group (n = 29) received training and their pre- and post-training scores for the SA tests were compared to a control group (n = 75). Both groups improved their mean scores in the follow-up SA test (P < 0.010). There was no significant difference in SA scores between the groups for either SA test (P = 0.31, P = 0.90). The SA scores for female students were significantly lower than for male students, both at baseline and follow-up (P < 0.010). Anatomy training and assessment were administered by the anatomy department of the medical school, and examination scores were not significantly different between the two groups post-intervention (P = 0.33). However, participants with scores in the bottom quartile for SA performed worse in the anatomy questions (P < 0.001). Spatial awareness training did not improve SA or anatomy scores; however, SA may identify students who may benefit from additional academic support. 相似文献
20.
Résumé De manière générale, l'évidence sensorielle et, plus particulièrement, visuelle constitue pour les étudiants le principal fondement du savoir scientifique: nul besoin de supposer pour connaître, tout est donné ou presque. Du point de vue de l'enseignement des sciences, cette croyance à saveur réaliste est particulièrement critique, notamment parce qu'elle conduit à penser que les concepts, lois et théories scientifiques procèdent d'un monde de matérialités plutôt que d'un monde de modèles et de relations. Au cours d'une recherche effectuée auprès d'un groupe-classe de 35 étudiants durant douze semaines, nous avons pu observer que, pour la majorité des étudiants, la compréhension du caractère construit et consensuel du savoir scientifique était facilitée par le développement d'une métaréflexion sur leurs propres productions de connaissance et les inévitables postulats et suppositions qui les fondent. Nous avons également pu observer qu'il découle de cette activité réflexive un modèle de science qui se distingue des modèles initialement tenus par les étudiants, par le pouvoir créateur et, surtout, le pouvoir de théoriser qu'il comporte: postuler, supposer, jauger collectivement de la plausibilité des résultats plutôt qu'en appeler à une instance occulte, voilà quelques-unes des conquêtes théoriques qu'ils ont effectuées et sur lesquelles nous allons nous attarder.
Sensorial, and more specifically, visual evidence is generally regarded by students as the basis for scientific knowledge: no need to postulate to understand, all is almost or practically given. From a science-teaching standpoint, this rather realistic approach is critical and leads to the belief that scientific concepts, laws, and theories stem from a world of materiality rather than from a world of models and relationships. During a 12-week study a group of 35 college students, we observed that for the majority of them, the development of metareflection on how they produce knowledge, with the inevitable and inherent postulates and conjecture, facilitated their understanding of the constructed and consensual character of scientific knowledge. We also observed that this reflexive activity facilitated the development of a new approach to science that differed from those models previously used by the students in its creative potential and, more importantly, in the power of its theoretics: to postulate, suppose, and collectively estimate the plausibility of results rather than calling up occult instances. These and other theoretical achievements will be discussed in this paper.相似文献