排序方式： 共有49条查询结果，搜索用时 15 毫秒
1.
Gianna Giachi Chiara Capretti Nicola Macchioni Benedetto Pizzo Ines Dorina Donato 《Journal of Cultural Heritage》2010,11(1):91-101
The aim of the work is to set up a methodological approach to verify the effectiveness of the treatments of decayed waterlogged archaeological wood and to point out the proper thermo-hygrometric conditions for its preservation after treatment. The treatments were performed on wood samples of maritime pine (Pinus pinaster Aiton), oak (Quercus sp. caducifolia), elm (Ulmus cf. minor) and strawberry tree (Arbutus unedo L.), obtained from stems pertaining to the original vegetation found in the excavation site of the Ancient Ships in Pisa (Italy), and dated from seventh century BC to second century AD The utilised products were: Polyethylene Glycols (PEG) of various molecular weights, a Polypropylene Glycol (PPG 425), Trehalose (α-D-glucopyranosyl-α-D-glucopyranoside), and their mixtures, and also a Hydroxypropylcellulose (Klucel). The main objective to be pursued by the treatments was considered the stabilisation of the original size and shape of samples. The various steps of this approach were: the execution of a preliminary diagnostic survey on untreated samples; the characterisation of treatment solutions ‘as such’ to establish the property to be monitored during the treatment; the evaluation of the main physical characteristics of wood after the treatment were determined. Among the latter, the coefficient of dimensional stability during the exposure to a series of selected thermo-hygrometric conditions and the retention of consolidants after the treatment. These two measurements allowed the definition of the ‘efficacy of a treatment’, φT, a new parameter firstly utilised in this work. It measures the stabilisation capability of the percent unit of retained product, and its value permits to put in evidence the consolidants that stabilise wood with the lowest amount of product. Conversely, it was not possible to measure the Anti-Shrink Efficiency (ASE), one of the most utilised parameters for the evaluation of treatments, because of the serious distortions and fractures observed in all the heavily degraded untreated samples. 相似文献
2.
3.
4.
The University of Michigan opened a new medical library in July 1980. The five-story structure combines the library with a learning-resources center. Overall, the building has operated smoothly and has been well accepted. The combining of two facilities designed to support the teaching and learning objectives of the health sciences curriculum will ensure long-term cooperation between them. 相似文献
5.
We believe that science journals can be used in the preschool classroom as tools for supporting and assessing children’s learning
of science- and literacy-relevant content and procedures. To support this argument, we review changes in attitudes about the
cognitive competencies of preschoolers and in teaching and learning expectations for early childhood education. We describe
practical aspects of using science notebooks with this age group and discuss specific ways that journals support children’s
learning. Finally, the role of journals in assessment is discussed. 相似文献
6.
Ohne Zusammenfassung 相似文献
7.
William L. Romine Troy D. Sadler Eric P. Wulff 《Journal of Science Education and Technology》2017,26(5):534-545
We describe the development of the Measure of Affect in Science and Technology (MAST), and study its usefulness for measuring science affect in middle school students via both classical and Rasch measurement perspectives. We then proceed to utilize the measurement structure of the MAST to understand how middle school students at varying levels of affect express their interest and attitudes toward science and technology and gender differences in how students express their affect. We found that affect in science and technology comprises a main dimension, science interest, and four peripheral dimensions: interest in careers in science and technology, attitudes toward science, and interest in attending science class. Of these, careers in science and technology carry the highest affective demand. While males showed higher levels of personal and situational interest in science, a greater interest in careers in science and technology was the biggest contributor to males’ higher affect toward science and technology. We argue that whether the MAST is used as a measure of a single construct or multiple subconstructs depends upon specific research or evaluation goals; however, both uses of the MAST yield measures which produce valid inferences for student affect. 相似文献
8.
Ines Ben Chobba Amine Elleuch Imen Ayadi Lamia Khannous Ahmed Namsi Frederique Cerqueira Noureddine Drira Néji Gharsallah Tatiana Vallaeys 《Journal of Zhejiang University. Science. B》2013,14(12):1084-1099
Endophytic flora plays a vital role in the colonization and survival of host plants, especially in harsh environments, such as arid regions. This flora may, however, contain pathogenic species responsible for various troublesome host diseases. The present study is aimed at investigating the diversity of both cultivable and non-cultivable endophytic fungal floras in the internal tissues (roots and leaves) of Tunisian date palm trees (Phoenix dactylifera). Accordingly, 13 isolates from both root and leaf samples, exhibiting distinct colony morphology, were selected from potato dextrose agar (PDA) medium and identified by a sequence match search wherein their 18S–28S internal transcribed spacer (ITS) sequences were compared to those available in public databases. These findings revealed that the cultivable root and leaf isolates fell into two groups, namely Nectriaceae and Pleosporaceae. Additionally, total DNA from palm roots and leaves was further extracted and ITS fragments were amplified. Restriction fragment length polymorphism (RFLP) analysis of the ITS from 200 fungal clones (leaves: 100; roots: 100) using HaeIII restriction enzyme revealed 13 distinct patterns that were further sequenced and led to the identification of Alternaria, Cladosporium, Davidiella (Cladosporium teleomorph), Pythium, Curvularia, and uncharacterized fungal endophytes. Both approaches confirmed that while the roots were predominantly colonized by Fusaria (members of the Nectriaceae family), the leaves were essentially colonized by Alternaria (members of the Pleosporaceae family). Overall, the findings of the present study constitute, to the authors’ knowledge, the first extensive report on the diversity of endophytic fungal flora associated with date palm trees (P. dactylifera). 相似文献
9.
Questionnaire data from the PIRLS 2006 study in Italy provided a number of indices in order to summarize factors of educational context influencing reading achievement. The aim of the present paper is to study the relationships between school factors, teacher factors, family factors, student factors and reading achievement by means of multilevel regression analysis. Results show that pupils＇ attainment in reading is significantly related to： （1） home educational resources （home/student level effect）; （2） parents＇ attitudes toward reading （home/student level effect）; （3） students＇ attitudes toward reading; （4） students＇ reading self-concept; and （5） teacher career satisfaction （school/teacher level）. 相似文献
10.
In primary care specialties, Morning Report is a traditional vehicle for expanding medical residents' training in diagnosis and treatment. At one academic medical center, residents and faculty in the Department of Family and Community Medicine use case-based teaching, centered around planning and reviewing patient management, to review intriguing cases from patient encounters in the department's hospital service. Seeking to improve the level of evidence-based information exchanged at Morning Report, department leaders invited reference librarians from the health sciences library to attend weekly Morning Report. The librarians saw this as an opportunity not only to improve residents' information-seeking skills, but also to improve librarians' teaching skills and understanding of the needs of users in clinical settings. This paper describes the evolution of librarians' involvement in Morning Report, examples of the kinds of contributions librarians have made in this setting, and changes made in Morning Report sessions to facilitate this activity. 相似文献