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101.
利用溶剂提取与DEAE—Sephadex A—25柱层析进行分离,根据高碘酸氧化、Smith降解,部分酸水解、甲基化及其产物的G.C.和G.C.—M.S.联机分析鉴定其结构.得出BJⅡa是多分枝结构的中性杂多糖,其主链是由1→2连接的葡萄糖和岩藻糖构成。 相似文献
102.
Robert W. Bell 《PRIMUS》2017,27(3):406-417
AbstractMentoring undergraduate students in research is both rewarding and challenging. In this paper we present how we established a summer Research Experience for Undergraduates (REU) program in the mathematical sciences at Michigan State University. A goal of our REU is to include students who are at an early stage of their study of mathematics. We share our experiences in recruiting students, designing research projects, and mentoring our participants. We discuss the challenges we faced and the solutions we found while working with a diverse group of undergraduate students from across the nation. 相似文献
103.
奚长生 《湖南城市学院学报》1993,(5)
自1951年B、chance研制成第一台双波长分光光度计以来,无机多组份体系分光光度测定方法,取得了显著的进展,发展了双波长分光光度法,三波长分光光度法,双显色双波长分光光度法,导数分光光度法,组合导数分光光度法,本文试就借助于仪器的输出信息,消除重叠光谱带的干扰,同时测定无机多组份体系的分光光度方法,作一简要的评述。 相似文献
104.
为适应城市居民生活“小区”化和以建设“明小区”为重点的社会工作路线,改变目前社区体育组织以“街道”为单一层次的基本结构,本课题采用献法、调查法、比较及逻辑法等,对“小型化”社区体育组织的现状、目标及发展模式进行了深入研究,并提出了辐射型、网络型、独立型三种递进式组织结构模式,为社区体育组织结构的转型发展提供参考依据。 相似文献
105.
Curt J. Dommeyer Paul Baum Kenneth S. Chapman Robert W. Hanna 《Assessment & Evaluation in Higher Education》2002,27(5):455-462
Business professors were surveyed to determine their attitudes towards two methods of collecting students' teaching evaluations of faculty--the traditional paper-and-pencil method conducted in class and the online method conducted via the Internet. Faculty preferred the traditional paper method, mainly because they believed it would produce a higher and more accurate response than the online method. Faculty characteristics were examined to determine whether they were related to attitudes towards the online method of collecting teaching evaluations. No characteristics were found to be significantly associated with attitudes towards the online method. Suggestions for future researchers are offered. 相似文献
106.
107.
Identification of Alcohol by Smell among Preschoolers: Evidence for Early Socialization about Drugs Occurring in the Home 总被引:1,自引:0,他引:1
This study tested preschoolers' ability to provide accurate verbal associations to alcoholic beverage odors and whether this ability was related to parental drinking patterns and motivations. Older preschoolers performed better than younger preschoolers; photographic cues improved performance; children who correctly identified a substance by smell had socially appropriate knowledge of the culturally appropriate users of the substance; children reported liking substances that are used mainly by children and adults, and generally reported disliking substances whose use is legally limited to adults only; children were better at identifying substances they commonly use, but success at recognition of alcoholic beverages was related to heavier parental drinking and use of alcohol for escape reasons. Findings have implications for theories of socialization to drug use and for models of prevention. 相似文献
108.
Michael J. Guralnick Robert T. Connor Brian Neville Mary A. Hammond 《Early education and development》2002,13(1):59-80
Mothers' perspectives of children's peer-related social development were obtained from matched groups of young children with developmental delays, communicative disorders, and typically developing children. Structured interviews elicited information on numerous issues including mothers' views of the importance of children's social skills development, rationales with respect to why children succeed or had difficulties on specific social tasks, and the socialization strategies mothers employ to promote children's peer-related social development. Mothers also reported on their efforts to arrange play with peers for their child and the degree to which they monitored that play. Results indicated that mothers rated children's social development as highly important, offered primarily internal rationales (e.g., traits, dispositions) for success or difficulties in achieving social tasks, and endorsed moderate and low power socialization strategies. Differences across the three groups were minimal. Mothers arranged play with peers least often for children with developmental delays and communication disorders, but monitored play more extensively for children with delays. These finding were discussed in terms of mothers adopting a developmental orientation to understand children's social development and their implications for maternal participation in peer competence intervention programs. 相似文献
109.
ABSTRACT Over the past three decades, urban sociologists have shed light on the intensifying social inequality between the wealthiest and poorest neighborhoods in global cities; yet limited research has been done to illuminate the relationships between urban polarization and school choice (i.e., where parents choose schools for their children). This study sociospatially examines the patterns of secondary school choice in the global city of Toronto to illuminate the relationship between urban polarization and school choice. In doing so, this study combines Pierre Bourdieu’s sociospatial theory with a geographic information systems (GIS) approach. Overall, we found that popular schools and schools with specialized choice programs tend to be located in high-status neighborhoods, defined as neighborhoods with residents in the top 20% of family income, home prices, education attainment, and representation from the dominant culture. We also show that mobile students who choose popular schools or highly sought-after specialized programs tend to come from advantaged neighborhoods. Meanwhile, local students who choose a regular school in their neighborhood tend to come from low-status neighborhoods. With a new interdisciplinary approach, this study contributes to a more spatialized understanding of how social inequality and polarization account for school choice. 相似文献
110.
中国共产党成立以后就着手开展工人运动 ,首先遇到的障碍是帮会。由于在工厂、码头、矿山、货栈等有劳苦工人的地方 ,几乎都有帮会的活动 ,又由于帮会在思想上禁锢着工人群众的觉悟 ,在组织上限制着工人群众的自由 ,阻碍工人运动的发展。为此 ,我党制定了一系列妥善处理帮会的策略 ,排除了帮会对工人运动的干扰 ,有力地推动了中国革命。 相似文献