分析壳聚糖衍生物膜在水果保鲜中的作用

水果保鲜是在水果采摘后至上架期间维持水果正常色泽、口感、营养,保持水果商品价值的重要手段和措施.壳聚糖衍生物由于其良好的成膜性、保湿性、抑菌性,能够有效地保持水果新鲜度,在当前果蔬保鲜领域内受到了人们更多的关注.本文介绍了壳聚糖及其衍生物,阐述了壳聚糖衍生物膜在水果保鲜中的作用机理,并对壳聚糖保鲜剂在水果保鲜中的应用进行了简单的叙述,论述了其对水果保鲜的作用和意义.     

壳聚糖涂膜对富川脐橙的保鲜机理与效果研究

研究了壳聚糖涂膜对富川脐橙的保鲜效果和保鲜机理.结果表明:3%壳聚糖浓度涂膜可明显延缓富川脐橙酸含量、总糖含量、Vc含量的降低,延长贮藏寿命.由于壳聚糖分子中基团的作用,有效抑制致病菌入侵;膜的特性及其对果实酶的诱导作用,抑制了脐橙呼吸强度,提高SOD活性,从而达到保鲜目的.     

壳聚糖涂膜对富川脐橙的保鲜机理与效果研究

研究了壳聚糖涂膜对富川脐橙的保鲜效果和保鲜机理。结果表明：3％壳聚糖浓度涂膜可明显延缓富川脐橙酸含量、总糖含量、Vc含量的降低，延长贮藏寿命。由于壳聚糖分子中基团的作用，有效抑制致病菌入侵；膜的特性及其对果实酶的诱导作用，抑制了脐橙呼吸强度，提高SOD活性，从而达到保鲜目的。     

天然高分子甲壳素类纤维的研究进展

综述了甲壳素及其衍生物纤维的制备和性能.介绍了制备甲壳素纤维的黄化法、含卤溶剂法和酰胺-氯化锂法.总结了壳聚糖纤维制备的一般方法和性能.简要介绍了甲壳素/壳聚糖酯类和醚类衍生物的纤维.讨论了甲壳素类纤维的应用.     

果蔬保鲜中壳聚糖的应用研究

壳聚糖是一种原材料丰富的天然高分子材料,被广泛应用于防腐、保鲜、水处理等领域.从果蔬保鲜技术的两个主要方面,介绍了壳聚糖成膜特性、保鲜机理及在果蔬保鲜中的应用效果,提供了果蔬保鲜的一种新的途径.     

壳聚糖的研究进展

本文对壳聚糖及其衍生物在废水的絮凝处理、含Cu2 废水处理方面的研究和应用做了综述。     

甲壳素、壳聚糖研究与应用进展

文章综述了甲壳素和壳聚糖的重要性质、制备、化学修饰及不同领域的研究与应用,并介绍了甲壳素及其衍生物在各领域的开发前景。     

天然高分子絮凝剂壳聚糖及其衍生物在水质净化工艺中的应用

壳聚糖及其衍生物来自天然高分子甲壳素，本文介绍了它们的结构及吸附、螯合 特性，综述了它们作为天然高分子絮凝剂在水质净化工艺中的应用．     

虾型壳聚糖掺杂钴离子保鲜剂的制备及应用

介绍了一种新型保鲜剂的制备方法,即将从廉价的虾壳中提取的甲壳素制成壳聚糖,然后用钴离子对其掺杂优化.保鲜对比实验结果表明,这种新型保鲜剂的保鲜效果优于壳聚糖,且对人体无毒无害.     

壳聚糖涂膜对芒果的保鲜效应

探讨了不同浓度壳聚糖涂膜剂对芒果生化指标和保鲜效果的影响。结果表明:2%浓度的壳聚糖涂膜剂对芒果呼吸作用有最好的抑制效果,总酸度和酶活性变化最小,腐烂率最低,具有最好的保鲜效果。     

地矿类院校资源环境与城乡规划管理专业比较与对策

本文针对以地质学为背景开设资源环境与城乡规划管理专业的7所地矿类院校,调研比较分析了其专业发展概况、课程设置及课程结构等状况。课程结构呈多样化,但并不突显行业特色与优势;课程设置不能依托地质领域优势专业平台进行学科建设;普遍重视实践课程模块建设,但教学内涵实现不足。在课程体系建设和教材质量改革等方面提出了建议。     

新闻传播教育存在的问题及对策研究

新闻传播专业是一门需要理论与实践紧密结合的专业,专业人才不仅需要具备良好的理论基础,更需要在实践中不断磨练。进入21世纪,随着新媒体的大量涌现,新闻专业人才正当其时,然而,新闻传播教育与就业需求的脱节也造成了大量教育资源的浪费。针对当前新闻传播教育重量轻质、资金匮乏、忽略素质教育、师资薄弱等问题,提出了改善师资、提高资金扶持力度、增加实践课程等应对策略。     

Student outcomes and perceptions of instructors' demands and support in online and traditional classrooms

In this study, seven graduate students were interviewed and 187 (91 online; 96 traditional) graduate students were surveyed about perceptions of differences in instructors' demands and support and student' motivation, self-regulation, satisfaction, and perceptions of learning in these environments. Results indicated significant differences in students' perceptions on all variables except self-efficacy. Results indicated a strong effect for differences between perceived instructor affective support in online and traditional classrooms. Although students in traditional classrooms ranked instructors' affective support higher, the variable had a stronger relationship with online students' satisfaction. Differences between online and traditional students' reports of instructors' academic support, instructors' demands, and students' satisfaction were significant with medium effect sizes. Results are important because they provide information about students' perceptions of the differences in environments created by instructors that relate to students' affective outcomes.     

论魏晋十六国时期中原王朝对西域的管辖经营

魏晋十六国时期，是中国历史上动荡割据的时代。然而，这时期西域和内地的密切联系以及一致性并非削弱；而且恰恰在这时，高昌地区形成了与内地同一的郡县行政管理体制。     

唐宋湖南僧道移民考论

唐宋时期,有部分僧、道宗教移民迁来湖湘之地,这部分宗教移民以僧人为主,南方之闽浙和北方之陕晋,都是主要迁出地,而湖南之衡山与潭州诸山是主要迁入地。在迁移时间上主要集中于唐中后期与北宋时期,迁徙原因主要与佛道之学传授有关。他们的到来对湖南宗教文化的发展发挥了积极的作用。     

魏晋南北朝后妃的才情与个性情状

魏晋南北朝时期,社会极端动荡,思想却极为自由活跃。在这样的复杂环境中,本时期皇后、妃嫔的生存状况、精神面貌大不同于其他时期,在中国古代后妃史上占有独特的地位。本文拟就此时期后妃展现出来的才情及迥异的个性作些探讨。     

Presence and Persistence: Poverty Ideology and Inner-city Teaching

This paper examines the role of poverty ideology in determining whether a teacher comes to teach at a poor school (presence) and whether s/he remains at this type of school over time (persistence). A sample of 400 teachers in San Diego California was administered a questionnaire that evaluated respondents’ attitudes toward poverty. Teachers who believed poverty was rooted in social structure were more apt to be present in and to persist at poor schools. It is argued that this presence and persistence in poor schools was because these teachers had developed a “structurally mitigated sense of occupational competence”. This sense of competence made these teachers more likely to understand the problems they encountered in the classroom in structural terms, and thus they were more likely to be both satisfied with and persist at their jobs.     

出土简帛所见楚、秦、汉用语比较(四则)

出土材料是可信的第一手材料，通过对睡虎地秦简、张家山汉简及包山楚简中有关的词语从字形、字义等方面进行比较，可探讨在战国末期至汉初这一段历史时期内，楚、秦和汉三在语言方面的继承与发展的关系。     

Relationship between affect and achievement in science and mathematics in Malaysia and Singapore

Background : The Trends in International Mathematics and Science Study (TIMSS) assesses the quality of the teaching and learning of science and mathematics among Grades 4 and 8 students across participating countries.

Purpose : This study explored the relationship between positive affect towards science and mathematics and achievement in science and mathematics among Malaysian and Singaporean Grade 8 students.

Sample : In total, 4466 Malaysia students and 4599 Singaporean students from Grade 8 who participated in TIMSS 2007 were involved in this study.

Design and method : Students’ achievement scores on eight items in the survey instrument that were reported in TIMSS 2007 were used as the dependent variable in the analysis. Students’ scores on four items in the TIMSS 2007 survey instrument pertaining to students’ affect towards science and mathematics together with students’ gender, language spoken at home and parental education were used as the independent variables.

Results : Positive affect towards science and mathematics indicated statistically significant predictive effects on achievement in the two subjects for both Malaysian and Singaporean Grade 8 students. There were statistically significant predictive effects on mathematics achievement for the students’ gender, language spoken at home and parental education for both Malaysian and Singaporean students, with R ² = 0.18 and 0.21, respectively. However, only parental education showed statistically significant predictive effects on science achievement for both countries. For Singapore, language spoken at home also demonstrated statistically significant predictive effects on science achievement, whereas gender did not. For Malaysia, neither gender nor language spoken at home had statistically significant predictive effects on science achievement.

Conclusions : It is important for educators to consider implementing self-concept enhancement intervention programmes by incorporating ‘affect’ components of academic self-concept in order to develop students’ talents and promote academic excellence in science and mathematics.     

高校仪器设备维护与维修的探讨

随着高校仪器设备数量的不断增加,日常的维护与维修工作越来越受到学校的重视。仪器设备的维护与维修是设备在使用过程中的客观需求,也是保证设备正常运行的必要手段。分析了现在高校在仪器设备维护与维修中存在的一些问题,结合本校的实际情况提出了建立制度、加大投入、科学管理的模式,并对维修方式进行了阐述。