R/S构型的平面确定法

对于一个旋光异构体的费什尔投影式中任一手性碳原子来说,若最小的原子在水平线或在垂线上,只要看其三个原子或基团在水平面上的走向,即可判断出其构型.     

中国文学史新"变"的三个视点

新时期中国学史的叙述在吸取前代和前期学史写作得失的基础上，不断深化着对学史的认识，以多元化的姿态不断丰富着学史的存在。他们的进步值得肯定，而困惑之处也值得反思，要改变困惑的局面，须求新“变”。求变的因素很多，我们的视点有三个：作方法论上的更新，学本位的回归，读接受的纳入。     

Fiber optic biosensor of immobilized firefly luciferase

Luciferase from firefly lantern extract was immobilized on CNBr-activated Sepharose 4B. The kinetic properties of immobilized luciferase were extensively studied. TheK _m′ for D-luciferin is 11.9 μmol/L, the optimum pH and temperature for Sepharose-bound enzyme were 7.8 and 25°C respectively. A luminescence fiber optic biosensor, making use of immobilized crude luciferase, was developed for assay of ATP. The peak light intensity was linear with respect to ATP concentration in range of 10⁻⁹–10⁻⁵ mol/L. A biological application was also demonstrated with the determination of serum ATP from rats bred in low versus normal oxygen environments.     

高校网络教学资源平台的建设

本文阐述构建高校网络教学资源平台的原则、主要内容、实现技术、特色和应用效果,为提高学生学习和科研能力起着促进作用。     

国内外大学校长选拔制度的比较分析

大学校长选拔制度有不同类型:选举与任命两段制、董事会领导下的学校自主遴选制、学校遴选与行政任命结合制、政府直接行政委任制、轮流出任制等等,不同类型的校长选拔制度有其优势与弊端。本文对国内外大学校长选拔制度的类型与优劣作了比较分析,在此基础上,提出了针对我国大学校长选拔的几点启示。     

Measures of Teachers' Workload

The measurement of teachers' workload has till now been subjective. Teachers feel that they have a great responsibility to their pupils and to society and their workload heavy, while non-teachers may have different views. This debate occurs even amongst teachers teaching different subjects and levels in a school as well as amongst teachers in different schools. A comparison of teachers' workload in different countries is also particularly difficult because of different class sizes, curriculum time, etc. It is therefore essential to provide a quantitative and objective measure for evaluating teachers' workload. This measure can then be used as a reference by school principals when allocating extra duties to teachers. It is also useful to education authorities when deploying teachers to various schools in centralized education systems.     

谈诗歌语言的形象性

诗歌语言的特征是 :形象鲜明 ,新奇动感 ,音韵和谐 ,增强语言形象感的艺术手法 :拟人拟物 ,夸张比喻 ,六根通感     

儿童急性呼吸道感染中流感嗜血杆菌的检测与分型

目的 :为了解儿童急性呼吸道感染中的流感嗜血杆菌与生物分型及其对抗生素的敏感情况。方法 :对 78例急性呼吸道感染儿童采用常规方法进行了培养 ,药敏试验与生物分型。结果 :共分离出流感嗜血杆菌 33株 ,检出率为 4 2 .3% ,在对所有分离株进行的生物分型结果中 ,共检出 5型 ,其中以Ⅳ ,Ⅵ型居多 ,分别为Ⅳ型 8例 (2 4 .2 % ) Ⅵ型 13例 (39.4 % )。 33株分离出的流感嗜血杆菌中 ,全部菌株对氯霉素 ,氧氟沙星敏感 ,头孢拉定株 2 1(6 3.6 % ) 、头孢唑林 19株 (5 7.6 % )、去甲万古霉素 2 3株 (6 9.7% ) 、苯唑青霉素 31株 (93.4 % ) 、复方磺鞍甲基异唑 11株 (33.3% )、红霉素 4株 (13.2 % )。结论 :儿童急性呼吸道感染中流感嗜血杆菌有较高的检出率 ,以生物Ⅵ型和Ⅳ型居多。流感嗜血杆菌存在着严重的耐药倾向。     

Continuity of Care,Caregiver–Child Interactions,and Toddler Social Competence and Problem Behaviors

ABSTRACT

Research Findings: Continuity of care is a recommended practice in child care intended to promote secure and supportive relationships between infants and toddlers and their caregivers. Toddlers (N = 115) between 12 and 24 months were observed in 30 continuity and 29 noncontinuity classrooms. The average duration of care for toddlers with caregivers was 14 months in the continuity rooms and 5 months in noncontinuity rooms. Toddlers observed in continuity rooms experienced higher levels of interactive involvement with their caregivers and were rated by their caregivers as having fewer problem behaviors compared with the toddlers in noncontinuity rooms. Toddlers in rooms with higher staff–child ratios also experienced more involved caregiving. We did not find evidence that the level of involved caregiving mediated the association between continuity of care and toddlers’ social competence or problem behaviors. Practice or Policy: Continuity of care may be a promising practice for programs that strive to provide high-quality care for infants and toddlers.     

甘薯根茎多糖研究进展

目前，国内外对甘薯活性物质的研究大都是以甘薯块根和甘薯茎蔓为对象，而对于甘薯生产的另外一批资源——甘薯根茎的研究却极为少见．其实，这是一部分生物量较大而又极具潜在价值的生物资源．用水作溶剂，采用破壁效果好的超声波技术提取甘薯根茎中的多糖，具有省时、环保、经济且不破坏功能成分结构等诸多优点，有着良好的发展前景．