茯苓对家兔利尿作用的观察

观察茯苓水煎醇沉液对兔的利尿作用。取雄性家兔24只随机均分Ⅳ组,兔称重全身麻醉后固定于手术台上,沿尿道口将导尿管插入膀胱内收集尿液,连续记录1h内排尿量。Ⅰ～Ⅳ组分别按0g/kg、0.5g/kg、1.5g/kg、2.5g/kg剂量耳缘静脉注射茯苓水煎醇沉液。结果:静注茯苓水煎醇沉液1.5g/kg、2.5g/kg剂量组利尿作用明显(P0.01),其中2.5g/kg剂量组在给药10min内尿量出现高峰。表明茯苓对兔具有明显的利尿作用,并且存在一定程度的正向量效关系。     

北大西洋大型常见冷水柳珊瑚潜在分布建模

Paragorgia arborea及Primnoa resedaeformis是北大西洋最常见的两类大型冷水柳珊瑚,该两种柳珊瑚显著增加了底栖环境的生境复杂度。其分布信息对资源管理及保护极其重要,但难以获取。本文基于随机森林模型及最大熵模型预测其在北大西洋Traena区域的潜在分布。预测精度评价表明随机森林模型较最大熵模型具有更好的预测性能。平均曲率（90 m尺度）是随机森林模型预测两种柳珊瑚分布的主导因子,表明其与两种柳珊瑚的分布具有较强生态相关性。预测结果显示两种柳珊瑚趋向于分布在珊瑚礁体上。本预测成果可为该区域冷水珊瑚保护提供决策辅助信息。模型对比研究可为大型底栖动物分布建模的模型选择提供依据。     

珊瑚砂对磷酸钾镁水泥砂浆力学特性与水化机理的影响（英文）

目的：在珊瑚岛礁上,构筑物因为潮汐和风浪的双重侵蚀作用而损伤严重。为确保修补有效和取材便利,人们采用磷酸钾镁水泥和珊瑚砂配制成砂浆对珊瑚岛礁构筑物进行修补。本文旨在探讨珊瑚砂对磷酸钾镁水泥砂浆的宏细观力学特性、抗侵蚀性及水化行为的影响规律,为磷酸钾镁水泥作为快速修补材料在珊瑚岛礁损伤构筑物中应用提供理论基础和技术支撑。创新点：1.揭示珊瑚砂对磷酸钾镁水泥砂浆宏细观力学特性和抗侵蚀性能的影响规律;2.采用定量分析的方法阐明珊瑚砂对磷酸钾镁水泥水化产物相组成和相对含量的影响规律。方法：1.利用抗压强度测试和显微硬度测试手段分析不同养护龄期下关键因素掺量对磷酸钾镁水泥-珊瑚砂浆宏细观力学特性的影响;2.将磷酸钾镁水泥砂浆暴露于Na₂SO₄溶液中,分析其在长期浸泡条件下抗压强度的劣化机制及抗盐溶液侵蚀的行为规律;3.利用扫描电子显微镜-能谱仪,揭示不同养护龄期下水化产物相形貌及微结构特征,结合X射线衍射,利用绝热法定量分析水化产物相相对含量随养护龄期的变化规律。结论：1.与磷酸钾镁水泥-河砂浆相比,磷酸钾镁水泥-珊瑚砂浆体的界面显微硬度值更高,且其界...     

3种抗HBV核苷(酸)类似物体外抗乙肝病毒作用

比较3种抗HBV核苷(酸)类似物(拉米夫定、恩替卡韦、替诺福韦)对HepG 2.2.15细胞的毒性作用和对HBsAg、HBeAg和HBV-DNA表达的抑制效果。用四甲基噻唑蓝(MTT)法检测药物的细胞毒性;酶联免疫(ELISA)法检测HBsAg和HBeAg表达水平;PCR-荧光探针法定量检测HBV-DNA含量。结果:在最高浓度200 mg/L时,拉米夫定组存活率为74.72%,恩替卡韦组存活率仅为36.74%,替诺福韦组存活率为95.22%;拉米夫定和替诺福韦对HBsAg、HBeAg表达无明显抑制,恩替卡韦对HBsAg、HBeAg表达有抑制并与其细胞毒性相一致。在第9天,3种药物对HBV-DNA抑制作用明显,在6.25 mg/L浓度时,抑制率均高于90%;3种药物在相同药物浓度下,恩替卡韦对HepG 2.2.15细胞毒性最大,替诺福韦几乎没有细胞毒性,拉米夫定有一定毒性。     

大众之柳与扬州之柳的文化对比阐释

柳,古往今来一直是很多人笔下灵性之物的代表,自然古朴,情与意的化身.众人之柳众人爱,扬州之柳扬州赞.扬州自古就有"绿杨城郭"的美誉.柳,本是情意化身,扬州的柳较之别处,更显婀娜风情,有着深刻的扬州印记.从另一角度折射出扬州特有的文化内涵.文章试图对大众之柳和扬州之柳作一番阐释,以期对柳文化有更深的认识.     

系统素与植物抗伤害作用

介绍系统素的结构与特性 ,系统素的抗伤害作用以及抗伤害作用的过程     

珊瑚漂白工艺的研究

本实验采用碳酸盐质白珊瑚,经过一系列的优化和处理,改善珊瑚的颜色、光泽和光洁度,使珊瑚真正具有商品价值。本文就珊瑚珠的前处理、漂白液配方设计和漂白条件试验进行了初步的研究,获得了较好的漂白液配方、最佳条件和满意的漂白结果。     

陶渊明五柳的误读与演变

陶门五柳又称为陶门柳,是陶渊明的象征。陶渊明是中国古代文人仰慕的文人,寄托了各朝文人的理想,陶门柳也具有了隐逸高洁的意义。然而这是误读,因为在陶渊明之前杨柳与隐逸没有关系,杨柳的象征意义是对生命长久、家业兴盛的祝愿。杨柳与陶渊明的祖先陶侃有着特别的关系,武昌柳是陶侃建立功勋和善于治军的标志。陶渊明借助五柳表达的意义应是建功立业、家业兴盛,而隐逸高洁是后人将陶渊明晚期的思想与生活赋予五柳的结果。陶渊明五柳本来是在宅边,而不是门边;五柳不是在彭泽县衙,而是在柴桑的布衣之居。空间位置的误读也为意义的误读提供了基础。误读既是后世文人的需要,也是清廉政治的需要。     

蚕沙中叶绿酸铜钠、叶绿酸铁钠的提制及应用

用蚕沙为原料研制出叶绿酸铜钠和叶绿酸铁钠,改进了叶绿酸铜钠的提制工艺,使工艺简化而总收率不变;在我国我们首次以蚕沙研制了叶绿酸铁钠提制工艺,以蚕沙计量收率可达1.0％．论述了它们的应用及开发前景．     

钠与酸反应的原理探析

金属钠与酸溶液反应的机理，历来有两种不同的观点。     

一元算符逻辑理论三探——狭义函数相对论视野下的现代模态逻辑

狭义函数相对论基本原理:对于任意二真值的逻辑变量p和由任意一元算符H与p所形成的二真值变量Hp,无论Hp是否为p的真值函数,它总会等值于p和独立于p的另一二真值变量q所形成的一个真值函数。由于有且仅有16个二真值二元函数式和有且仅有16个相应的基本二真值二元函数,所以有且仅有16个一元算符和有且仅有16个相应的基本二真值一元非函数。其他的二真值一元非函数由且仅由这16个一元算符叠置所形成。那么可进一步认为现代模态逻辑公理其实是按一阶逻辑对经典二真值函数做分类研究。模态命题逻辑中任一可能世界集W仅对应一组二元真值函数,相应的可能世界间的关系R就是这组函数共有的一种集合性质。任一公理模式在一框架内有效,就是将属于W的每个真值函数(式)按K-2分别依次代入该公理模式中的每一个"□",使得形成一组经典定理。     

美国K-12阶段技术教育:背景、现状与启示

着当代技术的高速发展,技术教育得到了世界各国的广泛重视。美国K-12阶段技术教育以技术素养的培养为目标,在课程内容设置上具有多样性,技术课堂教学强调技术设计,并重视技术教师培养和培训。美国K-12阶段技术教育的许多经验可为我国中小学技术教育提供借鉴。     

The transfer of nature of science understandings: a question of similarity and familiarity of contexts

It is important to question the generalizability of the knowledge about the nature of science (NOS), and thus know whether the knowledge about NOS can be transferred to various contexts. As such, the purpose of this study was to investigate whether students were able to transfer their acquired NOS understandings into contexts that vary in their similarity to the context of learning. Thirty-eight 7th grade students in two intact sections participated in the study. The treatment extended over seven weeks and involved teaching a unit about plate tectonics, earthquakes, and volcanoes. Only one of the two groups was explicitly taught about NOS in relation to the topics under study. To assess the change in students’ understandings of NOS and their ability to transfer these acquired understandings, a five-topic open-ended questionnaire and individual semi-structured interviews were used. Some of the questionnaire topics focused on scientific issues and were considered similar to the context of learning, while other topics were socioscientific and were considered less similar. Results showed that the transfer of participants’ acquired NOS understandings occurred when the context was similar to the context of learning and when the context was more familiar based on prior knowledge. Interpretations related to knowledge base schema, the distance between contexts, as well as the explicit teaching about transfer were discussed.     

Explaining variation in student efforts towards using math and science knowledge in engineering contexts

Previous research suggests that in classes that take an integrated approach to science, technology, engineering, and math (STEM) education, students tend to engage in fulfilling goals of their engineering design challenges, but only inconsistently engage with the related math and science content. The present research examines these inconsistences by focusing on student engagement, or effort, towards math and science concepts while working on an engineering challenge, through the lens of expectancy-value theory. Specifically, we examine how students’ perceptions of the value of math and science and expectancy for success with the math and science relate to the efforts they put towards using math and science while working on engineering challenges. Our results suggest that subjective task value significantly predicts efforts towards both math and science, whereas neither expectancy, nor the interaction between expectancy and value predicted effort. We argue that integrated learning environments need to help students understand how the domains of math, science, and engineering support their work in fulfilling the engineering project design goals. In other words, we argue that we, as educators, must help students to recognise the value of each of the domains addressed within STEM integrated learning environments. This paper discusses strategies for accomplishing this goal.     

Using psychological constructs from the MUSIC Model of Motivation to predict students’ science identification and career goals: results from the U.S. and Iceland

ABSTRACT

We investigated students’ perceptions related to psychological constructs in their science classes and the influence of these perceptions on their science identification and science career goals. Participants included 575 middle school students from two countries (334 students in the U.S. and 241 students in Iceland). Students completed a self-report questionnaire that included items from several measures. We conducted correlational analyses, confirmatory factor analyses, and structural equation modelling to test our hypotheses. Students’ class perceptions (i.e. empowerment, usefulness, success, interest, and caring) were significantly correlated with their science identification, which was correlated positively with their science career goals. Combining students’ science class perceptions, science identification, and career goals into one model, we documented that the U.S. and Icelandic samples fit the data reasonably well. However, not all of the hypothesised paths were statistically significant. For example, only students’ perceptions of usefulness (for the U.S. and Icelandic students) and success (for the U.S. students only) significantly predicted students’ career goals in the full model. Theoretically, our findings are consistent with results from samples of university engineering students, yet different in some ways. Our results provide evidence for the theoretical relationships between students’ perceptions of science classes and their career goals.     

美国K-12媒介素养教育课程及其特点分析

美国媒介素养教育发展历史虽不长,但其K-1 2媒介素养教育课程却独具特色,对美国K-1 2教育具有重要的补充作用,对提高学生的媒介素养水平具有重要意义。美国K-1 2媒介素养教育课程以保护主义为宗旨,教学主体大多为一线教师和民间组织,是一场自下而上的草根运动。课程实施方式大多以融入式课程为主,各州媒介素养教育课程设置状况和标准纷繁多样,并不统一。本文旨在结合美国的时代和历史背景对K-1 2媒介素养教育课程的特点进行分析。     

Opinions on computing education in Korean K-12 system: higher education perspective

The need for computing education in the K-12 curriculum has grown globally. The Republic of Korea is not an exception. In response to the need, the Korean Ministry of Education has announced an outline for software-centric computing education in the K-12 system, which aims at enhancing the current computing education with software emphasis. In this paper, we review the outline from a higher education perspective and provide insights into its constructive improvement based on our experience in computer science education in higher education and a study of global initiatives on computing education. We also consider the social environment for computing education in Korea. In the proposed implementation, we first discuss goals for software-centric computing education and identify areas of focus. The identified areas are discussed in terms of topics to be covered and appropriate exposure of knowledge depth in the three levels in the Korean K-12 system. We then discuss necessary preparations for the success of the plan from academic, governmental and social perspectives.     

可持续发展:版纳经济发展的必然选择

随着社会经济的不断进步,现行的发展模式已经越来越明显地呈现出它的弊端.实现西双版纳经济社会的再度繁荣发展,必须走可持续发展的道路,即要遵循人口、资源、环境、生态、经济、社会相互协调发展的准则,改善不良现状,修复正在缩小的原始森林、受污染的江河湖泊和逐渐流失的土地,开发生态旅游,给子孙后代留下一个无限发展的空间.     

论行动研究与教师专业发展

从梳理行动研究的历史发展入手,分析了行动研究的特点,着重探讨了行动研究对于教师专业发展的重要意义。     

制约中小学课堂运用教育技术的因素分析——美国中小学现代教育技术实施环境调查报告

通过对美国中小学教师进行问卷、访谈调查,研究目前制约中小学课堂教学中运用现代教育技术的几个因素.调查结果表明:教师时间缺乏、电脑网络技术问题得不到及时解决是阻碍教师课堂运用现代教育技术的主要障碍.进一步探索美国城乡之间、年级之间现代教育技术运用的环境是否存在差异,结果显示:郊区学校现代教育技术环境比城市和乡村好,但年级之间无显著差异.