Priming urban learners' attitudes toward the relevancy of science: A mixed-methods study testing the importance of context     

Phillip A. Boda  Bryan Brown 《科学教学研究杂志》2020,57(4):567-596

The development of three-dimensional learning among all K-12 student demographics remains a prominent goal for the field of science education. However, substantial research in science teacher education for urban populations showcases hurdles to overcome in order to achieve this goal, particularly for elementary teachers. Research shows that urban elementary teachers are often ill-prepared to develop a type of science pedagogy responsive to students' learning needs. The fidelity of such pedagogies that these teachers adhere to when trying to implement such a requested content–relationality between these populations and how their local contexts can be used as sites to learn science in relevant ways are often not fully realized, as well. Given that science achievement gaps exhibit racial disparities starting in primary grades and attitudes toward science have been shown to affect academic achievement and motivation, we argue that one way to ameliorate, in at least an incremental way, this disparity is to design novel learning experiences to prime students to see the relevancy of science in their local contexts before such three-dimensional designed learning is set to occur. In this research, we leveraged the immersive nature of Virtual Reality 360 videos and present a design-based research iteration testing how this novel technologically enhanced learning experience may have influenced close to 400 urban elementary students' attitudes toward science around those attitudes labeled as “behavioral beliefs” by the field. Using a concurrent, convergent mixed-methods design with a two-way multivariate analysis of covariance quantitative data set triangulated with students' qualitative self-reports that were transformed into quantitative preponderances in graphic form, the data support that our design iteration emphasizing the importance of context as a design focus can prime students who struggle to see science as relevant to change their attitudes. Implications are discussed around relationality, novel technological affordances, and the use of local contexts as learning resources.  相似文献   

超高含水原油混合流动及初始沉积特性     

邢晓凯  吕朝旭  刘珈铨 《中国科学院大学学报》2020,37(2):228-233

使用自行设计的实验装置，对超高含水原油的流动特性和初始沉积过程进行探究。系统研究实验温度、混合流速和体积含水率对超高含水原油初始沉积过程的影响，分析不同温度下原油的运动形态和初始沉积方式。初始沉积过程可分为蔓延沉积过程和粘连沉积过程，根据沉积特点和压降曲线的变化趋势将初始沉积过程分为3个阶段：沉积诱导期、快速沉积期和沉积动态平衡期。通过对沉积物碳数分布的分析，得知超高含水原油初始沉积过程中，同时存在剪切剥离作用、胶凝作用和分子扩散作用。实验温度和体积含水率主要通过改变胶凝作用和分子扩散来影响初始沉积过程，混合流速通过改变剪切剥离强度来影响初始沉积过程。  相似文献   

平行强外磁场中的氢分子离子的能量计算     

惠萍 《广东教育学院学报》2006,26(5):55-60

采用单中心展开方法和Bohn-Oppenheimer近似,用B-splines技术研究平行强外场下的氢分子离子的基态和低激发态能量的收敛性.在计算中,将径向波函数和角向波函数用B-splines基函数展开.外加磁场强度为2.35×103→2.35×106T,计算能量可以收敛到±10-6~±10-8eV.与其他计算结果比较表明,B-splines技术很适合用来研究强外磁场下的分子能量的计算,在强外磁场B=2.35×106T的情况下,仍可以获得±10-6eV精度.  相似文献   

章鱼在人工养殖环境中生活习性的探讨   总被引：4，自引：0，他引：4  

刘招龙 《宁德师专学报(自然科学版)》2004,16(4):356-357,369

章鱼人工养殖前人做得很少，通过探讨人工养殖环境中章鱼的生活习性等，为科学养殖章鱼提供参考．  相似文献   

CRISPR/Cas: a Nobel Prize award-winning precise genome editing technology for gene therapy and crop improvement     

Li  Chao  Brant  Eleanor  Budak  Hikmet  Zhang  Baohong 《Journal of Zhejiang University. Science. B》2021,22(4):253-284

Since it was first recognized in bacteria and archaea as a mechanism for innate viral immunity in the early 2010 s,clustered regularly interspaced short palindromic repeats(CRISPR)/CRISPR-associated protein(Cas) has rapidly been developed into a robust, multifunctional genome editing tool with many uses. Following the discovery of the initial CRISPR/Cas-based system, the technology has been advanced to facilitate a multitude of different functions. These include development as a base editor, prime editor, epigenetic editor, and CRISPR interference(CRISPRi) and CRISPR activator(CRISPRa) gene regulators. It can also be used for chromatin and RNA targeting and imaging. Its applications have proved revolutionary across numerous biological fields, especially in biomedical and agricultural improvement. As a diagnostic tool, CRISPR has been developed to aid the detection and screening of both human and plant diseases, and has even been applied during the current coronavirus disease 2019(COVID-19) pandemic. CRISPR/Cas is also being trialed as a new form of gene therapy for treating various human diseases, including cancers, and has aided drug development. In terms of agricultural breeding, precise targeting of biological pathways via CRISPR/Cas has been key to regulating molecular biosynthesis and allowing modification of proteins, starch, oil, and other functional components for crop improvement. Adding to this, CRISPR/Cas has been shown capable of significantly enhancing both plant tolerance to environmental stresses and overall crop yield via the targeting of various agronomically important gene regulators. Looking to the future, increasing the efficiency and precision of CRISPR/Cas delivery systems and limiting off-target activity are two major challenges for wider application of the technology. This review provides an in-depth overview of current CRISPR development, including the advantages and disadvantages of the technology,recent applications, and future considerations.  相似文献   

Evaluation and application of an efficient plant DNA extraction protocol for laboratory and field testing     

Qi WANG  Xiaoxia SHEN  Tian QIU  Wei WU  Lin LI  Zhi'an WANG  Huixia SHOU 《Journal of Zhejiang University. Science. B》2021,22(2):99

Nucleic acids in plant tissue lysates can be captured quickly by a cellulose filter paper and prepared for amplification after a quick purification.In this study,a published filter paper strip method was modified by sticking the filter paper on a polyvinyl chloride resin(PVC)sheet.This modified method is named EZ-D,for EASY DNA extraction.Compared with the original cetyl trimethylammonium bromide(CTAB)method,DNA extracted by EZ-D is more efficient in polymerase chain reaction(PCR)amplification due to the more stable performance of the EZ-D stick.The EZ-D method is also faster,easier,and cheaper.PCR analyses showed that DNA extracted from several types of plant tissues by EZ-D was appropriate for specific identification of biological samples.A regular PCR reaction can detect the EZ-D-extracted DNA template at concentration as low as 0.1 ng/μL.Evaluation of the EZ-D showed that DNA extracts could be successfully amplified by PCR reaction for DNA fragments up to 3000 bp in length and up to 80%in GC content.EZ-D was successfully used for DNA extraction from a variety of plant species and plant tissues.Moreover,when EZ-D was combined with the loop-mediated isothermal amplification(LAMP)method,DNA identification of biological samples could be achieved without the need for specialized equipment.As an optimized DNA purification method,EZ-D shows great advantages in application and can be used widely in laboratories where equipment is limited and rapid results are required.  相似文献   

湖南省10种天南星科作物DsMV和CMV的检测   总被引：2，自引：0，他引：2  

何煜波  桂明  李永伟  唐爱菊  陈集双 《科技通报》2005,21(4):400-404

利用^32P标记的cDNA探针对采集于湖南省永州等地的10种天南星科观赏植物和大田作物绿帝王(Philodendron sodiroi)、半夏(Pinellia ternata)、海芋(Alocasia macrorhiza)、马蹄莲(Zantedeschia aethiopica)、龟背竹(Monstera deliciosa)、尖尾芋(Alocasia cucullata)、白蝶合果芋(Sygonium podophyllum)、羽裂蔓绿绒(Philodendron selloum)、广东万年青(Aglaonema modestum)、芋(Colocasia esculenta)进行了芋花叶病毒(Dasheen mosaic virus，DsMV)和黄瓜花叶病毒(Cucumber mosaic virus，CMV)的检测，同时对部分样品进行病毒提纯、病毒粒子观察和内含体结构检查。结果显示：DsMV在10种植物上普遍存在．是最主要的病毒病原；同时首次在芋、绿帝王和广东万年青等3种植物上检测到CMV和DsMV的复合侵染。  相似文献   

分子伴侣、蛋白质聚集和大分子拥挤环境对蛋白质折叠的影响     

李剑  王志珍 《中国科学院研究生院学报》2002,19(2):215-218

研究了细胞内存在的分子伴侣、蛋白质聚集和大分子拥挤环境对蛋白质折叠的影响.首先,发现分子伴侣GroEL与底物蛋白的结合有"半位"和"全位"两种模式,它是由底物蛋白的分子形状、分子大小以及与GroEL的相互作用性质决定的.接着,发现两种不同的蛋白质一起复性时相互不干扰,提示细胞内蛋白质折叠可能不受其他蛋白聚集的影响;后又发现α-乳清蛋白的前熔球态不仅是分子伴侣也是蛋白质聚集体的作用对象.最后,研究大分子拥挤环境对蛋白质折叠热力学和动力学的影响,揭示了这种影响的复杂性和多样性.  相似文献   

分子伴侣、蛋白质聚集和大分子拥挤环境对蛋白质折叠的影响(英)     

李剑  王志珍 《中国科学院研究生院学报》2002,(2)

研究了细胞内存在的分子伴侣、蛋白质聚集和大分子拥挤环境对蛋白质折叠的影响.首先,发现分子伴侣GroEL与底物蛋白的结合有 半位 "和 全位"两种模式,它是由底物蛋白的分子形状、分子大小以及与GroEL的相互作用性质决定的.接着,发现两种不同的蛋白质一起复性时相互不干扰,提示细胞内蛋白质折叠可能不受其他蛋白聚集的影响;后又发现α 乳清蛋白的前熔球态不仅是分子伴侣也是蛋白质聚集体的作用对象.最后,研究大分子拥挤环境对蛋白质折叠热力学和动力学的影响,揭示了这种影响的复杂性和多样性.  相似文献   

硅微电子技术物理极限对策探讨   总被引：1，自引：0，他引：1       下载免费PDF全文

王占国 《中国科学院院刊》2007,22(6):480-485

根据国际半导体技术蓝图(ITRS)发布的未来半导体工艺技术预测,2016年世界集成电路主流工艺线宽为22纳米,2022年达到10纳米。届时,以硅为基础的微电子技术发展所遵循的摩尔定律将不再适用;为此,必须发展基于全新原理的新技术,以满足人类不断增长的对信息量的需求。本文首先介绍硅材料国内、外的发展现状与趋势,进而讨论后摩尔时代的微电子技术发展可能采取的对策,最后展望基于全新原理的纳米电子、分子电子、光计算和量子信息技术的发展前景。  相似文献