基于VR的分布式教学:理论模型与实现策略     

屠明将  刘义兵  吴南中 《电化教育研究》2021,42(1):93-99,121

基于VR的分布式教学模式是针对传统教学体验不佳、效率低下,尤其是此次疫情期间大规模在线学习暴露出的主要问题,而进行的一种教学改革的理论尝试。文章以开发研究为基本方法,秉持知识建构主义以及学习发生的社会文化属性,在具身认知理论与文化历史活动理论支撑下依托“VR+5G”技术优势,架构融合虚实相生情境性、多元一体分布性、人际交互实时性与教学方式多态性为一体的分布式教学模式。这种新型教学模式更加关注学生在VR课堂教学空间中的具身体验、情感交流和师生互动,将散落于不同节点的学生串联起来组成一个自组织的、开放的分布式系统,VR教学空间中的师生主体以规则为中介结成发展共同体,通过明确的任务分工方式对教学内容客体进行意义建构,为实现特定教学目标协同合作。基于VR的分布式教学模式的实现策略需要从理念转型、标准研发、资源建设、教师角色转换、网络教研以及家校共育等方面入手进行统整规划。  相似文献   

AQP-1和AQP-5在卵巢上皮性肿瘤的表达及临床意义     

杨建华  石一复  周彩云  王国萍 《科技通报》2006,22(6):781-784,791

目的探讨AQP1及AQP5在卵巢上皮性肿瘤的表达及临床意义。方法采用免疫组化法检测105例卵巢上皮性肿瘤和10例正常卵巢组织AQP1和AQP5蛋白的表达。结果AQP1主要表达于毛细血管及小血管内皮细胞．而AQP5表达于卵巢肿瘤细胞。随着卵巢上皮性肿瘤由良性向恶性发展，AQP1和AQP5的表达逐渐增加（P〈0．05）。Ⅲ、Ⅳ期卵巢癌AQP1的表达明显高于Ⅰ、Ⅱ期（P〈0．05），伴淋巴转移者AQP1明显高于无淋巴转移者（／9〈0．05）；腹水大于1000mL者AQP1和AQP5的表达明显高于小于1000mL者（P〈0．01）：低分化卵巢癌AQP5的表达明显高于高、中分化者（P〈0．05）；AQP1及AQP5的表达与腹水量呈正相关（r分别为0．40，0.31；P〈0．05）。结论AQP1和AQP5高表达与卵巢癌的发生、发展及预后有关，可能是卵巢癌腹水产生的主要原因。  相似文献   

Serum adenosine deaminase, 5′ nucleotidase and malondialdehyde in acute infective hepatitis     

K. Pratibha  Usha Anand  Rajni Agarwal 《Indian journal of clinical biochemistry : IJCB》2004,19(2):128-131

Serum adenosine deaminase (ADA), 5′ nucleotidase (5′NT) and malondialdehyde (MDA) were estimated in patients with acute infective hepatitis (AIH) along with the routine parameters of liver disease. Present study is done to evaluate these special parameters in patients with clinical history of AIH and to assess the utility of these parameters as diagnostic/ prognostic indices of liver function and to correlate special parameters with routine live function tests (LFT). ADA, 5′NT and MDA along with routine LFT was estimated in 25 patients with AIH and 25 samples from healthy voluntary blood donars served as the control group. Routine LFT was estimated by standard clinical chemistry procedures on dade behring analyser and ADA, 5′NT and MDA were estimated by berthlot reaction, fiske and subbarao method and thiobarbituric acid method respectively. Statistical analysis showed that serum ADA, 5′NT and MDA were significantly higher in patients as compared with the controls. There was a significant positive correlation between ADA and total bilirubin and MDA and total bilirubin. Hence we can conclude that these tests would be more sensitive to diagnose the patients with AIH and that the raised bilirubin levels could be looked upon, as a protective mechanism which the liver has evolved in order to combat oxidative stress.  相似文献   

浙江省暴雨预报技术研究   总被引：1，自引：0，他引：1  

杜惠良  钮学新  曾欣欣  郝世峰  董加斌 《科技通报》2006,22(3):309-314,318

针对浙江暴雨,通过对40年浙江历史暴雨的天气形势分类研究,建立了暴雨的相似预报方法.通过对近10年大暴雨个例的诊断分析,得到了大暴雨出现的流场及物理量分布特征.对大量历史暴雨的物理量诊断分析,得到两个诊断预报的物理量.引进美国MM5中尺度数值模式并进行本地化研究,建立适用于浙江的中尺度雨量数值预报模式.通过对大量历史暴雨的卫星、雷达与短时雨量的统计研究,建立了暴雨的短时雨量估算方法.经2003、2004年试用,预报效果较好.  相似文献   

高功率Ni/MH电池用AB5型负极储氢合金的研究   总被引：2，自引：0，他引：2  

叶辉  张宏 《中国科学院研究生院学报》2003,20(3):381-387

研究和开发具有优异高倍率特性的储氢电极合金是发展高功率型Ni/MH电池的技术关键,具有重大的理论意义和商业价值。基于合金热力学和动力学行为的讨论,研究了AB5型储氢电极合金的微结构对其倍率放电性能的影响。结果表明,由于非化学计量(B/A >5 )和高催化活性第二相的引入,B侧添加硼或钼可以显著提高合金的高倍率放电容量和低温放电容量。进一步结合A侧稀土成分优化,发展出一类具有优异倍率性能的MmNi3.55Co0.75Mn0.4Al0.3Bx(Mm为混合稀土)合金。该系列合金有望应用于高功率Ni/MH电池和低温( - 35 oC)Ni/MH电池。  相似文献   

乳腺癌耐受蛋白介导5-氟脲嘧啶的耐受及机制探讨     

袁建辉  贺智敏  吕辉  余艳辉  陈主初 《深圳特区科技》2005,(Z1):106-112

AIM To filtrate breast cancer resistance protein(BCRP)-mediated resistance agents and investigate the mechanism,so as to provide valuable datum for optimization clinical chemotherapy scheme to tumor with evaluation marker of BCRP expression. METHODS MTT assay was used to filtrate BCRP-mediated resistance agents with PA317/Tet-on/TRE-BCRP cell of different expression levels of BCRP after treated with different concentration anticancer agents. High performance liquid chromatography(HPLC) was applied to measure relative dose of intracellular retention resistance agents. Nuclear DNA fluorescence dye,Hochest 33258, staining and flow cytometry were adopted to detect apoptotic cells after treated with drugs. RESULTS There were shown increasing durg-resistance to 5-fluorouracil,methotrexate, doxirubicin, pirarubicin,etoposide and mitoxantrone followed with increasing expression of BCRP on PA317/Tet-on/TRE-BCRP cells(P＜0.05, n=3),but shown sensitive to paclitaxel, cisplatin, vincristine, mitomycin and vindesine. There also was shown significant negative correlation between the intracellular retention dose of 5-fluorouracil with different expression of BCRP(r=-0.885, P＜0.05, n=3).There were shown parallel results of that decreasing cellular apoptotic rate with increasing cellular expression of BCRP after treated with 5-fluorouracil by fluorescence dye staining and flow cytometry(P＜0.05, n=3),and also shown significate rise of the apoptotic rate of BCRP expression cells after treated with Ko143 (P＜0.05, n=3). Every group of cells could be different extently blocked in phase of G0/G1 treated with 5-fluorouracil. CONCLUSION Resistance of 5-fluorouracil could be especially mediated by conjugated with BCRP and acted as drug exclude-pump substrate. Cellular ability resistant to 5-fluorouracil-induced apoptosis could be reinforced by BCRP expression.  相似文献   

Reference Framework 5架构及其在数字图像处理中的应用   总被引：1，自引：0，他引：1  

杨家琳  黄昶 《中国科技信息》2006,(19):149-152

深入分析了Reference Framework（RF）5的原理和缝构，说明了各数据元素的作用及相点关系，并通过动态目标检测例程详细说明了Eeference Framework5在数字图像处理中的应用。  相似文献   

Mixed control of uncertain jumping time-delay systems     

Magdi S. Mahmoud  Fouad M. AL-Sunni  Yan Shi   《Journal of The Franklin Institute》2008,345(5):536-552

In this paper, we investigate a class of linear continuous-time systems with Markovian jump parameters. An integral part of the system dynamics is a delayed state with time-varying and bounded delays. The jumping parameters are modeled as a continuous-time, discrete-state Markov process. Employing norm-bounded parametric uncertainties and utilizing the second-method of Lyapunov, we examine the problem of designing a mixed controller which minimizes a quadratic performance measure while satisfying a prescribed -norm bound on the closed-loop system. It is established that sufficient conditions for the existence of the mixed controller and the associated performance upper bound could be cast in the form of linear matrix inequalities.  相似文献   

5-呋喃亚甲基若丹宁光度法测定铜的研究     

张小曼  崔永春  翟平 《昆明师范高等专科学校学报》2002,24(4):62-63

研究了新试剂5-呋喃亚甲基若丹宁(FR)与铜的显色反应,在冰乙酸介质中,乳化剂-OP存在下,FR与 Cu(Ⅱ)生成2:1的稳定络合物,λmax=440nm,ε=5.03×103 L·mol-1·cm-1.铜的含量在0～50μg/25mL内符合 比耳定律.方法用于烟草中微量铜的测定,结果满意.  相似文献   

Ag(I)-p-NBR-TritonX-100分光光度法测定微量银     

崔永春  张小曼  翟平  汤峨 《昆明师范高等专科学校学报》2002,24(4):58-59

研究了新试剂5-(p-硝基苄叉)若丹宁(p-NBR)与贵金属离子Ag(I)的显色反应,在pH=7.0的NH4Ac缓冲溶液介质中,TritonX-100存在下,Ag(I)与P-NBR生成1:2的黄色稳定络合物,λmax=400nm,ε=3.52×104L·mol-1·cm-1,银的含量在0～30μg/25mL范围内符合比尔定律.方法用于显影液及定影液中微量银的测定,结果满意.  相似文献