用场效应管放大电路测量可逆电池的电动势     

胡晓岚 《邵阳学院学报(社会科学版)》1997,(2)

本文介绍应用场效应管放大电路来测量电池电动势的新原理与新方法.该测量原理与方法简单、实用,不但更新了传统的测量原理,而且也提高了测量精度和学生的学习兴趣及动手能力.  相似文献   

化学教学科学方法的探讨     

薛岚 《楚雄师范学院学报》2004,19(3):84-86,126

通过现代观念与传统观念的对比，结合本地中学对化学教师素质的要求，重点探讨了化学教学中科学方法与思维的培养。  相似文献   

学校转型性变革中的评价改革——基于"新基础教育"成型性研究中期评估的探究     

叶澜  李政涛  吴亚萍 《教育发展研究》2007,(7):1-10

"新基础教育"通过成型性研究中期评估的研究和实践,形成了"推进型评价"概念.本文在分析学校转型性变革中推进型评价的性质基础上,介绍了推进型评价指标体系构成的特点与权重分配,同时揭示了"新基础教育"成型性研究中期评估活动过程中的方法论思想,及评估活动对所有参与者产生的评估效应和发展价值.  相似文献   

数据检索中索引技术的探讨     

李新英  韩南 《黄冈师范学院学报》2004,24(6):67-68,83

设计索引的目的是为了加快数据检索．文章就与索引相关的一些特征元素．提出了创建索引中数据目录项的3种不同方法．同时对B^ 索引进行了描述．分析了其在进行数据搜索的实现原理．简要个绍了在实现数据删除和插入时的优化思路．  相似文献   

基于关键帧的视像检索研究   总被引：1，自引：0，他引：1  

冯德旺  兰建容 《福建工程学院学报》2007,5(4):388-391

在分析视像数据结构的基础上,介绍了基于关键帧的颜色和纹理特征的提取方法,并给出了具体的训练及测试流程.  相似文献   

新型表面活性剂3-十二烷氧基-2-甲基丙酸钠的合成     

农兰平  刘杰凤  周统武 《茂名学院学报》2002,12(4):32-34

通过增加皂类表面活性剂分子中亲水基的总数，可以提高其抗硬水性能，为此，在亲油基与羧基之间引入烷氧基，该研究以甲基丙烯酸和十二醇的主要原料，采用加成，酯化，取代，皂化四步法合成3-十二烷基-2-甲基丙酸纳，其中，杂多酸对酯化反应起到了催化和阻聚双重作用；相转移催化剂用于取代反应，简化了操作，缩短了反应时间，提高了产率。  相似文献   

正确认识和对待私营企业主入党的问题     

兰迎春  张仁厚 《沙洋师范高等专科学校学报》2002,3(3):29-32

私营企业主能否入党是一个众说纷纭的敏感问题。我们认为有中国特色社会主义事业的建设的定性决定了优秀的私营企业主可以入党；发展优秀的私营主入党是扩大党的群众基础的需要。在发展优秀的私营企业主入党问题上，应该把握好发展党员的方针政策、原则和程序以及对优秀私营企业主的考察培养。  相似文献   

Tandem Biocatalysis by CotA-TJ102@UIO-66-NH2 and Novozym 435 for Highly Selective Transformation of HMF into FDCA     

Chang  Xin  Zhang  Chengyu  Gao  Lan  Liu  Xiao  You  Shengping  Qi  Wei  Wang  Kang  Guo  Xin  Su  Rongxin  Lu  Han  He  Zhimin 《天津大学学报(英文版)》2019,25(5):488-496

2,5-Furandicarboxylic acid(FDCA) is a potential biorenewable chemical for applications including plastics, polyamides, drugs, etc. The selective biosynthesis of FDCA from 5-hydroxymethylfurfural(HMF) by a specific enzyme poses a great challenge. In this study, we reported an efficient strategy to produce FDCA from HMF by the tandem biocatalysis of laccase(Cot A-TJ102@UIO-66-NH_2) and Novozym 435. For the first step, a nanoparticle metal–organic framework was synthesized as a carrier to immobilize Cot A-TJ102@UIO-66-NH_2, which was assigned for the production of 5-formyl-2-furancarboxylic acid(FFCA) and featured an enzyme loading of 255.54 mg/g, specific activity of 135.90 U/mg, and solid loading ratio of 99.65%. Under optimal conditions, an ideal FFCA yield of 98.5% was achieved, and the Cot A-TJ102@UIO-66-NH_2 presented a high recycling capacity after 10 cycles. For the second step, Novozym 435 was applied for the further conversion of FFCA into FDCA, presenting a high FDCA yield of 95.5% under the optimized conditions. Novozym 435 also exhibited a high recyclability after eight cycles. As a result, the tandem biocatalysis strategy provided a 94.2% FDCA yield from HMF, indicating its excellence as a method for FDCA production.  相似文献   

用Authorware构建多媒体软件框架的三种方法     

吴兰 《连云港师范高等专科学校学报》2004,(3):89-91

文章介绍了在Authorware多媒体软件中实用性很好的组建整体结构的三种方法：常见交互图标应用法、导航图标应用法、文字超级链接法。将课件中的多种信息模块化地组织在一起，为课件制作者带来很大的方便性和灵活性，且在媒体软件制作方面有着广泛的应用。  相似文献   

Investigation of iodine concentration in salt,water and soil along the coast of Zhejiang,China     

陆颖理  王宁荐  朱岚  王国兴  吴晖  匡琳  朱文明 《Journal of Zhejiang University. Science. B》2005,6(12):1200-1205

Objective: We aim to describe the environment iodine concentration in salt, water and soil along Zhejiang Province coast in the China foreland. It will be helpful for us to judge whether this area is insufficient in iodine and universal iodized salt is necessary or not. Methods: We collected iodized salt samples, drinking water samples (tap water in the towns, and well water or spring water in the villages), water samples from different sources (ditches, lakes, rivers) and soil samples through random sampling in June, 2005. Salt, water and soil iodine was detected by arsenic-cerium redox method. Statistical analysis was expressed as mean±SEMby Windows SPSS 13.0. Results: (1) The iodine concentration in salt was 27.9±4.33 mg/kg (n=108). (2) Seventy-five water samples were collected. The water iodine value was 0.6～84.8 μg/L (mean of 11.66 μg/L). The watershed along the Qiantang River has significantly higher iodine content than the water in Lin'an in mountain area (P＜0.01). The iodine content and mean iodine content of tap water, well or spring water and natural water sources were 4.30±2.43 μg/L (n=34), 23.59±27.74 μg/L (n=19)and 12.72±10.72 μg/L (n=22) respectively. This indicated that among environmental water sources, the ditch iodine content was the highest with river water iodine being the lowest (P＜0.01). (3) Soil iodine value was 0.11～2.93 mg/kg (mean of 1.32 mg/kg).Though there was no statistical difference of soil iodine in different districts (P=0.131), soil iodine content correlated positively with water iodine content. Conclusion: Iodine concentration in salt accords with national policy of adding iodine in salt. Foreland has more iodine in water than mountain area. The data reflected that water and soil iodine in foreland area was not high, which suggests universal iodized salt should be necessary. Environment iodine has relatively close association with pollution.  相似文献