共查询到20条相似文献，搜索用时 234 毫秒
1.
李红 《铜陵职业技术学院学报》2008,7(1):71-71
在桑叶上运用光合作用调节剂可以改善光合作用机构功能,协调光合作用产物的积累和转化,从而获得桑叶优质高产。研究表明：AM化学试剂能提高桑叶产质量与其能抑制硝酸还原酶的活性有关。 相似文献
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李春华 《江西电力职业技术学院学报》2008,21(3)
针对梅县发电厂#3机组凝结水溶氧量超标问题,分析凝结水溶氧量超标的危害性;结合该电厂现场系统设备情况,提出影响凝结水溶氧量的主要原因,并有针对性的进行处理。 相似文献
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通过对北京高校体育组和非体育组学生体成分、心肺功能进行对比研究,旨在了解二者之间相关关系,为大学生科学地参加体育活动提供参考依据。本文以北京高校体育专业和非体育专业男学生为主进行测试,结果表明二者身高、体重及体成分没有显著性差异,但相对摄氧量、最大摄氧量和在无氧阈时的摄氧量、相对摄氧量有显著性差异。 相似文献
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向琴莉 《中小学实验与装备》2003,(3):22-22
自主创造性学习将成为未来学生的基本素质之一。学生有活动的时间 ,有选择的权利 ,有展示的舞台 ,就有了更多的感知、观察、思考和探索的权利 ,就能给学生更多的锻炼机会。1 让学生有开放的活动时空教师在制定教学内容的认知要求和技能要求的同时 ,要根据学生的经验和认识实际 ,充分给予学生自主学习的时间和空间。例如教学《爱护青苗 绿化祖国》一课 ,活动的空间就不能仅仅局限在教室里 ,让学生走出课堂 ,走向社会 ,通过各小组测算学校内绿化面积 ,再根据各类植物的释氧量对照表 ,计算校内植物光合作用时的释氧量 ;同时 ,计算校园内人口… 相似文献
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王维军 《喀什师范学院学报》2007,28(6):77-79
采用文献资料法、对比法和数据统计法,对最大摄氧量及其间接测定方法进行了研究分析,初步总结出最大摄氧量受遗传、性别、年龄、环境、营养饮食状况、生活习惯和训练等因素的影响.运动时对心肺功能的测定是科学训练的一个重要方面.而评价心肺功能的最佳指标是最大摄氧量,最大摄氧量是反映有氧工作能力的有效指标之一.通过对最大摄氧量间接测定方法PWC170法与两步台阶实验法比较研究,有利于从测试的精确度、测试的简易性、测试的效率、测试费用及训练评价效果方面提供更好的理论依据. 相似文献
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<正>光合作用相关原理及其应用是高中生物教学中的重点与难点,也是高考命题的热点。在分析光合作用相关变量时,常常涉及呼吸作用,因此,对光合作用和呼吸作用原理进行必要的分析、扩展是很重要的。1利用光合作用图解理解环境对光合作用的影响教师可利用光合作用过程的图解(见图1)让学生理解环境因素(光照强度、CO_2浓度)对光合作用相关变量的影响。 相似文献
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下面是2006年高考江苏卷生物试题中第40题的题目:为了调查太湖某一水层是否有自养生物存在及其产氧量能否维持本层水体生物呼吸耗氧所需,可用黑白瓶法测定该水层生物昼夜平均代谢率来判定。白瓶为透明玻璃瓶,其水体溶解O2的昼夜变化值 相似文献
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1 光合作用与细胞呼吸过程的区别与联系
光合作用与呼吸作用两个生理过程有密切的关系，一方面光合作用的产物是呼吸作用的反应物，另一方面呼吸作用的产物又可作为光合作用的原料。但它们并不是可逆的反应，这是因为它们是在不同的场所进行，由不同的酶来催化；[H]和ATP的来源及去路不同；光合作用必须在有光的条件下进行，而呼吸作用时时刻刻都在进行。 相似文献
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一、心率作为负荷强度的依据通过长期的运动实践,人们常以单位时间的摄氧量以及能量代谢率等作为运动负荷强度指标。如用运动时的摄氧量占最大摄氧量的百分比,这是实验室的测定指标,如果要搬到运动现场测定是是困难的。因此,体育教师或教练员常把容易测定的心率指标作为运动负荷强度。心率与最大摄氧量的百分比的关系,用直线分别表示不同年龄的人心率与最大摄氧量的百分比的关系(见图一):1.心率与最大摄氧量的百分比成直线关系; 相似文献
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Ruth Stavy Yehudit Eisen Duba Yaakobi 《International Journal of Science Education》2013,35(1):105-115
Difficulties in the understanding of photosynthesis by Israeli junior high school students were examined. Thirty‐three students were interviewed and asked about chemical and ecological issues of photosynthesis. Difficulties were found in their understanding of the living body as a chemical substance, lack of knowledge about the chemical elements that compose the living body, and difficulties in understanding that gas (CO2) is the source of the plant's body. A major problem was the perception of photosynthesis as a type of respiration. Difficulties were also found in students’ understanding of concepts related to the ecosystem, such as the oxygen cycle in nature and autotrophic feeding as the first step of the food chain. Considering these difficulties, we recommend changing the way of teaching these issues. Such a programme is now being tested. 相似文献
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P. V. Sukumaran 《Resonance》2000,5(5):6-14
In Part 1 we described the early atmosphere which was rich in nitrogen and carbon dioxide and was oxygen deficient. In due
course photosynthesis liberated free O2 from CO2. The abundance of O2 reached modern levels by the turn of the Proterozoic
and triggered metazoan radiation. However tectonic activity exerted the ultimate control on the growth of atmospheric O2 by
enhanced organic carbon burial in sediments. 相似文献
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Students in a college nonscience majors' biology course took tests designed to reveal their conceptions of respiration and photosynthesis before and after course instruction. Even though most students had taken at least a full year of biology, serious misconceptions persisted. Most students gave definitions of respiration, photosynthesis, and food which were markedly different from those generally accepted by biologists. These incorrect definitions were associated with more fundamental misunderstandings about how plants and animals function. Most students could not explain how animal cells use either food or oxygen. They understood plants as vaguely analogous to animals, taking in food through their roots instead of mouths. Previous biology instruction seemed neither to improve student performance on the pretest nor to prepare them to master these conceptions during the course. Course instruction did improve student's understanding, but misconceptions persisted for many students. These results raise fundamental questions about the effectiveness of curriculum and instruction in current high school and college biology courses. 相似文献
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Jing-Ru Wang 《International Journal of Science and Mathematics Education》2007,5(2):307-328
The purpose of the study was to explore students’ alternative conceptions and their associative thinking regarding internal
transport in plants through administration of a refined diagnostic test. Questions of associative thinking and explanation
were added to form a third tier of the previous two-tier test. The study found three terms related to alternative conceptions:
capillary action, minerals, and nutrients produced by photosynthesis. The students’ associative thinking related to these
three terms suggested that: (1) capillary action is linked to a hair-water relation, (2) minerals are in the nutrients group,
and (3) oxygen is linked to nutrients. Finally, issues regarding the impacts of language on conceptual learning are discussed
under three strands: effects of language, Chinese language, and textbook language. 相似文献
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何道文 《内江师范学院学报》2007,22(4):74-77
对经过航天诱变的凤仙花SP2代的10个实验组与没有经过航天诱变的6个对照组植株的光合特性进行了比较.测得了光合速率等12个指标,进行相关分析发现:实验组中光照强度和光合速率呈极显著正相关,胞间CO2浓度和光合速率呈极显著负相关.对照组中,光照强度和光合速率正相关,胞间CO2浓度和光合速率为负相关.还对实验组以及对照组植株的光合色素含量等生理指标进行了测定,结果实验组光合色素含量大增,特别是叶绿素a含量增加更显著,叶绿素a与叶绿素b的比值也增大,而其可溶性糖含量极大地减少.本实验结果表明:航天诱变能对凤仙花的光合特性和生理生化方面产生显著且可遗传影响,能显著提高其光合能力. 相似文献
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Anna Vikström 《Journal of Science Teacher Education》2008,19(3):211-233
Within the framework of variation theory, 7- to 12-year-old students’ ways of understanding cellular respiration and photosynthesis
were investigated against the background of their teachers’ teaching. Eighteen students were selected by the teachers and
interviewed by the researcher. Lessons were observed and video recorded, and stimulated-recall interviews with the teachers
were conducted. The students’ understanding of the function of oxygen and sugar in plants was described in four categories.
The study concludes that young students can develop complex understanding if opportunities to learn are presented. The opportunities
depended mainly on the language used by the teachers, such as metaphors, pointing out critical aspects of the object of learning.
The study has implications for the relationship between teachers’ competence and students’ learning. 相似文献
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经济林光合作用研究进展 总被引：2，自引：0，他引：2
概述经济林光合作用的季节变化、日变化,内外因素、环境胁迫对光合作用的影响,光合产物的运输、分配和积累,光合效率与产量的关系,并探讨了今后研究和发展趋势。 相似文献
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Ilona Södervik Mirjamaija Mikkilä-Erdmann Henna Vilppu 《Journal of Science Teacher Education》2014,25(5):581-600
The purpose of this study was to investigate elementary school pre-service teachers’ understanding of photosynthesis and to examine if a refutational text can support understanding of photosynthesis better than a non-refutational text. A total of 91 elementary school pre-service teachers read either a refutational or a non-refutational text concerning photosynthesis and then answered open-ended questions. Our results indicate that there are critical problems associated with student teachers learning about the process of photosynthesis, even after it has been systematically taught in teacher education. However, the results positively indicate that refutational science texts seem to foster effective conceptual change among student teachers. The results interestingly showed that students who read a refutational text improved their systemic and factual understanding of photosynthesis more than did those who read a non-refutational text. Especially students who had naïve prior understanding regarding photosynthesis benefitted more from a refutational text. Thus, a refutational text may act as an effective facilitator of conceptual change. These results have implications for teacher education, where conceptual mastery of the most important science phenomena, such as photosynthesis, should be achieved. A refutational text is an easy and effective way to support conceptual change in higher education. Thus, this study highlights the importance of domain-specific science education in teacher programmes. 相似文献
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V. Krishnan 《Resonance》1997,2(12):77-86
One of the most important chemical reactions is electron transfer from one atomic/molecular unit to another. This reaction,
accompanied by proton and hydrogen atom transfers, occurs in a cascade in many biological processes, including photosynthesis.
The key chemical steps involved in photosynthesis and the many unsolved mysteries are described in this article. 相似文献