排序方式： 共有20条查询结果，搜索用时 15 毫秒
1.
游戏是孩子们自己的事,一般的情况下大人不要参与和干涉,教师指导也只是一般性的,不然,孩子们将感到游戏索然无味,甚至失去兴趣,渐渐地也就不想玩了。但是,角色游戏则不同,角色游戏是孩子们模仿大人,在游戏中充当某一角色的活动,如果没有教师的指导、帮助,孩子们反而不会尽兴,甚至最终玩不下去。从我们多年工作的实践来看,教师在角色游戏中起着非常重要的作用。因为,任何一种社会地位与身份的 相似文献
2.
一、中学化学教学中环境教育的必要性(一)环境问题相当严重在世界经济飞速发展的过程中,由于人们过于注重经济效益,忽视环境效益,结果造成诸如大气污染、水体污染、固体废弃物污染、噪声污染、水土流失、土地沙漠化等一系列环境问题。环境问题已成为人类所面临的三大问题(人口、能源、环境)之一,威胁着人类的健康和社会的持续发展。我国是一个发展中国家,在大力发展经济的过程中,同样出现了严重的环境问题,并且随着经济的不断发展而越来越突出。(二)公众的环境教育十分必要自1992年全国第一次环境教育工作会议提出“环境保护,教育为本”的口… 相似文献
3.
4.
从我国基础教育的整体水平来看,艺术教育仍然是学校教育的薄弱环节。当地优秀传统艺术对于培养学生的审美观念和审美能力．陶冶学生的道德情操具有重要的作用。加强学校艺术教育应通过多种途径渗透当地民间艺术,形成自身特色。 相似文献
5.
新课程改革明确提出要＂改变课程评价过于强调甄别与选拔的功能,发挥评价促进学生发展、教师提高和改进教学实践的功能＂。苏霍姆林斯基说：＂教育者的人道使命就在于,要使最落后的孩子也能感受到进步的欢乐,只有在这种条件下,他才是您的教育对象……＂教师年复一年、日复一日地教学,如何借助激励机制对学生课堂学习过程进行有效评价,使学生在轻松愉悦的氛围中学习知识、掌握技能、激发情感,促进学生良好学习习惯的养成,这是我们一直以来都在探索的问题。 相似文献
6.
7.
曹亚玲 《和田师范专科学校学报》2005,25(4):68-69
课程资源是新一轮国家基础教育课程改革提出的一个重要概念，是指形成课程的要素来源以及实施课程的必要而直接的条件，它们在很大程度上决定着课程的实施范围和水平。没有课程资源的广泛支持，再美好的课程改革设想也很难变成实际教育成果。目前，课程改革全面展开，课程资源开发与利用的研究与实践也在不断推进。但在此过程中，对于农村课程资源的开发与利用，特别是“小学科”化学课程资源开发与利用，理论探讨不多，实践中也尚未引起足够的重视。本文就农村中学化学课程资源开发与利用做一初步探讨。 相似文献
8.
From standpoint of floristic division, Sichuan is located in the middle part
of Eastern Asiatic Region (Takhtajan 1978) or is the area where Sino-Himalayan Forest
Subkingdom and Sino-Japan Forest Subkingdom meet (wu 1979). Here exist many so-
called Arcto-Tertiary elements and newly originated species or races. In order to bring
the light the origin and differentiation of Eastern Asiatic elements, cytological investi-
gation on plants of this region are very significant. The materials of the following 5
species were collected on Mt. Emei in Sichuan Province. Voucher specimens are kept in CDBI.
1. Toricellia angulata Oliver var. intermedia (Harms) Hu
PMC meiotic examination revealed n = 12 at diakinesis (Pl. I fig. 9)
Toricellia, consisting of 2 spp., is endemic to Eastern Asiatic Region. Based on
our result along with the report of Toricellia tiliifolia (Wall.) DC. (2n=24) by Kuro-
sawa (1977), we argue that the basic chromosome number of Toricellia is 12. Many
authors, such as Airy-Shaw (1973), Dahlgren (1975, 1977), Takhtajan (1969, 1980),
Thorne (1983), have adopted Hu’s (1934) treatment erecting it as a monotypic family
Toricelliaceae. Its systematic position, whether closer to Cornaceae than to Araliaceae
or vice versa, has been in dispute. Cytologically it seems closer to Araliaceae, as shown
anatomically (Lodriguez 1971), because the basic chromosome number of Cornaceae s.
1. is x=11, 9, 8 (Kurosawa 1977), whereas that of Araliaceae is 12 (Raven 1975).
2. Cardiocrinum giganteum (Wall.) Makino
Somatic chromosome number, 2n=24 was determined from root-tip cells (Ph. I. fig.
8).
Cardiocrinum (Endl.) Lindl., consisting of 3 spp., is endemic to Eastern Asiatic
Region. C. giganteum (Wall.) Makino is distributed from Himalayan region to S. W.
China. The present report is in accord with the number reported by Kurosawa (1966)
who got the material from Darjeeling of India. However the karyotype of the present
plant is slightly different from that given by Kurosawa. In the present material, the
satellites of the 1st. pair of chromosomes and the short arms of llst. pair of chromoso-
mes are visibly longer than those of Kurosawa’s drawing (fig. 1, 2) The plants from
Yunnan, Sichuan and Hubei Provinces, named as C. giganteum var. yunnanense (Leit-
chtlin ex Elwes) Stearn, differ slightly from those of Himalayan region also in outer
morphological characters. The taxon needs both cytological and taxonomical further
studies.
3. Disporum cantoniense (Lour.) Merr.
PMC meiotic examination revealed n=8 at diakinesis (Pl. I. fig. 6)
This species is widely distributed from Himalayan region through Indo-China to
our Taiwan Province and Indonesia. Three cytotypes (2n=14, 16, 30) were reported for
the taxon including its variety, var. parviflorum (Wall) Hara, by various authors (Ha-
segawa 1932, Mehra and Pathamia 1960, Kurosawa 1966, 1971 Mehra and Sachdeva
1976a). Some authors consider D. pullum Salisb. and D. calcaratum D. Don as synonyms
of D. cantoniense. So D. cantoniense may be a species aggregate with different extreme
races. Sen (1973a, b.) reports that the somatic chromosome numbers of D. pullum
and D. calcaratum from Eastern Himalayan region are 14, 16, 28, 30, 32. He also
discovered that chromosome alterations in species of Disporum involve not only the num-
ber but the structure as well. He found that in species of Liliaceae where the reproduc-
tion is mainly vegetative, polysomaty often occurs. In China we have not only D. can-
toniense and D. calcaratum but also D. brachystomon Wang et Tang which is similar
to D. cantoniense var. parviflorum (Wall.) Hara. These taxa need further critical
studies.
4. Paris fargesii Franch.
PMC meiotic examination revealed n=5+2B (Voucher no. 112) or n=5 (Voucher
no. 62) at MI and AI (Pl. I. fig. 1. 4. 5.). This is the first report for the species. A
bridge and a fragment were also observed at AI.
Paris polyphylla Smith is extraordinarily polymorphic species. Hara (1969) re-
gards all chinese extreme forms, such as P. fargesii Franch., P. violacea Lévl., P. pube-
scens (Hand. -Mzt.) Wang et Tang, etc. as infraspecific taxa of P. polyphylla. Need-
less to say, the various races of P. polyphylla Smith in China need further critical stu-
dies and are good material for further study to understand the speciation.
5. Reineckia carnea(Andr.) Kunth
Reineckia is a monotypic genus endemic to Eastern Asiatic Region. In the present
material somatic chromosome number in root-tip cells is determined as 2n=38 (Pl. I. fig.
7). According to the terminology defined by Levan et al., the karyotype formula is
2n=28 m+10 sm. The length of chromosomes varies from 14.28 μ to 5.5 μ. The idiogram
given here (fig. 3) is nearly the same as that presented by Hsu et Li (1984). The same
number has been previously reported by several authors, Noguchi (1936), Satô (1942),
Therman (1956). The karyotype is relatively symmetrical (2B, accorling to the classi-fication of stebbins 1971) in accord with the opinion of Therman (1956). 相似文献
9.
一、题库的提出题库的提出应考虑的问题:1.专业的全面性;要考虑对专业范围的设计要大一些,这样它的普及性才能广。2.题型的层次性;我们在建设题库时要分出层次来,比如,高级技校题库、普通技校题库、职业技能鉴定题库。3.题型的难易度;各种题型都要有相应的难度系数,比如:职业技能鉴定的初级、中级、高级工题型,它的难度系数也是不一样的。4.题型的多样性;在题库的每一套题应具有题目样式多的特点,比如:填空题、选择题、判断题、问答题、计算题、绘图题等等。5.知识点的覆盖性;知识点的采集在不超出教学大纲范围的条件下覆盖面要广,能渗透到… 相似文献
10.
曹亚玲 《常熟理工学院学报》2002,16(2):25-27
在合成对羟基苯甲酸乙酯过程中，采用固体超强酸SO4^2-/TiO2作催化剂，4A分子筛作脱水剂，能使酯化反应产率提高到84％。通过对影响化学反应各种因素的分析，得出最佳反应条件：醇酸物质的量比4：1，催化剂用量9％，反应时间3h，反应温度115-135℃。 相似文献