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1.
促进微生物实验技术创新水平的改革初探   总被引:7,自引:0,他引:7  
为了加强对本科生综合素质和能力的培养 ,激发学生的学习兴趣 ,我们对微生物实验课的教学内容进行了一系列改革 ,优化了实验项目 ,节约实验成本 ,并且引入科研成果转化实验 ,同时改进了实验方法和手段 ,实验结果更为准确。这些措施蕴含了较高的理论水平 ,增加了教学信息量 ,明显提高了教学效果 ,为培养高素质人才奠定了基础。  相似文献   

2.
亚热带丘陵茶园间作白三叶草的生态效应   总被引:33,自引:0,他引:33  
在亚热带丘陵区1a生幼龄茶园通过连续4a的大田对比试验,研究了茶园间作白三叶草的生态效应,结果发现:茶园间作白三叶草降低了土壤容重,提高了土壤孔隙度、有机质、全N、水解N的含量、K的活性、蚯蚓的数量和生物量,消耗了部分有效P;增加了土壤关键层次(0—20cm)和关键时期(4~6月)的水分含量,延缓和缩短了夏季高温干旱与秋季持续干旱时间;获得了土壤降温时增温、保温与升温时降温的双向动态调控效果,增加了同一层次土壤温度的稳定性,延缓了高温和低温的出现时间,缩短了过度高温时间,减少了高温对茶树生长产生的影响;抑制了杂草生长,增加了天敌的种类和种群数量,减少了虫害发生率。从而形成了立地环境.茶树.伴生生物群落系统自我调节的动态平衡,促进了茶树生长,改善了茶叶品质,显著增加了茶叶产量。与清耕茶园相比,茶园间作白三叶草后,春秋茶的酚氨比分别下降了17.10%和30.90%,产量提高了32.65%。  相似文献   

3.
伊克昭盟项目区水土保持的生态效益   总被引:4,自引:0,他引:4  
根据对伊克昭盟世行项目区的监测数据,分析了项目实施后水土保持的生态效益。结果表明,项目实施后,改善了土壤的理化性质,增加了土壤肥力;同时,提高了当地的林草植被覆盖度,改善了局地气候,促进了生物多样性的恢复和保护。  相似文献   

4.
背角无齿蚌心肌纤维的超微结构观察   总被引:1,自引:0,他引:1  
本文研究了背角无齿蚌心肌纤维的超微结构,在电子显微镜下观察了心脏各部结构固定的超薄切片,分析和讨论了河蚌心肌纤维的粗丝与细丝的排列状况和徽细结构,测最了粗丝和细丝的直径,并对线粒体,脂褐素等细胞器的形态结构,分布等进行了描述,对心肌纤维的连接方式进行了观察,并与脊椎动物心肌纤维的超微结构进行了相应的比较。  相似文献   

5.
远程教育培训给生物教学带来新的生机。夯实了专业知识,梳理了生物知识,使我认识到应该如何把握生物课堂教学,提高了课堂教学设计能力,凝聚了生物教师的力量,使老师们学到了很多知识和教学技能,解决了平时教学中的一些难题,提升了生物的教学水平。  相似文献   

6.
亚热带丘陵茶园间作白三叶的土壤环境调控效果   总被引:16,自引:1,他引:15  
在亚热带丘陵区1年生幼龄茶园通过连续4年间作白三叶大田试验,研究了其对茶园土壤环境及茶叶品质、产量的影响,结果表明,茶园间作白三叶降低了土壤容重,提高了土壤孔隙度、有机质、全氮、水解氮的含量及钾的活性,消耗了部分有效磷;增加了土壤关键层次(0~20cm)和关键时期(4~6月)的水分含量,延缓和缩短了夏季高温干旱与秋季持续干旱时间;获得了土壤降温时增温、保温与升温时降温的双向动态调控效果.增加了同一层次土壤温度的稳定性,延缓了高温和低温的出现时间,缩短了过度高温时间。从而促进了茶树生长,改善了茶叶品质,显著增加了茶叶产量。与清耕茶园相比,茶园间作白三叶后,春秋茶的酚氨比分别下降了17.10%和30.90%,产量提高了32.65%。  相似文献   

7.
无产阶级文化大革命以来,在毛主席革命路线指引下,泗洪县的病虫害预测预报工作,实行专业测报和群众测报相结合,向长中期预报迈进。1974年整理了过去16年小地老虎的蛾量、幼虫密度、危害率以及有关气象资料,并进行了统计分析,测定了单相关和多相关,找出了相应的预报发生量的迴归式,试作了1975年和1976年的长中期预报。通过实践,基本准确,不仅提高了预报水平,而且提高了服务质量,从而控制了小地老虎的危害。  相似文献   

8.
地质部、有关的大专院校和中国科学院三方面的11个单位,在过去的工作基础上,今年又在蓝田地区进行了大量考察和研究工作,井由中国科学院古脊椎动物与古人类研究所负责筹备举行了这次现场会议。现场会议是和全国第四纪第二次学术会议联合举行的,在第四纪学术会议之后,举行了现场会议。现场会议从11月3日下午起到8日止,共举行了5天半。会议广泛地讨论了蓝田新生界的问题,交流了工作经验,肯定了成绩,指出了缺点。会议开得很好,收获很大,基本上完成了大会所规定的任务  相似文献   

9.
胡荣 《生物学通报》2003,38(12):35-35
1通过食用菌栽培活动,能有效的使学生获得知识,掌握知识,扩大知识面在初中生物学教材中,介绍了大型真菌磨菇的形态和生活史,通过课堂传授,学生缺乏感性认识,印象不深,通过开展食用菌栽培活动,学生不仅详细地了解了食用菌的形态,而且还亲自目睹了食用菌的整个生长发育过程,既了解了食用菌生长所需的外界条件,又掌握了多种食用菌的栽培管理方法。许多学生反映,通过食用菌栽培活动,不仅对真菌的形态和生活史有了进一步的了解,而且还培养了学生科学实验的基本技能。既巩固了学到的书本知识,开阔了学生的视野,又使学生掌握了一门致富技术,可以为…  相似文献   

10.
土地利用变化与土壤养分的变化——以河北省遵化县为例   总被引:52,自引:5,他引:47  
土地利用变化可以引起土壤养分的变化,以河北省遵化县为例,研究该县1980年到1999年土地利用变化及土壤养分的变化,结果表明,近20a来,旱地、草地、水田面积大幅度减少,林地和村镇用地大幅度增加,旱地转换为林地,土壤有机质提高了21%,全氮提高了10%,碱解氮提高了65%,速效磷提高了17%,速效钾提高了17%。旱地转换为草地,土壤有机质提高38%,全氮提高了37%,碱解氮提高了71%,速效磷提高了2%,速效钾提高了28%。退耕还林还草不仅改变了土地棉覆被,而且提高了土壤养分。  相似文献   

11.
东北地区蒙古栎群落区系成分   总被引:5,自引:0,他引:5  
根据吴征镒、王荷生区系分析方法, 分析了东北地区蒙古栎群落中261 种维管植物的区系成分, 其中温带成分占47-47 % , 东亚成分占42-02 % , 中国特有成分占10-51 % ( 世界分布不统计在内) 。并分析了种所在属的分布区类型, 温带分布属占90-3% 。还分别分析了蒙古栎群落的乔木层、灌木层、草本层以及层间植物的区系成分。  相似文献   

12.
离体草鱼肠道对亮氨酸和酪氨酸的吸收与利用   总被引:2,自引:2,他引:0  
采用同位素示踪和肠道离体灌流方法,研究了草鱼离体肠道对亮氨酸(Leu)、酪氨酸(Tyr)的吸收转运与利用。实验结果表明:当Leu浓度从1.0mmol/L增加到5.0mmol/L、10mmol/L时,肠道吸收转运的速度表现出“高浓度抑制”效应,运输到肠道外的比例为83%、66%和35%;合成肠道蛋白质的比例为2%、5%和13%;肠道组织内游离形式的比例为9%、28%和49%;其他形式的比例为6%、1%和3%。Tyr浓度从0.5mmol/L增加到1.5mmol/L、2.5mmol/L时,肠道对Tyr的吸收转运速度也随之增加,运输到肠道外的比例为52%、55%和55%;合成肠道蛋白质的比例为17%、15%和16%:肠道组织内游离形式的比例为7%、10%和16%;其他形式的比例为24%、20%和13%。肠道在吸收转运Leu和Tyr的同时,也利用它们合成蛋白质的和其他方面,Leu的吸收利用受灌流试验氨基酸浓度影响较大、而Tyr受影响较小;随着肠道内灌流的试验氨基酸浓度增加,吸收转运到肠道外的比例下降、留存于肠道内的比例增加,肠道合成的蛋白质绝对量也增加。    相似文献   

13.
朱磊 《动物学杂志》2013,48(3):474-479
采用石蜡切片技术对白胸苦恶鸟(Amaurornis phoenicurus)的消化道进行了组织学观察.结果表明,食管皱襞发达,黏膜上皮为复层扁平上皮,食管腺发达,颈段多于胸段,黏膜肌层为一层纵肌,厚约0.06 ~0.26 mm.肌层为一层厚约0.19~0.27mm的环肌.腺胃被覆单层柱状上皮,固有层内有单管腺和复管腺两种腺体,单管腺仅深约0.11 ~0.20 mm;复管腺厚约1.19~1.26 mm,占管壁的77.8% ~80.4%.肌胃的类角质层发达,厚约0.16~0.24 mm.肌胃腺呈管状,与类角质层突起形成皱襞.肌层发达,由内环外纵两层平滑肌构成.肠绒毛无分支和中央乳糜管,十二指肠绒毛长而密集,空肠绒毛呈细长指状,直肠绒毛长且呈叶状.十二指肠与直肠肠绒毛内有大量致密淋巴小结,盲肠绒毛短,肠腺少.  相似文献   

14.
15.
Summary The general ultrastructural features of the hypothalamo-neurohypophysial system in rats with hereditary hypothalamic diabetes insipidus (DI-rats, Brattleboro strain) are described. There is no decisively distinguishing difference between the neurons of the supraoptic and paraventricular nuclei. The neurons of both nuclei show signs of active protein synthesis. The perikarya of the neurons are markedly hypertrophic, the nuclei are large and the nucleoli prominent. In the cytoplasm there are numerous ribosomes, abundant rough-surfaced endoplasmic reticulum and extensive Golgi complexes. However, very few neurosecretory granules are to be seen. The axons of the hypothalamo-neurohypophysial tract are likewise enlarged and the paucity of neurosecretory granules is a striking feature also in the area of the tract. The majority of nerve endings in the posterior pituitary of DI-rats are devoid of neurosecretory granules. Microvesicles are abundant in the nerve endings and there are findings which suggest that microvesicles are involved either in endoor exocytosis. The signs of active protein synthesis and the concomitant paucity of neurosecretory granules are interpreted to imply transportation of the secretory proteins in an extragranular phase. The possible mode of release of the secretory proteins from the nerve endings and the role of microvesicles therein are discussed.This study has been supported by grants from the Finnish Cultural Foundation and the Sigrid Jusélius Foundation. The collaboration of Professors Antti Arstila and Tapani Vanha-Perttula is gratefully acknowledged.The Brattleboro-rats were kindly provided by Dr. Heinz Valtin, to whom we express our thanks.  相似文献   

16.
M A Qayyum  M A Beg 《Acta anatomica》1975,93(4):554-567
The anatomy and neurohistology of the tongue of the Indian goat, Capra aegagrus, have been described. The apex linguae is notched in the centre. The foramen caecum is found to be absent. The sublingua could not be traced. The filiform papillae are the most common and divided into three types: the simple, giant, and true filiform papillae. The true filiform papillae are the most developed of the three types. The foliate papillae are absent. There are 13--14 circumvallate papillae arranged in two rows in a V-shaped pattern. The fungiform papillae are large and could easily be seen with the naked eye. They are scattered over the entire dorsum, being in abundance at the tip. The tongue of the goat is richly innervated. On the dorsum, the lamina propria is innervated by thick nerve fibres. In the fungiform papillae quite a large number of nerve fibres could be seen. The circumvallate papillae are also abundantly provided with nerves. A few ganglion cells are found below the circumvallate papillae. Thick nerve fibres are seen across the numerous glands and their ducts. Muscle fibres and connective tissue are also richly innervated.  相似文献   

17.
Summary The sperm of cotton were observed in the pollen tube in the style. They are true cells but relatively simple in organization. The nuclei are small and each contains a single, very small nucleolus. Nuclear pores are common and heterochromatin lines the nuclear membrane. The plastids and mitochondria are so reduced in internal structure that it is impossible to separately identify them. The suggestion is put forward that only mitochondria are present in the sperm. Dictyosomes are few but appear to be producing large numbers of vesicles. Single membrane vesicles of a large range of sizes are common. ER is scarce but polysomes are numerous.  相似文献   

18.
The sensory epithelium of the paratypanic organ (Vitali) was studied by means of the electron microscope. Two kinds of cells are present. One type extends from the basement membrane to the surface of the epithelium; their nuclei are arranged close to the connective tissue and are surrounded by a pale cytoplasm. The distal part of these cells, which are denser and richer in organelles, possess microvilli. The cells of the second type are located above the basement membrane and are found between the upper parts of the cells of the first type. Their cytoplasm is rich in small round vesicles, free ribosomes and cisternae of rough endoplasmic reticulum are present especially in the infranuclear zone. The apical part contains a Golgi apparatus lysosomes and multive sicular bodies. At the apex each cell possesses a cuticular plate numerous stereocilia and one kinocilium. The stereocilia become increasingly longer from one side of the cell surface to the other and the kinocilium is situated on the side where the stereocilia are longest. Nervous fibers are present in the epithelium and are in close contact with the cells of the second type. The cells we have described are remarkably similar to the supporting and hair cells of the vestibular sensory epithelium.  相似文献   

19.
The morphology of the gills, with their blood supply have been described in Notopterus notopterus and Colisa fasciatus in some detail. Gills are curved and perforated on the dorsolateral and ventrolateral wall of the pharynx. The gills consist of 2 rows of filaments which are stacked one above the other to form a space. The gill filaments are smaller on both the ends and larger in middle. The gill filaments are of pink colour as they are supplied with blood. Gill rakers are large in size in Notopterus notopterus while they are small in Colisa fasciatus. 3 pairs of basibranchials are present in Notopterus notopterus which are covered by median membranous bony plate while 2 basibranchials are present in Colisa fasciatus. 3 pairs of hypobranchials are present in both fishes. 5 pairs of ceratobranchials are present in which Vth ceratobranchial bears teeth. 4 pairs of epibranchials are present. 3 pairs of pharyngobranchials are present in which the tip of the IVth pharyngobranchial bears minute teeth in Notopterus notopterus while in Colisa fasciatus IInd and IIIrd pharyngobranchial bear minute ones. One afferent branchial vessel is present in Notopterus notopterus and Colisa fasciatus in each gill like in other teleostean fishes. One efferent branchial vessel is present in each gill of Notopterus notopterus while in Colisa fasciatus 2 efferent are represented in each gill.  相似文献   

20.
Results are presented from experimental observations of the statistical properties of scrape-off-layer plasma turbulence in the T-10 tokamak. The experimentally observed fluctuations in the fluxes and plasma density are intermittent in nature and obey a non-Gaussian statistics. The generalized property of plasma turbulence is its scale invariance. The experimental scalings for the moments of the distribution function of the difference in the amplitudes of fluctuations in the fluxes and plasma density are described by the log-Poisson model of strong turbulence. The self-similarity properties of turbulence that are associated with the topology of dissipative structures are investigated.  相似文献   

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