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1.
生理生态学的原则是随着纬度的升高,物种分布的海拔高度将随之降低。但是,云南一些植物特征成分的分布却与之相反,它们的分布与云南残留的古夷平面的分布相似,即随着纬度的升高,其分布的海拔高度也随之升高。二者的区别是云南古夷平面分布的趋势线的仰角大于那些特征成分分布的趋势线的仰角。可能的原因是:相对于剧烈的地质运动,物种的适应能力总是相对滞后的,并且物种的分布也受到其生长特性的制约;根据分布区形成的原则,这些成分的发生应早于夷平面的隆起。  相似文献   

2.
浅谈果树病虫害综合防治技术研究   总被引:2,自引:0,他引:2  
在我国的农业生产的过程中,对于果树的病虫害综合防治是农业生产效益的根本保障,我国是一个农业大国,尤其是在我国的北方,果树的栽培更是有着悠久的历史,在近些年中由于技术的进步果树的品种更新的速度也在不断的加快,但是随之而来的就是果树的病虫害的问题,它对于果树的影响非常的大,直接在经济上给果农带来严重的损失,为了能够让果农的经济效益得到保障,对于果树的病虫害防治就显得极为重要。本文主要是对东北地区的果树病虫害的现状进行简要的分析,并对果树病虫害的综合防治技术进行研究找出适当的对策,希望能有所裨益。  相似文献   

3.
绪言自从1950年召开的研究巴甫洛夫生理学说问题的苏联科学院及苏联医学科学院的科学会议以后,则产生了根据巴甫洛夫学说讲授中学的人体解剖生理学的必要性. 巴甫洛夫的高级神经活动学说是他的生理学说的顶峰,是中学学生所必需获得的,巴甫洛夫有关高级神经活动的概念,可以在人体解剖生理课程中阐明,但是它的形成在动物学的课程中就应当开始.高级神经活动的概念,在说明关于有机体为统一的整体的较为总括性的概念中,是起一个主导作用的.学生自觉的掌握巴甫洛夫的“高级神经活动”概念,将会有助于学生树立辩证唯物主义的、无神论的世界观.学生具备了高级神经活动的概念,则给中学10年级学习心理学打下了良好的基础.一直到现在为止,在学校的人体解剖生理学课程中树立高级神经活动概念的方法的问题,尚未得到必要的解决.  相似文献   

4.
对于罗红来说,热爱自然始于被自然的征服,始于非洲的原野上“生命就在你身边奔流”的时候,发现了“那么多的生命可以跟人类如此之近,有多美好”。同时也始于被蹂躏的自然的伤痛。于是他的镜头,才可能在动物的世界里,创造出“那么多让人热血沸腾的故事”。从一个旁观者的角度,进入到撼人心魄的生物圈,然后又选择了从数千米的高空,俯瞰这个世界的美丽。距离的远近不是心灵远近的同义词,罗红大气、美丽的自然,说出了一个普通而又意味深长的哲理。以一种爱的力量在很近的心灵的距离俯瞰宏大的自然,世界才会呈现出完全不同的意味。当然,这样的一个过程,是漫长而艰巨的,也是值得的。[编者按]  相似文献   

5.
在中学阶段的生物教学中,科学素质教育的任务是什么?笔者认为科学素质教育应包括运用科学的方法、选择适当的实验材料、执着的钻研精神、敏锐的观察能力、实事求是的态度以及耐得住清贫和寂寞的生活方式的教育等。科学品质的培养则依赖于正确的思想观念的确立和高尚的道...  相似文献   

6.
当代手术室护士素质能力要求   总被引:1,自引:0,他引:1       下载免费PDF全文
素质原本是心理学的一个专门术语,是指人的一种较稳定的心理特征。素质广义的解释分先天与后天两方面。先天的自然性的一面,是指人在某些方面的与生俱来的特点和原有基础,即天生的感知器官,神经系统,特别是大脑结构和功能上的一系列特点而言;素质的后天的社会性的一面是主要的,是指通过不断的培养、教育、自我修养、自我磨练而获得的一系列知识技能、行为习惯、文化涵养、品质特点的总和。护士的素质包括思想品质素质和专业素质两个方面。而对于手术室护士的素质就有更高更广泛的要求,特别是对于当代手术室护士的素质能力,只有提高了手术室护士的素质,才能改善医院手术室的护理质量,更好的适应当代手术室的工作要求。如何提高手术室护士的素质能力,是摆在我们面前的重要课题,作者结合多年担任手术室护士和护士长的经验就手术室护士应具有的素质能力,提高手术室护士素质的途径和方法做如下探讨。  相似文献   

7.
生物催化是指将酶或生物有机体用于有用的化学转化的过程,在人们对传统化学催化的环境影响抱有忧虑的情况下,生物催化提供了一种有吸引力的选择。在过去的几十年里,对生物催化剂的研究每出现一次大的进步,生物催化的发展就会出现一次高潮。因此,生物催化剂的发现与改造已成为当今研究的热点。宏基因组文库技术的出现克服了许多微生物不可培养的障碍,人们能够从自然资源中获得丰富的潜在的生物催化剂。而基于理性设计的分子改造技术的发展,可以使得人们对潜在的生物催化剂进行快速而有效的改造以满足工业化生产的需求。随着生物催化剂发现与改造的手段不断进步,更多的优良生物催化剂得到了广泛的应用,生物催化在工业生产中也得到了更深入的应用。结合作者的研究工作,总结了生物催化剂发现与改良的一些研究进展,以为获得更多优良的、能够实现工业应用的生物催化剂奠定理论基础。  相似文献   

8.
《化石》1977,(4)
当人们走进自然历史博物馆,看到巨大的恐龙骨架时,总是情不自禁地问道:这条恐龙有多少吨重?这就产生了怎样测量恐龙体重的问题。过去很长的一个时期,人们是依据恐龙骨架的大小,它的脚印的大小和凹陷的深浅,参考现代的一些脊椎动物的重量,作大体上的推测。例如要测量的恐龙骨架与现代的印度象差不多,就估计恐龙的体重约为5吨左右。显然这种方法并不准确。后来,有些研究恐龙的科学家不断提出测量恐龙体重的方案。目前,在我国普遍认为行之有效的测量恐龙体重的方法,是采用美国科尔伯特改进的用复原模型测量的方法。他的方法是,根据一个简单的物理学原理:体积×比重=体重。体积是用要测量的恐龙的复原模型求出来的。首先要依据待测恐龙的骨架的尺度,作出一个一  相似文献   

9.
课堂教学是教师以连续上课的形式进行的。课的类型是上课的具体形式的种类,课堂教学结构是课堂教学的组合形式,或称之为课堂教学环节、课的组成部分,课的结构是课的类型的具体体现。课的类型及其结构的多样化必须根据实现每门课的目的和任务与教材的要求把教学内容和所应完成各项任务进行具体合理的划分,使一系列不同类型的课合理安排,不仅能够保证各项教学任务的全面完成,而且还可以加快教学的进度。由于各类型课所完成的任务不同,生物课结构上具有不同的特点,从而显示出课与课  相似文献   

10.
生物进化的研究向来是以生物的表型为对象的,如蕨类植物的维管束,马的脚趾,哺乳动物的齿冠等,都是用古生物学方法来研究的。生物的进化当然是由自然选择理论来说明的,不过这些都是定性的说明而已。 用定量方法研究进化论,是从群体遗传学的理论研究开始的。种的进化不仅是个体水平的变化,主要是整个群体的遗传变化。例如某个种的一个基因变化  相似文献   

11.
The levels of endogenous phytohormones and respiratory rate in nine sorts of flowers such as Cymbidium faberi Rolfe, Nopalxochia ackermannii Kunth and others were investigated both at full bloom and senescence and meanwhile the effect of exogenous phytohormones on prolonging the blossoms and promoting ethylene production were tested. There is a high content of endogenous ethylene in all the long-lived flowere, about 3–16 folds higer than the short-lived ones. There is a high level of ABA at full blooming flowers of short-lived flowers, in which there is no or only some cytokinins in it, but the ratio of CTK (6BA+zeatin)/ABA is smaller(l.7). The endogenous ABA reached a much higher level at senescence in all nine sorts of flowers, so it is reasonable to consider that it is ABA which plays an important role of regulation in controlling flower's senescence. There is a much higher level of GA3 and zeatin in the long-lived flowers which is not demonstrated in the shortlived ones. The respiratory rate is one of the factors controtling the longevity of flowers, but it does not play a decided role. Application of 6BA and zeatin prolongs distinctly orchid’s longevity, however exogenous IAA through the promotive action on ethylene production, evidently extends the longevity of the flowers of the Nopalxochia ackermannii Kunth.  相似文献   

12.
Scales of spatial patterns of distribution of intertidal invertebrates   总被引:15,自引:0,他引:15  
Few comparative studies of spatial patterns at different scales have examined several species in the same habitat or the same species over a range of habitats. Therefore, variability in patterns among species or among habitats has seldom been documented. This study quantifies spatial patterns of a suite of intertidal snails and a species of barnacle using a range of statistical techniques. Variability in densities was quantified from the scale of adjacent quadrats (over a distance of centimeters) to tens of kilometers. Significant differences in abundances occurred primarily at two spatial scales. Small-scale differences were found at the scales of centimeters or 1–2 m and, for many species on many shores, these accounted for most of the variability in abundances from place to place. These are likely to be determined by behavioural responses to small-scale patches of microhabitat. Large-scale differences in abundance were also found in most species at the scale of hundreds of meters alongshore. These are likely to be due to variation in recruitment (and/or mortality) because of limited dispersal by adults of these species. There was little or no additional variation among shores, separated by tens of kilometers, than was shown among patches of shore separated by hundreds of meters. Identification of the scale(s) at which significant differences in abundance are found focus attention on the processes (and the scales at which these processes operate) that influence patterns of distribution and abundance. Some of the advantages and disadvantages of various procedures are discussed.  相似文献   

13.
不同种源山桐子果实脂肪酸组成变异分析   总被引:1,自引:0,他引:1  
以采自11个种源的山桐子为材料,测定其果实脂肪酸的组成及其变异情况,结果表明:山桐子果实中不饱和脂肪酸含量较高,尤以亚油酸含量最高,11个种源的平均值为63.58%,且种源间差异显著,分宜、宜昌种源亚油酸相对含量明显高于其他9个种源;饱和脂肪酸以棕榈酸为主,11个种源山桐子果实棕榈酸差异显著,且以平武种源最高;其余脂肪酸含量均较低,变异幅度较大;种子中棕榈酸和棕榈烯酸含量明显高于果肉,而亚油酸、亚麻酸及硬脂酸含量明显低于果肉,油酸含量相近:果实不饱和脂肪酸含量依次为果肉〉全果〉种子,且变异系数及相对极差均较小,尤以果肉中最小;除硬脂酸外,山桐子果实中其他4种主要脂肪酸组分受海拔等地理环境的影响均较小。  相似文献   

14.
Summary Ethanol administration to female rats before and during pregnancy resulted in decreased number of litters and increased activities of serum GOT, GPT and ALP. The hepatotoxicity of ethanol was indicated by the histological alterations both in the mother and siblings. There was increased levels of tissue lipids in mother and litters born to alcoholic rats. The concentration of TBARS in the liver and kidney were significantly increased in alcohol treated rats and their litters. The activities of the anti-peroxidative enzymes SOD and CAT were decreased on alcohol treatment in female rats. The glutathione content in liver and kidney decreased significantly in litters born to alcoholic rats.We have observed that the treatment with N-acetylcysteine offers protection against the toxic effect of alcohol in female rats during pregnancy and litters born to them. In N-acetylcysteine treated rats the number of litters as well as the average birth weight were close to that of control animals. Nacetylcysteine decreases the activities of serum GOT, GPT and ALP in female rats. We have also observed decreased levels of tissue lipids in mother and litters born to alcoholic rats given N-acetylcysteine when compared to alcoholic rats. The levels of TBARS in liver, kidney were also decreased both in mother and litter born to alcohol + N-acetylcysteine, while the activities of SOD and CAT were increased in liver of alcoholic rats given N-acetylcysteine when compared to alcoholic rats. Histopathological studies also showed the protective effect of N-acetylcysteine in both mother and litter in liver and kidney against alcoholic induced toxicity.  相似文献   

15.
Gorlenko  V. M. 《Microbiology》2004,73(5):541-550
The tendencies in the study of anoxygenic photosynthetic bacteria (APB) are considered in the review in the historical aspect, from the discovery of APB till the present day. The contribution made by the researchers of the Institute of Microbiology, Russian Academy of Sciences, to the study of the phylogeny, ecology, and morphophysiological diversity of APB is noted. At present, molecular biological approaches play a decisive role in ecology and taxonomy. The most important task at the modern stage of the development of microbiology is to maintain the continuity of the historically formed classical approaches in the study of APB diversity.  相似文献   

16.
A complex analysis of seasonal fluctuations of the mean group parameters of the system of regulation of lipid peroxidation has been performed in liver of Balb/c mice. Association of lipid characteristics and morphophysiological parameters is studied in the Balb/c mouse liver. An inter-connection is revealed between the liver index and the amount of lysoforms of phospholipids, the scale and character of the interconnection differing essentially depending on proportion of phos-phatidylcholine in mouse liver phospholipids.  相似文献   

17.
杨永 《生物多样性》2012,20(4):512-516
植物标本是物种存在的永久凭证,模式标本在保障命名体系稳定中有不可替代的作用。标本馆藏量和模式标本数量反映一个国家或地区的历史积累。作者通过对比分析,发现我国的标本馆藏量远低于国际平均水平,模式标本馆藏量也相对较少,历史积累不足。在数字化本土馆藏模式标本基础上,标本数字化平台项目应将国外馆藏的中国植物种类的模式标本"引渡"回国。今后我国植物分类学研究者的重要工作之一是加强空白地区和国外标本采集,提高馆藏标本的代表性。  相似文献   

18.
ABSTRACT. Six Leishmania species were studied comparatively, in order to determine the influence of temperature "in vitro" on differentiation, infectivily and protein synthesis. Differentiation ocurred in a heterogeneous manner, even in species that produce similar clinical manifestations. Thus, no association could be found between thermosensitivity and disease. The association between expression of proteins and increasing temperatures was analyzed at 34° C by polyacrylamide gel electrophoresis with sodium dodecyl sulphate (SDS-PAGE), using different incubation times, and employing a technique involving metabolic incorporation of [35S]-methionine. Protein synthesis was very similar in all the New World species apart from L. amazonensis , which expressed a protein of approximately 80 kDa when incubated at 34° C for 2 hours. All the tested species had in common the expression of a 70 kDa protein. Differences, however, were observed in relation to the time interval for protein expression. in L. chagasi , synthesis was detected after 30 minutes of incubation at 34° C, while L. braziliensis required 1 hour at the same temperature. The "in vivo" and "in vitro" infectivity of the differentiated forms was also analyzed, but no significant differences were observed.  相似文献   

19.
目的探讨肠道菌群和粪便炎性标志物在炎症性肠病(IBD)活动度评估中的临床价值。方法共纳入120例IBD患者为研究组,其中溃疡性结肠炎(UC)患者68例,克罗恩病(CD)患者52例。选择30例经结肠镜检查正常的健康体检者为对照组。采集全部研究对象的新鲜粪便标本进行粪便细菌培养及炎性标志物检测,比较不同疾病活动度IBD患者的肠道菌群及粪便钙卫蛋白(FC)、乳铁蛋白(LF)、基质金属蛋白酶-9(MMP-9)、髓过氧化酶(MPO)水平的变化。结果与对照组比,UC和CD患者肠道中肠杆菌、肠球菌、拟杆菌、消化球菌及酵母菌数量均明显增加(P0.05),双歧杆菌、乳杆菌及真杆菌数量明显减少(P0.05)。UC患者梭菌数量较对照组增加(P0.05),CD患者梭菌数量较对照组减少(P0.05)。UC、CD活动期患者肠杆菌、肠球菌、拟杆菌、消化球菌及酵母菌数量明显多于缓解期患者(P0.05),双歧杆菌、乳杆菌及真杆菌数量明显少于缓解期患者(P0.05),且重度活动期患者肠道菌群改变较轻、中度活动期改变更明显(P0.05)。UC活动期患者梭菌数量明显多于缓解期(P0.05),CD活动期患者梭菌数量明显少于缓解期(P0.05)。UC和CD患者粪便中FC、LF、MMP-9及MPO水平均显著高于对照组(P0.05)。UC、CD活动期患者FC、LF、MMP-9及MPO水平显著高于缓解期患者(P0.05),且重度活动期患者高于轻、中度活动期患者(P0.05)。结论肠道菌群变化和粪便中FC、LF、MMP-9及MPO水平可作为IBD患者疾病活动性评估的辅助指标。  相似文献   

20.
Summary Nitrate reductase activity of the terminal bud of tea shoots was greater than that in mature leaves, and exhibited greater activity in triethanolamine HCl–KOH buffer than in phosphate or Clark and Lubs buffers. There was some correlation between yield characteristics of different tea clones and the level of nitrate reductase activity in the terminal bud, and mulching of plants was found to cause a significant increase in activity of the enzyme.  相似文献   

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