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1.
2009年5月,繁花烂漫的季节,高等教育出版社迎来了55周年华诞,《生命世界》杂志也走过了5年不平凡的历程。我们出版的高质量的教材和学术著作为我国的生命科学人才培养和学科建设发挥了积极的重要作用,受到了广大师生和科研人员的欢迎。《生命世界》在传播生命科学知识、提高大众科学素养方面起到了很好的作用,全国人大常委会副委员长、中国科学院院长路甬祥院士和全国人大常委会副委员长、中国科协主席、  相似文献   

2.
2009年5月,繁花烂漫的季节,高等教育出版社迎来了55周年华诞,《生命世界》杂志也走过了5年不平凡的历程。我们出版的高质量的教材和学术著作为我国的生命科学人才培养和学科建设发挥了积极的重要作用,受到了广大师生和科研人员的欢迎。《生命世界》在传播生命科学知识、提高大众科学素养方面起到了很好的作用,全国人大常委会副委员长、中国科学院院长路甬祥院士和全国人大常委会副委员长、中国科协主席、  相似文献   

3.
华福花的解剖学特征及其同五福花的比较   总被引:1,自引:0,他引:1  
本文记载了华福花的地理分布,生长和繁衍的物理条件,详细描述了营养器官的解剖学特征和花粉形态。从四个方面比较了两种植物的共同点和不同点,强调了华福花和五福花相比处于更高的阶段,并在发展和分化中。  相似文献   

4.
李静  胡建鹏 《生物技术世界》2014,(4):176-177,179
本文从劳伦斯·韦努蒂提出的"归化"和"异化"的文化取向出发,分析了在这两种文化取向指导之下的中医基础理论基本名词术语英译的策略和方法,并提出了归化"和"异化"密不可分,二者的关系使得中医基础理论基本名词术语的英译在第三空间达到了互补和统一,即杂合。同时指出杂合翻译展现了原术语语言和文化的异质性,促进了语言文化之间的相互理解和交流,有助于中医文化的丰富和发展。  相似文献   

5.
西双版纳自然保护区地理信息系统的建立与保护区的管理   总被引:2,自引:0,他引:2  
对在西双版纳自然保护区建立的地理信息系统的理论框架、目标和系统的基本功能作了介绍 .地理信息系统对保护区的有效管理提供了基础和可能 ,应用这一系统对保护区的资源利用现状、砂仁种植的现状和管理对策和亚洲象的种群及分布等进行了初步研究 .  相似文献   

6.
研究了一类具有潜伏期和体液免疫应答的病毒感染模型的动力学性质.利用Lyapunov泛函和LaSalle不变集原理,对模型的未感染平衡点全局稳定性进行了分析,对体液免疫未激活和体液免疫已激活的感染平衡点给出了全局渐近稳定的充分条件.推广了Bonhoefler(1997)和Nowak(2000)等的工作,获得了一些新结果.  相似文献   

7.
本文就粗品肝素钠生产的原料控制、硬件设施、管理和环保等方面进行了论述,介绍了一些改进的方法和措施,并就该方面的一些问题进行了探讨,提出了解决的方法.  相似文献   

8.
后基因组时代的生物信息学   总被引:15,自引:3,他引:15  
陈铭 《生物信息学》2004,2(2):29-34
随着人类基因组计划的完成,不断积累的巨量的生物学数据和快速发展的信息学技术,给后基因组时代的生物信息学研究带来了新的挑战。该文对后基因组时代的生物信息学研究内容进行了比较全面的描述,分别就其研究对象和研究方向作了区别讨论,分析了生物信息学研究的现状和趋势,比较了国内外的研究发展情况和差距。针对我国在研究中所存在的主要问题,提出了建议并做了展望。  相似文献   

9.
介绍了蕨类植物管状分子的研究现状和进展,包括管状分子的形态、分类和生理学意义等;对管状分子的区别和定义做出了阐述;将蕨类植物、裸子植物和被子植物管状分子进行了比较;并对蕨类植物管状分子今后的研究做了展望.  相似文献   

10.
陕西省油松人工林的生产力与生态因素的相关分析   总被引:5,自引:0,他引:5  
本文研究了油松林分生产力和生态因素的关系,分析了地理、地形,气候、林分和土壤因素单独及综合对林分生产的影响,得到84个逐步回归方程和全回归方程,选出了6个最优方程。计算了各林分外部因素的标准回归系数,找出了影响林分不同部分生产量的因素重要性序列,还探讨了生产力与生态因素相关关系的研究在实践中的应用。  相似文献   

11.
采用聚丙烯酰胺凝胶电泳法检测伤寒杆菌和甲型副伤寒杆菌的CWDMs及其宁代细菌型和伤寒杆菌粗糙型的乳酸脱氢酶(LDH)同功酶,以了解沙门菌CWDMs生物氧化的特点和机制,探讨CWDMs变异的性质。结果表明,伤寒杆菌和甲型副伤寒杆菌的细菌型及伤寒杆粗糙型在聚丙烯酰胺凝胶电泳后显示出相同的4种具有不同泳动速率的LDH同功酶,但CWDMs仅显示2种LDH。CWDMs的2种LDH同功酶与其亲代细菌型及伤寒杆  相似文献   

12.
作者解剖观察了33种,隶于4目、7亚目、15科、19属的中国鳐类脑颅的形态。研究结果认为:锯鳐目和鳐目是原始类群,它们均具吻软骨,其中圆犂头鳐科和团扇鳐科是特化类群。电鳐目亦具吻软骨,它们是特化和退化类群。在较高等的鲼目则无吻软骨。依据鳐类不同的分类阶元,其脑颅亦各具有不同的式型。  相似文献   

13.
光照对蕨类植物配子体假根向重力性的影响   总被引:3,自引:0,他引:3  
对8种蕨类植物配子体假根向重力性反应的研究结果表明,除卷柏Selaginella tamariscina Spring配子体假根无向重力性反应并且其生长方向与光照方向无关外,其它7种的配子体假根均有向重力性反应,并且假根的向重力性反应在配子体发育初期,因光照的方向不同而异,表现为负向光性。随着配子体发育至片状体阶段,光对其向重力性反应的影响逐渐减弱,而重力的影响增强。在蕨类植物配子体发育初期,光对  相似文献   

14.
省沽油科叶解剖结构的分类学意义   总被引:1,自引:0,他引:1  
丁士友  于兆英 《植物研究》1992,12(2):177-184
本文对国产省沽油科 Staphyleaceae 4属植物叶的解剖结构进行了详细的比较研究。结果表明, 叶解剖结构特征在属间的区别较明显, 特别是瘿椒树属 Tapiscia 有着几乎与其他三属截然不同的独特性状。根据已有的孢粉学, 花、节及木材的解剖等方面的资料, 我们支持Тахтаджян(1987)将瘿椒树亚科分出而建立瘿椒树科 Tapisciaceae 的观点。瘿椒树属为我国特有属, 根据我们对采自不同产地的材料观察, 居群间的差异很小, 其可能仍为一单种属。  相似文献   

15.
目的:了解沙门菌细菌壁缺陷突变株(CWDMs)的生物氧化及遗传特点和探讨细菌壁缺陷变异的性质与机制。方法:采用PAGE电泳法和分光光度法检测伤寒沙门菌和甲型副伤寒沙门菌及其CWDMs和伤寒沙门菌粗糙型和苹果酸脱氢酶(MDH)同工酶的活性与类型。结果:伤寒沙门菌和甲型副伤寒沙门菌的细菌型和伤寒沙门菌粗糙型经PAGE电泳可见一条MDH同工酶带,CWDMs电泳后可见两条MDH同Ⅰ酶带,在CWDMs的MDH中有一条泳动速率与细菌型及粗糙型的相同,另一条则较快。分光光度法检测证实。细菌型与粗糙型的MDH活性相似,CWDMs的MDH活性则明显较低。结论:CWDMs保留了与亲代细菌型一致的MDH和形成了一种新的MDH,并且其MDH的活性已显著降低,此特性可能与CWDMs生物氧化特性的改变有关。  相似文献   

16.
A study of four species of Erysiphaceae (Uncinula salicis, Podosphaera leucotricha, Erysiphe cichoracearum, and Microsphaera diffusa) revealed that the binucleate stages of the ascocarp are initiated in a similar manner to those of Diporotheca rhizophila Gordon & Shaw. The “appendages” developing on immature ascocarps are considered to be receptive hyphae. Appendages characteristic of mature ascocarps are produced much later. Lysis of certain centrum cells occurs, and asci are initiated from some of the remaining binucleate centrum cells. Resorption of centrum cells by the asci is supported by this investigation, corroborating Björling's earlier studies on Erysiphe graminis.  相似文献   

17.
1. It is shown that the concentrations of different salts required to precipitate suspensions of gelatin-coated collodion particles in water are practically identical with the concentrations of the same salts required for the "salting out" of gelatin from aqueous solutions. Neither effect shows any relation to the electrical double layers surrounding the particles. 2. It is shown that at the isoelectric point of gelatin, suspensions of gelatin-coated collodion particles are not stable and it had been shown previously that gelatin is least soluble at the isoelectric point. The addition of salt increases both the solubility of gelatin in water as well as the stability of suspensions of gelatin-coated collodion particles in water, and both effects increase with the valency of one of the ions of the salt. 3. This latter effect is not due to any charges conferred on the gelatin particles by the salts, since the cataphoretic experiments show that salts like NaCl, Na2SO4, or CaCl2, which at the isoelectric point of gelatin increase the solubility of gelatin as well as the stability of suspensions of gelatin-coated collodion particles, leave the particles practically uncharged in the concentrations in which the salts are efficient. 4. It follows from all these facts that the stability of suspensions of gelatin-coated particles in water depends on the solubility of gelatin in water; e.g., on the chemical affinity of certain groups of the gelatin molecule for water. 5. Though crystalline egg albumin is highly soluble in water, the stability of collodion particles coated with crystalline egg albumin does not depend upon the affinity of the albumin molecule for water, but depends practically alone on the electrical double layer surrounding each particle. As soon as the P.D. of this double layer falls below 13 millivolts, the suspension is no longer stable. 6. The critical potential for the stability of suspensions of collodion particles coated with genuine egg albumin is the same as that for particles of boiled (denatured) white of egg. Since through the process of heating, egg albumin loses its solubility in water, it is inferred that egg albumin undergoes the same change when it forms a film around a solid particle like collodion. 7. The influence of electrolytes on the stability of suspensions of collodion particles coated with casein or edestin was similar to that of collodion particles coated with egg albumin. The experiments are, however, complicated by the fact that near the isoelectric point CaCl2 and even NaCl cause a suspension again at concentrations of about M/2 or 1 M, while still higher concentrations may cause a precipitation again. These latter effects have no connection with double layers, but belong probably in the category of solubility phenomena. 8. These experiments permit us to define more definitely the conditions for a general protective action of colloids. Protective colloids must be capable of forming a durable film on the surface of the suspended particles and the molecules constituting the film must have a higher attraction for the molecules of the solvent than for each other; in other words, they must possess true solubility. Only in this case can they prevent the precipitating action of low concentrations of electrolytes on particles which are kept in suspension solely by the high potentials of an electrical double layer. Thus gelatin films, in which the attraction of the molecules for water is preserved, have a general protective action, while crystalline egg albumin, casein, and edestin, which seem to lose their attraction for water when forming a film, have a protective action only under limited conditions stated in the paper.  相似文献   

18.
When wheat is germinated in high concentrations of certain auxins, the coleorhiza-epiblast grows in an excessive and disorganized manner and resembles a callus. Wheat was germinated in 10−3 M indoleacetic acid or in water. There was greater net synthesis of DNA, RNA, and protein in the tumor tissue than in control tissue. Control and tumor tissue was fixed for electron microscopy 1, 2, 3, and 4 days after sowing. In contrast to the controls, many more lipoidal bodies appeared in 1-day-old, auxin-treated tissue and thereafter diminished in number. In 2- and 3-day-old tumor tissue, small membraneous fragments were prominent but disappeared in older tissue. With time, the following changes became progressively more pronounced: cytoplasmic vacuolation, appearance of myelin figures, polyribosome configurations and extensive profiles of rough endoplasmic reticulum, and sloughing of cytoplasmic contents into and accumulation of electron-dense material in vacuoles. Possible factors in susceptibility of certain tissues to tumor formation are discussed.  相似文献   

19.
Studies on the morphology of the ascocarps of 39 species of Hypodermataceae revealed several previously unknown cytological features. Two basic and one intermediate type of centrum ontogeny are discussed. Ascal initiation within Type I centrum occurs in the basal cells of the pseudoparaphyses and involves anastomoses, while ascal initiation within Type II occurs in cells of a plectenchymatous centrum, with no visible anastomosing in the ascocarp. There is frequent anastomosing between vegetative hyphae well in advance of initiation of the ascocarp. Ascal initiation in the intermediate type has ontogenetic sequences similar to those in Types I and II.  相似文献   

20.
自从1975年(Hughes et al. 1975)发现脑啡肽以来,经多方面研究已认为脑啡肽可能是一种神经递质,它具有多种生理功能(范少光、汤健,1978)。据新近文献报道,脑啡肽与催产素及加压素三者具有共同存在的并存关系(Martin and Voigt。1981)。 已经证明,刺激迷走神经向中端,可引起脑内释放乙酰胆硷,从而促使神经垂体释放压加素和催产素,肾上腺释放肾上腺素(Chang, et al. 1937;1961,1964;吕运明等1965,1977;唐正荣1981)。但是,刺激迷走神经向中端,是否也能引起脑内脑啡肽的释放,迷走神经传入纤维与脑内脑啡肽能神经原之间,是否存有机能上的联系?关于这个  相似文献   

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