首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   85篇
  国内免费   4篇
  完全免费   18篇
  2013年   1篇
  2012年   3篇
  2011年   4篇
  2010年   5篇
  2009年   12篇
  2008年   11篇
  2007年   9篇
  2006年   8篇
  2005年   4篇
  2004年   3篇
  2003年   6篇
  2002年   3篇
  2001年   5篇
  2000年   7篇
  1997年   1篇
  1996年   3篇
  1995年   2篇
  1994年   1篇
  1993年   5篇
  1992年   7篇
  1991年   1篇
  1990年   3篇
  1989年   2篇
  1987年   1篇
排序方式: 共有107条查询结果,搜索用时 31 毫秒
1.
水产动物继饥饿或营养不足后的补偿生长研究进展   总被引:44,自引:3,他引:41  
综述了水产动物继饥饿或营养不足后的补偿生长研究进展,其中包括补偿生长的程度、影响因素、生理学机制、补偿生长研究的实验设计、补偿生长过程中生长率和生化组成的变化及存在的问题和应用前景。  相似文献
2.
中国对虾继饥饿后的补偿生长研   总被引:22,自引:3,他引:19       下载免费PDF全文
1999年7至8月份,在25.0±0.5℃条件下对中国对虾(湿重,1.454±0.150g)进行了不同时间的饥饿处理后再供食的恢复生长实验。对照组C连续饱食投喂32d;处理组S4、S8和S12分别饥饿4、8和12d后再饱食投喂28、24和20d。主要结果如下饥饿结束时各处理组的干重和湿重显著低于对照组(P<0.05);实验结束时S4组和对照组间的干重和湿重差异不显著(P>0.05),而S8和S12两组的干重和湿重仍显著低于对照组(P<0.05);恢复生长后各处理组的湿重摄食率显著高于对照组(P<0.05)。实验结果表明,中国对虾继饥饿后再恢复喂食出现完全或部分补偿生长效应,且这种补偿生长效应主要是通过恢复生长阶段食欲增大,摄食水平提高实现的。  相似文献
3.
Overcompensation by plants: Herbivore optimization or red herring?   总被引:19,自引:0,他引:19  
Summary The increased growth rates, higher total biomass, and increased seed production occasionally found in grazed or clipped plants are more accurately interpreted as the results of growth at one end of a spectrum of normal plant regrowth patterns, rather than as overcompensation, herbivore-stimulated growth, plantherbivore mutualisms, or herbivore enhanced fitness. Plants experience injury from a wide variety of sources besides herbivory, including fire, wind, freezing, heat, and trampling; rapid regrowth may have been selected for by any one of the many types of physical disturbance or extreme conditions that damage plant tissues, or by a combination of all of them. Rapid plant regrowth is more likely to have evolved as a strategy to reduce the negative impacts of all types of damage than as a strategy to increase fitness following herbivory above ungrazed levels. There is no evolutionary justification and little evidence to support the idea that plant-herbivore mutualisms are likely to evolve. Neither life history theory nor recent theoretical models provide plausible explanations for the benefits of herbivory.Several assumptions underlie all discussions of the benefits of herbivory: that plant species are able to evolve a strategy of depending on herbivores to increase their productivity and fitness; that herbivores do not preferentially regraze the overcompensating plants; that resources will be sufficient for regrowth; and that being larger is always better than being smaller. None of these assumptions is necessarily correct.  相似文献
4.
The costs of reproduction in plants   总被引:17,自引:1,他引:16  
5.
Following a period of food deprivation, gibel carp compensated for growth through increased feed intake and conversion efficiency, but increased conversion efficiency was not achieved by increasing digestibility or reducing activity.  相似文献
6.
四列藻在营养限制胁迫下的超补偿生长研究   总被引:13,自引:1,他引:12       下载免费PDF全文
四列藻在营养限制胁迫下培养 1 0 d后 ,在恢复营养进行培养的初期 ( 1~ 5 d) ,表现出较强的超补偿生长能力。与持续正常营养培养的对照组比较 ,两者间的生长表现出显著差异 ( P<0 .0 5 )。四列藻超补偿生长的主要特征表现是在恢复营养进行培养的初期 ,处理组的藻细胞比对照组平均相对生长率提高 ,细胞数增多 ,叶绿素 a含量和生物量增高 ,细胞数净增率最高达 68.2 %~ 1 2 1 .1 % ,生物量净增率最高达 2 1 .8%~95 .3%。随着培养时间的推移 ,由于环境容量的限制 ,处理组与对照组之间的差异逐渐减小。到了培养的后期 ,处理组和对照组的各生长参数都趋于一致。同时发现 ,在受到营养限制胁迫后 ,藻细胞内蛋白质、细胞内糖和蛋白质 /糖 ( P/C)的比值发生了变化 ,但是在恢复营养进行培养 1 0 d后 ,均基本上恢复至处理前的水平。藻类中存在的这种超补偿生长特性有可能是引起藻华和赤潮的一个生物内在因素。  相似文献
7.
Starvation of second sea winter farmed Atlantic salmon through February and March reduced body weight by 0.10% day−1 or 6.0% during the starvation period, whereas fed fish increased body weight by 0.10 day−1 or 5.9%. When fed again during 41 days in April and May, the starved group increased weight by 22.7% (0.55% day−1) compared with a 11.4% (0.28% day−1) gain in the unrestricted control. Ultrasound determination of sex and maturity in late May showed that the incidence of maturation was reduced by 48% among females and 32% among males in the starved group, compared with the unrestricted group.  相似文献
8.
Synopsis Experiments were conducted to monitor changes in body mass and metabolic energy expenditure before, during, and after periods of starvation in juveniles of three species of cyprinids: Leuciscus cephalus, Chalcalburnus chalcoides mento, and Scardinius erythrophthalmus. During the starvation period all fish lost weight at about the same rate and the total amount of oxygen consumed during an experimental period of 20 h was about 40% lower in the starved than in the fed groups. Upon refeeding, both mass specific maintenance; and routine rates of metabolism as well as relative growth rates increased rapidly, the peaks of these increases being directly proportional to the length of the starvation period. Maximum compensatory growth was observed after four weeks of starvation in C. chalcoides and S. erythrophthalmus, with relative growth rates reaching 30% d-1 during the first measuring interval after refeeding. The pattern of time-dependent compensatory growth displayed by these fish is similar to the responses of a colonial hydroid in which the rate of catch-up growth increased with the amount of stress to which the animals had been exposed. The exact cost of compensatory growth cannot be calculated because oxygen consumption and growth were not measured simultaneously. However, on the basis of data and calculations reported by Wieser & Medgyesy (1990) it appears that compensatory growth, if fuelled by the metabolic power indicated by our measurements of oxygen consumption, would have to be about twice as efficient as normal growth in the related species Rutilus rutilus.  相似文献
9.
水分胁迫和胁迫后复水对玉米叶片生长速率的影响   总被引:9,自引:0,他引:9  
玉米叶片延伸速率(LER)对水分状况的变化很敏感。快速干旱处理,水分消耗迅速,LER从最大到零需5h,叶水势改变0.5~0.6 MPa,缓慢干旱处理,水分消耗较慢,LER从最大到零需20h,叶水势改变1 MPa。缓慢干旱植株叶片成熟部位的渗透势,在任何LER下,均比快速干旱叶片更负。LER为零时,快速干旱叶渗透势为-1.3 MPa,缓慢干旱为一1.6MPa左右。短时间水分胁迫后复水,LER迅速增加,有部分补偿前期胁迫减少的生长量能力;长时间水分胁迫后复水,LER在6 h内不可能恢复到正常水平。  相似文献
10.
S. Xie  *  X. Zhu  Y. Cui  *  R. J. Wootton    W. Lei  * Y. Yang  * 《Journal of Fish Biology》2001,58(4):999-1009
To investigate the nature of compenstory growth in fish, an 8 week study at 28°C was performed on juvenile gibel carp Carassius auratus gibelio weighing 6·6 g. Fish were starved for 0 (control), 1 (S1) or 2 (S2) weeks and then re-fed to satiation for 5 weeks. Weekly changes in weight gain, feed intake and body composition were monitored during re-feeding. No significant difference was found in final body weight between the three groups, indicating complete compensation in the deprived fish. The deprived groups caught up in body weight with that of the control after 2 weeks of re-feeding. Body fat: lean body mass ratio was restored to the control level within 1 week of re-feeding. In the re-feeding period, weekly gains in body weight, protein, lipid, ash and energy in the S1 group were significantly higher than in the controls for 1 week. For the S2 group, weekly gains in body weight, lipid, ash and energy were higher than in the controls for 2 weeks, and gain in protein was higher than in the controls for 3 weeks, though gain in body energy became elevated again during the last 2 weeks of the experiment. Feed intake remained higher than the control level for 3 weeks in the S1 group and 4 weeks in the S2 group. Growth efficiency was not significantly different among the three groups in any of the weeks during re-feeding. Compensatory responses in growth and especially feed intake tended to last longer than the recovery of body composition.  相似文献
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号