首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
2.
Frank SA 《Nature》2003,425(6955):251-252
  相似文献   

3.
为了适应现代农业发展要求,对植物保护专业课《农业植物病理学》进行了一系列的教学改革。以面向21世纪课程教材《农业植物病理学》(北方本)为基础,结合新疆地域特点,通过调整课程结构和课时比例,合理使用Powerpoint多媒体课件等现代化教学手段,积极推进启发式、参与式和讨论式等教学方法,调整充实具有新疆特色的病害内容,以及完善课程教学环境和改革教学效果评价体系等措施,通过几年的教学探索,明显地提高了课程的教学质量。  相似文献   

4.
5.
Cyranoski D 《Nature》2007,446(7136):598-599
  相似文献   

6.
Patek SN  Korff WL  Caldwell RL 《Nature》2004,428(6985):819-820
Stomatopods (mantis shrimp) are well known for the feeding appendages they use to smash shells and impale fish. Here we show that the peacock mantis shrimp (Odontodactylus scyllarus) generates an extremely fast strike that requires major energy storage and release, which we explain in terms of a saddle-shaped exoskeletal spring mechanism. High-speed images reveal the formation and collapse of vapour bubbles next to the prey due to swift movement of the appendage towards it, indicating that O. scyllarus may use destructive cavitation forces to damage its prey.  相似文献   

7.
Cancer. A deadly inheritance   总被引:10,自引:0,他引:10  
B Vogelstein 《Nature》1990,348(6303):681-682
  相似文献   

8.
9.
10.
Carnivorous pitcher plants of the genus Nepenthes are not usually very selective about their prey, catching anything that is careless enough to walk on their slippery peristome, but Nepenthes albomarginata is an exception. We show here that this plant uses a fringe of edible white hairs to lure and then trap its prey, which consists exclusively of termites in enormous numbers. This singular feature accounts for the specialization of N. albomarginata for one prey taxon, unique so far among carnivorous plants.  相似文献   

11.
CD95's deadly mission in the immune system   总被引:91,自引:0,他引:91  
Krammer PH 《Nature》2000,407(6805):789-795
Apoptosis in the immune system is a fundamental process regulating lymphocyte maturation, receptor repertoire selection and homeostasis. Thus, death by apoptosis is as essential for the function of lymphocytes as growth and differentiation. This article focuses on death receptor-associated apoptosis and the role of CD95 (Apo-1/Fas)-mediated signalling in T-cell and B-cell development and during the course of an immune response. Gaining an insight into these processes improves our understanding of the pathogenesis of diseases such as cancer, autoimmunity and AIDS, and opens new approaches to rational treatment strategies.  相似文献   

12.
改革植物病理学实验教学提高学生动手和创新能力   总被引:5,自引:0,他引:5  
针对传统教学方法造成的学生对植物病理学实验兴趣不高,缺乏主动性等问题,在如何激发学生学习兴趣,提高实验教学的质量和效率等方面笔者进行了一些有益的尝试。结果表明,学生在实验中,其实验操作技能、分析问题和解决问题的能力得到很大地提高,同时提高了专业素质,激发了学习兴趣。  相似文献   

13.
Amelino-Camelia G 《Nature》2007,450(7171):801-803
  相似文献   

14.
针对客户同时有集货和送货需求时的定位路线问题,建立数学模型,设计两阶段启发式算法。第一阶段为定位配给问题,采用禁忌搜索算法,避免陷入局部最优;第二阶段为集配货一体化车辆路线问题,采用模拟退火算法,具有强收敛性,可以得到全局优化解;然后将两个阶段进行很多次循环迭代最终求得集配货一体化多站点定位路线问题的优化解。通过实例计算验证该启发式算法的可行性和有效性。  相似文献   

15.
16.
Focus on filaments: embryology to pathology   总被引:1,自引:0,他引:1  
B Lane  B Anderton 《Nature》1982,298(5876):706-707
  相似文献   

17.
18.
Wadman M 《Nature》2007,445(7130):800-801
  相似文献   

19.
20.
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