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31.
New record of predatory behavior by the mandrill in Cameroon   总被引:4,自引:0,他引:4  
The predatory behavior of the mandrill (Mandrillus sphinx,Linnaeus 1758), a forestliving baboon, on the bay duiker (Cephalophus dorsalis,Gray 1864) was observed under natural conditions. In the predatory episode, at least two mandrills (one adult female and one adult male) attacked a bay duiker, but no overt aggressive interactions between the attackers occurred during consumption. The estimated predation pattern based on scars—intensive attacking of the head and pulling of the hind legs to eat the thigh muscles first—resembled the predation patterns of captive mandrills observed experimentally. The findings suggest that the predatory behavior is established in mandrills as a feeding behavior pattern as in savanna-living baboons. New data are thus presented which are relevant to the discussion of the origins of hunting behavior in early hominids.  相似文献   
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Question: Does measurement of plant cover have consistent and comparable definitions in its applications for vegetation response in monitoring and research? Methods: A survey of the sources of definitions of cover was completed to determine common definitions and evaluate the comparability of the resulting cover methods between 1950 and 2007. Results: Methods for estimating and defining cover have varied, and relatively few citations often form the core of widely used sampling methods. Three common definitions were derived: Aerial cover – the proportion of each species at the uppermost surface of the vegetation (e.g., the aerial view), Species cover – the cover of the upper layer of each plant species independent of overhanging cover of other species, and Leaf cover – all the layers of each species from the uppermost surface to the surface of the soil (related to leaf area index). Aerial cover is the least time consuming and most easily linked to imagery, but emphasizes the dominant plants. Species cover better expresses the response of individual species but can be substantially more time consuming than aerial cover. Leaf cover correlates well to plant volume, biomass, and physiology, but can be prohibitively time consuming to collect. Conclusions: For common monitoring goals, such as species immigration (invasion) and emigration (loss of desired species), species cover can be a better choice. Publications often do not distinguish the type of cover being reported and this can lead to difficulty because the three cover methods do not result in directly comparable data, except in some unusual situations.  相似文献   
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Glucocorticoids (GCs) have been related to social rank in many studies across species, a particular rank giving rise to a particular stress-related physiological profile. Our aim was to examine the hypothesis that GCs levels in toddlers would be related to social dominance in a competitive resource situation. Subjects were 376 toddlers from the Quebec Newborn Twin Study. At 19 months of age, each subject was exposed to 2 unfamiliar situations known to be moderately stressful at that age. Saliva was collected before and after the unfamiliar situations, to assess pre-test and reactive cortisol. Then the toddler reaction to a competitive situation for a toy with an unfamiliar peer was assessed and we measured the proportion of time the child controlled the resource. In girls, no association between cortisol levels and the proportion of time the child got the toy was found. On the other hand, in boys, increased cortisol levels before the unfamiliar situation were significantly related to a decreased proportion of time they got the toy in the competitive situation (r174 = − 0.17, P = 0.02). These results show that even in toddlers with limited social experience, association between GCs levels and social dominance can be found, an association that is specific to boys.  相似文献   
35.
赵士洞  任毅 《生物多样性》2001,9(2):196-200
生物多样性观察年(IBOY)的核心项目包括4个大的主题:1)全球生物多样性现状;2)生物多样性的变化方式;3)生物多样性对人类生活的价值;4)人类如何保护生物多样性。本文对这些主题内的不同课题进行了介绍,同时对我国生物多样性科学的发展提出了相应的建议。  相似文献   
36.
现代人头骨面部几项非测量性状的观察   总被引:4,自引:3,他引:1  
用人类学观察法比较了中国云南、华北和欧洲现代人头骨的犬齿窝、颧骨缘突和梨状孔上外侧部膨隆的出现情况,以探讨其在人种、群体区分上是否有意义。结果:(1)在云南头骨,犬齿窝、颧骨缘突的出现率无性别差异,梨状孔上外侧部骨表面膨隆的出现率男性明显高于女性,而在欧洲头骨,这3项非测量必状的出现率男女间无差异。(2)上述3项性状,在中国云南和华北头骨(男性)的出现率无差异。(3)犬齿窝、梨状孔上外侧部骨表面膨隆的出现率,在现代欧洲人头骨明显高于现代中国人头骨。颧骨缘突的出现率在欧洲与中国现代人头骨上无差异。  相似文献   
37.
Chemical signals influence the selection of potential nest cavities by honey bee reproductive swarms. Attractants for swarms include the odors of old dark honey bee brood combs, odors from noncomb hive materials and propolis, and Nasonov pheromone, the odor released from the Nasonov glands of worker bees. Based on crossover and choice test experiments, swarms were shown to prefer, among otherwise identical cavities, those cavities containing Nasonov pheromone over cavities with only comb or other hive odors, cavities containing old comb over those with only noncomb odors or propolis, and cavities containing noncomb odors or propolis over those without bee or hive odor. Synergy between odors was not observed; that is, comb and/or noncomb hive odors did not enhance the attractiveness of Nasonov pheromone. The data support a model based on a hierarchy of olfactory attractants used by honey bee swarms, in order of highest to lowest: Nasonov pheromone, comb odor, noncomb and propolis odors, and, finally, absence of bee- or hive-produced odor.  相似文献   
38.
In a birth cohort living in Chitwan Valley, lowland Nepal, we have previously reported inverse associations between in utero levels of lead (Pb), arsenic (As) and neurodevelopment at birth measured by the Brazelton Neonatal Behavioral Assessment Scale, third edition (NBAS III). In the present paper, a follow-up of the same cohort was made on 24-month-old infants regarding the neurodevelopmental effects of these metals, taking the postnatal environment into account. In total, the same100 mother-infant pairs as the previous study, whose Pb, As, and Zn concentrations in cord blood were known, were recruited. Postnatal raising environment was evaluated using the Home Observation for Measurement of Environment (HOME) scale. Neurodevelopment of children at 24 months of age (n = 74) was assessed using the Bayley Scale of Infant Development, Second Edition (BSID II). Multivariable regression adjusting for covariates was performed to determine the associations of in utero levels of toxic and essential elements and the home environment with neurodevelopment scores. Unlike the NBAS III conducted for newborns, none of the BSID II cluster scores in 24-month-old infants were associated with cord blood levels of Pb, As, and Zn. The total HOME score was positively associated with the mental development scale (MDI) score (coefficient = 0.67, at 95% CI = 0.03 to 1.31). In this cohort, a detrimental effect of in utero Pb and As on neurodevelopmental indicators observed at birth disappeared at 24 months, while an association between neurodevelopment and home environment continued.  相似文献   
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目的:探讨单侧外固定架对不同部位胫腓骨严重开放性骨折的临床治疗效果及关节恢复功能情况。方法:回顾性分析我院自2013年1月至2015年1月共收治胫腓骨严重开放骨折行单侧外固定术治疗患者,根据骨折部位的不同将所有病例分为三组,A组12例,为胫腓骨近端骨折或波及膝关节,固定时需要跨膝关节固定,B组30例,为胫腓骨中段骨折,固定时不跨关节,C组18例,为胫腓骨远端骨折或波及踝关节,固定时需跨踝关节固定。分别对其进行单侧外固定架手术治疗,术后对所有患者骨折愈合情况及膝、踝关节活动度统计,对比观察各组手术疗效。结果:所有手术均获得成功,无不良事件发生,A组下肢功能优良率为83.3%;B组为96.7%;C组为83.3%。下肢功能恢复情况B组与A、C组相比差异具有统计学意义(P0.05),A组与C组相比差异无统计学意义(P0.05)。A组膝、踝关节功能恢复优良率分别为膝66.7%,踝91.7%;B组为膝93.3%,踝96.7%;C组为膝94.4%,踝72.2%。膝关节功能恢复情况A组与B、C组相比差异具有统计学意义(P0.05),B组与C组相比差异无统计学意义(P0.05)。踝关节功能恢复情况C组与A、B组相比差异具有统计学意义(P0.05),A组与B组相比差异无统计学意义(P0.05)。结论:单侧外固定架对不同部位胫腓骨严重开放性骨折的治疗效果良好,关节恢复情况满意,值得临床推广。  相似文献   
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