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1.
Four experiments studied 5 species of Larus gulls in England, Argentina, and the US to learn more about the relation between visibility, inter-nest distance, and aggression. Four of the species normally nest in marshes with vegetation that varies in density, structure, and placement, whereas the 5th species nests in a variety of habitats. Photographs taken with a fish-eye lens were used to measure visibility from gull nests. For all species the nearest neighbors nested in the direction of least visibility, and inter-nest distance directly related to visibility. The relation between the nearest neighbor and visibility varied for all species and related to the structure of the vegetation. Herring gulls nesting in habitats similar to those of the marsh-nesting species had equivalent relations between inter-nest distance and visibility. The amount of aggression increased when all vegetation was removed in experiments with 3 species. Given that visibility affects inter-nest distance and aggression levels, it indirectly affects the size and shape of gull territories. (47 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

2.
Testing model nesting and equivalence.   总被引:1,自引:0,他引:1  
When using existing technology, it can be hard or impossible to determine whether two structural equation models that are being considered may be nested. There is also no routine technology for evaluating whether two very different structural models may be equivalent. A simple nesting and equivalence testing (NET) procedure is proposed that uses random sample and model-reproduced moment matrices to evaluate both model nesting and equivalence. The analysis is “local” rather than “global” in nature, but its use with simulation or bootstrapping can imply global conclusions. Two standard applications of NET are to verify whether or not two proposed models are equivalent and whether a baseline model used in an incremental fit index is appropriately nested. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

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This article examines 2–3-year-olds' responses to specific (e.g., "Where did he go?") and neutral (e.g., "What?") requests for clarification. The focus is on children's ability to locate the linguistic errors that provoked neutral questions of clarification and their success in providing appropriate repair. It is argued that this behavior provides evidence for a speech monitor that detects errors and enables repair. Contrary to A. Karmiloff-Smith's (1992) claim, control over the production and comprehension of specific structures does not necessarily precede monitoring. Rather, metalinguistic abilities that are implicated in speech monitoring develop simultaneously with the acquisition of primary linguistic behavior and do not require awareness. It is claimed that such metaprocesses are fundamental to the use of language as a vehicle for the expression of intentional content. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

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A synthesis of previous studies suggests that food-storing birds are able to remember the spatial locations of large numbers of scattered caches for periods ranging from a few days to several months and use visual cues to do so. The birds can perform a number of operations on the remembered set of storage sites, including recalling which caches have been previously exploited and which have been lost to other animals. The behavior of food-storing birds is compared with that of other animals in laboratory studies of memory with respect to the number of items that can be recalled, the length of retention intervals, and serial-position effects. (French abstract) (62 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

7.
A breeding biology study of a genetically unselected variety of Muscovy duck Cairina moschata was conducted in an experimental duck unit in Maputo, Mozambique (25 degrees 58' S, 32 degrees 35' E), to gain insight into factors affecting hatchability during natural incubation. Nesting and incubation behaviors were recorded by daily nest visits. Of 1,338 nests investigated, 70% were incubated until hatching. In 23% of the incubated nests, eggs were laid by more than one duck in the same nest, indicated as dump nests. Artificial dump nests (15% of the incubated nests) were created by adding eggs (690 eggs) from nests abandoned by the duck before incubation had started. A total of 37% of the incubated nests contained eggs that were laid after the onset of incubation (nonterm eggs). Similar hatching rate was found between ducks raised in parks with or without access to swimming water. No significant difference was found in hatchability between normal (0.76) and dump nests (0.77). Artificial dump nests showed higher hatching rates than nests containing nonterm eggs. Dump nesting appears to be a reproductive strategy used by the Muscovy duck to enhance duckling production. Hatching rate was strongly influenced by the length of laying period (period between the ovoposition of the first egg until the onset of incubation) and reproduction cycle (laying period and incubation period). Hatchability was higher for clutches with a shorter reproduction cycle. It is concluded that nesting behavior of the domesticated Muscovy duck is similar to that of its wild ancestor.  相似文献   

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在电化学工作站AUTOLAB 上采用三电极体系以循环伏安法、计时电流法和计时电位法研究了LiF-SrF2-SrO熔盐体系于1253 K温度下锶在钨电极上的电化学还原过程及其控制步骤.研究结果表明:Sr2+在钨电极上的还原过程是一步得两个电子的准可逆反应,析出电位在-1.0 V 附近.阴极过程受离子的扩散步骤控制,计算得出扩散系数为6.07×10-5 cm2/s.  相似文献   

10.
Conditioned 6 chickens, 6 pigeons, and 5 ring-billed gulls, all with 1 eye covered, to withdraw from a previously neutral visual stimulus. Subsequent testing with the trained eye covered and the control eye open showed that transfer or nontransfer of conditioning was a function of the particular aversive stimulus used in conditioning; that is, transfer resulted when shock was used as the UCS but did not occur when the UCS was a rapidly looming visual stimulus or a loud noise. However, when both eyes of an S had been exposed to the conditioning procedure and then the response extinguished by repeatedly presenting the conditioned stimulus to 1 eye only, the conditioned response remained strong for the control eye regardless of the UCS used in the initial training. These findings were consistent regardless of the order of treatments, and no substantive differences among the 3 species were apparent. (24 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

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Twelve infants, aged 16–25 weeks and formerly breast-fed, were tested for their preference for the taste of salt in the first food fed to them. Preference was found to decline with infant age. Because preference for salted food is known to relate to dietary experience of salt in 6-month-old infants, this decline suggests that an initial salt preference is modified by exposure to a low-sodium diet, that is, breast milk. Infant feeding behaviors were found to be a reliable indicator of satiety, and they were also found to differ according to taste preference. (PsycINFO Database Record (c) 2011 APA, all rights reserved)  相似文献   

13.
The effects of subfornical organ (SFO) lesions on salt and water intakes after sodium depletion were studied. Water and salt intakes were measured over 45 hr during a regimen that combined furosemide diuresis and access to low-sodium diet. Water was solely available for 23 hr after diuresis, and water and 0.3 M NaCl solution were available in choice for the next 22 hr. After diuresis, rats with SFO lesions drank significantly less water in 2 hr than controls but achieved equivalent water and sodium balances before salt access 20 hr later. After salt access, rats with SFO lesions drank significantly less saline and water in 2 hr than controls but had similar saline and water intakes over the next 20 hr. Thus, SFO lesions blunted acutely, but not chronically, saline and water intakes to sodium depletion, and the blunted intakes are not explainable by hydrational status. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

14.
采用气氛烧结技术制备NiFe2O4-xNiO复合陶瓷材料(x为复合陶瓷中NiO的质量分数,%.x-0、5、10、17、25),并以该材料作阳极进行960℃的铝电解实验.分析烧结体的显微结构和物相组成以及电解试样的表层形貌与成分,研究NiO的添加对NiFe2O4陶瓷烧结性能和电解腐蚀性能的影响,并对该材料的烧结机制和熔盐腐蚀行为进行探讨.结果表明:氮气气氛下1 300℃烧结的NiFe2O4-NiO复合陶瓷存在NiO和NiFe2O4两种物相,NiO相含量高于理论值;NiFe2O4陶瓷的相对密度为98.54%,添加NiO后复合陶瓷材料的相对密度有所下降,但仍保持在95%以上;电解过程中阳极表面形成不含NiO相的致密保护层,阻止电解质熔盐的渗透;保护层厚50~80 μm,为含Al的尖晶石NiFe2O4相;随着NiO含量增加,阳极表面的致密层变得越发不平整.  相似文献   

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摘要:利用失重法,结合显微形貌、能谱分析、X射线衍射、电化学测试等手段,分析了中铬钢在高温高压含有CO2的盐溶液环境中腐蚀的萌生与发展,以及热处理工艺对中Cr钢的耐蚀性能影响规律。结果显示:7%Cr(质量分数)钢在有CO2的盐溶液中的腐蚀以点蚀为开端,随后形成由Cr(OH)3和FeCO3组成的非晶态产物膜,产物膜外层有颗粒状FeCO3附着,随着Cr(OH)3的大量产生产物膜中部分FeCO3溶解,随后CaCO3沉淀填补了颗粒状FeCO3溶解后留下的空隙。热处理后淬火试样耐蚀性最好,正火次之,轧制试样最差。  相似文献   

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Stereotyped fixed action patterns (FAPs) elicited in rats by oral infusions of taste solutions can be classified as either ingestive or aversive. They reflect the palatability of the taste and can be modified by learning and by the physiological state of the animal. The present 2 experiments, with 5 male Sprague-Dawley rats, demonstrated that when the physiological state of the S was altered by sodium depletion, the pattern of FAPs elicited by oral infusions of 0.5 M NaCl shifted from a mixture of ingestive and aversive components (while sodium replete) to exclusively ingestive ones (while sodium deplete). This shift in taste reactivity occurred the 1st time the Ss were made sodium deplete. A similar shift did not accompany infusions of 0.01 M HCl, a taste solution that also elicited mixed ingestive and aversive FAPs. This result suggests that the shift in response to NaCl was not due to a general change in ingestive bias or to a general taste deficit. On the basis of the change in FAPs, it is concluded that the palatability of highly concentrated salt solutions increases in sodium-deplete rats. Such a shift in salt palatability may be instrumental in directing the appetitive behavior of the animal. (33 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

18.
采用交流阻抗谱研究热风整平无铅喷锡处理印制电路板(PCB-HASL)和无电镀镍金电路板(PCB-ENIG)在盐雾环境下的电化学腐蚀行为,并结合体式学显微镜、扫描电镜、X射线能谱等手段分析两种不同表面处理工艺电路板的腐蚀产物形貌、组成和镀层失效机制.结果表明:盐雾环境下,PCB-HASL和PCB-ENIG均发生严重腐蚀;镀Sn层开始发生局部腐蚀,随后几乎整个表面都发生腐蚀,出现类似均匀腐蚀的现象,镀金板主要发生微孔腐蚀.在PCB-HASL腐蚀过程中,Cl-的侵蚀作用促进Sn层的腐蚀,后来由于逐渐形成大量的覆盖在镀层表面的腐蚀产物,使得腐蚀速率降低;而在PCB-ENIG腐蚀过程中,微孔处形成含Cl-电解质薄液层,Ni与Au构成腐蚀电偶,从而加速Ni的腐蚀,最终使Cu基底裸露,造成电路板失效.  相似文献   

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Considers that a question of the highest developmental and perceptual significance launched the experimental analysis of imprinting: How do animals come to identify members of their own species in the course of ontogeny? As laboratory research on imprinting in birds has become more and more removed from that primary question, it has neglected certain fundamental natural history and neuroembryological facts which are basic to the study of the development of species-specific perception in birds and perhaps other animals. These problems are discussed in the context of an empirical review of the development of the auditory and visual components of species identification in wild and domestic ducklings. (37 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

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