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81.
On emergence, agency, and organization   总被引:1,自引:1,他引:0  
Ultimately we will only understand biological agency when we have developed a theory of the organization of biological processes, and science is still a long way from attaining that goal. It may be possible nonetheless to develop a list of necessary conditions for the emergence of minimal biological agency. The authors offer a model of molecular autonomous agents which meets the five minimal physical conditions that are necessary (and, we believe, conjointly sufficient) for applying agential language in biology: autocatalytic reproduction; work cycles; boundaries for reproducing individuals; self-propagating work and constraint construction; and choice and action that have evolved to respond to food or poison. When combined with the arguments from preadaptation and multiple realizability, the existence of these agents is sufficient to establish ontological emergence as against what one might call Weinbergian reductionism. Minimal biological agents are emphatically not conscious agents, and accepting their existence does not commit one to any robust theory of human agency. Nor is there anything mystical, dualistic, or non-empirical about the emergence of agency in the biosphere. Hence the emergence of molecular autonomous agents, and indeed ontological emergence in general, is not a negation of or limitation on careful biological study but simply one of its implications.  相似文献   
82.
Collier J 《Bio Systems》2008,91(2):346-354
Anticipation allows a system to adapt to conditions that have not yet come to be, either externally to the system or internally. Autonomous systems actively control their own conditions so as to increase their functionality (they self-regulate). Living systems self-regulate in order to increase their own viability. These increasingly stronger conditions, anticipation, autonomy and viability, can give an insight into progressively stronger classes of models of autonomy. I will argue that stronger forms are the relevant ones for Artificial Life. This has consequences for the design of and accurate simulation of living systems.  相似文献   
83.
84.
Population Ecology - Adult populations of the sugi bark borer,Semanotus japonicus Lacordaire, which attacks the trunks of Japanese cedar and cypress, were studied in two cedar stands in 1981 and...  相似文献   
85.
Defending Robert Rosen's claim that in every confrontation between physics and biology it is physics that has always had to give ground, it is shown that many of the most important advances in mathematics and physics over the last two centuries have followed from Schelling's demand for a new physics that could make the emergence of life intelligible. Consequently, while reductionism prevails in biology, many biophysicists are resolutely anti-reductionist. This history is used to identify and defend a fragmented but progressive tradition of anti-reductionist biomathematics. It is shown that the mathematico–physico–chemical morphology research program, the biosemiotics movement, and the relational biology of Rosen, although they have developed independently of each other, are built on and advance this anti-reductionist tradition of thought. It is suggested that understanding this history and its relationship to the broader history of post-Newtonian science could provide guidance for and justify both the integration of these strands and radically new work in post-reductionist biomathematics.  相似文献   
86.

L'Isopode profond Cirolana borealis présente en milieu expérimental un rythme circadien endogène net d'émergence du sédiment, de géonégativité, et d'activité natatoire. Le rythme a pu être enregistré durant plus de 60 jours consécutifs en obscurité constante. Il se manifeste chez les animaux conditionnés à un éclairement de surface (100 à 10‐5 μW.cm‐2), chez ceux conditionnés à éclairement très réduit (10‐4 à 10‐11 μW.cm‐2), et chez ceux prélevés à ‐ 400 m, et immédiatement expérimentés. La phase d'activité, de durée variable selon les individus, est centrée sur le crépuscule. La période et l'amplitude sont sujettes à de fortes variations individuelles. Généralement inférieure à 24 h chez les animaux conditionnés au laboratoire, la période est le plus souvent supérieure à 25 h chez les animaux provenant directement du milieu naturel. La synchronisation semble essentiellement assurée par les variations lumineuses nycthémérales: un éclairement de valeur diurne provoque une géopositivité permanente et, le plus souvent, un enfouissement au moins partiel des individus, même durant la phase d'activité.  相似文献   
87.
目的:探讨蓝斑区(LC)去甲肾上腺素能神经元在orexin 促麻醉觉醒中作用。方法:应用异氟烷对成年SD 大鼠进行麻醉,15 分钟后,将SD 大鼠随机分为6 组,分别注射orexin-A/B (100pmol/0.3 滋L) 及其溶剂saline (0.3 滋L);orexin I 型受体拮抗剂 SB334867/ II型受体拮抗剂TCS-OX2-29(20 滋g/0.3 滋L及其溶剂DMSO(0.3 滋L),通过观察大鼠翻正反射的消失和恢复时间,研究 蓝斑区微注射orexin 及其拮抗剂对异氟烷麻醉的诱导和觉醒的影响。结果:蓝斑区(LC)微注射四种试剂或其溶剂均对SD 大鼠异 氟烷麻醉的诱导时间无明显影响;蓝斑区(LC)微注射orexin-A 能缩短SD 大鼠异氟烷麻醉觉醒时间(P<0.001),而微注射orexinI 型拮抗剂SB334867 能延长觉醒时间(P<0.001);orexin-B、orexin II型受体拮抗剂TCS-OX2-29 对大鼠异氟烷麻醉的觉醒无明显影 响。结论:蓝斑区(LC)的去甲肾上腺素能神经元介导了orexin 的促麻醉觉醒作用。  相似文献   
88.
Migration between populations can be a major evolutionary force. However, some disagreement exists as to precisely how migration affects population adaptation. Some theories emphasize the inhibitory effects of gene flow between locally adapted populations, whereas others propose that migration can enhance adaptation. Migration has also been theorized to rescue sink populations from extinction. In our experiments, we serially passaged bacteriophage Φ6 host range mutants under sink conditions on a novel host while manipulating the source and number of migrants into these experimental populations. Migrants from two sources were used: mutant Φ6 phage able to infect a novel host (treatment) and wild‐type Φ6 phage unable to infect a novel host (control). We used quadratic regressions to determine the relationship between the number of migrants per passage and the absolute fitnesses of experimental populations following 30 passages. Our results showed that migration from a control population had no effect on absolute fitnesses of our serially passaged populations following 30 passages. By contrast, the relationship between migrants per passage and absolute fitnesses for populations receiving migrants able to infect the novel host was best described by an upwardly concave curve. These results suggest that intermediate levels of migration can have favorable impacts on evolutionary adaptation.  相似文献   
89.
目的:统计全麻术后患者苏醒期躁动(EA)的发生率,并分析其影响因素。方法:本研究为回顾性研究,分析2021年5月~2021年6月期间我院收治的204例全麻手术患者的临床资料,采用躁动-镇静程度量表(RASS)评分评价患者术后是否发生EA,观察全麻术后患者EA发生率,并根据患者术后是否发生EA进行分组,采用logistic回归分析其影响因素。结果:204例患者中有47例发生EA,发生率为23.04%,纳为EA组,剩余的157例未发生EA,纳为非EA组。EA组、非EA组在性别、全麻方式、术前用药、苏醒时间方面对比差异无统计学意义(P>0.05)。EA组、非EA组在年龄、手术类型、手术时间、留置胃管/导尿管、麻醉时间、美国麻醉医师协会(ASA)分级、术后镇痛、术后疼痛方面对比差异有统计学意义(P<0.05)。logistic回归分析结果显示,年龄≥50岁、手术类型为妇科手术或泌尿外科手术、留置胃管/导尿管、ASA分级为Ⅱ级、术后疼痛是EA发生的危险因素,而术后镇痛是EA发生的保护因素(P<0.05)。结论:年龄、手术类型、留置胃管/导尿管、ASA分级、术后疼痛、术后镇痛是全麻术后患者EA发生的影响因素,临床需重点关注并给予相应防控措施。  相似文献   
90.
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