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861.
Advocates of the self-corrective thesis argue that scientific method will refute false theories and find closer approximations to the truth in the long run. I discuss a contemporary interpretation of this thesis in terms of frequentist statistics in the context of the behavioral sciences. First, I identify experimental replications and systematic aggregation of evidence (meta-analysis) as the self-corrective mechanism. Then, I present a computer simulation study of scientific communities that implement this mechanism to argue that frequentist statistics may converge upon a correct estimate or not depending on the social structure of the community that uses it. Based on this study, I argue that methodological explanations of the “replicability crisis” in psychology are limited and propose an alternative explanation in terms of biases. Finally, I conclude suggesting that scientific self-correction should be understood as an interaction effect between inference methods and social structures.  相似文献   
862.
考虑斑块环境下带有食饵阶段结构和比例依赖的常系数捕食-食饵时滞系统.利用比较原理得出模型解的正性和有界性,并建立该系统在初始条件下的一致持久性.给出食饵种群的非永久持久性的充分条件.  相似文献   
863.
衬底型五级超宽带带状线耦合器的设计   总被引:1,自引:0,他引:1  
设计一种0.35~3.80 GHz频段的6 dB五级超宽带耦合器.耦合器前两级采用衬底型平行耦合带状线结构,后三级采用传统侧边耦合带状线结构.在带状线级联处加载容性开路膜片补偿电路,改善电路的匹配性能,降低器件的回波损耗.衬底型紧耦合结构克服了印刷电路工艺对耦合带状线线间距的限制,且不需要高分辨率的制作过程,也不会引入焊点等不连续性结构.仿真的耦合系数和实测数据有较好的一致性.  相似文献   
864.
以国家火炬计划项目“择易企业管理系统WEB版”的实际应用为背景,阐述了基于WEB的前后台一体化的企业管理系统的总体设计,提出了系统的功能模块要求,描述了系统的技术原理,给出了系统部署的方法;并根据系统特点,提出了系统中多种客户的转换处理方法.  相似文献   
865.
《Journal of Natural History》2012,46(17):1359-1366
The population structure and reproduction of Pilumnus vespertilio were studied for the first time in Mozambique. Random samples of crabs were taken monthly from January to December 2002 from a pebble area of Inhaca Island, southern Mozambique. A clear sexual dimorphism was observed in the present population with males reaching greater sizes than females. Sex ratio was female‐biased, and the monthly size–frequency distributions were often bimodal. The annual reproductive cycle of Pilumnus vespertilio was continuous with peaks of breeding in summer. Results suggest that embryonic development may be synchronized within the population as a result of the very high reproductive activity observed in summer. Juveniles are recruited mostly in winter in the study area.  相似文献   
866.
《Journal of Natural History》2012,46(19-20):1325-1337
The pre-overwintering nest structure and the immature stages of the hornet Vespa fumida van der Vecht are for the first time reported. All three adult forms (queen, worker and drone) are briefly described. The eggs have many micropyles concentrated at the larger end of the egg. The mature larvae can be identified by having the ecdysial sulcus obliterated ventrally; the parietal band distinctly margined ventrally on the outer side; the palate with a median patch and a pair of dorsal patches; the collar processes of the spiracle long and thick, with many branches over almost all the surface. Morphology and distribution of the different types of sensilla (setae, conical papillae, campaniform sensilla, basiconic sensilla, etc.) and the spicules are illustrated in detail. Close relationship between the Vespa affinis-group and V. fumida previously suggested by adult morphology is briefly discussed in terms of the morphology of the mature larvae.  相似文献   
867.
《Journal of Natural History》2012,46(33-34):2131-2144
We recorded species abundance and richness of oribatid mites along 16 plots established in semi-deciduous forest fragments in Amazonia. The results were compared with a published dataset consisting of an inventory carried out in 38 plots in the surrounding savanna. Totals of 143 and 91 species were recorded in the forest fragments and savanna, respectively. Sørensen similarity index between both environments was 0.44. Ordination of sites according to oribatid mite species composition showed a clear separation between forest fragments and savanna. Rostrozetes ovulum, Archegozetes longisetosus and Eohypochthonius (Eohypochthonius) becki were abundant and frequent in the forest fragments but exceedingly rare in the savanna. Neoppia (Neoppia) schauenbergi, Pseudoppia sp. C, Microppia sp. A and Cosmochthonius sp. A were limited to the savanna. This study also represents an early step toward knowing which groups of species are exclusive to one or another vegetation type or are sensitive to their inherent environmental conditions.  相似文献   
868.
在国家提出发展低碳经济的背景下,为了分析低碳约束下青岛市就业结构优化水平,选取青岛市9个行业2004-2015年的数据,通过面板数据模型研究不同行业碳排放强度和就业结构之间的关系。结果表明,青岛市同行业自身的碳排放强度存在差异,与就业人口的关系也存在较大差异。最后根据评价结果,提出调整能源结构、寻找绿色经济增长点以及促进绿色就业从而实现低碳约束下就业结构优化的建议。  相似文献   
869.
870.
采用未淡化的海砂制备超高性能混凝土(UHPC)和普通混凝土,研究了不同氯离子含量的海砂对UHPC抗压强度、孔结构、快速氯离子渗透性以及内置钢筋耐久性的影响,并与普通混凝土进行分析比较。结果表明,海砂中的氯离子含量对UHPC抗压强度并不会产生较大的消极影响;海砂UHPC的临界孔半径约为2 nm,与海砂普通混凝土不同,孔隙率随海砂中氯含量的增加而增加;即使海砂氯离子含量高达0.636%,海砂UHPC的氯离子渗透性仍可忽略不计;海砂UHPC中钢筋在28 d后处于钝化状态并趋于稳定。  相似文献   
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