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141.
In order to observe three-dimensional (3D) expression patterns of genes in whole animals, whole organs, or whole tissues, in situ hybridization (ISH) of many sections must be carried out and then used to construct a 3D image. For this purpose, we have developed an automatic microtome to prepare tissue sections with an adhesive film. We used commercially available film suitable for sectioning and ISH. We constructed a microtome and, after adherence of the film to a paraffin-embedded tissue block, cut the block with a blade to prepare sections on film. Then, the sections-on-film were automatically set in a plastic frame that was the same size as a conventional glass slide. With this automatic microtome, tissue sections can be made for ISH or immunohistochemistry in addition to conventional hematoxylin and eosin staining without specific training. We demonstrate that we can construct 3D images of gene expression patterns obtained by ISH on sections prepared with this automatic microtome. We have designated this method as 'Film Tomography (FITO)'.  相似文献   
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提出了一种基于独立元分析(ICA)的视觉皮层简单细胞工作机制的模型。用Gabor函数逼近对自然图像进行ICA而获得的基函数,揭示了ICA基函数与视觉皮层简单细胞感受野反应间存在内在的关系。并对水平条纹的图像进行ICA,模拟在特殊视觉环境下生长的幼年动物的视觉皮层发育过程,证实了1970年Blakemore和Cooper在幼猫上的实验结果。从而说明ICA可以模拟动物的视觉皮层简单细胞工作过程。  相似文献   
143.
城市森林发挥着改善和维护城市生态环境质量的作用, 研究城市森林生物量和分布特点对其生态系统服务评价和林分经营均具有重要意义。该文根据上海城市森林的种植分布和经营状况利用2011年6月-2012年6月样地实测森林生物量数据和同期Landsat ETM+遥感图像, 在基于逐步回归分析建立森林生物量反演模型的基础上, 引入回归残差及空间分析, 研究了城市森林及其主要优势树种樟(Cinnamomum camphora)林分的生物量分布特征, 探讨了区域尺度森林生物量的遥感估测方法。结果表明: (1)上海城市森林生物量密度总体呈现中心城区(静安区、黄浦区等)较高, 生物量密度集中在35-70 t·hm-2之间, 郊区(嘉定区、青浦区等)空间分布状况相对较低, 生物量密度介于15-50 t·hm-2之间的变化特征。上海优势树种樟林分生物量密度范围为20-110 t·hm-2; 空间上呈现出东北部较高、西南部较低的变化特征。(2)上海城市森林及樟林分的生物量总量分别为3.57 Tg和1.33 Tg。林地面积小, 具有较高森林生物量密度的上海中心城区, 其森林生物量占总量的6.1%, 其中林地面积最小的静安区生物量最低, 仅占总量的0.11%。在所有区县中, 林地面积最大的崇明县、浦东新区具有较高的森林生物量, 分别占总量的20.08%和19.18%。(3)所建立的基于回归反距离插值的城市森林生物量估测模型, 其标准误差、平均绝对误差、平均相对误差分别为8.39、6.86、24.22%, 较回归模型分别降低了57.69%、55.43%、64.00%, 较空间插值的方法分别降低了62.21%、58.50%、65.40%。残差的引入减少了由于空间变异引发的城市森林生物量遥感估测的不确定性。相比基于实测数据通过空间插值的估测, 遥感为快速便捷、客观高效的森林生物量监测提供了可能, 更加完善的结果和模型的优化有待引入其他信息源如高分高光谱信息或改善残差空间分析方法获得。  相似文献   
144.
Although many previous studies have shown that eye-like images promote generosity, the mechanism of this “watching eyes effect” remains unclear. One possible cause is the concern for a good reputation as a generous person, while the other is the concerns for a bad reputation as a norm violator. To elucidate which of these two concerns is the main influencer, the present study conducted a laboratory experiment that investigated whether the watching eyes effect changed depending on social norms. If the concern for a good reputation leads to the effect, prosocial behavior would be more likely in the presence of watching eyes, regardless of the social norms involved. However, if the concern for avoiding a bad reputation as a norm violator leads to the effect, watching eyes promote prosocial behavior only in the existence of prosocial norms. In the original study, participants were asked to make a charitable donation under conditions in which eye-like images either were or were not present. In addition to the eye-like images, we manipulated prosocial norms by informing each participant of either high or low mean donation amounts given by previous participants. We found that watching eyes promoted donations only when a prosocial norm existed. This supports the idea that the watching eyes effect is caused by a concern for avoiding a bad reputation from violating norms. However, in a replication study, we were unable to replicate the original results; watching eyes did not promote generosity regardless of the norm. Taken together, we discussed the moderation effect of norms and the possibility of other moderators.  相似文献   
145.
Fluctuating asymmetry (FA), deviation from perfect bilateral symmetry, is thought to reflect an organism's relative inability to maintain stable morphological development in the face of environmental and genetic stressors. Previous research has documented negative relationships between FA and attractiveness judgments in humans, but scant research has explored relationships between the human voice and this putative marker of genetic quality in either sex. Only one study (and in women only) has explored relationships between vocal attractiveness and asymmetry of the face, a feature-rich trait space central in prior work on human genetic quality and mate choice. We therefore examined this relationship in three studies comprising 231 men and 240 women from two Western samples as well as Hadza hunter–gatherers of Tanzania. Voice recordings were collected and rated for attractiveness, and FA was computed from two-dimensional facial images as well as, for a subset of men, three-dimensional facial scans. Through meta-analysis of our results and those of prior studies, we found a negative association between FA and vocal attractiveness that was highly robust and statistically significant whether we included effect sizes from previously published work, or only those from the present research, and regardless of the inclusion of any individual sample or method of assessing FA (e.g., facial or limb FA). Weighted mean correlations between FA and vocal attractiveness across studies were ?.23 for men and ?.29 for women. This research thus offers strong support for the hypothesis that voices provide cues to genetic quality in humans.  相似文献   
146.
‘Controlling images’ are central to the reproduction of racial, class, and gender inequality, yet there is a dearth of knowledge pertaining to Latinos. Drawing from sixty-two in-depth, life history interviews with Latino men, we ask: How do controlling images of Latinos as gang members and sports athletes impose constraints and channel emotions? How do Latinos respond to these images? We document how institutions and people deploying controlling images blockade access to education and upward mobility. We find that life course stage shapes Latinos’ responses to this imagery. In their youth, Latino respondents used emotional strategies to resist racial subjugation. As adults, respondents resisted racist controlling images through leadership activities in the professional realm. Since adults possess more social power than youth, adults were better equipped to engage in leadership endeavours as resistance as compared to youth who, constrained by age, predominately utilized emotional resistance strategies.  相似文献   
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