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排序方式: 共有8142条查询结果,搜索用时 84 毫秒
141.
142.
Laurà R Magnoli D Zichichi R Guerrera MC De Carlos F Suárez AÁ Abbate F Ciriaco E Vega JA Germanà A 《Microscopy research and technique》2012,75(3):359-366
The zebrafish pineal gland plays a fundamental role in the regulation of the circadian rhythm through the melatonin secretion. The pinealocytes, also called photoreceptive cells, are considered the morphofunctional unit of pineal gland. In literature, the anatomical features, the cellular characteristics, and the pinealocytes morphology of zebrafish pineal gland have not been previously described in detail. Therefore, this study was undertaken to analyze the structure and ultrastructure, as well as the immunohistochemical profile of the zebrafish pineal gland with particular reference to the pinealocytes. Here, we demonstrated, using RT-PCR, immunohistochemistry and transmission electron microscopy, the expression of the mRNA for rhodopsin in the pineal gland of zebrafish, as well as its cellular localization exclusively in the pinealocytes of adult zebrafish. Moreover, the ultrastructural observations demonstrated that the pinealocytes were constituted by an outer segment with numerous lamellar membranes, an inner segment with many mitochondria, and a basal pole with the synapses. Our results taken together demonstrated a central role of zebrafish pinealocytes in the control of pineal gland functions. 相似文献
143.
Mario Simoes Correia Antonio Sousa Miranda Marta Cristina Oliveira Carlos Alexandre Capela Antonio Sergio Pouzada 《The International Journal of Advanced Manufacturing Technology》2012,59(9-12):977-986
The ejection force of injection-moulded thermoplastics depends on the contact conditions at the moment of ejection. Replication of the polymer part surface occurs onto the mould surface during injection of the melt. Ejection takes place in a very short time, hence the static coefficient of friction must be considered for modelling the ejection process. To understand the contribution of the mechanisms involved in the friction during the ejection stage, a mixed approach was followed: analytical simulation of the ploughing, numerical simulation of the deformation, and experimental inference of the adhesion. The relevance of roughness, temperature and contact pressure in the coefficient of friction was evidenced. 相似文献
144.
Tian Gao Emmanuel Siéfert Antonio DeSimone Benoît Roman 《Advanced materials (Deerfield Beach, Fla.)》2020,32(47):2004515
Many active materials used in shape-morphing respond to an external stimulus by stretching or contracting along a director field. The programming of such actuators remains complex because of the single degree of freedom (the orientation) in local actuation. Here, texturing this field in zigzag patterns is shown to provide an extended family of biaxial active stretches out of an otherwise single uniaxial active deformation, opening a larger parameter space. By further modulating the zigzag patterns at the larger scale of the structure, its deployed shape can be controlled. This notion of texturing over hierarchical length scales follows geometrical principles, and is robust against changes in size and materials. The robustness of the approach is demonstrated by considering three different responsive materials: inextensible flat fabrics, channel-bearing elastomer (respectively, contracting and expanding perpendicularly to the director field when actuated pneumatically), and 3D-printed thermoplastic (composed of extruded filaments that contract when heated). It is shown that large-scale shape-morphing structures can be generated and that their geometry can be controlled with high accuracy. 相似文献
145.
Rubén Ibáñez Amine Ammar Elías Cueto Antonio Huerta Jean-Louis Duval Francisco Chinesta 《International journal for numerical methods in engineering》2019,120(6):727-747
Solutions of partial differential equations could exhibit a multiscale behavior. Standard discretization techniques are constraints to mesh up to the finest scale to predict accurately the response of the system. The proposed methodology is based on the standard proper generalized decomposition rationale; thus, the PDE is transformed into a nonlinear system that iterates between microscale and macroscale states, where the time coordinate could be viewed as a 2D time, representing the microtime and macrotime scales. The macroscale effects are taken into account because of an FEM-based macrodiscretization, whereas the microscale effects are handled with unidimensional parent spaces that are replicated throughout the domain. The proposed methodology can be seen as an alternative route to circumvent prohibitive meshes arising from the necessity of capturing fine-scale behaviors. 相似文献
146.
María Luz Gmiz Antonio Jesús Lpez‐Montoya María Dolores Martínez‐Miranda Rocío Raya‐Miranda 《Quality and Reliability Engineering International》2019,35(1):99-115
The objective of this paper is to find out possible patterns of failure occurrences in a repairable system. We develop a graphical exploratory tool and perform visual inference considering non‐parametric local linear kernel estimators for the rate of occurrence of failures (ROCOF) and its first derivative. The shape characteristics of the ROCOF function are distinguished from those which are merely an artefact of the sampling variability of the data through the construction of confidence intervals for the first derivative. The proposal is illustrated with several real data sets, and its performance is evaluated through an extensive simulation study. 相似文献
147.
Yao Chen Wei Huang Vinod K. Sangwan Binghao Wang Li Zeng Gang Wang Yan Huang Zhiyun Lu Michael J. Bedzyk Mark C. Hersam Tobin J. Marks Antonio Facchetti 《Advanced materials (Deerfield Beach, Fla.)》2019,31(4)
High‐performance solution‐processed metal oxide (MO) thin‐film transistors (TFTs) are realized by fabricating a homojunction of indium oxide (In2O3) and polyethylenimine (PEI)‐doped In2O3 (In2O3:x% PEI, x = 0.5–4.0 wt%) as the channel layer. A two‐dimensional electron gas (2DEG) is thereby achieved by creating a band offset between the In2O3 and PEI‐In2O3 via work function tuning of the In2O3:x% PEI, from 4.00 to 3.62 eV as the PEI content is increased from 0.0 (pristine In2O3) to 4.0 wt%, respectively. The resulting devices achieve electron mobilities greater than 10 cm2 V?1 s?1 on a 300 nm SiO2 gate dielectric. Importantly, these metrics exceed those of the devices composed of the pristine In2O3 materials, which achieve a maximum mobility of ≈4 cm2 V?1 s?1. Furthermore, a mobility as high as 30 cm2 V?1 s?1 is achieved on a high‐k ZrO2 dielectric in the homojunction devices. This is the first demonstration of 2DEG‐based homojunction oxide TFTs via band offset achieved by simple polymer doping of the same MO material. 相似文献
148.
Cristino Talita Mariane Faria Neto Antonio Costa Antonio Fernando Branco 《Scientometrics》2018,114(3):1275-1326
Scientometrics - This study uses bibliometrics methods to analyze the specialized literature of energy efficiency in buildings, including the Scopus database during the period of time ranging from... 相似文献
149.
Chinchilla-Rodríguez Zaida Miguel Sandra Perianes-Rodríguez Antonio Sugimoto Cassidy R. 《Scientometrics》2018,115(3):1485-1504
Scientometrics - International collaboration in the creation of knowledge is changing the structural stratification of science, with implications for science policy. Analyses of collaboration in... 相似文献
150.