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排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Yeongin Kim Chenxin Zhu Wen-Ya Lee Anna Smith Haowen Ma Xiang Li Donghee Son Naoji Matsuhisa Jaemin Kim Won-Gyu Bae Sung Ho Cho Myung-Gil Kim Tadanori Kurosawa Toru Katsumata John W. F. To Jin Young Oh Seonghyun Paik Soo Jin Kim Lihua Jin Feng Yan Jeffrey B.-H. Tok Zhenan Bao 《Advanced materials (Deerfield Beach, Fla.)》2023,35(1):2203541
Hemispherical image sensors simplify lens designs, reduce optical aberrations, and improve image resolution for compact wide-field-of-view cameras. To achieve hemispherical image sensors, organic materials are promising candidates due to the following advantages: tunability of optoelectronic/spectral response and low-temperature low-cost processes. Here, a photolithographic process is developed to prepare a hemispherical image sensor array using organic thin film photomemory transistors with a density of 308 pixels per square centimeter. This design includes only one photomemory transistor as a single active pixel, in contrast to the conventional pixel architecture, consisting of select/readout/reset transistors and a photodiode. The organic photomemory transistor, comprising light-sensitive organic semiconductor and charge-trapping dielectric, is able to achieve a linear photoresponse (light intensity range, from 1 to 50 W m−2), along with a responsivity as high as 1.6 A W−1 (wavelength = 465 nm) for a dark current of 0.24 A m−2 (drain voltage = −1.5 V). These observed values represent the best responsivity for similar dark currents among all the reported hemispherical image sensor arrays to date. A transfer method was further developed that does not damage organic materials for hemispherical organic photomemory transistor arrays. These developed techniques are scalable and are amenable for other high-resolution 3D organic semiconductor devices. 相似文献
992.
尾气遥测作为一种快速监测技术广泛应用于机动车排放监测,然而其动态检测的准确性评价手段有限。通过对比机动车尾气遥测系统的静态的校准方法,发现燃烧方程的辅助计算可以修正测量数据,克服仪器在动态测试中气体扩散的影响。利用燃烧方程分别归纳了以1,3丁二烯与丙烷为碳氢标志物的标准气体的比例关系,并配制和验证了2种标准气体用于机动车尾气遥测系统的动态准确度检测。研究结果表明符合燃烧方程的标准气体能够更好地表征仪器对低浓度组分动态测量结果的准确性。研究结果可为机动车尾气遥测仪检测用标准气体制备提供指导,优化动态准确度的计量检测条件。 相似文献
993.
994.
DZ Xiang EK Verbeken AT Van Lommel M Stas I De Wever 《Canadian Metallurgical Quarterly》1998,28(2):260-271
PURPOSE: After catheterization, 42% to 100% of central venous catheters are surrounded by a "fibrin sleeve." This sleeve has been considered the cause of catheter-related infections, withdrawal occlusion, and pulmonary embolism. The reactions between the vein wall and the catheter were studied. METHODS: A silicone catheter was placed in the anterior caval vein of 123 rats. After in situ fixation at scheduled intervals, the pathologic changes were studied on semi-serial histologic sections by means of light microscopy, transmission electron microscopy, and scanning electron microscopy (SEM). In 36 rats, the catheter was withdrawn immediately; in 72 rats, it was left in situ up to 6 months; and in 15 rats, the study was performed up to 10 months after withdrawal of a catheter that had remained in situ for 6 months. RESULTS: In the group in which the catheter was withdrawn immediately, mural thrombi disappeared by day 7. In the group in which the catheter remained in situ, thrombi remained around the proximal portion of the catheter. This pericatheter thrombosis (PCT) was invaded by migrating and proliferating smooth muscle cells (SMCs), originating from an injured vein wall, and transformed from day 7 into a tissue composed predominantly of SMCs and collagen and covered by endothelial cells. Later, the number of cells decreased, and the relative amount of collagen increased. Up to 10 months after withdrawal of the catheter, the collapsed sleeve was still present within the vein. CONCLUSION: The sleeve around a central venous catheter is not a fibrin sleeve, but a stable cellular-collagen tissue covered by endothelium. It is mainly formed by smooth muscle cells migrating from the injured vein wall into the early pericatheter thrombus. 相似文献
995.
采用马弗炉和四角燃烧炉对煤中矿物质在加热过程中组分和含量变化利用X-射线衍射进行分析。结果表明,在燃烧炉内煤灰矿物质行为与在马弗炉内加热煤灰的矿物质行为基本一致;煤灰矿物质行为与原煤中矿物组成及含量关系较大。 相似文献
996.
997.
依据GB7714-87《文后参考文献著录规则》,对390篇来稿所引用的参考文献进行统计,分析了几种不规范的著录方式,并给出正确的表达方法,可为科技论文写作者及科技期刊编缉提供参考。 相似文献
998.
Xiang Y 《Applied optics》1998,37(13):2637-2639
One-step two-wavelength holography is obtained with twointerferometric beams with different wavelengths by means of apolarizing modulation produced by a liquid-crystal lightvalve. This holographic method eliminates the need for preliminarystatic recording of the hologram and permits one-step two-wavelengthholographic testing to produce results easily in real time. 相似文献
999.
1000.
In this work, we directly observed the evolution of air/water interfaces suspended between polydimethylsiloxane (PDMS) microlines
when water droplets reduced their sizes due to evaporation. The inclined angles of the microline sidewalls were slightly larger
than 90°. Two important phenomena were observed regarding the transition from Cassie–Baxter to Wenzel States. First, when
a water droplet gradually shrank, an air/water interface between two neighboring microlines increased its deflection but decreased
its angle with the vertical direction. In the meanwhile, the two edges of this interface were still at the top corners of
the two microlines. Second, once water passed the top corners of these two microlines, it kept moving down and filled the
gap. Based on these two phenomena, the equilibrium of a triple line and the uniformity of pressure inside a small water droplet,
critical values of droplet sizes and Laplace pressure were derived to predict when the transition would occur on microlines.
The derived theoretical relationships indicate that air/water interfaces may be stationary on both top corners and sidewalls
of microlines if the inclined angles of the microline sidewalls are less than 90°. Otherwise, the interfaces can only be stationary
at the top corners of the microlines. The predicted values of droplet sizes for the case that the inclined angles of these
sidewalls are larger than 90° were validated by experimental results on three arrays of PDMS microlines. In addition, we also
directly observed the evolution of air/water interfaces on PDMS microlines when a water droplet was slowly pressed using a
glass slide. The critical values of the droplet sizes derived in the case of evaporation applied to this pressing case as
well, and had a good match with experimental results on the three arrays of PDMS microlines. In addition to the cases of evaporation
and pressing, the theoretical relationships derived in this work may also apply to other cases, in which Laplace pressure
is gradually increased inside a liquid droplet and half sizes of the droplet are less than the capillary length of the liquid.
Finally, based on developed transition criteria, a set of criteria were also proposed to design microlines for reducing the
critical droplet size that triggers the transitions from Cassie–Baxter to Wenzel States. 相似文献