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31.
We have investigated the sputtering by fission fragments of Cu, Al and Nb doped with 0.1 at % 235U and bombarded with thermal neutrons. This was primarily a search for micron-size particles emitted from the surfaces of the doped sources. Kaminsky et al. have observed large particles (several microns in size) emitted from the surface of samples bombarded by 14 MeV neutrons, with a maximum knock-on energy of 600 keV in Nb. The fission energy deposition of 200 MeV should be more than adequate to yield any observable effects that might be present at 600 keV. The concentration of fission events was 10 times the concentration of primary knock-ons in the Kaminsky experiments. With scanning electron microscope and energy dispersive X-ray analyses of our sputtering collectors both before and after irradiation, we found no sputtered particles larger than our detection limit of 0.1 μm. 相似文献
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Costas Busch Malik Magdon-Ismail Marios Mavronicolas 《Journal of Parallel and Distributed Computing》2007
In bufferless networks the packets cannot be buffered while they are in transit; thus, once injected, the packets have to move constantly. Bufferless networks are interesting because they model optical networks. The objective of this work is to demonstrate that efficient bufferless packet switching is achievable in particular, interesting network topologies. 相似文献
34.
典型的虹膜识别算法都是针对单个虹膜样本采用图像处理的方法提取虹膜特征,只强调个体信息,而忽略了虹膜样本间的联系.本文提出了一种基于普通向量的虹膜识别算法,从模式分析的角度,利用普通向量方法融合虹膜的个体特征和统计特征,并且通过高效的睫毛滤除和眼皮定位的算法,进一步提高了识别的精度和算法的稳定性.实验结果表明了该算法具有良好的性能. 相似文献
35.
Multifunctional Transmembrane Protein Ligands for Cell‐Specific Targeting of Plasma Membrane‐Derived Vesicles 下载免费PDF全文
Chi Zhao David J. Busch Connor P. Vershel Jeanne C. Stachowiak 《Small (Weinheim an der Bergstrasse, Germany)》2016,12(28):3837-3848
Liposomes and nanoparticles that bind selectively to cell‐surface receptors can target specific populations of cells. However, chemical conjugation of ligands to these particles is difficult to control, frequently limiting ligand uniformity and complexity. In contrast, the surfaces of living cells are decorated with highly uniform populations of sophisticated transmembrane proteins. Toward harnessing cellular capabilities, here it is demonstrated that plasma membrane vesicles (PMVs) derived from donor cells can display engineered transmembrane protein ligands that precisely target cells on the basis of receptor expression. These multifunctional targeting proteins incorporate (i) a protein ligand, (ii) an intrinsically disordered protein spacer to make the ligand sterically accessible, and (iii) a fluorescent protein domain that enables quantification of the ligand density on the PMV surface. PMVs that display targeting proteins with affinity for the epidermal growth factor receptor (EGFR) bind at increasing concentrations to breast cancer cells that express increasing levels of EGFR. Further, as an example of the generality of this approach, PMVs expressing a single‐domain antibody against green fluorescence protein (eGFP) bind to cells expressing eGFP‐tagged receptors with a selectivity of ≈50:1. The results demonstrate the versatility of PMVs as cell targeting systems, suggesting diverse applications from drug delivery to tissue engineering. 相似文献
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Andreas Schrader Darren V. Carlson Dominik Busch 《Personal and Ubiquitous Computing》2008,12(4):299-306
In this paper we describe a novel approach for interactive cinema based on context-aware narration using handheld computers.
The paper describes both the artistic approach and the ubiquitous computing framework developed to realize the scenario. This
framework has been used in various projects, including the described video production course at the ISNM, where five interactive
cinema concepts have been developed and shown during a public demonstration. In our approach, a new type of user experience
has been established by placing the viewer inside the movie’s physical locations during playback. Moreover, the developed
ubiquitous computing framework provides a foundation for future work in the area of ad-hoc, service-oriented Ubicomp scenarios. 相似文献
39.
It is common knowledge that structural design on the basis of stress limitation leads to an overestimation of the damage potential of low cycle dynamic loads (e.g. seismic events).Until now the high effort needed for step-by-step numerical evaluation of nonlinear dynamic structural response is a serious obstacle for a more realistic design based on strain limitation.The concept of energy dissipation and structural hardening as functions of strain range leads to the definition of a set of 1-DOF-substitute structures gained by a limited number of quasi-static non linear computations or by a certain knowledge of the yield behaviour of structural members. Step-by-step numerical computations are restricted to the substitutes and thus the effort for a strain limitation design is reduced to a bearable level. 相似文献
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