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排序方式: 共有653条查询结果,搜索用时 31 毫秒
11.
Kwang‐Jea Kim Sangmin Kwon Hyun Kim Patit P. Kundu Yong‐Wook Kim Yong‐Keun Lee Kyu Jong Lee Byung H. Lee Soonja Choe 《应用聚合物科学杂志》2003,87(2):311-321
The mixing cycle‐dependent degree of dispersion and degree of mixing of a calcite (calcium carbonate) agglomerate in high‐density polyethylene (HDPE), low‐density polyethylene (LDPE), and linear low‐density polyethylene (LLDPE) matrices upon stretching was investigated using three different techniques: mechanical property, morphological behavior, and image analyzer analyses. The mechanical properties analyzed in terms of the tensile strength and maximum elongation resulted in that the second mixing was the best for giving a better property for all systems except the LDPE system, which exhibited no significant difference between the second and third mixings. The morphological behavior of the three compounds were different, but no distinctive difference was observed to differentiate the degree of mixing from system to system. The number‐, weight‐, and z + 1‐average diameters of the air hole and the aspect ratio upon the stretching and mixing cycle were calculated to analyze the degree of mixing of the calcite‐filled composites. As a consequence, no difference in the average diameter of the air hole was obtained among the three systems, but the aspect ratios of the air hole varied significantly. Thus, the degree of dispersion and the degree of mixing may be influenced by the average calcite agglomerate size, the average diameter of the air hole, and the aspect ratio upon stretching and mixing cycles. Those factors would be formed by the difference in chemical characteristics upon various microstructures of polyethylene and its molecular weight and molecular weight distribution. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 87: 311–321, 2003 相似文献
12.
Donghyon Kim Jung-ok Beak Youngson Choe Wonho Kim 《Korean Journal of Chemical Engineering》2005,22(5):755-761
The cure kinetics of blends of epoxy resin (4,4’-tetraglycidyl diaminodiphenyl methane; TGDDM)/curing agent (diaminodiphenyl
sulfone; DDS) with ATPEI (amine terminated poly-etherimide) -CTBN (carboxyl terminated poly (butadiene-co-acrylonitrile))
block copolymer (AB type) were studied using differential scanning calorimetry under isothermal conditions to determine the
reaction kinetic parameters such as activation energy and reaction constants. Final cure conversion decreased with increasing
amount of AB in the blends. A diffusion controlled reaction was observed as the cure conversion increased, and the curing
reaction was successfully analyzed by incorporating the diffusion control term in the rate equation for the epoxy/DDS/AB blends.
The fracture toughness was improved to about 350% compared to that of the unmodified resin at 30% of AB block copolymer. This
is attributed to the formation of co-continuous morphology between the epoxy phase and AB block copolymer phase. By increasing
the amount of AB, the modulus of the cured blends decreased, which was due to the presence of CTBN rubbery phases. 相似文献
13.
Gwangmin Choe Caihong Yuan Tianjiang Wang Qi Feng Gyongil Hyon Chunhwa Choe Jonghwan Ri Gumhyok Ji 《Multimedia Tools and Applications》2016,75(18):11447-11468
Human eye perceives an object as the entity with global information and local information. Human salience is distinctive local information in matching pedestrians across disjoint camera views, and matching on overall foreground guarantees reliable and robust identification. In this paper, we propose a strategy for the matching of mean salience to identify pedestrians. Also, we consider that person re-identification based on the local single directional matching suffers from the variations of pose, illumination and overlapping, and propose a global bi-directional matching to solve the challenging problems of person re-identification. Furthermore, our matching of mean salience is tightly combined with the global bi-directional matching. Patch matching is utilized to handle the misalignment problem in pedestrian images. We test our feature and matching approaches in person re-identification scenario. Experimental results demonstrate that the mean salience and the global bi-directional matching have promising discriminative capability in comparison with other ones. 相似文献
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16.
Choe Sungyul Kim Junho Lee Haeyoung Lee Seungyong 《IEEE transactions on visualization and computer graphics》2009,15(1):160-173
Previous mesh compression techniques provide decent properties such as high compression ratio, progressive decoding, and out-of-core processing. However, only a few of them supports the random accessibility in decoding, which enables the details of any specific part to be available without decoding other parts. This paper proposes an effective framework for the random accessibility of mesh compression. The key component of the framework is a wire-net mesh constructed from a chartification of the given mesh. Charts are compressed separately for random access to mesh parts and a wire-net mesh provides an indexing and stitching structure for the compressed charts. Experimental results show that random accessibility can be achieved with competent compression ratio, which is only a little worse than single-rate and comparable to progressive encoding. To demonstrate the merits of the framework, we apply it to process huge meshes in an out-of-core manner, such as out-of-core rendering and out-of-core editing. 相似文献
17.
Solar Cells: Multidimensional Anodized Titanium Foam Photoelectrode for Efficient Utilization of Photons in Mesoscopic Solar Cells (Small 34/2017)
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18.
Ferroelectrically Gated Atomically Thin Transition‐Metal Dichalcogenides as Nonvolatile Memory
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19.
Kien Tiek Wong Boris Brigljević Jeong Hyeon Lee So Yeon Yoon Seok Byum Jang Choe Earn Choong Inwook Nah Hyeongjun Kim Hyun-Seog Roh Sang Kyu Kwak Hankwon Lim Min Jang 《Small (Weinheim an der Bergstrasse, Germany)》2023,19(1):2204336
This study focuses on the applicability of single-atom Mo-doped graphitic carbon nitride (GCN) nanosheets which are specifically engineered with high surface area (exfoliated GCN), NH2 rich edges, and maximum utilization of isolated atomic Mo for propylene carbonate (PC) production through CO2 cycloaddition of propylene oxide (PO). Various operational parameters are optimized, for example, temperature (130 °C), pressure (20 bar), catalyst (Mo2GCN), and catalyst mass (0.1 g). Under optimal conditions, 2% Mo-doped GCN (Mo2GCN) has the highest catalytic performance, especially the turnover frequency (TOF) obtained, 36.4 h−1 is higher than most reported studies. DFT simulations prove the catalytic performance of Mo2GCN significantly decreases the activation energy barrier for PO ring-opening from 50–60 to 4.903 kcal mol−1. Coexistence of Lewis acid/base group improves the CO2 cycloaddition performance by the formation of coordination bond between electron-deficient Mo atom with O atom of PO, while NH2 surface group disrupts the stability of CO2 bond by donating electrons into its low-level empty orbital. Steady-state process simulation of the industrial-scale consumes 4.4 ton h−1 of CO2 with PC production of 10.2 ton h−1. Techno-economic assessment profit from Mo2GCN is estimated to be 60.39 million USD year−1 at a catalyst loss rate of 0.01 wt% h−1. 相似文献
20.
Multicore architectures are evolving with the promise of extreme performance for the classes of applications that require
high performance and large bandwidth of memory. Irregular reduction is one of important computation patterns for many complex
scientific applications, and it typically requires high performance and large bandwidth of memory. In this article, we propose
region-based parallelization techniques for irregular reductions on multicore architectures with explicitly managed memory
hierarchies. Managing memory hierarchy in software requires a lot of programming efforts and tends to be error-prone. The
difficulties are even worse for applications with irregular data access patterns. To relieve the burden of memory management
from programmers, we develop abstractions, particularly targeted to irregular reduction, for structuring parallel tasks, mapping
the parallel tasks to processing units and scheduling data transfers between the memory hierarchies. Our framework employs
iteration reordering based on regions of data along with dynamic scheduling of parallel tasks. We experimentally evaluate
the effectiveness of our techniques for irregular reduction kernels on the Cell processor embedded in a Sony PlayStation3.
Experimental results show the speedups of 8 to 14 on the six available SPEs. 相似文献