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排序方式: 共有501条查询结果,搜索用时 15 毫秒
1.
Injun Lee Taeseong Jung Junggi Kim Suho Ro Chulsu Kim Yeji Lee Youngmi Kim Juhyun Lee Misook Kang 《Journal of Industrial and Engineering Chemistry》2008,14(6):869-873
This study focuses on the relationship between photo-catalytic performance and optical property over Si-incorporated TiO2. The Si-incorporated TiO2 particles exhibited a pure structure of anatase having a particle size of less than 20 nm and surface area of more than 190 m2/g. The absorbance did not shift to a higher wavelength in spite of the incorporation of the Si ions, but the intensity of the photoluminescence (PL) curve was the smallest in the case of the 2.0 mol% Si-TiO2, which was related to the recombination between the excited electrons and holes. Based on these results, the photodecomposition of methyl orange in the liquid reaction was enhanced over the 2.0 mol% Si-incorporated TiO2 compared with that over pure TiO2: Methyl orange at 10.0 ppm was completely decomposed after 100 min when 1.0 g of the 2.0 mol% Si-incorporated TiO2 was used. 相似文献
2.
Jeong Ho Moon Hak Soo Han Yong Gun Shul Do Hoon Jang Muyng Do Ro Du Suk Yun 《Progress in Organic Coatings》2007
This study relates to the development of coatings for optical discs in high-density digital versatile disc systems (HD-DVD or blue lay disk) that use a high numerical aperture of 0.85 at 405 nm wavelength and have a protective top layer over a primer layer for protection against damage and dust. Ultraviolet-curable raw materials of two acrylic monofunctional monomers ( isobornylacrylate, IBA and tetrahydrofurfurylacrylate, THFA) and two kinds of urethaneacrylate oligomers (OUMD and OUME) have been easily mixed with photoinitiators. Curing rate of these materials was characterized by FT-IR. In case of top coats, VTES (vinyltriethoxysilane) and acrylic acid were added to enhance the abrasion resistance. These two kinds of UV-curable resinous materials having no solvent were synthesized and investigated as means for making a blue ray disk having good optical and mechanical properties. In addition, dynamic characteristics including reflectivity, fluctuation of RF signal and noise level were also investigated. 相似文献
3.
MH Saboorian H Huffman R Ashfaq AG Ayala JY Ro 《Canadian Metallurgical Quarterly》1997,21(9):1069-1074
beta-Glucosidase of indigo plant (Polygonum tinctorium) has a high substrate specificity for indican (indoxyl beta-D-glucoside). To examine the localization of this beta-glucosidase, we fractionated the cells of the leaves and analysed them immunocytochemically. Immunoelectron micrographs with specific antibodies against the beta-glucosidase clearly showed that the beta-glucosidase was localized in the stroma of the chloroplasts in mesophyll cells, but not in the thylakoid membrane. Chloroplasts were isolated from the crude homogenate of the fresh leaves by Percoll density gradient centrifugation and then subjected to suborganellar fractionation. beta-Glucosidase activity was specifically detected in the stromal fraction, but not in the thylakoid membrane. This was also supported by the result of an immunoblot of the fraction with anti-beta-glucosidase antibodies. The beta-glucosidase was immunocytochemically localized in the chloroplasts of mesophyll cells, but not in any chloroplasts in marginal cells of the vascular bundle or epidermal cells; ribulose 1,5-bisphosphate carboxylase (Rubisco), a typical stromal protein, was observed in all chloroplasts in these cells. These results suggest that beta-glucosidase is tissue specific in its expression in the leaves of the indigo plant. 相似文献
4.
Companies across industries have admired the success of Dell Computersin using modularity as part of a mass customization strategy to achieve build-to-order and a streamlined supply chain. Many companies are attempting to emulate this successful model, including the American automotive industry. This paper focuses on how the auto industry has been attempting to move to modularity, in part, motivated by a desire to build cars to order. This movement has led to major changes in supply chain practices based partly on imitation of successful keiretsu models in Japan and a move toward modules. This study finds significant impact of modularity on outsourcing, product development, and supply chain coordination based on interviews conducted with automakers and suppliers from 2000-2003. Based on our interviews, we observe that modularity has accompanied a major reorganization of the automotive supplier industry. We identify two major issues that appear to block U.S. automakers from gaining most of the advantages possible through modularity. First, most modularity activities appear to be primarily strategically cost reduction driven, leaving the potential of modularity for mass customization largely untapped. Second, the shift in industry reorganization has not been accompanied by changes in the supply chain infrastructure to encourage long-term partnerships. We contrast this to the more gradual approach used by Toyota as it incorporates modularity on a selective basis and moves to a build-to-order model 相似文献
5.
JG Izzo VA Papadimitrakopoulou XQ Li H Ibarguen JS Lee JY Ro A El-Naggar WK Hong WN Hittelman 《Canadian Metallurgical Quarterly》1998,17(18):2313-2322
Cyclin D1 proto-oncogene is a key regulator of the mammalian cell-cycle acting at the restriction point in late G1. Amplification of the cyclin D1 locus, located on chromosome 11q13, as well as cyclin D1 protein overexpression have been reported in several human malignancies. The purpose of this study was to evaluate cyclin D1 gene copy status and protein expression during the multistep process of head and neck tumorigenesis, using a combination of fluorescence in situ hybridization and immunohistochemistry techniques. From 29 selected patients presenting with head and neck squamous carcinoma and whose tumor cytospins had been previously screened for presence (16 cases) or absence (13 cases) of amplification at the 11q13 band, we analysed 46 paraffin-embedded tissue specimens that demonstrated, besides the primary tumor, the presence of contiguous adjacent normal tissue and/or premalignant lesions. Of the 16 amplified cases, nine demonstrated a continuous progression from premalignant to invasive carcinoma and seven (77.7%) of these cases showed cyclin D1 gene amplification in premalignant lesions prior to development of invasive carcinoma. Increased cyclin D1 protein expression was observed in all 16 amplified tumors and five of the 13 (38.4%) non-amplified tumors. Interestingly, dysregulated cyclin D1 expression was also found in the premalignant lesions adjacent to all 16 amplified tumors, and it appeared to precede cyclin D1 gene amplification. In contrast no dysregulated expression was detected in the premalignant lesions of the non-amplified tumors. In conclusion, these findings provide strong evidence for early dysregulation of cyclin D1 expression during the tumorigenesis process and suggest that dysregulated increased expression precedes and possibly enables gene amplification. 相似文献
6.
The current paper examined the relationship between perceived characteristics of the learning environment in an e‐module in relation to test performance among a group of e‐learners. Using structural equation modelling, the relationship between these variables is further explored in terms of the proposed double mediation as outlined by Ning and Downing. These authors initially proposed that motivation and self‐regulation strategies are mediators between the perception of the learning environment and performance. In our replication and extension study, we substituted self‐reported self‐regulation with behavioural indicators of self‐regulation using navigation log files and focused on test‐taking rather than general motivation. We proposed that navigational patterns captured using log files can also help deduce self‐regulation in e‐modules and provide information in the absence of self‐reports. Path analyses provide partial support for our navigational hypotheses and the model. Implications of our results for the use of e‐module data and conclusions based on navigation are discussed. 相似文献
7.
Hyung-Il Kim Jae Young Choi Seung Ho Lee Yong Man Ro 《Multimedia Tools and Applications》2016,75(12):6887-6908
Automatic face recognition (FR) based applications in low computing power constrained systems, such as mobile and smart camera, have become particularly interesting topic in recent years. In this context, we present computationally efficient FR framework underpinning the so-called feature scalability algorithm. The proposed framework aims at implementing robust FR systems under low-computing power restriction and varying face resolution. Key beneficial property of our proposed FR framework based on feature scalability is to require low computational complexity without sacrificing a level of FR performance. To do this, using feature scalability algorithm enables to directly estimate the features (from pre-enrolled gallery images) that are well matched with the feature of an input probe image with different resolution (generally lower resolution) without any complex process. In addition, our method is helpful for relieving storage shortage problem as it does not require a large amount of training and gallery images with different face resolutions. Results show that our proposed feature scalability algorithm can be seamlessly embedded into state-of-the-art feature extraction methods extensively used for FR by achieving impressive recognition performance. Also, according to the results on computational complexity measurement, the proposed method is proven to be useful for substantially saving FR operation time. 相似文献
8.
Alireza Kargar Supanee Sukrittanon Chang Zhou Yun Goo Ro Xiaoqing Pan Shadi A. Dayeh Charles W. Tu Sungho Jin 《Small (Weinheim an der Bergstrasse, Germany)》2017,13(21)
The growth and characterization of an n‐GaP/i‐GaNP/p+‐GaP thin film heterojunction synthesized using a gas‐source molecular beam epitaxy (MBE) method, and its application for efficient solar‐driven water oxidation is reported. The TiO2/Ni passivated n‐GaP/i‐GaNP/p+‐GaP thin film heterojunction provides much higher photoanodic performance in 1 m KOH solution than the TiO2/Ni‐coated n‐GaP substrate, leading to much lower onset potential and much higher photocurrent. There is a significant photoanodic potential shift of 764 mV at a photocurrent of 0.34 mA cm?2, leading to an onset potential of ≈0.4 V versus reversible hydrogen electrode (RHE) at 0.34 mA cm?2 for the heterojunction. The photocurrent at the water oxidation potential (1.23 V vs RHE) is 1.46 and 7.26 mA cm?2 for the coated n‐GaP and n‐GaP/i‐GaNP/p+‐GaP photoanodes, respectively. The passivated heterojunction offers a maximum applied bias photon‐to‐current efficiency (ABPE) of 1.9% while the ABPE of the coated n‐GaP sample is almost zero. Furthermore, the coated n‐GaP/i‐GaNP/p+‐GaP heterojunction photoanode provides a broad absorption spectrum up to ≈620 nm with incident photon‐to‐current efficiencies (IPCEs) of over 40% from ≈400 to ≈560 nm. The high low‐bias performance and broad absorption of the wide‐bandgap GaP/GaNP heterojunctions render them as a promising photoanode material for tandem photoelectrochemical (PEC) cells to carry out overall solar water splitting. 相似文献
9.
Efficient monitoring of parametric context-free patterns 总被引:1,自引:0,他引:1
Patrick O’Neil Meredith Dongyun Jin Feng Chen Grigore Roşu 《Automated Software Engineering》2010,17(2):149-180
Recent developments in runtime verification and monitoring show that parametric regular and temporal logic specifications
can be efficiently monitored against large programs. However, these logics reduce to ordinary finite automata, limiting their
expressivity. For example, neither can specify structured properties that refer to the call stack of the program. While context-free
grammars (CFGs) are expressive and well-understood, existing techniques for monitoring CFGs generate large runtime overhead
in real-life applications. This paper demonstrates that monitoring parametric CFGs is practical (with overhead on the order of 12% or lower in most cases). We present a monitor synthesis algorithm for CFGs based on an
LR(1) parsing algorithm, modified to account for good prefix matching. In addition, a logic-independent mechanism is introduced
to support matching against the suffixes of execution traces. 相似文献
10.