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991.
Yi‐Yeol Lyu Jeonghun Kwak Woo Sung Jeon Younghun Byun Hyo Sug Lee Doseok Kim Changhee Lee Kookheon Char 《Advanced functional materials》2009,19(3):420-427
A novel host material containing silicon‐cored spirobifluorene derivative (SBP‐TS‐PSB), is designed, synthesized, and characterized for red phosphorescent organic light‐emitting diodes (OLEDs). The SBP‐TS‐PSB has excellent thermal and morphological stabilities and exhibits high electroluminescence (EL) efficiency as a host for the red phosphorescent OLEDs. The electrophosphorescence properties of the devices using SBP‐TS‐PSB as the host and red phosphorescent iridium (III) complexes as the emitter are investigated and these devices exhibit higher EL performances compared with the reference devices with 4,4′‐N,N′‐dicarbazole‐biphenyl (CBP) as a host material; for example, a (piq)2Ir(acac)‐doped SBP‐TS‐PSB device shows maximum external quantum efficiency of ηext = 14.6%, power efficiency of 10.3 lm W?1 and Commission International de L'Eclairage color coordinates (0.68, 0.32) at J = 1.5 mA cm?2, while the device with the CBP host shows maximum ηext = 12.1%. These high performances can be mainly explained by efficient triplet energy transfer from the host to the guests and improved charge balance attributable to the bipolar characteristics of the spirobifluorene group. 相似文献
992.
Attempts are being made at the international level within the framework of the Codex Alimentarius to establish guidelines for health claims. An important issue that has to be addressed is the process of substantiating any health claim. Previous papers have addressed aspects relating to the development and regulatory control of functional foods and certain issues relating to claims. This paper addresses several issues concerning the substantiation of health claims through the examination of the regulations and guidelines in several countries. They include (1) importance of human- and product-based studies; (2) concept of scientific consensus; (3) authorization of claim wording; (4) availability of scientific evidence to public (confidentiality). The paper finally proposes a system based on generic and innovative health claims. 相似文献
993.
You-Shin Shim Won-Jin Yoon Jaeho Ha Dongwon Seo Kwang-Won Lee Woo-Young Lee Kwang-Il Kwon Tae-Seok Kang Jin-Ha Lee Hyun-Jeong Kim Hae-Jung Kwak Sam-Pin Lee So-Jung Kim Won-Kap Yun Junsoo Lee Jin-Bong Hwang 《Food science and biotechnology》2013,22(6):1567-1571
An analytical method for the simultaneous determination of 16 types of structural amino acids in infant formula using an automated amino acid analyzer was validated through tests of precision, accuracy and linearity. The automated analysis of the amino acids was performed on an ion-exchange packed column with a visible detector. The certificated reference material (CRM) 1546 from NIST was used as the test sample to determine the precision and accuracy of the analytical method. The regression analyses revealed good correlations [correlation coefficient (r 2)] that were greater than 0.99. The recovery values of the amino acids were ranged from 87.18 to 118.08%. The limits of detection and limits of quantification were less than 0.059 mg/100 g and less than 0.198 mg/100 g, respectively. The intra- and inter-day precisions were less than 14.62% in the CRM sample. 相似文献
994.
In order to investigate the possible application of ZnO films as a transparent conducting oxide (TCO) electrode for AC PDP, ZnO:Al films were prepared by DC magnetron sputtering method. The effects of discharge power and doping concentration on the structural and electrical properties of ZnO films were mainly studied experimentally. Five-inch PDP cells using either a ZnO:Al or indium tin oxide (ITO) electrode were also fabricated separately under the same manufacturing conditions. The luminous properties of both the PDP cells were measured and compared with each other.By doping the ZnO target with 2 wt% of Al2O3, the film deposited at a discharge power of 40 W resulted in the minimum resistivity of 8.5 × 10−4 Ω-cm and a transmittance of 91.7%. However, a high doping concentration of 3 wt% of Al2O3 and excessive sputtering power over 40 W may induce high defect density and limit the growth of small grains. Although the luminance and luminous efficiency of the cell using ZnO:Al are lower than those of the cell with the ITO electrode by about 10%, these values are sufficient enough to be considered for the normal operation of AC PDP. 相似文献
995.
Recently, the importance of vehicle safety supporting system has been highlighted as autonomous driving and platooning has attracted the researchers. To ensure driving safety, each vehicle must broadcast a basic safety message (BSM) every 100 ms. However, stable BSM exchange is difficult because of the changing environment and limited bandwidth of vehicular wireless communication. The increasing number of vehicles on the road increases the competition to access wireless networks for BSM exchange; this increases the packet collision rate. An increased packet collision rate impairs the transmission and reception of BSM information, which can easily cause a traffic accident. We propose a solution, the vehicular safety support system (V3S), which exchanges BSMs reliably even when many vehicles are on the road. The V3S uses a clustering scheme to decrease network traffic by reducing the amount of data exchanged between a vehicle and the roadside unit (RSU). In addition, the V3S reduces the collision rate of wireless network packets by broadcasting the vehicle's BSM in an allocated timeslot using the time division multiple access (TDMA) MAC protocol. The V3S also deals with insufficient bandwidth for dedicated short-range communications (DSRC) by changing DSRC channels according to traffic flow. In evaluating the packet error rate for stable BSM packet delivery, the V3S demonstrates an excellent packet error rate of less than 1%, compared to the 802.11p with its packet error rate of 82%. 相似文献
996.
A numerical procedure for the analysis of the elasto-plastic contact problems under large deformation is presented. The contact surface is assumed unbonded and frictionless. Considering large strain and large displacement, a minimization problem with suitable contact conditions is proposed and the equivalence to the governing equations is shown. A recursive quadratic programming problem based on the finite element technique is adopted for solution method. The method is illustrated by two numerical examples and the results are compared with existing experimental results. 相似文献
997.
998.
International Journal of Computer Vision - This paper presents the first attempt to learn semantic boundary detection using image-level class labels as supervision. Our method starts by estimating... 相似文献
999.
1000.