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991.
Fu-Yuan Shih Tsung-Hung Chen Mei-Chin Lu Wu-Fu Chen Zhi-Hong Wen Yueh-Hsiung Kuo Ping-Jyun Sung 《International journal of molecular sciences》2013,14(11):21781-21789
Two new eunicellin-based diterpenoids, cladieunicellins K (1) and L (2), were isolated from an octocoral Cladiella sp. The structures of 1 and 2 were elucidated by spectroscopic methods and 2 exhibited moderate cytotoxicity towards the MOLT-4 human leukemia. 相似文献
992.
The durability of proton exchange membrane fuel cells is one of the key issues hindering their widespread commercialization. This study uses the complex accelerating degradation protocol to investigate the performance decay of a membrane electrode assembly. The complex accelerating protocol includes OCV, RH cycling and load cycling. Linear sweep voltammetry, cyclic voltammetry, AC impedance and polarization curves were used to measure key MEA characteristics. The experimental results in this work revealed that the Nafion® film underwent significant thinning after the 1040th cycle. Moreover, during accelerated degradation testing, the electrochemical surface area decreased and was therefore found to be the main factor affecting the performance decay of the MEA. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
993.
Chun-Kuang Shih Chia-Jung Ho Sing-Chung Li Shwu-Huey Yang Wen-Chi Hou Hsing-Hsien Cheng 《Food chemistry》2011
This study included F344 rats which were fed AIN-93G-based 14% high-fat diets and were divided into the following six groups: Groups B and N, 14% soybean oil (SO); group P, 14% SO containing 0.04% piroxicam; group L, 5% rice bran oil (RBO) and 9% SO; group M, 9% RBO and 5% SO; and group H, 14% RBO. All the rats—except those in group B—were administered 1,2-dimethylhydrazine/dextran sodium sulphate to induce colitis-related colon carcinogenesis. The rats were sacrificed, and their colons were removed to examine aberrant crypt foci (ACF) and mucin-depleted foci (MDF). The results revealed that the rats from all the RBO group rats exhibited significantly reduced colon tumour formation, MDF, and ACF, especially sialomucin (SIM)-producing ACF. The hepatic antioxidant status, including the glutathione (GSH) and thiobarbituric acid reactive substance levels as well as superoxide dismutase and catalase activities, was superior among the RBO groups, which might contribute to the potential of RBO with respect to delaying colon carcinogenesis. 相似文献
994.
Shih‐Chuan Liu Deng‐Jye Yang Hsin‐Yi Chen Su‐Lin Chen Mei‐Ling Chen 《International Journal of Food Science & Technology》2011,46(8):1768-1774
Model fructose/glycine systems with fructose concentration between 0.035 and 0.28 m were incubated at temperature 45–90 °C for investigating the effects of fructose and temperature on the brown colour development, pH change and the antioxidative activity developments of Maillard reaction. The result showed that effects of fructose followed logarithm‐order kinetics on brown colour and DPPH (2,2‐diphenyl‐1‐picrylhydrazyl) radical scavenging activity (SDPPH) development, and first‐order kinetics on system pH decrease. However, the effect of fructose on ABTS·+ (2,2′‐azino‐bis[3‐ethylbenzthiazoline‐6‐sulphonic acid]) radical scavenging activity (SABTS) development was first order at 60–90 °C and logarithm order at 45 °C, which revealed the mutual synergistic interaction of concentration with temperature on SABTS development. Activation energy for SDPPH development was lower than that for SABTS development, revealing that DPPH radical was more vulnerable than ABTS·+ radical to fructose/glycine MRPs at low temperature. But the relative vulnerability would invert at high temperature, as the Q10 value for SDPPH development was lower than that for SABTS development. 相似文献
995.
Shao-Kuan Lee Wei-Hsing Tuan Yin-Yin Wu Shao-Ju Shih 《Journal of the European Ceramic Society》2013,33(2):277-285
The thermal conductivity of Cu/Al2O3 bilayers prepared by a direct-bonding technique was determined. The direct-bonding process started with the pre-oxidation treatment of a Cu plate at a temperature less than 600 °C. Though a thin oxide layer was located on the surface of the plate after treatment, the oxygen solutes began to diffuse into the interior of Cu plate prior to bonding. Bonding occurred by a eutectic liquid formed at 1075 °C. No reaction interphase was observed at the Cu–Al2O3 interface. The thermal resistance of the Cu/Al2O3 interface is very low. The extremely low thermal resistance can be related to the clean interface between the two materials. 相似文献
996.
We propose a novel power efficient adaptive hybrid dynamic power management (AH-DPM) algorithm. To adapt well to bursty request arrival patterns with self-similarity and a service provider (SP, i.e., hard disk or WLAN NIC, in this paper) with multiple inactive states, the proposed AH-DPM first derives the average idle time of the SP in the bursty (ON) period and non-bursty (OFF) period separately. Then, to achieve better power saving, we use the average idle time in the ON period to adjust the timeout value more precisely and use the average idle time in the OFF period to decide which inactive state the SP should be switched to. Experimental results based on real traces show that, for the hard disk, the average power consumption of the proposed AH-DPM is better than that of the Adaptive Timeout (ATO), Machine Learning (ML), Predictive, Static Timeout (STO), and Stochastic algorithms. In addition, the average response time of the proposed AH-DPM algorithm is still lower than that specified in a typical hard disk specification. As to the WLAN NIC, experimental results show that the average power consumption of the proposed AH-DPM is comparable to that of the Oracle (theoretically optimal), ATO, and Predictive algorithms, and is better than that of the ML, STO, and Stochastic algorithms. However, the average packet transmission delay of the proposed AH-DPM is better than that of the ATO and Predictive algorithms. Therefore, by providing a better tradeoff between average power consumption and average response time (or average packet transmission delay), the proposed AH-DPM algorithm is very feasible for extending the battery lifetime of ever increasing mobile devices that are equipped with hard disks and WLAN NICs. 相似文献
997.
Abstract The study investigated the effect of compartmentalization of anaerobic zone on sludge settling property in an enhanced biological phosphorus removal (EBPR) system. Continuous‐flow pilot‐plant experiments with synthetic influent were performed at varied anaerobic‐oxic volume ratios (Van : Vo , 1 : 9 and 2 : 8), involving 5, 10 and 15 days of sludge retention times (SRTs). Experimental results indicated that, regardless of Van : Vo and SRT, satisfactory removal of COD and phosphate were achieved during all test runs. However, extremely high sludge volume index (SVI) values were observed when there were 5 days of SRT. Further experiments with compartmentalization of anaerobic zone were therefore conducted to confirm the necessity of incorporating the kinetic selection mechanism of bulking control into an EBPR process operated at a low SRT. These results revealed that the two factors, Van : Vo and anaerobic compartmentalization, had interaction with respect to sludge settling property in terms of SVI. When anaerobic retention time increased from 0.72hr to 1.36hr, compartmentalizing anaerobic zone significantly decreased the SVI value because of generating high COD concentration gradient and phosphate release in the anaerobic zone. This result implies that supplementing kinetic selection pressure of bulking control exhibits a critical influence on sludge settling when the EBPR process operates at a lower SRT. 相似文献
998.
This paper provided a content analysis of studies in the field of cognition in e-learning that were published in five Social Sciences Citation Index (SSCI) journals (i.e. Computers and Education, British Journal of Educational Technology, Innovations in Education and Teaching International, Educational Technology Research & Development, and Journal of Computer Assisted Learning) from 2001 to 2005. Among the 1027 articles published in these journals from 2001 to 2005, 444 articles were identified as being related to the topic of cognition in e-learning. These articles were cross analyzed by published years, journal, research topic, and citation count. Furthermore, 16 highly-cited articles across different topics were chosen for further analysis according to their research settings, participants, research design types, and research methods. It was found from the analysis of the 444 articles that “Instructional Approaches,” “Learning Environment,” and “Metacognition” were the three most popular research topics, but the analysis of the citation counts suggested that the studies related to “Instructional Approaches,” “Information Processing” and “Motivation” might have a greater impact on subsequent research. Although the use of questionnaires might still be the main method of gathering research data in e-learning cognitive studies, a clear trend was observed that more and more studies were utilizing learners’ log files or online messages as data sources for analysis. The results of the analysis provided insights for educators and researchers into research trends and patterns of cognition in e-learning. 相似文献
999.
Huang S.C.-H. Hsiao-Chun Wu Shih Yu Chang Xian Liu 《Communications, IEEE Transactions on》2010,58(2):405-410
In this paper, we propose a new family of 64- QAM based sequences for achieving the lowest PMEPR and the highest code rate compared to all other 64-QAM based schemes, which can be applied for OFDM systems. The construction of the proposed sequences is simple and the theoretical analysis is presented. 相似文献
1000.
With the popularization of computer and communication technologies, researchers have attempted to develop computer-assisted testing and diagnostic systems to help students improve their learning performance on the Internet. In developing a diagnostic system for detecting students’ learning problems, it is difficult for individual teachers to address the exact relationships between the test items and the concepts. To cope with this problem, this study proposes an innovative approach to eliciting and integrating the weightings of test item-concept relationships from multiple experts. Based on the proposed approach, a testing and diagnostic system has been implemented; moreover, an experiment was conducted to evaluate the performance of our approach. By analyzing the results from four groups of students using learning suggestions provided by different models, it was found that the learning performance of the students who received learning suggestions by applying the innovative approach was significantly better than for those who received guidance based on the original model. 相似文献