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排序方式: 共有758条查询结果,搜索用时 31 毫秒
41.
Minh Van Nguyen Sigurjon Arason Gudjon Thorkelsson Agusta Gudmundsdottir Kristin Anna Thorarinsdottir Boi Ngoc Vu 《Journal of the American Oil Chemists' Society》2013,90(3):317-326
Effects of added phosphates on retardation of lipid oxidation of salted cod during processing, storage and after rehydration were investigated. Lipid hydrolysis progress and development of color, primary and secondary lipid oxidation products and fluorescence intensities were determined. Added phosphates significantly retarded lipid hydrolysis and lipid oxidation progress, resulting in lower free fatty acid , lipid hydroperoxides (PV), thiobarbituric acid-reactive substances (TBARS) as well as fluorescence intensities (δF or and δF aq). Significant correlation between the lipid oxidation products (PV, TBARS, δF or and δF aq) and yellow/brownish discoloration (b* value) of salted cod was observed. Principal component analysis showed that TBARS, b* value and δF or were the strongest indicators of lipid oxidation during salting and storage. 相似文献
42.
Actions and social interactions in multi-agent systems 总被引:3,自引:3,他引:0
43.
Marie‐Hélène Famelart Ngoc Huyen Tran Le Thomas Croguennec Florence Rousseau 《International Journal of Food Science & Technology》2013,48(9):1940-1948
The role of thiol/disulphide exchanges during acid gelation of preheated milk was studied with milk samples with or without N‐ethylmaleimide (NEM), a thiol‐blocking agent, and acidified to pH 4 by the addition of glucono‐delta‐lactone at 20 °C. Active or total thiol groups, particle size with light scattering measurements in a dissociating solvent or by SDS‐agarose electrophoresis were determined on acidified milk samples. Diffusing wave spectroscopy and rheology in low strain were applied during acidification of sample, while rheology in large strain was applied on final acid gels. The only effect of the presence of NEM was a reduced firmness of acid gels as measured at large strain and a reduced tendency to form large aggregates at pH<5.5. In conclusions, thiol/disulphide exchanges during acidification of milk played only a minor role in the building of acid gel networks from heated milk. 相似文献
44.
45.
Chien DN Tanaka M Tanaka K 《Journal of the Optical Society of America. A, Optics, image science, and vision》2002,19(8):1649-1657
The scattering phenomenon from an arbitrary-shaped end of a asymmetrical slab waveguide for the cases of TE and TM guided modes is simulated by means of boundary integral equations that are called guided-mode extracted integral equations. The integral equations that we derive can be solved by the conventional boundary-element method. Numerical results are presented for problems of three-layer asymmetrical waveguides with tilted ends. The reflection coefficient, reflected and scattered powers, and radiation patterns are calculated numerically for the cases of incident TE and TM guided modes. 相似文献
46.
Morvan L Lai ND Dolfi D Huignard JP Brunel M Bretenaker F Le Floch A 《Applied optics》2002,41(27):5702-5712
A new principle of lidar-radar is theoretically and experimentally investigated. The proposed architecture is based on the use of an rf modulation of the emitted light beam and a direct detection of the backscattered intensity. Use of a radar-processing chain allows one to obtain range and Doppler measurements with the advantages of lidar spatial resolution. We calculate the maximum range of this device, taking into account different possible improvements. In particular, we show that use of a pulsed two-frequency laser and a spatially multimode optical preamplification of the backscattered light leads to calculated ranges larger than 20 km, including the possibility of both range and Doppler measurements. The building blocks of this lidar-radar are tested experimentally: The radar processing of an rf-modulated backscattered cw laser beam is demonstrated at 532 nm, illustrating the Doppler and identification capabilities of the system. In addition, signal-to-noise ratio improvement by optical pre-amplification is demonstrated at 1.06 microm. Finally, a two-frequency passively Q-switched Nd:YAG laser is developed. This laser then permits two-frequency pulses with tunable pulse duration (from 18 to 240 ns) and beat frequency (from 0 to 2.65 GHz) to be obtained. 相似文献
47.
PP Sayeski MS Ali DJ Semeniuk TN Doan KE Bernstein 《Canadian Metallurgical Quarterly》1998,78(1-3):19-29
It has been 100 years since the discovery of renin by Tigerstedt and Bergman. Since that time, numerous discoveries have advanced our understanding of the renin-angiotensin system, including the observation that angiotensin II is the effector molecule of this system. A remarkable aspect of angiotensin II is the many different physiological responses this simple peptide induces in different cell types. Here, we focus on the signal transduction pathways that are activated as a consequence of angiotensin II binding to the AT1 receptor. Classical signaling pathways such as the activation of heterotrimeric G proteins by the AT1 receptor are discussed. In addition, recent work examining the role of tyrosine phosphorylation in angiotensin II-mediated signal transduction is also examined. Understanding how these distinct signaling pathways transduce signals from the cell surface will advance our understanding of how such a simple molecule elicits such a wide variety of specific cellular responses. 相似文献
48.
The problem of integrating data from multiple data sources—either on the Internet or within enterprises—has received much attention in the database and AI communities. The focus has been on building data integration systems that provide a uniform query interface to the sources. A key bottleneck in building such systems has been the laborious manual construction of semantic mappings between the query interface and the source schemas. Examples of mappings are element location maps to address and price maps to listed-price. We propose a multistrategy learning approach to automatically find such mappings. The approach applies multiple learner modules, where each module exploits a different type of information either in the schemas of the sources or in their data, then combines the predictions of the modules using a meta-learner. Learner modules employ a variety of techniques, ranging from Naive Bayes and nearest-neighbor classification to entity recognition and information retrieval. We describe the LSD system, which employs this approach to find semantic mappings. To further improve matching accuracy, LSD exploits domain integrity constraints, user feedback, and nested structures in XML data. We test LSD experimentally on several real-world domains. The experiments validate the utility of multistrategy learning for data integration and show that LSD proposes semantic mappings with a high degree of accuracy. 相似文献
49.
50.
Ngoc Thanh Nguyen 《控制论与系统》2013,44(6):542-562
Is the intelligence of a collective larger than the intelligence of its members? How does one determine the knowledge of a collective on the basis of the knowledge of its members? In this paper, we try to answer these questions. Many examples show that the knowledge of a collective is not a usual union of the knowledge of its members. If we assume that the members of a collective possess their knowledge states about some common real world, and these states reflect to some degree the proper (real) state of the knowledge about the real world, then a question arises: How does one determine the knowledge of the collective, and what is its quality? In this paper, we use Consensus Theory to solve this problem and to show that, in many cases, the collective knowledge state is more proper than the knowledge states of the collective intelligence. 相似文献