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排序方式: 共有705条查询结果,搜索用时 31 毫秒
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83.
WenGao LionelM.Ni Zhi-WeiXu S.C.Cheung LiCui QiongLuo 《计算机科学技术学报》2005,20(1):105-117
As a joint effort between the Chinese Academy of Sciences and the Hong Kong University of Science and Technology, the BLOSSOMS sensor network project aims to identify research issues at all levels from practical applications down to the design of sensor nodes. In this project, a heterogeneous sensor array including different types of application-dependent sensors as well as monitoring sensors and intruding sensors are being developed. Application-dependent power-aware communication protocols are also being studied for communications among sensor nodes. An ontology-based middleware is built to relieve the burden of application developers from collecting, classifying and processing messy sensing contexts. This project is also developing a set of tools allowing researchers to model, simulate/emulate, analyze, and monitor various functions of sensor networks. 相似文献
84.
Conclusions Extraction with trichloroethylene was found to be an effective method of reducing the free gossypol content of flaked cottonseed
meats. The reduction was found to be a function of both extraction temperature and residual extractables in the extracted
meal. Because of the low temperatures involved the meal produced by this method has a higher soluble protein content than
a meal in which the free gossypol is reduced by heat treatment. 相似文献
85.
Spiegel Don; Keith-Spiegel Patricia; Abrahams Joel; Kranitz Lionel 《Canadian Metallurgical Quarterly》1969,33(4):504
During an interview 20 patients who had attempted suicide and 20 matched nonsuicidal patients were asked to relate their favorite joke. Jokes were told by 12 attempters and 9 controls. 2 raters, blind to the purpose and nature of the study, rated each joke for direction of punishment expressed in the themes. Based on the combined chi-square probabilities associated with ratings by the 2 judges, suicidal Ss told significantly more jokes with a self-punishing theme than did nonsuicidal controls. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
86.
Lionel Bretillon Niyazi Acar Olivier Berdeaux Alain Bron Catherine Creuzot‐Garcher 《Lipid Technology》2010,22(6):130-133
According to demographic forecasts, the elderly population will represent a growing part of the developed societies in the near future. Eye diseases are the second most prevalent pathologies after the age of 65 years. Age‐related macular degeneration (AMD) is the leading cause of irreversible vision loss in western countries. The number of people suffering from ocular pathologies is expected to increase sharply in the near future, becoming a socio‐economic burden. Recent data indicate that lipid nutrients may represent new tools in the prevention of eye diseases, and especially AMD. 相似文献
87.
A number of coverage criteria have been proposed for testing classes and class clusters modeled with state machines. Previous research has revealed their limitations in terms of their capability to detect faults. As these criteria can be considered to execute the control flow structure of the state machine, we are investigating how data flow information can be used to improve them in the context of UML state machines. More specifically, we investigate how such data flow analysis can be used to further refine the selection of a cost‐effective test suite among alternative, adequate test suites for a given state machine criterion. This paper presents a comprehensive methodology to perform data flow analysis of UML state machines—with a specific focus on identifying the data flow from OCL guard conditions and operation contracts—and applies it to a widely referenced coverage criterion, the round‐trip path (transition tree) criterion. It reports on two case studies whose results show that data flow information can be used to select the best transition tree, in terms of cost effectiveness, when more than one satisfies the transition tree criterion. The results also suggest that different trees are complementary in terms of the data flow that they exercise, thus, leading to the detection of intersecting but distinct subsets of faults. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
88.
Sabine Grüschow Dr. Emma J. Rackham Benjamin Elkins Philip L. A. Newill Lionel M. Hill Dr. Rebecca J. M. Goss Dr. 《Chembiochem : a European journal of chemical biology》2009,10(2):355-360
Pacidamycins, mureidomycins and napsamycins are structurally related uridyl peptide antibiotics that inhibit translocase I, an as yet clinically unexploited target. This potentially important bioactivity coupled to the biosynthetically intriguing structure of pacidamycin make this natural product a fascinating subject for study. A precursor‐directed biosynthesis approach was employed in order to access new pacidamycin derivatives. Strikingly, the biosynthetic machinery exhibited highly relaxed substrate specificity with the majority of the tryptophan analogues that were administered; this resulted in the production of new pacidamycin derivatives. Remarkably, 2‐methyl‐, 7‐methyl‐, 7‐chloro‐ and 7‐bromotryptophans produced their corresponding pacidamycin analogues in larger amounts than the natural pacidamycin. Low levels or no incorporation was observed for tryptophans substituted at positions 4, 5 and 6. The ability to generate bromo‐ and chloropacidamycins opens up the possibility of further functionalising these compounds through chemical cross‐coupling in order to access a much larger family of derivatives. 相似文献
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90.
Muhammad Shahzad Kamal Syed M. Shakil Hussain Lionel Talley Fogang Izhar A. Malik 《Journal of surfactants and detergents》2019,22(4):795-806
Substantial efforts are underway to improve the recovery factor from existing oil reserves to meet the ever-growing global oil demand. Surfactants are known to increase oil recovery through reducing interfacial tension (IFT) and/or altering the rock wettability. The selection of surfactants for high-salinity high-temperature oil fields is a challenging task owing to poor thermal stability, precipitation, and adsorption of surfactants on reservoir rocks. Sulfobetaine-based polyoxyethylene zwitterionic surfactants have shown excellent thermal and surface properties. However, their solubility in high-salinity brines becomes poor particularly with a long hydrophobic tail (>C17). Recently, we synthesized such types of surfactants by incorporating ethylene oxide (EO) units into the hydrophobic tail, which improved the solubility in formation water (213,734 ppm) and seawater (SW) (57,643 ppm). In this work, we investigated the IFT, thermal stability, rheological behavior, and foaming properties of two polyoxyethylene zwitterionic surfactants having different degrees of ethoxylation. Aging experiments exhibited excellent thermal stability and no change in the chemical structure was detected. The surfactant with lesser EO units (EASB-1a) showed a lower IFT compared to the surfactant with higher EO units (EASB-1b). Rheological studies revealed that the addition of both surfactants reduced the viscosity of the acrylamide copolymer. However, the effect of EASB-1a was more prominent compared to that of EASB-1b. The surfactant with a higher degree of ethoxylation showed lower adsorption compared to the surfactant with a lesser degree of ethoxylation. Both surfactants showed excellent foamability and foam stability compared to the commercial surfactants. Excellent thermal stability, water solubility under harsh reservoir conditions, foaming properties, and lower adsorption make them a suitable choice for high-temperature, high-salinity reservoirs. 相似文献