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排序方式: 共有1464条查询结果,搜索用时 31 毫秒
71.
Erik Berg Schmidt Jeppe Hagstrup Christensen Inge Aardestrup Trine Madsen Sam Riahi Vibeke Ellegaard Hansen Helle Aarup Skou 《Lipids》2001,36(1):S65-S68
There is some evidence from epidemiology that intake of n-3 polyunsaturated fatty acids (PUFA) from seafood may protect against coronary artery disease (CAD). This hypothesis is further supported from animal data showing a beneficial effect of n-3 PUFA on thrombosis and atherosclerosis in animals fed fish oils in most, but not all, studies. There are several mechanisms by which an increased intake of marine n-3 PUFA may protect against CAD; the most universal finding is a reduction of plasma triglycerides. It is puzzling, however, that a very low amount of n-3 PUFA, with no known beneficial biochemical effects, seems to be cardioprotective. It has therefore been of paramount interest to perform clinical trials. Such evidence and trials are discussed in later chapters, and the results have been very encouraging. 相似文献
72.
Freestanding fiber mats of zeolitic imidazolate framework 7 via one‐step,scalable electrospinning
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Seongpil An Ji Sun Lee Bhavana N. Joshi Hong Seok Jo Kirill Titov Jong‐San Chang Chul‐Ho Jun Salem S. Al‐Deyab Young Kyu Hwang Jin‐Chong Tan Sam S. Yoon 《应用聚合物科学杂志》2016,133(32)
We demonstrated the fabrication of freestanding zeolitic imidazolate framework 7 (ZIF‐7) nanofiber (NF) mats by means of one‐step, scalable electrospinning. The formation of ZIF‐7 nanoparticles embedded in polymer fibers was unambiguously pinpointed via X‐ray diffraction, transmission electron microscopy, and adsorption studies. The NF mats exhibited excellent characteristics, with an average diameter of 245 nm, in the adsorption and desorption of carbon dioxide (CO2); this makes them attractive candidates for gas separation and other selective filtration applications. This excellent property of the ZIF‐7 mats was explained by the gate‐opening phenomenon of ZIF‐7, which yielded a stepwise increase in the overall CO2 uptake capacity. The mechanical strength of the NF mats was also obtained via large‐strain uniaxial tensile deformation, which enabled preliminary assessment of the mat's suitability for textiles and membranes in targeting separation and filtration applications with large‐area permeability. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43788. 相似文献
73.
Byungjun Kang Kyung Dong Lee Jong-gun Lee Jae-Wook Choi Sam S. Yoon Yoonmook Kang Hae-seok Lee Donghwan Kim 《Journal of Thermal Spray Technology》2016,25(3):465-472
In this study, we investigated cold-sprayed copper as a front contact for crystalline silicon solar cells. Copper powder was deposited on a monocrystalline silicon wafer with variation of the particle velocity during deposition. The particle velocity was varied by varying the heating temperature from 250 to 400 °C using a gas pressure of 0.45 MPa. The particle velocities were calculated using empirical equations, and were found to increase with an increase in the carrier gas temperature. Grid patterns were formed on a phosphorus-doped n-type emitter of a p-type silicon substrate. The electrode thickness increased with increasing particle velocity. The electrical properties of the grids were evaluated using the transfer length method. The specific contact resistance of the n-type emitter was in the range of 2.6-26.4 mΩ-cm2. Damage to the p-n junction was investigated via minority carrier lifetime measurement of the substrate. The copper-silicon interface was evaluated using transmission electron microscopy. The contact properties were affected by the interface conditions. 相似文献
74.
75.
Bioplastics produced from meat and bone meal (MBM) suffer from rapid and drastic mechanical property deterioration because of their hydrophilic nature. This study investigates mechanical and water stability of composites produced from introduction of a minor component of a synthetic polyethylene as a binder phase to consolidate MBM. The milled and sieved MBM was compounded with 5–60 wt % linear low‐density polyethylene (LLDPE) and formed into composite sheets by calendering, which is an industrially relevant process. Results indicated that a minimum of 15 wt % LLDPE content was required to form a nominally continuous binder phase that allowed for good processability and environment stability of the composites. As expected, the water vapor permeability (WVP) and water absorption characteristics of the composites were intermediate between those of MBM and LLDPE. Sheets containing 15 wt % LLDPE absorbed up to 35 wt % water. Composites tested after being soaked in water showed an initial decrease in TS of about 30% for the first hour but then remained fairly unchanged in the next 72 hours, confirming their moderate environment stability. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 41145. 相似文献
76.
Sam 《中国眼镜科技杂志》2021,(1)
光致变色(Photochromics),或许是很长一段时间内眼镜与时尚的复合领域里最Sexy的一个词.经过各种领域与应用场景下对于变色镜片使用效果的研究,有着稳定且成熟的市场需求的变色片在今天似乎有了新的演绎:是一种生活方式,更是一种个人品位与追求的宣示. 相似文献
77.
Richard M. Gunner Rory P. Wilson Mark D. Holton Phil Hopkins Stephen H. Bell Nikki J. Marks Nigel C. Bennett Sam Ferreira Danny Govender Pauli Viljoen Angela Bruns O. Louis van Schalkwyk Mads F. Bertelsen Carlos M. Duarte Martin C. van Rooyen Craig J. Tambling Aoife Gppert Delmar Diesel D. Michael Scantlebury 《Journal of the Royal Society Interface》2022,19(186)
The combined use of global positioning system (GPS) technology and motion sensors within the discipline of movement ecology has increased over recent years. This is particularly the case for instrumented wildlife, with many studies now opting to record parameters at high (infra-second) sampling frequencies. However, the detail with which GPS loggers can elucidate fine-scale movement depends on the precision and accuracy of fixes, with accuracy being affected by signal reception. We hypothesized that animal behaviour was the main factor affecting fix inaccuracy, with inherent GPS positional noise (jitter) being most apparent during GPS fixes for non-moving locations, thereby producing disproportionate error during rest periods. A movement-verified filtering (MVF) protocol was constructed to compare GPS-derived speed data with dynamic body acceleration, to provide a computationally quick method for identifying genuine travelling movement. This method was tested on 11 free-ranging lions (Panthera leo) fitted with collar-mounted GPS units and tri-axial motion sensors recording at 1 and 40 Hz, respectively. The findings support the hypothesis and show that distance moved estimates were, on average, overestimated by greater than 80% prior to GPS screening. We present the conceptual and mathematical protocols for screening fix inaccuracy within high-resolution GPS datasets and demonstrate the importance that MVF has for avoiding inaccurate and biased estimates of movement. 相似文献
78.
H. Ismail S. T. Sam A. F. Mohd Noor A. A. Bakar 《Polymer-Plastics Technology and Engineering》2013,52(6):641-650
Nickel zinc ferrite (Ni-ZnFe2O4)-filled natural rubber (NR) composite was prepared at various loading of ferrite. The tensile properties included in this study were tensile strength, tensile modulus and elongation at break. The tensile strength and elongation at break of the composites increased up to 40 parts per hundred rubber (phr) of ferrite and then decreased at higher loading whereas the tensile modulus was increased gradually with increasing of ferrite loading. Scanning electron microscopy (SEM) was used to determine the wettability of filler in rubber matrix. From the observation, the increase of filler loading reduced the wettability of the filler. Thermal stability of the composites was conducted by using a thermogravimetry analyser (TGA). The incorporation of ferrite in NR composites enhanced the thermal stability of NR composites. The swelling test results indicate that the swelling percentage of the composites decreased by increasing of ferrite loading. The initial permeability, μi and quality factor, Q of magnetic properties of NR composites achieved maximum value at 60 phr of ferrite loading for frequency range between 5000–40,000 kHz. The maximum impedance, Z max of the NR composites was at the highest value at 80 phr ferrite loading for frequency range between 200–800 MHz. 相似文献
79.
Racemic heavy isotope analogs of 1-O-alkyl-sn-glycero-3-phosphocholine (lysoPAF) and 1-O-alkyl-2-O-acetyl-sn-glycero-3-phosphocholine (PAF) were prepared for use as internal standards to facilitate quantitative studies based on mass
spectrometry. Starting from pentadencane-1,15-diol andrac-glycerol-1,2-acetonide, a convergent synthesis of 1-O-[16′-2H3]hexadecyl and 1-O-[18′-2H3]octadecylrac-glycero-3-phosphocholine and their acetyl derivatives is described. Three deuterium atoms were introduced at the terminal
position of the 1-O-alkyl group by displacement of thep-toluensulfonyl group from 1-O-alkyl-15′-p-toluensulfonate and 1-O-alkyl-17′-p-toluensulfonate with [2H3]-methylmagnesium iodide. The 1-O-alkyl-17′-p-toluensulfonate was obtained by reaction of the 1-O-alkyl-15′-p-toluensulfonate with allylmagnesium bromide, followed by reductive ozonolysis and treatment withp-toluenesulfonyl chloride. The hydroxyl group at C-2 was protected by a benzyl group and removed at a late stage in the synthesis.
This provided the corresponding lysoderivatives or allowed preparation of racemic PAF by subsequent acetylation of the free
hydroxy group. The phosphocholine moiety was introduced at glycerol C-3 by reaction with bromoethyldichlorophosphate and trimethylamine.
The synthetic compounds were analyzed by FAB/MS and GC/NICIMS. They were shown to contain less than 0.6% protium impurity. 相似文献
80.
Tirthankar?GhoshEmail author Niki?Pissinou Kami?Sam?Makki 《Mobile Networks and Applications》2005,10(6):985-995
Designing a trusted and secure routing solution in an untrustworthy scenario is always a challenging problem. Lack of physical
security and low trust levels among nodes in an ad hoc network demands a secure end-to-end route free of any malicious entity.
This is particularly challenging when malicious nodes collude with one another to disrupt the network operation. In this paper
we have designed a secure routing solution to find an end-to-end route free of malicious nodes with collaborative effort from
the neighbors. We have also extended the solution to secure the network against colluding malicious nodes, which, to the best
of our knowledge, is the first such solution proposed. We have also proposed a framework for computing and distributing trusts
that can be used with out trusted routing protocol. Our proposed framework is unique and different from the other schemes
in that it tries to analyze the psychology of the attacker and quantifies the behavior in the computational model. Extensive
simulation has been carried out to evaluate the design of our protocol.
Partially funded by Department of Defense Award No. H98230-04-C-0460, Department of Transportation Project No. FL-26-7102-00
and National Science Foundation Grant Nos. ANI-0123950 and CCR-0196557.
Tirthankar Ghosh is a PhD candidate in the Telecommunications and Information Technology Institute at Florida International University. His
area of research is routing security and trust computation in wireless ad hoc and sensor networks. He received his Bachelor
of Electrical Engineering from Jadavpur University, India and Masters in Computer Engineering from Florida International University.
Dr. Niki Pissinou received her Ph.D. in Computer Science from the University of Southern California, her M.S. in Computer Science from the
University of California at Riverside, and her B.S.I.S.E. in Industrial and Systems Engineering from The Ohio State University.
She is currently a tenured professor and the director of the Telecommunication & Information Technology Institute at FIU.
Previously Dr. Pissinou was a tenured faculty at the Center for Advanced Computer Studies at the University of Louisiana at
Lafayette where she was also the director of the Telecommunication & Information & Technology Laboratory partially funded
by NASA, and the co-director of the NOMAD: A Wireless and Nomadic Laboratory partially funded by NSF, and the Advanced Network
Laboratory. Dr. Pissinou is active in the fields computer networks, information technology and distributed systems.
Dr. Kami (Sam) Makki has earned his Ph.D. in Computer Science from the University of Queensland in Brisbane Australia, his Masters degree in Computer
Science and Engineering from the University of New South Wales in Sydney Australia, and his Bachelor and Masters Degrees in
Civil Engineering from the University of Tehran Iran. Before joining the department of Electrical Engineering and Computer
Science at the University of Toledo he has held a number of academic positions and research appointments at the Queensland
University of Technology in Brisbane, Royal Melbourne Institution of Technology in Melbourne and at The University of Queensland
in Brisbane Australia. He is an active researcher in the fields of distributed systems, databases, mobile and wireless communications,
and has more than 30 publications in peerreviewed journals and international proceedings. He has served as a chair and technical
program committee member and reviewer for a number of IEEE and ACM sponsored technical conferences and has received a number
of achievement awards. 相似文献