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排序方式: 共有456条查询结果,搜索用时 15 毫秒
41.
Glenwick David S.; Brodsky Stanley L.; Franks Cyril M.; Hess Allen K.; Balch Katherine; Frank Jerome B.; Garfield Sol L.; Jason Leonard A. 《Canadian Metallurgical Quarterly》1987,42(4):405
Discusses the factors that should be considered when preparing to edit a high-quality, scholarly psychology book. The issues discussed include the book editor–publisher relationship, the book editor–chapter contributor relationship, and what makes a good final product. Three laws of editing are offered: (1) conceptualize clearly; (2) edit fiercely; and (3) edit for the reader, not the writer. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
42.
Berge P Ratel J Fournier A Jondreville C Feidt C Roudaut B Le Bizec B Engel E 《Environmental science & technology》2011,45(15):6584-6591
The study investigated the feasibility of using volatile compound signatures of liver tissues in poultry to detect previous dietary exposure to different types of xenobiotic. Six groups of broiler chickens were fed a similar diet either noncontaminated or contaminated with polychlorinated dibenzo-p-dioxins/-furans (PCDD/Fs; 3.14 pg WHO-TEQ/g feed, 12% moisture), polychlorinated biphenyls (PCBs; 0.08 pg WHO-TEQ/g feed, 12% moisture), polybrominated diphenyl ethers (PBDEs; 1.63 ng/g feed, 12% moisture), polycyclic aromatic hydrocarbons (PAHs; 0.72 μg/g fresh matter), or coccidiostats (0.5 mg/g feed, fresh matter). Each chicken liver was analyzed by solid-phase microextraction - mass spectrometry (SPME-MS) for volatile compound metabolic signature and by gas chromatography - high resolution mass spectrometry (GC-HRMS), gas chromatography - tandem mass spectrometry (GC-MS/MS), and liquid chromatography - tandem mass spectrometry (LC-MS/MS) to quantify xenobiotic residues. Volatile compound signature evidenced a liver metabolic response to PAH although these rapidly metabolized xenobiotics are undetectable in this organ by the reference methods. Similarly, the volatile compound metabolic signature enabled to differentiate the noncontaminated chickens from those contaminated with PBDEs or coccidiostats. In contrast, no clear signature was pointed out for slowly metabolized compounds such as PCDD/Fs and PCBs although their residues were found in liver at 50.93 (±6.71) and 0.67 (±0.1) pg WHO-TEQ/g fat, respectively. 相似文献
43.
Solid Oxide Electrolyzer Cells (SOECs) are promising energy devices for the production of syngas (H2/CO) by H2O and/or CO2 electrolysis. Here we developed a Cu–Ce0.9Gd0.1O2−δ/Ce0.8Gd0.2O2−δ/Ba0.5Sr0.5Co0.8Fe0.2O3−δ-Ce0.8Gd0.2O2−δ cell and performed H2O and CO2 electrolysis experiments in the intermediate temperature range (600°C–700 °C). As a baseline, the cell was first tested in fuel cell operation mode; the sample shows a maximum power density peak of 104 mW cm−2 at 700 °C under pure hydrogen and air. H2O electrolysis testing revealed a steady production of hydrogen with a Faraday's efficiency of 32% at 700 °C at an imposed current density of −78 mA cm−2. CO production was observed during CO2 electrolysis but higher cell voltages were required. A lower efficiency of about 4% was obtained at 700 °C at an imposed current density of −660 mA cm−2. These results confirm that syngas production is feasible by water and carbon dioxide electrolysis but further improvements from both the manufacturing and the electrocatalytic aspects are needed to reach higher yields and efficiencies. 相似文献
44.
Effects of caffeine on lipoprotein lipase gene expression during the adipocyte differentiation process 总被引:1,自引:0,他引:1
Cyril Couturier Brigitte Janyier Delphine Girlich Gilbert Béréziat Marise Andréani-Mangeney 《Lipids》1998,33(5):455-460
In this study, the effects of caffeine on lipoprotein lipase (LPL) gene expression were investigated in the 3T3-F442A preadipocyte
cell line during the adipocyte differentiation process by determining LPL enzymatic activity and its messenger RNA (mRNA)
level. The results demonstrate that caffeine acts on the gene expression of LPL, an early marker of adipocyte differentiation.
It has a biphasic action: it increases gene expression in terms of mRNA when it is added to preadipocytes during the early
stage of differentiation, but this is accompanied by a reduction of enzymatic activity. On the other hand, when caffeine is
added for long periods during differentiation and/or when it is added to mature adipocytes, it induces marked inhibition of
mRNA levels, correlated with a marked reduction of secreted enzymatic activity. The inhibitory effect of caffeine on LPL mRNA
level can be reproduced by theophylline, a phosphodiesterase inhibitor, and by dibutyryl cyclic AMP, a non-metabolizable analog
of cyclic AMP. However, the effect of caffeine and theophylline lasts longer than that of cyclic AMP, suggesting that a mechanism
other than inhibition of cyclic AMP hydrolysis may be involved in the action of caffeine. 相似文献
45.
Deepak Shamvedi Oliver J. McCarthy Eoghan O’Donoghue Cyril Danilenkoff Paul O’Leary Ramesh Raghavendra 《Virtual and Physical Prototyping》2018,13(4):301-310
This research relates to the design, modelling and fabrication of 3D metal printed heat sinks. The heat sinks presented in the research are the commonly used longitudinal fin solid heat sink (LFSHS) and three LFSHS lattice structure designs, differing only in their lattice sizes, fabricated using the Direct Metal Laser Sintering (DMLS) technique in Maraging Steel (MS1), on an EOSINT M280 system. In order to increase the heat sink surface area, the heat sinks are manufactured with mesh lattices along the length of the fins, while keeping the overall heat sink volume constant. The research is focused on pushing the limitations of the DMLS technique for the development of repeating unit, lattice structures heat sinks, and to examine the effect of incrementally varying the lattice sizes with regards to the resultant surface area of the heat sink and the thermal performance of the system. The results obtained under natural convection show that the thermal performance of the LFSHS outperformed all lattice structure heat sinks. This is due to the fact that, the pressure drop across the lattice heat sinks were so high, due to lattice meshes that it negated the positive effect of the greater surface area. 相似文献
46.
Myriam Gharbi Patrice Peyre Cyril Gorny Muriel Carin Simon Morville Philippe Le Masson Denis Carron Rémy Fabbro 《Journal of Materials Processing Technology》2013,213(5):791-800
The direct metal deposition (DMD) with laser is a free-form metal deposition process for manufacturing dense pieces, which allows generating a prototype or small series of near net-shape structures. One of the most critical issues is that produced pieces have a deleterious surface finish which systematically requires post machining steps. This problem has never been fully addressed before.The present work describes investigations on the DMD process, using an Yb-YAG disk laser, and a widely used titanium alloy (Ti–6Al–4V) to understand the influence of the main process parameters on the surface finish quality. The focus of our work was: (1) to understand the physical mechanisms responsible for deleterious surface finishes, (2) to propose different experimental solutions for improving surface finish.In order to understand the physical mechanisms responsible for deleterious surface finishes, we have carried out: (1) a precise characterization of the laser beam and the powder stream; (2) a large number of multi-layered walls using different process parameters (P(W), V(m/min), Dm (g/min), Gaussian or uniform beam distribution); (3) a real time fast camera analysis of melt pool dynamics and melt-pool – powder stream coupling; (4) a characterization of wall morphologies versus process parameters using 2D and 3D profilometry.The results confirm that surface degradation depends on two distinct aspects: the sticking of non-melted or partially melted particles on the free surfaces, and the formation of menisci with more or less pronounced curvature radii. Among other aspects, a reduction of layer thickness and an increase of melt-pool volumes to favor re-melting processes are shown to have a beneficial effect on roughness parameters. Last, a simple analytical model was proposed to correlate melt-pool geometries to resulting surface finishes. 相似文献
47.
48.
Chong Peter H. J. Leung Cyril 《International Journal of Wireless Information Networks》2003,10(1):17-31
Reuse partitioning (RP) is a simple technique that can be used to increase the traffic capacity in a cellular system. With RP, a cell is divided into several concentric regions, each associated with a different cluster size. In this article, a traffic model is developed to analyze the impact of mobile users on a two-region RP system using fixed channel assignment. The influence of user speed and cell size on the new call blocking probability, Pb, and the call dropping probability, Pd, is investigated. A simpler model that can be used to estimate Pb and Pd in some cases is described. The effect on system capacity of reserving some channels for handoff calls is also studied. It is found that even though prioritized handoff can reduce Pd, it may also degrade the capacity. The accuracy of the analysis is verified using simulation for three mobility models. 相似文献
49.
Stephen Alstrup Cyril Gavoille Haim Kaplan Theis Rauhe 《Theory of Computing Systems》2004,37(3):441-456
Several papers describe linear time algorithms to preprocess a tree, in order to answer subsequent nearest common ancestor
queries in constant time. Here, we survey these algorithms and related results. Whereas previous algorithms produce a linear
space data structure, in this paper we address the problem of distributing the data structure into short labels associated
with the nodes. Localized data structures received much attention recently as they play an important role for distributed
applications such as routing. We conclude our survey with a new simple algorithm that labels in O(n) time all the nodes of
an n-node rooted tree such that from the labels of any two nodes alone one can compute in constant time the label of their
nearest common ancestor. The labels assigned by our algorithm are of size O(log n) bits. 相似文献
50.