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排序方式: 共有221条查询结果,搜索用时 15 毫秒
1.
R Gouider E LeGuern J Emile S Tardieu F Cabon M Samid J Weissenbach Y Agid P Bouche A Brice 《Canadian Metallurgical Quarterly》1994,44(12):2250-2252
Fistulas secondary to Crohn's disease occur in about 33% of patients. A colobronchial fistula complicating Crohn's disease is very rare, having been reported only twice previously. We present an unusual fistula secondary to Crohn's colitis that originated from the splenic flexure and crossed the diaphragm to involve the bronchial tree. 相似文献
2.
F. D. McDaniel B. L. Doyle C. H. Seager D. S. Walsh G. Vizkelethy D. K. Brice C. Yang P. Rossi M. Nigam M. El Bouanani G. V. Ravi Prasad J. C. Schwartz L. T. Mitchell J. L. Duggan 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2002,190(1-4):1-10
A new ion beam analysis-based, single ion technique called the time to first photon has been developed to measure the decay of the luminescence signal of phosphors. Such measurements are currently needed to study luminescence decay mechanisms following high-density excitations and to identify strongly luminescent phosphor coatings with short lifetimes for ion photon emission microscopy (IPEM). The samples for this technique consist of thin phosphor layers placed or coated on the surface of PIN diodes. Single ions from an accelerator strike this sample and simultaneously create ion beam induced luminescence (IBIL) from the phosphor that is measured by a single-photon-detector, and an ion beam induced charge collection (IBICC) signal in the PIN diode. In this case, the IBICC signal provides the start pulse and the IBIL signal the stop pulse to a time to amplitude converter. It is straightforward to show that this approach also measures a signal proportional to activity versus time with an accuracy of 5% as long as the number of detected photons per ion is less than 0.1, which usually requires the use of absorbers for the IBIL detector or electronic discrimination for the IBIL signals. Details of the new analysis are given together with examples of luminescence decay measurements of several ceramic phosphors being considered to coat IPEM samples. IPEM is currently being developed at Sandia National Laboratory (SNL), the University of North Texas in Denton, and the Universities and INFN of Padova and Torino. 相似文献
3.
Compared with driving or flight simulation, little is known about self-motion perception in riding simulation. The goal of this study was to examine whether or not continuous roll motion supports the sensation of leaning into bends in dynamic motorcycle simulation. To this end, riders were able to freely tune the visual scene and/or motorcycle simulator roll angle to find a pattern that matched their prior knowledge. Our results revealed idiosyncrasy in the combination of visual and proprioceptive information. Some subjects relied more on the visual dimension, but reported increased sickness symptoms with the visual roll angle. Others relied more on proprioceptive information, tuning the direction of the visual scenery to match three possible patterns. Our findings also showed that these two subgroups tuned the motorcycle simulator roll angle in a similar way. This suggests that sustained inertially specified roll motion have contributed to the sensation of leaning in spite of the occurrence of unexpected gravito-inertial stimulation during the tilt. Several hypotheses are discussed.
Practitioner Summary: Self-motion perception in motorcycle simulation is a relatively new research area. We examined how participants combined visual and proprioceptive information. Findings revealed individual differences in the visual dimension. However, participants tuned the simulator roll angle similarly, supporting the hypothesis that sustained inertially specified roll motion contributes to a leaning sensation. 相似文献
4.
The multiplication of cores in today’s architectures raises the importance of intra-node communication in modern clusters and their impact on the overall parallel application performance. Although several proposals focused on this issue in the past, there is still a need for a portable and hardware-independent solution that addresses the requirements of both point-to-point and collective MPIoperations inside shared-memory computing nodes. 相似文献
5.
Multivalent Interactions between an Aromatic Helical Foldamer and a DNA G‐Quadruplex in the Solid State 下载免费PDF全文
Dr. Pradeep K. Mandal Dr. Benoît Baptiste Dr. Béatrice Langlois d'Estaintot Dr. Brice Kauffmann Dr. Ivan Huc 《Chembiochem : a European journal of chemical biology》2016,17(20):1911-1914
Quinoline‐based oligoamide foldamers have been identified as a potent class of ligands for G‐quadruplex DNA. Their helical structure is thought to target G‐quadruplex loops or grooves and not G‐tetrads. We report a co‐crystal structure of the antiparallel hairpin dimeric DNA G‐quadruplex (G4T4G4)2 with tetramer 1 —a helically folded oligo‐quinolinecarboxamide bearing cationic side chains—that is consistent with this hypothesis. Multivalent foldamer–DNA interactions that modify the packing of (G4T4G4)2 in the solid state are observed. 相似文献
6.
Brice Mvou Lekogo 《International journal of food microbiology》2010,141(3):242-247
Heat resistance of spores is affected by many factors such as temperature, pH, water activity (aw) and others. Previous studies have reported that free fatty acids can affect the germination and growth of bacterial spores. In this study, we investigated the influence of free fatty acids in heating medium or in recovery medium on the heat resistance of spores of Bacillus cereus NTCC 11145 and Clostridium sporogenes Pasteur 79.3. Four free fatty acids were studied: palmitic, palmitoleic, stearic and oleic acids. During thermal treatments, the impact of these FFA in heating media was generally low, but the presence of free fatty acids in the recovery medium highly decreases bacterial spore apparent heat resistance, particularly with unsaturated fatty acids. A mathematical model was developed to describe and quantify the influence of free fatty acids in recovery media on the D-values. The z′FFA parameter values which quantify the impact of free fatty acids were determined. The variation of this parameter value according to the free fatty acid type was compared with MIC value variation given in the literature. The model enables the decrease in D-values in the presence of free fatty acids to be estimated. The high concentrations of free fatty acids in liver or canned duck may explain the microbial stability with low sterilization values applied. 相似文献
7.
Networks and Spatial Economics - Urban planning is a complex problem which includes choosing a social objective for a city, finding the associated optimal allocation of agents and identifying... 相似文献
8.
The sociodemographic diversity of residential customers can affect the level of financial risk that an electricity provider experiences in the retail market. To demonstrate the relationship between sociodemographic diversity and financial risk, electricity consumption data drawn from the United Kingdom Power Networks ‘Low Carbon London’ project was analyzed to explore the relationship between sociodemographic diversity and financial risk experienced by electricity retailers. The results show that when increasing the sociodemographic diversity amongst a group of residential customers the effect on financial risk depends on the electricity consumption patterns of individual customers and the relationship of consumption patterns between residential customers. Increasing sociodemographic diversity amongst residential customers with very distinct energy consumption patterns can decrease the overall financial risk associated with the aggregated revenue received from these customers. However, the results showed that adding customers to a customer base without consideration for their sociodemographic background can cause the overall financial risk associated with the aggregated revenue received to change erratically. Whilst previous studies have considered customer diversity and its influence on peak electricity demand, this research advances the state-of-the-art by showing the importance of customer diversity to the financial quantity risk experienced by electricity retailers. This finding has serious implications for electricity providers seeking to mitigate financial risk in the retail electricity market. 相似文献
9.
10.
Camden Debruler Wenda Wu Kevin Cox Brice Vanness T. Leo Liu 《Advanced functional materials》2020,30(24)
Here, a pH neutral aqueous organic redox flow battery (AORFB) consisting of three electrolytes channels (i.e., an anolyte channel, a catholyte channel, and a central salt water channel) to achieve integrated energy storage and desalination is reported. Employing a low cost, chemically stable methyl viologen (MV) anolyte, and sodium ferrocyanide catholyte, this desalination AORFB is capable of desalinating simulated seawater (0.56 m NaCl) down to 0.023 m salt concentration at an energy cost of 2.4 W h L?1 of fresh water—competitive with current reverse osmosis technologies. Simultaneously, the cell delivers stored energy at 79.7% efficiency with a cell voltage of 0.85 V. Furthermore, the cell is also capable of higher current operation up to 15 mA cm?2, providing 4.55 mL of fresh water per hour. Combining energy storage and water desalination into such a bifunctional device offers the opportunity to address two growing global issues from one hardware installation. 相似文献