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排序方式: 共有1390条查询结果,搜索用时 15 毫秒
1.
F Foussadier P Menard R Zaza J Pillet JC Bertrand 《Canadian Metallurgical Quarterly》1993,94(5):312-317
The use of osseointegrated implants to provide support for auricle prosthesis as been carried out by Tjellstrom. This method has provided the maxillofacial surgeon with another approach to the treatment of defect of the auricle. The principles and concepts of extra-oral osseointegrated implants are the same as those of the intra-oral application developed by Branemark 26 years ago. This simple and reliable method allow the attachment to splint bar fixated to three or two mastoid osseointegrated implants. This method represent an interesting possibility for the management of auricle defects. We report on our experience of 11 cases. 相似文献
2.
Batch process industries are characterized by complex precedence relationships between operations, which renders the estimation
of an acceptable workload very difficult. A detailed schedule based model can be used for this purpose, but for large problems
this may require a prohibitive large amount of computation time. We propose a regression based model to estimate the makespan
of a set of jobs. We extend earlier work based on deterministic processing times by considering Erlang-distributed processing
times in our model. This regression-based model is used to support customer order acceptance. Three order acceptance policies
are compared by means of simulation experiments: a scheduling policy, a workload policy and a regression policy. The results
indicate that the performance of the regression policy can compete with the performance of the scheduling policy in situations
with high variety in the job mix and high uncertainty in the processing times.
Correspondence to: C.V. Ivanescu 相似文献
3.
Nourh ne Boudhrioua Bertrand Broyart Catherine Bonazzi Jean-Dominique Daudin 《Drying Technology》2005,23(12):2313-2335
A method is presented for computing the values of apparent diffusivity in solids with respect to the concentration of the diffusing substance (water or sodium chloride). This method does not require any assumption upon the mathematical relationship between diffusivity and concentration. It can be applied to experimental measurements of local concentration versus position within the solid (profiles) with relatively few measurements (circa 10) and a mathematical smoothing of the experimental data by using an artificial neural network model. The method was first validated on simulated data obtained by using a constant diffusivity value and on experimental profiles when the relation between diffusivity and concentration was given. It was then applied to original experimental moisture profiles obtained by putting gelatin gels with different initial moisture contents into contact for up to 14 days. The method was also successfully applied to five sets of experimental moisture and sodium chloride profiles taken from the literature and obtained from different food products. Apparent diffusivities calculated by our method were found in agreement with those obtained by authors using different numerical methods to compute the diffusivity values. 相似文献
4.
P Brouqui HT Dupont M Drancourt Y Berland J Etienne C Leport F Goldstein P Massip M Micoud A Bertrand 《Canadian Metallurgical Quarterly》1993,153(5):642-648
OBJECTIVE: Chronic Q fever is seldom recognized; before 1989, only 234 cases had been reported in the literature. The 92 cases of chronic Q fever collected at the French National Reference Center for Rickettsioses from 1982 through 1990 represent the largest series ever reported. PATIENTS: The patients included in the study were diagnosed between July 31, 1982, and August 1, 1990, at the French National Reference Center for Rickettsioses as having chronic Q fever by the following criteria: presence of antibody against Coxiella burnetii phase I antigen at a titer greater than or equal to 800 for IgG and 50 for IgA by the indirect immunofluorescence test. Epidemiologic, clinical, laboratory, and treatment data were collected from 39 different collaborative hospitals throughout France. MAIN OUTCOME MEASURE: For each serologically selected patient, a computerized questionnaire was utilized to record 188 different items of demographic, epidemiologic, clinical, laboratory, and therapeutic data, which were analyzed. RESULTS: Chronic Q fever occurs more frequently in city dwellers than in rural inhabitants, and exposure to domestic ruminants and raw milk is an important feature. Immunocompromising conditions (20.2%) and underlying heart disease (88.4%) or vascular disease are the most important risk factors to consider in potential cases of chronic Q fever. The mortality in these patients with endocarditis was high (23.5%). The clinical spectrum of 84 patients included 57 cases of endocarditis, three cases of vascular prosthesis infection, three cases of aneurysmal infection, three cases of osteoarthritis, four cases with lung localizations, nine asymptomatic cases, three cases of hepatitis, and two cases with cutaneous forms of the disease. CONCLUSIONS: In patients with unexplained fever, negative blood cultures, and a history of underlying vascular or cardiac disease, Q fever should be considered. 相似文献
5.
M Divaris M Rosenstiel M Slama GF Cancemi JC Bertrand F Guilbert 《Canadian Metallurgical Quarterly》1996,97(3):178-189
The cardiovascular effects of a partially purified extract of fish oil, enriched in the n-3 series fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), were studied in stroke-prone spontaneously hypertensive rats (SHR-SP) fed with high- and low-sodium diets during 5 weeks. Addition of salt to the low-salt control diet at a level commonly found in human food items (6% NaCl of the dry weight of the diet) produced a remarkable rise in blood pressure, an increase in left ventricular weight-to-body weight ratio (LVH-index) and an increase in kidney weight-to-body weight ratio (RH-index). Fish oil (20% of the dry weight of the diet) did not significantly influence the blood pressure or LVH-index or RH-index during the low-salt control diet. However, fish oil completely prevented the remarkable rise in blood pressure and clearly antagonized the rise of both LVH- and RH-indices, induced by the high-salt diet. The fish oil supplementation increased the levels of the polyunsaturated fatty acids of the n-3 series and decreased those of the n-6 series in plasma and kidney, irrespective of the salt content of the diet. Fish oil lowered serum thromboxane B2 concentration by approximately 75%. During the high-salt diet, fish oil markedly decreased water intake and urine volume, and increased urinary sodium concentration by about 60%. Our findings show that, in addition to an antihypertensive effect, fish oil also decreases LVH and RH. These effects appear to be due to an improved ability to excrete sodium and could be explained by the observed changes in the fatty acid composition and metabolism. 相似文献
6.
D. Trmouilles G. Bertrand M. Bafleur F. Beaudoin P. Perdu N. Guitard L. Lescouzres 《Microelectronics Reliability》2003,43(1):71-79
The number of circuit design iterations due to electrostatic discharge (ESD) failures increases with the complexity of VLSI technologies and their shrinking. In this paper, we show how TCAD and ESD SPICE modeling can be used to solve ESD protection issues in an analog CMOS technology. 相似文献
7.
M. Safar D. Bertrand P. Robert M. F. Devaux C. Genot 《Journal of the American Oil Chemists' Society》1994,71(4):371-377
The combination of attenuated total reflectance (ATR) and mid-infrared spectroscopy (MIRS) with statistical multidimensional
techniques made it possible to extract relevant information from MIR spectra of lipid-rich food products. Wavenumber assignments
for typical functional groups in fatty acids were made for standard fatty acids: Absorption bands around 1745 cm−1, 2853 cm−1, 2954 cm−1, 3005 cm−1, 966 cm−1, 3450 cm−1 and 1640 cm−1 are due to absorption of the carbonyl group, C−H stretch, =CH double bonds of lipids and O−H of lipids, respectively. In
lipid-rich food products, some bands are modified. Water strongly absorbs in the region of 3600–3000 cm−1 and at 1650 cm−1 in butters and margarines, allowing one to rapidly differentiate the foods as function of their water content. Principal
component analysis was used to emphasize the differences between spectra and to rapidly classify 27 commercial samples of
oils, butters and margarines. As the MIR spectra contain information about carbonyl groups and double bonds, the foods were
classified with ATR-MIR, in agreement with their degree of esterification and their degree of unsaturation as determined from
gas-liquid chromatography analysis. However, it was difficult to differentiate the studied food products in terms of their
average chainlength. 相似文献
8.
Christophe Lombard Stephane Le Doze Eric Marencak Paul-Marie Marquaire David Le Noc Grégory Bertrand François Lapicque 《International Journal of Hydrogen Energy》2006
The paper reports the results of on-site regeneration catalytic bed of the natural gas reformer in a 5 kW PEM fuel cell system. The Ni catalyst previously poisoned by sulphur from the available natural gas, could be re-activated by injection of pure water steam, following the method developed for industrial reformers using the same metal catalyst: this method was shown to be perfectly efficient, provided no natural gas was fed during the operation. Results of the tests conducted are presented and discussed in relation to published data on S-sorption on Ni surfaces. 相似文献
9.
Benedetto Bozzini Bertrand Busson Claudio Mele Abderrahmane Tadjeddine 《Journal of Applied Electrochemistry》2008,38(7):897-906
We report on potential-dependent in situ SFG and DFG spectroscopy carried out at Au(111), Au(210), polycrystalline Au, Au–Cu
and Au–Ag–Cu electrodes in contact with aqueous solutions containing CN− and 4-cyanopyridine (4CP). Spectroelectrochemical work was complemented by cyclic voltammetry. The chief stress has been
placed on systematising and quantifying the interaction between 4CP and CN− and the attending effects on the vibrational and electronic structures of the interface. The voltammetric behaviour of the
investigated electrodes, modified by the addition of 4CP to the CN− electrolyte, denote changes in the CN− adsorption characteristics and effects of the adsorbed CN− layer on the electrodic reactivity of 4CP. The differences among the investigated electrodes can be explained in terms of
their respective degrees of atomic packing or with alloying effects on the stability of adsorbed CN−. The potential-dependent spectra have been analysed quantitatively with a model for the second order non linear susceptibility
accounting for vibrational and electronic effects. The spectral changes induced by addition of 4CP denote interaction of the
aromatic with the electrode through the CN− monolayer. The non-resonant contribution yields information on the effects of 4CP on the fine structure of the bound electron
density of states. 相似文献
10.
Jehl X. Sanquer M. Bertrand G. Guegan G. Deleonibus S. Fraboulet D. 《Nanotechnology, IEEE Transactions on》2003,2(4):308-313
Coulomb blockade has been widely reported in silicon and metallic structures without intentional tunnel barriers. In particular, a simple constriction in silicon-on-insulator (SOI) allows to build a three-terminal silicon single-electron transistor (SET) operating at moderate temperature. The key parameters are the access resistances confining the electrons and the size of the gate-channel overlap, which sets the Coulomb energy. Thin films of doped silicon with sheet resistance of a few tens of h/e/sup 2/ are well suited for fabricating optimized access resistances. Low doped extensions with typical resistivity 1000 /spl Omega//spl mu/m (at 300 K) are also good candidates. We illustrate this MOS-SET principle in SOI constriction and standard MOSFET of similar size. Although relying on different concepts, the ultimate MOSFET and MOS-SET are shown to be technologically close, differing mostly by the ratio between the channel resistance over the access resistance. Because this ratio is decreasing as the gate length shrinks, single electron effects should become more and more important at high temperature in the subthreshold regime of standard field effect transistor devices. 相似文献