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31.
Assume that the probability density function for the lifetime of a newly designed product has the form: [H(t)/Q()] exp{–H(t)/Q()}. The Exponential(), Rayleigh, WeibullW(, ) and Pareto pdf's are special cases.Q() will be assumed to have an inverse Gamma prior. Assume thatm independent products are to be tested with replacement. A Bayesian Sequential Reliability Demonstration Testing plan is used to eigher accept the product and start formal production, or reject the product for reengineering. The test criterion is the intersection of two goals, a minimal goal to begin production and a mature product goal. The exact values of various risks and the distribution of total number of failures are evaluated. Based on a result about a Poisson process, the expected stopping time for the exponential failure time is also found. Included in these risks and expected stopping times are frequentist versions, thereof, so that the results also provide frequentist answers for a class of interesting stopping rules.This research was supported by NSF grants DMS-8703620 and DMS-8923071, and forms part of the Ph.D. Thesis of the first author, the development of which was supported in part by a David Ross grant at Purdue University. The authors thank the editors and a referee for insightful comments and suggestions. 相似文献
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Asner DM Athanas M Bliss DW Brower WS Masek G Paar HP Gronberg J Korte CM Kutschke R Menary S Morrison RJ Nakanishi S Nelson HN Nelson TK Qiao C Richman JD Roberts D Ryd A Tajima H Witherell MS Balest R Cho K Ford WT Lohner M Park H Rankin P Smith JG Alexander JP Bebek C Berger BE Berkelman K Bloom K Browder TE Cassel DG Cho HA Coffman DM Crowcroft DS Dickson M Drell PS Dumas DJ Ehrlich R Elia R Gaidarev P Garcia-Sciveres M Gittelman B Gray SW Hartill DL Heltsley BK Henderson S Jones CD 《Physical review D: Particles and fields》1996,53(3):1039-1050
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The variation in the lifetime of flash-excited gaseous benzophenone with pressure and temperature indicates that (1) self-quenching is a relatively inefficient process for the long-lived emission, ksq = 9 × 105 M?1 s?1 (estimated from solution data) at 25°C and 1.2 × 107 M?1 s?1 at 170°C and (2) the lifetime decreases with increasing temperature as a result of photochemical and photophysical decay pathways which have significant activation energies. The importance of diffusion to the walls on lifetime measurements is discussed. 相似文献
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Preparation of Stilbenyl Derivatives of Isoxazoles Schiff's bases derived from 3- and 5-(p-formylphenyl)-phenylisoxazoles and o- or p-chloroaniline are reacted with various p-tolyl substituted aromatic heterocycles in the presence of dimethylformamide and potassium hydroxide or potassium t-but-oxide to yield the corresponding heterocyclic substituted stilbenes (‘Anil synthesis’). 5-[4-(Chlorphenylimino-methyl)phenyl]-phenylisoxazoles react less readily than the corresponding 3-isomers. 相似文献
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C. Matei D. Berger P. Marote S. Stoleriu J.P. Deloume 《Progress in Solid State Chemistry》2007,35(2-4):203-209
Lanthanum-based perovskites, LaMO3 (where M = Mn, Fe, Co, Ni), have been synthesised from lanthanum precursors and corresponding 3d transition metal salts in molten alkali metal nitrates or nitrites. The reactivity of eight precursors in three molten salts of different basicity was analysed. Single phase orthorhombic LaMnO3.11, and orthorhombic LaFeO3 have been obtained in molten NaNO2 at 723 K, for 2 h. LaCoO3 is also formed in molten nitrite, but an increase of basicity, by adding Na2O2, was necessary to obtain LaNiO3. The reaction systems were investigated by thermal analysis. X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX) and specific surface area measurements (BET method) were used to characterise the synthesised nanopowders. 相似文献
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Pagel K Seeger K Seiwert B Villa A Mark AE Berger S Koksch B 《Organic & biomolecular chemistry》2005,3(7):1189-1194
We report here an advanced approach for the characterization of the folding pattern of a de novo designed antiparallel coiled coil peptide by high-resolution methods. Incorporation of two fluorescence labels at the C- and N-terminus of the peptide chain as well as modification of two hydrophobic core positions by Phe/[15N,13C]Leu enable the study of the folding characteristics and of distinct amino acid side chain interactions by fluorescence resonance energy transfer (FRET) and NMR spectroscopy. Results of both experiments reveal the antiparallel alignment of the helices and thus prove the design concept. This finding is also supported by molecular dynamics simulations. Electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI-FTICR-MS) in combination with NMR experiments was used for verification of the oligomerization equilibria of the coiled coil peptide. 相似文献