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961.
The release of aroma compounds from rehydrated French beans in an artificial mouth system and in the mouths of 12 assessors was studied by gas chromatography combined with flame ionisation detection and sniffing port detection. In an artificial mouth system, volatile compounds were isolated under mouth conditions, such as temperature, salivation, and mastication. No significant differences were determined between the aroma release from the beans in the artificial mouth and release in the mouths of assessors. However, both the real and artificial mouth systems differed significantly from a purge-and-trap and a dynamic headspace system in aroma release. In order to study aroma release over time, volatile compounds were isolated from rehydrated French beans for 1, 1.5, 3 and 12 min in the artificial mouth system and analysed by gas chromatography/sniffing port analysis. 2-Methylpropanal, 2-/3-methylbutanal, hexanal, 2-methyl-2-butenal, 1-octen-3-one, and dimethyl trisulphide possessed detectable odours when isolated from the French beans in the artificial mouth for all time periods. The odour active compounds 2-/3-methylbutanal and hexanal were shown to be released at a constant rate. Different sampling times resulted in identical selections of aroma compounds, while mutual proportions were retained. 相似文献
962.
A simultaneous detection sequential injection analysis (SIA) system is proposed for the determination of S and R captopril using a potentiometric, enantioselective membrane electrode based on maltodextrin (DE=14-17) for the assay of S-captopril and an amperometric biosensor for the assay of R-captopril. The proposed SIA system can be utilized reliably for the on-line simultaneous detection of the enantiomers in the synthesis process at a rate of 38 samples per hour in the following linear concentration ranges: 100-1000 nmol/l (R-captopril) and 1-1000 mumol/l (S-captopril) with a RSD better than 0.009% (n=10). 相似文献
963.
McCormack DA Kroes GJ Olsen RA Groeneveld JA van Stralen JN Baerends EJ Mowrey RC 《Faraday discussions》2000,(117):109-32; discussion 161-89
We perform six-dimensional (6D) quantum wavepacket calculations for H2 dissociatively adsorbing on Cu(100) from a variety of rovibrational initial states. The calculations are performed on a new potential energy surface (PES), the construction of which is also detailed. Reaction probabilities are in good agreement with experimental findings. Using a new flux analysis method, we calculate the reaction probability density as a function of surface site and collision energy, for a variety of initial states. This approach is used to study the effects of rotation and vibration on reaction at specific surface sites. The results are explained in terms of characteristics of the PES and intrinsically dynamic effects. An important observation is that, even at low collision energies, reaction does not necessarily proceed predominantly in the region of the minimum potential barrier, but can occur almost exclusively at a site with a higher barrier. This suggests that experimental control of initial conditions could be used to selectively induce reaction at particular surface sites. Our predictions for site-reactivity could be tested using contemporary experimental methods: The calculations predict that, for reacting molecules, there will be a dependence of the quadrupole alignment of j on the incident vibrational state, v. This is a direct result of PES topography in the vicinity of the preferred reaction sites of v = 0 and v = 1 molecules. Invoking detailed balance, evidence for this difference in preferred reaction site of v = 0 and 1 molecules could be obtained through associative desorption experiments. 相似文献
964.
965.
966.
Schmidt KS Filippov DV Meeuwenoord NJ van Der Marel GA van Boom JH Lippert B Reedijk J 《Angewandte Chemie (International ed. in English)》2000,39(2):375-377
Cross-linking ability is possible with the oligonucleotide-tethered, monofunctional trans-Pt(II) complex shown. It was synthesized by a novel solid-phase approach comprising conjugation of immobilized tetrathymidylic acid with a trans-a(2)Pt(II) building unit, ammonolysis, and transformation of the resulting complex (R=1-N-cyclohexylmethylthyminate) into the chloro derivative (R=Cl). a=NH(2)CH(3), T=thymine. 相似文献
967.
Hongbo Li C. H. M. van der Werf A. Borreman J. K. Rath Ruud E. I. Schropp 《固体物理学:研究快报》2008,2(4):157-159
In this letter we report the result of an a‐Si:H/nc‐Si:H tandem thin film silicon solar mini‐module fabricated on plastic foil containing intrinsic silicon layers made by hot‐wire CVD (efficiency 7.4%, monolithically series‐connected, aperture area 25 cm2). We used the Helianthos cell transfer process. The cells were first deposited on a temporary aluminum foil carrier, which allows the use of the optimal processing temperatures, and then transferred to a plastic foil. This letter reports the characteristics of the flexible solar cells obtained in this manner, and compares the results with those obtained on reference glass substrates. The research focus for implementation of the hot‐wire CVD technique for the roll‐to‐roll process is also discussed. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
968.
969.
Three-dimensional tomography using a cubic-phase plate extended depth-of-field system 总被引:1,自引:0,他引:1
We use cubic-phase plate imaging to demonstrate an order-of-magnitude improvement in the transverse resolution of three-dimensional objects reconstructed by extended depth-of-field tomography. Our algorithm compensates for the range shear of the cubic-phase approach and uses camera rotation to center the reconstructed volume on a target object point. 相似文献
970.
F Ackermann L Walls R van der Meer M Borman 《The Journal of the Operational Research Society》1999,50(3):195-204
Despite undoubtedly being one of the latest fads, Business Process Reengineering (BPR) has provoked much debate about how organisations should be managed if dramatic improvements in performance are to be achieved. This paper takes a multidisciplinary view of BPR and focuses upon a number of the emergent issues. These include the role of strategy making, the promotion of communication and creativity, the role of statistics, and the effective use of performance measurement systems within a learning environment. The paper develops a framework that capitalises on the role of modelling in MS/OR as well as the various disciplines of the authors. As such, the framework draws on recent advances, as well as established thinking, in the areas of strategy development, information systems, quality management and statistical science. More importantly, the framework also provides an iterative approach to BPR enabling organisations to design, implement and monitor progress on an ongoing basis. Emphasis is placed on building effective communications, developing an organisational memory and supporting organisational learning. 相似文献