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排序方式: 共有758条查询结果,搜索用时 15 毫秒
1.
Sufficient conditions for the existence and uniqueness of solutions of singular systems of 2-D difference equations with constant coefficients are formulated. Linear transformation of the matrix coefficients leads to recursive forms of such systems of equations. The results are applied to standard 2-D state-space models of discrete systems and sufficient conditions of BIBO stability of these singular systems are obtained.  相似文献   
2.
The energy level alignment between organic semiconductors (OSCs) and the respective (metal) electrodes in organic electronic devices is of key importance for efficient charge carrier injection. For many years, researchers have attempted to control this energy level alignment by means of functional self‐assembled monolayers or the insertion of thin injection layers (made, e.g., of doped OCSs or pure dopants). The present work demonstrates an alternative to these approaches, namely the use of phthalocyanine monolayers as contact primers, which are deposited onto noble metal electrodes by means of vacuum deposition. It is shown that polar as well as non‐polar phthalocyanines modify the work functions of clean Au(111) and Ag(111) surfaces as a function of their coverage and thus enable quantitative control of the metal work functions. This behavior is successfully replicated for the respective polycrystalline metal surfaces and it is found that full monolayers can even withstand air exposure when protected by sacrificial multilayers, which are afterward removed by thermal desorption.  相似文献   
3.
Gaussian process modeling of EEG for the detection of neonatal seizures   总被引:1,自引:0,他引:1  
Gaussian process (GP) probabilistic models have attractive advantages over parametric and neural network modeling approaches. They have a small number of tuneable parameters, can be trained on relatively small training sets, and provide a measure of prediction certainty. In this paper, these properties are exploited to develop two methods of highlighting the presence of neonatal seizures from electroencephalograph (EEG) signals. In the first method, the certainty of the GP model prediction is used to indicate the presence of seizures. In the second approach, the hyperparameters of the GP model are used. Tests are carried out with a feature set of ten EEG measures developed from various signal processing techniques. Features are evaluated using a neural network classifier on 51 h of real neonatal EEG. The GP measures, in particular, the prediction certainty approach, produce a high level of performance compared to other modeling methods and methods currently in clinical use for EEG analysis, indicating that they are an important and useful tool for the real-time detection of neonatal seizures.  相似文献   
4.
A new vertical transition between a substrate integrated waveguide in a low‐temperature co‐fired ceramic substrate and an air‐filled standard waveguide is proposed in this paper. A rectangular cavity resonator with closely spaced metallic vias is designed to connect the substrate integrated waveguide to the standard air‐filled waveguide. Physical characteristics of an air‐filled WR‐22 to WR‐22 transition are compared with those of the proposed transition. Simulation and experiment demonstrate that the proposed transition shows a ?1.3 dB insertion loss and 6.2 GHz bandwidth with a 10 dB return loss for the back‐to‐back module. A 40 GHz low‐temperature co‐fired ceramic module with the proposed vertical transition is also implemented. The implemented module is very compact, measuring 57 mm × 28 mm × 3.3 mm.  相似文献   
5.
Zusammenfassung Die Nichtstärke-Polysaccharide (NSP) der Kakaobohne wurden nach ihrer Löslichkeit in Wasser und Natronlauge steigender Konzentration fraktioniert. Die Fraktionen wurden durch das Muster der Zuckerbausteine nach Hydrolyse bzw. Methanolyse charakterisiert und gelchromatographisch aufgetrennt. Im Verlauf der Kakaoverarbeitung waren nennenswerte Veränderungen nur beim Alkalisieren des Kakaopulvers zu beobachten. Die Meßwerte für die wasserlöslichen Kakao-NSP können bei der Analyse der Dickungsmittel in Kakaoerzeugnissen berücksichtigt werden.
Non-starch polysaccharides of cocoa
The non-starch polysaccharides (NSP) of the cocoa bean were fractionated according to their solubility in water and in solutions of increasing alkalinity. In these fractions, the monosaccharide patterns after hydrolysis or methanolysis and the molecular mass distributions were determined. During cocoa processing, distinct changes in the NSP composition were observed only for the solubilisation of cocoa powder by alkaline treatment. The results obtained for the water-soluble cocoa NSP may be considered as blank values for the analysis of thickeners and gums in cocoa products.
  相似文献   
6.
The overlying retinal blood vessels were abnormal in five cases of congenital hypertrophy of the retinal pigment epithelium. This illustrated the well-recognized association between outer retinal degeneration and obliteration of the overlying retinal vasculature. The proposed pathophysiological mechanisms, however, seem inadequate to explain completely the morphological changes of the retinal blood vessels in the presence of atrophy of the outer retina.  相似文献   
7.
Sustaining the quality of seeds is a major task in attempting to supply nutrition to the growing world population. In this study, the seeds of Cicer arietinum were exposed to cold atmospheric plasma (CAP). A significant reduction of the natural microbiota attached to the seed surface was observed for increasing CAP treatment times—2 and 5 min were sufficient to achieve a 1 and 2 log reductions, respectively. Furthermore a 1 min CAP treatment showed a strongly improved seed germination (89.2 %), speed of germination (7.1?±?0.1 seeds/day), and increased seed vigor, beside a decrease in the mean germination time (2.7 days) compared with controls. The roughness profile of the seed cotyledon was altered significantly, only in case of longer treatment times from 5 min. These results suggest that CAP technology has the potentiality to reduce health risks associated with contaminated seeds, while improving food quality.  相似文献   
8.
We report an optimized low‐input FAIRE‐seq (Formaldehyde‐Assisted Isolation of Regulatory Elements‐sequencing) procedure to assay chromatin accessibility from limited amounts of yeast cells. We demonstrate that the method performs well on as little as 4 mg of cells scraped directly from a few colonies. Sensitivity, specificity and reproducibility of the scaled‐down method are comparable with those of regular, higher input amounts, and allow the use of 100‐fold fewer cells than existing procedures. The method enables epigenetic analysis of chromatin structure without the need for cell multiplication of exponentially growing cells in liquid culture, thus opening the possibility of studying colony cell subpopulations, or those that can be isolated directly from environmental samples.  相似文献   
9.
Mörlein D  Link G  Werner C  Wicke M 《Meat science》2007,77(4):504-511
This study aimed at characterising 606 crossbred pigs of three commercially available breed types in terms of their carcass and meat quality. Breed G and H were German Large White (LW) × German Landrace (LR) sows sired with Pietrain (PI) boars, i.e. PI × (LW × LR). Breed S was 25% Duroc (DU), i.e. PI × (DU × LR). Most of the parameters were affected by breed and/or date of slaughter. The meat of crossbred pigs with 25% Duroc proportion appeared most favourable because of higher intramuscular fat content, lower drip loss and higher sensory liking scores. Conductivity is closely related to drip loss while the data suggests that the relationship is dependent on breed and carcass weight. The application of conductivity and lean meat yield thresholds to select carcasses with uniform and superior meat quality effectively decreased drip loss and increased intramuscular fat content as well as sensory liking scores. The variation of meat quality traits remains high, though.  相似文献   
10.
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