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排序方式: 共有574条查询结果,搜索用时 15 毫秒
91.
Stahl A Schellewald C Stavdahl ? Aamo OM Adde L Kirker?d H 《IEEE transactions on neural systems and rehabilitation engineering》2012,20(4):605-614
Cerebral palsy (CP) is a perinatally acquired nonprogressive brain damage resulting in motor impairment affecting mobility and posture. Early identification of infants with CP is desired to target early interventions and follow-up. During early infancy, distinct motion patterns occur which are highly predictive for later disability. These motor patterns can be observed and recorded. In this paper, a method to predict later CP based on early video recordings of the infants' spontaneous movements, applying optical flow and statistical pattern recognition, is presented. We extract motion information from video recordings of young infants using a total variation related optical flow method. By using wavelet analysis features from motion trajectories of points initiated on a regular grid were extracted and classified using a support vector machine. 相似文献
92.
Line R. Christensen Ole Hassager Anne L. Skov 《American Institute of Chemical Engineers》2019,65(2):859-864
Energy transduction of dielectric elastomers involves minute electrical and mechanical losses, both of which potentially increase the temperature within the elastomer. Thermal breakdown of dielectric elastomers occur when heat generated therein cannot be balanced by heat loss on the surface, which is more likely to occur in stacked dielectric elastomers. In this article an electro-thermal model of a multilayered dielectric elastomer able to predict the possible number of layers in a stack before thermal breakdown occurs is presented. Simulation results show that point of breakdown is greatly affected by an increase in surrounding temperature and applied electric field. Furthermore, if the stack diameter is large, thermal insulation of the cylindrical surface is a valid approximation. Two different expressions for the electrical conductivity are used, and it is concluded that the Frank-Kamenetskii expression is more conservative in prediction of point of breakdown than the Arrhenius expression, except at high surrounding temperature. © 2018 American Institute of Chemical Engineers AIChE J, 65: 859–864, 2019 相似文献
93.
Knowledge‐Based Conceptual Synthesis of Industrial‐Scale Downstream Processes for Biochemical Products 下载免费PDF全文
Karin Backhaus Mirka Lochmüller Markus Christian Arndt Ole Riechert Gerhard Schembecker 《化学工程与技术》2015,38(3):537-546
A generic, knowledge‐based guideline assisting downstream process synthesis for biochemical products is presented. It offers process designers a structured process design methodology supporting them in capturing potentially relevant information, which might be beyond their expertise. The guideline is based on heuristic knowledge which was collected, structured in a generic way, and clearly represented. The generation of alternative downstream routes as starting points for experiments, simulation, and cost calculation is hereby accelerated. The application of the guideline is demonstrated on the example of penicillin V downstream processing from fermentation broth. 相似文献
94.
Standards have played an important but often unrecognized role in the development of modern organizations. This role is accentuated by today’s growth of large business and government infrastructures, in the turbulent processes of globalization. In this paper, we investigate the relationships – and tensions – between standardization strategies and service innovation in the health-care sector. Our empirical material is seven longitudinal case studies in the Norwegian health-care sector, collected and analysed over a period of 20 years. We identify three generic standardization strategies; anticipatory standardization, integrated solutions and flexible generification. We argue that the first two strategies do not support service innovation while the strategy of flexible generification does so. We consider our results important for the evolution of the future ICT-enabled service economy. 相似文献
95.
IV Ole?chik 《Canadian Metallurgical Quarterly》1998,98(2):13-19
A clinical and follow-up study of 155 young adults with a symptomcomplex of "juvenile asthenic deficiency"--"endogener juveniler asthenischer Versagensyndrome" (J.Glatzel, G.Huber, 1968) was carried out. It was found that protracted states in the youth with prevalence of educational disadaptation, weakening of initiative, psychophysical fatiguability should be attributed to atypical depressions, characterized by predominance of ideatoric disturbances with obliterated thymic and motor components. Depending on the specificities of ideatoric disturbances, 3 basic typological varieties of such depressions were recognized, i.e. depressions with prevalence of inhibition, disautomatization or distortion of cognitive processes, which statistically correlated reliably with definite nosological forms (affective disorders, schizophrenia). Depending on the nosologic belonging the studied states differed also in frequency of comorbid disturbances (obsessive-phobic, depersonalization, overvalued ideas), which occurred significantly rarer in the cases of affective disorders, than in schizophrenia. On the whole, follow-up study revealed relatively favourable prognosis of youth endogenous depressions with a clinical picture of "juvenile asthenic deficiency": in cases of affective disorders the course of disease was more frequently in the form of a single cyclothymic attack, while in cases of schizophrenia it took the form of protracted atypical pubertal attack. 相似文献
96.
The thermoelectric (TE) power output, \(f_P\), and conversion efficiency, \(f_{\eta }\), for segmented thermoelectric generators (TEGs) have been optimized by spatially distributing two TE materials (BiSbTe and Skutterudite) using a numerical gradient-based topology optimization approach. The material properties are temperature-dependent, and the segmented TEGs are designed for various heat transfer rates at the hot and cold reservoirs. The topology-optimized design solutions are characterized by spike-shaped features which enable the designs to operate in an intermediate state between the material phases. Important design parameters, such as the device dimensions, objective functions and heat transfer rates, are identified, investigated and discussed. Comparing the topology optimization approach with the classical segmentation approach, the performance improvements of \(f_P\) and \(f_{\eta }\) design problems depend on the heat transfer rates at the hot and the cold reservoirs, the objective function and the device dimensions. The largest performance improvements for the problems investigated are \(\approx \) 6%. 相似文献
97.
Ole Rechner Susanne Neugart Monika Schreiner Sasa Wu Hans-Michael Poehling 《Journal of chemical ecology》2016,42(10):989-1003
Light of different wavelengths affects various physiological processes in plants. Short-wavelength radiation (like UV) can activate defense pathways in plants and enhance the biosynthesis of secondary metabolites (such as flavonoids and glucosinolates) responsible for resistance against certain herbivorous insects. The intensity of light-induced, metabolite-based resistance is plant- and insect species-specific and depends on herbivore feeding guild and specialization. In this study, broccoli (Brassica oleracea var. italica) plants were grown for 4 weeks in a climate chamber under conventional fluorescent tubes and were additionally treated with UV-B (310 nm), UV-A (365 or 385 nm), or violet (420 nm) light generated with UV-B tubes or light-emitting diodes (LEDs). The objective was to determine the influence of narrow bandwidths of light (from UV-B to violet) on plant secondary metabolism and on the performance of the cabbage aphid Brevicoryne brassicae (a specialist) and the green peach aphid Myzus persicae (a generalist). Among flavonol glycosides, specific quercetin and kaempferol glycosides increased markedly under UV-B, while among glucosinolates only 4-methoxy-3-indolylmethyl showed a 2-fold increase in plants exposed to UV-B and UV-A. The concentration of 3-indolylmethyl glucosinolate in broccoli plants increased with UV-B treatment. Brevicoryne brassicae adult weights and fecundity were lower on UV-B treated plants compared to UV-A or violet light-treated plants. Adult weights and fecundity of M. persicae were increased under UV-B and UV-A treatments. When specific light wavelengths are used to induce metabolic changes in plants, the specificity of the induced effects on herbivores should be considered. 相似文献
98.
Glycosphingolipids are found on all vertebrate cells and constitute major cell surface determinants on all nerve cells, where they contribute to cellular diversity and function. We report a method for the analysis of glycosphingolipid metabolism in single cells. The ganglioside GM1 was tagged with the fluorescent dye tetramethylrhodamine. This labeled compound was taken up and metabolized by a culture of pituitary tumor (AtT-20) cells. After 50 h, the cells were formalin fixed. Cells were aspirated into a fused-silica capillary and lysed, and components were separated by capillary electrophoresis with a laser-induced fluorescence detector. All metabolic products that retained the fluorescent dye could be detected at the low-zeptomole level. A total of 54 AtT-20 cells were individually analyzed using this procedure. The electrophoretic profiles were remarkably reproducible, which facilitated identification of components based on the migration time of fluorescently labeled standards. Eleven components were detected, and the average peak height of these components spanned more than 2 orders of magnitude, so that trace metabolites can be detected in the presence of abundant components. The most highly abundant components generated 10% relative standard deviation in normalized abundance. The average cell took up roughly 2 amol (10(6) copies) of the labeled substrate. This method allows determination of cell-to-cell diversity and regulation of glycosphingolipid metabolism. 相似文献
99.
We derive a spin-orbital model for manganites which includes the complete e
g and t
2g
superexchange of S=2 spins at Mn3+ ions and predicts that the same type of antiferromagnetic and orbital ordering is stabilized in insulating La3Mn2O7 as in LaMnO3 by a purely electronic mechanism dominated by the e
g-superexchange. At finite doping we consider a model of t–J variety which describes a metal–insulator transition due to a competition between lattice polarons and kinetic energy in the metallic ferromagnetic ground state. 相似文献
100.
We analyze co-movements between the prices of crude oil and major refined products during the period 1992–1998. Specifically, we explore the existence of long-run equilibrium price relationships, and whether deviations from estimated equilibrium can be utilized for predictions of short-term price changes and for risk management. The econometric evidence strongly supports the hypothesis that crude and product prices are co-integrated. Past deviations from long-term equilibrium are significant in an error correction specification of short-term product price changes. The results represent valuable information for hedging, particularly in integrated oil companies for which price risk is related to margin variations. 相似文献