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排序方式: 共有748条查询结果,搜索用时 15 毫秒
1.
Michael Lommel Vera Froese Moritz Sieber Marvin Jentzsch Tim Bierewirtz Ümit Hasirci Tim Rese Josef Seefeldt Sebastian Schimek Ulrich Kertzscher Christian Oliver Paschereit 《Indoor air》2021,31(6):1860-1873
The SARS-CoV-2 pandemic has created a great demand for a better understanding of the spread of viruses in indoor environments. A novel measurement system consisting of one portable aerosol-emitting mannequin (emitter) and a number of portable aerosol-absorbing mannequins (recipients) was developed that can measure the spread of aerosols and droplets that potentially contain infectious viruses. The emission of the virus from a human is simulated by using tracer particles solved in water. The recipients inhale the aerosols and droplets and quantify the level of solved tracer particles in their artificial lungs simultaneously over time. The mobile system can be arranged in a large variety of spreading scenarios in indoor environments and allows for quantification of the infection probability due to airborne virus spreading. This study shows the accuracy of the new measurement system and its ability to compare aerosol reduction measures such as regular ventilation or the use of a room air purifier. 相似文献
2.
Moritz Raab Simon Maier Ralph-Uwe Dietrich 《International Journal of Hydrogen Energy》2021,46(21):11956-11968
A large-scale point to point hydrogen transport is one strategy for a prospective energy import scenario for certain countries. The case for a hydrogen transport from Australia to Japan has been addressed in several studies. However, most studies lack transparency and detailed insights into the made assumptions thus a fair evaluation of different transport pathways is challenging. To address this issue, we developed a model where a large-scale point to point hydrogen transport of liquid hydrogen is compared with the transport via liquid organic hydrogen carrier (LOHC), namely via methyl cyclohexane and hydrogenated dibenzyl toluene. We analyzed, where energy is required along the different pathways, where hydrogen losses do occur and how the costs are put together. Furthermore, the influence of hydrogen feed costs is also considered. For hydrogen production costs of 5 €2018/kgH2 the total delivery costs are in the range of 6.40– 8.10 €2018/kgH2. 相似文献
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Matthias Zobel Joachim Denzler Benno Heigl Elmar Nöth Dietrich Paulus Jochen Schmidt Georg Stemmer 《Machine Vision and Applications》2003,14(1):26-34
Abstract. This contribution introduces MOBSY, a fully integrated, autonomous mobile service robot system. It acts as an automatic dialogue-based
receptionist for visitors to our institute. MOBSY incorporates many techniques from different research areas into one working
stand-alone system. The techniques involved range from computer vision over speech understanding to classical robotics.
Along with the two main aspects of vision and speech, we also focus on the integration aspect, both on the methodological
and on the technical level. We describe the task and the techniques involved. Finally, we discuss the experiences that we
gained with MOBSY during a live performance at our institute. 相似文献
5.
We report on compound formation in the system HgCdTeO. Samples were prepared by solid state reaction of mixtures of the binary oxide components. Specific phases were identified and characterized by X-ray and microprobe techniques. For some of these compounds small single crystals could be prepared and structural data of which are reported. Three groups of phases could be distinguished, most of them being of low symmetry, with Te in +4, +6, and in mixed oxidation states. The monotellurites HgTeO3 and CdTeO3 are structurally different and exhibit a large miscibility gap, whereas for the di-tellurites complete solid solution between CdTe2O5 and HgTe2O5 was found. As to the tellurates, phases with the compositions MTeO4 and M3Te2O9 (M = Hg, Cd) have been prepared. The Cd3Te2O9-structure is stabilized by 30 mole% Hg. Another tellurate, monoclinic Hg2TeO4, was found to be isomorphous to the respective selenate and sulfate and is identical with the mineral magnolite. The interaction of Te2O5 with the metal oxides led to the formation of mixed valence compounds with both Te(+4) and Te(+6) of the types M2Te2O7 and MTe2O6. 相似文献
6.
A. I. Ageev I. V. Bogdanov V. V. Zubko S. S. Kozub P. I. Slabodchikov V. V. Sytnik L. M. Tkachenko P. A. Shcherbakov K. Blachet J. Cauhertz G. Moritz 《Atomic Energy》2002,93(6):957-960
The superconducting dipoles developed as part of the UNK project have reached a magnetic field 6 T at a rate of up to 0.8 T/sec. Experimental data are presented on the conditioning, rate dependences, and dynamic losses for magnets with two types of superconducting cable (zebra and oxide). Possible ways to decrease the heat release in a dipole operating in rapid-cycling magnetic fields are examined. The results of an analysis of heat release and temperature conditions are presented for a dipole with a winding made of improved current-carrying components. 相似文献
7.
U Ziemann M Winter CD Reimers K Reimers F Tergau W Paulus 《Canadian Metallurgical Quarterly》1997,49(5):1292-1298
We investigated 14 patients with amyotrophic lateral sclerosis (ALS) by paired conditioning-test transcranial magnetic stimulation to test the hypothesis that the motor cortex is hyperexcitable in ALS. Intracortical (corticocortical) inhibition was significantly less in the ALS group than in an age-matched healthy control group (85.3 +/- 27.0% versus 45.2 +/- 15.5%, respectively; p < 0.0001). In contrast, intracortical facilitation, motor threshold, and cortical silent period duration in the ALS patients were not different from the control group. We suggest that the selective abnormality of intracortical inhibition is best compatible with an impaired function of inhibitory interneuronal circuits in the motor cortex that in turn renders the corticomotoneuron hyperexcitable. 相似文献
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Modeling of electromagnetic propagation in the troposphere has been advanced in the last decade to the point where both the vertical and horizontal variation of refractivity can be accommodated readily. A hybrid ray-optics/parabolic equation model is utilized to predict propagation loss for a range-varying refractive structure to demonstrate the model obeys the Sommerfeld-Pfrang statement of the Lorentz reciprocity theorem 相似文献