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101.
102.
A demountable fibre connector which uses two interlocking sets of three balls to locate the fibres accurately and simultaneously to align the two parts of the connector has been constructed. The samples tested so far, using Corning stepindex fibre, have shown average losses of less than 0.2 dB with index matching and less than 0.5 dB without. The connector is cheap, easy to make and could be assembled in the field. 相似文献
103.
1. The effect of thermal stimulation of the spinal cord on the rate of oxygen consumption was studied in five unanaesthetized rats during exposure to various ambient temperatures. 2. In a warm environment, cooling the spinal cord had no effect on the rate of oxygen consumption but in thermoneutral and cold environments the rate of oxygen consumption increased proportionally to the intensity of spinal cooling. Heating the spinal cord decreased the level of oxygen consumption and, if intense enough, suppressed the thermoregulatory increase in metabolic rate. 3. It is concluded that, in the control of oxygen consumption in the rat, the afferent signals from thermal sensors in the spinal cord and skin are added. 相似文献
104.
Thomas Ströder Jürgen Giesl Marc Brockschmidt Florian Frohn Carsten Fuhs Jera Hensel Peter Schneider-Kamp Cornelius Aschermann 《Journal of Automated Reasoning》2017,58(1):33-65
While automated verification of imperative programs has been studied intensively, proving termination of programs with explicit pointer arithmetic fully automatically was still an open problem. To close this gap, we introduce a novel abstract domain that can track allocated memory in detail. We use it to automatically construct a symbolic execution graph that over-approximates all possible runs of a program and that can be used to prove memory safety. This graph is then transformed into an integer transition system, whose termination can be proved by standard techniques. We implemented this approach in the automated termination prover AProVE and demonstrate its capability of analyzing C programs with pointer arithmetic that existing tools cannot handle. 相似文献
105.
自轮胎工业诞生以来,橡胶就一直是它的原材料。这段历史使轮胎工业积累了宝贵的胶料加工经验。但是,尽管有这些经验,如何有效地加工胶料仍是每个轮胎公司生产部门面临的挑战。 相似文献
106.
Viktoriia Barreau René Hensel Nathalie K. Guimard Animangsu Ghatak Robert M. McMeeking Eduard Arzt 《Advanced functional materials》2016,26(26):4687-4694
Biologically inspired, fibrillar dry adhesives continue to attract much attention as they are instrumental for emerging applications and technologies. To date, the adhesion of micropatterned gecko‐inspired surfaces has predominantly been tested on stiff, smooth substrates. However, all natural and almost all artificial surfaces have roughnesses on one or more different length scales. In the present approach, micropillar‐patterned PDMS surfaces with superior adhesion to glass substrates with different roughnesses are designed and analyzed. The results reveal for the first time adhesive and nonadhesive states depending on the micropillar geometry relative to the surface roughness profile. The data obtained further demonstrate that, in the adhesive regime, fibrillar gecko‐inspired adhesive structures can be used with advantage on rough surfaces; this finding may open up new applications in the fields of robotics, biomedicine, and space exploration. 相似文献
107.
Stark T Lang R Keller D Hensel A Hofmann T 《Molecular nutrition & food research》2008,52(10):1201-1214
Besides flavan-3-ols, a family of N-phenylpropenoyl-L-amino acids (NPAs) has been recently identified as polyphenol/amino acid conjugates in the seeds of Theobroma cacao as well as in a variety of herbal drugs. Stimulated by reports on their biological activity, the purpose of this study was to investigate if these amides are absorbed by healthy volunteers after administration of a cocoa drink. For the first time, 12 NPAs were quantified in human urine by means of a stable isotope dilution analysis with LC-MS/MS (MRM) detection. A maximum amount was found in the urine taken 2 h after the cocoa consumption. The highest absolute amount of NPAs excreted with the urine was found for N-[4'-hydroxy-(E)-cinnamoyl]-L-aspartic acid (5), but the highest recovery rate (57.3 and 22.8%), that means the percentage amount of ingested amides excreted with the urine, were determined for N-[4'-hydroxy-(E)-cinnamoyl]-L-glutamic acid (6) and N-[4'-hydroxy-3'-methoxy-(E)-cinnamoyl]-L-tyrosine (13). In order to gain first insights into the NPA metabolism in vivo, urine samples were analyzed by LC-MS/MS before and after beta-glucuronidase/sulfatase treatment. As independent of the enzyme treatment the same NPA amounts were found in urine, there is strong evidence that these amides are metabolized neither via their O-glucuronides nor their O-sulfates. In order to screen for caffeic acid O-glucuronides as potential NPA metabolites, urine samples were screened by means of LC-MS/MS for caffeic acid 3-O-beta-D-glucuronide and 4-O-beta-D-glucuronide. But not even trace amounts of one of these glucuronides were detectable, thus excluding them as major NPA metabolites and underlining the importance of future investigations on a potential O-methylation or reduction of the N-phenylpropenoyl moiety in NPAs. 相似文献
108.
Michael Hensel 《Architectural Design》2006,76(5):104-108
Founded in the early 1990s, OCEAN was one of the first collaborative geographically distributed practices to realise the potential of telecommunication and digital design technologies. Here Michael Hensel recounts the various mutations and fluid transformations of the experimental groupings that came to form OCEAN net. Accordingly, Hensel's account is more akin to a band biography than a staid sociology of a professional office. Moreover, he explores how the molecular model of distributed authorship presents difficulties, either by confounding external expectations of a singular identity or signature behind the various design processes, or internally as a stable whole of identities attempting to re-emerge and fix its collaborative mixings into a rigid hierarchy. As OCEAN's biography attests, true collaboration is inherently flat, distributed and transformative, situating architecture as more than just a service profession and transforming it into an intensive practice of living. Collective intelligence in these terms is embedded in the distributed evolutionary processes of the practice as a design project in itself. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
109.
S. Abedrabbo J. C. Hensel A. T. Fiory N. M. Ravindra 《Journal of Electronic Materials》1999,28(12):1390-1393
From emissometry measurements in lightly doped Si at elevated temperatures, we have observed an anomalous absorption band
in the wavelength range of 1–5 μm. The wavelength at which the band peaks, λ≈2.3 μm, shows a negligible dependence on temperature
while the peak intensity increases with temperature presumably as a result of the increasing intrinsic carrier concentration.
Spitzer and Fan reported a similar absorption band in direct absorption measurements at room temperature for n-type Si with
extrinsic electron concentrations of 1014 to 1019cm−3. No such structure was found in extrinsic p-type Si. Spitzer and Fan were unable to identify the mechanism for this anomalous
absorption. In both the experiments, this absorption of free electrons is due to intraband transitions in the conduction band
from the Δ1 conduction band edge across an energy gap of E ∼ 0.5 eV to a higher lying Δ2′ conduction band. 相似文献
110.