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91.
Mike Santarni 《电子设计技术》2009,16(9):82-82,83
并非只有宇宙才诞生于大爆炸。目前硅谷最火的汽车电子新创企业PLX Devices也诞生于创始人的引擎爆炸。PLX最新的产品是一款能够监测汽油使用状况,鼓励节油驾驶的插入式器件。它源自公司28岁的首席执行官Paul Lowchareonkul在驾车与奔驰赛车跑坏了引擎后发明的一个空气燃油比测量仪。这两款器件均采用了赛灵思FPGA平台。 相似文献
92.
Incorporation in pasta of either of two soluble fibres, carboxymethylcellulose sodium salt (CMC) and guar gum (GG), was found to significantly reduce the rate of invitro starch digestion. The amount of reducing sugars produced over 300 min was reduced by 18% at 1.5% CMC incorporation and 24% at 20% GG incorporation. Negative effects on sensory and technological properties were seen at the high levels of GG needed to reduce the rate of in vitro digestion, and a ‘matty’ layer covering the surfaces of starch granules was observed by scanning electron microscopy and confocal scanning laser microscopy. By contrast, levels of CMC incorporation giving large reductions in in vitro digestion had no negative effects on pasta properties. No significant alteration in pasta structure on CMC incorporation was observed by microscopy. The large difference in the amounts of soluble fibre required to bring about equivalent reductions in digestion rate suggests that different mechanisms may be involved in the two cases. 相似文献
93.
Mike Koss 《Cryptologia》2013,37(3):204-210
The Enigma Machine is a complex electromechanical device used by the Germans in World War II to achieve what they thought was complete communications security. While the original machine weighed over 20?lbs, the central mechanics of the machine can be simulated manually by manipulating strips of paper. A Paper Enigma is presented that can be cut out of a single sheet of paper. The resulting simulator is compatible with the electromechanical original in that messages can be encoded on one, and decoded on the other. Copies of The Paper Enigma can be downloaded from http://mckoss.com/crypto/enigma.htm. 相似文献
94.
Mike Ashby 《Scripta materialia》2013,68(1):4-7
Architectured or “hybrid” materials are combinations of two or more materials or of materials and space, configured in such a way as to have attributes not offered by any one material alone. This paper describes the rationale for creating architectured materials and criteria for deciding which combinations and configurations show the most promise. 相似文献
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欧洲化学品管理局(ECHA)现已将重铬酸盐列入了高关注物质(SVHC)的名单.用含有重铬酸钾和重铬酸钠等的媒介染料染制羊毛的工厂正面临着越来越大的压力.这意味着采用这种技术的染厂未来可能要得到特别授权才能使用这种化学品. 相似文献
98.
Osborn TJ Hulme M 《Philosophical transactions. Series A, Mathematical, physical, and engineering sciences》2002,360(1796):1313-1325
Daily precipitation in the UK has changed over the period 1961-2000, becoming on average more intense in winter and less intense in summer. Recent increases in total winter precipitation are shown to be mainly due to an increase in the amount of precipitation on wet days, with a smaller contribution in the western UK from a trend towards more wet days. If the wet-day amounts are modelled using a gamma distribution, then positive trends in its scale parameter are found across almost all of the UK, consistent with an increased frequency of heavy winter precipitation. Non-parametric analyses confirm an increase in the contribution of heavy events to winter precipitation totals. Analysis of multi-day sequences of heavy rainfall indicate a corresponding increase in their frequency. Results for summer show almost opposite trends: decreased precipitation totals (driven more equally by fewer wet days and reduced wet-day amounts), decreases in gamma scale parameter (although accompanied by a trend towards a less positively skewed distribution) and decreases in the occurrence of heavy precipitation (whether defined parametrically or non-parametrically). A more sparse network of weather stations with data back to 1901 suggests that the recent winter changes are unusual, while the recent summer changes are not, though the poorer coverage reduces the confidence in these longer-period results. 相似文献
99.
The essential fatty acid arachidonate is oxidized by cytochrome P-450 epoxygenases to four epoxyeicosatrienoic acids (EETs): 14,15-, 11,12-, 8,9-, and 5,6-EETs. Each of the four EET regioisomers and their hydrolysis products (DHETs) has multiple paracrine and autocrine functions and may also potently dilate blood vessels and activate potassium channels. The present work describes a method to resolve EETs and DHETs by capillary electrophoresis (CE) using trimethyl-beta-cyclodextrin and CH3CN as buffer additives. While stored at 25 degrees C, most of the EET and DHET regioisomers remained intact when suspended in alkaline vehicle. However, under these same conditions, 5,6-EET rapidly broke down to a lactone and was slowly converted to 5,6-DHET. When subjected to CE, the EET and DHET regioisomers were baseline resolved (R > or = 1.3); 10 pg of an EET or a DHET regioisomer was readily detectable at 194 nm. In addition, the UV spectra were regiospecific and identical to those obtained during HPLC except that an additional, weak absorption occurred at 235 nm. Together, the high-sensitivity, high-resolution, and differential UV spectra permitted the identification and quantification of EETs in phospholipids isolated from murine liver. Thus, CE was successfully used for the trace analysis of eicosanoids. 相似文献
100.
We examine the light-activation properties of micrometer-sized gear structures fabricated with polysilicon surface micromachining techniques. The gears are held in place on a substrate through a capped anchor post and are free to rotate about the post. The light-activation technique is modeled on photon radiation pressure, and the equation of motion of the gear is solved for this activation technique. Experimental measurements of torque and damping are found to be consistent with expected results for micrometer-scale devices. Design optimization for optically actuated microstructures is discussed. 相似文献