共查询到16条相似文献,搜索用时 109 毫秒
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利用研制的三通道渗透管装置发生摩尔分数范围为0.1~1.0μmol/mol的硫化氢、甲基硫醇、二甲基硫醚混合气体,用于校准检测口腔气体检测仪。校准装置可以在固定输出总流量不变的情况下,快速改变发生硫化物的摩尔分数。对校准装置的温控系统和流量系统进行了测试,通过总硫分析仪对校准装置发生的低含量硫化物的量值进行了比较和验证。该校准装置发生的低含量硫化物量的相对扩展不确定度不大于6.8%(k=2)。 相似文献
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国防科工委化学计量一级站为满足海军武器装置对湿度计量器具检定工作的需要,经过一年多的努力,研制安装了八台湿度计量标准装置(SB—94A湿度发生器),并于1995—03—25提交海军航空工程学院验收,经逐台测试,一次验收合格。该产品是 相似文献
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A BIOFILM USED AS ULTRAVIOLET-DOSIMETER 总被引:2,自引:0,他引:2
L. E. Quintern G. Horneck U. Eschweiler H. Bücker 《Photochemistry and photobiology》1992,55(3):389-395
Abstract— A UV-dosimeter has been developed for routine measurements which mainly weights the various components of the spectrum in relation to their damaging effects on a microorganism. For this purpose a biofilm was constructed, comprising dried spores of Bacillus subtilis (wild-type or DNA repair defective strain), immobilized on transparent polyester plastic sheets. After irradiation, the biofilm was incubated in a growth medium. The proteins, synthesized by the immobilized microorganisms after spore germination and several cell divisions, were stained and determined by photometry, giving a measure of the biological activity. The "biologically effective dose" was determined from a calibration curve. It reflects the dose equivalent to that of the calibration source producing the same effect.
The UV-response of the biofilm is additive and follows the reciprocity law in the range of fluence rates investigated. The response is nearly independent of temperature within the range of -20°C to +70°C as well as of humidity between about 37 and 80% relative humidity. Storage for up to 9 months at <70% relative humidity and room temperature does not significantly influence the viability of the spores. 相似文献
The UV-response of the biofilm is additive and follows the reciprocity law in the range of fluence rates investigated. The response is nearly independent of temperature within the range of -20°C to +70°C as well as of humidity between about 37 and 80% relative humidity. Storage for up to 9 months at <70% relative humidity and room temperature does not significantly influence the viability of the spores. 相似文献
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Determination of apparent reducing sugars, moisture and acidity in honey by attenuated total reflectance-Fourier transform infrared spectrometry 总被引:1,自引:0,他引:1
Luiz C.M. Pataca Waldomiro Borges Neto Maria C. Marcucci Ronei J. Poppi 《Talanta》2007,71(5):1926-1931
Attenuated total reflectance-Fourier transform infrared spectrometry, in conjunction with multivariate calibration, was used for determination of reducing sugars, humidity and acidity in honey bee samples. Multivariate calibration models were built using partial least squares (PLS) and were refined through variable selection per interval (iPLS) and genetic algorithms. The calibration models show satisfactory results for all parameters with average relative errors of 6% for acidity, 1% for reducing sugars and 2% for humidity. For the acidity and reducing sugars parameters, variable selection was irrelevant, but for humidity it was essential. For the humidity parameter, it was necessary to use two variable selection techniques (by intervals and genetic algorithm) concomitantly in order to obtain a satisfactory calibration model. 相似文献
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Optical sensors for environmental humidity have been constructed from poly (N-isopropylacrylamide)-co-acrylic acid (pNIPAm-co-AAc) microgels. The devices were constructed by first depositing a monolithic layer of pNIPAm-co-AAc microgels on a Au-coated glass substrate followed by the addition of another Au layer on top. The resultant assembly showed visual color, and exhibited multipeak reflectance spectra. We found that the thickness of the device's microgel layer depended on environmental humidity, which corresponded to a change in the device's optical properties. Specifically, at low humidity the microgel layer was collapsed, while it absorbed water from the atmosphere (and swelled) as the humidity increased. Additionally, we investigated how the deposition of the hygroscopic polymer poly (diallyldimethylammonium chloride) (pDADMAC) onto the microgel layer (prior to final Au layer deposition) influenced the devices humidity response. We found that the devices were more sensitive to humidity as the number of pDADMAC layers in the device increased. Finally, we evaluated the device performance at various temperatures, and found that the sensitivity was enhanced at low temperature, although the response was more linear at elevated temperature. 相似文献
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Tadeusz A. Przylibski Jakub Bartak Elżbieta Kochowska Lidia Fijałkowska-Lichwa Krzysztof Kozak Jadwiga Mazur 《Journal of Radioanalytical and Nuclear Chemistry》2010,285(3):599-609
The article presents new Polish probes SRDN-3, developed at the Institute of Nuclear Chemistry and Technology in Warsaw, equipped with a semi-conductor detector used for continuous measurements of 222Rn activity concentration. Due to a relatively high lower detection limit, the device is dedicated for use in underground spaces—caves, adits, mines, tourist routes in strongholds, pyramids, etc. Its structure allows for difficult conditions in which the device is transported to the measurement site, as well as hard operating conditions caused chiefly by large ambient relative humidity, reaching up to 100%. The authors present calibration results of these appliances, as well as the results of their work in a cave and an adit in the Sudetes (SW Poland). After almost 2 years of working in difficult conditions, the probes displayed high reliability. No defects of the semi-conductor detectors or the electronics were observed, which ensured problem-free communication of the probe-programmer-PC set. Thanks to this, the authors have a 2 year stock of data, recorded hourly by five probes, at their disposal. The only element that did not withstand the test of extreme operating conditions was one of the combined relative humidity and temperature sensors. No powering problems were observed either, and the batteries were replaced once a year, before the winter season. Also the programmer functioned faultlessly, enabling data transmission to a PC, which, being much more sensitive to operating conditions, had been placed away from the site of probe exposure. After using more sensitive temperature, relative humidity and pressure sensors, SRDN-3 probes will certainly prove an excellent tool for microclimate measurements (including measurement of air-atmosphere exchange) in caves and other underground sites. Even nowadays they are already a satisfactory tool for monitoring 222Rn concentration in underground spaces. 相似文献
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采用混合菌BODseed制备微生物传感器快速监测生化需氧量(BOD),研究了矫正溶液选择、样品自降解及恒温装置对测量准确度的影响。 结果表明,采用葡萄糖 谷氨酸矫正溶液测得污水处理厂污水结果较BOD5方法偏低50%以上,而以污水本身制作矫正曲线取得了与BOD5一致的测试结果;样品在保存6 h后有机物自降解会使测量结果偏低40%;快速BOD在线监测时不仅需要对微生物传感器恒温,同时也需要对样品及缓冲溶液恒温,这有利于样品快速接近缓冲溶液温度,减少空气饱和时间,从而提高监测效率,提升测试准确度。 相似文献