共查询到20条相似文献,搜索用时 15 毫秒
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Jaakko Yli-Ojanperä Jyrki M. Mäkelä Marko Marjamäki Antti Rostedt Jorma Keskinen 《Journal of aerosol science》2010,41(8):719-728
A concept of realizing a standard for aerosol particle number concentration was tested, based on generating singly charged aerosol particles in the size range from 10 up to 500 nm. To this end, a device named single-charged aerosol reference (SCAR) was designed, built, and tested. The device is based on electrical charging of nanoparticles and subsequent growth of the particles. With an accurate measurement of volume flow and electrical current from the singly charged particles, the number concentration can be accurately, and in the end, traceably determined. Laboratory tests have shown that the device can be used to generate a narrow (GSD<1.3) particle size distribution of singly charged particles. The device can be used for traceable calibration of instruments measuring the number concentration of the particles. 相似文献
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研究了终止剂、抗氧剂的种类及用量对粘接型氯丁橡胶甲苯溶液色泽以及生胶贮存稳定性的影响。结果表明:当采用盐酸羟胺做终止剂,2.6-二叔丁基对甲基苯酚做抗氧剂,所得氯丁橡胶具有良好的贮存稳定性,其甲苯溶液色泽较浅。 相似文献
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The properties of current shade sorting geometries are evaluated on a mathematically generated, spherical population of normally distributed data points. The results compare well with those obtained from preuiously cited populations of textile production goods. Thefixed-grid geometries (cubic, rhombic dodecahedra1 and truncated octahedral) are not as efficient in terms of the numbers and uniformity of shade sorting groups as the grid-free spherical clusters employed by Clemson Color Clustering (CCC). 相似文献
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A method based on the effective carbon number (ECN) has been developed for the prediction of the vapor pressures of carboxylic acids over a range of temperatures. Good representation of the vapor pressures is obtained in the range 1 kPa to HOkPa with an overall average absolute deviation of 2.26%for 31 carboxylic acids which included saturated as well as unsaturated acids. The method requires a knowledge only of the normal boiling point or the boiling point at 1.3 kPa (lOmmHg) of the substance 相似文献
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An investigation of the correlation between visual colour assessment and instrumental colour acceptance determination using regression analysis has been carried out. Three colour-difference equations, CIELAB, CMC(2:1) and CIE94(2:1:1), were studied in order to determine which is the best for generating a uniform colour space/microspace for allocating the colour population in shade sorting. Determination of optimum colour tolerance for further shade sorting was also undertaken. Some 1320 pairs of dyed samples distributing around 20 shade standards were measured instrumentally and also evaluated visually by a panel of 32 observers. Percentage rejection was plotted against colour difference and different mathematical regression relationships were then imposed. As a result, both CMC and CIE94 showed better correlation between the two colour assessment methods than the CIELAB colour-difference equation. Consequently, optimum colour tolerance limits were determined for subsequent development of shade sorting, with the findings being equally applicable to colour acceptance (shade passing). 相似文献
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The nominal 50 kg h−1 dry coal biodepyritization pilot plant was built at Porto Torres (Sassari, Italy) in the area of EniChem S.p.A. Chemical Works, with financial support of the Commission of European Communities and with the participation of the DMT of Essen (Germany), the Mining and Mineral Processing Department of the University of Cagliari (Italy), the Technical University of Delft (The Netherlands) and the Warren Spring Laboratory of Stevenage (UK). The plant went on stream in early September 1992. Test runs were carried in the range 6.5–41.5% solids concentration. For every solids concentration the steady state was attained in about 10 d. For all the test runs the assays showed that more than 90% pyrite removal is achieved in the first five bioreactors; for a pulp flow rate of 6.94 × 10−2 dm3 s−1, (250 l h−1) and useful bioreactor volume of 7.5 m3, this corresponds to a residence time of 540 345 s, i.e., 6.254 d, and to a pyritic iron biosolubilization rate of 36 mg dm−3 h−1. The pyrite biosolubilization rate constant is 1.53 × 10−2 h−1. The power input per bioreactor operating on a 40% solids pulp is 4 kW with cos Φ = 0.76. Hence, the power required for processing 100 kg h−1 coal at 40% solids in the bioreactor section is 4 × 5 = 20 kW h, i.e. 200 kW h per tonne dry coal. 相似文献
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分式色数和点色数是图的两个重要参数。本文在文献 [1]的基础上给出了两类距离图G(Z ,Dm ,k,k + 1)与G(Z ,Dm ,k ,k + 1,k + 2 )的分式色数和点色数。 相似文献
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Hiroyuki Kameda Jinwang Li Dam Hieu Chi Ayumi Sugiyama Koichi Higashimine Tomoya Uruga Hajime Tanida Kazuo Kato Toshihiko Kaneda Takaaki Miyasako Eisuke Tokumitsu Tadaoki Mitani Tatsuya Shimoda 《Journal of the European Ceramic Society》2012,32(8):1667-1680
We report a novel low-temperature crystallization path for perovskite lead zirconate titanate (PZT) from solution. The modification of a PZT solution by monoethanolamine (MEA) resulted in a change in the crystallization behavior. MEA was strongly coordinated to the metal ions, resulting in destroy of multinuclear metal organic complexes. This led to a remarkably increased pyrolysis temperature, and Pb2+ was reduced into Pb0 because of a reducing environment at 200–300 °C. Nanoscopic separations of Pb0 was later transformed into uniformly distributed α-PbO nanocrystals and clusters in the amorphous Zr/Ti–O matrix, and finally the sample crystallized into perovskite at 400–500 °C. On the other hand, pyrochlore phase was observed in the conventional crystallization process. The avoidance of pyrochlore formation is the key for the low-temperature crystallization of perovskite. X-ray absorption fine structure (XAFS) analysis was performed to reveal the structures in solutions and amorphous phases. 相似文献
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<正> 环氧粘合剂在国内50年代开始研制,迄今已有不少品种牌号。这些产品均是包含环氧树脂基体(包括增塑剂及填料等)和固化剂的双组分环氧粘合剂,又称二液型环氧粘合剂。使用时须临时进行称量、搅拌混和,而且胶的适用时间极短。另外,使用时需要现配,这样给施工带来麻烦,剩余的胶也不能再用,从而造成浪费。单组分环氧粘合剂采用独特的固化剂及催化剂,调配均匀,一组分包装,故又称一液型环氧粘合剂。它具有很长的贮存期(即适用期),可达半年以上不变质,因此使用方便,大大改进了双组分环氧粘合剂的缺点,达到提高劳动生产率和节省粘合剂的目的。单组分环氧粘合剂所采用的固化剂,在常温和加 相似文献
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Dresselhaus MS Dresselhaus G Jorio A Souza Filho AG Pimenta MA Saito R 《Accounts of chemical research》2002,35(12):1070-1078
A review is presented on the observation of the resonant Raman spectra from one isolated single wall carbon nanotube, focusing on the important structural information that is provided by single nanotube spectroscopy including the (n, m) determination of the individual tubes. The special sensitivity of the radial breathing mode to the (n, m) determination is emphasized, and the corroboration of this (n, m) assignment by diameter- and chirality-dependent phenomena in other Raman modes, such as the G-band, D-band, and G'-band features is also discussed. The significance of single nanotube spectroscopy for future nanotube research in general is briefly reviewed. 相似文献