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1.
The performance of a double sided silicon strip detector (DSSSD), which is used for the position and energy detection of heavy ions, is reported. The analysis shows that although the incomplete charge collection (ICC) and charge sharing (CS) effects of the DSSSD give rise to a loss of energy resolution, the position information is recorded without ambiguity. Representations of ICC/CS events in the energy spectra are shown and their origins are confirmed by correlation analysis of the spectra from both the junction side and ohmic side of the DSSSD. 相似文献
2.
声环境是环绕人们的并对其生存产生很大影响的重要条件,但以往人类只注意发展声环境的正向方面,而对于由此产生的隐伏的声危害却关注不够,从而致使声环境会给人类带来灾难性的环境压力,危及人类健康.本文重点介绍突出的灾害噪声问题及其控制技术. 相似文献
3.
Three-dimensional size and orientation of the precipitates in AZ91 magnesium alloys measured by TEM techniques 下载免费PDF全文
Knowledge of the microscopic structure, including three-dimensional
(3-D) size and orientation of the precipitates, is essential to
fully understand the mechanical properties of the magnesium
alloys and designing the alloys with better performance. Analytical
TEM with high spatial resolution offers the simultaneous
measurements of 3-D size, structure, orientation, composition of the
precipitates from one typical sample along an established
crystallographic axis. Besides popular Burgers orientation
relationship (OR), other ORs such as Pitsch--Schrader OR, Crawley
OR, Potter OR and a new OR with the form of [0001]α
1.0° from [311]γ and (11\bar 20)α
2.0° from (03\bar 3)γ between the magnesium
matrix and the precipitate γ -Mg17Al12 are
identified by TEM imaging and diffraction techniques. As a case study,
the thicknesses of the individual precipitates with Burgers OR are
further measured to be 100--200~nm through both electron energy-loss
spectroscopy and x-ray energy dispersive spectroscopy combining
differential x-ray absorption and extrapolation, which are in
agreement with the overall 3-D size statistic distribution results
obtained through analysing various samples along various directions.
Furthermore, the fabricated wedge-shape structure provides a
platform on which to study the dependence of the interfacial strain on the
variation of the thickness. 相似文献
4.
For a non-linear system excited by a stochastic load which is expressed as a time series,a recursive method based on the Z-transform is presented.To identify the obtained response time series,a discrete wavelet transform (DWT) technique is proposed. 相似文献
5.
IntroductionInengineering,thenonlinearityofshellstructureissometimesobvious.Itisverydifficulttosolvetheproblemofthenonlinearrandomvibration .Inthispaper,wetrytosolveitinthefrequencydomainbyanimprovedstatisticlinearizationmethod .Weconsideronlythegeometr… 相似文献
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选用1-乙烯基-3-乙基咪唑四氟硼酸盐([VElm]BF4,一种离子液体)作为功能单体,以Co2+为介导离子,结合1-丁基-3-甲基咪唑四氟硼酸盐([BMIM]BF4)/二甲基亚砜(DMSO)二元致孔体系制备了绿原酸印迹整体柱。经过对制备参数的考察,确定最佳比例为绿原酸:Co2+:[VElm]BF4:EDMA(乙二醇二甲基丙烯酸酯)(摩尔比)=1:1:5:20,[BMIM]BF4:DMSO=3:1(V/V),最大印迹因子达2.10。通过优化色谱条件,最终在乙腈:20 mmol/L乙酸钠缓冲液(pH 4.2)=70:30(V/V)时实现了绿原酸及其类似物的完全分离。由此可见,以离子液体为功能单体及致孔剂,在金属介导策略下制备的分子印迹聚合物可实现绿原酸的特异性识别及分离。 相似文献
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