排序方式: 共有19条查询结果,搜索用时 15 毫秒
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对12年前经离子注入处理后的GCr15轴承钢表面耐磨性能的时间效应进行了探讨。发现离子注入材料的改性效果存在时间效应性。利用AES和X射线衍射分析发现,掺杂原子及材料表面吸附的氧原子的多元迁移和硬质相的生成是造成离子注入材料改性时效的原因。 相似文献
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A number of polysiloxanes have been shown to be sensitive to acids when dissolved in chloroform. At 26O°C polysiloxanes were found to degrade under the influence of several compounds used or produced during the preparation of glass capillary columns. 相似文献
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Solvothermal Preparation and Effects of Mixed Solvent on the Properties of Copper Indium Diselenide Nanoalloys 下载免费PDF全文
Yu‐Chen Lin Wang‐Lin Liu Hsiao‐Chun Chu Tsair‐Rong Chen Shih‐Chieh Hsu Ching‐Hsiang Chen 《中国化学会会志》2014,61(2):274-278
We have developed a simple solvothermal method by using solvent mixtures of ethylenediamine with ethanol and deionized water to produce the CuInSe2 nanoalloys. The phase structure, morphology, elemental composition and optical band gap (Eg) of synthesized the CuInSe2 nanoalloys were characterized by Raman spectroscopy, X‐ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X‐ray spectroscopy (EDS) and zeta potential particle sizer measurements. The factors affecting product purity in the mixed solvent are also discussed. The results showed that CuInSe2 nanoalloys with a chalcopyrite tetragonal structure were produced by adjusting the ratio of ethylenediamine to ethanol (1:2.33 by volume) and their corresponding energy band gap was found to be 1.27 eV. In addition, we prepared and coated the CuInSe2 ink on the Mo substrate by the doctor blade method to produce a compact thin film. The crystallinity and the morphology of these polycrystalline CuInSe2 films were characterized. 相似文献
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A method using focused beamforming to measure the distribution image (underwater image) of submarine and surface ship's noise sources is presented. Level linear array can measure the target image on water level, but the multi-path interference of underwater acoustic channel may affect the quality of it. Virtual time reversal mirror and virtual array can both solve the problem very well; they make the image with high resolution. 相似文献
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David Schuldberg Jennifer Gottlieb 《Nonlinear dynamics, psychology, and life sciences》2002,6(3):231-257
How are momentary microscopic assessments of behavioral dynamics related to traditional macroscopic, static measures? The present study used the computerized “mouse paradigm” to assess near-instantaneous changes in affect over a short time. Dynamic indices were computed from approximately 1400 measurements from the last 2.5 minutes of a 3-minute assessment. Subjects monitored and reported emotional states by moving a cursor along a dimension from “Sadder” to “Happier.” They also completed self-report measures: Scales 2 (Depression) and 9 (Mania) of the MMPI-2, the Positive and Negative Affect Scale, and the Wisconsin scales of Physical Anhedonia and Hypomanic traits. The instantaneous data yielded a summary measure of mean affect, as well as indices of variability. Complexity indices were derived and examined. Mean affect ratings correlated in expected directions with the paper and pencil measures. There was evidence for low-dimensional chaos in short-term affect dynamics. As hypothesized, greater complexity was associated with Pleasant Affect and Hypomania but was negatively correlated with Anhedonia. 相似文献
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处理网络计划的不确定性的一种进度模型 总被引:2,自引:0,他引:2
在应用网络计划技术进行工程项目管理中,常常需要对工程项目中潜在的不确定性进行处理,而传统的网络计划技术中,缺乏对工程项目中潜在的不确定性的处理。章通过建立评估不确定性的影响因子区间的模型与方法,提出了在工程项目的进度管理中动态地对潜在的不确定性进行处理的有效方法。 相似文献
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Yu-hua Shan Jun-quan Sun~ 《高分子科学》2005,(3):301-310
A neutral nickel (Ⅱ) catalyst D, { [O-(3-cyclohexyl)(5-Cl)C6H2-ortho-C(H)=N-2,6-C6H3(i-Pr)2]Ni(Ph3P)(Ph)} has been synthesized and characterized by 1H-NMR, FTIR and elemental analysis. The results indicate that Al(i-Bu)3 is an effective cocatalyst for the neutral nickel catalyst. With bis(1,5-cyclooctadiene) nickel(0) [Ni(COD)2] or Al(i-Bu)3 as a cocatalyst, the neutral nickel catalyst D is active for ethylene polymerisation and copolymerisation with polar monomers (tertbutyl 10-undecenoate(BU), methyl 10-undecenoate (MU), allyl alcohol (AA) and 4-penten-1-ol (PO)) under mild conditions.The resulting polymers were characterized by 1H-NMR, FTIR, DSC, and GPC. From the comparative studies, Ni(COD)2 is more active than Al(i-Bu)3 for ethylene homopolymerization, while Al(i-Bu)3 is more effective than Ni(COD)2 for ethylene copolymerisation with polar monomers. The polymerization parameters which affect both the catalytic activity and properties of the resulting polyethylene were investigated in detail. Under the conditions of 20 μmol catalyst D and Ni(COD)2/D = 3(molar ratio) in 30 mL toluene solution at 45℃, 12 × 105 Pa ethylene for 20 min, the polymerization activity reaches as High as7.29×105gPE.(mol.Ni·h)-1and Mηis 7.16×104g.mol-1.For ethylene copolymerization with polar monomers,the effect of comonomer concentrations was examined. As high as 0.97 mol% of MU, 1.06 mol% of BU, 1.04 mol% of AA and 1.37 mol% of PO were incorporated into the polymer, respectively, catalyzed by D/Al(i-Bu)3 system. 相似文献
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The sensitivity of Doppler wind lidar is an important parameter which affects the performance of Doppler wind lidar. Aerosol scattering ratio, atmospheric temperature, and wind speed obviously affect the mea- surement of Doppler wind lidar with iodine filter. We discuss about the relationship between the measurement sensitivity and the above atmospheric parameters. The numerical relationship between them is given through the theoretical simulation and calculation. 相似文献