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51.
35Cr25Ni12奥氏体耐热钢中碳化物的电子显微分析   总被引:1,自引:0,他引:1  
应用扫描电镜(SEM)和透射电镜(TEM)研究了长期使用前后的35Cr25Ni12奥氏体耐热钢中的碳化物演变行为;该钢固溶时效后的组织由初晶奥氏体及M23C6共晶碳化物组成,奥氏体基体中析出了二次M23C6,二次碳化物总是与基体保持立方-立方取向关系;长期使用(3、5年)后,奥氏体中析出的二次碳化物量明显增加,部分M23C6已转变为M6C,M6C与奥氏体基体以及二次碳化物M23C6保持[001]M6C//[221]A//[221]M23C6孪晶取向关系。  相似文献   
52.
Au nanoparticles were precipitated inside Au+-doped glass samples after irradiation by femtosecond laser or x-ray. Femtosecond laser and X-ray irradiation result in decreasing of anneal temperature and critical size for the precipitation of Au nanoparticles.  相似文献   
53.
GFFs with less than 0.4 dB peak-to-peak error functions are routinely fabricated using commercially available coating machines by utilizing the natural error compensation mechanism of wavelength variable turning point optical monitoring method.  相似文献   
54.
<正> [Au13Ag12(μ-Br)1(μ3-Br)2 (Ph3P)10Br2] Br, monoclinic. space group C2/m, a = 36. 496(17). b=16. 878(7), c-=19. 772(9) A , β=99. 87(5)°, V=11998. 9 A3.Z=2. The final R(Rw) is 0. 097(0. 109) for 3779 reflections with I>3σ(I). The structure can he considered as two icosahedral cluster units (AurAg6) sharing one vertex and linked hy six bromine atoms. The Au - Au, Au - Ag. and Ag-Ag distances fall in the ranges of 2. 69-2. 96. 2. 84-3. 02. and 2. 92-3. 26 A, respectively.  相似文献   
55.
闪光X射线照相技术是研究动载荷及其效应的重要测试手段,特别适用于研究物质在爆炸作用下的瞬变过程,本文介绍了闪光Ⅰ号加速器应用于X射线爆轰照相的基本状况,以及用于观察金属射流穿过高密度物质钨靶的实验技术。  相似文献   
56.
在HL-1托卡马克上进行了辅助加热、加料、电流驱动的物理实验研究。在改善等离子体约束方面,某些实验取得了较好的结果。在适当的稳定放电条件下,低杂波电流驱动和弹丸注入辅助加料,均能使等离子体能量约束得到一定程度的改善,与相同密度条件下的欧姆加热放电相比,能量约束时间提高了约30%。在电子回旋共振加热等离子体实验中,等离子体总能量明显增加,但与相同密度条件下的欧姆加热放电相比,能量约束时间减少了约20%。  相似文献   
57.
Usually, Sm2+ ions could be reduced by heating the materials in reducing atmospheres. Exposure to ionizing radiations is also known to cause Sm3+→Sm2+ conversion. In this work, BaBPO5 doped with the samarium ion was prepared by high temperature solid-state reaction. Sm2+ ions were obtained by two different reduction methods, i.e., heating in H2 reduced atmosphere and X-ray irradiation. The measurements of X-ray diffraction (XRD), and scanning electron microscope (SEM) were investigated. It is found that the conversion of Sm3+→Sm2+ is very efficient in BaBPO5 hosts after X-ray irradiation. Sm2+ ions under these two reduction methods exhibit different characteristics that were studied by measurements of luminescence and decay. The results showed that the luminescence properties of Sm2+ ions in BaBPO5 were highly dependent on the sample preparation conditions.  相似文献   
58.
The adsorption behavior and thermal activation of carbon dioxide on the Cu(1 1 1), Cu(1 0 0), and Cu(1 1 0) surfaces have been investigated by means of density functional theory calculations and cluster models and periodic slabs. According to the cluster models, the optimized results indicate that the basis set of C and O atoms has a distinct effect on the adsorption energy, but an indistinct one on the equilibrium geometry. For the CO2/Cu(hkl) adsorption systems studied here, the final structure of adsorbed CO2 is near linear and the preferred modes for the adsorption of CO2 onto the Cu(1 1 1), Cu(1 0 0), and Cu(1 1 0) surfaces are the side-on adsorption at the cross bridge site with an adsorption energy of 13.06 kJ/mol, the side-on adsorption at the short bridge site (13.54 kJ/mol), and the end-on adsorption on the on-top site with C–O bonds located along the short bridge site (26.01 kJ/mol), respectively. However, the calculated adsorption energies from periodic slabs are lower as compared to the experimental data as well as the cluster model data, indicating that the periodic slab approach of generalized gradient approximation in the density function theory may be not suitable to obtain quantitative information on the interaction of CO2 with Cu(hkl) surfaces.  相似文献   
59.
The investigation on capillary electrophoretic enantioseparation of six synthetic compounds containing vicinal diol groups has been undertaken to acquire the optimum conditions using native beta-cyclodextrin (beta-CD) as chiral selector and borate as a background electrolyte. The separation was carried out in an uncoated capillary (58.5 cm x 75 microm i.d., effective length 48.5 cm) and the effects of several important factors were investigated in detail. The results showed that beta-CD as a chiral selector exhibited good enantioselectivity and that the enantioseparation was greatly influenced by the structure of the diols, the borate concentration and the buffer pH. The optimum performance was obtained for the chiral vicinal diols under the conditions of 200 mM borate buffer of pH 9.8 containing 1.7% beta-CD at an applied voltage of 15 kV and a capillary temperature of 20 degrees C. Under the conditions, four diols were baseline separated with fast analysis time and the good theoretical plate numbers (above 10 x 10(4)) and favorable migration-time reproducibilities (RSDs below 3.0%) were obtained. The separation results were satisfactory.  相似文献   
60.
A simple “chimney” method was used to eliminate the voids in an arrangement of quantum dots sized 2 nm on a solid substrate, which resulted in a large well ordered superlattice of area in the order more than 1 μm2. Based on the principle of speeding up the interparticle interaction of nanoparticles to overcome the particle-substrate one, a lateral centripetal force originated from a glass tube acting as a chimney in a simple evaporation device is imposed. This method allows the packing process to be controlled in a mechanical force field, that is, with the same nanogold dispersion different patterns on a substrate—from separate dots to an ordered compact monolayer or even a multilayer structure—could be easily obtained.  相似文献   
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