共查询到20条相似文献,搜索用时 31 毫秒
1.
为了减轻机场跑道除胶工作人员的劳动强度,提高除胶工作效率,文章提出了一种基于机器视觉的胶痕自动查找和识别方法,设计了基于ARM单片机控制的图像无线采集和基于PC机控制的图像接收、图像预处理和图像识别系统。文章通过分析预处理后的数据特点,确定了基于细胞神经网络算法的胶痕识别算法,然后在MATLAB仿真环境下确定了该算法的最优模型和参数,最后在Visual C++ 6.0环境下完成了该算法的程序编译,调试并完成了对胶痕的自动识别过程。理论仿真和程序测试的结果证明了文章提出的方法在胶痕自动识别系统中的可行性,也为机场特种设备的无人化和智能化提供了参考。 相似文献
2.
The proton NMR spectra of dimethyl dichalcogenides and diethyl dichalcogenides were measured. The experimental results do not show the evidence for the existence of rotational isomerism in each molecules. 相似文献
3.
H. Montigaud S. Courjault B. Tanguy G. Demazeau J. Peyronneau D. Andrault 《高压研究》2013,33(1-6):213-219
Abstract Basing on “ab-initio” calculations, C3N4 was claimed to be an ultra-hard material with a bulk-modulus close to that of diamond. Five different structural varieties were announced: the graphitic form, the zinc blende structure, the α and β forms of Si3N4 and another form, isostructural with the high pressure variety of Zn2Si04. Using the same strategy as that developed for diamond or c-BN synthesis, it appears that the graphitic form could be an appropriate precursor for preparing the 3D varieties. Two main problems characterize the C3N4 synthesis: (-) the temperature should be reduced in order to prevent nitrogen loss, (-) the reactivity of the precursors should be improved. Consequently, we have developed a new process using the solvothermal decomposition of organic precursors containing carbon and nitrogen in the presence of a nitriding solvent. The resulting material, with a composition close to C3N4, has been characterized by different physico-chemical techniques. 相似文献
4.
Antimony segregation is a common feature in Fe-Sb mixed oxides, which have been widely applied as catalysts in selective oxidation and ammoxidation reactions. This paper attempts to shed a light on the cause of such a common feature and on the nature of the antimony-enriched surface layer over FeSbO4 by means of XPS surface analysis. Single-phase FeSbO4 samples prepared by different methods were studied, and the antimony in their surface layer is a mixture of both Sb5+ and Sb3+ rather than single Sb5+. Their surface composition is close to FeSb2O6, which could be described as (FeSbO4)(Sb2O4)δ, δ = 0.5, and it is not “Fe(II)Sb(V)2O6” as suggested in literature. Fe-Sb mixed oxides with Sb/Fe > 1 (mol/mol) are mixtures of FeSbO4 and Sb2O4, and the surface of FeSbO4 grains would be a layer of (FeSbO4)(Sb2O4)δ, δ ≥ 0.5. Fe-Sb mixed oxides with Sb/Fe < 1 are mixtures of FeSbO4 and Fe2O3, and the surface of FeSbO4 grains would be a layer of (FeSbO4)(Sb2O4)δ, δ ≤ 0.5, but the remaining Fe2O3 would be encapsulated by a layer of FeSbO4. 相似文献
5.
Infrared spectra of rat tissues, RNA tumor virus (Rauschler) and pure RNA and DNA are examined by the technique of frustrated multiple internal reflection (FMIR). An attempt has been made to characterize biologically important tissue components on the basis of infrared spectral analysis and published literature on the subject. Under the conditions described, rat tissues may be grouped according to their infrared spectra. The spectral differences in vivo between normal and N-nitroso-dimethylamine (DMN)-injected rat liver have been presented to show the usefulness of the FMIR technique for rapid detection of induced changes in the tissue composition. 相似文献
6.
Abstract Hydrothermal and solvothermal (isopropanol) treatments of gadolinium oxide and silica were investigated under different pressure and temperature conditions. Products were examined by infrared vibrational spectroscopy (IR), x-ray powder diffraction (XRD) and thermal analysis (DTA, TG). Hexagonal gadolinium hydroxide was obtained in hydrothermal conditions, even in presence of silica, while no change was observed from isopropanolic medium treatment. Hydrothermally treated samples are more reactive as precursors for solid state reactions in inorganic synthesis. 相似文献
7.
R. Kita N. Hosoya N. Otawa S. Kawabata T. Nakamura O. Miura M. Mukaida K. Yamada A. Ichinose K. Matsumoto M.S. Horii Y. Yoshida 《Physica C: Superconductivity and its Applications》2009,469(15-20):1157-1160
We investigated the effects of added Tm2O3, Sc2O3, and Yb2O3 on the superconducting properties of sintered Er123 samples. Tm2O3 addition caused the least Tc degradation, exhibiting a Tc above 90 K even for 17 vol% addition. Samples with added Sc2O3 maintained a Tc at above 90 K up to an addition of 7.2 vol%, while Yb2O3-containing samples showed a monotonic decrease in Tc with increased vol% of added Yb2O3. Tm2O3-containing samples exhibited a slight increase in Jc(0.1 T)/Jc(0) and had constant Jc values even for 17 vol% addition. XRD and SEM results indicate that the Tm2O3 is very stable in the superconducting matrix. 相似文献
8.
采用射频磁控溅射方法制备了两种用于相变存储器的Ge1Sb2Te4和Ge2Sb2Te5相变薄膜材料,对其结构、电学输运性质和恒温下电阻随时间的变化关系进行了比较和分析.X射线衍射(XRD)和原子力显微镜(AFM)的结果表明:随着退火温度的升高,Ge1Sb2Te4薄膜逐步晶化,由非晶态转变为多晶态,表面出现均匀的、
关键词:
硫系相变材料
1Sb2Te4')" href="#">Ge1Sb2Te4
2Sb2Te5')" href="#">Ge2Sb2Te5 相似文献
9.
Investigations of oxide superconductors by x-ray absorption,photoemission and cognate spectroscopies
X-ray absorption spectra, X-ray photoelectron spectra and Auger spectra of cuprate superconductors are discussed. The studies establish the absence of Cu3+ for all practical purposes, but point out the importance of oxygen holes. X-ray photoelectron spectra of BaBi0.25Pb0.75O3 and related compounds are also examined. 相似文献
10.
用熔炼和甩带的方法制备了组分为Ni50FexMn25-xGa 25(x=0—25) 的系列样品.x射线衍射实验结果表明,当Fe取代Mn的含量x<17时,用熔炼和甩带的方法均 能合成高度有序的L21结构的Heusler相.而当x>17时,普通熔炼方法只能得到 低有序度的 γ相,只有采用甩带急冷的方法才能获得高度有序的纯L21结构的化合物.根据 交流磁化率 和分子磁矩的测试结果,初步分析了Fe原子对化合物磁性的贡献,认为Fe原子占据了Mn原子 的位置后,具有高于一般含铁合金的原子磁矩,可达2.55—3.55μB.
关键词:
Heusler合金
50FexMn25-xGa25 sub>')" href="#">Ni50FexMn25-xGa25 sub> 相似文献
11.
Daisuke Nishio-Hamane M. Katagiri K. Niwa A. Sano-Furukawa T. Okada T. Yagi 《高压研究》2013,33(3):379-388
The post-corundum phase transition has been investigated in Ti2O3 on the basis of synchrotron X-ray diffraction in a diamond anvil cell and transmission electron microscopy. The new polymorph of Ti2O3 was found at about 19 GPa and 1850 K, and this phase was stable even at about 40 GPa. A new polymorph of Ti2O3 can be indexed on a Pnma orthorhombic cell, and the unit-cell parameters are a=7.6965 (19) Å, b=2.8009 (9) Å, c=7.9300 (23) Å, V=170.95 (15) Å3 at 19 GPa, and a=7.8240 (2) Å, b=2.8502 (1) Å, c=8.1209 (3) Å, V=181.10 (1) Å3 at ambient conditions. The Birch–Murnaghan equation of state yields K 0=206 (3) GPa and K′0=4 (fixed) for corundum phase, and K 0=296 (4) GPa and K′0=4 (fixed) for the post-corundum phase. The molar volume decreases by 12% across the phase transition at around 20 GPa. The structural identification was carried out on a recovered sample by the Rietveld method, and a new polymorph of Ti2O3 can be identified as Th2S3-type rather than U2S3-type structure. The transition from corundum-type to Th2S3-type structure accompanies the drastic change of the form of polyhedron: from TiO6 octahedron in the corundum-type to TiO7 polyhedron in the Th2S3-type structures. 相似文献
12.
We describe the structural properties and electrical characteristics of thin thulium oxide (Tm2O3) and thulium titanium oxide (Tm2Ti2O7) as gate dielectrics deposited on silicon substrates through reactive sputtering. The structural and morphological features of these films were explored by X-ray diffraction, X-ray photoelectron spectroscopy, secondary ion mass spectrometry, and atomic force microscopy, measurements. It is found that the Tm2Ti2O7 film annealed at 800 °C exhibited a thinner capacitance equivalent thickness of 19.8 Å, a lower interface trap density of 8.37 × 1011 eV−1 cm−2, and a smaller hysteresis voltage of ∼4 mV than the other conditions. We attribute this behavior to the Ti incorporated into the Tm2O3 film improving the interfacial layer and the surface roughness. This film also shows negligible degrees of charge trapping at high electric field stress. 相似文献
13.
Solid xenon layers are proposed as an alternative to graphite catchers for collecting samples at on-line separators. The formation
of solid xenon layers is described. Sample atoms of bismuth have been held for up to a day in such layers before being released
as cold free atoms for laser spectroscopy measurement. An application to studying daughter nuclei produced by α-decay is considered. It involves a two-stage process where daughter recoils are first accumulated in the xenon layer and
subsequently released into flowing helium for laser-ionization and counting. 相似文献
14.
15.
This paper presents the adsorption and thermal decomposition mechanism of formic acid on an H-birnessite sample. Changes in the surface and structure were characterized using infrared spectroscopy, N2 gas adsorption–desorption, and thermal analysis techniques. The acid sites of H-birnessite were investigated by infrared and thermal analysis using pyridine as a molecular probe. Decomposition of formic acid started on H-birnessite at 120°C and was complete at 400°C. Infrared spectra revealed that the molecularly adsorbed formic acid species were transformed to a formate species, and the formate species were transformed to CO. The most stable adsorption structure for formic acid was found as a molecular monodentate configuration. 相似文献
16.
采用固相合成工艺,制备了Bi05Ba05Fe05Ti049Nb001O3(BBFTN)热敏陶瓷,借助X射线衍射仪、扫描电子显微镜、阻温测试仪和交流阻抗谱考察其微结构、直流电阻、介电特性、阻抗和电学模量方面的电学性能. 结果表明:BBFTN材料依然为立方钙钛矿结构,平均晶粒尺寸约为10 μm,晶格常数相对于BaTiO3的晶格常数有所变大;室温电
关键词:
05Ba05Fe05Ti049Nb001O3')" href="#">Bi05Ba05Fe05Ti049Nb001O3
微结构
电学性能 相似文献
17.
Calculated vibrational frequencies are reported for the PMo12O40 3– ion according to a 53-atomic tetrahedral model (Td). The results are compared with calculated frequencies for fragments of this structure, viz. PO4 (Td), Mo3O13 (C3v), Mo3O7 (C3v, Mo2O11 (Cs) and Mo2O10 (Cs). A complete vibrational analysis of the PMo12O40 3– ion has been performed. The adopted model of Td symmetry is an idealization of x-ray structure data. 1 The normal modes of vibration according to this model are distributed as: 相似文献
18.
Xin Yin Jiyang Wang Huai-jin Zhang Shao jun Zhang hai-kuai Kong 《Optics & Laser Technology》2004,36(7):2501-593
A new method has been proposed to measure the electro-optical coefficients of the crystals which have optical activity. By using this method, the half-wave voltage and the electro-optical coefficients of the optically active crystals La3Ga5SiO14 (LGS), La3Ga5..5Nb0.5O14 (LGN), La3Ga5.5Ta0.5Si14 (LGT) have been determined. The resultants obtained are: γ11(LGS)=1.9 pm/V, γ11(LGN)=0.75 pm/V, γ11(LGT)=0.57 pm/V. This method can also be used to simulate the on–off state of the electro-optical Q switch in the laser cavity, whether the switch is made of the ordinary crystals or the optically active crystals. 相似文献
19.
The stability, frontier orbitals, bond character, and static linear polarizability of the fluorinated fullerene H20@C80F60
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This paper uses the density functional theory under generalised gradient approximation to analyse the stability,frontier orbitals,bond character,and static linear polarizability of H20@C80F60,which has not been isolated,as well as those of the synthesised H 20 @C 80 H 60.The H20@C80F60 should be considerably stable by analysing its energy and aromaticity.The inside H and outside X will play different role in the chemical reaction involving H 20 @C 80 X 60(X=H and F).The covalence of C-H bond is in the order that the inside C-H bond of H20@C80F60 > the inside C-H bond of H 20 @C 80 H 60 > the outside C-H bond of H 20 @C 80 H 60,whereas the C-F bond of H20@C80F60 have both the covalent and ionic characters.The static linear polarizabilities of C 80 and H 20 @C 80 X 60(X=H and F) are all isotropic. 相似文献
20.
Superconductivity is found in tetragonal La3−x
Ba3+x
Cu6O14+δ and La, Ba)6−x
Sr
x
Cu6O14+δ even though they do not possess Cu-O chains or the K2NiF4 structure. Resistivity measurements confirm the occurrence of a transformation from chain-superconductivity to sheet-superconductivity
in YBa2Cu3O7−δ as δ is varied in the range 0.0–0.5.
Contribution No. 481 from the Solid State and Structural Chemistry Unit 相似文献