飞机跑道胶痕的自动识别系统设计与实现

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。     

SrBi2Ta2O9/Bi4Ti3O12复合铁电薄膜的制备与特性研究

采用溶胶凝胶工艺在p-Si衬底上制备了SrBi₂Ta₂O₉/Bi₄Ti₃O₁₂复合铁电薄膜. 研究了SrBi₂Ta₂O₉/Bi₄Ti₃O₁₂复合薄膜的微观结构与生长行为、铁电性能和疲劳特性. 研究表明: Si衬底Bi₄Ti< 关键词： 2Ta₂O₉')" href="#">SrBi₂Ta₂O₉ 4Ti₃O₁₂')" href="#">Bi₄Ti₃O₁₂ 复合铁电薄膜 溶胶凝胶工艺     

Nb对C-15结构V2(HfZr)系列的超导转变温度的影响

本文中研究了C-15结构V₂Hf_1-xNb_x,V₂Zr_1-xNb_x和V₂Hf_0.5Zr_0.5-xNb_x系列的超导转变温度T_c与Nb合量x的关系,发现V₂Zr,V₂Hf加Nb后与V₂Hf_0.5Zr_0.5加Nb后性能显著不同。测定了V₂Zr,V₂Hf和V₂Hf_0.5Zr_0.5的X射线光电子能谱。结果表明,当Hf原子和Zr原子共存于AB₂化合物的A位上时,发生了一种增强原子间相互作用的新的电荷转移。这个事实支持由角动量分波表象能带论方法分析电声耦合超导原理的结果对四元V₂(HfZrNb)系列的超导行为提出的一种可能解释:4d-5d原子配位可能有助于提高4d导带的杂化程度,从而有利于提高超导T_c。 关键词：     

Ca和Ce双原子复合填充p型CamCenFexCo4－xSb12化合物的合成及热电性能

用高温熔融法合成了Ca和Ce复合填充的单相p型Ca_mCe_nFe_{xCo4-xSb12化合物，探索了两种原子复合填充对其热电性能的影 响规律.研究结果表明，填充分数相同时，Ca和Ce两种原子复合填充的p型CamCe nFexCo4-xSb12化合物的载流子浓度和电 导率介于Ca或Ce一种原子单独填充的化合物之间，且随两种原子填充分数m+n的增加而降低 ；赛贝克系数随两种原子填充总量，尤其是Ce填充分数m的增加以及温度的上升而增加；在 相同填充分数时，两种原子复合填充的p型CamCenFexC o4-xSb12化合物的晶格热导率较Ca或Ce一种原子单独填充的化合物 的晶格热导率低，当总填充分数m+n为0.3左右，且Ca和Ce的填充量大致相等时，化合物的晶 格热导率最低.p型Ca0.18Ce0.12Fe1.45Co2.55Sb12.21化合物的最大热电性能指数ZT值在750K时达到1.17. 关键词： skutterudite化合物 双原子复合填充 合成 热电性能}     

Evaluation of ligand field stablization in spinels using mössbauer determined cation distributions

The Mössbauer determined cation distributions of FeV₂O₄, FeCr₂O₄, FeMn₂O₄, Fe₃O₄, FeCo₂O₄, CoV₂O₄, CoCr₂O₄, CoMn₂O₄, CoFe₂O₄ and Co₃O₄ are compared with the quantitative d-orbital stablization energies of McClure and of Dunitz and Orgel. They are also compared with the qualitative ligand field stabilization energies of Cotton. These theories do not account for observation in the cases of FeMn₂O₄, FeCo₂O₄ and CoFe₂O₄.     

Structure of Artificial Grain Boundaries in Sapphire Bicrystals with Intermediate Layers

The structure of the artificial grain boundaries in Al₂O₃ bicrystals withY₃Al₅O₁₂ and Y-stabilizedZrO₂ (Y-ZrO₂) intermediate layers was studiedwith high resolution electron microscopy, electron diffraction and energydispersive X-ray analysis. TheY₃Al₅O₁₂ intermediate layer wasfound to be polycrystalline with three different orientation relationshipsbetween the ₂O₃ and theY₃Al₅O₁₂. The structure of theY₃Al₅O₁₂/₂O₃ interfaces is described.Also₂O₃ bicrystals with an Y-ZrO₂/₂O₃/Y-ZrO₂/₂O₃/Y-ZrO₂intermediate layer, prepared at two different temperatures, werestudied.Recry stallization of the intermediate layers occurred during thesolid phase intergrowth of the ₂O₃ bicrystalsparts and only an Y-ZrO₂ layer was found as intermediatelayer. The misorientation between the consecutive Y-ZrO₂grains was less than 1.5°. Misfit dislocations and atomic height stepsdecorate the Y-ZrO₂/₂O₃interface.     

Dielectric properties of the Li0.07Na0.93Ta0.1Nb0.9O3 and Li0.07Na0.93Ta0.111Nb0.889O3 solid solutions

Dielectric properties of perovskite ferroelectric solid solutions Li_0.07Na_0.93Ta_0.1Nb_0.9O₃ and Li_0.07Na_0.93Ta_0.111Nb_0.889O₃ are studied over the 290?C700 K range of temperature within the frequency range of 25?C10⁶ Hz. A decrease of the Curie temperature (??75 K) compared with Li_0.07Na_0.93Ta_0.1Nb_0.9O₃ synthesized from mechanical mixture of pentoxides Ta₂O₅ and Nb₂O₅ is observed in Li_0.07Na_0.93Ta_0.111Nb_0.889O₃ synthesized from co-precipitated pentoxide Ta_2y Nb_{2(1 ? y)}O₅.     

The study of phase,microstructure, and magnetocaloric properties in LaFe11.6*xSi1.4B0.1 alloys

The effect of Fe on the phase and magnetocaloric property of LaFe_11.6*xSi_1.4B_0.1 alloys with x = 1.0–1.4 have been studied. The results show that the excess of Fe will make the α-Fe phases increase, but the easy corrosion LaFeSi phase reduces in LaFe_11.6*xSi_1.4B_0.1 alloys. All LaFe_11.6*xSi_1.4B_0.1 alloys keep the first-order magnetic phase transition. The saturation magnetizations of LaFe_11.6*xSi_1.4B_0.1 alloys with x > 1 are much higher than LaFe_11.6Si_1.4B_0.1 alloy under 2T magnetic field. This results in the maximum isothermal magnetic entropy changes, and the relative cooling power of LaFe_11.6*xSi_1.4B_0.1 alloys is bigger than for LaFe_11.6Si_1.4B_0.1 alloys.     

一种车辆状态通用自动监测装置设计与实现

当前装备车辆底盘数据大都通过仪表盘进行显示,而没有对数据进行采集和存储,造成对车辆的基本状态无法进行有效的评估和故障趋势分析;针对这种情况,设计一种对车辆底盘运行参数进行采集和存储的装置,通过一个通用的多PIN接口与车辆仪表盘信号线相连,采用高速AD芯片、高速主控芯片和RS485通讯接口实现对仪表盘接线输出信号的采集、计算与数据的传输存储;应用表明,此装置解决了多种车辆底盘参数的采集记录问题,具有广泛的推广应用价值。     

Effect of heat treatment on the structure and the thermoelectric properties of Sb<Subscript>0.9</Subscript>Bi<Subscript>1.1</Subscript>Te<Subscript>2.9</Subscript>Se<Subscript>0.1</Subscript> thin films and composites based on them

This work considers the effect of vacuum annealing on the thermoelectric properties of Sb_0.9Bi_1.1Te_2.9Se_0.1 thin film and Sb_0.9Bi_1.1Te_2.9Se_0.1–C composites with various carbon contents produced by ion-beam deposition in an argon atmosphere. The electrical resistivity and the thermopower of Sb_0.9Bi_1.1Te_2.9Se_0.1–C nanocomposites are found to be dependent on not only the carbon concentration but also the type and the concentration of intrinsic point defects of the Sb_0.9Bi_1.1Te_2.9Se_0.1 solid solution, which determine the type of conductivity of Sb_0.9Bi_1.1Te_2.9Se_0.1 granules. The power factors are estimated for films of Sb_0.9Bi_1.1Te_2.9Se_0.1 solid solution and films of Sb_0.9Bi_1.1Te_2.9Se_0.1–C composites and found to have values comparable with the values for nanostructured materials on the basis of (Bi,Sb)₂(Te,Se)₃ solid solutions.     

Catalytic effect of water,water dimer,water trimer,HCOOH, H2SO4, CH3CH2COOH and HN(NO2)2 on the isomerisation of HN(NO2)2 to O2NNN(O)OH: a mechanism study

In this article, the isomerisation mechanisms of HN(NO₂)₂ to O₂NNN(O)OH without and with catalyst X (X = H₂O, (H₂O)₂, (H₂O)₃, HCOOH, H₂SO₄, CH₃CH₂COOH and HN(NO₂)₂) have been investigated theoretically at the CBS-QB3 level of theory. Our results show that the catalyst X (X = H₂O, (H₂O)₂, (H₂O)₃, HCOOH, H₂SO₄ and CH₃CH₂COOH) shows different positive catalytic effects on reducing the apparent activation energy of the isomerisation reaction processes. Such different catalytic effects are mainly related to the number of hydrogen bonds and the size of the ring structure in X (X = H₂O, (H₂O)₂ and (H₂O)₃)-assisted transition states, as well as different values of pK_a for H₂SO₄, HCOOH and CH₃CH₂COOH. Very interesting is also the fact that H₂SO₄-assisted reaction is the most favourable for the hydrogen transfer from HN(NO₂)₂ to O₂NNN(O)OH, due to the smallest pK_a (?3.0) value of H₂SO₄ than H₂O, HCOOH, H₂SO₄ and CH₃CH₂COOH, and also because of the largest ∠X???H???Y (the angle between the hydrogen bond donor and acceptor) involved in H₂SO₄-assisted transition state. Compared to the self-catalysis of the isomerisation mechanisms of HN(NO₂)₂ to O₂NNN(O)OH, the apparent activation energy of H₂SO₄-assisted channel also reduces by 9.6 kcal?mol^?1, indicating that H₂SO₄ can affect the isomerisation of HN(NO₂)₂ to O₂NNN(O)OH, most obvious among all the catalysts H₂O, (H₂O)₂, (H₂O)₃, HCOOH, H₂SO₄, CH₃CH₂COOH and HN(NO₂)₂.     

Valence states of copper atoms in cuprates determined from the change in the electron-capture constant of 64Cu

The change in the ⁶⁴Cu electron-capture constant for the compounds Cu₂O, YBa₂Cu₃O₇, YBa₂Cu₃O₆, Nd₂CuO₄, Nd_1.8Ce_0.2CuO₄, La₂CuO₄, La_1.7Sr_0.3CuO₄, Tl₂Ba₂CaCu₂O₈, and Bi₂Sr₂CaCu₂O₈ has been measured. It is concluded that the copper in YBa₂Cu₃O₇, Nd₂CuO₄, La₂CuO₄, La_1.7Sr_0.3CuO₄, Tl₂Ba₂CaCu₂O₈, and Bi₂Sr₂CaCu₂O₈ is exclusively divalent, whereas in Cu₂O, YBa₂Cu₃O₆, and Nd_1.8Ce_0.2CuO₄ univalent copper is present. Fiz. Tverd. Tela (St. Petersburg) 39, 1793–1794 (October 1998)     

IR-Spectra of M2UO2F4.H2O Complexes

This work is devoted to the study of and Rb₂UO₂F₄.H₂O and Cs₂UO₂F₄. H₂O IR-spectra with the aim of obtaining a set of vibration frequencies characterising M₂U0₂F₄.H₂O complexe elucidating the role and nature of water bonds in the structures of the above-mentioned compounds; and receiving preliminary information on the structure of M₂UO₂F₄.H₂O. The investigated compounds were synthesized in accord with our previous paper¹. M₂UO₂D₂O and M₂UO₂F₄.HDO were obtained by recrystallizing M₂UO₂F₄.H₂O from D₂O and HDO respectively     

The system Na2CO3–CaCO3–MgCO3 at 6 GPa and 900–1250°C and its relation to the partial melting of carbonated mantle

In order to constrain the Na₂CO₃–CaCO₃–MgCO₃ T–X diagram at 6?GPa in addition to the binary and pseudo-binary systems we conducted experiments along the Na₂CO₃–Ca_0.5Mg_0.5CO₃ join. At 900–1000°C, melting does not occur and isothermal sections are presented by one-, two- and three-phase regions containing Ca-bearing magnesite, aragonite, Na₂CO₃ (Na₂) and Na₂(Ca_1–0.9Mg_0-0.1)_3-4(CO₃)_4-5 (Na₂Ca_3-4), Na₄(Ca_1–0.6Mg_0–0.4)(CO₃)₃ (Na₄Ca), Na₂(Ca_0-0.08Mg_1–0.92)(CO₃)₂ (Na₂Mg) phases with intermediate compositions. The minimum melting point locates between 1000°C and 1100°C. This point would resemble that of three eutectics: Mgs–Na₂Ca₃–Na₂Mg, Na₂Mg–Na₂Ca₃–Na₄Ca or Na₂Mg–Na₄Ca–Na₂, in the compositional interval of [45Na₂CO₃·55(Ca_0.6Mg_0.4)CO₃]–[60Na₂CO₃·40Ca_0.6Mg_0.4CO₃]. The liquidus projection has seven primary solidification phase regions for Mgs, Dol, Arg, Na₂Ca₃, Na₄Ca, Na₂ and Na₂Mg. The results suggest that extraction of Na and Ca from silicate to carbonate components has to decrease minimum melting temperature of carbonated mantle rocks to 1000–1100°C at 6?GPa and yields Na-rich dolomitic melt with a Na# (Na₂O/(Na₂O?+?CaO?+?MgO))?≥?28?mol%.     

Photocatalytic activity of Nb2O5/SrNb2O6 heterojunction on the degradation of methyl orange

The pure SrNb₂O₆ powders were prepared at 1400 °C by a conventional solid-state method and characterized by X-ray powder diffraction and UV-vis diffuse reflection spectrum. The powders of Nb₂O₅ and SrNb₂O₆ were ball-milled together and annealed to form the Nb₂O₅/SrNb₂O₆ composite. Photocatalytic activities of the composites were investigated on the degradation of methyl orange. The results show that the proportion of Nb₂O₅ to SrNb₂O₆ and the annealing temperature greatly influence the photocatalytic activities of the composites. The best photocatalytic activity occurs when the weight proportion of Nb₂O₅ to SrNb₂O₆ is 30% and the annealing temperature is 600 °C. The tremendously enhanced photocatalytic activity of the Nb₂O₅/SrNb₂O₆ composite compared to Nb₂O₅ or SrNb₂O₆ is ascribed to the heterojunction effect taking place at the interface between particles of Nb₂O₅ and SrNb₂O₆. The powders also show a higher photocatalytic activity than commercial anatase TiO₂.     

Surface modification of Mg2B2O5 whisker and its effect on the mechanical properties and thermostability of polycarbonate/Mg2B2O5w composites

The Mg₂B₂O₅ whiskers (Mg₂B₂O₅w) were modified by boric acid ester (BE) coupling agent and used to prepare polycarbonate (PC) composites. Surface wettability test and evaluation of dispersibility of BE-modified Mg₂B₂O₅w (BE-Mg₂B₂O₅w) in n-heptane were carried out by water contact angle measurement and polarizing microscopy, respectively. The surface chemical characteristics of BE-Mg₂B₂O₅w and estimation of the amount of tightly bonded organic modifier were examined by Fourier transform infrared spectrometry (FT-IR) and thermogravimetric analysis (TGA), respectively. The influence of BE-Mg₂B₂O₅w on the mechanical property, morphology and thermostability of PC composites was investigated by using universal testing machine, scanning electron microscopy (SEM), dynamic mechanical analysis (DMA) and TGA, respectively. It was found that BE was successfully grafted to the surface of Mg₂B₂O₅w, and the hydrophobic BE-Mg₂B₂O₅w leads to high ratio of adhesion work to interfacial tension between PC and BE-Mg₂B₂O₅w, and its better dispersibility in n-heptane. Furthermore, the incorporation of BE-Mg₂B₂O₅w into PC matrix resulted in higher tensile properties of PC/BE-Mg₂B₂O₅w than that of PC/Mg₂B₂O₅w composites and lower maximum weight loss rate than that of PC. The storage modulus of the PC/Mg₂B₂O₅w composites increased obviously as a function of whisker content, especially for the composites with BE-Mg₂B₂O₅w, but the T_g value changed little.     

包钴型γ-Fe2O3磁粉矫顽力的研究

包钴型γ-Fe₂O₃磁粉分为包钴γ-Fe₂O₃(简记为Co-γ-Fe₂O₃)和包钴包亚铁γ-Fe₂O₃(简记为CoFe-γ-Fe₂O₃)两种,它们的矫顽力可比γ-Fe₂O₃磁粉的提高100至400Oe左右,本工作对这两种磁粉矫顽力增大的原因作了探讨,认为它们矫顽力增大的机制不同:CO-γ-Fe₂O₃矫顽力增大是由于表面包覆一层Co(OH)₂使表面各向异性增大,而CoFe-γ-Fe₂O₃则是由于表面包覆的是钴铁氧体,γ-Fe₂O₃与钴铁氧体之间发生耦合作用,使矫顽力增大。     

Synthesis of spherical LiNi1/3Co1/3Mn1/3O2 cathode materials for Li-ion batteries

Spherical LiNi_1/3Co_1/3Mn_1/3O₂ was successfully prepared by controlled crystallization. The preparation started with the spherical coprecipitate of Ni_1/3Co_1/3Mn_1/3CO₃ from NiSO₄, CoSO₄, MnSO₄, NH₄HCO₃, and NH₃·H₂O, followed by pyrolysis of Ni_1/3Co_1/3Mn_1/3CO₃ at 600°C for 3 h. The X-ray diffraction analysis showed that the homogeneous cubic (Ni_1/3Co_1/3Mn_1/3)₃O₄ was obtained after the pyrolysis. Spherical LiNi_1/3Co_1/3Mn_1/3O₂ was obtained by sintering of the mixture of as-obtained (Ni_1/3Co_1/3Mn_1/3)₃O₄ and LiOH·H₂O at 900°C for 6 h in air. As-prepared spherical LiNi_1/3Co_1/3Mn_1/3O₂ presented initial discharge capacity of 162.9 mA h g⁻¹ and capacity retention of 98% at 50th cycle.     

CH3NH3 + as a quantum and classical rotor

Spin-lattice relaxation time T ₁ is determined for protons in three polycrystals (CH₃NH₃)₅Bi₂Cl₁₁, (CD₃NH₃)₅Bi₂Cl₁₁ and (CH₃ND₃)₅Bi₂Cl₁₁. The temperature dependence of the relaxation times obtained for (CH₃NH₃)₅Bi₂Cl₁₁ and (CD₃NH₃)₅Bi₂Cl₁₁ are interpreted as a result of correlated motions of the three-proton groups of the monomethylammonium cation. ²H NMR lines of (CD₃NH₃)₃Sb₂Br₉ have been recorded between 5 K and 291 K using solid echo method. The ²H NMR line shape analysis shows that characteristic shape of tunnelling methyl group appears at about 25 K and coming down with temperature up to 5 K is more distinct. From theoretical calculation, it has been found that in the quadrupolar constants is 161.3 kHz and tunnelling frequency is above 3 MHz.     

Ternary compounds and isothermal section in Lu–Fe–Ga ternary system at 773 K

The isothermal section of the Lu–Fe–Ga ternary system at 773?K was investigated and constructed based on X-ray powder diffraction analysis. Thirteen binary compounds, Lu₂Fe₁₇, Lu₆Fe₂₃, LuFe₂, LuGa₃, LuGa₂, Lu₃Ga₅, LuGa, Lu₃Ga₂, Lu₅Ga₃, Fe₃Ga, Fe₆Ga₅, Fe₃Ga₄, FeGa₃, nine ternary solid solutions, T₁-LuFe_2–1.43Ga_0–0.57, T₂-LuFe_1.34–0.92Ga_0.68–1.08, T₃-LuFe_0.52–0.26Ga_1.48–1.74, T₅-LuFe_2.04–1.72Ga_0.96–1.28, T₆-Lu₆Fe_23–21.4Ga_0–1.6, T₇-Lu₂Fe_17–14.5Ga_0–3.5, T₈-Lu₂Fe_12.9–8.1Ga_4.1–8.9, T₉-LuFe_6.8–5.5Ga_5.2–6.5, T₁₀-LuFe_5.2–4.5Ga_6.8–7.5, and two ternary compounds, T₄-LuFe_2.35Ga_0.65 and T₁₁-Lu₂FeGa₈ have been confirmed. The structures of the five new ternary compounds or solid solution T₂, T₃, T₄, T₅ and T₈ are determined by Rietveld refinement method.