基于DSP的机动车抗眩目系统设计

为了解决车辆在夜间行驶时,对面车灯给驾驶员造成的眩目问题,提出了一种机动车抗眩目系统的设计方案.采用视频解码芯片SAA7111A和视频编码芯片AL250完成视频信号的A/D和D/A转换;利用数字信号处理器DSP对亮度值过高的像素点进行消亮处理,以达到抗眩目的目的;可编程逻辑器件CPLD完成对整个系统的逻辑控制以及提供存储器写数据的地址.系统经实际运行,性能稳定,抗眩目效果明显.     

Structure study on the thermoelectric materials CexCo4Sb12 (x = 0.5, 1.0) by neutron diffraction

In order to understand the relationship between crystal structure and thermoelectric properties, the neutron diffraction patterns of the thermoelectric materials with the nominal composition Ce_xCo₄Sb₁₂ (x = 0.5, 1.0) were measured at room temperature, the data were fitted by the Rietveld profile refinement method using the Fullprof2k program. It is found that the sample Ce_0.5Co₄Sb₁₂ is composed of two phases, its major phase is CoSb₃ with skutterudite-structure and the Ce atom is not incorporated into the lattice, the impurity is monoclinic CoSb₂. In the case of Ce_1.0Co₄Sb₁₂, the major phase is filled skutterudite, about 10% of the 2a site is occupied by Ce atom, the second phase is monoclinic CoSb₂.     

橡塑磁条在永磁音像微特电机中的应用

本文简述了橡塑磁条的制造工艺及在永磁音像电机规模生产中的应用，与铁氧体烧结磁环进行比较，阐述了橡塑磁条在音像微特电机中使用的优势。     

高精度位置检测原理及应用

介绍了无线感应位置检测原理 ,提出了提高定位精度的方法 ,并给出了电原理框图。     

Growth and optical properties of Er,Yb:YAl3(BO3)4 crystal

Single crystal of erbium, ytterbium-codoped yttrium aluminum tetraborate Er,Yb:YAl₃(BO₃)₄(Er,Yb:YAB) has been grown by the flux method. The absorption spectrum in the visible and NIR regions of Er,Yb:YAl₃(BO₃)₄ crystal are measured at room temperature and fluorescence spectrum of Er,Yb:YAl₃(BO₃)₄ crystal are also measured at room temperature, excited by 976 nm laser. Not only the strong NIR emission peaks located at 1548 nm was observed, but also the visible up-conversion luminescence has been found. The specific heat of the Er/Yb:YAB crystal at room temperature is 0.81 J/g °C.     

Comparison of corrosion behavior of zirconium bombarded with self-ion and molybdenum ion

In order to study the effects of zirconium and molybdenum ion bombardment on the aqueous corrosion behavior of zirconium, one group of specimens was implanted with zirconium ions with ions surface densities ranging from 1 × 10¹⁵ to 2 × 10¹⁷ ions/cm² at about 170 °C, using a metal vapor vacuum arc (MEVVA) source operated at an extraction voltage of 50 kV. The other group of specimens was bombarded with molybdenum ion with ions surface densities ranging from 1 × 10¹⁶ to 5 × 10¹⁷ ions/cm² at about 160 °C, using a MEVVA source operated at an extraction voltage of 40 kV. The valence states and depth distribution of elements in the surface of the samples were analyzed by X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES), respectively. Polarization curves measurement was employed to evaluate the aqueous corrosion resistance of the zirconium samples in a 1N H₂SO₄ solution. It was found that the aqueous corrosion resistance of zirconium implanted with 5 × 10¹⁶ Zr ions/cm² is the best in first group samples. For molybdenum ion implantation, the aqueous corrosion resistance of samples declined with raising ions surface densities. The natural corrosion potentials of zirconium samples bombarded with self-ions are more negative than that of the as-received zirconium. While, as for molybdenum ion implantation, the results are opposite. Finally, the mechanisms of the corrosion behavior of the zirconium samples implanted with zirconium and molybdenum ions are discussed.     

A numerical study of the heterogeneous porosity effect on self-propagating high-temperature synthesis (SHS)

Self-propagating high-temperature synthesis (SHS), or the so-called micropyretic/combustion synthesis, is a technique whereby a material is synthesized by the propagation of a combustion front across a powder. Heterogeneous distributions of porosities are common during self-propagating high-temperature synthesis when powders are pressed and the conventional modeling treatments thus far have only considered uniform systems. Heterogeneities in the porosity are thought to result in local variations of such thermophysical/chemical parameters for the reactants as density and thermal conductivity further changing the combustion temperature, the propagation velocity, and the propagation pattern of a combustion front. This study investigates the impact of porosity variations during self-propagating high-temperature synthesis with Ti + 2B. In addition, the simulations for the propagation of combustion fronts across a non-uniform compact where the porosity is monotonically decreased or increased along the specimens due to die wall friction are also carried out.     

用单片机实现各音色电子琴

介绍了音色概念以及音色的决定性因素。针对传统电子琴采用以滤波网络电路对某次谐波量进行放大或衰减来模拟音色的方法,提出了一种新的实现方案,即采用以单片机为主体的数字电路,"软硬"兼施,模拟音色的波形,再通过D/A输出,从而达到听觉上的模拟音色的目的。解决了传统的模拟音色电子电路的设计的复杂性和多变性问题。给出了具体的实现电路、软件设计方法和步骤。     

彩云易散琉璃脆——白乐天《简简吟》等感伤诗对宋词的影响

白居易自分其诗为讽喻、闲适、感伤、杂律等四类,最重讽喻之作,在其诗集中冠之卷首.宋代词人的接受视域中,最重“感伤”、“闲适”之作.如果说白居易《长恨歌》是将目光投向了家国兴替与李杨悲欢,是以最高统治者为关注对象的,《琵琶引》更多的是诗人自我怜惜,自伤零落栖迟.那么《简简吟》、《花非花》等作品则是以普通女性为关注对象,感伤美好事物易逝.     

Phase formation mechanism and kinetics in solid-state synthesis of undoped and calcium-doped lanthanum manganite

LaMnO_3+δ and La_0.7Ca_0.3MnO₃ were synthesized from La₂O₃(La(OH)₃), CaCO₃ and MnO₂ powder mixture with solid-state reaction technique. X-ray diffraction and thermal analysis were employed in the present study on the process of synthesizing of the two compound powders. The kinetic study on solid-state reaction between La₂O₃ and MnO₂ in the powder mixture was isothermally carried out for LaMnO_3+δ formation. The result showed that the reaction process was controlled by three-dimensional solid-ionic diffusion. Both Jander and Ginstling-Brounstein model can be used to describe the reaction kinetics satisfactorily. The relevant apparent activation energy values obtained were as great as 205 ± 11 and 189 ± 8 kJ/mol. The reaction process of La_0.7Ca_0.3MnO₃ preparation from La₂O₃, SrCO₃ and MnO₂ powder mixture was also studied using X-ray diffraction and thermal analysis. The result indicated that the following steps composed the overall reaction: the decomposition of the reactant; the formation of La_1−xCa_xMnO_3+δ; La₂O₃ and Mn₃O₄ reacted with La_1−xCa_xMnO₃ to form final La_0.7Ca_0.3MnO₃ phase. The latest step was the most time-consuming one among others in the overall reaction.