轴类零件内部缺陷超声检测与重构方法研究

为了探究轴类零件内部缺陷的无损检测方法,本文以曲轴为研究对象,基于超声ALOK技术对其内部多个小孔进行了无损检测实验,并建立了相应的声学仿真有限元模型,提出利用声程—角度散点图中的趋势线,可快速判别内部缺陷特征和位置的方法。并且改进了ALOK算法,即采用邻近探头构建的方程或曲线重构缺陷,模拟和实验结果表明使用改进的算法提高了缺陷位置和尺寸的检测精度,通过实验数据重构所得的缺陷位置误差和半径误差分别在2 mm和0.5 mm左右。研究结论对于轴类零件内部缺陷精确定量化无损检测提供了理论和技术指导。     

基于LabVIEW的大型轴类零件圆柱度在位测量系统

本文根据波兰凯尔采科技大学提出的V型块法设计了一种大型轴类零件圆柱度的在位测量装置。将在位测量装置所采集到的信号通过数据采集卡在Labview软件平台上进行数据分析和处理,得出被测轴类零件最小二乘圆柱度的值,验证了V型块法在位测量大型轴类零件圆柱度的可行性。     

基于双CCD的大型轴类零件直径非接触检测方法研究

针对重型机械工业生产中对大型轴类零件外径测量的需求,基于双CCD传感器测量原理研究了一种新型高效率、高精度的轴径检测方法。介绍了CCD测径系统的检测原理,针对单一CCD传感器测量范围小的缺点,提出了双CCD传感器组合测量大型轴类零件直径(Φ150mm~Φ300mm)的方法,并对影响精度的主要误差来源进行了分析。为了验证该方法的有效性,通过对7种不同直径的标准轴件进行测量,实验表明,测量精度小于±3μm,满足大型轴类零件外径测量的要求。     

轴类超声检测的波束扩散成像

大型轴类工件安装完成后通常只能从其端面进行检测,危害性的裂纹类缺陷不易检出。针对上述问题,该文提出了轴类对象基于波束扩散的端面网格化超声检测层析成像方法,搭建了轴类超声检测试验平台,在端面对其内部的平底孔缺陷进行检测,基于波束扩散设计叠加算法进行数据处理,然后根据结果重构出代表每个深度内部信息的伪彩色横截面图像,以方便快速识别内部缺陷位置和范围。与常规方法对比得出,基于波束扩散的叠加算法处理数据成像质量更佳,检测数据信号增益能够达到12 dB以上。     

相对论速调管三轴提取腔的分析与设计

分析了同轴漂移管中电子束的空间电荷限制流和能量分布，为了降低S波段相对论速调管放大器(RKA)中电子束空间电荷效应及势能，提高RKA的束波转换效率，提出了三轴结构的输出腔，理论分析RKA的束波转换效率达到36%，比同轴提取腔的束波转换效率提高了9个百分点. 采用数值计算程序设计了三轴提取腔，粒子模拟了S波段RKA的微波提取，取得了与理论分析一致的结果. 采用590kV/5kA的空心电子束，经过预调制腔和群聚腔等两个腔的调制后，采用三轴提取腔提取微波，得到了约1.0GW的微波功率，效率35%. 理论研究结果与实验结果吻合得较好. 关键词： 相对论速调管放大器 三轴提取腔 空间电荷限制流     

类O(6)原子核三轴形变的解析描述

在相互作用玻色子模型(IBM)的内禀态下,用自治Q算符框架(CQF),引入L=3的三体势,建立用IBM解析描述原子核三轴形变参数β、γ的理论方案. 计算了Xe、Ba和Ce偶偶核素的三轴形变参数,与硬三轴转子模型(RTRM)的结果进行比较,较精确地描述了原子核的三轴形变性质.     

二色补血草不同部位总黄酮类物质提取及抗氧化能力的研究

测定了二色补血草不同部位总黄酮含量并进一步研究了它们的抗氧化能力。分别采用邻二氮菲-Fe^2＋-H2O2体系和普鲁士蓝法研究了二色补血草各部位抗氧化能力。结果表明,二色补血草各部位中总黄酮含量存在较大差异,以二色补血草花含量为最高（27.792mg/g）,二色补血草茎为最低（5.828mg/g）。二色补血草不同部位均具有抗氧化性,抗氧化能力与黄酮含量、结构有关。     

向心力与火车转弯

分析了火车转弯时向心力的来源、转弯时的安全措施、转弯时有关现象的原因.     

用Mathmatica软件绘制铁磁材料基本磁化曲线和磁滞回线

Mathmatica语言具有良好的环境，处理数据速度好，拟合的曲线准确生动，在物理实验中有很好的用途。本文给出了用Mathmatica语言处理铁磁材料基本磁化曲线和磁滞回线实验数据的处理过程，结果精确，效果非常好。     

蓝色显示材料及器件的研究

用Ｈ２和ＣＳ２还原法制备Ｃｅ：ＳｒＳ发光材料，分析了两种方法对材料的结构及发光特性的影响，得到了最高亮度为９５０ｃｄ／ｍ＾２（１０００Ｈｚ）的Ｃｅ：ＳｒＳ薄膜电致发光（ＴＦＥＬ）器件；用高温固相法得到Ｃｅ：ＳｒＧａ２Ｓ４荧光粉，用射频溅射沉积的Ｃｅ：ＳｒＧａ２Ｓ４薄膜在６００℃以上、Ｈ２Ｓ气氛下快速热处理可以改善薄膜结晶性能，提高杂质激发峰强度，得到好的光致发光（ＰＬ）发光性能，以陶瓷片作为基片同     

Realistic one-particle density matrix and single-particle description of nuclei

Starting from the experimental data on elastic electron scattering, realistic one-particle density matrices for ¹⁶O and ⁴⁰Ca are obtained, both with fractional occupation numbers and full occupation of the first A natural orbitals. A phenomenological single-nucleon Hamiltonian is then constructed and diagonalized. The deduced single-particle energies are compared with those obtained in the Hartree-Fock approximation. The consistency of all experimental data concerning the ground state is checked with the aid of a sum rule for the total binding energy involving only the one-particle density matrix and the hole energies.     

Subjective and Objective Quality Assessments of Display Products

In recent years, people’s daily lives have become inseparable from a variety of electronic devices, especially mobile phones, which have undoubtedly become necessity in people’s daily lives. In this paper, we are looking for a reliable way to acquire visual quality of the display product so that we can improve the user’s experience with the display product. This paper proposes two major contributions: the first one is the establishment of a new subjective assessment database (DPQAD) of display products’ screen images. Specifically, we invited 57 inexperienced observers to rate 150 screen images showing the display product. At the same time, in order to improve the reliability of screen display quality score, we combined the single stimulation method with the stimulation comparison method to evaluate the newly created display products’ screen images database effectively. The second one is the development of a new no-reference image quality assessment (IQA) metric. For a given image of the display product, first our method extracts 27 features by analyzing the contrast, sharpness, brightness, etc., and then uses the regression module to obtain the visual quality score. Comprehensive experiments show that our method can evaluate natural scene images and screen content images at the same time. Moreover, compared with ten state-of-the-art IQA methods, our method shows obvious superiority on DPQAD.     

Realistic and effective interactions in the study of nuclear matter

The equation of state of symmetric nuclear matter is addressed starting both from a realistic interaction derived from nucleon-nucleon scattering processes and from a low-momentum effective potential. The approach is based on finite temperature Green’s functions. The internal energy per particle is estimated from the summation of diagrams and through the Galitskii-Koltun sum rule. The text was submitted by the author in English.     

光栅莫尔条纹在机床数控改造中的应用研究

从机床数控改造的实际出发,针对我国目前国产机床加工精度普遍不高,数控化程度较低等问题,提出了一种全新的设计方案,利用光栅作为位置检测元件,形成全闭环控制系统,结果表明既能够大大提高零件的加工精度,又能节省改造成本,为机床数控改造提供了参考。     

Non-Local Realistic Theories and the Scope of the Bell Theorem

According to a widespread view, the Bell theorem establishes the untenability of so-called ‘local realism’. On the basis of this view, recent proposals by Leggett, Zeilinger and others have been developed according to which it can be proved that even some non-local realistic theories have to be ruled out. As a consequence, within this view the Bell theorem allows one to establish that no reasonable form of realism, be it local or non-local, can be made compatible with the (experimentally tested) predictions of quantum mechanics. In the present paper it is argued that the Bell theorem has demonstrably nothing to do with the ‘realism’ as defined by these authors and that, as a consequence, their conclusions about the foundational significance of the Bell theorem are unjustified.